<p> Magnetic susceptibility data indicate that Tb2Mo2O7 undergoes a spin glass transition at 25 K. The crystal structure is consistent with the fully ordered pyrochlore model. Short range order, involving ferromagnetic and antiferromagnetic correlations, is observed down to 8 K by neutron scattering. </p> <p> Sr2Cr03F and SrLaCr04 have the same magnetic structure. The neutron diffraction data are consistent with two different models. In both cases the magnetic cell is √2a and c and the magnetic moments lie out of the plane. However, in one model the in-plane projection is canted and in the other it is colinear. Sr2Cr03F has a Tc value of 132(2) K and a susceptibility maximum at 280 K. SrLaCr04 has a Tc value of approximately 200 K and a susceptibility maximum near 400 K. The critical· exponent β for Sr2Cr03F is 0.26(4). The (100) magnetic reflection of both SrLaCr04 and Sr2Cr03F shows short range order correlations above Tc. </p> / Thesis / Master of Science (MSc)

Landslides in the Southern Appalachian Mountains of East Tennessee often activate and reactivate. Often triggered by high-intensity or prolonged rainfall, landslides are responsible for infrastructure damage, closure of transportation routes, and even fatality. The study area is defined by the New River Watershed which has high elevation and steep slopes cutting through State Route 116. The route has hairpin turns and has experienced damage from past landslide events. The geology here is mostly shale and sandstones with coal bedding throughout. Much of the soil consists of a fine-loamy texture. Most drainage occurs from the New River, fed by runoff from slopes into roadways. This area experiences heavy rainfall with a yearly average of 70 inches. Landcover consists of a mostly forested landscape with shrubs and grassland. In response to previous landslides, the Tennessee Department of Transportation (TDOT) recently repaired six areas within the route intercepted by recent landslides. Aside from the landslides near TDOT’s corridors, approximately 50 additional landslides have been found using Google Earth and LiDAR data. Landslide hotspots were identified using kernel density estimation and the nearest neighbor index. A heuristic landslide susceptibility model was prepared by weighing the ArcGIS layers: slope, soil particle, geology, curvature, elevation, distance from the stream, and land cover, in their contribution to the previous landslides. Results indicate that additional sites in Anderson and Morgan County should be studied further for potential landslide-related damage. The study will improve the proactive decisions of TDOT and justify timely monitoring, maintenance, and strategic protection of the route from slope hazards.

Health misinformation is prevailing on Chinese social media like WeChat – a multi-functional social networking infrastructure in China – and it affects people’s choice and food and health care, which then influences people's health and sometimes cause panic. Many literatures have focused on health misinformation related to pandemic, vaccines or emergent diseases. However, few of them studies daily lifestyle related misinformation on social media. Also, many literatures suggest that aging plays a role in increased vulnerability to misinformation, but few discuss about it in the context of daily lifestyle related misinformation. In this study, an online survey (N=1,141) was conducted to study people’s susceptibility to daily lifestyle related health misinformation on WeChat, and the associated factors from the perspectives of misinformation topics, health belief, cultural belief, social networks and media. The results indicate that perceived severity and benefits increases people’s susceptibility to health misinformation. Alliance of people’s pre-existing belief with the underlying construct of the misinformation also increases their susceptibility to health misinformation. Additionally, lower rating of self-reported health status also plays a role in such susceptibility. Yet, in the contrast to existing literature, this study finds that self-efficacy has no effect on assisting people in identifying health misinformation. Regarding health information sharing, people tend to share what they consider credible but with different motivations to WeChat connections in different social settings. In a relatively more semi-public platform (WeChat Moments) with generalized social connections, they are motivated by the goal of sharing useful information and maintaining social relationships. Yet, in relatively more private settings like individual chat or group chat, they are motivated by altruism when sharing with strong ties while by maintaining social relationships when sharing with weak ties. The results also reveal that the increase in age increases the frequency of health information sharing behavior. In addition to the survey, I conducted a follow up interview with 30 participants of different age groups to explore how people access, process and share health information on WeChat. The interview contains a think-aloud protocol that can detect the criteria people employ to evaluate health mis/information on WeChat. Building on Elaborative Likelihood Model of Persuasion, the interview results reveal that in addition to relevance of topic and ability to process the mis/information, time constraints also contribute to which route people take on when processing information, especially with busy daily schedules and overwhelming amount of available health information on WeChat. When taking on the peripheral route, besides author credibility, older and younger generations use different peripheral cues to process health mis/information, and employ different criteria in evaluating the quality.

