No description available.

No description available.

No description available.

In this thesis, the hydrodynamics of massive star interiors are explored. Our primary theoretical tool is multi-dimensional hydrodynamic simulation using realistic initial conditions calculated with the one-dimensional stellar evolution code, TYCHO. The convective shells accompanying oxygen and carbon burning are examined, including models with single as well as multiple, simultaneously burning shells. A convective core during hydrogen burning is also studied in order to test the generality of the flow characteristics. Two and three dimensional models are calculated. We analyze the properties of turbulent convection, the generation of internal waves in stably stratified layers, and the rate and character of compositional mixing at convective boundaries.

Designing monitoring networks that can discriminate among competing conceptual models is a key challenge for hydrologists. This issue is examined by considering the impact of network design on the utility of measurements for constraining hydrologic prediction uncertainty. Specifically, a three-staged approach was developed and is presented as a set of modeling case studies. The first case study presents a sensitivity analysis that examines conditions under which the proposed measurement method is likely to detect observations associated with the hydrologic process and properties of interest. This application is focused on the use of geomorphic information to estimate infiltration on arid alluvial fans.The second stage is an assessment of the likely utility of the measurement method to determine whether proposed measurements are likely to be useful for identifying hydraulic properties or hydrologic processes. This objective screening approach could reduce the number of unsuccessful uses of geophysical and other indirect measurement methods. A hypothetical site assessment examines whether the measurement method, temporal gravity change, is likely to detect signals associated with drawdown in an unconfined aquifer that occurs in response to pumping. Also, the utility of these measurements for identifying hydraulic conductivity and specific yield was considered.The third stage, an analysis of optimal network design, compares the projected measurement costs with the expected benefits of constraining hydrologic prediction uncertainty. The final case study presents a network design approach for a feasibility assessment of a proposed artificial recharge site. Predefined sets of proposed measurements of temporal gravity change were considered for various measurement times. An ensemble approach was used to assess the likely impact of measurement error on prediction error and uncertainty for different combinations of measurement sets. The ensemble of prediction errors was translated to probability-weighted performance costs for each measurement set using a cost function. Total cost was calculated as the sum of the performance and measurement costs. The optimal measurement set, defined as the set with the lowest total cost, depends on the prediction of interest, the per measurement cost, the maximum risk-based cost associated with the hydrologic prediction, and the treatment of uncertainty in defining performance costs.

This thesis is an assessment of the dynamics of trade affinities and how they have influenced trade flows in the European continent. The focus is how trade affinities have altered over a time span of four time periods stretching from the 1970s up to today and how these alterations have influenced globalization. A total of 41 countries belonging to the European continent have been selected. Furthermore four variables were selected to represent trade affinities; distance, border, colony, and language. These have been selected as they are generally believed to be static and thus should not change over time. Also, this thesis aims to show the separate influence of each trade affinity as other papers usually estimate trade affinities as one collective variable. By the use of a gravity model 9 variables are tested in order to determine their influence on trade flows. This is done through a regression with a log-log equation where the dependent variable is Export and the affinity variables are estimated as dummy variables. The regression is divided into four time periods in order to more easily determine how the trade affinity variables have altered in influence on trade flows in Europe. The first time period represent an average of the time period 1974-1976, the second 1984-1986, the third 1994-1996 and the fourth 2004-2006. The regression results illustrate that the majority of the selected variables are significant but most importantly that the trade affinity variables are proven to have altered over the time periods. The performance of a Wald estimation gives an indication that trade affinities are in fact dynamic although the results are not entirely significant for all variables. Based on the results, it is apparent that trade affinities still have a significant effect on trade flows in the European continent. Although, their effects have altered to become less significant in some cases while others have become stronger they all jointly share the attributes of affecting trade. These alterations can in turn be interpreted as dependent on the globalization process of the European continent. As globalization has progressed some affinities have decreased in influence while others have regained new importance.

In this thesis factors that explain Swedish pharmaceutical export as been analyzed. The period investigated is from 1995 to 2010. The investigation is concluded through the use of a gravity model. It investigates not only the GDP and distance variable but also the effects of GDP/capita, exchange rates and the effect of being a part of the internal market of EU. The effects of having access to the ocean and if the country has English as its official language is investigated as well as the effect of sharing the same religion. The results show that only a smaller subset of countries make up for most of the pharmaceutical export. The results also shows that the pharmaceutical export can be explained by the same variables as most other goods.

No description available.

Modeling gravity recovery of platinum group minerals (PGMs) in the grinding circuit is based on three components: Ore characterization of gravity recoverable platinum group minerals (GRPGM), their behavior in grinding mills and hydrocyclones, and the performance of the gravity recovery units. This thesis focuses on the first two components. / A laboratory methodology to characterize gravity-recoverable platinum group minerals (GRPGMs) in an ore with four incremental liberation and recovery stages was developed. It was applied to quantify GRPGM content of four ore samples from Canada. To measure the behavior of GRPGMs in the grinding circuit, a methodology to characterize the already liberated (or available) GRPGMs in the circuit streams was developed. The availability of GRPGM in streams, such as ball mill discharge, was used to model the behavior of the GRPGMs in the ball mills and hydrocyclones. Combining with the potential GRPGM in an ore, they can be used for design and/or optimization of platinum group mineral recovery circuit. / The GRPGM content measured by this methodology varied from 5 to 81% depending on the ore. The GRPGM size distribution varied from fine (most GRPGM below 37mum) to coarse (significant content above 212 mum). The stage size-by-size recovery and the total GRPGM content indicate that the methodology can quantify the GRPGM content of ores. / Based on the measurement of the availability of GRPGM in process streams, the behavior of PGMs in ball mills and hydrocyclones is characterized in terms of the less common cumulative selection functions and conventional classification efficiency curves. Mineralogical analysis indicates that sperrylite (PtAs 2) is the dominant platinum mineral at the Clarabelle mill. Its classification efficiency is similar to that of gold, despite its lower density, while grinding rate is significantly higher than gold. The cumulative selection function of platinum and palladium is 1.3 times higher than the ore for size classes above 212 mum and 50 to 70% of the ore below 212 mum. / As a result, sperrylite accumulates in finer sizes than native gold in the grinding circuit. The cumulative selection function of the platinum group minerals was calculated for the Clarabelle grinding circuit based on the survey data and the GRPGM contents in the ball mill discharge, cyclone underflow, and overflow. / The methodology of characterizing the content of GRPGMs in an ore also offers a way to concentrate the minerals for mineralogical study. The use of secondary electron microscopy (SEM), variable pressure SEM and QEM*SEM for qualitative analysis of platinum group mineral mineralogy is presented and discussed. Most of the GRPGMs recovered are well liberated. Qualitative mineralogical analysis of the GRPGM and its associations in ore samples are also discussed.

St. Barnabé fault, in St. Hyacinthe plain of the St. Lawrence lowlands, was postulated by Clark (1947) on his geological study of this area. Structural features of this type are of great interest to the geophysicist to establish relation between physical quantities measured at the surface and geometry of such structures. A subsurface fault can be diagnosed, under density contrast condition, with surface gravity measurements. The present detailed gravity survey was undertaken to determine if such a condition existed, to correlate geological information with gravity data, and to assess this data in terms of possible parameters of the fault structure. The field work was carried out in the summer months of 1964 with a Worden gravimeter. [...]