bluuebunny/crossref_metadata_2025_split huggingface dataset:
Current methods of subsea production systems survey in the conditions of the Arctic region
Authors: Smirnov E , Kharchenko U 
Published: November 2021

Abstract
The development of deposits in the Arctic region and the Far Eastern shelf of Russia is complicated by the presence of ice conditions. The duration of the ice period can vary from 5 up to 9 months, during which the underwater equipment of the field is inaccessible for inspection and repair. This work discusses the methods of inspection and maintenance of subsea production systems that can be used in the development of Arctic deposits.
Status and needs for ice tank testing in a changing climate
Authors: Jochmann P , Ziemer G , Myland D , Reimer N , Hisette Q 
Published: November 2021

Abstract
150 years ago, the first modern icebreaker in the world was designed by the naval architect Carl Ferdinand Steinhaus and built for purpose of removing ice barriers on the river Elbe in Hamburg, Germany. No model tests were performed at that time. Later, in the first half of the 20th century, “model tests” for ships were carried out in natural ice on lakes. In the 1950th the first-generation ice model basins were put in operation and ice model testing became a standard method in the icebreaker design process. This paper discusses the influence of the economic and environmental development in arctic regions, driven by shipping and offshore activities in environmental changing Arctic Waters, on the ice model basin design, equipment and testing methods. The developments will be presented with examples from The Hamburg Ship Model Basin (HSVA). To complete the overview, an outlook to future trends is attempted.
Complex geodynamic indicators for forecasting hydrocarbon deposits in the arctic zone
Authors: Minaev V A , Stepanov R O , Faddeev A O 
Published: November 2021

Abstract
In the article, in relation to the Arctic zone of the Russian Federation, a new method of forecasting hydrocarbon deposits based on computer geodynamic modelling procedures is considered. It is less expensive compared to field and analytical methods. The approbation of the method on the example of the Laptev Sea shelf zone showed a good interpretability of its results and their compliance with the forecast obtained by other methods. The rationality of using six geodynamic indicators for forecasting: the distributions of vortex structures of the velocity vectors of horizontal shear deformations and vortex structures of normal linear deformations; the values of the velocity vectors of horizontal shear deformations and velocity vectors of horizontal normal linear deformations; the distributions of the anomalous gravitational field in isostatic reduction and the reduced temperature. The sequence of stages in determining the potential of hydrocarbon deposits in the studied territories is described, which is associated with the solution of six interrelated sequential tasks: the choice of local territorial areas of optimal size - the calculation of geodynamic indicators – the allocation of homogeneous territorial clusters – the detailing and improvement of geodynamic indicators – the determination of the potential of oil and gas fields in the cluster – the localization of oil and gas fields in each cluster – construction of a digital forecast map of the location of oil and gas fields in the study area.
Multi-functional oilfield production chemicals: maleic-based polymers for gas hydrate and corrosion inhibition
Authors: Kelland M A , Pomicpic J , Ghosh R , Undheim C , Hemmingsen T H , Zhang Q , Varfolomeev M A , Pavelyev R S , Vinogradova S S 
Published: November 2021

