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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Protein - polysaccharide complexes at the oil/water interface

Ward-Smith, R. Stephen January 1995 (has links)
No description available.
22

A life cycle analysis and assessment of chemical emulsions

Ram Reddi, Manogaran 24 May 2011 (has links)
MSc (Eng), School of Chemical and Metallurgical Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand / This study utilises the Life Cycle Environmental Management tool, Life cycle Assessment (LCA) to compare the overall environmental impact of the life cycles of three manufactured emulsions. The emulsions - Aquapel, Hi-phase/composite (liquid/solid rosin) - fulfil a specific function as a sizing agent in the cardboard box industry within the confines of South Africa. As the origins and use of these emulsions are different, the impact assessments of each were evaluated. Using the Simapro Impact 2002+ assessment method, the mid-point impact categories show the most significant impacts in descending order to be Toxicity Impacts on terrestrial ecosystems, Respiratory Inorganics, Climate Change and Non Renewable Energy resources. It would appear that toxicity impacts on terrestrial ecosystems, is the most significant impact. Emission of respiratory inorganics followed by effluent treatment, then electricity used in the emulsion process itself has the next highest contribution in all three processes. The higher contribution to respiratory inorganics by the process using liquid rosin is due to a relatively high contribution from the production of tall oil, a relatively energy intensive process. Climate change is the third most significant contribution. Non renewable energy resources for the Aquapel process shows the highest impact because of its raw material, wax. It is also based on a non-renewable energy resource, crude-oil, whilst the raw material for the Hi-phase/composite process, rosin, is bio-based. When comparing the three emulsion processes according to the Impact 2002+ damage or end point impact categories the relative contributions of the processes shows the relatively close performance of the three processes. The liquid rosin process shows slightly higher potential damages in three out of the four damage categories. The explanation for the differences between the systems follows from the explanations given for the mid-point impact categories. The sensitivity analysis for the Aquapel emulsion process shows negative impacts are produced in descending order for liquid effluent in the ecosystem and human health damage categories. For electricity and paraffin wax negative impacts in the human health and climate change damage categories. The best interventions to reduce life cycle damages is to reduce water and electricity consumption and if possible to find a substitute for paraffin wax. For the Hi-phase/composite liquid / solid rosin emulsion process shows negative impacts are produced in descending order for liquid effluent in the ecosystem and human health / climate change and resources damage categories respectively. The electricity and steam used in both the liquid / solid process produce negative impacts in the human health and climate change damage categories. The best interventions to reduce life cycle damages for the rosin emulsion process are to reduce water, electricity and steam consumption.
23

Pharmaceutical studies of epirubicin emulsion.

January 1991 (has links)
by Kenneth Kwing-chin Lee. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1991. / Includes bibliographical references. / ACKNOWLEDGEMENT / ABSTRACT / Chapter CHAPTER I : --- INTRODUCTION AND SOME DISPOSITION PRINCIPLES --- p.1-16 / Chapter CHAPTER II: --- DETERMINATION OF EPIRUBICIN IN BIOLOGICAL FLUIDS --- p.17-26 / Chapter CHAPTER III : --- DISPOSITION OF EPIRUBICIN IN PATIENTS WITH HEPATIC CARCINOMA --- p.27-44 / Chapter CHAPTER IV : --- DESIGN OF THE EMULSION FOR INJECTION --- p.45-85 / Chapter CHAPTER V : --- STUDIES ON THE ACUTE TOXICITY OF THE FORMULATED EMULSION --- p.86-113 / Chapter CHAPTER VI : --- PHARMACOKINETIC STUDIES OF THE FORMULATED EMULSION IN RABBITS --- p.114-123 / REFERENCES --- p.124-130 / APPENDICES
24

Formation and study of particle-stabilized high internal phase emulsions.

