bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Students' Familiarity, Adoption, and Use of Social Media in Bahrain
Authors: Paliktzoglou Vasileios , Giousmpasoglou Charalampos , Marinakou Evangelia
Published: November 2016

Social media is used in many higher education institutions for educational purposes in numerous new and innovative ways. However, in Bahrain the number of higher education students who are aware of and use social media is not clear. It was therefore necessary to conduct an empirical study that would investigate the students' use of social media in higher education in Bahrain. Moreover, the actual adoption of social media in everyday learning situations still remain underexplored, especially in higher education settings. This paper describes a study conducted to investigate the influence of social media use by student in Bahrain. The aims of this study are to assess students' level of familiarity, engagement and frequency of use with social media. The data was collected using two questionnaires. The findings indicate that social media has introduce a new culture of learning among students. In addition, social media applications which are on the increase in usage by students for activities that include studying, access of education content, social communication.
Managing Changes in Service Oriented Virtual Organizations
Authors: Obidallah Waeal J. , Raahemi Bijan
Published: November 2016

Virtual Organizations in a dynamic environment need efficient methods of change management to initiate changes to partners' services. In this paper, the authors present a structural and a procedural framework for change management in Service-Oriented Virtual Organizations. The structural framework categorizes changes into three layers of change and identifies triggers of changes. The procedural framework incorporates various components including the six layers of change processes, change control, change actors, and related management processes. A prototype with different scenarios of change is developed to validate the change management process in a collaborative environment. The authors employ the functionalities of the IBM Business Process Manager, including its recent Web 2.0 capabilities, to enhance collaboration between partners in the process of change. They demonstrate that the proposed solutions facilitate and enhance the process of change by effectively engaging all partners in a dynamic and collaborative way.
Influence of Calcite in the Filtration Properties of Clay Dispersions
Authors: Nóbrega Karine Castro , Amorim Luciana Viana
Published: November 2016

This project had as objective to evaluate the influence of the content and particle size of the calcite in the filtration properties of clay dispersions. For that, it was realized the characterization of a bentonite clay sample using X-Ray Fluorescence and X-Ray Diffraction. In addition, two samples of calcite (CaCO3) were granulometrically analyzed by Laser Diffraction. The dispersions were prepared with fixed concentration of clay (10g) and different concentrations of carboxymethylcellulose of low viscosity (0 to 2g), and calcite (0 to 20g). After 24 hours of repose, it were determined the filtration properties (filtrate volume (FV), mudcake thickness (h), and mudcake permeability (k)). It was observed that the lowest filtrate volume was acquired using CaCO3 sample with the lowest average diameter, and, also, a bigger concentration of calcite was not able to promote a considerable reduction of the filtrate.
Pozzolanicity Evaluation of Mineral Additions by Electrical Conductivity Measurements
Authors: Cedrim Felipe Araujo , de Oliveira e Silva Guilherme Augusto , Santos Tiago Assunção , Ribeiro Daniel Véras
Published: November 2016

The search for alternative materials that can replace Portland cement promotes discussion about the use of pozzolanic materials in cementitious matrices. Several techniques and procedures can determine the pozzolanic properties of a particular material based on electrical conductivity. Being an innovative and a subject of demand and minimum resource method, this article seeks validation by the comparison with chemical titration tests. To this end, were tested several possible pozzolanic materials (silica fume, metakaolin and eucalyptus ash) through the mentioned techniques
Permeability of Porous Ceramic Membranes Obtained from Waste of the Coal Extraction Process
Authors: Gislon Edivelton Soratto , Simão Lisandro , Coelho Kétlin , Fortes Nilo Meira , Innocentini Murilo Daniel de Mello , Montedo Oscar Rubem Klegues
Published: November 2016

The coal extraction generates large amounts of coal waste. Powders of this waste can be pressed with the addition of binder in order to obtain ceramics, such as ceramic membranes. In this case, polymeric fibers can be used to increase permeability. This work aims to study the permeability of ceramic structures composed by coal waste and different amounts of polymeric fibers. The compositions were homogenized, pressed and thermally treated at 1050 °C. Samples were characterized in relation to porosity determination, permeability and microstructural features. The results showed that the permeability increased with the increase of the fiber content. However, the composition containing 0.5 vol% of polypropylene fibers showed the best results for using in aerosol filtration permeability.
Internal Coating of Oil Refining Pipes with Alumina from the Recycling Process of Aluminum Anodizing
Authors: de Carvalho M.F. , de Sousa Andréa Gonçalves , Domingues Rebeka Oliveira , de Araújo Rogério Pontes , Ferreira Ricardo Arthur Sanguinetti , Yadava Yogendra Prasad
Published: November 2016

