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The Development and Characterisation of Microemulsions for the Separation of Pharmaceutical Analytes by HPLC and CE
Get PDFMicroemulsions are unique dispersions of oil in water or water in oil which are stabilised by a surfactant and co-surfactant. The formation of such a mixture was first reported by Hoar and Schulman in the 1940s when they noticed a mixture of hydrocarbon and surfactant turned from milky to clear on the addition of alcohol. The ability of microemulsions to simultaneously solubilise either aqueous or organic components while remaining isotropically clear and thermodynamically stable attracted much attention, particularly in the 1970s for use in tertiary oil recovery. During the early 1990s these surfactant based systems were reported in separation science as mobile phases in HPLC and background electrolytes in CE.
Given the capability of microemulsions to dissolve both aqueous and non-aqueous compounds, their use as eluents in HPLC (MELC) and background electrolytes in CE (MEEKC) was further examined. In order to effectively test the ability of microemulsions to separate a diverse range of compounds, they were applied to the simultaneous analysis of oil- and water-soluble vitamins. A novel MELC method was developed for the simultaneous isocratic separation of oil- and water-soluble vitamins. Similarly, a MEEKC method was also developed for separating the same range of vitamins. In addition to separation, all microemulsion compositions examined in the development of the MEEKC method were characterised in terms of droplet size, surface tension, conductivity, and refractive index. When cross correlated with the MEEKC vitamin separation, relationships between choice of microemulsion components, physicochemical measurements and separation were observed.
Also, a commonly reported SDS based microemulsion was characterised and applied to the MEEKC separation of pharmaceutical analytes. Initially a pseudoternary phase diagram was constructed to establish a range of possible compositions. Microemulsions across an aqueous dilution line were prepared and physicochemical measurements conducted to establish microemulsion phase type and transition. Results indicated that the measurement techniques employed were capable of describing microemulsion phase type. Furthermore, it was seen that the microemulsion phase type could be correlated with a MEEKC separation
Innovation and firm’s interaction behaviour: Is innovation associated with local or non-local interactions? An investigation of clustered micro and small technology-based firms in Brazil
Get PDFThe changes in the nature of the global economy in the last 30 years have increased the
focus on the role of innovation directly affecting competitiveness of organizations and
countries. These changes have provoked the need for new strategies to enable
companies to compete with each other in a dynamic and globalized market. Academics
from different disciplines such as economic geography, business management and
sociology have attempted to explain the gains in competitiveness through innovation.
The great majority seem to agree that innovation depends on many factors that include
location and network-based environments. From the spatial perspective, previous
research shows that innovation seems to be influenced by locational factors which in
essence, due to geographic proximity, tend to facilitate local relational linkages
impacting the firm’s innovation activities. In this context, this thesis focuses on
Brazilian clustered micro and small technology-based firms and investigates the extent
to which innovation is associated with local or non-local interactions. The results of this
study reveal that innovation is not a solitary phenomenon restricted to the firm itself.
Innovation seems to be an interactive phenomenon where geographic distance does not
seem to be a problem but both local and non-local interactions are important to the
development of innovation activities. In fact, the empirical evidence suggests that
innovation arises in many contexts involving both local and non-local interactions.
According to this study, the general level of interactivity does not seem to be
determined by the geographic scope of the relational linkages, but by the quality and
perception of gains or benefits of the innovation sources
Distributed Algorithms for Computing Closed Itemsets Based on an Iterative MapReduce Framework
Get PDFClosed Itemset mining is a major task both in Data Mining and Formal
Concept Analysis. It is an efficient way to determine patterns which are
hidden in raw data. These patterns may be expressed as association rules
which capture relations between variables in databases. In the case of Formal
Concept Analysis, Closed Itemsets form the basis of formal concepts. A
concept consists of an extent and intent. It turns out that the intent is
exactly a closed itemset whose support is the cardinality of extent. With
the increasing application of Data Mining and Formal Concept Analysis in
knowledge discovery, Closed Itemset mining is fast becoming an attractive
research area.
