<p> Ferromagnetic nanostructures are under considerable interest for producing larger capacity magnetic storage devices. Denser magnetic storage leads to finer magnetic grains and smaller bit size, however, as bit size shrinks it approaches a limit, such that, a single magnetic grain is only capable of holding a single bit of information. Therefore, changes in nanoscale morphology can produce different magnetic properties, so characterizing nanostructures is crucial. Atomic force microscopy (AFM) is a common way to model the morphology of ferromagnetic thin films atop of nanosphere templates. In our research, we used AFM images of polystyrene nanospheres on top of silicon substrates to define the morphology of the AFM tip geometry. We calculated &thetas;L to be approximately 4.30 &plusmn; 1.07&deg;, &thetas;R to be approximately 21.14 &plusmn; 0.33&deg;, the tip apex radius r to be 37.87 &plusmn; 2.43 nm, and a total angle of 25.44&deg; with an error of 15.2% from manufacture specifications. After analyzing the same sample scanned at 4 different angles, 0&deg;, 45&deg;, 90&deg;, and 135&deg;, relative to the cantilever, we determined the optimal scan direction for our samples was 0&deg; relative to the cantilever, due to the geometry of the AFM tip. After scanning several samples containing 600 nm nanospheres with 20 nm and 40 nm of Permalloy thin film deposited on top, the AFM images were obtained. Further research is needed, such as, modification of the geometrical relationship between the tip and the layers atop of the nanospheres to clearly model the structure of Py atop of nanospheres.</p><p>

M.Sc. / Please refer to full text to view abstract

No description available.

On the basis of his study of the female genitalia, Scudder (1959) suggested that in the Heteroptera-Hemiptera, the families Saldidae and Mesoveliidae might be closely related; the present morphological study was undertaken to determine whether a study of other characters also supports their inclusion in a natural group. In these two families, comparison of the head structures revealed that they are quite distinct. The thorax revealed two types: a Saldula type, and a Mesovelia type, and since it is shown that the structure of the thorax is of little taxonomic value in distinguishing the suprafamilial categories, it was considered that the differences between the Saldidae and the Mesoveliidae need not necessarily indicate a fundamental taxonomic difference. In the abdomen, the presence of the clasping organ in the Saldidae completely separates this family from the Mesoveliidae, The present study shows that the Saldidae and the Mesoveliidae are not closely related as might be inferred from comparisons of the female genitalia; they are quite distinct morphologically. The taxonomic position of the two families was also considered. Most authorities believe that the Mesoveliidae are appropriately placed in the Amphibicorisae, and this is supported by the present study. The position of the Saldidae, on the other hand, has heretofore been very uncertain since this family shows some Pentatomomorph features as well as some Cimicomorph features. Two alternatives have been suggested in this thesis regarding the systematic position of the Saldidae. According to the first, the Saldidae may be considered a Cimicomorph which branched off from the main stem of Cimicomorpha, and subsequently developed Pentatomomorph characters - an assumption which presupposes that parallel evolution has occurred. Alternatively, the Saldidae may be considered a branch of the Pentatomomorpha, which arose after the evolution of some Pentatomomorph characters, but before the evolution of the complete Pentatomomorph complex of characters. This latter alternative takes cognisance of the fact that the Pentatomomorph complex of characters evolved gradually and not by a single 'saltation'. It has been concluded, however, that the data available at present are not sufficient to enable one to state which of the two alternatives mentioned above is the correct one, although I am inclined to consider the former as the more plausible. In addition to the foregoing, two general aspects of the morphology of the Heteroptera were considered, namely the interpretation of the head sclerites and the variation in the thoracic structure between apterous and macropterous forms of the two families. / Science, Faculty of / Zoology, Department of / Graduate

Laser-Induced Breakdown Spectroscopy (LIBS) is a method of analytical chemistry that provides a qualitative and quantitative analysis of a sample. The ablation process of a sample is fast and dynamic and the change of plasma in time and space is a question of a few microseconds. An examination that provides a good time and space resolution is necessary to understand better the physical processes. For this reason, the goal of this thesis is to design a basic optomechanic construction for this type of experiment. Furthermore, it is important to check the functionality of this design and to use it for a basic comparison between the spectroscopic and imaging data. Also, the time development of plasma will be observed under different experimental conditions. The goal of this thesis, in general, is to prove that the morphology of plasma is as it is described in available related literature.

This study intends to provide a quantitative and qualitative histological account of two aspects of mammary gland morphology. First, the normal mouse during different functional phases including inactivity, pregnancy, lactation and involution is presented. Second, the abnormal changes of mammary hyperplasia and neoplasia - both spontaneous and exogenous - are examined.

