bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Damping on VIV Response in Umbilicals and Flexible Risers
Authors: Hansen-Zahl Kay , Henøen Veronica , Baarholm Rolf , Parsinejad Farzan , Constantinides Yiannis 
Published: October 2015

The fatigue life assessment of umbilicals and flexible risers due to vortex-induced vibrations (VIV) require special attention to the structural properties of the flexible bundle due to stick/slip behavior of helical elements in bending. The VIV response on umbilicals and flexible risers is complex, and it is controlled by several parameters. Structural damping is one of these parameters, but this is typically calculated based on the material damping of the structure. Similar to flexible risers and umbilicals, hysteresis damping due to the stick/slip behavior in the helical layers may be significant for cable structures. The purpose of this study is to evaluate the effect of the hysteresis damping on VIV response, and to demonstrate a procedure for consistent VIV fatigue analysis of flexible risers and umbilicals.
The stick/slip hysteresis varies with varying contact force, and the contact force is dependent on internal pressure and effective tension. The effect of varying these parameters is included in the study. Furthermore, the study includes different riser system configurations and current profiles.
In this paper, the stick/slip hysteresis has been established for two umbilicals and two flexible risers, with varying internal pressure and effective tension. Combined with five different configurations (both shallow and deep water) and 16 different current profiles, the VIV modes have been calculated and the corresponding stick/slip modal damping ratio has been established.
Finally, using fatigue current profiles, fatigue life estimates have been made based on different damping ratios, including the estimated stick/slip damping ratio.
The study presented in this paper has been carried out as part of the Norwegian Deepwater Programme (NDP).
Mooring Analysis of a Turret Moored FPSO in a Squall Environment
Authors: Oberlies Robert , Guha Amitava , Slocum Scott 
Published: October 2015

The transient dynamic response of a FPSO in a squall environment is dependent on several input parameters. Because the response’s dependence on these input parameters is unclear prior to performing the analysis, a large number of parameter combinations need to be considered to find the combination that gives a worst-case load or response as required by reference [1]. Because the required time-domain simulations are computationally intensive, there is often a practical need to limit the number of simulations that are performed, raising questions about how many are necessary to meet the analysis objectives.
This study investigates the effect of different squall scenarios on a turret moored FPSO in the West African offshore environment. A large number of cases with selected vessel headings, squall types, squall approach directions and vessel drafts are studied and parameters affecting the critical mooring loads and turret positions are identified. Possible reductions in the load case matrix along with a sensitivity study of a few parameters affecting the results are also discussed.
Two-Dimensional Numerical Simulations of Wall Proximity Effect on Cylinders
Authors: Li Zhong , Jaiman Rajeev K. , Tham Mun Yew Daniel , Khoo Boo Cheong 
Published: October 2015

In the oil and offshore industry, it is a common phenomenon that subsea pipelines placed on or in the proximity of the seabed are exposed to underwater waves and currents. Free spanning in sections along the length of pipeline frequently results from the erosion of sediments or the irregular terrain. This scenario can be modelled by a much more simplified set-up, where a circular cylinder situated near a plane wall is subjected to the oncoming flows. In this case, unlike the well-studied isolated cylinder, the hydrodynamic forces exerting on the near-wall cylinder will depend largely upon on the gap between the wall and the cylinder itself.
In this work, flows around a stationary and a freely vibrating two-dimensional circular cylinder near a plane boundary are numerically simulated using the Immersed Interface Method (IIM) and Finite Element Method (FEM) with Arbitrary Lagrangian-Eulerian (ALE) approach, respectively. In the case of a stationary cylinder, instead of a fixed wall, a moving wall with no-slip boundary is considered in order to avoid the complex involvement of the boundary layer and to focus only on the shear-free wall proximity effects in evaluating the lift and drag forces in the low Reynolds number regime (Re ≤ 200), with the aim of validating our IIM solver since it is the first time to apply IIM in solving flows past a near-wall cylinder. The gap ratio e/D is typically taken from 0.1 to 2.0 in this part of studies, where e denotes the gap between the cylinder and the wall and D denotes the diameter of the cylinder. The key findings are that the mean drag coefficient increases and peaks at e/D = 0.5 with the increase of e/D and keeps decreasing from e/D = 0.5 to e/D = 2.0, while the mean lift coefficient decreases monotonically with the increase of e/D. In the case of the freely vibrating cylinder in both transverse and in-line directions, the fixed wall is used to include the shear-layer effect from the bottom wall in considering the near-wall vortex-induced vibration (VIV) by using FEM with ALE approach. It can be concluded from our observations that when the cylinder is brought closer to the wall from e/D = 10.0 to e/D = 0.75, the peak transverse displacement amplitude decreases, while the peak in-line displacement amplitude increases, by greater than 20 times that of an isolated cylinder.
Strategies for Quantifying the Installation Reliability of Skirted Subsea Foundations
Authors: Bransby M. F. , White D. J. , Xie Y. 
Published: October 2015

