A Multibody Dynamics Model of a Motorcycle with a Multi-link Front Suspension

The development of motorcycles has been around for over a century. Nowadays, it has become one of the most popular means of transportation in the world. It is well known that the telescopic fork is the most widely used front suspension for motorcycles, because the first motorcycle was a bicycle with a small engine attached to the frame. However, there are a number of shortcomings inherent in this design. Therefore, a novel multi-link suspension has been designed for the front assembly of the motorcycle in this research. In order to compare the performance between telescopic fork and multi-link front suspension motorcycles, linear and nonlinear models were built and simulated under a variety of different conditions. Furthermore, an appropriate method of comparison between conventional and multi-link models was developed, and the assessment standard of performance for conventional and multi-link models was explored in this research

The United States Implementing Legislation of the Uruguay Round Agreement on Antidumping: Its Problems and Effects on the Bilateral Trade Relation Between the United States and Korea

Antidumping laws were designed to protect domestic industries from unfair predatory price discrimination from foreign companies, yet these laws are often alleged to be used to protect domestic industries from competition. The U.S. has not been a stranger to these accusations since the 1980s as the U.S.’s trade deficit grew. The Uruguay Round negotiations were aimed at ending this protectionist use of antidumping laws, but many issues were left unsettled by the Uruguay Round antidumping agreement. In particular, interpretation of the agreement is deferred to each country primarily. Thus, the Dispute Settlement Body of the WTO can only determine a violation of the agreement in cases of obvious arbitrary interpretation. This thesis analyzes the enacted U.S. implementing legislation following the Uruguay Round, concentrating on provisions which may be inconsistent with the Uruguay Round agreement. The thesis also focuses on bilateral trade between the U.S. and Korea, both before and after the Uruguay Round

Local Electrical Stress-Induced Doping and Formation of 2D Monolayer Graphene P-N Junction

We demonstrated doping in 2D monolayer graphene via local electrical stressing. The doping, confirmed by the resistance-voltage transfer characteristics of the graphene system, is observed to continuously tunable from N-type to P-type as the electrical stressing level (voltage) increases. Two major physical mechanisms are proposed to interpret the observed phenomena: modifications of surface chemistry for N-type doping (at low-level stressing) and thermally-activated charge transfer from graphene to SiO2 substrate for P-type doping (at high-level stressing). The formation of P-N junction on 2D graphene monolayer is demonstrated with complementary doping based on locally applied electrical stressing.Comment: 12 pages, 4 figure

Simulation and Analysis of Unconventional Reservoirs Using Fast Marching Method and Transient Drainage Volume

Unconventional tight/shale reservoirs have become an important component of the world’s energy map in the recent decade and have been attracting a lot of interests in both academia and industry. However, the industry today still faces significant challenges in understanding the fundamental mechanisms. Unconventional tight/shale reservoirs are characterized by low or ultra-low permeability, such that the transient pressure behavior might last throughout the production lifetime. Recent research has proposed a novel approach for unconventional reservoir analysis based on the high-frequency asymptotic approximation of diffusivity equation. By solving the Eikonal equation with the Fast Marching Method (FMM), one can rapidly obtain the diffusive time of flight (DToF) which depicts the pressure transient propagation process. A fast DToF-based forward simulation is further proposed to solve the fluid flow equation in a 1D equivalent coordinate system, with the DToF as the spatial coordinate. In this study, we first adopt the DToF-based simulation as a rapid forward simulator to formulate an efficient hydraulic fracture design and optimization workflow. The DToF-based simulation can be orders of magnitude faster than the conventional finite difference/volume based simulation, and is ideal for optimization process where hundreds or thousands of simulations are necessary. Our workflow focuses on optimizing the number of hydraulic fracture stages, their spacing, and the allocation of proppant. The workflow also accounts for the geologic uncertainty, which given by different natural fracture distributions. Next, we extend this DToF-based simulation from Cartesian and corner point grid system to unstructured grids to better characterize the complex fracture geometry induced by hydraulic fracturing job. Two different constructions of the local Eikonal equation solver, based on Fermat’s principle and Eulerian discretization, are investigated and compared. Numerical examples are presented to illustrate the power and validity of this extended DToF-based simulation workflow. Finally, we propose a model-free production data analysis method to analyze the performance of unconventional reservoirs when a full simulation model is not available. The transient drainage volume is derived directly based on bottom-hole pressure and production rate. We further define the drainage volume derivative and instantaneous recovery ratio, which can measure how effectively the hydraulic fractures have stimulated the reservoir. This technique is then applied to select candidate wells for refracturing

THE CHARACTERISTICS OF FEMALE SOCCER KICKING REVEALED BY 3D KINEMATICS AND ELECTROMYOGRAPHY

Soccer is the mosl popular sport in the world' and rapidly becoming one of the most popular sports in North America. Despite its popularity, little research has been done to facilitate the rapid demand of quantitative findings. Even less attention is being paid to the fact that females now make up almost half the players worldwide. This study initiates a research on female soccer kicking using state-of-the-art technology. The high-tech unit consists of a 3D motion capture system with 9 high-speed cameras (120 Hz) and wireless electromyography (EMG) collection. The results revealed that a) Elite subjects combined the f1exion and extension of the hip, knee and ankle joint to perform the kick while novice subjects primarily used the knee to generate momentum; b) elite group showed a significant higher EMG intensity