The aluminum anodizing is a used technique used to produce decorative and protective film of high quality. This anodizing process results in a large volume of industrial sludge, containing amounts of aluminum hydroxide colloidal problematic for these industrial waste disposal due to the environmental impact. This study aims to accomplish the treatment of these residues, which were thermally sintered at temperatures of 200 °C, 1000 °C and 1400 °C. After the heat treatment, the residues were subjected to analysis of X-ray diffraction and X-ray fluorescence. In evaluating these results, there was a gradual increase of the percentage of alumina at 1400 °C to achieve 95%. With the acquisition of the ceramic high alumina content, the objective is the fabrication of refractory linings for pipes used in the oil refining process. And this study will serve to solve an environmental problem arising from the metallurgical industry and simultaneously presenting an alternative material for the industry.
Evaluation of Physical Parameters of a Clay with the Incorporation of Industrial Ash Waste by Means of Variance Analysis
Authors: Nunes Francine Machado , Ferreira C.C. , Pavan Flávio André , Guterres M.X. , Quintana L.M.H.
Published: November 2016

This work evaluates the incorporation of solid industrial waste such as rice husk ash, bottom ash from mineral coal and ash coming from the washing of sheep wool in Red Ceramic Mass (MRC) composed of clay. These raw materials were collected from industries in the municipality of Bagé-RS, Brazil. Percentages of 0, 5, 10, 20 and 30% of these wastes were added to (MRC) in order to reduce the environmental impacts, both by the clay extraction as well as for waste disposal. The physical tests (Atterberg limits) made with the clay, follow a normative standard. However, the tests made in the formulations served to compare the formulations’ behavior in relation to the clay. In order to verify if the tests proposed in (MRC) and if the formulations have changed significantly the investigated indexes, an Analysis of Variance (ANOVA) was performed. The results generally indicate that there are statistically significant differences, mainly regarding the Plasticity Index (PI) and the Liquidity Limit (LL), as ash was added in the formulations.
Effect of Multi Walled Carbon Nanotubes Incorporated on Refractory Castables
Authors: de Oliveira Jr. Norval Rodrigues , Ribeiro Fabíola A.S. , Salles Gustavo C. , Furtado Clascídia A. , Brito Modestino A. , Figueiredo Jr. Aloyso O. , Fernandes Manoel R.F. , Santos Adelina P.
Published: November 2016

Two different types of multi walled carbon nanotubes (MWCNT) were introduced in a calcium aluminate refractory castable used in steelmaking process. The first MWCNT was purchased from Cheap Tubes (USA), a hydroxyl (-OH) functionalized, outer diameter of 50-80 nm, length of 10-20 μm, and, the second one was supplied by Nanocyl (Belgium), not functionalized, outer diameter of 9.5 nm, and length of 1.5 μm. Both types of MWCNT were incorporated into the dry castable mixture before water addition. The workability and properties of the final product, such as apparent density, apparent porosity and hot modulus of rupture were evaluated. The nanocarbons were characterized by SEM, TEM, TGA and Raman spectroscopy. In both cases, the incorporation of MWCNT had a negative effect on the rheology of wet castables, decreasing their workability. No significant improvements on mechanical properties of the castables were observed with the incorporation until MWCNT concentration reached 0.15 % (m/m), except for the increase of hot modulus of rupture observed for Cheap Tubes MWCNT introduction.
Crystallization Kinetics of β-Spodumene/Cordierite-Based Glass-Ceramics
Authors: Nuernberg Rafael Bianchini , Montedo Oscar Rubem Klegues
Published: November 2016

This work aims to investigate the crystallization kinetics of β-spodumene/cordierite glass-ceramics. Thus, three glasses with compositions based predominantly on cordierite (C), β-spodumene (L) and in a molar ratio 1:1 of both phases (CL) were prepared. The kinetics parameters such as activation energy for crystallization (ranging from 160 to 358 kJ/mol) and Avrami exponent (ranging from 1.4 to 10.7) were determined by means of non-isothermal methods using differential scanning calorimetry (DSC). Additionally, the samples were crystalized according to DSC analyses and characterized by using x-ray diffraction (XRD). The main detected crystalline phases were β-spodumene to the glass L, cordierite to the glass C and β-quartz, mulite and spinel to the glass CL. Considering the thermal and electrical properties of these crystalline phases, these glass-ceramics have potential use for LTCC (Low Thermal Co-fired Ceramics) applications.
Arctic Monitoring: A Remote Sensing Analysis of Former Wellsites
Authors: Brunke Suzanne , Dacre Cynthia , Oldak Anna , Mercer Sean , Rockwell Greg , Bakker Adrian , Bertrand John
Published: November 2016

