bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Rock and Wettability Heterogeneity on the Efficiency of WAG Flooding in Carbonate Reservoirs
Authors: Ahmed Elfeel M. O. , Al-Dhahli A. , Jiang Z. , Geiger S. , van Dijke M. I. 
Published: September 2013

Abstract
Carbonate reservoirs contain more than half of the world's remaining petroleum reserves and are increasingly becoming targets for water-alternating-gas (WAG) flooding as secondary or tertiary recovery. Heterogeneity in carbonate reservoirs spans from pore- to reservoir-scale. This is exacerbated by the presence of natural fractures and post-depositional dissolution. Furthermore, carbonate reservoirs tend to have variable wettability that impacts fluid flow which adds to reservoir uncertainty and renders managing WAG floods difficult.
In this work, we examine the effect of rock and wettability heterogeneity on recovery profiles in naturally fractured carbonate reservoirs (NFCR). To simulate WAG flooding in NFCR with arbitrary wettability, we use saturation functions derived from a state-of-the-art pore network model to preserve multi-scale heterogeneities at the pore-scale. We study the interplay of capillary, gravity and viscous forces at an intermediate scale, then simulate WAG flooding in the presence of fractures in a heterogeneous carbonate ramp outcrop model.
Adding the permeability and wettability heterogeneities impacts ultimate recoveries during water injection cycles by up to 6% and 14% absolute, respectively. Both heterogeneities affect the speed of recovery during gas injection cycles. Depending on its relation to permeability distribution, non-uniform wettability of matrix blocks can have a substantial impact on recovery during water injection cycles while recovery efficiency during the gas injection cycle can be reduced by a factor of 50%.
Our work identifies the key factors that must be considered when modelling WAG floods in NFCR. We evaluate the reliability of conventional dual-porosity/dual-permeability numerical simulation approaches for NFCR by comparing results with multistage upscaled models through which we capture the fundamental controls on multi-phase flow. Hence, we can offer explanations for possible NFCR responses to WAG flooding and novel ways to improve the predictive ability of field-scale numerical simulation models.
Parallel Adaptive Mesh Refinement for Capturing Front Displacements: Application to Thermal EOR Processes
Authors: Mesri Youssef , Gratien Jean Marc , Ricois Olivier , Gayno Raphael 
Published: September 2013

Abstract
This paper presents a parallel adaptive mesh refinement scheme, that allows the achievement of an optimal accuracy by using dynamic mesh adaptation. The mesh refinement is close to the high error of temperature field. Periodic adaptive refinement is performed such as the refined zones describe accurately the temperature front displacement. This is based on the definition of an error estimator and the search of the optimal mesh that minimizes the error estimator under the constraint of a given number of cells.
The main bottleneck of adaptive mesh refinement in a parallel context is the load unbalance between processes due to refinement around local physical phenomena. This paper presents also, a parallel mesh adaptation algorithm able to deal with partitioned and distributed meshes. Unbalance detection is also taken into account by using a load balancing algorithm capable to improve effectively the performance of the simulation. All AMR algorithms are integrated as a part of Arcane [4], a IFPEN-CEA parallel object oriented framework. Application of this dynamic meshing approach in simulation models with steam injection demonstrates that efficient dynamic meshing can be implemented in a general purpose simulator to provide sufficient physical and spatial details in meaningful field or pattern models for EOR.
Fully Implicit Two-phase Reservoir Simulation with the Additive Schwarz Preconditioned Inexact Newton Method
Authors: Liu Lulu , Keyes David E. , Sun Shuyu 
Published: September 2013

