Indiana University-Purdue University Indianapolis (IUPUI) / Non-rainfall waters such as fog and dew are considered as important source of water in drylands, and the knowledge of possible sources of its formation is very important to make future predictions. Prior studies have suggested the presence of radiation fog in drylands; however, its formation mechanism still remains unclear. There have been earlier studies on the effects of fog on soil moisture dynamics and groundwater recharge. On the contrary, no research has yet been conducted to understand the contribution of soil moisture and groundwater to fog formation. This study, therefore, for the first time intends to examine such possibility in a fog-dominated dryland ecosystem, the Namib Desert. The study was conducted at three sites representing two different land forms (sand dunes and gravel plains) in the Namib Desert. This thesis is divided into two parts: the first part examines evidences of fog formation through water vapor movement using field observations, and the second part simulates water vapor transport using HYDRUS-1D model. In the first part of the study, soil moisture, soil temperature and air temperature data were analyzed, and the relationships between these variables were taken as one of the key indicators for the linkage between soil water and fog formation. The analysis showed that increase in soil moisture generally corresponds to similar increase in air or soil temperature near the soil surface, which implied that variation in soil moisture might be the result of water vapor movement (evaporated soil moisture or groundwater) from lower depths to the soil surface. In the second part of the study, surface fluxes of water vapor were simulated using the HYDRUS-1D model to explore whether the available surface flux was sufficient to support fog formation. The actual surface flux and cumulative evaporation obtained from the model showed positive surface fluxes of water vapor. Based on the field observations and the HYDRUS-1D model results, it can be concluded that water vapor from soil layers and groundwater is transported through the vadose zone to the surface and this water vapor likely contributes to the formation of non-rainfall waters in fog-dominated drylands, like the Namib Desert.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第17887号 / 工博第3796号 / 新制||工||1581(附属図書館) / 30707 / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 田中 功, 教授 酒井 明, 教授 邑瀬 邦明 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20966号 / 医博第4312号 / 新制||医||1026(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 原田 浩, 教授 富樫 かおり, 教授 宮本 享 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

No description available.

Volumetric CO2 data from patients in anaesthesia delivery systems are sought after by physicians. The CO2 data obtained with the commonly used sidestream sampling technique are not considered adequate for volumetric CO2 estimation due to distortion and desynchrony with patient flow. The purpose of this thesis was to explore the possibility of using signal enhancing methods to the sidestream data to accurately estimate CO2 flow using a Flow-i anaesthesia delivery system. To evaluate sidestream performance, experimental data was acquired using a mainstream and a sidestream capnograph connected in series to a FRC test lung with known CO2 content, ventilated by a Flow-i anaesthesia machine. The data was then enhanced and analysed using signal processing methods including sigmoid modelling and neural networks. A Feed Forward Neural Network achieved results closest resembling the mainstream capnogram of the evaluated signal processing methods. The mainstream capnogram, considered the benchmark, produced large internal scattering and approximately 25 % offset from actual CO2 flow while using the inherent patient flow data produced by the Flow-i anaesthesia system. When using patient flow data from a Servo-i ventilator, the resulting CO2 flow estimates were drastically improved, producing estimates within 10 % error. This thesis concludes that there are several potential processing methods of the sidestream data to approximate the mainstream signal, however the patient flow of the Flow-i system are a suspected source of error in the CO2 flow estimation.

A procedural method is proposed to generate volumetric data for terrain using a surface height map and information about materials as input. In contrast to previous explored methods this approach takes advantage of the extensive research on surface terrain generation by adapting the material layers to the topology of the input terrain. The method allows the user to specify materials as stratified or eroded, which are generated differently: stratified materials are stacked to generate material layers while eroded materials accumulate on even terrain. We compare a thermal erosion method and an original approach that uses information about the slope of the terrain as a shortcut to generate eroded layers and performs significantly better. The advantages and drawbacks of each technique are explored and discussed. / En proceduell metod har framställts för att generera volymdata för terränger med hjälp av en höjdkarta samt information om terrängens material. Till skillnad från tidigare metoder har följande nyttjat den omfattande forskningen kring genererad terräng. Det här genom att anpassa materialens lager till terrängens topologi. Metoden tillåter användaren att specifiera materialen som stratifierade eller eroderade, vilket genereras olika: stratifierat material staplas och generar på så vis materialen i lager, medan eroderat material samlas på jämn terräng. Vi jämför en termisk erosionsmetod med originellt tillvägagångssätt som nyttjar användarinformation om terrängens lutning som en genväg till att generera eroderade lager samt presterar signifikant bättre. Fördelar samt nackdelar med båda teknikerna utforskas och diskuteras.

