Student Abstracts: Environmental Science

A Brief Evaluation of Common Methods for Extraction and Analysis of Technetium-99 in Contaminated Soil. ANNE HYLDEN (College of St. Benedict, St. Joseph, MN, 56374) CHRISTOPHER F. BROWN (Pacific Northwest National Laboratory, Richland, WA, 99352)

Technetium-99 (Tc-99) is a contaminant of interest at numerous nuclear facilities because it is mobile in subsurface environments and is a key contributor to long-term risk. Therefore, the proper quantification of Tc-99 is important for scientists at the Hanford Site in Richland, WA who deal with legacy waste from plutonium production during WWII and the Cold War era. This study investigated the relative accuracy of three common methods for extracting Tc-99 from contaminated sediment: water extraction, acid extraction, and microwave-assisted digestion. A lab-prepared control sample containing a known amount of Tc-99 and twenty-five sediment samples from the Hanford Site were extracted using these three methods. Half of the filtrate from each extraction was immediately analyzed for Tc-99 content by inductively coupled plasma mass spectrometry (ICP-MS); the other half was treated with TEVA® resin (Eichrom Technologies, LLC) prior to analysis. Microwave digestion of the contaminated sediment samples consistently produced higher results than water and acid extraction. In the case of the untreated control sample, water extraction only recovered 70% of the Tc-99 in the sample and acid extraction recovered 90%, while microwave digestion of the sediment gave average recoveries of 120%. Upon treatment of the samples using TEVA® resin, analysis by microwave digestion became more accurate; recoveries of Tc-99 from the laboratory control samples averaged 102%, whereas the recoveries for water and acid extraction remained at 70% and 90%, respectively. These results indicate that microwave-assisted digestion followed by TEVA® resin treatment is the most appropriate extraction technique to fully quantify Tc-99 concentrations in sediments.

A characterization of N status in Populus trichocarpa inoculated with an endophytic bacteria. NOAH BUNCHER (The Evergreen State College, Olympia, PA, 98505) ALISTAIR ROGERS (Brookhaven National Laboratory, Upton, NY, 11973)

Producing biomass for energy that does not negatively impact food supply will require the establishment of biofuel species on poor quality soils that are not used for agriculture. The association of endophytic bacteria with their plant hosts has been shown to have a growth-promoting effect for many different plant species and suggests that plant-endophyte interactions may allow improved growth on marginal soils. However, few relationships between plants and these endophytes have been characterized and studied in detail. Previously, the endophytic bacteria enterobacter 638 was shown to promote growth in Populus trichocarpa (poplar). We grew poplar cuttings in Hoagland’s solution and investigated the impact of enterobacter on the N status of poplar. To account for possible differences in growth rate, we selected leaves for harvest and analysis using the leaf plastochron index (LPI). In the youngest leaves (LPI 2), nitrate levels were significantly and markedly (120%) higher in poplars inoculated with enterobacter suggesting that these plants were better able to take up nitrate. Free amino acid content and starch content was not altered by the presence of enterobacter, but leaf protein content was reduced by c.10%. These data provide preliminary evidence that poplar inoculated with enterobacter may have an improved ability to acquire and assimilate nitrate, a trait that would be desirable for feedstock species suitable for growth on marginal soils.

A Comparison and Contrast of the Surface Energy Balance at Lamont, OK During the Summers of 2006 and 2007. RACHEL DEARING (Northern Illinois University, DeKalb, IL, 60115) BRAD ORR (Argonne National Laboratory, Argonne, IL, 60439)

The objective of this project was to analyze the differences in surface energy balance between the summers of 2006 and 2007 at the Lamont, OK Southern Great Plains (SGP) Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF). The Oklahoma summer months of June, July and August of each year were analyzed. This project utilized solar radiation, surface energy flux and surface meteorological data collected at the SGP site and downloaded from the ARM online data archive to illuminate the differences between these two contrasting summers. Daily, monthly and seasonal plots of this data were created and examined. Closure of the surface energy balance and also correlation between the surface fluxes and net radiation was calculated. Analysis of these two summers showed differences in the number of weather events, the amount of precipitation, latent and sensible heat flux, net solar radiation, closure, and strength of correlation between various fluxes. The conclusion of this project was that the summer of 2006 received more solar energy than summer 2007, that average closure of the surface energy balance was better in summer 2007, and that there were significant correlations between the surface fluxes and net radiation during both summers. A greater understanding of the surface energy balance at the SGP ACRF site was obtained, which can be used to guide future research and further the understanding of the surface energy balance at other locations. It is suggested that a longer span of time be analyzed at Lamont, OK.

