This thesis presents an experiment and an analysis that evaluates some of the long-standing assumptions in deep vertical borehole ground heat exchanger (GHX) theory. These assumptions neglect ground heterogeneity and depth variations in GHX output and the ground temperature response (GTR). This thesis describes an apparatus and an experiment that measured the GTR at several depths, times, and at two different horizontal distances from a GHX both during and immediately after its operation. This thesis also reports the temperature response data, which may not be available from other sources in such detail. The experiment showed that the GTR can be highly depth dependant. The analysis involved a parametric study to characterize the GTR by developing an effective computer simulation of the experiment. The analysis showed that ground heterogeneity significantly affected the GTR and the GHX output in this study. Furthermore, this GHX output showed depth and time, dependence.

Presently in ground vehicle industries, conducting durability tests with a high acceleration factor have become increasingly demanding for the less time and cost involvement. In the previous work, to accelerate the field test, the standard ‘test tailoring’ approach has been modified due to the requirement of high acceleration factors and the limitations of testing implementation. In this study, a computer-aided testing method is developed for the validation of this modified approach. Hence, a new test-piece has been designed by a conjugative approach involving the finite element technique and fatigue analysis. Afterwards, the accelerated durability loading profiles synthesized via the modified approach have been applied on the designed test-piece and the fatigue life has been simulated to verify the effectiveness of those loading profiles. Simulation results show that loading profiles with an acceleration factor up to 330 can be successfully generated with an accuracy of 95% by this modified approach.

No description available.

Since the integration of women into the United States armed forces, servicemen have been expected to be the fighters while servicewomen largely occupied safe or nurturing support roles as dictated by American society at large. The ground combat exclusion policy, which officially barred women from all positions involving ground fighting, limited women to support units which, in theory, were strategically located in the rear and far removed from the dangers of the front lines. As we experienced in the recent wars in Afghanistan and Iraq, the differentiation of gender roles became irrelevant in asymmetrical wars with no established front lines. Female soldiers found themselves in a variety of combat situations of indirect and direct nature, as I learned through the qualitative interviews that I conducted at Fort Hood, Texas, and Fort Bragg, North Carolina. In this dissertation, I examined the narratives of female and male soldiers who experienced combat in Afghanistan and Iraq, to discern: 1) whether females and males discussed their scenarios differently; 2) whether experiencing combat affected soldiers’ ideas about their various gender roles; 3) whether perceptions on servicewomen’s combat participation differed by sex; and 4) whether soldiers’ opinions on women’s inclusion in combat arms military occupation specialties differed by sex. What I found in my study was that: 1) female and male soldiers largely discussed their combat experiences in similar ways; 2) while familial gender roles were largely unchanged as a result of combat deployment, the majority of female and male soldiers perceived changes in their roles as women and men – where women often discussed feeling stronger, empowered, and independent, and men often identified their changes in terms of maturity and personal growth; 3) that exposure to women’s roles in combat deployments had a more positive effect on the perceptions of male soldiers than those of female soldiers; and 4) that both female and male participants largely disagreed with the ground combat exclusion policy for women.

This thesis reports on the investigations of resistive-capacitive (RC) loaded bow-tie antennas with special emphasis on impulse ground penetrating radar applications. Impulse radiation for ground penetrating radar is a challenging research topic because of the unique problem arising from impulse radiation: late-time ringing, which usually masks the important echo signals from the targets. While resistive loading is a common solution for eliminating late-time ringing, use of resistive loading typically sacrifices the radiation efficiency. In this thesis, a resistive-capacitive loading technique is investigated for a circular bow-tie antenna in the attempt to reduce/suppress the late-time ringing as well as to maintain a relatively high radiation efficiency. To implement the system, a microstrip differentiator, which converts a monopulse into a Gaussian-like monocycle to be used as input impulse, is presented. Further, specially designed coplanar waveguide/coplanar strip (CPW/CPS) baluns embedded with Chebyshev transformers of characteristic impedance up to 120 have been constructed and tested. To evaluate the system, instead of using the conventional peak voltage value of the radiated waveform, average radiated energy, average ringing energy, relative radiation efficiency and relative ringing efficiency are utilized and these metrics are easily established using low-cost low-sensitivity probes. Measurement results show that the RC-loading scheme is functioning as expected and the impulse system as a whole is capable of reducing the late-time ringing energy to 50% while maintaining average radiation energy as 83% when compared with capacitive loading cases.