A Rubber Balloon Soil Densitometer is one of the essential apparatuses in Geotechnical Engineering to measure the in-place volume of compacted soil to calculate the soil density. In 2019, some renowned institutions and organizations, Vattenfall, Luleå University of Technology, Uppsala University, Lund University, and HydroResearch AB, were involved in a research project. As a part of that research project, a small earth-rockfill dam was built in Älvkarleby, Vattenfall. During the construction of the experimental dam, to test the sufficiency of the degree of compaction in the core layers, the Rubber Balloon Soil Densitometer of the German company called Headquarters of Magdeburger Prüfgerätebau GmbH, in short HMP, was used. However, it was suspected that some of the HMP densitometer test results showed measured volumes of the excavated holes lower than the expectation. Hence, it aroused the necessity to check the correctness of the balloon test apparatus and its test procedure. This thesis topic aims to fulfill that necessity. The objective of this research is to determine whether the volumetric measurements achieved by this apparatus are accurate. If the volumes measured by this apparatus are inaccurate, it is crucial to find the reasons behind the inaccuracy. It is also essential to determine the inaccuracy causes and pursue the solution to obtain precision in volumetric measurement. This thesis topic is vital for engineers and researchers of civil engineering and other departments because concluding the research would help collect better soil density data using an HMP Rubber Balloon Soil Densitometer and other similar densitometers. All the laboratory works of this thesis were conducted at the Soil Laboratory of Luleå University of Technology. At the beginning of the laboratory work, a pit was excavated in a compacted mixed fine-grained silty sand type of soil inside a bucket to conduct a densitometer test. The actual volume of this pit was determined using the water replacement method. The HMP densitometer measured a volume of this pit smaller than its actual volume. Then, the apparatus itself was tested to evaluate its function. It was found that the plexiglass cylinder has different inner circular cross-sectional areas at different heights, which do not match the inner circular cross-sectional area mentioned in the HMP sticker on the plexiglass. As time passes, slight deformation of a plexiglass cylinder is normal and can happen because of temperature, applied pressure, and repetitive usage. The precision in percentage from the actual volume of a pit indicates the stuck air between the pit surface and the rubber balloon during a densitometer test. For engineering purposes, a precision in percentage smaller than one percent can be considered reasonable. The results showed that the actual volume of a pit should be at least around one liter to achieve precision in percentage from the actual volume of the pit smaller than about one percent. Additionally, pits with larger actual volumes have smaller precision in percentages from the actual volumes of the pits. The imperfection of the plexiglass cylinder has a lesser influence on larger pits during a densitometer test. Compacted coarse-grained soil can absorb the stuck air during a densitometer test because of having a sufficient quantity of pores. However, compacted fine-grained soil is so airtight that the soil can not absorb the stuck air. Transparent bowls and non-transparent bowls and a bucket were considered artificial pits of different sizes and shapes in compacted fine-grained soil, and densitometer tests were conducted with them. The results showed that the extended Ucsan bowl had the appropriate shape and size among these artificial pits. Because the average percentage of stuck air inside it was the smallest. However, the topmost diameter of an artificial pit or a real pit should be the same as the inner diameter of the metal ring of the HMP apparatus. Putting two stripes of industrial cleaning cloth perpendicularly inside an artificial or a real pit during a densitometer test was considered a solution to the stuck air problem. After applying this solution for the densitometer tests with all the artificial pits, the results showed that a real pit's appropriate shape and size with this solution should be similar to the extended Ucsan bowl. This was proved at the end of the laboratory work when a pit was excavated through the metal ring of the apparatus in a compacted mixed fine-grained silty sand type of soil inside a bucket to conduct densitometer tests. This pit was given a shape and size similar to the extended Ucsan bowl during excavation. This time, two industrial cleaning cloth stripes were placed perpendicularly inside the pit before the tests. The results showed that almost all the stuck air could be dissipated during a densitometer test by placing two stripes of industrial cleaning cloth perpendicularly inside a pit with a shape and size similar to the Ucsan bowl. During laboratory work, the HMP apparatus continuously measured volumes smaller than the actual volumes in all the densitometer tests.

