Electromagnetic induction (EMI) has been used in archaeology for decades, but still lags in use and development when compared to magnetometry and ground-penetrating radar. While it has become more popular than electrical resistivity area survey, it is now less commonly used than electrical resistivity tomography. The EMI method is likely underutilized due to drift problems and a lack of multi-sensor, vehicle-towed systems capable of rapid, high-density data collection. In this article we demonstrate not only the effectiveness of EMI survey, but a case where entire villages would have remained undetected without it. At the Singer-Hieronymus Site in central Kentucky, USA, a vehicle-towed frequency domain EMI survey detected the location of plazas, residential areas, and trash disposal areas across multiple Fort Ancient villages that contained both intact and heavily disturbed deposits. Additionally, three new villages were revealed. Through this process, we discovered how Fort Ancient village dynamics may be studied through a geophysical investigation of village shape, size, and spatial organization.

Indiana University-Purdue University Indianapolis (IUPUI) / Objective: To investigate the effect of the size of the space between the restoration and the dentinal wall of the tooth (i.e. the dentinal portion of the gap) on the development of secondary caries. Methods: Tooth-resin-matrix composite specimens were mounted on custom-made gap-model stages. Specimens were divided into four groups (n=10). Group 1 had a uniform gap size of 30μm throughout both enamel and dentin. Group 2 had a 30μm enamel gap size with a 530μm dentinal gap. Group 3 had 525μm gaps in both enamel and dentin. Group 4 had 525μm and 1025μm gaps in enamel and dentin, respectively. Specimens were attached to plastic Petri plates, gas-sterilized and then incubated in a microbial caries model with S. mutans TH16 in (1% sucrose tryptic soy broth for 1 h, 4 times/day, and with a buffer solution for the rest of the day). After 8 days of incubation, tooth specimens were sectioned and stained with a rhodamine B solution. Digital images were taken under a confocal microscope and analyzed for lesion size at the enamel outer lesion (EOL), enamel wall lesion (EWL), dentin wall lesion next to the DEJ (DWL-A) and dentin wall lesion at 750µm from the DEJ (DWL-B). Results: No difference in EOL size was found between the groups. DWL-A and -B were larger in group 3 than groups 1and 2. Larger DWL-B was found in group 3 than group 4. Group 4 had marginally significant larger EWL than groups 1 and 2 (p=0.0652 and p=0.0648, respectively). Also, group 4 had marginally significant (p=0.0607) larger DWL-B than group 1. Conclusions: Based on the results of this study, it can be concluded that the presence of additional space at the dentinal wall area did not affect secondary caries development as long as the enamel gap was small. However, with enamel gaps of ≈500 µm, the presence of the additional gap space at the dentinal wall led to the development of smaller dentinal wall lesions at the deeper parts of the simulated cavity. Also, in uniform gaps, the size of the interface was positively correlated with size of the dentinal wall lesions.

This study is a part of a project at Q-linea that aims to present a rapid diagnostic instrument to speed up the process of identification of pathogens and determination of MIC-values (Minimal Inhibitory Concentration) of antibiotic needed to treat patients with sepsis. Specifically, this report is aimed to describe the development and implementation of algorithms that examine susceptibility profiles ofsepsis related pathogens where the bacteria have been exposed to different antibiotics and by different lapse of concentrations. The developed algorithms are based on a clustering technique that identify inhibited growth and present the lowest concentration needed to slow down the growth of the pathogen. The implemented solution was tested on sepsis related pathogens and the determined MIC values were compared to MIC values generated with a method commonly used in healthcare today. Approximately 90% of instances were correctly classified based on data from six hours long tests which is significantly faster than the reference method which takes 16-24 hours to complete. Furthermore, each result comes with a set of quality measures for validation of the algorithm results. Although, further studies are necessary to increase the performance at the four-hour target time, and more data is needed to validate the developed quality measures.

Great Smoky Mountains National Park (GRSM) received 12.5 million visitors in 2020. With a high traffic volume, it is imperative roadways remain open and free from obstruction. Annual unanticipated rockfall events in GRSM often obstruct traffic flow. Using the Unstable Slope Management Program for Federal Land Management Agencies (USMP for FLMA) protocols, this study analyzes high priority unstable rock slopes through 1) creation of an unstable slope geodatabase and 2) generation of a final rockfall risk model using Co-Kriging from a preliminary risk model and susceptibility model. A secondary goal of this study is to provide risk estimation for the three most traveled transportation corridors within GRSM, as well as investigate current rockfall hazard warning sign location to ultimately improve visitor safety with regards to rockfall hazards.

