Why have group-party alliances become more common since the mid-twentieth century? This dissertation employs both qualitative and statistical tools to address the puzzle of contemporary special interest partisanship. After tracing partisanship across several measures, I develop a continuum of group-party relationships, running from fluid, unstructured interactions (akin to political pluralism) to highly institutionalized alliances (as we might see in a firm). Drawing on pluralist scholarship and theories of firm formation and evolution, I explore the costs and benefits of different arrangements, and explain why we might expect to see movement along the continuum over time. On the one hand, pluralism offers flexibility to parties and groups, and alliances have little value when parties are too weak to discipline their members in Congress. On the other, institutionalized alliances offer significant efficiency gains, which are especially valuable during periods of growth. I argue that changes in group-party relations stem from the growth of national party organizations over the second half of the twentieth century, which increased the value of group resources and intensified parties' need for efficiency. Until this period, parties were weak on the national level and strong on the state and local levels, and patronage was the primary currency of politics, leaving little room for issues in political competition. The New Deal's historic expansion of federal power disrupted this balance, temporarily strengthening local parties by offering new sources of patronage, while also sparking gradual, interconnected processes that would ultimately undermine machine power--most notably, the growth of groups and the rise of issue politics as a site of electoral competition. Realizing the economies of scale necessary to build strong national parties required movement away from pluralism into more structured, long-term relationships. Moreover, in order for the new site of competition to help Republicans build a coalition to compete with the long-dominant New Deal Democrats, distinct issue positions were necessary. The result of this party-building process is a pattern of group-party alliances quite unlike the bipartisan relations V.O. Key, David Truman, and others observed in the mid-twentieth century.

Metal oxides containing ruthenium have a surprisingly varied range of low-temperature physical properties including the superconductor Sr2RuO4 and the metallic ferromagnet SrRuO3. The exceptionally broad manifold of itinerate and localised electronic phenomena is derived from broad Ru 4d bands and a wide number of Ru and O containing crystallographic structures. High-pressure is a powerful tool for manipulating crystal structures and tuning the associated electronic and magnetic properties. In this body of work, pressure has been utilised in two roles for the study of ternary ruthenates with perovskite and pyrochlore structures; as a synthetic method and for in situ studies (crystallographic or physical) of existing compounds. Chapter 3 details pressure dependent changes in the crystal structure of the perovskite PbRuO3 by powder x-ray diffraction up to 46 GPa and down to 20 K. PbRuO3 transformed on cooling, from orthorhombic spacegroup (Pnma) to an orbitally ordered low temperature phase, which is also an orthorhombic space group (Imma) and applied pressure reduced the critical temperature totally inhibiting the transition at 5.5 GPa. Additionally PbRuO3 was found to undergo a reversible pressure induced structural phase transition at 30 GPa and 290 K with a 10 % reduction in unit-cell volume. Indexing indicated an orthorhombic symmetry with a Pnna spacegroup. Pnna is not a spacegroup associated with perovskite or related perovskite structures despite the √2 x 2 x √2 perovskite superstructure being maintained across the transition. high-pressure resistivity and Raman measurements indicated that a metal-insulator transition accompanied the structural transition. In Chapter 4 high-pressure high-temperature (HP-HT) synthesis has been used to isolate dense phases that could not be produced at ambient pressure. The ortho-perovskite LaRuO3 with space group Pnma (# 62) was synthesised by conventional solid state methods. However to extend the series by substituting the smaller rare-earth cations, Ln3+ on the A-site of the same perovskite structure HP-HT (10 GPa and 1200° C) conditions were required. A powder diffraction study confirmed the Pnma structure of LnRuO3 where, Ln = Pr, Nd, Sm, Eu, Gd, Dy and Ho, of which the later rare-earth compounds, where Ln = Sm to Ho have not been synthesised before. Neutron powder diffraction studies of LnRuO3 where Ln = La, Pr and Nd down to 7 K suggests a ~ 10 % non-stoichiometry on the Ru site, leading to the adjusted formula LnRu0.9O3 with an unusually low Ru3.3+ valency. A possible exception to the low Ru oxidation state is EuRuO3, which has a larger unit-cell, suggesting a Eu2+Ru4+O3 charge distribution with the more common Ru4+, however, this is not concordant with magnetisation measurements. Additionally neutron diffraction suggests that the RuO6 octahedra are distorted by spin-orbit coupling. Magnetometry and resistivity measurements indicate that the compounds are semiconducting paramagnets down to 7 K. Finally in Chapter 5 is presented the analysis of a high-pressure powder x-ray diffraction experiment of the pyrochlore Tl2Ru2O7. Carried out at synchrotron facilities, we have extended the pressure-temperature phase diagram to 3.7 GPa and 25 K. Previously it had been reported that, when cooled, Tl2Ru2O7 undergoes a structural phase transition from a cubic (Fd-3m) phase to a low temperature, orthorhombic (Pnma) phase that forms Haldane chains - an unusual one-dimensional orbital ordering. As for PbRuO3 high-pressure conditions are found to inhibit the orbital ordering, to reduce the critical temperature and to suppress the transition at pressures exceeding 3.0 GPa.

