bluuebunny/crossref_metadata_2025_split huggingface dataset:
2D Numerical Viscous Predictions of Wave Impact Effects on an Idealized Seawall Rooted in Large Scale Experiments (1:4)
Authors: Tremblay Olivier G. , Frandsen Jannette 
Published: October 2015

This study aims to investigate the free-surface flow involved in a wave impact and the vibrational characteristics of an idealized seawall to achieve an improved insight in the design of seawalls and coastal infrastructures subjected to moderate and storm wave conditions. This type of structure can be subjected to frequently occurring as well as high impact wave loadings. In addition to the structural concerns, it is also important to evaluate the importance of the coupling between both fluid and structure motion.
In the various steps to design proper wall deflector (wave guide) and to predict pressures and forces following a wave impact, we first present a comparison between numerical results from a CFD model and experimental recordings conducted in a large scale flume in the new Quebec Coastal Physics Laboratory, Canada. A CFD model performance is tested to investigate the more fundamental mechanisms of the underlying processes and to assess real conditions around seawalls to facilitate design process. The preliminary results are based on the assumption of treating the fluid-structure interaction physics as decoupled processes and the wall as a rigid plate. Modal analysis performed on the structure indicates that this approach is adequate, since loadings are of short duration (less than 1 ms) compared to the wall natural frequencies. A maximum local wall pressure of 3.5 MPa has been obtained from an air-pocket impact which generates an instantaneous horizontal force of 4.3×106 N/m.
Mathematical Model for Efficient Prediction of Lifeboat Sailaway Performance in Calm Water and Waves
Authors: Quadvlieg Frans , Tonelli Roberto , Palermo Elia , Teigen Per 
Published: October 2015

Free fall lifeboats have been developed for emergency evacuation from offshore installations, when conventional means of transportation cannot be applied. As a consequence, the ability of the lifeboats to perform safe drop- and sail away under all circumstances has to be demonstrated. This paper focuses on efficient and robust numerical simulation of these operations.
To predict the lifeboat behavior under a large variety of stochastic conditions, such as irregular waves, in combination with wind and current, calls for many individual simulations of the sailaway performance. The present paper presents a brand new mathematical model that is able to predict the behavior of a free fall lifeboat during drop-phase, the submerged phase, the surfacing phase and the “sailing in waves” phase (combined, not gluing time traces from different predictions together).
The proposed mathematical model is completely non-linear in nature and considers instantaneous submergence and attitude of the lifeboat. All forces and moments in 6 degrees of freedom are calculated instantaneously.
Consequently, accelerations, velocities and displacements, are calculated based on this. The paper describes the build-up of the mathematical model. This is based on a summation of forces due to impact forces, cross flow drag forces, generated lift, centrifugal forces, buoyancy forces, propulsion (propeller and nozzle), steering forces due to steering action and resistance. Obviously, also the instantaneous added masses play an important role. This results in a mathematical model for rigid body motions in 6 degrees of freedom, which can be used for predicting the motion response during drop- and sail away. This means a validity range in very extreme weather and in calm water. The paper will show basic validation and several applications.
Quantifying Spatial Variability of As-Laid Embedment for Subsea Pipeline Design
Authors: Westgate Zack , White Dave 
Published: October 2015

In deep water, the pre-service embedment of on-bottom pipelines is mainly controlled by the lay process and its effects on the soil strength. Predicted ranges in local pipeline embedment are often very wide due to uncertainties associated with the surface soil properties, the influence of the sea state and vessel motions on soil remolding, and the complexity of the large-deformation process of pipe-seabed penetration. Pipeline embedment has a significant impact on pipe-soil interaction resistance — commonly described by the ‘friction factors’ used for pipeline design. Most design checks, such as for controlled lateral buckling, need to be satisfied under both low and high extremes of pipe-soil resistance and therefore pipe embedment. A wide range in pipe embedment can create significant design challenges for pipeline engineers, for example where engineered buckle mitigation structures are required to alleviate potential high strains in the pipeline.
Data obtained from as-laid field surveys of subsea pipeline embedment have been analyzed to illustrate quantitatively how embedment varies along a pipeline route. This variation is linked to both anthropogenic influences, for example as a result of the stop-start pipeline construction process, as well as natural variability in (i) soil conditions along the route and (ii) sea state conditions during laying. Accounting for this variability through statistical analysis of as-laid embedment, and incorporation of appropriate length scales relevant to each design check, can have significant beneficial impacts on pipeline design through reductions in the ranges of pipe-soil friction factors. In some cases these may reduce or negate the need for expensive mitigation. The approaches illustrated in this paper have already found beneficial use on real projects.
Benchmarking Experiments for Wave Absorption Modeling
Authors: Magee Allan R. , Nelko Varjola , Lim Kian Yew , Chew Lup Wai 
Published: October 2015