Numerous exploratory wellsites were established in Canada's Arctic during the second half of the 20th century and were subsequently closed. Due to the logistic challenges of monitoring such sites through conventional approaches, the operator engaged the service provider to conduct a study using remote sensing techniques and high-resolution optical imagery on several closed wellsites (7 sites on-shore) in the Mackenzie River Delta of Northwest Territories, Canada. The project focused on demonstrating the ability to track changes in site conditions (retrospectively), distinguishing cyclic from progressive changes, and evaluating the potential cost for routine site monitoring at different intervals. Available sources of optical imagery were used; from 1 m IKONOS to 0.5 m WorldView-2, with dates ranging from 2002 through 2014. The optical analysis utilized the Normalized Difference Vegetation Index (NDVI) ratio of near infrared and red bands to provide an index of biomass density. A variety of processing techniques and analyses were performed that focused on four major areas: relative water levels, vegetation health, condition of infrastructure, and the proximity of nearby receptors. Synthetic Aperture Radar (SAR) imagery from RADARSAT-2 was also used successfully to detect pilings that were not visible in the optical imagery.
Case Studies in Application of Design of Experiments Methodology to Ice Basin Testing
Authors: Fenz D. M. , Foltz R. R. , Sarlis A. A. , Younan A. H. , Jochmann P. , Schroeder C. , Myland D. , Ziemer G. , Spencer D.
Published: November 2016

This paper describes four case studies highlighting applications of Design of Experiments (DOE) methodology in ice basin testing. The case studies are (1) an investigation of methods for model ice ridge preparation and property testing, (2) managed first-year ridge interaction with an axisymmetric floater, (3) interaction of first-year ridges with a multi-leg GBS and (4) towing of a gravity-based structure and axisymmetric floater in ice. These experiments illustrate a different approach to ice basin testing. Rather than trying to reproduce natural conditions and scale up loads, critical design scenarios are isolated and DOE methodology is used to determine the most influential parameters on response quantities of interest.
A 3-D Random Lattice Model of Sea Ice
Authors: van den Berg Marnix
Published: November 2016

This paper demonstrates the application of a 3-D random lattice model based on Voronoi tessellation. The model may be applicable in a wide range of sea ice modelling scenarios. Lattice models based on Voronoi tessellation give accurate results in fracture modelling of brittle, inhomogeneous, and/or polycrystalline materials such as concrete and rock. Therefore, our hypothesis is that a similar model might also yield good results in the modelling of sea ice failure. This paper demonstrates that a random lattice model is capable of predicting the deformation of an ice plate on a Winkler foundation. Additionally, it shows a range of other possible applications. Most notably, an application of the model in numerical ice ridge generation is demonstrated.
Common Operational Picture COP Requirements for Floating Drilling in Pack Ice
Authors: Shafrova Svetlana , Holub Curtis , Harris Matthew , Cheng Tao , Matskevitch Dmitri , Foltz Raymond , Mitchell Douglas
Published: November 2016

A Common Operational Picture (COP) can generally be described as a system of hardware and software that produces a shared display of information to facilitate situational awareness and decision making. A brief history of the development and use of COP technology in Arctic operations is provided. Experience and learnings from ExxonMobil's research into the use of COPs in ice management and Arctic floating drilling is described. Experience gained from simulations, desktop studies, and field observations is used to frame preliminary functional requirements for such technology needed for future Arctic floating drilling operations in high concentration ice. The COP must facilitate the planning and execution of complex and remote operations with many geographically distributed assets (e.g., drilling rig; icebreakers; shore base; manned or unmanned aviation) and stakeholders (e.g., icebreaker captains, drilling management, ice analysts, weather forecasters) at times communicating over limited bandwidth channels. The COP will serve to collect, store, communicate, and display the necessary data and information. The role of COP components (e.g., databases; communication network, displays) is described and functional requirements are outlined.
Passive Particle Continuum Ice Model for Efficient Load Estimation
Authors: Berg Joris van den
Published: November 2016

Based on ideas taken from geophysical models, a 2D continuum ice flow model is derived and tested. The model can be used to simulate ice loads on a vessel. The model aims to fill the gap between strictly empirical models excluding load variations and a fully 6D solid bodies approach that is typically too costly for real time simulation and computation of long term statistics. In addition it could be used to obtain the far field solution for use in combination with more detailed models close to the ship.

To guarantee conservation of mass and momentum, a 2D finite volume approach is used as a starting point. Instead of a flux solver, passive tracer particles are used. These include collision handling at the finite volume cell interfaces and with line segments representing any vessel hull. The passive tracer particles carry mass and momentum from one finite volume cell to another. Model extensions for relative current drag and friction can be added on the cell averaged level.

The resulting 2D hybrid continuum model yields promising first results: The computational speed is sufficient to simulate large ice fields (>5km squared, >5,000 ice floes) at more than real time speed.Qualitatively, the ice flow is realistic and the flow properties can be tuned using relatively straightforward parameters.
A 3D Time-Domain Model for Iceberg Impacts with Offshore Platforms and Subsea Equipment
Authors: Fuglem Mark , Younan Adel
Published: November 2016

When designing oil and gas platforms for offshore arctic and subarctic regions, operators may need to consider the influence of iceberg impacts on optimal structure configuration and ice strengthening requirements. Icebergs have complex and varied shapes, are mostly underwater and are usually moving in currents and waves. Previous iceberg profiles developed from sonar profiles and above water measurements have varying limitations in accuracy, necessitating approximations in modeling both the overall and local shape of the icebergs. A field program was conducted to obtain high resolution full three dimensional (3D) iceberg profiles that allow for detailed modeling of icebergs. Following the field program, a number of studies were conducted to utilize this data to develop improved tools both for calculating design iceberg impact loads for offshore structures and for improving ice management. One of these studies, described here, entails development of a full 3D timedomain simulation model for icebergs impacting fixed and floating platforms in 6 and 12 degrees of freedom (DOF) respectively. A key requirement of the model is that existing scale dependent models for global ice crushing failure pressure can be incorporated. The main objective in developing the model was to provide a tool for evaluating specific iceberg impact scenarios that considers 3D effects and requires fewer assumptions regarding interaction mechanics than previous methods.

