Caves on carbonate islands are useful indicators of past sea level because cave formation is dependent on sea-level controlled freshwater lens position (flank margin caves), or form in direct contact with coastal processes (sea caves). Sea-level curves present a useful proxy for glacioeustatic and paleoclimate studies, so caves offer useful data. Once a flank margin cave is breached, it may be modified and eroded by waves. This overprinting leads to morphology similar to that of sea caves. While both indicate past sea level, they reveal differing information about the amount of denudation that has occurred to expose them (a paleoclimate indicator), so differentiation of these cave types is important. This study presents some of the first sea cave data from carbonate islands, and makes morphological comparisons between flank margin caves and sea caves from the Bahamas, California, and Maine. Using morphometric techniques, these caves can be distinctly identified.

Tafoni have been confusingly defined in many ways: variations in size, rock type, and forming mechanisms. This study addresses tafoni in Quaternary eolian carbonates to help better define the term. Large tafoni were differentiated from other coastal caves in the Bahamas, specifically flank margin and sea caves, using morphometric analyses. The differentiation is important as all three cave types form in the same area, but flank margin and sea caves can be used as paleo-sea level indicators, while tafoni cannot. Small tafoni show a growth rate of 0.022 m3/yr; and may amalgmate to form larger tafoni, which grew at 0.65 m3/yr. Petrographic analysis helped identify tafoniorming mechanisms; results revealed no evaporites present, removing crystal wedging as a mechanism, while indicating wind erosion as the primary mechanism. This analysis found significantly greater cements within the Holocene rocks compared to previous studies, and SEM analysis revealed organic cements preserved by oil-based cutting.

Communities of resistance are increasingly turning to radical tactics, including acts of civil disobedience, to fight back against encroaching fossil fuel infrastructure. The fight against the Mountain Valley Pipeline (MVP) is no exception. The MVP is a 303-mile long proposed fracked gas pipeline in Virginia and West Virginia. I apply radical flank effect (RFE) theory and the theory of movement dynamism to understand the role of civil disobedience, as a radical flank, in the MVP resistance movement. I contribute to the literature on RFEs by focusing primarily on how the radical flank of this movement has affected within-movement social dynamics, like trust, unity, and interpersonal relations. I rely on 15 semi-structured interviews with pipeline fighters, both those who have and have not participated in acts of civil disobedience, to gain insight into the use of civil disobedience, as a radical flank in the movement. This movement has used diverse tactics to challenge construction of the MVP, making it a strong case for understanding the role of radical tactics, and their relationship to moderate tactics. I find several positive RFEs (energizing effects, connecting effects, engaging effects, uniting effects, and movement outcome effects) and some potential negative RFEs (conflict/alienation, fear of consequences and organizational risks). I also find evidence of movement dynamism in the form of an ecosystem of tactics which emerged in the MVP resistance movement. Movement actors kept moderate and radical flanks publicly separate for strategic reasons while overlapping membership bridged the social dynamics of the movement, encouraging cohesion and collective movement identity. / Master of Science / Communities concerned about climate change are increasingly breaking the law in order to make their voices heard and stop dangerous coal, oil and natural gas projects. These actions are called civil disobedience and they have been used for decades in the United States, most prominently in the Civil Rights Movement. One such example in the fight against climate change is the resistance to the Mountain Valley Pipeline, a 303-mile long proposed natural gas pipeline in Virginia and West Virginia. I use social movement theories to understand the role that civil disobedience has played in the Mountain Valley Pipeline resistance movement. Specifically, I look at how the use of civil disobedience in this movement has affected the social dynamics of the movement, like trust, unity, or relationships in the movement. I spoke with 15 community members who have been active in fighting this pipeline to learn more. This movement has involved a wide range of different tactics, including civil disobedience, so it is a strong example to study for this research. My interviews with the community members revealed several positive effects as a result of the use of civil disobedience in the movement as well as a few potential risks/dangers. I also found that civil disobedience was able to work together with other types of tactics in a vibrant ecosystem that included mutual benefit. At the same time, I find that community members sought to keep some of the illegal tactics separate from more moderate tactics, like lawsuits or public comment submissions, in order to keep the moderate tactics safe. Despite this separation, I find that significant overlap of community members across different types of tactics was able to maintain a cohesive, common identity and unify people who were participating in different tactics, but fighting the same pipeline.

