Gangliosides are sialic acid-containing glycosphingolipids located on the cell surface of all animal cell types. They play a role as receptor molecules, share in cell-to-cell interaction and protect the cell against harmful environmental factors by increasing of rigidity of cell surface. This diploma thesis studies an influence of experimental cholestasis on hepatic ganglioside composition. Cholestasis was induced by bile duct ligation in Wistar rats. A significant increase of total lipid bound sialic acid and b-series gangliosides (GD1b, GT1b, event. GD3) was found in cholestatic liver when compared with controls. These results found in obstructive cholestasis correspond with the results Majer et al. Biomed. Chromatogr., 21, 446-450 (2007), described in 17α− ethinylestradiol induced cholestasis, but the increase of b-series gangliosides was milder in our study. As a second point, an effect of modulated heme-oxygenase 1 (HO-1) activity was investigated in cholestatis induced bile duct ligation (HO-1 activator- hemine, HO-1 inhibitor- Sn-mesoporphyrin). An increase of a total lipid sialic acid was found in Sn-mesoporphyrin treated animals, but a decrease of some a- and b- series gangliosides was observed. In group with activated HO-1 total sialic acid increased, but the composition of gangliosides...

Gangliosides are sialic acid-containing glycosphingolipids located on the cell surface of all animal cell types. They play a role as receptor molecules, share in cell-to-cell interaction and protect the cell against harmful environmental factors by increasing of rigidity of cell surface. This diploma thesis studies an influence of experimental cholestasis on hepatic ganglioside composition. Cholestasis was induced by bile duct ligation in Wistar rats. A significant increase of total lipid bound sialic acid and b-series gangliosides (GD1b, GT1b, event. GD3) was found in cholestatic liver when compared with controls. These results found in obstructive cholestasis correspond with the results Majer et al. Biomed. Chromatogr., 21, 446-450 (2007), described in 17ethinylestradiol induced cholestasis, but the increase of b- series gangliosides was milder in our study. As a second point, an effect of modulated heme-oxygenase 1 (HO-1) activity was investigated in cholestatic rats (HO-1 activator- hemine, HO- 1 inhibitor- Sn- mesoporphyrin). An increase of a total lipid sialic acid was found in Sn-mesoporphyrin treated animals but without significant changes in gangliosides composition. Lipid sialic acid and gangliosides were not changed in animals with hemine activated HO-1. Expression of mRNA of key...

Fans are often used in equipment such as home appliances andelectronic equipment where the margin of profit is small butcustomers demands on a low noise level are high. Therefore,methods for predicting the noise emitted by an applicationincluding one or several fans are desirable in order toimprove, accelerate and reduce the cost of low-noise design.The Noise Shaping Technology (NST) has been developed withinthe EC-project NABUCCO in order to fulfil the aboverequirements on a prediction method. According to NST, thenoise source (not necessary a fan) is described by one orseveral noise descriptors, CSSs, and the correspondingtransmission paths through the structure described by one orseveral transfer functions, ACFs. In this thesis, theapplicability of NST is evaluated on a cabinet for electronicequipment where small axial cooling fans constitute the primarysources of the airborne sound. As an axial fan is a complex source of sound,simplifications are necessary when modelling its acousticproperties. Therefore, the sound radiation of an axial fan infree space was examined by expanding the generated soundpressure field into spherical harmonics. The conclusion on asource model for the cabinet example, where the fans are moreor less In-duct mounted, is a modified single axial dipole. Themodel is expected to be valid in the entire frequency range ofinterest except in the mid-frequency range where the modaldensity is low. In order to improve the source model in thisfrequency range, a future model based on a rotating dipole isproposed. The sound power of a small axial fan is measured in an ISO10302 test-rig. In order to take account of flow conditions,acoustically transparent ducts have been developed. These shallbe attached to the test-rig when measuring the sound power ofthe fan. A simple but practical method of how to correct thesound power for the baffling effect of the test-rig has alsobeen developed. Finally, the sound power can be converted intodipole force, which is the airborne CSS corresponding to thesingle axial dipole model. The corresponding airborne transfer function (ACF), i.e.,from dipole force at the source point to sound pressure at thereceiver point, is measured reciprocally by taking use ofLyamshevs reciprocity relation. From multiplication of the CSS and the ACF, the soundpressure can be predicted. The prediction shows quite goodagreement with the measured values. <b>Keywords:</b>axial fan, airborne sound, sourcecharacterisation, transmission path analysis, In-duct,spherical harmonics, rotating dipole, installation effects, ISO10302, flow conditions, baffling effect, acousticallytransparent ducts, Lyamshevs reciprocity relation, reciprocity,CSS, ACF, GSM, NST. / NR 20140805

The application of the Hershcel-Quincke (HQ) tube as a noise reduction device for one-dimensional plane-wave sound fields has been studied in great detail in previous years. In this thesis, an analytical technique is developed to investigate the potential of the HQ tube concept to control higher-order duct modes. This analytical method involves modeling the tube-duct interfaces as finite piston sources, which couple the acoustic field inside the main duct with the acoustic field within the HQ tube(s). The acoustic field within the HQ tube is modeled as plane-waves and the acoustic field within the main duct is modeled by expanding the sound field in terms of the higher-order modes. This model is then used to investigate the noise reduction mechanisms behind the attenuation of higher-order modes. These mechanisms involve both the reflection of the incident wave as well as the reconstruction and recombination of the modal content of the incident disturbance into other modes. The effects of the modal content of the disturbance along with the HQ tube geometric parameters, such as tube axial position, length, distance between interfaces, and cross-sectional area, are studied with respect to the frequencies of attenuation and the reduction obtained. These results show the potential of the Herschel-Quincke tube concept to reduce higher-order modes in ducts. / Master of Science

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18272号 / 工博第3864号 / 新制||工||1593(附属図書館) / 31130 / 京都大学大学院工学研究科原子核工学専攻 / (主査)教授 功刀 資彰, 教授 中部 主敬, 准教授 横峯 健彦 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

No description available.

