bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinically silent magnetic resonance imaging findings after subdural strip electrode implantation
Authors: Al-Otaibi Faisal A. J. , Alabousi Abdullah , Burneo Jorge G. , Lee Donald H. , Parrent Andrew G. , Steven David A. 
Published: July 2009

Object
Subdural strip electrodes (SSEs) are often used as part of the workup in patients being considered for epilepsy surgery. To assess for complications or to confirm electrode placement, postoperative imaging is often performed. Imaging performed with the electrodes in situ is limited by streak artifact on CT and susceptibility artifact on MR imaging. Therefore, the first opportunity for high-quality postoperative imaging is following explantation of electrodes. There is no data available to determine what would be the expected MR imaging appearance following insertion of SSE. The purpose of this study is to describe the MR imaging findings in asymptomatic patients who underwent insertion of SSEs.

Methods
Twenty consecutive patients who underwent SSE insertion were studied. Within 24 hours after removal of the electrodes, each patient underwent MR imaging that included axial T2-weighted, gradient echo, diffusion weighted, and coronal FLAIR sequences. No significant symptoms were reported by any of the patients. The studies were reviewed by an experienced, blinded neuroradiologist and categorized.

Results
Of the 20 patients studied, 11 were female (mean age 36 years). Clinically silent postexplantation MR imaging abnormalities were found in all patients: subdural hematomas in 7 (35%), cortical contusions in 5 (25%), local edema in 5 (25%), trans–bur hole cortical herniation in 5 (25%), subdural hygromas in 2 (10%), and pneumocranium in 4 (20%). The MR imaging abnormalities were subdivided into 2 types: Type A, abnormalities related to the site of electrode insertion; and Type B, abnormalities related to the location of the electrodes. The most common location for a Type A abnormality was occipitotemporal, with cortical contusions occurring in this location in 18% of cases, local edema in 24%, and trans–bur hole herniation in 24%. The next most common location was frontal, with cortical contusions found in this location in 10% of cases, local edema in 5% and trans–bur hole herniation in 5%. The most common Type B abnormality was a subdural hematoma, followed by pneumocranium and subdural hygroma.

Conclusions
Clinically silent MR imaging abnormalities are common following SSE placement. Knowledge of these findings would be of assistance in interpreting MR imaging results in patients being assessed for complications.
Clinical Profile of Diabetes Mellitus in Children and Adolescents under Eighteen Years of Age
Authors: Mohsin Fauzia , Zabeen Bedowra , Zinnat Rahelee , Azad Kishwar , Nahar Nazmun 
Published: July 2009

A total number of 125 patients with diabetes mellitus (DM) under eighteen years of age were admitted in the Paediartic department of BIRDEM hospital between January 2001 to October 2002. Eighty-eight patients (71%) were newly detected. Female to male ratio was 3:1. Out of the total admission 38 (30.4%) patients had type 1 DM (group 1), 37 (29.6%) patients had fibrocalculous pancreatic FCPD diabetes (group II), 48 (38.4%) patient had malnutrition modulated diabetes mellitus MMDM (group III) and 2 (1.6%) patients had type 2. Mean age of onset was 9±3.9 yrs in group I and 13±2.3 yrs in group II and group III. All groups had very high glucose and HbA1c value at presentation. The mean fasting glucose (mmol/l) was 19±7.14, 22.39±9 and 19.54±7.9 in group I, group II and group III respectively. The Mean HbA1c (%) value in the three groups was 14.4±2.7, 16.72±2.26 and 15.27±3.05 respectively. FCPD patients had poorest glycaemic status. Acute complications were more common in type 1 patients. Twelve (31.5%) patients had diabetic ketoatin DKA and two (5%) patients had hypoglycaemia in group I. Chronic complications were present in all three groups. MMDM patients had highest rate of complications. which was present in 2.6%, 21.6% and 33.3% patients in group I, group II and group III respectively. The rate of microalbuminuria was 5.3%. 10.8% and 18.8% in the three groups respectively. The rate of neuropathy was 2.6%, 16.2% and 20.8% in the three groups respectively. Among the associated problems skin infection, pulmonary tuberculosis and bilateral parotid swelling were common. Malnutrition was present in 66%, 86% and 100% in group I, group II and group III respectively. Majority (50% in group I, 91.6% in group II and 100% in group III) of our patients came from poor socio-economic background. Ibrahim Med. Coll. J. 2007; 1(1): 11-15 Key words: Diabetes mellitus doi: 10.3329/imcj.v1i1.2889
Les rencontres 2006 des professionnels de l'IST. Les archives ouvertes et la veille scientifique, deux axes de réflexion
Authors: Chazelas Martine , Courtial Francine , Dassa Michèle , Janik Joanna , Jannès-Ober Emmanuelle , Martin Caroline 
Published: July 2009

