Sources of uncertainties in modelling black carbon at the global scale

Our understanding of the global black carbon (BC) cycle is essentially qualitative due to uncertainties in our knowledge of its properties. This work investigates two source of uncertainties in modelling black carbon: those due to the use of different schemes for BC ageing and its removal rate in the global Transport-Chemistry model TM5 and those due to the uncertainties in the definition and quantification of the observations, which propagate through to both the emission inventories, and the measurements used for the model evaluation. The schemes for the atmospheric processing of black carbon that have been tested with the model are (i) a simple approach considering BC as bulk aerosol and a simple treatment of the removal with fixed 70% of in-cloud black carbon concentrations scavenged by clouds and removed when rain is present and (ii) a more complete description of microphysical ageing within an aerosol dynamics model, where removal is coupled to the microphysical properties of the aerosol, which results in a global average of 40% in-cloud black carbon that is scavenged in clouds and subsequently removed by rain, thus resulting in a longer atmospheric lifetime. This difference is reflected in comparisons between both sets of modelled results and the measurements. Close to the sources, both anthropogenic and vegetation fire source regions, the model results do not differ significantly, indicating that the emissions are the prevailing mechanism determining the concentrations and the choice of the aerosol scheme does not influence the levels. In more remote areas such as oceanic and polar regions the differences can be orders of magnitude, due to the differences between the two schemes. The more complete description reproduces the seasonal trend of the black carbon observations in those areas, although not always the magnitude of the signal, while the more simplified approach underestimates black carbon concentrations by orders of magnitude. The sensitivity to wet scavenging has been tested by varying in-cloud and below-cloud removal. BC lifetime increases by 10% when large scale and convective scale precipitation removal efficiency are reduced by 30%, while the variation is very small when below-cloud scavenging is zero. Since the emission inventories are representative of elemental carbon-like substance, the model output should be compared to elemental carbon measurements and if known, the ratio of black carbon to elemental carbon mass should be taken into account when the model is compared with black carbon observation

Dynamic digital factories for agile supply chains: An architectural approach

Digital factories comprise a multi-layered integration of various activities along the factories and product lifecycles. A central aspect of a digital factory is that of enabling the product lifecycle stakeholders to collaborate through the use of software solutions. The digital factory thus expands outside the company boundaries and offers the opportunity to collaborate on business processes affecting the whole supply chain. This paper discusses an interoperability architecture for digital factories. To this end, it delves into the issue by analysing the key requirements for enabling a scalable factory architecture characterized by access to services, aggregation of data, and orchestration of production processes. Then, the paper revises the state-of-the-art w.r.t. these requirements and proposes an architectural framework conjugating features of both service-oriented and data-sharing architectures. The framework is exemplified through a case study

Semantic discovery and reuse of business process patterns

Patterns currently play an important role in modern information systems (IS) development and their use has mainly been restricted to the design and implementation phases of the development lifecycle. Given the increasing significance of business modelling in IS development, patterns have the potential of providing a viable solution for promoting reusability of recurrent generalized models in the very early stages of development. As a statement of research-in-progress this paper focuses on business process patterns and proposes an initial methodological framework for the discovery and reuse of business process patterns within the IS development lifecycle. The framework borrows ideas from the domain engineering literature and proposes the use of semantics to drive both the discovery of patterns as well as their reuse

SOA-Based Model for Value-Added ITS Services Delivery

Integration is currently a key factor in intelligent transportation systems (ITS), especially because of the ever increasing service demands originating from the ITS industry and ITS users. The current ITS landscape is made up of multiple technologies that are tightly coupled, and its interoperability is extremely low, which limits ITS services generation. Given this fact, novel information technologies (IT) based on the service-oriented architecture (SOA) paradigm have begun to introduce new ways to address this problem. The SOA paradigm allows the construction of loosely coupled distributed systems that can help to integrate the heterogeneous systems that are part of ITS. In this paper, we focus on developing an SOA-based model for integrating information technologies (IT) into ITS to achieve ITS service delivery. To develop our model, the ITS technologies and services involved were identified, catalogued, and decoupled. In doing so, we applied our SOA-based model to integrate all of the ITS technologies and services, ranging from the lowest-level technical components, such as roadside unit as a service (RS S), to the most abstract ITS services that will be offered to ITS users (value-added services). To validate our model, a functionality case study that included all of the components of our model was designed