An increasing number of well-related and pipeline-related subsea structures (e.g. PLETs, ILTs, buckle initiators, etc.) are being placed on the seabed. Many of these structures are founded on unskirted and skirted mudmat foundations as a cost-effective, low risk solution.
Much attention has been placed in the literature on the geotechnical capacity of subsea mudmat foundations, but less attention on how these types of foundations are installed. In some soil conditions this can be a critical aspect of design: the requirement to add skirts to ensure sufficient foundation capacity comes with the penalty of increasing the necessary foundation weight to ensure that these skirts can be reliably installed. The addition of weight to a foundation increases its installation and fabrication cost and so requires careful treatment in design. As an example of this design optimization process, attention is given to dealing with uncertainty associated with variable soil conditions. It is shown how probabilistic geotechnical analysis can give a clearer perspective of cost and risk and how carefully targeted site investigation can also be used in this context.
Vortex-Induced Motions of a Model Scale Column Stabilized Floater With Round Columns in Calm Water and Random Waves
Authors: Pontaza Juan P. , Baar Job , Liu Nicole 
Published: October 2015

When an offshore platform is exposed to a steady current, alternating vortices are shed from its aft at a regular period, creating oscillatory hydrodynamic forces. Under these forces, the platform experiences vortex-induced motions (VIM) close to its natural period. VIM still poses a design challenge for new deep-water platform moorings and risers. VIM imparts cyclic fatigue loads on the riser’s hang off and touchdown points and on the mooring chains — and an accurate prediction of VIM is important in estimating and allocating fatigue damage budgets to the risers and mooring chains.
High-performance computing numerical simulation tools are used to simulate the VIM response of a 1:50 model scale semisubmersible with round columns. Computational fluid dynamics (CFD) coupled to a structural model is used to predict the VIM response for a range of flow conditions and headings, including wave action. The simulation results are compared side-by-side to the measured response from model scale physical measurements and good agreement instills confidence towards full-scale simulations. The simulation results confirm that inclusion of wave action, in the form of a background sea state, results in diminished VIM.
A novel approach to background subtraction in contrast‐enhanced dual‐energy digital mammography with commercially available mammography devices: Polychromaticity correction
Authors: Contillo Adriano , Di Domenico Giovanni , Cardarelli Paolo , Gambaccini Mauro , Taibi Angelo 
Published: October 2015

Purpose:Contrast‐enhanced digital mammography is an image subtraction technique that is able to improve the detectability of lesions in dense breasts. One of the main sources of error, when the technique is performed by means of commercial mammography devices, is represented by the intrinsic polychromaticity of the x‐ray beams. The aim of the work is to propose an iterative procedure, which only assumes the knowledge of a small set of universal quantities, to take into account the polychromaticity and correct the subtraction results accordingly.Methods:In order to verify the procedure, it has been applied to an analytical simulation of a target containing a contrast medium and to actual radiographs of a breast phantom containing cavities filled with a solution of the same medium.Results:The reconstructed densities of contrast medium were compared, showing very good agreement between the theoretical predictions and the experimental results already after the first iteration. Furthermore, the convergence of the iterative procedure was studied, showing that only a small number of iterations is necessary to reach limiting values.Conclusions:The proposed procedure represents an efficient solution to the polychromaticity issue, qualifying therefore as a viable alternative to inverse‐map functions.
Analytic image reconstruction from partial data for a single‐scan cone‐beam CT with scatter correction
Authors: Min Jonghwan , Pua Rizza , Kim Insoo , Han Bumsoo , Cho Seungryong 
Published: October 2015