In this paper, the basic framework of the 3D time-domain model is described, and initial model results are presented for several example applications: icebergs impacting a cylindrical GBS, a stepped cylindrical GBS and a moored spar floating production unit (FPU), the probability of iceberg pinnacles impacting a platform topsides, and subsea interactions. For the cylindrical Gravity Base Structure (GBS), sensitivity analyses are presented for ice strength, friction, drag coefficient, damping coefficients, platform diameter and iceberg velocity.
Numerical Evaluation of Permafrost Thawing in Arctic Pipelines and Mitigation Strategies
Authors: Abdalla Basel A. , Mei Haixia , McKinnon Colin , Gaffard Vincent
Published: November 2016

Permafrost thaw induced settlement is a major concern for pipeline design and operation in the Arctic region. For a buried warm pipeline in permafrost, heat losses can thaw the frozen water in the surrounding soil and create a thaw bulb around the pipeline. The underlying soil will then settle and consequently cause settlement of the supported pipeline. Uneven settlement along the pipeline will induce pipeline bending, and may even damage pipeline during operation if resulting strains exceed allowable values. Using finite element analyses to predict pipeline behavior due to permafrost thaw induced settlement can provide guidance on pipeline engineering considerations such as pipeline design, installation and mitigation.

The authors previously presented a finite element model (FEM) developed to study the thaw induced settlement and stresses in pipeline by sequentially coupling a 2D heat transfer model and a 3D soil consolidation/soil-pipe interaction model. The heat transfer and thaw settlement were validated by comparing the numerical output with respective analytical solutions. As a continuation of the FEM development, a three-dimensional (3D) fully coupled model to simulate heat transfer and soil consolidation is developed in this paper. This model solves all field equations simultaneously, including temperature, pore pressure and displacement variables. Heat transfer process can be continuously updated as soil consolidation and pipeline settlement occur. Conclusively, the 3D fully coupled model can capture the transient behaviour and interaction between heat transfer, soil consolidation, and pipeline deformation, and simulate the involved mechanisms more realistically. The 3D fully coupled model is compared with the verified sequentially coupled model.

Thermosyphons are then implemented into the fully coupled model to mitigate thaw induced settlement. The effects of thermosyphons on thaw bulb growth around warm pipe and thaw induced pipe settlement are studied.
Steel Lazy Wave Riser with Tether for FPSO with Dis-Connectable Turret for Iceberg Conditions
Authors: Karunakaran Daniel , Frønsdal Magne
Published: November 2016

Recently turret-Moored FPSOs have been used in many deep water developments worldwide, with consideration of dis-connectable turrets for harsh environment with iceberg conditions. This trend makes the interactions between FPSO and risers system more important. Further, Steel Lazy Wave Risers (SLWR), which is a compliant variant of the mostly commonly used Steel Catenary Risers (SCR), is becoming an attractive riser option.

The paper provides a review of two riser systems that can be considered for turret-moored FPSOs, and specific emphasis on Steel Lazy Wave Risers. A detailed case study of Steel Lazy Wave Risers for a typical turret moored FPSO with dis-connectable turret is presented. The design drivers are; to reduce the turret pay load, especially in disconnected condition, the selected riser system should have minimum tension variation so that the disconnected turret is stable and an optimum installed overall cost of the system. To achieve the design objectives an improvised Steel Lazy Wave Riser configuration called "Tethered Steel Lazy Wave Risers" (TSLWR) is developed.

Pros and cons for TSLWR are discussed, with consideration of the particular challenges of turretmoored FPSOs with large floater motions, hang-off geometry constraints at turret, hang-off loads, riser interferences, risers pre-installation, and turret disconnection constraints.
Optimization Methods for Arctic Pipeline Route Selection
Authors: Devine Christine A. , Haneberg William C.
Published: November 2016

As arctic regions become more accessible for oil and gas exploration and development, the need for subsea export pipelines and flowlines will continue to grow. To reduce risks to the pipeline from hazards of natural or geologic origin, it is critical to consider a more sophisticated approach to route selection compared to traditional manual routing practices based on only the shortest length of pipe or connectivity to existing infrastructure. Arctic environments have unique geologic complexities compared to other types of subsea environments. It is important to identify and avoid or mitigate significant hazards such as ice gouges, strudel scours, or permafrost upheaval zones for subsea pipeline routes in arctic environments. In this paper, we demonstrate a workflow to identify and map multiple geohazards, incorporate pipeline-related criteria, classify and weight features based on their inferred risk to a subsea pipeline, develop a composite map of hazards, and perform GIS-based, leastcost pipeline routing techniques to produce the optimal pipeline route options. This approach has been used in deepwater and shallow water settings around the world. We will demonstrate the advantages of following this methodology using multibeam echosounder (MBES) bathymetry data from an arctic location to illustrate the approach for a hypothetical pipeline project in the early stages of development.
Optimizing Geochemical and Sediment Sampling in Frontier Areas by Reviewing Past Projects and Analyzing the Benefits of Introducing New Technologies and Practices
Authors: Carey Nigel , De Coster Molly , Silliman Al , Carter James
Published: November 2016

