Dissertations / Theses on the topic 'Structural stone'

An important problem encountered by foundation engineers involves partially saturated soils which possess considerable in-situ dry strength that is largely lost when the soils become wetted. Foundation design in such soils is difficult at best. In many cases, deep foundations may be required to transmit foundation loads to suitable bearing strata below the 'collapsible' soil deposit. This research has studied the behaviour and performance of stone columns confined and not confined by geofabrics and rigid piles, as deep foundations, in collapsible soil subjected to inundation. Laboratory tests were carried out, under controlled conditions of sand density and surcharge pressure, using six different types of foundation supports (a sand column, sand columns confined by T700, T1000, T1500 or T2000 geofabrics and a rigid pile). Each type of foundation was considered in three different lengths 250 mm, 300 mm and 410 mm. This work consisted of installing and loading 'model' foundations into a stress controlled pot containing a collapsible soil and allowing a slow rise of the water level inside it. The tests were designed to investigate the efficiency of these types of foundation supports on the improvement of the carrying capacity and on the reduction of settlement of the ground. The reduction in vertical compression of the 'piles' was also studied analytically using an analytical approach adopted and developed from models applied to soft soils. The experimental results are compared with analytical predictions. The comparisons show that the reduction in vertical compression of the 'pile' is governed by its stiffness and its length. These variables are of prime importance in the general performance of the 'pile'.

Situated within the intersections of stereotomy (the art of cutting solids), the evolution of machine tools and structural design principles; this research investigates contemporary digital stereotomic practice, both its historical context and current contribution to the Architectural discipline. This dissertation develops modular prototypes of subtractive fabrication methods with a focus on utilising variations of osteomorphic blocks (based on Abeille’s vault) for interlocking joint systems. Interlocking assemblies in the construction industry have gained acceptance for their versatility and reduced labour costs in comparison to traditional brick and mortar methods. The ease of assembly and disassembly make using these mortar-less interlocking blocks for arched and vaulted spaces appropriate. Past methods of stereotomic practice and emerging multi-axis robotic fabrication techniques are investigated in relation to case studies of specific structural conditions. These include a novel approach towards robotic fabrication of wave jointed blocks, columns and arches, followed by beam and cantilever structures. Examining the machine generation of specific geometries of wave block modules forms a base to establish criteria for testing material outcomes. This thesis aims to highlight the value of ‘crafting’ through robotic technologies. The structural prototyping workflows, quantitative test results of failure mechanisms and contribution to historical knowledge of this thesis, can extend to the wider manufacturing industries and heritage conservation departments. Here, the implementation of the design and production workflows of interlocking self-supporting assemblies can be used to adapt past methods of traditional stone carving and assembly techniques. Further extending to the construction of spaces in extreme climates and unstable conditions where flexibility of structures is beneficial. Allowing humanity to progress further and explore new environments and habitats.

This construction programme deals with a hermit colony located in the western part of the Vysočina Region. This hermit colony has been established to provide accommodation for women living in this area permanently while offering an opportunity of occasional relaxation for people who are living hectic lives in urban environment. The aim of my project is to design the remaining parts of the colony, i.e. two hermitages and the community’s chapel. A hermitage is a one-storey building intended for one person only. The load-bearing walls of the individual hermitages are designed to be built from different materials (wooden and masonry constructions) whereas the elevational structures of all the buildings are to be the same. The chapel’s wall system combines stone and wood. The chapel will serve solely the purposes of the community. The main objective of my project is to respect and maintain the natural features of the landscape to the maximum extent possible.

L’obiettivo di molte ricerche attuali riguarda nuove soluzioni costruttive per l'edilizia futura. In particolare, la ricerca si focalizza sullo sviluppo tecnologico di materiali naturali preesistenti con lo scopo di realizzare strutture innovative, sicure ed ecosostenibili. La presente tesi si propone di studiare la possibilità di utilizzare materiali naturali, come la pietra, per la costruzione di strutture portanti. Il calcare Cabouca è stato scelto per la realizzazione di una trave a blocchi, resa resistente e compatta attraverso la tecnica della precompressione. Le prove meccaniche sui campioni di pietra e successivamente, la costruzione e la prova a flessione della trave sono stati effettuati presso il Laboratório de Estruturas Pesadas, Faculdade de Ciências e Tecnologia, presso l'Università di Lisbona. I risultati soddisfacenti hanno evidenziato un sostanzioso incremento della capacità flessionale della trave precompressa rispetto a quella non armata, potendo quindi dimostrare che la precompressione è efficace nella pietra naturale come nel calcestruzzo. Il presente lavoro si propone come un punto di partenza valido per l'evoluzione di strutture portanti in pietra precompressa eleganti, sicure e conformi ai principi del Green building.

Abstract Slate and shale are not usually considered as building stone for the construction of entire buildings in the vernacular farm architecture of the area north of the Vaal River (historically known as the Transvaal). Sandstone and granite as principal building stone types were more common. Slate and shale are two different stone types but due to their similar layered structure they are often used together in the construction of the same wall. Current research has revealed that slate and shale did play a significantbutselectiveroleinvernacularbuildingtechnologyintheregion.Slatewasusedforfinishing and solving specificproblemsinfolkbuildingtechnology.Oneofthereasonswhythesestonetypes were less popular as building material is the isolated occurrences of outcrops in the region. Sandstone and granite are more common and readily available. The few buildings constructed with slate and shale had a unique character reflectedinthewalltexturewhenthestoneislaidflat.Becausethe stone is released from its rock bed in thin plates with an almost completely flatsurfaceonbothsides, it is usually laid flatandneedslittlemortartosecureastablewall.Thispaperintroducesratherthan analyses the use of these materials in the vernacular architecture of the former Transvaal region.

Este trabalho tem por objetivo estudar algumas variações do teorema de Banach- Stone. Elas podem ser encontradas no artigo Variations on the Banach- Stone Theorem, [14]. Além disso, apresentamos um resultado, provado por D. Amir em [1], que generaliza a versão clássica do Teorema de Banach- Stone. Consideramos os espaços C(K) e C(L), que representam os espaços de funções contínuas de K em R e de L em R respectivamente, onde K e L são espaços Hausdor compactos. O enunciado da versão clássica do teorema de Banach- Stone é a seguinte: \"Sejam K e L espaços Hausdor compactos. Então C(K) é isométrico a C(L) se e somente se, K e L são homeomorfos\". Apresentamos a primeira das variações que considera isomorfismo entre álgebras e foi feita por Gelfand e Kolmogoro em [15], no ano de 1939. A segunda versão apresentada trata de isomorfismo isométrico e a demonstração é originalmente devida a Arens e Kelley e é encontrada em [2]. Finalmente, estudamos o teorema provado por D. Amir e apresentado em [1]. Este teorema generaliza o teorema clássico de Banach- Stone e tem o seguinte enunciado: Se K e L são espaços Hausdor compactos e T é um isomorfismo linear de C(K) sobre C(L), com ||T||.||T^||< 2 então K e L são homeomorfos
This work aims to study some variations of the Banach- Stone theorem. They can be found in the article Variations on the Banach- Stone Theorem, [14]. In addition, we present a result, proved by D. Amir in [1], that generalizes the classic version of the Theorem Banach- Stone. We consider the spacesC(K) andC(L), representing the spaces of continuous functions from K into R and from L into R respectively, where K and L are compact Hausdor spaces. The wording of the classic version of the Banach- Stone theorem is as follows: \"Let K e L be compact Haudor spaces. Then C(K) isisometrictoC(L) if,andonlyif, K and L are homeomorphic\".Here the first of the variations that considers isomorphism between algebras and was made by Gelfand and Kolmogoro in [15], in 1939. The second version presented is about isometric isomorphisms and the demonstration is originally due to Arens and Kelley and it is found in [2]. Finally, we study the theorem proved by D. Amir and presented in [1]. This theorem generalizes the classical theorem Banach- Stone and states the following: \"Let K e L be compact Haudor spaces and let T be a linear isomorphism from C(K) into C(L), with ||T||.||T^||< 2. Then K and L are homeomorphic\".

Parmi les risques naturels, les tremblements de terre ont une incidence significative sur l'environnement bâti et engendrent des pertes économiques et sociales. Les pertes élevées causées par les derniers tremblements de terre destructeurs mettent en évidence la nécessité d'une évaluation de la vulnérabilité sismique des bâtiments existants. Parmi les bâtiments les plus vulnérables, les bâtiments anciens en maçonnerie de pierre sont nombreux dans les centres historiques urbains de l'Est du Canada, comme le Vieux-Québec, et représentent un patrimoine architectural et culturel dont la valeur est difficilement mesurable. Ces bâtiments ont été construits pour résister aux charges de gravité et offrent généralement une faible résistance aux charges sismiques. L’évaluation de leur vulnérabilité sismique est donc la première étape nécessaire au développement d’un programme de mitigation du risque et de mise à niveau sismique. L'objectif de cette étude est de développer un ensemble d’outils analytiques probabilistes pour l'évaluation de la vulnérabilité sismique des bâtiments en maçonnerie de pierre et l’analyse efficace des incertitudes inhérentes au processus d’évaluation. En premier lieu, une approche méthodologique simplifiée est proposée pour la modélisation de la vulnérabilité des bâtiments et le traitement systématique des incertitudes. Les courbes de capacité sont développées à l’aide d’un modèle mécanique équivalent à un degré de liberté. Les courbes de fragilité, donnant le degré de dommages en fonction du déplacement spectral, sont développées sur la base de déplacements critiques des murs de maçonnerie de pierre. Une analyse probabiliste simplifiée de la demande sismique est proposée pour déterminer l’influence de l'incertitude combinée de la capacité et de la demande sur les courbes de fragilité. En deuxième lieu, une procédure pour le développement de fonctions de fragilité et de vulnérabilité sismique en termes d’une mesure d’intensité indépendante de la structure (l'accélération spectrale) est proposée. La procédure est efficace pour réaliser rapidement l’évaluation de la vulnérabilité des bâtiments en maçonnerie de pierre et peut facilement être adaptée et appliquée à une autre classe de bâtiment. En troisième lieu, une analyse de sensibilité est réalisée pour quantifier l’influence des incertitudes associées aux paramètres utilisées dans la procédure de modélisation de la vulnérabilité sismique. Finalement, la méthodologie proposée est appliquée à l’estimation des dommages pour 1220 bâtiments existants du Vieux-Québec selon un scénario sismique de magnitude 6,2 à une distancé épicentrale de 15km pour une probabilité de dépassement de 2% en 50 ans. Les courbes de fragilité des autres types de bâtiments ont été développées avec la procédure proposée à partir des courbes de capacité proposées dans Hazus. Ce scénario montre que la plupart des dommages prévus sont concentrés aux vieux bâtiments de maçonnerie de brique non-armée et aux bâtiments en maçonnerie de pierre.

