Despite popular and scientific interest in mummies, very few studies of ancient Egyptian mummy collections, especially from the same area, have been conducted. As such, this research is the first comprehensive analysis of mummies from Akhmim, Egypt and is one of only a few studies that investigate a large mummy collection from both a biological and cultural point of view. A group of 25 mummies from the Akhmim Mummy Studies Consortium database was evaluated using computed tomography. Using computed tomography and the associated imaging software, two dimensional (2D) x-ray scan images were analyzed, then processed and edited to generate three dimensional (3D) models of each mummy. Both the 2D and 3D images of each mummy were used to collect both biological information and cultural data in a nondestructive manner. Results from this study indicated that the population of Akhmim was very diverse. Furthermore, this research both supports and challenges conventional wisdom on how ancient Egyptians were mummifying their dead.

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Accurately characterizing the distribution of hydraulic parameters is critical for any site investigation, particularly those dealing with solute or contaminant transport. Despite the fact that many tools are currently available for both characterizing (e.g. soil core analysis, slug and pumping tests, direct push techniques, etc.,) and modeling (e.g. geostatistical interpolators, construction of geological models, etc.,) heterogeneous aquifers, this still remains a challenge. In this thesis, hydraulic tomography (HT), a recently developed tool for characterizing and modeling heterogeneous aquifers is evaluated under both laboratory and field conditions. To date, both steady state hydraulic tomography (SSHT) and transient hydraulic tomography (THT) have been demonstrated at the laboratory scale, however, only SSHT has been rigorously validated through the prediction of independent tests (those not used for estimating the distribution of hydraulic parameters), and comparison to other characterization/modeling techniques. Additionally, laboratory and field validations of HT using comparisons other than the prediction of independent pumping tests (e.g. prediction of solute transport) are lacking. The laboratory studies performed in this thesis address some of these gaps by: i) rigorously validating THT through the prediction of independent pumping tests, and comparison to other characterization techniques; ii) using HT estimated parameter distributions to predict the migration of a conservative tracer in a heterogeneous sandbox aquifer; and, iii) predicting the flow of water to a well in a heterogeneous, unconfined, sandbox aquifer. For all three cases, HT was compared to more traditional characterization/modeling approaches, such as; the calculation of homogeneous effective parameters, kriging of point data, or the creation and calibration of a geological model. For each study the performance of HT was superior to the other characterization methods. These laboratory experiments demonstrated both the ability of HT to map aquifer heterogeneity, and the critical need for accurately understanding heterogeneity in order to make accurate predictions about a system. In this regard, HT is a powerful tool at the laboratory scale where the forcing functions (i.e., boundary conditions, flow rates, etc.,) are accurately known. While several field scale HT studies have been reported in the literature, none attempt to validate 3D THT through the prediction of independent pumping tests, or through comparison to known geology. The application of THT at the field scale presents unique challenges not faced in the laboratory setting. For example, boundary conditions are not accurately known and it is not possible to instrument a field site as densely as a sandbox aquifer. In the field studies conducted as part of this thesis, THT was validated by comparing estimated hydraulic parameter fields to known geology (borehole data) and simulating 9 pumping tests that were performed at the site. The THT analysis was able to capture the salient features of the aquifer (the presence of a double aquifer separated by an aquitard), and was able to reasonably reproduce most of the pumping tests. For comparison purposes, a homogeneous model and three additional heterogeneous models were created: i) permeameter estimates of hydraulic conductivity from soil cores were interpolated via kriging; ii) the transition probability/Markov Chain approach was used to interpret material classifications from borehole logs; and iii) a stratigraphic model was created and calibrated to pumping test data. Of these cases, THT and the calibrated stratigraphic model performed best, with THT performing slightly better. This work indicates that it is possible to interpret multiple pumping tests using hydraulic tomography to estimate the 3D distribution of hydraulic parameters in heterogeneous aquifer systems. Also, since hydraulic tomography does not require the collection and analysis of a large number of point samples, it is likely comparable in cost to other characterization/modeling approaches.