No description available.

In einem 2-jährigen Forschungsprojekt entstand ein Modellsystem, das die Wertschöpfung der sächsischen Landwirtschaft mit und ohne Flächenförderung abbildet. GIS-Komponenten ermöglichen die räumliche Darstellung der ökonomischen Leistungen der Regionen unter variablen Marktbedingungen. Direktzahlungen sind als überlagerte Stufenförderung sowohl in ihrer Einkommenswirkung als auch in Bezug zu Umweltzielgebieten darstellbar. Die Modellanwendung soll dazu beitragen, die flächendeckende Landwirtschaft zu gewährleisten und zusätzlich Förderzielgebiete mit Umweltbezug abzuleiten. Zur Simulation von Mittelverteilungen kann das Modell an Umweltkriterien, Bruttoinlandsprodukt oder sozioökonomische Größen angepasst werden. Die Modelle sollen die Ausgestaltung der Förderperiode GAP ab 2014 begleiten.

Die Broschüre gibt einen Überblick zu Methoden, mit denen die Bodenfruchtbarkeit von Ackerflächen bewertet werden kann, sowie Hinweise zu deren Anwendung. Dazu gehören unter anderem die Spatendiagnose, Bodenuntersuchungen und Nährstoffbilanzierungen.

Die Schadstoffsituation der Böden der Siedlungsgebiete von Annaberg-Buchholz und Aue (Erzgebirge) wurde mit unterschiedlichen methodischen Ansätzen und Interpolationsverfahren flächenhaft dargestellt und evaluiert. Festgestellt wurde, dass sich Punktinformationen zu Schadstoffgehalten auch in Siedlungsbereichen des Erzgebirges zumeist mit ausreichender Aussagesicherheit in Karten darstellen lassen. Dabei erwies sich keine der bislang bekannten Methoden für die Übertragung von Punktinformationen auf die Fläche als grundsätzlich vorteilhaft; jede Methode zeigte gebietsspezifisch und für einzelne Metalle Stärken und Schwächen. Erstmals kam ein Verfahren der künstlichen Intelligenz (Software advangeo®) erfolgreich zum Einsatz. Die Vorteile dieses Verfahrens zeigten sich gerade in sehr klein strukturierten Siedlungsbereichen und der Vielzahl von Einflussgrößen auf die Stoffgehalte. Damit ließ sich der Einfluss der oberflächennahen Erzgänge auf die Arsen-Konzentration der Böden im Siedlungsgebiet Annaberg gesichert abbilden. Die Erfahrungen aus den Testgebieten münden in Empfehlungen zur optimalen Anwendung der methodischen Ansätze und untersuchten Verfahren.

Climate change stabilization requires an unprecedented effort to change our current approach to energy production and consumption. While rising energy prices are drawing increased attention to reducing energy demand, heightened concern about the environmental consequences of fuel choice requires that this demand be met at lower emission levels. In Canada, the realization of commitments to our GHG emission goals entails reducing residential energy use - a sector responsible for close to 20 percent of end-use energy consumption. This study focuses on the energy demand and emission levels of space and water heating, since these two components comprise 76 percent of residential energy demand. Ground source heat pumps (GSHPs) are a technology that provides heating at 25 to 30 percent of the energy consumed by even the most efficient conventional alternatives. GSHPs have been identified as the most energy-efficient, environmentally clean, and cost-effective space conditioning systems available. However, their drawbacks have been high capital costs, and uncertainty about whether the electric power used by heat pumps has higher system-wide emissions. This thesis delineates how adoption of GSHPs in the residential sector can help align Canada’s technology choices with commitments made to the Kyoto Protocol. The manuscripts delineate conditions under which GSHP systems achieve the largest net emission reductions relative natural gas, heating oil, and electric heat counterparts. Electricity generation methods and emissions embodied in inter-provincial and international electricity trade are shown to significantly affect the emission savings achievable through GSHP. The thesis quantifies how relative fuel prices influence annual operating savings that determine how rapidly the technology can achieve payback. This analysis reveals GSHPs to hold significant potential for substantial GHG reductions at a cost savings relative to conventional alternatives; the time horizons for payback are as short as nine years for average-sized homes, and significantly shorter for larger homes.