Endogenous Limits on Proposal Power

We present a dynamic model of legislative bargaining in which policy making proceeds until the proposer has no more incentive to make a new proposal to replace the previously approved policy. We characterize stationary Markov perfect equilibria for the game and show that in all pure-strategy equilibria, a majority of voters without proposal power have an incentive to protect each others' benefits to secure their own long-term bargaining positions in the legislature. As a consequence, the value of proposal power is constrained.Parliamentary democracy, proportional representation, government formation, policy dynamics, lack of commitment, inefficiency.

Mathematical models of combustion at high pressure

In this dissertation, we develop new mathematical theories of flame propagation that are valid at elevated, or extreme, pressures. Of particular interest is the regime of burning in which the pressure exceeds the critical pressure of the species undergoing chemical reaction. Fluids and flames are known to behave differently under these extreme conditions as opposed to atmospheric pressure. The focus of this dissertation is to investigate these differences by deriving reduced models that contain the unique features. In the first part of this dissertation, we analyze the structure of laminar diffusion flames at high pressure in the limit of large activation energy for the particular configuration of a steady flame in counterflow. We consider a dense fluid in which normal Fickian diffusion of the fuel is limited, and thermal diffusion, i.e., the Soret effect, is the dominant mechanism for fuel mass transport. Temperature and species profiles, as well as flame temperature and location, are determined as a function of Damköhler number and Soret diffusion coefficient. In particular, we find that oxidant is entirely consumed by the flame, while some fuel leaks through. For light fuels, the fuel profile is found to have a local peak on the oxidant side as a result of thermal diffusion. Our analysis includes a description of extinction phenomenon, including explicit criteria in terms of the Soret diffusion coefficient, ratio of temperature of the two streams, and the Damköhler number at extinction. In the second part of this dissertation, we derive an asymptotic theory of laminar premixed flames in high density fluids in the limit of large activation energy. The model is intended to provide insights into the structure and dynamics of deflagration waves in high pressure, dense fluids where normal Fickian diffusion is limited. In such cases, particularly under conditions exceeding the thermodynamic critical point of the fluid, the primary mode of species transport is through thermal diffusion, i.e., the Soret effect. Such a model for diffusive transport is considered, and we derive a model with an explicit dependence on the Soret effect for a one-step overall reaction. The density is assumed sufficiently high to adopt a constant density formulation. The local reaction-diffusion structure is found to be fundamentally different from that of an ideal gas with Fickian diffusion, which results in new conditions relating the equations for thermal and mass transport in the bulk flow. The model is used to investigate the basic structure of planar flames, as well as their stability. Stability boundaries are identified that mark the transition from planar to either steady, spatially periodic structures, or time-dependent modes of propagation. The combined effects of the Soret diffusion coefficient and Lewis number are discussed. Furthermore, a weakly nonlinear analysis of the derived model is carried out, resulting in a modified Kuramoto-Sivashinsky (K-S) equation, accounting for effects of Soret Diffusion. Linear stability analysis shows that the flame front is unstable with respect to long-waves in a range of Soret diffusion coefficient that corresponds to no and weak Soret effect. However, there exists a range of Soret diffusion coefficient for which a flame front is unconditionally stable

Investigating and preventing ankle sprain

This book will be valuable for anyone with an interest in sports technology, including those in industry, academia, sports organisations and athletes themselves

KINEMATICS ANALYSIS OF FIVE ANKLE INVERSION LIGAMENTOUS SPRAIN INJURY CASES IN TENNIS

Ankle sprain injury is very common in sport and this study investigated its kinematics. Five injury incidents captured in televised tennis competitions were analysed by a modelbased image-matching motion analysis technique. Results showed a trend of sudden ankle inversion and internal rotation but not plantarflexion. The peak inversion was achieved explosively in a very short time, which is within 0.09-0.17s, after the foot strike. All but one case presented with a slightly inverted ankle joint at foot strike of 10-24 degrees, which should have incited the injury event. We recommend tennis players who perform repetitive sideward cutting motions to attempt to land with a neutral ankle orientation, and to keep their centre of plantar pressure from shifting to the lateral aspect, in order to prevent an ankle inversion sprain injury

INVESTIGATING AND PREVENTING SPORT-RELATED ANKLE SPRAIN INJURY

Ankle sprain injury is very common in sports. It is worth investigating and preventing it. From the literature, two aetiologies were identified: (1) incorrect landing posture, and (2) delayed peroneal muscle reaction. To investigate the injury mechanism, a model-based image-matching motion analysis technique was developed to analyze real injury incidents captured in televised events. The study provided data for establishing a threshold to identify ankle sprain injury hazard by the inversion velocity as monitored by a uni-axial gyrometer. To prevent the injury, a myoelectric stimulation system was developed to initiate peroneal muscle contraction in a very short time (within 25ms) to accommodate the injurious motion (within 50ms) before the muscle could react (60-90ms). The invention will be commercialized as a prophylactic sport apparel in the coming years

Casimir probe based upon metallized high Q SiN nanomembrane resonator

We present the instrumentation and measurement scheme of a new Casimir force probe that bridges Casimir force measurements at microscale and macroscale. A metallized high Q silicon nitride nanomembrane resonator is employed as a sensitive force probe. The high tensile stress present in the nanomembrane not only enhances the quality factor but also maintains high flatness over large area serving as the bottom electrode in a sphere-plane configuration. A fiber interferometer is used to readout the oscillation of the nanomembrane and a phase-locked loop scheme is applied to track the change of the resonance frequency. Because of the high quality factor of the nanomembrane and the high stability of the setup, a frequency resolution down to $2\times10^{-9}$ and a corresponding force gradient resolution of 3 $\mu$N/m is achieved. Besides sensitive measurement of Casimir force, our measurement technique simultaneously offers Kelvin probe measurement capability that allows in situ imaging of the surface potentials

of Management, Northwestern University.

Recent theoretical and empirical studies on comparative constitutions have deepened our understanding of how political institutions shape economic policies. Models by Persson and Tabellini (1999), Lizzeri and Persico (2001), and Milesi-Ferretti et al. (2002), for example, compared how different electoral rules lead to different fiscal policie

Maintenance of dynamic single-legged stability with delayed peroneal reaction time in collegiate footballers during a prolonged football simulation

The purpose of this study was to examine the change of peroneal reaction time and dynamic single-legged stability during a prolonged football match simulation. 12 collegiate footballers participated a Loughborough intermittent shuttle run protocol, within which peroneal reaction time and dynamic single-legged stability were measured to record the change. Results showed that during a prolonged fatiguing protocol, the peroneal reaction time increased significantly, whereas two indicators of the dynamic single-legged stability, root mean square of the mediolateral ground reaction force in 0.4 second of landing and late dynamic mediolateral ground reaction force, remained unchanged. The outcome indicated that the body might adopt different mechanism to maintain sensorimotor control in fatigue state