bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimizing Proppant Conductivity and Number of Hydraulic Fractures in Tight Gas Sand Wells
Authors: Abass Hazim , Sierra Leopoldo , Tahini Ashraf 
Published: May 2009

Abstract
A substantial future potential for gas production lies in tight gas reservoirs with porosity of 5-8% and permeability less than 0.1 mD (micro-Darcy range). To construct a commercial well in these reservoirs, a well must contact as much as possible a large drainage area of the reservoir. Therefore, wells drilled in these challenging reservoirs must be hydraulically fractured to yield commercial gas production rate. The number of hydraulic fractures and their conductivities are vital parameters to ensure production increase and production sustainability during the life of the well. This paper focuses on the proppant fracture conductivity and the optimum number of fractures required along a horizontal well in a tight gas sand (TGS) reservoir.
The flow system in TGS reservoirs include matrix and natural/induced hydraulic fractures that contribute to the gas transport in a very complex manner. Laboratory tests were performed to determine the stress dependant permeability as a function of stress. A tensile natural fracture was simulated by splitting a whole core by failing it under tension using a Brazilian test procedure. The tensile fractured core was then propped with a small mesh proppants and the permeability of the propped fracture was determined. The experimental results of stress dependant permeabilities provided a basis for optimum fracture conductivity based on the flow properties of the porous components of a given reservoir (matrix, natural fractures, and propped fractures).
The results from the experimental phase were employed in a reservoir simulation study to determine the optimum fractures along a horizontal well required to convert a marginal well into an economic well. A series of reservoir simulation runs were performed given a set of well and reservoir characteristics. Common factors include reservoir properties, PVT, drainage area, well geometry, and created fracture geometry. The controlling factors include number of fractures, reservoir permeability, skin damage, and fracture conductivity. The number and optimum fracture conductivity required for appreciable production increase in tight gas reservoirs is demonstrated. A comparison between stress dependant and the stress independent permeabilities indicates the importance of including the effect of stress in any reservoir simulation of tight gas reservoirs.
Application of Hybrid Fracture Treatment to Tight Gas Sands in East Texas Cotton Valley Sands
Authors: Sani Abu M. , Nadezhdin Sergey V. , Villarreal Ruben , Chabernaud Thierry , Brown Ernest J. 
Published: May 2009

Abstract
Hydraulic fracture treatments are necessary to ensure the best deliverability of tight gas from east Texas Cotton Valley Sands. Historically these treatments have been performed using a wide variety of techniques using a range of fluids including slick water, linear gel, crosslinked polymers and CO2 emulsions. Most of the productive sands are associated with nearby water sands that are often intersected by the hydraulic fractures as their heights grow which results in high water production and a subsequent significant reduction in produced gas. An integrated engineering process of reservoir and production analyses was used to evaluate the stimulation treatment carried out for several offset wells throughout the field. The analyses determined the fracture geometry: fracture length, fracture conductivity, and permeability. The results were then used to calibrate a log-derived permeability and stress models. An advanced petrophysical analysis using these models improved the identification and characterization of potential movable water zones. A perforation scheme was proposed to minimize intersecting the water sands. Several stimulation techniques based on the rock mechanical model of the sands were evaluated. These included treatment with slick water, crosslinked polymer, hybrid (combination of slick water and crosslinked gel), CO2-based emulsions, and viscoelastic fluids. A high-rate hybrid treatment was selected because of the fracture geometry it would generate: bigger width, longer length, and minimal height growth.
The first new well came on production with a significantly low water-gas-ratio (WGR), from a first-year average of 483 bbl/MMscf for the offset wells to 135 bbl/MMscf for the new well. The first-year gas from this new well was more than double that of the offset wells average (163 MMscf versus 65 MMscf) and 88% higher than that of the best offset well. The polymer concentration was lowered to ensure better and earlier cleanup. On the next well drilled in the area, the same hybrid treatment was applied only to the portion of the Taylor sand located in the Cotton Valley sands. It came on line with higher gas production than the offset wells. For the first 6 months, total gas produced was 56 MMscf compared with the 40-MMscf average of the offsets, and the WGR was 147 bbl/MMscf compared with 397 bbl/MMscf.
Nanofluid Coreflood Experiments in the ARAB-D
Authors: Kanj Mazen Y. , Funk Jim J. , Al-Yousif Zuhair 
Published: May 2009

