896 research outputs found
A study of the effect of process parameter variation upon the characteristics of screen printed piezoelectric materials
No full textA study of the effect of composition and processing of screen printable piezoelectric materials has been undertaken. Printable pastes of various compositions were produced using a commercially available Lead Zirconate Titanate (PZT) powder mixed with binder and solvents. A range of devices were produced by printing PZT pastes onto alumina (Al_2O_3) substrates. Devices were fired using variations on common thick film processing techniques and poled under varying conditions. Samples were compared by measurement of piezoelectric charge constant, d_3_3 and using scanning electron microscopy techniques. An optimised method for the measurement of d_3_3 was developed. Results show that formulations may be produced that enhance the final value of d_3_3 whilst promoting mechanical strength. Firing temperature, firing time, poling time and poling temperature are all shown to effect the final value of d_3_3 achieved. (author)Available from British Library Document Supply Centre-DSC:DXN027105 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
Trends of Europeanization in social welfare politics. IHS Political Science Series 82, July 2002
No full textFritz W. Scharpf (2000 and 2002) defines the term Europeanization as the progressive shift of governmental tasks to the European level. According to this understanding he identifies four modes of Europeanization. Further, he recognizes the establishment of minimum standards and the open method of co-ordination as specific modes of Europeanization. This paper first relates the welfare political goals and problems of both named methods of Europeanization in social welfare politics, then describes the political processes which accompany them, and subsequently tests whether Scharpf’s analysis can be affirmed
Art and the artist in the literary works of Elsa Triolet
No full textThis thesis takes a representative selection of Triolet's works to study the themes of writing and creativity as they are presented in the novels. These are all portraits of artists and the accounts of the search for a synthesis of aesthetic freedom and ethical responsibility. It considers Triolet's importance as a foreign writer, adopting a new creative language to be adopted by a different cultural
environment, to be essential in understanding her importance to the French literary tradition. By emphasising her formative years in the avant-garde circles of prerevolutionary Russia, my study demonstrates her considerable contribution to the meeting of Russian and French aesthetic theories. I extend this with close textual
readings of certain works to demonstrate her techniques in novelistic construction which reveal many Formalist practices before Formalist works in translation made
their official influence on creative methods.
The introduction considers the reasons for Triolet's neglect as a writer. It then considers various contemporary and recent critical appraisals which indicate
the interest she has received until present and which allow me to define my own critical approach. Part One traces Triolet's literary evolution from her formative
years in Russia, through exile to her first publications in Russian. It then considers her insertion into French literary activity, and her association with the schools of
socialist realism and the "nouveau roman".
Part Two examines two traditional novels which portray the creative and metaphorical roles of the artist and his work, showing the constant conflict between private and public lives. In Part Three, I show how aspects of novelistic
traditionalism are gradually foregrounded so that the work develops a dual-sided character where it both narrates and examines the processes of its own narration. In Part Four, this move to highly self-conscious aesthetics demonstrates an idiosyncratic exploration of new paths for the novel that bring visual, auditive and cinematographic media into the traditional domain of written art. Accompanying
the very post-modernist experimentation, I show how this research within the novel into the novel's own future has an ethical and redemptive purpose whose final conclusion is that creativity and human freedom are inexorably interwoven
LGBT+ in Kakuma: The Fire This Time
No full textThis is one of two blogs that were put together in late February 2022, and draw on Facebook messages from Jones Graham and Isa Mubiru. Peter Keogh’s name has been included as co-author. The blog is written with first names only to protect the LGBT+ people still living in Kakuma Block 13. Read their other blog here.
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This material is part of the Covid Chronicles from the Margins project, funded by The Open University and The Hague. The project aims to highlight the impact of the pandemic on refugees, asylum seekers & undocumented migrants.
This item can also be found on the Covid Chronicles website.</p
The Smoking Gun: Still no LGBT+ Safety in Kakuma
No full textThis is one of two blogs that were put together in late February 2022, and draw on Facebook messages from Jones Graham and Isa Mubiru. Peter Keogh’s name has been included as co-author. The blog is written with first names only to protect the LGBT+ people still living in Kakuma Block 13. Read their other blog here.
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This material is part of the Covid Chronicles from the Margins project, funded by The Open University and The Hague. The project aims to highlight the impact of the pandemic on refugees, asylum seekers & undocumented migrants.
