An acid rock drainage (ARD) stream emanating from the Zn-Pb XY-deposit in the Yukon Territory was examined in order to evaluate the physico-chemical and geochemical processes governing the distribution of dissolved elements from the creek. The creek showed very high concentrations of metals (300 mg/L Fe, 500 mg/L Zn, 15 000 µg/L Ni, 1300 µg/L Cu and 4500 µg/L Cd), low water temperatures (1 – 12°C) and was acidic to moderately acidic (pH 3.1 – 5.0). It was found that this stream experienced a strong seasonal evolution, with increased sulphate and metal concentrations and decreased pH over the course of the summer. The mineral precipitates that formed under low pH conditions were a mixture of schwertmannite, goethite, jarosite and barite, while those that formed under moderately acidic conditions were a mixture of jurbanite, hydrobasaluminite, gibbsite and an X-ray amorphous Al-sulphate phase. Most of the mineral precipitates were of inorganic origin, although microbes may have played a role in mineral formation and trace metal sequestration in some of the precipitates. All of the mineral precipitates contained anomalous concentrations of trace elements (up to 1.5 % wt Zn) and showed a seasonal evolution in their mineralogy, both of which were determined to be a function of the pH and prevailing geochemical conditions. The geochemistry of the ARD creek draining the XY-deposit was compared to another ARD creek in the area that was likely draining shales. The two creeks were compared in order to determine if ARD geochemical characteristics can be used as a tool for the mineral exploration industry.

The n-solvable filtration of the link concordance group, defined by Cochran, Orr, and Teichner in 2003, is a tool for studying smooth knot and link concordance that yields important results in low-dimensional topology. We focus on the first two stages of the n-solvable filtration, which are the class of 0-solvable links and the class of 0.5-solvable links. We introduce a new equivalence relation on links called 0-solve equivalence and establish both an algebraic and a geometric characterization 0-solve equivalent links. As a result, we completely characterize 0-solvable links and we give a classification of links up to 0-solve equivalence. We relate 0-solvable links to known results about links bounding gropes and Whitney towers in the 4-ball. We then establish a sufficient condition for a link to be 0.5-solvable and show that 0.5-solvable links must have vanishing Sato-Levine invariants.

Normally the operational amplifier is used as a component in active filter design. The goal for future components in filter design is large bandwith and the use of low supply voltages. The use of current-mode instead of voltage-mode circuits gets a step closer to the required performance. A component that use current as the signal conveying part is the current conveyor. In this report a comparative study between two current conveyor structures of second generation (CCII) is performed. The most suited is later implemented and simulated using the CMOS process AMS.C035. The component is also tested in a continuous-time elliptic low-pass filter of leapfrog type. The filter does not behave as it should. However, better performance can be obtained by redesigning the current conveyor.

<p>This dissertation consists of three chapters relating to various topics in empirical Industrial Organization. The first two chapters deal with the empirical treatment of sales in online markets. The third chapter explores the level of pass-through for taxes on soft drinks.</p><p>In the first chapter I demonstrate that when dealing with online market places it is important to take into account the fact that multiple listings coexist. Traditionally, the economic literature has treated listings as independent. In reality, however, buyers often have the choice between multiple contemporaneous listings. I demonstrate that it is important to take this fact into account since sellers who list their items simultaneously are in direct competition. More specifically, I show that the sale probability of a given item decreases when the number of simultaneous listings increases. Thus, the aforementioned assumption of independence can lead to wrong results.</p><p>In the second chapter, I specify and estimate a structural model of mechanism choice in online markets. I consider both sides of the market: On the demand side, buyers' choices among available listings are equilibrium outcomes of an entry game. On the supply side, sellers take competition into account and make equilibrium decisions when choosing sales mechanisms and prices. I estimate this model using data from sales of baseball tickets on eBay. I find that sellers' outside options, dynamic incentives, and risk preferences affect mechanism choice. Using the estimation results from my model I analyze the welfare effects of a hybrid mechanism (buy-it-now auctions) eBay offers. I find that the existence of buy-it-now auctions increases the consumer surplus and reduces the producer surplus. The reason for this is that buy-it-now auctions diminish sellers' potential for diversification via mechanism choice and thus strengthen competition.</p><p>The third and last chapter focuses on the incidence of soda taxes by studying the pass-through level of these taxes. It lays out a framework for thinking about the determinants of the pass-through level. More specifically, it builds theoretical models that examine the pass-through under more complex supply structures with multiple manufactures and retailers. In addition to providing some intuition behind theoretical predictions of the models, this chapter also presents empirical results found in the data along with their implications.</p> / Dissertation