Passive wave absorption is usually employed at the downstream end of a wave flume or basin to avoid the build-up of wave energy in the tank. However, absorption of waves is not perfect in physical tanks. A beach of different shape and/or composition can result in different absorption efficiency. Laboratory investigations of various passive beach configurations are costly and time-consuming. A more efficient approach is to perform studies using a numerical wave tank (NWT), which in turn requires empirical data to tune the dissipative effects.
This study attempts to better understand the quality of waves simulated in a laboratory flume with a uniformly inclined porous beach and a parabolic-shaped solid beach. The data will be used to validate a newly-developed NWT with passive wave absorption. Different incident wave properties are examined and the reflection coefficient is calculated primarily with the two-probe method proposed by Goda & Suzuki (1976) and compared with other methods. An overview of the experiments, absorption analysis and numerical simulation is presented and discussed.
Comparison of Numerical Simulations With Experimental Measurements for the Response of a Modified Submerged Horizontal Cylinder Moored in Waves
Authors: Roy André R. , Beatty Scott J. , Mishra Virag , Steinke Dean M. , Nicoll Ryan S. , Buckham Bradley J. 
Published: October 2015

Ocean industries such as oil and gas, defence, and marine renewables, face the challenge of costly and risky deployments and operations due to their complex and capital intensive nature. Numerical simulation tools are valuable assets that can be used to anticipate motions and stresses and therefore inform structural and operational design before deployment. Simulation tools that can capture all pertinent hydrodynamic phenomena increase their value by reducing design time, uncertainty, risk and capital associated with a deployment.
Validation of numerical tools is critical to ensure accuracy and reliability. The following paper reviews a framework for simulation of moored, multi-body, floating systems, including the component models employed, the results of a model verification study, and the challenges encountered in the project. Tank test data of a moored horizontal cylinder was provided for the purposes of numerical tool validation.
Large Scale Experimental Wave Impact on Walls in the Québec Coastal Physics Laboratory
Authors: Frandsen Jannette B. , Bérubé Francis 
Published: October 2015

The present tests are conducted in the new Québec Coastal Physics Laboratory, Canada. The flume has a depth and a width of 5 m and is 120 m long.
This paper presents large scale experiments of water wave impact on a vertical wall following wave runup on a mixed sand-gravel-cobble beach. This present study is concerned with advancing knowledge on rapidly varying pressure magnitude and distributions on different types of sea/river/harbor walls. Protection against extreme events and subsequent coastal erosion is a key theme of application. Herein is presented preliminary test series which has focus on forces on vertical walls. Specifically, 27 pressure sensors are mounted on the vertical wall with a total test area of 1.2 m wide and 2.4 m high and is a stiffened aluminum plate. The outer regions of the wall are made of steel to span the entire width of the tank. The wall is designed to behave as a rigid plate. The geometric model to full scale is about 1:4.
The incoming waves evolve on a flat bed to climb the final 25 m on a beach with slope with constant slope of 1:10. A small regular wave train forms the basis for investigations of force patterns on the wall. Herein, our preliminary findings reported are based on selected 6 test series (18 impacts out of 150 impacts). In general, wall pressures greater than 1 MPa and 10 m run-up are easily developed even with moderate amplitude waves at the inlet. We will discuss some details of the underlying mechanism of various types of breaking and impact on the wall. The peak pressure identified on the wall with the mixed gravel beach surface was 1.23 million N/m2 occurring in 0.2 milli seconds. It was cuased by a plunging breaker with a relatively large air pocket (∼0.11 m2). It was further identified that the maximum pressure on the wall does not necessarily give the maximum jet velocity (equivalent to vertical force considered in design of on parapets). They are independent quantities in these very random rapid processes. The maximum jet velocity was in the order of 35 m/s but could higher on a different beach surface. Further, it was found that the maximum waves are not necessarily the most critical ones as the waves break and therefore dissipates its energy before reaching the wall. A plunging breaker with a relatively large airpocket with a crest tip located at the top part of the wall resulted in max. peak wall pressure. One impact case caused a near simultaneous double peak pressure generated by a plunging breaker with two relatively small airpockets (0.003 m2 and 0.01 m2). This was the impact case responsible for the max. vertical jet velocity. We further found that the max. peak water pressure of the plunging breakers had a similar order of magnitude as the max. pressure within an air pocket.
Assessment of Weld Fatigue by Effective Notch Stress Approach
Authors: Anvari Majid , Fagnastøl Øyvind , Leira Bernt J. 
Published: October 2015

