The effect of internal combustion engine operation upon the viscometric properties of polymer thickened multi-viscosity crankcase oils

The effects of engine mileage upon the viscometric properties of seven different brands of multi-viscosity engine oils were examined by subjecting each brand of oil to an average of 1500 miles of service in the crankcases of different passenger cars. Oil samples were taken every 500 miles after the oil was put in the crankcase. The control oil sample was taken from a can of oil at the time the oil was put in the engine. The viscosity indices and kinematic viscosities at 100° F and 210° F were calculated for each sample of oil. The percent change in viscosity index and kinematic viscosity for each sample of each brand was calculated relative to the control\u27s viscosity index and kinematic viscosity. The viscosity index and kinematic viscosities of each brand\u27s samples were plotted as a function of mileage. All of the oils showed a decrease in kinematic viscosity at 210°F. Some of the oils showed a decrease in kinematic viscosity at 0°F. The viscosity index change varied from sample to sample of the same brand. The viscosity index increased for some brands and decreased for others. Six out of seven oils no longer qualified as the original SAE rating of the oil

IDENTIFICATION, DESIGN AND SYNTHESIS OF OXYGENATED HYDROCARBON-BASED CO2-SOLUBLE POLYMERS FOR CHEMICAL AND PETROLEUM ENGINEERING APPLICATIONS

Over the past two decades the use of near-/super-critical carbon dioxide has received much attention as a green alternative to organic solvents for chemical reactions, separations, and extractions because of its pressure-tunable physicochemical properties and economic advantages. However the advantages are diminished because of a relative narrow range of CO2-soluble materials. The goal of this work is to identify, design and synthesize oxygenated hydrocarbon-based CO2-soluble polymers that are able to serve as construction blocks for copolymers, dispersants, surfactants, thickeners, and chelating agents. Without concerning on the cost and the environmental persistence like fluorinated materials, the inexpensive, environmentally benign materials would significantly enhance the viability of near-/super-critical carbon dioxide-based technology. Based on both experimental heuristics and ab initio simulation results of molecular modeling (performed by Dr. Johnson's group), we proposed specific new polymer structures: poly(3-acetoxy oxetane) (PAO), poly(vinyl methoxymethyl ether) (PVMME), poly(vinyl 1-methoxyethyl ether) (PVMEE), and cellulose triacetate (CTA) oligomers. Phase behavior studies were also performed with novel CO2-philic compounds containing vinyl acetate, propylene glycol, or multiple tert-butyl groups. PAO, PVMME and PVMME were soluble in CO2, but not as soluble as poly(vinyl acetate). Oligomers of cellulose triacetate with as many as four repeat units solubilized into dense CO2 less than 14 MPa in the concentration range of 1-5 wt%. Phase behaviors of more than thirty compounds in dense CO2 were studied in this project. A new type of phase behavior for solid (at ambient temperature) CO2-philes that melt and dissolve in CO2 was detailed using a model binary mixture of β-D-maltose octaacetate and CO2. Copolymers of tetrafluoroethylene (TFE) and vinyl acetate (VAc) exhibited lower miscibility pressures than either of the homopolymers, probably due to quadradentate binding configurations with CO2. Phase behavior investigation of poly(propylene glycol) (PPG) monobutyl ether in CO2 demonstrated ether-CO2 interactions should receive as much attention as carbonyl-CO2 interactions when designing CO2-philic functional groups. 1,3,5-tri-tert-butylbenzene and tri-tert-butyl-phenol were both extraordinarily soluble in CO2, and are excellent candidates for CO2-soluble sand binders. In summary, although a new CO2 thickener was not identified, new non-fluorous CO2-soluble materials were identified that were, in general, acetate-rich with flexible chains, weak self-interactions, and multidentate interaction between CO2 and solute functional groups

Microfluidic Viscometer for Tear Films and Other Biofluids

A microfluidic viscometer platform is developed and validated for measuring microliter-volume liquid samples, such as human tear films. The microfluidic viscometer combines an optically clear acrylic chip with a hydrophobic surface coating together with a syringe pump to control the sample flow rate. Additional functionally supporting devices, including a camera and a differential pressure transducer, were used for analysis. It has been demonstrated that the microfluidic viscometer could measure the viscosities of both Newtonian and non-Newtonian liquid samples, and their relevant calculations are presented. The microfluidic viscometer has potential applications in measuring the rheological properties of biofluids for diagnostic applications

Towards a Benign and Viable Rhodium Catalyzed Hydroformylation of Higher Olefins: Economic and Environmental Impact Analyses, Solvent Effects and Membrane-based Catalyst Separation