No description available.

Pressure screens are used for contaminant removal and fibre length fractionation in the production of pulp and paper products. Axial variations and entry effects in the screen are known to occur and these variations have not been adequately quantified. This thesis describes a fundamental study of the axial variations of several factors that occur within an industrial pressure screen; namely, pulp consistency, fibre length distribution, rotor pressure pulse, and feed annulus tangential velocity. Axial variations of pulp consistency in the screen annulus and the accept chamber of the screen were studied using an internal radial sampling method. Localised pulp samples were taken and evaluated and common measures of screen performance such as fibre passage ratio and fractionation efficiency were calculated along the screen. Consistency generally increased along the length of the screen although under certain conditions the consistency toward the front of the screen was lower than the feed consistency. A two passage ratio model that incorporated forward and reverse passage ratio was derived to elucidate the flow of both fibre and fluid through the screen and their effects on overall screen performance. The passage of fibre through the screen decreased with screen length which generally had a positive effect on the fractionation efficiency toward the back of the screen. The passage of individual fibre length fractions was also studied and it was found that long fibre had a much lower passage than short fibre which caused the average fibre length in the annulus to increase. Rotor induced pressure pulse variations along the screen length were also investigated. The magnitude of the pressure pulse was significantly lower (up to 40 %) at the rear of the screen. The variation in pressure caused by the rotor is due to a Venturi effect and the shape of the rotor. The relative velocity of the fluid and the rotor, called the slip factor, also directly affects the size of the pressure pulse in the annulus. The slip factor decreases along the length of the screen due to the increase in tangential velocity of the fluid. Pressure pulse data was also used to estimate the instantaneous aperture velocity and back-flush ratio. The instantaneous aperture velocity was calculated to vary considerably from the superficial aperture velocity by up to 5 m/s in the forward direction and 10 m/s in the reverse direction. Computational Fluid Dynamics (CFD) was used to model tangential velocity changes in simplified screen annuli with axial through flow. For a smooth screen rotor the mean tangential velocity increased over the entire length of the annulus without reaching a maximum value. A step and bump rotor were modelled and the shape of the pressure pulses showed good agreement with experimentally measured pulses. The mean tangential velocity and the entrance length were found to be heavily dependant on the screen rotor used.

Glaucoma is characterized by retinal ganglion cell apoptosis leading to a corresponding loss of the visual field. Elevated intraocular pressure is the principal clinical association of this disease and its reduction remains the mainstay of current therapy. This research established an in-vitro glaucoma model and investigated the direct effects of increased hydrostatic pressure on retinal ganglion cell survival as well as the cellular response to changes in pressure. In the first part of this thesis (chapter 3) the direct effects of pressure on retinal ganglion cell survival was established. The differentiated RGC5 cell line was subjected to elevated pressure 100 mmHg for a period of two hours in a pressure chamber. Cell apoptosis was then detected by TdT-mediated dITP Nick-End Labelling (TUNEL). Quantitative analysis of the percentage of apoptotic cells between the control and pressure groups by Laser Scanning Cytometry (LSC) revealed that pressure alone induced significant apoptosis. Furthermore, caspase-3 cleavage was detected in the pressure treated cells by Western blot analysis. The next three chapters investigated how the applied pressure may be mediated through cellular mechno-sensitive structures. TWIK Related Arachiodonic Acid stimulated K+ channel (TRAAK) is a mechano-gated neuronal potassium channel, which can be opened by pressure and arachidonic acid. In chapter 4, TRAAK was identified as expressed on the rat RGC5 cell line. This was determined by both immunostaining and RT-PCR. Opening this channel by arachidonic acid induced significant apoptosis in RGC5 neurons; elevated extracellular K+ concentration and blockage of TRAAK by gadolinium inhibited both arachidonic acid and pressure-induced apoptosis. These results indicated that elevated pressure resulted in opening of the outward potassium channel-TRAAK and consequently potassium ion efflux and apoptotic volume decrease (AVD). Data from chapter 5 revealed that pressure also caused actin reorganization with both F- and G-actin shifts. At the early stage (following 2 hours pressure treatment), actin polymerization led to G-actin pool decrease and disinhibition of DNase1 in the cytoplasm. This has been suggested to lead to DNase1 nuclear translocation and contribution to DNA fragmentation associated with apoptosis. The preliminary microarray results of chapter 6 revealed pressure effects on gene expression Included in the many up- and down-regulated genes was; down-regulation of antiapoptotic gene- BcL-x and up- regulation of Damage-Induced Neuronal Endopeptidase (DINE) after pressure treatment. This study showed that elevated pressure induced RGC5 apoptosis and affected multi cellular mechanosnesitive structures. These results may indicate new mechanisms of RGC neuron apoptosis and further therapeutic strategies.