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Although a considerable amount of research exists on geometrical aspects of 5-axis flank milling, the dynamics of this efficient milling operation have not yet been given proper attention. In particular, investigating machining chatter in 5-axis flank milling remains as an open problem in the literature. The axial depth of cut in this operation is typically quite large, which makes it prone to machining chatter. In this thesis, chatter in 5-axis flank milling is studied by developing analytical methods of examining vibration stability, generating numerical simulations of the process, and conducting experimental investigations. The typical application of 5-axis milling includes the machining of thermal resistant steel alloys at low cutting speeds, where the process damping dominates the machining vibration. The results of experimental study in this thesis showed that the effect of process damping is even stronger in flank milling due to the long axial engagement. Accordingly, the first part of the thesis is devoted to studying process damping, and in the second part, the modeling of chatter in flank milling is presented. Linear and nonlinear models have been reported in the literature that account for process damping. Although linear models are easier to implement in predicting stability limits, they could lead to misinterpretation of the actual status of the cut. On the other hand, nonlinear damping models are difficult to implement for stability estimation analytically, yet they allow the prediction of “finite amplitude stability” from time domain simulations. This phenomenon of “finite amplitude stability” has been demonstrated in the literature using numerical simulations. In this thesis, that phenomenon is investigated experimentally. The experimental work focuses on uninterrupted cutting, in particular plunge turning, to avoid unduly complications associated with transient vibration. The experiments confirm that, because of the nonlinearity of the process damping, the transition from fully stable to fully unstable cutting occurs gradually over a range of width of cut. The experimental investigation is followed by developing a new formulation for process damping based on the indentation force model. Then, the presented formulation is used to compute the stability lobes in plunge turning, taking into account the effect of nonlinear process damping. The developed lobes could be established for different amplitudes of vibration. This is a departure from the traditional notion that the stability lobes represent a single boundary between fully stable and fully unstable cutting conditions. Moreover, the process damping model is integrated into the Multi-Frequency Solution and the Semi Discretization Method to establish the stability lobes in milling. The basic formulations are presented along with comparisons between the two approaches, using examples from the literature. A non-shallow cut is employed in the comparisons. Assessing the performance of the two methods is conducted using time domain simulations. It is shown that the Semi Discretization Method provides accurate results over the whole tested range of cutting speed, whereas higher harmonics are required to achieve the same accuracy when applying the Multi Frequency Solution at low speeds. Semi Discretization method is modified further to calculate the stability lobes in flank milling with tools with helical teeth. In addition to the tool helix angle and long axial immersion, the effect of instantaneous chip thickness on the cutting force coefficients is considered in the modified formulation of Semi Discretization as well. Considering the effect of chip thickness variation on the cutting force coefficients is even more important in the modeling of 5-axis flank milling, where the feedrate, and consequently the chip thickness, varies at each cutter location. It also varies along the tool axis due to the additional rotary and tilt axis. In addition to the feedrate, the tool and workpiece engagement geometry varies at each cutter location as well. The actual feedrate at each cutter location is calculated by the dynamic processing of the toolpath. The tool and workpiece engagement geometry is calculated analytically using the parametric formulation of grazing surface at the previous and current passes. After calculating the instantaneous chip thickness and tool/workpiece engagement geometry, they are integrated into the Semi Discretization Method in 5-axis flank milling to examine the stability of vibration at each cutter location. While the presented chatter analysis results in establishing stability lobes in 3-axis flank milling, it results in developing a novel approach in presenting the stability of the cut in 5-axis flank milling. The new approach, namely “stability maps”, determines the unstable cutter locations of the toolpath at each spindle speed. The accuracy of established 3-axis flank milling stability lobes and 5-axis stability maps is verified by conducting a set of cutting experiments and numerical simulations.