Due to the large geographical areas typically associated with frontier regions, the need to enhance techniques for gathering information on petroleum systems and prospect charge is critical to ensure efficient and accurate results. Small changes in efficiencies of acquisition techniques and use of ever improving technology can significantly improve the chances of success.

The results from a 2015 geochemical sampling program offshore Labrador and Newfoundland were reviewed, to determine areas of improvement and efficiency for future work in this and other frontier areas. Seismic data acquired offshore Newfoundland and Labrador plus surficial satellite seep mapping hinted at active petroleum systems and thus a need for a geochemical survey to assess these was determined. Evaluated areas were divided into two groups, one to identify regional petroleum systems and the other to reduce prospect charge risk. Core samples, heatflow and bathymetry were among the data collected.

Using the concept of 'intelligent sampling' the authors are developing systems and procedures to ensure efficiency and improve the chances of analytical success. Dedicated vessels with DP systems are utilized, complete with a full range of multi-beam sonars, sub-bottom profilers, dedicated launch and recovery systems, and sub-surface positioning to ensure coring accuracy. Further innovations included core barrel mounted cameras and coring rope load monitoring.

Based on the 2015 survey, modified approaches are proposed to improve sample acquisition, many of which are being implemented in the 2016 survey:core recovery (ensure cores penetrate below the biogenic zone) with revisions to the drop core assembly design;evaluation of appropriate coring methods (gravity, piston and vibro);new technologies for live slick sampling (traditionally difficult in areas of rough weather or sea conditions) are analysed with oil detection radars and seaborne/airborne drones;methods to reduce probability of sample contamination; and,best practice storage methods to meet the needs of the variety of analytical methods proposed.
A Numerical Study of Interaction Between Ice Particles and Complex Ship Structures
Authors: Seo Dong Cheol , Pallard Robert
Published: November 2016

This paper describes a numerical method of ship-ice interaction. Identifying an operational risk to an ice breaking vessel such as serious interference or sudden efficiency reduction by ice is necessary at early design stage. CFD-DEM coupled approach can be used for this prediction. Combining two numerical approaches, free floating ice particles can interact with the surrounding fluid as well as the rigid hull surface effectively. Ship-ice interaction becomes more complicated around the stern area considering the swirling flow of the propulsion device and the complex hull appendages. Using CFD-DEM method, simulation of ship-ice interaction during the astern operation was carried out. To evaluate the simulation performance, three example cases were conducted. The first and second case is the astern operation with/without the propeller action. For reducing the computational load, a virtual disc model for the propeller action is selected. Then, a simple sensitivity analysis on the ice friction coefficient was carried out to verify if the friction model is working appropriately. CFD-DEM simulation provides a promising result showing a similar ice jamming and pileup pattern with the physical model test. The suggested method can help to understand the ice movement effectively including the hydrodynamic force and the contact dynamics together.
Verifying Permeability Distribution Using Interventionless Production Logging Technology
Authors: Williams Brock
Published: November 2016

This paper reviews the use of intelligent chemical tracer technology that provides quantitative insight into the inflow distribution across the reservoir interval.

Arctic developments are frequently characterized by complex reservoir geology, challenging directional drilling requirements and complicated wellbore design. Understanding the permeability distribution that is encountered in these wells is key to optimizing the future well placement and field reservoir management decisions.

Assessing permeability distribution is best performed by measuring the reservoir inflow distribution under flowing conditions. Acquiring inflow distribution using conventional technologies, such as production logging tools, is very problematic in the arctic operational environment where wireline intervention into live wells is a major risk and cost.

Intelligent tracer technology provides insight into the inflow distribution without requiring any intervention into the well or major modification to the completion design. Unique chemical tracers are incorporated in polymers comprising an intelligent tracer system. These tracer systems are embedded into completion components during the manufacturing process. The completion components are assembled as part of the completion without any impact to normal operations. The components containing the tracer systems are placed at strategic locations along the completion interval.

Inflow from the reservoir contacts the intelligent tracers which release unique chemical molecules that can be detected at 1 part per trillion. Each of the tracers contain a unique molecule. The flow from the reservoir transports the molecules to the surface where samples of the well's production are acquired and analyzed for the concentration of each type of molecule. The concentration profile of each type of molecule is used to assess the inflow occurring at that location.

This capability can yield answers to very valuable reservoir management questions such as: Are all the intervals producing?What is the relative contribution of each interval?Where is water break-thru occurring?