A Distribution Survey of the New York State Threatened Banded Sunfish (Enneacanthus obesus) Conducted in the Peconic River Drainage on Long Island, NY. TYRA BUNCH (Southern University at New Orleans, New Orleans, LA, 70126) DR. TIM GREEN (Brookhaven National Laboratory, Upton, NY, 11973)

The New York State threatened banded sunfish (Enneacanthus obesus) inhabit rivers, lakes, and ponds along the Atlantic coast. Because the banded sunfish is a voracious predator of mosquito larvae, they provide a biologically efficient means of controlling the mosquito population. Previous population assessments completed in Zeke’s Pond and the Peconic River has suggested that the fish’s populations are at risk of declining. In order to formulate a plan to promote the growth of the species, a distribution study of the sunfish was performed in Zeke’s Pond, The Peconic River, and the Peconic River Drainage. The study began by observing and identifying the aquatic vegetation in each pond along with documenting the location of each pond with a Global Positioning System (GPS) unit. The next step was to seine and dip net in areas identified with vegetation favored by the banded sunfish. The fish and predatory species obtained were then measured, documented, and released. A rubric was devised to evaluate the correlation between the banded sunfish’s distribution and the aquatic vegetation present in the seined areas. A total of twenty-seven bodies of water have been studied obtaining 321 individuals of various predatory species. Of the twenty-seven waterways, twelve bodies of water yielded 329-banded sunfish. Results of the distribution survey indicate a correlation between the banded sunfish and ponds with a higher density of bladderwort, white water lilies, and smartweed. Of the sites surveyed by this team, results revealed banded sunfish to be present in all of the ponds listed on the New York State Department of Environmental Conservation’s (DEC) historic banded sunfish sites. This distribution survey was part of a larger ongoing survey that is being conducted by the DEC in preparation for developing a recovery plan for this species.

A Distribution Survey of the New York State Threatened Banded Sunfish (Enneacanthus obesus) in the Peconic River Drainage. CARMEN MALDONADO (Southern University at New Orleans, New Orleans, LA, 70116) DR. TIMOTHY GREEN (Brookhaven National Laboratory, Upton, NY, 11973)

Biofuel Sustainability Analysis Using System Dynamics: Economic Impacts. ELLEN ROYBAL (College of Idaho, Caldwell, ID, 83605) JAKE JACOBSON (Idaho National Laboratory, Idaho Falls, ID, 83415)

As the demand for renewable energy rises, careful study must be given to the sustainability of these renewable resources. In particular, the production of ethanol is influenced by many factors and has far-reaching impacts. To better understand the complex web of components relating to ethanol production, a system dynamics model can be used. Programs such as STELLA or Vensim can account for the relationships between variables as the big picture changes over time. These programs can also incorporate "soft" variables, chart a range of probable behavior, and allow the user to see the impacts of one variable change in several areas quickly and easily. This model simulates the behavior of cost/benefit analysis on the part of markets at large. Three in particular are the focus of this model: the grain market, the biomass market, and the ethanol market. Each of these markets are linked together, as demand in one market will drive the incentive to produce up, which in turn drives production in other areas. The other side of this model charts revenues for a one-acre plot of land over the course of a three-year crop rotation. Costs are fixed, but revenues depend upon market prices for the grain and the biomass produced on that plot of land. The user of this model has the option of adjusting various factors built into this model. For example, the user may select the crop rotation over three years. This type of modeling system allows the user to see the interaction of many variables simultaneously. This particular model allows the user, among other things, to see the relationship between inelastic demand for fuel and pricing of corn grain, profit maximization practices by the market, and the interaction between grain crops and their residues. This model will be used by Jake Jacobson and the INL as part of a big-picture biofuel sustainability analysis.