The mainstream of current VLSI design and logic synthesis is based on traditional CMOS logic circuits. However, various new logic circuit design styles based on pass-transistor logic (PTL) have been proposed. The advantage of PTL is higher speed, smaller area and lower power for some particular circuits such as XOR. Since most current automatic logic synthesis tools (such as Synopsys Design Compiler) are based on conventional CMOS standard cell library, the corresponding logic minimization for CMOS logic cannot be directly employed to generate efficient PTL circuits. In this thesis, we develop a novel PTL synthesizer that can efficiently generate PTL-based circuits. We proposed a new synthesis method (hybrid PTL/CMOS Library design) that has multiple driving strengths and multiple threshold voltages to achieve better performance in area, speed, and power. Since PTL-based circuits are constructed by only a few basic PTL cells, the layouts in PTL cells can be easily updated as the process technology migrates rapidly in current Nano technology era. The proposed PTL logic synthesis flow employs the popular Synopsys Design Compiler (DC) to perform logic translation and minimization based on the standard cell library composed of PTL and CMOS logic cells. Thus, the PTL design flow can be easily embedded in the standard cell-based ASIC design flow.

This thesis realizes miniature bandpass filters using integrated passive device technology. The bandpass filters are designed based on coupled resonator method with single-band and dual-band responses, using a transformer structure with high-density winging pattern. In addition, the designs adopt the electric- and magnetic-field cancellation and the feedback mechanism to produce transmission zeros in the filter responses for enhancing selectivity and stopband rejection. In order to satisfy the specific requirements of commercial bandpass filter products, this thesis designed and implemented a trisection filter with cross coupling on a low-loss RT/Duroid substrate to generate a transmission zero very near the passband.

Recently, with advances in CMOS process, the RF receiver which is integrated into the SOC chip can effectively reduce production costs. When designing the wireless receiver, one of the most important technologies is to design channel-selection filter. Typically, the design of the channel-selection filter in multi-standard high-frequency will take up a large chip area and higher power consumption. Therefore, in order to reduce the area and power consumption, this thesis designed a low-power OTA and low-pass filter. This thesis presents a multi-mode wireless communication application in the receiver channel selection filter. This filter is designed to use the fifth-order Butterworth low pass filter, the filter range can be used in Bluetooth, cdma2000, wideband CDMA, and IEEE 802.11a/b/g/n wireless LAN. Using floating transistor architecture in the input stage of OTA can effectively increase the THD performance. Using MOS transistors operating in triode region and combined with current multiplier can achieve the voltage-to-current conversion. Using the trans-linear loop can reach a wide tunable range, and the OTA operating in weak inversion region can significantly reduce the transconductance. Implementation is to use the TSMC 0.18£gm CMOS process. Simulation results show that the successful operation of this filter can be between 650 kHz ~ 22MHz frequency range. The filter may have compatibility in different wireless communication applications. 14.5mW to 17.5mW, respectively, is the smallest to the largest power consumption. The supply voltage is 1.2 volts.

