bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved localized surface plasmon resonance responses of multi-metallic Ag/Pt/Au/Pd nanostructures: systematic study on the fabrication mechanism and localized surface plasmon resonance properties by solid-state dewetting
Authors: Sui M , Kunwar S , Pandey P , Pandit S , Lee J 
Published: November 2019

Abstract
Multi-metallic nanoparticles (NPs) can offer dynamic and tunable localized surface plasmon resonance (LSPR) properties that are suitable for various catalysis, sensing and energy harvesting applications due to the wide range of tunability and applicability. In this work, the systematic fabrication and improved LSPR characteristics of multi-metallic alloy NP arrays are demonstrated based on the solid-state dewetting (SSD) of multi-layers of Ag/Pt/Au/Pd on sapphire (0001). The evolution of surface NPs in terms of configurational and elemental specifications yields vary strong and dynamic LSPR bands in the UV and VIS wavelengths based on the excitation of various plasmonic modes, i.e. dipolar (DR), quadrupolar (QR), multipolar (MR) and higher order (HO) bands, which is further exploited by the finite difference time domain simulations. Through the systematic control of multi-layer thickness, layer ratio and growth conditions, various nanostructures such as voided nanoclusters, network-like NPs and isolated semispherical NPs are obtained, which are unique in terms of morphology and elemental composition at each stage of dewetting process. The growth mechanism of multi-metallic alloy NP arrays is proposed based on the temperature driven thermal diffusion, alloying, Rayleigh-like instability and energy minimization mechanisms. Due to the subsequent sublimation of Ag atoms at above 650 °C, a sharp alteration in the elemental and morphological characteristics is demonstrated. In specific, the high percentage of Ag alloy NPs exhibits strong LSPR bands and gradually weakened along with the Ag sublimation. At the same time, however, the alloy or mono-metallic NPs without Ag still demonstrate much stronger LSPR bands as compared to the monometallic NPs by the SSD of pure films.
Optimal sea floor placement of the oil/gas production equipment
Authors: Arsenyev-Obraztsov S S , Ermolaev A I , Kuvichko A M 
Published: November 2019

Abstract
In the construction designing of oil field surface facilities, exists a problem of the seabed production equipment optimal placement. As an initial approximation, we can represent this task in the form of the linear Boolean programming problem. An application of routine methods of discrete programming can theoretically give the desired solution. However, these methods do not take into account the specific nature of the problem. This problem belongs to the NP class. So we can run into significant computational difficulties. This situation is typical for construction of the ground surface or subsea located facilities for real oil/gas fields. To overcome it, we propose to replace a discrete programming model with a linear programming one, which takes into account problem-specific properties. Also, we present examples of the application of the proposed parallel optimization algorithms. Input data for them: the seabed profile, geometry, and space distribution of oil/gas reserves. Optimization problem objective function is the penalty for the irrational placement of seabed production equipment elements.
Mechanical behavior of aluminum honeycomb sandwich structures under extreme low temperature conditions
Authors: Zaoutsos S P 
Published: November 2019

Abstract
The current study is an effort to characterize the mechanical response of panels that are used as structural elements at low temperature applications. For the above reason, plaques of aluminum honeycomb sandwich were exposed for a certain period of time at different low temperature profiles ranging from 23°C to -70°C so that possible variation of their mechanical properties due to temperature exposure to be justified. Four different temperatures namely 23°C, 0°C, -40°C and -70°C were applied to these plaques prior mechanical testing that was performed at different loading modes. Specimens were obtained from these plaques in order to study the effect of low temperature on mechanical behavior and damage response of the specific sandwich structures. Extensive mechanical testing was carried out by means of tensile, compression and bending loading and the respective mechanical properties occurring from these tests were determined. From the results occurring from experimental data obtained from mechanical testing it is evident that there is a moderate decrease of ultimate strength and yield strength of the material as service temperature decreases in tensile, edgewise and flatwise compression as well as in three point bending loading modes. Moreover a drop in temperature results in a decrease in strain at rupture at tensile and compression loading.
Flexural dynamic behavior of submerged cylindrical structures under wave loads
Authors: Giotis T , Pavlou D , Belibassakis K A 
Published: November 2019