January 2011 (has links)
Sun, Guanqing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references. / Abstracts in English and Chinese. / 摘要 --- p.I / ABSTRACT --- p.III / TABLE OF CONTENTS --- p.V / ACKNOWLEDGEMENT --- p.VIII / CHAPTER 1 --- p.1 / Chapter 1.1 --- Definition of Emulsions --- p.1 / Chapter 1.2 --- Emulsion Instability --- p.3 / Chapter 1.3 --- Stabilization of Emulsions by Surfactants --- p.6 / Chapter 1.4 --- Types of Emulsions --- p.8 / Chapter 1.5. --- Particle-Stabilized Emulsions (Pickering Emulsions) --- p.10 / Chapter 1.5.1 --- The Adhesion of Colloidal Nanoparticles at an Interface --- p.10 / Chapter 1.5.2 --- An Overview of Particle-Stabilized Emulsions --- p.13 / Chapter 1.5.3 --- Particle-Stabilized HIPEs --- p.16 / Chapter 1.6 --- Objective of the research --- p.17 / Chapter 1.7 --- References --- p.18 / CHAPTER 2 --- p.21 / Chapter 2.1 --- Introduction to Particle-Stabilized HIPEs --- p.21 / Chapter 2.2 --- Experimental Part --- p.22 / Chapter 2.2.1 --- Materials --- p.22 / Chapter 2.2.2 --- Polystyrene-co-PMAA Particle Synthesis and Characterization --- p.23 / Chapter 2.2.3 --- Particle-Stabilized Emulsion Preparation and Characterization --- p.26 / Chapter 2.3 --- Results and Discussion --- p.27 / Chapter 2.3.1 --- pH-Triggered Inversion --- p.27 / Chapter 2.3.2 --- Salt-Triggered Inversion --- p.31 / Chapter 2.3.3 --- Phase Diagram and Rhcological Properties --- p.34 / Chapter 2.4 --- Conclusions --- p.38 / Chapter 2.5 --- References --- p.38 / CHAPTER 3 --- p.40 / Chapter 3.1 --- Introduction --- p.40 / Chapter 3.2 --- Experiments and Discussion --- p.42 / Chapter 3.2.1 --- Materials --- p.42 / Chapter 3.2.2. --- PS-co-AEMH Particles Synthesis and Characterization --- p.42 / Chapter 3.3.3 --- Particle-Stabilized Emulsion Formation --- p.45 / Chapter 3.3 --- Conclusions --- p.45 / Chapter 3.4 --- References --- p.46 / FUTURE PERSPECTIVES --- p.47 / PUBLICATION --- p.48
25

A PDMS-glass capillary-teflon tube composite device and its application for emulsion formation.

January 2008 (has links)
Tang, Xiaoju. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 45-50). / Abstracts in English and Chinese. / Abstract --- p.1 / 摘要 --- p.iii / Acknowledgement --- p.iii / Table of Contents --- p.iv / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Introduction to microfluidics --- p.1 / Chapter 1.2 --- Aqueous two phase system (ATPS) --- p.4 / Chapter 1.3 --- Emulsion --- p.7 / Chapter 1.4 --- Objective of the research --- p.9 / Chapter 2. --- Two-Phase Emulsion --- p.10 / Chapter 2.1 --- Emulsions in microfluidic channels --- p.10 / Chapter 2.2 --- Fabrication of the microfluidic device --- p.12 / Chapter 2.3 --- Generation of water-in-oil emulsion --- p.15 / Chapter 2.3.1 --- Generation of water-in-oil emulsion --- p.15 / Chapter 2.3.2 --- Formation conditions of water in oil emulsions.........................................................: --- p.16 / Chapter 2.4 --- Generation of emulsion with aqueous two phase system --- p.22 / Chapter 2.4.1 --- Introduction and application of emulsions of ATPS --- p.22 / Chapter 2.4.2 --- Generation of emulsion with aqueous two phase system --- p.23 / Chapter 2.4.3 --- Forming conditions of ATPS emulsions --- p.24 / Chapter 2.5 --- Generation of emulsions with flow focusing device --- p.30 / Chapter 2.5.1 --- Fabrication of the flow-focusing device --- p.30 / Chapter 2.5.2 --- Generation of emulsions --- p.31 / Chapter 2.5.3 --- Results and discussion --- p.32 / Chapter 2.6 --- Conclusion --- p.34 / Chapter 2.6.1 --- Generation of emulsions with coaxial device --- p.34 / Chapter 2.6.2 --- Generation of emulsions with flow focusing device --- p.34 / Chapter 3. --- Double Emulsion --- p.35 / Chapter 3.1 --- Double emulsion in microfluidic channels --- p.35 / Chapter 3.2 --- Fabrication of the microfluidic device --- p.36 / Chapter 3.3 --- Generation of double emulsion --- p.36 / Chapter 3.4 --- Results and discussion --- p.37 / Chapter 3.5 --- Conclusion --- p.42 / Chapter 4. --- Conclusion --- p.43 / Chapter 4.1 --- Microfluidic device --- p.43 / Chapter 4.2 --- Two phase emulsion --- p.43 / Chapter 4.3 --- Double emulsion --- p.44 / Reference --- p.45
26

