bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrate Management for Hydrate Deposition in Gas-Filled Vertical Pipes
Authors: Sum Amadeu K. , Zhang Xianwei , Sa Jeong-Hoon , Lee Bo Ram , Austvik Torstein , Li Xiaoyun , M. Askvik Kjell 
Published: April 2019

Abstract
Deadlegs are defined as pipe sections in intermittent use for production or special services in oil/gas production systems. Deadlegs often pose hydrate control challenges to gas and oil production systems as the fluid inside is close to stagnant and therefore can be rapidly cooled by the environment without proper insulation or heat tracing. Water vapor can condense in the deadleg, resulting in a potential hydrate risk. Over time the deadleg may be blocked completely by hydrates. The hydrate challenges, if not properly managed, can cause severe consequences in terms of safety and cost for oil/gas productions. A systematic study has been performed to better understand the process and mechanism of hydrate deposition in deadlegs. To study hydrate deposition in deadlegs experimentally, laboratory scale deadleg systems were designed and built to consider pipe sizes of 1-, 2-, 3-, and 4-in. inner diameter and approximately 50 in. long. The pipes were gas-filled and saturated with water from a reservoir at the bottom of the pipe. The experimental work focused on measuring hydrate deposition, and in some cases, plugging, for different water reservoir temperatures (30 to 80 °C), pipe wall temperatures (-10 to 15 °C), and duration (1 to 84 days). The results from measurements provided insights into the dynamic process of hydrate deposition, such as the mechanism for hydrate deposition, plugging, and distribution along the pipe.
The Subsea Revolution: Execution Excellence Through Standardization
Authors: Gable Brent David , Amadeus Wolfgang 
Published: April 2019

Abstract
A revolutionary application of existing technology, driven by the downturn in the industry, has enabled operators to adopt the high-quality existing standards of service companies instead of implementing project-specific, single-use requirements and documentation. This has created economic viability through total expenditure (totex) reductions as well as early production benefits for operators. This paper showcases how one operator and supplier achieved a 12-month subsea tree delivery while minimizing cost through standardization.
Legacy project execution models make a 12-month subsea tree delivery unachievable while driving up costs through extended alignment phases, large project teams, and procurement of project-specific components. Achieving prealignment through robust documentation, technical workshops, and a unique approach to assessing risk of perceived gaps between organizations has proven successful in the execution of an offshore project in the Caspian Sea and clearly highlights the benefits of standardization.
An enhanced industry-standard offering leads to both competitive and sustainable advantages, ensuring marginal fields are economically viable. The objective of a standard system offering is delivering a subsea production system at maximum capital efficiency and minimal lead time to optimize operators' return on investment while driving industry-leading safety, peak reliability and uptime, and superior quality. The Caspian Sea project execution methodology will discuss the benefits achieved in using standard products in a subsea production system and elaborate on the potential further benefits this approach would have on a larger brownfield application.
Wave Energy Converter Arrays: Optimizing Power Production While Minimizing Environmental Effects
Authors: Raghukumar Kaus , McWilliams Samuel , Chang Grace , Roberts Jesse , Jones Craig 
Published: April 2019

Abstract
The nascent marine renewable energy (MRE) industry requires robust tools to maximize power output while evaluating the potential environmental effects of marine hydrokinetic (MHK) devices. Wave energy converter (WEC) devices in particular, are in early stages of development and may deploy a wide range of technologies to harness wave energy. The technical activities and processes used to assess WEC arrays for both power production and environmental effects requires streamlining to lower the levelized cost of wave energy projects and facilitate timely, cost-effective environmental review and compliance. A robust approach using numerical models to simulate the WEC devices and array layouts is presented that simultaneously evaluates power production and assesses environmental effects. "WEC-friendly" open-source numerical tools have been developed that are capable of assessing the environmental force on and potential changes to the environment caused by the energy extraction by WEC arrays. A case study is presented to demonstrate how the changes in WEC array configurations can be mapped and quantified using a validated model. A discussion of how changes in WEC devices and array configurations are developed to provide critical information on both engineering and environmental risk. This allows for optimization of WEC deployments to maximize power capture while minimizing environmental impacts.
Considerations and Strategies for Financing Integrated LNG-to-Power Projects
Authors: Viertl Béla , Guccione Danielle 
Published: April 2019