Energy is one of the most important engineering challenges of this time. Gas turbine engines a,re responsible for nearly twenty-percent of all electricity produced in the United States today. A small increase in the operating efficiency of these engines could lead to massive reduction in the emission of greenhouse gases into the atmosphere as well as the financial burden on the average homeowner paying the monthly energy bill. In order to improve the efficiency of the engine, the Turbine Inlet Temperature of the hot gas coming from the combustor is continually increased. This requires increasingly advanced active cooling methods to maintain component life in the hot stages of the turbo machine. In this study, a complete experiment is developed for accurate testing of the complex heat transfer and aerodynamic characteristics present in the active cooling design applied to the transition duct of a land-based gas turbine. The transition duct is the component that channels the hot gases from the combustor to the first stage of the turbihe. It is in contact with the hottest mainstream gas flow in the entire machine. The unique cooling design applied to this component is a combination the three main cooling methods. It is characterized by an impinging jet inlet, which splits into two identical channels flowing in exactly opposite directions. The flow travels through these channels, cooling the hot surfaces of the duct through which they are formed. At the flow exit, it is expelled into the hot gas stream flowing from the can-annular combustor to the turbine stage. The channel exit provides a thin film of cool air coverage that protects the metal surface from the harsh temperatures of the hot gas.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第24499号 / 医博第4941号 / 新制||医||1064(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 伊藤 貴浩, 教授 中島 貴子, 教授 藤田 恭之 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

A hot-flow axisymmetric Air Augmented Rocket (AAR) test apparatus was constructed to test various mixing duct configurations at static conditions. Primary flow for the AAR was provided through a liquid methanol-gaseous oxygen bipropellant rocket. Experimental thrust measurements were recorded and propellant mass flow rates and chamber conditions were calculated using an iterative solver dependant on recorded propellant line stagnation pressures. Primary rocket flow produced thrust ranging from 14 to 17.9lbf. Primary mass flow rate through testing ranged from 0.071 to 0.085lbm/s with calculated chamber pressures between 298-362psia. Calculated primary flow velocity ranged from 6,600ft/s to 8,000ft/s depending on propellant pressure inputs and calculated chamber conditions. The AAR test apparatus was capable of testing various mixing duct geometries and measuring the axial thrust of the mixing ducts separately from the total thrust of the system. Two mixing duct geometries, a straight wall mixing duct and diverging wall mixing duct, with identical exterior dimensions and inlet geometry were tested for a range of air/fuel mixture ratios from 0.82 to 2.2 spanning the stoichometric mixture ratio of 1.5. Mixing duct thrust did not vary greatly with primary flow characteristics. Straight mixing duct thrust averaged 0.97lbf and diverging mixing duct thrust averaged 0.18lbf. Total system thrust decreased by an average of 0.62lbf with a straight mixing duct and 0.74lbf with a diverging mixing duct. Decreases in total thrust are attributed to low pressure flow interaction between the mixing duct and the primary rocket assembly. Visual flow comparison between mixing duct configurations and fuel ratio cases were carried out using high definition video recording with a grid reference for comparison. The diverging mixing duct produced the greatest variation in visible flow when compared to a straight mixing duct and no mixing duct configuration. This indicated that the diverging mixing duct had a greater influence on primary and secondary flow field mixing than the straight mixing duct.

Cold-flow tests were performed using a simulated Air Augmented Rocket (AAR) operating as a mixer-ejector in order to investigate the effects of varied primary nozzle lip thickness on mixing and entrainment. The simulated primary rocket ejector was supplied with nitrogen at a maximum chamber stagnation pressure of 1712 psi, and maximum flow rate of 1.67 lbm/s. Secondary air was entrained from a plenum, producing pressures as low as 6.8 psi and yielding maximum stagnation pressure ratios as high as 160. The primary ejector nozzles each had an area ratio of approximately 20, yielding average primary exit Mach numbers between 4.34 and 4.57. The primary flow was ejected into an 18.75 inch-long mixing duct with a rectangular cross-sectional area of 2.10 in2. The secondary flow was entrained into the mixing duct through a total cross section of 0.94 in2. Two mixing duct configurations were used, one with plexiglass upper and lower surfaces for flow visualization and one with pressure ports along the lower surface for primary plume measurements. Shadowgraph images were used to characterize the mixing duct flow field, while pressure and temperature instrumentation allowed for calculation of various ejector performance characteristics. Experimentally-calculated performance characteristics were compared to inviscid theoretical predictions. Varying degrees of flow field asymmetry were observed with each nozzle. Test repeatability was found to be excellent for all nozzles. Several distinct phenomena were observed in both the primary plume and secondary streams. The duration of secondary flow choking was found to be inversely proportional to nozzle lip thickness, due to the primary plume being physically closer to the secondary flow with a thinner nozzle lip. This indicated that the ejector’s ability to choke the secondary flow is primarily an inviscid phenomenon. Secondary flow blockage was demonstrated in two consecutive tests using the thickest nozzle lip. Only the left secondary duct became blocked in each case. Blockage was only demonstrated in the centerline pressure configuration, so no visual evidence was able to support the blocked flow theory. At every pressure ratio, entrainment ratio was shown to increase with nozzle lip thickness. The original conical nozzle produced the largest level of entrainment, indicating that the angle of primary flow impingement was the largest contributing factor to secondary entrainment. The increase in efficiency resulting from a bell-mouth nozzle was less than the increase in entrainment efficiency of a conical nozzle, indicating that the conical design was more efficient overall for air augmented rocket applications.