bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multidetector computed tomography and coronary risk stratification — From research to clinical practice
Authors: Gonsorcik J. , Dobrovicova Adela , Gibarti C. 
Published: September 2011

Abstract
Cardiovascular disease due to atherosclerosis is the foremost cause of premature mortality and of disability-adjusted life years in Europe. Risk stratification management includes variety of clinical, laboratory and special diagnostic methods with different relevance. However, because global risk scores tend to underestimate risk in most persons, atherosclerosis imaging has been introduced for the refinement of stratification. Cardiac techniques including computed tomography (CT) have evolved rapidly for the study of cardiovascular structure and function. Multidetector CT is an additional relevant potential tool for assessment of coronary artery disease in selected patients and scientific data will be continuing to expand into clinical practice. Our findings showed that utility may be helpful also in non-diabetic patients with arterial hypertension or renal insufficiency and in elderly with degenerative aortic stenosis.
Atrial fibrillation as prognostic factor of myocardial infarction and/or acute heart failure
Authors: Špinar Jindřich , Ludka O. , Sepši M. , Ajibona O. , Pařenica J. , Jarkovský J. 
Published: September 2011

Abstract
Atrial fibrillation (AF) is a supraventricular tachyarrhythmia characterized by uncoordinated atrial activation with consequence deterioration of atrial mechanical function. It has an incidence of approximately 6 million people in European Union as a result of the aging population and affects about 1 percent of patients younger than 60 years and about 8 percent of patients older than 80 years [2, 10]. AF is also the most common supraventricular arrhythmia in patients with acute myocardial infarction (MI) and/or acute heart failure (AHF), complicating its course with an incidence between 6–21% in hospitalized patients with MI although recent advances in pharmacological treatment of myocardial infarction has probably changed the impact of this arrhythmia and vice versa. These two diseases (AF + MI) are a growing health concern all over the world and when one considers the occurrence of these two diseases simultaneously, the relevance of AF in the course of MI and vice versa cannot be overemphasized in cardiovascular health care and more importantly its treatment and prevention. Aim: This article therefore aims to correlate data from controlled studies to summarize the incidence of AF in MI and vice versa and the impact of pharmacotherapy. Data from our registry Brno (3502 patients with MI and/or AHF) show that AF is not a predictor of short-term mortality in patients with myocardial infarction and/or heart failure, but is a strong predictor of long-term mortality.
Echocardiography in sports cardiology: LV remodeling in athletes' heart — Questions to be answered
Authors: Zdravkovic M. , Vujusić-Tesic B. , Krotin M. , Nedeljkovic I. , Mazic S. , Stepanovic J. , Tesic M. , Ostojic M. 
Published: September 2011

AbstractAn enhanced risk of undesirable events has been described in individuals who take part in mainly high intensity physical activities. Underlying cardiac disorders are the most common cause of sudden death during sports activities. Left ventricular remodeling is associated with a long-term athletic training. Echocardiography is an easy, non-invasive and efficient way to the precise distinction between these exercise-induced changes, called “physiological” hypertrophy, that revert after detraining, and those of cardiac disorders or “pathological” hypertrophy. The identification of a cardiac disease in an athlete usually leads to his disqualification in an attempt to reduce the risk. On the other hand, a false diagnosis of a cardiac disease in an athlete may also lead to disqualification, thus depriving him of the various benefits from sports participation. Pronounced left ventricular dilatation and hypertrophy should always be suspected for underlying cardiac disease. Physiological left ventricular remodeling is associated with normal systolic and diastolic left ventricle function. Both global and regional left ventricle diastolic function should be evaluated. New echocardiographic techniques (tissue Doppler imaging, strain rate) have revealed “super — diastolic” left ventricle function in athletes, adding the new quality in differential diagnosis od athlete's heart syndrome.
New Standard for Evaluating Casing Connections for Thermal-Well Applications
Authors: Nowinka Jaroslaw , Dall'Acqua Dan 
Published: September 2011