Abstract
An analytical solution for the dynamic response of submerged slender circular cylindrical structure subjected to linear wave loads is presented. A double Laplace transform with respect to temporal and spatial variables is applied both to motion equation and boundary conditions. The dynamic deflection of the beam is obtained by inversion of the Laplace transform. The latter with respect to spatial variable is obtained analytically, while the one concerning the temporal variable is numerically calculated using Durbin numerical scheme. Results in the case of a representative example for a monopile foundation subjected to Airy waves are presented and discussed, and the analytical result is compared against numerical dynamic and static solutions.
Machine learning in reservoir permeability prediction and modelling of fluid flow in porous media
Authors: Zolotukhin A B , Gayubov A T 
Published: November 2019

Abstract
Reliable data on the properties of the porous medium are necessary for the correct description of the process of displacing hydrocarbons from the reservoirs and forecasting reservoir performance. The true permeability of the reservoir is one of the most important parameters which determination is time-consuming, costly and require skilled labor. The paper describes the methodology for determining the permeability of a porous medium, based on machine learning. The results of laboratory experiments, available in the database (terrigenous reservoirs with permeability in the range from 12 to 1132 md), are used to train the neural network, and then to predict the reservoir permeability. Comparison of the predicted and calculated permeability values showed a fairly good match between them with the determination coefficient of 0.92. The last task considered in this paper is to obtain an analytical expression describing a fluid flow in a porous medium using machine learning. This procedure enabled to obtain a resultant equation of fluid flow in a wide range of reservoir parameters and pressure gradients, which can be used in reservoir simulators.
Strength analysis of 3D printed carbon fibre reinforced thermoplastic using experimental and numerical methods
Authors: Ghebretinsae F , Mikkelsen O , Akessa A D 
Published: November 2019

Abstract
A study of strength of composite materials produced by 3D printing technology is presented. The samples fabrication and tests to determine the strength both in bending and in tension of the composite materials have been carried out. The composite samples were additively manufactured using Markforged® 3D printer of type Mark-Two. The fabricated composite samples were of carbon fiber filament combined with a thermoset plastic matrix, by its producer named “Onyx”. The tests provided sample mean value for the ultimate tensile strength of 560 MPa and the tensile modulus of 25 GPa. Based on the three point bending tests the ultimate flexural strength of 271 MPa and flexural modulus of 16 GPa were estimated. The tests are reported and discussed in view of stress analysis modeling the layered composite with finite element models.
Numerical study on the ventilation performance of a livestock house built in porous panels in Cold Regions
Authors: Xu Y , Mustafa M Y , Calay R K , Sørensen B R 
Published: November 2019

Abstract
This paper presents a numerical prediction on the assessment of natural ventilation on a livestock house built in porous panels, aided by Computational Fluid Dynamics techniques. A typical climatic environment in Cold Regions was taken into consideration. The ventilation performances have been assessed by the distribution of indoor air velocity, turbulence intensity and local mean age of air through the cases: the house without porous panels, with wind erosion porous panels, and with snow erosion porous panels. The study has found that the porous panels improve the indoor environment in term of the reduction of air velocity and turbulence, and the wind erosion panel performs better than the snow erosion panel. However, applying porous panels may have negative effects on air exchange effectiveness. The presented numerical model is easy to be constructed, flexible to investigate different case scenarios, and quick and cheap to get solutions.
Fatigue design challenges: Recent linear and nonlinear models
Authors: Pavlou D G 
Published: November 2019

Abstract
Reliable fatigue design rules affect the proactive identification of safety parameters in engineering structures. Numerous fatigue crack initiation and propagation models, linear and nonlinear, have been developed for designing purposes or estimation of the remaining life of aging structures. Depending on the adopted assumptions, the accuracy varies for different loading histories, loading types, and materials. Semi empirical models are simple but yield significant inaccuracies. Models with better theoretical basis provide better accuracy, but implementation in real conditions is problematic. In the present work, a review of author’s recent fatigue crack initiation and propagation models based on physical mechanisms is presented and improvements are proposed. Verification of the models on test results is provided and discussed.
Buckling capacity of simulated patch corroded tubular columns – laboratory tests
Authors: Vo T , Hestholm K , Ersdal G , Oma N , Sivertsvik M 
Published: November 2019