Purpose:A beam‐blocker composed of multiple strips is a useful gadget for scatter correction and/or for dose reduction in cone‐beam CT (CBCT). However, the use of such a beam‐blocker would yield cone‐beam data that can be challenging for accurate image reconstruction from a single scan in the filtered‐backprojection framework. The focus of the work was to develop an analytic image reconstruction method for CBCT that can be directly applied to partially blocked cone‐beam data in conjunction with the scatter correction.Methods:The authors developed a rebinned backprojection‐filteration (BPF) algorithm for reconstructing images from the partially blocked cone‐beam data in a circular scan. The authors also proposed a beam‐blocking geometry considering data redundancy such that an efficient scatter estimate can be acquired and sufficient data for BPF image reconstruction can be secured at the same time from a single scan without using any blocker motion. Additionally, scatter correction method and noise reduction scheme have been developed. The authors have performed both simulation and experimental studies to validate the rebinned BPF algorithm for image reconstruction from partially blocked cone‐beam data. Quantitative evaluations of the reconstructed image quality were performed in the experimental studies.Results:The simulation study revealed that the developed reconstruction algorithm successfully reconstructs the images from the partial cone‐beam data. In the experimental study, the proposed method effectively corrected for the scatter in each projection and reconstructed scatter‐corrected images from a single scan. Reduction of cupping artifacts and an enhancement of the image contrast have been demonstrated. The image contrast has increased by a factor of about 2, and the image accuracy in terms of root‐mean‐square‐error with respect to the fan‐beam CT image has increased by more than 30%.Conclusions:The authors have successfully demonstrated that the proposed scanning method and image reconstruction algorithm can effectively estimate the scatter in cone‐beam projections and produce tomographic images of nearly scatter‐free quality. The authors believe that the proposed method would provide a fast and efficient CBCT scanning option to various applications particularly including head‐and‐neck scan.
Genome Sequences of Five Additional Brevibacillus laterosporus Bacteriophages
Authors: Merrill Bryan D. , Berg Jordan A. , Graves Kiel A. , Ward Andy T. , Hilton Jared A. , Wake Braden N. , Grose Julianne H. , Breakwell Donald P. , Burnett Sandra H. 
Published: October 2015

ABSTRACT

Brevibacillus laterosporus
has been isolated from many different environments, including beehives, and produces compounds that are toxic to many organisms. Five
B. laterosporus
phages have been isolated previously. Here, we announce five additional phages that infect this bacterium, including the first
B. laterosporus
siphoviruses to be discovered.
Complete Genome Sequence of Streptococcus agalactiae Serotype III, Multilocus Sequence Type 283 Strain SG-M1
Authors: Mehershahi Kurosh S. , Hsu Li Yang , Koh Tse Hsien , Chen Swaine L. 
Published: October 2015

ABSTRACT

Streptococcus agalactiae
(group B
Streptococcus
) is a common commensal strain in the human gastrointestinal tract that can also cause invasive disease in humans and other animals. We report here the complete genome sequence of
S. agalactiae
SG-M1, a serotype III, multilocus sequence type 283 strain, isolated from a Singaporean patient suffering from meningitis.
Whole-Genome Sequence of Staphylococcus aureus S54F9 Isolated from a Chronic Disseminated Porcine Lung Abscess and Used in Human Infection Models
Authors: Aalbæk Bent , Jensen Louise Kruse , Jensen Henrik Elvang , Olsen John Elmerdahl , Christensen Henrik 
Published: October 2015

ABSTRACT

We obtained a draft genome sequence of
Staphylococcus aureus
strain S54F9, which was isolated from a chronic disseminated porcine lung abscess and used in porcine infection models. Genes coding for a number of toxins, including enterotoxins and superantigen, were demonstrated in this strain.
Draft Genome Sequence of the Polychlorinated Biphenyl-Degrading Bacterium Pseudomonas stutzeri KF716 (NBRC 110668)
Authors: Hirose Jun , Yamazoe Atsushi , Hosoyama Akira , Kimura Nobutada , Suenaga Hikaru , Watanabe Takahito , Fujihara Hidehiko , Futagami Taiki , Goto Masatoshi , Furukawa Kensuke 
Published: October 2015

