Thesis advisor: Seth C. Kruckenberg / The Burlington Mylonite Zone (BMZ) is a northeast-trending, greenschist- to amphibolite-facies shear zone located entirely within the Boston Avalon terrane in Eastern Massachusetts along the tectonic boundary with the Nashoba terrane (the trailing marginal terrane of Ganderia). The juxtaposition of these terranes, and the development of the BMZ, is hypothesized to represent the amalgamation of Avalon and Laurentia during the late Silurian-early Devonian Acadian orogeny, but the timing of its formation and its structural evolution remain largely unconstrained. Field observations and microstructural analysis using electron backscatter diffraction (EBSD) of 24 samples from 16 field sites throughout the BMZ provide new constraints on the kinematics and conditions of deformation that facilitated the development of this large-scale crustal shear zone. The BMZ samples comprise a heterogeneous mix of quartzofeldspathic +/- hornblende-bearing gneisses and quartzites with varying microstructures. Nearly all samples contain abundant mixed, but predominantly sinistral, kinematic indicators (e.g., asymmetric porphyroclasts, tiled feldspars) and a strong crystallographic preferred orientation (CPO). Quartz – the dominant mineral by mode in all of the samples analyzed – is known from experimental deformation studies to develop distinct patterns of CPO which vary as a function of deformation kinematics, temperature, and strain geometry. Patterns of CPO in quartz are used to determine the dominant intracrystalline deformation mechanisms that accommodated the formation of the BMZ. Quartz CPO patterns in the BMZ samples are characterized by variably developed c- and a-axis distributions, broadly consistent with patterns expected for mixed<a> to prism<a> slip at intermediate temperatures of deformation. Corresponding intragranular misorientation axis plots are more diagnostic and indicate dominant prism<a> slip in all of the shear zone samples analyzed, consistent with microstructures observed in thin section (e.g., undulose extinction, subgrain development, grain boundary migration, dynamic recrystallization) and metamorphic conditions inferred from shear zone mineral parageneses. Application of the quartz recrystallized grain size piezometer places additional constraints on deformation conditions, indicating that the BMZ rocks record differential stresses ranging from ~44 to 92 MPa. Field and microstructural observations of shear sense indicators are combined with two analytical methods for determining aspects of kinematic vorticity and deformation geometry in the BMZ. This study applies a new analytical method - crystallographic vorticity axis (CVA) analysis - that leverages rotational statistics on crystallographic orientations within the interiors of grains to constrain the dominant axis of material rotation in deformed samples. This dominant axis provides a uniquely objective proxy for the vorticity normal reference frame required for further quantitative kinematic vorticity analyses. The rotational axis of kinematic vorticity, and its relationship to structural fabrics (i.e. foliation and lineation), provides an important constraint on the geometry of the deforming zone (e.g., monoclinic versus triclinic shear zones). The results of the CVA analysis are invariable across the entire length of the BMZ; the kinematic vorticity axis lies within the plane of mylonitic foliation perpendicular to lineation – the pattern expected for monoclinic deformation geometries. The mean kinematic vorticity number (Wm: a measure of the relative contribution of pure and simple shear) is calculated using Rigid Grain Net (RGN) analysis for the BMZ mylonites and ranges from 0.4-0.5, indicating general shear. Combined field, microstructural, and vorticity analyses are interpreted to suggest that crustal strain localization along the Avalon-Nashoba boundary, as recorded in the BMZ mylonites, involved the combined effects of pure and simple shear in a predominantly sinistral, monoclinic transpressional shear zone. Rock microstructures, patterns of crystallographic preferred orientation, and paleostress estimates suggest that mylonitization occurred at or near the brittle-ductile transition under relatively high stress conditions. This study demonstrates the power of new microstructural methods, such as CVA analysis of electron backscatter diffraction data, to augment traditional field-based methods of kinematics and deformation analysis in enigmatic, large-scale crustal shear zones.

The adult mammalian brain harbours at least two germinal - or neurogenic - niches in which new neurons are born throughout life. These neurogenic niches comprise the subependymal zone which lines the ventricular system, and the subgranular zone in the hippocampal dentate gyrus. Post-natal hippocampal neurogenesis was in fact first identified experimentally in the 1960s. However perhaps due partly to aforementioned institutionalised belief and partly to a lack of accessible experimental tools, the phenomenon of hippocampal neurogenesis was widely recognised by the scientific community only shortly before the millennium. Consequent study has established that adult hippocampal neurogenesis has been conserved through millions of years of evolution in nearly every mammalian species studied to date. Importantly, post-mortem studies and radioisotope carbon dating techniques suggest that it also occurs in humans. A great deal of this research has focused on understanding the inner workings of the cells that undergo the transformation to become new adult-born neurons. By contrast, relatively little is known about the potential regulatory role of the surrounding extracellular microenvironment. This might be useful to know in light of much evidence that the extracellular matrix is a key regulator of developmental neurogenesis. This thesis describes my study of whether extracellular matrix regulates hippocampal neurogenesis.

