bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal Characterization of Reservoir Rock and Crude Oil for Reservoir Characterization
Authors: Baysal Banu 
Published: June 2009

This paper was presented as part of the student paper contest associated with the European Petroleum Conference.

Abstract
Three wells selected in Raman field of South Eastern Turkey had exhibited different gas contents as determined by TPAO. The wells were located at different blocks separated by faults. The aim was to characterize the crude oil and core samples from 3 wells to understand if the differences exist which can be related to reservoir properties. Thermal analysis techniques were used as a novel technique for characterization. The tests were conducted under nitrogen and air atmospheres to simulate pyrolysis and oxidation behavior. The oxidation and pyrolysis results were evaluated to calculate parameters such as peak reaction temperatures, maximum heat flow data, enthalpy changes, activation energy. Comparing the peak temperatures during pyrolysis and heat flow values during oxidation of DSC experiments, S1/S2 and (S1+S2)/S3 ratios, and diagnostic plots, indicate that Raman Well 84 crude oil was different than the other two samples. In order to understand the cause for this difference, detailed analysis of the geology, source rock and migration paths as well as connectivity between faults is justified.

Introduction
Thermal analysis is composed of several experimental techniques which have similar operating principles and are used to characterize samples by studying the chemical or physical reactions occuring under a programmed temperature increase.
Many researchers have studied the characterization of crude oils and their fractions by using TGA and DSC. With the pioneering work of Tadema, thermal analysis methods had become a way to analyze crude oils for insitu combustion. Some of the researchers like Bae studied the characterization of crude oil for fire flooding by thermal analysis. Morgan et al. had investigated the combustion characteristics of coals by thermal analysis.
Pore Scale Modelling of NMR Response in Mixed Porous Media
Authors: Beilby P. S. 
Published: June 2009

Abstract
This project was undertaken to investigate the fundamental physics associated with Nuclear Magnetic Resonance (NMR) logging and to incorporate any findings into the framework of existing pore scale modelling techniques. The study starts by looking analytically at the NMR response and an attempt is made to define a relationship between T¯2,, the mean transverse relaxation time, and pore radius.
An analytical relationship was derived and a Monte Carlo simulation model validated this. A relationship was also found for ‘the number of collisions that a proton makes before relaxing’ to the relaxivity constant. The simulation model validated the analytical expression and indeed proved it to be more accurate than the present industry standard approximation, T¯2−1=ρ.(sv). Results showed that the use of either the present industry approximation, or using the simple assumption that the pore space is water wet could both lead to large discrepancies when determining the pore size distribution, and consequently have a major impact on reserve estimation.
Study of Turbulent Break-up of Oil Droplets in Choke Valves
Authors: Muntinga J.H. 
Published: June 2009

This paper was presented as part of the student paper contest associated with the European Petroleum Conference.

Abstract
Production of a well at high water cut is associated with problems in separation efficiency of the oil-in-water emulsion. In this, the smallest sizes of the oil droplets are the decisive factor, negatively and greatly influenced by the choke valve. This valve breaks the produced distribution down to too many and too small droplets for the separation equipment to economically clean the water and isolate the oil.
Laboratory experiments allowed us to investigate the break-up effects of choke valves and to validate existing predictive theories. By using different choke types, significant reduction of break-up was accomplished. The effect of choke geometry on break-up is explained by an interplay of the time that droplets remain in a choke on the one hand, and the time needed for complete break-up under the current turbulence regime on the other. Hereby, the spatial distribution of energy dissipation, linked to the geometry of the choke, plays an important role.

