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Economies of scale drive container ship owners towards ordering larger vessels. Terminals need to ensure a safe (un)loading operation of these vessels, which can only be guaranteed if the mooring equipment is not overloaded (lines, fenders and bollards) and if the motions of the vessel remain below set limits, under external forces. This paper aims to focus on the passing vessel effect as a potential disturbing factor in the Port of Antwerp.

Motion criteria for allowing safe (un)loading of container vessels are established by considering the container handling process and existing international standards (PIANC). A case study simulation is presented where the behaviour of the moored vessel under ship passages is evaluated. Starting from a representative event, the effect of changes in passing speed and distance is discussed.

The study illustrates the influence of passing velocity and distance on the behaviour of the moored vessel, showing that when passing speeds are higher and/or distances lower than the reference event, safety limits are potentially exceeded. Possible mitigating measures, including the use of stiffer mooring lines and/or a change in arrangement, are discussed.

This paper serves as a basis for future research on safety criteria and optimisation of the mooring equipment and configuration to deal with passing vessel effects.

The presented results can be used by ship and terminal designers to gain familiarity with passing vessel effects and adopt suggested best practice.

By restricting the motions of the passing vessels, the focus and general well-being of the crane operator is enhanced, as is the safety of workers.

The paper provides a unique combination of container fleet observation, safety criteria establishment and case study application.

Emissions produced by oceangoing vessels not only negatively affect the environment but also may deteriorate health of living organisms. Several regulations were released by the International Maritime Organization (IMO) to alleviate negative externalities from maritime transportation. Certain polluted areas were designated as “Emission Control Areas” (ECAs). However, IMO did not enforce any restrictions on the actual quantity of emissions that could be produced within ECAs. This paper aims to perform a comprehensive assessment of advantages and disadvantages from introducing restrictions on the emissions produced within ECAs. Two mixed-integer non-linear mathematical programs are presented to model the existing IMO regulations and an alternative policy, which along with the established IMO requirements also enforces restrictions on the quantity of emissions produced within ECAs. A set of linearization techniques are applied to linearize both models, which are further solved using the dynamic secant approximation procedure. Numerical experiments demonstrate that introduction of emission restrictions within ECAs can significantly reduce pollution levels but may incur increasing route service cost for the liner shipping company.

Two mixed-integer non-linear mathematical programs are presented to model the existing IMO regulations and an alternative policy, which along with the established IMO requirements also enforces restrictions on the quantity of emissions produced within ECAs. A set of linearization techniques are applied to linearize both models, which are further solved using the dynamic secant approximation procedure.

Numerical experiments were conducted for the French Asia Line 3 route, served by CMA CGM liner shipping company and passing through ECAs with sulfur oxide control. It was found that introduction of emission restrictions reduced the quantity of sulfur dioxide emissions produced by 40.4 per cent. In the meantime, emission restrictions required the liner shipping company to decrease the vessel sailing speed not only at voyage legs within ECAs but also at the adjacent voyage legs, which increased the total vessel turnaround time and in turn increased the total route service cost by 7.8 per cent.

This study does not capture uncertainty in liner shipping operations.

The developed mathematical model can serve as an efficient practical tool for liner shipping companies in developing green vessel schedules, enhancing energy efficiency and improving environmental sustainability.

Researchers and practitioners seek for new mathematical models and environmental policies that may alleviate pollution from oceangoing vessels and improve energy efficiency. This study proposes two novel mathematical models for the green vessel scheduling problem in a liner shipping route with ECAs. The first model is based on the existing IMO regulations, whereas the second one along with the established IMO requirements enforces emission restrictions within ECAs. Extensive numerical experiments are performed to assess advantages and disadvantages from introducing emission restrictions within ECAs.

Based on past studies on the bank effect, the purpose of this paper is to use hydrodynamic principles to simulate the overtaking and the head-on encounter phenomenon of two ships.

The ship model used in this study was established through a computer aided design (CAD) tool. Computational fluid dynamics (CFD) package was used to simulate the hydrodynamic interaction effect of the overtaking and the head-on encounter situation between two ships of different speeds. The conditions for simulation include such parameters as the speed of the ship model, the distance between the ships, and the navigation time.

A chart is also used to demonstrate the two ships ' distribution of flow field and pressure, and to continually compare the changes in the sway force and the yaw speed. A relationship diagram of the overtaking and the head-on encounter process is also established to serve as a reference in maritime science in terms of research regarding the complex fluid dynamics that occurs when ships are merged with the sea.

The application of CFD simulation results presented in this study for the ship-ship interaction support the following major conclusions: first, it is evident from the two analysis charts of angular velocity, and sway force that the cycle gradually becomes shorter with the decrease of speed of the V1 vessel during the overtaking and the head-on process; this phenomenon is most significant when the ship width is at 0.5B. Second, the ship-ship interaction increase significantly for a S2S value of 0.5B. Thus, the results indicate that the ship-ship interaction effects must be taken into consideration when performing ship handling maneuvers involving passing and meeting.