Thermocompression bonding of gold is a promising technique for the fabrication and packaging microelectronic and MEMS devices. The use of a gold interlayer and moderate temperatures and pressures results in a hermetic, electrically conductive bond. This paper documents work conducted to model the effect of patterning in causing pressure non-uniformities across the wafer and its effect on the subsequent fracture response. A finite element model was created that revealed pattern-dependent local pressure variations of more than a factor of three. This variation is consistent with experimental observations of bond quality across individual wafers A cohesive zone model was used to investigate the resulting effect of non-uniform bond quality on the fracture behavior. A good, qualitative agreement was obtained with experimental observations of the load-displacement response of bonds in fracture tests. / Singapore-MIT Alliance (SMA)

Truckload shipments constitute a significant portion of the freight transportation industry. In recent years, truckload industry is facing a serious problem of high driver turn over rate. In this research, we present a mathematical model for multi-zone dispatching method to solve this issue. Multi-zone dispatching is a method in which a service area is divided into many zones. Truckload within a zone is carried by local drivers and the truckload between zones is carried by lane drivers. Apart from reducing the driver tour length to a desirable level, the model for multi-zone also contains some unique constraints to address some issues from the perspectives of the company and the customer. The binary integer program is solved by exact methods. As the problem size increases, exact methods fail quickly. Hence, a construction heuristic within tabu search framework is developed to solve the model. Analysis of various parameters concerned is provided to gain better insights of varied aspects of the problem. Computational results for analysis of parameters and comparison of exact and heuristic methods are provided.

This study aims to understand the influence of external forcing (i.e. climate, human influences) changes on the inputs of terrigenous materials from the Kaoping River as well as the biogeochemical responses of carbon and nutrients to riverine fluxes in the Kaoping coastal zone. The Kaoping River exhibits contrasting patterns in water discharge and material fluxes between wet and dry seasons. In general, river discharge is about 12 times higher in the wet season than in the dry season. Riverine fluxes of terrigenous materials (DOC¡BPOC¡BDSi¡BDIN¡BDIP¡BTDN and TDP) are about 3 to 10 times higher in the wet season than in the dry season. Consequently, distribution patterns of carbon, nutrients and hydrochemical parameters are significant difference among four seasons in the Kaoping coastal zone. Distributions of DOM (dissolved organic matter), POM (particulate organic matter) and nutrients in the Kaoping coastal zone show that the highest concentration is generally found in the area close to the Kaoping estuary, and the concentration decreases with the distance away from the land. The riverine fluxes also affect the ratios of DOC/TOC and £GPOC/£GPN in the coastal zone. The characteristics of DIN and DIP distributions and their ratios imply that the primary productivity may be largely limited by nitrogen (DIN < 1£gM¡AN/P < 10) rather than phosphorus (DIP < 0.2£gM¡AN/P < 30) in the Kaoping coastal zone. The occurring probability of nitrogen limitation varies from season to season during the study period, roughly ranging from 4% to 42% (winter, summer > spring, autumn). The GP (gross production) ranges from 708-19819 mg C m-2 d-1 in spring, from 2451-16230 mg C m-2 d-1 in summer, and from 844-5549 mg C m-2 d-1 in winter. The DCR (dark community respiration) ranges from 970-6284 mg C m-2 d-1 in spring, from 861-12418 mg C m-2 d-1 in summer, and from 997-5781 mg C m-2 d-1 in winter. Both GP and DCR display the highest value in summer, indicating the significant influence of terrigenous fluxes on biological production and respiration during summer. Meanwhile, correlations are significantly positive between GP (DCR) and temperature and nutrients, but significantly negative between GP (DCR) and salinity, also indicating the impacts of terrigenous inputs on GP and DCR. In the Kaoping coastal zone, the BCD (bacterial carbon demand) is about 15% GP and 64% GP, respectively, in winter and summer, inplying that the contribution of GP to BCD is more important in winter than in summer. Judging from the ratio of GP/DCR in different seasons and sampling stations, we conclude that the study area near the Kaoping estuary is likely to be autotrophic throughout the study period, the other stations are also likely to be autotrophic during summer. Nevertheless, the offshore stations appear to be heterotrophic during the winter season.