Carbon Dioxide Induced Density Driven Brine Convection: Enhancement of CO2 Sequestration. KA WAI TSE (Diablo Valley College, Pleasant Hill, CA, 94523) TIMOTHY J. KNEAFSEY (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

This paper presents a two-part experimental study on Density Driven Convection (DDC), a highly desired fluid flow that can greatly enhance carbon dioxide (CO₂) storage in geological media. The first part of the study investigated the subsurface conditions in which DDC occurs. We conducted a series of tests in which gaseous CO₂ was introduced into a pressure vessel containing brine and a porous medium at moderate temperature and pressure. We studied the effects of porous medium permeability and brine salinity by altering these variables in each test and comparing the resulting rate of CO₂ uptake into the brine. In our tests, we discovered that the rate of CO₂ uptake in brine was phenomenally faster in systems of high permeability, indicating that DDC took place. This is because a more permeable system allowed convective flow to occur more easily. Salinity, on the other hand, had an opposite impact; salt made the brine denser which reduced CO₂ dissolution thus DDC was not as likely to occur. Salt also decreased the solubility of CO₂ which further minimized CO₂ dissolution. In the second part of the experimental study, we conducted similar CO₂-brine tests in a transparent Hele-Shaw Cell, two parallel plates attached on the sides and bottom leaving a small aperture. The Hele Shaw cell was a visualization tool that allowed us to see how DDC developed and observe the different stages in the CO₂ uptake process. Our comprehensive experiment provided a data set against which numerical models can be compared since the processes occur over many size scales.

Characterization of Attendant Shelf Clouds over the Tropical Western Pacific Warm Pool. JACOB BILLINGS (Tallahassee Community College, Tallahassee, FL, 32304) MICHAEL JENSEN (Brookhaven National Laboratory, Upton, NY, 11973)

Research in the field of atmospheric science improves not only our understanding of atmospheric interactions, but also our abilities to predict meteorological and climactic events. The following research, through Brookhaven National Laboratory (BNL), and the Department of Energy’s Atmospheric Radiation Measurement (ARM) program, characterizes one aspect of our atmosphere, attendant shelf clouds (ASC). Measurements taken over the tropical western pacific (TWP) warm pool (WP) region (off the north-eastern Australian coast), often show the presence of thin clouds at and around the freezing level stable layer. Typically, these shelf-like clouds extend from cumulo-nimbus or cumulo-congestus cells. Our characterization of this cloud type began by sampling information from an array of data products developed through the ARM program. The data were then organized using a collection of original computer scripts. Through analysis of the resultant material, ASCs were determined to occur approximately 15% percent of the time, to come about in the presence of slightly more than average stable layer above the freezing level, to contain an average of 0.00521 cm of liquid water, and to induce a cloud forcing of -237.22 W/m2. After examining our results, we find that attendant shelf clouds occur frequently enough to be considered a normal aspect of tropical meteorology. Identification of the unique parameters of ASCs allows us, first, to describe a more complete understanding of our atmosphere. Further, by this increased knowledge, we can better critique the verisimilitude of computational models of our atmosphere, and hence improve our predictive abilities.

Characterization of Research and Development Laboratory Spaces for Metal Contaminants. NICOLE CHIU and ALBERT KIM (State University of New York at Stony Brook, Stony Brook, NY, 11790) JOHN PETERS (Brookhaven National Laboratory, Upton, NY, 11973)

Metals such as antimony, arsenic, beryllium, cadmium, chromium, cobalt, lead and nickel are known for irritating the skin and eyes, and when inhaled, may be very hazardous. Repeated low dose exposures can lead to possible lung, liver, and kidney damage. All of these metals are toxic. Cadmium, lead and nickel are carcinogenic. The Department of Energy (DOE), Brookhaven National Laboratory (BNL) Environmental Safety and Health (ES&H) directorate, has a characterization plan for metal contaminants in surface dust underway in laboratories with prior or current use of these metals. Air and wipe samples were collected for possible metal contamination and the results were then reviewed for compliance with BNL’s guidance levels and regulatory standards. Using the Chemical Management System database, we strategically chose high and low probability locations within a building that would provide a comprehensive analysis of the room. The air sampling pumps were calibrated to 2.5 L/m and sampled for four hours using closed--faced PVC filters. In addition, surface samples were taken using pre-moistened Ghost Wipes in an area of 100cm2. The results were analyzed and compared to applicable OSHA and DOE regulatory standards, ACGIH guidance levels and BNL Acceptable Surface Contamination (ASC) level. The contaminant’s source was determined through investigating historical usage at the site. Laboratories that show elevated levels are reviewed with the ESH coordinators and specific corrective procedures are determined in cooperation with the BNL Industrial Hygiene Department.