No description available.

The 2007 Energy Independence and Security Act mandates the production of 135 billion liters of transportation fuel achieved through the use of alternative energy sources. The most economically and sustainably competitive bioenergy crops will need to be high yielding, perennial species which require minimal inputs coupled with the ability to grow on marginal land. Grower adoption will be imperative to the success of this industry. Our results indicate that after three years of growth, several species including Arundo donax and Miscanthus × giganteus are able to produce up to 48.2 and 61.4 Mg ha⁻¹ dry weight of feedstock respectively. We also found that weed management may not be necessary under ideal growing conditions, but a group of herbicides appear promising for preemergence and postemergence application timings, tested under greenhouse conditions. The herbicides pyroxasulfone, sethoxydim and nicosulfuron may prove to be useful tools for the control of bioenergy crops if they escape cultivation. The potential for many of these exotic and highly competitive species to become invasive has hindered advancement of this industry. We develop a beginning framework to evaluate the potential for seeded Miscanthus × giganteus to become invasive, as no proven formula currently exists. We developed a novel methodology to assess the invasive potential of bioenergy crops across a continuum of invasiveness, which proved to be critical to the interpretation of our results. This methodology allows us to make relative comparisons of risk, evaluating our otherwise isolated results in broader context. We chose to evaluate M. × giganteus in a direct comparison with known exotic invasives, as well as with species that are known not to be invasive. We use a tiered approach, combining qualitative risk assessment models with quantitative field trials. Results from two weed risk assessment models indicate that many bioenergy feedstocks are of high risk, but agronomic crops such as Oryza sativa were also found to be high risk. Subsequent field trials indicate that seedling establishment for M. × giganteus in perennial systems may be low as only 0.1% of emerged seedlings survived after six months, while up to 10% of the invasive Microstegium vimineum survived. Spread of fertile M. × giganteus seedlings into annual systems with low competition had greater success; we observed 316 culms m⁻², at a distance of 1.5 m from the planted plot, after three years of growth. The observed spread of fertile M. × giganteus, in the low competition environment, did not differ from that of our positive control species; however, spread of fertile M. × giganteus seedlings into areas of high competition was significantly lower than our positive controls, up to 3 m from the cultivated plot. Importantly, A. donax and sterile M. × giganteus never spread from the cultivated plot. Results from our study and application of this novel methodology will help to prepare for the expansion of this burgeoning industry while providing useful information for the implementation of best management practices and improved stewardship. / Ph. D.

As populations of the European gypsy moth (Lymantria dispar L.) move into the southeast, laboratory studies indicate that the potential exists for defoliation and possible tree mortality in mixed pine-hardwood stands. This dissertation describes a field study that was initiated to determine the susceptibility and vulnerability of pure and mixed stands of loblolly pine, oaks and sweetgum in pine-oak and pine-sweetgum cover types in the Atlantic Coastal Plain physiographic province. Sixteen stands were defoliated between 1992 and 1996. Stand susceptibility was significantly related to stand composition; stands with a greater proportion of susceptible species experienced greater defoliation. Oaks and sweetgum were heavily defoliated. Pines did not suffer extensive defoliation, and results of the study indicate that the probability of widespread gypsy moth defoliation in pine plantations appears to be low. A multiple linear regression model for the prediction of mean stand defoliation is also presented. Trends in tree mortality were similar to those previously described in northeastern forests. Susceptible tree species were heavily impacted, however, oaks displayed greater vulnerability than sweetgum. Suppressed and intermediate trees in the understory, and trees that were in poor or fair condition, had a greater probability of dying subsequent to defoliation. However, under- and overstory basal area mortality rates were not significantly different in the pine-oak type, and stem mortality rates were not significantly different in either type. Loblolly pine mortality was observed, but it was difficult to isolate the source, and thereby determine whether gypsy moth defoliation was a primary causal factor. In general, the potential for extensive pine mortality in mixed pine-hardwood stands does not appear to exist. Logistic regression was found to be a useful tool in the prediction of individual tree mortality and two logistic regression equations were derived and validated for use in pine-oak and pine-sweetgum cover types. / Ph. D.