Preparation and physico-chemical characterisation of microemulsion-based nanoparticles

Graf, Anja, n/a January 2008 (has links)
Purpose: The purpose of this study was to investigate possible effects of different microemulsion structure-types and types of monomer used on the formation of poly(alkylcyanoacrylate) nanoparticles, the entrapment into and release of insulin from these formulations as well as the bioactivity of the insulin upon intragastric delivery of the insulin-loaded nanoparticles dispersed in the microemulsion template. Methods: For two different microemulsion systems consisting of water, isopropyl myristate and either sugar-based surfactants or a macrogol glyceride-based surfactant-mixture, pseudo-ternary phase diagrams were established. Microemulsion samples therein were identified and characterised with polarising light microscopy, viscosity and conductivity measurements, differential scanning calorimetry, cryo-field emission scanning electron microscopy and self-diffusion nuclear magnetic resonance to determine the microemulsion structure-type. Nanoparticles were prepared from various microemulsion templates by interfacial polymerisation using ethyl (2) cyanoacrylate and butyl (2) cyanoacrylate. Particle size distribution and surface charge were measured using photon correlation spectroscopy and electrophoretic mobility. The morphology of the particles was characterised by scanning and transmission electron microscopy. Insulin was used as a model protein and the amount entrapped into and released from the particles was determined using a reverse phase HPLC assay. A diabetic rat model was employed to examine the bioactivity of different nanoparticle-microemulsion formulations with blood glucose and serum insulin as parameters measured by a proprietary glucometer and enzyme-linked immunosorbent assays, respectively. Results: The microemulsion system based on sugar-surfactants only formed solution-type microemulsions which could not all satisfactorily be used as a polymerisation template in the presence of insulin. The system however also showed an environmentally responsive gelling behaviour which may be suitable for depot delivery. The macrogol glyceride-based microemulsion system resulted in microemulsions with a continuous transition from water-in-oil to oil-in-water droplet-types via the bicontinuous structure-type. Microemulsion samples of each structure-type could serve as nanoparticle templates and resulted in particles with similar properties. Entrapment efficiency of insulin into the nanoparticles was template and monomer dependent. However, insulin was found to interfere with the polymerisation leading to a high variability in entrapment and release kinetics of these drug delivery systems. The degree of interference depended on the type of monomer and the size of the aqueous pseudo-phase of the microemulsion template. The interpretation of the results was further complicated by a possible competitive polymerisation initiation of insulin with the surfactant-mixture. Upon intragastric administration of the insulin-loaded nanoparticles dispersed in the oil-in-water microemulsion template a significant reduction in blood glucose could be achieved for up to 30 hours. However, no significant serum insulin concentration was detectable. Conclusions: Structurally different microemulsion templates resulting in nanoparticles with similar properties may offer increased formulation flexibility, in that a microemulsion template can be chosen which best solubilises the drug. Thus the microemulsions investigated in this thesis may serve as nanoparticle templates for designing entrapment processes for peptides and proteins with a simple one-step preparation by interfacial polymerisation. However, only if one was able to optimise and control the factors leading to the high entrapment and release variability these nanoparticles on the basis of microemulsions might be promising carriers for the oral delivery of peptide and protein bioactives.
27

