The main concern of this study is to obtain an optimal time path of crude oil and natural gas production by controlling the pressure at the bottom of any producing well in Walton Canyon Reservoir. To achieve this goal, the following objectives were obtained: (a) an estimation of the reservoir properties at different levels of the reservoir pressure; (b) an estimation of an optimal time path of joint production using the estimated reservoir properties and the expected prices and costs in the absence and presence of severance, state, and federal income taxes, and depletion of allowances; and (c) an analysis of the changes in the rates of extraction, firms' profits, revenues to local, state, and federal governments, and welfare losses as a result of changes in tax policies. To conduct this study, an optimization model is used to maximize the present value of net revenues of firms producing oil and gas in the reservoir, subject to the available stock of oil in the ground. Cost per unit of time is discussed at three stages of production (naturally flowing, pumping, and secondary recovery or pressure maintenance). Using the assumption that all producing wells in the reservoir are at the pumping stage of production, the conclusion is made that only the operating cost is related to the bottom well-hole flowing pressure. Since the goal is to control the rates of joint production by controlling the bottom well-hole flowing pressure, the operating cost of the whole reservoir is minimized through separable programming. The non-linear cost equation is solved for the values of the bottom well-hole flowing pressure under a competitive condition in the absence of externalities. In order to estimate the optimal rates of oil and gas production, the expected prices are computed using the actual domestic prices of oil, gas, and electricity. The optimal rates of oil and gas production are obtained through dynamic programming which is applied to the optimization model using a 15 percent discount rate. However, discount rates of 10 percent and 20 percent also are used to determine the influences on the optimal production plan, allowing the production period for twenty years. The empirical results indicate that the production of oil and gas from this reservoir will be profitable in the future, using a 15 percent discount rate, prior to imposition of any taxes. The whole recoverable stock of oil by pump will be extracted within three years beginning with a higher production rate in 1998 and ending with a lower production rate in the year 2000. A 10 percent discount rate influenced the net revenue of the whole reservoir but did not change the production plan. However, the optimization model and, in particular, the production plan are affected by the 20 percent discount rate. In other words, the joint production is profitable in the early years, using a 20 percent discount rate, beginning with a higher production rate in 1982 and ending with a lower production rate in 1985. The important conclusion is that imposing various taxes and depletion allowances, while using a 15 percent discount rate, did not change the optimal time path of production from that time path, which was obtained in the absence of taxation using the same discount rate. The presence of taxation, however, affected revenues and, thereby, resulted in welfare changes in the producing firms and local, state, and federal governments.

For the same reasons which prompted its ratification in 1990 as the Global Stratotype Section and Point for the Mid-Carboniferous boundary, namely, section completeness, abundant fossils, and excellent exposure, the Morrowan Arrow Canyon Bird Spring strata is recommended as a candidate standard sequence stratigraphic reference for the Morrowan portion of the Lower Absaroka I supersequence. The stratigraphic architecture of Morrowan strata in Arrow Canyon was largely controlled by high-amplitude (100-m), high-frequency sea-level changes. Outcrop data and facies stacking patterns define 59 fifth-order fundamental cycles. These fundamental cycles stack into ten third-order sequences with an average duration of 320 ka. Changes in both cycle thickness and fundamental cycle type indicate that the second-order sea-level curve of Golonka and Keissling for the Lower Absaroka Ia supersequence should be modified to reflect rising sea-level from the Mid-Carboniferous boundary with maximum flooding conditions ~120 to 135 meters above the Mid-Carboniferous boundary, followed by falling sea-level to ~6 meters below the Morrowan-Atokan boundary in Arrow Canyon. Additionally, cycle diagnostic conodonts and foraminifera permit correlation of selected third-order sequences to basins containing time-equivalent strata.