Abstract
The fully implicit approach is attractive in reservoir simulation for reasons of numerical stability and the avoidance of splitting errors when solving multiphase flow problems, but a large nonlinear system must be solved at each time step, so efficient and robust numerical methods are required to treat the nonlinearity. The Additive Schwarz Preconditioned Inexact Newton (ASPIN) framework, as an option for the outermost solver, successfully handles strong nonlinearities in computational fluid dynamics, but is barely explored for the highly nonlinear models of complex multiphase flow with capillarity, heterogeneity, and complex geometry. In this paper, the fully implicit ASPIN method is demonstrated for a finite volume discretization based on incompressible two-phase reservoir simulators in the presence of capillary forces and gravity. Numerical experiments show that the number of global nonlinear iterations is not only scalable with respect to the number of processors, but also significantly reduced compared with the standard inexact Newton method with a backtracking technique. Moreover, the ASPIN method, in contrast with the IMPES method, saves overall execution time because of the savings in timestep size.
Water-Encroachment Monitoring Applied to Offshore Oil Field
Authors: Al-Dhafeeri A. M. , Al-Beshri F. S. , Al-Sadah A. , Kottuthala J. S. , Ortegon L. R. , Shaqlouf H. , Azam H. 
Published: September 2013

Abstract
A methodology for tracing the advancement of water encroachment from an aquifer by extensive use of behind-casing saturation evaluation logs is introduced. This approach relies on a large number of behind-casing saturation evaluation logs with a large coverage in space and time. A visualization of water saturation, populated through a smooth interpolator in a 3D grid at prescribed timestep, is obtained. Water movement can be visualized in cross sections and maps per reservoir layer. These results aid in the understanding of the path of water invasion and can be used for history-matching a reservoir simulation model at a later stage.
Data required are behind-casing saturation logs (sigma) as well as interpreted elemental volumes from openhole logs, production logs, production history, and perforated intervals. The time-lapsed saturation is cross-checked against water-breakthrough evidence, such as water-production history and production-log runs. The perforated intervals aid in the verification of the depths of entry of water. Unreliable evaluations are screened out. Time-lapsed saturation is interpolated in time for standard timesteps on a well-by-well basis. A form of production history transformed into a form of time-lapsed well log format is used to supplement the water saturation. The saturation logs are filtered for nonreservoir rock and then used to populate the 3D grid. This methodology was used in evaluating water advancement in a reservoir in the Middle East. Petrophysical evaluations were performed to review the openhole logs for consistency and determine the time-lapsed water saturation. Using the water population in the 3D grid, the advancement of the aquifer was evaluated. A series of well fences and average saturation maps per reservoir subzones were created to show the water advancement evolution through time in high resolution. Maps of reservoir potential by subzone were created, and areas of interest for infill drilling were identified.
The methodology proved capable of revealing the water paths in the reservoir where the density of data is large. Upward movement of bottom-aquifer rise, water invaded upper intervals, can be visualized. The results, where applicable, provide a cross-check and aid history matching of reservoir simulation models.
Experience Using the Heidelberg Retina Angiograph 2 with a Wide-Field Contact Lens System in Diabetic Retinopathy Cases
Authors: Shiibashi Miyo , Yoshimoto Miwako , Shigeeda Takashi , Kitano Shigehiko , Kato Satoshi 
Published: September 2013

Introduction:
HRA (Heiderberg Retina Angiograph) 2 uses a confocal scanning laser system which can provide high quality digital images but its imaging field is only 30°at most. HRA2 with a wide-field contact lens system allows an imaging field of up to 150°.

Methods:
We examined the advantages and disadvantages of HRA2, with a wide-field contact lens, for the evaluating diabetic retinopathy (DR).

Results:
HRA2 was beneficial for obtaining images of the entire retina simultaneously, without missing peripheral retinal non-perfusion and neovascularization. On the other hand, clear images connot be acquired in cases with media opacities such as corneal dystrophy, cataract and asteroid hyalosis, or in those with yellow tinted IOL.

