<p>This thesis focuses on the electromechanical processes of generation and damping of transient waves in bars with attached piezoelectric members. In particular, the influence of amplifier and electrical circuitry on the mechanical waves is of interest.</p><p>A straight bar element containing piezoelectric members is viewed as a linear system with one electrical and two mechanical ports where it interacts with external electrical and mechanical devices through voltage, current, forces and velocities. For the modelling of the piezoelectric bar element (PBE) and its environment, coupled piezoelectric theory is used with allowance for the dynamics of the PBE and attached electrical and mechanical devices.</p><p>Two applications are considered for a PBE that constitutes a part of a long bar, viz. generation and damping of extensional waves. In the first, simulations and experiments were performed when the PBE was driven by a power amplifier. In the second, simulations and experiments were performed when the PBE supplied an output voltage to an external load.</p><p>In the case of wave generation, the influence of amplifier characteristics in terms of DC voltage gain, 3 dB cut-off frequency, output impedance and current constraints on the output voltage and current of the amplifier and the waves generated are studied. Further, generation of waves of prescribed shapes are studied for a specific amplifier. In general, good agreement between simulated and experimental results was obtained.</p><p>In the case of wave damping, the influence of external electrical loads and incident waveforms on reflected and transmitted waves, and on gener-ated voltage, current, electrical power and dissipated energy, are studied. In general, fair agreement between simulated and experimental results was obtained. The fractions of a few percent of wave energy dissipated in the exter-nal load were well below the 50 percent achievable for a harmonic wave under condition of electrical impedance matching.</p>

This thesis focuses on the electromechanical processes of generation and damping of transient waves in bars with attached piezoelectric members. In particular, the influence of amplifier and electrical circuitry on the mechanical waves is of interest. A straight bar element containing piezoelectric members is viewed as a linear system with one electrical and two mechanical ports where it interacts with external electrical and mechanical devices through voltage, current, forces and velocities. For the modelling of the piezoelectric bar element (PBE) and its environment, coupled piezoelectric theory is used with allowance for the dynamics of the PBE and attached electrical and mechanical devices. Two applications are considered for a PBE that constitutes a part of a long bar, viz. generation and damping of extensional waves. In the first, simulations and experiments were performed when the PBE was driven by a power amplifier. In the second, simulations and experiments were performed when the PBE supplied an output voltage to an external load. In the case of wave generation, the influence of amplifier characteristics in terms of DC voltage gain, 3 dB cut-off frequency, output impedance and current constraints on the output voltage and current of the amplifier and the waves generated are studied. Further, generation of waves of prescribed shapes are studied for a specific amplifier. In general, good agreement between simulated and experimental results was obtained. In the case of wave damping, the influence of external electrical loads and incident waveforms on reflected and transmitted waves, and on gener-ated voltage, current, electrical power and dissipated energy, are studied. In general, fair agreement between simulated and experimental results was obtained. The fractions of a few percent of wave energy dissipated in the exter-nal load were well below the 50 percent achievable for a harmonic wave under condition of electrical impedance matching.

In 2002, Pensacola Beach was identified by the United States Lifesaving Association as being the most hazardous beach in the continental United States for beach drowning by rip currents. Recent studies suggest that the rip currents at Pensacola Beach are associated with a transverse bar and rip morphology that develops with the migration of the bars and recovery of the beachface following an extreme storm. Combined with an alongshore variation in wave forcing by transverse ridges on the inner-shelf, the bar cycle (of bar response and recovery to extreme storms) is hypothesized to create both rip current hotspots and periods of rip activity. However, it is unknown at what stage, or stages, the bar cycle is associated with the formation of these hotspots and the greatest number of rips. To determine how the accretional rip hazard varies in response to the nearshore bar cycle, this thesis will quantify the alongshore variation in the nearshore bar morphology on Santa Rosa Island from 1951 to 2004. Aerial photographs and satellite images are collected for the study area and nearshore features are digitized in ArcGIS and evaluated using wavelet analysis. Specifically, a continuous wavelet transform is used to the identify times and locations when a transverse bar and rip morphology is present or is in the process of developing. The findings suggest that the rip-scale variation in bar morphology (~100-250m) is superimposed on an alongshore variation consistent with the scale of the transverse ridges (~1000m). From the outer bar to the shoreline, and as the bar migrates landward, the variation becomes increasingly dominated by the rip-scale variation. Hotspots of rip current activity were found consistently between years at Fort Pickens Gate, San Souci, Holiday Inn, Casino Beach, Avenida 18 and Portofino, as clusters of rip-scale variation.

No description available.

