bluuebunny/crossref_metadata_2025 huggingface dataset:
Microwave Irradiation Applied to Calcination and Sintering of Strontium Titanate Ceramics
Authors: Chaves André Silva , Gelfuso Maria Virginia , Thomazini Daniel
Published: November 2016

Alternative synthesis routes to obtain ceramics with advanced electronics applications have been investigated to improve the properties of these materials. Calcination and sintering by microwave irradiation is a very promising production method, which performs a rapid solid-state reaction and consolidation of particles due to the high heating rates (about 1000°C/min) aided by the microwave irradiation effect. To produce strontium titanate powder (SrTiO3 - STO), TiO2 and SrCO3 raw precursors were mixture in a ball mill for 3.5 h and after, this mixture was dried at 70°C for 24h. The resulting mixture was divided in two portions to produce STO powders following two procedures: (i) in the conventional method (STO-cC), the mixture was calcined at 1000°C with a heating rate of 10oC/min for 2h, and (ii) in the microwave method (uC) other part of mixture was calcined at 1000°C with a heating rate of 1000°C/min for 15 min, 30 min and 60 min. The powders obtained by both methods were characterized by X-ray diffraction (XRD) to evaluate the crystalline phase presents in the powders. The STO crystalline phase was identified in both samples, but it was also noted the presence of SrCO3 spurious phase in the STO-cC and STO-uC (15 and 30min). On the other hand, STO-uC powder calcined for 60 minutes did not showed this spurious phase. Dilatometric analysis was performed on STO-cC and STO-uC (60min) discs shaped powders by uniaxial load pressing (180 MPa) in order to determine the sintering temperature. Green bodies were sintered at 1380oC in conventional oven for 2h (cS) and in microwave oven at three different soaking times: 15, 30 and 60 minutes (uS). The microstructures of the cS and uS ceramics were analyzed by scanning electron microscopy (SEM). Significant difference between densification of the STO-cC-cS (88%) and STO-uC-uS (99%) ceramics were obtained to ceramics sintered by 60 minutes. The values of grain size of ceramics obtained by uC/uS indicates that microwave irradiation is an effective technique to avoid grain growth.
Determination of Solar Reflectance Index of Ceramic Coatings for Use in outside Surfaces
Authors: Jacinto Luiza Izabel , da Silva Maria Eduarda Xavier , Marinoski Deivis Luis , Fredel Márcio Celso , Schabbach Luciana Maccarini
Published: November 2016

In this study, thermal and optical properties (emittance and reflectance of solar radiation) of different colors ceramic tiles for use in outside surfaces were measured. Although widely used in the brazilian residential market, these materials are not properly characterized with respect to these properties. The thermal emittance measures were performed using an emissometer (D&S pattern SA1) and the solar reflectance using a spectrophotometer UV-Vis-NIR (model Lambda 1050). These properties are important for the determination of Solar Reflectance Index, SRI, that may help designers and consumers to choose the appropriate materials to make their buildings more energy efficient and comfortable. The SRI indicates the ability of a surface to reflect solar radiation and mitigate the temperature rise of surfaces, being used in LEED certification (Leadership in Energy and Environmental Design) to evaluate the performance of some opaque elements in constructions. The studies revealed a wide variation of SRI (values are between 72 and 22) in the same product with different colors. In particular two samples showed SRI lower than 29, which place them even below the minimum requirement of LEED for application in some types of outside surfaces, as steep roofs and pavement materials (LEED v. 2009 used in Brazil).
Use of Composite SiO2 (62-68)-MgO + CaO (29-39) in Ceramic Protection Mass Injection Machines in the Iron Notch and Liquid Slag Hole in Blast Furnaces
Authors: Magnago Roberto de Oliveira , Nogueira Anderson Carvalho , da Silva Paula Cipriano , de Souza José Vitor Candido , dos Santos Claudinei
Published: November 2016

The article describes the use of protection ceramic composed of SiO2 (62-68)-MgO+CaO (29-39) in the frontal region of machines that inject refractory mass to stop pig iron running and liquid slag in blast furnaces. The new protection model (prototype) showed an annual saving of approximately R$ 32,000 compared to the compound previously used CaO-Al2O3-SiO2. It also presented lower toxicity, once it has in its morphology less amount of fiber. These fibers when inhaled cause damage to internal lungs tissues becoming harmful to health. Production rates remained, since in all the new ceramic protection samples that were tested the frontal part was preserved allowing the refractory mass to be injected in proper quantity and pressure for reconstitution of the hole length, which removes iron and slag from blast furnace. Therefore, this enables a larger internal volume in order to produce more. The protection models used were from the company Morganite-Brasil. The material morphology and crystallographic characterization were realized by Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD), respectively.
Synthesis and Characterization of LaCr1-xSnxO3 Nanopowders (x = 0 and 0.1)
Authors: Costa Antonio Carlos Silva , Peres A.P.S. , Lima A.C. , Bergmann C.P. , Acchar Wilson
Published: November 2016

