scholarly journals The Influence of the Ship’s Speed and Distance to an Arbitrarily Shaped Bank on Bank Effects

2015 ◽  
Author(s):  
Evert Lataire ◽  
Marc Vantorre ◽  
Guillaume Delefortrie
Keyword(s):  
Cross Section ◽  
Water Depth ◽  
Ship Motions ◽  
Return Flow ◽  
Asymmetric Flow ◽  
Data Set ◽  
Close Proximity ◽  
Unique Model ◽  
Bank Effects ◽  
Insight Into

A displacement vessel — obviously — displaces a (large) amount of water. In open and deep navigation areas this water can travel almost without any restriction underneath and along the ship’s hull. In restricted and shallow waterways, however, the displaced water is squeezed under and along the hull. These bathymetric restrictions result in increased velocities of the return flow along the hull. The resulting pressure distribution on the hull causes a combination of forces and moments on the vessel. If generated because of asymmetric flow due to the presence of a bank, this combination of forces and moment is known as bank effects. By far the most comprehensive and systematic experimental research program on bank effects has been carried out in the Towing Tank for Manoeuvres in Shallow Water (cooperation Flanders Hydraulics Research – Ghent University) at Flanders Hydraulics Research (FHR) in Antwerp, Belgium. The obtained data set on bank effects consists of more than 14 000 unique model test setups. Different ship models have been tested in a broad range of draft to water depth ratios, forward speeds and propeller actions. The tests were carried out along several bank geometries at different lateral positions between the ship and the installed bank. The output consists of forces and moments on hull, rudder and propeller as well as vertical ship motions. An analysis of this extensive database has led to an increased insight into the parameters which are relevant for bank effects. Two important parameters are linked to the relative distance between ship and bank and the ship’s forward speed. The relative position and distance between a ship and an arbitrarily shaped bank is ambiguous. Therefore a definition for a dimensionless distance to the bank will be introduced. In this way the properties of a random cross section are taken into account without exaggerating the bathymetry at a distance far away from the ship or without underestimating the bank shape at close proximity to the ship. The dimensionless velocity, named the Tuck number (Tu), considers the water depth and blockage, and is based on the velocity relative to the critical speed. The latter is dependent on the cross section (and thus the bank geometry) of the waterway.

scholarly journals The Influence of the Ship's Speed and Distance to an Arbitrarily Shaped Bank on Bank Effects

2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Evert Lataire ◽  
Marc Vantorre ◽  
Guillaume Delefortrie
Keyword(s):  
Return Flow ◽  
Asymmetric Flow ◽  
Dimensionless Velocity ◽  
Test Conditions ◽  
Close Proximity ◽  
Unique Model ◽  
Bank Effects ◽  
Yaw Moment ◽  
Sailing Ship ◽  
Restricted Waterways

In shallow and restricted waterways, the water displaced by a sailing ship is squeezed under and along its hull. These confinements result in increased velocities of the return flow along the hull and the induced pressure distribution on the hull causes a combination of forces and moments on the vessel. If generated because of asymmetric flow due to the presence of a bank, this combination of forces and moment is known as bank effects. A comprehensive experimental research program on bank effects has been carried out in the towing tank for maneuvers in shallow water (cooperation Flanders Hydraulics Research—Ghent University) at Flanders Hydraulics Research (FHR) in Antwerp, Belgium. The obtained data consist of more than 14,000 unique model test conditions. The relative position and distance between a ship and an arbitrarily shaped bank is ambiguous. Therefore, a definition for a dimensionless distance to the bank is introduced. In this way, the properties of a random cross section are taken into account without exaggerating the bathymetry at a distance far away from the ship or without underestimating the bank shape at close proximity to the ship. Also, a dimensionless velocity is introduced to take the influence of the water depth, forward speed, and blockage into account. The proposed mathematical model for bank effects, often described as a sway force and yaw moment, is instead decomposed in two sway forces at each perpendicular.

scholarly journals Satisfiers and Hygiene Factors: Residents' Perceptions of Strengths and Limitations of Their Learning Environment

