Blue-Phase liquid crystal display possesses potential to become next generation display technology because of its submillisecond response time, alignment-layer-free process and wide view angle. Intrinsically, BP only operates across a narrow temperature range due to the influence of intrinsic structural defects. Recently, the temperature range of BP has been successfully extended beyond 60K through the polymer-stabilized effect. Unfortunately, the structure of the polymer networks poses a number of problems, for instance, hysteresis effect, which degrades the accuracy of grayscale control, and residual birefringence, which decreases the contrast ratio of LCDs. This paper investigates the voltage-induced hysteresis and residual birefringence in the polymer-stabilized blue phase I and II, under various phase separation conditions and material ratio. Based on experiment result, the polymer network morphology, distribution and pure BP temperature can result in a variety of PSBP electro-optical properties. Hysteresis and residual transmittance free PSBP display could be achieved by choosing appropriated phase separation condition and material ratio. Key word¡Gblue phase¡Bmonomer¡Bhysteresis¡Bresidual transmittance

¡@¡@This paper uses the unemployment rate in quarterly data from 1987 to 2011, empirical exploration whether unemployment rate of with Taiwan¡¦s frequent trading countries has a hysteresis effect, as government policy on the basis. ¡@¡@In general circumstances, there are different results by using traditional unit root tests (ADF, PP, KPSS, the DF-of GLS and NP). And the possible reasons are getting the lower power of individual series because of the small simples and without considering about the structural break results in the series with problem of type I error. Therefore, in order to solve the problem, Kyung So, Im, Junsoo Lee, and the Margie Tieslau (2010) constructed an unit root test of panel data which needs to consider the structural break of level and trend. Moreover, the correlation between the inter-individual series by using the cross-sectionally augmented (CA) method from Pesaran (2007) also needs to be considered. ¡@¡@As the results of panel data unit root tests, series of unemployment rate do not reject the null hypothesis, that is, with hysteresis effect which breaks natural unemployment rate continuously. In this case, the government must set up policies to intervene to recover the unemployment rate.

In previous studies, I learned the curing of the electro-optical effects in polymer stabilize blue phase liquid crystal under different temperature, such as the hysteresis effect, residual transmittance, drive voltage. So find out before curing blue phase temperature range is very important. Since previous studies have used methods is polarizing microscope and measuring reflectance spectra. In order to the blue phase be used in the display. If we use of Bragg reflectors in the visible blue phase liquid crystal. Resulting in the dark state is not good, the contrast reduction, so we must use the blue phase liquid crystal reflectance spectra in the non-visible light. But this liquid crystal cannot use the previously described methods to define the blue phase liquid crystal temperature range. In our experiment, we use different ways to recognized liquid crystal. We have used polarizing microscope, DSC, Kossel diagram and measuring reflectance spectra. We cannot see blue phase by polarizing microscope and Kossel diagram because the blue phase liquid crystal reflectance spectra in the non-visible light. The liquid crystal material absorbs the UV light. Our DSC resolution is not enough to found the blue phase temperature range. When we recognized liquid crystal, we found the light run through the liquid crystal box. In different phase have different lateral scattering intensity. When we cooling temperature can found the lateral scattering intensity is weak in isotropic. When we phase enter the blue phase II, the lateral scattering intensity rise slowly. When the blue phase II into the blue phase I, we can see first decreased and then increased curve. Last when into the cholesterol phase, the lateral scattering intensity rises quickly. We observe this property can discriminate the blue phase temperature range. When we found the blue phase temperature range, we analyze the hysteresis and drive voltage in different curing temperature. We found this material property. When we curing in high temperature. The drive voltage has decrease, but the hysteresis has increase. When curing in low temperature. The drive voltage has increase, but the hysteresis has decrease. Last we use SEM analyze the polymer structure. But we lost the slight polymer structure when we wash the liquid crystal. So we cannot analyze the slight polymer structure.

Flow-induced vibration of small elastic cylinders mounted in the shear flow of a two-dimensional jet is investigated experimentally. There has been a great deal of work concerned with different vibrating conditions and practical dynamic responses by way of mass ratios and diameters of various different cylinders. In such cases, the amplitude of the cylinder oscillation changed along with the variation of the jet velocity is due to the influence of fluid elastic instability. The experiment is based on the method of the magnetic field induction to measure the motion of the small cylinder, and it involves measurements of the varying velocity in a jet through the hot- wire anemometer. The critical velocity of the cylinder vibration in the shear flow with different diameters, mass ratios and damping factors are examined. Moreover, the oscillation traces of the cylinder by fluid elastic instability were observed when the jet velocity was increased, and then decreased for examination of hysteresis phenomena. The results show that the bifurcation of the cylinder vibration traces is remarkable especially for cylinders with high mass ratios. By the amplitude diagrams of the cylinder vibration, the critical velocity for onset of fluid elastic vibration was determined. The dependence of the critical velocity and hysteresis phenomena on the mass ratio and damping factor are discussed.