Researchers at the Center for Environmentally Beneficial Catalysis (CEBC) had previously reported a novel rhodium-based hydroformylation process concept based on the use of CO2-expanded liquids (CXLs) to intensify rates and obtain higher linear/branched aldehydes selectivity at relatively mild temperatures (30-60 °C) and pressures (~4 MPa). This dissertation continues investigations aimed at addressing the fundamental and practical issues associated with this concept. ReactIR studies of Rh/triphenylphosphine-catalyzed 1-octene hydroformylation, complemented by microkinetic and reactor modeling investigations revealed that the intrinsic kinetic rate constants are of similar magnitude with or without CO2 addition to the reaction mixture. This implies that the enhanced reaction rate observed in CXL is due to the increased hydrogen solubility in that medium. Environmental impact analysis revealed that the overall toxicity index for the CEBC process is approximately 40 times less than the Exxon process against which the CEBC process was benchmarked. Economic analysis of the CXL concept revealed that at an aldehyde production rate of 19,900 kg / (kg Rh h), 99.8% rhodium has to be recovered per pass for the CEBC process to be competitive with the Exxon process. Assuming a similar hydroformylation turnover frequency, rhodium recovery levels that exceed this criterion for economic viability were successfully demonstrated in a membrane-based nano/ultra-filtration reactor system using polymer supported phosphorus ligands, synthesized and provided by researchers from the Department of Chemistry. During continuous filtration of a toluene-based solution containing polymer-supported Rh complexes, the Rh and P concentrations in the permeate, quantified using ICP analysis, were on the order of a few tens of ppb. During continuous 1-octene hydroformylation studies in the membrane reactor at a syngas pressure of 0.6 MPa and 60 °C, the 1-octene conversion and product (mostly aldehydes) concentrations reached a steady state with the Rh concentrations in the permeate stream being lower than 120 ppb. However, the conversions and product concentrations during the continuous run are lower than those obtained in a batch ReactIR under identical operating conditions. This is attributed to syngas starvation in the membrane reactor that might be caused by inadequate mixing. In complementary investigations, it was found that the dissolution of CO2 in the organic phase (to create CO2-expanded liquids) decreases the viscosities of the mixtures with increasing CO2 pressure. This offers an opportunity to enhance mixing and also tune the membrane flux so as to increase the throughput of the membrane filter. The demonstrated technology concept, when fully optimized, should find applications in a variety of other applications in homogeneous catalysis, including hydrogenation and carbonylation of conventional and biomass-based substrates

Characterization of Porous Media and Refractory Materials

Because of its unique advantages on energy savings and casting complex shaper, Lost Foam Casting (LFC) has been widely used as a replacement to the conventional techniques (sand and investment castings). In order to continuously improve the quality of the Lost Foam Casting process for reducing scrap rate and increasing energy savings, the US Department of Energy through its National Industrial Competitiveness through Energy, Environment, and Economics (NICEEE) program sponsored the present study to develop new characterization techniques for enhancing the understanding of the fundamental properties of the refractory materials used in The Lost Foam Casting process. In this study, new techniques are proposed to characterize the refractory materials’ properties such as particle size, particle shape, rheological behavior, transport properties, microstructure, thickness, as well as packing properties. The rheological properties of the refractory coating slurries are characterized by a series of laboratory experiments using a rotational rheometer including the creep and recovery test, the thixotropic loop test, and oscillatory tests. A number of commercial particle sizing instruments based on different theoretical backgrounds are investigated for evaluating a suitable technique for reliable characterization of slurries used in this research. A quantitative approach to characterize particle shape is also investigated for particles in the refractory coating slurry. This study also proposes a new apparatus to evaluate the transport properties and microstructure of the refractory coatings. The proposed interpretation method of measured gas flow data considers the “slippage” and inertia effects that occur in measuring gas permeability of porous materials. The microstructure information obtained from the proposed technique is found to be well correlated with the transport properties of the porous coating materials. A procedure using a three-dimensional computational fluid dynamics code (FLOW3D) is developed to simulate experimental gas flow data for solving complex boundary value problems. This paper also presents a novel coating thickness measurement system for the dry refractory LFC coatings. By comparing a number of commercially available refractory coatings, it is found that the coating thickness on the expandable polystyrene foam patterns is not uniform and depends on the coating type, topography of the foam surface, and coating properties such as surface tension, thixotropic loop area, mean particle size diameter, and viscosity. In this study, the effects of dilution and dispersion on the coating properties such as transport properties and microstructures are also investigated. Results show that the dilution and dispersion have opposing influences on the pore size and transport properties. The pore characterization technique developed in this study is used to determine the effects of drying (oven versus air dry) on the pore size and transport properties. In addition, this study also includes another part of the permeability system, the un-bonded granular materials used in the Lost Foam Casting process. Three types of particle sizing techniques (sieve analysis, Laser Light Scattering and Imaging Analysis) are used to characterize the particle size and shape information of two types of un-bonded granular materials (sand and mullite). A three-dimensional (3-D) computer program is developed to simulate the packing behavior of granular materials at a loose state using a “drop and roll” method. This study provides a systematic characterization of the LFC refractory coating slurries, dried refractory coating, and the granular media. This study also demonstrates the application of proposed characterization techniques for coating quality control using statistical process control charts. In addition, numerical models are also developed to predict the coating performance such as its coating thickness and transport properties. The results from this study are likely to have a significant impact on improving the Lost Foam Casting process. The characterization tools developed in this study are being currently used in a large Lost Foam Casting foundry for improving the process at production scale