This item can also be found on the Covid Chronicles website. </p
The biology of three teleost species with divergent life cycle characteristics and their implications for fisheries management
No full textThe overall aim of this thesis was to determine the size and age compositions, growth and reproductive biology of Western Blue Groper (Achoerodus gouldii), Blue Morwong (Nemadactylus valenciennesi) and Yellowtail Flathead (Platycepahlus endrachtensis) in south-western Australian waters, in which these three species have divergent life cycle characteristics. As A. gouldii and N. valenciennesi are commercially and recreationally important in coastal waters and P. endrachtensis is one of the most recreationally important species in the Swan River Estuary, these biological data were then used to produce estimates of mortality and spawning stock biomass per recruit for each of these species. The biological data and stock assessment parameters were finally employed comparatively to ascertain whether any of the three species possessed characteristics that would make them particularly susceptible to the effects of fishing and whether there was evidence that any of the species is fully or even overexploited.
Achoerodus gouldii typically uses reefs in protected inshore waters along the coast and around neighbouring islands as a nursery habitat and then, as it increases in size, moves to deeper, offshore reefs, where it spawns between early winter and mid-spring. The maximum total length and age of A. gouldii were 1162 mm and 70 years, the latter being the greatest age by far yet recorded for any species of labrid. However, most growth occurs in the first 20 years of life. Histological and demographic analyses demonstrated that all individuals begin life as females and, after attaining maturity, many become males, i.e. A. gouldii is a monandric protogynous hermaphrodite. The L50 at maturity and sex change were 653 and 821 mm, respectively, which correspond to ages of c. 17 and 37 years, respectively. As sex change took place over a narrower range in lengths (650 to 900 mm) than in ages (15 to 49 years), that change is apparently related more to size than age. Since sex change is typically accompanied by a change from green to blue, body colour can be used as a proxy for determining the length (L50) at which females change to males. von Bertalanffy growth curves fitted to the lengths at age of individuals of each sex of this hermaphroditic species using a novel technique demonstrated that, with increasing age, the lengths of males became increasingly greater than those of females. Thus, at ages 15, 30 and 60 years, the estimated lengths at age of females were c. 600, 670 and 680 mm, respectively, whereas those of males were c. 695, 895 and 975 mm, respectively.
As A. gouldii is very long-lived and sexual maturity, and even more particularly sex change, occur late, this labrid is potentially very susceptible to overfishing. Thus, because the mortality estimates and per recruit analyses indicated that, at present, this species is close to or fully exploited, fisheries managers will need to take a precautionary and watchful approach to managing and thus conserving the stocks of this species.
As with A. gouldii, N. valenciennesi moves to deeper, offshore waters as it increases in size and then matures and spawns in those waters. Although N. valenciennesi has a maximum length of nearly 1 m and thus, like A. gouldii, is moderately large, it has a far shorter life span, i.e. 19 vs 70 years. While female N. valenciennesi does not grow to as large a size as its males (max. lengths = 846 and 984 mm, respectively), the maximum age of both sexes was 19 years. From the growth curves, the females by ages 3, 6 and 10 years havd attained, on average, lengths of 435, 587 and 662 mm, respectively, compared with 446, 633 and 752 mm, respectively, for males. Both sexes grew little after 10 years of age.
Juvenile N. valenciennesi < 400 mm in total length were found exclusively in shallow, coastal waters on the south coast, whereas their adults were abundant in offshore waters of both the south and lower west coasts. The females and males typically mature in offshore waters of the south coast at lengths of c. 600-800 mm and ages of c. 7-9 years. In contrast, the vast majority of females caught in offshore waters of the lower west coast (where they were of a similar length and age range to those in offshore waters on the south coast) became mature at lengths of 400-600 mm and 3-4 years of age. The attainment of maturity by N. valenciennesi at far lesser lengths and ages on the lower west coast than south coast suggests that the former coast provides better environmental conditions for the gonadal maturation and spawning of this species. Furthermore, the contrast between the almost total absence of the juveniles of N. valenciennesi in nearshore waters on the lower west coast and their substantial numbers in comparable waters on the south coast indicates that the larvae of this species produced on the lower west coast are transported southwards to the south coast, where they become juveniles. As spawning occurs between mid-summer and late autumn, the larvae, which spend a protracted period in the plankton, would be exposed, on the lower west coast, to the influence of the southwards-flowing Leeuwin Current at the time when that current is at its strongest.
Although N. valenciennesi is caught by recreational line fishing and commercial gillnet fishing when they are as young as 3-4 years old, they do not become fully vulnerable to these fisheries until they are about 9 years old. Consequently, the individuals of this species can potentially breed over a number of years before they become particularly prone to capture by fishers. Mortality estimates and per recruit analyses suggested that N. valenciennesi in south-western Australia is not currently overfished. A greater resilience to fishing by N. valenciennesi than A. gouldii presumably reflects, in part, its far shorter lifespan, earlier maturity and possession of gonochorism rather than hermaphroditism.
