Information and misinformation, an analysis of the press relations of the french mission of the Church of Jesus Christ of Latter-Day Saints

Thesis (M.S.)--Boston Universit

Fracture behavior across interfaces in seal lithologies

Faults and fracture networks at depth are important fluid pathways, especially in fine-grained, low permeability seal lithologies. Discontinues in sealing lithologies can create seal bypass systems, leading to the failure of CO2 geosequestration sites or hydrocarbon traps. We characterize the occurrence of and changes in discontinuity patterns and the associated changes in elastic moduli across sedimentologic interfaces to document the importance of these discontinuities for fluid management in the subsurface and potential for re-activation in high-pressure injection scenarios. We evaluate well-exposed, fine-grained, low-permeability Mesozoic and Paleozoic units that are seals of potential CO2 repositories on the Colorado Plateau and show evidence for open fractures and fluid flow in the subsurface. Field observations document changes in fracture distributions across lithologic boundaries allowing us to identify mechano-stratigraphic units and focus on the effect of lithologic interfaces on fracture distribution. An interface marks the boundary between facies in a seal and in this study the fractures are shown to deflect or arrest at the interface. In outcrop fracture intensity varies in from 1 to 18 fractures per meter and fracture apertures range from mm to cm. The mineralized fractures often have associated alteration halos along their boundaries; their general orientation follows that of discontinuities within the underlying reservoir facies or adjacent faults. The recognition of these changes in fracture distribution is important for forward modeling of fluid flow and risk management. Studying the occurrence of and changes in fracture patterns from outcrops and scaling it up for use in modeling at a field scale is difficult due to the lack of direct correlation between outcrop observations and subsurface data. Due to the size and amount of data needed to model fluid flow at the field scale the meso-scale (cm to m) variability of rock properties is often neglected. We evaluate this meso-scale variability in elastic moduli, where possible. We combine mechano-stratigraphic outcrop observations with elastic moduli calculated from publically available wire line log data to evaluate the variability in rock strength within the heterolithic top seal. Relationships between changes in Young’s modulus to resulting fracture distribution can then be observed. The outcome of this analysis can be used for modeling the effectiveness of seal for storage of CO2 in the underlying reservoirs. Digitized publically available wire line well log data were used to calculate Poisson’s ratio and Young’s modulus over the Carmel Formation and upper most 3 m of the underlying Navajo Sandstone. Our calculations show that Young’s Modulus can range between 15 to 34 GPa across 60 cm of the intra-seal interfaces, and an average difference of 5 GPa across the reservoir seal interface. These variations will affect fracture distributions and fluid behavior in the subsurface. These data provide a means to closely tie outcrop observations to derived estimates of subsurface rock strength. The characterization of rock strength variability is especially important for modeling the response of seals to increased pressure, due to CO2 injection, and will allow for better site screening and fluid management once injection projects are underway

Use of wire line logs for estimation of strength variability in cap-­‐rock lithologies

The characterization of cap-rock, low permeability and high capillary entry pressure lithologies is important for modeling the response of cap-rocks to increased pressures due to CO2 injection. We evaluate the use of publically available wireline log data to provide empirical estimate of rock strength in order to determine the strength of top seal over a range of scales. This method is being used to characterize cap-rock lithologies in systems proposed for CO2 geosequestration, these data will be combined with outcrop fracture density observations, petrology, lithologic stacking patterns and mineralogy to predict the potential for bypass. Analysis to date includes wells with monopole and dipole sonic logs for comparison of the relationships established empirically by other workers and used in this study to estimate the dynamic values for Poisson’s Ratio and Young’s Modulus from publically available vintage well log data in Utah. This study focuses specifically on the Jurassic Carmel Formation, which is a cap-rock to the underlying proposed CO2 injection reservoir, the Navajo Sandstone. This study compliments the well data with outcrop characterization of the Carmel Formation, which we split into 3 mechanical units based on lithologic stacking patterns, fracture density, and relationships observed between the percent shale and fracture spacing ratio. Results obtained from the well log analysis fall within the published ranges for these rock types, however the data show a variability which is being evaluated further to understand if these observations are related to geology or artifacts associated with the wireline data. In future the use of these empirical estimates will provide a lower estimate for subsurface rock strength, as well as provide a means to closely tie outcrop observations to those made from subsurface data

CEO Compensation And Firm Performance: Is There Any Relationship?

Recent media and public attention has focused on CEO compensation.  This study looks at the relationship between CEO compensation and several measures of firm performance across a wide variety of industries.  The study used a database of CEO compensation for 200 large public companies which filed proxy statements with the SEC for 2007.  Total CEO compensation consists of:  base salary, cash bonuses, perks, stock awards, and option awards.  The measures of firm performance were:  company revenue, year-to-year change in net income, and year-to-year change in total shareholder return (TSR).  Correlation and regression analysis were used to test various hypotheses.  We expected that total CEO compensation and its components would be directly related to financial measures of company performance

Unsaturated Transient Flow Through Heterogeneous Soils: Numerical Solutions and Analyses of Three-dimensional Axisymmetric Flows

