Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 181-190).

Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2009 / Fluid Mechanics is the study of fluids either at rest (fluids static) or in motion (fluids dynamics and kinematics) and the subsequent effects of the fluids upon the boundaries which may be either solid surfaces or interfaces with other fluids. It is worth noting that both gases and liquids are classified as fluids according to Batchelor [8]. Fluids, unlike solids, lack ability to offer sustained resistance to a deforming force. Thus, a fluid is a substance which deforms continuously under the action of shearing forces, however small they may be. Deformation is caused by shearing forces - forces that act tangentially to the surfaces to which they are applied according to Douglas et al. [23].

No description available.

Phenylephrine hydrochloride is a potent adrenergic agent and β-receptor sympathomimetic drug, used in its optically active form (Pandey et al., 2003; Pandey et al., 2006). As an α1-adrenergic receptor agonist, phenylephrine hydrochloride is used ocularly as a decongestant for uveitis and as an agent to dilate the pupil (Lang, 1995). High intraocular doses have been reported to cause tachycardia, hypertension, and headache. These side effects are caused by large amounts of the drop draining into the nasal cavity. Eye drops that contain phenylephrine hydrochloride have proven to have low intra-ocular bioavailability because of a short contact time with the eyes which reduces the amount of drug reaching the site of action. Formulations of phenylephrine hydrochloride eye drops have varying shelf-lives of approximately two to four years. The aim of this study was to formulate and manufacture an eye drop product containing phenylephrine hydrochloride. Important characteristics that were targeted were increased ocular absorption by increasing the viscosity of the product and reduced degradation of phenylephrine hydrochloride. A variety of phenylephrine hydrochloride formulations were manufactured on a laboratory scale using hydroxypropyl methylcellulose (HPMC), glycerol, and sodium carboxy methylcellulose as viscosity modifying agents (VMA). The concentration of phenylephrine hydrochloride was ten percent. Ten millimeters of each formulation was made in triplicate. The quantity in each was evaluated using a previously validated high performance (pressure) liquid chromatography method. Physicochemical properties including pH and colour were also evaluated. Stability was assessed using real time and accelerated stability conditions in accordance with the International Conference on Harmonization (ICH) guidelines. Formulations containing hydroxypropyl methylcellulose (HPMC) as the viscosity modifying agents proved to be stable under all storage conditions when compared with formulations containing other viscosity modifying agents (VMA). However, sodium citrate dihydrate; sodium metabisulphite and EDTA also stabilized the formulations to a certain extent Changes in the appearance and colour of products containing glycerol under accelerated storage conditions were observed. The sodium carboxy methylcellulose (SCMC) containing formulation was found to be physically and chemically stable in two conditions, namely 30 °C/65 percent RH and 25 °C/60 percent RH. The formulations containing hydroxypropyl methylcellulose along with an antioxidant showed to be most stable as it remained aesthetically pleasing did not change colour and did not have a reduction in phenylephrine hydrochloride concentrations. This meant that phenylephrine hydrochloride did not degrade while the viscosity modifying agents remained stable. Rheological tests showed differences in the viscosities of the formulations as glycerol had increased in viscosity over time while HMPC and SCMC displayed relative similarities. The formulations were compared to a marketed eye drop containing polyvinyl alcohol as a VMA. After rheological analysis the formulation containing HPMC displayed better viscosity than the product with polyvinyl alcohol. The preservatives in the formulations were active against the microbial organisms use to challenged them.

No description available.

No description available.

