11 resultados para Nature study.
em CORA - Cork Open Research Archive - University College Cork - Ireland
Resumo:
When porous InP is anodically formed in KOH electrolytes, a thin layer ~40 nm in thickness, close to the surface, appears to be unmodified. We have investigated the earlier stages of the anodic formation of porous InP in 5 mol dm-3 KOH. TEM clearly shows individual porous domains which appear triangular in cross-section and square in plan view. The crosssections also show that the domains are separated from the surface by a ~40 nm thick, dense InP layer. It is concluded that the porous domains have a square-based pyramidal shape and that each one develops from an individual surface pit which forms a channel through this near-surface layer. We suggest that the pyramidal structure arises as a result of preferential pore propagation along the <100> directions. AFM measurements show that the density of surface pits increases with time. Each of these pits acts as a source for a pyramidal porous domain, and these domains eventually form a continuous porous layer. This implies that the development of porous domains beneath the surface is also progressive in nature. Evidence for this was seen in plan view TEM images. Merging of domains continues to occur at potentials more anodic than the peak potential, where the current is observed to decrease. When the domains grow, the current density increases correspondingly. Eventually, domains meet, the interface between the porous and bulk InP becomes relatively flat and its total effective surface area decreases resulting in a decrease in the current density. Quantitative models of this process are being developed.
Resumo:
This thesis is a study of Konrad Bayer's dramatic texts. It has evolved out of various attempts to read those texts, some filed and some more successful. It does not claim to be authoritative or complete, since the nature of Bayer's texts, as will become clear in the course of the ensuing chapters, means that they resist such an interpretation. To accept this was an important prerequisite for the writing of this thesis, but a difficult one to fulfill because for the Bayer commentator it constitutes a certain acceptance of defeat even before one begins. Chapter 1 will begin by providing some introductory information about Konrad Bayer, including details of his life and his membership of the Wiener Gruppe, a formative phase in his development as a writer. It will also consider the historical and cultural climate of 1950s Austria that provided the backdrop for Bayer's literary work. The phenomenon of the Wiener Gruppe will then be examined against the background of preceding experimental movements, for the purpose of situating Bayer's work historically and artistically. The aim of this historical and artistic survey is to prepare for the confrontation with Bayer's texts that makes up the other chapters of the thesis. Chapter 2 will constitute a close textual study of one of Bayer's dramatic texts using criteria from the field of text linguistics. Such a study will offer an entry point into Bayer's texts and will supply material which will form the basis for the interpretative investigations of the chapters that follow it. Chapter 3 will consider the influence of language and the individual. In chapter 4 the figure of the Lion of Belfort, a recurring figure in Bayer's dramatic texts, is discussed. The final chapter of this thesis will examine the recurring motifs of violence and cannibalism and will consider them in terms of the findings of preceding chapters.
Resumo:
The fundamental aim of this thesis is to examine the effect of New Public Management (NPM) on the traditional roles of elected representatives, management and community activists in Irish local government. This will be achieved through a case study analysis of one local authority, Cork County Council. NPM promises greater democracy in decision-making. Therefore, one can hypothesise that the roles of the three key groupings identified will become more influenced by principles of participatory decision-making. Thus, a number of related questions will be addressed by this work, such as, have the local elected representatives been empowered by NPM? Has a managerial revolution taken place? Has local democracy been enhanced by more effective community participation? It will be seen in chapter 2 that these questions have not been adequately addressed to date in NPM literature. The three groups identified can be regarded as stakeholders although the researcher is cautious in using this term because of its value-laden nature. Essentially, in terms of Cork County Council, stakeholders can be defined as decision-makers and people within the organization and its environment who are interested in or could be affected directly or indirectly by organizational performance. This is an all-embracing definition and includes all citizens, residents, community groups and client organizations. It is in this context that the term 'stakeholder' should be understood when it is occasionally used in this thesis. In this case, the perceptions of elected councilors, management and community representatives with regard to their changing roles are as significant as the changes themselves. The chapter begins with a brief account of the background to this research. This is followed by an explanation of the methodology which is used and then concludes with short statements about the remaining chapters in the thesis.