Applicability of different approaches, i.e. nominal stress-, structural hot spot- and effective notch stress approach, for fatigue assessment of welded structures has been discussed.
The effective notch stress approach was validated for a cruciform fillet welded and fully penetration welded joint, according to DNV guideline [1]. The same fillet welded joint was further investigated for varying weld sizes. The results show that with changing weld size, there are considerable differences between calculated stresses, and specially calculated fatigue lives, when comparing with nominal stress approach. Further investigations revealed that there is a nonlinear relation between effective notch stress and weld sizes, while comparison of the notch stress and nominal stress approaches indicate that a linear relation is to be expected. Based on the established methodology for the cruciform joint, another joint, i.e. a knee plate located in a horizontal brace of a drilling vessel, was assessed for weld root fatigue. Based on the proposed equations and the linear relation found between the nominal- and the notch stress S-N curves, a weld size providing a longer fatigue life at the weld root, rather than that at the toe, was proposed.
Dynamic Responses of Ship Propulsion Shaft Under Hull Excitations at Bearings
Authors: Zhang Cong , Tian Zhe , Yan Xinping 
Published: October 2015

With the development of ship enlargement and economization, dynamic interaction of a propulsion shaft and ship hull is more and more evident, especially when it is travelling in rough seas. Bearings, as the connection between propulsion shaft and ship hull, transmit the forces from ship hull to propulsion shaft. Thus, the model of shaft with the excitations at bearings can be seen as a simplified propulsion shaft-ship hull system to analyze the effect of hull deformation.
Based on the theory of vibration of shaft, in this paper, equations of shaft motion and boundary conditions are presented. Moreover, in the continuity conditions equations at each support, harmonic forces from hull is included. Dynamic responses of propulsion shaft under hull deformation excitations are gained by analytical method. The effects of supports stiffness, locations of hull deformation excitations, the amplitude of excitations and shaft size are discussed by comparing the response displacements of observed points. At the same time, numerical calculation is set to validate the accuracy and feasibility of analytical method. The conclusions could apply the accordance for design and optimization of the ship propulsion shaft, when the hull deformation excitations at bearings are considered.
Interlaboratory Collaboration for Optimized Screening for Urinary Tract Infection
Authors: Russcher Anne , Kusters Elske , Wolterbeek Ron , Kuijper Ed J. , Cobbaert Christa M. , van der Beek Martha T. 
Published: October 2015

ABSTRACT
As the majority of urine samples submitted for culture yields a negative result, rapid screening that accurately predicts culture outcome benefits clinicians by reducing the time to result and improves the efficiency of the microbiological laboratory. Automated urinalysis using the IRIS Diagnostics iQ200 Elite (iQ200) analyzer permits just such a fast and large-scale screening. We aimed to predict and thus to reduce negative cultures with a screening algorithm based on iQ200 urinalysis in a tertiary university hospital. In parallel, we evaluated the performance of the iQ200 screen compared to that of Gram stain for sample quality. We screened 1,442 samples submitted for bacterial culture using the iQ200 analyzer; of these samples, 357 (24.8%) had a positive culture result. We identified the absence of microorganisms in the iQ200 screen as the strongest solitary predictor for a negative culture, with a sensitivity of 90.5% (323/357). The algorithm was further improved by performing logistic regression on leukocyte counts, which gave a cutoff of 65 leukocytes/μl to obtain the desired sensitivity of >95% (95.2%; 95% confidence interval [CI], 92.5 to 97.0), a negative predictive value of 97.3% (95% CI, 95.7 to 98.3), and an anticipated culture workload reduction of 44% (95% CI, 41 to 46). Concordance between sample quality based on Gram stain and iQ200 screening was only 72%, which was probably a result of interobserver effect in evaluation of the Gram stain. In conclusion, in our setting, screening by iQ200 proved to be a safe and cost-effective means to provide faster culture results, and it has the added benefit of a more objective evaluation of sample quality.
Cost-Effectiveness of 30- Compared to 20-Milliliter Blood Cultures: a Retrospective Study
Authors: Cheruvanky Anita , Kirn Thomas J. , Weinstein Melvin P. 
Published: October 2015

