Physical Sciences and Mathematics Commons^™

Liberation Of Acidity And Arsenic From Schwertmannite: Effect Of Fulvic Acid, Chamindra Vithana, Leigh Sullivan, Edward Burton, Richard Bush

Chamindra Vithana

Schwertmannite is one of the major components that produces acidity in acid mine drainage (AMD) and acid sulfate soils (ASS) and is also known to be an effective scavenger of Arsenic (As) in such environments. Fulvic acid (FA) is an active component of natural organic matter (NOM) and is known to interact strongly with both schwertmannite and As. Two main environmental hazards related to schwertmannite are acidity liberation and potential re-mobilization of adsorbed or co-precipitated As upon hydrolysis. This study focused on understanding the behaviour of As-substituted schwertmannite with regard to the potential of acidity liberation, the effect of FA …

Jarosite Quantification In Soils: An Enhanced Sequential Extraction Procedure, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton

Chamindra Vithana

A two-step sequential extraction procedure established for the quantification of acidity producing ferric and ferrous sulfate minerals such as melanterite and jarosite in acid mine wastes was evaluated for quantification of jarosite spiked in soils. The procedure involves in sequence anoxic water extraction, roasting the solid residue after anoxic water extraction at 550 °C for 1 h, and 4 M HCl extraction of the roasted solid. Soil and quartz samples were spiked with known amounts of synthetic and natural jarosite and their recovery was measured using the suggested two-step sequential extraction procedure. The recoveries of synthetic and natural jarosite were …

Evaluation Of Acidified Ammonium Oxalate Technique For The Identification Of Schwertmannite In Soil Materials, Chamindra Vithana, Leigh A. Sullivan, Richard T. Bush, Edward D. Burton

Chamindra Vithana

No abstract provided.

Readily Available Acidity In Schwertmannite, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton

Chamindra Vithana

Schwertmannite and jarosite are considered as less soluble ironhydroxy sulfate minerals which are present in highly acidic environments (pH < 3). These minerals release acidity in the long run as they weather by hydrolysis [1]. However, 1M KCl extraction of soil samples (Clarence and Quartz) spiked with those two minerals showed that schwertmannite has some acidity that may be readily available.

Effect Of Fulvic Acid On Liberation Of Acidity And Arsenic Form Arsenic Substituted Schwertmannite, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton

Chamindra Vithana

INTRODUCTION

Schwertmannite is one of the main secondary iron hydroxy sulfate minerals contributing to acidity in acid sulfate soils (ASS). While it is an important source of acidity in ASS, schwertmannite is also known to be a potential sink for trace metals such as arsenic (As) and chromium (Cr) (Fukushi et al. 2003; Regenspurg and Peiffer. 2005).Trace metal adsorption/substitution is known to stabilize schwertmannite which in turn retards its transformation to goethite which is one of the main processes of acidity generation in ASS. Fulvic Acid (FA) is a subclass of natural organic materials that are ubiquitous in aquatic environments …

A Critical Evaluation Of Retained Acidity (Ar) Estimating Methods In Acid Base Account (Aba) Approach For Acid Sulfate Soils (Ass), Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton

Chamindra Vithana

No abstract provided.

Underestimation Of Retained Acidity Measured Using Chromium Suite In Acid Sulfate Soils Containing Schwermannite And Jarosite, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton

Chamindra Vithana

No abstract provided.

Assessment And Behaviour Of Secondary Iron(Iii) Minerals In Acid Sulphate Soil Materials, Chamindra Vithana

Chamindra Vithana

This study examined two aspects of acidity generating secondary Fe(III) minerals (i.e. schwertmannite and jarosite) in acid sulfate soils (ASS) environments: i) accurate identification and quantification, and ii) improving our understanding of their behaviour in ASS.The study showed that current assessment methods have a number of limitations and are not reliable for accurate estimation of both minerals in ASS environments. The study also showed that in natural environments, these minerals can behave in a manner different to current conceptual understanding. The broad implication of this study was identification of the need for development of improved management techniques for ASS.