Battery Management System (BMS) is an essential part in battery powered applications where large battery packs are in use. BMS ensures protection, controlling, supervision and accurate state estimation of battery pack to provide efficient energy management. However the particular application determines the accuracy and requirements of BMS where it has to implement; in electric vehicles (EVs) accuracy cannot be compromised. The software part of BMS estimates the states of the battery pack and takes the best possible decision. In EVs one of the key tasks of BMS’s software part is to provide the actual state of charge (SOC), which represents a crucial parameter to be determined, especially in lithium iron phosphate (LiFePO4) batteries, due to the presence of the high hysteresis behavior in the open circuit voltage than other kind of lithium batteries. This hysteresis phenomena appears with two different voltage curves during the charging and discharging process. The value of the voltage that the battery is going to assume during the off-loading operation depends on several factors, such as temperature, loop direction and ageing. In this research work, hybrid method is implemented in which advantages of several methods are achieved by implementing one technique combined with another. In this work SOC is calculated from coulomb counting method and in order to correct the error of SOC, an hysteresis model is developed and used due to presence of hysteresis effect in LiFePO4 batteries. An hysteresis model of the open circuit voltage (OCV) for a LiFePO4 cell is developed and implemented in MATLAB/Simulink© in order to reproduce the voltage response of the battery when no current from the cell is required (no load condition). Then the difference of estimated voltage and measured voltage is taken in order to correct the error of SOC calculated from coulomb counting or current integration method. To develop the hysteresis model which can reproduce the same voltage behavior, lot of experiments have been carried out practically in order to see the hysteresis voltage response and to see that how voltage curve change with the variation of temperature, ageing and loop direction. At the end model is validated with different driving profiles at different ambient temperatures.

The Diesel Oxidation Catalyst (DOC) is a key component in the exhaust after-treatment system of diesel engines. In this study two aspects of a DOC were investigated: catalyst distribution and reactant species interactions. In the first part, the effect of an axial Pt distribution along a DOC was investigated by comparing a standard sample, with a homogeneous Pt distribution along the length, with a zoned sample, where the Pt was non-homogeneously distributed along the length. Temperature-programmed oxidation (TPO) and spatially-resolved gas-phase concentration measurement experiments were used to compare the CO, C3H6 and NO oxidation performance of the standard and zoned catalysts. Both catalyst types had the same total amount of Pt but different distributions. The zoned catalyst, with more Pt located in the upstream portion, showed better performance than the standard catalyst, especially at high total flow rate and when a mixture of the reactants were used. The superior performance of the zoned sample is due to a larger, localized exotherm in the upstream region, where more Pt is located, and a decrease in the self-poisoning effect downstream, where reaction light-off occurs. In addition, catalyst durability against thermal degradation was tested by exposing the whole catalyst (homogeneous aging) and part of the catalyst (heterogeneous aging) to high temperatures. In general, the zoned catalyst showed better performance than the standard catalyst after thermal aging, especially after heterogeneous aging. The reason for the superior performance of the zoned catalyst, especially after heterogeneous aging, is that the back of the catalyst, which is exposed to higher temperature, contains less Pt than the front; therefore, most of the Pt particles in the zoned catalyst were not affected by thermal aging. However, after homogeneous aging, the performance of the standard catalyst was better than the zoned catalyst at higher flow rate and temperature most likely due to the different sintering rates in the zoned sample compared to the standard one. In the second part of this research, the interactions between CO, C3H6, H2, and NO were tested over a commercial Pt/Al2O3 monolith sample by studying these reactions during ignition and extinction (warm-up and cool-down). Results showed that CO, C3H6, and NO inhibit their own oxidation and each other’s oxidation due to the self-poisoning effect and competitive adsorption over active sites. In the case of a CO + C3H6 mixture, interesting CO and C3H6 oxidation trends were observed during the extinction phase. As the C3H6 concentration increased in the mixture, the catalytic activity of CO oxidation during the extinction phase decreased until it was actually poorer than that during the ignition phase. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) showed different C3H6 oxidation intermediates during the extinction phase on the catalyst surface, thus blocking active sites and lowering catalyst activity.

Thesis (M.Eng. (Chemical Engineering)) -- Universiteit van Pretoria, 2006. / Includes bibliographical references.

Dissertation (Ph.D.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references.

Thesis (M.Eng.(Chemical Engineering))--University of Pretoria, 2004. / Title from opening screen (viewed March 18, 2005). Includes summary. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 141-161).