Introduction
Often water is produced along with oil. When the age of a well matures, the water cut tends to increase. In the after-life of a well, the percentage of water can by far exceed that of oil. Wells with water cuts of 95% are no exception, which implies that these wells produce an oil-in-water emulsion.
Chokes are installed on every well to control the pressure and flow rate. They work on the basis of energy dissipation by increased turbulence. Downstream of the valve the pressure is brought down to safer values to work with, and the emulsified liquids must be separated. This should be done carefully in order not to loose valuable oil and to clean the water before disposal. The efficiency of a separator is confined by the droplet-size distribution offered to it.
Using the International Classification of Functioning, Disability and Health as a Framework to Examine the Association Between Falls and Clinical Assessment Tools in People With Stroke
Authors: Beninato Marianne , Portney Leslie G. , Sullivan Patricia E. 
Published: June 2009

BackgroundFalls in people with stroke are extremely common and present a significant health risk to this population. Development of fall screening tools is an essential component of a comprehensive fall reduction plan.ObjectiveThe purpose of this study was to examine the accuracy of clinical measures representing various domains of the International Classification of Functioning, Disability and Health (ICF) relative to their ability to identify individuals with a history of multiple falls.DesignA case series study design was used.SettingThe study was conducted in a community setting.ParticipantsTwenty-seven people with stroke participated in the study.MeasurementsClinical assessment tools included the lower-extremity subscale of the Fugl-Meyer Assessment of Sensorimotor Impairment (FMLE) and Five-Times-Sit-to-Stand Test (STS) representing the body function domain, the Berg Balance Scale (BBS) representing the activity domain, the Activities-specific Balance Confidence (ABC) Scale as a measure of personal factors, and the physical function subscale of the Stroke Impact Scale (SIS-16) as a broad measure of physical function. We used receiver operating characteristic (ROC) curves to generate cutoff scores, sensitivities, specificities, and likelihood ratios (LRs) relative to a history of multiple falls.ResultsThe FMLE and the STS showed a weak association with fall history. The BBS demonstrated fair accuracy in identifying people with multiple falls, with a cutoff score of 49 and a positive LR of 2.80. The ABC Scale and the SIS-16 were most effective, with cutoff scores of 81.1 and 61.7, respectively, positive LRs of 3.60 and 7.00, respectively, and negative LRs of 0.00 and 0.25, respectively.LimitationsA limitation of the study was the small sample size.ConclusionThe findings suggest that the ICF is a useful framework for selecting clinical measures relative to fall history and support the need for prospective study of tools in more-complex domains of the ICF for their accuracy for fall prediction in people with stroke.
Allowing Intralimb Kinematic Variability During Locomotor Training Poststroke Improves Kinematic Consistency: A Subgroup Analysis From a Randomized Clinical Trial
Authors: Lewek Michael D. , Cruz Theresa H. , Moore Jennifer L. , Roth Heidi R. , Dhaher Yasin Y. , Hornby T. George 
Published: June 2009

BackgroundLocomotor training (LT) to improve walking ability in people poststroke can be accomplished with therapist assistance as needed to promote continuous stepping. Various robotic devices also have been developed that can guide the lower limbs through a kinematically consistent gait pattern. It is unclear whether LT with either therapist or robotic assistance could improve kinematic coordination patterns during walking.ObjectiveThe purpose of this study was to determine whether LT with physical assistance as needed was superior to guided, symmetrical, robotic-assisted LT for improving kinematic coordination during walking poststroke.DesignThis study was a randomized clinical trial.MethodsNineteen people with chronic stroke (&gt;6 months’ duration) participating in a larger randomized control trial comparing therapist- versus robotic-assisted LT were recruited. Prior to and following 4 weeks of LT, gait analysis was performed at each participant's self-selected speed during overground walking. Kinematic coordination was defined as the consistency of intralimb hip and knee angular trajectories over repeated gait cycles and was compared before and after treatment for each group.ResultsLocomotor training with therapist assistance resulted in significant improvements in the consistency of intralimb movements of the impaired limb. Providing consistent kinematic assistance during robotic-assisted LT did not result in improvements in intralimb consistency. Only minimal changes in discrete kinematics were observed in either group.LimitationsThe limitations included a relatively small sample size and a lack of quantification regarding the extent of movement consistency during training sessions for both groups.ConclusionsCoordination of intralimb kinematics appears to improve in response to LT with therapist assistance as needed. Fixed assistance, as provided by this form of robotic guidance during LT, however, did not alter intralimb coordination.
Randomized, double-blind, placebo-controlled, pilot trial of high-dose methylprednisolone in aneurysmal subarachnoid hemorrhage
Authors: Gomis Philippe , Graftieaux Jean Pierre , Sercombe Richard , Hettler Dominique , Scherpereel Bernard , Rousseaux Pascal 
Published: June 2009

Object
The object of this study was to determine the efficacy of methylprednisolone in reducing symptomatic vasospasm and poor outcomes after subarachnoid hemorrhage (SAH).