Abstract
The role of liquefied natural gas (LNG) in the global energy system is increasing. In 2000, 11 countries were importing LNG. By 2017, that number had risen to 40 (International Gas Union, 2017). In the Middle East alone, LNG imports have increased by more than 380% over the last three years (S&P Global Platts, 2017). This trend is expected to continue as countries throughout the region, along with others across Asia, Africa, and South America seek to capitalize on cleaner burning and abundant natural gas supplies worldwide.
With increasing population growth and deficits in power generation capacity in many developing parts of the globe, the LNG-to-power concept has emerged as an important driver of future sustainability. However, the costs involved in transitioning power projects to make use of LNG are enormous. One significant challenge that these projects face is the co-development and potential co-financing of the LNG plant, along with supply, distribution and underlying power infrastructure. LNG-to-power projects can also potentially suffer from "project-on-project" risk due to the interdependency of the construction and commissioning of facilities and infrastructure.
Overall, the ability to secure financing from a variety of debt and equity sources throughout the project lifecycle is critical to success. Innovative project financing structures allow for the generation of large debt capacities, while passing project risk to the lenders. In such cases, sponsors are able to assume limited recourse after project start-up and in many cases, enjoy flexibility of loan repayment, thus contributing to overall project economics. Co-financing also alleviates investment risk and helps raise capital at a relatively low cost, which benefits sponsors and investors alike. Financing solutions must be tailored to meet the needs of the project, with risk and returns being borne by the sponsor and different classes of investors (i.e., equity holders, debt providers, quasi-equity investors, etc.).
This paper will discuss the many challenges that must be addressed in order to bring LNG-to-power projects to life, with a particular focus on the unique risk elements that are presented to lenders and investors throughout development.
The Effect of Bayesian Updating in the Hazard Assessment of Submarine Landslides
Authors: Das Roneet , Varela Patricia , Medina-Cetina Zenon 
Published: April 2019

Abstract
This paper introduces a Bayesian methodology to conduct landslide hazard assessment. The proposed approach demonstrates how a probabilistic method can incorporate evolving information about a site for progressively more certain geotechnical characterization. The probabilistic method presented herein is called the Bayesian framework, which integrates a physics-based model defining certain characteristic or phenomenon related to the site, state of evidence on the model parameters, and experimental observations to produce an updated state of evidence on the model parameters and more confident model predictions. This study focuses on landslide geohazard of a site using the physics-based infinite block slope model to estimate the probability of submarine slope failure. The probability of failure against sliding is estimated using the predictions of the infinite slope model under static loading condition for different states of evidence on the model parameters. A state of evidence reflects the level of knowledge about a parameter which describes an attribute of the site such as bathymetry or geotechnical properties of the in-situ soil. This research studies the influence of increasing states of evidence on the confidence gain in model predictions and subsequent updates in the estimates of probability of failure. Predictions based on the infinite slope model are made using the Monte-Carlo algorithm through random sampling of the model parameters. The state of evidence on the model parameters is incorporated in the algorithm by considering the model parameters as random variables following a probability distribution function. These probability distributions, also known as the prior probability distributions, represent the initial state of evidence on the model parameters. The Bayesian framework is used to conduct sequential calibration of the infinite slope model using synthetically generated data on the shear strength of the in-situ soil. These experimental observations represent the state of evidence on the soil conditions. In this paper two sets of data containing 5 and 20 data ‘sample’ points, respectively are used to calibrate the infinite slope model. Calibration of the model results in an updated state of evidence on the model parameters and generates a new set of probability distributions known as the posterior probability distributions. The posterior distributions more accurately describe the potential range of value that the parameters can attain. Comparison between the model predictions based on the initial state of evidence and the updated states of evidence shows a gain in the certainty of the model predictions.
Behavior of Laterally Loaded Offshore Wind Monopiles in Sands
Authors: Gilbert Robert , Huang Yunhan , Stokoe Kenneth , Wang Shin-Tower , Munson James , Bauer Jonas , Hosseini Reihaneh , Hussien Ahmed , Fadaifard Hossein , O'Connell Daniel 
Published: April 2019

