Physical Sciences and Mathematics Commons^™

A Fossilized Energy Distribution Of Lightning, Matthew A. Pasek, Marc Hurst

School of Geosciences Faculty and Staff Publications

When lightning strikes soil, it may generate a cylindrical tube of glass known as a fulgurite. The morphology of a fulgurite is ultimately a consequence of the energy of the lightning strike that formed it, and hence fulgurites may be useful in elucidating the energy distribution frequency of cloud-to-ground lightning. Fulgurites from sand mines in Polk County, Florida, USA were collected and analyzed to determine morphologic properties. Here we show that the energy per unit length of lightning strikes within quartz sand has a geometric mean of ~1.0 MJ/m, and that the distribution is lognormal with respect to energy per …

Geochemistry Of Upper Cretaceous Sediments Of Bozeş Formation (Apuseni Mts., Romania) – Provenance Implications, Luminiţa Zaharia, Romona Bălc, Cosmin C. Stremţan, Adriana Socaciu

School of Geosciences Faculty and Staff Publications

A whole-rock geochemical study was carried out on sandstones from the Upper Cretaceous Bozeş Formation in the southeastern part of the Apuseni Mountains (Romania) in order to constrain their provenance and depositional setting. The geochemical results were compared and integrated with previously reported provenance indicators, such as framework composition and heavy mineral assemblages. The chemical composition is similar for all samples investigated, with limited ranges for both major oxides and trace elements. The sandstones are potassic (Na₂O/K₂O < 1) and can be classified mainly as arenites with a few greywackes. Their immature to relatively mature character is revealed by the SiO₂/Al₂O₃ ratios, ranging between 3.90 and 11.25, as well as their high Sr/Rb ratios. The …

Encrustation Of Inarticulate Brachiopods On Scaphitid Ammonites And Inoceramid Bivalves From The Upper Cretaceous U. S. Western Interior, Neil H. Landman, Joshua S. Slattery, Peter J. Harries

School of Geosciences Faculty and Staff Publications

The inarticulate brachiopod Discinisca is a rare faunal element in the Upper Cretaceous of the U.S. Western Interior. We report two occurrences of encrustation of Discinisca on a scaphitid ammonite (scaphite) and several inoceramids from the lower Maastrichtian Baculites baculus/Endocostea typica Biozones of the Pierre Shale at two localities. Six specimens of Discinisca are present on a single specimen of Hoploscaphites crassus from east-central Montana. They occur along the furrow at the mature apertural margin. Because the brachiopods are restricted to the margin and do not occur on the rest of the shell, it is likely that they …

Geographically Isolated Wetlands Are Part Of The Hydrological Landscape, Mark Rains, S. G. Leibowitz, M. J. Cohen, I. F. Creed, H. E. Golden, J. W. Jawitz, P. Kalla, C. R. Lane, M. W. Lang, D. L. Mclaughlin

School of Geosciences Faculty and Staff Publications

No abstract provided.

Evaluation Of Aster-Like Daily Land Surface Temperature By Fusing Aster And Modis Data During The Hiwater-Musoexe, Guijun Yang, Qihao Weng, Ruiliang Pu, Feng Gao, Chenhong Sun, Hua Li, Chunjiang Zhao

School of Geosciences Faculty and Staff Publications

Land surface temperature (LST) is an important parameter that is highly responsive to surface energy fluxes and has become valuable to many disciplines. However, it is difficult to acquire satellite LSTs with both high spatial and temporal resolutions due to tradeoffs between them. Thus, various algorithms/models have been developed to enhance the spatial or the temporal resolution of thermal infrared (TIR) data or LST, but rarely both. The Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) is the widely-used data fusion algorithm for Landsat and MODIS imagery to produce Landsat-like surface reflectance. In order to extend the STARFM application over …

Recent Increases In Arctic Freshwater Flux Affects Labrador Sea Convection And Atlantic Overturning Circulation, Qian Yang, Tim Dixon, Paul G. Myers, Jennifer Bonin, Don Chambers, M.R. Van Den Broeke, Mads H. Ribergaard, John Mortensen

School of Geosciences Faculty and Staff Publications

The Atlantic Meridional Overturning Circulation (AMOC) is an important component of ocean thermohaline circulation. Melting of Greenland’s ice sheet is freshening the North Atlantic; however, whether the augmented freshwater flux is disrupting the AMOC is unclear. Dense Labrador Sea Water (LSW), formed by winter cooling of saline North Atlantic water and subsequent convection, is a key component of the deep southward return flow of the AMOC. Although LSW formation recently decreased, it also reached historically high values in the mid-1990s, making the connection to the freshwater flux unclear. Here we derive a new estimate of the recent freshwater flux from …

