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This version is available at https://strathprints.strath.ac.uk/47206/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the AbstractIn this paper, the main alternative propulsion plants based on reciprocating internal combustion engines of a ferry or RoRo ship operating in routes that include Emission Control Areas (ECAs) are comparatively assessed. Specifically, a dual fuel engine propulsion plant is compared with a conventional Diesel engine plant. For both cases, the installation of a Waste Heat Recovery system, which covers a part of the ship electric energy demand, is also considered. The ship main DF engines are assumed to operate using LNG and a small amount of MDO for initiating combustion, whereas low sulphur MDO was regarded as the fuel for the case of the Diesel engine plant. The installation of selective catalytic reduction (SCR) after-treatment unit for reducing the NOx emissions for the case of Diesel engines plant is also taken into account. The propulsion plants were modelled under steady state conditions, and the simulation results were analysed in order to compare the alternative configurations.Furthermore, the energy efficiency design index (EEDI) values were calculated and the two examined propulsion system cases were compared on EEDI basis. Finally, the Life Cycle Cost for each alternative propulsion plant was calculated and used for completing an economic evaluation of the Dual fuel propulsion plant versus the conventional designs applied in ferries.

In this work, an integrated thermal gas flow sensor was fabricated and evaluated using a new thermal isolation technique based on a porous silicon membrane over an air cavity in silicon. The fabrication process of a thermal gas flow sensor employing this type of micro-hotplate is described together with the theoretical estimation of the thermal distribution around the heater of the sensor. Experimental results of the thermal isolation achieved are shown. A flow evaluation of the sensor is presented and discussed. All the results obtained are compared with the corresponding ones for an identical sensor using a micro-hotplate made of porous silicon membrane but without the air cavity underneath. The improvement achieved by the air cavity is evaluated.

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An improvement of porous silicon technology for local thermal isolation on bulk crystalline silicon is presented. The technique consists of forming an air cavity below the porous layer to increase the thermal isolation efficiency. Both porous silicon and the cavity underneath are formed during the same electrochemical process in two steps: in step 1 the current density used is below a critical value, and in step 2 it is switched to a value above the critical current for electropolishing. In this way, porous silicon is formed first, followed by the formation of the cavity underneath. Experimental results and simulations are shown together with an application of this process in a thermal silicon flow sensor.

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In this work, the masking technology for selective porous silicon formation by creating n-type areas on a p-type substrate by ion implantation was investigated and the optimum conditions were found. The most critical parameter in the process is the surface concentration of dopants. However, in all cases, some corrosion of the masking area was observed. The main efficiency-limiting factor of the technique is pointed out and a solution is proposed. The optimum conditions developed were used to fabricate suspended monocrystalline silicon membranes on bulk silicon.