Hydrogeologically important features of fault zones include undamaged country rock, the damage zone, and the core zone. Fault cores generally have low porosity and permeability, and often act as a barrier to groundwater flow. The damage zone, by contrast, consists of small faults and fracture networks, which can act as conduits. Timpoweap Canyon near Hurricane, Utah has superb exposures of the fault core and damage zone of the Hurricane Fault. Also within the canyon, springs discharge from the damage zone into the Virgin River, providing an ideal natural laboratory for the study of groundwater discharge from a fault zone. The Hurricane fault is an active, steeply dipping, normal fault that is 250 km long, and exhibits about 2500 m of displacement. The damage zone in Timpoweap Canyon controls thermal groundwater (~40°C) and CO2 gas discharge from highly fractured limestone. Total spring discharge is 260 L/s. Approximately 4 L/s of CO2 gas also discharges with the springs. The δ^2H and δ^16O composition of the springs exhibits a geothermal shift from the global meteoric waterline. This suggests that the circulation depth is about 3 km below the ground surface (bgs) in basement bedrock. The CO2 gas discharging originates from either magmatic sources or from diagenesis. The fracture density in a typical damage zone decreases with increasing distance from the fault, thus spring discharge should also decrease with increasing distance from the fault. The damage zone in Timpoweap Canyon does not follow this pattern because pre-existing fractures that developed from Laramide and Sevier Orogeny stresses suppress the pattern. Collapse structures from gypsum dissolution and large fractures also control the location of spring discharge.

Time synchronization is critical for the operation of radio base stations (RBS) in telecommunication companies. Global navigation satellite system (GNSS) is an existing technology to provide precise timing information to distributed RBSs. GNSS timing receiver is used for providing higher timing accuracy than normal GNSS receiver in this synchronization domain.In this thesis, an experiment method for GNSS timing receiver performance in urban canyon has been designed and implemented to evaluate information and the quality of the one pulse per second (1PPS) signal generated by two different GNSS timing receivers. Multi-path signals and the gathered satellite geometry caused by poor sky visibility is identified as the main influential factors to the performance of the GNSS timing receivers. A mathematical model has been built for estimating the multi-path effect. GNSS planning tools are used to simulate the number of line-of-sight (LOS) satellites and Dilution of Precision (DOP) value.Sentinel is a 1PPS signal analyzing equipment from Calnex. Sentinel has an embedded rubidium clock, GNSS antenna, and receiver, and it can produce 1PPS signals to be used as a reference. In this report, we installed our GNSS antenna of Sentinel on the roof and test GNSS antenna in two specified positions representing urban canyon and rooftop. Recorded NMEA messages from GNSS receiver can help us to study the number of visible satellites, PDOP value and multi-path signals in realistic situations.The results show how the noise and time phase of 1PPS signals will be influenced in urban canyons. Since, the geometry of used satellites is similar to the rooftop situation, the multi-path effect of signals is identified as the main reason of this difference.This information is useful when telecommunication companies want to install their radio base station in urban canyons. It will help Ericsson to understand how their GNSS timing receiver is working and how the urban canyon will influence its performance. / Tidssynkronisering är kritisk för driften av radiobasstationer (RBS) i telekommunikationsföretag. Global Navigation Satellite System (GNSS) är en befintlig teknik för att ge exakt tidsinformation till distribuerade basstationer. GNSS-baserade tidsmottagare används för att ge högre timing-noggrannhet än vanlig GNSS mottagare i denna synkroniseringsdomän. I denna avhandling har en experimentmetod för GNSS-timingmottagarnas prestanda i urban canyon utformats och implementerats för att utvärdera den genererade informationen och kvaliteten på en puls per sekund-signal (1PPS). Flervägssignaler och den samlade satellitgeometrin som orsakas av dålig himmelsynlighet identifieras som de mest inflytelserika faktorerna för GNSS-tidsmottagarnas prestanda. En matematisk modell har donstruerats för att estimera multi-path-effekten. GNSS-planeringsverktyg används för att simulera antalet LOS-satelliter och DOP-värde (Dilution of Precision). Sentinel är en 1PPS signalanalysutrustning från Calnex. Sentinel har en inbyggd rubidiumklocka, GNSS-antenn och mottagare, och den kan producera 1PPS-signaler som ska användas som referens. I den här rapporten installerade vi vår GNSS-antenn på Sentinel på taket och GNSS-testantennen i två angivna positioner som representerar urban canyon och tak. Inspelade NMEA-meddelanden från GNSS-mottagare kan hjälpa oss att studera antalet synliga satelliter, PDOP-värde och flervägssignaler i realistiska scenarier. Resultatet visar att ljud- och tidsfasen för 1PPS-signaler påverkas i urban canyons. Eftersom satellitgeometrin liknar den för antenner placerade på taket, så är identifieras flervägsutbredningen som huvudorsak för denna skillnad. Denna information är användbar när telekommunikationsföretag vill installera sina radiobasstationer i urban canyons. Det kommer att hjälpa Ericsson att förstå hur deras GNSS-timingmottagare arbetar och hur urban canyon påverkar dess prestanda.