Lanthanum chromite (LaCrO3) has been considered a promissing candidate for use as interconnect materials for solid oxide fuel cells (SOFCs), due to their excellent electrical properties. In this work, LaCr1-xSnxO3 (x = 0 and 0.1) ceramic powders were prepared using the following synthesis routes: Flame spraying (FS) and microwave assisted combustion method (MCM). The powders were characterized by TGA, XRD and TEM. The TG curves showed weigh losses corresponding the dehydration of compounds as well as decomposition of secondary phases and organic matter. The XRD patterns indicated the formation of Sn doped LaCrO3 phase by FS. The crystallite sizes of samples are in the range 20-36 nm. The TEM images revealed the presence of particles with spherical shape and uniform particle size distribution.
Synthesis and Characterization of CaMgSi2O6 Activated by Eu2+
Authors: Misso Agatha Matos , Brito Hermi F. , Rodrigues Lucas C.V. , Morais Vinicius R. , Yamagata Chieko
Published: November 2016

Rare earth silicate based MnMgSi2O5+n (M = Ca, Sr or Ba and n=1-2) phosphors, have attracted interest of researchers due to their high efficiency as a host, excellent thermal and chemical stability and high brightness adding to their low cost. These phosphors showed great potential in various applications such as fluorescent lamps, white light emitting diodes, and display components. High temperature solid-state reactions are usually employed to synthesize those compounds. This paper proposes an alternative method of obtaining nanophosphor host based on Eu-doped CaMgSi2O6 (CMS:Eu), persistent luminescence phosphor. Sol gel technique combined to a modified molten salt method was used. The resulted powder was calcined for 3h under an atmosphere of 5% H2 and 95% Ar2. Phase identification by XRD and the measurements of photoluminescence (PL) and photoluminescence excitation (PLE) were performed. Single phased CMS:Eu with persistent luminescence characteristics was prepared.
Behavior of Fiberglass Polymer Composites under Ballistic Impact and Quasi-Static Punch Shear Tests
Authors: Fernandes Agnys Jony Gomes , de Amorim Jr. Wanderley Ferreira , Filho Walter Belarmino , Guedes Isac Paiva , Silva Andréa Lopes , Porto Wagner Luis
Published: November 2016

In the last decades, the composite materials were used in the modern ballistic armor systems. Thus, techniques have been developed to predict its mechanical properties, damage mechanisms and strength associated to ballistic impact penetration. The objective of this work was the ballistic impact and quasi-static punch shear behavior of fiberglass polymer composites. The materials used in the experiments were: woven fabric and chopped strand mat E-glass fiber and polyester resin. The composites submitted to ballistic impact and quasi-static punch shear tests had 1, 5, 10, 15, and 20 layers and 5, 8, 10, 12, 14, 15, and 20 layers, respectively. A quasi-static punch shear fixture test was developed. The best ballistic performance composite was the 10 layers woven fabric. In quasi-static punch shear test, it was possible to analyze the internal fracture of composites, and the load x displacement behavior was observed.
Development of WC-Fe3Al Composites by Spark Plasma Sintering Process
Authors: Ybarra Luis Antonio C. , Chimanski Afonso , Gama Sergio , da Silva Ricardo A.G. , Machado Izabel Fernanda , Yoshimura Humberto Naoyuki
Published: November 2016

Tungsten carbide (WC) based composites are usually produced with cobalt, but this binder has the inconvenience of shortage, unstable price and potential carcinogenicity. The objective of this study was to develop WC composite with intermetallic Fe3Al matrix. Powders of WC, iron and aluminum, with composition WC-10 wt% Fe3Al, and 0.5 wt% zinc stearate were milled in a vibration mill for 6 h and sintered in a SPS (spark plasma sintering) furnace at 1150 °C for 8 min under pressure of 30 MPa. Measured density and microstructure analysis showed that the composite had significant densification during the (low-temperature, short time) sintering, and X-ray diffraction analysis showed the formation of intermetallic Fe3Al. Analysis by Vickers indentation resulted in hardness of 11.2 GPa and fracture toughness of 24.6 MPa.m1/2, showing the feasibility of producing dense WC-Fe3Al composite with high mechanical properties using the SPS technique.
Al2O3-YAG Biphasic Composite Phase Determination Using Rietveld Method Measurements
Authors: Cabral R.F. , de Campos José Brant , Lima Eduardo Sousa
Published: November 2016

TheAl2O3-YAG biphasic composite has been extensively studied since this system has important properties such as high resistance to corrosion and creep in harsh environments. This material system is potentially very attractive for high temperatures applications. In this work, the precursor powders of Al2O3 and Y2O3, were homogenized in planetary ball mill for 2h, dried in oven at 120oC for 48h, sieved and deagglomerated. It was performed a series of heat treatments over the powder for verification of the YAG phase formation, using1100, 1200, 1300°C and 1400 °C for 3.0 h time. The powders of the starting mixture after grinding and calcinations were characterized for phase quantification using the Rietveld method. The complete formation of the YAG phase in the composite was determined at1300°C after 3h.
Study of the Substitution of Natural Fine Aggregates by Stone Dust in the Concrete of the Portland Cement
Authors: Acchar Wilson , Duarte Joao B. , Silva Vamberto Monteiro
Published: November 2016

