bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantifying rapid changes in cardiovascular state with a moving ensemble average
Authors: Cieslak Matthew , Ryan William S. , Babenko Viktoriya , Erro Hannah , Rathbun Zoe M. , Meiring Wendy , Kelsey Robert M. , Blascovich Jim , Grafton Scott T. 
Published: October 2017

AbstractMEAP, the moving ensemble analysis pipeline, is a new open‐source tool designed to perform multisubject preprocessing and analysis of cardiovascular data, including electrocardiogram (ECG), impedance cardiogram (ICG), and continuous blood pressure (BP). In addition to traditional ensemble averaging, MEAP implements a moving ensemble averaging method that allows for the continuous estimation of indices related to cardiovascular state, including cardiac output, preejection period, heart rate variability, and total peripheral resistance, among others. Here, we define the moving ensemble technique mathematically, highlighting its differences from fixed‐window ensemble averaging. We describe MEAP's interface and features for signal processing, artifact correction, and cardiovascular‐based fMRI analysis. We demonstrate the accuracy of MEAP's novel B point detection algorithm on a large collection of hand‐labeled ICG waveforms. As a proof of concept, two subjects completed a series of four physical and cognitive tasks (cold pressor, Valsalva maneuver, video game, random dot kinetogram) on 3 separate days while ECG, ICG, and BP were recorded. Critically, the moving ensemble method reliably captures the rapid cyclical cardiovascular changes related to the baroreflex during the Valsalva maneuver and the classic cold pressor response. Cardiovascular measures were seen to vary considerably within repetitions of the same cognitive task for each individual, suggesting that a carefully designed paradigm could be used to capture fast‐acting event‐related changes in cardiovascular state.
Bounding Analysis of Drinking Water Health Risks from a Spill of Hydraulic Fracturing Flowback Water
Authors: Rish William R. , Pfau Edward J. 
Published: October 2017

AbstractA bounding risk assessment is presented that evaluates possible human health risk from a hypothetical scenario involving a 10,000‐gallon release of flowback water from horizontal fracturing of Marcellus Shale. The water is assumed to be spilled on the ground, infiltrates into groundwater that is a source of drinking water, and an adult and child located downgradient drink the groundwater. Key uncertainties in estimating risk are given explicit quantitative treatment using Monte Carlo analysis. Chemicals that contribute significantly to estimated health risks are identified, as are key uncertainties and variables to which risk estimates are sensitive. The results show that hypothetical exposure via drinking water impacted by chemicals in Marcellus Shale flowback water, assumed to be spilled onto the ground surface, results in predicted bounds between 10−10 and 10−6 (for both adult and child receptors) for excess lifetime cancer risk. Cumulative hazard indices (HICUMULATIVE) resulting from these hypothetical exposures have predicted bounds (5th to 95th percentile) between 0.02 and 35 for assumed adult receptors and 0.1 and 146 for assumed child receptors. Predicted health risks are dominated by noncancer endpoints related to ingestion of barium and lithium in impacted groundwater. Hazard indices above unity are largely related to exposure to lithium. Salinity taste thresholds are likely to be exceeded before drinking water exposures result in adverse health effects. The findings provide focus for policy discussions concerning flowback water risk management. They also indicate ways to improve the ability to estimate health risks from drinking water impacted by a flowback water spill (i.e., reducing uncertainty).
Supply‐ versus Demand‐Side Policies in the Presence of Carbon Leakage and the Green Paradox
Authors: Hagem Cathrine , Storrøsten Halvor Briseid 
Published: October 2017

AbstractWe consider a climate coalition that seeks to reduce global emissions in the presence of carbon leakage and resource exhaustibility. We show that a credible announcement of future unilateral supply‐side policies delays foreign emissions, and we derive the optimal combination of consumer taxes and producer taxes when we consider leakages from free riders, both within periods and across periods. The tax shares generally differ over time. A decline in the present value of the social cost of carbon over time supports a time path where the consumers’ tax share of the total carbon tax also declines over time. We illustrate our findings with a numerical model.
Bottom Supported Tension Leg Tower for Offshore Wind Turbines
Authors: Sarkar Arunjyoti , Gudmestad Ove Tobias 
Published: October 2017

