Cognition of the hydraulic properties of soils is important in civil and environmental projects such as for water supply, geotechnical investigations and evaluation of pollutant spreading. This pilot project aims to develop and test a new method for characterization of the homogeneity and isotropy of different soils by using geophysical measurements. The method is based on geoelectrical (resistivity) measurements using a radial array. Using a radial array with electrode lines in various orientations crossing a midpoint at which water was infiltrated, it was possible to build a 3D-block model showing the water penetration into a soil body. Based on the infiltration pattern it was possible to evaluate the hydraulic heterogeneity and anisotropy of the material. Several common Swedish types of soils were tested. Measurement and evaluation techniques including software were developed. The project shows that geoelectrical measurements using a radial array and geoelectrical instruments available on the market can be used for rapid evaluation of the hydraulic heterogeneity and anisotropy of soils and rock.

Switched reluctance motors (SRMs) possess many desirable qualities for the long-term sustainability of electrified transportation such as cheap production costs and simple, robust configurations. However, high acoustic noise and torque ripple are two performance imperfections that have prevented the widespread implementation of SRMs. This thesis investigates design techniques to reduce the acoustic noise produced by an 8/6 SRM while also analyzing the impact each design has on the motor’s performance. The fundamentals of SRMs are discussed including the operating principles, modelling and control strategies. The multiphysics finite element analysis (FEA) toolchain used to accurately model acoustic noise and vibrations of SRMs is described. Using the network of FEA tools, nodal forces and natural frequencies of a four phase 8/6 SRM are analyzed to study the acoustic noise and vibration behaviours. The FEA process is validated experimentally by matching measured vibration modes and acoustic noise sound pressure level (SPL) with FEA numerical results. Through inspiration from an extensive literature review, various design techniques are applied to a baseline four phase 8/6 SRM and compared for both acoustic noise reduction and EM performance criteria. The investigated designs were split into two categories, stator-housing modifications that aim to increase the stiffness of the assembly and rotor modifications that aim to reduce the magnitude of radial forces while preserving performance. The best design strategies as determined by the comparative analysis were then further optimized to combine the best techniques together for the 8/6 SRM. The proposed structural improvements included the modifications of the stator yoke shape along with increasing the number of fastening components involved in the assembly. Additionally, an iterative procedure for the parametric modelling of windows introduced to the rotor poles is outlined. The best design considerations are combined to create the design of a novel 8/6 SRM which significantly reduces the acoustic noise produced by the motor with little impact to performance. / Thesis / Master of Applied Science (MASc)

No description available.

No description available.

No description available.

The study of geometric group theory has suggested several theorems related to subdivision tilings that have a natural hyperbolic structure. However, few examples exist. We construct subdivision tilings for the complement of every nonsingular, prime alternating link and all torus links, and explore some of their properties and applications. Several examples are exhibited with color coding of tiles.

Consolidation theory states that decreasing the spacing of prefabricated vertical drains will decrease the time required to achieve primary consolidation. Previous field tests have shown that there exists a "critical" drain spacing, which is the point at which further spacing decrease does not decrease the time of primary consolidation. This "critical" spacing is thought to be due to disturbance effects from installation of the drains. Previous studies have found that the "critical" drain spacing may be dependent upon soil layering and drain and mandrel dimensions. Thin, interbedded clay layers have been found to be affected greatly due to the smear zone, while few tests have been conducted to determine the validity for thick bedded clays. Currently two design and analysis methods are in existence, neither of which is standardized. The two methods are the modeling of the smear zone, which requires knowledge of soil parameters within that zone, and the modeling using a back-calculated Ch/Cv ratio.In order to evaluate the validity of these design methods and to obtain more data that can be used in determining the relationship between anchor type, drain spacing, and soil profile, full-scale field tests were conducted at Mountain View Corridor in Lehi, Utah. These field tests were performed along a test section that was divided into sections containing 5.8, 5.0, 4.0 and 3.0 ft triangular spacings and rebar or plate anchors. By using the smear zone model, with a Ch/Cv ratio of 1.25 and ds of 3.07 times dm, the time rate of settlement was able to be predicted reasonably well, while using the back-calculated Ch/Cv ratio, with no smear zone, also predicted the time rate reasonably well. From the testing, it was found that the thick clay profile can facilitate closer spacings than a thin clay profile. Also, it was found that the rebar anchor type causes about twice the disturbance of the plate anchor. The results helped validate the existing models and show that the effectiveness of the drains is dependent upon drain spacing, soil profile, and anchor type