The concept of sustainable construction throughout the building life cycle has motivated several studies on the application of waste to replace partially or totally some materials such as aggregates. This study evaluated the feasibility of stone dust use, replacing the natural sand in the production of structural concrete. In the initial stage it was carried out physical and chemical characterization of the applied materials and then molded cylindrical specimens with FCK 20, 25 and 30 MPa at 28 days, in compositions at levels of 10% stone powder, 30%, 50%, 100% e 100% with additive. After curing they were subjected to compressive strength tests and mechanical tests showed that the composition with 10% presented promising results.
Geopolymer Obtention Using Calcined Rice Husk Ash
Authors: Pereira Carlos Eduardo , da Silva André Miranda , Santos Josiele Souza Batista , de Sousa Bianca Viana
Published: November 2016

This study aimed to synthesize geopolymer materials using the ash of burned rice husk. The material was prepared from bauxite slurry, rice hull ash was calcined at 600 °C, metakaolin and sodium hydroxide 12 M solution. The material was cured at 60 °C for 6 h and then at ambient temperature for up to 28 days. We used the same mixture of experimental design to synthesize geopolymer. Through techniques spectroscopy energy dispersive X rivers and X-ray diffraction, it appears that the silica and alumina contents of the identified raw material meets the conditions laid down as minimum for precursors with geopolymer activation potential, as evidenced by the molar ratio Si/Al sample. Geopolymer obtained from the XRD patterns showed characteristic peaks of hydrated calcium silicate. It was found that the particles had irregular shapes and sizes, and the presence of voids affecting the strength of the material. The geopolymeric material obtained showed improvements in the bending strength in a curing time of 28 days.
Feasibility Study of Zirconia Waste Recycling Obtained during the Machining of Single and Multiple Dental Prosthesis
Authors: Silva Yankel B.F. , Acchar Wilson , Silva Vamberto Monteiro
Published: November 2016

Zirconia ceramic stabilized with 3% yttria (3Y - TZP) is the most used ceramic dental materials. During the machining of zirconia blocks in the laboratory to prepare the various types of prostheses, much of the material is lost in powder form, which is subsequently discarded. This study investigates the possibility to recycling of zirconium oxide powder obtained during milling of dental crowns and bridges. Uniaxial and isostatic pressed samples were prepared, sintered and compared to the commercial material. The results indicated that the isostatic pressed samples shows good physical and mechanical properties, comparable to the commercial material, demonstrating the viability to use this recycle material in the same process.
Photodegradation of Phenol Red in a Compound of Type ZnO@Cr Core/Shell
Authors: Silveira Gisele Santos , Nobre Marcos A.L. , Lanfredi Silvania
Published: November 2016

urface properties core/shell nanoparticles have been investigated in recent years due to their promising reactivity in catalysis surface. In this work, the ZnO@Cr core/ shell nanoparticles were synthesized by Modified Pechini method and characterized by X-ray diffraction and scanning electron microscopy (SEM). The structural parameters were evaluated as a function of chromium coatings on the ZnO structure, using the Rietveld method. From the refinement of experimental diffractogram determined the crystallographic structure of the investigated system as being of the hexagonal type with space group P63mc. The coating of ZnO with chrome led to an increase of the structural parameters. Photocatalytic activity of ZnO@Cr nanoparticles was studied using a low power reactor and the phenol red dye in acid and basic medium. The nanoparticles showed level of degradation in acid medium 1.24 times higher than that in basic medium. The photodegradation follows a first order kinetics.
Morphological Characterization of Nickel-Silica Nanocomposite in Residual Carbon Obtained by Direct Polymeric Route
Authors: Barbosa Graciele Vieira , de Sá Igor Silva , Fischer Eliane Kujat , de Medeiros Tiziana Azario , da Silva Margarete Soares , Cavalheiro Alberto Adriano
Published: November 2016

Nickel-silica nanocomposites can be obtained by direct chemical route, such as the Polymeric Precursor Method. That methodology type permits to obtain material powders with significant specific area and porosity suitable for reactive gases or fluids permeation, which are required characteristics for application in heterogeneous catalysis process. The composite material obtained from pyrolysis of polymeric precursor has its porosity strongly dependent from precursor constitution, which affects the decomposition kinetic. In this study, it was obtained a polyester precursor based on triethylene glycol, which has been submitted at pyrolysis at 600 oC for several times in nitrogen atmosphere. The nickel-silica nanocomposite obtained through that methodology presents a residual amorphous carbon phase playing an important rule on the mechanism of pore formation. Nickel nanoparticles nucleate with sizes close to 10 nm in diameter and are highly dispersed in a hybrid amorphous carbon-silica matrix. The composite pore volume, calculated through the JBH method, presents a continuous increasing as a function of pyrolysis time, reaching more than 0.15 cc/g after 7 hours from initial decomposition process.
Synthesis of Nickel-Silica Nanocomposite Embedded in Amorphous Carbon through the Polymeric Precursor Method
Authors: de Sá Igor Silva , Fischer Eliane Kujat , Barbosa Graciele Vieira , de Medeiros Tiziana Azario , da Silva Margarete Soares , Cavalheiro Alberto Adriano
Published: November 2016