Abstract
Several chemical problems can occur during the production of oil and gas through flow lines. This includes corrosion, scale deposition and gas hydrate plugging. Three separate chemicals may be needed to treat these issues. Kinetic hydrate inhibitors (KHIs) are used in cold oil or natural gas production flow lines to prevent the formation and plugging of the line with gas hydrates. They are often injected concomitantly with other production chemicals such as corrosion and scale inhibitors. KHIs are specific low molecular weight water-soluble polymers with amphiphilic groups formulated with synergists and solvents. However, many corrosion inhibitors (CIs) are antagonistic to the KHI polymer, severely reducing the KHI performance. It would be preferable and economic if the KHI also could act as a CI. We have explored the use of maleic-based copolymers as KHIs as well as their use as film-forming CIs. KHIs were tested using a natural gas mixture in high pressure rocking cells using the slow constant cooling test method. A terpolymer from reaction of vinyl acetate:maleic anhydride copolymer with cyclohexy lamine and 3,3-di-n-butylaminopropylamine (VA:MA-60% cHex-40% DBAPA), gave excellent performance as a KHI, better than the commercially available poly(N-vinyl caprolactam) (PVCap). CO2 corrosion inhibition was measured by Linear Polarization Resistance (LPR) in a 1 litre CO2 bubble test equipment using C1018 steel coupons. The new terpolymer gave good CO2 corrosion inhibition in 3.6 wt% brine, significantly better than PVCap, but not as good as a commercial imidazoline-based surfactant corrosion inhibitor. The terpolymer also showed good corrosion inhibition efficiency at high salinity conditions, (density 1.12 g/cm3). VA:MA-60% cHex-40% DBAPA shifted the open-circuit potential to more positive values and significantly decreased the corrosion rate.
Top of line corrosion in gas-condensate pipelines
Authors: Seiersten M. , Dugstad A. , Nossen J. , Sendstad O. 
Published: November 2021

AbstractLow alloyed carbon steel is the only viable material of construction for long pipelines transporting unprocessed gas-condensate. The water that condenses is highly corrosive because it contains dissolved acid gases, i.e., CO2, H2S and organic acids like acetic and formic acid. The high velocity gas also contains droplets of water and condensate, and these will deposit if they hit the steel surface. Monoethylene glycol (MEG) injected to prevent ice and hydrates must be considered when predicting the composition and corrosivity of the aqueous phases in the pipeline. The liquids gathering at the bottom of the pipe have a higher heat capacity than the gas, and the temperature at the top of the pipe will be slightly lower than at the bottom. As the produced fluids cool during the transport from the hot wells to the process plant, water will condense on the cold pipe surface and more at the top than at the bottom. The literature on Top-of-line corrosion (ToLC) has grown steadily since the first reported case in 1960. There are also several prediction models for ToLC. This review is an overview of the main factors that cause ToLC and how these are modelled. Mass transfer from the aqueous phase at the bottom to the top contribute to the condensation. Despite the low MEG to water ratio in the gas due to the difference in vapour pressure, the fraction of MEG in the condensing water may be considerable. The concentration of MEG in the aqueous phase at the top depends on the mass transfer from bottom. The same is the case for organic acids. Liquid droplets entrained in the gas may deposit top of line and contribute to the chemistry of the aqueous phase. Models for ToLC must thus not only predict the composition of the condensing phases but also the mass transfer to be able to estimate the corrosion rate.
Effectiveness of common water-reducing admixtures in alkali-activated slag pastes with different types of activator
Authors: Bilek V , Iliushchenko V , Hruby P , Kalina L 
Published: November 2021

Abstract
Rheology of alkali-activated slag (AAS) is a very complex issue, where the activator nature as well as its dose play an important role. Moreover, the use of water-reducing admixtures in these systems is an issue, as they often do not work properly. This could be attributed to the high pH as well as to the surface chemistry of AAS. Therefore, lignosulfonate-, polynaphthalene- and polycarboxylate-based superplasticizers were used to modify AAS pastes with sodium waterglass, hydroxide and carbonate activator. These pastes were tested using a rotational rheometer in an oscillatory shear mode of increasing shear strain to observe the evolution of viscoelastic moduli and to determine the oscillatory stress corresponding to the linear viscoelastic region limit (“yield point”) and to the crossover point, where the storage modulus equals the loss modulus (“flow point”). In most cases, the used plasticizers did not improve the rheological properties; the only exception was the lignosulfonate one in sodium hydroxide-activated slag.
Fracture parameters of fly ash geopolymer mortars with carbon black and graphite filler
Authors: Simonova H , Mizerova C , Rovnanik P , Lipowczan M , Schmid P 
Published: November 2021