Methods
Ninety-five patients with proven SAH were recruited into a double-blind, placebo-controlled, randomized trial. Starting within 6 hours after angiographic diagnosis of aneurysm rupture, placebo or methylprednisolone, 16 mg/kg, was administered intravenously every day for 3 days to 46 and 49 patients, respectively. Deterioration, defined as development of a focal sign or decrease of more than 1 point on the Glasgow Coma Scale for more than 6 hours, was investigated by using clinical criteria and transcranial Doppler ultrasonography, cerebral angiography, or CT when appropriate. The end points were incidence of symptomatic vasospasm (delayed ischemic neurological deficits associated with angiographic arterial narrowing or accelerated flow on Doppler ultrasonography, or both) and outcome 1 year after entry into the study according to a simplified Rankin scale (Functional Outcome Scale [FOS]) in living patients and the Glasgow Outcome Scale in all patients included.

Results
All episodes of deterioration and all living patients with a 1-year outcome were assessed by a review committee. In patients treated with methylprednisolone, the incidence of symptomatic vasospasm was 26.5% compared with 26.0% in those given placebo. Poor outcomes according to FOS were significantly reduced in the Methylprednisolone Group at 1 year of follow-up; the risk difference was 19.3% (95% CI 0.5–37.9%). The outcome was poor in 15% (6/40) of patients in the Methylprednisolone Group versus 34% (13/38) in the Placebo Group.

Conclusions
A safe and simple treatment with methylprednisolone did not reduce the incidence of symptomatic vasospasm but improved ability and functional outcome at 1 year after SAH.
Circulating endothelial progenitor cells in malignant gliomas
Authors: Rafat Neysan , Beck Grietje Ch. , Schulte Jutta , Tuettenberg Jochen , Vajkoczy Peter 
Published: June 2009

Object
Recent experimental work suggests that circulating endothelial progenitor cells (cEPCs) are recruited to the angiogenic vascular system of malignant gliomas. Consequently, the level of cEPCs has been proposed as a novel biomarker for the diagnosis and monitoring of these lesions. The aim of the present study was to examine the level of cEPCs and the level of EPC mobilizing mediators in the blood of patients with malignant gliomas. The authors were also interested in whether a correlation could be observed between the level of cEPCs and the extent of glioma angiogenesis determined by conventional methods.

Methods
Peripheral blood mononuclear cells from the whole blood of 12 patients with malignant gliomas (all glioblastomas multiforme [GBMs]), 10 with metastases to the brain, and 10 healthy volunteers were isolated using Ficoll density gradient centrifugation. The number of cEPCs was quantified by fluorescence-activated cell sorting analysis using antibodies against CD34, CD133, and VEGFR-2. Serum concentrations of VEGF and granulocyte-macrophage colony-stimulating factor (GM-CSF) were determined using the enzyme-linked immunosorbent assay. Histological analysis of tumor blood vessel density was performed by CD34 immunohistochemical staining.

Results
The number of cEPCs was significantly higher in patients with GBMs than in those with metastases (p < 0.04) or in the healthy volunteers (p < 0.004). The serum VEGF concentrations in patients with GBMs and metastases were significantly higher than in the healthy volunteers (p < 0.0001). Similar findings were observed for concentrations of GM-CSF. In addition, the patients in the GBM group with higher levels of cEPCs had significantly higher tumor blood vessel densities (1.71 ± 1.17% of total area) compared with patients who had low levels of cEPCs (0.62 ± 0.28% of total area; p < 0.02).

