The next generation of nuclear safety analysis computer codes will require detailed modeling of two-phase fluid flow. The most complete and fundamental model used for these calculations is known as the two-fluid model. It is the most accurate of the two-phase models since it considers each phase independently and links the two phases together with six conservation equations. A major drawback is that the current two-fluid model, when area-averaged to create a one-dimensional model, becomes ill-posed as an initial value problem when the gas and liquid velocities are not equal. The importance of this research lies in obtaining a model that overcomes this difficulty. It is desired to develop a modified one-dimensional two-fluid model for horizontal flow that accounts for the pressure difference between the two phases, due to hydrostatic head, with the implementation of a void fraction distribution parameter. With proper improvement of the one-dimensional two-fluid model, the next generation of nuclear safety analysis computer codes will be able to predict, with greater precision, the key safety parameters of an accident scenario. As part of this research, an improved version of the one-dimensional two-fluid model for horizontal flows was developed. The model was developed from a theoretical point of view with the three original distribution parameters simplified down to a single parameter. The model was found to greatly enhance the numerical stability (hyperbolicity) of the solution method. With proper modeling of the phase distribution parameter, a wide range of flow regimes can be modeled. This parameter could also be used in the future to eliminate the more subjective flow regime maps that are currently implemented in today's multiphase computer codes. By incorporating the distribution parameter and eliminating the flow regime maps, a hyperbolic model is formed with smooth transitions between various flow regimes, eliminating the unphysical oscillations that may occur near transition boundaries in today's multiphase computer codes. / Graduation date:2006

Thesis (M.S.)--Rochester Institute of Technology, 2007. / Typescript. Includes bibliographical references (leaves 66-68).

In this thesis, we are interested in empirical likelihood (EL) methods for two-sample problems, with focus on the difference of the two population means. A weighted empirical likelihood method (WEL) for two-sample problems is developed. We also consider a scenario where sample data on auxiliary variables are fully observed for both samples but values of the response variable are subject to missingness. We develop an adjusted empirical likelihood method for inference of the difference of the two population means for this scenario where missing values are handled by a regression imputation method. Bootstrap calibration for WEL is also developed. Simulation studies are conducted to evaluate the performance of naive EL, WEL and WEL with bootstrap calibration (BWEL) with comparison to the usual two-sample t-test in terms of power of the tests and coverage accuracies. Simulation for the adjusted EL for the linear regression model with missing data is also conducted.

Tumor Susceptibility Gene, TSG101, has been identified as a tumor susceptibility gene with multiple functions. TSG101 encodes a 46 kDa protein composed of 390 amino acids. As previous studies reported, TSG101 participates in cell-cycle control, membrane proteins¡¦ trafficking, and transcriptional regulation. To identify the proteins that mediated function involved TSG101, we perform yeast two-hybrid cDNA library screening to search for TSG101-interacting proteins. A construct pAS2-1-TSG101 was used as a bait to screen a human testis cDNA library. This screening selected 68 TSG101 interacting clones, including 17 known proteins. These proteins were functionally classified as participating in cell-cycle alteration, protein sorting, transcriptional regulation, modification, signal transduction and other functions. Our results provide the evidences which not only confirm the results of previous studies, but also provide further information related to TSG101 biological functions worth intensive study. Among these clones, we choose KLIP1 gene, which encodes a transcription factor, for further study to elucidate the functional role of TSG101 in nucleus. In vitro GST pull-down assay and in vivo co-immunoprecipitation assay were performed using GST-KLIP1 and HA-tagged KLIP1, respectively, have demonstrated that TSG101 and KLIP1 indeed interact with each other within mammalian cells. Detailed biological function mediated through this TSG101 and KLIP1 interaction awaits further investigation.