No description available.

Volumetric optical microscopy has the advantages of quantitative and global measurement of three-dimensional (3D) biological specimens with high spatial resolution and minimum invasion. However, current volumetric imaging technologies based on light transmission, scattering or fluorescence cannot reveal specimen’s chemical distribution that brings insights to study the chemical events in organisms and their metabolism, functionality, and development. Stimulated Raman scattering (SRS) microscopy allowing visualization of chemical contents based on their intrinsic molecular vibrations is an emerging imaging technology to provide rapid label-free volumetric chemical imaging. This dissertation describes three methodologies for developing advanced volumetric SRS imaging technologies to address the challenges of imaging in vivo samples, imaging speed, and axial resolution. In the first methodology, SRS volumetric imaging is enabled by axially scanning the laser foci for sectioning different depth layers. In Chapter 2, we utilize a piezo objective positioner to drive the objective. Combining with the tissue clearance technique, we realize volumetric SRS imaging up to 500 µm depth in brain tissues showing the potential for 3D staining-free histology. The limitations of piezo scanning are slow speed and disturbance to in vivo samples while rapidly scanning the objective. To tackle the limitations, in Chapter 3, we develop a remote-focusing volumetric SRS microscope based on a deformable mirror and adaptive optics optimization, allowing focal scanning without physically moving the objective or sample. We demonstrate in vivo monitoring of chemical penetration in human sweat pores. In the second methodology, instead of axially scanning the laser foci, the SRS volumetric imaging is enabled by projection imaging with extended depth-of-focus (DOF) beams such as Bessel beams and low numerical-aperture beams. The extended DOF beams integrate SRS signals along the propagation direction to form projection images; thus, a single lateral scan obtains the volumetric chemical information, significantly increasing the volumetric imaging speed for measuring chemical content over a large volume. In Chapter 4, we describe a stimulated Raman projection microscope for fast quantitation of chemicals in a 3D volume. However, projection imaging intrinsically loses axial resolution. We addressed the limitation by developing SRS projection tomography. Mimicking computed tomography, the axial information is reconstructed by angle-dependent projection images obtained by sequentially rotating the sample in a capillary glass tube within the SRS focus. Nevertheless, sample rotation is complicated and not compatible with in vivo samples. To address the difficulty, in Chapter 5, we develop tilted-angle-illuminated stimulated Raman projection tomography which utilizes tilted-angle beams with a tilted angle respected to the optical axis of the objective to obtain angle-dependent projections. This scheme is free of sample rotation and enables fast projection scanning for pushing the imaging speed. The calibration approach and vector-field back-projection algorithm are developed for the multi-view tomographic reconstruction. In the third methodology, we improve the spatial resolution in miniature volumetric SRS imaging via the innovation of metasurface photonics. In developing an SRS endoscope for volumetric chemical imaging inside the human body, the axial resolution deteriorates due to chromatic and monochromatic aberrations induced by poorly made miniature objective lenses. In Chapter 6, we develop a silicon metasurface tailored for compensating the phase errors between the pump and Stokes wavelengths of a singlet refractive lens. Integrating the metasurface with the refractive lens, the hybrid achromatic metalens is compact and provides nearly diffraction-limit resolution, demonstrating a way for developing high resolution chemical imaging endoscopy.

There are many different techniques to display 3D information. However, not many of them are able to provide sufficient depth cues to the observers to sense or feel the images as real three-dimensional objects. Volumetric three-dimensional displays generate images within a real 3D space, so they provide most of the depth cues automatically. This thesis discusses the basic notions required to understand three-dimensional displays. Also discussed are different techniques used to display 3D information and their advantages and disadvantages as well as their current limitations. Several rare-earth doped fluoride crystals that are excited to emit visible light by sequential two photon absorption have been investigated as display medium candidates for static volumetric three dimensional displays. A scalable display medium is suggested to enable large 3D displays. This medium is a dispersion of particles of the rare earth doped fluoride crystals in a refractive index-matched polymer matrix. Detailed experiments are described to prepare such a scalable display medium using a wide variety of polymers. The scattering problem in such a medium was greatly reduced by index-matching the polymer to the crystalline particles. An index-matching condition that optimizes the performance was identified and demonstrated. A potential near-future solution is demonstrated and improvements are suggested.