The direct synthesis methods such as Polymeric Precursor Method can be used as direct route for the synthesis of ceramic-metal composites with high dispersion of metallic nanoparticles. The control of the polymer decomposition in order to avoid the organic matter combustion permits the pyrolysis occurrence, which originates the metallic phase embedded in the ceramic matrix. In this work, a nickel-silica nanocomposite in additional amorphous carbon interphase was successfully obtained through the Polymeric Precursor Method. It was observed by Transmission Electronic Microscopy that metallic nickel nanoparticles nucleate with sizes from 10 to 50 nm inside the mesopore matrix composite. The analysis of Nitrogen Adsorption-Desorption Isotherms for samples pyrolysed at several times showed the existence of two sizes of mesopores, one with diameter of 3.8 nm, associated to the silica-carbon matrix and other above 10 nm, associated to the meso and macropores containing nickel nanoparticles.
Study of Synthesis of Nanoparticulate Zinc Oxide Aiming at the Confection of Appropriated Targets for the Production of Radioisotopes
Authors: Mohallem Nelcy D.S. , da Silva Juliana B. , Rezende Cristiana P.
Published: November 2016

Zinc Oxide (ZnO) is a multifunctional material, which produces radionuclides of gallium by irradiation, widely used in diagnosis and nuclear medicine. In this work, two precursors were tested as well as two routes of synthesis, with the objective of obtaining nanoparticles appropriate to the production of pellets with grain size and porosity suitable for target preparation used in the radioisotope production by irradiation. The sintered pellets obtained from zinc acetate and NH4OH, and freeze-dried presented density of 90% of the theoretical density, average particle size of 1 μm and macropore size of 500 nm. These targets generated radionuclide of gallium (67Ga and 66Ga) inside the pores, without rupture of the pellets, confirmed by gamma spectroscopy, at low cost of production.
Porous Ceramics Obtained by Slip/Starch Casting Consolidation Method (SSCC)
Authors: Fernandes Rodrigo Sampaio , de Campos Elson , Santana Jerusa Góes Aragão , Mota Rogério Pinto
Published: November 2016

Slip/starch casting consolidation (SSCC) is a technique for obtaining porous ceramics, which joins the forming process by starch consolidation with the slip casting method. In this work, a slip which contains ceramic powders, starch and dispersant, is poured into a porous mold and is taken to an oven so that the gelling process occurs. After sintering, it is noticed that the ceramics show different characteristics from the ones obtained exclusively by slip casting or by starch consolidation. Alumina ceramics were produced by using the three methods presented in this work. The ceramics were characterized by apparent porosity, mechanical resistance and scanning electron microscopy. The ceramics produced by SSCC presented the highest mechanical resistance value (289 MPa), while the ones produced by starch consolidation and slip casting presented values of 126 MPa and 191 MPa, respectively.
Devitrification in SiO2-B2O3-Al2O3-La2O3-TiO2 Glass during the Infiltration of Ceramic Composite
Authors: Chimanski Afonso , Jordão Amanda Martins , Cesar Paulo Francisco , Yoshimura Humberto Naoyuki
Published: November 2016

Dental prostheses made of ceramic composites infiltrated with glasses have been used due to their biocompatibility and possibility to mimic the natural teeth. In this study, the devitrification behavior of 20SiO2-25B2O3-25Al2O3-15La2O3-15TiO2 glass during the infiltration process in a porous alumina preform was investigated. Glass frits were prepared by melting the raw materials at 1500 °C for 60 min. The glass was infiltrated into the alumina preform at 1,150 or 1,200 °C for 60 min. The specimens were characterized by X-ray diffraction analysis and scanning electron microscopy. After the infiltration, it was possible to note that the devitrification process occurred in the remaining glass (excess glass that did not infiltrate in the preform), forming mostly aluminum borate and mullite crystalline phases. However, within the infiltrated composite no devitrification was noticed in the infiltrated glass. Possible explanations for this behavior are discussed.
Physical Ice Management Operations - Field Trials and Numerical Modeling
Authors: Neville M. A. , Scibilia F. , Martin E. H.
Published: November 2016

Physical ice management is a critical element of station keeping operations in waters characterized by drifting sea ice: it minimizes ice related downtime. Ice management represents also an important cost driver for Arctic offshore developments. The ice management fleet needs to be assembled considering the particular site, season of interest and corresponding expected environmental conditions, the particular facility capabilities to operate in ice covered waters, and the desired operability of the entire system.

The paper describes the physical ice management trials performed during the Offshore Newfoundland Research Expedition in April 2015. These trials were planned and executed with the purpose to generate data to support the development of numerical models for simulating key aspects of the ice management operation.

The results of this paper are applicable to ice management fleet design. Particular focus is on Arctic and sub-Arctic areas characterized predominantly by open water, but still containing the risk of sea ice invasions, and vessels expected to operate in such areas.

