Master of Science in Engineering - Engineering / An investigation was conducted on the failures of 88kV line surge arrestors at an Eskom Distribution substation. The surge arrestor failed when one phase of the transmission line was open circuited and all three phases were not isolated by the protection relays. The transformer was lightly loaded and a surge arrestor blocked the neutral path to the ground. The investigation used a modified version of an equivalent circuit proposed by Marti [1]. Transformer magnetising losses, the non-linear resistance of the neutral surge arrestor and the transformer magnetising reactance of the closed-circuit phases were all included. The investigation revealed that the failure of the arrestor was due to the combined volt drops across the open circuited phase of the transformer magnetising reactance and the neutral surge arrestor. A resonance condition lowered the magnetising reactance of the open circuited phase of the transformer and forced the transformer into saturation. This resonance is characteristic of the fundamental frequency ferroresonance condition [2].

In this thesis, PN simulations of drying are compared with experimentally obtained data fromdrying of a representative 2D microfluidic network in SiO2 under varying thermal conditions withthe aim to identify governing physical pore scale effects. Gravity and viscous effects aredisregarded in this thesis. Instead drying with slight local temperature variation and drying withimposed thermal gradients are studied. Based on this investigation, a powerful non-isothermalPNM is developed. This model incorporates i) the phenomena associated with the temperaturedependency of pore scale invasion, namely thermally affected capillary invasion and vapor flow aswell as ii) the secondary effects induced by wetting liquid films of different morphology. This studyclearly evidences that the macroscopic drying behavior is fundamentally dictated by thetemperature gradient imposed on the PN and moreover by the secondary capillary invasion aswell. In agreement with literature, invasion patterns as in invasion percolation with progressiveevaporation of single clusters are observed in drying with negligible local temperature variation;gradients with temperature decreasing from the surface (negative temperature gradient) canstabilize the drying front, evolving between the invading gas phase and the receding liquid phase,whereas temperature increasing from the surface (positive temperature gradient) leads todestabilization of the liquid phase with early breakthrough of a gas branch and initiation of asecond invasion front migrating in opposite direction to the evaporation front receding from theopen surface of the PN. Special attention is paid on the distinct drying regimes found in thesituation of a positive gradient because they are associated with different pore scale invasionprocesses. More precisely, temperature dependency of surface tension dictates the order ofinvasion as long as the liquid phase is connected in a main liquid cluster (usually found during thefirst period of drying). In contrast to this, detailed study of the vapor transfer mechanismsemphasizes that vapor diffusion through the partially saturated region can control the pore leveldistributions of liquid and gas phase during the period of drying when the liquid phase isdisconnected into small clusters. This is also related to the cluster growth induced by partialcondensation of vapor. It is shown and discussed in detail in this thesis that this effect not onlydepends on direction and height of the temperature gradient for a given pore size distribution butthat moreover the overall evaporation rate influences the cluster growth mechanism. This indicatesthat liquid migration during drying of porous media might be controlled by the interplay of thermalgradients and drying rate. In summary, the study of thermally affected drying of the 2-dimensionalPN reveals complex pore scale mechanisms, usually also expected in drying of real porous media.This leads to the development of a strong mathematical pore scale model based on experimentalfindings. It is demonstrated how this model might be applied to understand and develop moderndrying processes based on the simulation of thermally affected pore scale mass transfer

by Chan Cheung-wing. / Bibliography: leaves 62-63 / Thesis (M.Ph.)--Chinese University of Hong Kong, 1986

Graph and network theory have become commonplace in modern life. So widespread in fact that most people not only understand the basics of what a network is, but are adept at using them and do so daily. This has not long been the case however and the relatively quick growth and uptake of network technology has sparked the interest of many scientists and researchers. The Science of Networks has sprung up, showing how networks are useful in connecting molecules and particles, computers and web pages, as well as people. Despite being shown to be effective in many areas, network theory has yet to be applied to mechanical engineering design. This work makes use of network science advances and explores how they can impact Computer Aided Design (CAD) data. CAD data is considered the most valuable design data within mechanical engineering and two places large collections are found are educational institutes and industry. This work begins by exploring 5 novel networks of different sized CAD collections, where metrics and network developments are assessed. From there collections from educational and industrial settings are explored in depth, with novel methods and visualisations being presented. The results of this investigation show that network science provides interesting analysis of CAD collections and two key discoveries are presented: network metrics and visualisations are shown to be effective at highlighting plagiarism in collections of students' CAD submissions. Also when used to assess collections of real world company data, network theory is shown to provide unique metrics for analysis and characterising collections of CAD and associated data.

