Ground-penetrating radar observations of enhanced biological activity in a sandbox reactor

In this study, we evaluate the use of ground-penetrating radar (GPR) to investigate the effects of bacterial activity in water saturated sand. A 90-day laboratory-scale controlled experiment was conducted in a flow-through polycarbonate sandbox using groundwater from the Kansas River alluvial aquifer as inoculum. After 40 days of collecting baseline data, bacterial growth was stimulated in the sandbox by the addition of a carbon and nutrient solution on a weekly basis. Radar signal travel time and attenuation were shown to increase downgradient of the nutrient release wells relative to upgradient locations. After 60 days, the frequency of nutrient injections was increased to twice per week, after which gaseous bubbles were visually observed downgradient of the nutrient release wells. Visual observation of active gas production correlated spatially and temporally with a rapid decrease in radar signal travel time, confirming that GPR can monitor the generation of biogenic gases in this system. Analysis of the sediments indicated microbial lipid biomass increased by approximately one order of magnitude and there were no changes in the inorganic carbon content of bulk sediment mineralogy. These findings suggest that the increase in biomass and gas production may be responsible for the observed changes in radar signal travel time reported in this study. Therefore, this study provides evidence that GPR can be used to monitor biological activity in water saturated sand.Funding for this project was through the National Science Foundation CAREER grant 0134545 awarded to J.F. Devlin and NSF EAR/IF-0345445 for acquisition of GPR instrumentation awarded to G. Tsoflias. The opinions, findings, and recommendations of this study are the views the author(s) and do not necessarily reflect the views and opinions of the National Science Foundation. We would like to thank Mike McGlashan, Kwan Yee Cheng, Kelly Peterson, Lindsay Mayer, and Breanna Huff for assistance with this project. We also thank two anonymous reviewers for their helpful comments that led to the improvement of this manuscript

Bail-In from an Insolvency Law Perspective

Coherent privaatrech

Strom aus erneuerbaren Energien in Deutschland Aktuelle Situation und Perspektiven

Inhalt: Strommarkt in der BRD; Anreize zur Foerderung erneuerbaren Energien in der BRD; Erzeugungskapazitaeten ern. Energien in der BRD; Marktdaten fuer gruenen Strom in der BRD.(GL)Contents: Power market in Germany; incentives for financing renewable energy in Germany; power capacity of this energy source; market data for ''Green Power'' in Germany.(GL)SIGLEAvailable from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Design and construction status of the energy system for the ZTH experiment

A large scale reversed-field pinch fusion experiment, called ZTH, is being designed and built at Los Alamos. Initially, the machine will be operating at a 1.7 MA plasma current, however, the machine can be upgraded to a 4 MA current with many of the components, such as the torus, coil system and electrical power source already having the 4 MA capability. The first plasma discharges are expected to take place in the spring of 1993. Major electrical power equipment components, such as a 1430 MVA generator, controlled power supplies, isolation and opening switches, current interrupter, capacitor banks and transfer resistor are being designed and procured for this experiment. The design philosophy of the electrical system is explained. Test results of in-house research are described and the procurement status of the major components are summarized. 6 refs., 2 figs