Dissertations / Theses on the topic 'The effect of oil on differential characteristics'

This master’s thesis deals with the design of equipment for testing differentials. The aim of the thesis is therefore the design of a special device that will be able to measure the steady and transient characteristics of differentials. Master’s thesis is divided into four chapters. The first chapter points out the disadvantages of fully open and closed differentials, the second deals with a basic overview of the structures and design of self-locking differentials. The third chapter deals with research of existing devices that test and measure the characteristics of differentials. The fourth chapter then discusses the possible drives of the tested unit. The fifth chapter focuses on the actual construction design of the test equipment. The subsequent sixth chapter then solves the strength calculations of the chosen structural elements of this device.

An extensive literature survey of the subject of gear dynamics is undertaken and the increasing recognition of the role of the lubricating oil film in this field, especially as a damping source, is highlighted. The oil film separating the mating surfaces of involute spur gears is analysed assuming hydrodynamic conditions, rigid teeth (as far as the film shape is concerned) and pressure dependent viscosity. Gear tooth mesh stiffness is expressed as a function of the dynamic load and the position of contact. simple model of a pair of spur gears is subjected to a transient response analysis and the behaviour of the lubricating oil film observed. According to the motions of equivalent masses of the apars under these transient conditions damping due to the oil film is determined. The numerical solutions obtained at various operating conditions are combined to form an approximate formula to predict the damping ratio in terms of the dynamic tooth load, rolling speed of the tooth surfaces and the viscosity of the lubricating oil. A digital computer simulation of the dynamic motion of the pair of gears is carried out incorporating the above damping ratio formula. The actual load sharing between the pairs of teeth (when more than one pair of teeth are in mesh), considering the tooth deflections, pitch errors, oil film thicknesses and the differences in mesh stiffnesses, is taken into account. The variations of the total maximum dynamic load and the maximum tooth load are studied under different nominal loads, contact ratios, oil viscosities and pitch errors over a wide range of speeds covering the resonance area. The variations of the dynamic load, individual tooth load, mesh stiffness and the oil film thickness during complete mesh cycles are also analysed under different operating conditions to identify particular areas where high loads and minimum film thicknesses occur. Theoretical results are compared with the experimental results obtained on a back-to-back gear test rig.

Since the Exxon Valdez accident in 1987, renewed interest has come forth to better understand and predict the fate and transport of crude oil lost to marine environments. The short-term fate of an Arabian Crude oil was simulated in laboratory experiments using artificial seawater. The time-dependent changes in the rheological and chemical properties of the oil under the influence of natural weathering processes were characterized, including dispersion behavior of the oil under simulated ocean turbulence. Methodology included monitoring the changes in the chemical composition of the oil by Gas Chromatography/Mass Spectrometry (GCMS), toxicity evaluations for the oil dispersions by Microtox analysis, and quantification of dispersed soluble aromatics by fluorescence spectrometry. Results for this oil show a sharp initial increase in viscosity, due to evaporative losses of lower molecular weight hydrocarbons, with the formation of stable water-in-oil emulsions occurring within one week. Toxicity evaluations indicate a decreased EC-50 value (higher toxicity) occurring after the oil has weathered eight hours, with maximum toxicity being observed after weathering seven days. Particle charge distributions, determined by electrophoretic techniques using a Coulter DELSA 440, reveal that an unstable oil dispersion exists within the size range of 1.5 to 2.5 um, with recombination processes being observed between sequential laser runs of a single sample.