ABSTRACT

Pseudomonas
stutzeri KF716 (NBRC 110668) utilizes biphenyl as a sole source of carbon and energy and degrades polychlorinated biphenyls. Here, we report the first draft genome sequence of a biphenyl-degrading strain of the species
P. stutzeri
.
Draft Genome Sequence of Yellow Pigmented Jeotgalibacillus alimentarius JY-13
T
, the First Halophile Strain of the Genus
Jeotgalibacillus
Authors: Yaakop Amira Suriaty , Chan Kok-Gan , Gan Han Ming , Goh Kian Mau 
Published: October 2015

ABSTRACT

Jeotgalibacillus alimentarius
JY-13
T
(=KCCM 80002
T
= JCM 10872
T
) is a moderate halophile. In 2001, this was the first strain of the newly proposed
Jeotgalibacillus
genus. The draft genome of
J. alimentarius
was found to consist of 32 contigs (
N
50
, 315,125 bp) with a total size of 3,364,745 bp. This genome information will be helpful for studies on pigmentation as well as applications for this bacterium.
Draft Genome Sequence of Burkholderia cordobensis Type Strain LMG 27620, Isolated from Agricultural Soils in Argentina
Authors: Draghi Walter Omar , Mancini Villagra Ulises M. , Wall Luis Gabriel , Zorreguieta Angeles 
Published: October 2015

ABSTRACT

Bacteria of the genus
Burkholderia
are commonly found in diverse ecological niches in nature. We report here the draft genome sequence of
Burkholderia cordobensis
type strain LMG 27620, isolated from agricultural soil in Córdoba, Argentina. This strain harbors several genes involved in chitin utilization and phenol degradation, which make it an interesting candidate for biocontrol purposes and xenobiotic degradation in polluted environments.
Draft Whole-Genome Sequence of
Xenorhabdus
sp. Strain GDc328, Isolated from the Indigenous South African Nematode Host
Steinernema khoisanae
Authors: Soobramoney Lee-Anne O. , Featherston Jonathan , Gray Vincent M. 
Published: October 2015

ABSTRACT

Here, we describe the draft genome sequence of
Xenorhabdus
sp. GDc328, an endosymbiont of the native South African entomopathogenic nematode host,
Steinernema khoisanae
. The total genome size of the bacteria is 4.09 Mb. The genome comprises a total of 3,608 genes with a molecular G+C content of 44.64%.
Draft Genome Sequence of Aeromonas caviae Strain 429865 INP, Isolated from a Mexican Patient
Authors: Padilla Juan Carlos A. , Bustos Patricia , Castro-Escarpulli Graciela , Sánchez-Varela Alejandro , Palma-Martinez Ingrid , Arzate-Barbosa Patricia , García-Pérez Carlos A. , López-López María de Jesús , González Víctor , Guo Xianwu 
Published: October 2015

ABSTRACT

Aeromonas caviae
is an emerging human pathogen. Here, we report the draft genome sequence of
Aeromonas caviae
strain 429865 INP which shows the presence of various putative virulence-related genes.
Rapid diagnostic pathways for suspected colorectal cancer: views of primary and secondary care clinicians on challenges and their potential solutions
Authors: Redaniel Maria Theresa , Ridd Matthew , Martin Richard M , Coxon Fareeda , Jeffreys Mona , Wade Julia 
Published: October 2015

ObjectivesTo ascertain the challenges associated with implementation of the 2-week wait referral criteria and waiting time targets for colorectal cancer and to identify recommendations for improvements to the pathway.DesignQualitative research using semistructured interviews and applying thematic analysis using the method of constant comparison.Setting10 primary care surgeries and 6 secondary care centres from 3 geographical areas in the England.ParticipantsPurposive sample of 24 clinicians (10 general practitioners (GPs), 7 oncologists and 7 colorectal surgeons).ResultsGPs and specialists highlighted delays in patient help-seeking, difficulties applying the colorectal cancer referral criteria due to their low predictive value, and concerns about the stringent application of targets because of potential impact on individual care and associated penalties for breaching. Promoting patient awareness and early presentation, clarifying predictive symptoms, allowing flexibility, optimising resources and maximising care coordination were suggested as improvements.ConclusionsChallenges during diagnosis and treatment persist, with guidelines and waiting time targets producing the perception of unintended harms at individual and organisational levels. This has led to variations in how guidelines are implemented. These require urgent evaluation, so that effective practices can be adopted more widely.
QUASI-EXPERIMENTAL STUDY OF A LEARNING COLLABORATIVE TO IMPROVE PUBLIC PRESCHOOL QUALITY AND CHILDREN'S LANGUAGE OUTCOMES IN CHILE
Authors: Arbour MaryCatherine , Yoshikawa Hirokazu , Atwood Sidney , Duran Francis Romina , Godoy Felipe , Trevino Ernesto , Snow Catherine E 
Published: October 2015