Submarine canyons incising the continental shelf and slope are hot spots for topography-internal wave interactions, with elevated dissipation and mixing contributing to regional transport and biological productivity. At two Barkley Canyon sites (the continental slope below the shelf-break, and deep within the canyon), four overlapping years of horizontal velocity time-series data are used to examine the effects of irregular topography on the internal wave field. Mean currents are topographically guided at both sites, and in the canyon there is an inter-annually consistent, periodic (about a week) up-canyon flow (-700 to -900 m) above a near-bottom down-canyon layer. There is elevation of internal wave energy near topography, up to a factor of 10, 130 m above the slope, and up to a factor of 100, 230 m above the canyon bottom. All bands display weak inter-annual variability, but significant seasonality. Sub-diurnal and diurnal flows are presumably sub-inertially trapped along topography, and the diurnal band appears to be forced locally (barotropically). Both sites have high near-inertial energy. At the slope site, near-inertial energy is attenuated with depth, while in the canyon it is amplified near the bottom. Both sites show intermittent near-inertial forcing associated with wind events, downward propagation of high-mode internal waves, and the seasonal mixed-layer depth, though fewer events are observed in the canyon. Free semidiurnal internal tides are focused and reflected near critical shelf-break and canyon floor topography, and appear to experience both local and remote (baroclinic) forcing. The high-frequency internal wave continuum has enhanced energy near bottom at both sites (up to 7 times the open-ocean Garrett-Munk spectrum), and inferred dissipation rates increasing from a background of less than 10^-9 W kg^-1 and reaching 10^-7 W kg^-1 near topography. Dissipation is most strongly correlated with the semidiurnal (M2) constituent at both sites, with secondary contributions from the sub-diurnal (Sub_K1) band on the slope, and the near-inertial (NI) band in the canyon. Power laws for these dependencies are dissipation ~ M2^0.83 + Sub_K1^0.59 at the slope, and dissipation ~ M2^1.47 + NI^0.24 in the canyon. There is evidence in spectra of a near-buoyancy frequency build-up of energy correlated with high-frequency continuum variability, with a power law fit of 'shoulder' power ~ dissipation^0.34 that is independent of site topography. Though some general results are expected from observations at other slope and canyon sites, the greater temporal extent of these data provide a uniquely long-term evaluation of such processes. / Graduate