Conclusions:
HRA2 with a wide-field contact lens is useful for visualizing peripheral retinal lesions in DR cases.
A Riemann-Hilbert problem with a vanishing
coefficient and applications to Toeplitz operators
Authors: Perälä A. , Virtanen J. A. , Wolf L. 
Published: September 2013

Abstract
We study the homogeneous Riemann-Hilbert problem with a
vanishing scalar-valued continuous coefficient. We characterize
non-existence of nontrivial solutions in the case where the
coefficient has its values along several rays starting from the
origin. As a consequence, some results on injectivity and existence
of eigenvalues of Toeplitz operators in Hardy spaces
are obtained.
L'Église catholique brésilienne et le Nord-Est : premiers pas et impasses au temps du populisme (1961-1964)
Authors: Marin Richard 
Published: September 2013

Sous la triple pression de la grande peur cubaine, du mouvement social et de l'Etat populiste, l'Eglise brésilienne découvre le peuple au début des années 60 à travers la syndicalisation rurale et le Mouvement d'Education de Base dans le Nord-Est.
Cette première avancée, très contradictoire dans ses motivations et qui par certains aspects annonce l'Eglise d'aujourd'hui, sera brusquement interrompue par le coup d'Etat militaire de 1964, approuvé par l'épiscopat.
Le tableau français des achats et ventes des secteurs de production
Authors: Thionet P. 
Published: September 2013

Dans une première partie : Présentation de la méthode française. — Ses différences avec les méthodes d'imput. output. — Aspect comptable du tableau français formé de deux tables d'achats et de ventes. — Notion d'équilibre comptable d'un couple de tables « achats-ventes », affecté d'erreurs d'évaluations. — Méthode pratique pour assurer un tel équilibre à mesure que le tableau s'améliore.
Une deuxième partie est consacrée à l'utilisation du tableau pour la prévision : La méthode générale et les hypothèses de structure. — Les possibilités spéciales du tableau français exposées sur le cas concret du gaz de ville : elles permettent de s'affranchir de la nécessité de considérer un secteur en bloc et par exemple de faire l'hypothèse que le gaz de Lorraine suffit à l'expansion des besoins. — Les difficultés créées par l'agriculture, la distribution et les services. — L'ajustement du nombre des équations sur le nombre des inconnues. —— Résolution du système par approximations successives. — La façon d'introduire des variations de prix entre l'année de base et l'année de projection.
Variations de structure de la consommation depuis 50 ans
Authors: Brousse Henri 
Published: September 2013

On s'est proposé pour but, dans l'étude qui suit, de se faire une idée approximative des modifications intervenues depuis une cinquantaine d'années dans l'importance respective des divers biens de consommation et services achetés par les particuliers. Comme il fallait s'y attendre, ce travail n'a pu être achevé faute d'avoir pu chiffrer le total des dépenses des ménages il y a 40 ou 50 ans, comme il a pu être chiffré par le CREDOC en 1950-1955. Aucune des sources utilisées ne couvrait le total des dépenses ni l'ensemble des professions, il y a un demi-siècle.
Telle qu'elle est, cependant, cette étude apporte des précisions partielles. Beaucoup de variations relatives entre les consommations de divers biens y sont mises en évidence et beaucoup d'éléments disparates, relatifs à la période 1905-1914 se trouvent rassemblés et confrontés aux chiffres correspondants de l'époque actuelle.
Cryptococcal meningitis with secondary cutaneous involvement in an immunocompetent host
Authors: Tabassum Saadia , Rahman Atiya , Herekar Fivzia , Masood Sadia 
Published: September 2013

Cryptococcosis is a potentially fatal fungal disease caused by variants of Cryptococcus neoformans species. The respiratory tract is the usual portal of entry, with a peculiar predilection to invade the central nervous system. The skin can be secondarily involved in disseminated infection or be exceptionally involved as primary cutaneous infection by inoculation. The disease is mostly seen in immunodeficiency states. The diagnosis is frequently unsuspected in immunocompetent patients. We report a case of disseminated cryptococcal meningitis in an immunocompetent young adult. The cutaneous eruption prompted the accurate diagnosis. The patient, a 20-year-old female, had fever, cough, headache and intractable vomiting for the past two months and was being managed as a case of tuberculous meningitis. Two weeks after starting antituberculous treatment she developed umbilicated papules on the head and neck region. Necessary laboratory workup identified C. neoformans in cerebrospinal fluid (CSF) and skin specimens. The titers of cryptococcal antigen were measured in CSF and serum for diagnostic and prognostic purposes. Anti-fungal treatment resulted in regression of the cutaneous lesions and resolution of systemic complaints. The case highlights the need for high degree of suspicion, especially in healthy young adults, in the diagnosis of cryptococcosis. The cutaneous eruptions can be the first manifestation or a diagnostic clue of enormous significance.
Interferon-α Abrogates the Suppressive Effect of Apoptotic Cells on Dendritic Cells in anIn VitroModel of Systemic Lupus Erythematosus Pathogenesis
Authors: Abeler-Dörner Lucie , Rieger Cosima C. , Berger Bartlomiej , Weyd Heiko , Gräf Daniela , Pfrang Sandra , Tarner Ingo H. , Schwarting Andreas , Lorenz Hanns-Martin , Müller-Ladner Ulf , Krammer Peter H. , Kuhn Annegret 
Published: September 2013