Developing Priority Variables (“Ecosystem Essential Ocean Variables” — Eeovs) For Observing Dynamics And Change In Southern Ocean Ecosystems, Andrew J. Constable, Daniel P. Costa, Oscar Schofield, Louise Newman, Edward R. Urban Jr., Elizabeth A. Fulton, Jessica Melbourne-Thomas, Tosca Ballerini, Philip W. Boyd, Angelika Brandt, Eileen E. Hofmann

CCPO Publications

Reliable statements about variability and change in marine ecosystems and their underlying causes are needed to report on their status and to guide management. Here we use the Framework on Ocean Observing (FOO) to begin developing ecosystem Essential Ocean Variables (eEOVs) for the Southern Ocean Observing System (SOOS). An eEOV is a defined biological or ecological quantity, which is derived from field observations, and which contributes significantly to assessments of Southern Ocean ecosystems. Here, assessments are concerned with estimating status and trends in ecosystem properties, attribution of trends to causes, and predicting future trajectories. eEOVs should be feasible to collect …

Mathematical And Anthropological Analysis Of Northern Luzon Funeral Textile, Ma. Louise Antonette N. De Las Peñas, Analyn V. Salvador-Amores

Mathematics Faculty Publications

The study presents a mathematical analysis and provides an anthropological perspective of the funeral textile of the indigenous communities in northern Luzon, Philippines. In particular, a symmetry analysis is performed, based on principles of group theory and transformation geometry, on the various repeating patterns found in funeral garments and blankets. Results show that particular frieze groups and plane crystallographic groups are favored due to choice of motifs which are reflective of cultural beliefs and funeral traditions, as well as weaving style and methodology. The results of the analysis point to the depth of mathematics present in the work of the …

Crystal Structure Of Ethyl 4-[(E)-(4-Hy-Droxy-3-Meth-Oxy-Benzyl-Idene)Amino]-Benzoate: A P-Hy-Droxy Schiff Base, Jing Ling, Padmini Kavuru, Lukasz Wojtas, Keith Chadwick

Chemistry Faculty Publications

The title p-hy-droxy Schiff base, C17H17NO4, was synthesized via the condensation reaction of benzocaine with vanillin. The benzyl-idine and benzoate rings are inclined to one another by 24.58 (8)°, and the conformation about the C=N bond is E. In the crystal, mol-ecules are linked by O-H⋯N hydrogen bonds, forming zigzag chains propagating along [010]. Adjacent chains are linked by C-H⋯π and weak offset π-π inter-actions [inter-centroid distance = 3.819 (1) Å], forming sheets parallel to (10-2).

Inactivation Of Peptidylglycine Α-Hydroxylating Monooxygenase By Cinnamic Acid Analogs, Neil R. Mcintyre, Edward W. Lowe Jr, Matthew R. Battistini, James W. Leahy, David J. Merkler

Chemistry Faculty Publications

Peptidylglycine α-amidating monooxygenase (PAM) is a bifunctional enzyme that catalyzes the final reaction in the maturation of α-amidated peptide hormones. Peptidylglycine α-hydroxylating monooxygenase (PHM) is the PAM domain responsible for the copper-, ascorbate- and O₂-dependent hydroxylation of a glycine-extended peptide. Peptidylamidoglycolate lyase is the PAM domain responsible for the Zn(II)-dependent dealkylation of the α-hydroxyglycine-containing precursor to the final α-amidated peptide. We report herein that cinnamic acid and cinnamic acid analogs are inhibitors or inactivators of PHM. The inactivation chemistry exhibited by the cinnamates exhibits all the attributes of a suicide-substrate. However, we find no evidence for the formation …

Nucleophile Promoted Gold Redox Catalysis With Diazonium Salts: C-Br, C-S And C-P Bond Formation Through Catalytic Sandmeyer Coupling, Haihui Peng, Rong Cai, Chang Xu, Hao Chen, Xiaodong Shi

Chemistry Faculty Publications

Gold-catalyzed C-heteroatom (C-X) coupling reactions are evaluated without using sacrificial oxidants. Vital to the success of this methodology is the nucleophile-assisted activation of aryldiazonium salts, which could be an effective oxidant for converting Au(i) to Au(iii) even without the addition of an assisting ligand or photocatalyst. By accelerating the reaction kinetics to outcompete C-C homo-coupling or diazonium dediazoniation, gold-catalyzed Sandmeyer reactions were achieved with different nucleophiles, forming C-Br, C-S and C-P bonds in high yields and selectivities.

