Design, development and control of a new generation high performance linear actuator for parallel robots and other applications

The main focus of this research is to design and develop a high performance linear actuator based on a four bar mechanism. The present work includes the detailed analysis (kinematics and dynamics), design, implementation and experimental validation of the newly designed actuator. High performance is characterized by the acceleration of the actuator end effector. The principle of the newly designed actuator is to network the four bar rhombus configuration (where some bars are extended to form an X shape) to attain high acceleration. Firstly, a detailed kinematic analysis of the actuator is presented and kinematic performance is evaluated through MATLAB simulations. A dynamic equation of the actuator is achieved by using the Lagrangian dynamic formulation. A SIMULINK control model of the actuator is developed using the dynamic equation. In addition, Bond Graph methodology is presented for the dynamic simulation. The Bond Graph model comprises individual component modeling of the actuator along with control. Required torque was simulated using the Bond Graph model. Results indicate that, high acceleration (around 20g) can be achieved with modest (3 N-m or less) torque input. A practical prototype of the actuator is designed using SOLIDWORKS and then produced to verify the proof of concept. The design goal was to achieve the peak acceleration of more than 10g at the middle point of the travel length, when the end effector travels the stroke length (around 1 m). The actuator is primarily designed to operate in standalone condition and later to use it in the 3RPR parallel robot. A DC motor is used to operate the actuator. A quadrature encoder is attached with the DC motor to control the end effector. The associated control scheme of the actuator is analyzed and integrated with the physical prototype. From standalone experimentation of the actuator, around 17g acceleration was achieved by the end effector (stroke length was 0.2m to 0.78m). Results indicate that the developed dynamic model results are in good agreement. Finally, a Design of Experiment (DOE) based statistical approach is also introduced to identify the parametric combination that yields the greatest performance. Data are collected by using the Bond Graph model. This approach is helpful in designing the actuator without much complexity.

Transposon mutagenesis in bifidobacterium breve: construction and characterization of a Tn5 transposon mutant library for bifidobacterium breve UCC2003

Bifidobacteria are claimed to contribute positively to human health through a range of beneficial or probiotic activities, including amelioration of gastrointestinal and metabolic disorders, and therefore this particular group of gastrointestinal commensals has enjoyed increasing industrial and scientific attention in recent years. However, the molecular mechanisms underlying these probiotic mechanisms are still largely unknown, mainly due to the fact that molecular tools for bifidobacteria are rather poorly developed, with many strains lacking genetic accessibility. In this work, we describe the generation of transposon insertion mutants in two bifidobacterial strains, B. breve UCC2003 and B. breve NCFB2258. We also report the creation of the first transposon mutant library in a bifidobacterial strain, employing B. breve UCC2003 and a Tn5-based transposome strategy. The library was found to be composed of clones containing single transposon insertions which appear to be randomly distributed along the genome. The usefulness of the library to perform phenotypic screenings was confirmed through identification and analysis of mutants defective in D-galactose, D-lactose or pullulan utilization abilities.

Characterization of the Galactic White Dwarf Population in the Next Generation Virgo Cluster Survey

Halo white dwarfs remain one of the least studied stellar populations in the Milky Way because of their faint luminosities. Recent work has uncovered a population of hot white dwarfs which are thought to be remnants of low-mass Population II stars. This thesis uses optical data from the Next Generation Virgo Cluster Survey (NGVS) and ultravoilet data from the GALEX Ultraviolet Virgo Cluster Survey (GUViCS) to select candidates which may belong to this population of recently formed halo white dwarfs. A colour selection was used to separate white dwarfs from QSOs and main-sequence stars. Photometric distances are calculated using model colour-absolute magnitude relations. Proper motions are calculated by using the difference in positions between objects from the Sloan Digital Sky Survey and the NGVS. The proper motions are combined with the calculated photometric distances to calculate tangential velocities, as well as approximate Galactic space velocities. White dwarf candidates are characterized as belonging to either the disk or the halo using a variety of methods, including calculated scale heights (z> 1 kpc), tangential velocities (vt >200 km/s), and their location in (V,U) space. The 20 halo white dwarf candidates which were selected using Galactic space velocities are analyzed, and their colours and temperatures suggest that these objects represent some of the youngest white dwarfs in the Galactic halo.