Pendant mes travaux de thèse, j'ai développé et appliqué des méthodes informatiques utilisant des données de réseaux afin d'aider l'analyse des données biologiques à haut-débit. Ma thèse consiste en trois projets : L'identification de protéines supplémentaires dans des approches de protéomique différentielle à l'aide des réseaux d'interaction protéiques, l'identification de réseaux régulatoires sous-jacents aux réponses aux stress abiotiques dans arabidopsis thaliana et l'analyse de signature transcriptomique de réponse immunitaire d'hôte spécifique à différentes étapes d'infection par shigella flexneri. / In the course of my Ph.D work, i have developed and applied methods making use of network information to adavance the analysis of high-throughput biological data. My thesis comprises three projects :- The identification of additional proteins in differential protemics using protein interaction networks. In this study, we developed a novel computational approach based on protein-protein interaction networks to identify a list of proteins that might have remained undetected in differential proteomic profiling experiments.- The transcriptional regulatory networks underlying responses to environmental stresses. Based on publicly available data, measuring the response of A. Thaliana to a set of abiotic stresses in a time-resolved manner, we applied two complimentary approaches to derive gene regulatory networks underlying the plant's response to the perceived stresses.- The analysis of transcriptional host immune response signatures specific for distinct stages of infection by shigella flexneri. During their host invasion process, shigella localize to different subcellular niches.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Automatic Vehicles is a possible future, but it does not mean that we should forget about improving the present day to day life. Most vehicles have Cruise Control, and few have Adaptive Cruise Control, but very few have Cooperative Adaptive Cruise Control(CACC) because it's an integration of software and hardware as different companies produce different vehicles it's hard to get on common ground. CACC at the core is communication among vehicles and sharing information; in this thesis, I tried to make it usable in any car with just the software used in a smartphone. As everybody has a phone in their hand with an inbuilt GPS, it is easier to use it directly rather than have a unique mechanical device embedded with a software application. My application gives the estimated speed usable at a particular time based on the other two vehicles, and it keeps changing based on other cars. It does not depend on any external sensors; hence, no environmental change can affect the data give by my vehicle. This application is a guide that could be used in the snow, rain, or hail when even eyes or technology cannot help. Location and speed are something, and using them and providing safety is my thesis all about.

Interpersonal relationships connect household groups and communities into the social interaction networks that characterize all human societies. Interaction networks structure, and are structured by, relationships created and maintained through time, which may serve a variety of social, economic, and political purposes for those who engage in them. These relationships are important aspects of social organization that must be distilled from the archaeological record when written accounts are unavailable. Such is the case with the Middle Preclassic (c. 900 – 350 B.C.) in the Maya Lowlands, which was pivotal in the development of complex society in the region. Its temporal position between the earliest permanent settlements and the Late Preclassic, when clear evidence for hereditary inequality became widespread, makes the relationships and structures that characterized Middle Preclassic society critical targets for understanding the origins of Maya social complexity. This dissertation explores Middle Preclassic Maya social organization and development through the lenses of materials exchange and consumption, which are used to analyze participation in socioeconomic networks by different social groups. It synthesizes data from six seasons of excavation at Cahal Pech, Belize, where previous research revealed substantial Middle Preclassic occupation and suggested the early development of social ranking. I present analyses of architectural investment and depositional patterns across multiple artifact categories that suggest prevalent models of Middle Preclassic social organization do not adequately explain variability in the data, and I develop a new framework to interpret social relationships in terms of network structures. The network model combines sociological research on small-world networks with anthropological conceptions of household and community interactions. It can be employed to analyze interactions at the local, regional, and interregional scales and is grounded in an understanding of material sources and how goods move across the landscape. Socioeconomic networks are defined by linking the depositional contexts of artifacts with known source areas, and networks can be compared among different groups to discern differences in internal and external exchange connections. My research suggests that dynamic interactions within small-world networks created increasingly complex social relationships throughout the Middle Preclassic, which likely influenced the development of institutionalized hierarchy and later Maya civilization. / 1 / Sherman W Horn III

No description available.

Thesis (M.S.)--State University of New York at Binghamton, Dept. of Electrical & Computer Engineering, 2006. / Includes bibliographical references.