This thesis has determined that using fly ash as a mineral filler in asphalt pavements can help strengthen and reduce asphalt moisture damage. Also, dynamic shear rheometer tests show that these additives have a stiffening effect on asphalt binder. Moisture related damage is considered one of the main causes of asphalt pavement failure. As water infiltrates a layer of asphalt, it slowly strips away asphalt binder, weakening the aggregate/binder bond. This process, combined with the cyclic loading of traffic, can lead to several different types of asphalt failure including rutting, raveling, bleeding, and cracking. For several decades, research has been conducted to find a solution to this problem. Currently in practice, hydrated lime and a variety of amine-based chemicals are being used as anti-stripping agents. However, as an emphasis towards sustainability has increased, waste products are now being investigated for this purpose. This thesis investigated the anti-stripping effectiveness of two waste products: fly ash and cement kiln dust (CKD), and compared them with hydrated lime and an amine-based chemical additive. The results indicate that class C fly ash can be used as an asphalt anti-stripping additive; however it is more costly than lime or amine chemicals.

X-ray diffraction (XRD) patterns, electron probe microanalysis(EPMA), electron paramagnetic resonance (EPR) powder spectra (9 and 34 GHz) and the magnetic susceptibility of BaTiO3 + 0.04 BaO + 0.01 V2O5 ceramics were studied to investigate the valence states of V ions and their solubility in the BaTiO3 lattice. In samples sintered at 1400 °C in air, only about 0.1 mol% V is incorporated in the BaTiO3 lattice being in V4+ and V5+ valence state, respectively. 95% of the nominal V dopant content occurs in the secondary phase Ba3(V/Ti)2O8. All BaTiO3 samples investigated are in tetragonal phase at room temperature. In the as-sintered samples V4+ is detected at temperatures T < 20 K by its hyperfine structure (HFS) octet due to the nuclear spin 7/2 of 51V. Samples post annealed in H2/Ar atmosphere at 1200 °C exhibit a further HFS octet occurring at T > 25 K and vanishing at T > 250 K, which is caused by V2+ ions. This spectrum is characterized by a simultaneous HFS and fine structure splitting constituted by allowed and forbidden transitions. Both V4+ and V2+ ions are incorporated at Ti4+ sites of the BaTiO3 lattice

No description available.

The measurement of meteorite physical properties (i.e. density, porosity, magnetic susceptibility) supplements detailed chemical and isotopic analyses for small samples (thin sections or ~300 mg portions) by providing whole-rock data for samples massing in the tens of grams. With the advent of fast, non-destructive and non-contaminating measurement techniques including helium ideal-gas pycnometry for grain density, the Archimedean ―glass bead‖ method for bulk density and (with grain density) porosity, and the use of low-field magnetometry for magnetic susceptibility, all of which rely on compact and portable equipment, this has enabled a comprehensive survey of these physical properties for a wide variety of meteorites. This dissertation reports on the results of that survey, which spanned seven major museum and university meteorite collections as well as the Vatican collection. Bulk and grain densities, porosities and magnetic susceptibilities are reported for 1228 stones from 664 separate meteorites, including several rare meteorite types that are underrepresented in previous studies. Summarized here are data for chondrites (carbonaceous, ordinary and enstatite) and stony achondrites. Several new findings have resulted from this study. From the use of a ―weathering modulus‖ based on grain density and magnetic susceptibility to quantify weathering in finds, it is observed that the degree of weathering of ordinary chondrites is dependent on their initial porosity, which becomes reduced to less than ~8% for all finds, but for enstatite chondrites iii weathering actually increases porosity. Grain density and magnetic susceptibility, which have been shown to distinguish H, L and LL ordinary chondrites, also may distinguish shergottites, nakhlites and chassignites from each other, but the two groups of enstatite chondrites (EH and EL) remain indistinguishable in these properties. H chondrite finds exhibit a slight negative trend in porosity with increasing petrographic type, and all chondrite falls together exhibit a pronounced negative trend in porosity spanning all petrographic types. The overall trend corresponds roughly to a positive trend in porosities with respect to both degree of oxidation and percentage of matrix. It also corresponds to the macroporosities of analogous asteroids. These traits constrain models of conditions in the solar nebula and the formation of chondrite parentbody precursors.

