Various total syntheses of the Lycorine-type pharmacologically active alkaloids hippadine and pratosine have been developed. However, most of these synthetic routes require prohibitively expensive materials and/or achieve yields that are subpar, making these schemes unlikely to be used in an industrial setting. Current research involves developing better synthetic methods for these two alkaloids starting with a 6,7-disubstituted isoquinoline. These syntheses are appealing since they utilize readily available starting materials and avoid expensive catalysts. The key step in the synthetic scheme centers around an intramolecular de Mayo photocyclization which involves a reaction between an alkene moiety in the isocarbostyril system and a 1,3-diketone (a functionalized tether on nitrogen), which forms a third ring in the structure of the molecule. Research on a model system (an isocarbostyril without the substituents at positions 6 and 7) for these natural products has been done in order to elucidate the optimal conditions for each step on the synthetic strategy. Initial attempts were made in order to synthesize the 6,7-disubstituted isocarbostyril with the 1,3-diketone tether so that the deMayo photocyclization could be performed. However, the established synthetic strategy led to compounds along the synthetic route that had very undesirable solubility properties. To resolve this issue, the substituents were replaced with bulkier, more non-polar moieties in order to increase the solubility of the compound in ethyl ether.

The Barby Formation makes up part of the Konkiep Terrane, which is a major Mesoproterozoic arc complex along the Kalahari craton margin in southwest Namibia. Previous mapping indicates that the Barby Formation contains a laterally and vertically complex series of basaltic to rhyolitic lavas, rhyolitic ignimbrites, and associated hypabyssal intrusions. Our new work shows that significant basaltic to andesitic pyroclastic successions are also present within the unit and record a wide variation in eruption styles.

Detailed mapping reveals the presence of Hawaiian, Strombolian and phreatomagmatic pyroclastic deposits forming successions up to X m thick emplaced close to source vents and intercalated with fine-grained lacustrine strata in an area ~20 km2. The most abundant deposits consist of basaltic to andesitic spatter accumulations formed from vigorous lava fountains during Hawaiian-style eruptions. These sequences show random vertical transitions on the scale of a few meters from moderately agglutinated to densely welded spatter, which reflect variations in pyroclast accumulation rates. Individual spatter pieces are up to x cm long. The densely welded spatter forms lava-like units, but we see no evidence of clastogenic lava flows. Sequences of basaltic lapillistone with dispersed ribbon and fusiform bombs up to 50 cm across record Strombolian eruptions during episodes of lower magma flux without involvement of external water. The spatter accumulations typically grade upward into phreatomagmatic deposits containing minor amounts of spatter and cauliflower bombs mixed with poorly vesicular lapilli tuff, in which particle shapes are controlled mostly by fracture surfaces rather than broken bubble walls; up to 30% lacustrine sediment is intermixed with juvenile lapilli and ash in these deposits. We infer that changes in eruptive style in this part of the arc sequence were controlled at least partly by variations in magma ascent rates at shallow depths, as documented in numerous other volcanic provinces. Transitions from Hawaiian to phreatomagmatic eruptions may at least partly reflect a decrease in magma flux in the presence of external water, lowering the magma-to-water mass ratio so that hydrovolcanic explosions became possible.

Northwestern South America is highly deformed due to the transpressive boundary with complex interactions among the Caribbean plate, the South American plate, the Nazca plate and the Panama arc. Previous studies suggest that the Cenozoic uplifting of the Mérida Andes and Eastern Cordillera of Colombia affected sediment dispersal patterns in the region, shifting from a Paleocene foreland basin configuration with an axial major fluvial system, to the modern configuration of isolated basins with distinctive sediment dispersal patterns. Well-exposed Cretaceous to Pliocene strata in the Táchira saddle between the Easter Cordillera and Merida Andes provide a unique opportunity to test proposed sediment dispersal patterns in the region. U-Pb detrital zircon geochronology and supplementary XRD heavy mineral identification were used together to document provenance of Cretaceous to Pliocene clastic rocks collected from the area of La Alquitrana. Results from the U-Pb detrital zircon geochronology show that there are six age groups recorded in this samples. Two groups related with Precambrian Guyana shield Terranes and Putumayo basement in the Eastern Cordillera, and four groups related to different magmatic episodes during the Andean Orogenic process. Three major paleogeography changes were also recorded in these detrital signatures, including a transition between the Cretaceous passive margin and the Paleocene foreland basin, the initial uplifting of the Eastern Cordillera with the isolation the Llanos Basin and Táchira Saddle from the Central Cordillera and the Magdalena Valley in the Early Oligocene, and the uplifting of the Mérida Andes by the Early Miocene. The outcomes of this study emphasize the importance of the Mérida Andes and Eastern Cordillera Uplift in controlling the evolution of the sediment dispersal patterns in northern South America and represent a contribution in the understanding of the paleogeographic evolution in the region.