Schwertmannite In Soil Materials: Limits Of Detection Of Acidified Ammonium Oxalate Method And Differential X-Ray Diffraction, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton

Chamindra Vithana

Schwertmannite is a secondary iron mineral, found in acid mine drainage (AMD) and acid sulfate soils (ASS), that generates acidity when it transforms to stable mineral phases. Acidity liberated during schwertmannite transformation can seriously diminish water quality and soil health. Acidified ammonium oxalate (AAO) extraction in the dark coupled with differential X-ray diffraction (DXRD) analysis is routinely used to identify and to quantify poorly crystalline iron oxide phases such as schwertmannite in AMD environments. However, management of ASS environments is largely impacted due to lack of reliable methods to identify/quantify schwertmannite in soil materials. Our study aimed to evaluate the …

Stability Of Schwertmannite And Jarosite In An Acidic Landscape: Prolonged Field Incubation, Chamindra Vithana, Leigh Sullivan, Edward Burton, Richard Bush

Chamindra Vithana

Schwertmannite and jarosite are two of the main secondary iron(III) minerals commonly found in acidic, iron and sulfate-rich environments such as acid mine drainage and coastal acid sulfate soils (CASS). Both minerals exert major influence on the water and soil quality in these environments.While there are many studies conducted on the stability of these two minerals under controlled laboratory conditions, the behaviour of schwertmannite and jarosite under field conditions and the factors influencing their behaviour have not been investigated directly. In the present study, we examined the net transformation of introduced schwertmannite and jarosite samples incubated in a typical acidic …

Understanding The Behaviour Of Schwertmannite And Jarosite In Acid Sulfate Soils, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton

Chamindra Vithana

No abstract provided.

Molecular Network Control Through Boolean Canalization, David Murrugarra, Elena S. Dimitrova

Mathematics Faculty Publications

Boolean networks are an important class of computational models for molecular interaction networks. Boolean canalization, a type of hierarchical clustering of the inputs of a Boolean function, has been extensively studied in the context of network modeling where each layer of canalization adds a degree of stability in the dynamics of the network. Recently, dynamic network control approaches have been used for the design of new therapeutic interventions and for other applications such as stem cell reprogramming. This work studies the role of canalization in the control of Boolean molecular networks. It provides a method for identifying the potential edges …

Understanding Acceptable Level Of Risk: Incorporating The Economic Cost Of Under-Managing Invasive Species, Alisha D. Davidson, Chad L. Hewitt, Donna R. Kashian

Environmental Science and Geology Faculty Research Publications

Management of nonindigenous species includes prevention, early detection and rapid response and control. Early detection and rapid response depend on prioritizing and monitoring sites at risk for arrival or secondary spread of nonindigenous species. Such monitoring efforts require sufficient biosecurity budgets to be effective and meet management or policy directives for reduced risk of introduction. Such consideration of risk reduction is rarely considered, however. Here, we review the concepts of acceptable level of risk (ALOR) and associated costs with respect to nonindigenous species and present a framework for aligning risk reduction priorities with available biosecurity resources. We conclude that available …

Evaluation Of Low-Cost Low Impact Development Practices In Southwest Florida For The Control Of Urban Runoff, Laura Kathren Rankin

USF Tampa Graduate Theses and Dissertations

Stormwater management is required due to development and alteration of the natural environment. It is heavily regulated in Florida and at the national level. Over the last two decades, Low Impact Development (LID) has been promoted as a sustainable and environmentally friendly method of controlling urban runoff. Case studies, provided in Chapter 2, show that LIDs can restore watershed hydrology by balancing the water budget. The difference in runoff between pre-development and post-development appears to increase with soil perviousness. However, the potential for mitigating the impacts of urbanization through runoff reduction is also greater for pervious, sandy soils that dominate …

Operation And Monitoring Of Parabolic Trough Concentrated Solar Power Plant, Harsha Vardhan Amba

USF Tampa Graduate Theses and Dissertations

The majority of the power generated today is produced using fossil fuels,emitting carbon dioxide and other pollutants every second. Also, fossil fuels will eventually run out. For the increasing worldwide energy demand, the use f reliable and environmentally beneficial natural energy sources is one of the biggest challenges. Alongside wind and water, the solar energy which is clean, CO2-neutral and limitless, is our most valuable resource.

Concentrated solar power (CSP) is becoming one of the excellent alternative sources for the power industry. The successful implementation of this technology requires the efficient design of tracking and operation system of the CSP …

Land-Use & Water Quality In The Headwaters Of The Alafia River Watershed, Jaime Alison Swindasz

USF Tampa Graduate Theses and Dissertations

The objective of this study is to investigate land-use changes and water quality trends within the headwaters of the Alafia River watershed. Water quality data were obtained from the Environmental Protection Commission of Hillsborough County (EPCHC). Eleven water quality parameters selected for analysis included: temperature (˚C), dissolved oxygen (DO), percent saturation of DO, conductivity, pH, total phosphorous (TP), total nitrogen (TN), ammonium, chlorophyll-a (uncorrected), fecal coliforms, and enterococci. ArcMap® & SWFWMD data were used to map EPCHC sampling stations, calculate contributing watershed size, and determine land-use changes over the course of the sampling period; 17 stations were chosen for this …