THESIS ABSTRACT The bulk of Internet Service Providers adopt two-part tariff. Two-part tariff means users should pay a fixed rental every month, and pay a varied fee base on their connecting hours. Internet Service Provider group their customers by analyzing customer¡¦s demand level, and provides different group different Pay-Rating. We call this situation Multiple Pay-Rating. If Internet Service Provider provide their customers single Pay-Rating. We call this situation Single Pay-Rating. People always analyze two-part tariff in monopoly market. In this thesis I will analyze two-part tariff in oligopoly market.Then compare with the former, and we will know whether two-part tariff erode customer¡¦s welfare. I will create a differentiate-product demand function base on Logit model, and build two-part tariff oligopoly competition model. Analyze the equilibrium in Single Pay-rating and in Multiple Pay-rating. And I drew several conclusions from the analysis. 1. In oligopoly market structure two-part tariff not necessarily deprive of customer¡¦s welfare. On the contrary if ISP group their customers, customer¡¦s welfare will improve. 2. If there are no differentiation between customers¡¦ utilities, nonlinear pricing will degraded to linear pricing. If customers¡¦ utilities are different, ISP will set up the unit connect fee equal to the unit cost, and the month rental will raised with the increasing differentiation between customers¡¦ utilities. 3. If Internet service provider group their customer and provide them different Pay-rating, the final equilibrium will be symmetrical equilibrium or non-symmetrical equilibrium.

Thesis (Ph. D.)--Washington State University, May 2009. / Title from PDF title page (viewed on Feb. 12. day, 2010). "Department of Physics and Astronomy." Includes bibliographical references (p. 186-199).

Not available / text

In this thesis, we are interested in empirical likelihood (EL) methods for two-sample problems, with focus on the difference of the two population means. A weighted empirical likelihood method (WEL) for two-sample problems is developed. We also consider a scenario where sample data on auxiliary variables are fully observed for both samples but values of the response variable are subject to missingness. We develop an adjusted empirical likelihood method for inference of the difference of the two population means for this scenario where missing values are handled by a regression imputation method. Bootstrap calibration for WEL is also developed. Simulation studies are conducted to evaluate the performance of naive EL, WEL and WEL with bootstrap calibration (BWEL) with comparison to the usual two-sample t-test in terms of power of the tests and coverage accuracies. Simulation for the adjusted EL for the linear regression model with missing data is also conducted.

DNA photocleaving reagents are a unique class of molecules that display the ability to cleave DNA, causing strand breaks, upon exposure to an irradiation source. In terms of biological applications, achieving excitation through a two-photon absorption event provides for unique benefits that can be useful in such applications as photodynamic therapy and cell viability studies. Thus, this thesis pertains to the study of a class of photocleaving reagents that have been shown to become excited through a twophoton process during irradiation with a pulsed femtosecond laser at 775 nm. N-(Alkoxy)pyridinethiones were selected as possible oxygen-based radical generators upon irradiation at two-photon wavelengths. Experiments were carried out with pBR 322 plasmid DNA to determine if these N-(alkoxy)pyridinethiones could cause strand cleavage and if so how efficient they are in doing so. Several compounds were found to be effective DNA strand cleavers when irradiated at two-photon wavelengths, displaying the utility of two-photon excitation in biological studies. Rationale is suggested for the observed variation in cleaving efficiency based on inherent properties of the generated radicals. A second study was done to measure the two-photon cross section of the compound N-(anthracenoyloxy)pyridinethione. The two-photon cross section was found by measuring the fraction of substrate remaining after specific periods of femtosecond laser irradiation at 775 nm, and the two-photon cross section was found to be 0.051 GM.

An innovative two-stroke engine has been under development at Queen’s University. Traditional crankcase-scavenged two-stroke engines have laboured to meet emissions standards and achieve fuel economy comparable to four-stroke engines. The engine in question makes use of a modified Eaton-type supercharger to enable air-only scavenging, with this it utilizes direct fuel injection which occurs after the exhaust ports have closed, these two elements combine to eliminate the combustion of lubricating oil in the cylinder and short-circuiting of the fuel-air mixture into the exhaust. By having passive check valves in the cylinder head to regulate the inflow of scavenging air, and exhaust ports located near bottom centre this results in a top-down uniflow-scavenged configuration, as well as retaining a simplistic engine design. In the two-stroke cycle, using the intake charge to replace the combustion products with fresh air during scavenging is critical to engine performance. In this engine the scavenging charge is produced by a set of passive intake check valves, and because of this the scavenging timing is important. These valves are important because they govern the volume of combustion products that are forced out of the cylinder during scavenging, and hence the efficiency of combustion in the engine. To evaluate the engine design criteria, a validated computational fluid dynamic (CFD) model was used to offer insight into how the in-cylinder flow developed during scavenging. The CFD model of this engine was used to test different check-valve geometries to see how they affect the scavenging flow in the cylinder. The goal of this is to assist in entraining more of the combustion products which would result in more being exhausted from the cylinder. A more favourable design was found, and a design produced to be taken onto the next step of testing. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2010-07-12 17:09:58.81