Aims : Patients with mild heart failure (HF) who are clinically compensated may have normal left ventricular (LV) stroke volume (SV). Despite this, altered intra-ventricular flow patterns have been recognized in these subjects. We hypothesized that, compared with normal LVs, flow in myopathic LVs would demonstrate a smaller proportion of inflow volume passing directly to ejection and diminished the end-diastolic preservation of the inflow kinetic energy (KE). Methods and results : In 10 patients with dilated cardiomyopathy (DCM) (49 ± 14 years, six females) and 10 healthy subjects (44 ± 17 years, four females), four-dimensional MRI velocity and morphological data were acquired. A previously validated method was used to separate the LV end-diastolic volume (EDV) into four flow components based on the blood's locations at the beginning and end of the cardiac cycle. KE was calculated over the cardiac cycle for each component. The EDV was larger (P = 0.021) and the ejection fraction smaller (P < 0.001) in DCM compared with healthy subjects; the SV was equivalent (DCM: 77 ± 19, healthy: 79 ± 16 mL). The proportion of the total LV inflow that passed directly to ejection was smaller in DCM (P = 0.000), but the end-diastolic KE/mL of the direct flow was not different in the two groups (NS). Conclusion : Despite equivalent LVSVs, HF patients with mild LV remodelling demonstrate altered diastolic flow routes through the LV and impaired preservation of inflow KE at pre-systole compared with healthy subjects. These unique flow-specific changes in the flow route and energetics are detectable despite clinical compensation, and may prove useful as subclinical markers of LV dysfunction.

The Pressure-Volume-Temperature (PVT) for polymer/gas solutions is an important fundamental property of which accurate data measurement has not been reported until recently. The diffusivity, solubility, and surface tension are critical physical properties of polymer/gas solutions in understanding and controlling polymer processing such as, foaming, blending, and extracting reaction. However, the determination of these properties relies on accurate PVT data as a prerequisite. Due to the difficulties involved in measuring the specific volume while maintaining a sufficiently high pressure and temperature to achieve a single-phase polymer/gas solution, accurate PVT data or volume swelling measurement of polymer/gas solutions is not yet available. In this research, a new methodology was proposed and developed for direct measuring the PVT properties of polymer melts saturated with high-pressure gas at elevated temperatures. The ultimate goal is to develop and construct an apparatus that would provide more accurate fundamental properties through PVT measurement to the foaming industry, which is heavily involved with polymer/gas mixtures.

This thesis is concerned with the modeling of the stator of a piezoelectric traveling wave rotary ultrasonic motor. Existing models for piezoelectric traveling wave rotary ultrasonic motors are either too complicated to be used in motor control or do not reflect the real behavior of the motor and are of limited use in developing a controller for the motor. Finite Element methods have been used in the past to examine the properties of piezoelectric structures however, the Finite Volume Method has always been ruled out without justification. The main goal of this thesis is to provide a Finite Volume modeling approach for the stator of the piezoelectric traveling wave rotary ultrasonic motor taking into account the basic theoretical principles from piezoelectricity and structural mechanics. This model can in future be extended to develop a complete model of the motor in addition to other piezoelectric structures. The Finite Volume Method is shown to have the following specific advantages over the Finite Element Method especially for structures with simple geometries: 1. the Finite Volume Method respects the PDEs conservation law structure due to the fact that the fluxes are conserved between cells/domains/subregions, 2. the Finite Volume Method involves only surface integrals thus making it easier to implement a rotor-stator contact model as the contact mechanism occurs at the boundary of the stator, and 3. the Finite Volume Method yields a system of ODEs that more intuitively map onto circuit simulation software. The Finite Volume Method is initially used to model a simple piezoelectric plate. A corresponding circuit of the piezoelectric plate model, based on the Finite Volume Method, is generated. Two additional but more complex models are considered: one for a unimorph plate and one for the stator of an ultrasonic motor. The modeling results obtained with the Finite Volume Method are validated by comparing them with the results obtained with Finite Element simulations performed with COMSOL. Two test platforms designed to test and validate the Finite Volume and COMSOL results for the simple piezoelectric plates and piezoelectric traveling wave rotary ultrasonic motors are also presented in this thesis.

A computational fluid dynamics model has been developed to study an oil-coated particle immersed in a uniform aqueous flow, to determine the conditions that favour oil separation. The governing flow equations are discretized using a finite volume approach, and the oil/water interface is captured using the Volume-of-Fluid (VOF) method in a 2D spherical coordinate system. The model predicts different mechanisms for oil separation. At a Reynolds number, Re, equal to 1, and at a low capillary number, Ca << 1, the high interfacial tension can induce rapid contact line motion, to the extent that the oil film can advance past its equilibrium position and separate from the particle. This mechanism requires that the contact angle measured through the oil phase is large. On the other hand, as Ca approaches 1, the shear exerted by the external flow stretches the oil into a thread that will eventually rupture and separate.