Conclusions
Endothelial progenitor cells are increasingly mobilized in patients with malignant gliomas, and their levels correlate with tumor angiogenic activity. Therefore, the authors' results suggest that cEPCs may have the potential to serve as a novel biomarker for the identification of patients who would benefit from antiangiogenic therapy for GBM.
Perioperative management of neurosurgical patients with methicillin-resistant Staphylococcus aureus
Authors: Akins Paul T. , Belko John , Banerjee Amit , Guppy Kern , Herbert David , Slipchenko Tamara , DeLemos Christi , Hawk Mark 
Published: June 2009

Object
The emergence of methicillin-resistant Staphylococcus aureus (MRSA) has posed a challenge in the treatment of neurosurgical patients. The authors investigated the impact of MRSA colonization and infection in the neurosurgical population at a community-based, tertiary care referral center.

Methods
Hospitalized patients under the care of the Kaiser Permanente inpatient neurosurgery service were prospectively entered into a database. In Phase I of the study, 492 consecutive patients were followed. Per hospital policy, the 260 patients from this group who were admitted to the intensive care unit (ICU) underwent screening for MRSA based on nasal swab cultures and a review of their medical history for prior MRSA infections. These patients were designated as either MRSA positive (17 patients, 6.5% of screened patients) or MRSA negative (243 patients). The 232 patients admitted to non-ICU nursing units did not undergo MRSA screening and were designated as unscreened. In Phase II of the study, the authors reviewed 1005 neurosurgical admissions and completed a detailed chart review in 62 MRSA-positive patients (6.2%). Eleven patients received nonoperative treatment. Five patients presented with community-acquired neurosurgical infections, and the causative organism was MRSA in 3 cases. Forty-six patients underwent 55 procedures, and the authors reviewed their perioperative management.

Results
In Phase I of the study, the authors found that for the MRSA-positive, MRSA-negative, and unscreened groups, the rates of postoperative neurosurgical wound infections caused by all pathogens were 23.5, 4.1, and 1.3%, respectively. For MRSA wound infections, the rates were 23.5, 0.8, and 0%, respectively. In Phase II, patients with MRSA were noted to have the following clinical features: male sex in 63%, a malignancy in 39.1%, diabetes in 34.8%, prior MRSA infection in 21.7%, immunosuppressed state in 17.4%, and a traumatic injury in 15.2%. The rate of postoperative neurosurgical wound infection in patients who received MRSA-specific prophylactic antibiotic therapy (usually vancomycin) was 7.4% (27 procedures) compared with 32.1% (28 procedures) in patients who received the standard treatment (usually cefazolin) (p = 0.04). Wound care for ICU patients was standardized for postoperative Days 0–7 with chlorhexidine cleaning at bandage changes at 3-day intervals. Wound cultures from neurosurgical site infections in patients with prior MRSA colonization or infection grew MRSA in 7 of 11 patients.

Conclusions
Neurosurgical patients identified with MRSA colonization or a prior history of MRSA infections benefit from specific perioperative care, including prophylactic antibiotics active against MRSA (such as vancomycin) and postoperative wound care with coverings and chlorhexidine antisepsis to reduce MRSA wound colonization.
Enantioselectivity of Enzymes
Authors: Hollmann Frank , Otten Linda G. 
Published: June 2009

AbstractThe enantioselectivity of enzymes plays a central role within life and is manifold exploited by using biocatalysis as a key step in the development of fine chemicals and drug synthesis. Some of the most relevant examples are summarized in this article. Understanding the molecular background of this enantioselectivity is an ongoing topic in modern enzymology. Current approaches aiming at in‐depth comprehension comprise structure‐based molecular modeling as well as empirical methods. Based thereon, strategies to gain control over the enantioselectivity are developed including (semi‐)rational and purely random mutagenesis. In addition, reaction engineering approaches are discussed. In this respect, fast and robust methods to determine enzyme enantioselectivity are pivotal. Here, an overview of the current knowledge and the most exciting developments in the area of understanding, controlling, and exploiting enzyme enantioselectivity is given.
Osteoarthritis
Authors: Gosset Marjolaine , Sellam Jérémie , Jacques, Claire , Berenbaum, Francis 
Published: June 2009