Results from the field trials are presented and discussed. The paper elaborates on the schemes for numerical modeling of ice management, the challenges, and how field trial data can support the development of effective simulation tools.
Investigation and 3D Discrete Element Modeling of Fracture of Sea Ice Beams
Authors: Mohammadafzali S. , Sarracino R. , Taylor R. , Stanbridge C. W. , Marchenko A.
Published: November 2016

Flexural failure of sea ice is of interest in many different applications, ranging from understanding rubble formation processes to modeling bending failure of ice sheets against sloped structures and ship hulls. In this paper we present a brief summary of recent in-situ experiments carried out on side-loaded sea ice beam specimens on the ice fields near Storfjorden, Svalbard. Results from these tests have been used to parameterize a discrete element model of ice fracture under flexural loading. Simulations of these experiments in 3D have been carried out using a new material model within the open-source Discrete Element Method (DEM) code WooDEM which features cohesive bonds in tension, shear, flexure and torsion based on a contact model with normal, shear, torsional and flexural springs. A comparison of simulated and field test results, along with recommendations for future work is provided.
A Shipborne Measurement System to Acquire Sea Ice Thickness and Concentration at Engineering Scale
Authors: Lu Wenjun , Zhang Qin , Lubbad Raed , Løset Sveinung , Skjetne Roger
Published: November 2016

Sea ice concentration and thickness are important parameters for the calculations of ice actions and their effects on Arctic offshore structures and for the evaluation of icebreaker performance. Various methods exist nowadays to monitor these parameters, ranging from geophysical scale to local scale. During the Oden Arctic Technology Research Cruise 2015 (OATRC’ 15), we installed both Ice Concentration and Ice Thickness cameras and developed corresponding algorithms to achieve real time quantification of ice concentration and visual estimation of ice thickness information. For the ice concentration analysis, we utilized both the global Otsu method to categorize an image into two regions (black water and white ice); and the K-means method to identify more regions based on the gray scale from the image. With the methods, we conducted a case study by analyzing the ice concentration in a selected time window. In the case study, we include both dry ice (in white color) and wet ice (in gray color, generally composed of ice rubbles, young ice, and melt ponds) as ice region for the K-means method. The K-means method yields higher ice concentration values in comparison to the global Otsu method, in which, melt ponds/young ice was frequently mistaken as open water. It turns out that the K-means method enables more flexibility to cope with the complicated ice environment by separating the image into more regions that can be included as ice in an ice concentration analysis. For the ice thickness camera, the intention was to capture the events while a broken ice piece is tilted, next to the ship side, and expose its thickness region to the camera. In this paper, we developed an automatic tracking algorithm to sift these events out from all the images taken by the Ice Thickness acquisition system. After projecting a grid with physical length onto the image, the ice thickness information can be visually quantified. We compared the ice thickness obtained from the Ice Thickness camera and that obtained by an Electro-Magnetic inductive device in a selected time window. The results agree well with each other. Considering the advantages and disadvantages of each method, this demonstrates the benefits of combining redundant approaches for obtaining the ice thickness information with a higher degree of confidence.
Probabilistic Assessment of Multi-Year Sea Ice Loads on Upward Sloping Arctic Structures
Authors: Thijssen Jan , Fuglem Mark , Croasdale Ken
Published: November 2016

Multi-year (MY) ridge and level ice interactions with sloping and conical structures involve complex ice feature shapes and ice failure mechanisms. The limited available field data makes calibration of associated load models difficult. To account for associated randomness and uncertainty, models may tend to be on the conservative side.

New deterministic algorithms were recently developed to calculate loads more accurately for interactions of MY level ice and MY ridges with an upward sloping structure. This paper presents the application of these recently developed formulations in a probabilistic framework using SILS. SILS is a Monte-Carlo type simulator developed by C-CORE following the general procedures outlined in ISO 19906. Ice and metocean input parameters are defined by the user either as a fixed value (e.g. friction coefficients) or a random distribution (e.g. ice drift speed, floe size). The yearly encounter frequency is first estimated for these ice features for the site of interest. The ice loads are then determined for each of simulated interaction event occurring over the model timespan, using the deterministic load formulations. By simulating a large number of years of ice interactions, design ice loads can be determined that correspond to various low annual probability of exceedances.

This paper demonstrates how complex loading scenarios, modelled in terms of idealized deterministic models, can be incorporated within a Monte-Carlo framework to provide design level loads. During the model implementation and analysis of results, significant improvements were identified and implemented in the deterministic model, resulting in a more robust model and better design estimates. The results provide valuable insights regarding model inputs and behaviour corresponding to the extreme design ice loads. An example of a full probabilistic analysis is presented in the paper to illustrate the models. Here the probabilistic framework of SILS is used to assess a Base Case scenario and a number of sensitivity cases using different environmental inputs and model parameters.
Labrador Deepwater Exploration Insights into its Prospectivity From Broadband Seismic AVO Analysis and Seabed Coring
Authors: Wright Richard , Atkinson Ian , Carter James
Published: November 2016