Adapting Near-Ultraviolet Colorimetry For Long-Term In Situ Monitoring Of Hexavalent Chromium In Groundwater Aquifers, Janine Carter

Graduate Student Theses, Dissertations, & Professional Papers

This paper briefly describes sources of hexavalent chromium [Cr(VI)] and the risk it poses to human health and the environment; current methods used to regulate, monitor, and measure Cr(VI); the basic design of a submersible, direct-reading sensor in development for long-term monitoring of Cr(VI) concentration in natural waters; and the means developed to correct sensor readings for two common analytical interferences, turbidity and pH, that could lead to an incorrect measurement of Cr(VI). The principal purposes of this study are to analyze the current methods used to compensate for sample turbidity, to develop methods to compensate for sample pH, and …

Magnetic Field Non-Uniformity Challenges In Neutron Electric Dipole Moment Experiments, Nima Nouri

Theses and Dissertations--Physics and Astronomy

A new neutron Electric Dipole Moment (nEDM) experiment was proposed to be commissioned at the Fundamental Neutron Physics Beamline at the Spallation Neutron Source (SNS) of the Oak Ridge National Laboratory (ORNL). The underlying theme of this experiment (first conceived by Golub and Lamoreaux in 1994) is the search for new physics beyond the Standard Model of particle physics. The discovery of a non-zero nEDM would be of revolutionary importance to physics, with the discovery of such providing for evidence for new-beyond-the-Standard-Model physics required for a resolution to the unresolved puzzle of why the universe is dominated by matter, as …

Organic Geochemistry And Element Distribution In Coals Formed In Eocene Lagoon Facies From The Eastern Black Sea Region, Ne Turkey, Çi̇ğdem Saydam Eker, İbrahi̇m Akpinar, Ferkan Si̇pahi̇

Turkish Journal of Earth Sciences

The amount and type, the inorganic element content, and the maturity of organic materials of Eocene coals, shaly coals, and coaly shales exposed in the Gümüşhane and Bayburt districts of the Eastern Black Sea Region of Turkey were investigated. The depositional environments and hydrocarbon potentials were also interpreted. The total organic carbon concentrations in the studied samples ranged from 0.50% to 63.08%. The samples from Özyurt, Kayadibi, and Tarhanas contained types II and III kerogen, and those from Sökmen and Manas contained type III kerogen. The samples contained Co, Cs, Ga, Hf, Th, U, Y, Mo, Be, Cd, Sb, and …

Effects Of Variable Viscosity And Thermal Conductivity On Magnetohydrodynamic Free Convection Flow Of A Micropolar Fluid Past A Stretching Plate Through Porous Medium With Radiation, Heat Generation, And Joule Dissipation, Gopal Chandra Hazarika, Bandita Phukan

Turkish Journal of Physics

The effects of temperature-dependent viscosity and thermal conductivity on free convection magnetohydrodynamic flow of an optically thin gray, viscous, and incompressible micropolar fluid and heat transfer past a stretching plate through porous medium in the presence of radiation, heat generation, and Joule dissipation were studied. The fluid viscosity and thermal conductivity were assumed to vary as inverse linear functions of temperature. Using similarity transformation, the governing partial differential equations of motion were reduced to ordinary ones, which were solved numerically for prescribed boundary conditions using the shooting method. Numerical results for the velocity, angular velocity, and temperature profiles are shown …

Amplitude Modulation Of Ion-Acoustic Waves In Magnetized Electron-Positron-Ion Plasma With Q-Nonextensive Electrons And Positrons, Basudev Ghosh, Sreyasi Banerjee

Turkish Journal of Physics

Using a standard reductive perturbation technique, a nonlinear Schrödinger equation has been derived that describes the nonlinear evolution of ion-acoustic waves in magnetized electron-positron-ion plasma with electrons and positrons following q-nonextensive distribution. It is shown that excitation of both bright and dark envelope solitary structures is possible in the model plasma under consideration. The conditions for the excitation and structure of these envelope solitary waves are shown to depend sensitively on the strength of the external magnetic field, obliqueness of wave propagation relative to the external magnetic field, and other plasma parameters such as the q-nonextensivity of plasma species, positron …

Effects Of Variable Viscosity And Thermal Conductivity On Magnetohydrodynamic Free Convection Dusty Fluid Along A Vertical Porous Plate With Heat Generation, Gopal Chandra Hazarika, Jadav Konch

