Predicting the effect of biofouling on ship resistance using CFD

This paper proposes a Computational Fluid Dynamics (CFD) based unsteady RANS model which enables the prediction of the effect of marine coatings and biofouling on ship resistance and presents CFD simulations of the roughness effects on the resistance and effective power of the full-scale 3D KRISO Container Ship (KCS) hull. Initially, a roughness function model representing a typical coating and different fouling conditions was developed by using the roughness functions given in the literature. This model then was employed in the wall-function of the CFD software and the effects of a typical as applied coating and different fouling conditions on the frictional resistance of flat plates representing the KCS were predicted for a design speed of 24 knots and a slow steaming speed of 19 knots using the proposed CFD model. The roughness effects of such conditions on the resistance components and effective power of the full-scale 3D KCS model were then predicted at the same speeds. The resulting frictional resistance values of the present study were then compared with each other and with results obtained using the similarity law analysis. The increase in the effective power of the full-scale KCS hull was predicted to be 18.1% for a deteriorated coating or light slime whereas that due to heavy slime was predicted to be 38% at a ship speed of 24 knots. In addition, it was observed that the wave resistance and wave systems are significantly affected by the hull roughness and hence viscosity

Connecting key competencies and social inquiry in primary social studies pedagogy: initial teacher education students' planning decisions and reflections.

Over 2007-2009 we have worked with the national curriculum's key competencies to establish their place and purpose in the social sciences learning area. As a result, our initial teacher education (ITE) primary social studies programmes involve pedagogy that conceives key competencies as analogous to social inquiry thinking and skills processes. Our team was keen to research ways ITE students identify and embed key competencies in their social inquiry planning decisions. The research also sought student reflection of how engagement with key competencies might influence their future social studies teaching and learning. The article offers a storying of ways the curriculum element of key competencies has been developed, implemented, researched and reflected upon within ITE primary social studies curriculum

Parametric rolling in regular head waves of the Kriso container ship : numerical and experimental investigation in shallow water

The IMO Intact Stability Code considers the parametric rolling phenomenon as one of the stability failure modes because of the larger roll angles attained. This hazardous condition of roll resonance can lead to loss of cargo, passenger discomfort, and even (in the extreme cases) the ship's capsize. Studies as such are mostly conducted considering wave characteristics corresponding to wave lengths around one ship length (lambda approximate to L-PP) and wave amplitudes varying from moderate to rough values. These wave characteristics, recognised as main contributors to parametric rolling, are frequently encountered in deep water. Waves with lengths of such magnitudes are also met by modern container ships in areas in close proximity to ports, but with less significant wave amplitudes. In such areas, due to the limited water depth and the relatively large draft of the ships, shallow water effects influence the overall ship behaviour as well. Studies dedicated to parametric rolling occurrence in shallow water are scarce in literature. In spite of no accidents being yet reported in such scenarios, its occurrence and methods for its prediction require further attention; this in order to prevent any hazardous conditions. The present work investigates the parametric roll phenomenon numerically and experimentally in shallow water. The study is carried out with the KRISO container ship (KCS) hull. The numerical investigation uses methods available in literature to study the susceptibility and severity of parametric rolling. Their applicability to investigate this phenomenon in shallow water is also discussed. The experimental analysis was carried out at the Towing Tank for Manoeuvres in Confined Water at Flanders Hydraulics Research (in co-operation with Ghent University). Model tests comprised a variation of different forward speeds, wave amplitudes and wave lengths (around one L-PP). The water depth was fixed to a condition equivalent to a gross under keel clearance (UKC) of 100% of the ship's draft

Secondary Privatization in the Czech Republic: Changes in Ownership and Enterprise Performance in Voucher-Privatized Firms