Résumé Les rencontres 2006 organisées par l’Institut de l’information scientifique et technique (INIST/CNRS) à l’intention des professionnels de l’IST se sont déroulées du 19 au 21 juin 2006 à Nancy où se sont retrouvées plus de quatre cents personnes exerçant principalement dans le monde de la recherche et de l’enseignement. Outre les présentations de différents projets de l’INIST et d’autres organismes de recherche et de nombreuses séances de posters, deux grands thèmes ont été abordés lors des conférences : « Archives institutionnelles et archives ouvertes » et « Veille scientifique, veille stratégique »
Removal of a Hydrate Plug from a Subsea Xmas-Tree Located in Ultradeepwaters with the Aid of a Heat-Releasing Treating Fluid
Authors: Evangelista Eliezer , Chagas C.M. , Melo Jose Antonio Fonseca , Filho Ney Brandao , Rocha Jose Dante Henriques , do Carmo Marques Luiz Carlos 
Published: July 2009

Abstract
The paper describes the actions taken to re-entry a well located in ultra-deep waters (1541 m water depth) whose sub sea Christmas-tree was blocked by a solid hydrate plug and therefore could not be liberated by means of its standard releasing tools.
A heat-releasing treating fluid - the so-called self-generated nitrogen (SGN) fluid - was successfully applied to heat and dissociate the hydrate plug, which was totally blocking the locking mechanism of the Production Vertical Connection Mandrel (PVCM) of the tree. The heat applied around the Xmas-tree body was conveyed by the pumped SGN fluid batches. By doing so, the hydrate plug was completely dissociated (melted down) and then the unlatching mechanism became operational again.
This paper comprehensively describes the steps of this different hydrate treatment job. In broad terms, a technically challenging job which encompassed the following issues: - development of a " tailor-made?? environmental-friendly SGN formulation, - heat exchange simulations to design the optimum volume for the SGN treatment batch, - a review of the theoretical aspects of hydrate formation/dissociation, - use of an instrumented/insulated drill pipe riser (DPR), - and job safety procedure reviews. A PLT logging tool (PLT) was also used to keep a record of the temperature profile inside the DPR.
In view of the pioneer aspects of the operation, the combined use of an ROV and PLT was of paramount importance to monitor every step of the operation since its very beginning. Along the job, the Christmas-tree, the reactivity of the treating fluid batches, the temperature changes, and the hydrate blockage, were monitored on a permanent basis. The combination of these two tools has provided precious pieces of information that have enabled us to gain insight into what was going on along the job and take the necessary measures to its real-time optimization.

Introduction
Hydrate and paraffin blockages are currently the major causes of oil production losses in Campos Basin´s deepwater scenarios. In many instances, these blockage problems have been solved by means of a treatment with the heating-releasing SGN fluids.
Deepwater Subsea Tie-In Between Chevron Blind Faith and Devils Tower Export Pipelines
Authors: Phan Huy Thanh , Tarlton Oran , Charalambides John 
Published: July 2009