Power production from the high energy density offshore wind has now emerged as a potential source of renewable energy for the future of mankind. While the installed global cumulative offshore wind capacity in 2014 was around 8 GW [1], almost all of this came from the shallow water sites (water depths equal to 25m or less) where typical bottom founded structures (such as: monopole, jacket, concrete gravity type, etc.) are used to support the turbines.
Today, most of the shallow water sites are exhausted, and the industry is looking for setting up turbines at the deeper water sites, where the existing bottom founded structures tend to become massive and expensive. On the other hand, the floating wind turbine concept, apart from being expensive, is more suitable for water depth of 100 m or more.
It is expected that in the near future, the industry will primarily focus on concepts that may extend the application range of the existing bottom founded structures towards the deeper waters.
In this paper, a novel support structure concept termed “Bottom supported tension leg tower” is presented, and its preliminary technical feasibility is checked for a monopile type structure for 50 m water depth. The concept can also be used with a jacket or a gravity type support structure. The potential of using the monopile based structure at 100m water depth is also briefly addressed.
Improvement of Side-by-Side LNG Offloading Operability Calculations Using Monte Carlo Simulations and Scattered Data Multidimensional Interpolation
Authors: Auburtin Erwan , Lefebvre Timothée , Paquet Stéphane 
Published: October 2017

In order to properly design the mooring and offloading equipment, and assess the availability of Floating Liquefied Natural Gas (FLNG) units during the engineering phase, TechnipFMC has paid a particular attention to the operability prediction of LNG offloading operations. For the FLNG projects currently under construction, the chosen offloading solution is the Marine Loading Arms (MLA) technology with the LNG carrier (LNGC) moored in side-by-side (SBS) configuration.
In this paper, an improved methodology using Monte Carlo simulations is proposed to create a representative sample of a typical hindcast for North West Australia, assuming the case of a 147,000 m3 LNGC moored side-by-side to a TechnipFMC in-house design FLNG. It is shown that the random sampling is very well suited for large number of dimensions implied by the driving parameters (e.g. significant height, peak period, relative heading) of multiple wave partitions. In a second step, different multidimensional scattered data interpolation techniques are evaluated in order to further improve the accuracy. Since this would not be practical in time-domain and because the objective for this study is to compare the sampling and interpolation techniques to a benchmark on the whole hindcast, the vessels’ motions and SBS offloading operability are calculated in frequency-domain. The conclusions could also be applied to time-domain simulations. The paper also presents the sensitivity studies to the different interpolation methods and their key parameters and discusses the suitability of the proposed solutions.
Safety Challenges of LNG Offshore Industry and Introduction to Risk Management
Authors: Forte Karina , Ruf Diane 
Published: October 2017

Over many years, onshore plants have been deployed to liquefy the gas extracted from offshore wells and regasify the liquefied gas before sending it to the consumer grid. Currently the LNG Offshore Industry crosses a new development period since LNG Offshore Floating Units are considered as good options to improve the viability of gas supply.
Nevertheless this paper will introduce the main safety challenges usually identified on LNG Offshore facilities, such as the space constraints on LNG Liquefaction Offshore Floating Units and injuries to personnel due to the cryogenic properties of the LNG. Moreover, it will be demonstrated that each hazard has a particular solution which has to be carefully assessed in order to ensure that the risks linked to an installation dealing with LNG are well understood and under control at the same time that the expectations of the project are achieved and compliance with recognized international health and safety standards is respected.
Gaining knowledge about the properties of hazardous substances processed and operations performed in the installations is crucial to ensure safety in LNG Industry. Therefore this paper also aims at ensuring the awareness and understanding concerning the issues that could compromise the safety in LNG installations. As previously mentioned, a great concern in the LNG Offshore Industry is related to the space constraints in the site, once in case of a gas release followed by ignition there is the probability of escalation occurrence through the whole installation, what would affect personnel, environment and assets. Despite the space constraints found on offshore installations, it is important to consider minimum safety distances among the LNG facility systems. Thus, control of major hazards is of key importance, and prevention of escalation from an initial incident is critical. Also, it is important to understand what conditions could cause physical effects such as a pool fires, rapid phase transitions and vapour cloud explosions. Since this paper details and compares the safety challenges related to LNG processes, it will be presented some examples of accidents occurred in LNG facilities. The lessons learned from previous accidents can enable the companies to justify the investment to improve the safety in the installation and develop an effective Risk Management, which provides several benefits for the LNG operations (i.e.: the fewer accidents so lower employee absence, lessened threat of legal actions against the company, better reputation and consequently, reduced costs, increased productivity and greater profit.).
Effect of Installation on Collapse Performance of Flexible Pipes
Authors: Caleyron Fabien , Le Corre Vincent , Paumier Laurent 
Published: October 2017