The main theorem of the thesis asserts that if B is a JB*-subtriple of a JB*triple A such that B separates oe(An U {O}, then if A or B is postliminal, A=B. The main theorem and many of the other key results of the thesis are generalisations of the results of Kaplansky (1951) and Glimm (1960) on the Stone-Weierstrass conjecture for C* -algebras. We first prove a Stone-Weierstrass theorem for postliminal JB-algebras. This plays an essential role in the proof of the main theorem and is also important in the proof of our second main result, the Glimm-Stone-Weierstrass theorem for JB-algebras. Vital to the Glimm-Stone-Weierstrass proof, we show that if A is a universally reversible prime and antiliminal JB-algebra, then S(A) C P(A). Conversely, if A is universally reversible and of dimension greater than one, S(A) C P(A) implies A is prime and antiliminal. The C* -algebra version of this theorem is due to Tomiyama and Takesaki (1961). By means of the universal enveloping C*-algebra functor, we show that if , the Stone-Weierstrass conjecture is true for C* -algebras then it is true for JB-algebras. Employing a similar technique we prove Stone-Weierstrass theorems for semi-finite JW-algebras and type I JW-algebras, building on results of Akemann (1969- 70). The crucial result of the thesis reduces the Stone-Weierstrass separation condition for JB*-triples locally to that of JB*-algebras. Using this in conjunction with the Stone-Weierstrass theorem for postliminal JB-algebras is an essential part of the proof of the main theorem

The development of transparent synthetic soil has enabled non-intrusive measurement of internal soil displacement and detection of pre-failure strains using laser aided imaging and Particle Image Velocimetry. The work described in this paper applies this novel methodology to evaluate the deformation and failure behaviour of stone column foundations in reduced scale physical models. The overall accuracy and precision of the test system were optimised to 53 μm and 0-4.3μm respectively through the implementation of newly developed image enhancement and photogrammetric correction techniques. This represented a considerable improvement compared to the previous state of the art in transparent soil modeling. A total of 7 isolated column tests and 6 column strip footing tests were carried out in repeatable transparent clay beds. Visualisation of real-time internal displacement has indicated that isolated stone columns fail in an axisymmetric manner through a combination of compression and bulging with only a small amount of column base penetration, indicating a critical column length of 4d. Consequently, increasing column length from 4d to 6d and 8d lead to only moderate increases of 8.5% and 13% in bearing capacity respectively In contrast to the isolated columns, local shear failure, bulging, bending, punching and block failure were all observed for column strip foundations, depending on the geometrical configurations employed. Column length played a particularly important role in optimising the bearing capacity of column strip foundations. Increasing column length from 4d to 6d and 8d was shown to improve the load capacity of the composite foundation by 29% and 67%. It was concluded that the critical length in terms of optimising the bearing capacity of a vibro strip foundation is 8d. However, increasing foundation size rather than column length was found to be more effective in increasing the load capacity in both cases. Increasing footing size and correspondingly increasing Ar from 3 to 4 and 5 was seen to protect the upper column from bulging and increase its radial zone of influence of the column in the surrounding soil, resulting in increases in load capacity of 28% and 51% for isolated columns and 22% and 29% for strip foundations respectively. It was concluded that provision of a footing overhang of over 0.4d should prevent shear failure in vibro strip foundations. A new design approach has been proposed which accounts for the size of the footing. The performance of each isolated column foundation was predicted to within 6% of the measured load capacity for all area ratios tested, while the load capacities of the strip foundations were predicted to within 14%. Thus although the new method does not model the ‘group effect’, it offers an improvement on cavity expansion based design methods, as column structure interaction is accounted for. Overall, the nature of the configuration of vibro strip foundations and their limited size in practice limit the bearing capacity of stone columns within a strip configuration to values only slightly over that of a single column, if at all.