Objective.An increased incidence of apoptotic cells and an increased activation of dendritic cells (DC) may be involved in the pathogenesis of systemic lupus erythematosus (SLE). We investigated the characteristics of apoptotic neutrophils and monocyte-derived DC of patients with SLE, their interaction, and the influence of autoantibodies and inflammatory cytokines on this interaction.Methods.Kinetics of neutrophil apoptosis and DC activation were studied by flow cytometry. To analyze the interaction of apoptotic cells with phagocytes, crossover coculture experiments were performed with DC from patients with SLE and apoptotic Jurkat T cells as well as with apoptotic neutrophils from patients with SLE and the monocytic cell line U937. SLE serum and cytokines were added to this coculture, and activation and suppression of DC were quantified by levels of inflammatory cytokine secretion.Results.Apoptotic neutrophils and DC from patients with SLE showed no inherent defects compared to healthy controls, and the suppressive nature of their interaction was not affected. Autoantibodies as well as the inflammatory cytokines interleukin 17 (IL-17) and IL-1β had no influence on the interaction in this setup. Interferon (IFN)-α, however, substantially reduced the suppressive effect of apoptotic cells on DC.Conclusion.The data suggest that aberrant immune reactivity in SLE is not generally due to an intrinsic defect in apoptotic cells, their processing, or their interaction with DC, but likely arises from the milieu in which this interaction takes place. Our study highlights the importance of IFN-α during early stages of SLE and its potential as a therapeutic target.
Orthopedic Surgery in Rheumatoid Arthritis in the Era of Biologic Therapy
Authors: Leon Leticia , Abasolo Lydia , Carmona Loreto , Rodriguez-Rodriguez Luis , Lamas Jose Ramon , Hernandez-Garcia Cesar , Jover Juan Angel ,   for the emAR Study Group
Published: September 2013

Objective.To analyze sociodemographic and clinic-related factors associated with the use of orthopedic surgical procedures in rheumatoid arthritis (RA), focusing on the potential role of new biologic therapies.Methods.A retrospective medical record review was performed in a probability sample of 1272 patients with RA from 47 units distributed in 19 Spanish regions. Sociodemographic and clinical features, use of drugs, and arthritis-related joint surgeries were recorded following a standardized protocol.Results.A total of 94 patients (7.4%) underwent any orthopedic surgery during their disease course, with a total of 114 surgeries; 47 (41.2%) of these surgeries were total joint replacement (TJR). The median time to first orthopedic procedure was 7.9 years from the onset of RA symptoms, and the rate of orthopedic surgery (excluding TJR) was 4.5 procedures per 100 person-years from the beginning of RA, while the rate of TJR was 2.25 interventions per 100 person-years. A higher risk of undergoing an orthopedic surgical procedure was associated with taking nonsteroidal antiinflammatory drugs (NSAID) in the previous 2 years, female sex, longterm disease, and the presence of extraarticular complications. The risk factors for undergoing a TJR were being old, having a longterm disease, and taking biologic therapies.Conclusion.In the era of biologics, our national audit found a low percentage of patients who underwent orthopedic surgery, probably reflecting a thorough management of the RA. Sociodemographic factors, longterm RA, extraarticular complications, and NSAID were associated with orthopedic surgery.
Herpes Zoster Vaccination in SLE: A Pilot Study of Immunogenicity
Authors: Guthridge Joel M. , Cogman Abigail , Merrill Joan T. , Macwana Susan , Bean Krista M. , Powe Tiny , Roberts Virginia , James Judith A. , Chakravarty Eliza F. 
Published: September 2013