Prenatal exposure to Zika virus (ZIKV) can result in microencephaly and congenital Zika syndrome but why some brain cells and structures are initially spared by the virus is unknown. Here, a novel murine model of ZIKV infection incorporating in utero electroporation with cell type specific promotors was used to identify the time course of ZIKV infection and to determine which neural precursor cells are initially infected or spared. In vivo time course studies revealed early presence of ZIKV in apical radial glial cells (aRGCs) while infection of basal intermediate progenitor cells climbed after three days of virus exposure. ZIKV-exposed fetal brains exhibited microencephaly as early as 1 day post injection, caused by apoptosis and reduced proliferation, and this change in brain size persisted until birth regardless of developmental age at infection. During infection, 60% of aRGC basal fibers were perturbed while 40% retained normal morphology, indicating that aRGCs are not uniformly vulnerable to ZIKV infection. To evaluate this heterogeneous vulnerability, we generated cell type-specific fate mapping plasmid probes using a previously published single cell RNA-Seq dataset on the E15.5 mouse neocortical wall. The results indicate that one class of aRGC preferentially expresses the putative ZIKV entry receptor AXL, and that these cells are more vulnerable to ZIKV infection than the other aRGC subtypes with low AXL expression. Together, these data highlight important temporal and cellular details of ZIKV fetal brain infection and may be important for prevention strategies and for management of congenital Zika syndrome.

Cardiovascular diseases (CVD) are the number one causes of death in the world. According to the world Health Organization (WHO) 17.5 million people died from cardiovascular disease in 2005, representing 30 % of all global deaths . Of these deaths, 7.6 million were due to heart attacks and 5.7 million due to stroke. If current trends are allowed to continue, by 2015 an estimated 20 million people will die annually from cardiovascular disease. The trends are similar in the United States where on an average 1 person dies every 37 seconds due to CVD. In 2008 an estimated 770,000 Americans will experience a new heart attack (coronary stenosis) and 600,000 will experience a first stroke. Although the exact causes of cardiovascular disease are not well understood, hemodynamics has been long thought to play a primary role in the progression of cardiovascular disease and stroke. There is strong evidence linking the fluid mechanical forces to the transduction mechanisms that trigger biochemical response leading to atherosclerosis or plaque formation. It is hypothesized that the emergence of abnormal fluid mechanical stresses which dictate the cell mechanotransduction mechanisms and lead to disease progression is dependent on the geometry and compliance of arteries, and pulsatility of blood flow. Understanding of such hemodynamic regulation in relation to atherosclerosis is of significant clinical importance in the prediction and progression of heart disease as well as design of prosthetic devices such as stents. The current work will systematically study the effects of compliance and complex geometry and the resulting fluid mechanical forces. The objective of this work is to understand the relationship of fluid mechanics and disease conditions using both experimental and computational methods where (a) Compliance effects are studied in idealized stenosed coronary and peripheral arteries using Digital Particle Image Velocimetry (DPIV), (b) Complex geometric effects of stented arteries with emphasis on its design parameters is investigated using CFD, Also (c) a novel method to improve the accuracy of velocity gradient estimation in the presence of noisy flow fields such as in DPIV where noise is inherently present is introduced with the objective to improve accuracy in the estimation of WSS, which are of paramount hemodynamic importance. The broad impact of the current work extends to the understanding of fundamental physics associated with arterial disease progression which can lead to better design of prosthetic devices, and also to better disease diagnostics. / Ph. D.

京都大学 / 新制・課程博士 / 博士(生命科学) / 甲第24985号 / 生博第514号 / 新制||生||68(附属図書館) / 京都大学大学院生命科学研究科高次生命科学専攻 / (主査)教授 北島 智也, 教授 見学 美根子, 教授 今吉 格 / 学位規則第4条第1項該当 / Doctor of Philosophy in Life Sciences / Kyoto University / DFAM