Sedimentation is one of the consequences of hydropower plant construction. Such structures not only have an influence on reservoir morphology, but also have great impact on both upstream and downstream river morphology. This study focuses on fluvial morphological changes in between two hydropower plants on the Drava River, Austria. The influence of both reservoir management methods (flushing) and human intervention (groynes) have been investigated. The first stage started with validating an unsteady Delft3D morphodynamic model of the meandering reach. This validation shows the importance of spatial grain size distribution in predicting bed load transport. Analysis of the flushing method includes investigation of the duration of gate-opening before and after peak flood. The results show that the duration of lowering the water level at the hydropower plant (by opening the gate) before starting the peak flood will not have a big influence on the river morphology upstream of the reservoir. However, the duration of maintaining the low water level after the peak flood has a large influence on both the river morphology in the upstream portion of the reservoir and on the sediment transport toward the reservoir In the second part of this study, hydraulic structural groynes were applied in the river reach. The objective was to design a groyne field that will minimize sediment transport to the reservoir. Both emerged and submerged groynes were investigated. In addition, the influences of both groyne head shape and the distribution of sediment grain size in the groyne zone were examined. This study shows that under an unsteady simulation, when the groynes are submerged by 1m at normal flow, the sediment supply to the groyne zone decreases compared to the emerged case. However, if the groynes are submerged by 0.5m, the sediment supply to the groyne zone will be greater than the emerged case for an aspect ratio in between (0.5-2). Finally, applying L-head groynes produces less erosion in the main stream and a higher sediment supply compared to straight groynes.

Recent progress in layered transition metal dichalcogenides (TMDs) has led to various promising electronic and optoelectronic applications. However, the structure of materials plays a critical role in electronic and optoelectronic devices, and determines performance. Electronic and optoelectronic devices typically consist of multiple layers that form electrical homojunctions or heterojunctions. Therefore, in a device it can be expected that a WS2 layer may serve as the substrate for a subsequent layer in a multilayer device stack and determine how the layer grows. In transistor structures, roughness at the channel/gate dielectric interface introduces field variations and charge scattering. Therefore, understanding the relations between processing, surface morphology and properties is important. In this project, the effects of pulsed laser deposition (PLD) processing conditions on the surface morphology of few layered WS2 films were studied. WS2 films were synthesized under processing conditions that represent the extremes of surface supersaturation and kinetic energy transfer from the flux to the growing films, and evolution of the surface morphology was studied. The specific conditions were 1Hz/50mJ, 10Hz/50mJ, 1Hz/300mJ, and 10Hz/300mJ respectively. Combining AFM, XRD and Raman analyses, it was determined that deposition at 10Hz/300mJ, provided the best structural properties and surface morphology. Growth appeared to be 3D-cluster, and was governed by supersaturation rather than by surface diffusion processes. No clear correlation between mobility and surface roughness was found. Hall measurements and XPS data show the highest mobility was obtained with the highest S/W ratio, indicating that point defect scattering rather than scattering from surface roughness was dominant.

This project is the result of a summer long internship I worked on with Dr. Beverly Smith in the ETSU Department of Physics and Astronomy. It was completed with the support of a grant from the NASA Tennessee Space Grant Consortium. Quenching galaxies are galaxies that are rapidly evolving from strongly star forming systems to galaxies with mostly old stars and low star formation rates. When identifying quenching galaxies, there are several methods in common use. Furthermore, there are several ways astronomers estimate the Star Formation Rate (SFR), in Solar Masses per year, and Stellar Mass (M*), in Solar Masses, of galaxies. For a large sample of galaxies, we used 6 derivations of M* and 4 for SFR, plotting them against each other for comparison. We also calculated and compared the specific SFR (sSFR), equal to SFR/M*, and compared the different methods of defining quenched galaxies. Finally, we divided up these plots by classification, Red Sequence/Green Valley/Blue Cloud, and different values of log (SFR) *

Eastern Newts (Notophthalmus viridescens) are a ubiquitous member of eastern North America’s caudate fauna. Unlike the typical amphibian, their life cycle is split into three phases instead of two, commonly called a triphasic life cycle. The larvae of N. viridescens are fully aquatic, eventually metamorphosing to become terrestrial juveniles, called efts. Upon sexual maturity, the eft will metamorphose into a semi-aquatic adult where its external morphology is typical of an aquatic salamander. Since there are apparent differences in their ecological niche, there are different forces acting on their skeletons. We hypothesize that due to differences in buoyancy, torsion, and locomotion, differences are expected in the morphology of the axial skeleton. Using image data generated on a SkyScan 1273 micro-computed tomography (µCT) scanner, 3D shape analyses will be used to quantify shape differences between vertebrae and test the hypothesis. Three dimensional digital models of each vertebrae of interest will be rendered from the scans in Dragonfly (Object Research Systems). Each 3D model is then loaded into SlicerMorph (3D Slicer), where landmarks are placed upon homologous structures on each vertebra. A Generalized Procrustes Analysis (GPA) followed by a Principal Component Analysis (PCA) is conducted for each vertebra to test for potential shape differences between each life stage. GPA and PCA analysis will be conducted on 10 terrestrial juveniles, 10 semi-aquatic adults, 5 aquatic juveniles, and 5 paedomorphic adults. The 5 aquatic juveniles and 5 paedomorphic adults, eastern newts that remain in the water through their entire lives, will validate if the semi-aquatic adult is truly adapting towards an aquatic lifestyle. If GPA and PCA indicate statistical shape differences between certain vertebrae, those vertebrae will be run through the Automated Landmarking through Pointcloud Alignment and Correspondence Analysis (ALPACA) module of SlicerMorph to produce heatmap data on the 3D models showing where exactly the shape changes are occurring in the vertebra.