The Labrador Sea, extending from the Davis Strait in the north, through the Saglek Basin and down to the Hopedale Basin in the south, is one of the largest under-explored areas along the eastern Canadian Margin. Exploration of this region has focused on the continental shelf with 30 wells drilled during the 1970's and 1980's. Most of the wells targeted shelfal structural traps. No exploration has occurred in the slope and deepwater areas. From 2011 to 2015, long offset, broadband 2D seismic data (42,400 km) has been acquired by TGS-PGS in the slope and deepwater regions. The broadband image quality has led to the identification of significant new plays and leads in a region that was never before considered prospective. Several of these leads have the potential for large accumulations of oil and gas. The possibility for oil plays in the area is supported by the presence of natural oil seeps along the slope that were identified by satellite surveys in 2010. The long offset (8 km cable) seismic data has identified AVO anomalies on the far stacks. A new regional rock physics study (2014-15) has permitted the careful analysis of these AVO leads and this is helping to reduce exploration risk factors. The analysis shows the importance of the long offsets to identify and characterize these Class II AVO anomalies. In 2015, a seabed coring survey was conducted to target areas near the oil seeps and over large potential traps. Early results from this work are positive and analysis will continue through the spring of 2016. Heatflow measurements taken during the coring survey are providing inputs for a basin modelling study. In addition, several of the shelfal wells were resampled and fluid inclusion analysis was performed. Early results are showing the presence of liquid hydrocarbon inclusions. All of this work has led to the identification and analysis of large potential traps that could hold major oil accumulations. This paper will provide insights from the new seismic data and the recent studies and analyses to demonstrate this prospectivity.
The Ford’s Bight Diatreme A Cretaceous Alnöite Pipe from the Northern Labrador Coast and Possible Onland Remnant from the Opening of the Labrador Sea
Authors: Wilton Derek , Burden Elliott , Greening Adam
Published: November 2016

The Ford’s Bight Diatreme is an apparently rare feature on the Precambrian coast of Labrador. Originally described as a Jurassic-Cretaceous sedimentary breccia cut by lamprophyric dykes, an early report of marine microfossils in the strata poses an interesting sedimentary and petroleum geology problem. In revisiting the area, the succession is now viewed as a rift related diatreme with a Cretaceous (ca. 137 Ma) radiometric age. In earlier work, this rock was dated from assemblages of poorly preserved Jurassic and early Cretaceous marine microfossils. Our own lengthy search for fossils in igneous rocks and clasts and carbonate matrix was fruitless. Some apparently carbonized debris is identified in microscopy and with some oddly shaped (non-biologic) microcrystalline structures seen under SEM. With an age and origin for this feature established from basic geology and radiometric dating, this therein leaves an unresolved petroleum exploration risk - and, namely, did Jurassic marine conditions cover this part of the Labrador coast before earliest Cretaceous volcanism?
Analysis of First Year Ice Surface Ocean Current and Ice Floe Drift Speed and Motion Offshore Newfoundland and Labrador from Satellite-Tracked Buoys During the 2015 Ice Season
Authors: Rahman M. S. , Turnbull I. D. , Taylor R. S. , Veitch B.
Published: November 2016

This paper presents an analysis of the dynamics of ice, current, and wind based on the data collected on land-fast ice and ice floes from the offshore environment of Newfoundland and Labrador during April-August 2015 using satellite-tracked beacons. The beacons were deployed in three sets of three as follows: fast ice beacons (FIB) 2, 3, and 5 were deployed in a triangular array on the land-fast ice offshore Makkovik; fast ice beacons (FIB) 1, 4, and 6 were deployed in a triangular array on the landfast ice offshore Nain, and ice floe beacons (IFB) 7590, 1590, and 0650 were deployed on drifting ice floes offshore Makkovik. Ten ocean drifter beacons were deployed on May 22, 2015 in open water in the vicinity of ice floe beacons 1590 and 0650 to study the characteristics of surface ocean current dynamics. The drift velocities of the two ice floes have been compared with the wind velocities measured by the two weather stations deployed on the ice floes. The buoy drift rose and exceedance probability plots have been presented to analyze the dynamical characteristics of first year ice and ice floes in the offshore Labrador ice environment.
Improved Equations for the Actions of Thick Level Ice on Sloping Platforms
Authors: Croasdale Ken , Brown Tom , Wong Chee , Shrestha Noorma , Li George , Spring Walt , Fuglem Mark , Thijssen Jan
Published: November 2016

In ISO19906 (2010) (Arctic Offshore Structures) specific algorithms are provided for level ice loads on sloping structures; they are based on the separate work of Ralston and Croasdale. These methods were developed decades ago and comparisons with full scale data, especially from Confederation Bridge, suggest that certain idealizations can be improved; more importantly that they may be over-predicting the measured loads. For these reasons it was decided to critically review the existing Croasdale et al algorithm (as specified in ISO) and update it based on learnings from Confederation Bridge, other experience and new ideas.

During the study, over 50 ice interaction events at Confederation Bridge were chosen as geometrically similar to thick ice acting on an Arctic structure. The interaction process and relevant parameters (such as ride-up height) were documented in detail and the measured loads compared with predictions for each event. The model, as currently specified in ISO, generally over-predicted by a factor of about 1.6. The model was improved in the course of the work; especially the physics of breaking and ride-up. The new model is capable of matching the Bridge measurements without bias.