Abstract
This presentation will concentrate on the design challenges, experience and learning from the SIT and offshore installation of two deepwater pipeline tie-ins using first-of-its-kind subsea technology and installation methodologies on the " Blind Faith?? project. The Blind Faith Subsea Tie-Ins join the Blind Faith oil and gas pipelines with the Canyon Chief gas pipeline and the Mountaineer oil pipeline in 5100 feet of water. Both of the Blind Faith oil and gas pipelines are terminated with conventional PLEMs providing a horizontal connector for the tie-in and a vertical connector for a future tie-in connection point. The connectors are ROV operable / installable clamp style connectors.
The method of joining to the DT oil and gas export pipelines and the type of jumper employed are unique to the tiein. An ROV operable / installable mechanical pipe end connector connects the bare ends of the Canyon Chief and Mountaineer pipelines. The mechanical pipe end connector is fitted with an integral clamp connector hub and rests on an ROV installed mud mat. After installation of the mechanical connector, metrology was performed to create a neutral state horizontal jumper for joining the mechanical connector hub and the Blind Faith PLEM.
The neutral state horizontal jumper is a compliant " Z-Bend?? design. During installation the jumper was elastically pre-deformed using a bowstring system. Pre-deformation of the jumper provided installation clearances and facilitated the neutral stress state after installation. Once landed the jumper bowstring was relaxed, allowing the jumper to expand to fit between the hubs. After expansion and make-up, the clamp connectors were tightened via an ROV operated hydraulic torque wrench. A seal test verified the integrity of the connections. After installation the jumper remains in a minimal residual stress state atypical of most horizontal jumpers.
The horizontal jumper was chosen over the vertical jumper because it provides a more compact and lighter weight connection system. This also allows a wider choice of installation vessels. In addition the horizontal " Z-Bend?? provides the greatest amount of compliancy for the neutral state jumper. Lastly, the successful installation (and deployment) of the jumpers (and tooling packages) proved out the desired goals of installation by any medium size MSV vessel retrofitted with any work class ROV system.
Deepwater In-Line SLED Installation Methods and its Application to Frade Project
Authors: Huang Kevin , Ji Andy , Uribe Edgar 
Published: July 2009

Abstract
Flexible flowlines and risers have been increasingly used for deepwater and ultra-deepwater field applications, partially because of its low submerged weight and better dynamic characteristics comparing to rigid pipelines. The offshore installation of flowline itself is fast. However, its low bending stiffness brings challenges for installation when it contains heavy subsea equipments to be tied-in. Recently we have successfully installed a total of more than 100km flexible flowlines with 24 in-line SLEDs/PLETs in water depth up to 1300m. This paper reflects these subsea equipments installation experience and lessons learnt during the Frade project.
In this paper we highlight the installation issues and solutions during the in-line SLEDs and PLETs installation. First we discuss three of the possible installation options. For each option we modeled the whole installation sequence with finite element analysis software tools and analyzed each critical stage to ensure the product and equipment integrity. Based on each option's pros and cons we defined their application scopes. Then we present some of the installation concerns such as current drag forces, rigging snatching loads, SLED-sea floor interaction during landing, etc, their analysis investigation, and adopted solutions. After that we present the high level installation procedures used for offshore installation, including different flowline type and installation scenarios, such as flowline installation with single or multiple in-line SLEDs, flowline initiation with PLET, and flowline laydown with PLET. Some of the lessons learnt are also discussed as well. Finally, the conclusions are drawn.
It is concluded that the present SLEDs/PLETs installation methods are effective and efficient, and proven by successful field operations. These methods are also applicable to the tie-in operations of all other similar subsea equipments for flexible flowlines in deepwater fields.

Introduction
The Frade field is located in the northern Campos Basin approximately 76 miles (120km) from the nearest Brazilian shoreline and 135 miles (220km) north-east of Macae. Chevron Corporation, through its affiliate Chevron Frade Limited Liability Company, along with partners Petrobras and Frade Japao Petroleo Limitada (FJPL), a joint vehicle company of INPEX, Sojitz and JOGMEC, developed the Frade oil field offshore Brazil. The Frade Field contains an estimated 200 million to 300 million barrels of recoverable oil and has a water depth range from 1000m to 1300m. It is expected to begin production in early 2009, with production capacity of approximately 100,000 barrels of crude oil per day and estimated peak annual production of 85,000 oil-equivalent barrels and 300 million cubic feet of natural gas per day. Crude oil export will be by tanker, while natural gas will be transported through the local natural gas pipeline infrastructure.
Materials, Manufacturing and Testing Requirements for Offshore Mooring Steel Wire Ropes, Sockets and Pins
Authors: Lohne Per William 
Published: July 2009