Design Models for Service-based Software Application

Context: The use of a Service Oriented Architecture (SOA) offers a new and distinct approach to creating software based applications (SBAs) around the idea of integrating distributed autonomous computing resources. A widely available realisation of an SOA exists in the form of web services. However, to date no standard techniques have emerged for developing SBAs. There is also a lack of consistency in describing the concept itself, and the published literature offers little evidence derived from the experience of developing `real world examples. Aims: The objective of the work described in this thesis was to conduct a series of studies to explore systematically the concept of what constitutes an SOA by using the published literature, to employ this to construct a proof of concept SOA design model based on a real world problem, and in doing so, to investigate how well existing design notations are able to support this architectural style. Method: The research described in this thesis has been conducted in an evolutionary manner by employing a range of empirical methods. A mapping study was performed to investigate how the concept of SOA is interpreted by the research community. Based upon this model of SOA, a participant-observer case study was employed to construct an SOA design model and a use case model for an energy engineering application to demonstrate use for a real world problem. Finally, expert knowledge was employed for evaluation of the case study through the use of walkthroughs. Results: From the mapping study we created an integrated model of what constitutes an SOA for the use with the case study. The case study outcomes include a design for a renewable energy control system together with codified experience of constructing and recording the SOA design model. The experience of employing the walkthrough method for evaluation, and the outcomes of the evaluation are also discussed. Conclusion: From this research we conclude that the SOA research community needs to develop a clearer shared understanding and agreement on the model of what constitutes an SOA and the vocabulary used to describe the SOA concept. This will aid designers to communicate their mental models more effectively and will provide the semantics needed for devising the new notations that this study implies are needed for SBA design. Further, some lessons about SBA design have been derived from the case study experiences

Non-thermal plasma system for marine diesel engine emissions control

Air pollutants generated by ships in both gaseous and particulate forms, have a long term effect on the quality of the environment and cause a significant exposure risk to people living in proximities of harbors or in neighboring coastal areas. It was recently estimated, that ships produce at least 15% of the world’s NOx (more than all of the world’s cars, buses and trucks combined), between 2.5 - 4% of greenhouse gases, 5% black carbon (BC), and between 3-7% of global SO2 output. Estimation of contribution of maritime shipping to global emissions of VOC and CO is not yet available. In order to reduce the environmental footprint of ships, the International Maritime Organization (IMO) recently issued the legislation of Marpol Annex VI guidelines which implies especially the introduction of, inter alia, stricter sulphur limits for marine fuel in ECAs under the revised MARPOL Annex VI, to 3.50% (from the current 4.50%), effective from 1 January 2012; then progressively to 0.50 %, effective from 1 January 2020, subject to a feasibility review to be completed no later than 2018. The limits applicable in Emission Control Zones (ECAs) for SOx and particulate matter were reduced to 1.00%, beginning on 1 July 2010 (from the original 1.50%); being further reduced to 0.10 %, effective from 1 January 2015. The Tier III controls apply only to the specified ships built from 2016 while operating in Emission Control Areas (ECA) established to limit NOx emissions, outside such areas the Tier II controls apply. The United States and Canada adopted national regulations enforcing IMO Tier III equivalent limits within the North American ECA effective 2016. The US Environmental Protection Agency (EPA) rule for Category III ships, however, references the international IMO standards. If the IMO emission standards are indeed delayed, the Tier III standards would be applicable from 2016 only for US flagged vessels. One of the proposed solutions towards marine diesel emission control is the non-thermal plasma process. We designed and built a non-thermal plasma reactor (NTPR) using a combination of Microwave (MW) and Electron Beam (EB) for treatment of marine diesel exhaust gas. A numerical model has been developed to better understand the marine exhaust gas/plasma kinetics. The reactor modelling and design can sustain 10kW of combined MW and EB power with a gas flow rate of 200l/s. The removal of NOx and SOx was continuously monitored using a portable dual Testo gas analyzer system while all other parameters (MW power, EB power, gas temperature/flow rate, etc.) were remotely recorded & stored through a Labview DAQ system. The reactor performance in NOx and SOx removal will be tested on a 200 kW two stroke marine engine. This study is a part of the DEECON (Innovative After-Treatment System for Marine Diesel Engine Emission Control) FP7 European project.The work was supported by the European Commission under DEECON FP7 European Project "Innovative After-Treatment System for Marine Diesel Engine Emission Control", contract No. 284745