This paper investigates the effect of installation on collapse performance of flexible pipes.
In the design of flexible pipelines for offshore field developments, one of the critical failure modes being associated with external pressure and bending loadings is the hydrostatic collapse. In accordance with standards, Technip methodology for flexible pipe collapse resistance determination ensures a robust and competitive design. The model has an analytical basis, leading to a fast and straightforward use. It has been validated with more than 200 tests performed on all possible pipe constructions on straight and curved configurations.
As the industry is moving to deeper and deeper water, there is a greater need to understand all factors which could affect collapse. This includes residual effects due to the high installation loads from the laying system. As a consequence, Technip has performed several collapse tests on samples previously submitted to a loading representative of installation conditions (tension and crushing). Moreover, Technip and IFP Energies Nouvelles have developed and improved over the past few years a Finite Elements model dedicated to collapse prediction. The model accounts for the detailed geometry of the wires (carcass, pressure vault, spiral), ovalization, cyclic plasticity, contacts and residual stresses due to manufacturing. It allows to evaluate the effect of installation on the ovalization and plasticity of each layer and the collapse performance of the flexible pipe.
The purpose of this paper is to present the collapse tests results and the corresponding calculations performed with the Finite Elements Model on several cases representative of Technip flexible pipes portfolio.
UHB of Flexible Flowlines: Design and Analysis
Authors: Liu M. , Cross C. 
Published: October 2017

The predictive upheaval buckling (UHB) for un-bonded flexibles can be challenging due to their complex multilayer structure and nonlinear properties. A combination of design data preparation and interpretation, in-place analysis methodologies, and installation can result in a varied UHB screening exercise and results. For flexible flowlines prone to UHB, pre-pressurisation is widely used prior to trenching and backfill to improve their UHB performance.
This paper is intended to present a study on the issues associated with the flexible UHB assessment. The solidity and veracity of the current UHB screening and analysis procedure is examined for pre-pressurised flexibles in particular. The initial effective tension induced by pre-pressurisation prior to backfill is investigated in detail. Pitfalls and inconsistencies in the methodologies are reviewed.
It is demonstrated that due to the neglect of nonlinearity, potential misuse of design parameters and assumptions made for the UHB design screening and analysis procedure can be compromised and open to rationalisation. The tangible benefit of initial pressurisation may be inaccurately evaluated for UHB mitigation. It is established that for the same flexible flowline, its UHB resistance performance can be either overpredicted or underestimated in certain conditions. An alternative approach is developed and proposed to redress some deficiencies. A case study is presented to show the key results and conclusions.
Acceptable Target Probability of Failure for Subsea Pipeline UHB Design
Authors: Liu M. , Cross C. 
Published: October 2017

For subsea pipeline UHB design, it is essential to establish appropriate UHB load factors by undertaking a structural reliability analysis based on a target acceptable probability of failure. The current practice is to setup the acceptable probability of failure according to the best industrial practice coded in DNV OS F101 and ISO16708 but regardless of trench performance, imperfection details and inspection results.
This paper is intended to discuss the relationship between the UHB failure probability for the whole pipeline and the trench performance and imperfection frequency statistics. A detailed statistic and reliability analysis is undertaken to address some disparity in the current practice. It is shown that in order to achieve a specific reliability level required for the entire pipeline, it is paramount to calibrate the target probability of failure based on the survey data. The common practice for UHB is shown un-conservative giving rise to an insufficient safety level and non-compliant OOS design. An improved approach is outlined to address the critical issues allowing for a robust OOS assessment by means of case studies.
Effect of Elastic Properties of the Fluids on the Particle Settling Velocity
Authors: Arnipally Sumanth Kumar , Kuru Ergun 
Published: October 2017