Fluvio-lacustrine systems are prone to experiencing significant flood events separated by longer low energy periods. During low flow, sediment is stored upstream of the lake as mid-channel and side-attached bars. During high-discharge events, water level rises above the topographically low delta front levees, the turbulent jet of the river is positioned upstream of the levee terminus where levees are less confining, and the previously stored sediment is flushed from the channel into the lake basin laterally as sheets. This process forms a laterally extensive, well sorted wedge shaped deposit of fine grained sand called a blowout wing (after Tomanka, 2013). These wings are documented in the ancient within the Kayenta Formation, UT, where the sand wings demonstrated a significant increase in connectivity between statistically clustered fluvio-lacustrine channel belts. In this research, we document two examples of blowout wings forming in the modern. The first example is a lake sourced by a mud dominated river (Denton Creek, Lake Grapevine, TX), and the second is a lake sourced by a sandy, bedload dominated river (Red River, Lake Texoma, TX). Wings are composed of fine to medium grained, well sorted, and clean sand. The deposits are thin and laterally continuous, with measured thicknesses of 5-10 cm that thin away from channel axis. Wings have an aerial extent up several hundred meters, scaling to 4-6 times the channel width. The Red River at Lake Texoma has a channel width of 125m and deposits wings with an aerial extent of 250-350m long along the levee of the delta channel and 300-500m laterally. As the Red River has prograded into the basin, 5-6 individual blowout wings form a wing complex 1500m long and 500-600m laterally from the channel. Denton Creek at Lake Grapevine has a channel width of 25m and deposits wings on the order of 50-125m along the levee of the delta channel and 60-150m laterally. Three wings at Lake Grapevine form a wing complex 300m long and 100-150m laterally. The amalgamation and statistical clustering of fluvio-deltaic channel belts is increased by the presence of blowout wings, resulting in higher total reservoir size and connectivity. Blowout wings should be, and are, found in modern systems and subsequently the rock record recording fluvio-lacustrine environments of deposition.

Thin sand sheets presumed to be terminal splay bodies have potential to serve as hydrocarbon reservoirs. The few studies of terminal splays managed from arid systems has provided insight, but ground study of the humid equivalent is lacking. Deposited in the distal zone of a distributary fluvial system (DFS), the splay bodies are formed as rivers terminate from loss of slope into unconfined dispersive flow and deposit bed load as splays and advect mud to more distal floodplains. The splay sheets and floodplain together provide potential for both reservoir and seal. We examined terminal splay deposits in a modern humid terminal splay system, Andean foreland of northern Argentina, and in ancient foreland deposits, Paleocene Raton Formation of the Colorado Raton Basin. I am going to compare the two locations in terms of grain-size, sedimentary structures, geometry, and scale and see how they relate. I hypothesize that the two are going to have similar grain sizes, and that the sedimentary structures and geometries will also be analogous but expect them to be scaled down in the Raton Basin.
The modern splay in Argentina is nearly 1.3 km wide and 1.9 km long and was deposited during a single large flood in 2012. Cross sections generated by hand augers show a maximum thickness of 0.8 m, an average of 0.5 m, and a consistently very fine-grained to lower medium-grained sand texture throughout. Total sand deposited in the flood event is ~ 1.2 million cubic meters (~2.0 million cubic meter maximum), and accumulates over earlier splay deposits separated by weakly developed soils that are locally removed by splay incision. Subsequent dissection of the splay permits examination of sedimentary structures, which are dominantly climbing ripples, planar laminations, and cross sets, but climbing antidunes are locally found near the splay apex. Ancient terminal splays of the Raton Formation are made of thinner sand sheets (~0.25 m) and tend to have thicker muddy floodplain deposits between. Grain-size distribution, sheet geometry, and sedimentary structures however are consistent between the modern and ancient examples. Both the Argentina and Raton examples reflect the distal end of a humid Distributive Fluvial System, however, the Raton system appears to have been of smaller scale. This is consistent with the comparatively smaller scale of the Raton vs. Andean tectonic system.