Two independent mathematical models have been developed that provide the ability to quantitatively determine the reservoir inflow that is associated with the change in the molecular concentration. These models are referred to as the tracer arrival method and the flush out method.

This paper reviews how intelligent tracers work, laboratory testing to develop quantitative interpretation models and case histories that demonstrate the validity of the mathematical model.
Conceptual Design and Testing of an Ice Force Measurement System
Authors: Hinse Philipp
Published: November 2016

In this paper the force measurements system which was tested on the CCGS Amundsen Trail in April and May 2015 is presented. Ice forces were measured on the ship hull by force sensors during drifting motion of the vessel. Four test runs were conducted around St. Johns and Labrador coast. Based on an adapted sensor calibration the measurement results are presented as well as the analysis of ship ice floe interaction is discribed. At the end trail experiences of the measurement- system are reflected and further prospect for ice force measurements are given.
Study on Ice Formation and Its Effect in Oil Pipelines
Authors: Xu H. , Pereyra E. , Dellacase E. , Volk M.
Published: November 2016

Ice may form in pipelines where ambient temperature is below freezing point of water. It was reported that ice delayed the restart of the Poplar pipeline system which gathers crude from Montanan and North Dakota (Sunne, 2015). Concerns of ice also exist in the Trans-Alyeska Pipeline System. The declining throughput makes the oil get colder much faster. If oil temperature is below the freezing point, ice forms, which may coat critical valves, accumulate in the pipe and restrict flow (APSC, 2011).

This paper investigates the mechanisms of ice formation, its behaviors and impacts on oil transportation systems. A 2-inch inner diameter carbon steel flow loop was instrumented to measure pressure, temperature, and differential pressure. The effects of pipeline components, fluid properties, and water fractions were analyzed using the experimental setup. The experimental results show that ice formation can restrict flow at the low sport in front of the flow meter, the inserted thermocouples, and the perforated plate. Annular ice deposition was found at the pipe wall. The morphology of the deposition on the pipe wall was rime ice, indicating the deposition was due to small ice crystals sticking to the pipe surface. In addition, the formation of annular deposition requires a negative temperature gradient. The mechanisms for ice deposition along the pipe are discussed.
Representing Ice Loads with Pressure Patches in the Analysis of Ship Structures
Authors: Kõrgesaar M. , Kujala P.
Published: November 2016

Current design standards for ships operating in ice-covered waters involve great deal of uncertainty in the associated risk level. The main reason for this uncertainty is the stochastic nature of ice failure process during ice-structure interaction, which means that the load imposed by ice on structures cannot be accurately defined. Therefore, rule requirements by Classification Societies define the pressure loads on patches of predefined sizes, which cannot accurately represent the real ice-structure interaction process. To partly overcome this limitation, this paper proposes alternative approaches for applying pressure, discusses the relevance of these loading scenarios and compares the resulting structural damage to the one obtained with current design approach.
Model Based Estimation of Sea Ice Parameters
Authors: Prasad S. , Zakharov I. , Bobby P. , Power D. , McGuire P.
Published: November 2016

The work focuses on retrieving sea ice parameters using reanalysis, climatological and remote sensing data. A numerical sea ice model was implemented with a data assimilation scheme on a high performance computer. The model input includes atmospheric reanalysis and ocean climatological data. The assimilation of data acquired from satellite microwave radiometer improves model accuracy. The advantage of the model is the possibility to forecast ice parameters such as concentration, thickness, draft, ridging etc. on a high resolution scale. The modeled ice parameters can be used for risk analysis for offshore infrastructure and ship navigation in the ice covered regions. The results can also be used in regional climate studies by coupling with ocean-atmospheric models. The model was extensively tested and evaluated with satellite data and field measurements. The simulated ice draft results demonstrated a good agreement with the measurements from upward looking sonar (ULS) deployed on the Makkovik Bank (in the Labrador Sea). For example, the standard deviation (STD) of level ice draft is less than 5.0 cm and the bias is less than 0.2 cm for March-April of 2009. The simulated ice thickness was also compared with the thickness derived from Soil Moisture Ocean Salinity - Microwave Imaging Radiometer using Aperture Synthesis (SMOS-MIRAS) (). The results show that the estimated thickness from the model is within the uncertainty limits of the SMOS product.
Geotechnical Considerations for Man-Made Islands in the Alaskan Beaufort Sea
Authors: Bashaw E. , Hebeler G. , Musial M. , Crowell W.
Published: November 2016