The present study tested the hypothesis that contiguity, regarding time of administration of the Tellegen Absorption Scale (TAS), differentially influences hypnotic susceptibility. Forty-eight subjects were administered the TAS immediately prior to assessment of hypnotic susceptibility versus 43 subjects who received the TAS one to three days before assessment of hypnotic susceptibility. Absorption, when measured in the temporally versus nontemporally contiguous context did not appear to affect hypnotic susceptibility. Absorption did, however, correlate significantly with hypnotic susceptibility in the temporally contiguous group as compared to a non-significant correlation in the nontemporally contiguous group. This finding suggests is a relationship between differential administration of the TAS with regard to time of administration and hypnotic susceptibility.

The present study was designed to test Frankel and Orne's hypothesis that persons with a clinically significant phobia also show high susceptibility to hypnosis. The hypnotic susceptibility scores of 10 persons who sought treatment with hypnosis for agoraphobia were compared with the susceptibility scores of a control group of 20 persons having comparable motivation to succeed in hypnosis. The susceptibility measure was the Stanford Hypnotic Susceptibility Scale: Form C (SHSS:C, Weitzenhoffer & Hilgard, 1962). The groups were also compared on: a) the Archaic Involvement Measure (AIM; Nash, 1984); b) the Field Depth Inventory (FDI; Field, 1965); and c) the Tellegen Absorption Scale (TAS; Tellegen & Atkinson, 1974). No significant differences were found between the groups on the dependent measures. Factors which qualify the results are discussed.

Magnetic fabric, magma flow and tectonic deformation in volcano-plutonic systems ABSTRACT This Ph.D. thesis aims to investigate dynamics of emplacement and tectonic history of selected volcano-plutonic complexes in a continental magmatic arc and back arc setting. The thesis presents new data sets from five field areas, presented in separate chapters, which could be viewed as representing a vertical sections through upper part of an intermediate to felsic magmatic system. From top to bottom in this ‛imaginary' vertical system, the examined units are: (1) andesitic lava domes and (2) sub-volcanic magma chambers (<3 km deep) of the Miocene Štiavnica volcano- plutonic complex, Western Carpathians (Slovakia), (3) Shellenbarger pluton (<3 km depth) within the mid-Cretaceous Minarets caldera, Sierra Nevada batholith in California (USA), and ~7-10 km deep granitoids of (4) Lower-Cretaceous Wallowa batholith, Blue Mountains province in Oregon (USA) and (5) Late Devonian Staré Sedlo complex, central Bohemian Massif (Czech Republic). The research incorporates extensive field and structural data, supported by analysis of igneous textures and anisotropy of magnetic susceptibility (AMS). The latter is further accompanied by detailed examination of magnetic mineralogy using thermomagnetic measurements and optical and back...

La majeure partie de cette thèse concerne l’étude de la susceptibilité diamagnétique en champ magnétique nul d’un gaz d’électrons de Bloch à température et densité fixées dans la limite de sfaibles températures. Pour les électrons libres (i.e. en l’absence de potentiel périodique), la susceptibilité diamagnétique a été calculée par L. Landau en 1930 ; le résultat est connu sous le nom de formule de Landau. Quant au cas des électrons de Bloch, E.R. Peierls montra en 1933 que dans l’approximation des électrons fortement liés, la formule pour la susceptibilité diamagnétique reste la même en remplaçant la masse de l’électron par sa ”masse effective” ; ce résultat est connu sous le nom de formule de Landau-Peierls. Depuis, de nombreuses tentatives pour clarifier les hypothèses de validité de la formule de Landau-Peierls ont vu le jour. Le résultat principal de cette thèse établit rigoureusement qu’à température nulle, lorsque la densité d’électrons tend vers zéro, la contribution dominante à la susceptibilité diamagnétique est donné par la formule de Landau-Peierls avecla masse effective de la plus petite bande d’énergie de Bloch. / The main part of this thesis deals with the zero-field diamagnetic susceptibility of a Blochelectrons gas at fixed temperature and fixed density in the limit of low temperatures. For a freeelectrons gas (that is when the periodic potential is zero), the steady diamagnetic susceptibilityhas been computed by L. Landau in 1930 ; the result is known as Landau formula. As for the Blochelectrons, E.R. Peierls in 1933 showed that under the tight-binding approximation, the formula forthe diamagnetic susceptibility remains the same but with the mass of the electron replaced by its”effective mass” ; this result is known as the Landau-Peierls formula. Since, there were very manyattempts in order to clarify the assumptions of validity of the Landau-Peierls formula. The mainresult of this thesis establishes rigorously that at zero temperature, as the density of electrons tendsto zero, the leading contribution of the diamagnetic susceptibility is given by the Landau-Peierlsformula with the effective mass of the lowest Bloch energy band.