Hydroflux Synthesis: A New and Effective Technique for Exploratory Crystal Growth

Exploratory crystal growth is the best way to discover new phases with potentially improved properties or new crystal structures that could lead to new properties. As time goes on and researchers explore the synthetic techniques in the literature, diminishing returns will be met. Innovation in the synthetic tools used for synthesis is necessary to keep the field of materials chemistry advancing at its current pace and to allow us to reach more shallow minima of phase space. By combining wet hydroxide flux synthesis and hydrothermal synthesis, a hybrid technique for crystal growth has been created. Using hydroxide hydrofluxes, a number of new materials have been synthesized and their relevant physical properties have been characterized. New oxides, hydroxides and oxyhydroxides incorporating transition metals in reduced states, manganese in highly oxidized states, rare earth ions, and iron in a new and unusual framework have been grown by this method. Crystal growth and physical properties of these systems are the focus of this dissertation. These investigations demonstrate the capabilities of hydroflux synthesis as a new route for exploratory synthesis

Recovering a Sense of Place in the Edge City

The edge city is often criticized as being a center of placelessness. It is the devaluation and commodification of place in contemporary approaches to urban design and planning that is stifling the prosperity of place identity and subsequently the ability for edge cites to create \u27a sense of place\u27. It is probable that a broadened understanding of the situational context and the role of human experience in place making can suggest alternatives to current practices that reduce place to location. Capturing the essence of place inspires superior strategies for producing place identity and a grasp on the meaning of how recovering ‘a sense of place’ is fundamental in turning edge cities from consumable space into real and lasting places

Conglomerate

I use my sculptures to explore a variety of dualities and dichotomies within the Self through formal and material relationships. I am interested in both the rough and the refined, the stable and the precarious, the intuitive and the analytical -- I am fascinated by the points where these contrasting tendencies meet. I juxtapose organic, ambiguous vessels with architectonic structures to create a complex landscape of forms that encourages intent observation and asks the viewer to consider their position within society and the wider natural world. I strive to find balance, both within my practice and the work itself. I am interested in the subtle and unobtrusive beauty that emerges from the thoughtful confluence of contrasting elements. When these elements are brought into harmony, they produce a tranquil beauty that encourages reflection in the viewer. Within my practice, I work to balance intention and emergence; intuition and analysis; my role as artist, as student, as teacher. To strive for balance is to strive to become more oneself. When these contrasting elements are brought together within exhibition, their impact is intensified.Includes bibliographical references

Optical properties of current carrying molecular wires

We consider several fundamental optical phenomena involving single molecules in biased metal-molecule-metal junctions. The molecule is represented by its highest occupied and lowest unoccupied molecular orbitals, and the analysis involves the simultaneous consideration of three coupled fluxes: the electronic current through the molecule, energy flow between the molecule and electron-hole excitations in the leads and the incident and/or emitted photon flux. Using a unified theoretical approach based on the non-equilibrium Green function method we derive expressions for the absorption lineshape (not an observable but a ueful reference for considering yields of other optical processes) and for the current induced molecular emission in such junctions. We also consider conditions under which resonance radiation can induce electronic current in an unbiased junction. We find that current driven molecular emission and resonant light induced electronic currents in single molecule junctions can be of observable magnitude under appropriate realizable conditions. In particular, light induced current should be observed in junctions involving molecular bridges that are characterized by strong charge transfer optical transitions. For observing current induced molecular emission we find that in addition to the familiar need to control the damping of molecular excitations into the metal substrate the phenomenon is also sensitive to the way in which the potential bias si distributed on the junction.Comment: 56 pages, 8 figures; submitted to JC

A New Digital Image Compression Algorithm Based on Nonlinear Dynamical Systems

In this paper we discuss the formulation of, and show the results for, a new compression/decompression algorithm called DYNAMAC, that has its basis in nonlinear systems theory. We show that we are able to achieve significant compression of RGB image data while maintaining good image quality. We discuss the implementation of this algorithm in hardware, show that the same process is applicable to other digital forms of data, demonstrate that the decompression process is ideal for streaming applications, and show that the algorithm has an exploitable aspect of encryption useful for digital rights management and secure transmission. We discuss our methodology for the improvement of the performance of this codec

2016-2017 Master Class and Mini-Recital - Michael Lewin (Piano)

https://spiral.lynn.edu/conservatory_masterclasses/1007/thumbnail.jp

Effect of Khat (Catha edulis) Use on the Bioavailability, Plasma Levels and Antimalarial Activity of Chloroquine.