Summary
Casing connections in thermal wells experience extreme loads owing to exposure to high temperatures ranging as high as 200 to 350°C, stresses exceeding the elastic limit, and cyclic plastic deformation. To date, no standard procedure has been adopted by the industry to qualify casing connections for such conditions. In particular, the existing evaluation standard published jointly by the International Organization for Standardization (ISO) and American Petroleum Institute (API) ISO 13679/API 5C5 (ISO 2002) does not apply to tubular loads beyond pipe body yield and temperatures above 180°C. Proprietary procedures have been used to qualify connections for individual thermal operations, but none of those has been accepted as an industry standard.
This paper introduces a new protocol for evaluating casing connections for thermal applications: Thermal Well Casing Connection Evaluation Protocol (TWCCEP). While founded on longstanding work in the thermal-well arena, TWCCEP was developed through a multiclient project sponsored by several major operators and connection manufacturers. Following project completion, TWCCEP was released to the public domain and submitted to ISO for adoption as an international standard.
TWCCEP uses both analytical and experimental procedures to assess performance of a candidate connection under conditions typical of service in thermally stimulated wells. The objective of the analytical component is to assess sensitivities of the candidate connection to selected design variables, and identify worst-case combinations of those variables for configuration of specimens for physical testing. The purpose of the physical testing is to verify performance of the connection specimens under assembly-and- loading conditions simulating thermal-well service.
In addition to an overview of TWCCEP, this paper illustrates how engineering analysis, numerical simulation, and reduced-scale physical testing were used to examine the impacts of various design and loading variables on connection strength and sealability, and subsequently to formulate the analysis-and-test matrix prescribed in the TWCCEP evaluation procedure.
Adoption and consistent use of TWCCEP is expected to increase operational reliability and decrease failure potential of casing strings in thermal wells. Learnings from the protocol development process will also help in the formulation of guidelines for connection requalification for thermal applications, in cases when one or more of the design variables change.
Understanding the Roles of Inflow-Control Devices in Optimizing Horizontal-Well Performance
Authors: Li Zhuoyi , Fernandes Preston , Zhu D.. 
Published: September 2011

Summary
An inflow-control device (ICD) is completion hardware that is deployed as part of well completions aimed at distributing the inflow evenly. Even though the detailed structures vary from one design to another, the principle for different ICDs is the same—restrict flow by creating additional pressure drop and therefore adjusting wellbore pressure distribution to achieve an evenly distributed flow profile along a horizontal well. With a more evenly distributed flow profile, one can reduce water or gas coning, prevent sand production, and solve other drawdown-related production problems. In general, ICDs are not adjustable; once installed in the well, the location of the device and the relationship between rate and pressure drop are fixed. This makes the design of a well completion and ICDs extremely critical for production. ICDs can be either beneficial or detrimental to production, depending on the reservoir condition, well structure, and completion design. Realizing that reservoir conditions will change during the life of a well, the impact of an ICD is a function of time. Reservoir heterogeneity and uncertainty can complicate the situation easily. The ICDs sometimes can be overlooked if the design is based only on reservoir flow simulations at initial conditions.
In this paper, we will investigate how and when an ICD should be used. An integrated analysis method of inflow (reservoir) and outflow (wellbore) is used to generate the flow profile of a horizontal well, and additional frictional pressure drop created by ICDs will be considered. Two conditions that result in production problems, wellbore pressure drop and reservoir heterogeneity, will be addressed. The focus will be on when and how an ICD can optimize production. Examples will be used to illustrate that it is critical to understand the reservoir conditions and wellbore dynamics together when designing a well completion with ICDs. The observations from this study show that overdesigned ICDs will not just increase the cost of well completion, but also will impact the well performance negatively. ICDs are not a universal solution of production problems. The application requires a thorough understanding of long-term reservoir behavior and upfront reservoir characterization for implementation.
Estimates of Fracture Lengths in an Injection Well by History Matching Bottomhole Pressures and Injection Profile
Authors: Suri Ajay , Sharma Mukul M. , Peters Ekwere J. 
Published: September 2011

