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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The provenance of Bronze Age pottery from Central and Eastern Greece

White, Selina January 1981 (has links)
Samples from nearly 800 Bronze Age pottery sherds from Euboea, Eastern Boeotia and Eastern Thessaly were analysed together with 9 raw clays from the same areas. The-analysis was carried out in an attempt to identify areas of pottery manufacture, to discover the origin of specific groups of pottery, to relate pottery to, raw clays and to see how far pottery compositions can be associated with, and predicted by, geology. The work was done on the same lines as earlier studies at the Oxford Laboratory and at the British School at Athens. The main analytical technique used was therefore optical emission spectroscopy. Some 25% of the total number of sherds were also analysed by atomic absorption spectrophotometry so that the results obtained by the two techniques could be compared. The interpretation of the results was facilitated by the use of, computer program packages for cluster and discriminant analysis. Both optical emission and atomic absorption analysis resulted in broadly similar groupings although the absolute concentrations were not directly comparable. The groupings obtained after atomic absorption analysis had the narrower concentration ranges. Nine elements were measured by both techniques but in atomic absorption potassium was added and proved; useful as an additional discriminant. Six composition groups were distinguished from the data. One of them was identified as Euboean, 2 as Boeotian and 3 as coming from different regions of Thessaly. The greatest movement of pottery within these areas was from Euboea to Thessaly. No composition group which originated from outside these regions was identified. Six of the 9 raw clays were associated with the prevailing composition group in the area from which they came. It was not possible to predict trends in pottery composition by examination of the local geology.
2

The provenance of Bronze Age pottery from Central and Eastern Greece

White, Selina January 1981 (has links)
Samples from nearly 800 Bronze Age pottery sherds from Euboea, Eastern Boeotia and Eastern Thessaly were analysed together with 9 raw clays from the same areas. The-analysis was carried out in an attempt to identify areas of pottery manufacture, to discover the origin of specific groups of pottery, to relate pottery to, raw clays and to see how far pottery compositions can be associated with, and predicted by, geology. The work was done on the same lines as earlier studies at the Oxford Laboratory and at the British School at Athens. The main analytical technique used was therefore optical emission spectroscopy. Some 25% of the total number of sherds were also analysed by atomic absorption spectrophotometry so that the results obtained by the two techniques could be compared. The interpretation of the results was facilitated by the use of, computer program packages for cluster and discriminant analysis. Both optical emission and atomic absorption analysis resulted in broadly similar groupings although the absolute concentrations were not directly comparable. The groupings obtained after atomic absorption analysis had the narrower concentration ranges. Nine elements were measured by both techniques but in atomic absorption potassium was added and proved; useful as an additional discriminant. Six composition groups were distinguished from the data. One of them was identified as Euboean, 2 as Boeotian and 3 as coming from different regions of Thessaly. The greatest movement of pottery within these areas was from Euboea to Thessaly. No composition group which originated from outside these regions was identified. Six of the 9 raw clays were associated with the prevailing composition group in the area from which they came. It was not possible to predict trends in pottery composition by examination of the local geology.
3

The states and status of clay : material, metamorphic and metaphorical values

Buzz, Lu La January 2018 (has links)
This doctoral project combines a performance-led practice with contextual research in order to demonstrate how arts practice can challenge historical perceptions of clay and enhance its material status. The core knowledge deduced from this research is that embodied performance transforms connectivity between artist and clay and produces a unified incarnation of both elements. Through the use of immersive research methods I gained insights which could not have been predicted - particularly that my experiential performances were a process of ‘clay becoming’ in which I ultimately became the clay. In terms of locality, the practice, comprising eight performance-led works and related documentation, focuses on the China Clay and Ball Clay of South West England. Traditionally in the arts, these materials are associated with ceramics, where through heating, clay becomes rigid and fixed. In contrast, my research investigates the textural fluidity and metamorphic potential of these clays in their raw state. The practice encompasses two interrelated groups of work; the In-breath and Out-breath. These terms are significant in three respects. Firstly they define two different modes and moments of practice. Secondly they refer to myself as a living component of these practices. Thirdly they reflect the cultural associations of clay as a metaphor for life. During the initial exploratory ‘In-breath’ phase of my practice, comprising four site-specific pieces, I engaged with clay at sites of historical relevance, building an expansive knowledge of my material. During the later ‘Out-breath’ phase, identification with site was relinquished. These works took place within neutral spaces, allowing the clay to be explored in relation to my body. The introduction of layering, where photographic elements of private clay rituals were situated within the context of a live performance, allowed a texturally dynamic and immersive experience to be created for both artist and viewer. By collecting and preserving clay traces from these live performances (e.g. foot and body prints) additional value was given to the embedded significance of the clay.
4

Interactions argiles naturelles-effluents teinturiers : influence des propriétés de surface des argiles et mécanismes d'adsorption des colorants / Interactions natural clay-effluent-dyes : influence of surface properties of clays and dyes adsorption mechanism

Abidi, Nejib 01 April 2015 (has links)
Les effluents industriels issus des activités de textile présentent souvent une importante charge polluante colorante difficilement biodégradable. Des travaux antérieurs ont montré le potentiel des argiles naturelles non traitées à dépolluer ces effluents teinturiers alors qu’ils sont généralement composés de colorants anioniques difficilement adsorbables sur ces supports. Or, les effluents contiennent également d’autres composés chimiques utilisés dans les différentes étapes du procédé de teinture, et qui sont de natures variées (sels, acides, bases, détergents, dérivés enzymatiques, etc…). Il semblerait que ces produits auxiliaires jouent un rôle dans l'adsorption de colorants anioniques sur l'argile non traitée. Cependant, aucune étude connue à ce jour, n'a porté sur l'effet des additifs de teinture dans le processus de décoloration par des absorbants en général, et par les argiles en particulier. Cette étude est la première à s’intéresser au système colorant-additif-argile. Des tests d’adsorption / désorption en batch ont été menés en considérant différents systèmes colorant-additif-argile. Les résultats des tests montrent que les additifs de type enzymatique favorisent l’adsorption de colorant anionique sur l’argile en neutralisant les charges négatives et en renforçant les liaisons argile-colorant. D’autres additifs ont un effet contraire mais n’annulent pas l’effet positif des additifs enzymatiques lorsqu’ils sont mélangés dans l’effluent. Des hypothèses d’interactions mises en jeu lors de l’adsorption de colorant ont été faites en s’aidant des résultats de la spectrométrie infra-rouge et de masse, de la zétamétrie et de la modélisation des isothermes d’adsorption. / Industrial effluents from textile activities often have a high pollution load readily biodegradable. Previous work has shown the potential of natural untreated clays to clean up these dyers effluents although anionic dyes are not easily absorbable on these media. The effluents also contain other chemical compounds used in the different stages of the dyeing process, and which are of various natures (salts, acids, bases, detergents, enzyme derivatives, etc ...). It appears that these auxiliary products play a role in the adsorption of anionic dyes on untreated clay. However, no currently known study has examined the effect of the additives from the dyeing process on the adsorption of dye onto clay. This is the first study to focus on the dye-clay-additive system. Adsorption / desorption batch tests were conducted considering different dye additive-clay systems. The tests’ results show that the enzyme like additives enhance the adsorption of anionic dye on the clay by neutralizing the negative charges and reinforcing clay-dye links. Other additives have the opposite effect, but do not offset the positive effect of enzyme like additives when mixed in the effluent. Assumptions of interactions involved in dye adsorption were made with the help of the results of infrared and mass spectrometry, zetametry and the modeling of adsorption isotherms.

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