The objective of this research was to systematically study the effect of processing conditions on crystallization behavior and destabilization mechanisms of oil-in-water (o/w) emulsions. The effects of oil content (20 and 40 wt %); crystallization temperature (Tc = 10, 5, 0, -5, -10 °C); homogenization conditions, such as high shear (HS), very low pressure homogenization (VLPH), and high pressure homogenization (HPH); and cooling rate (0.2 and 30 °C/min) on both thermal behavior and destabilization mechanisms were analyzed. Docosahexaenoic acid (DHA) was added to VLPH emulsions and its effect on the physicochemical and oxidative stabilities and flavor was studied. Emulsions with 20% oil were less stable than those with 40% oil with a fast-cooling rate; however, stability increased when the emulsions were cooled slowly. Stability was also affected by oil and droplet size; the smaller the droplet the more stable the system. Smaller droplets (i.e., VLPH, HPH) had an effect on crystallization by delaying the onset of the crystal formation, which was promoted in emulsions with larger droplets (i.e., HS); 20% o/w emulsion crystallization was delayed more than 40%; and in emulsions crystallized using a slow-cooling rate, the crystal formation was less inhibited (i.e., crystals formed at a higher onset temperature [Ton], but at lower Tc) than when using a fast-cooling rate. The formation of lipid crystals either helped stabilize (small droplets) the emulsion and melted in a less fractionated manner or destabilized (big droplets) the emulsion. In addition, fast-cooling rates have greater fractionation than slow-cooling rates. Due to the greater stability of VLPH emulsions after thawing from being at -10 °C for 3 h, DHA was added to evaluate its effect on flavor (besides the effect on stability) of the emulsion. A descriptive panel was used to evaluate four attributes: oxidized, rancid, fishy, and buttery. The panelists were given samples after 72 h, because contrary to the TBA analysis which showed no significant differences between samples with and without DHA, the fishy smell was evident. The sensory evaluation results showed that there was a significant (p < 0.05) difference in fishiness between the VLPH emulsions with and without DHA, and that the odor was repulsive. No significance was seen for rancid and buttery flavors, and only a marginal significance was seen for oxidized.

Thesis (M.S.)--West Virginia University, 2009.
Title from document title page. Document formatted into pages; contains vii, 115 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

碩士
國立成功大學
土木工程學系碩博士班
101
Asphalt from different crude oil plays an important role on pavement performance, in order to make asphalt have suitable functionality, provide road durability and driving comfort by analyzing asphalt. In this study, sampling different crude oil refining vacuum residues (VR) for test, and adding heavy vacuum gas oil (HVGO), blown asphalt, were subjected to physically and chemically characteristic test respectively. Physical part of asphalt by basic physical test, and dynamic shear rheometer (DSR) to obtain the mass flow parameters; Chemical properties by Fourier transform infrared spectroscopy (FT-IR), Thin-layer Chromatography Flame lionization Detector (TLC-FID) and High performance gel permeation chromatography (HP-GPC), discussed asphalt functional groups, chemical composition and molecular size distribution respectively. Succeeding term aging tests in laboratory simulations, then follow fresh asphalt physical properties and chemical testing operations. Finally, combining the above test results, analysis the correlation between physical and chemical properties Asphalt is mainly composed of saturate, aromatic, resin and asphaltene. the composition ratio of VR affected physical properties. In the early aging of aromatic transferred to resin by chemical change, and then resin changes into the asphaltene, and the functional group of ketones and sulfoxide have major increase in the aging process , ketone and sulfoxide increase means that the colloidal structure of polar molecules (asphaltene, resin) increased. Finally, the study base on physical characteristics for mixing, when mixing sample with the same viscosity or penetration, the Asphaltene Index (IA), and Polydispersity Index (PDI) values of Soft asphalt blending air blown asphalt were higher than the hard asphalt blending heavy vacuum gas oil. In the other hand, Colloidal instability Index (IC) are almost the same. However, the Aging Index (AI) of short-term aging is higher than the hard asphalt blending heavy vacuum gas oil. Because the chemical characteristic of colloid changes significantly, physical properties varied greatly.

碩士
國立中山大學
機械與機電工程學系研究所
98
In this study, Reometer AR2000 is used to investigate the effect of shear rate on viscosity of emulsion. And a model for the effective viscosity of emulsion is established. Moreover, another model for the hydrodynamic lubrication with binary mixtures of non-Newton fluids is developed. The coupled modified Reynolds are solved by combining the advanced multilevel method with the Newton-Raphson method. The effect of shear rate on lubrication characteristics of hydrodynamic lubrication of emulsion is investigated in cold rolling process. Research results show that the viscosity of emulsion is decreased with increasing the shear rate. Hence,the oil film thickness, oil preasure and oil concentration under hydrodynamic lubrication are increased with decreasing the slide-to roll ratio. Emulsion will be Newton fluid under high shear rate. In the cold rolling process, the emulsion shows the high shear rate, and the elastic deformation of roller and strip are considersd. Hence the end point of plastic zone of strip is moved to oulet zone due to the lubricated zone is increased, so that the film thickness is higher than that for rigid body. When roller radius is increased, the effective elastic modulus and the thickness reduction of strip are decreased, then the lubrication characteristics in cold rolling process are influenced by elastic deformation. When the rolling speed is increased , the inlet film thickness is increased, and the roll torque is slightly increased, but the rolling force and peak preasure are almost not influenced.