Abstract
This paper addresses a critical step on the road to having in-situ reservoir agents. It targets the limiting size of these devices and endeavors to model their transport mechanisms in the rock matrix. It also details an experimental study on nanofluid coreflood experiments in the ARAB-D formation of the giant Ghawar field in Saudi Arabia. The study aims to test the feasibility and future reality for displacing molecular nanoagents in the reservoir. The testing objectives, process, and results are further detailed herein.
Modeling Complex Dispersive Capacitance in Carbonates using NMR T2 Distributions
Authors: Funk James J. , Al-Harbi Ahmad M. 
Published: May 2009

Abstract
One frequently used model for miscible displacement in carbonates uses a capacitance mass exchange process to model both concentration profiles as a function of position and effluent profiles as a function of time. The capacitance effect in carbonates is quantified as a concentration driven mass exchange between a poorly connected system (stagnate fraction) and the miscible flowing fraction.
In a simple yet elegant experiment we have been able to expand this model to carbonate rocks that contain bi-modal pore size distributions. By combining experimental single phase dispersion tests with continuous nuclear magnetic resonance (NMR) T2 distribution measurements we observe directly velocity and concentration gradients. Results illustrate that the micro-porous system in select skeletal-oolitic rock types is preferentially connected and that intra-pore system fluid transport is more pronounced than that occurring between micro and macro pore systems. Using a combination of effluent and in-situ measurements we are able to model time dependent capacitance effects not apparent with the conventional capacitance dispersion model. The new model accurately captures early micro-macro system fluid exchange and late time capacitance effects modeled using effluent profiles.
Metaphor and the Work of Cultural Studies
Authors: Harewood Susan 
Published: May 2009

This article examines the political project of Cultural Studies by calling for a re-examination of the cultural studies research practices. The metaphors used by cultural studies researchers are explored, as these demonstrate the ways in which researchers have sought to emphasize openness and fluidity. However, it is argued that the desire for openness is not enough; that without rigorous consideration of methodology Cultural Studies lays itself open to many of the academic research problems it seeks to challenge. The article therefore offers a rethinking of the metaphors of cultural studies research. The question is, what alternative metaphors do we have for imagining a cultural politics? (Hall, 1996, p. 288)
Anomalous enhancements of low-energy fusion rates in plasmas: the role of ion momentum distributions and inhomogeneous screening
Authors: Coraddu Massimo , Lissia Marcello , Quarati Piero 
Published: May 2009

Abstract
Non-resonant fusion cross-sections significantly higher than corresponding theoretical predictions are observed in low-energy experiments with deuterated matrix target. Models based on thermal effects, electron screening, or quantum-effect dispersion relations have been proposed to explain these anomalous results: none of them appears to satisfactory reproduce the experiments. Velocity distributions are fundamental for the reaction rates and deviations from the Maxwellian limit could play a central role in explaining the enhancement. We examine two effects: an increase of the tail of the target Deuteron momentum distribution due to the Galitskii-Yakimets quantum uncertainty effect, which broadens the energy-momentum relation; and spatial fluctuations of the Debye-Hückel radius leading to an effective increase of electron screening. Either effect leads to larger reaction rates especially large at energies below a few keV, reducing the discrepancy between observations and theoretical expectations.
Techniques of aligning carbon nanotubes
Authors: Iakoubovskii Konstantin 
Published: May 2009

Abstract
This paper reviews major techniques of aligning carbon nanotubes, either during the growth or by the post-growth processing. A number of post-processing alignment techniques are discussed, which employ mechanical stretching, fracture, compression, friction, filtration, fiber drawing, gas flow, liquid crystals, Langmuir-Blodgett technique, acoustic, magnetic and electric fields. The suitability of those techniques to industrial applications is analyzed.
Habeas Corpus
Authors: Froment Meurice Marc 
Published: May 2009