Optical Studies Of 13 Hard X-Ray Selected Cataclysmic Binaries From The Swift-Bat Survey, Jules P. Halpern, John R. Thorstensen

Dartmouth Scholarship

From a set of 13 cataclysmic binaries that were discovered in the Swift Burst Alert Telescope (BAT) survey, we conducted time-resolved optical spectroscopy and/or time-series photometry of 11, with the goal of measuring their orbital periods and searching for spin periods. Seven of the objects in this study are new optical identifications. Orbital periods are found for seven targets, ranging from 81 minutes to 20.4 hr. PBC J0706.7+0327 is an AM Herculis star (polar) based on its emission-line variations and large amplitude photometric modulation on the same period. Swift J2341.0+7645 may be a polar, although the evidence here is less …

Shopminer: Mining Customer Shopping Behavior In Physical Clothing Stores With Passive Rfids, Longfei Shangguan, Zimu Zhou, Xiaolong Zheng, Lei Yang, Yunhao Liu, Jinsong Han

Research Collection School Of Computing and Information Systems

Shopping behavior data are of great importance to understand the effectiveness of marketing and merchandising efforts. Online clothing stores are capable capturing customer shopping behavior by analyzing the click stream and customer shopping carts. Retailers with physical clothing stores, however, still lack effective methods to identify comprehensive shopping behaviors. In this paper, we show that backscatter signals of passive RFID tags can be exploited to detect and record how customers browse stores, which items of clothes they pay attention to, and which items of clothes they usually match with. The intuition is that the phase readings of tags attached on …

Design And Synthesis Of Novel Chloroquine-Based Antimalarials, Kevin Vincent Murphy

Dissertations and Theses

Malaria is an infectious, often fatal disease that afflicts nearly 200 million people every year. The disease, characterized by recurring and extreme flu-like symptoms, is caused by the protozoan parasite Plasmodium falciparum. Victims usually contract the disease through a mosquito vector. Chloroquine is a chemotherapeutic that was introduced in the 1940s. For many years the drug was the foremost treatment of malaria, being effective and producing few side effects. Unfortunately, tolerance to chloroquine developed when the parasite evolved a resistance mechanism. Newer drugs have been developed and implemented, but these medicines also show a decreasing effect with continued administration. …

U.S. Drought Monitor, November 3, 2015, David Miskus

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for November 3, 2015 (11/3/15) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.

Exploring Rapid Radiochemical Separations At The University Of Tennessee Radiochemistry Center Of Excellence, Howard L. Hall, John D. Auxier Ii

Faculty Publications and Other Works -- Institute for Nuclear Security

The University of Tennessee formed its Radiochemistry Center of Excellence (RCoE) in 2013 with support from the U.S. National Nuclear Security Administration. One of the major thrusts of the RCoE is to develop deeper understanding of rapid methods for radiochemical separations that are relevant to both general radiochemical analyses as well as post-detonation nuclear forensics. Early work has included the development and demonstration of rapid separations of lanthanide elements in the gas phase, development of a gas-phase separation front-end for ICP-TOF-MS analysis, and the development of realistic analytical surrogates for post-detonation debris to support methods development.

Street-Level Predictive Modeling Of Nuisance Flooding Verified Via Crowdsourced App Data In Norfolk, Va, J. D. Loftis, H. V. Wang, D R. Forrest

Presentations

No abstract provided.

Resonant Quantum Dynamics Of Few Ultracold Bosons In Periodically Driven Finite Lattices, Simeon I. Mistakidis, T. Wulf, A. Negretti, P. Schmelcher

Physics Faculty Research & Creative Works

The Out-Of-Equilibrium Dynamics Of Finite Ultracold Bosonic Ensembles In Periodically Driven One-Dimensional Optical Lattices Is Investigated. Our Study Reveals That The Driving Enforces The Bosons In Different Wells To Oscillate In-Phase And To Exhibit A Dipole-Like Mode. A Wide Range From Weak-To-Strong Driving Frequencies Is Covered And A Resonance-Like Behavior Of The Intra-Well Dynamics Is Discussed. In The Proximity Of The Resonance A Rich Intraband Excitation Spectrum Is Observed. The Single Particle Excitation Mechanisms Are Studied In The Framework Of Floquet Theory Elucidating The Role Of The Driving Frequency. The Impact Of The Interatomic Repulsive Interactions Is Examined In Detail …

A College Level Geology Field Trip In Western Connecticut And Vicinity, Stanley Schleifer, Nazrul I. Khandaker, Keshaw Narine, Ezazul Haque, Ratan Dhar