ABSTRACT

The importance of blood culture (BC) volume for detection of bloodstream infections (BSIs) is documented. Recently, improved diagnostic sensitivity was demonstrated for 30- versus 20-ml BCs in adults (Cockerill FR, Wilson JW, Vetter EA, Goodman KM, Torgerson CA, Harmsen WS, Schleck CD, IIstrup DM, Washington JA, Wilson WR. Clin Infect Dis 38:1724–1730, 2004,
http://dx.doi.org/10.1128/JCM.01314-11
). Hospitals receive higher reimbursement for patients with documented septicemia. We determined the cost-effectiveness of 30-ml versus 20-ml BCs using results from our institution and previously published data. Positive BC results from 292 bacteremic episodes were reviewed. The costs of the reagents, equipment, phlebotomist, and technologist time were determined. The medical records department provided Medicare reimbursement (MR) data for patients with selected ICD-9 codes. These data provided an estimate of the annualized increase in MR versus costs associated with conversion to 30-ml BCs. MR for 464 annual primary BSIs was $24,808/episode. An expected 7.2% increase in BSIs detected using 30-ml BCs would add 34 additional cases annually and increase MR by $843,472. Comparative MR data for cases where septicemia complicated another diagnosis were available for 4 International Classification of Diseases, Ninth Revision (ICD-9) codes: laparoscopic cholecystectomy, biliary tract disorders, pneumonia, and cellulitis. The mean incremental MR was $9,667 per episode, which projected to a $483,350 revenue increase annually. The annual cost associated with conversion to 30-ml BCs was estimated to be $157,798. Thus, the potential net increase in hospital revenue would be $1,169,031 for 30-ml versus 20-ml BCs. Our results suggest that conversion to 30-ml BCs may not only improve patient care by detecting more BSIs but also increase hospital revenue substantially.
Detection of
mecA
- and
mecC
-Positive Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates by the New Xpert MRSA Gen 3 PCR Assay
Authors: Becker Karsten , Denis Olivier , Roisin Sandrine , Mellmann Alexander , Idelevich Evgeny A. , Knaack Dennis , van Alen Sarah , Kriegeskorte André , Köck Robin , Schaumburg Frieder , Peters Georg , Ballhausen Britta 
Published: October 2015

ABSTRACT

An advanced methicillin-resistant
Staphylococcus aureus
(MRSA) detection PCR approach targeting SCC
mec-orfX
along with
mecA
and
mecC
was evaluated for
S. aureus
and coagulase-negative staphylococci. The possession of
mecA
and/or
mecC
was correctly confirmed in all cases. All methicillin-susceptible
S. aureus
strains (
n
= 98; including staphylococcal cassette chromosome
mec
element [SCC
mec
] remnants) and 98.1% of the MRSA strains (
n
= 160, including 10
mecC
-positive MRSA) were accurately categorized.
High Incidence of Invasive Group A Streptococcus Disease Caused by Strains of Uncommon
emm
Types in Thunder Bay, Ontario, Canada
Authors: Athey Taryn B. T. , Teatero Sarah , Sieswerda Lee E. , Gubbay Jonathan B. , Marchand-Austin Alex , Li Aimin , Wasserscheid Jessica , Dewar Ken , McGeer Allison , Williams David , Fittipaldi Nahuel 
Published: October 2015