Turkish Journal of Physics

The present study investigated the effects of variable viscosity and thermal conductivity on a two-dimensional steady laminar magnetohydrodynamic (MHD) free convective boundary layer flow of a dusty fluid over a vertical porous flat plate with viscous dissipation, Joule heating, and heat generation/absorption. Governing partial differential equations of motion were reduced to a system of ordinary differential equations using similarity transformations. The resulting boundary value problem was then solved numerically using the shooting technique. Velocity, temperature, and species concentration profiles of fluid and solid particles were obtained for different flow governing parameters. The results are presented in graphs. We found that …

Pp-Waves In Modified Gravity, Ahmet Baykal

Turkish Journal of Physics

The family of metrics corresponding to the plane-fronted gravitational waves with parallel propagation, commonly referred to as the family of pp-wave metrics, is studied in the context of various modified gravitational models in a self-contained and coherent manner by using a variant of the null coframe formulation of Newman and Penrose and the exterior algebra of differential forms on pseudo-Riemannian manifolds.

Structure And Stability Of Primordial Stars, Aysel İbrahi̇m Karafi̇stan

Turkish Journal of Physics

For decades large-scale cosmic structures have been modeled as the gravitational amplification of small-density perturbations of the cosmological recombination epoch of the Big Bang. In astrophysics, cosmological nucleosynthesis is considered responsible for the production of the pristine gas, which should be found in the first-generation stars in the form of hydrogen and helium as the main constituents. In the later type of second-generation stars, hydrogen is converted into helium by the CN-cycle reactions, in which heavier elements are produced. These elements are believed to enrich the intergalactic medium by possible star bursts at the last stages of evolution. Stability criteria …

Drying Methods For The Fabrication Of Polymer Foam Material, Dalton Echard

Theses and Dissertations

This is a report on the study of the drying of nanoporous polymer foam material fabricated by photolithogtaphic methods. Three drying methods were employed, which were air drying, supercritical drying and freeze drying. After fabrication and drying, physical properties of the polymer foams were measured. These measurements included density of the material, Young’s modulus, surface area, and the shape of the skeletal particles. The measurements determined the effect of the polymer concentration and the effect of drying methods. It was determined that polymer concentration had a much larger effect on the properties of the materials than the drying method.

Automated Conjecturing Approach To The Discrete Riemann Hypothesis, Alexander Bradford

Theses and Dissertations

This paper is a study on some upper bounds of the Mertens function, which is often considered somewhat of a ``mysterious" function in mathematics and is closely related to the Riemann Hypothesis. We discuss some known bounds of the Mertens function, and also seek new bounds with the help of an automated conjecture-making program named CONJECTURING, which was created by C. Larson and N. Van Cleemput, and inspired by Fajtowicz's Dalmatian Heuristic. By utilizing this powerful program, we were able to form, validate, and disprove hypotheses regarding the Mertens function and how it is bounded.

Beyond Conventional C-Plane Gan-Based Light Emitting Diodes: A Systematic Exploration Of Leds On Semi-Polar Orientations, Morteza Monavarian

Theses and Dissertations

Despite enormous efforts and investments, the efficiency of InGaN-based green and yellow-green light emitters remains relatively low, and that limits progress in developing full color display, laser diodes, and bright light sources for general lighting. The low efficiency of light emitting devices in the green-to-yellow spectral range, also known as the “Green Gap”, is considered a global concern in the LED industry. The polar c-plane orientation of GaN, which is the mainstay in the LED industry, suffers from polarization-induced separation of electrons and hole wavefunctions (also known as the “quantum confined Stark effect”) and low indium incorporation efficiency that …

Systematic Postsynthetic Modification Of Nanoporous Organic Frameworks And Their Performance Evaluation For Selective Co2 Capture, Timur Islamoglu

Theses and Dissertations

Porous organic polymers (POPs) with high physicochemical stability have attracted significant attention from the scientific community as promising platforms for small gas separation adsorbents. Although POPs have amorphous morphology in general, with the help of organic chemistry toolbox, ultrahigh surface area materials can be synthesized. In particular, nitrogen-rich POPs have been studied intensively due to their enhanced framework-CO₂ interactions. Postsynthetic modification (PSM) of POPs has been instrumental for incorporating different functional groups into the pores of POPs which would increase the CO₂ capture properties. We have shown that functionalizing the surface of POPs with nitro and amine groups …