Abstract
This paper presents the experimental test results for the buckling capacity of tubular columns exposed to simulated unsymmetrical patch corrosion damage. These tests were performed to investigate how the results of these experiments compare with the capacities obtained for the formulae provided in the 2004 revision of NORSOK N-004. Formulae for patch corroded tubular columns are needed in standards and as such it is unfortunate that these formulae are removed from the present revision of the NORSOK N-004 standard. Prior to suggesting introducing these previous formulae in standards, experimental tests to confirm good correlation between experiments and formulae are needed. The tests performed in this work are presented in this paper for 100% (intact columns), 69%, 34% and 0% remaining wall thickness in the patch.
Inspection planning for fatigue cracks in offshore structures by Monte Carlo simulations
Authors: Neeraas H , Ersdal G , Oma N , Hellevig N-Ch 
Published: November 2019

Abstract
Probability-informed inspection planning has traditionally a tendency to produce longer inspection intervals for older structures in contrast with the intuitive assumption that shorter inspection intervals are needed. In this paper an alternative method for probability-informed inspection planning is suggested based on a parameter updating rather than the general updating used in most cases. The proposed method produces constant inspection intervals after the theoretical first inspection. Further, the method produces reasonable inspection intervals more or less in line with what is used in practise in the offshore industry at present.
Acceptable fatigue crack occurrence rate
Authors: Vårdal O T , Moan T 
Published: November 2019

Abstract
In fatigue management, it is essential to know the fatigue crack growth potential. The lessons learned from use of refined fatigue analyses, fracture mechanics and probabilistic methods for platforms in-service are presented. For ageing offshore units of semi-submersible design, the inspection history of more than 20 000 NDT inspections and detection of close to 1000 fatigue cracks, are used in this study. These experience data are used to assess the fatigue failure potential. The fatigue crack growth capacities are influenced by the extent of gross errors in the design, construction and operation phase in addition to the normal uncertainties of design, construction and inspection. Corrosion in combination with not detected weakening of the capacity against fatigue crack growth is one of the main challenges. Assessments based on collected in-service observations are mandatory.
An efficient approach for ship collision design of reinforced concrete pontoon walls
Authors: Sha Y , Amdahl J , Yang K 
Published: November 2019

Abstract
This paper presents an efficient method for collision design of prestressed concrete pontoon walls. High fidelity finite element models of a container ship bow and a prestressed concrete pontoon wall are first established. Integrated numerical simulations are conducted to study the structural deformation of the pontoon wall during the collision. Parametric studies are also carried out to investigate the effect of the pontoon wall thickness. Based on the failure mode of the pontoon wall, a punching shear check procedure is proposed. This method yields a good accuracy while significantly reduces computational efforts. Hence, the proposed approach can be used for collision analysis in the preliminary design phase of floating pontoons.
Development of a method for evaluation of measures used for winterization of offshore facilities and units
Authors: Jacobsen S R , Viddal S , Dørum K G , Gudmestad O T , Wiencke H S 
Published: November 2019

Abstract
The environmental conditions in the Barents Sea include low temperatures, wind, snow and precipitation influencing safety, working environment, operations and equipment functionality. The conditions are not extreme compared to other Arctic areas, however they do necessitate protection and winterization of the facility. A study performed for the Petroleum Safety Authority (PSA) in 2016 identified known measures for winterization of facilities in the Barents Sea. The study found uncertainties related to the effect the measures have on winterization when considering environmental conditions. Further work was recommended to evaluate the effect of measures when considering performance influencing factors. A new study was initiated by PSA to develop a method to evaluate the efficiency of measures and a means to document the results. The method considers how well a measure achieves a specific safety and winterization goal, effect of the measure on energy consumption, effect of the measure on investment cost and operating cost, and vulnerability of the measure, including operational and organizational factors. In order to refine and test the method, it was applied to case studies considering a year-round production facility, a light well intervention vessel and a drilling facility used in the winter season in the Barents Sea. The paper is not intended to be a research paper but is a presentation of a method that has been developed to perform an initial evaluation of the effectiveness of winterization methods.
Pipeline shore crossing approaches in Arctic conditions
Authors: Kurbonshoeva L , Gudmestad O T , Zolotukhin A 
Published: November 2019