Purpose To examine soft contact lens fitting characteristics using anterior segment imaging techniques and comfort. The specific aims of each chapter are as follows: Chapter 2: To calibrate the new ZEISS VisanteTM anterior segment optical coherence tomographer (OCT) using references with known physical thickness and refractive index equal to the human cornea and to compare the Visante measures to those from a previous generation OCT (Zeiss-Humphrey OCT II). Chapter 3: The first purpose of this study was to measure the repeatability of the Visante TM OCT in a normal sample. The second was to compare corneal thickness measured with the Visante TM OCT to the Zeiss-Humphrey OCT II (model II, Carl Zeiss Meditec, Jena Germany) adapted for anterior segment imaging and to the Orbscan II TM (Bausch and Lomb, Rochester New York). Chapter 4: Conjunctival displacement observed with the edges of the contact lens, when imaged may be real or may be an artefact of all OCT imagers. A continuous surface appears displaced when the refractive index of the leading medium changes at the edge of a contact lens. To examine this effect, edges of the contact lenses were imaged on a continuous surface using the UHR-OCT. Contact lens edges on the human conjunctival tissue were also imaged to see if the lens indentation on the conjunctival tissue is real or an artefact at the edge of the lens. Chapter 5: The main purpose of this study was to determine if we can predict end of the day discomfort and dryness using clinical predictive variables. The second purpose of the study was to determine if there was any relationship between lens fitting characteristics and clinical complications and especially to the superior cornea and conjunctiva with a dispensing clinical trial. Methods Chapter 2: Twenty two semi-rigid lenses of specified thicknesses were manufactured using a material with refractive index of 1.376. Central thickness of these lenses was measured using VisanteTM OCT and Zeiss-Humphrey OCT II (Zeiss, Germany). Two data sets consisting of nominal measures (with a standard pachymeter of the lenses and one obtained using a digital micrometer) were used as references. Regression equations between the physical and optical (OCT) measures were derived to calibrate the devices. Chapter 3: Fifteen healthy participants were recruited. At the Day 1 visit the epithelial and total corneal thickness, across the central 10mm of the horizontal meridian were measured using the OCT II and the Visante TM OCT. Only total corneal thickness across the central 10mm of the horizontal meridian was measured using the Orbscan II. The order of these measurements was randomized. These measurements were repeated on Day 2. Each individual measurement was repeated three times and averaged to give a single result. Chapter 4: (2-D) Images of the edges of marketed silicone hydrogel and hydrogel lenses with refractive indices (n) ranging from 1.41-1.51 were taken placing them concave side down on a continuous surface. Five images for each lens were taken using a UHR-OCT system, operating at 1060 nm with ~3.2um (axial) and 10μm (lateral) resolution at the rate of 75,000 A-scans/s. The displacement of the glass slide beneath the lens edge was measured using Image J. Chapter 5: Thirty participants (neophytes) were included in the study and the four lenses (Acuvue Advance 8.3, Acuvue Advance 8.7, Pure Vision 8.3, and Pure Vision 8.6) were randomly assigned for each eye. The lenses were worn for a period of two weeks on a daily wear basis for 8 to 10hrs per day. Lens performance was monitored over the 2week period. Assessment of subjective comfort was made using visual analogue scales. Total corneal and epithelium thickness was measured using the Visante OCT, the lens edge profiles of the contact lenses were observed using the ultra-high resolution OCT and the conjunctival epithelial thinning was measured using the RTVue OCT. Conjunctival blood velocity was measured at the baseline and 2 week visit using a high magnification camera. Results Chapter 2: Before calibration, repeated measures ANOVA showed that there were significant differences between the mean lens thicknesses from each of the measurement methods (p<0.05), where