Development of An Enhanced Oil Sands Fluid Tailings Generation Model

Bitumen extraction from surface-mined oil sands results in the production of large volumes of Fluid Fine Tailings (FFT). Through Directive 085, the Province of Alberta has signaled that oil sands operators must improve and accelerate the methods by which they deal with FFT production, storage and treatment. This thesis aims to develop an enhanced method to forecast FFT production based on specific ore characteristics. A mass relationship and mathematical model to modify the Forecasting Tailings Model (FTM) by using fines and clay boundaries, as the two main indicators in FFT accumulation, has been developed. The modified FTM has been applied on representative block model data from an operating oil sands mining venture. An attempt has been made to identify order-of-magnitude associated tailings treatment costs, and to improve financial performance by not processing materials that have ultimate ore processing and tailings storage and treatment costs in excess of the value of bitumen they produce. The results on the real case study show that there is a 53% reduction in total tailings accumulations over the mine life by selectively processing only lower tailings generating materials through eliminating 15% of total mined ore materials with higher potential of fluid fines inventory. This significant result will assess the impact of Directive 082 on mining project economic and environmental performance towards the sustainable development of mining projects.

Exploring the feasibility of applying data mining for library reference service improvement : a case study of Turku Main Library

Data mining, as a heatedly discussed term, has been studied in various fields. Its possibilities in refining the decision-making process, realizing potential patterns and creating valuable knowledge have won attention of scholars and practitioners. However, there are less studies intending to combine data mining and libraries where data generation occurs all the time. Therefore, this thesis plans to fill such a gap. Meanwhile, potential opportunities created by data mining are explored to enhance one of the most important elements of libraries: reference service. In order to thoroughly demonstrate the feasibility and applicability of data mining, literature is reviewed to establish a critical understanding of data mining in libraries and attain the current status of library reference service. The result of the literature review indicates that free online data resources other than data generated on social media are rarely considered to be applied in current library data mining mandates. Therefore, the result of the literature review motivates the presented study to utilize online free resources. Furthermore, the natural match between data mining and libraries is established. The natural match is explained by emphasizing the data richness reality and considering data mining as one kind of knowledge, an easy choice for libraries, and a wise method to overcome reference service challenges. The natural match, especially the aspect that data mining could be helpful for library reference service, lays the main theoretical foundation for the empirical work in this study. Turku Main Library was selected as the case to answer the research question: whether data mining is feasible and applicable for reference service improvement. In this case, the daily visit from 2009 to 2015 in Turku Main Library is considered as the resource for data mining. In addition, corresponding weather conditions are collected from Weather Underground, which is totally free online. Before officially being analyzed, the collected dataset is cleansed and preprocessed in order to ensure the quality of data mining. Multiple regression analysis is employed to mine the final dataset. Hourly visits are the independent variable and weather conditions, Discomfort Index and seven days in a week are dependent variables. In the end, four models in different seasons are established to predict visiting situations in each season. Patterns are realized in different seasons and implications are created based on the discovered patterns. In addition, library-climate points are generated by a clustering method, which simplifies the process for librarians using weather data to forecast library visiting situation. Then the data mining result is interpreted from the perspective of improving reference service. After this data mining work, the result of the case study is presented to librarians so as to collect professional opinions regarding the possibility of employing data mining to improve reference services. In the end, positive opinions are collected, which implies that it is feasible to utilizing data mining as a tool to enhance library reference service.

Generation and Characterisation of a Canine EGFP-HMGA2 Prostate Cancer In Vitro Model

The architectural transcription factor HMGA2 is abundantly expressed during embryonic development. In several malignant neoplasias including prostate cancer, high re-expression of HMGA2 is correlated with malignancy and poor prognosis. The let-7 miRNA family is described to regulate HMGA2 negatively. The balance of let-7 and HMGA2 is discussed to play a major role in tumour aetiology. To further analyse the role of HMGA2 in prostate cancer a stable and highly reproducible in vitro model system is precondition. Herein we established a canine CT1258-EGFP-HMGA2 prostate cancer cell line stably overexpressing HMGA2 linked to EGFP and in addition the reference cell line CT1258-EGFP expressing solely EGFP to exclude EGFP-induced effects. Both recombinant cell lines were characterised by fluorescence microscopy, flow cytometry and immunocytochemistry. The proliferative effect of ectopically overexpressed HMGA2 was determined via BrdU assays. Comparative karyotyping of the derived and the initial CT1258 cell lines was performed to analyse chromosome consistency. The impact of the ectopic HMGA2 expression on its regulator let-7a was analysed by quantitative real-time PCR. Fluorescence microscopy and immunocytochemistry detected successful expression of the EGFP-HMGA2 fusion protein exclusively accumulating in the nucleus. Gene expression analyses confirmed HMGA2 overexpression in CT1258-EGFP-HMGA2 in comparison to CT1258-EGFP and native cells. Significantly higher let-7a expression levels were found in CT1258-EGFP-HMGA2 and CT1258-EGFP. The BrdU assays detected an increased proliferation of CT1258-HMGA2-EGFP cells compared to CT1258-EGFP and native CT1258. The cytogenetic analyses of CT1258-EGFP and CT1258-EGFP-HMGA2 resulted in a comparable hyperdiploid karyotype as described for native CT1258 cells. To further investigate the impact of recombinant overexpressed HMGA2 on CT1258 cells, other selected targets described to underlie HMGA2 regulation were screened in addition. The new fluorescent CT1258-EGFP-HMGA2 cell line is a stable tool enabling in vitro and in vivo analyses of the HMGA2-mediated effects on cells and the development and pathogenesis of prostate cancer.