Resumo:
Quantum dashes are elongated quantum dots. Polarized edge-photovoltage and spontaneous emission spectroscopy are used to study the anisotropy of optical properties in 1.5μm InGaAsP and AlGaInAs-based quantum dash lasers. Strain, which causes TM-polarized transitions to be suppressed at the band edge, coupled with carrier confinement and dash shape leads to an enhancement of the optical properties for light polarized along the dash long axis, in excellent agreement with theoretical results. An analysis of the integrated facet and spontaneous emission rate with total current and temperature reveals that, in both undoped and p-doped InGaAsP-based quantum dash lasers at room temperature, the threshold current and its temperature dependence remain dominated by Auger recombination. We also identify two processes which can limit the output power and propose that the effects of the dopant in p-doped InGaAsP-based lasers dominate at low temperature but decrease with increasing temperature. A high threshold current density in undoped AlGaInAs-based quantum dash laser samples studied, which degrade rapidly at low temperature, is not due to intrinsic carrier recombination processes. 1.3μm GaAs-based quantum dots lasers have been widely studied, but there remains issues as to the nature of the electronic structure. Polarized edge-photovoltage spectroscopy is used to investigate the energy distribution and nature of the energy states in InAs/GaAs quantum dot material. A non-negligible TM-polarized transition, which is often neglected in calculations and analyses, is measured close to the main TE-polarized ground state transition. Theory is in very good agreement with the experimental results and indicates that the measured low-energy TM-polarized transition is due to the strong spatial overlap between the ground state electron and the light-hole component of a low-lying excited hole state. Further calculations suggest that the TM-polarized transition reduces at the band edge as the quantum dot aspect ratio decreases.
Resumo:
To investigate the symptom burden experiences of individuals with inflammatory bowel disease (IBD). An explanatory sequential mixed methods study was conducted. A cross-sectional, correlational survey was first undertaken. Symptom burden was measured using a modified disease specific version of the Memorial Symptom Assessment Scale, which was administered to a consecutive sample of individuals with IBD (n = 247) at an IBD Outpatients department in one urban teaching hospital in Ireland. Disease activity was determined using clinical disease activity indices, which were completed by the consulting physician. A sequential qualitative, descriptive study was then conducted aimed at explaining noteworthy quantitative findings. A criterion-related purposeful sample of seven participants from the quantitative study was recruited. Semi-structured face to face interviews were conducted using an interview guide and data were analysed using content analysis. Findings revealed that participants experienced a median of 10 symptoms during the last week, however as many as 16 symptoms were experienced during active disease. The most burdensome symptoms were lack of energy, bowel urgency, diarrhoea, feeling bloated, flatulence and worry. Total symptom burden was found to be low with a mean score of 0.56 identified out of a possible range from 0 to 4. Participants with active disease (M = 0.81, SD = 0.48; n = 68) had almost double mean total symptom burden scores than participants with inactive disease (M = 0.46, SD = 0.43; n = 166) (p < 0.001). Mean total psychological symptom burden was found to be significantly greater than mean total physical symptom burden (rho = 0.73, n = 247, p < 0.001). Self-reported disease control, gender, number of flare ups in the last two years, and smoking status was found to be significant predictors of total symptom burden, with self-reported disease control identified as the strongest predictor. Qualitative data revealed tiredness, pain, bowel symptoms, worry and fear as being burdensome. Furthermore, symptom burden experiences were described in terms of its impact on restricting aspects of daily activities, which accumulated into restrictions on general life events. Psychological symptom burden was revealed as more problematic than physical symptom burden due to its constant nature, with physical and psychological symptoms described to occur in a cyclical manner. Participants revealed that disease control was evaluated not only in terms of symptoms, but also in terms of their abilities to control the impact of symptoms on their lives. This study highlights the considerable number of symptoms and the most burdensome symptoms experienced by individuals with IBD, both during active and inactive disease. This study has important implications on symptom assessment in terms of the need to encompass both physical and psychological symptoms. In addition, greater attention needs to be placed on psychological aspects of IBD care.