This paper presents the final methodology and equations which resulted from the study which was conducted over several years and resulted in an extensive report and documentation. The equations are closed form and can be applied relatively simply. Examples of using the method are provided. A more comprehensive description of the complete study is given in KRCA (2014) and Croasdale et al. (2016a).
Integrated Design and Analysis for Virtual Arctic Simulation Environment
Authors: Hamilton Matthew , Maynard Aaron , Jujuly Muhammad , Adeoti Ibraheem , Rahman Aziz , Adey Matthew
Published: November 2016

We present an integration of new capabilities of simulation and visualization for subsea analysis and design into an existing virtual arctic simulation environment (VASE). The existing system (previously presented) provides interactive, high-fidelity simulation capabilities for remotely-operated vehicles (ROV) in arctic environments for subsea trenching along with support for visualization of integrated data from sub-bottom and multibeam sonar imaging devices. This paper describes integration of the existing VASE with computation fluid dynamics (CFD) simulation capability for simulation of flow assurance and fluid-structure interaction design issues relevant to arctic subsea oil and gas field design.

The presented integrated simulation system allows for rapid, streamlined evaluation of pipeline designs in an integrated data, whole-field context. In particular, detailed analysis of pipeline fatigue risk factors due to slugging and effects of hydrate formation can be performed through integrated CFD analysis capabilities. The system's intuitive pipeline design allows for rapid alteration of pipe and flow lines in response to feedback from bathymetry and soil data, ROV accessibility requirements and structural analysis through flow induced vibration and fluid structure-interaction simulations.

It is demonstrated how various pipeline and jumper designs can be rapidly created in the VASE with design strategies motivated by the integrated whole field data visualization environment. Once pipe and jumper designs are specified, they can be exported for external analysis. We demonstrate this analysis through two fluid-structure interaction models (slugging and hydrate formation model). This allows for effective design in arctic environments, including design of pipeline routes in context of trenching and general management of cold water conditions. Overall, the system can also serve to function as a planning and data management system for subsequent training of pilots for inspection as part of asset integrity management.
Improvement of Visibility and Severe Sea State Forecasting on the Grand Banks of Newfoundland and Labrador
Authors: Bullock Terry , Isaac George A. , Beale Jennifer , Hauser Tristan
Published: November 2016

Fog in northern climates and Arctic environs can be a risk to helicopter operations and shipping interests, as are high seas from severe storms that frequent these regions. Visibility conditions and forecasts determine whether helicopters can safely land on offshore facilities, or if personnel will need to be transferred by ship. High sea state conditions can affect offshore oil and gas exploration and production operations, including drilling, logistics, crane operations and emergency response.

A workshop on Metocean Monitoring and Forecasting for the Newfoundland & Labrador Offshore, held 22-24 September 2014, identified the need of improving the visibility and severe sea state forecasting for Grand Banks which can have a positive contribution to safety and operations in the harsh North Atlantic Canada offshore environment. This has led to an open and collaborative multi-year Metocean Research and Development Project that is presently in its third year. Some twenty government, academic, and industry agencies are participating in this project.

Detailed buoy and offshore installations-based scientific measurements have been collected over the past three years where previously there has been a lack of good quality observations. A climatology of low visibility (less than 1km) events shows a high frequency (about 55% of the time) during summer months. A "conceptual model" of Grand Banks fog has been developed, that defines the physical conditions under which fog develops, is maintained, moves and dissipates. The conceptual model will be the basis for the development of new visibility prediction systems which currently are not well established or verified. High seas, with wave heights over 6m, occur more frequently during winter. Sea state prediction systems are being evaluated for severe ocean wave conditions where they have reduced predictive skill. Currently, work is underway to establish the accuracy and consistency of several existing visibility and sea state prediction systems.

This paper will illustrate results from the climatological studies and some of the unique metocean monitoring data being collected. The forecasting techniques (e.g. numerical atmospheric and oceanic prediction models, satellite-based schemes, and rules based systems) being evaluated, are outlined.
Numerical Simulations of Ice Loads on Fixed and Floating Offshore Structures using the Discrete Element Method
Authors: Liu Jiancheng Jessie , Liu Xiang , Chen Yingying , Long Xue , Ji Shunying
Published: November 2016

Existing standards and codes do not comprehensively address and provide all necessary guidance and requirements for the design of Arctic offshore structures. Reliably assessing ice loads on offshore structures remains a challenge for industry, especially as "new" Arctic platform concepts are proposed for deployment in lighter ice operations, e.g. Arctic SEDU (Self- Elevating Drilling Units) and Arctic CSDU (Column-Stabilized Drilling Units). As a pragmatic solution, a comprehensive approach including relevant field measurements, physical model tests and numerical simulations is usually adopted in assessing the ice loads for a particular design. Field measurement results are limited in number and there is often uncertainty concerning actual ice conditions and load measurement techniques. Furthermore several data sets are constrained with proprietary restrictions. In particular no direct field data is available for the example "new" structures (SEDUs and CSDUs). Physical model tests always present challenges due to scale issues, ice property calibration, measurement uncertainties and high costs. Therefore, numerical simulations using the validated DEM tool based on the related field/model test data are anticipated to provide supplementary information for standards/rule-based designs.