The first part (‘Some Parts’) deals with Corpus, by Nancy, in contrast with Artaud's experience of his ‘own’ death in the psychiatric hospital in Rodez. The second part, (‘A corpus is not a discourse …, and it is not a narrative’) develops a quasi-narrative which points toward a greater corpus, at once ‘mad’ and undeniably true. ‘Interferon’, ‘Dragon Naturally Speaking’, the (Egyptian) ‘Book of the Dead’, all of these names embody powerful techniques to alter the self and displace the limits of experience ‘itself’. Corpus ‘is’ a writing without writing, or a writing from with/out. *
Internal model principle‐based control of exponentially damped sinusoids
Authors: Lu J. , Brown L. J. 
Published: May 2009

AbstractAn internal model principle‐based adaptive algorithm for identifying and canceling disturbances composed of sums of exponentially damped sinusoidal (EDS) signals is presented. The state variables of an internal model principle controller in a feedback loop can provide estimates of the EDS signal parameters, the frequency and the damping factor. By using additional integral controllers, the parameter errors can be eliminated to achieve perfect cancelation. The convergence of the proposed adaptive algorithm and the stability of the feedback control system adopting the algorithm are justified using singular perturbation theory and averaging theory. Simulation results demonstrate the performance of the algorithm. Copyright © 2009 John Wiley & Sons, Ltd.
Phase II study of bryostatin 1 and vincristine for aggressive non‐Hodgkin lymphoma relapsing after an autologous stem cell transplant
Authors: Barr Paul M. , Lazarus Hillard M. , Cooper Brenda W. , Schluchter Mark D. , Panneerselvam Ashok , Jacobberger James W. , Hsu Jack W. , Janakiraman Nalini , Simic Aleksandra , Dowlati Afshin , Remick Scot C. 
Published: May 2009

AbstractBryostatin 1, isolated from a marine bryozoan, enhances the efficacy of cytotoxic agents through modulation of the protein kinase C pathway and is active in combination with vincristine for diffuse large B‐cell lymphoma. Further, the apoptotic frequency of peripheral blood T lymphocytes as determined by flow cytometry may predict which patients will respond to this combination. We tested the efficacy and safety of bryostatin 1 50 μg/m2 given over 24 hr and vincristine 1.4 mg/m2 on days 1 and 15 every 28 days in aggressive B‐cell non‐Hodgkin lymphoma (NHL) relapsing after autologous stem cell transplantation. End points included tumor response, toxicity, and survival. Responses were correlated with an increase in apoptotic frequency of CD5+ cells by flow cytometry using annexin V staining. Fourteen patients were enrolled with 13 being evaluable for a response. The overall response rate was 31% with two patients achieving a complete response. The most common toxicities were Grade 3 lymphopenia (seven patients), Grade 3 to 4 neutropenia (two patients), and Grade 3 hypophosphatemia (two patients). Median progression‐free and overall survivals for all patients were 5.7 and 21.4 months, respectively. One patient demonstrated an increase in T‐cell apoptotic frequency, also achieving a complete response. Bryostatin 1 and vincristine have efficacy in select patients with aggressive NHL. Future investigations of agents targeting the protein kinase C pathway may benefit from early response assessment using flow cytometry to evaluate T‐cell apoptosis. Am. J. Hematol., 2009. © 2009 Wiley‐Liss, Inc.
Differences in diet and activity pattern between two groups ofAlouatta palliataassociated with the availability of big trees and fruit of top food taxa
Authors: Dunn Jacob C. , Cristóbal‐Azkarate Jurgi , Veà Joaquím J. 
Published: May 2009

AbstractThe threat that forest fragmentation and habitat loss presents for severalAlouattataxa requires us to determine the key elements that may promote the persistence of howler monkeys in forest fragments and to evaluate how changes in the availability of these elements may affect their future conservation prospects. In this study we analyzed the relationship between the availability of both big trees of top food taxa (BTTFT) (diameter at breast height>60) and fruit of top food taxa (FrTFT) in the home ranges of two groups ofAlouatta palliata mexicanaoccupying different forest fragments in Los Tuxtlas, Mexico, and their diet and activity pattern. Both study groups preferred big trees for feeding and the group with lower availability of BTTFT in their home range fed from more, smaller food sources. Furthermore, both study groups also increased the number of food sources when their consumption of fruit decreased, and the group with lower availability of FrTFT in their home range fed from more food sources. The increase in the number of food sources used under such conditions, in turn, set up a process of higher foraging effort and lower rest. In summary, our results support other studies that suggest that the availability of big trees and fruit may be two important elements influencing the persistence of howler monkeys in forest fragments. Am. J. Primatol. 71:654–662, 2009. © 2009 Wiley‐Liss, Inc.
Social dynamics of the golden snub‐nosed monkey (Rhinopithecus roxellana): female transfer and one‐male unit succession
Authors: Qi Xiao‐Guang , Li Bao‐Guo , Garber Paul A. , Ji Weihong , Watanabe Kunio 
Published: May 2009