Summary
An injection-well model is presented and used to history match a field injector's bottomhole pressures (BHPs) and injection profile (injection rate into each layer), taking into account plugging of formation caused by suspended solids in the injection water, poro- and thermoelastic stresses, injector shut-ins/restarts, and changes in both the injection rates and the average reservoir pressure. Fracture lengths and injection profile are estimated for a field injector as a case study. The injection-well fracture model is very similar to the Perkins and Gonzalez (1985) model except that it has integrated a more comprehensive and experimentally tested internal filtration model (Rajagopalan and Tien 1976; Pang and Sharma 1997; Gadde and Sharma 2001; Suri 2000; Wennberg and Sharma 1997) for calculating permeability reduction. It has also added a pressure-transient model that makes the earlier reservoir flow models more accurate.
The solids deposition is modeled using a filtration model (Rajagopalan and Tien 1976). The fluid flow in the reservoir is modeled using three approximated composite zones with uniform saturations and average mobilities, and the pressure for the fractured wellbore is calculated with the help of Gringarten's (1974) infinite-conductivity solution. The induced-fracture lengths are calculated on the basis of the Perkins and Gonzalez fracture-propagation model (1985) that accounts for the thermal and poroelastic stresses. The model is developed into a semianalytical numerical simulator that can predict and history match an injector's daily BHP, fracture lengths, and injection profile. Future estimates of pump pressures, BHP, injectivity, skin, front locations, fracture lengths, and injection profile can be obtained from this model. Both short-term pressure transients and long-term pseudosteady pressures observed over several years of injection can be history matched to capture effects that are important at both short and long time scales.
Finally a field-case injection-well study is presented in which BHP and injectivity are history matched over a period of 3 years. We show that the model can be used to estimate the minimum horizontal stresses in the layers if they are not known. Estimates of fracture lengths, fraction of flow, permeability reduction, and skin and front locations are also obtained. There is significant uncertainty in the results because of uncertainty in the model inputs and in the completeness of the physics of the model of fracturing itself. Both the solids deposition and the opening/closing of the injection-induced fractures had to be accounted for to obtain the history match. The layer/sand stresses and the water quality are the most important parameters that determine the well's injectivity, fracture growth, and injection profile. Microseismic surveys and PLTs are needed to confirm fracture lengths in injection wells.
Best Practices in the Allocation, Commissioning, and Maintenance of Ultrasonic Gas-Leak Detectors
Authors: Naranjo Edward , Neethling Gregory A. 
Published: September 2011

Summary
Ultrasonic gas-leak detection (UGLD) is gaining broader acceptance in the oil and gas industry as a means for detecting combustible-gas leaks. UGLD responds to high-pressure leaks by measuring the airborne ultrasound emitted, which when detected by the sensor provides a measure that is proportional to the leak rate. Principal advantages of the technology are that it does not require gas to be transported to the detector and it provides coverage for a relatively large area, up to 20 m in radius, suggesting that UGLD is suitable for detecting gas releases in open, well-ventilated sections of offshore platforms.
Despite such advantages, the location criteria and commissioning and routine-maintenance procedures for UGLD are not as well understood as those for conventional gas detectors. A reason might be that UGLD requires the establishment of an ambient ultrasonic background-noise level to decide the alarm level and assist with selection of optimal location, a requirement that has no parallel with point infrared (IR) or catalytic sensors. Location of ultrasonic gas-leak detectors is also based on identifying the potential sources of leaks and taking into account acoustic reflections and interferences caused by continuous or short-time-scale background ultrasonic noise.
Such newness might be enough to give some would-be users pause. They may believe that UGLD is for people with high technical competence or that mapping, commissioning, and maintenance are best left to UGLD-equipment manufacturers. Experience by one of the authors of this monograph suggests the contrary. UGLD, for its reliance on ultrasound as a proxy for a gas leak, is a simple concept to understand. Over the course of more than 3,000 installations during the last 10 years, offshore-platform personnel have developed best practices that reduce the time and cost required for installing and commissioning ultrasonic gas monitors and that ease the burden on maintenance. In this report, we examine several of these procedures and highlight the simplicity of installation and maintenance of this method of gas detection.
LNG for Petroleum Engineers
Authors: Choi Michael S. 
Published: September 2011