In this dissertation, a numerical method to design a curved surface for accurately flank milling with a general tool of revolution is presented. Instead of using the ruled surface as the design surface, the flank millable surface can better match the machined surface generated by flank milling techniques, and provide an effective tool to the designer to control the properties and the specifications of the design surface. A method using the least squares surface fitting to design the flank millable surface is first discussed. Grazing points on the envelope of the moving tool modeled by the grazing surface are used as the sample points and a NURBS surface is used to approximate the given grazing surface. The deviation between the grazing surface and the NURBS surface can be controlled by increasing the number of the control points. The computation process for this method is costly in time and effort. In engineering design, there is a need for fast and effortless methods to simplify the flank millable surface design procedure. A technique to approximate the grazing curve with NURBS at each tool position is developed. Based on the characteristics of the grazing surface and the geometries of the cutting tool, these NURBS representations at a few different tool positions, namely at the start, interior and end, are lofted to generate a NURBS surface. This NURBS surface represents the grazing surface and is treated as the design surface. Simulation results show that this design surface can accurately match the machined surface. The accuracy of the surface can be controlled by adding control points to the control net of the NURBS surface. A machining test on a 5-axis machine was done to verify the proposed flank millable surface design method. The machined surface was checked on a CMM and the obtained results were compared with the designed flank millable surface. The comparison results show that the machined surface closely matches the design surface. The proposed flank millable surface design method can be accurately used in the surface design.

In this dissertation, a numerical method to design a curved surface for accurately flank milling with a general tool of revolution is presented. Instead of using the ruled surface as the design surface, the flank millable surface can better match the machined surface generated by flank milling techniques, and provide an effective tool to the designer to control the properties and the specifications of the design surface. A method using the least squares surface fitting to design the flank millable surface is first discussed. Grazing points on the envelope of the moving tool modeled by the grazing surface are used as the sample points and a NURBS surface is used to approximate the given grazing surface. The deviation between the grazing surface and the NURBS surface can be controlled by increasing the number of the control points. The computation process for this method is costly in time and effort. In engineering design, there is a need for fast and effortless methods to simplify the flank millable surface design procedure. A technique to approximate the grazing curve with NURBS at each tool position is developed. Based on the characteristics of the grazing surface and the geometries of the cutting tool, these NURBS representations at a few different tool positions, namely at the start, interior and end, are lofted to generate a NURBS surface. This NURBS surface represents the grazing surface and is treated as the design surface. Simulation results show that this design surface can accurately match the machined surface. The accuracy of the surface can be controlled by adding control points to the control net of the NURBS surface. A machining test on a 5-axis machine was done to verify the proposed flank millable surface design method. The machined surface was checked on a CMM and the obtained results were compared with the designed flank millable surface. The comparison results show that the machined surface closely matches the design surface. The proposed flank millable surface design method can be accurately used in the surface design.

Despite a large demand from industry, a realistic chatter modeling for hard turning has not been available due to the complexity of the problem, which is mainly caused by flank wear and nonlinearity in hard turning. This thesis attempts to develop chatter models for predicting chatter stability conditions in hard turning with the considerations of the effects of flank wear and nonlinearity. First, a linear model is developed by introducing non-uniform load distribution on a tool tip to account for the flank wear effect. Second, a nonlinear model is developed by further incorporating nonlinearity in the structure and cutting force. Third, stability analysis based on the root locus method and the describing function approach is conducted to determine a critical stability parameter. Fourth, to validate the models, a series of experiment is carried out to determine the stability limits as well as certain characteristic parameters for facing and straight turning. From these, it is shown that the nonlinear model provides more accurate predictions than the linear model, especially in the high-speed range. Furthermore, the stabilizing effect due to flank wear is confirmed through a series of experiments. Fifth, to fully account for the validity of linear and nonlinear models, an empirical model is proposed to fit in with the experimental stability limits in the full range of cutting speed. The proposed linear and nonlinear chatter models will help to improve the productivity in many manufacturing processes. In addition, chatter experimental data will be useful to develop other chatter models in hard turning.