Effect of Experience on Alibi Generation and Expectation

Members of the general population have high expectations of people who are asked to corroborate an alibi for the suspect of a crime. The general belief is that it is easy to provide an alibi if a person is innocent, and therefore guilt should be assumed when an alibi cannot be provided. The possibility that having to generate an alibi oneself could influence expectations was examined. Additionally, potential changes in opinion after being provided with positive or negative feedback were explored. Results showed a significant difference in expectations based on whether participants were correct or incorrect in identifying the suspect, that is, whether participants were able to provide an alibi. Those who were incorrect had lower expectations of themselves and of others than those who were correct. Making jurors aware of the difficulty in providing an alibi may lead to fairer treatment of suspects who have difficulty providing one.

Our own language: Scots verse translation and the second-generation Scottish renaissance

This thesis examines the role of Scots language verse translation in the second-generation or post-war Scottish Renaissance. The translation of European poetry into Scots was of central importance to the first-generation Scottish Renaissance of the nineteen twenties and thirties. As Margery Palmer McCulloch has shown, the wider cultural climate of Anglo-American modernism was key to MacDiarmid’s conception of the interwar Scottish Renaissance. What was the effect on second-generation poet-translators as the modernist moment passed? Are the many translations undertaken by the younger poets who emerged in the course of the nineteen forties and fifties a faithful reflection of this cultural inheritance? To what extent are they indicative of a new set of priorities and international influences? The five principal translators discussed in this thesis are Douglas Young (1913-1973), Sydney Goodsir Smith (1915-1975), Robert Garioch (1909-1981), Tom Scott (1918-1995) and William J. Tait (1918-1992). Each is the subject of a chapter, in many cases providing the first or most extensive treatment of particular translations. While the pioneering work of John Corbett, Bill Findlay and J. Derrick McClure, among other scholars, has drawn attention to the long history of literary translation into Scots, this thesis is the first extended critical work to take the verse translations of the post-MacDiarmid makars as its subject. The nature and extent of MacDiarmid’s influence is considered throughout, as are the wider discourses around language and translation in twentieth-century Scottish poetry. Critical engagement with a number of key insights from theoretical translation studies helps to situate these writers’ work in its global context. This thesis also explores the ways in which the specific context of Scots translation allows scholars to complicate or expand upon theories of translation developed in other cultural situations (notably Lawrence Venuti’s writing on domestication and foreignisation). The five writers upon whom this thesis concentrates were all highly individual, occasionally idiosyncratic personalities. Young’s polyglot ingenuity finds a foil in Garioch’s sharp, humane wit. Goodsir Smith’s romantic ironising meets its match in Scott’s radical certainty of cause. Tait’s use of the Shetlandic tongue sets him apart. Nonetheless, despite the great variety of style, form and tone shown by each of these translators, this thesis demonstrates that there are meaningful links to be made between them and that they form a unified, coherent group in the wider landscape of twentieth-century Scottish poetry. On the linguistic level, each engaged to some extent in the composition of a ‘synthetic’ or ‘plastic’ language deriving partly from literary sources, partly from the spoken language around them. On a more fundamental level, each was committed to enriching this language through translation, within which a number of key areas of interest emerge. One of the most important of these key areas is Gaelic – especially the poetry of Sorley MacLean, which Young, Garioch and Goodsir Smith all translated into Scots. This is to some extent an act of solidarity on the part of these Scots poets, acknowledging a shared history of marginalisation as well as expressing shared hopes for the future. The same is true of Goodsir Smith’s translations from a number of Eastern European poets (and Edwin Morgan’s own versions, slightly later in the century). The translation of verse drama by poets is another key theme sustained throughout the thesis, with Garioch and Young attempting to fill what they perceived as a gap in the Scots tradition through translation from other languages (another aspect of these writers’ legacy continued by Morgan). Beyond this, all of the writers discussed in this thesis translated extensively from European poetries from Ancient Greece to twentieth-century France. Their reasons for doing so were various, but a certain cosmopolitan idealism figures highly among them. So too does a desire to see Scotland interact with other European nations, thus escaping the potentially narrowing influence of post-war British culture. This thesis addresses the legacy of these writers’ translations, which, it argues, continue to exercise a perceptible influence on the course of poetry in Scotland. This work constitutes a significant contribution to a much-needed wider critical re-assessment of this pivotal period in modern Scottish writing, offering a fresh perspective on the formal and linguistic merits of these poets’ verse translations. Drawing upon frequently obscure book, pamphlet and periodical sources, as well as unpublished manuscripts in the National Library of Scotland and the Shetland Archives, this thesis breaks new ground in its investigation of the role of Scots verse translation in the second-generation Scottish Renaissance.

