Results of a Tracker Study Conducted Within Constructed Wetlands with Varying Cell Characteristics

2010 S.C. Water Resources Conferences - Science and Policy Challenges for a Sustainable Futur

Overview of Stable Isotope Results from a Comprehensive Savannah River Study

2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Regio

Dynamics of Oxygen Demand Within the Middle and Lower Savannah River Basins

2010 S.C. Water Resources Conference - Science and Policy Challenges for a Sustainable Futur

Understanding Hydrologic Variation Through Time-Series Analysis

2010 S.C. Water Resources Conference - Science and Policy Challenges for a Sustainable Futur

Results of an Intensive Water Quality Study of the Middle and Lower Savannah River Basin

2010 S.C. Water Resources Conference - Science and Policy Challenges for a Sustainable Futur

IV sotalol use in pediatric and congenital heart patients: A multicenter registry study

Background There is limited information regarding the clinical use and effectiveness of IV sotalol in pediatric patients and patients with congenital heart disease, including those with severe myocardial dysfunction. A multicenter registry study was designed to evaluate the safety, efficacy, and dosing of IV sotalol. Methods and Results A total of 85 patients (age 1 day-36 years) received IV sotalol, of whom 45 (53%) had additional congenital cardiac diagnoses and 4 (5%) were greater than 18 years of age. In 79 patients (93%), IV sotalol was used to treat supraventricular tachycardia and 4 (5%) received it to treat ventricular arrhythmias. Severely decreased cardiac function by echocardiography was seen before IV sotalol in 7 (9%). The average dose was 1 mg/kg (range 0.5-1.8 mg/kg/dose) over a median of 60 minutes (range 30-300 minutes). Successful arrhythmia termination occurred in 31 patients (49%, 95% CI [37%-62%]) with improvement in rhythm control defined as rate reduction permitting overdrive pacing in an additional 18 patients (30%, 95% CI [19%-41%]). Eleven patients (16%) had significant QTc prolongation to \u3e465 milliseconds after the infusion, with 3 (4%) to \u3e500 milliseconds. There were 2 patients (2%) for whom the infusion was terminated early. Conclusions IV sotalol was safe and effective for termination or improvement of tachyarrhythmias in 79% of pediatric patients and patients with congenital heart disease, including those with severely depressed cardiac function. The most common dose, for both acute and maintenance dosing, was 1 mg/kg over ~60 minutes with rare serious complications

Global modeling of microwave transistors using a full-band Cellular Monte Carlo/full-wave Maxwell simulator

A full-band Cellular Monte Carlo (CMC)/full-wave Maxwell simulator is presented and applied to the global modeling of high-frequency submillimeter and microwave transistors. In this work, global modeling refers to the combination of solid-state device physics with full-wave electromagnetics (EM). This approach attempts to provide a more complete physical model of the device and its interaction with the surrounding environment. Two different three-dimensional EM solvers have been implemented and self-consistently coupled to an existing full-band, CMC device simulator. The first is based upon the conventional finite-difference time-domain (FDTD) approach. The second one utilizes the alternate-direction implicit (ADI) method which relaxes the Courant-Fredericks-Levy (CFL) stability criterion and reduces the total number of simulation timesteps required. Both solvers are implemented with state-of-the-art perfectly matched layer (PML) absorbing boundary conditions to effectively truncate the working simulation space. The numerical methods and techniques utilized within the full-band CMC device simulator and both EM solvers are explained in detail and benchmarking results are presented to validate the accuracy of the employed techniques. The coupled full-band/full-wave simulator is then used to study the high-frequency response of metal-semiconductor field effect transistors (MESFETs) via direct S-parameter extraction from coupled device simulations. This work demonstrates the usefulness of this new simulation tool in the development of microwave transistors and submillimeter-wave device technologies

High Density Lagrangian Sampling for Pathogen Source Identification

Proceedings of the 2013 Georgia Water Resources Conference, April 10-11, 2013, Athens, Georgia.In compliance to the Clean Water Act, each US state compiles a list of water bodies not meeting regulatory criteria. The most common impairment in US water bodies is elevated pathogens measured by fecal indicator bacteria (FIB). Reasons for this prevalence probably include the true magnitude of pathogen contamination, monitoring bias from human health concern, inaccuracy of FIB monitoring compared to other parameters, and difficulty estimating background condition. In practice, identification and citation of impairment is extensive, while development of plans that identify the source with certainty and implement high probability remediation lags behind. The difficulty in confidently identifying sources of impairment is an impediment to the protection of water bodies and increases the cost of remediation due to the need for casting a wider net of lower probability solutions. With a high proportion of resources directed to pathogen contamination, it is important to confidently identify sources. Increased confidence will improve efficacy of remediation and ability to secure funding. To achieve these objectives, we designed a study method to investigate Rocky Creek, a pathogen impaired stream in Augusta, GA. This method applied a Lagrangian FIB sampling approach to reduce confounding variability and a high sampling density to identify high contribution watershed areas. We then layered typical pathogen sources (e.g. septic, pet waste, sewer, wildlife) and alternative sources (e.g. sediment, instream growth) along with their GIS data over the FIB data. In this way, we were able to target remediation efforts on the convergence of sources and regions and thereby decrease the scale of remediation efforts.Sponsored by: Georgia Environmental Protection Division; U.S. Department of Agriculture, Natural Resources Conservation Service; Georgia Institute of Technology, Georgia Water Resources Institute; The University of Georgia, Water Resources Faculty.This book was published by Warnell School of Forestry and Natural Resources, The University of Georgia, Athens, Georgia 30602-2152. The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of The University of Georgia, the Georgia Water Research Institute as authorized by the Water Research Institutes Authorization Act of 1990 (P.L. 101-307) or the other conference sponsors