This is an analysis of flank and shift effects in political sociology that focuses on anti-immigrant parties in eight European countries. In a positive radical flank effect the radical party makes the moderate and mildly-threatening parties look good. In turn, that moderate party then gains power or at least many of their ends. A negative radical flank effect occurs when the actual or perceived association of the moderate party with the radical party causes the moderate party to lose support. Radical shift effects are when the moderate or conservative party shifts its policy toward the radical direction. In this case, the radical party may become a coalition partner with the moderate or conservative party. And conservative or moderate shift is when the radical party shifts its policy toward a more moderate direction in order to assume power or court votes. The radical flank effects have some currency in the civil rights literature, but the other two effects have been largely ignored. This thesis shows that the radical shifts, radical flank, and moderate shift effects do have explanatory value in political sociology.

This dissertation combines mineralogical data and petrographic and field observations with geochemical analysis (major, trace and isotope) to provide new insights into the hydrology and geochemistry of mid-ocean ridge hydrothermal systems. Two study areas were chosen to study two different aspects of hydrothermal circulation: high-temperature on-axis hydrothermal systems were studied using samples from the Hess Deep Rift (Cocos Plate, Equatorial Pacific) and low-temperature off-axis hydrothermal systems were studied at the Troodos Ophiolite in Cyprus. Significant findings include the documentation of a previously unknown warm fluid that pervades the lavas leaching Li from newly formed crust. This finding corroborates a model of broad hydrothermal discharge in the sheeted dikes. In the off-axis low-temperature regime, lateral flow of warm fluid is documented in the lavas, advecting heat from the oceanic lithosphere, with minor geochemical changes to the lavas. The sedimentary cover was found to influence alteration in two ways. The longer an area remains unsedimented allowing the free ingress and egress of seawater, the deeper the enrichment of alkali metals is observed. The maximum enrichment in alkali metals (K, Rb, Cs) however, is similar in both locations. The sedimentary cover can also modify the seawater before it becomes impermeable to fluid flow; early metaliferrous oxide sediments react with seawater, creating a fluid that mobilizes and fractionates the REEs and Y. The fractionation results in negative Ce anomalies, positive Eu anomalies, and negative Y anomalies. Basalts altered under these conditions also lack the ubiquitous Fe-oxides and Fe-oxyhydroxides that are commonly associated with alkali metal uptake. In situ trace element analysis of alteration minerals formed at low-temperature confirmed that secondary phyllosilicates are strongly enriched in alkali metals (K, Rb, Cs and Li), Ba is found in adularia and zeolites, Sr is hosted in carbonates, and no phases were found to be enriched in U. The concentrations of K2O, Rb, Cs (as well as B) are highest in celadonites, whereas Li concentrations are highest in smectites (saponite, Al-saponite, beidellite) and smectite-chlorite mixtures, and much higher than previously reported. Alkalis are also taken up into palagonite, with Li having the highest concentrations, over 1000 ppm in one analysis. Crystal chemical factors were found to be the dominant control on trace element uptake, and for the phyllosilicates no correlation was found between the temperature, age of the crust, texture of the phyllosilicates. In phyllosilicates the K, Rb and Cs are adsorbed as exchange cations, with enrichment (Cs > Rb > K) increasing with decreasing hydration energy, whereas the uptake of Li and B does not correlate with the hydration energy. Lithium concentrations also do not correlate with the Mg content, suggesting substitution of Li for Mg is not the only mechanism of Li uptake into phyllosilicates as has been suggested. / Graduate