82 research outputs found
KISS (Keep It Sustainable and Smart): A Research and Development Program for a Zero-Emission Small Crafts
This paper reviews a state-of-the-art zero emission propulsion system for a battery-powered small craft. The main aspects considered are the available propulsion systems, energy storage, and dock battery charging. This underlying activity is part of the KISS project, a research and development program in the frame of the EU-funded “Piano Operativo Regionale CALABRIA FESR-FSE 2014–2020 ASSE I–PROMOZIONEDELLA RICERCA E DELL’INNOVAZIONE”, which is aimed at designing and building a physical prototype. Its hull form is based on previous research conducted by the authors, and the powering performances were preliminarily predicted by CFD simulation. The KISS project represents a successful example of an electric small craft with performances and a mission profile comparable to competitors with conventional propulsion. Such a target has been achieved by a concurrent design that considers the hull form, engine, propulsion system, and energy storage onboard. Safety issues and the regulatory frame are also highlighted
Adverse Drug Reactions in Children—A Systematic Review
Adverse drug reactions in children are an important public health problem. We have undertaken a systematic review of observational studies in children in three settings: causing admission to hospital, occurring during hospital stay and occurring in the community. We were particularly interested in understanding how ADRs might be better detected, assessed and avoided
Vulnerability assessment of surf-riding-broaching and pure loss of stability for Systematic Series D1 model
This paper is focused on the first and second level vulnerability assessment of Surf riding/Broaching and Pure Loss of Stability Criteria according to IMO second generation intact stability criteria. The calculations are performed for the semi-displacement twin-screw round-bilge hull form model D1 of the Systematic Series D. This model has hull form and service speed representative of corvettes built in 90-ties. The considered loading condition is obtained from Italian Navy ships statistics. Both criteria are analysed for different operational characteristics to evaluate the speed limits where the ship is not vulnerable. Model D1 is found to be vulnerable to both failure modes at service speed. Performing 2nd level of both criteria 'safe' speed is around 19 knots for surf-riding and around 15, 5 knots for pure loss. The obtained results are commented and compared against similar ships from the relevant state of the art papers
The Impact of Different Bow Shapes on Large Yacht Comfort
The importance of comfort during transfer and stationing becomes a key performance parameter for large yacht design, on the same level as propulsive issues. Such a matter extends questions in terms of form and service demand to the motion behaviour of the unit in waves. Relevant studies refer to outdated hull forms not specific to modern large yachts. In this study, five hull forms with different bow concepts represent the most common design solutions for yachts at constant draught and displacement. The preliminary ranking on the effect of alternative bows on comfort requires the definition of internationally accepted comfort standards. Here, the AWI 22834 guidelines for large yachts provide the service and environmental conditions and criteria for the comfort analysis, being the only reference specific to yachts. The calculations employ a strip-theory-based numerical model to provide results of easy understanding for designers during the early design stage. The obtained ranking among the design solutions on a reference large yacht favours the option nested with a bulb, contradicting the expectations in favour of a vertical bow concept. The discussion and conclusions provide a way forward for additional analyses and investigations aimed at proposing suitable multicriterial design guidelines for large yachts. However, the results also show the unsuitability of AWI environmental and encounter conditions for hull form ranking
Application of the 2nd Generation Intact Stability Criteria for fast semi displacement ships
The Second Generation Intact Stability Criteria (SGISC) are developing since 2002 after a series of naval ac-cidents, which clearly demonstrated that actual stability criteria are not adequate to account for significant changes in the design and operation characteristics of new commercial ships. The philosophy is a multi-level approach in which successive levels are less conservative and more accurate, arriving, if necessary, to the Di-rect Assessment of stability failures. In this paper, Level 1 and 2 of the three main stability failure modes of the SGISC: The Parametric Roll, Pure Loss of Stability and Surf-riding/Broaching are studied on four naval ships the Systematic Series D two-parent hulls, the ONRT, benchmark ship from research version of the US Navy, and FREMM, a class of mul-ti-purpose French- Italian frigates. For every ship typology, when one was found vulnerable to 2nd level, the corresponding criteria were analyzed by navigation conditions to estimate operational limits
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