This paper presents recent investigation results and geotechnical considerations used to design a manmade gravel island in support of offshore oil production in the Beaufort Sea off the coast of Alaska. Winter geotechnical investigations were conducted in 1997, 1998, 2013, 2014, and 2015 along multiple subsea pipeline alignments and several proposed island locations and included finding a gravel resource, analyzing sea ice safety, drilling boreholes, performing cone penetrometer tests, recording subsea ground temperatures, and laboratory testing to measure engineering properties of the soils. The results were used to characterize the geologic setting and permafrost conditions, estimate thaw settlement of the gravel fill and underlying permafrost, compressibility and strength of seabed sediments, island slope stability, and shear resistance to global ice forces. The island site is located in 20 feet of water with a finish elevation 15 feet above sea level for a total fill thickness of 35 feet. Total island surface settlement outside of the well row is estimated at three feet in the long term. A soft marine organic deposit underlies the island and critical slope stability conditions will occur during construction when steep subsea perimeter slopes are possible. Fill placement above the water line integrates a 30-foot setback from the edge of submerged fill to maintain minimum factors of safety and improve constructability. After consolidation and soil strength gain, the island stability factor of safety increases and long term ice pack loading and local wave scour management become more critical. Based on island geometry, seabed soil properties, and global ice forces, the island has an expected safety factor of 3.0 against shear failure. The results of the geotechnical investigations allowed permitting efforts to proceed by confirming conventional and proven island construction materials and methods can be used with some additional engineering considerations.
Experimental Investigation of Wave Loads on Ice Masses at Different Proximity to Fixed Offshore Structure
Authors: Sayeed Tanvir , Colbourne Bruce , Molyneux David , Akinturk Ayhan
Published: November 2016

Wave driven iceberg and bergy bits’ impact load with an offshore structure is an important design concern. Hydrodynamic interaction between iceberg / bergy bit and an offshore structure in close proximity is an important factor that governs the impact load. Recently, a set of experiments has been conducted at Ocean Engineering Research Center (OERC) at Memorial University of Newfoundland to measure the wave loads on different sized spherical ice masses at different proximity to a fixed structure. A six component dynamometer was used to measure the loads in a quasi-static manner in six regular head waves. The objective was to investigate change in wave loads as the ice mass approaches to the structure. The experimental results show that the distance to wavelength ratio dictates the corresponding wave loads in horizontal and vertical directions. The mean drift force in the horizontal direction becomes negative (against the direction of wave propagation) for most of the cases when the body is close to the structure. Also, as the body is positioned closer to the structure, the non-dimensional RMS forces in the horizontal direction decrease and the non-dimensional RMS forces in the vertical direction increase.
Adaptive Heading Controller on an Underwater Glider for Underwater Iceberg Profiling
Authors: Zhou Mingxi , Bachmayer Ralf , deYoung Brad
Published: November 2016

A Slocum-class underwater glider has been modified for autonomous mapping of the underside of icebergs. A scanning sonar has been integrated inside the extended nose-section of the vehicle. The sonar is oriented to scan a sector to forward-side of the vehicle. A control algorithm using returns from the sector scanning sonar has been implemented in order to adapt the path of the vehicle around an iceberg. With the sonar implemented together with the adaptive heading controller, the Slocum glider is programmed to circumnavigate the target iceberg at a desired standoff distance. In this paper, the design of the adaptive control algorithm will be presented. Initially, the control algorithm is validated in a simulation environment that models the iceberg-profiling mission for a moving iceberg with the modified Slocum underwater glider. In July 2015, the Slocum glider was deployed to map an iceberg in Conception Bay, Newfoundland, with the proposed adaptive controller integrated. The detailed planning for this field trial together with results will be presented. The results show that using the Slocum-class underwater glider for underwater iceberg profiling has the potential of reducing the operational cost, while improving the quality of the data obtained on icebergs. The operation of underwater glider only requires minimal number of operational personnel and equipment. The acoustic noise is much lower than for a larger support vessel, and the glider can stay closer to the iceberg resulting in improved quality of the sonar measurements. More importantly, environmental data around the iceberg, such as salinity, water temperature and potentially water current profiles, are also measured during the mission that is necessary for scientists in understanding iceberg dynamics leading to an improved iceberg drift prediction model.
An Iceberg Drift Prediction Study Offshore Newfoundland
Authors: Andersson L. E. , Imsland L. , Scibilia F.
Published: November 2016

Iceberg drift forecast is a challenging process. Large uncertainties in iceberg geometry and in the driving forces – current, wind and waves – make accurate forecasts difficult. The two forecast schemes, the ancillary current and the inertial current estimation-forecast scheme are presented. In both schemes, the moving horizon estimator is used, to estimate the needed parameters. Furthermore, a switching scheme is proposed, which switches between the two iceberg drift forecast schemes. A criterion is introduced that identifies when to switch between both schemes. The switching scheme is implemented and tested on an iceberg drift trajectory, measured during a research expedition offshore Newfoundland conducted by ArcticNet and Statoil. It is shown, that the use of two forecast schemes and a timely decision which scheme to use, improves the iceberg drift forecast compared to using only one scheme.
Safely Extending the Drilling Season from a Warranty/Claims Perspective
Authors: Bintcliffe Chris
Published: November 2016

There has been much in the press about Arctic oil exploration and the oil majors' hopes of extending the drilling season. The controversy surrounding the environmental impacts and risks associated with ice have not materialized, from a warranty/claims perspective, in the claims witnessed to date. Instead, conventional claims have been brought forth, such as ones for broken towlines, underpowered tugs with mechanical problems and heavy weather damage. This leads to the question: Is ice really the critical issue, or is it just a distraction from the conventional limitations of tows when mobilizing and demobilizing assets in the Arctic?