The Late Paleozoic Ouachita fold-and-thrust belt extends from the southern terminus of the Appalachian thrust belt in eastern Mississippi up through central Arkansas, southeastern Oklahoma, and Texas terminating in northeastern Mexico. A series of Carboniferous foreland basins were formed sequentially to the thrust front. The interaction between the Laurentian craton and the Appalachian-Ouachita orogenic belts controlled sedimentation in the southern midcontinent region throughout the Paleozoic. In contrast to the Appalachian orogenic belt to the east, the Ouachita orogenic belt and associated sediments remain poorly documented and less constrained.
In this study, seven Ordovician to Mississippian aged clastic units from the Ouachita Mountain in central Arkansas were sampled and tested using U-Pb detrital zircon geochronology. Three major age peaks are prominent, including the Grenville Province (~0.95-1.2 Ga), the Granite-Rhyolite Province (~1.3-1.5 Ga), and the Superior Province (>~2.5 Ga) in Ordovician to Silurian aged rocks. A change in this signature becomes clear at the beginning of the Carboniferous from Early Mississippian Stanley Group samples showing the additional Paleozoic age peak (~490-520 Ma) potentially derived from the Appalachian orogenic belt to the east, and/or from peri-Gondwanan terranes accreted to Laurentia just before the collision with Gondwana. This stratigraphic variation of detrital zircon age signature suggests that the transition from a passive to an active margin in the Ouachita trough started, at the latest, in early Mississippian times. Results of this study is the first systematic study of the U-Pb detrital zircon signature of the Ouachita orogenic belt and have important implications in sediment dispersal, provenance interpretations, and paleogeography reconstructions in North America, especially in the southern mid-continent and surrounding areas.

The Eagle Ford Shale in south Texas is one of the most prolific unconventional hydrocarbon plays in the world (Breyer, 2016). In 2015, natural gas and oil from this field hit peak production numbers at 5,539 MMcf (million cubic feet) and 1,118,648 Bbl (barrels) per day, respectively (Texas RRC, 2016).  In order for this low-permeability formation to produce, companies are using hydraulic fracturing, a stimulation treatment used in low-permeability rock whereby fluids are pumped at high pressures into reservoirs, causing new fractures to form and possibly reactivating existing fractures (Schlumberger, 2016).  The aim of this study is to identify any geomechanical and geochemical properties that optimize fracture connectivity within the Boquillas Formation, the West Texas Eagle Ford equivalent.  Energy-dispersive x-ray fluorescence (ED-XRF) and strength/hardness data from this study suggests that fracture frequency and length are affected by the clay and calcium carbonate content, and, by inference, the strength of the rock.

The winding number of a continuous function on the unit circle counts how many times a graph of the function loops around the origin. It is homotopy invariant and has applications to several areas of Mathematics.
Toeplitz operators with continuous symbol are bounded linear operators on the Hardy Space involving multiplication by a continuous function. The index of such a Toeplitz operator is closely connected to the winding number of its symbol.
This connection is examined and then extended for Toeplitz operators with crossed product symbols.

An algebraic integer is a complex number that is a root of a monic polynomial with integer coefficients. It is well-known that there is not always a single algebraic integer that can generate the ring of algebraic integers contained in a field extension of the rational numbers. The index of an algebraic integer is a natural number that measures how far a ring of integers is from having such a "primitive element." We investigate these indices in cubic fields and determine which natural numbers occur as indices in given families.