Objective.Patients with systemic lupus erythematosus (SLE) are at increased risk of herpes zoster (HZ). Although a vaccine for HZ has been approved by the US Food and Drug Administration, its use in immunocompromised individuals remains controversial because it is a live-attenuated virus vaccine. We performed a pilot study of the immunogenicity of the HZ vaccine (Zostavax) in patients with SLE.Methods.Ten patients with SLE and 10 control subjects ≥ age 50 years participated in this open-label vaccination study. All were seropositive for varicella zoster virus (VZV). Patients with SLE were excluded for SLE Disease Activity Index (SLEDAI) > 4, or use of mycophenolate mofetil, cyclophosphamide, biologics, or > 10 mg prednisone daily. Followup visits occurred at 2, 6, and 12 weeks. Clinical outcomes included the development of adverse events, particularly HZ or vesicular lesions, and SLE flare. Immunogenicity was assessed with VZV-specific interferon-γ-producing enzyme-linked immunospot (ELISPOT) assays and with antibody concentrations.Results.All subjects were women. Patients with SLE were slightly older than controls (60.5 vs 55.3 yrs, p < 0.05). Median baseline SLEDAI was 0 (range 0–2) for patients with SLE. No episodes of HZ, vesicular rash, serious adverse events, or SLE flares occurred. Three injection site reactions occurred in each group: mild erythema or tenderness. The proportion of subjects with a > 50% increase in ELISPOT results following vaccination was comparable between both groups, although absolute SLE responses were lower than controls. Antibody titers increased only among controls following vaccination (p < 0.05).Conclusion.The HZ vaccination yielded a measurable immune response in this cohort of patients with mild SLE taking mild-moderate immunosuppressive medications. No herpetiform lesions or SLE flares were seen in this small cohort of patients.ClinicalTrials.govID:NCT01474720.
Aberrant CpG Islands’ Hypermethylation of ABCB1 in Mesenchymal Stem Cells of Patients with Steroid-associated Osteonecrosis
Authors: Sun Zhibo , Yang Shuhua , Ye Shunan , Zhang Yukun , Xu Weihua , Zhang Bo , Liu Xianzhe , Mo Fengbo , Hua Wenbin 
Published: September 2013

Objective.Patients carrying an ABCB1 polymorphism have a higher risk of developing osteonecrosis of the femoral head (ONFH). We investigated whether aberrant dinucleotide CpG islands’ hypermethylation of ABCB1 gene existed in mesenchymal stem cells (MSC) of patients with ONFH, which results in cell dysfunction.Methods.Bone marrow was collected from the proximal femur of patients with glucocorticoid (GC)-associated ONFH (n = 22) and patients with new femoral neck fractures (n = 25). MSC were isolated by density gradient centrifugation. We investigated cell viability, intracellular reactive oxygen species (ROS) level, mitochondrial membrane potential (MMP), the amount of P-glycoprotein (P-gp) and ABCB1 transcripts, and methylation at CpG islands of ABCB1 promoter from both the femoral neck fractures group and the GC-associated ONFH group treated with or without the DNA methyltransferase inhibitor, 5′-Aza-2-deoxycytidine (5′-Aza-dC).Results.We observed that MSC from GC-associated ONFH groups showed reduced proliferation ability, elevated ROS levels, and depressed MMP when compared with the other 2 groups. Low levels of P-gp and ABCB1 transcript, as well as ABCB1 gene hypermethylation, in patients with GC-associated ONFH were also noted. Treatment with 5′-Aza-dC rapidly restored ABCB1 expression. Analysis of general expression revealed that aberrant CpG islands’ hypermethylation of ABCB1 caused sensitivity to GC and induced changes in the proliferation and oxidative stress of MSC under GC administration.Conclusion.These data suggest that aberrant CpG islands’ hypermethylation of ABCB1 gene may be responsible for individual differences in the development of GC-associated ONFH.