The purpose of the study was to examine the existence of an association between child blood pressure (BP) and exposure to domestic jet aircraft noise in the context of the construction of a new parallel north-south runway at Sydney (Kingsford-Smith) Airport. The baseline study was commissioned and funded by the Federal Airports Corporation (FAC), with measurements conducted in 1994 and 1995. A follow-up longitudinal component to the study was subsequently commissioned and funded by the FAC in 1997, and measurements conducted in the same year. As the same individuals were measured and re-measured over changing conditions of exposure to aircraft noise, the quasiexperimental nature of the study allowed inferences to be made regarding exposure to aircraft noise and child BP. The main hypotheses for testing were that BP, and within-subject longitudinal changes in BP, are positively related to domestic jet aircraft noise exposure and longitudinal changes in domestic jet aircraft noise exposure respectively. Subsidiary hypotheses tested for evidence of short- and long-term BP adaptation effects where BPs were related to prior changes to aircraft noise exposures. A sample of 75 primary schools within a 20 km radius of Sydney Airport under various noise exposure conditions, both existing and those projected with the advent of the new runway, participated in the study. The baseline cohort comprised 1,230 Year 3/4 children attending the schools in 1994 and 1995, and the follow-up participants comprised 628 of the original baseline sample re-measured in 1997. Study participants were enrolled by active parental consent. The baseline response rate was approximately 40% of children in the participating schools. Systolic (SBP) and diastolic (DBP) blood pressure readings of the children were taken using automated BP measuring equipment along with anthropometric measurements (heights, weights, skinfold thicknesses and waist measurements). Parental surveys captured items pertaining to the child�s ethnic background as measured by the country of birth of the child and parent(s), residential address and housing structure, child eating habits and activity levels, along with family and child history of high blood pressure. Aircraft noise exposure data were collected by the National Acoustic Laboratories and processed into the energy-averaged noise metric used in Australia for aircraft noise exposure assessment called the Australian Noise Exposure Index (ANEI). Mean exposures for a given calendar month were used in the analysis. ANEI values were geocoded to exact geographic locations using digitised street maps from which values for each house and school address, also geocoded, were interpolated. A child BP measured in a given month was matched to a aircraft noise exposure value both at their school and residential address for that month for analysis. After adjusting for confounding and other factors, the cross-sectional relationship between BP and aircraft noise exposure was found to be inconsistent. SBP was nonsignificantly negatively associated with school aircraft noise exposure at baseline (0.05 mmHg/ANEI, cluster-sampling-adjusted p&gt0.05), but positively and non-significantly associated with school aircraft noise exposure at follow-up (0.05 mmHg/ANEI, p&gt0.05). As for SBP, baseline DBP was significantly negatively related to school aircraft noise exposure at (0.09 mmHg/ANEI, p&lt0.001) and non-significantly positively associated with school aircraft noise exposure at follow-up (0.05 mmHg/ANEI, p&gt0.05). Within-subject BP changes, occurring from baseline to follow-up, regressed on corresponding longitudinal changes in aircraft noise exposures produced inconsistent results. SBP change was positively and non-significantly (0.027 mmHg/ANEI, p&gt0.05) associated with corresponding school aircraft noise exposure change, while SBP change was negatively associated total aircraft noise exposure change (statistically nonsignificant, 0.06 mmHg/ANEI, p&gt0.05). DBP changes were similarly and nonsignificantly related to corresponding aircraft noise exposure changes. Some evidence for short-term BP adaptation to recent changes in aircraft noise exposure was found. Consistent negative associations between systolic and diastolic BP and recent changes in school aircraft noise exposure were found. This association was statistically significant at study baseline (SBP: 0.19 mmHg/ANEI, p&lt0.001; DBP: 0.12 mmHg/ANEI, p&lt0.001), and of similar magnitude although not statistically significant at follow-up (SBP: 0.14 mmHg/ANEI; DBP: 0.10 mmHg/ANEI, p&gt0.05). In the presence of inconsistent cross-sectional BP-aircraft noise exposure associations, this finding is consistent with evidence of a homoeostatic BP response to recent changes in aircraft noise exposure, where resting BP returns to pre-existing levels unrelated to aircraft noise exposure. The public health implication of this finding appears to be benign.