2012 ◽  
Vol 4 (1) ◽  
pp. 122-127 ◽  
Author(s):  
Ingrid Philibert
Keyword(s):  
Learning Environment ◽  
Cross Section ◽  
Career Counseling ◽  
New Technology ◽  
Data Set ◽  
Procedural Volume ◽  
Wide Range ◽  
Hygiene Factors ◽  
Insight Into

Abstract Background Efforts are underway to enhance learner input into the accreditation of educational programs, including residencies and fellowships. Objectives To aggregate the perspectives of residents and fellows from a cross-section of specialties to highlight common dimensions in learners' perceptions of strengths and opportunities for improvement (OFIs) in their program and to assess whether the ACGME Resident Survey captures areas important to residents' perceptions of their learning environment. Results The data set included 206 core and 193 subspecialty programs representing a wide range of specialties and subspecialties. Comments on strengths and OFIs addressed most of the items in the Resident Survey, with items not addressed in the survey also not represented in the ACGME requirements. The findings suggest that some program attributes are mentioned only in their absence (hygiene factors), whereas other dimensions (satisfiers), particularly quality and quantity of residents' interactions with faculty, procedural volume, and variety and didactic offerings, are critical to learners' perceptions of the quality of their learning environment. For some strengths, residents indicated their programs exceeded the ACGME standards, and for areas identified as OFIs, comments suggested programs were in compliance, but the residents desired more. Mentioned in this context were opportunities to perform research, access to board preparation courses and career counseling, and availability of new technology, including new patient care modalities. Conclusions The findings allow insight into program attributes important to residents' perceptions of their learning environment. Programs may find the results helpful in suggesting areas for improvement in their learning environment.

Through-Space Transmission of 19F-13C Coupling Via an Intermediate Bond. An Experimental and Theoretical Study

1987 ◽  
Vol 40 (12) ◽  
pp. 1923 ◽  
Author(s):  
ID Rae ◽  
ID Rae ◽  
A Staffa ◽  
A Staffa ◽  
AC Diz ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Lone Pair ◽  
Electron Excitation ◽  
Carbonyl Groups ◽  
Polarization Propagator ◽  
Close Proximity ◽  
Fermi Contact ◽  
Intramolecular Hydrogen ◽  
Intermediate Bond ◽  
Insight Into

In order to obtain a deeper insight into the title effect, several compounds with an F atom very close to a C-H of a nearby functional group were synthesized and the relevant couplings measured. The most conspicuous case was that of 8-fluoro-2-hydroxynaphthalene-1-carbaldehyde where a close proximity between the F and H atoms is the result of fluorine-oxygen repulsion and the formation of an intramolecular hydrogen bond between the hydroxyl and carbonyl groups. The experimental four-bond J(F,CHO) coupling is 26.2 Hz. A compound very similar to this one, but without the OH group, was chosen on which to perform a polarization propagator analysis of the through-space (TS) coupling pathways, at the RPA-INDO level. The expression for the TS coupling in terms of the projected polarization propagator and perturbators was numerically analysed. It is found that this coupling is completely dominated by a TS component of the Fermi contact (FC) term, the main features of which are: ( i ) It decays exponentially with the F-H distance; (ii) Its main contribution comes from an electron excitation involving the F lone-pair, the C-H bond of the CHO moiety and its corresponding antibonding orbital;(iii) The π-type lone-pair does not contribute to the TS coupling pathway of the FC term.

scholarly journals Combining Multiple Organizational-level Databases: An Empirical Evaluation of Different Matching Methods

2021 ◽  
pp. 004912412098618
Author(s):  
Tim de Leeuw ◽  
Steffen Keijl
Keyword(s):  
Empirical Evaluation ◽  
Organizational Level ◽  
Random Errors ◽  
Data Set ◽  
Future Studies ◽  
Matching Methods ◽  
Matching Process ◽  
Significant Relationships ◽  
Research Findings ◽  
Insight Into

