bluuebunny/crossref_metadata_2025_split huggingface dataset:
Timing of Blood Pressure Measurement Related to Caffeine Consumption
Authors: Mort Jane R , Kruse Heather R 
Published: December 2007

Objective: To determine whether patients should wait 30 minutes after caffeine consumption to have their blood pressure measured. Data Sources: Literature was obtained by searching MEDLINE (1980–September 2007), International Pharmaceutical Abstracts (1980–September 2007), and the Cochrane Database of Systematic Reviews (1994–September 2007). Search terms included caffeine and blood pressure. Literature was also obtained from citations in relevant articles. Study Selection and Data Extraction: Articles that examined caffeine's acute effect on blood pressure were reviewed, with additional focus on caffeine tolerance and hypertensive status. Data Synthesis: Caffeine appears to affect blood pressure through adenosine receptor inhibition and an increased release of select neurotransmitters. Caffeine levels peak 30–120 minutes after oral intake and caffeine's half-life is 3–6 hours. The effect of caffeine on blood pressure has been examined for decades, with variable results depending on factors such as population examined (eg, hypertensive status, physical stressors, age) and study design (eg, acute effects, chronic ingestion, retrospective epidemiologic review). Caffeine tolerance diminishes the acute effect of caffeine on blood pressure, and hypertensive individuals are more susceptible to blood pressure changes. Reviews of caffeine's acute effect on blood pressure indicate changes of 3–15 mm Hg systolic and 4–13 mm Hg diastolic. Typically, blood pressure changes occur within 30 minutes, peak in 1–2 hours, and may persist for more than 4 hours. Conclusions: Having a patient abstain from caffeine for 30 minutes prior to blood pressure monitoring is not adequate to avoid caffeine's potential effects. An alternative approach to blood pressure monitoring would be to ask the patient about recent caffeine consumption and interpret the blood pressure reading based on this information. In addition, healthcare practitioners should provide education regarding caffeine's effects.
Use of Renin—Angiotensin—Aldosterone System Inhibitors Within the First Eight to Twelve Weeks After Renal Transplantation
Authors: Jennings Douglas L , Taber David J 
Published: December 2007

Objective: To evaluate the safety and efficacy of early initiation of inhibitors of the renin–angiotensin–aldosterone system (RAAS) in renal transplant patients. Data Sources: A literature search was conducted using MEDLINE (1950–September 2007), PubMed (1966–September 2007), and International Pharmaceutical Abstracts (1970–September 2007) with combinations of the following terms: angiotensin-converting enzyme (ACE) inhibitors, angiotensin II type 1 receptor blockers (ARBs), and kidney transplant Articles obtained from this search were cross-referenced and bibliographies were checked for all relevant information. Study Selection and Data Extraction: All articles that examined the early (within 12 wk) initiation of either an ACE inhibitor or an ARB in renal transplant patients were included. Data Synthesis: A search of the literature revealed 7 studies that had examined the safety or efficacy of early use of ACE Inhibitors and ARBs in posttransplant patients. One study examined only plasma levels of a common marker for tissue fibrosis and one included only patients who had early graft dysfunction. Of the other 5 studies, 3 primarily reported safety endpoints and 2 reported clinical efficacy endpoints. Safety data in patients with functioning grafts (serum creatinine ranged from <2.5 to 3.0 mg/dL) show that early therapy with inhibitors of the RAAS did not result in appreciable increases in serum creatinine or potassium levels after up to 9 months of therapy. Results from the efficacy trials indicate that early initiation of an ACE inhibitor may be more effective than a β-blocker in reducing left ventricular hypertrophy and proteinuria after 24 months of treatment. Conclusions: It appears that the early initiation of RAAS inhibitors is safe in posttransplant patients with functioning grafts. It is reasonable to consider these agents as first-line pharmacotherapy in patients with hypertension and compelling indications (ie, diabetes or heart failure) in the first 12 weeks following transplant. Data are insufficient to recommend these drugs in patients with early graft dysfunction.
A new subfamily of bacterial glutamate/aspartate receptors
Authors: Singh Birendra , Röhm Klaus-Heinrich 
Published: December 2007