Research on biophysical evaluation of the human vestibular system

The human vestibular function was studied by the combined approach of advanced measurement and mathematical modelling. Fundamental measurements of some physical properties of endolymph and perilymph, combined with nystagmus measurements and fluid mechanical analysis of semicircular canal function furthered the theory of canal mechanical response to angular acceleration, caloric stimulation and relating linear acceleration. The effects of adaptation seen at low frequency angular stimulation were studied and modelled to remove some shortcomings of the torsion pendulum models. Otolith function was also studied experimentally and analytically, leading to a new set of models for subjective orientation. Applications to special problems of space, including the case of rotating spacecraft were investigated and the interaction of visual and vestibular cues and their relation to proprioceptive information was explored relative to postural control

Fluid characterisation and drop impact in inkjet printing for organic semiconductor devices

An inkjet printer can deposit a very small volume of liquid with high positional accuracy, high speed and low cost. As a maskless, non-contact additive patterning method, inkjet printing technology is increasingly being explored as an alternative to lithography, etching and vapour deposition processes to pattern electrical conductors and thin films with applications in printed electronic devices. The functional inks used in many of the applications involve non-linear viscoelasticity and their behaviours in the context of inkjet printing have not been fully understood. This thesis aims to characterise Newtonian and non-Newtonian properties of inkjet fluids and identify the key parameters affecting drop impact and spreading processes. Various fluid characterisation techniques such as the filament stretching rheometer and piezoelectric axial vibrator are explored. We propose an experimental method to assess the jettability of non-Newtonian inkjet fluids, without using an inkjet print head. The oblique collision of two continuous liquid jets leads to the formation of a thin oval liquid sheet bounded by a thicker rim which disintegrates into ligaments and droplets. Under certain conditions the flow structure exhibits a remarkably symmetrical “fishbone” pattern composed of a regular succession of longitudinal ligaments and droplets. Good correlation was found between the maximum included angle of the fishbone pattern and the maximum ligament length in the jetting experiments, which suggests that a test based on oblique impinging jets may be useful in the development of fluids for ink jet printing. High-speed imaging is used to analyse the impact and spreading of sub-30 μm drops of diethyl phthalate or polystyrene solutions in diethyl phthalate on to smooth glass surfaces with controlled wettability at speeds from 3 to 8 m s-1, under conditions representative of drop-on-demand inkjet printing. Data on drop height and spreading diameter are generated with high time and spatial resolution, over eight orders of magnitude in timescale. The effects of fluid viscosity and elasticity, which significantly affect jetting performance, are negligible throughout the whole deposition process, with no significant difference between spreading curves. The values of the fluid surface tension and the substrate wettability also have no effect on the kinematic, spreading or relaxation phases, but a marked influence on the wetting phase, in terms of the speed of expansion of the contact diameter and the final spreading factor

Sonochemically induced reactions of oils

This work will describe the use of the ultrasonic power for the modification of a wide range of oils from vegetable, through to mineral and synthetic oils. It will be shown that ultrasound is effective in cleaving the chains of carbon-based oils with the generation of products with a lower viscosity. The proposed mechanism through which these less viscous products are generated involves the formation of radical species which can be either oxygen or non-oxygen related. The process can be improved by the addition of nucleating agents, with the achieved lower viscosity being stabilised by the addition of radical scavengers. It will be also shown that ultrasound is effective as a power source to drive organic chemistry reactions such as the alkaline hydrolysis of triglycerides (saponification reaction). Benefits of this work will be related to the possible production of more easily degradable oils and to the possibility of using such oils as alternative energy sources, with a particular interest in investigating the environmental and energetic benefits of this approach

Evaluation of liquid lift approach to dual gradient drilling

In the past, the oil and gas industry has typically used the single gradient system to drill wells offshore. With this system the bottom hole pressure was controlled by a mud column extending from the drilling rig to the bottom of the wellbore. This mud column was used to achieve the required bottom hole pressure. But, as the demand for oil and gas increased, the industry started exploring for oil and gas in deep waters. Because of the narrow margin between the pore and fracture pressures it is somewhat difficult to reach total depth with the single gradient system. This led to the invention of the dual gradient system. In the dual gradient method, heavy density fluid runs from the bottom hole to the mudline and a low density fluid from the mudline to the rig floor so as to maintain the bottom hole pressure. Several methods have been developed to achieve the dual gradient drilling principle. For this research project, we paid more attention to the liquid lift, dual gradient drilling (riser dilution method). This method of achieving dual gradient drilling was somewhat different from the others, because it does not utilize elaborate equipment and no major changes are made on the existing drilling rigs. In this thesis the technical feasibility of using the liquid lift method over the other methods of achieving dual gradient drilling was determined. A computer program was developed to simulate the wellbore hydraulics under static and dynamic conditions, injection rate and base fluid density required to dilute the riser fluid and finally, u-tubing phenomena. In this thesis we also identified some problems associated with the liquid lift method and recommendations were made on how these problems can be eliminated or reduced. Emphases were placed on the effect of u-tubing, injection rate of base fluid at the bottom of the riser and well control issues facing this system