Although multiple organizational-level databases are frequently combined into one data set, there is no overview of the matching methods (MMs) that are utilized because the vast majority of studies does not report how this was done. Furthermore, it is unclear what the differences are between the utilized methods, and it is unclear whether research findings might be influenced by the utilized method. This article describes four commonly used methods for matching databases and potential issues. An empirical comparison of those methods used to combine regularly used organizational-level databases reveals large differences in the number of observations obtained. Furthermore, empirical analyses of these different methods reveal that several of them produce both systematic and random errors. These errors can result in erroneous estimations of regression coefficients in terms of direction and/or size as well as an issue where truly significant relationships might be found to be insignificant. This shows that research findings can be influenced by the MM used, which would argue in favor of the establishment of a preferred method as well as more transparency on the utilized method in future studies. This article provides insight into the matching process and methods, suggests a preferred method, and should aid researchers, reviewers, and editors with both combining multiple databases and describing and assessing them.

scholarly journals Were VCF patients at higher risk of mortality following the 2009 publication of the vertebroplasty “sham” trials?

2017 ◽  
Vol 29 (2) ◽  
pp. 375-383 ◽  
Author(s):  
K. L. Ong ◽  
D. P. Beall ◽  
M. Frohbergh ◽  
E. Lau ◽  
J. A. Hirsch
Keyword(s):  
Mortality Risk ◽  
Cox Regression ◽  
Compression Fracture ◽  
Balloon Kyphoplasty ◽  
Data Set ◽  
Mortality Risks ◽  
Medicare Data ◽  
Kaplan Meier ◽  
Risk Of Mortality ◽  
Insight Into

Abstract Summary The 5-year period following 2009 saw a steep reduction in vertebral augmentation volume and was associated with elevated mortality risk in vertebral compression fracture (VCF) patients. The risk of mortality following a VCF diagnosis was 85.1% at 10 years and was found to be lower for balloon kyphoplasty (BKP) and vertebroplasty (VP) patients. Introduction BKP and VP are associated with lower mortality risks than non-surgical management (NSM) of VCF. VP versus sham trials published in 2009 sparked controversy over its effectiveness, leading to diminished referral volumes. We hypothesized that lower BKP/VP utilization would lead to a greater mortality risk for VCF patients. Methods BKP/VP utilization was evaluated for VCF patients in the 100% US Medicare data set (2005–2014). Survival and morbidity were analyzed by the Kaplan-Meier method and compared between NSM, BKP, and VP using Cox regression with adjustment by propensity score and various factors. Results The cohort included 261,756 BKP (12.6%) and 117,232 VP (5.6%) patients, comprising 20% of the VCF patient population in 2005, peaking at 24% in 2007–2008, and declining to 14% in 2014. The propensity-adjusted mortality risk for VCF patients was 4% (95% CI, 3–4%; p < 0.001) greater in 2010–2014 versus 2005–2009. The 10-year risk of mortality for the overall cohort was 85.1%. BKP and VP cohorts had a 19% (95% CI, 19–19%; p < 0.001) and 7% (95% CI, 7–8%; p < 0.001) lower propensity-adjusted 10-year mortality risk than the NSM cohort, respectively. The BKP cohort had a 13% (95% CI, 12–13%; p < 0.001) lower propensity-adjusted 10-year mortality risk than the VP cohort. Conclusions Changes in treatment patterns following the 2009 VP publications led to fewer augmentation procedures. In turn, the 5-year period following 2009 was associated with elevated mortality risk in VCF patients. This provides insight into the implications of treatment pattern changes and associated mortality risks.

How to foster employee satisfaction by means of coaching, motivation, emotional salary and social media skills in the agri-food value chain

New Medit ◽  
2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Keyword(s):  
Social Media ◽  
Value Chain ◽  
Employee Satisfaction ◽  
Data Set ◽  
Business Skills ◽  
A Value ◽  
The Social ◽  
Use Of Social Media ◽  
Food Value ◽  
Insight Into

Most employee satisfaction studies do not consider the current digital transformation of the social world. The aim of this research is to provide insight into employee satisfaction in agribusiness by means of coaching, motivation, emotional salary and social media with a value chain methodology. The model is tested empirically by analysing a survey data set of 381 observations in Spanish agribusiness firms of the agri-food value chain. The results show flexible remunerations of emotional salary are determinants of employee satisfaction. Additionally, motivation is relevant in the production within commercialisation link and coaching in the production within transformation link. Whole-of-chain employees showed the greatest satisfaction with the use of social media in personnel management. Findings also confirmed that employees will stay when a job is satisfying. This study contributes to the literature by investigating the effect of current social and digital business skills on employee satisfaction in the agri-food value chain.