Abstract
The specificity of bacterial nutrient importers of the ATP-binding cassette (ABC) type depends on external receptor proteins that not only bind the solute to be transported, but also initiate the transport process by inducing ATP hydrolysis in the cytoplasmic nucleotide-binding domains. Here we propose a mode of ligand binding to the solute-binding protein AatJ that is required for glutamate uptake by the AatJMQP transporter in Pseudomonas putida KT2440. A homology model of the AatJ-glutamate complex was constructed using the E. coli glutamine-binding protein GlnH as the template. The general validity of the model was then confirmed by alanine scanning mutagenesis of several residues predicted to interact with the ligand and by semi-quantitative binding studies with [14C]-Glu and [14C]-Asp. A database search indicated that AatJ is a member of a distinct subfamily of the family 3 solute-binding proteins with specificity towards glutamate and aspartate.
Fracture Toughness of Hydrided Zircaloy-4 Sheet Under Through-Thickness Crack Growth Conditions
Authors: Raynaud P. A. , Koss D. A. , Motta A. T. , Chan K. S. 
Published: December 2007

Abstract
The susceptibility of fuel cladding to failure in the case of a postulated reactivity-initiated accident may be determined by crack initiation within a hydride blister or rim and subsequent crack growth through the thickness of the cladding. This study has determined the fracture toughness of hydrided cold-worked stress relieved Zircaloy-4 sheet subject to through-thickness crack growth at both 25 and 300°C. The experimental approach utilizes a novel procedure in which a narrow linear strip of brittle hydride blister across the specimen width creates a well-defined precrack upon initial loading. The subsequent crack growth resistance is then characterized by four-point bending of the specimen and an elastic-plastic fracture mechanics analysis. At room temperature, the through-thickness fracture toughness (Kq) is sensitive to the orientation of the hydride platelets and Kq≅25 MPa√m for crack growth through a mixed in-plane/out-of-plane hydride field. In contrast, Kq is much higher (≅75 MPa√m) when the hydride platelets are oriented predominantly in the plane of the sheet and therefore normal to both the crack plane and the crack growth direction. At 300°C, the material exhibits greater ductility as the hydride particles within the matrix resist fracture such that Kq≅83 MPa√m, despite the much lower flow stress of the material.
Present Technology In Offshore Mobile Drilling Vessels And Subsea Equipment
Authors: Hammett Dillard S. 
Published: December 2007

ABSTRACT
This paper presents an overview of the present technology in Offshore Mobile Drilling Vessels. Examples of the capability of these vessels' performance in environmental conditions offshore the People's Republic of China are discussed.
The evolution of mobile drilling equipment as technology developed while drilling from shallow marshes (4 ft.) to deepwater (5000 ft.) using inland barges, jackups/barges, ship-shape and semi-submersible drilling vessels is illustrated. Specific technical topics are presented on drilling in hostile ocean environments, operating limits, mooring, motion, safety, survival conditions, subsea BOP controls, well safety and personnel requirements.
Water Treating Plant Design and Operation
Authors: Caudle Danny Dearl 
Published: December 2007

ABSTRACT
Produced water must be treated to remove oil and solids and to control corrosion. Treating plants to do this consist of one or more processes such as skimming/settling, flotation, filtration, coalescence, and chemical treating. Design considerations and problems with these processes are discussed. Data from several sources are used to illustrate the performance of several treating plants.
Carbonate Reservoir Description
Authors: Jardine Daniel , Wilshart John William 
Published: December 2007