Resumo:
The enculturation of Irish traditional musicians involves informal, non-formal, and sometimes formal learning processes in a number of different settings, including traditional music sessions, workshops, festivals, and classes. Irish traditional musicians also learn directly from family, peers, and mentors and by using various forms of technology. Each experience contributes to the enculturation process in meaningful and complementary ways. The ethnographic research discussed in this dissertation suggests that within Irish traditional music culture, enculturation occurs most effectively when learners experience a multitude of learning practices. A variety of experiences insures that novices receive multiple opportunities for engagement and learning. If a learner finds one learning practice ineffective, there are other avenues of enculturation. This thesis explores the musical enculturation of Irish traditional musicians. It focuses on the process of becoming a musician by drawing on methodologies and theories from ethnomusicology, education, and Irish traditional music studies. Data was gathered through multiple ethnographic methodologies. Fieldwork based on participant-observation was carried out in a variety of learning contexts, including traditional music sessions, festivals, workshops, and weekly classes. Additionally, interviews with twenty accomplished Irish traditional musicians provide diverse narratives and firsthand insight into musical development and enculturation. These and other methodologies are discussed in Chapter 1. The three main chapters of the thesis explore various common learning experiences. Chapter 2 explores how Irish traditional musicians learn during social and musical interactions between peers, mentors, and family members, and focuses on live music-making which occurs in private homes, sessions, and concerts. These informal and non-formal learning experiences primarily take place outside of organizations and institutions. The interview data suggests these learning experiences are perhaps the most pervasive and influential in terms of musical enculturation. Chapter 3 discusses learning experience in more organized settings, such as traditional music classes, workshops, summer schools, and festivals. The role of organizations such as Comhaltas Ceoltóirí Éireann and pipers’ clubs are discussed from the point of view of the learner. Many of the learning experiences explored in this chapter are informal, non-formal, and sometimes formal in nature, depending on the philosophy of the organization, institution, and individual teacher. The interview data and field observations indicate that learning in these contexts is common and plays a significant role in enculturation, particularly for traditional musicians who were born during and after the 1970s. Chapter 4 explores the ways Irish traditional musicians use technology, including written sources, phonography, videography, websites, and emerging technologies, during the enculturation process. Each type of technology presents different educational implications, and traditional musicians use these technologies in diverse ways and some more than others. For this, and other reasons, technology plays a complex role during the process of musical enculturation. Drawing on themes which emerge during Chapter 2, 3, and 4, the final chapter of this dissertation explores overarching patterns of enculturation within Irish traditional music culture. This ethnographic work suggests that longevity of participation and engagement in multiple learning and performance opportunities foster the enculturation of Irish traditional musicians. Through numerous and prolonged participation in music-making, novices become accustomed to and learn musical, social, and cultural behaviours. The final chapter also explores interconnections between learning experiences and also proposes directions for future research.
Resumo:
This research provides an interpretive cross-class analysis of the leisure experience of children, aged between six and ten years, living in Cork city. This study focuses on the cultural dispositions underpinning parental decisions in relation to children’s leisure activities, with a particular emphasis on their child-surveillance practices. In this research, child-surveillance is defined as the adult monitoring of children by technological means, physical supervision, community supervision, or adult supervised activities (Nelson, 2010; Lareau, 2003; Fotel and Thomsen, 2004). This research adds significantly to understandings of Irish childhood by providing the first in-depth qualitative analysis of the surveillance of children’s leisure-time. Since the 1990s, international research on children has highlighted the increasingly structured nature of children’s leisure-time (Lareau, 2011; Valentine & McKendrick, 1997). Furthermore, research on child-surveillance has found an increase in the intensive supervision of children during their unstructured leisure-time (Nelson, 2010; Furedi, 2008; Fotel and Thomsen, 2004). This research bridges the gap between these two key bodies of literature, providing a more integrated overview of children’s experience of leisure in Ireland. Using Bourdieu’s (1992) model of habitus, field and capital, the dispositions that shape parents’ decisions about their children’s leisure time are interrogated. The holistic view of childhood adopted in this research echoes the ‘Whole Child Approach’ by analysing the child’s experience within a wider set of social relationships including family, school, and community. Underpinned by James and Prout’s (1990) paradigm on childhood, this study considers Irish children’s agency in negotiating with parents’ decisions regarding leisure-time. The data collated in this study enhances our understanding of the micro-interactions between parents and children and, the ability of the child to shape their own experience. Moreover, this is the first Irish sociological research to identify and discuss class distinctions in children’s agentic potential during leisure-time.