Climate Change Effects on Leaf Gene Expression of Avena barbata in a Californian Grassland Ecosystem. LALEH ESMAILI (Laney College, Oakland, CA, 94607) GARY L. ANDERSEN (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

Global climate changes are impacting the environmental conditions of many ecosystems. In order to develop an informed understanding of the effects of climatic changes on a grassland ecosystem, a study was conducted to examine plant response to altered rainfall pattern and increased nitrogen availability. Avena barbata, an abundant species in many Californian annual grasslands, was grown on natural soil in a climate-controlled greenhouse and submitted to three precipitation treatments (low, ambient and high rainfall), two vegetation types (mixed communities and A. barbata monocultures) and two levels of nitrogen in the soil (ambient and addition of NH₄NO₃). Samples were collected from the leaves of A. barbata during the reproductive stage, and the mRNA transcript abundance of six genes that play a role in carbon or nitrogen metabolism (RbcS, GS1, GS2, AGPS, Nia, Fd-GOGAT) were studied using real-time RT-PCR. This study shows that these genes respond differently to varying environmental conditions. Vegetation type had the most significant effect on RNA yield; monocultures yielded significantly more RNA content. The addition of NH₄NO₃ solution was thought to increase the amount of mRNA transcript abundance in RbcS, GS2, and AGPS, but the opposite trend was seen. The results from this study suggest that the developmental stages of the plants and the growth conditions at the time of sampling influence the response of mRNA transcript abundance to changes in environmental conditions. This information on leaf gene expression will be used together with data from soil conditions, root gene expression, microbial activity and other data from this project in a model to predict ecosystem response to climate change.

CO2 Emissions from the Conversion of Pasture Grasslands to Switchgrass for Bioenergy Production. JOHN ODACKAL (New York University, New York, NY, 10011) JULIE JASTROW (Argonne National Laboratory, Argonne, IL, 60439)

Soil and plant biomass contain roughly 2.7 times more carbon dioxide (CO2) than the earth’s atmosphere. While the earth’s terrestrial system is currently a CO2 sink, local CO2 sequestration and emission is heavily dependent on land management. The conversion of lands to bioenergy crop fields, an increasingly common practice in the US and global community might have a significant impact on global atmospheric CO2 concentration and global warming. This study examines factors affecting soil respiration, a CO2 emission source, in a brome pasture grassland site recently converted to a switchgrass field. The study site was prepared for planting by burning and herbiciding a 37 year-old brome field. Three different methods were used to investigate CO2 emission from the switchgrass field. These different methods were CO2 flux analysis, Keeling plot analysis, and aggregate analysis. CO2 respiration was measured for flux analysis using an infrared gas analyzer. Gas samples for Keeling plot analysis were collected at CO2 concentrations ranging from 450-800 ppm to disaggregate net soil CO2 emission into root and microbial CO2 respiration. Soil samples were collected at depths of 0-5 cm for aggregate structure analysis. The results from CO2 flux analysis show that the average respiration rate of the brome site was nearly double that of the switchgrass field at 1-week and 5-weeks after switchgrass planting (p < 0.0002 for both time periods). Comparison of CO2 emission sources at 1-week after planting using Keeling Plot analysis showed that while root respiration was significantly lower in the switchgrass field (p < 0.0001), both the brome and switchgrass sites had similar microbial respiration rates (p = 0.93). Initial aggregate analysis shows no significant difference in aggregate distribution between switchgrass and brome sites. It is possible that in the cleared pasture grassland studied, organic material is not the limiting factor of microbial activity. This suggests that long-term studies contextualized by local limiting factors are needed in order to accurately quantify CO2 emission from the clearing of some land-types to produce bioenergy crops.

Comparing Surface Energy Balances for the Black Forest, Germany, Niamey, Niger, and Southern Great Plains, Oklahoma Atmospheric Radiation Measurement Sites. RYAN BOURGART (Valparaiso University, Valparaiso, IN, 46383) BRAD ORR (Argonne National Laboratory, Argonne, IL, 60439)

Determining a Relationship Between Standing Water Area and Amphibian Population and Diversity in a Constructed Wetland at Argonne National Laboratory, Illinois. ANNE CZAWLYTKO (Immaculata University, Immaculata, PA, 19345) KIRK LAGORY (Argonne National Laboratory, Argonne, IL, 60439)