碩士
輔仁大學
食品營養學系
92
Chinese soft-shelled turtle is one of the major aquaculture in south of Taiwan. It is considered as a tasty food with high nutritive value and a potentially health food. The objectives of this study were to analysis the proximate composition of different parts of soft-shelled turtle, characteristics of it oils, and to investigate the effect of soft-shelled turtle oils (STO) on lipid metabolism of hamsters. The crude protein is the highest in muscle (about 21%), crude ash is highest in shell (about 25%), and fat contents of soft-shelled turtle in muscle, viscera and shell were 6.9%, 13.1% and 2.3%, respectively. Triacylglycerol (TG) is the maximum fragments in lipid classes( about 86%). Oleic acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) content of fatty acid composition were 32, 3 and 8%, respectively. Total fatty acid of STO contained 28% polyunsaturated fatty acid (PUFA), 42% monounsaturated fatty acid (MUFA) and 28% unsaturated fatty acid (SFA). MUFA is the major esterified fatty acid fraction in cholesterol ester, while PUFA is in phospholipids (PL). EPA and DHA is integrate in sn-1,3 position of TG. In animal experiment, 6 week-old hamsters were divided into 5 groups of 8 animals, fed control diet, high fat diet, high fat diets containing 2, 4 and 6% STO respectively for 4 weeks. Results showed that diets containing 2-6% STO decreased liver triacylglycerol (TG) in hamsters, and diets containing 4% or 6% STO decreased serum TG but increased serum total cholesterol and liver phospholipids. In addition, enzyme activities of liver malic enzyme and glucose-6-phosphate dehydrogenase were lower in hamsters fed 4% or 6% STO than those fed high fat diet, but no effect of fatty acid synthase. Addition of STO increased n-3/n-6 fatty acids ratio of tissues. Animals fed 4% or 6% STO had higher n-3/n-6 ratio than that of animals fed 2% STO. In conclusion, soft-shelled turtle oil is rich in oleic acid, EPA and DHA. And that n-3 PUFA integrate in sn-1,3 position of TG. Animal study showed that dietary 6% STO might decrease serum and liver TG concentration by diminishing enzyme activities involved in liver fatty acid synthesis, and might increase the ratio of n-3/n-6 fatty acids of tissues.