The numerical simulation of two‐dimensional incompressible complex flows of viscoelastic fluids is presented. The context is one, relevant to the food industry (dough kneading), of stirring within a cylindrical vessel, where stirrers are attached to the lid of the vessel. The motion is driven by the rotation of the outer vessel wall, with various stirrer locations. With a single stirrer, both a concentric and an eccentric configuration are considered. A double‐stirrer eccentric case, with two symmetrically arranged stirrers, is also contrasted against the above. A parallel numerical method is adopted, based on a finite element semi‐implicit time‐stepping Taylor‐Galerkin/pressure‐correction scheme. For viscoelastic fluids, constant viscosity Oldroyd‐B and two shear‐thinning Phan‐Thien/Tanner constitutive models are employed. Both linear and exponential models at two different material parameters are considered. This permits a comparison of various stress, shear and extensional properties and their respective influences upon the flow fields generated. Variation with increasing speed of vessel and change in mixer geometry are analysed with respect to the flow kinematics and stress fields produced. Optimal kneading scenarios are commended with asymmetrical stirrer positioning, one‐stirrer proving better than two. Then, models with enhanced strain‐hardening, amplify levels of localised maxima in rate‐of‐work done per unit power consumed. Simulations are conducted via distributed parallel processing, performed on work‐station clusters, employing a conventional message passing protocol (PVM). Parallel results are compared against those obtained on a single processor (sequential computation). Ideal linear speed‐up with the number of processors has been observed.

The purpose of this paper is to clarify the effect of material hardening model and lump-pass method on the thermal-elastic-plastic (TEP) finite element (FE) simulation of residual stress induced by multi-pass welding of materials with cyclic plasticity.

Nickel-base alloy and stainless steel, which are used in J-type weld for manufacturing the nuclear reactor pressure head, can easily harden during multi-pass welding. The J-weld welding experiment is carried out and the temperature cycle and residual stress are measured to validate the TEP simulation. Thermal-mechanical sequence coupling method is employed to get the welding residual stress. The lumped-pass model and pass-by-pass FE model are built and two materials hardening models, kinematic hardening model and mixed hardening model, are adopted during the simulations. The effects of material hardening models and lumped-pass method on the residual stress in J-weld are distinguished.

Based on the kinematic hardening model, the stresses simulated with the lumped-pass FE model are almost consistent with those obtained by the pass-by-pass FE model; while with the mixed hardening material model, the lumped-pass method has great effect on the simulated stress.

A computation with mixed isotropic-kinematic material seems not to be the appropriate solution when using the lumped-pass method to save the computation time.

In the simulation of multi-pass welding residual stress involved in materials with cyclic plasticity, the material hardening model should be carefully considered. The kinematic hardening model with lump-pass FE model can be used to get better simulation results with less computation time. The results give a direction for welding residual stress simulation for the large structure such as the reactor pressure vessel.

IN recent years, much attention has been given to spontaneous ignition problems because of the high skin temperatures of aircraft operating at high Mach numbers. The problem is not really new, however, since for many years aircraft engines have been operating with carcase temperatures above the laboratory closed vessel spontaneous ignition temperatures for fuels and lubricants, and installation engineers have collected a good deal of ad hoc data to justify the safety of particular power plants. FIG. 1 indicates the main risk areas for a typical subsonic by‐pass jet installation.

The Equal Pay Act 1970 (which came into operation on 29 December 1975) provides for an “equality clause” to be written into all contracts of employment. S.1(2) (a) of the 1970 Act (which has been amended by the Sex Discrimination Act 1975) provides:

Investigates the differences in protocols between arbitral tribunals and courts, with particular emphasis on US, Greek and English law. Gives examples of each country and its way of using the law in specific circumstances, and shows the variations therein. Sums up that arbitration is much the better way to gok as it avoids delays and expenses, plus the vexation/frustration of normal litigation. Concludes that the US and Greek constitutions and common law tradition in England appear to allow involved parties to choose their own judge, who can thus be an arbitrator. Discusses e‐commerce and speculates on this for the future.

IN the later stages of the War, aerial maoœuvres at high altitude became increasingly frequent for well‐defined reasons, and, since the War, the tendency has been to provide certain types of aircraft capable of a rapid climb to heights in excess of 25,000 ft. Much work on high‐altitude flying has been done in this and other countries, and notably in the United States, where the present height record of 43,166 ft. is held. This climb was achieved on June 4, 1930, by Lt. Soucck, U.S.N. in an Apache aeroplane. The previous record of 41,794 ft. was held by a German pilot, Willy Neuenhofen, flying a Junkers monoplane. What these figures mean and how they were calculated need not be discussed, for the heights are so huge as to make any comment unnecessary, and when the difficulties of maintaining engine power, effective breathing, necessary warmth of the pilot, and the freedom of controls in temperatures approximating to 90 deg. F. of frost are considered, the performances stand out as unique in technical skill and physical endurance.