OBJECTIVES This study aimed to evaluate the effect of khat (Catha edulis) on chloroquine (CQ) bioavailability in healthy Yemeni adults and its effect on CQ plasma levels and parasite clearance among malaria patients. METHODS This study took place between January and April 2007 in Bajil and Sana'a, Yemen. Two CQ doses (600 mg each) were given to 15 healthy males on separate occasions; the first dose was followed by a khat-chewing session (phase one) while controls abstained from khat-chewing for the second (phase two). Additionally, 103 patients with Plasmodium falciparum-induced malaria, including both regular khat chewers (n = 57) and non-khat chewers (n = 46), were treated with CQ (25 mg/kg) over three days. Pharmacokinetic parameters were analysed among both controls and malaria patients. Parasite clearance was also investigated for the latter group. RESULTS The mean area under the concentration-time curve (AUC) was 2,108.9 versus 2,797.4 ng/hour/mL, mean peak plasma concentration (Cmax) was 415.6 versus 508.7 ng/mL and mean time to reach Cmax was 3.8 versus 3.6 hours for controls in phase one versus phase two, respectively; both AUC and Cmax levels were significantly reduced by khat-chewing (P <0.050). For khat- versus non-khat-chewing malaria patients, mean plasma CQ concentrations were 266.4 ng/mL versus 427.5 ng/mL (P <0.001). Furthermore, CQ was effective in 71.7% and 75.4% of non-khat and khat-chewing malaria patients, respectively (P = 0.823). CONCLUSION Khat-chewing was found to significantly reduce plasma CQ levels among healthy volunteers and malaria patients. While receiving CQ treatment, patients should be advised not to chew khat

Vortex Dynamics and Defects in Simulated Flux Flow

We present the results of molecular dynamic simulations of a two-dimensional vortex array driven by a uniform current through random pinning centers at zero temperature. We identify two types of flow of the driven array near the depinning threshold. For weak disorder the flux array contains few dislocation and moves via correlated displacements of patches of vortices in a {\it crinkle} motion. As the disorder strength increases, we observe a crossover to a spatially inhomogeneous regime of {\it plastic} flow, with a very defective vortex array and a channel-like structure of the flowing regions. The two regimes are characterized by qualitatively different spatial distribution of vortex velocities. In the crinkle regime the distribution of vortex velocities near threshold has a single maximum that shifts to larger velocities as the driving force is increased. In the plastic regime the distribution of vortex velocities near threshold has a clear bimodal structure that persists upon time-averaging the individual velocities. The bimodal structure of the velocity distribution reflects the coexistence of pinned and flowing regions and is proposed as a quantitative signature of plastic flow

Stock Forecasts with LSTM and Web Sentiment

Traditional time-series techniques, such as auto-regressive and moving average models, can have difficulties when applied to stock data due to the randomness inherent to the markets. In this study, Long Short-Term Memory Recurrent Neural Networks, or LSTMs, have been applied to pricing data along with sentiment scores derived from web sources such as Twitter and other financial media outlets. The project team utilized this approach to complement the technical indicators observed at the end of each trading day for three stocks from the NASDAQ stock exchange over a 12-year span. A common benchmark to assess model performance on time series data is using the prior day’s closing price of a given stock to predict the next day’s closing value, which is a naive, but surprisingly accurate method when calculating the mean absolute error. The main objective of the paper is to use predictions from the various models assembled for the research, and then calculate whether the next day’s closing price will rise or fall when compared against the last predicted value. All models showed on average a roughly 2% accuracy improvement over the largely balanced up and down movements for the tickers used in the study