Truckload shipments constitute a signi&#64257;cant portion of the freight transportation industry. In recent years, truckload industry is facing a serious problem of high driver turn over rate. In this research, we present a mathematical model for multi-zone dispatching method to solve this issue. Multi-zone dispatching is a method in which a service area is divided into many zones. Truckload within a zone is carried by local drivers and the truckload between zones is carried by lane drivers. Apart from reducing the driver tour length to a desirable level, the model for multi-zone also contains some unique constraints to address some issues from the perspectives of the company and the customer. The binary integer program is solved by exact methods. As the problem size increases, exact methods fail quickly. Hence, a construction heuristic within tabu search framework is developed to solve the model. Analysis of various parameters concerned is provided to gain better insights of varied aspects of the problem. Computational results for analysis of parameters and comparison of exact and heuristic methods are provided.

The Okitsu mélange in the Shimanto accretionary complex, the onshore extension of the modern Nankai accretionary prism, consists of a kilometer-size duplex of oceanic basalt and trench-fill sedimentary rocks, and is thought to represent rocks underplated to the prism along the subduction plate-boundary at seismogenic depth. An internal, horsebounding thrust of the duplex, referred to as the Suzume fault, juxtaposes basalt in the hanging wall and sedimentary rocks in the footwall. Structure and fabric of the fault was characterized at the mesoscale to investigate the processes and structural evolution along a plate-boundary décollement. The fault zone in the hanging wall consists of decimeterthick ultracataclasite bounded by a several m thick zone of fractured basalt, and likely records 2+ km displacement along the thrust. The footwall consists of decimeter-thick ultracataclasite bounded by a 20-m-thick zone of ductile shear in flattened sedimentary host rock, and likely records 30+ km of displacement. The asymmetric structure across the Suzume fault, as well as inferred displacement fields and timing relations, are consistent with a tectonic model in which the footwall records early ductile, compactive deformation of poorly consolidated sediments during underthrusting at the prism toe region, followed by extremely localized cataclasis at the underplating depth. In contrast, the hanging wall is deformed by intense cataclasis, and only during underplating. Deformation style and strain state in the footwall of the Suzume fault is qualitatively similar to the modern Costa Rica underthrust section at the toe region. Similarity in the structure and fabric of the hanging wall between the Suzume fault and modern décollement zones sampled through scientific drilling suggests that intense cataclasis under horizontal contraction likely is a common feature for the hanging wall of the décollement zone throughout the toe to underplating regions. Structures in the Suzume fault that are not in common with the modern décollements imply progressive consolidation during underthrusting from the toe to underplating depths may be responsible for the localization of shear in the footwall. At several kilometers depth, displacement along the plate boundary is likely accommodated within an extremely narrow zone as recorded in the ultracataclasite of the Suzume fault.

The coastal planning has been developed in purpose of the ¡§safely¡¨, ¡§landscaping¡¨, ¡§ecology¡¨ and ¡§water affinity¡¨ in Taiwan nowadays. Moreover, the hendland bay beachs and beach nourishment have been hailed for the protection of shoreline. One of the main affection of erosion is a storm, which retreads shoreline and reduces nearshore by storm surge. This essay reports an application of 2-D SBEACH software to simulate the beach profile changes. The data of large wave tank (LWT), which tests by the Coastal Engineering Research Center (CERC), US Army Corps of Engineers, is used to calibrate the parameters by SBEACH. Then, using the results of experimentation to indicate the accuracy of model from Grosser Wellen Kanal (GWK), which tests by the University of Hannor. Finally, simulating beach profile, with a berm (height of 2.5m and width of 100m) and a slope of 1:25, is used to simulate the profile changes and analyze the results by different storm conditions from CECI. The purpose of this paper is to estimate the suitable distance of shoreline and location of bar for a beach buffer zone by SBEACH during different storm conditions. The present study confirms that the simulated results of shoreline erosion rate and the position of bar crest by SBEACH comform to the LWT and GWK experiments. The major parameters of SBEACH, the transport rate coefficient, K influences the sediment transport, coefficient for slope-dependent term, £` controls the slope of beach profile and shape of bar, the transport rate decay coefficient multiplier, Kb affects the shoreline erosion, and the landward surf zone depth, db influences the shape of berm. The result of analysis by SBEACH indicates that a constant slope beach profile changes by different storm conditions and the extent of non-dimensional shoreline retreat Xt/Lo is found in good linear relationship with deepwater wave steepness Ho/Lo. Therefore, the linear regress function is used to compute the less beach buffer zone in different storm conditions.

Tesis doct.--Facultad de derecho--Universidad complutense de Madrid, 2001. / Bibliogr. p [329]-348.

Texte remanié de: Thèse de doctorat--Droit public--Université de Paris X-Nanterre, 1984. / Bibliogr. p. 215-218.