Changing Our Perspective to Increase Our Understanding of Basic Aquatic Ecosystem Function

Proceedings of the 2013 Georgia Water Resources Conference, April 10-11, 2013, Athens, Georgia.Aquatic ecosystems are dynamic mixtures of physical, chemical, biological, geological, and meteorological elements. Understanding how that mixture produces the observed water quality at a given location is one of our greatest challenges. To a large degree, our understanding has been limited by the availability of tools and by our research approach. Advances within the last two decades have allowed us to go beyond synoptic sampling (data collection from many sites without regard to travel time) to multiple site, continuous sampling efforts (high frequency data from multiple fixed locations). While those data are important for assessing regulatory water quality, fixed position sampling (Eulerian perspective) falls short of providing a true understanding of aquatic ecosystem function because of the significant spatiotemporal gaps between data collection sites. Continuous data from multiple locations increases data resolution but connecting those data within the context of advective transport requires simulation; this results in far more simulated than measured data. Continuous measurements while following the same parcel of water as it is advectively transported (Lagrangian perspective) is another important approach to understanding aquatic ecosystem function. This approach allows for better spatiotemporal resolution and can lead to better understanding of ecosystem function. The Lagrangian perspective is however limited by the costs and time associated with conducting this type of data collection effort and data sets may be limited in the range of seasonal and stochastic conditions. For six years, Southeastern Natural Sciences Academy has been collecting water quality data with Eulerian data collection methods throughout the Middle and Lower Savannah River Basins. In June 2012, we launched our first Lagrangian research expedition along 233 kilometers (145 miles) of the Middle Savannah River Basin. The goal of this paper is to discuss some of the differences between our Eulerian and Lagrangian data sets and the challenges that lie ahead.Sponsored by: Georgia Environmental Protection Division; U.S. Department of Agriculture, Natural Resources Conservation Service; Georgia Institute of Technology, Georgia Water Resources Institute; The University of Georgia, Water Resources Faculty.This book was published by Warnell School of Forestry and Natural Resources, The University of Georgia, Athens, Georgia 30602-2152. The views and statements advanced in this publication are solely those of the authors and do not represent official views

Preliminary Data from a Comprehensive Savannah River Study: The First 6 Months

Proceedings of the 2007 Georgia Water Resources Conference, March 27-29, 2007, Athens, Georgia.Southeastern Natural Sciences Academy has initiated a two year comprehensive study to assess the upstream impacts on water quality in the Savannah River with emphasis on the Augusta urban corridor. One of the driving forces of the study is characterization of the upstream contribution of oxygen demanding substances to the Savannah Harbor. The ongoing study began in January 2006 and encompasses the physical, chemical, and biological domains of limnology. We have employed both Eulerian and Lagrangian approaches through continuous collection of data from static multiparameter probe stations and through flow based chemistry sampling events, respectively, with stations spanning from River Mile 148 (near Plant Vogtle) to River Mile 215 (above Augusta, GA). This presentation represents a portion of the first 6 months of collected Eulerian and Lagrangian data. Preliminary Eulerian results showed that, on average, temperature and conductivity increased steadily from river mile 215 to river mile 148 with the highest variability for both parameters at the downstream station. The overall trend for pH showed no net change from River Mile 215 to 148 but pH increased by nearly 1 unit at River Mile 202 and was most variable at that location. The overall trend for dissolved oxygen showed a net loss of ~0.5 mg O2/L from River Mile 215 to 148 but increased by an average of 1.5mg O2/L at River Mile 202 and remained elevated through River Mile 185. Lagrangian sampling results for the May sampling event showed that increases in conductivity from River Mile 215 to 148 mostly resulted from downstream increases in sodium, alkalinity (as CO3), sulfate, chloride, potassium, calcium, and iron. Total organic carbon, almost entirely in the dissolved phase, increased from River Mile 215 to 148. This increase was equivalent to ~700 kg C added to the river over that reach, none of which was characterized as a biologically oxygen demanding substance (BOD5) but may have been characterized as an oxygen demanding substance under harsher conditions (COD).Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, Natural Resources Conservation Service, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602-2202. The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of The University of Georgia, the U.S. Geological Survey, the Georgia Water Research Institute as authorized by the Water Resources Research Act of 1990 (P.L. 101-397) or the other conference sponsors