This study deals with unsaturated, unsteady water movement through hetergeneous porous media. The specific problem investigated is the transient three-dimensional sxisymmetric flow resulting from water being applied on a horizontal circular area. The heterogeneity of the soil is described by allowing any or all of the five parameters in the Brooks-Corey equations to be any continuous function of depth. Methodologies for obtaining numerical solutions to the resulting nonlinear partial differential equation and its associated initial-boundary value problem have been developed an dimplemented in a computer program. The numerical solution is based on the Crank-Nicolson method of finite differencing and the solution to the resulting system of non-linear algebraic equations for each time step is by the Newton method combined with the line successive over-relaxation (LSOR) method. The numerical solutions provide the follwoing at each time step used: (1) the distribution of soil water saturation throughout the region, (2) the distribution of capillary pressure throuout the region, (3) the distribution of hydraulic head throughout the region, (4) the rate of infiltration if the area of application is specified at a given moisture level, (5) the extent and amount of lateral and vertical water movement, and (6) the rate of advance position of the wetting front. The solutions resulting from various variations of linearly specified heterogeneities have been studied and their influence of such quantitites are infiltration rate or intake capacities and wetting front movement, have been analyzed. To determine the effects of lateral water movement, solution results from the axisymmetric solutions have been compared with solutions from a one-dimensional vertical flow model that permitted the same specification of heterogeneity. A number of graphs are presented that illustrate influences of different soil hetergeneities. Coaxial graphs were developed to summarize the results of a number of solutions that relate the different in infiltration in hetergeneous and homogeneous soils to the variations of the five parameters in the Brooks-Corey equations. The numerical solutiosn are verified with reasonable agreement with field data at the Reynolds Creek experimental watershed obtained from experiments which duplicate the geometry of the mathematical model clostely, if not the heterogeneity, also

Kotimaiset tieteelliset julkaisusarjat ja avoimuus

Peer reviewe

Pressure-dependent EPANET extension

In water distribution systems (WDSs), the available flow at a demand node is dependent on the pressure at that node. When a network is lacking in pressure, not all consumer demands will be met in full. In this context, the assumption that all demands are fully satisfied regardless of the pressure in the system becomes unreasonable and represents the main limitation of the conventional demand driven analysis (DDA) approach to WDS modelling. A realistic depiction of the network performance can only be attained by considering demands to be pressure dependent. This paper presents an extension of the renowned DDA based hydraulic simulator EPANET 2 to incorporate pressure-dependent demands. This extension is termed “EPANET-PDX” (pressure-dependent extension) herein. The utilization of a continuous nodal pressure-flow function coupled with a line search and backtracking procedure greatly enhance the algorithm’s convergence rate and robustness. Simulations of real life networks consisting of multiple sources, pipes, valves and pumps were successfully executed and results are presented herein. Excellent modelling performance was achieved for analysing both normal and pressure deficient conditions of the WDSs. Detailed computational efficiency results of EPANET-PDX with reference to EPANET 2 are included as well

Expression of a barley cystatin gene in maize enhances resistance against phytophagous mites by altering their cysteine-proteases

Phytocystatins are inhibitors of cysteine-proteases from plants putatively involved in plant defence based on their capability of inhibit heterologous enzymes. We have previously characterised the whole cystatin gene family members from barley (HvCPI-1 to HvCPI-13). The aim of this study was to assess the effects of barley cystatins on two phytophagous spider mites, Tetranychus urticae and Brevipalpus chilensis. The determination of proteolytic activity profile in both mite species showed the presence of the cysteine-proteases, putative targets of cystatins, among other enzymatic activities. All barley cystatins, except HvCPI-1 and HvCPI-7, inhibited in vitro mite cathepsin L- and/or cathepsin B-like activities, HvCPI-6 being the strongest inhibitor for both mite species. Transgenic maize plants expressing HvCPI-6 protein were generated and the functional integrity of the cystatin transgene was confirmed by in vitro inhibitory effect observed against T. urticae and B. chilensis protein extracts. Feeding experiments impaired on transgenic lines performed with T. urticae impaired mite development and reproductive performance. Besides, a significant reduction of cathepsin L-like and/or cathepsin B-like activities was observed when the spider mite fed on maize plants expressing HvCPI-6 cystatin. These findings reveal the potential of barley cystatins as acaricide proteins to protect plants against two important mite pests

Ambulatory dispersal in Tetranychus urticae: an artificial selection experiment on propensity to disperse yields no response

Dispersal to new hosts is an important process for an invasive herbivore, such as the two-spotted spider mite. A recent study, using artificial selection experiments, has suggested that genetic variation and genetic trade-offs are present for propensity to disperse in this species. However, due to the experimental setup alternative explanations for the response to selection could not be ruled out. Using an altered setup, we investigated whether the propensity for ambulatory dispersal differs genetically between individuals and whether genetic correlations with life-history traits exist. Upward and downward selection on propensity to leave the colony was performed for seven generations in four replicate artificial selection experiments and the results were compared to control lines. No consistent responses to selection were found and no significant effect on life-history traits (oviposition rate, juvenile survival, development rate and number of adult offspring) or sex ratio was present across the replicates. The data suggest that our base population of spider mites harbours at best a low amount of additive genetic variation for this behaviour