ABS has expended efforts to develop practical and advanced tools to assess the ice loads on offshore structures for several years. One promising numerical approach, a graphic processing unit (GPU) based Discrete Element Method (DEM) model, processes the computations in parallel and solves the DEM model with millions of particles for complicated ice-structure interaction problems, e.g. ice simultaneously loading on multiple legs and ice loading on a large CSDU. The paper presents details of the developing ABS GPU-DEM tool, status of the verification program, plans for the current and the future developments and applications. Included are brief descriptions of background technologies, an approach to derive the DEM model bonding strength inputs, and validation studies of ice breakage simulations based on the Bohai Bay Jacket ice data. The ice load simulations for fixed and floating structures, i.e. jack-up legs and the Kulluk floating drilling platform, are also shown to demonstrate the tool's capability and feasibility for Arctic offshore structure design. The interactions of ice and fixed/floating structures were analyzed, which provides useful references for future ice load modelling and offshore structure design.
Modeling of Heat Loss from Offshore Buried Pipeline through Experimental Investigations and Numerical Analysis
Authors: Chakraborty Suvra , Talimi Vandad , Muzychka Yuri , McAffee Rodney
Published: November 2016

Offshore oil and gas production in arctic areas is challenging due to harsh environmental conditions. Pipeline burial and trenching in those areas are now one of the prime methods to avoid ice gouge risks and other threats. Thermal management becomes critical when the ambient temperature is low such as the typical seawater temperature on the sea bed. The flow temperature and pressure affect viscosity of the fluid traveling through the pipeline and determines the state of the fluid (single or multiphase). The effect of freezing around oil and gas pipes in the vicinity of permafrost is considered as another concern for flow properties of oil and gas in arctic regions. Theoretical shape factor model has been widely utilized to estimate heat loss from buried pipelines. This study examines the validity of using this method for flow assurance calculations. Several steady state and transient experiments have been carried out to model the heat loss considering different parameters such as burial depth, backfill soil, trench geometries etc. Natural convection can play a significant role in the overall heat loss process from the buried pipeline. The total heat loss increases significantly when the backfill soil is loose or sandy. This paper illustrates the effects of heat conduction and natural convection in the heat loss mechanism from buried pipelines. The outcome of this paper will provide valuable heat loss models based on experimental and numerical analysis results. These outputs can be used largely in petroleum industries for designing pipelines in offshore arctic areas and to mitigate several flow assurance issues (e.g. wax and hydrate formation in the pipeline effectively). The methodology used in this research i.e. analyzing the experimental data with two steps of validation will ensure the validity of the proposed model. Using different parameters such as burial depths, trench geometries, and backfill soil this paper provides an effective model for the offshore pipeline design.
Experimental Study on Shear Strength of Freeze Bonds in Freshwater Ice
Authors: Boroojerdi M. T. , Ghobadi M. , Taylor R. , Bailey E.
Published: November 2016

The strength of rubble mass depends on the degree of consolidation between the ice blocks as well as the strength of the ice blocks themselves. The origin of the contact forces between the ice blocks is uncertain, but has been attributed to thermal freezing and sintering. A series of freeze-bond tests were conducted on freshwater ice blocks to gain a greater understanding of the fundamental physical properties affecting ice bonding. The parameters investigated in this test program were the contact period/submersion time and the initial temperature of the ice blocks. Freeze bonds were made by putting two ice blocks in contact in a confinement frame and applying a normal load. The frame was then submerged in water at freezing point for a specific period of time before testing. The bond was sheared using Asymmetric Four Point Bending (AFPB) method, which produces a nearly pure shear stress state in center of the specimen. Results showed that varying the submersion time from 1 minute to 26 hours for ice samples with initial ice temperature of −18°C, the strength of the bond initially increased and reached the maximum at 5 minutes and then started to gradually decrease, reaching a constant value after 3 hours of submersion. The effect of initial ice temperature on the bonding process was also studied by varying the temperature from 0°C to −18°C, whilst the submersion time was kept constant at 30 minutes. As the temperature was decreased an increase in strength was observed.
A GIS Approach to Quantitative Ice Gouge Depth Mapping, Analysis, and Prediction
Authors: Haneberg William C. , Brumley Kelley , Kucera Michael S.
Published: November 2016

We describe and illustrate the application of a geographical information system (GIS) approach to map ice gouge locations and depths from high-resolution multibeam echo sounder (MBES) bathymetric surfaces by calculating residuals relative to spatially variable moving trend surfaces. The workflow can be used to rapidly characterize gouges over large areas and, because minimal human intervention is required, is especially attractive in heavily gouged areas where traditional manual measurement techniques would be tedious and produce highly uncertain results. The method produces maps showing gouge depth as a continuous field rather than point measurements or cross-gouge profiles, so that variations in depth along gouges can be easily visualized and analyzed. Once gouges have been delineated, gouge depth distribution statistics can be further used to estimate exceedance probabilities for gouge depths within local neighborhoods. Seafloor roughness maps can also be generated to highlight the spatial variability of seafloor disturbance and, in a relative sense, visualize the ages of different gouges if certain assumptions are satisfied. We illustrate application of the method using a sample MBES data set depicting a heavily gouged portion of seafloor.