The vital ecosystems of natural wetlands in the United States have often been destroyed. In an effort to preserve the remaining wetlands in the United States, there has been legislation leading to an overarching concept of "no net loss;" there must be a constructed wetland to compensate for destroyed wetland. In 1990, Argonne National Laboratory began to build the Advanced Photon Source (APS) and several wetlands were destroyed in the process. In order to comply with the Clean Water Act and the policy of "no net loss," Wetland R was constructed to the south of the APS facility. The health and progress of Wetland R has been monitored from 1992-1996 and yearly since 2002; in 2006 an amphibian survey was completed. The purpose of this research is to determine if there was a correlation between the area of the standing water and the amphibian population size and diversity. This potential relationship was determined through the use of a weekly timed catch using a dip net (to determine the species diversity) and a timed walk around the wetland to determine the number of amphibians sighted per minute (thereby estimating the population size). In addition to data collected in 2008, data from the 2006 study were included to determine correlation coefficients between the standing water area and the diversity and population size. The expected result of a strong positive linear correlation between the standing water area and the population size and diversity of amphibians was not supported by the study results. The correlation coefficient between the standing water compared to the species diversity was .880. The correlation coefficient between the standing water area and the population size was .0655. Further studies to determine if these findings were based on other variables should be completed.

Determining Commercial Water Usage in California Through End Uses: What is the Current Water Use and are More Water Savings Available? WEN-FENG TSENG (University of California, Irvine, Irvine, CA, 92617) JAMES (JIM) MCMAHON (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

Determining Commercial Water Usage in California through End Uses: What is the Current Water Use and are More Water Savings Available? WEN-FENG A. TSENG (University of California, Irvine, CA 92697) JAMES E. MCMAHON (Lawrence Berkeley National Laboratory, Berkeley, CA 94720) Even though water use in commercial and institutional (CI) sectors involves approximately one fourth of the total water demand in an urban area, CI water uses have received less attention than the residential sector in developing statewide water conservation initiatives. From reading through professional and academic publication, interviewing experts in water efficient technologies, searching through industry reports and unpublished documents, this study examined current CI water use in California to see if there are more water savings available through water-efficient technologies and water-conservation behaviors. This research found that with the exceptions of hospitals and hotels, other CI subsectors have opportunities to reduce annual water usage beyond the projected estimates in 2003. The average 2008 potential water savings corresponds to over 72% of pre-1992 water use (baseline). Potential additional water savings in 2008 when compared with the estimated water usages in 2003 by Pacific Institute assessment are in the range of 5 to 37 percent, with 20 to 26 percent being typical. Within CI sector there is a wide divergence of how subcategories are defined, because not all water utilities include the same type of subsector. More research and collaborative endeavors will be needed to categorize subsectors specifically for determining water use. Since the current state of information on the end uses of water in CI customers remained vague, this research suggests that building managers make information on water usage more visible and available to everyone. Other research will need to account for climate change, type of buildings that use water, and other CI water use besides kitchen and bathroom water use.

Determining the Flowpaths in Partially Saturated Sediment Samples. KELLY HINKEL (University of Kentucky, Lexington, KY, 40502) MELANIE MAYES (Oak Ridge National Laboratory, Oak Ridge, TN, 37831)

The objective of this study was to determine the relationship between water flowpaths, water content, and particle size in intact, partially saturated sediment core samples collected from the U.S. Department of Energy’s (DOE) Hanford site in Richland, WA. These physical relationships govern the mobility of radionuclides and contaminants in the Hanford subsurface, which is of concern due to the proximity of the Columbia River. The core samples were oriented such that flow was either parallel (horizontal) to or across (vertical) sedimentary beds. In 2008, the cores were injected with a dye tracer (Brilliant Blue FCF) to identify the flowpaths which contributed to the mobility of these contaminants. We found that in 3 (Vertical Coarse,VC, Vertical Fine,VF, and Horizontal Fine, HF) out of the 4 cores dissolved dye tracer eluted from the cores, which provided the transport time for the dye to move through the cores. Dye transport times were delayed compared to nonreactive tracers, which was consistent with batch isotherm experiments showing chemical reactivity of the dye with the sediments. Four cores were photographed and dissected into approximately 100 samples as a function of sedimentary layering. Each core and subsample was carefully collected and weighed. In the horizontal core, in which flow was parallel to bedding, we were able to see that flowpaths followed certain sedimentary layers and avoided others. In contrast, in the vertical cores in which flow crossed beds, the dye spread across entire layers. This was surprising because much of the pore space was occupied by air rather than water. Each sample was dried for 24 hours and weighed again to determine the mass wetness. From this information, the water content and bulk density of each core was determined. From selected samples, particle size analysis (PSA) was conducted using the bouycous hydrometer method to determine the percent of sand, silt, and clay within each sedimentary layer. From the PSA, we determined that VF and HF cores had a much higher percentage of clays than VC. The distribution of mass wetness and the percent of fines were expected to be key components in determining the flowpaths. The flowpaths were all observed to be different due to the orientation of the cores, indicating that flow may isolate into specific sedimentary layers under unsaturated conditions. This information will be used to determine the mobility of the contaminants with respect to the Columbia River.