Most discrete time filters use Switched Capacitor structures, but Switched capacitor circuits have finite sampling rate and high power consumption. In this paper we use Switched Current structure to increase sampling rate and reduce power consumption. In this paper, we use a Class-AB structure to compose a double sampling third order low-pass filter. In this paper there are two integrator types. Modified backward Euler and modified forward Euler integrators were realized with double sampling technology from the backward Euler and forward Euler integrators. Compared with other circuits, the circuit has low power supply¡Blow power consumption ¡Bhigh sampling speed. We employ HSPICE and MATLAB to simulate and design the circuit. We use TSMC 0.35£gm process to implement this circuit. The power supply is 1.8V, the cut-off frequency is 3.6MHz, the sampling frequency is 72MHz, and the power consumption is 1.303mW.

My dissertation studies various questions falling into the broad context of macroeconomics and international economics. The questions have macroeconomic components because they are concerned with the behavior of aggregates. Specifically, the second and third chapters of my dissertation study the causes of fluctuations in aggregate macroeconomic variables and the way policy can be coordinated internationally to reduce these fluctuations, respectively. In addition, chapters III and IV address questions that fall into the realm of international economics. They are concerned with the optimal exchange rate regime between two countries, the consequences of partial exchange rate pass-through and the effect of an increase in vertical Foreign Direct Investment (FDI) by domestic firms. The framework of my analysis is given by different versions of general equilibrium models. The second chapter of my dissertation decomposes fluctuations in aggregate observables for the UK economy during the 1980s recession. Using a modern accounting procedure, I estimate parameters that describe the economy using annual data from 1970 to 2002. Then, I simulate different versions of the model to find the distortions that are essential in driving the observed fluctuations. I find labor market distortions to be crucial in accounting for the episode, suggesting that the policies of the time were well targeted and effective. The third chapter of my dissertation studies policy coordination in a two-country framework allowing for partial pass-through. In particular, both countries are assumed to have monetary and fiscal stabilization instruments available. The optimal setting of these instruments under differing pass-through regimes is analytically derived. Fiscal policy is found to be used in a counter-cyclical fashion. In addition, the magnitude of fiscal stabilization is the largest when pass-through is partial. In the fourth chapter, I study the consequences of vertical FDI on aggregate productivity and welfare. The framework allows for heterogeneity across firms in two dimensions. It is firms that are at a disadvantage with respect to manufacturing costs that are benefiting most from moving their production process abroad. Overall, the ability to engage in vertical FDI increases productivity, lowers prices and thus increases welfare.

The major purpose of this study was to determine how no pass, no play has impacted the perceptions of academic player eligibility as perceived by high school coaches in Educational Service Center, Region 20, Texas. Variables such as coach characteristics, school characteristics, and community characteristics were researched. In addition, the study examined the influence gender and ethnicity of the coach had on their perceptions of no pass, no play. The study focused on the perceptions of coaches to no pass, no play relating to (1) student motivation, (2) instructional issues, (3) ethnicity specific variables, (4) student suspension variables. The relationship between poverty status in the district, annual household income, the type of sport, and demographic variables such as the gender, experience level, and ethnicity of the coach were also examined. Respondents’ answers were dependent upon a number of variables. The gender of the coach was a variable that reappeared as significant throughout the study. The ethnicity of the coach and minority population in the school also showed to be significant variables. Lastly, the type of sport, poverty status in the district, percentage of economically disadvantaged students on the campus, the annual dropout rate, and annual household income were also variables that significantly impacted the study. Findings of the study included: 1. Female coaches were four times more likely than male coaches to believe that no pass, no play was an effective motivational tool. 2. Female coaches were 87% more likely to feel that allowing students to practice while they are ineligible to participate motivated students to stay in school. 3. As the annual household income in the district increased, so did the likelihood that the coach perceived students to feel threatened by no pass, no play, resulting in increased study time by the students. 4. The type of sport did not have an impact on coaches’ perceptions that in order to influence student eligibility, parents and student-athletes challenge failing grades assigned by teachers. 5. As the number of ineligible students increased, the likelihood of an athlete making better grades following suspension decreased.