FABRICATION, CHARACTERIZATION, AND IRRADIATION OF AN AUSTENITIC OXIDE DISPERSION STRENGTHENED STEEL SUITED FOR NEXT GENERATION NUCLEAR APPLICATIONS

As nuclear energy systems become more advanced, the materials encompassing them need to perform at higher temperatures for longer periods of time. In this Master’s thesis we experiment with an oxide dispersion strengthened (ODS) austenitic steel that has been recently developed. ODS materials have a small concentration of nano oxide particles dispersed in their matrix, and typically have higher strength and better extreme temperature creep resistance characteristics than ordinary steels. However, no ODS materials have ever been installed in a commercial power reactor to date. Being a newer research material, there are many unanswered phenomena that need to be addressed regarding the performance under irradiation. Furthermore, due to the ODS material traditionally needing to follow a powder metallurgy fabrication route, there are many processing parameters that need to be optimized before achieving a nuclear grade material specification. In this Master’s thesis we explore the development of a novel ODS processing technology conducted in Beijing, China, to produce solutionized bulk ODS samples with ~97% theoretical density. This is done using relatively low temperatures and ultra high pressure (UHP) equipment, to compact the mechanically alloyed (MA) steel powder into bulk samples without any thermal phase change influence or oxide precipitation. By having solutionized bulk ODS samples, transmission electron microscopy (TEM) observation of nano oxide precipitation within the steel material can be studied by applying post heat treatments. These types of samples will be very useful to the science and engineering community, to answer questions regarding material powder compacting, oxide synthesis, and performance. Subsequent analysis performed at Queen’s University included X-ray diffraction (XRD) and inductively coupled plasma optical emission spectrometry (ICP-OES). Additional TEM in-situ 1MeV Kr2+ irradiation experiments coupled with energy dispersive X-ray (EDX) techniques, were also performed on large (200nm+) non-stoichiometric oxides embedded within the austenite steel grains, in an attempt to quantify the elemental compositional changes during high temperature (520oC) heavy ion irradiation.

An Islanding Detection Method based on Impedance Estimation and Grid Identification for Grid-Tie Distributed Power Generation Systems

Power system policies are broadly on track to escalate the use of renewable energy resources in electric power generation. Integration of dispersed generation to the utility network not only intensifies the benefits of renewable generation but also introduces further advantages such as power quality enhancement and freedom of power generation for the consumers. However, issues arise from the integration of distributed generators to the existing utility grid are as significant as its benefits. The issues are aggravated as the number of grid-connected distributed generators increases. Therefore, power quality demands become stricter to ensure a safe and proper advancement towards the emerging smart grid. In this regard, system protection is the area that is highly affected as the grid-connected distributed generation share in electricity generation increases. Islanding detection, amongst all protection issues, is the most important concern for a power system with high penetration of distributed sources. Islanding occurs when a portion of the distribution network which includes one or more distributed generation units and local loads is disconnected from the remaining portion of the grid. Upon formation of a power island, it remains energized due to the presence of one or more distributed sources. This thesis introduces a new islanding detection technique based on an enhanced multi-layer scheme that shows superior performance over the existing techniques. It provides improved solutions for safety and protection of power systems and distributed sources that are capable of operating in grid-connected mode. The proposed active method offers negligible non-detection zone. It is applicable to micro-grids with a number of distributed generation sources without sacrificing the dynamic response of the system. In addition, the information obtained from the proposed scheme allows for smooth transition to stand-alone operation if required. The proposed technique paves the path towards a comprehensive protection solution for future power networks. The proposed method is converter-resident and all power conversion systems that are operating based on power electronics converters can benefit from this method. The theoretical analysis is presented, and extensive simulation results confirm the validity of the analytical work.

Evolutions of an Online Generation: Education, Industry and IMC

This paper traces the evolutions of a new generation of students who are predominantly the ‘online generation’; explores the emerging impact of this generation on industry; identifies the changing role of education from traditional classroom to an online environment; and explores the contribution related to integrated marketing communications (IMC). Educational requirements from a business perspective must incorporate global business demands; virtual learning environments progress the online generation towards a post-modern learning state. The central proposition of this paper is that the emergence of IMC in evolving industry practices is influenced by student generations who are producing a new paradigm of alignment between education and industry. This is purely a conceptual exploration using limited examples to provide some context and illustrate the questions raised for consideration.