Resumo:
Aim: This thesis examines a question posed by founding occupational scientist Dr. Elizabeth Yerxa (1993) – “what is the relationship between human engagement in a daily round of activity (such as work, play, rest and sleep) and the quality of life people experience including their healthfulness” (p. 3). Specifically, I consider Yerxa’s question in relation to the quotidian activities and health-related quality of life (HRQoL) of late adolescents (aged 15 - 19 years) in Ireland. This research enquiry was informed by an occupational perspective of health and by population health, ecological, and positive youth development perspectives. Methods: This thesis is comprised of five studies. Two scoping literature reviews informed the direction of three empirical studies. In the latter, cross-sectional time use and HRQoL data were collected from a representative sample of 731 school-going late adolescents (response rate 52%) across 28 schools across Cork city and county (response rate 76%). In addition to socio-demographic data, time use data were collected using a standard time diary instrument while a nationally and internationally validated instrument, the KIDSCREEN-52, was used to measure HRQoL. Variable-centred and person-centred analyses were used. Results: The scoping reviews identified the lack of research on well populations or an adolescent age range within occupational therapy and occupational science; limited research testing the popular assumption that time use is related to overall well-being and quality of life; and the absence of studies that examined adolescent 24-hour time use and quality of life. Established international trends were mirrored in the findings of the examination of weekday and weekend time use. Aggregate-level, variable-centred analyses yielded some significant associations between HRQoL and individual activities, independent of school year, school location, family context, social class, nationality or diary day. The person-centred analysis of overall time use identified three male profiles (productive, high leisure and all-rounder) and two female profiles (higher study/lower leisure and moderate study/higher leisure). There was tentative support for the association between higher HRQoL and more balanced time use profiles. Conclusion: The findings of this thesis highlight the gendered nature of adolescent time use and HRQoL. Participation in daily activities, singly and in combination, appears to be associated with HRQoL. However, the nature of this relationship is complex. Individually and collectively, adolescents need to be educated and supported to create health through their everyday patterns of doing.
Resumo:
This dissertation examines medieval literary accounts of visions of the afterlife with an origin or provenance in Ireland from the perspective of genre, analysing their structural and literary characteristics both synchronically and diachronically. To this end, I have developed a new typology of medieval vision literature. I address the question in what manner the internationally attested genre of vision literature is adapted and developed in an Irish literary milieu. I explore this central research question through an interrogation of the typological unity of the key texts, both in formal arrangement and in the eschatological themes they express. My analysis of the structure and rhetoric of these narratives reveals the primary role of identity strategies, question-and-answer patterns and exhortation for their narrative cohesion and didactic function. In addition, I was able to make a formal distinction at text-level between the adaptation of the genre as an autonomous unit and the adaptation of thematic motifs as topoi. This further enabled me to nuance the distribution of characteristic features in the genre. My analysis of the spatial and temporal aspects of the eschatological journey confirms a preoccupation with personal eschatology. It reveals a close connection between the development of the aspects of graded access and trial in the genre and a growing awareness of an interim state of the soul after death. Finally, my dissertation provides new editions, translations and analyses of primary sources. My research breaks new ground in the hitherto underexplored area of genre adaptation in Ireland. In addition, it contributes significantly to our understanding of the nature of vision literature both in an Irish and a European context, and to our knowledge of the transmission of eschatological thought in the Latin West. Discusses the visions of: Laisrén, Fursa, Adomnán, Lóchán, Tnugdal, Owein and Visio Sancti Pauli Redactions VI and XI.
Resumo:
Surface modification of silicon with organic monolayers tethered to the surface by different linkers is an important process in realizing future (opto-)electronic devices. Understanding the role played by the nature of the linking group and the chain length on the adsorption structures and electronic properties of these assemblies is vital to advance this technology. This Thesis is a study of such properties and contributes in particular to a microscopic understanding of induced changes in the work function of experimentally studied functionalized silicon surfaces. Using first-principles density functional theory (DFT), at the first step, we provide predictions for chemical trends in the work function of hydrogenated silicon (111) surfaces modified with various terminations. For nonpolar terminating atomic species such as F, Cl, Br, and I, the change in the work function is directly proportional to the amount of charge transferred from the surface, thus relating to the difference in electronegativity of the adsorbate and silicon atoms. The change is a monotonic function of coverage in this case, and the work function increases with increasing electronegativity. Polar species such as −TeH, −SeH, −SH, −OH, −NH2, −CH3, and −BH2 do not follow this trend due to the interaction of their dipole with the induced electric field at the surface. In this case, the magnitude and sign of the surface dipole moment need to be considered in addition to the bond dipole to generally describe the change in work function. Compared to hydrogenated surfaces, there is slight increase in the work function of H:Si(111)-XH, where X = Te, Se, and S, whereas reduction is observed for surfaces covered with −OH, −CH3, and −NH2. Next, we