ABSTRACT

An outbreak of type
emm59
invasive group A
Streptococcus
(iGAS) disease was declared in 2008 in Thunder Bay District, Northwestern Ontario, 2 years after a countrywide
emm59
epidemic was recognized in Canada. Despite a declining number of
emm59
infections since 2010, numerous cases of iGAS disease continue to be reported in the area. We collected clinical information on all iGAS cases recorded in Thunder Bay District from 2008 to 2013. We also
emm
typed and sequenced the genomes of all available strains isolated from 2011 to 2013 from iGAS infections and from severe cases of soft tissue infections. We used whole-genome sequencing data to investigate the population structure of GAS strains of the most frequently isolated
emm
types. We report an increased incidence of iGAS in Thunder Bay compared to the metropolitan area of Toronto/Peel and the province of Ontario. Illicit drug use, alcohol abuse, homelessness, and hepatitis C infection were underlying diseases or conditions that might have predisposed patients to iGAS disease. Most cases were caused by clonal strains of skin or generalist
emm
types (i.e.,
emm82
,
emm87
,
emm101
,
emm4
,
emm83
, and
emm114
) uncommonly seen in other areas of the province. We observed rapid waxing and waning of
emm
types causing disease and their replacement by other
emm
types associated with the same tissue tropisms. Thus, iGAS disease in Thunder Bay District predominantly affects a select population of disadvantaged persons and is caused by clonally related strains of a few skin and generalist
emm
types less commonly associated with iGAS in other areas of Ontario.
Evaluation of the Lyra Direct Strep Assay To Detect Group A Streptococcus and Group C and G Beta-Hemolytic Streptococcus from Pharyngeal Specimens
Authors: Boyanton Bobby L. , Darnell Elizabeth M. , Prada Anne E. , Hansz Dana M. , Robinson-Dunn Barbara 
Published: October 2015

ABSTRACT

The Lyra Direct strep assay was compared to culture for its ability to detect
Streptococcus
group A and β-hemolytic groups C/G using rapid antigen-negative pharyngeal specimens (
n
= 161). The Lyra assay correctly detected all β-hemolytic streptococci (group A,
n
= 19; group C/G,
n
= 5). In batch mode, the Lyra assay reduced intralaboratory turnaround time by 60% (18.1 h versus 45.0 h) but increased hands-on time by 96% (3 min 16 s versus 1 min 40 s per specimen).
Hepatocyte Heparan Sulfate Is Required for Adeno-Associated Virus 2 but Dispensable for Adenovirus 5 Liver Transduction
In Vivo
Authors: Zaiss Anne K. , Foley Erin M. , Lawrence Roger , Schneider Lina S. , Hoveida Hamidreza , Secrest Patrick , Catapang Arthur B. , Yamaguchi Yu , Alemany Ramon , Shayakhmetov Dmitry M. , Esko Jeffrey D. , Herschman Harvey R. 
Published: October 2015

ABSTRACT

Adeno-associated virus 2 (AAV2) and adenovirus 5 (Ad5) are promising gene therapy vectors. Both display liver tropism and are currently thought to enter hepatocytes
in vivo
through cell surface heparan sulfate proteoglycans (HSPGs). To test directly this hypothesis, we created mice that lack
Ext1
, an enzyme required for heparan sulfate biosynthesis, in hepatocytes.
Ext1

HEP

mutant mice exhibit an 8-fold reduction of heparan sulfate in primary hepatocytes and a 5-fold reduction of heparan sulfate in whole liver tissue. Conditional hepatocyte
Ext1
gene deletion greatly reduced AAV2 liver transduction following intravenous injection. Ad5 transduction requires blood coagulation factor X (FX); FX binds to the Ad5 capsid hexon protein and bridges the virus to HSPGs on the cell surface. Ad5.FX transduction was abrogated in primary hepatocytes from
Ext1

HEP

mice. However, in contrast to the case with AAV2, Ad5 transduction was not significantly reduced in the livers of
Ext1

HEP

mice. FX remained essential for Ad5 transduction
in vivo
in
Ext1

HEP

mice. We conclude that while AAV2 requires HSPGs for entry into mouse hepatocytes, HSPGs are dispensable for Ad5 hepatocyte transduction
in vivo
. This study reopens the question of how adenovirus enters cells
in vivo
.

IMPORTANCE
Our understanding of how viruses enter cells, and how they can be used as therapeutic vectors to manage disease, begins with identification of the cell surface receptors to which viruses bind and which mediate viral entry. Both adeno-associated virus 2 and adenovirus 5 are currently thought to enter hepatocytes
in vivo
through heparan sulfate proteoglycans (HSPGs). However, direct evidence for these conclusions is lacking. Experiments presented herein, in which hepatic heparan sulfate synthesis was genetically abolished, demonstrated that HSPGs are not likely to function as hepatocyte Ad5 receptors
in vivo
. The data also demonstrate that HSPGs are required for hepatocyte transduction by AAV2. These results reopen the question of the identity of the Ad5 receptor
in vivo
and emphasize the necessity of demonstrating the nature of the receptor by genetic means, both for understanding Ad5 entry into cells
in vivo
and for optimization of Ad5 vectors as therapeutic agents.