2004/2005
Se si considerano i carboidrati non solo per il loro più semplice ruolo di riserva energetica nel sostentamento de11a vita ma anche per que11o più intrigante di modulatori della comunicazione cellulare, entriamo nel campo della glicobiologia. Quest'aspetto non-triviale della funzione dei glicani deriva dalla loro inerente complessità strutturale (grande varietà di legami e possibilità di ramificazione) e dalla loro localizzazione ubiquitaria nella cellula e nella matrice extracellulare. La maggior parte dei glicani ricopre densamente la parte esterna della superficie cellulare ed è esposta ad un ambiente ricco di proteine (come i fattori di crescita, citochine, tossine, enzimi ed altro). Questa posizione preferenziale permette loro di mediare numerose interazioni tra cellule o tra cellula e matrice extracellulare e di fungere da "agenti del traffico" in molti processi cellulari (riconoscimento, adesione, proliferazione e differenziamento). Perciò, la comprensione della funzione biologica peculiare svolta dai carboidrati, non può prescindere dalla caratterizzazione strutturale dei saccaridi, considerati o come catene a se stanti o come parte integrante di glicoconiugati, e dei loro partners d'interazione proteici. Scopo. Lo scopo del presente lavoro è essenzialmente di tipo metodologico, ossia rivolto allo sviluppo di tecniche e procedure sperimentali per l'analisi (identificazione/rilevamento, caratterizzazione, sintesi) di determinate sequenze saccaridiche frequentemente riscontrate in natura, di glicoproteine e di proteine che legano carboidrati. l. Derivatizzazione di saccaridi per il rilevamento UV-visibile all'elettroforesi capillare (CE) Per quanto riguarda la determinazione della composizione in monosaccaridi, che spesso rappresenta il primo passo per la completa elucidazione strutturale di un campione zuccherino, abbiamo sviluppato ed ottimizzato delle metodologie sperimentali volte ad un migliore rilevamento UV-visibile di mono- ed oligosaccaridi presenti in glicoproteine di mammiferi e pianta. I carboidrati sono privi di gruppi cromofori e debbono essere opportunamente derivatizzati, cioè legati covalentemente ad un cromoforo, solitamente per amminazione riduttiva, prima di essere analizzati alla CE. Le rese di derivatizzazione, tuttavia, dipendono dalla natura del residuo saccaridico e gli zuccheri N-acetilati, come l'N-acetilgalattosammina (GalNAc) e l'Nacetilglucosammina (GlcNAc) che occupano, rispettivamente, il terminale riducente di 0- ed N-glicani, sono notoriamente difficili da derivatizzare. Si è quindi condotto uno studio comparativo finalizzato al miglioramento della procedura di derivatizzazione, aumentando il grado di rilevabilità degli zuccheri N-acetilati. I risultati hanno mostrato come, tra vari agenti derivatizzanti comunemente usati, l'acido 2-aminobenzoico sia il più efficiente, otirendo alta e pari sensibilità al detector UV-vis per tutti i saccaridi analizzati. Inoltre, scegliendo adeguate condizioni di corsa alla CE, una miscela di undici monosaccaridi è stata efficientemente separata in un intervallo di tempo assai ristretto. 2. Sintesi di N-acetillattosamina (LacNAc) con beta-galattosidasi immobilizata I risultati sopra menzionati, relativi ad una efficace procedura di derivatizzazione di zuccheri riducenti, sono stati applicati con successo al rilevamento di LacNAc da miscele di reazione grezze via CE. Questo disaccaride è solitamente situato nella porzione più esterna di oligosaccaridi complessi facenti parte della superficie cellulare ed è quindi direttamente coinvolto in processi di riconoscimento cellulare. Qui è stata provata la sintesi enzimatica in fase eterogenea di LacNAc. Lo scopo dello studio era quello di migliorare sia la resa del prodotto ma anche il recupero del biocatalizzatore attraverso la sua immobilizzazione su supporto solido (polimeri commerciali Eupergit® e Sepabeads) in confronto alla stessa sintesi effettuata con enzima libero in soluzione. La biosintesi è stata fatta per reazione di transglicosilazione con betagalattosidasi da B. circulans partendo da p-nitrofenil galattopiranoside (come glicosil donatore) e GlcNAc (come glicosil accettore). La reazione è stata seguita monitorando via CE la produzione di disaccaride in funzione del tempo. L'analisi cinetica ha rivelato che la procedura di immobilizzazione non sopprime l'attività catalitica ma, al contrario, incrementa l'efficienza di trasferimento di galattosio dell'enzima. I profili cinetici delle reazioni effettuate con Eupergit® o Sepabeads sono risultate essere molto diversi, suggerendo che le proprietà chimico-fisiche delle matrici di supporto influenzano il comportamento dell'enzima. La resa molare massima di LacNAc (64%) è stata ottenuta usando Eupergit® come carrier polimerico. 3. Analisi strutturale di glicani L'identificazione e l'analisi quantitative di porzioni oligosaccaridiche di glicoproteine di importanza biotecnologica, come la beta-glucosidasi, o terapeutica, come le proteine di membrana di linee cellulari epatiche, è stata qui affrontata seguendo due strategie di processamento glicoproteico alternative. (3a) Prima del rilascio sul mercato, beta-glucosidasi (GCasi) ricombinante prodotta da semi di tabacco transgenico, deve essere ampiamente caratterizzata al fine di verificare se lo schema di glicosilazione della glicoproteina espressa in pianta somiglia a quello della CGasi da placenta umana. Il trattamento con acido trifluoroacetico ha portato ad idrolisi esaustiva del campione saccaridico e sui monosaccaridi rilasciati si è svolta un'analisi CE. Dal momento che non sono stati ritrovati né fucosio né xilosio, unità monosaccaridiche frequenti in glicoproteine vegetali, si è potuta escludere una potenziale immunogenicità per la somministrazione all'uomo. (3b) La rilevanza scientifica dello studio della struttura glicanica di proteine di membrana, differentemente espresse in linee cellulari epatiche sane o cancerose, sta nella possibile diagnosi di markers tumorali saccaridici, presenti già nella fase precoce dell'insorgere del tumore. Al fine di sviluppare e ottimizzare delle procedure metodologliche, basate sulla deglicosilazione enzimatica in soluzione o in gel (con PNGasi F) con rilascio delle catene oligosaccahridiche intatte e analisi LC/MS dell'idrolizzato, da esportare poi ali' analisi del pattern di glicosilazione delle proteine di membrana, è stata qui utilizzata fetuina bovina commerciale come modello di una proteina pesantemente glicosilata. Dai dati ottenuti, una struttura biantennaria e due triantennarie sono state infine assegnate. 5. Biosintesi su ampia scala di un lisozima da H.pylori Un grande sforzo è stato dedicato allo studio di un Iisozima da H.pylori (Lys ), un enzima che sembra svolgere un ruolo chiave nell'autolisi del batterio durante la colonizzazione dell'epitelio gastrico dei primati. Al fine di tentare una caratterizzazione strutturale della proteina, sola ò in associazione con il suo substrato saccaridico (acido N-acetylmuramico), si è reso necessario lo "'scaling-up" dei processi di biosintesi e purificazione. Ciò è stato possibile dopo l'identificazione del gene codificante la sequenza del lisozima in H.pylori e clonaggio del frammento di DNA di interesse inun vettore d'espressione adeguato, promuovendo l'espressione ad alti livelli in E. coli. Due sistemi d'espressione sono stati provati: Il sistema pGEX ha prodotto il Lys come proteina di fusione con la GST, preferenzialmente prodotta in Eco/i come corpi di inclusione, specialmente quando sono stati usati grandi volumi di colture batteriche. La proteina è stata isolata dal precipitato cellulare insolubile, solubilizzata e successivamente ripiegata con successo. Dopo purificazione e taglio proteolitico con trombina per la rimDziDne della coda GST da Lys, le prove di attività litica sono risultate essere positive, nonostante la fallita separazione tra le due proteine. Studi di affinità su tali campioni condotti alla CE, non hanno portato nessuna evidenza a favore dell'affinità di Lys per un disaccaride (LacNAc) che mima il substrato naturale di Lys. Quindi il vettore pET è stato successivamente scelto per esplorare una stategia di clonaggio alternativa. Il sistema d'espressione ha fornito Lys con coda poliistidinica C-terminale. Anche in questo caso la proteina è stata recuperata quasi interamente nella frazione insolubile del lisato cellulare. Dopo processo di rinaturazione, direttamente effettuato in colonna d'affinità Ni-NTA agarosio, si è ottenuta proteina ad un elevato grado di purezza ma inattiva. L'intero lavoro è stato svolto all'Università di Trieste, nel dipartimento di Biochimica, Biofisica e Chimica delle Macromolecole nel laboratorio del Prof. S.Paoletti sotto la supervisione della dott.ssa A.Gamini, dove ho avuto la possibilità di imparare i rudimenti della biochimica analitica. All'intemo del progetto lisozima da H.pylori, è stata di grande importanza la permanenza durata 4 mesi all'Università di Halle-Wittenberg all'Istituto di Biotecnologia (Germania) nel laboratorio del Prof R.Rudolph e sotto la supervisione del Dott. C.Lange che mi ha portato ad acquisire esperienza nel campo della chimica delle proteine.
lf carbohydrates are viewed not merely as energy suppliers for sustaining life but their intriguing biological role, chiefly as modulators of cell communication, is investigated, then we approach the field of glycobiology. This nontrivial task of glycans arises from their inherent structural complexity (great variety of linkage and branching occurrence) an d their ubiquitous location in the cell and extracellular matrix. Most glycans densely cover the outer cellular surface and are exposed to an environment of many proteins (such as growth factors, cytokines, toxins, enzymes and others). This particular position enables them to mediate several cell-cell or cell-matrix interactions and act as recognition determinants in a great variety of important cellular events ( adhesion, proliferation and differentiation). Therefore, the comprehension of the unique function of carbohydrates in biology calls for a structural characterization of saccharides, considered either as sugar chains or as integral part of glycoconjugates, and their interaction partners, such as carbohydratebinding proteins. The aim of the present work was essentially methodological in kind, i.e. directed towards the development of techniques and experimental procedures for the analysis (identification/detection, characterization, synthesis) of given carbohydrate sequences, frequently occurring in nature, glycoproteins and sugar-binding proteins. l. Derivatization of saccharides for UV -visible detection on capillary electrophoresis CE). Concerning the compositional monosaccharide determination of a hydrolyzed glycan pool, which is frequently the first step in oligosaccharide mapping, we developed and optimized experimental methods aimed to improve the UV -vis detection of monoand oligosaccharides present as widespread components in mammalian and plant glycoproteins. Saccharides inherently lack chromophores and must be suitably derivatized, i.e. covalently linked to a chromophore usualiy through reductive amination, prior to detection on CE. Derivatization yield, however, depends on the nature of the sugar residue and N-acetylamino sugars, such as N-acetylgalactosamine (GalNAc) and N-acetylglucosamine (GlcNAc), occupying the reducing end of respectively 0- and N-glycan sequences, are notoriously difficult to label. A comparative study aimed at the improvement of a labelling procedure, enhancing the detectability of N -acetylamino sugars, was therefore performed. The results showed that, among frequently used tagging dyes, 2-aminobenzoic acid turned out to be the most efficient, offering high and comparable sensitivity at the CE UV -vis detector for ali saccharides tested. Choosing adequate CE running conditions, a mixture of eleven monosaccharides was efficiently separated in a very short time frame. 2. Immobilized beta-galactosidase-based synthesis ofN-acetyllactosamine (LacNAc) The abovementioned findings of suitable derivatization procedure for the UV -vis detection of reducing sugars was successfully applied to the detection of LacNAc from crude reaction mixtures via CE. This disaccharide is very commonly located at the outermost portion of complex celi surface oligosaccharides of glycoconjugates and is therefore directly involved in recognition processes between cells. The enzymatic synthesis in heterogeneous phase of the LacNAc disaccharide was here attempted. The goal of the study was to improve both product yield and recovery of the biocatalyst through its immobilization on solid supports (commercial polymers Eupergit® and Sepabeads ), in comparison with the synthesis performed with the free enzyme in solution. The biosynthesis was performed through transglycosylation reaction with beta-galactosidase from B. circulans starting from p-nitrophenyl galactopyranoside as the glycosyl donor and GlcNAc as the acceptor. The reaction was followed monitoring via CE the disaccharide production in function of time. The kinetic analysis revealed that the immobilization procedure did not suppress catalytic activity, but, on the contrary, improved the galactose transfer efficiency of the enzyme. Kinetic profiles of the reactions performed with Eupergit® or Sepabeads were qui te different, suggesting that the physico-chemical properties of the supporting matrices infuence enzyme behaviour. Maximum LacNAc molar yield (64%) was obtained using Eupergit® as solid carrier. 3. Glycan structure analysis The identification and quantitative analysis of oligosaccharide portions of glycoproteins of biotechnological, like beta-glucosidase, or therapeutical interest, such as membrane proteins of hepatic celllines, was here carried out according to two alternative glycoprotein processing strategies. (3a) Prior to commercialization, recombinant beta-glucosidase (GCase) produced in transgenic tobacco seeds must be first thoroughly characterized in order to test whether the glycosylation pattem of the glycoprotein expressed in plant resembles that of the human placenta} GCase. Treatment with trifluoroacetic acid led to exhaustive hydrolysis of the glycan moiety and o n the released monosaccharides a CE analysis was carried out. Since neither fucose nor xilose, frequent sugar residues found in plant glycoproteins, could be detected, potential immunogenicity for delivery to humans was excluded. (3b) The scientific relevance of studying the glycan structure of membrane-bound proteins, differently expressed in a healthy and hepatoma cell line, relies on the possible detection of early-stage saccharidic tumoral markers. In order to develop and optimize a methodological procedure, based on the in-solution or in-gel enzymatic release (with PNGase F) of entire oligosaccharide chains and analysis through LC/MS of the hydrolizate, that could be exported to the glycosylation pattem analysis of membrane proteins, the commerciai bovine fetuin was here used as a model of a heavily glycosylated protein. From the obtained data, a biantennary and two triantennary oligosaccharide structures, pertaining to the N-glycosylation profile of Fet, could be finally assigned. 5. Large-scale biosynthesis of a Hpylori lysozyme Much effort has been devoted to the study of a Hpylori lysozyme (Lys), an enzyme that seems to play a key role in the autolysis of the bacterium during colonization of the gastric epithelium of primates. In order to attempt structural characterization of the protein, either alone or in complexed form with its saccharidic substrate (Nacetylmuramic acid), the scaling-up of the biosynthesis and the purification procedures were required. This could be performed after identification of the gene encoding the lysozyme sequence in Hpylori and cloning the DNA sequence of interest into a suitable expression vector and promoting high-level expression of the Lys in E. coli. Two expression systems were tested: the pGEX system yielded the Lys as fusion protein with GST, which was produced preferentially as inclusion body in E. coli host cells, especially when larger culture volumes were used. The protein was isolated from insoluble cell pellet, solubilized and successfully refolded. After purification and digestion with thrombin protease to remove the GST fusion tag from the Lys protein, tests for lytic activity were positive, even though separation could not be achieved. Binding studies performed through affinophoresis on these samples, unfortunately did not provide any evidence of the affinity of Lys fora disaccharide (LacNAc) mimicking the natural sugar substrate. The pET vector was therefore chosen for an alternative cloning strategy. The expression system gave the Lys with a C-terminai 6xHis-tag. Also in this case the protein was almost totally recovered in the insoluble fraction of the celllysate. After a refolding step, directly performed on Ni-NTA agarose affinity column, highly pure, but unactive protein was obtained. The whole work was carried out at the University of Trieste, department of Biochemistry, Biophysics and Macromolecular Chemistry in the laboratory of Prof. S.Paoletti under the supervision of Dr. A.Gamini, where I had the opportunity to learn the basic issues of analytical biochemistry. Within the Hpylori lysozyme project, a four-months stay at the Martin-Luther University of Halle-Wittenberg at the Institute of Biotechnology (Germany) in the laboratory of Prof. R.Rudolph and under the supervision of Dr. C.Lange was of great importance for getting expertise in the field of protein chemistry.
XVIII Ciclo
1974
Versione digitalizzata della tesi di dottorato cartacea.

This thesis is focused on the evaluation of existing stone structures, particularly stone bridges. It contents a summary of the most frequently used structure types and materials of historic bridges as well as it presents some contemporary technologies. Thesis also presents methods of the construction stone testing, both laboratory and in situ. The process of the assessment of existing structures from ČSN ISO 13822 is being applied on the evaluation of stone structures, taking into account their specifics. These specifics results from the natural origin of the building material. The experimental part describes the survey and assessment of an existing stone bridge in Dobromilice, including a proposal for an adequate way of reconstruction.

2003/2004
Le recenti innovazioni scientifiche e tecnologiche hanno reso possibile la realizzazione di dispositivi su scala nanometrica che hanno guidato il trend di miniaturizzazione nelle industrie elettronica e dei semiconduttori. L 'utilizzo di interfacce molto ordinate tra due metalli, tra un metallo e un semi conduttore o tra un film organico ed un metallo, è stato dimostrato essere molto promettente per lo sviluppo di nuovi dispositivi grazie all'alta mobilità elettronica indotta dall'assenza di difetti e dall'alto grado di ordine di questi sistemi. La realizzazione di tali interfacce avviene tramite la crescita epitassiale di materiali in condizioni di ultra alto vuoto. La crescita epitassiale eterogenea è inoltre una tecnica largamente utilizzata per produrre materiali artificiali; una opportuna scelta del substrato di crescita infatti, permette di introdurre e controllare proprietà strutturali del film che si cresce e di regolarne in questo modo le proprietà elettroniche. Per questi motivi la capacità di studiare le proprietà non solo spettroscopiche ma anche strutturali di questi sistemi è diventata di fondamentale importanza negli ultimi anni. Nel presente lavoro un approccio multi-tecnica è stato applicato per ottenere una caratterizzazione completa dal punto di vista strutturale e morfologico di alcuni sistemi presi come esempio. I film sottili considerati sono stati studiati per mezzo della diffrazione a raggi X ad incidenza radente (GIXRD), diffrazione di fotoelettroni (PED), spettroscopia di assorbimento vicino soglia (NEXAFS), diffrazione di atomi di elio (HAS) e diffrazione di elettroni a bassa energia (LEED). Il lavoro è stato eseguito presso la linea di luce ALOISA del sincrotrone ELETTRA di Trieste. Viene riportata una breve introduzione alle tecniche sperimentali utilizzate. Due esperimenti su sistemi semplici vengono esposti per descrivere l'applicazione delle tecniche GIXRD (la determinazione delle proprietà strutturali della ricostruzione l x2 della superficie Au(ll 0)), PED e NEXAFS (determinazione dell'orientazione del gruppo CN sulla superficie Pd(llO)) e di come esse possono venire utilizzate sulla linea ALOISA. Nel caso di sistemi più complessi, l'utilizzo simultaneo di più tecniche è necessario per una caratterizzazione completa. Due esempi in questo senso vengono riportati nella presente tesi: l. Crescita di un film di N i sulla superficie Pd(l 00) I film metallici sottili, quando cresciuti su substrati opportuni, possono presentare proprietà chimiche e magnetiche inusuali, date dalle distorsioni strutturali indotte dal substrato. Uno studio strutturale di questi sistemi è necessario per otteneme una caratterizzazione completa. Nel caso del Ni su Pd(lOO), nelle prime fasi della deposizione gli atomi di Ni formano un reticolo di tipo fcc (cubico a facce centrate) distorto, con il parametro laterale pari a quello del substrato (fase pseudomorfa). Precedenti studi PED suggeriscono che una transizione strutturale di fase avviene quando il film raggiunge uno spessore di 9-12 strati atomici. A queto stadio il film si suppone assumere la struttura fcc tipica per il Ni. Noi abbiamo usato le tecniche GIXRD e PED per caratterizzare l'evoluzione delle due fasi in funzione dello spessore del film. Uno spessore critico di 10 strati atomici è stato determinato per l'inizio della transizione alla fasefcc. Le misure GIXRD hanno inoltre messo in evidenza come la transizione, caratterizzata da un forte rimescolamento dei due metalli all'interfaccia, proceda con una crescita laterale di domini di Nifcc a spese della fase pseudomorfa. I film di metallo-ftalocianine sono tra i semi conduttori organici più promettenti per applicazioni in elettronica, celle solari, sensori di gas. Le loro proprietà di trasporto possono essere migliorate ottimizzando le proprietà morfologiche, che dipendono dalla struttura dell'interfaccia con il substrato sui cui vengono cresciuti; per questo motivo lo studio dei primi stadi di deposizione della CuPe è rilevante per possibili applicazioni. Noi abbiamo studiato la struttura di un film sottile di CuPe su Au(llO) con le tecniche HAS, LEED, NEXAFS e GIXRD in funzione dello spessore, nell'intervallo tra O e 2 strati molecolari. Abbiamo evidenziato come diverse ricostruzioni della superficie vengono indotte dall'interazione molecole-substrato al variare dello spessore del film. In particolare due fasi con due diverse ricostruzioni lungo la direzione [l 00] del substrato sono state identificate: una ricostruzione x5 è presente a ricoprimento minore di uno strato molecolare; quando il primo strato molecolare del film è formato appare infine una ricostruzione x3. Misure GIXRD hanno permesso di determinare la struttura della cella x3 del substrato, che è presente in entrambe le fasi ed è accompagnata nella fase x5 da celle x2 residue della ricostruzione della superficie pulita. L'utilizzo di due tecniche sensibili in modo diverso alla superficie come HAS e LEED ha permesso di distinguere tra il grado di ordine del substrato e quello delle molecole del film; mentre allo spessore di uno strato molecolare il film è parzialmente disordinato, il substrato presenta ordine a lungo raggio. Grazie agli spettri NEXAFS si è determinata l'orientazione della molecola rispetto al substrato. E' stata misurata un'inclinazione di 25 gradi del piano molecolare rispetto alla superficie, consistente con la distorsione asimmetrica della struttura della cella x3 trovata con le misure GIXRD.
The semiconductor and electronic industry has seen a remarkable miniaturization trend driven by many scientific and technologic innovations in which the device fabrication and control on the nanometric lengthscales have become a fundamental issue. The experimental quest for highly ordered metal-semiconductor, metal-metal and organic-inorganic interfaces in the modem electronics is further motivated by the observed increased electric charge carrier mobility over well ordered and defect free layers, which can be produced by epitaxial film growth under Ultra-High- Vacuum conditions. Furthermore, heterogeneous epitaxy is a widely exploited technique to fabricate artificial materials, since a proper choice of the substrate allows to introduce controlled structural modifications of the growing film and to tune in this way its electronic properties. For these reasons the capability of studying not only the spectroscopic but also the structural properties of these systems has become of fundamental importance in the last years. In this work a multi-technique experimental approach has been applied to reach an exhaustive comprehension of the interface structure and morphology on a few case studies. Thin films have been studied by means of Grazing Incidence X-Ray Diffraction (GIXRD), X-ray Photoelectron Diffraction (PED), Near Edge X-ray Absorption Fine Structure spectroscopy (NEXAFS), Helium Atom Scattering (HAS) and Low Energy Electron Diffraction (LEED). The thesis work has been performed at the ALOISA beamline of ELETTRA Synchrotron in Trieste. A brief review of the experimental techniques is given. Two experiments on simple systems are presented to describe the application of GIXRD (the structural determination of the l x2 missing row Au(llO) surface reconstruction) and PED and NEXAFS ( determination of the diatomic molecule CN orientation on Pd(llO) substrate) techniques and their implementation in the experimental apparatus of ALOISA. In the case of more complex systems, a complete structural characterization requires the simultaneous use of most of the above introduced techniques. Two case studies are reported in this thesis.l. Ni film growth on Pd(lOO) surface. Thin metallic films, when grown on suitable substrates can display unusual chemical and magnetic properties due to the strain induced by the substrate. To reach a better understanding of these heterosystems a structural characterization is needed. In the case of Ni on Pd(OOl), in the early stages of deposition, Ni atoms forma tetragonally strained fcc phase with the same laterallattice spacing of the substrate (pseudomorphic phase). Previous PED measurements suggested a structural transition occurring when the film thickness exceeds approximately 9-121ayers. At this stage the film was supposed to transform into its bulk-like Ni fcc structure. We have used GIXRD and PED to fully characterize the evolution of the two phases as a function of the thickness. A critical value of l O layers has been determined as the onset for the transition to the bulk phase. The morphology and the distribution of the two species of the system has been determined. GIXRD scans analysis puts in evidence how the transition, accompanied by a strong increase of the intermixing at the Ni/Pd interface, proceeds by the lateral growth of the Ni fcc domains at the expense of the pseudomorphic phase. 2.The structural characterization of a thin Copper-Phthalocyanine (CuPc) fùm grown on Au(llO) surface. Metal-Phthalocyanines films are among the most promising organic semiconductors devices for applications in electronics, solar celis, gas sensors. Their transport properties can be improved by optimizing the film morphology, which depends on the interface structure; for this reason the study of the early stages of deposition of CuPc on metals is relevant for possible applications. W e have studied the structure of a thin Cu-Pc film on the Au(llO) surface by means of HAS, LEED, NEXAFS and GIXRD as a function of thickness in the 0-2 monolayer range. W e have shown how different reconstructions are induced by the interaction between the molecules and the substrate as a function of the film thickness. In particular, two phases have been studied displaying different reconstructions along the [l 00] direction of the surface: a x5 reconstruction is present in the submonolayer range; at the monolayer coverage a x3 phase appears. GIXRD measurements allowed to determine the structure of the x3 cell which is present in the both phases and is accompanied by residua! x2 cell of the clean surface in the x5 phase. The use of two differently surface sensitive techniques · such as HAS and LEED allowed to distinguish between the order of the substrate and the organic layer; while the molecular film is partly disordered at the monolayer stage, the substrate presents well defined long range order. The NEXAFS spectra determine the molecules orientation with respect to the substrate. A tilt angle of about 25 degrees between the molecular plane and the surface in the x3 phase has been determined, consistent with an asymmetric distortion of the structure of the x3 cell.
XVII Ciclo
1974
Versione digitalizzata della tesi di dottorato cartacea.

1997/1998
Questa tesi, intitolata Visione Tridimensionale per la stima di Struttura e Moto, tratta di tecniche di Visione Artificiale per la stima delle proprietà geometriche del mondo tridimensionale a partire da immagini numeriche. Queste proprietà sono essenziali per il riconoscimento e la classificazione di oggetti, la navigazione di veicoli mobili autonomi, il reverse engineering e la sintesi di ambienti virtuali. In particolare, saranno descritti i moduli coinvolti nel calcolo della struttura della scena a partire dalle immagini, e verranno presentati contributi originali nei seguenti campi. Rettificazione di immagini steroscopiche. Viene presentato un nuovo algoritmo per la rettificazione, il quale trasforma una coppia di immagini stereoscopiche in maniera che punti corrispondenti giacciano su linee orizzontali con lo stesso indice. Prove sperimentali dimostrano il corretto comportamento del metodo, come pure la trascurabile perdita di accuratezza nella ricostruzione tridimensionale quando questa sia ottenuta direttamente dalle immagini rettificate. Calcolo delle corrispondenze in immagini stereoscopiche. Viene analizzato il problema della stereovisione e viene presentato un un nuovo ed efficiente algoritmo per l'identificazione di coppie di punti corrispondenti, capace di calcolare in modo robusto la disparità stereoscopica anche in presenza di occlusioni. L'algoritmo, chiamato SMW, usa uno schema multi-finestra adattativo assieme al controllo di coerenza destra-sinistra per calcolare la disparità e l'incertezza associata. Gli esperimenti condotti con immagini sintetiche e reali mostrano che SMW sortisce un miglioramento in accuratezza ed efficienza rispetto a metodi simili Inseguimento di punti salienti. L'inseguitore di punti salienti di Shi-Tomasi- Kanade viene migliorato introducendo uno schema automatico per lo scarto di punti spuri basato sulla diagnostica robusta dei campioni periferici ( outliers ). Gli esperimenti con immagini sintetiche e reali confermano il miglioramento rispetto al metodo originale, sia qualitativamente che quantitativamente. Ricostruzione non calibrata. Viene presentata una rassegna ragionata dei metodi per la ricostruzione di un modello tridimensionale della scena, a partire da una telecamera che si muove liberamente e di cui non sono noti i parametri interni. Il contributo consiste nel fornire una visione critica e unificata delle più recenti tecniche. Una tale rassegna non esiste ancora in letterarura. Moto tridimensionale. Viene proposto un algoritmo robusto per registrate e calcolare le corrispondenze in due insiemi di punti tridimensionali nei quali vi sia un numero significativo di elementi mancanti. Il metodo, chiamato RICP, sfrutta la stima robusta con la Minima Mediana dei Quadrati per eliminare l'effetto dei campioni periferici. Il confronto sperimentale con una tecnica simile, ICP, mostra la superiore robustezza e affidabilità di RICP.
This thesis addresses computer vision techniques estimating geometrie properties of the 3-D world /rom digital images. Such properties are essential for object recognition and classification, mobile robots navigation, reverse engineering and synthesis of virtual environments. In particular, this thesis describes the modules involved in the computation of the structure of a scene given some images, and offers original contributions in the following fields. Stereo pairs rectification. A novel rectification algorithm is presented, which transform a stereo pair in such a way that corresponding points in the two images lie on horizontal lines with the same index. Experimental tests prove the correct behavior of the method, as well as the negligible decrease oLthe accuracy of 3-D reconstruction if performed from the rectified images directly. Stereo matching. The problem of computational stereopsis is analyzed, and a new, efficient stereo matching algorithm addressing robust disparity estimation in the presence of occlusions is presented. The algorithm, called SMW, is an adaptive, multi-window scheme using left-right consistency to compute disparity and its associated uncertainty. Experiments with both synthetic and real stereo pairs show how SMW improves on closely related techniques for both accuracy and efficiency. Features tracking. The Shi-Tomasi-Kanade feature tracker is improved by introducing an automatic scheme for rejecting spurious features, based on robust outlier diagnostics. Experiments with real and synthetic images confirm the improvement over the original tracker, both qualitatively and quantitatively. 111 Uncalibrated vision. A review on techniques for computing a three-dimensional model of a scene from a single moving camera, with unconstrained motion and unknown parameters is presented. The contribution is to give a critical, unified view of some of the most promising techniques. Such review does not yet exist in the literature. 3-D motion. A robust algorithm for registering and finding correspondences in two sets of 3-D points with significant percentages of missing data is proposed. The method, called RICP, exploits LMedS robust estimation to withstand the effect of outliers. Experimental comparison with a closely related technique, ICP, shows RICP's superior robustness and reliability.
XI Ciclo
1968
Versione digitalizzata della tesi di dottorato cartacea.

2002/2003
L'oggetto di questa tesi è un'analisi di alcuni modelli per portafogli di rischi di credito, con speciale attenzione agli strun1enti usati in essi per rnodelizzare la dipendenza fra i default individuali, la quale è una delle rnaggiori fonti di preoccupazione nel management del rischio di credito. Focalizzererno in particolar modo la nostra attenzione su alcuni modelli per più gruppi ornogenei di rischi di credito, e specialrnente affrontererno il problerna della stirna dei loro parametri tramite il rnetodo della n1assima verosirniglianza; a tale scopo introdurremo un'approccio basato sull'uso dell'algoritmo E~1 (Expectation-l\1aximization). Nel prin1o capitolo introduciamo i principali stnunenti maternatici che verranno usati nel seguito. Presentiamo brevernente la teoria delle successioni scarnbiabili di variabili aleatorie, e mostriamo una dimostrazione, nel caso di vettori aleatori, del principale risultato in quest'ambito, il teorema di De Finetti. Poi introduciamo il concetto di copula, e mostriarno il teorerna di Sklar, facendone vedere il funzionarnento nel caso di variabili aleatorie con funzioni di distribuzione continue. Attraverso alcuni esempi illustriarno in che rnodo le copule descrivano la struttura di dipendenza nelle distribuzioni rnultivariate. Mostriamo anche corne sia possibile attraverso le copule esprirnere in n1odo naturale il coefficiente di dipendenza nelle code, una misura alternativa alla correlazione lineare per descrivere la dipendenza nel cornportarnento delle variabili aleatorie rappresentanti i rischi. Nel secondo capitolo analizziamo i due tipi più cornuni di rnodelli per portafogli di rischi di credito, i rnodelli a variabili latenti e i modelli di mistura di Bernoulli. Si rnostra come essenzialmente tutti i modelli a variabili latenti siano basati sulla copula Gaussiana, e si presenta un esempio di una generalizzazione ad una struttura di dipendenza più generale. Dopodiché si fanno alcuni esernpi di rnodelli di mistura di Bernoulli, e si presenta un sernplice risultato che perrnette di riscrivere i modelli a variabili latenti corne rnodelli di rnistura di Bernoulli. Alla fine del capitolo introduciamo il primo dei modelli per più gruppi omogenei di rischi di credito che verranno studiati in dettaglio nel seguito. Nel terzo capitolo analizziarno i due modelli su cui si è concentrato il maggior sforzo del nostro lavoro di tesi: il modello ad urna rnultidirnensionale e il rnodello a scherna iterativo di urne. Essi sono due esempi di modelli di mistura di Bernoulli multifattoriali la cui struttura di dipendenza è determinata da una generalizzazione del modello ad urna di Pòlya, in modo tale da introdurre dipendenza non solo fra i default nella stesso gruppo omogeneo di rischi, ma anche fra quelli in diversi gruppi (ad esempio diverse classi di rating), introducendo cioè una forma di contagio fra i default. Di entrarnbi i rnodelli, grazie all'uso degli strumenti forniti dalla teoria delle successioni scarnbiabili di variabili aleatorie, calcoliamo la distribuzione congiunta del nurnero dei default nelle varie classi di rating. La complessità della stirna statistica del valore dei parametri di suddetti rnodelli ci porta ad introdurre l'algoritmo EM (Expectation-Maxirnization), un'algoritrno per il calcolo iterativo delle stime di massirna verosirniglianza, il quale è l' argornento del quarto capitolo. In esso descriviarno brevernente la teoria generale riguardo all'algoritmo EM, e poi mostriamo corne applicarlo al caso dei tre rnodelli considerati. N el quinto capitolo affrontiarno gli aspetti tecnici dell'irnplementazione pratica dell'algoritmo nei casi considerati e presentiamo i risultati ottenuti, discutendone la bontà ed i vantaggi e gli svantaggi dell'uso dell'algoritrno. Infine nell'ultimo capitolo attraverso alcuni grafici effettuiarno un'analisi comparativa dei modelli studiati e indaghiamo la loro capacità di esprimere la dipendenza fra i default nelle differenti classi di rating.
The subject of this thesis is an analysis of sorne models for portfolios of credit risks, with a special attention to the tools used in them to model the dependence between individuai defaults, which is one of the main concerns in credit risk modeling and rnanagement. We will especially focus our attention to son1e rnodels for several groups of exchangeable risks; in particular we will tackle the problerns related to the rnaxirnum likelihood estimation of the pararneters involved, and to this purpose we introduce an approach based on the utilization of the Expetation-Maximization algoritlun. In the first chapter we introduce the rnain rnathernatical tools used in the the thesis. We describe briefly the theory of exchangeable sequences of randorn variables and we show a proof, for the case of randorn vectors, of the main result about them, the De Finetti's theoren1. Then we introduce the concept of copula and we present the Sklar's theorem, showing how it works in the case of continuous distribution functions. Through sorne examples we illustrate how copulas can be used to describe the dependence structures in rnultivariate distributions. We also show how it is possible to express in a natural way the coefficient of tail dependence, an alternative measure of dependence between random variables, by mean of copulas. In the second chapter we review the two most cornrnon classes of rnodels for dependent credit risks, the latent variables rnodels and the Bernoulli rnixture models. We see how essentially alllatent variables models are based on the Gaussian copula, and we ci te an example of a generalization to a more generai dependence structure. Then we show some exarnples of Bernoulli rnixture models, and we present a simple result that allows to rewrite latent variable models as Bernoulli mixture ones. At the end of the chapter we introduce the first model for several exchangeable groups of risks that we will study in detail in the following. In the third chapter we analyze the two rnodels on which we have devoted the rnajor attention: the multidimensional and iterative urn schernes. They are two examples of rnulti factors Bernoulli mixture models whose dependence structure is introduced by generalizations of the Pòlya urn scheme, in such a way that it allows for dependence both in the same rating group and in different rating groups, introducing then some form of contagion between defaults. For both of them, by using the tools of the theory about exchangeable sequences of random variables, we derive the expression of the joint default probability for the number of defaults in the different rating groups. The cornplexity involved in the statistica! estimation of the parameters of these models lead us to introduce the Expectation-11axirnization algorithm for iterative rnaximum likelihood estimations, which is the subject of chapter four. We briefly present the generai theory about it, and then show how to apply it in the case of the three models considered. In the fifth chapter we face the technical aspects of the irnplernentation of the algorithm and present the results obtained, discussing about advantages and disadvantages of the use of the algorithrn. In the last chapter we plot sorne graphics to compare qualitatively the rnodels and to analyze their capacity of expressing the dependence between defaults in different rating classes.
XVII Ciclo
1970
Versione digitalizzata della tesi di dottorato cartacea.

The in-situ examination of historical structures for diagnostic and monitoring purposes is a troublesome work that necessitates the use of non-destructive investigation (NDT) techniques. The methods of quantitative infrared thermography (QIRT) and ultrasonic testing have distinct importance in this regard. The key concern of the study was developing the in-situ use of QIRT for assessment of stone masonry wall sections having different sublayer(s) and failures. For that purpose, the non-destructive in-situ survey composed of QIRT and ultrasonic testing was conducted on a 16th century monument, Cenabi Ahmet PaSa Camisi, suffering from structural cracks, dampness problems and materials deterioration. The combined use of these two methods allowed to define the thermal inertia characteristics of structural cracks in relation to their depth. The temperature evolution in time during the controlled heating and cooling process was deployed for the cracks/defects inspection. The superficial and deep cracks were found to have different thermal responses to exposed conditions which made them easily distinguishable by QIRT analyses. The depth of cracks was precisely estimated by the in-situ ultrasonic testing data taken in the indirect transmission mode. The inherently good thermal resistivity of the wall structure was found to have failed due to entrapped moisture resulting from incompatible recent plaster repairs. The IRT survey allowed to detect the wall surfaces with different sublayer configurations due to their different thermal inertia characteristics. The knowledge and experience gained on the experimental set-ups and analytic methods were useful for the improvement of in-situ applications of QIRT and ultrasonic testing.

Finite element modelling is an efficient tool for the performance assessment of masonry structures. In particular, it facilitates the accurate prediction of the seismic response of a structure to earthquakes using dynamic analysis procedures. Numerical models using response spectrum analysis based on modal analysis allow to predict realistic failure modes observed after preceding seismic events with reasonable computational effort, a characteristic which is suitable for engineering practice. This thesis deals with modelling as a finite element model and analyse using response spectrum analysis of masonry buildings and the subsequent discussion of the obtained results. SAP2000 software is used for developing the numerical models, which are then analysed on the basis of design acceleration response spectra obtained according to the different building codes for different regions. Different structural demands under static and dynamic loading are obtained from the models and compared with theoretical results made with various mathematical models.

“For it is ultimately the function of art, in imposing a credible order upon ordinary reality, and thereby eliciting some perception of an order in reality, to bring us to a condition of serenity, stillness and reconciliation; then leave us as Virgil left Dante, to proceed toward a region where that guide can avail us no farther." T.S. Eliot This thesis is a search for an imposed credible order in a town library. As such it is simply a vehicle developing a process to produce architecture which is stable, whole and meaningful.
Master of Architecture

There are many forces at work in a design process. Each element of a design sketch reacts to ones before and after it. As a designer, one must be able to look at each individually and as part of the whole. In addition, the ideals and experiences brought to a project works its magic as well. It is the tension and the balance between the elements and ideals that create architecture. With a Bed and Breakfast as a project vehicle, the connection to the site, the relationship between public and private areas, and how the materials and structure form spaces were studied. These considerations led to a process of discovery and the challenge to weave the site, structure, and materials in a cohesive design.
Master of Architecture

Le contexte actuel engage les différents acteurs du domaine de l'architecture et de la construction à réinterroger de plus en plus les méthodes de conception et les techniques de production architecturales, au regard des problématiques liées au changement climatique et à la raréfaction de certaines ressources. Dans cette optique, la réhabilitation de l'utilisation du matériau pierre par rapport aux matériaux dits contemporains semble bénéficier d'un intérêt grandissant, depuis quelques décennies, pour plusieurs raisons : qualités mécaniques, durabilité importante, potentielle ressource de proximité. On s’intéresse notamment aux structures clavées, c'est-à-dire constituées de claveaux en pierre, géométriquement déterminés, taillés et appareillés. Ce type de structures constitue une importante proportion du patrimoine bâti historique : arcs, voûtes, dômes, plates-bandes, etc. Leurs propriétés mécaniques fascinantes font encore aujourd'hui l'objet d'une grande diversité de travaux de recherches qui mettent en œuvre différentes approches pour l'étude de leur stabilité, selon les cas. La modélisation avancée de ces monuments permet ensuite d’alimenter une réflexion poussée sur la conception de typologies de structures en pierre inédites (structures mixtes, structures réciproques, collages, optimisation de la forme, de l’utilisation de la matière) et plus seulement sur le diagnostic mécaniques de l’existant.Pour cela, deux types de modélisations dites bloc à bloc sont implémentées dans ce travail. La Méthode des Eléments Finis (MEF) permet de simuler de manière détaillée les déformations et contraintes dans les blocs et dans les joints de mortier, via des routines mathématiques solidement ancrées dans la recherche structurelle depuis les tout premiers ordinateurs. Une modélisation avancée par la MEF est notamment réalisée dans le cadre du chantier scientifique pour l’évaluation de la stabilité des voûtes de la cathédrale Notre Dame de Paris, suite à l’incendie de 2019. L'utilisation conjointe de la modélisation par Analyse Limite (AL) permet de contourner les difficultés inhérentes à la MEF : gourmandise en ressources de calculs, implémentation et traitement des résultats complexes. L’AL permet, au contraire, de déterminer relativement aisément et rapidement un domaine de stabilité à partir des seules hypothèses (i) de géométrie des blocs, considérés comme infiniment rigides, (ii) des critères de rupture aux interfaces de joints et (iii) des chargements extérieurs. L'application de cette méthode a trouvé écho dans une longue tradition d'études des structures en maçonneries patrimoniales qui ont ainsi pu faire les preuves de son efficacité, malgré un compromis sur la nature et la précision des réponses qu’elle permet de donner selon les cas, relativement à d’autres méthodes non linéaires comme la MEF. On se propose donc d'implémenter numériquement l’approche en AL de la manière la plus générale possible en s'appuyant sur des outils de résolutions mathématiques avancés (programmation conique), dans le but de rendre son utilisation accessible au plus grand nombre. Plusieurs études de cas concrets utilisant en parallèle l’approche par MEF et l’approche par AL permettent de rendre compte des avantages et limites de cette dernière selon les applications
The current context urges the various players in the field of architecture and construction to increasingly question architectural design methods and production technologies, regarding issues linked to climate change and the scarcity of resources. That's why for a few decades there has been a renewed interest for using stone material, for several reasons (mechanical qualities, important durability, potential local resource...) and in particular for stereotomic masonry structures made up of stone voussoirs, cut and fitted. The fascinating properties of these different types of structures (arches, vaults, domes, jack arch, etc.) are still the subject of a great research diversity today which implements different approaches in order to model their stability, depending on the different cases. The advanced modeling of these monuments then makes it possible to fuel in-depth reflection on the design of new typologies of stone structures (mixed structures, reciprocal structures, collages, optimization of shape, use of material) and not only on the mechanical diagnosis of the existing. Two types of block-to-block modeling are thus implemented in this work. The Finite Element Method (FEM) makes it possible to simulate the deformations and stresses into blocks and mortar joints, via mathematical routines firmly anchored in structural research since the very first computers. Advanced modeling by the FEM is carried out as part of the scientific project to evaluate the stability of the vaults of Notre Dame de Paris cathedral, following the 2019 fire. The use of Limit Analysis modeling (LA) makes it possible to circumvent the difficulties in FEM: greedy calculation resources, complex implementation and processing results. LA is used, on the contrary, to determine relatively easily and quickly a stability domain based solely on the assumptions of (i) the geometry of the blocks, considered as infinitely rigid, (ii) the failure criteria at the joint interfaces and (iii) ) the external loads. The application of this method has found echo in a long tradition of heritage masonry structures studies which have thus been able to demonstrate its effectiveness, despite a compromise on the nature and precision of the answers, relative to other non-linear methods such as FEM.The AL approach is therefore implemented in the most general possible way by relying on advanced mathematical resolution tools (conic programming), with the aim of making its use accessible to as many users as possible (architects, historians, stone cutters, engineers…). Several concrete case studies using the FEM approach and the AL approach in parallel show the advantages and limitations of the latter depending on the applications

Nonlinear static analysis is an efficient tool for performance assessment of masonry structures. In particular, it facilitates the accurate prediction of seismic response of a structure to earthquakes. Numerical models based on Equivalent Frame Method allow to predict realistic failure modes observed after preceding seismic events with reasonable computational effort, a characteristic which is suitable for engineering practice. This thesis deals with nonlinear incremental static (pushover) analysis of masonry buildings and the subsequent discussion of the obtained results. TreMuri software is used for developing the numerical models, which are then analysed on the basis of elastic acceleration response spectra obtained according to the Nepal National Building Code. Different structural improvement techniques are implemented in the models and compared in order to determine their impact on seismic performance. Elastic stiffness obtained with the nonlinear analysis is examined in contrast to analytical estimation of the same, made with various mathematical models.

The overall focus of this doctoral thesis is the examination of the role of store design-architecture in consumer perceptions of retail brand loyalty. More specifically, it examines how consumers’ perceptions at the store design-architecture level promote brand loyalty and attachment at the overall retail-level. This research, therefore, aims to address the underdeveloped extant knowledge of the role of the store design-architecture in retail branding. This thesis addresses two research questions: 1) is it possible to improve on the specification or measurement of the store environment beyond the novelty, complexity collative constructs proposed in traditional studies of the store environment?; and 2) what effect, if any, do these improved store environment constructs (from answering research question number one) have in explaining the role of store design-architecture in consumer perceptions of retail brand loyalty? In its examination of the role of store-level design-architecture in overall retail-level branding, the theoretical significance of this thesis is based on two activities. First, this thesis proposes a conceptual framework that draws on multiple, diverse literatures from design-architecture, psychology and marketing. The critical review of pertinent literatures from these three sources then enables the second activity: the generation of novel empirical insights based on surveys of consumer perceptions of store-level design-architecture. A research instrument is developed that compares higher and lower levels of design in two stores of Penneys, a discount fashion retailer. The responses of 145 consumers are examined in an Exploratory Factor Analysis (EFA). A separate dataset of 403 consumer responses are analysed using Confirmatory Factor Analysis (CFA) and Structural Equations Modelling (SEM). Multiple-group invariance testing is also completed on this dataset. The primary theoretical contributions of this thesis to the extant literature are five-fold. First, the principal contribution of this thesis confirms that store aesthetic preference is positively associated with retail brand loyalty. Thus, the second research question is satisfactorily addressed; I explain that there is a mild association between store aesthetic preference and the emotionally valenced retail brand attachment construct in higher-level design contexts. Instead, a store aesthetic preference association is observed with the more behaviourally valenced retail brand loyalty construct in lower-level designs. Consequently, this principal contribution to the extant literature reveals the perceptive dynamic of how consumers processing of store-level design-architecture correspond with their perceptions of retail-level brand loyalty. A host of global-attribute, objective-subjective, and cognitive-emotional perceptive processing at the store and retail levels are observed in the proposed theoretical framework. Second, to confirm the role of store design-architecture in retail brand loyalty, I develop: a new scale for retail brand product; modify scales for store prototype, store novelty, store aesthetic preference, store complexity and retail brand price; and introduce scales for brand attachment and brand loyalty from non-retail contexts into a retail context for the first time. This research, therefore, addresses research question number one by making a notable conceptual and measurement contribution to the specification of the store environment. Third, as a progression from the previous contribution, I use these improved store environments constructs to better specify the store environment, and examine the associations between store prototype, store novelty and store aesthetic preference. I demonstrate that theory such as the preference-for-prototypes literature helps to improve the extant understanding of the associations between store prototype, store novelty and store aesthetic preference. The confirmation of the existence of these associations essentially means that the proposed model is robust, credible and able to account for consumers objective-subjective, global-attribute discriminations of the store-level aesthetic. Fourth, in an effort to explain the relative visual and non-visual contributions to retail brand attachment and retail brand loyalty, I examine associations concerning retail brand product and retail brand price. Retail brand product is confirmed to have stronger associations with retail brand attachment than store aesthetic preference or store prototypicality. Thus, this research extends the extant knowledge of the relative contributions of visual and non-visual constructs to understanding retail brand loyalty. Fifth, this research contributes to the extant understanding of how non-invariance analysis can be employed in Structural Equations Modelling (SEM) to confirm differences between groups. This research examines differences in parameter values to confirm differences in perception of the higher and lower levels of store design-architecture. This type of use of non-invariance analysis is not frequently employed in SEM and I propose that this research instrument can be generalised to other retail contexts also. Finally, this thesis concludes by presenting the limitations of this research. It makes suggestions on potential future research that could be completed, and raises some pertinent implications for practitioners arising from this research.

The department store retailing concept grew out of the nineteenth century dry goods retail trade. Dry goods stores were usually housed in a group of nineteenth century commercial buildings. As the United States became more prosperous during the late nineteenth century, dry goods establishments outgrew their buildings and developed a new department store building type. The "second generation" store design was generally tripartite: large ground floor display windows, intermediate stories with regular banks of windows, and decorative upper one or two stories capped with an elaborate cornice. These flagship buildings were expanded and remodeled until the 1950s, when the focus of department store retailing shifted to the suburban branch stores. The branch stores anchored shopping centers in the 1950s and 1960s and enclosed shopping malls thereafter.
Department of Architecture

The Judge Earl Stone House, built in 1849, is one of the oldest existing structures in Noblesville, Indiana, the county seat of Hamilton County, which is located immediately north of Indianapolis and Marion County. Originally built as a residence, it has been used for commercial purposes since the middle of the twentieth century. Last occupied in 1998 when it was used as a gift store, it has remained vacant, causing its condition to deteriorate.This creative project documents the current condition of the building, offers recommendations for the preservation of the exterior and foundation of the structure, provides a maintenance schedule to prevent further deterioration, and recommends two adaptive reuses.
Department of Architecture

This thesis explores the boundaries and transitions within architecture. What makes a solid boundary? And what blurs the lines of transition in between? Possibilities were explored and limits pushed through the studying of elements such as thickness, transparency, material, texture, and light. The result is an architectural space in which a person can experience nature, while being separate from it. The building becomes a transition into nature while also a part of the landscape. The intent of this thesis is to bring the site together with the thesis idea and program in a cohesive way.
Master of Architecture

Le mégalithisme est l'expression architecturale monumentale d'un ensemble de sociétés qui ont édifiées des structures funéraires et des pierres dressées. La genèse du mégalithisme, phénomène humain de la fin de la préhistoire, puise ses origines dans de multiples conjugaisons des différents courants de la néolithisation aux traditions variées, aux influences géographiques parfois lointaines, aux époques différentes. La combinaison de nombreux éléments sociaux de ces sociétés agro-pastorales a généré des générations d’architectes bâtisseurs et contribué à mettre en œuvre une diversité architecturale La volonté de mise œuvre des maisons des morts au même niveau que les maisons des vivants semble répondre à des critères sociaux et culturels. Une perception visuelle actualisée des mégalithismes, adaptée aux récentes thématiques développées amène un fil conducteur original d’étude de plusieurs mondes qui se sont combinés. L’état des connaissances depuis le milieu du XXème siècle a permis une appréhension différente des mégalithismes : - dans les années 1980, une connaissance plus complète des masses tumulaires et leurs liens étroits avec les chambres sépulcrales (Joussaume, 1997, 1999, 2003 ; Joussaume et al. 2006). - dans les années 2000 une prise en compte de l’histoire des monuments (Joussaume et al. 2006 ; Laporte, 2010 ; Laporte et al. 2004, 2011). - de nos jours, une appréhension différente des articulations entre les pierres dressées, les tumulus et les chambres sépulcrales (Laporte, 2015 ; Laporte et al. 2011). Le processus de cette monumentalisation architecturale a souvent fait l’objet d’études distinctes, les espaces sépulcraux et les pierres dressées servant de bases à deux axes de recherches séparées. Seule l’étude des stèles en remploi avait fait l’objet d’une attention particulière (L’Helgouac’h, 1983 ; Cassen, 2009b) et d’un rapprochement des deux dispositifs. Ce n’est que récemment que la complémentarité entre les espaces sépulcraux et les pierres dressées a réellement été proposée (Laporte, 2015b). Disposant d’un important corpus actualisé des mégalithes du département du Morbihan, il a donc été proposé de développer dans cette thèse cette notion de complémentarité entre les différents dispositifs qui constituent les mégalithismes. Les hypothèses formulées sont de démontrer que les processus de monumentalisation sont issus d’un croisement architectural entre les pierres dressées, les espaces sépulcraux et les masses tumulaires. Nous tenterons également de montrer les liens étroits qui semblent se dessiner entre trois mondes très différents mais intimement liés (le monde des vivants, le monde des morts et le monde naturel)
Megalithism is the monumental architectural expression of a group of societies that have built funerary structures and erected stones. The genesis of megalithism, the human phenomenon of the end of prehistory, draws its origins from multiple conjugations of the different currents of neolithization with varied traditions, geographical influences sometimes distant, at different times. The combination of many social elements of these agro-pastoral societies has generated generations of architects and contributed to the implementation of architectural diversity The desire to put the houses of the dead to the same level as the houses of the living seems to meet social and cultural criteria. An updated visual perception of megalithisms, adapted to the recent themes developed, brings an original thread of study of several worlds that have combined. The state of knowledge since the middle of the 20th century allowed a different apprehension of megalithisms: - in the 1980s, a more complete knowledge of the tumular masses and their close links with the sepulchral chambers (Joussaume, 1997, 1999, 2003, Joussaume et al., 2006). - in the 2000s, taking into account the history of monuments (Joussaume et al., 2006, Laporte, 2010, Laporte et al., 2004, 2011). - today, a different apprehension of the articulations between the erected stones, the tumuli and the sepulchral chambers (Laporte, 2015, Laporte et al., 2011). The process of this architectural monumentalization has often been the subject of separate studies, sepulchral spaces and erected stones serving as bases for two separate lines of research. Only the study of stelae in reuse had been the object of particular attention (L'Helgouac'h, 1983, Cassen, 2009b) and a comparison of the two devices. It is only recently that the complementarity between sepulchral spaces and erected stones has actually been proposed (Laporte, 2015b). It has therefore been proposed to develop in this thesis the notion of complementarity between the different mechanisms that constitute megalithisms. The hypotheses formulated are to demonstrate that the processes of monumentalisation are the result of an architectural crossing between the erected stones, the sepulchral spaces and the tumular masses. We will also try to show the close ties that seem to be taking shape between three very different but intimately linked worlds (the world of the living, the world of the dead and the natural world)

In this study, characterization of activated carbon produced from apricot stones by chemical activation technique using phosphoric acid (H3PO4) as activating agent, at relatively low temperatures (300, 400 and 500oC), was investigated. To produce activated carbon acid impregnated samples were heated
at a heating rate of 20oC/min to the final carbonization temperatures, 300oC, 400oC and 500oC. For each temperature four different carbonization time (90, 120, 180 and 210 min.) were used to produce twelve different activated carbons. The pore structures of activated carbons were determined as follows: The volume and area of macropores in the pore diameter range of 8180-50 nm were determined by mercury intrusion porosimetry. Mesopore (in the range of 50-2 nm) areas and volumes were determined by N2 gas adsorption technique at -195.6oC, BET surface areas of the samples were also determined, in the relative pressure range of 0.05 to 0.02, by the same technique. The pore volume and the area of the micropores with diameters less than 2 nm were determined by CO2 adsorption measurements at 0oC by the application of Dubinin Radushkevich equation. N2 (BET) and CO2 (D-R) surface areas of the samples were in the range of 444-709m2/g and 433-650m2/g, respectively. AC4.2 sample (carbonization temperature of 400oC and carbonization time of 120 min.) was found to have the maximum BET and CO2 area as 709m2/g and 650m2/g, respectively. Surface areas of the samples consisting of around 10% mesopores and over 90% micropores. N2 adsorption isotherms also confirm that pores are in the micropore range.

This paper discusses runic inscriptions from the middle ages on Gotland and how they portray social structure. It focuses on three themes: (1) fixed time and space, (2) women and the nuclear family and (3) profession and social status/structure. It also discusses changes brought on by a more structured and established Christianity, as well as differences between medieval rune stones on Gotland and their predecessors Viking Age rune stones in the Mälar Valley.

For the period of several centuries, the influence of several distinct cultures produced rich and diverse cultural heritage that we see today in East Africa countries. The most tangible remains of these heritages are stone built buildings and structures including, palaces, mosques, residential houses and tombs. At present, these heritages are in different physical state, some are in relatively good condition while many are in an appalling condition. The presence of these historical monuments has benefited these countries economically and culturally therefore, it is essential to ensure that these monuments continue to exist. Material characterisation of the historical buildings and associated structures was used to develop a suitable method of intervention that is sympathetic to the original materials. Mortar is the most damaged material therefore, historical mortar from Stone Town historical buildings and associated structures has been characterised by visual examination, optical microscopy, x-ray diffraction and hydrostatic weighing and the results have been compared. The historical mortar is mainly comprised of calcite, quartz and feldspar. The mortar condition has been divided into hard mortar, soft mortar and, soft and friable mortar. The deteriorated mortar that required consolidation is soft mortar and, soft and friable mortar with a porosity of approximately 27%. Calcium hydroxide solution (limewater) has been selected as consolidant and the consolidation procedure involves two steps. Firstly a limewater impregnation procedure has been developed and secondly, the effect of limewater treatment has been determined. For the application procedure it has been observed that, when limewater comes into contact with calcium carbonate a precipitation reaction occurs and that is the cause of poor penetration ability of calcium hydroxide solution. Major influencing factors on the penetration ability of calcium hydroxide solution have been established as, application method and absorption capacity of the treated material during the impregnation process. Optimization of the penetration ability of calcium hydroxide solution has been achieved by impregnating from the middle of the impregnated specimen. Sugar has been used to study the influence of additive on enhancing calcium hydroxide solubility. It has been verified that solubility of calcium hydroxide in a solution of sugar is proportional to the amount of sugar in the solution. Porosity and strength tests have been used to study the effectiveness of calcium hydroxide treatment. Under the conditions studied no appreciable change of porosity has been detected. It is postulated that the calcium hydroxide was deposited at the binder/aggregate interface and at the secondary pores. In terms of strength, evidence has been found to suggest the strength increment varies quantitively with the amount of calcite crystals deposited.
QC 20100803

The use of discontinuous Galerkin (DG) methods to solve fluid thermal structure interaction problems in numerical modelling is known to offer several advantages. In particular, DG methods provide the flexibility of using different approximations in different elements, which makes the methods ideal for hp-adaptivity. The first objective of this thesis is to present a framework for the computation of fluid thermal structure interaction problems within both the single and multi-solid domain using DG methods on unstructured grids. The full solver consists of four main components: the incompressible fluid solver, the conjugate heat transfer solver, the linear elastic solver and the fluid to structure interaction solver. Based on an earlier developed DG solver for the incompressible Navier-Stokes equation, the fluid advection-diffusion equation, the Boussinesq term, the solid heat equation and the linear elastic equation are introduced using an explicit DG formulation. A Dirichlet-Neumann partitioning strategy has been implemented to achieve the data exchange process via the numerical flux of interface quadrature points in the fluid-solid interface. Formal h and p convergence studies employing the method of manufactured solutions demonstrate that the expected order of accuracy is achieved. Computational effort is documented in detail demonstrating precisely that for all cases the highest order accurate algorithm has several magnitudes lower error than lower-order schemes for a given computational effort. Secondly, this thesis has proposed a detailed compact thermoelectric cooler (TEC) modelling method based on an existing black box like compact TEC model. Close comparisons validate that both the detailed and the black box like compact model are accurate enough to simulate the conduction only case. When air convection is required to carry out a system-level thermal management optimization, the detailed compact modelling method is more reliable.

Nowadays, huge amounts of data are stored outside the rigid boundary of highly- structured and traditional database management systems, such as World Wide Web, application data that deals with non-standard data formats, legacy systems and structured documents. On the one hand, this data does not conform to a pre-defined structure and yet it is not completely un-structured. This data is classified as semi- structured data. There is a need to store and manage the large existing collections of semi-structured data and to query it efficiently in a way similar to traditional databases. But as yet, a mature technology for doing so does not exist. However, eXtensible Markup Language (XML) has emerged as the lingua franca of the web. XML has the ability to represent all form of structured data (highly-, semi- and un-structured). This research aims to enhance the performance of storing, querying and retrieving XML data that contain a combination of highly-structured and semi-structured data (this hybrid structuring can be described as partially-structured data), so as to better support classes of application where there is a fixed formal framework for data, but also an ad hoc component. One way to manage XML data is by using relational database management systems. This is based on the robust, well established and optimised performance relational database management systems can offer. The research presented in this thesis is concerned with seeking ways of further exploiting the latter advantages in adapting relational technology to store XML data. To this end, the research has proposed a hybrid relational-XML storage model to store partially-structured XML encoded data, in which a combination of structure mapping and XML types are used within a relational database management system, so as to exploit pre-knowledge of the highly-structured part in query processing while allowing flexibility to store the semi-structured part. A set of experiments were designed to evaluate the query performance for partially-structured data using structure mapping to relational tables, XML types and the hybrid model. These experiments were evaluated using a standard benchmark set of queries. The analyses of the experiments' results establish the impact on query performance as structuredness, volume and query characteristics change. The results of the experiments showed that there was no one storage model that outperforms all other models in all cases. In most of the cases, this hybrid model performed better than both the relational and XML data type models. The research proposed a method, by which the results of the performance analysis can be utilised by the database designer to seek optimal relational storage models for XML-encoded partially-structured data.

This master’s study concerns a Tswana stone-walled site in the North West Province. Within this province, the Zeerust-Rustenburg-Pilanesberg region has been of particular interest to Tswana settlement studies. In this region, the Tswana built stone-walled settlements from the mid 17th to the 19th century CE; altering their settlement style from dispersed to aggregated during this time. The aggregated settlements reflect a centralisation of socio-political authority in the region. However, prior research has focussed predominantly on these aggregated settlements, with little research conducted on small-scaled sites. To further understand the communities inhabiting this region during this time we need to look at varying scaled sites. A more nuanced view of regional interaction, group association, and identity is formed from this perspective. This research utilises historical, ethnographic, and archaeological data to interpret a small scaled site, termed Lebenya. The historical data presents a possible identity of the past community who inhabited the site, the Phiring. However, the archaeological data could not conclusively link the site to this past group. Nonetheless, the archaeological data presents new spatial and excavated data for the region, specifically expanding the range of documented small-scaled sites.
Dissertation (MA)--University of Pretoria, 2016.
Anthropology and Archaeology
MA
Unrestricted

Coastal defense structures have primary importance from obtainabilty of resources and benefits served by the coastal regions point of view. However, the construction of coastal defense structures demand a high amount of investment. Therefore, in order to reduce the risk of collapse of these structures, model studies should be carried during the design process. In this study, model investigations were carried out on Eastern Black Sea Highway Project regarding the serviceability and damage thus stability parameters. 5 different models were constructed as berm type rubble-mound breakwaters using Van Der Meer&rsquo
s approach and berm design guidelines, with a scale of 1/31.08 and they were tested both for breaking and non-breaking waves. The experiments took place in the Coastal and Harbor Engineering Laboratory of the Middle East Technical University, Civil Engineering Department. The models were constructed and tested with different berm widths and armor stone sizes forming the back armor layer in order to examine the effect of these design parameters on the stability and serviceability of the coastal defense structure to obtain the optimum alternative cross-section. Cumulative damage was minimum for the cross-section constructed with berm width 15 m assigning the width of the prototype. Water spray and run-up values were also not significant. The test results were confirming with Van Der Meer design approach.

Research concerning the formation and removal of black crusts on various historical objects is approached from many different angles. The so-called “yellowing effect”, observed after laser treatment for cleaning purposes, has also received a lot of attention. Evidence regarding this phenomenon differs considerably and the actual mechanisms are still speculated on by researchers. In an attempt to elucidate the processes involved in the yellowing effect associated with laser cleaning, a new analytical technique has been used to investigate the black crust, a region of the sample cleaned by laser irradiation at 1064 nm and another region of the same sample subjected to further laser irradiation at 355 nm, on a limestone sample from the cathedral of Seville in Spain. Micro-Raman spectrometry offers the advantage of spatial chemical characterization of the stone, based upon its molecular makeup and was performed on the bulk body of the stone. Raman and scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDXS) results indicate that the surfaces cleaned by irradiation at 1064 nm and by double irradiation at 1064 and 355 nm differed in terms of their calcium sulphate, calcium oxalate and iron oxide content, and that this could contribute to the difference in colour observed.

Partout où la pierre est facilement disponible, on trouve des constructions en maçonnerie de pierre. Suivant les coutumes et les usages, les blocs de pierres sont assemblés bruts, simplement ébauchés ou parfaitement taillés, avec ou sans l'ajout d'un liant. Supplantée par le béton dans les constructions neuves depuis le milieu du XX} siècle, les ouvrages en maçonnerie demeurent majoritaires dans le patrimoine bâti français, un patrimoine qu'il convient d'entretenir rationnellement. L'objectif de ce travail de thèse est de poursuivre l'élaboration d'un cadre scientifique rigoureux et opérationnel afin de donner aux décideurs et aux gestionnaires les outils nécessaires pour mener à bien leur mission. Nous proposons ici deux outils d'évaluation de la stabilité d'ouvrages de soutènement en maçonnerie basés sur l'utilisation conjointe du calcul à la rupture avec des méthodes d'homogénéisation. Dans un premier temps, nous mettons d'abord au point un outil analytique permettant de dimensionner des ouvrages neufs ou d'évaluer la stabilité d'ouvrages peu déformés. Cet outil permet également de dimensionner des solutions de renforcement par clouage lorsque cela est jugé nécessaire. Dans un deuxième temps, nous implémentons cet outil dans un code numérique afin de lui donner la souplesse nécessaire à l'étude d'ouvrages non-conventionnels, de grandes taille ou fortement pathologique. Enfin, nous mettons en oeuvre plusieurs campagnes expérimentales qui nous fournissent les données nécessaires à la validation de ces modèles de calcul
Wherever stone is readily available, we encounter stone masonry buildings. Depending on customs or dedicated use, the blocks are used raw, lightly faced or perfectly cut, with or without the use of mortar. Althougth concrete has replaced masonry in new construction for some decades, the better part of the French built heritage is made of masonry, an heritage we are responsible for. This works aims at contributing to create a reliable scientific frame for that purpose. This thesis uses the yield design theory alongside with homogenisation techniques to study the stability of stone masonry earth retaining walls. First, we provide an analytical tool suitable for designing new structures or assessing the stability of existing ones that are still in good shape. Should it be needed, this tools allows for the design of a strengthening solution based on soil-nailing. Then, we implement it in a finite element code to give it the versatility required to study unconventionnal structures or structures badly damaged. We then present several experimental campaigns aiming at validating the proposed tools

The number of people aged 60 years and above is increasing in the UK. In total, this age group represents 22% of the population with estimates indicating a rise to 29% by 2050 (United Nations, 2009). One market sector that is extremely important to the health and wellbeing of older people is grocery retail (Khan, 1981). However, little previous research has addressed how older people rate the service delivered by their grocery provider, particularly in regard to satisfaction. To reconcile this gap in theoretical understanding, a sequential transformative mixed-method research design was specified using 36 qualitative interviews and quantitative questionnaires with 524 subjects. A model including both drivers and consequences of satisfaction was formulated using past research. As such, an antecedent scale for grocery store image was developed via procedures suggested in the extant literature (e.g. DeVellis, 2003). Pre-existing scales (i.e. commitment and loyalty) representing exemplary reliability and validity were borrowed and specified as consequences. The scales were modified and integrated into a ‘structural equation model’. Older people were found to place a high level of importance in aspects of merchandise, store environment, personnel and services. Price/promotions and clientele were found to be insignificant in driving satisfaction. Differences in factor mean scores and structural parameters were then analysed using ‘finite mixture structural equation modelling’ to identify segments of similar respondents (Jedidi et al, 1997). Using posterior probabilities, the emerging segments were subjected to profiling using personal and behavioural variables (Hahn et al, 2002). Market Segmentation showed three groups of similar respondents in the sample population, differing in factor mean scores and psychological operationalisation of satisfaction. Nonetheless, only several differences in personal and behavioural characteristics were found between the segments. Whilst, the results show that segmenting this group is necessary when measuring satisfaction, basing this purely on a priori descriptive variables might be erroneous given the inherent levels of unobserved heterogeneity. The model developed and tested in this study is considered the most up-to-date available in the literature.