Technical and economic feasibility of organic Rankine cycle-based waste heat recovery systems on feeder ships: Impact of nitrogen oxides emission abatement technologies

The International Maritime Organization recently revised the regulations concerning nitrogen and sulphur oxides emissions from commercial ships. In this context, it is important to investigate how emission abatement technologies capable of meeting the updated regulation on nitrogen oxides emissions affect the performance of waste heat recovery units to be installed on board new vessels. The objective of this paper is to assess the potential fuel savings of installing an organic Rankine cycle unit on board a hypothetical liquefied natural gas-fuelled feeder ship operating inside emission control areas. The vessel complies with the updated legislation on sulphur oxides emissions by using a dual fuel engine. Compliance with the nitrogen oxides emission regulation is reached by employing either a high or low-pressure selective catalytic reactor, or an exhaust gas recirculation unit. A multi-objective optimization was carried out where the objective functions were the organic Rankine cycle unit annual electricity production, the volume of the heat exchangers, and the net present value of the investment. The results indicate that the prospects for attaining a cost-effective installation of an organic Rankine unit are larger if the vessel is equipped with a low-pressure selective catalytic reactor or an exhaust gas recirculation unit. Moreover, the results suggest that the cost-effectiveness of the organic Rankine cycle units is highly affected by fuel price and the waste heat recovery boiler design constraints

Temporal Relations in Multimedia Objects: WWW Presentation from HyTime Specification

The representation of temporal relations in multimedia objects is based on models of time that allow the identification and the specification of temporal relations among different media, particularly those relations relevant to the process of multimedia synchronization. Initially, this paper discusses the use of HyTime for the specification of binary temporal relations. Next, the paper discusses an approach to the automatic transformation of the HyTime synchronization specifications into elements to be presented in the context of the World Wide Web environment. Keywords: Media Scheduling and Synchronization; Synchronization Specification; HyTime; WWW presentation. 1. Introduction Research in multimedia systems involves the investigation of problems that arise in the integration of distinct media such as text, images, audio and video. The presentation of continuous media such as audio and video, when components of a multimedia object, requires the correct positioning in time of each ..

A DAVIC-based Architecture for Hypermedia Applications over the Internet

This paper presents an architecture aimed at supporting distributed hypermedia applications focusing on the exchange of multimedia objects over the Internet, their processing and presentation. The model is based on DAVIC proposals for interactive TV, which means that MHEG-5 is adopted as the representation standard for multimedia objects and DSM-CC as the real time protocol for data delivery. Keywords: DAVIC (Digital Audio-Visual Council), MHEG-5 (Multimedia and Hypermedia information coding Expert Group), DSM-CC (Digital Storage Media Command and Control), Multimedia Objects, Real Time Delivery. 1 Introduction The distribution of data and processing is a strong candidate in answer to the requirements of new applications, as seen in the case of hypermedia systems [1]. However, such a solution also demands the adoption of standards for representing and interchanging multimedia information. The great rise in the number of machines connected to the global network Internet, the widespr..