Abstract
The conventional design methods for laterally loaded offshore foundations in sand, API RP 2GEO (2014) and DNV (2018), were not developed for wind turbine monopiles that experience lateral loads imposing relatively small lateral displacements in service. This paper presents the results of research to evaluate the suitability of existing guidance for the design of laterally loaded monopiles at small displacements and to provide recommendations for improving design methods for monopile foundations. The research included applying existing techniques to measure the non-linear stiffness of sand at small shear strains, utilizing a three-dimensional finite element method (3-D FEM) model that incorporates the non-linear stiffness of sand to predict the lateral response of a monopile, testing the proposed approach with foundation model tests in the laboratory, and applying the proposed approach to the lateral load tests conducted on Mustang Island in 1966 that provided the original basis for current design methods.
The following major conclusions are drawn from this research:
Model tests and field tests consistently show that the conventional p-y curves from current design practice tend to underestimate the initial stiffness for laterally loaded piles and fail to capture the non-linearity of the stiffness at small lateral displacements. A 3-D FEM model that incorporates a constitutive model to characterize the small-strain properties of sand, including the maximum shear stiffness at very small strains and the relationships between shear stiffness and both shear strain and effective confining stress, is capable of predicting the response of laterally loaded piles both at model and field scales.
These conclusions lead to the following recommendations for the design of laterally loaded monopiles in sand:
Exercise caution in using conventional p-y curves for sand to predict the performance of offshore wind turbine monopiles in service. The conventional p-y curves used in current design practice do not adequately predict the stiffness and non-linearity of laterally loaded piles at the small lateral displacements relevant for offshore wind turbine monopiles in service. Measure directly or empirically establish the in-situ maximum ("small-strain") shear modulus, the relationship between shear modulus and shear strain, and the relationship between shear modulus and effective confining pressure. These small-strain properties are needed to predict the stiffness and non-linearity of laterally loaded piles at small lateral displacements. Establish improved p-y curves to be used in design directly from 3-D FEM analyses using representative properties of the sand in-situ at small strains.
The Spectral Radius Formula for Fourier–Stieltjes Algebras
Authors: Ohrysko Przemysław , Roginskaya Maria 
Published: April 2019

AbstractIn this short note we first extend the validity of the spectral radius formula, obtained by M. Anoussis and G. Gatzouras, for Fourier–Stieltjes algebras. The second part is devoted to showing that, for the measure algebra on any locally compact non-discrete Abelian group, there are no non-trivial constraints among three quantities: the norm, the spectral radius, and the supremum of the Fourier–Stieltjes transform, even if we restrict our attention to measures with all convolution powers singular with respect to the Haar measure.
Disqualification of Company Directors: Safeguarding the Public Interest in the Kenyan Investment Market
Authors: Mwaura Kiarie 
Published: April 2019

Over the last two decades, Africa has gone through tremendous economic transformation. It was only in 2004 when the Prime Minister for the UK, Tony Blair, described Africa as the “scar on the conscience of the world” when he was establishing the Commission for Africa. A decade later, he described Africa as “the most exciting continent on the planet because of its opportunities.” Within less than twenty years, the continent has become the world’s most rapidly growing economic region. This economic growth has been attributed largely to the active private sector. Kenya, for example, has realized the highest growth rate in the East African region due to its private sector, which makes a major contribution to the country’s GDP. For this growth rate to continue, African countries need to create competitive legal frameworks that continue to attract investors and protect their interests.One of such is the disqualification framework for company directors that seeks to protect the public by placing a prohibition on a miscreant director from being involved, for a specific period, in the management of companies. An efficient disqualification framework also prevents people without the necessary qualifications from managing companies and deters those who might be tempted to engage in fraudulent activities. Without a strict disqualification framework, investors are unlikely to be attracted to a country, as they risk losing their investments when their companies are managed by incompetent, negligent, or fraudulent directors, especially those with a track record of mismanaging other companies. This philosophy was captured clearly by the Kenyan Government when it enacted the Companies Act 2015 and stated that one of its key objectives was to facilitate commerce, industry, and other socio-economic activities. It is against this backdrop that this Article examines whether the disqualification framework under the Companies Act 2015 is adequate to protect the interests of investors. This framework is contrasted with the one that existed under the repealed Companies Act 1962 with a view to assessing whether the reforms are likely to bring about the desired changes.
Aeromagnetic Map Constrains Jurassic-Early Cretaceous Synrift, Break Up, and Rotational Seafloor Spreading History in the Gulf of Mexico
Authors: James Pindell , Ernesto Miranda C. , Alejandro Cerón , Leopoldo Hernandez 
Published: April 2019