Bibliography: p. 283-311. / xxii, 311 p. : ill. (some col.), photos (col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, School of Mechanical Engineering, 2004

Thesis (Ph.D.)--University of Delaware, 2006. / Principal faculty advisors: Suresh G. Advani, Dept. of Mechanical Engineering, and Eric D. Wetzel, Army Research Laboratory. Includes bibliographical references.

Pen-based computers bring the promise of tapping into people’s expressiveness with pen and paper and producing a platform that feels familiar while providing new functionalities only possible within an electronic medium. To this day, pen computers’ success is marginal because their interfaces mainly replicate keyboard and mouse ones. Maximizing the potential of pen computers requires redesigning their interfaces so that they are sensitive to the pen’s input modalities and expressiveness. In particular, pressure is an important and expressive, yet underutilized, pen input modality. This dissertation advances our knowledge about pressure-aware, pen-based interactions and how people use these techniques. We systematically explore their design by first investigating how pressure can affect pen interactions. We propose novel techniques that take advantage of the pressure modality of a pen to control, link, and annotate digital video. We then study people’s performance using pressure to navigate through a set of elements and find that they can discriminate a minimum of six different pressure regions. We introduce the concept of Pressure Widgets and suggest visual and interaction properties for their design. We later explore pressure’s use to enhance the adjustment of continuous parameters and propose Zliding, a technique in which users vary pressure to adjust the scale of the parameter space, while sliding their pen to perform parameter manipulations. We study Zliding and find it a viable technique, which is capable of enabling arbitrarily precise parameter adjustments. We finally present a novel interaction technique defined by the concurrent variation in pressure applied while dragging a pen. We study these pressure marks and find that they are a compact, orientation-independent, full interaction phrase that can be 30% faster than a stateof-the-art selection-action interaction phrase. This dissertation also makes a number of key contributions throughout the design and study of novel interaction techniques: -It identifies important design issues for the development of pressure-sensitive, pen operated widgets and interactions, -It provides design guidelines for interaction techniques and interface elements utilizing pressure-enabled input devices, -It presents empirical data on people’s ability to control pressure, and -It charts a visual design space of pressure-sensitive, pen-based interactions.

The objective of this project was to design and implement an experimental hydraulic system that simulates joint flexibility of a single rigid link flexible joint robot manipulator, with the ability of changing the joint flexibilitys parameters. Such a system could facilitate future control studies of robot manipulators by reducing investigation time and implementation cost of research. It could also be used to test the performance of different strategies to control the movement of flexible joint manipulators.<p>A hydraulic rotary servo motor was used to simulate the action of a flexible joint robot manipulator. It was a challenging task, since the control of angular acceleration was required. <p>A single-rigid-link, elastic-joint robot manipulator was mathematically modeled and implemented using Matlab. Joint flexibility parameters such as stiffness and damping, could be easily changed. This simulation was considered as a function generator to drive the hydraulic flexible joint robot. In this study the desired angular acceleration of the manipulator was used as the input to the hydraulic rotary motor and the objective was to make the hydraulic system follow the desired acceleration in the frequency range specified. The hydraulic system consisted of a servovalve and rotary motor. <p>A hydraulic actuator robot was built and tested. The results indicated that if the input signal had a frequency in the range of 5 to 15 Hz and damping ratio of 0.1, the experimental setup was able to reproduce the input signal with acceptable accuracy. Because of the inherent noise associated with the measurement of acceleration and some severe non-linearities in the rotary motor, control of the experimental test system using classical methods was not as successful as had been anticipated. This was a first stage in a series of studies and the results provide insight for the future application of more sophisticated control schemes.<p>