This paper addresses this question by identifying the key risks of Arctic exploration from a warranty/claims perspective and by determining how these risks can be mitigated in advance of exploration operations. New numerical simulation tools are providing information previously unavailable to the industry, and they are helping to mitigate claims that the insurance market often considers preventable. These tools use Monte Carlo methods to model both the return-period weather criteria and the human aspects of vessel navigation. A captain's decision mimic is used to vary route, speed, and go/no-go criteria, providing a more comprehensive picture of the risks than was previously available.

Through preemptive risk simulations and calculations for the probability of exceedance, key cut-off points can be identified to mandate mobilization and demobilization dates. By creating bespoke simulations of assets prior to mobilization, options such as safe havens, shelter, and tug selection can be addressed statistically to bring risk to acceptable levels from an underwriter's perspective. This can be used to define drilling seasons and to screen prospective asset capabilities.
Investigation of Iceberg Hydrodynamics
Authors: Talimi Vandad , Ni Shaoyu , Qiu Wei , Fuglem Mark , MacNeill Andrew , Younan Adel
Published: November 2016

As offshore oil and gas developments increase in northern areas such as the Grand Banks and the Arctic region, the operators face challenging conditions. Icebergs are among one of the challenges for both surface and subsea structures if they drift toward those facilities. Prediction of the iceberg drift and dynamic response to any towing process requires a good understanding of hydrodynamic effects induced by currents, waves, tow lines, etc. A reasonable estimation of added mass and RAOs are other prominent parameters required when modeling iceberg dynamics is of interest. Having access to the high resolution full 3D iceberg profiles collected in 2012 (Younan et al. 2016), it is now possible to investigate iceberg hydrodynamics using numerical and experimental methods.

This paper presents an overview of the numerical simulation results and lessons learned during various hydrodynamic simulations such as decay analysis, towing, and iceberg-structure interaction. The Diffraction Model and Computational Fluid Dynamics (CFD) are the tools utilized in these simulations. The conclusions provide key findings and suggestions for future analysis of iceberg hydrodynamics.
New Low Temperature Alloy Core-Shell Structures for Joining Applications
Authors: Stephenson Richard , Bandaccari Kyle , Imhof Howard
Published: November 2016

Silver and copper core-shell powder materials are introduced and discussed in low temperature joining applications. Properties of the core-shell powders are reviewed and suggested process conditions are shown. Examination of ductile fracture area corroborate bonding strength results for both silver and copper core-shell materials. Selectable materials sets are presented to address different application process needs for lead-free systems.
Use it or lose it: tonic activity of slow motoneurons promotes their survival and preferentially increases slow fiber-type groupings in muscles of old lifelong recreational sportsmen
Authors: Mosole Simone , Carraro Ugo , Kern Helmut , Loefler Stefan , Zampieri Sandra
Published: November 2016

Histochemistry, immuno-histochemistry, gel electrophoresis of single muscle fibers and electromyography of aging muscles and nerves suggest that: i) denervation contributes to muscle atrophy, ii) impaired mobility accelerates the process, and iii) lifelong running protects against loss of motor units. Recent corroborating results on the muscle effects of Functional Electrical Stimulation (FES) of aged muscles will be also mentioned, but we will in particular discuss how and why a lifelong increased physical activity sustains reinnervation of muscle fibers. By analyzing distribution and density of muscle fibers co-expressing fast and slow Myosin Heavy Chains (MHC) we are able to distinguish the transforming muscle fibers due to activity related plasticity, to those that adapt muscle fiber properties to denervation and reinnervation. In muscle biopsies from septuagenarians with a history of lifelong high-level recreational activity we recently observed in comparison to sedentary seniors: 1. decreased proportion of small-size angular myofibers (denervated muscle fibers); 2. considerable increase of fiber-type groupings of the slow type (reinnervated muscle fibers); 3. sparse presence of muscle fibers co-expressing fast and slow MHC. Immuno-histochemical characteristics fluctuate from those with scarce fiber-type modulation and groupings to almost complete transformed muscles, going through a process in which isolated fibers co-expressing fast and slow MHC fill the gaps among fiber groupings. Data suggest that lifelong high-level exercise allows the body to adapt to the consequences of the age-related denervation and that it preserves muscle structure and function by saving otherwise lost muscle fibers through recruitment to different slow motor units. This is an opposite behavior of that described in long term denervated or resting muscles. These effects of lifelong high level activity seems to act primarily on motor neurons, in particular on those always more active, i.e., on the slow motoneurons. The preferential reinnervation that follows along decades of increased activity maintains neuron and myofibers. All together the results open interesting perspectives for applications of FES and electroceuticals for rejuvenation of aged muscles to delay functional decline and loss of independence that are unavoidable burdens of advanced aging. Trial Registration: ClinicalTrials.gov: NCT01679977.