ABSTRACT
Carbonate reservoirs are characterized by extremely heterogeneous porosity and permeability-These heterogeneities are caused by the wide spectrum of environments in which carbonates are deposited and by subsequent diagenetic alteration of the original rock fabric. Pore systems range from thick, vuggy reservoirs in the coarse grained skeletal-rich facies of the reef margin or platform margin to highly stratified, often discontinuous reservoirs in the reef interior, platform interior and nearshore facies.
Eight pools from the Western Canada Basin have been selected to illustrate the variety of reservoir configurations which can be found. Boundary Lake and Steelman are thinly bedded sequences of cyclic nearshore carbonates which are best suited to pattern waterflood. Quirk Creek is a thick, overthrusted open platform gas pool in which fractures associated with the leading edge of the structure provide high deliverabllity in an otherwise low-permeability reservoir. Clarke Lake is a fractured, dolomitized platform margin gas reservoir which is highly susceptible to water channelling. Golden Spike, Judy Creek, Norman Wells and Redwater are reef bioherms which display the classic reservoir configuration of highly permeable reef margin facies enclosing strongly stratified reef interior sediments. With increasing reef size, the relative volume occupied by oil becomes smaller and the aquifer becomes larger and more effective.
Golden Spike was entirely filled with oil when discovered and early production was characterized by rapidly declining pressure. An initial gas flood depletion plan was followed by a gravity-controlled, gas-driven miscible flood. This was very effective until the miscible bank was broken up and dispersed by several thin impermeable beds in the reef interior which proved to be barriers to vertical flow.
Judy Creek had a small ineffective original aquifer and was produced initially by a downdip peripheral waterflood- This ultimately proved to be ineffective in repressuring the discontinuous porosity in the reef interior and was supplemented with a pattern waterflood.
Depletion plans for these pools require detailed, integrated geological-engineering studies to develop accurate reservoir models. These models are then used in computer simulation studies to forecast reservoir behavior under various depletion methods and to assist in on-going reservoir surveillance studies.
Reservoir Characterization By Areal Seismic Methods
Authors: McDonald John Andrew , Gardner Gerald H. F. , Morris Robert Irwin 
Published: December 2007

ABSTRACT
The areal seismic method has been developed over the last few years as a means of correctly imaging geological structure. However it was soon realized that many of the parameters which characterized hydrocarbon reservoirs could also be measured by the use of areal techniques. In the common-depth-point method (CDP) of collecting seismic reflection data the aim is to achieve a plane of seismic information in distance along the surface and in time into the geological section. The CDP stacking method is used to improve the signal-to-noise ratio, to remove multiples and it will give a representation of the subsurface particularly if the data are collected up-or-down dip. Thus the parameters characterizing a reservoir could be measured by a CDP line but the result would be information in only one dimension, along an up-or-down dip line through the reservoir.
Data can be collected in two-dimensions in space and one in time by a variety of techniques. The objective is to adequately sample the subsurface so that changes in various parameters can be mapped areally. Methods of data collection commonly used include the dragging of a cable along lines which are sufficiently close together and the shooting into lines of detectors which are at some angle to the lines of sources. Each seismic trace then represents a sampling of the subsurface. Variations in any measured parameter such as the amplitude, phase or power in the seismic signal or the velocity of propagation can be interpreted as an indication of changes in the physical properties of the rock matrix.
Having collected and processed what is essentially a cube of information a final problem remains: this is, display and interpretation. It is possible to display this information as a series of layers cut horizontally or vertically through the earth. This may be done on a television screen for video reproduction. The addition of an interactive computer system to the video presentation enables a three-dimensional interpretation of the cube to be made. The interpretation may then also be stored for video reproduction.
Trace Inversion for Interpreting Reservoir Continuity and Lithology
Authors: Harris Donald G. , Sarg J. F. , Branisa F. , Vail P. R. 
Published: December 2007