Abstract
The development of the Arctic region will entail the construction of new infrastructure, in particular, subsea pipelines. Considering the lack of actual field practice, ecosystem vulnerability and lack of common Arctic international standards, their development will be a big challenge, in particular, in the shore crossing zone. The design and construction of pipelines in the shore crossing area require a special approach that takes into account environmental and technological aspects of development. This work is aimed at analysing and determining environmental and technological factors influencing the design of offshore pipelines in the Arctic coastline. The paper presents theoretical and analytical work and the research is applied to a specific case study (pipelines from the Leningraskoye field to shore), through engineering calculations. Currently, there are five Arctic projects with shore transition areas for which trenching has been implemented. In order to determine the best shore crossing approach, it is important to consider the following environmental conditions: ice encroachment; ice ridges; shoreline erosion; permafrost thawing. Environmental characteristics should predetermine the choice of approach. Among three existing methods: trenching, tunnelling and horizontal directional drilling (HDD), the micro-tunnelling method is recommended for the Leningradskoye field in combination with a cofferdam corridor to protect the buried pipe from waves and ice in the nearshore area. In order to protect the surrounded permafrost from melting seasonal cooling-device is recommended to be used. The burial depth is determined to be more than 3.52 m in accordance with Force model calculations of ice ridges scouring depth. On the basis of research, the general choice-making diagram was proposed for Arctic shore crossing areas.
Features of geotechnical surveys and leg penetration analysis for drilling platforms in the Arctic seas
Authors: Marchenko I 
Published: November 2019

Abstract
In recent years, one of the most important direction in the development of offshore hydrocarbon exploration is the expansion of the oil, gas and gas condensate fields of the Russian Federation to the Arctic shelf areas. Extensive and complex engineering surveys are actively performed in the Barents Sea and the Kara Sea. In the last year, a wide range of engineering investigations has been implemented on prospecting and exploratory wells. The geotechnical surveys are mandatory before the drilling of exploratory and production wells to obtain the data for the upper part of the geological profile to provide necessary information for safe positioning of drilling rigs. This is extremely important as the upper part of the soil interacts with an engineering structure whether it is a drilling rig, pipeline, subsea production system or any other structure. The data of the stated surveys is used for optimal location selection for drilling rig positioning and the necessary stability calculations. The use of geophysical and geotechnical methods in engineering surveys provide an effective solution for the geological challenges and ensures the availability of sufficient information regarding soil composition, properties and strength conditions.
The Barents Sea of the Norwegian Continental Shelf: drilling through carbonates, modelling, risk management and well planning
Authors: Mosesyan M A , Hartwig A , Edin K M , Rabey A S , Surguchev L M 
Published: November 2019

Abstract
There are a number of geological and hydrogeochemical modelling techniques used in order to ascertain formation of the hydrogen sulphide (H2S) in the formation fluid within a geological setting in several blocks of the Norwegian Barents Sea. Careful consideration of the regional and chemical factors causing H2S generation can also be used in the drilling context. Thermochemical sulphate reduction (TSR) is the most likely process of H2S formation in this setting. Risk picture becomes different when presence of H2S is closely coupled with occurrence of Permian and Carboniferous carbonate plays prone to causing severe drilling fluid losses and increasing exposure time of the downhole equipment to the H2S. Using appropriate analogues and adequate well offset analysis tend to demonstrate that most of the risk factors can be well mitigated.
Problem and models of multicriteria decision making and risk assessment of the arctic offshore oil and gas field development
Authors: Zolotuhin A B , Stepin Yu P 
Published: November 2019

Abstract
The article is devoted to the systematic solution of problems of multi-criteria assessment and the possibility of implementing projects for the development of hydrocarbon deposits on the Arctic shelf under conditions of uncertainty and risk. Risks are considered in a narrow and broad sense. It is shown that the solution of tasks, in this case, comes down: 1) to a multi-criteria assessment of the quality level of a field based on a hierarchy analysis method that takes into account uncertainties and risks of operating objects through the relevant necessary indicators (criteria); 2) determining, with the help of game theory adopted with the nature of the criteria for selecting the best Bayesian strategies, of development options under both partial and full uncertainty conditions; 3) selection using the rules of the Borda, Pareto and multi-criteria dispersive risk model for choosing the best development strategy.
Field development optimization of waterflooding process using data assimilation methods
Authors: Guliev R , Zolotukhin A 
Published: November 2019

Abstract
The application of data assimilation methods for field development optimization has been the subject of intense investigation during the past 10 years. Lately has seen remarkable progress in the ability of data assimilation approach in reservoir characterization and based on this, improvements of field development optimization. In this review paper, we have summarized key achievements in field development optimization of waterflooding process with data assimilation approach and review many of the achievements of the past time, including developments in the field of search for modifications of Ensemble Kalman Filter (EnKF) and Ensemble Smoothers (ES). An attempt has been made to discuss different data assimilation methods and to identify possible limitations of each. Current challenges and future research opportunities for improved data assimilation methods for field development optimization of waterflooding process are also discussed.