Abstract
We present a reduced-to-pole, total magnetic intensity map derived from merged aeromagnetic surveys in and around the Gulf of Mexico. Most of the deep central Gulf crust has a magnetic pattern of orthogonally intersecting features similar to, and interpreted as, fracture zones and ridge segments of oceanic crust formed by seafloor spreading. This spreading or drift phase occurred after the primary synrift phase of continental stretching across the greater Gulf of Mexico region, and thus the ocean crust rests within a broader zone of stretched continental crust with Yucatán, western Florida, the southern USA, and eastern Mexico forming the surrounding continental margins. We identify three regional magnetic anomaly trends that can be used to constrain the Gulf of Mexico’s Late Jurassic through earliest Cretaceous spreading history. A central magnetic anomaly trend is interpreted to accord with the later increments and cessation of seafloor spreading, for which a stage pole of rotation is estimated. Two flanking magnetic anomaly trends to the north and south of the central one, respectively, occur just basin-ward from the inferred depositional limits of autochthonous Callovian-Early Oxfordian salt. These anomalies appear to define the landward limits of oceanic crust in the northern and southern Gulf, and probably lie in crust that is medial or Late Oxfordian in age. They have similar mapped patterns that can be reconstructed onto one another and hence are probably genetically related but separated by spreading. These landward anomalies are best fit around a different stage pole than the central anomaly; thus the rotation pole appears to have jumped during spreading in the Gulf. Seismic reflection data show that the two outer anomalies occur at the basement “step ups” to the oceanic crust or the basinward shoulders of the “outer marginal troughs.” Until specific magnetic source modelling is done on the outer anomaly pair, we favor an edge-effect interpretation caused by the intrusive interface between Oxfordian oceanic crust and serpentinized and exhumed subcontinental mantle, the latter of which we infer forms the step ups to the oceanic crust. In addition, the aeromagnetic map shows a north-south trending “Campeche Magnetic Anomaly” downslope from the western shelf edge of Yucatán that we argue helps to constrain the reconstruction of Yucatán along Texas at the start of the synrift stage. Thus, the aeromagnetic map provides vital insights into the kinematics of all three stages of the basin's development, namely the synrift, the drift, and the interpreted intervening transitional phase of crustal hyperextension/mantle exhumation along the Gulf’s magma-poor continent-ocean transitions.
Pre-Albian Biostratigraphical and Paleoecological Observations from the De Soto Canyon Area; Gulf of Mexico, USA
Authors: Weber Ryan D. , Parker Brandon W. 
Published: April 2019

Abstract
A biostratigraphical review of eight exploration boreholes located within the De Soto Canyon protraction area in the Gulf of Mexico yields a repeatable and predictive evolutionary and paleoecological sequence with implications to paleogeography. The Oxfordian section within these boreholes contains primitive planktic foraminifera such as Globuligerina oxfordiana. Near the end of the Kimmeridgian (or slightly above the nannofossil Calcivascularis cassidyi extinction), nannofossils are of low abundance, and dominated by Cyclagelosphaera spp. Weakly developed benthic foraminifera abundance gives rise to Reinholdella A which is coincident with a nannofossil dominance switch to Polycostella spp. Planktic foraminifera are not observed in this section
In the overlying section, the extinction of nanno-fossil genus Polycostella, the origination and dominance of Nannoconus, and minute benthic foraminifera gradually increase. Here, the suggested datum, Polycostella beckmanii extinction, is observed consistently higher than the Reinholdella A extinction in the early Tithonian. The fossil assemblage change through this section suggests a change in water masses, which has implications to major reorganization in oceanic circulation.
The Lower Cretaceous continues with multiple nannofossil originations that persist into the Valangin-ian. Here, a significant, diverse, and abundant benthic foraminifera and ostracod assemblage occurs in multiple, rapid abundance increases followed by gradual upward decreases, suggesting cyclical change in the shallower, upslope paleoenvironments. The cause of cyclical changes is unclear and may be the result of sea level change, progradation, and/or changes in ocean composition.
The Hauterivian to Aptian section varies greatly in thickness with the maximum thickness in the northern De Soto Canyon area and thinning to the south. Nannoconus continues to dominate the nannofossil assemblage through the Aptian; benthic foraminifera and ostracods disappear rapidly during the Hauterivian and remaining sparse until the Albian when there is an increase of Nezzazata spp. The significance of these fossil sequences and respective assemblages are discussed in a paleoecological and paleogeographical context, which has implications to depositional history and correlation.
Enzyme‐Instructed Self‐Assembly (EISA) and Hydrogelation of Peptides
Authors: Gao Jie , Zhan Jie , Yang Zhimou 
Published: April 2019

AbstractSelf‐assembly is a powerful tool for constructing supramolecular materials for many applications, ranging from energy harvesting to biomedicine. Among the methods to prepare supramolecular materials for biomedical applications, enzyme‐instructed self‐assembly (EISA) has several advantages. Herein, the unique properties and advantages of EISA in preparing biofunctional supramolecular nanomaterials and hydrogels from peptides are highlighted. EISA can trigger molecular self‐assembly in situ. Therefore, using overexpression enzymes in disease sites, supramolecular materials can be formed in situ to improve the selectivity and efficacy of the treatment. The precursor may be involved during the EISA process, and it is actually a two‐component self‐assembly process. The precursor can help to stabilize the assembled nanostructures of hydrophobic peptides formed by EISA. More importantly, the precursor may determine the outcome of molecular self‐assembly. Recently, it was also observed that EISA can kinetically control the peptide folding and morphology and cellular uptake behavior of supramolecular nanomaterials. With the combination of other methods to trigger molecular self‐assembly, researchers can form supramolecular nanomaterials in a more precise mode and sometimes under spatiotemporal control. EISA is a powerful and unique methodology to prepare supramolecular biofunctional materials that cannot be generated from other common methods.