Abstract
The trend to produce oil at constantly deeper water has led to the development of floating production solutions for the exploitation of the energy resources in these areas. Steel wire ropes have been used and are being proposed used, as line segments in the majority of the mooring systems of these units. Typical applications covered are mobile offshore units and permanent moored floating production, storage and offloading systems.
Choice of wire rope construction and extent of corrosion protection is of vital importance and should be evaluated as a function of field design life and possibilities for replacement of the wire rope segments.
Performance criteria should be specified for the socketing compound. During production these criteria should be verified by relevant tests. Socketing procedures should be established and controlled before casting of resin.
Steel material for the wire ropes and sockets should be properly documented and be subjected to relevant tests. Mechanical test samples should be taken from full size sockets or from test coupons specially approved.
A design assessment including prototype testing of the wire rope construction and socket should be performed. Wire rope manufacture and manufacture and assembly of sockets and accessories should be according to a Quality Plan accepted by the parties involved.
This paper may serve as a technical reference document in contractual matters between the purchaser and manufacturer. It may also serve as a guideline for designers, purchasers and contractors.

Introduction

Steel Wire Rope Constructions
Steel wire rope segments of mooring lines could be of various constructions as shown in Figure 1. Other type of constructions may also be used if relevant experience can be documented.
The stranded rope constructions include a number of strands wound in the same rotational direction around a center core to form the wire rope. The number of strands and wires in each strand (e.g. 6×19, 6×36, 6×61) are governed by required strength and bending fatigue considerations for the wire rope. This construction generates torque as tension increases.
The torque balanced spiral rope constructions (spiral strand, half locked and full locked coils) do not generate significant torque with tension changes. These constructions use layers of wires (or bundles of wires) wound in opposing directions to obtain the torque balanced characteristics. The half locked and full locked coil constructions consist of one or more layers of shaped wires over the basic spiral rope construction resulting in a design more resistant to the ingress of corrosion media. The shaped layer(s) of wires will also prevent any outer wire fracture from unwinding. These constructions will normally give higher load capacity related to nominal diameter due to the increased metallic area, compared to other constructions.
SS: Tahiti On-Line Monitoring System for Steel Catenary Risers and Flowlines
Authors: Karayaka Metin , Chen Jen-hwa , Blankenshipp Curtiss , Ruf Wolfgang , Podskarbi Mateusz 
Published: July 2009

Abstract
The Riser and Flowline Monitoring (RFM) project deployed one of the most comprehensive subsea structural monitoring systems to date on a Tahiti infield (production) Steel Catenary Riser (SCR) and associated flowline. State-of-the-art motion and strain measurement devices are optimally placed along the SCR to continuously measure and store real-time full scale riser response. In addition, RFM project is the first to implement monitoring devices on a flowline to measure the flowline buckling, a phenomenon that is predicted during repeated start up/shut down. The project goals are two-fold:Understand fundamental hydrodynamic behavior of SCRs and flowlines, specifically, floater motion induced response of catenary risers, Vortex Induced Vibration of catenary risers, riser behavior at the pull tube exit region, riser-soil interaction at the touchdown region, flowline buckling, flowline axial walking, and flow assurance characteristics of infield flowlines. The information generated will be used in future riser designs.The information will be used to validate Tahiti riser and flowline system robustness and conduct " health checks?? on the fatigue critical risers and flowlines, particularly after significant environmental or operational events.
This paper describes the monitoring system configuration, the technology deployed, and the installation methods.