A computational fluid dynamics model has been developed to study an oil-coated particle immersed in a uniform aqueous flow, to determine the conditions that favour oil separation. The governing flow equations are discretized using a finite volume approach, and the oil/water interface is captured using the Volume-of-Fluid (VOF) method in a 2D spherical coordinate system. The model predicts different mechanisms for oil separation. At a Reynolds number, Re, equal to 1, and at a low capillary number, Ca << 1, the high interfacial tension can induce rapid contact line motion, to the extent that the oil film can advance past its equilibrium position and separate from the particle. This mechanism requires that the contact angle measured through the oil phase is large. On the other hand, as Ca approaches 1, the shear exerted by the external flow stretches the oil into a thread that will eventually rupture and separate.

The main objective of this study was to investigate if natural honey can be used as a cryoprotecting agent (CP) in vitrification medium to improve the viability of vitrified-warmed bovine oocytes. The first study was conducted to investigate the dehydration capability of natural honey compared with sucrose, and to determine the proper concentration of honey-based medium and the optimum time for sufficiently safe dehydration of bovine oocytes. Matured cumulus-oocyte complexs (COCs) were denuded and introduced individually into different concentrations (0.25, 0.5, 1.0, 1.5 or 2.0 M) of honey and sucrose-based medium followed by rehydration in control media (TCM). Video images were recorded during dehydration and rehydration, and oocyte images were captured at 12 time intervals to calculate oocyte-volume changes during dehydration and rehydration. Results demonstrated that, in honey-based media, the maximum oocyte shrinkage was achieved after 60 sec exposure in 0.25M, 0.5M and 1.0M concentrations; while at higher concentrations 1.5M and 2.0M, the maximum dehydration occurred at 30 and 20 seconds respectively. In sucrose-based medium, the maximum oocyte shrinkage was achieved after 60 sec exposure in 0.25 or 0.5M concentrations. However, at higher concentrations (1M, 1.5M or 2M), the maximum dehydration occurred at 30, 20 and 10 sec. For rehydration, oocytes dehydrated in honey or sucrose-based medium were able to regain their original volume within 60-120 sec. However, oocytes dehydrated in higher concentrations (2M honey, and 1.5M and 2M sucrose) were rehydrated back to their original volume within 20 sec. This study concluded that natural honey and sucrose caused similar cell dehydration. Only oocytes dehydrated in 1M honey-based media reached maximal dehydration after 60 sec and equally regained original volume. Therefore, 1M of honey-based medium is suggested for sufficient and safe oocyte dehydration during vitrification. The second study was conducted to determine in vitro maturation (IVM), in vitro fertilization (IVF) and embryonic development of bovine oocytes vitrified in honey-based vitrifcation media. In Experiment 1, bovine COCs were randomly distributed in control group (non-vitrified; G1), 0.5M sucrose group (second control; G2), and 0.5M, 1M and 1.5M honey groups (G3, G4 and G5 respectively). The COCs were exposed to equilibration solution 1 (VS1) at ~ 22 oC for 5 min and to vitrification solution 2 (VS2) for 1 min, mounted on Cryotops and plunged into LN2. COCs were warmed in TCM and honey/sucrose medium at 38.5oC for 1 min, washed, matured in vitro (IVM), denuded, and immunostained to evaluate maturation. Maturation rate was significantly higher (80.7%) in control group (G1) than in vitrified groups (56, 52, 55 and 51% in G2, G3, G4 and G5, respectively) (P<.0001), whereas there was no significant difference among the vitrified groups (P>0.05). In Experiment 2, bovine COCs distributed in control (not vitrified, G1) and vitrified groups using 1M honey and 0.5M sucrose (G2 and G3 respectively), underwent for IVM, IVF and in vitro culture (IVC) for 9 days. Cleavage rate was significantly higher (P<.0001) in the control group (74%, G1, n=183) than rates of vitrified groups (51% in G2, n=137; and 42% in G3, n=131), whereas no differences among vitrified groups (P=0.0723). Rate of blastocyst formation was significantly higher (34%) in G1 than in the vitrified groups (P<.0001); however, blastocyst formation rates in the honey group were significantly higher (P=0.0026) than in the sucrose group (13% and 3% respectively). Addition of natural honey (1.0M; or 21.7%w/v) in vitrification medium can safely and sufficiently dehydrate bovine oocytes during vitrification procedure. The vitrification of bovine oocytes in 1M honey improved their post-warming maturation abtility and embryonic development.