碩士
國立屏東科技大學
動物科學與畜產系所
106
The objectives of this study were to evaluate the effect of supplementation of essential oil mixture (EOM) on growth performance, immunity response and carcass characteristics in broilers. In experiment 1, four hundred day-old Arbor Acres broilers were randomly allotted into 4 treatments × 4 replicates experimental design with 25 birds in each pen. The experimental diets were divided into two phases as starter and grower. The four treatment groups were fed diets with A (Corn-Soy basal diet), B (with 10 ppm antibiotic), C (with 300 ppm EOM) and D (with 500 ppm EOM) in the starter phase. During the grower phase, the groups of C and D were reduced the concentration of EOM to 200 and 300 ppm, respectively. Four birds from each treatment were injected 0.05 mL phytohaemagglutinin into wattles and measured the swelling degree at 32 days of age. In experiment 2, there hundred and sixty-eight day-old Arbor Acres broilers were randomly allotted into 4 treatments × 4 replicates experimental design with 23 birds in each pen. The four treatment groups were fed diets with A (Corn-Soy basal diet), B (with 10 ppm antibiotic), C (with 300 ppm EOM) and D (with 250 ppm probiotics). In experiment 3, three hundred and twenty day-old Ross male broilers were randomly allotted into 4 treatments × 4 replicates experimental design with 20 birds in each pen. The four treatment groups were fed diets with A (Corn-Soy basal diet), B (with 250 ppm EOM), C (with 500 ppm EOM) and D (with 750 ppm EOM). Feed and water were provided ad libitum through the trial. Birds were weighed individually and feed consumptions were recorded at 21 and 35 days of age in Exp. 1 and 2; at 14, 28 and 42 days of age in Exp.3. In Exp. 1, eight birds from each treatment were randomly selected at the end of the growth trial for the carcass test. The jejunum and ileum samples were taken from the sacrificed chickens and measured for villus height and crypt depth under an optical microscope. In Exp. 2, six birds from each treatment were randomly selected, two birds for gut microbial test, another four birds for carcass test. The metabolic test, eight birds in experiment 1 and four birds from each treatment in experiment 2 were placed into individual cages at 28 days of age. In Exp. 3, three birds from each treatment were randomly selected at the end of the growth trial for the carcass test. The results in Exp. 1, showed that all treatment groups had no significant differences in growth performances during the whole experimental period. The results of carcass characteristics showed that group with 300 ppm EOM significantly increased the wing meat percentage than that of control group (9.16 vs. 8.29%). The result of intestinal morphology showed that the group with 200 ppm EOM decreased crypt depth (113.51 vs. 142.81 μm) in jejunum and increased villus height (342.75 vs. 283.22 μm) in ileum than that of antibiotic group. In the immunity response, 200 and 300 ppm EOM increased swelling degree and peripheral blood T lymphocyte subsets than that of control group. The result in Exp. 2, showed that EOM treatment groups had no significant differences than that of control group in growth performances and gut microbials of jejunum. In carcass characteristics, the group with 300 ppm EOM significantly increased the breast meat percentage than the group with antibiotics (28.19 vs. 25.33%). The result of growth performances in Exp. 3, showed that the group with 250 ppm EOM significantly increased body weight (3111.60 vs. 2891.64 g) and average daily gain (93.11 vs. 86.67g) than the control group at 14-42 days of age. The result of carcass characteristics showed that the breast meat percentage of broiler in group with 500 ppm EOM were higher than that control group (29.80 vs. 27.31%). The group with 250 ppm EOM were significantly increased in gizzard weight percentage compared to the control group. The bursa weight percentage of broiler in groups with 250 ppm and 750 ppm EOM were higher than that group with 500 ppm EOM(0.15、0.16 vs. 0.09%). Overall, the experimental results showed that the supplementation of essential oil mixtures may improve intestinal morphology, immunity response and carcass characteristics, hence positively impacting on growth performances of broilers.

by Chan Cheong Shing.
Thesis (M.Phil.)--Chinese University of Hong Kong, 1990.
Bibliography: leaves 155-161.
ACKNOWLEDGEMENTS --- p.i
TABLE OF CONTENTS --- p.ii
LIST OF ILLUSTRATIONS --- p.iii
LIST OF TABLES --- p.iv
ABSTRACT --- p.v
Chapter 1. --- INTRODUCTION --- p.1
Chapter 2. --- THEORIES OF HUMAN MIGRATION --- p.9
Chapter 3. --- THE EFFECT OF INFORMATION UPON MIGRANTS' DECISION --- p.22
Chapter 4. --- THE CASE STUDY IN HAINAN --- p.57
Chapter 5. --- POLICY RECOMMENDATIONS --- p.114
Chapter 6. --- CONCLUSION --- p.147
WORKS CITED --- p.155

碩士
國立高雄海洋科技大學
輪機工程研究所
104
This experiment by vertical single cylinder four stroke diesel generator set as the experimental machine, and use the current domestic general type of fishing boats as diesel engine fuel. Oil type by burning oil for fishing vessels and fishing boats oil mixed pure ethyl ether, according to the proportion (0.5%, 1%, 1.5%, 2%) mixed way. In the four kinds of resistive loads measuring the physical properties of exhaust gas temperature and burning diesel engine exhaust product quantity and remaining oxygen content. Test results can understand the four different load conditions, different ether added, four type combustion boat pure ether of diesel oil and adding different ratios of prime mover caused by physical and chemical conditions. Explore ether added to diesel oil to the improving effect of air pollution, and the choice of additives for the future reference.