study the hydrogen passivated Si(111) surface modified with alkyl chains of the general formula H:Si–(CH2)n–CH2 and H:Si–X–(CH2)n–CH3, where X = NH, O, S and n = (0, 1, 3, 5, 7, 9, 11), at half coverage. For (X)–Hexyl and (X)–Dodecyl functionalization, we also examined various coverages up to full monolayer grafting in order to validate the result of half covered surface and the linker effect on the coverage. We find that it is necessary to take into account the van der Waals interaction between the alkyl chains. The strongest binding is for the oxygen linker, followed by S, N, and C, irrespective of chain length. The result revealed that the sequence of the stability is independent of coverage; however, linkers other than carbon can shift the optimum coverage considerably and allow further packing density. For all linkers apart from sulfur, structural properties, in particular, surface-linker-chain angles, saturate to a single value once n > 3. For sulfur, we identify three regimes, namely, n = 0–3, n = 5–7, and n = 9–11, each with its own characteristic adsorption structures. Where possible, our computational results are shown to be consistent with the available experimental data and show how the fundamental structural properties of modified Si surfaces can be controlled by the choice of linking group and chain length. Later we continue by examining the work function tuning of H:Si(111) over a range of 1.73 eV through adsorption of alkyl monolayers with general formula -[Xhead-group]-(CnH2n)-[Xtail-group], X = O(H), S(H), NH(2). The work function is practically converged at 4 carbons (8 for oxygen), for head-group functionalization. For tail-group functionalization and with both head- and tail-groups, there is an odd-even effect in the behavior of the work function, with peak-to-peak amplitudes of up to 1.7 eV in the oscillations. This behavior is explained through the orientation of the terminal-group's dipole. The shift in the work function is largest for NH2-linked and smallest for SH-linked chains and is rationalized in terms of interface dipoles. Our study reveals that the choice of the head- and/or tail-groups effectively changes the impact of the alkyl chain length on the work function tuning using self-assembled monolayers and this is an important advance in utilizing hybrid functionalized Si surfaces. Bringing together the understanding gained from studying single type functionalization of H:Si(111) with different alkyl chains and bearing in mind how to utilize head-group, tail-group or both as well as monolayer coverage, in the final part of this Thesis we study functionalized H:Si(111) with binary SAMs. Aiming at enhancing work function adjustment together with SAM stability and coverage we choose a range of terminations and linker-chains denoted as –X–(Alkyl) with X = CH3, O(H), S(H), NH(2) and investigate the stability and work function of various binary components grafted onto H:Si(111) surface. Using binary functionalization with -[NH(2)/O(H)/S(H)]-[Hexyl/Dodecyl] we show that work function can be tuned within the interval of 3.65-4.94 eV and furthermore, enhance the SAM’s stability. Although direct Si-C grafted SAMs are less favourable compared to their counterparts with O, N or S linkage, regardless of the ratio, binary functionalized alkyl monolayers with X-alkyl (X = NH, O) is always more stable than single type alkyl functionalization with the same coverage. Our results indicate that it is possible to go beyond the optimum coverage of pure alkyl functionalized SAMs (50%) by adding a linker with the correct choice of the linker. This is very important since dense packed monolayers have fewer defects and deliver higher efficiency. Our results indicate that binary anchoring can modify the charge injection and therefore bond stability while preserving the interface electronic structure.
Resumo:
The child is the most precious asset and the focal point of development for any country. However, unless children are brought up in a stimulating and conducive environment getting the best possible care and protection, their physical, mental, emotional and social development is susceptible to permanent damage. Ethiopia, being one of the least developed countries of the world due to interrelated and complex socio-economic factors including man-made and natural calamities, a large portion of our population - especially children - are victimized by social evils like famine, disease, poverty, mass displacement, lack of education and family instability. Owing to the fact that children are the most vulnerable group among the whole society and also because they constitute half of the population it is evident that a considerable number of Ethiopian children are living under difficult circumstances. Therefore, as in a number of other third world countries there are many poor, displaced, unaccompanied and orphaned children in our country. A considerable proportion of these children work on the street with some even totally living on the street without any adult care and protection. These children are forced to the streets in their tight for survival. They supplement their parents meagre income or support themselves with the small incomes they earn doing menial jobs. In doing this, street children face the danger of getting into accidents and violence, they get exploited and abused, many are forced to drop out of school or never get the chance to be enroled at all and some drift into begging or petty crime. This study is undertaken mainly for updating the findings of previous studies, monitoring changing trends, examining new facts of the problem and getting a better understanding of the phenomenon in the country by covering at least some of the major centres where the problem is acute. Thus, the outcome of this research can be useful in the formation of the social welfare programme of the country. Finally, in recognition of the urgency of the problem and the limited resources available, the Ministry of Labour and Social Affairs expresses appreciation to all agencies engaged in the rehabilitation of street children and prevention of the problem. The Ministry also calls for more co-operation and support between concerned governmental and non-governmental organizations in their efforts for improving the situation of street children and in curbing the overwhelming nature of the problem.