Visante measurements were significantly different from the other three (OCT II, MG and OP) methods (p<0.05). Visante thickness was significantly higher than the microgauge measures (453±37.6 µm compared to 445.1±38.2 µm) and the OCT II was significantly lower (424.5±36.1 µm both, p<0.05). After calibration using the regression equations between the physical and optical measurements, there were no differences between OCT II and Visante OCT (p<0.05). Chapter 3: Mean central corneal and epithelial thickness using the Visante™ OCT after calibration at the apex of the cornea was 536± 27 µm (range, 563-509 µm) and 55± 2.3 µm (range, 57.3-52.7 µm), respectively. The mean corneal and epithelial thickness using OCT II at the apex was 520±25µm and 56±4.9 µm, respectively. The mean of total corneal thickness measured with the Orbscan II was 609±29µm. Visante OCT was the most repeatable for test-retest at the apex, nasal and temporal quadrants of the cornea compared to OCT II and Orbscan II. COR’s of Visante OCT ranged from ±7.71µm to ±8.98µm for total corneal thickness and ± 8.72 µm to ± 9.92 µm for epithelial thickness. CCC’s with Visante OCT were high for total corneal thickness for test-retest differences ranging from 0.97 to 0.99, CCC’s for epithelial thickness showed moderate concordance for both the instruments. Chapter 4: Results showed that artefactual displacement of the contact lens edge was observed when the lenses were imaged on the glass reference sphere, custom made rigid contact lenses (1.376) and on the conjunctival tissue. The displacement measured on the conjunctival tissue ranged from 7.0±0.86 µm for the Air Optix Night and Day to 17.4±0.22 µm for the Acuvue Advance contact lenses. The range of displacement with the soft lens edges imaged on the rigid contact lens was from 5.51±0.03 µm to 9.72±0.12 µm. Chapter 5: The lenses with the steepest sag (Acuvue Advance 8.3, Pure Vision 8.3) resulted not only with the tightest fit, but with compromise to the superior conjunctiva. This was especially seen with the Acuvue Advance lenses. The steeper lenses caused more total corneal swelling, superior epithelial thinning, mechanical compression of conjunctiva, conjunctival staining, bulbar hyperemia, conjunctival indentation and reduced blood flow at the lens edge. Not many associations were observed between baseline clinical and 2 weeks sensory variables. However, significant associations were observed when comparing the baseline clinical variables to end of the day sensory variables. Baseline clinical variables compared to 2 week clinical variables also showed significant correlations. Conclusions Chapter 2: Using reference lenses with refractive index of the cornea (1.376) allows rapid and simple calibration and cross calibration of instruments for measuring the corneal thickness. The Visante and OCT II do not produce measurements that are equal to physical references with refractive index equal to the human cornea. Chapter 3: There is good repeatability of corneal and epithelial thickness using each OCT for test-retest differences compared to the between instruments repeatability. Measurements of epithelial thickness are less repeatable compared to the total corneal thickness for the instruments used in the study. Chapter 4: When contact lenses are imaged in-situ using UHR-OCT the conjunctival tissue appeared displaced. This experiment indicates that this displacement is an artefact of all OCT imagers since a continuous surface (glass slide) was optically displaced indicating that the displacement that is observed is a function of the refractive index change and also the thickness of the contact lens edges. Chapter 5: Discomfort is a complex issue to resolve since it appears to be related to ocular factors such as the corneal and conjunctival topography and sagittal depth; to lens factors that is 1) how the sag depth of the lenses relate to the corneal/conjunctival shape and depth and therefore how well it moves on the eye. 2) Also with the lens material; whether they are high or low modulus, low or high water content, dehydration properties, wetting agents used and its resistance to deposits, lens edge profile and thickness and its interaction with the upper eyelid.

Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 50-51). / xi, 51 leaves, bound ill. 29 cm

Organic solar cells using carbon based materials have the potential to deliver cheap solar electricity. The aim is to be able to produce solar cells with common printing techniques on flexible substrates, and as organic materials can be made soluble in various solvents, they are well adapted to such techniques. There is a large variation of organic materials produced for solar cells, both small molecules and polymers. Alterations of the molecular structure induce changes of the electrical and optical properties, such as band gap, mobility and light absorption. During the development of organic solar cells, the step of mixing of an electron donor and an electron acceptor caused a leap in power conversion efficiency improvement, due to an enhanced exciton dissociation rate. Top performing organic solar cells now exhibit a power conversion efficiency of over 10%. Currently, a mix of a conjugated polymer, or smaller molecule, and a fullerene derivative are commonly used as electron donor and acceptor. Here, the blend morphology plays an important role. Excitons formed in either of the donor or acceptor phase need to diffuse to the vicinity of the donor-acceptor interface to efficiently dissociate. Exciton diffusion lengths in organic materials are usually in the order of 5-10 nm, so the phases should not be much larger than this, for good exciton quenching. These charges must also be extracted, which implies that a network connected to the electrodes is needed. Consequently, a balance of these demands is important for the production of efficient organic solar cells. Morphology has been found to have a significant impact on the solar cell behaviour and has thus been widely studied. The aim of this work has been to visualize the morphology of active layers of organic solar cells in three dimensions by the use of electron tomography. The technique has been applied to materials consisting of conjugated polymers blended with fullerene derivatives. Though the contrast in these blends is poor, three-dimensional reconstructions have been produced, showing the phase formation in three dimensions at the scale of a few nanometres. Several material systems have been investigated and preparation techniques compared. Even if excitons are readily dissociated and paths for charge extraction exist, the low charge mobilities of many materials put a limit on film thickness. Although more light could be absorbed by increased film thickness, performance is hampered due to increased charge recombination. A large amount of light is thus reflected and not used for energy conversion. Much work has been put into increasing the light absorption without hampering the solar cell performance. Aside from improved material properties, various light trapping techniques have been studied. The aim is here to increase the optical path length in the active layer, and in this way improve the absorption without enhanced extinction coefficient. At much larger dimensions, light trapping in solar cells with folded configuration has been studied by the use of optical modelling. An advantage of these V-cells is that two materials with complementing optical properties may be used together to form a tandem solar cell, which may be connected in either serial or parallel configuration, with maintained light trapping feature. In this work optical absorption in V-cells has been modelled and compared to that of planar ones.

Masters Research - Master of Philosophy (Physics) / Fluoro-deoxyglucose (FDG) labeled with fluorine-18 is commonly used in positron emission tomography (PET) imaging. PET imaging is a powerful tool used primarily in the diagnosis and management of cancer. The growth of PET has been limited partly by the difficulties associated in producing fluorine-18. This project involves a theoretical investigation of a novel method of producing fluorine-18 utilising proton generation via the 3He(d,p)4He nuclear reaction. Currently the most common method of producing fluorine-18 for PET is with a medical cyclotron that accelerates protons to mega-voltage energies. These protons are then directed onto a target rich in oxygen-18. This initiates the 18O(p,n)18F reaction to produce fluorine-18. The 3He(d,p)4He reaction, utilized for the present study, has a Q-value of 18.35 MeV and this results in protons being produced at energies similar to that produced in a medical cyclotron. This reaction was investigated as an alternative proton source for the 18O(p,n)18F reaction. The expected advantage of this method over the cyclotron is that particles need only be accelerated to keV energies rather than the tens of MeV that a medical cyclotron accelerates protons to. This is expected to significantly reduce the cost and associated size of the system. Two systems based on the 3He(d,p)4He reaction were designed and calculations were performed to determine the respective yields of fluorine-18. The first system involved separate targets for the 3He(d,p)4He and 18O(p,n)18F reactions. Helium-3 ions are initially fired onto a deuterated plastic target. A heavy-water (H2O18) target is placed immediately behind this plastic target to absorb mega-voltage protons produced by the reaction 3He(d,p)4He in the plastic. The second system involved a single, super heavy water (D2O18) target onto which helium-3 is fired so that both the 3He(d,p)4He and 18O(p,n)18F reactions can occur concurrently in the one target. The input parameters of energy and beam current for the helium-3 beam required for the 3He(d,p)4He reaction were selected on the basis of the performance of currently available ion sources and in particular the saddle-field ion source. Practical considerations such as radiation safety, target degradation and lifetime and ultra high vacuum (UHV) issues were also investigated to further determine the feasibility of the two systems. With the beam current and energy at the extreme limits of the saddle-field ion source it was calculated that insufficient fluorine-18 could be produced daily to supply a PET facility with FDG. It was also found that the high helium-3 beam currents and energy required to produce significant amounts of fluorine-18 resulted in prohibitive temperature rises in the targets that would likely result in target vaporization.

Thesis (PhD)--University of South Australia, 1999