For effective reservoir management and production optimization, it is important to understand drained volumes, pressure depletion and reservoir well rates at all flow times. For conventional reservoirs, this behavior is based on the concepts of reservoir pressure and energy and convective flow. But, with the development of unconventional reservoirs, there is increased focus on the unsteady state transient flow behavior. For analyzing such flow behaviors, well test analysis concepts are commonly applied, based on the analytical solutions of the diffusivity equation. In this thesis, we have proposed a novel methodology for estimating the drainage volumes and utilizing it to obtain the pressure and flux at any location in the reservoir. The result is a semi-analytic calculation only, with close to the simplicity of an analytic approach, but with significantly more generality. The approach is significantly faster than a conventional finite difference solution, although with some simplifying assumptions. The proposed solution is generalized to handle heterogeneous reservoirs, complex well geometries and bounded and semi-bounded reservoirs. Therefore, this approach is particularly beneficial for unconventional reservoir development with multiple transverse fractured horizontal wells, where limited analytical solutions are available. To estimate the drainage volume, we have applied an asymptotic solution to the diffusivity equation and determined the diffusive time of flight distribution. For the pressure solution, a geometric approximation has been applied within the drainage volume to reduce the full solution of the diffusivity equation to a system of decoupled ordinary differential equations. Besides, this asymptotic expression can also be extended to obtain the well rates, producing under constant bottomhole pressure constraint. In this thesis, we have described the detailed methodology and its validation through various case studies. We have also studied the limits of validity of the approximation to better understand the general applicability. We expect that this approach will enable the inversion of field performance data for improved well and/or fracture characterization, and similarly, the optimization of well trajectories and fracture design, in an analogous manner to how rapid but approximate streamline techniques have been used for improved conventional reservoir management.

The Pressure-Volume-Temperature (PVT) for polymer/gas solutions is an important fundamental property of which accurate data measurement has not been reported until recently. The diffusivity, solubility, and surface tension are critical physical properties of polymer/gas solutions in understanding and controlling polymer processing such as, foaming, blending, and extracting reaction. However, the determination of these properties relies on accurate PVT data as a prerequisite. Due to the difficulties involved in measuring the specific volume while maintaining a sufficiently high pressure and temperature to achieve a single-phase polymer/gas solution, accurate PVT data or volume swelling measurement of polymer/gas solutions is not yet available. In this research, a new methodology was proposed and developed for direct measuring the PVT properties of polymer melts saturated with high-pressure gas at elevated temperatures. The ultimate goal is to develop and construct an apparatus that would provide more accurate fundamental properties through PVT measurement to the foaming industry, which is heavily involved with polymer/gas mixtures.

This thesis is concerned with the modeling of the stator of a piezoelectric traveling wave rotary ultrasonic motor. Existing models for piezoelectric traveling wave rotary ultrasonic motors are either too complicated to be used in motor control or do not reflect the real behavior of the motor and are of limited use in developing a controller for the motor. Finite Element methods have been used in the past to examine the properties of piezoelectric structures however, the Finite Volume Method has always been ruled out without justification. The main goal of this thesis is to provide a Finite Volume modeling approach for the stator of the piezoelectric traveling wave rotary ultrasonic motor taking into account the basic theoretical principles from piezoelectricity and structural mechanics. This model can in future be extended to develop a complete model of the motor in addition to other piezoelectric structures. The Finite Volume Method is shown to have the following specific advantages over the Finite Element Method especially for structures with simple geometries: 1. the Finite Volume Method respects the PDEs conservation law structure due to the fact that the fluxes are conserved between cells/domains/subregions, 2. the Finite Volume Method involves only surface integrals thus making it easier to implement a rotor-stator contact model as the contact mechanism occurs at the boundary of the stator, and 3. the Finite Volume Method yields a system of ODEs that more intuitively map onto circuit simulation software. The Finite Volume Method is initially used to model a simple piezoelectric plate. A corresponding circuit of the piezoelectric plate model, based on the Finite Volume Method, is generated. Two additional but more complex models are considered: one for a unimorph plate and one for the stator of an ultrasonic motor. The modeling results obtained with the Finite Volume Method are validated by comparing them with the results obtained with Finite Element simulations performed with COMSOL. Two test platforms designed to test and validate the Finite Volume and COMSOL results for the simple piezoelectric plates and piezoelectric traveling wave rotary ultrasonic motors are also presented in this thesis.

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