This study is an attempt to combine Nietzschean thought with postmodernism (already greatly influenced by Nietzsche) to take what I am calling a "pastiche approach." I do not mean pastiche in the strictest sense of the word as simply a hodgepodge of various things with little connection to one another but as a combination of modernist schools of thought, such as the structuralists, with various postmodern and poststructural "schools," such as those strains of thought coming from figures such as Jean Baudrillard, Jean Francois Lyotard and Jacque Derrida. I am also referring to various methodological approaches, such as ethnography, historical comparative, textual and content analysis and positivistic approaches. These approaches are used in concert in order to paint a "portrait" from a stance of Nietzschean perspectivism of barworkers as people operating in cultural patterns both local and global.

In this thesis, two separate research topics are undertaken both in the general area of compact RF/microwave circuit design. The first topic involves characterizing the parasitic effects and error due to unused post-production tuning bars. Such tuning bars are used in microwave circuit designs to allow the impedance or length of a microstrip line to be adjusted after fabrication. In general, the tuning bars are simply patterns of small, isolated sections of conductor adjacent to the thru line. Changing the impedance or length of the thru line involves bonding the appropriate tuning bars to the line. Unneeded tuning bars are simply not removed and left isolated. Ideally, there should be no coupling between these unused tuning bars and the thru line. Therefore, the unused tuning bars should have a negligible effect on the circuit??s overall performance. To nullify the parasitic effects of the tuning bars, conventional wisdom suggests placing the bars 1.0 to 1.5 substrate heights away from the main line. While successful in the past, this practice may not result in the most efficient and cost-effective placement of tuning bars in today??s compact microwave circuits. This thesis facilitates the design of compact tuning bar configurations with minimum parasitic effects by analyzing the error attributable to various common tuning bar configurations with a range of parameters and offset distances. The error is primarily determined through electromagnetic simulations, and the accuracy of these simulations is verified by experimental results. The second topic in this thesis involves the design of compact microwave resonators using the transmission line approach to create negative refractive index metamaterials. A survey of the major developments and fundamental concepts related to negative refractive index technology (with focus on the transmission line approach) is given. Following is the design and measurement of the compact resonators. The resonators are also compared to their conventional counterparts to demonstrate both compactness and harmonic suppression.

將台灣的泡沫紅茶產業模式引進英國 / Exporting the Taiwanese Tea Bar Business Model to the UK Market

Thesis (Ph. D.)--University of Pennsylvania, 1936. / Includes bibliographical references (p. 381-383) and index.

Thèse--Nancy. / At head of title: Université de Nancy. Faculté de droit et des sciences économiques. eContent provider-neutral record in process. Description based on print version record. Bibliography: p. [9]-12.

This is a two-part story looking at women’s professional soccer in the United States. First, it is a look at the newly formed National Women’s Soccer League. The league is the third attempt to establish a women’s professional soccer league in the U.S. Low attendance, low-ticket sales, and poor team ownership spelled the end for past leagues. The United States Soccer Federation’s involvement in the league has team owners and players overwhelming confident that the league will be a success. Challenges await them as the NWSL looks to learn from the mistakes of its predecessors. The second part looks at women’s professional soccer in Texas. The first audio story focuses on the Houston Aces and Lauren Prewitt. Prewitt plays semi-professional soccer for the Aces. At 30 years old, she still has dreams to play professionally. Aces owner William Brumbaugh is hoping his team can be the first women’s soccer team from Texas, to play in a women’s top league. The second audio story puts a focus on the Austin Nationals and the Austin Women’s Soccer League. Both are attempting to build women’s soccer in Austin but are going about it different manners. Anna Villarreal is attempting to establish a team that is not as reliant on ticket sales as most teams are. Through community outreach and partnerships with local businesses she is hoping to build a team to compete in Europe come 2014. The AWSL is a local soccer league for women that is trying to establish itself in Austin. They receive little outside support in terms of funding but president and vice president Angela Molock and Casey Gannon are hoping the changes they have brought to the league can help it grow. The “Soccer In Austin” piece focuses on the local establishments that have given soccer fans a place to go to watch their favorite clubs on television. Fadó Irish Pub and Cuatro’s have established themselves as the more popular locales when it comes to showing soccer games on television. Others have attempted to emulate Fadó’s and Cuatros’ popularity but many have struggled to attract the committed fan base that have helped Fadó and Cuatro’s become the go-to spots to watch a soccer game in Austin. Aside from showing soccer matches, these places provide people who share interests to come together and interact. For those who come from soccer loving countries such as England and Ireland, these places help to remind of home. While not quite the same in every aspect, the fans have fully embraced having a place to go where they can watch a soccer match while drinking a pint and engage in some friendly banter. / text