BackgroundDecades of research shows that early childhood interventions can positively impact children's short- and long-term health, academic and economic outcomes, but that interventions' effectiveness depend on their quality. Interest in continuous quality improvement (CQI) methods is rising among early childhood clinicians, educators and policymakers. We report on a study that integrated CQI into an existing professional development program that aimed to improve the quality of preschool education in Chile and the outcomes of participating children.ObjectivesTo analyze how CQI methods can be applied in education to impact child development, in the context of a project centered on literacy instructional strategies supported by health, socio-emotional skills and family involvement.MethodsTeachers from 40 low-income classrooms received training in instructional strategies. A subset of 18 early adopters participated in a Collaborative that taught CQI methods and facilitated shared learning. Children's language skills were assessed at the beginning and end of a 2 year period using an internationally validated test. Quasi-experimental methods (propensity scores and inverse-propensity weighting) were used to estimate the impact of professional development in instructional strategies combined with CQI methods versus professional development in instructional strategies alone.ResultsChildren in classrooms whose teachers received professional development in language instruction plus CQI methods had larger increases in language skills (vocabulary, effect size 0.31, p<0.05) than children whose teachers received language instructional strategies alone.ConclusionsCQI may be a valuable addition to promote change via professional development in low-income schools in Chile and warrant further examination for early childhood interventions in diverse contexts globally.
IDENTIFYING PRIORITIES FOR IMPROVED CHILD HEALTHCARE: A MIXED METHODS ANALYSIS OF SAFETY INCIDENT REPORTS
Authors: Rees Philippa , Edwards Adrian , Powell Colin , Williams Huw , Hibbert Peter , Makeham Meredith , Luff Donna , Parry Gareth , Sheikh Aziz , Donaldson Liam , Carson-Stevens Andrew 
Published: October 2015

BackgroundGlobally children are failed on numerous indicators of care quality, most of which is provided in the primary care setting. There is a paucity of research and development to explain iatrogenic harm in the primary care setting, not least safety events involving children.ObjectivesWe identified priority issues (by frequency and level of harm) reported by clinicians from the England and Wales National Reporting and Learning System (NRLS). The concepts and content within reports empirically informed a systems-level Driver diagram for improvement of child health.MethodsWe undertook a retrospective cross-sectional mixed methods study of safety incident reports from primary care involving ‘unwell’ children between 2003–2013. We classified incident types, contributory factors, and harm outcomes. Data underwent exploratory analysis to explore the relationship between variables, and thematic analysis provided in-depth contextual insights. Subject matter experts identified key drivers for improvement.ResultsOf 2191 incidents identified, priority improvement areas included: medication provision in the community pharmacy setting; diagnosis, assessment, and timely referral of acutely unwell children in out of hours care settings; and communication with and about the child. Reported causes are outlined in the attached Ishikawa diagrams (figures 1–3) and the related Driver diagram (figure 4) summarises opportunities to mitigate priority concepts.ConclusionsAnalysis of incident reports can be used to inform national-level improvement initiatives when there is a paucity of existing available evidence. Further validation and development of the proposed designs are needed with the clinical teams responsible for care delivery.Figure 1Ishikawa diagram illustrating the factors and incidents frequently reported as contributing to medication incidents.Figure 2Ishikawa diagram illustrating the factors and incidents frequently reported as contributed to diagnosis, assessment, and referral incidents.Figure 3Ishikawa diagram illustrating the factors and incidents frequently reported as contributing to communication incidents.Figure 4Driver diagram illustrating opportunities to improve the safety of primary care for children.