AbstractAmong primates that form multilevel societies, understanding factors and mechanisms associated with the movement of individuals between groups, clans, and one‐male social units offers important insight into primate reproductive and social strategies. In this research we present data based on an 8‐year field study of a multilevel troop of Sichuan snub‐nosed monkeys (Rhinopithecus roxellana) in the Qinling Mountains of China. Our study troop contained 78–126 individuals, and was usually organized into 6–8 one‐male units (OMU). The majority of OMUs were composed of networks of unrelated females and their offspring. We found that 59.7% (43/72) of subadult and adult females in our study troop transferred between OMUs (n=66) or disappeared (n=7) from the troop. In the majority of cases, two or more females transferred together into new OMUs or troops. InR. roxellana, new OMUs formed in several ways. During 2001–2008, 16 adult males appeared in the study troop. Over this period, we observed 13 different males who became harem leaders either by taking over an existing harem or by attracting females from other OMUs into their harem. We also observed four OMUs from a neighboring troop to successfully immigrate into the study troop. The number of individuals in these newly immigrated OMUs was significantly smaller than that number of individuals in resident OMUs. During harem formation, fighting between adult males was rarely observed, and female mate choice appeared to play a crucial role in harem male recruitment and replacement. These results suggest that golden snub‐nosed monkeys are organized in a nonmatrilineal social system. Female mate choice and possibly incest avoidance appear to play important roles in female transfer, male tenure, and OMU stability. Am. J. Primatol. 71:670–679, 2009. © 2009 Wiley‐Liss, Inc.
Why programs are no longer enough: An interview on collaborating at the U.S. TSA
Authors: Cohen Judith 
Published: May 2009

AbstractHow a federal agency, with tens of thousands of employees and the nation's security in its mission, remade its conflict resolution processes into a full‐fledged decisionmaking and management system. The U.S. Transportation Security Administration's Deborah A. Katz is interviewed by New York conflict resolution consultant Judith Cohen in the first of two parts.
The rest of the Sept. 11 cases–those that went to Court–are settled via mediation
Authors: Bleemer Russ 
Published: May 2009

AbstractThe federal judge overseeing the litigation brought by family members of Sept. 11 victims, as well as injured survivors, has closed the book on nearly all the cases. He cited mediation efforts by New York attorney Sheila L. Birnbaum that settled 72 of the 95 outstanding matters. Birnbaum discusses her special master assignment, and the emotionpacked mediation sessions.
Pharmacokinetics of intravenous immunoglobulin and outcome in Guillain‐Barré syndrome
Authors: Kuitwaard Krista , de Gelder Jenny , Tio‐Gillen Anne P. , Hop Wim C. J. , van Gelder Teun , van Toorenenbergen Albert W. , van Doorn Pieter A. , Jacobs Bart C. 
Published: May 2009

