>Magister Scientiae - MSc / Over the past 5 years, South Africa has been experiencing a severe drought. This has caused industrial and agricultural processes, to compete for a limited supply of water. Since the economy relies mostly on agricultural activities, water consumption by industrial processes is taking its toll. One of these processes is the introduction of wet flue gas desulphurization (FGD) treatment at Eskom coal fired power stations. This dissertation explores the possibility of using membrane technology as a means of water recovery after the coal combustion flue gas has been treated with wet FGD. A lab-scale permeance testing system was specially built and modified to have complete thermal control of the environment inside the system. The permeance testing system produced a gas, similar to that of a wet FGD treated flue gas, which was then tested. A tubular lab-scale membrane module was designed and produced for the permeance testing system. The permeance figures of both Nitrogen gas and water vapour were determined for the membrane used in module production. These figures coincided with figures provided by the supplier, which warranted successful permeance testing. After success of the lab-scale testing, the data was used to design and develop a pilot-scale membrane module. This module was designed to meet pre-determined requirements as set forth by the project team. Producing lab-scale membrane modules helped identify and address possible problems in pilot-scale module design. This lead to the successful design and construction of a pilot-scale membrane module that could be used to recover the water that is needed to run the wet FGD process.

Digital Image Correlation is used to generate high-spatial-density full-field displacement<br />and strain data of a connection box outer diameter for use in the calibration of finite element<br />make-up models. Image acquisition and data processing techniques are discussed and best<br />practice recommendations are made. 3D-wedge models consisting of a twenty-degree sweep of<br />the connection geometry are generated from manufacturer supplied profiles. Deformation<br />plasticity material models are developed from identified minimum strength material coupons.<br />Axisymmetric and 3D meshing schemes are used to capture the geometric complexity, supply<br />enough resolution to represent seal performance, and provide a solution in an acceptable<br />timeframe. Several techniques for achieving good contact resolution are presented. The<br />mechanics of the full 3D connection makeup are decomposed into simple idealized<br />representations. Finite element boundary conditions are developed to adequately represent the<br />360-degree make-up mechanics in a wedge section. The wedge model is loaded to achieve a<br />torque-rotation coupling which satisfies the experimental make-up conditions. This model<br />displays a much improved ability to capture box outer diameter strain and displacement fields,<br />and thus better represents the mechanics of a connection make-up. A 3D inspired axisymmetric<br />pretension loading scheme is developed which enables the 3D-wedge seal conditions to be<br />replicated in a computationally efficient axisymmetric form for connection performance<br />evaluation. Seal metrics are developed and converged to evaluate connection sealing capabilities<br />in the power-tight configuration. Modeling error metrics are developed, and the final 3D-wedge<br />model is evaluated relative to the experimental DIC data. / Master of Science

Carbon nanotube forests are vertically grown tubular formations of graphene. Samples were grown with an injection chemical vapor deposition method on substrates of silicon with various deposited layers and bare fused silica. The morphology of the forest is characterized by the height, density, and presence of defects. Total diffuse reflectance and transmittance measurements were taken in the 2-16 �m spectral range and correlated to the forest’s specific morphology. From these correlations, the conditions necessary to maximize the absorption of the forest were found and exploited to cater sample growth for specific substrates to make ideal absorbers. From the transmittance data, the absorption coefficient is found via Beer-Lambert’s Law and also correlated to sample morphology, giving us an indication of the height of the forest needed for ideal absorption. Two models were used to attempt to reproduce the experimental absorption coefficient: an effective medium theory using a Maxwell Garnett approximation and by treating the carbon nanotube forest as an effective cylindrical waveguide with walls of graphite. Each model leads to a set of fitting parameters providing a better physical understanding of the forests. It was found that the effective medium theory gave results loosely corroborated with electron microscopy, but had trouble fitting the experimental data, and the index of refraction it provides does not behave like a unified medium. The waveguide model fits the data well, but it requires more experimental evidence to be more conclusive. The theoretical models need more work, but fabrication of ideal absorbers has been achieved on various substrates providing framework for their usage in radiometry and spectroscopy.

The search for new and additional sources of energy -- from sun, wind, waves, and ocean currents -- is necessitating the development of structures in the open environment of the oceans as well as on land. The advantages of round or tubular members for use in such structures are shown; and to avoid the uncertainties of welded joints, two bolted connections are proposed and their feasibility explored.

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第12831号 / 論医博第2080号 / 新制||医||1005(附属図書館) / 31369 / (主査)教授 川口 義弥, 教授 柳田 素子, 教授 小川 修 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第12920号 / 論医博第2095号 / 新制||医||1010(附属図書館) / 32130 / (主査)教授 髙橋 良輔, 教授 松田 文彦, 教授 瀬原 淳子 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).