Publications and Research

There are a number of excellent locations for field exposure for college students in, and around Western Connecticut. These are accessible for a one day field trip within striking distance of New York City, Bridgeport and New Haven, CT and other nearby locations. They are also suitable for an expanded weekend field trip. The field locations include; Kent Falls State Park, Kent, CT, Dinosaur State Park, Rocky Hill, CT, the Hubbard Mining Museum, Kent, CT, Bash Bish Falls in Mt. Washington, Massachusetts, Macedonia Brook State Park in Kent, CT and various outcrops exposed along U. S. Route 7 north of …

In Situ Studies Of Limestone Dissolution In A Coastal Submarine Spring, Rachel Marie Schweers

USF Tampa Graduate Theses and Dissertations

Limestone dissolution in karst environments is likely due to geochemistry of the water, the actions of microbial communities, and the effect of water flow. We explored the rate of limestone dissolution and will examine here the microbial communities associated with the limestone. A conduit within the brackish cave, Double Keyhole Spring, on the coast of central west Florida was the site of the experiment. PVC pipes (5cm x 16cm) were filled with crushed limestone that was screened to a 1.9cm – 2.54cm size range. There were three treatments (5 replicates each): Control - sealed autoclaved controls with limestone and conduit …

Neither Dust Nor Black Carbon Causing Apparent Albedo Decline In Greenland's Dry Snow Zone: Implications For Modis C5 Surface Reflectance, Chris Polashenski, Jack E. Dibb, Mark G. Flanner, Justin Y. Chen, Zoe R. Courville, Alexandra M. Lai, James J. Schauer, Martin M. Shafer, Mike Bergin

Earth Sciences

Remote sensing observations suggest Greenland ice sheet (GrIS) albedo has declined since 2001, even in the dry snow zone. We seek to explain the apparent dry snow albedo decline. We analyze samples representing 2012–2014 snowfall across NW Greenland for black carbon and dust light-absorbing impurities (LAI) and model their impacts on snow albedo. Albedo reductions due to LAI are small, averaging 0.003, with episodic enhancements resulting in reductions of 0.01–0.02. No significant increase in black carbon or dust concentrations relative to recent decades is found. Enhanced deposition of LAI is not, therefore, causing significant dry snow albedo reduction or driving …

Hohenberg-Kohn Theorems In Electrostatic And Uniform Magnetostatic Fields, Xiao-Yin Pan, Viraht Sahni

Publications and Research

The Hohenberg-Kohn (HK) theorems of bijectivity between the external scalar potential and the gauge invariant nondegenerate ground state density, and the consequent Euler variational principle for the density, are proved for arbitrary electrostatic field and the constraint of fixed electron number. The HK theorems are generalized for spinless electrons to the added presence of an external uniform magnetostatic field by introducing the new constraint of fixed canonical orbital angular momentum. Thereby, a bijective relationship between the external scalar and vector potentials, and the gauge invariant nondegenerate ground state density and physical current density, is proved. A corresponding Euler variational principle …

A Utility-Driven Approach To Supplier Evaluation And Selection: Empirical Validation Of An Integrated Solution Framework, Alptekin Ulutas, Nagesh Shukla, Senevi Kiridena, Peter Gibson

Nagesh Shukla

Supplier evaluation and selection (SES) problems have long been studied, leading to the development of a wide range of individual and hybrid models for solving them. However, the lack of widespread diffusion of existing SES models in the industry points to a need for simpler models that can systematically evaluate both qualitative and quantitative attributes of potential suppliers while enhancing the flexibility decision-makers need to account for relevant situational factors. Furthermore, empirical validations of existing models in SES have been few and far between. With a view to addressing these issues, this paper proposes an integrated solution framework that can …

Pathway Variation Analysis (Pva): Modelling And Simulations, Nagesh Shukla, Sudi Lahiri, Darek Ceglarek

Nagesh Shukla

Maintaining a care pathway within a hospital to provide complex care to patients is associated with challenges related to variations from the pathway. This occurs due to ineffective decision-making processes, unclear process steps, the interactions, conflicting performance measures for speciality units, and the availability of resources. These variations from the care pathway or standard care delivery processes lead to longer patient waiting times and lower patient throughput. Traditional approaches to improve the pathway focus primarily on reducing variations within the care pathway such as bottlenecks or throughput within the pathway rather than examining variations from the care pathway. In this …

An Approach To Plan And Evaluate The Location Of Radiotherapy Services And Its Application In The New South Wales, Australia, Nagesh Shukla, Rohan Wickramasuriya, Andrew Alexis Miller, Pascal Perez

Nagesh Shukla

No abstract provided.