ABSTRACT
Seismic trace inversion sections show variations in acoustic impedance that might represent lithologic changes important to reservoir description. However, trace inversion techniques must be used carefully to avoid pitfalls associated with the interpretation of seismic data. Only where high-quality seismic data is available, 1ithology-impedance relationships are distinct and seismic stratigraphy procedures are utilized can trace inversion contribute to reservoir studies.
New Approaches in Well Testing
Authors: Zakirov S. N. , Indrupskiy I. M. , Zakirov E. S. , Anikeev D. P. , Tarasov A. I. , Bradulina O. V. 
Published: December 2007

Abstract
Modern methodology of well testing is the result of efforts of many scientists for more than 50 years. It is mainly based on the theory of single-phase flow. Few publications consider two-phase flow. However, they were also generally reduced to single-phase inverse problems.
During the last several years, authors have been developing an alternative trend in well testing. Its distinctive features are:
creation of bi-directional two-phase flow in the nearwellbore region or forced creation of two- or three-phase fluid flow; interpretation of well test results based on 1D, 2D or 3D multiphase optimization problems.
Obviously in this case well testing techniques are rather more complicated. They become science-intensive. On the other hand, they firstly extend the list of parameters and relations determined -those required for up-to-date 3D flow simulations. Added features include relative permeabilities for oil, gas and water, capillary pressures and full tensor permeability. Secondly, these parameters and relations characterize the effective (realistic) pore space. It is the effective, not absolute, pore space where the real reservoir flow processes take place. Turning to the effective pore space improves the degree of certainty in 3D modeling and enables proper use of well test results in the process of history matching 3D reservoir models.
The developed approach displayed noticeable advantages when applied to carbonate formations. In this case it enables more reliable characterization, compared to laboratory core experiments, including determination of
formation type (i.e. single- or dual-porosity) and parameters and relations required for 3D dual-porosity simulations.
In the paper the authors present a review of results obtained up to date.
New Approximate Analytical Solutions of Well Testing for Simple Boundary Shapes
Authors: Shimamoto T. 
Published: December 2007

ABSTRACT
One-dimensional radial flow equation, of which permeability and porosity are in inversely proportional to the radius, is equivalent to the equation of linear flow. In other words, if we take the radial variations of permeability and porosity into consideration, we can represent the linear flow by one-dimensional radial flow equation. To expand this idea and to apply it for various types of inner and outer boundary shapes, we defined the S-function by "The functions of reservoir properties in radail direction which should be used for a radial composite model in order to represent the pressure transient behavior at the well location for given inner- and/or outer- boundary shapes". The pressure behavior of the radial multi-composite model includes lots of pressure type curves. For example, one can reproduce the pressure transient behavior of channel type, sealing fault and hydraulic fractured well, etc by the radial multi-composite model with assigning the permeability and porosity distribution along radial direction adequately.
We found that the approximate S-function can be easily estimated from steady state streamlines. The composite models with the S-functions reproduce "sealing fault", "channel type", "horizontal sink" and "the reservoir which has different transmissibility regions". We compared the results with the conventional analytical solutions by commercial software, and obtained excellent agreement.
Not only its high novelty and expandability, but its calculation speed and visibility, this methodology (S-function) will be a powerful tool for pressure transient analyses.
Quantification of Uncertainty Due to Subgrid Heterogeneity in Reservoir Models
Authors: Okano H. , Pickup G. E. , Christie M. A. , Subbey S. , Sambridge M. 
Published: December 2007