This thesis analyzes the characteristics of flow pattern and vehicle-emitted pollutant dispersion in roughness surface layer. In an urban environment, wind flow and transported-pollutant source interfere strongly with buildings and other roughness elements on the surface ground, which results in complex characteristics of flow pattern and pollutant dispersion in 3D circumstances. The present study intends to simplify the research domain and investigate the fundamental modeling problems that exist in the field. The current physical research topic is restricted to 2D street canyon in equilibrium conditions. The study is motivated by the fact that characteristics of flow pattern and pollutant distribution inside street canyons are important for public health. The research has applied the computational fluid dynamics (CFD) methodology. To date, insights have typically focused on idealized street canyons without strictly limited boundary conditions and turbulence models. Those approaches face challenges related to their applicability to real urban scenarios or the reliability of prediction results. The thesis examines the influence of grid density, turbulence models and turbulent Schmidt number on pollutant distribution at windward and leeward surfaces of street canyon. Since numerical results usually are validated with wind-tunnel measurement data, the results between full-size model and wind-tunnel model are compared in order to test the Reynolds number effect. The lack of measurement data means that the morphometric method is used to generate upcoming wind profile, including the mean vertical velocity and turbulence parameters. The thesis also analyzes the potential errors brought by the method (Scenario A). Based on the evaluated numerical model, the thesis continues to study the impacts of surrounding buildings and geometry of street canyon on flow and pollutant distribution inside street canyons. The effect of wind on pollutant distribution inside street canyons was also investigated (Scenario A). Furthermore, the influence of roof shape and configuration of street canyon on characteristics of flow and pollutant distribution is also systematically studied, with the results shown in scenario B. The main conclusions of the thesis are that the uncertainty of numerical results derives from different aspects. Wind profile in the inlet profile generated by morphometric method brings major error to the simulation results. Current turbulence models cannot compromise the simulation results between flow field and pollutant distribution field. Ignored small-scale obstacles also need to be handled carefully. Numerical results revealed that flow and pollutant distribution inside street canyons are mainly dominated by the geometry of the street canyon itself. Medium-spaced surrounding buildings are also better able to transport pollutant out of the street canyon. Through systematic analysis, roof shape is proven to have a significant effect on flow and pollutant distribution inside a street canyon. The major impact is altered turbulence intensity depth and strength of shear layer inside the street canyon, which is important for pollutant removal process out of the street canyon. In the future, advanced turbulence models accompanied by small-obstacle effect models need to be developed in order to reliably simulate flow and pollutant dispersion simultaneously. Based on the advanced turbulence model, simulation of flow and pollutant dispersion in a complex 3D environment is essential in the next steps for the purpose of engineering application. Accurate vertical wind profile provided for inlet profile is another interesting direction for further development. Keywords: Flow; Pollutant dispersion; CFD; Street canyon; Reliability / <p>QC 20130215</p>

A well-preserved flora has been collected from the Upper Cretaceous Blackhawk Formation near Salina, Utah. This formation is part of the Mesaverde Group and consists mostly of deltaic sediments deposited along the western margin of a Cretaceous sea. The Blackhawk Flora is comprised of the following species: Eguisetum sp., Osmunda hollickii, Allantodiopsis erosa, Saccoloma gardneri, Araucaria longifolia, Ginkgo laramiensis, Protophyllocladus polymorphus, Sequoia affinis, Geonomites imperialis, Sabalites montanus, Dryophyllum subfalcatum, Juglans similis, Cinnamomum sezannense, Magnolia ampifolia, Menispermum dauricumoides, Ficus glasconea, Ficus planicostata, Ficus puryearensis var. elongata, Myrtophyllum torreyi, Nymphaeites dawsonii, Dalbergia (?) prewilcoxiana, Salix lesquereuxii, and Trapa paulula. Two independent studies were used to determine the climatic conditions that existed when the Blackhawk Flora was living. The first study was an analysis of the fossil leaf features compared with features of modern leaves whose climatic requirements are known. It was determined that the fossil leaves of the woody dicotyledonous species exhibit a high percentage of entire margins, pinnate venation, simple organization, thick texture, large size, and dripping points. These are characters possessed by modern floras living in warm, humid climates. The second study was of the distribution of the nearest living relatives of the fossil plants. This investigation indicated that the modern correlatives of the Blackhawk Flora prefers climates that are warm-temperate to subtropical. Both paleoclimatic studies indicate that the Blackhawk Flora lived in a humid, warm-temperate to subtropical climate.

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