Making and breaking of water in crude oil emulsions

Mehta, Shweta D. 12 April 2006 (has links)
An understanding of the processes involved in oil spills, and how they interact to alter the composition and behavior of the oil with respect to time is essential to determine an effective oil spill response. The review of past research has shown more focus on the laboratory methods and computerized modeling schemes to estimate the formation and breaking of emulsions after an oil spill. However, relatively less effort has gone into the study of emulsions corresponding to actual field conditions. This research aims to simulate an oil spill at sea by developing a new technique to make water in oil emulsions, without disturbing the marine wildlife. Further, this research also attempts to analyze the viscosities of water in oil emulsions and determine appropriate emulsion breakers for different crude oil emulsions. The overall test design for the study includes a test apparatus for spreading and evaporation, three different crude oils, a mixing chamber to form the emulsion, and emulsion breakers. Experiments in this research attempt to gain a better understanding of the processes that occur after oil spills at sea. In particular, the rate of evaporation of different crude oils and the formation of crude oil emulsions on the sea surface have been investigated. It was observed that different crude oils behave differently when subjected to the same weathering procedure. Results indicate that the behavior of the crude oil on the sea surface, subjected to spreading, evaporation, and emulsification, can be predicted by using the new technique developed in this research. This technique can also assist the development of effective recovery equipments and materials.
28

Making and breaking of water in crude oil emulsions

Mehta, Shweta D. 12 April 2006 (has links)
An understanding of the processes involved in oil spills, and how they interact to alter the composition and behavior of the oil with respect to time is essential to determine an effective oil spill response. The review of past research has shown more focus on the laboratory methods and computerized modeling schemes to estimate the formation and breaking of emulsions after an oil spill. However, relatively less effort has gone into the study of emulsions corresponding to actual field conditions. This research aims to simulate an oil spill at sea by developing a new technique to make water in oil emulsions, without disturbing the marine wildlife. Further, this research also attempts to analyze the viscosities of water in oil emulsions and determine appropriate emulsion breakers for different crude oil emulsions. The overall test design for the study includes a test apparatus for spreading and evaporation, three different crude oils, a mixing chamber to form the emulsion, and emulsion breakers. Experiments in this research attempt to gain a better understanding of the processes that occur after oil spills at sea. In particular, the rate of evaporation of different crude oils and the formation of crude oil emulsions on the sea surface have been investigated. It was observed that different crude oils behave differently when subjected to the same weathering procedure. Results indicate that the behavior of the crude oil on the sea surface, subjected to spreading, evaporation, and emulsification, can be predicted by using the new technique developed in this research. This technique can also assist the development of effective recovery equipments and materials.
29

Study on Lubrication Film of Emulsion Using Laser Measurement Method

Chen, Yen-an 08 September 2008 (has links)
Abstract Since emulsions combine good lubricating and cooling capabilities, they have been widely used in metal rolling and cutting. This study first uses AR2000 rheometer to measure viscosity of emulsions under atmospheric pressure. The results of the test show that the viscosity of emulsions is approximately the highest in the 80% oil volume fraction. Meanwhile, the viscosity drops along with increasing the shear rate, it proves that emulsions are a pseudoplastic fluid. This study uses an EHL squeeze tester to explore the effects of squeeze velocity, load and volume fraction concentration of oil phase of emulsions on the dimple film thickness in the contact conjunction of squeezing lubrication. Results show that the dimple becomes deeper with increasing squeeze velocity. When the load increases, the dimple can keep longer due to higher hertz pressure. Furthermore, emulsions which have the higher oil volume fraction, have the higher maximum dimple depth under the same load and squeeze velocity. The results are different that the viscosity of 80% emulsions is higher than crude oil under atmospheric pressure. It is because that the significantly effect of pressure on the viscosity of oil phase, and the surface viscosity between oil and water phases can be ignored. Keywords: emulsions, EHL, dimple
30

Dynamic behavior characterization of fine powders consisting of a homogeneous emulsion & Synthesis and decomposition of methane gas hydrate : a reaction engineering study /

Narasimhan, Sridhar. January 2000 (has links)
Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains xiii, 111 p. : ill. Includes abstract. Includes bibliographical references.

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