INTRODUCTION
The Tahiti field development is located in the Gulf of Mexico at 4,000 feet of water. More detailed information about the field and the riser systems can be found in References [1], and [2], respectively. Steel Catenary Risers (SCRs) have a proven track record and have been successfully installed in water depth of up to 8,000 feet. However, there is industry wide acceptance that a reasonable level of uncertainty exists with respect to the ability to predict riser performance. Calibration of analytical SCR response prediction models with full scale field measurements will improve design methods, design allowables, and operation integrity. RFM project's main drivers for development of a full scale monitoring system are to understand fundamentals of riser hydrodynamics with full-scale field measurements, calibrate design tools, and validate Tahiti riser system robustness. The monitoring devices and locations are specifically selected to characterize SCR behavior with respect to:Vessel Induced Motion (VIM)Vortex Induced Vibration (VIV)Effectiveness of VIV suppression devices (strakes)Riser behavior at the pull tube exit regionsRiser-soil interaction at the touchdown regionFlowline buckling, axial walkingFlow assurance characteristics of infield flowlines
Choices For LNG FPSO's
Authors: Festen Leo J.F.M. , Leo Jos 
Published: July 2009

Abstract
An estimated quarter of the world gas reserves is presently " Stranded?? in offshore gas fields.
The energy markets and dwindling oil reserves show the necessity to find new ways for offshore gas production.
LNG FPSO's will be required to develop the fields that are too far from the market for pipelines or in too deep water. Despite many design studies, technical and economic constraints have prevented LNG FPSO's from being developed as fast as Oil FPSO's.
A guide on the main choices in the development of a LNG FPSO is given based on a decade of development work by CB&I Lummus.
The following questions are crucial in realizing an offshore LNG production development:
-Which gas fields will be the preferred candidates for early development? -What type of storage tank to use? -Which offloading system? -What liquefaction process shall be selected? What is the lay-out philosophy? What are the options for power generation? How should the project be organized?
Eventually it will be possible to develop sour or high-nitrogen gas fields, fields in harsh environments, and very large gas fields, but these fields will initially not be selected.
The process on a FPSO will be determined by the feed gas composition and the sales spec of the LNG. For storage tanks both membrane and self-supporting types have their advantages; but newer types shall also be considered. Selection of offloading system follows from metocean data: in harsher environments tandem offloading with hoses will be the most flexible but requires dedicated carriers. First projects will use side-by-side offloading with conventional carriers. In the future, remote buoy offloading systems will become available.
Power generation could be dual fuel diesel engines or gas turbines; larger fields favor combined cycle power plants. Safety considerations should determine the layout of the FPSO. Safety and availability will strongly favor electric motor driven compressors.
Choice of liquefaction process is related to capacity; small and medium size will strongly favor expander processes.
For project approach, the choice is between leased and owned units.
The experience of an integrated design team is crucial for both.
Parametric Study of Ice Class Ship Structure
Authors: Abraham Jacob , Daley Claude 
Published: July 2009

Abstract
The new IACS Polar Rules for Ships contain plastic limit state models of frame capacity. Those limit states were analytically derived using relatively simple energy methods, validated by finite element analysis. This paper examines an expanded range of frames and employs a technique called Design of Experiments (DOE) and non-linear finite element analysis to examine the plastic capacity of frames. The results are compared to the IACS Polar Rule limit states. The paper may serve as the basis for discussing an update of the Polar Rules. The paper also provides owners/designers/regulators with a methodology to examine a wide variety of alternative plastic designs within a broad design space.

Introduction
Stiffened plates are the basic structural building blocks of many onshore and offshore structures, where high strength to weight ratio is a major criteria dictating design. The behavior of stiffened plate in the elastic region is well understood. In the recent years there has been a renewed interest in estimating plastic response of ship structures.
Ship design rules are changing from traditional working stress approach to new rules which allow plastic limit states, particularly in the case of ice class vessels. The rationale behind this move is the recognition that structure tends to have a large reserve capacity after it yields and before it finally collapses.
The capacity of a frame is currently estimated using the IACS rules. The pressure causing collapse in the case of a beam fixed at two ends and loaded at the center is given by IACS Polar Rules as (Daley, 2000):
Equation (1)
Equation (2)
The above pressure reflects the onset of significant plastic deformation and it ignores contributions from large deformations and membrane stresses. Hence the analytical solutions may not accurately estimate capacity of all frames. The reliable methods to estimate capacity are either to conduct a full scale experiment or a nonlinear finite element analysis. These methods are either very expensive or too complex. There is a need for a simple regression equation which can predict capacity taking into account all the non linear behavior of the structure.