Located inside the Large Magellanic Cloud, fierce explosions called supernovae have thrown out massive amounts of gas in every direction. A portion of this gas is aimed toward the Milky Way and is on a crash course with our galaxy. We are observing this gas with the Wisconsin H-Alpha Mapper, which provides a window into how the gas is distributed. These observations show two periods of supernovae explosions that created two distinct gas winds. One of these winds is currently active while the other was produced roughly 300 Million years old. Studying these gas clouds will provide information on how massive these winds are and the rate at which they are produced. The ejected gas is headed toward the Milky Way could supply our galaxy with additional gas to form stars in the future.

Graphene oxide (GO) inherits high transparency, substantial conductivity, high tensile strength from its parent materials graphene. Apart from these properties, it emits fluorescence which makes it a potential material to use in optoelectronics and bio-sensing applications. In this work, we have utilized systematic ozone treatment to alter the optical band gap of single-layered graphene oxide in aqueous suspensions. Due to controlled ozonation, additional functionalization takes place in GO graphitic sheet which changes GO electronic structure. This is confirmed by the increase in vibrational transitions of a number of oxygen-containing functional groups with treatment and the appearance of the prominent carboxylic group feature at c.a. 1700 1/cm. Albeit, timed ozone induction introduces only slight change in color and absorption spectra of GO samples, the emission spectra show a gradual increase in intensity with a significant blue shift up to 100 nm from deep red to green. This large blue shift suggests an increase in optical band gap with additional functionalization introduced by ozone treatment. We utilize a semi-empirical theoretical approach to describe the effects of functionalization-induced changes. This model attributes the origins of fluorescence emission to the quantum confined sp² carbon islands in GO encircled by the functional groups. As we decrease the graphitic carbon cluster size on the GO sheet, the optical bandgap calculated via HyperChem molecular modeling increases, which supports the experimentally observed blue shifts in emission. This theoretical result is further supported by the TEM measurement of ozone-treated samples, which shows a decreasing trend of average ordered graphitic carbon cluster size on GO sheets with treatment time. Theoretical modeling, as well as the experimental results, indicate that the optical bandgap and emission intensity of GO are alterable with controlled ozone treatment, which allows tailoring the optical properties of GO for specific applications in optoelectronics and bio-sensing.

The Open Cluster Chemical Abundances and Mapping (OCCAM) survey is a systematic survey of Galactic open clusters using data primarily from the SDSS-III/APOGEE-1 survey. However, neutron capture elements are limited in the IR region covered by APOGEE. In an effort to fully study detailed Galactic chemical evolution, we are conducting a high resolution (R~60,000) spectroscopic abundance analysis of neutron capture elements for OCCAM clusters in the optical regime to complement the APOGEE results. As part of this effort, we present Ba II, La II, Ce II and Eu II results for a few open clusters without previous abundance measurements using data obtained at McDonald Observatory with the 2.1 m Otto Struve telescope and Sandiford Echelle Spectrograph.

The goal of this study was to conduct a survey of 913 M-dwarf stars from the Lepine and Shara Proper Motion(LSPM) catalog within 33 parsecs. This research was conducted to improve upon the statistics of nearby multiple M-dwarf star systems. Identifying and confirming multiple systems at both wide and small separations will expand understanding of M-dwarf formation by comparing these results to existing star formation models. Data for these targets was collected with the Robo-AO camera on the Palomar 60in telescope. Separation and position angles were determined and compared for two epochs of the images containing multiple stars, one taken in 2012 and the other taken in 2014, to look for changes in these values. Stars with little change in position with respect to one another suggest they are common proper motion pairs. The Washington Double Star(WDS) catalog and other resources were used to further determine binarity. There were 50 multiple star system candidates found with a multiplicity fraction of 28.6±3.0 and a companion star fraction of 34.7±2.1.

A galaxy environment influences its internal properties. All galaxies start out small and grow bigger after merging with other galaxies. We are conducting a statistical study on isolated and interacting galaxies to determine how their environment impacts on their star-formation ability. We are using observations from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which has already observed more than 3000 galaxies. We are examining the differences and similarities of the gas and stars in isolated and interacting galaxies to explore their past and current star formation activity. From these comparisons, we will identify which conditions promote and hinder star formation to learn how different types of galaxies evolved. An example of an isolated galaxy is shown here.