Summary
While remote parts of the world are awash with hundreds of trillions of cubic feet (Tcf) of natural gas, the industrialized West and emerging economies of the East cannot get enough of the clean-burning, environmentally friendly fuel. The problem is transporting this compressible fluid long distances and across major bodies of water. For markets more than 1,500 miles distant, liquefied natural gas (LNG) has proved to be the most economic option. By refrigerating natural gas (primarily methane) to–260°F (–162°C), thereby shrinking its volume by 600:1, natural gas in the form of LNG can be transported in large insulated cryogenic tankers at a reasonable cost.
Natural-gas liquefaction is a series of refrigeration systems similar to home air-conditioning (AC) systems, consisting of a compressor, condenser, and evaporator to chill and condense the gas. The difference is in the scale and magnitude of the refrigeration. A typical single-train LNG plant may cost USD 1.5 billion and consume 6 to 8% of the inlet gas as fuel. Because many of the impurities (e.g., water vapor, carbon dioxide, hydrogen sulfide) and heavier hydrocarbon compounds in natural gas would freeze at LNG temperatures, they must first be removed and disposed of or marketed as separate products.
This paper will provide an overview of LNG liquefaction facilities, from inlet gas receiving to LNG storage and loading. However, the focus is on the liquefaction process and equipment. Differences among the commercially available liquefaction processes (e.g., cascade, single mixed refrigerant, propane precooled mixed refrigerant, double-mixed refrigerant, nitrogen) will be discussed. The aim is to provide SPE members with a clear understanding of the technologies, equipment, and process choices required for a successful LNG project.
Leveraging a Common Infrastructure To Support Qatar's Rapid LNG Expansion
Authors: Al-Amoodi Ahmed , Felton Keith C. , Kasim Kamal , Whitehead Mike , Kouki Khaled 
Published: September 2011

Summary
The State of Qatar is rapidly expanding to capture almost one-third of the world's liquefied-natural-gas (LNG) market. By 2010, LNG exports from the State of Qatar are projected to reach 77 million tonnes per annum (Mt/a) (This was the outlook in late 2009). In addition to the LNG production, there will be a sizeable quantity of byproducts (condensate, propane, butane, and sulfur) as a result of the LNG production. These byproducts are expected to reach production rates of approximately 80 000 m3/d [500,000 barrels per day (B/D)] of condensate, 20 000 tonnes per day (t/d) of propane, 13 000 t/d of butane, and 12 000 t/d of sulfur.
To support this expansion, the State of Qatar has embarked on a pioneering approach to the storage and loading of LNG and its byproducts that will serve as an example of significant capital-investment savings, operational flexibility, and reduced land requirements. Traditionally, dedicated storage and loading facilities (infrastructure) have been designed and built to support a specific LNG production train and its associated byproducts. The State of Qatar's innovative approach has been the design and construction of a fully integrated common infrastructure to support all of the joint-venture-owned LNG production trains and other gas-related projects in Ras Laffan Industrial City (RLC). This paper will describe the unique aspects of this fully integrated infrastructure, its benefits, and the complexities and challenges associated with making the vision of a fully integrated LNG infrastructure come to fruition.
Commissioning and Operational History of Nkossa II LPG FSO
Authors: McLean David , Stott Conor , Foster Stephen , Hesse Emmanuelle 
Published: September 2011