Dissolution behaviours of structured particles

The work presented in this thesis aims at the fundamental understanding and investigation of dissolution behaviors of structured particles. This topic is relevant to numerous industrial applications including detergent, pharmaceutical, agrochemical and energy products. Both experimental works and theoretical analyses were carried out in this work. The particles of several different materials including sodium carbonate and polymers with specific characteristic and structure were used into the experimental works in this thesis. Polymers used in this thesis included carboxymethyl celluslose, croscarmellose sodium and crospovidone. The studies on characteristics of these particles included the determination of particle size, shape and structure with several measurement techniques. The dissolution process was measured with experimental methods under different solution conditions including temperature, stirring speed and pH. Based on these measured data, the dissolution kinetics such as dissolution rate constant were quantified with mathematical models and analyzed with theoretical studies. In this way, the dissolution behaviors of different structured particles could be finally identified and analyzed with the quantified data of dissolution process and dissolution kinetics. Additionally according to the quantification process, the effects of these solution conditions on dissolution kinetics could also be determined and identified that how these conditions impact dissolution kinetics. Main conclusions of my work on dissolution experiments in this thesis were simply summarized as the following that: • An increasing in the temperature and stirring speed leads to the increases of dissolution rate and dissolution rate constant of sodium carbonate particles in all cases. • The dissolution rate and the rate constant decreases with the increasing of pH value of solution. • Carboxymethyl cellulose and crospovidone show a clear effect to enhance the dissolution rate and the rate constant of sodium carbonate-polymer composite tablets. • Cropovidone also has a stronger effect to enhance the dissolution process and kinetics than carboxymethyl cellulose • Croscarmellose sodium shows a clear effect to weaken the dissolution rate and the rate constant of sodium carbonate-polymer composite tablet

Electrooptic matched filter controlled by independent voltages applied to multiple sets of electrodes

Analysis and experimental results on a polarization independent electrooptic matched filter (EMF) with a center wavelength of 1.53 μm are reported. The EMF utilizes electrooptic phase-matched TE↔TM conversion in a Ti-diffused waveguide on a LiNbO3 substrate. The operation of the EMF to select an optical frequency channel is controlled by applying independent voltages to interdigital electrode sets cascaded along a single mode waveguide. The device is inherently polarization independent and has the potential for submicrosecond tuning. The number of selectable channels N is related to the number of electrode sets P by the formula / 2 1 N P = + . A matrix analysis is used to determine the TE↔TM conversion efficiency for the case that 8 P = and 5 N = . A driving circuit for the EMF was implemented using a digital-to-analog converter (DAC) array controlled from a personal computer (PC). Transmittance spectra of a filter produced in a LiNbO3 substrate are presented. A raised cosine weighting function applied along the 3.8 cm length of an EMF provides a sidelobe suppression level better than Â17 dB with a 1.0 nm 3-dB bandwidth

Ultrasensitive Magnetometry and Imaging with NV Diamond

NV centers in a diamond are proving themselves to be good building blocks for quantum information, electron spin resonance (ESR) imaging, and sensor applications. The key feature of the NV is that it has an electron spin that can be polarized and read out at room temperature. The readout is optical, thus the magnetic field imaging can also be done easily. Magnetic field variation with feature sizes below 0.3 microns cannot be directly resolved, and so in this region magnetic resonance imaging must be employed. To realize the full sensitivity of NV diamond, the spin transition linewidth must be as narrow as possible. Additionally, in the case of NV ensembles for micron-sized magnetometers, there must be a high concentration of NV. To this end three techniques are explored: (1) Electron paramagnetic resonance (EPR) imaging with microwave field gradients, (2) Magic angle rotation of magnetic field, and (3) TEM irradiation to optimize the yield of NV in a diamond. For the EPR imaging demonstration a resonant microwave field gradient is used in place of the usual DC magnetic gradient to obtain enough spatial resolution to resolve two very close "double NV" centers in a type Ib bulk diamond. Microfabrication technology enabled the micron-size wire structure to sit directly on the surface of millimeter-scale diamond plate. In contrast to conventional magnetic resonance imaging pulsed ESR was used to measure the Rabi oscillations. From the beating of Rabi oscillations from a "double NV," the pair was resolved using the one-dimension EPR imaging (EPRI) and the spatial distance was obtained. To achieve high sensitivity in nitrogen-doped diamond, the dipole-dipole coupling between the electron spin of the NV center and the substitutional nitrogen (14N) electron must be suppressed because it causes linewidth broadening. Magic angle spinning is an accepted technique to push T2 and T2 * down toward the T1 limit. An experiment was performed using the HPHT diamond with a high concentration of nitrogen, and a rotating field was applied with a microfabricated wire structure to reduce line broadening. In this experiment, ~50% suppression of the linewidth was observed and the effective time constant T2* improved from 114 ns to 227 ns. To achieve the highest possible sensitivity for micro-scale magnetic sensors the concentration of NV should be large. Since the unconverted N are magnetic impurities they shorten T2 and T2*, giving a tradeoff between NV (and therefore N) concentration and sensitivity. To construct a damage monitor, a type Ib HPHT sample was irradiated with electrons from a transmission electron microscope (TEM) and the effects on the ESR transition were seen well before physical damage appeared on the diamond and thus this proved to be a sensitive metric for irradiation damage