Abstract
In this study, the effect of carbon black and graphite filler on the crack initiation and fracture parameters of fly ash geopolymer mortar is investigated. The carbon black was added in the amount of 0.5 and 1.0% and graphite powder in the amount of 5 and 10% relative to the fly ash mass. The reference mixture without any filler was also prepared. The fracture characteristics were determined based on the results of the three-point bending test of prismatic specimens provided with an initial central edge notch. The fracture experiments were conducted at the age of 48 days. The vertical force (F), the displacement measured in the middle of the span length (d), and the crack mouth opening displacement (CMOD) were continuously recorded during the test. The records of fracture tests were subsequently evaluated using the effective crack model, work-of-fracture method, and double-K fracture model. The addition of both fine fillers led to a decrease in monitored mechanical fracture parameters in comparison with reference mortar.
Fibre-reinforced cementitious composite: parameter identification using Ohno shear beam test
Authors: Lehký D , Pukl R , Novák D , Lipowczan M 
Published: November 2021

Abstract
Computational-experimental methodology based on artificial neural networks used to identify the material parameters of fibre-reinforced cementitious composite is presented and applied for Ohno shear beam test. The aim is to provide techniques for an advanced assessment of the mechanical fracture properties of these materials, and the subsequent numerical simulation of components/structures made from them. The paper describes the development of computational and material models utilized for efficient material parameter determination with regards to a studied composite. The data is used in inverse analysis based on artificial neural networks together with sensitivity analysis which plays an important role in the process. Developed software tool FRCID-S is also briefly described.
Long period fibre gratings inscribed by sinusoidal intensity modulated femtosecond laser
Authors: Zhao Xiaofan , Li Hongye , Rao Binyu , Wang Meng , Wu Baiyi , Wang Zefeng 
Published: November 2021

Abstract
To the best of our knowledge, this is the first study to propose and verify a novel and simple direct inscription method for long-period fibre gratings (LPFGs) with an arbitrary grating period using a sinusoidal intensity modulated femtosecond laser. This method induces a sine refractive index modulation, which makes the LPFGs have no higher-order harmonic resonance that exists in the normal square-wave modulation method. This is beneficial for reducing the insertion loss of the LPFGs and optimising the transmission spectrum. Using this method, we also conveniently realise the inscription of superimposed, apodised, and chirped LPFGs. This work presents a simple but effective inscription scheme for various types of LPFGs using a femtosecond laser.
Generating a 3D optical needle array with prescribed characteristics
Authors: Zeng Yongxi , Yu Yanzhong , Chen Musheng , Wu Pinghui , Huang Han 
Published: November 2021

Abstract
Unlike the general optical needle along the optical axis, we propose a method to generate a three-dimensional (3D) array formed by optical needles with prescribed length and polarization direction. Moreover, the geometric model of the created array can be specified. With the aid of antenna array pattern synthesis theory and time reversal technology, a virtual uniform line source (ULS) antenna array arranged regularly near the confocal region of two objectives of high numerical apertures is employed to obtain the required illumination in the pupil plane for creating the desired focal fields. Numerical results demonstrate that there is a one-to-one correspondence between the focal field and the elements of the virtual ULS antenna array The length and polarization direction of the optical needles depend on the length and spatial direction of the virtual ULS antenna. The peculiarities of the focal field array, such as the polarization, length, number, spatial position and array structure, can be customized according to application requirements. The created optical needle array can be used for such applications as 3D synchronous particle acceleration and manipulation, and 3D parallel fabrication.
Layer and material-type dependent photoresponse in WSe2/WS2 vertical heterostructures
Authors: Fu ZhuangEn , Hill Josh W , Parkinson Bruce , Hill Caleb M , Tian Jifa 
Published: November 2021