AbstractObjectiveIntravenous immunoglobulin (IVIg) is the first choice treatment for Guillain‐Barré syndrome (GBS). All patients initially receive the same arbitrary dose of 2g per kg body weight. Not all patients, however, show a good recovery after this standard dose. IVIg clearance may depend on disease severity and vary between individuals, implying that this dose is suboptimal for some patients. In this study, we determined whether the pharmacokinetics of IVIg is related to outcome in GBS.MethodsWe included 174 GBS patients who had previously participated in 2 randomized clinical trials. At entry, all patients were unable to walk unaided and received a standard dose of IVIg. Total IgG levels in serum samples obtained immediately before and 2 weeks after the start of IVIg administration were determined by turbidimetry and related to clinical outcome at 6 months.ResultsThe increase in serum IgG (ΔIgG) 2 weeks after IVIg treatment varied considerably between patients (mean, 7.8g/L; standard deviation, 5.6g/L). Patients with a low ΔIgG recovered significantly more slowly, and fewer reached the ability to walk unaided at 6 months (log‐rank p < 0.001). In multivariate analysis adjusted for other known prognostic factors, a low ΔIgG was independently associated with poor outcome (p = 0.022).InterpretationAfter a standard dose of IVIg treatment, GBS patients show a large variation in pharmacokinetics, which is related to clinical outcome. This may indicate that patients with a small increase in serum IgG level may benefit from a higher dosage or second course of IVIg. Ann Neurol 2009;66:597–603
Recombinant C1 inhibitor in brain ischemic injury
Authors: Gesuete Raffaella , Storini Claudio , Fantin Alessandro , Stravalaci Matteo , Zanier Elisa R. , Orsini Franca , Vietsch Helene , Mannesse M. L. Maurice , Ziere Bertjan , Gobbi Marco , De Simoni Maria‐Grazia 
Published: May 2009

AbstractObjectiveC1 inhibitor (C1‐INH) is an endogenous inhibitor of complement and kinin systems. We have explored the efficacy and the therapeutic window of the recently available human recombinant (rh) C1‐INH on ischemic brain injury and investigated its mechanism of action in comparison with that of plasma‐derived (pd) C1‐INH.MethodsrhC1‐INH was administered intravenously to C57Bl/6 mice undergoing transient or permanent ischemia, and its protective effects were evaluated by measuring infarct volume and neurodegeneration. The binding profiles of rhC1‐INH and pdC1‐INH were assessed in vitro using surface plasmon resonance. Their localization in the ischemic brain tissue was determined by immunohistochemistry and confocal analysis. The functional consequences of rhC1‐INH and pdC1‐INH administration on complement activation were analyzed by enzyme‐linked immunosorbent assay on plasma samples.ResultsrhC1‐INH markedly reduced cerebral damage when administered up to 18 hours after transient ischemia and up to 6 hours after permanent ischemia, thus showing a surprisingly wide therapeutic window. In vitro rhC1‐INH bound mannose‐binding lectin (MBL), a key protein in the lectin complement pathway, with high affinity, whereas pdC1‐INH, which has a different glycosylation pattern, did not. In the ischemic brain, rhC1‐INH was confined to cerebral vessels, where it colocalized with MBL, whereas pdC1‐INH diffused into the brain parenchyma. In addition, rhC1‐INH was more active than pdC1‐INH in inhibiting MBL‐induced complement activation.InterpretationrhC1‐INH showed a surprisingly wider time window of efficacy compared with the corresponding plasmatic protein. We propose that the superiority of rhC1‐INH is due to its selective binding to MBL, which emerged as a novel target for stroke treatment. Ann Neurol 2009;66:332–342
Pathogenic CD8+ T cells in multiple sclerosis
Authors: Friese Manuel A. , Fugger Lars 
Published: May 2009

AbstractTraditionally, autoimmune pathogeneses have been attributed to CD4+ T lymphocytes, as in multiple sclerosis (MS), rheumatoid arthritis, type 1 diabetes mellitus, and/or to B lymphocytes, as in myasthenia gravis and systemic lupus erythematosus. That is because their primary genetic associations are mostly with certain human leukocyte antigen class II alleles, whose gene products present antigens to CD4+ T cells. Because few autoimmune diseases show stronger associations with major histocompatibility complex class I alleles (ankylosing spondylitis, Behçet's disease, and psoriasis), CD8+ T cells, which interact with major histocompatibility complex class I molecules, have been largely ignored in autoimmunity research. However, a variety of findings has recently revived interest in this population, particularly in MS. First, it shows associations with major histocompatibility complex class I alleles. Second, its lesions show a predominance of CD8+ T cells. Third, these represent effectors that can directly damage central nervous system target cells. Furthermore, several clinical trials of monoclonal antibodies specifically against CD4+ T cells, or the polarizing cytokines on which they depend, have failed to show any therapeutic benefit in MS, unlike broader‐spectrum antibodies that deplete all T cells. Here, we review the evidence that CD8+ T cells play a role in MS pathogenesis. Ann Neurol 2009;66:132–141