Platycephalus endrachtensis spawns in the Swan River Estuary between late spring and early autumn and completes the whole of its life cycle in this system. Although females attain a far larger length (615 mm) than males (374 mm), females and males were present in each age class. These data, together with a detailed examination of histological sections of a wide size and age range of individuals, demonstrated that this species, unlike some of its relatives, is not a protandrous hermaphrodite, i.e. it does not change from male to female with increasing body size. The combination of the presence of females and males in all age classes and the observation that all of the large number of individuals between 374 and 615 mm were females shows that the far greater length attained by that sex is largely related to its faster growth rate. The fact that females outnumbered males in each age class of P. endrachtensis in which the sample size was substantial, i.e. > 25, with the overall sex ratio being 2.7 females: 1 male, indicate that there has been strong selection for egg production in this species. As the minimum legal length for retention of P. endrachtensis is 300 mm, and relatively few males exceeded this length, the recreational fishery which targets this species is based largely on its females.
The estimates of mortality and results of per recruit analyses provided no evidence that P. endrachtensis is currently overfished. From a management point of view, it is advantageous that the current size limit for this species exceeds the average length at which its females (259 mm) attain maturity. Furthermore, this species appears to be resilient to capture and release.
The data presented in this thesis demonstrate that A. gouldii possesses biological characteristics which make it potentially more prone to the effects of fishing than is the case with either N. valenciennesi or P. endrachtensis. This presumably accounts, at least in part, for the indications that A. gouldii is the only one of these three species that is likely to be close to or at full exploitation
A new look at the pathogenesis of asthma
No full textAsthma is an inflammatory disorder of the conducting airways that has strong association with allergic sensitization. The disease is characterized by a polarized Th-2 (T-helper-2)-type T-cell response, but in general targeting this component of the disease with selective therapies has been disappointing and most therapy still relies on bronchodilators and corticosteroids rather than treating underlying disease mechanisms. With the disappointing outcomes of targeting individual Th-2 cytokines or manipulating T-cells, the time has come to re-evaluate the direction of research in this disease. A case is made that asthma has its origins in the airways themselves involving defective structural and functional behaviour of the epithelium in relation to environmental insults. Specifically, a defect in barrier function and an impaired innate immune response to viral infection may provide the substrate upon which allergic sensitization takes place. Once sensitized, the repeated allergen exposure will lead to disease persistence. These mechanisms could also be used to explain airway wall remodelling and the susceptibility of the asthmatic lung to exacerbations provoked by respiratory viruses, air pollution episodes and exposure to biologically active allergens. Variable activation of this epithelial-mesenchymal trophic unit could also lead to the emergence of different asthma phenotypes and a more targeted approach to the treatment of these. It also raises the possibility of developing treatments that increase the lung's resistance to the inhaled environment rather than concentrating all efforts on trying to suppress inflammation once it has become established.<br/
"Coordinating Regional Policy in the EU"
No full text[From the Introduction]. EU regional policy is an instrument to promote development in economically weaker areas of Europe as well as to facilitate integration and ensure the success of the single market (European Commission, 2003). The territorial nature of EU regional policy demands complex coordination among various levels of government as well as across several policy sectors. Coordination, however, is often unsuccessful. Vertical coordination, inherently necessary for regional policy, is often precluded due to power struggles among supranational, national and regional governments. Likewise, conflicting policy goals and competing interests across policy sectors curtails the achievement of cross-sectoral coordination. Challenges to cross-sectoral coordination often arise since regional policy, based upon redistribution and Keynesian economics, has found itself at odds with underlying principles of the EU, namely neo-liberalism and free market competition
Developing a partnership of indigenous peoples, conservationists, and land use planners in Latin America
No full textIllustrating from a rich body of case material, Poole's report reflects a shift away from the traditional view - represented by certain national parks and similar protected areas - that indigenous peoples be allowed to occupy and use an area's resources following rules set by conservationists. Under the new paradigm that is developing, indigenous peoples are seen as an integral part of protected area planning through agreements worked out in partnership with conservation authorities. An example of this new approach is the role that indigenous peoples are playing in the design of biosphere reserves. Poole suggests that the Bank and other development organizations pay more attention to vernacular economies - economies based on local resources, used either for subsistence or as a source of revenue. He also recommends more research into economics and resource implications of these local activities to harvest wild resources, especially in environmentally delicate areas such as tropical rainforests.Environmental Management,Tourism and Ecotourism,Water Conservation,Natural Resources Management,Wetlands
More on the chronology of Celtic sound changes
No full textGraham Isaac’s recent monograph (2007) deals with the chronology of Celtic sound changes. Remarkably, the author completely disregards the relative chronology which I published 28 years earlier (1979). In the following I shall discuss the main issues on which our views differ
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