Physical Sciences and Mathematics Commons^™

Energy Aware Communications Framework For Ieee 802.15.4 Wireless Sensor Networks, Rodolfo De Paz Alberola

Theses

A wireless sensor network (WSN) is a network of sensor nodes that functions in a cooperative manner to monitor the changes in the physical environment. Typically, sensor nodes are deployed in places with difficult access, if any, to an external power supply thus requiring battery power. Therefore, WSN communication protocols must be designed with energy efficient and self-organizing capabilities in mind. In this context, the IEEE 802.15.4 standard is being widely employed for the lower layers of low-cost, low-rate and low-power wireless sensor communications due to its potential to fulfil requirements of various monitoring and control applications. However, the specification …

Novel Lc-Ms Methods For The Determination Of Environmental And Food Contaminants Incorporating Analyte Confirmation Using High Resolution Ms, Michael George Cahill

Theses

The contamination of the aquatic environment with pesticides has become an emerging environmental issue because of the potential risk to human health and wildlife. Effluent from wastewater treatment plants (WWTPs) have been identified as an important source of micro­organic contaminants in the environment. The EC have implemented several directives for the control of pesticides in the environment including the 98/83/EEC directive establishing the concentration of pesticide allowed for human consumption, the 2000/60/EC directive set up to monitor priority pollutants that are hazardous substances in the environment and REACH ensuring these substances are registered, controlled, therefore ensuring that the industry is …

Optically Injected And Mutually Coupled Frequency Distinct Semiconductor Lasers, Beatriz Baselga-Pascual

Theses

In the following work we examine the dynamics of semiconductor lasers under different types of coupled oscillator configurations, namely optical injection and mutual coupling. We examine both discrete-mode quantum well lasers and distribute feedback quantum dot lasers. First we describe optical injection experiments carried out on single mode semiconductor lasers. Conventional diagnostic tools such as optical spectra, RF spectra and intensity time series are used to describe the dynamics. We also describe a novel interferometric technique used to experimentally resolve the phase of the slave laser. This new technique has proved successful, revealing some heretofore hidden dynamical features and showing …

A Qos Aware Framework For Wireless Sensor Networks In Industrial Environments, Berta Carballido Villaverde

Theses

Wireless Sensor Networks (WSNs) are a key enabling technology for industrial monitoring applications where the use of wireless infrastructure allows high adaptivity and low cost in terms of installation and retrofitting. Although WSNs present several advantages over traditional wired monitoring systems, there is significant concern as to the reliability of wireless communications due to the unpredictability of the wireless channel, which is inhibiting the widespread adoption of the technology. Furthermore, due to the diverse range of monitoring applications that are found in industrial environments and their differing requirements, there is a need for quality of service (QoS) provisioning so that …

Semi-Automatic Management Of Knowledge Bases Using Formal Ontologies, Andreas Textor

Theses

This thesis presents an approach that deals with the ever-growing amount of data in knowledge bases, especially concerning knowledge interoperability and formal representation of domain knowledge. There arc multiple issues that must be addressed with current systems. A multitude of different formats, sources and tools exist in a domain, and it is desirable to develop their use further towards a standardised environment. Such an environment should support both the representation and processing of data from this domain, and the connection to other domains, where necessary. In order to manage large amounts of data, it should be possible to perform whatever …

Development, Validation And Application Of Uhplc-Ms/Ms Methods For The Detection Of Veterinary Drug Residues In Food Of Animal Origin, Michelle Whelan

Theses

Ultra high pressure liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-MS/MS) technology was utilized for the development of analytical methods for the detection of veterinary drug residues in foods of animal origin. Initial work focused on the development of the mass spectrometry (MS) method for the detection of the analytes of interest and subsequent chromatographic separation. The MS method was optimised to detect both positively and negatively ionised analytes from different classes in a single injection in a 13 minute run time at μg kg^-1levels.

Sample preparation procedures were modified to extract the residues from muscle and …

High Resolution Hybrid Mass Spectrometry For The Determination Of Marine Biotoxins, Azaspiracids, And Their Biotransformation Products., Zuzana Skrabakova

Theses

Azaspiracids (AZAs), polyether marine toxins, are produced by marine microalgae and accumulate in filter-feeding bivalve molluscs, such as mussels, clams, oysters and scallops, while grazing on phytoplankton, from which they derive nutrition. Although being discovered quite recently, AZAs have caused several human intoxication events and thus became a problem for health authorities and shellfish industries. The rapid development of highly sensitive liquid chromatography multiple tandem mass spectrometry (LC-MS/MS, LC-MS") methods enabled the identification of numerous AZA analogues and added to the control of shellfish contamination. Tandem mass spectrometry techniques, while being highly selective and sensitive for determination of AZAs in …

Design Of A Centralised Anaerobic Digestion Plant In Ireland., Diarmuid O'Meara

Theses

Climate change is brought about by greenhouse gases emitted to the earth’s atmosphere by fossil fuels. Renewable energy sources are seen as an alternative to fossil fuels. Examples of renewable energy sources are biofuels which are a method of reducing the emission of greenhouse gases. One form of biofuels is biogas that is produced during the anaerobic digestion process. In this thesis pig slurry is used to produce biogas.

In this project, the optimum design process for a centralised anaerobic digestion plant was established in the literature review, The optimum process for anaerobic digestion plant design in Ireland was investigated. …

Quantum Engineering Of Laser-Cooled Atoms: Experiments And Theory, Kieran Deasy

Theses

In this thesis, laser cooling and trapping techniques are implemented to forrn a cold atom cloud of 85Rb atoms in a magneto-optical trap (Mon configuration. The system produces an atom cloud of~ 1.5 mm in diameter, containing ~ 108 atoms and an average temperature in the sub-Doppler range. Tapered optical fibres (TOFs) are also detailed here, including their guiding properties and the process used for their fabrication. Many possible applications for TOFs have been proposed and one such application is investigated, i.e. the use of TOFs as highly sensitive atom probes. The research results contained within this thesis describe two …

A Machine-Learning Approach For Workflow Identification From Low-Level Monitoring Information, Thorsten Stein

Theses

Knowing which workflows are executed within Service Oriented Architectures (SOA) is essential for successful IT management. In many cases, SOAs grew out of previous existing IT architectures; existing components are used as single services and therefore as parts of newly created workflows. Since such workflows consist of newly developed and legacy services, traditional workflow management systems often cannot be applied. This thesis presents a method for gathering information about the executed workflows within such heterogeneous environments. An implementation of a framework is presented. This framework allows the training of machine-learning algorithms with workflow models and the mapping of low-level monitoring …