Abstract
Due to the lack of data, a reservoir engineer needs to calibrate unknown petrophysical parameters based on production history. However, because the observations cannot constrain all the subsurface properties over a field, production forecasts for reservoirs are essentially uncertain. In general, many parameters of the model must be adjusted in the history-matching process, and the amount of computation required to solve the inverse problem may be prohibitive.
To address this issue, we proposed a new methodology which restricts the parameter ranges of the calibration by using physically based prior information, extracted from geological and petrophysical input. The aim of the work is to have a sound basis for forecasting uncertainty in reservoir production. We demonstrate the applicability of the methodology using quarter five-spot pattern waterflooding models.
The petrophysical properties to be adjusted in this paper are coarse-scale relative permeabilities. Coarse-scale models have the disadvantage of omitting the effects of fine-scale heterogeneity and suffering from solution errors, although in practice they are often employed in field-scale simulation because of the computational cost. Here, we history-match relative permeabilities at the coarse scale in order to encapsulate physical dispersion and compensate for numerical dispersion.
The prior information was estimated from a range of possible geostatistical parameters. It allowed us not only to determine the parameterisation of the grouped relative permeabilities but also to set up the bounds of each type of curve. We used a synthetic data set for which the true solution is known. The resulting posterior expectations and P10 / P90 cut-offs of the production data and the relative permeabilities were examined in comparison with the reference results. We conclude that this new approach enabled us to quantify the uncertainty of sub-grid heterogeneity through the use of coarse-scale relative permeabilities without refining the model.
Schedule Optimisation To Complement Assisted History Matching and Prediction Under Uncertainty
Authors: Jutila H. A. , Goodwin N. H. 
Published: December 2007

AbstractRecently our business has had great success in developing tools for using full physics simulators in Assisted History Matching (AHM) and prediction of future performance. However, the end user is often left wondering what to do with the large number of forecasts from these studies; any optimisation of the remaining potential has to be done manually.This paper discusses a method in which the principles of AHM are used to optimise the development. In AHM the practitioner attempts to minimise the error between the observed and simulated data; the ‘objective function’. A large number of ‘geological’ variables to the simulator are sensitised. ‘Control’ variables are used in the predictive work. These are only limited by the scheduling features of the reservoir simulator and would normally be the number and location of development wells; change in facilities constraints; re-completion; workovers etc. The objective function for development optimisation tends to be an economic one, i.e. Net Present Value (NPV) or some other profitability indicator. The method described in this paper has an advanced feature for generating additional results based on the simulator output time series.Schedule optimisation is known to be a very difficult problem, not amenable to standard mathematical programming algorithms, and we describe how, in conjunction with the use of a proxy model, we have successfully applied genetic algorithm optimization techniques, to solve the scheduling problem with minimal CPU processing.The method has been used a number of times and its application is described by some case studies; optimising the number and location of development wells and timing of scheduling events. As a very large number of possible combinations of variables are used the optimisation tends to be less subjective than a manual giving generally better results.
Water Injection Methods
Authors: Mitchell Robert William , Bowyer Paul Melvin 
Published: December 2007

Abstract
It is generally acknowledged that the first waterflood occurred as a result of accidental water injection in the Pithole City area of Pennsylvania in 1865 (1). As long ago as 1880 it was concluded that water, finding its way into a wellbore from shallow sands, would move through oil sands and be beneficial in increasing oil recovery! Since that time waterflooding has become the dominant technique employed in world wide oil recovery operations.
An area of particular interest at the present time is the use of sea water as an injection fluid, particularly in the North Sea, where the number of offshore oil production facilities is rapidly increasing. The high expense of offshore operations plus the high capital cost of the platform very often impose severe constraints on the design engineer, particularly in terms of the size and the weight of the water treatment facilities. The final design of any system will be governed by a variety of factors, generally with economics predominating. This paper discusses the influence of external constraints and reservoir criteria on offshore water injection system design. Examples are drawn mainly from BP's 5 years operational experience with the Forties Field Sea Water Injection System.
The design of a waterflood project requires two major facets of work, the reservoir engineering aspects, to predict recovery performance by waterflooding, and the production engineering, to evaluate all the surface requirements. Work on the former is normally limited to reservoir simulation studies to determine the water injection volume and pattern requirements. An important factor in the success of a waterflood project, although often neglected in production engineering, is the quality of the water required for injection into the reservoir rock. This definition has three major considerations: