Masonry arch bridges have played a significant role in the road and rail transportation network in the world for centuries. They are exposed to damage due to overloading and deterioration caused by environmental actions. In order to reestablish their performance and to prevent their collapse in various hazardous conditions, many of them require strengthening. Fibre reinforced polymer (FRP) systems are increasingly used for repair and strengthening of structures, with particularly widespread application to concrete structures. However, the application of FRP composites to masonry structures is less well established due to the complexity of masonry caused by the material discontinuity. FRP strengthening masonry arch bridges has been even less studied due to the additional complexity arising from the co-existence of the normal interfacial stress and the shear interfacial stress at the curved FRP-to-masonry bondline. This thesis presents an extensive study investigating the behaviour of FRP strengthened masonry bridges. The study started with a laboratory test of a two span masonry arch bridge with sand backfill. A single ring arch bridge was first tested to near failure, and then repaired by bonding FRP into their intrados and tested to failure. It was found that the FRP strengthening not only improved the loading capacity and stiffness of bridge, but also significantly restrained the opening of cracks in the masonry. Shear and peeling debonding of FRP was observed. There have been two common strategies in finite element (FE) modelling of FRP strengthened structures in meso-scale: direct model and interface model. The former is necessary when investigating the detailed bond behaviour but challenges remain due to the difficulties in concrete modelling. A new concrete damage model based on the plastic degradation theory has been developed in this study to study the bond behaviour of FRP strengthened concrete structure. This robust model can successfully capture this bond behaviour and simulate the entire debonding process. A numerical study of masonry arch bridges including the backfill was conducted to study the behaviour of masonry arch bridge. A total of four modelling strategies were examined and compared. Although they all can successfully predict the behaviour of arch, a detailed solid model newly developed in this study is more suitable for modelling both plain masonry and FRP strengthened structures. Finally, a numerical study of bond behaviour and structural response of FRP strengthened masonry arch structures with sand backfill was conducted. In addition to the masonry and backfill, the mixed mode interfacial behaviour was modelled by the aforementioned interface model strategy and investigated in detail to achieve a deeper understanding of the behaviour of FRP strengthened masonry arch structures. The results are in close agreement with test results, and highlight the influence of the key parameters in the structural response to failure and revealed the mechanisms on how the load is transmitted through this complex multi-component structural system.

This thesis investigates strengthening slender steel columns with carbon fibre reinforced polymer (CFRP) plates of various moduli. Three different types of CFRP were used in the study: Ultra-high modulus (430GPa), High modulus (212GPa) and Normal modulus (168GPa). In this study, specimens were grouped according to measured initial out-of-straightness values. The first section examines the effect of adding CFRP plates to the column flanges when buckling about the weak axis. Twelve columns, with a slenderness ratio of 197, were tested, of which nine were strengthened with CFRP. The main parameters tested were the level of initial out-of-straightness (length (L)/8387 to L/1020), CFRP modulus (168 to 430 GPa), CFRP reinforcement ratio (13% to 34%) and the length of CFRP plate (33% to 95% of L). The gain in axial strength due to CFRP retrofitting ranged from 11% to 29%, depending on the various parameters. The gain generally increased as CFRP modulus, initial out-of-straightness, or CFRP reinforcement ratio increased. Global buckling consistently governed the maximum load. In the case of the 430 GPa CFRP, buckling was followed by CFRP crushing in compression, then rupture in tension. The second section of the thesis examines the effect of CFRP plates added to the flanges and tested for buckling in the strong axis. Eight columns, with a slenderness ratio of 83, were tested of which five were strengthened with CFRP. The main parameters examined were the level of initial out-of-straightness (L/28889 to L/1635), CFRP modulus (168 to 430 GPa), CFRP reinforcement ratio (13% to 34%) and the axis of bending. The gain in axial strength due to CFRP retrofitting ranged from 0% to 25%, depending on the various parameters. The gain generally increased as initial out-of-straightness, or CFRP reinforcement ratio increased. The higher modulus did not perform as expected, showing no gain in strength, because the compressive strains were too large and the CFRP crushed before the specimen experienced any gain. Specimens compared with the weak axis, strengthened with normal modulus CFRP, had similar percentage gains in strength. / Thesis (Master, Civil Engineering) -- Queen's University, 2014-06-27 15:19:03.397

In this thesis the researcher argues that churches in Africa are being planted rapidly but are not growing to maturity, which produces troubling consequences. The Baptist Union of Southern Africa (BUSA) is then given as a representative case study of church planting in Afiica, because from 1990 they have seen as many as 413 new churches started. Yet there is growing concern over the stability of many of these young churches and their leaders. Key leaders in the BUSA are calling for an analysis of the church planting and a greater emphasis on church strengthening and equipping. Next, the researcher lays the exegetical foundation for building mature churches, drawing from Acts and the Pauline epistles. In Acts, keys for the growth of the church are given. In Paul's writings, the researcher identifies the core principles and content used in establishing churches. Next come the field research findings that show the condition of churches and church planting in the BUSA The research was conducted through church leader surveys and key interviews, supplemented by observations of Christ Seminary faculty in their training of pastors from these churches. Some disturbing statistics and characteristics of these young churches emerge. The researcher then seeks to demonstrate how to analyse the health of churches and church planting in Africa by interacting with the field research in light of Scripture. An analysis is given of the strengths and weaknesses of the BUSA's younger churches, in the areas of their evangelism, their establishing of the members, and their entrusting of leadership. Cautions were given against unbiblical church growth trends. Finally, the researcher offers suggestions and strategies for building stronger churches in Africa. He states, "In order for the gospel to steadily advance through the BUSA or through any churches in Africa, mother churches and church planters must take responsibility for strengthening young churches until they have qualified elders and are mature, reproducing churches." / Thesis (Ph.D. (Pastoral))--North-West University, Potchefstroom Campus, 2004.

No description available.

Thesis--Auburn University, 2008. / Abstract. Vita. Includes bibliographical references (p. 235-246).

Thesis (M. Sc.)--University of Alberta, 2009. / Title from pdf file main screen (viewed on August 7, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Mechanical Engineering, University of Alberta." Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains xi, 94 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 88-89).

Thesis (M.S.)--University of Akron, Dept. of Polymer Engineering, 2005. / "August, 2005." Title from electronic thesis title page (viewed 11/28/2005) Advisor, Lloyd Goettler; Faculty Reader, Avraam I. Isayev; Department Chair, Sadhan C. Jana; Dean of College, Frank N. Kelley; Dean of Graduate School, George R. Newkome. Includes bibliographical references.

Thesis (M.S.)--University of Missouri, School of Mines and Metallurgy, 1948. / Vita. The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed July 8, 2010) Includes bibliographical references (p. 49).

Les interruptions sont une menace pour la réalisation des procédures dans un contexte opérationnel critique tel que l’aéronautique. De nombreux accidents et incidents étudiés par des organismes d’enquêtes ont révélé que l’un des nombreux facteurs impliqué concerne les interruptions. Elles entraînent des effets délétères au niveau des performances à la fois en matière de temps et d’erreurs dans la mesure où elles créent la nécessité de reprendre la tâche interrompue, induisant alors une tâche de mémoire prospective. Notre travail vise à améliorer les performances d’individus qui, comme les pilotes, effectuent de mémoire des procédures dont la suite d’actions est spatialement située dans leur environnement de travail alors même que les instructions sont présentées verbalement. Nous appuyant sur le modèle d’activation de buts (Altmann & Trafton, 2002) mais aussi sur des travaux connexes qui nous suggèrent des conditions favorisant la récupération des intentions d’actions, nous explorons la possibilité de diminuer les effets délétères des interruptions en réalisant des changements dans l’environnement des individus. Ces modifications interviendront soit lors de l’encodage de la procédure soit lors de son exécution pour aider à reprendre la tâche interrompue. Deux expériences, dans lesquelles les participants devaient réaliser une procédure mimant le comportement attendu lors d’une procédure normale de vol, ont permis d’évaluer les changements proposés. Nous avons collecté des données générales temporelles et d’erreurs en nous intéressant particulièrement à la principale mesure étudiée dans la littérature sur les interruptions (le temps de reprise de la tâche principale). Ces expériences ont été complétées par un pré-test de l’adaptation du protocole avec des pilotes de ligne.Tout d’abord, lors l’encodage de la procédure, nous montrons à travers l’expérience 1 que favoriser des formats d’instruction qui respectent les caractéristiques spatiales de la procédure va améliorer les performances des individus. Le format d’instruction visuo-spatial, qui fournit les relations spatiales entre les objets de la procédure améliore en effet les performances, comparé au format verbal et favorise notamment la reprise de la tâche interrompue. La diminution du niveau d’interférence permet au but suspendu d’être récupéré plus rapidement et efficacement. Ensuite, lors de la phase d’exécution de la tâche, les résultats de l’expérience 2 montrent qu’il est possible de soutenir plus directement la récupération du but interrompu après une interruption de tâche en fournissant un indice visuel qui améliore la reprise de la tâche. Ce résultat s’observe notamment lorsque l’indice indique la prochaine action correcte (indice prospectif) comparé à un indice sur la dernière action effectuée (indice rétrospectif). Avec ces expériences, nous proposons également de nouvelles mesures d’ajustement du temps et des erreurs, ainsi qu’un possible effet diffus de l’interruption que nous avons observé après la reprise de la tâche. Finalement, nous fournissons des recommandations pour la conception de systèmes embarqués destinés à aider le pilote lors de la réalisation des procédures de vol. / Interruptions are a major threat for procedures completion especially in critical contexts such as aeronautics. A lot of accidents analyzed by legal security organizations have underscored the role of interruption as one of the many factors involved in accident frequency. In fact, interruptions create a prospective memory task as interrupting someone implies that he must remember the main task to continue it after the interruption. As a result, interruptions could bring negative effects such as long resumption lag or errors when someone tries to remember what he was doing. Our work aims to increase individuals’ performance, such as pilots, when they are performing procedures known by heart in a spatialized work environment with mostly verbal instructions. From the goal activation memory model (Altmann & Trafton, 2002) and others works, we will explore ways to decrease the negative effect of interruptions by modifying encoding format of the task and by providing cues in order to help them recovering the suspended goal. In our two experiments, people had to realize procedures that mimic aeronautical ones. These procedures are designed to collect general data (time and error), and most particularly concerning the main effect of interruption which is the resumption lag of the primary task. These two experiments have been followed by an adaptation of the method with pilots on a flight simulator. First, for the procedure encoding (experiment 1), results showed that when we use an instruction format that match the task characteristics, individual’s performance increases. Indeed, visuo-spatial format that gives spatial relationship between tasks’ elements, increases individuals’ performance compared to the verbal format. These results are linked to the decrease of the interference level due to the balanced strengthening goals. Second, we have focused our attention on the execution phase of the task (experiment 2) and our results showed that giving a visual cue may increase the performance especially concerning the resumption lag. These results can be observed when the cue concerns the next correct action of the sequence (prospective cue) rather than the last action before the interruption (retrospective cue). Along these experiments, we also propose new adjustment measures of time and error and a possible diffuse effect of the interruption after the task resumption. Finally, we will give recommendations to conceive future system that aims to help pilots to perform their job.