Electronic Structure And Stability Of Ligated Superatoms And Bimetallic Clusters, William H. Blades

Theses and Dissertations

Quantum confinement in small metal clusters leads to a bunching of states into electronic shells reminiscent of shells in atoms. The addition of ligands can tune the valence electron count and electron distribution in metal clusters. A combined experimental and theoretical study of the reactivity of methanol with Al_nI_m⁻ clusters reveals that ligands can enhance the stability of clusters. In some cases the electronegative ligand may perturb the charge density of the metallic core generating active sites that can lead to the etching of the cluster. Also, an investigation is conducted to understand how the bonding …

Effect Of Disulfide Bond Scrambling On Protein Stability, Aggregation, And Cytotoxicity, Colina Dutta

Dissertations, Master's Theses and Master's Reports

Proteins are nano-machines that carry out majority of the cellular functions. Thermodynamically they are functional and stable within a very narrow range (1 kcal/mol). External perturbations in the form of pH change, thermal, or oxidative/reducing stress can destabilize the protein resulting in misfolding and aggregation. Prolonged environmental stress can affect the cells adaptive response resulting in loss of ability to refold or recycle proteins. This can lead to accumulation of misfolded or aggregated proteins within the cell. Such accumulation of aggregated proteins have been associated with neurodegenerative disorders such as Amyotrophic Lateral Sclerosis (ALS), Parkinson’s, Huntington’s, and Alzheimer’s disease. There …

Tabulating Pseudoprimes And Tabulating Liars, Andrew Shallue

Scholarship

This paper explores the asymptotic complexity of two problems related to the Miller-Rabin-Selfridge primality test. The first problem is to tabulate strong pseudoprimes to a single fixed base $a$. It is now proven that tabulating up to $x$ requires $O(x)$ arithmetic operations and $O(x\log{x})$ bits of space.The second problem is to find all strong liars and witnesses, given a fixed odd composite $n$.This appears to be unstudied, and a randomized algorithm is presented that requires an expected $O((\log{n})^2 + |S(n)|)$ operations (here $S(n)$ is the set of strong liars).Although interesting in their own right, a notable application is the search …

Maximum Efficiency Of A Wind Turbine, Marisa Blackwood

Undergraduate Journal of Mathematical Modeling: One + Two

The concept of a wind turbine is not new technology, however, in a day and age where renewable energy is popular, the interest in wind turbines has increased dramatically. This project investigates multiple aspects of a wind turbine and will derive the maximum power efficiency of an ideal wind turbine, first introduced by Albert Betz in 1919. This project will also calculate the size of a wind turbine at maximum efficiency given certain parameters and determine the optimum outlet velocity as a function of wind speed to maximize the mechanical energy produced. These equations will be derived by using concepts …

Why Law Now Needs To Control Rather Than Follow Neo-Classical Economics, John William Draper

Librarian Scholarship at Penn Carey Law

Selfish utilitarianism, neo-classical economics, the directive of short-term income maximization, and the decision tool of cost-benefit analysis fail to protect our species from the significant risks of too much consumption, pollution, or population. For a longer-term survival, humanity needs to employ more than cost-justified precaution.

This article argues that, at the global level, and by extension at all levels of government, we need to replace neo-classical economics with filters for safety and feasibility to regulate against significant risk. For significant risks, especially those that are irreversible, we need decision tools that will protect humanity at all scales. This article describes …

Greenc5: An Adaptive, Energy-Aware Collection For Green Software Development, Junya Michanan

Electronic Theses and Dissertations

Dynamic data structures in software applications have been shown to have a large impact on system performance. In this paper, we explore energy saving opportunities of interface-based dynamic data structures. Our results suggest that savings opportunities exist in the C5 Collection between 16.95% and 97.50%. We propose a prototype and architecture for creating adaptive green data structures by applying machine learning tools to build a model for predicting energy efficient data structures based on the dynamic workload. Our neural network model can classify energy efficient data structures based on features such as the number of elements, frequency of operations, interface …

Implementing Agile Development At Scale: An Industry Case Study, Nikita Kataria

Electronic Theses and Dissertations

Agile software development methodologies are extremely popular. Their dynamic restructuring of the development process has been seen as the silver bullet for increasing the productivity of software development. A significant number of studies have analyzed the impact of implementing agile techniques. However these are mostly evaluated only in smaller team settings. There is very little reporting done on how agile development methods can be implemented at the team level and scaled up at the program/portfolio level in large software organizations.

We present the results of an empirical study conducted at Pearson Education. The study focuses on the penetration of agile …