scholarly journals TARGETED ADVERTISING IN THE BREAKFAST CEREAL INDUSTRY

2017 ◽  
Vol 49 (3) ◽  
pp. 382-399 ◽  
Author(s):  
JOSHUA BERNING ◽  
ADAM N. RABINOWITZ
Keyword(s):  
Product Differentiation ◽  
Food Product ◽  
Television Advertising ◽  
Breakfast Cereal ◽  
Data Set ◽  
Policy Makers ◽  
Relationship Of ◽  
Cereal Industry ◽  
The Relationship ◽  
Insight Into

AbstractWe examine the relationship of product characteristics of ready-to-eat breakfast cereal and targeted television advertising to specific consumer segments. We compile a unique data set that includes brand-packaging characteristics, including on-box games, nutrition information, and cobranding. We find that the relationship of television advertising and a cereal's brand-packaging characteristics varies by target audience. Our results provide insight into understanding how manufacturers strategically utilize branding, packaging, and television advertising. This can help industry and policy makers develop food product advertising policy. This analysis extends to other product markets where extensive product differentiation and promotion are present as well.

The systematics of Raspailiidae (Demospongiae: Poecilosclerida: Microcionina) re-analysed with a ribosomal marker

2007 ◽  
Vol 87 (6) ◽  
pp. 1571-1576 ◽  
Author(s):  
Dirk Erpenbeck ◽  
Sue List-Armitage ◽  
Belinda Alvarez ◽  
Bernard M. Degnan ◽  
Gert Wörheide ◽  
...  
Keyword(s):  
Gene Tree ◽  
Morphological Characters ◽  
Character Evolution ◽  
28S Rdna ◽  
The Other ◽  
Data Set ◽  
Rdna Gene ◽  
Insight Into

We present a 28S rDNA gene tree of selected Raspailiidae, Axinellidae and other demosponges to obtain insight into raspailiid phylogeny and character evolution. The Raspailiidae in our data set cluster in a well-supported clade, distinguished from Axinellidae, Agelasida and Hadromerida. Raspailia (s.s.), Eurypon, Sollasella, Aulospongus and Ectyoplasia form a Raspailiidae clade. Some Raspailia subgenera, in particular R. (Parasyringella), are not retrieved monophyletically. Trikentrion falls into the Thrinacophorinae, and not the Cyamoninae as earlier hypothesized. The axinellid genera Ptilocaulis and Reniochalina also cluster with Raspailiidae, distant from the other Axinellidae. The suitability of particular morphological characters for raspailiid phylogeny is discussed.

Hydrodynamic Properties of an Asymmetric Deepwater Riser Bundle

2006 ◽  
Author(s):  
Charles Zimmermann ◽  
Richard James ◽  
Blaise Seguin ◽  
Mattias Lynch
Keyword(s):  
Cross Section ◽  
Water Depth ◽  
Hydrodynamic Characteristics ◽  
Cfd Analysis ◽  
Effective Solution ◽  
Hydrodynamic Properties ◽  
Global System ◽  
Field Development ◽  
Hydrodynamic Behaviour ◽  
Deepwater Riser

The BP operated Greater Plutonio field development offshore Angola comprises a spread-moored FPSO in 1,300 m water depth, serving as a hub processing the fluids produced from or injected into the subsea wells. The selected riser system is a riser tower tensioned by a steel buoyancy tank at its top end and distributed foam buoyancy along a central structural tubular. The riser bundle is asymmetric in cross-section and this paper presents the work performed to determine the specific hydrodynamic characteristics of the design. Both basin tests and CFD analysis results are presented with discussion on some specific hydrodynamic issues: vortex-induced vibration (VIV) of the global riser tower system, VIV of individual risers, and the dynamic stability of the global system (i.e. galloping). Finally, guidelines for the assessment of the hydrodynamic behaviour of such system geometries are proposed. The results of this paper demonstrate that the Greater Plutonio riser bundle represents an effective solution in term of hydrodynamic behaviour and is not sensitive to VIV fatigue or galloping.

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