Magnetic Resonance Imaging (MRI) is a widely used, non-invasive imaging technique that provides a means to reveal structural and functional information of different body tissues in detail. Susceptibility Weighted Imaging (SWI) is a field in MRI that utilizes the information from the magnetic susceptibility property of different tissues using the gradient echo phase information. Although longer echo times (TEs) have been widely used in applications involving SWI, there are a few problems related with the long TE data, such as the strong blooming effect and phase aliasing even at macroscopic levels. In this thesis, the use of very short TEs is proposed to study susceptibility mapping. The short TEs can be used to study structures with susceptibilities an order of magnitude larger (such as air and bones in and around the brain sinuses, skull and teeth) than those within soft tissue. Using a new iterative susceptibility mapping technique that we recently developed, it becomes possible to map the geometry of such structures, which to date has proven difficult due to the lack of water content (for sinuses) or due to very short T2* (for bones). The method of phase replacement inside the sinuses proposed in this thesis provides more accurate phase information for the inversion than assuming zero or some arbitrary constant inside these structures. The first and second iterations were responsible for most of the changes in mapping out the susceptibility values. The mean susceptibility value in the sphenoid sinus is calculated as +9.3 ± 1.1ppm, close to the expected value of +9.4ppm for air. The reconstruction of the teeth in the in-vivo data provides a mean Δχ(teeth-tissue)=–3.3ppm, thanks to the preserved phase inside the jaw. The mean susceptibility inside a relatively homogeneous region of the skull bone was measured to be Δχ(bone-tissue)=–2.1ppm. Finally, these susceptibilities can be used to help remove the unwanted background fields prior to applying either SHARP or HPF. In addition, the effects of the background field gradient on flow compensation are studied. Due to the presence of these background gradients, an unwanted phase term is induced by the blood flow inside the vessels. Using a 3D numerical model and in vivo data, the background gradients were estimated to be as large as 1.5mT/m close to the air-tissue interfaces and 0.7mT/m inside the brain (leading to a potential signal loss of up to 15%). The quantitative susceptibility mapping (QSM) results were improved in the entire image after removing the confounding arterial phase thanks to the reduced ringing artifacts. Lastly, a novel approach to improve the susceptibility mapping results was introduced and utilized to monitor the changes in venous oxygen saturation levels as well as the changes in oxygen extraction fraction instigated by the vasodynamic agents, caffeine and acetazolamide. The internal streaking artifacts in the susceptibility maps were reduced by giving an initial susceptibility value uniformly to the structure-of-interest, based on the a priori information. For veins, the iterative results, when the initial value of 0.45 ppm was used, were the best in terms of the highest accuracy in the mean susceptibility value (0.453 ppm) and the lowest standard deviation (0.013 ppm). Using this technique, the venous oxygen saturation levels (inside the internal cerebral veins (ICVs)) for normal physiological conditions, post-caffeine and post-Diamox for the first volunteer were calculated as (mean ± standard deviation): Y_Normal = 69.1 ± 3.3 %, Y_Caffeine = 60.5 ± 2.8 % and Y_Diamox = 79.1 ± 4.0%. For the caffeine challenge, the percentage change in oxygen extraction fraction (OEF) for pre and post caffeine results was calculated as +27.0 ± 3.8%; and for the Diamox challenge, the percentage change in OEF was calculated as −32.6 ± 2.1 % for the ICVs. These vascular effects of Diamox and caffeine were large enough to be easily measured with susceptibility mapping and can serve as a sensitive biomarker for measuring reductions in cerebro-vascular reserve through abnormal vascular response, an increase in oxygen consumption during reperfusion hyperoxia or locally varying oxygen saturation levels in regions surrounding damaged tissue. In conclusion, our new approach to QSM offers a means to monitor venous oxygen saturation reasonably accurately and may provide a new means to study neurovascular diseases where there are changes in perfusion that affect the oxygen extraction fraction. / Thesis / Doctor of Philosophy (PhD) / Magnetic Resonance Imaging (MRI) is a widely used, non-invasive imaging technique that provides a means to reveal structural and functional information of different body tissues in detail. Susceptibility Weighted Imaging (SWI) is a field in MRI that utilizes the information from the magnetic susceptibility property of different tissues using the gradient echo phase information. Firstly, we demonstrate that using our phase replacement technique, it becomes possible to map the geometry of structures with almost no MR signal, which to date has proven difficult due to the lack of water content (for sinuses) or due to very short T2* (for bones). Secondly, the effects of the background field gradient on flow compensation were studied. Due to the presence of these background gradients, an unwanted phase term is induced by the blood flow inside the vessels. And, lastly, we present our new approach utilizing SWI data, offering a means to monitor venous oxygen saturation reasonably accurately and, potentially, a new means to study neurovascular diseases where there are changes in perfusion that affect the oxygen extraction fraction.

<p> The magnetic susceptibility of samarium orthophosphate (SmPO4) has been measured over the temperature range from 0.4 to 270°K. A theoretical expression for the susceptibility has been developed assuming a crystal field of cubic symmetry and fitted to the experimental data. </p> / Thesis / Master of Science (MSc)