While many prominent algorithms have been developed to mine closed
itemsets in both Formal Concept Analysis and Frequent Closed Itemset mining
area, they are typically unsuitable for distributed implementation. The
root cause is that the theoretical foundation of closed itemset mining is
based on a centralized data representation. By examining the features of
closed itemset, we propose distributed closed itemset computing theories for
Formal Concept Analysis and Frequent Closed Itemset mining in a distributed
environment. Additionally, taking the MapReduce framework as our
inspiration we propose a general distributed approach for performing closed
itemset mining. We then provide representative exemplars of how the classic
centralized algorithms in Formal Concept Analysis and Frequent Closed
Itemset mining can be implemented in a distributed fashion using our methodology
and present a family of MR* algorithms, where the abbreviation
stands for MapReduce and * stands for the underlying algorithm that has
been adapted. To analyse the factors which impact a distributed algorithm's
performance, we compare our MR* algorithms with the state-of-the-art. Experiments
conducted on real datasets demonstrate that the MR* algorithms
for Formal Concept Analysis are efficient and scalable. The MR* algorithm
and theory for Frequent Closed Itemset mining of this work set the scene for
future developments. We analyze our experimental results and discuss the
bottlenecks which we will focus on in future work
Combinatorial polynomials as moments, Hankel transforms and exponential Riordan arrays
Get PDFIn the case of two combinatorial polynomials (the Bell polynomials and the Eulerian polynomials), we show that they can exhibited as moments of paramaterized families of
orthogonal polynomials, and hence derive their Hankel transforms. Exponential Riordan arrays are the main vehicles used for this
An Investigation Into Human-centred Peer-support Education Systems for Students with Learning Difficulties
Get PDFThis research investigates the potential application and use of ICT in the development of peersupport networks centered on learners with Specific Learning Difficulties at third level education. Utilising a theoretical model based on both the social and medical models of disability, it is intended to develop a system that will allow learners to develop through interaction with their peers actionable education frameworks, adaptive learning strategies and reusable learning resources in a safe and contextualised learning environment. Primary research will be performed with the student population of Waterford Institute of Technology as a case study. The longitudinal goal is the improved retention, resilience and performance of the target population
QoE Testbed Infrastructure and Services: Enriching the End User’s Experience
Get PDFQuality of Experience (QoE) is the subjective judgment of the satisfaction an end user perceives from an application running over a given network topology and configuration. The information provided by end users regarding their QoE preferences, experience and feedback is invaluable in providing a service that meets with their mobile activity needs within various access networks. The PERIMETER project progresses the QoE thematic research area by taking end user-related QoE factors for end user-centric mobility experimentation, thus empowering them to always have a service in which their QoE is high. This paper will detail the components of the PERIMETER framework and the user centric scenario based process adopted to implement and develop such a framework. This paper provides an insight into the federated testbed infrastructure, testing methodology and tools, operating system and applications used in the project, thus demonstrating PERIMETER’s innovative advances within the QoE end user domain
The restricted Toda chain, exponential Riordan arrays, and Hankel transforms
Get PDFWe re-interpret results on the classification of Toda chain solutions given by Sheffer
class orthogonal polynomials in terms of exponential Riordan arrays. We also examine
associated Hankel transforms
Architecture & Implementation of a Testbeds Repository
Get PDFFederations of testbeds have an intrinsic characteristic: they are composed of heterogeneous resources and services residing in different geographic locations. To support description of these resources, there is a need for a common repository to be made available to the overall Panlab testbed federation architecture. In creating and integrating this repository, a number of design decisions were made to produce a flexible solution. We describe the structure of the repository software architecture and discuss the information model and derived data model. Finally, implementation details are further described at a functional level based on observations during the work carried out
Seamless Mobile Communications for mHealth
Get PDFThere is a growing trend in the health domain to incorporate Smartphones and other wireless technologies to
provide more efficient, cost effective, and higher quality
healthcare. With newer more sophisticated mobile devices for
example, Smartphones this is an escalating practice. To date the use of mobile phone technology in the healthcare domain (mHealth) has been limited to uses such as disseminating information. However, mHealth is beginning to include software and data applications based on mobile devices and technologies. This movement is largely due to the advent of newer technologies associated with Smartphones. Some Smartphones can now be considered to be intelligent sensors with sensing capabilities such as GPS location, proximity and accelerometers. This paper examines the use of such technology in providing seamless mobile communications for mHealth