An experimental study was performed to investigate the influence of fluid elastic properties on the settling velocity of spherical particles in viscoelastic polymer fluids. The Particle Image Shadowgraph (PIS) technique was used to measure the settling velocity of the spherical particles (with average diameter of 2mm) in the hydrolyzed poly acrylamide (HPAM) polymer test fluids.
Test fluids were prepared by mixing 3 different grades of HPAM (with molecular weights of; 500,000; 8,000,000; and 20,000,000) at polymer concentrations of 0.09 and 0.1% by weight. Shear viscosity and oscillatory measurements were carried out to characterize the test fluids.
The test fluids were formulated in such a way that they had almost identical shear viscosity characteristics while showing significantly different elastic properties. The relaxation time was used to quantify the elastic characteristics of the fluids.
To quantify the impact of elasticity, the experimentally measured settling velocities were compared to the values calculated by using the model developed for predicting settling velocity of spherical particles in power law (visco-inelastic) fluids [1]. Experimental results indicated that the settling velocity of spherical particles in visco-elastic fluids decreased significantly with the increasing elasticity (measured in terms of relaxation times) of the fluids.
Temperature Dependent Torque and Drag for 3-D Wells: Model Description and Field Case Study
Authors: Wiktorski Ekaterina , Tveiterå Martin , Sui Dan , Aadnoy Bernt S. 
Published: October 2017

Wellbore friction represents one of the biggest limitations for drilling and completion of long 3-dimensional wells. Traditionally, wellbore friction forces calculation is performed using soft-string torque and drag models, which assume tubular to be in contact with the wellbore at any point along its length. However, precise results are needed for wells with complex geometry and high doglegs.
This paper presents a novel way regarding wellbore friction forces calculation, which takes into account both wellbore deviation and wellbore tortuosity. To locate contact points of the string and the wellbore, a Dogleg Severity filter, or DLS-filter is proposed. The DLS-filter is integrated into soft-string torque and drag models by taking into account dogleg, wellbore geometry and depth. Such simple implementation of DLS-filter makes it applicable for any case only if survey data is available.
Fundamental understanding of drillstring mechanics and drilling fluids properties is essentially required in planning phase and drilling operations. To enhance the accuracy of torque and drag calculation, thermal effects on buoyancy forces and viscous forces have been studied. Experiments using one oil-based mud (OBM) recipe and one water-based mud (WBM) recipe have been conducted to measure viscosity and density of fluids in different pressure and temperature conditions. Based on the obtained results, viscosity model and density model as functions of pressure and temperature have been developed for better model interpretation of fluids thermal effects in HPHT conditions. Friction factor is a critical parameter to affect wellbore friction, which depends on fluids composition, contact surface, rotary speed, temperature, etc. Conventionally it is set constant for friction forces calculation. Experimental results show that the friction factor is heavily dependent on the temperature. In this study, friction factor was assumed to increase linearly with temperature for torque and drag calculation.
The new approach provides more correct values for torque and drag, and gives a better understanding of the downhole environment, as cuttings transport and drillstring dynamics. The study can be further used for the evaluation and recommendation of drilling muds for HPHT wells. Such analysis will aid in the design of appropriate drilling mud in the integrated well planning phase.
Subsea Pipelines and Flowlines Decommissioning: What We Should Know for a Rational Approach
Authors: Manouchehri Soheil 
Published: October 2017

Offshore and subsea decommissioning will increase in the next five years or so as many producing fields are matured and cease production while the oil price continues to remain low. This emphasizes the need for a thorough decommissioning plan to ensure a safe and technically feasible solution while it is economically viable and safeguards the environment.
Offshore and subsea decommissioning is commonly considered on a case-by-case basis using the Comparative Assessment (CA) process in which the best decommissioning solution is obtained. Health, Safety and Environmental (HSE) considerations are always paramount in any decommissioning process. The aim is to significantly reduce the long term risks to other benefactors of the sea while the associated short term risks to those responsible for decommissioning operations are minimized.
A major part of any decommissioning project is subsea pipelines decommissioning (by “pipelines”, it is meant to include flowlines, trunklines and flexible too). There are a number of techniques available for decommissioning of subsea pipelines ranging from preservation for potential future use to full recovery or leaving in-situ. However, each subsea pipeline decommissioning technique should be considered on its own merit. Selection of each decommissioning technique depends on many parameters, inter alia, size of pipeline, type of pipeline (e.g. single pipe, pipe-in-pipe, piggyback), type of conveying fluid, operational environment (location), production history, Inspection, Repair and Maintenance (IRM) records, HSE considerations, connection to other facilities, technical feasibility (including potential use of advanced technologies), regulatory authorities requirements and socio-economic considerations.
This paper will look at specifics of subsea pipelines decommissioning. It will examine the procedures to be undertaken from desk top activities (e.g. planning and CA) up to operational activities (e.g. pigging, flushing, cleaning, removal or leaving in-situ). Different scenarios are discussed and potential advantages and disadvantages of each scenario are presented. In addition, a guide is proposed for future pipelines decommissioning projects to follow a rational approach.