AbstractOsteoarthritis (OA) is considered the most common skeletal disorder and is characterized by cartilage degradation and osteophyte formation in joints. Although it is the most common joint disease, OA is often difficult to define because it is heterogeneous in its presentation style, rate of progression, and manifestations. Recently, new insights into the molecular biological basis of chondrocyte differentiation and cartilage homeostasis have been reported. The pathology of osteoarthritis is now interpreted as the disruption of balance between anabolic and catabolic signals. This article focuses on the risk factors, cellular and molecular mechanisms involved in OA, tools to study OA such as animal models and biomarkers, as well as treatment. Findings with regard to the physiologic and pathologic mechanisms involved in OA have made it possible to target therapeutic approaches more accurately, which allows the development of new drugs to reduce or block the progression of the disease.
Blood‐Brain Barrier, Considerations in Drug Development and Delivery
Authors: Miller David S. , Hawkins Brian T. 
Published: June 2009

Abstract
The brain capillary endothelium, which comprises the blood‐brain barrier, provides an exceptionally effective barrier to the entry of foreign chemicals into the central nervous system (CNS). As such, it limits pharmacotherapy of major CNS diseases, which include neurodegenerative diseases, epilepsy, brain cancer, and neuro‐AIDS. Two elements of the endothelium are largely responsible for its barrier properties. First, tight junctions between endothelial cells present a physical barrier. Second, endothelial cells themselves express high levels of adenosine triphosphate (ATP)‐driven drug efflux transporters, which present a selective/enzymatic barrier. Together, the physical and enzymatic barriers effectively limit blood to CNS delivery of both small‐molecule and macromolecule drugs. Developing strategies to circumvent these barriers is a major challenge for both medicinal chemists and pharmacologists.
Decontamination Methods for Drinking Water Treatment and Distribution Systems
Authors: McFee John , Krishnan Radha , Piao Haishan , Randall Paul 
Published: June 2009

Abstract

Once contamination has occurred in drinking water systems and the contaminated segment has been isolated from other parts of the system, there will be great urgency to decontaminate the areas as rapidly and cost effectively as possible. This article describes available and developing technologies for
in situ
and
ex situ
decontamination of systems and contaminated water for classes of potential contaminants. Three relevant research programs are described that first address the potential for agents to adhere to water system surfaces and impede returning the system to function. Subsequent research evaluates the effectiveness of selected treatment and decontamination agents. The applicability, decontamination/treatment effectiveness and limitations for addressing chemical, biological, and radiological contaminants are tabulated for a number of physical and chemical technologies.
The Military Roots of Critical Infrastructure Analysis and Attack
Authors: Rinaldi Steven M. 
Published: June 2009

AbstractCritical infrastructures underpin the political, military, economic, and social fabrics of societies. In recent years, it has become widely recognized that infrastructure disruptions could disproportionately affect the normal functioning of a nation. However, the understanding that the destruction of key infrastructure nodes and linkages could disproportionately affect national and economic security is not new; its early origins can be traced to military writings and application in the early 1900s. During World War I, attempts to attack key nodes were hampered by operational considerations, such as the inability to bomb accurately during adverse weather and darkness, and technological limitations including crude bombsights and small, dumb bombs. By the end of the century, however, significant improvements in technology enabled precision targeting of and attacks against critical infrastructures. In this article, we trace the military roots of critical infrastructure analysis and attack from World War I to the post‐Desert Storm era.
Detection of Hidden Information, Covert Channels and Information Flows
Authors: Johnson Neil F. , Sallee Phil A. 
Published: June 2009

AbstractSteganography is the art and science of writing hidden messages in such a way that no one apart from the intended recipient knows of the existence of the message. Hiding or embedding steganographic data digitally is accomplished through the use of mathematical techniques to add information content to digital objects—often images, video, and audio, but even other digital objects such as executable code. Steganalysis is the examination of an object to determine the presence of steganographic content, and potentially to characterize or extract such embedded information. Watermarking refers to embedding content that conveys some information about the cover object (e.g. copyright information). In this context, digital data forensics is the use of science and technology to determine information about how a digital object was formed or modified, even in the absence of the original object. Detection of covert information flows relies on the ability to detect information hidden within a stream of information that is transmitted from one system to another.