Summary
In the mid-1990s, our client realized that their recent offshore find would yield viable liquefied-petroleum-gas (LPG) content. With the proposed field located more than 20 nautical miles offshore from an underdeveloped area, the option of exploitation on site was identified. Oil floating storage/offloading (FSO) units, usually adaptations of existing oil tankers, were already an established alternative to piping product ashore at that time. Therefore, tenders were invited for the provision of an LPG FSO unit. Any party tendering for this task would be covering new ground because this installation would be among the first of its kind. In particular, the physical properties of LPG demand different handling systems and techniques compared to oil.
In tendering, we drew from the diverse marine enterprises within our group. We also engaged a partner specialized in offshore solutions. We had access to existing LPG tonnage of suitable capacity and our own yard for conversion work. We also had a competent technical support structure and potential within our personnel base for operational requirements. As with any new project, once tender requirements were met and accepted, evolution occurred. This evolution is of course not limited to the period leading up to commissioning but has continued through to the present.
It is often the case that delivery of a specialized service holds a narrow spectrum of interest. However, it is our hope that this project, although relatively specialized, may also have value for any concern engaged in offshore storage and offloading. By this time, we have operated the unit for almost 15 years and can share some valuable experience.
Cervical arthroplasty in two dogs with disk-associated cervical spondylomyelopathy
Authors: Adamo Pietro Filippo 
Published: September 2011

Abstract
Case Description—A 4-year-old sexually intact male Doberman Pinscher (dog 1) was evaluated for signs of recurrent cervical pain and ataxia, and a 12-year-old neutered male mixed-breed dog (dog 2) was evaluated for a 4-month history of ataxia and tetraparesis.
Clinical Findings—Examination via magnetic resonance imaging (MRI) revealed spinal cord compression due to disk-associated cervical spondylomyelopathy at C6–7 in dog 1 and at C5–6 in dog 2.
Treatment and Outcome—Both dogs were surgically treated with a ventral slot procedure and spinal cord decompression, followed by insertion of a titanium cervical disk prosthesis at the affected site. Evaluation of radiographs obtained immediately after surgery indicated that each prosthesis was appropriately placed and provided adequate distraction. Radiographic and neurologic evaluations were performed 2 weeks and 3, 6, and 12 months after surgery in both dogs and 18 months after surgery in dog 1. Distraction of the vertebral bodies decreased moderately over time in both dogs. Intervertebral mobility determined via radiographic assessment of the prosthetic disk during neutral positioning, flexion, and traction of the cervical vertebral column was lost over time in dog 1 and was not achieved in dog 2. Eighteen months after surgery, results of MRI in dog 1 indicated adequate spinal cord decompression with no degeneration in other cervical disks.
Clinical Relevance—Cervical arthroplasty was well tolerated with no complications, and outcome was excellent in both dogs; prosthesis presence did not affect ability to reassess the area via MRI. Studies of cervical arthroplasty in dogs with disk-associated cervical spondylomyelopathy are warranted.
Dysuria caused by a partially obstructing urethral membrane in a female dog
Authors: Lechner Elizabeth S. , Cooke Kirsten L. 
Published: September 2011

Abstract
Case Description—A 3.5-year-old spayed female Labrador Retriever was examined for dysuria of unknown duration.
Clinical Findings—Urogenital examination revealed a recessed vulva and a persistent hymen. The hymen was broken down digitally. Results of urinalysis at the referral examination were unremarkable, and no clinically relevant abnormalities were detected on clinicopathologic analysis of blood and serum samples or cytologic evaluation of a vaginal smear. After clinical signs persisted, retrograde contrast vaginourethrocystography was performed; results were considered normal. During uroendoscopic examination, a translucent membranous structure was detected that partially obstructed the urethral lumen near the junction of the urethra and bladder.
Treatment and Outcome—Passage of the endoscope into the urinary bladder ruptured the membranous structure. The dog recovered from the procedure uneventfully and was treated with colchicine (0.03 mg/kg [0.014 mg/lb], PO, q 24 h for 14 days). One month later, the owner reported resolution of clinical signs. Fourteen months later, the patient was evaluated for recurrence of dysuria of several months' duration. Uroendoscopic examination revealed a membranous structure similar to that originally detected; this tissue was also ruptured during endoscopy. The patient was discharged and the owner was instructed to administer colchicine at the same dosage. Recurrence of dysuria was reported again 10 months following the second procedure.
Clinical Relevance—To the authors' knowledge, this type of membranous urethral obstruction has not been previously described in a dog. Administration of colchicine did not prevent recurrence, but potential effects of drug administration on time to recurrence could not be evaluated.