This volume contains the output of country research undertaken in the Czech Republic in 2000–2001 by EvDen Kocenda and Juraj Valachy (CERGE) under the international comparative project 'Secondary Privatization: the Evolution of Ownership Structures of Privatized Enterprises.' The project was supported by the European Union's Phare ACE* Programme 1997 (project P97-8201 R) and was coordinated by Barbara Blaszczyk of the Center for Social and Economic Research (CASE) in Warsaw, Poland. The support of the ACE Programme made it possible to organize the cooperation of an international group of scholars (from the Czech Republic, France, Poland, Slovenia and the U.K.). The entire project was devoted to the investigation of secondary ownership changes in enterprises privatized in special privatization schemes (i.e., mass privatization schemes and MEBOs**) in three Central European countries – the Czech Republic, Poland and Slovenia. Through a combination of different research methods, such as secondary analysis of previous research, analysis of legal and other regulatory instruments, original field research, statistical data base research and econometric analysis of individual enterprise data, the project aimed to investigate the scope, pace and trends in secondary ownership changes, the factors and barriers affecting them and the degree of ownership concentration resulting from them. Following the presentation of a clear picture of the economic outcomes of the voucher privatization in the Czech Republic, the paper turns to the initial changes in ownership structures of privatized companies. The main types of new owners are identified and the emerging trends of ownership concentration analyzed. The second part of this publication is devoted to a description of post-privatization transactions and their influence on the further re-allocation and concentration of ownership. The interconnection between secondary changes in ownership structure and economic performance of a sample of companies traded on the Prague Stock Exchange is investigated using various econometric instruments.privatization, secondary transactions, corporate governance, transition economies, Czech Republic, Slovenia, Poland

Wave-resistance computation via CFD and IGA-BEM solvers : a comparative study

This paper delivers a preliminary comparative study on the computation of wave resistance via a commercial CFD solver (STAR-CCM+®) versus an in-house developed IGA-BEM solver for a pair of hulls, namely the parabolic Wigley hull and the KRISO container ship (KCS). The CFD solver combines a VOF (Volume Of Fluid) free-surface modelling technique with alternative turbulence models, while the IGA-BEM solver adopts an inviscid flow model that combines the Boundary Element approach (BEM) with Isogeometric Analysis (IGA) using T-splines or NURBS. IGA is a novel and expanding concept, introduced by Hughes and his collaborators (Hughes et al, 2005), aiming to intrinsically integrate CAD with Analysis by communicating the CAD model of the geometry (the wetted ship hull in our case) to the solver without any approximation

FDI in Post-Production Services and Product Market Competition

Post-production services, such as sales, distribution, and maintenance, comprise a crucial element of business activity. A foreign firm faces a higher cost to perform such services than its domestic rival because of the lack of proximity to customers. We explore an international duopoly model in which a foreign firm can reduce its cost for post-production services by foreign direct investment (FDI), or alternatively can outsource such services to its domestic rival. Trade liberalization, if not accompanied by liberalization of service FDI, can hurt domestic consumers and decrease world welfare, but the negative welfare impacts can be mitigated and eventually turned into positive ones as service FDI is also liberalized. This finding yields important policy implications, given the reality that the progress of liberalization in service sectors is limited compared to the substantial progress already made in trade liberalization.post-production services, trade liberalization, FDI, outsourcing, international oligopoly

Analysis of Policy Issues Relating to Public Investment in Private Freight Infrastructure, MTI Report 99-03

The Norman Y. Mineta International Institute for Surface Transportation Policy Studies (IISTPS) at San José State University conducted this study to review the issues and implications involved in the investment of public funds in private freight infrastructure. After thorough legal research, the project team reached the following conclusions: LEGAL ANALYSIS: The California legislature has the legal power to invest public funds in privately-owned freight infrastructure projects State Highway funds, excepting gas tax revenues, may be used for investment in freight infrastructure projects. Gas tax revenues are restricted to highway use by current interpretations of the California Constitution. A challenge to this interpretation is not recommended. Gas tax revenues may be invested in roadway segments of freight infrastructure projects. RECOMMENDATIONS An analytical system of guidelines should be developed to score and evaluate any proposed freight infrastructure project. Economic development must be included in these scoring guidelines. Public agencies should maintain political contacts in order to control the political short-circuits of the planning process. The California Department of Transportation should develop a Freight Improvement Priority System for the purpose of prioritizing all freight improvement projects