Ultrasound measurement of change in kidney volume is a sensitive indicator of severity of renal parenchymal injury. Am J Physiol Renal Physiol 319: F447–F457, 2020. First published July 20, 2020; doi:10.1152/ajprenal.00221.2020.—Noninvasive determination of the severity of parenchymal injury in acute kidney injury remains challenging. Edema is an early pathological process following injury, which may correlate with changes in kidney volume. The goal of the present study was to test the hypothesis that “increases in kidney volume measured in vivo using ultrasound correlate with the degree of renal parenchymal injury.” Ischemia-reperfusion (IR) of varying length was used to produce graded tissue injury. We first determined 1) whether regional kidney volume in rats varied with the severity (0, 15, 30, and 45 min) of warm bilateral IR and 2) whether this correlated with tubular injury score. We then determined whether these changes could be measured in vivo using three-dimensional ultrasound. Finally, we evaluated cumulative changes in kidney volume up to 14 days post-IR in rats to determine whether changes in renal volume were predictive of latent tubular injury following recovery of filtration. Experiments concluded that noninvasive ultrasound measurements of change in kidney volume over 2 wk are predictive of tubular injury following IR even in animals in which plasma creatinine was not elevated. We conclude that ultrasound measurements of volume are a sensitive, noninvasive marker of tissue injury in rats and that the use of three-dimensional ultrasound measurements may provide useful information regarding the timing, severity, and recovery from renal tissue injury in experimental studies.

Yes / In order to improve the efficiency of the structural lateral resistance system, a new type of Grid tubular-Double Steel Plate (GDSP) concrete composite shear walls is proposed and investigated in this paper. Six test specimens, namely one reinforced concrete (RC) shear wall, three GDSP concrete composite shear walls, one concrete-filled steel tube (CFST) frame, one CFST frame and GDSP concrete composite shear wall combined system were physically tested to failure. The seismic performance of the six test specimens, including hysteresis behavior, ductility, energy dissipation, degradation of stiffness and strength, are recorded and compared. The results show that the GDSP concrete composite shear walls exhibited typical bending failure under low reversed cycle loading, achieving good seismic performance with full hysteresis curve, high bearing capacity, excellent ductility, slow degradation of stiffness and bearing capacity. Under the same axial compression ratio, the yield load of GDSP concrete composite shear wall was about 2.73 times, whilst the peak load was 3.23 times, respectively, of those of RC shear wall. On the other hand, the peak displacement of GDSP concrete composite shear wall was 5 times while ultimate displacement was 3.86 times, respectively, of those of RC shear wall. For GDSP concrete composite shear walls, with the increase of axial compression ratio, the peak load of the new types of concrete composite shear wall increases, but the ductility decreases, gradually. The CFST frame and GDSP concrete composite shear wall can work together co-ordinately. The hysteretic curve of the combined system is fuller, the ductility is improved, the degradation of stiffness and strength are slow when compared with GDSP concrete composite shear wall. Under reversed cyclic loading, the GDSP concrete composite shear wall exhibits low stiffness degradation characteristics and excellent fatigue resistance. / The authors would like to acknowledge the financial support to the work by the Natural Science Foundation of Jiangsu Province, China (BK20201436), the Open Foundation of Jiangsu Province Engineering Research Center of Prefabricated Building and Intelligent Construction (2021), the Science and Technology Project of Jiangsu Construction System (2018ZD047, 2021ZD06), the Science and Technology Project of Gansu Construction System (JK2021-19), the Science and Technology Cooperation Fund Project of Yangzhou City and Yangzhou University (YZU212105), the Science and Technology Innovation Fund of Yangzhou University (2020-65) and the Blue Project Youth Academic Leader of Colleges and Universities in Jiangsu Province (2020).

No / This paper presents the behaviour and design of axially loaded concrete filled stainless steel circular and square hollow sections. The experimental investigation was Conducted using different concrete cube strengths varied from 30 to 100 MPa. The column strengths and load-axial shortening curves were evaluated. The study is limited to cross-section capacity and has not been validated at member level. Comparisons of the tests results together with other available results from the literature have been made with existing design methods for composite carbon steel sections-Eurocode 4 and ACI. It was found that existing design guidance for carbon steel may generally be safely applied to concrete filled stainless steel tubes. though it tends to be over-conservative. A continuous strength method is proposed and it is found to provide the most accurate and consistent prediction of the axial capacity of the composite concrete filled stainless steel hollow sections due largely to the more precise assessment of the contribution of the stainless steel tube to the composite resistance.