Abstract
Transition metal dichalcogenide (TMD) heterostructures are promising for a variety of applications in photovoltaics and photosensing. Successfully exploiting these heterostructures will require an understanding of their layer-dependent electronic structures. However, there is no experimental data demonstrating the layer-number dependence of photovoltaic effects (PVEs) in vertical TMD heterojunctions. Here, by combining scanning electrochemical cell microscopy (SECCM) with optical probes, we report the first layer-dependence of photocurrents in WSe2/WS2 vertical heterostructures as well as in pristine WS2 and WSe2 layers. For WS2, we find that photocurrents increase with increasing layer thickness, whereas for WSe2 the layer dependence is more complex and depends on both the layer number and applied bias (Vb
). We further find that photocurrents in the WSe2/WS2 heterostructures exhibit anomalous layer and material-type dependent behaviors. Our results advance the understanding of photoresponse in atomically thin WSe2/WS2 heterostructures and pave the way to novel nanoelectronic and optoelectronic devices.
Tannin-furanic foams used as biomaterial substrates for SERS sensing in possible wastewater filter applications
Authors: Sabathi Gebhard , Reyer Andreas , Cefarin Nicola , Sepperer Thomas , Eckardt Jonas , Neubauer Jonas , Jan Wendisch Fedja , D’Amico Francesco , Vaccari Lisa , Tondi Gianluca , Musso Maurizio 
Published: November 2021

Abstract
Simple substrates for surface enhanced Raman spectroscopy (SERS), producible in a cost-efficient way, are of growing interest both for scientific and for environmental applications. In this study, we demonstrate the use of three types of bio-based tannin-furanic rigid foams as precursor materials for SERS substrates. Coated with a silver layer, these substrates allowed the detection of several well-known analytes in the mM regime by Raman spectroscopy. Specific optimization of the standard tannin-furanic foam morphology by tuning the chemical synthesis led to a smaller and more homogeneously distributed pore structure, supplying more active hot spot areas. Thus, we obtained a significant increase and a lower relative standard deviation (RSD) of the SERS signal recorded over the mapped SERS substrate area, for several analytes, in particular for Malachite Green dye. This work represents a feasibility study opening several potential applications of this biopolymers in fields such as the detection of water pollutants, virtually combining filtration and SERS capabilities driven by a controlled porosity.
Study on the hydrogen-induced delayed fracture behavior of Q-P980 and MS980
Authors: Zhao Wei-yan , Chen Wei-jian , Zhao Zheng-zhi , Kuang Shuang , Liu Jing-bao , Sun Lu 
Published: November 2021

Abstract
In this paper, the hydrogen diffusion behavior and hydrogen induced delayed fracture (HIDF) of Q-P980 (Q-P: Quenching and Partitioning) and MS980 (MS: Martensitic steel) steels were investigated using hydrogen penetration, slow strain rate tensile (SSRT) tests, thermal desorption spectroscopy (TDS) tests, fracture analysis, and microstructural examination in this paper. The austenite in Q-P980 is massive retained-austenite (RA) with low stability. The TRIP (Transformation Induced Plasticity) effect will occur in the process of strain and change into high carbon martensite. HIDF is caused by a substantial amount of surplus hydrogen being enriched at the border and flaws. The fracture has a broad cleavage surface and is a typical quasi-cleavage fracture. MS980 has been sufficiently tempered, resulting in a substantial quantity of distributed spherical cementite (150nm) precipitating around the lath martensite. This size and form of cementite may successfully trap hydrogen while maintaining the material’s mechanical characteristics. And tempering can effectively reduce the local stress level of steel, so MS980 has a very low HE susceptibility. HIDF is related to local stress and hydrogen accumulation. We suppose that Z is a constant and Z
C is a critical value which associated to σ and C
H (the local stress and local hydrogen concentration), rising as σ and C
H rises. The atomic bonds at the crack tip, lattice position and the phase interface will fracture when Z
C reaches a particular value Z. Tempering to minimize local stress and carbide precipitation to capture hydrogen are two strategies for reducing hydrogen embrittlement (HE) susceptibility, particularly for dislocation strengthened steel. Microalloying elements can generate precipitates that function as hydrogen traps and obstruct the HELP (Hydrogen Enhanced Localized Plasticity) process, lowering local stress and hydrogen accumulation.
Numerical study of POD-Galerkin-DEIM reduced order modeling of cardiac monodomain formulation
Authors: Khan Riasat , Ng Kwong T 
Published: November 2021

