At Site-300, Lawrence Livermore National Laboratory (LLNL), CA, trichloroethene (TCE) is present along with tetraalkoxysilanes such as tetrabutoxysilane (TBOS) and tetrakis(2-ethylbutoxy) silane (TKEBS), as subsurface contaminants. Intrinsic transformation of TCE to cis-dichloroethene (c-DCE) was observed in the groundwater at locations co-contaminated with TBOS or TKEBS. Attenuation of TBOS and TKEBS by abiotic hydrolysis and biological mineralization and the role played by TBOS and TKEBS in driving the TCE transformation were investigated. Under abiotic conditions, TBOS and TKEBS were found to slowly hydrolyze to 1-butanol and 2-ethylbutanol, respectively, and silicic acid. Hydrogen was produced as a result of the fermentation of the alcohols to the corresponding acids, and then subsequently to carbon dioxide. The hydrogen likely served as the electron donor for the microbially-mediated reductive dechlorination of TCE. The rates of hydrolysis of TBOS and TKEBS were determined and typical rates at pH 7, 30��C and 28 ��M initial concentration, were 0.32 and 0.048 ��/day, respectively. The TBOS hydrolysis reaction was observed to be acid and base catalyzed and independent of temperature from 15 to 30��C. All hydrolysis experiments were conducted at concentrations above the solubility limit of TBOS and TKEBS and the rate of hydrolysis increased with concentration of TBOS or TKEBS. An aerobic microbial culture from the local wastewater treatment plant that could grow and mineralize the alkoxysilanes was enriched. The enriched culture rapidly hydrolyzed TBOS and TKEBS and grew on the hydrolysis products. The microorganisms grown on TBOS cometabolized TCE and c-DCE. TCE and c-DCE degradation was inhibited by acetylene indicating the stimulation of a monooxygenase enzyme. Acetylene did not inhibit the hydrolysis of TBOS. / Graduation date: 1999

Thesis; Thesis information not provided; 17 Jul 2003. / Published through the Information Bridge: DOE Scientific and Technical Information. "UCRL-LR-154423" Maxwell, R M; Tompson, A F B; Richardson, J H; El-Naser, H; Rihani, J. F F; Subah, A.; El Sha'r, W A; Al-Hadidi, Khair; Al-Awamleh, M; Al-Foqaha, M; Abu-Eid, O; Hayyaneh, R A. 07/17/2003. Report is also available in paper and microfiche from NTIS.

Approved for public release, distribution is unlimited / This thesis analyzes the potential impact of incorporating wireless technologies, specifically an 802.11 mesh layer architecture and 802.16 Orthogonal Frequency Division Multiplexing, in order to effectively and more efficiently transmit data and create a symbiotic operational picture between Coast Guard Cutters, their boarding teams, Coast Guard Operation Centers, and various external agencies. Two distinct collaborative software programs, Groove Virtual Office and the Naval Postgraduate School's Situational Awareness Agent, are utilized over the Tactical Mesh and OFDM network configurations to improve the Common Operating Picture of involved units within a marine environment to evaluate their potential impact for the Coast Guard. This is being done to increase the effectiveness and efficiency of Coast Guard units while they carry out their Law Enforcement and Homeland Security Missions. Through multiple field experiments, including Tactical Network Topology and nuclear component sensing with Lawrence Livermore National Laboratory, we utilize commercial off the shelf (COTS) equipment and software to evaluate their impact on these missions. / Lieutenant Commander, United States Coast Guard / Lieutenant, United States Coast Guard