Gasification is a flexible technology which is applied in industry for electricity generation, hydrogen production, steam raising and liquid fuels production. Furthermore, it can utilize one or more feedstocks such as coal, biomass, municipal waste and petroleum coke. This versatility, in addition to being adaptable to various emissions control technologies (including carbon capture) renders it an attractive option for years to come. One of the most common gasifier types is the entrained-flow slagging gasifier. The behaviour of inorganic fuel components in these gasifiers is still ill-understood even though it can be the determining factor in their design and operation. A literature review of inorganic matter transformation sub-models for entrained-flow slagging gasifiers is provided. Slag viscosity was identified as a critical property in the sub-models. Slag viscosity models are only applicable to a limited range of slag compositions and conditions, and their performance is not easily assessed. An artificial neural network model was developed to predict slag viscosity over a broad range of temperatures and slag compositions. Furthermore, a toolbox was developed to assist slag viscosity model users in the selection of the best model for given slag compositions and conditions, and to help users determine how well the best model will perform. The slag viscosities of coal, petroleum coke and coal/petroleum coke blends were measured in the temperature range of 1175-1650ºC. Interaction of vanadium-rich slags with various materials was investigated. The results from the first two parts of a three-part research program which involves fuel characterization, testing in a 1 MWth gasifier, and computational fluid dynamics (CFD) modeling for entrained-flow slagging gasification are presented. The end goal is to develop a CFD model which includes inorganic matter transformations. Fuel properties were determined with prioritization based on their application; screening of potential fuels, ensuring proper gasifier operation, gasifier design and/or CFD modeling. Using CanmetENERGY’s 1 MWth gasifier, five gasification tests were completed with the characterized coals. Solid samples from the refractory liners, in-situ gas sampling probe sheaths and impingers, the slag tap, the slag pot, quench discharge water and scrubber water were collected and characterized.

Results of forced vibration tests in longitudinal and transverse modes on three different rocks are presented. The experimental investigation leads to evaluation of solid viscosity parameters as a function of frequency and logarithmic decrement. Linear viscoelasticity theory is applied to the test results within the frequency range studied. The test results indicate that the rheological parameter viscosity of the rocks tested, quartzite, granodiorite and an argilite, is of the order of 10⁸ to 10⁹ poises. Methods of predicting solid viscosity parameters from forced vibration resonance tests by linear viscoelastic theories are derived. The correspondence principle, which is based on the solution to steady state sinusoidal oscillation is not strictly applicable, but does yield results which are of the same order as the measured relationships. The behaviour of rocks to idealized rheological models has been examined. Measurements of the viscosity and complex moduli are described and from a consideration of the results obtained the type of mechanical model most respresentative of the behaviour of rocks is suggested. A method for predicting directional properties of rocks using photo-elastic studies for different loading conditions is examined. This enables allowances to be made for the wide variation in dynamic test results on rocks. However, it is felt that the dynamic method of determining viscosity may have more application in the examination of rock structure, since a comparison of the laboratory and field test results at the same temperature and pressure yields a method for structural design involving rocks. / Applied Science, Faculty of / Mining Engineering, Keevil Institute of / Graduate

Ice cream has been defined as » frozen dairy-product, with or without natural flavoring, containing sugar, and a specified amount of butter fat as required by the laws or regulations of the various states and the Federal government. Ordinarily ice cream consists of cream, sugar, flavoring, and some stabilizer which is usually gelatin. These are the principal ingredients, but rich cream may be thinned by the addition of skim milk, or skim-milk powder may be added, to build up the solid s-not- fat and thus improve the body. Ice cream is truly a frozen dairy-product, although other products than cream may enter into its makeup. The different ingredients that enter into an ice cream mix exist in different grades, concentrations and forms. It is desirable, therefore, in order to obtain constructive data, to follow a logical approach which would be to study first, simple isolated portions of the system m that is, the different types of dispersed phases in the dispersion medium taken singly - and then the effects of the combinations of such systems, gradually increasing the complexity.

The Reflected Quasipotential V(x) is the solution to a variational problem that arises in the study of reflective Brownian motion. Specifically, the stationary distributions of reflected Brownian motion satisfy a large deviation principle (with respect to a spatial scaling parameter) with V(x) as the rate function. The Skorokhod Problem is an essential device in the construction and analysis of reflected Brownian motion and our value function V(x). Here we characterize V(x) as a solution to a partial differential equation H(DV(x))=0 in the positive n-dimensional orthant with appropriate boundary conditions.  H(p) is the Hamiltonian and DV(x) is the gradient of V(x). V(x) is continuous but not differentiable in general. The characterization  will need to be in terms of viscosity solutions. Solutions are not unique, thus additional qualifications will be needed for uniqueness. In order to prove our uniqueness result we consider a discounted version of V(x) in a truncated region and pass to the limit. In addition to this characterization of V(x) we explore the possibility of cyclic optimal paths in 3 dimensions. / Ph. D.