Abstract
The three-dimensional cardiac monodomain model with inhomogeneous and anisotropic conductivity characterizes a complicated system that contains spatial and temporal approximation coefficients along with a nonlinear ionic current term. These complexities make its numerical modeling computationally challenging, and therefore, the formation of an efficient computational approximation is important for studying cardiac propagation. In this paper, a reduced order modeling approach has been developed for the simplified cardiac monodomain model, which yields a significant reduction of the full order dynamics of the cardiac tissue, reducing the required computational resources. Additionally, the discrete empirical interpolation technique has been implemented to accurately estimate the nonlinearity of the ionic current of the cardiac monodomain scheme. The proper orthogonal decomposition technique has been utilized, which transforms a given dataset called ‘snapshots’ to a new coordinate system. The snapshots are computed first from the original system, and they encapsulate all the information observed over both time and parameter variations. Next, the proper orthogonal decomposition provides a reduced order basis for projecting the original solution onto a low-dimensional orthonormal subspace. Finally, a reduced set of unknowns of the forward problem is obtained for which the solution involves significant computational savings compared to that for the original system of unknowns. The efficiency of the model order reduction technique for finite difference solution of cardiac electrophysiology is examined concerning simulation time, error potential, activation time, maximum temporal derivative, and conduction velocity. Numerical results for the monodomain show that its solution time can be reduced by a significant factor, with only 0.474 mV RMS error between the full order and reduced dimensions solution.
Male courtship reduces the risk of female aggression in web-building spiders but varies in structure
Authors: Wignall Anne E , Herberstein Marie E 
Published: November 2021

AbstractMale courtship serves multiple functions in addition to inducing females to accept them as a mate. In predatory species, male courtship can function to reduce the risk of sexual cannibalism. This is particularly important in web-building spiders in which males risk being mistaken for prey when they enter the female’s predatory trap—the web—in order to commence courtship. Male spiders generate vibrations by shuddering in the female’s web. Shudder vibrations can delay female aggression, even toward prey struggling in the web. We predicted that shudder vibrations are highly conserved across species of web-building spider as males all face the same constraint of not being mistaken for prey by females. We examined how conserved shudder vibrations are across web-building spiders by testing whether female Trichonephila plumipes delay aggressive behavior toward real prey struggling in the web during playback of conspecific or heterospecific (Argiope keyserlingi) male shudder vibrations. We found that while conspecific shudder vibrations do indeed delay female predatory behavior, heterospecific male shudder vibrations do not. There is evidence of shudder or shudder-like vibrations in male courtship behavior across web-building spider families, but these vary in structure. This suggests that despite strong constraints on courtship signal design to separate predatory responses from sexual responses, there is additional selection driving the divergence of signals across distantly related spider species.
Mapping the Matrix: Understanding the Structure and Position of Social Work in Mental Health Services in England and Wales
Authors: Tucker Laura , Webber Martin , Jobling Hannah 
Published: November 2021

AbstractSocial work is one of the core professions within mental health services in the UK, though its position as local authority ‘outsider’ excludes it from health-based workforce planning, leaving the exact national composition of mental health social work shrouded in mystery. In the context of increasing demand and limited resources, this lack of clarity precludes effective use of the mental health workforce. This study aimed to map the provision of mental health social work across England and Wales. A cross-sectional design was used, with brief surveys issued to all local authorities and National Health Service trusts responsible for providing social work or mental health services. These surveys collected the number of mental health social workers in each agency and their employment contexts for subsequent descriptive statistical analysis. Responses were received from 96.6 percent of agencies, employing 6,584 social workers. Findings indicated that mental health social work varies widely across both nations, with little clear rationale for, or consistency in, how social work is structured within mental health services. While these findings establish the first robust framework for understanding the size and scope of mental health social work provision, further research is required to establish temporal and contextual understandings to inform future service planning.