Determining the Structure and Defects of Manganese Oxides using X-Ray Absorption Spectroscopy. STANLEY QUAN (University of California, Berkeley, Berkeley, CA, 94720) JOHN BARGAR (Stanford Linear Accelerator Center, Stanford, CA, 94025)

Since manganese oxides are stable over time, and studies suggest that their biologically and abiotically formed states are distinguishable, they possess the key properties to be useful as biosignatures. Biosignatures are biological indicators of life and may be used to search for extraterrestrial life. Because bacteria form poorly crystallized manganese oxides in nature, we must refine detailed crystal structures before being able to utilize them as biosignatures. After performing X-ray Absorption Spectroscopy (XAS) on various manganese oxides and fitting to a single scattering model with Mn-O and Mn-Mn shells, the Extended X-ray Absorption Fine Structure (EXAFS)-derived fit data was compared to X-Ray Diffraction (XRD)-predicted local structure results. In particular, we were able to explain the significantly lower EXAFS coordination numbers for the O and Mn shells compared to the XRD results. Also, by constraining to XRD parameters for fitting, we found increases in disorder and reduced chi square that indicate defects and that EXAFS is a better representation of the structures. We were able to rank the manganese oxides by ideal structure as predicted by XRD, from the least ideal to the most ideal: small tunnel (pyrolusite, ramsdellite), tunnel (coronadite, cryptomelane), layer (chalcophanite, lithiophorite, birnessite), to layer/tunnel (todorokite).

Determining the Temperature Dependence of Perfluorocarbon Tracer Release Rates from Permeation Sources. MONICA TORREJON (Bronx Community College, Bronx, NY, 10453) JOHN HEISER (Brookhaven National Laboratory, Upton, NY, 11973)

The Tracer Technology Group at Brookhaven National Laboratory (BNL) performs atmospheric transport studies using perfluorocarbon tracers (PFT). As part of these studies, the tracers must be released into the atmosphere (e.g., outdoors or indoors) and the release rate must be well known. One method of releasing small quantities (uL/min vapor) of PFTs is through the use of permeation sources. These sources generate small emissions rates through the permeation of a volatile fluid (in this case the PFT) through a membrane. The PFT emission rate can be determined by measuring the PFT weight loss over a time and at a given temperature. Since the sources are used indoors and outdoors, they are subject to widely differing temperatures. The emission rate is temperature dependent and this dependency must be well characterized for the sources to be useful in atmospheric studies. The objective of this research was to measure the emission rates of several PFTs through a silicone membrane and to examine the correlation between the PFT emission rate and temperature. In order to achieve this, sixty permeation sources produced and placed in constant temperature chambers of 8ºC, 20ºC, 30ºC, and 40ºC for a period of two weeks per temperature. These sources were small vials, each filled with one of six different liquid PFT types and capped with a permeable silicone rubber membrane. For each temperature test, the sources were weighed daily using a high precision balance and their weights were recorded on EXCEL spreadsheets. The weight loss of each source was calculated by subtracting the last from the initial weight along two-week data. Then, the PFT weight losses were plotted as a function of time, and from these slopes, the PFT weight loss rates were obtained. As expected, the results showed that the weight loss rates of the tracers were greatest in the 40ºC temperature chamber since at this higher temperature, the tracers become more volatile and the diffusion is increased. From the relationship between the weight loss rates versus temperature, the equation of linear least-square relations is the temperature dependency which is used to obtain the rate of PFT release experimental source term for the mega sources at given temperatures.

Development of Non-Precious Nano-Catalysts for a Proton Exchange Membrane (PEM) Fuel Cell. KURIAN KUTTIYIEL (State University of New York at Farmingdale, Farmingdale, NY, 11735) DR.DEVENDRA MAHAJAN (Brookhaven National Laboratory, Upton, NY, 11973)

While a fuel cell, especially the PEM, is expected to be an important source of clean energy, the major hindrance for commercialization is its high cost and lack of durability. The Platinum (Pt) catalyst is the most expensive component in a PEM fuel cell system; consequently, extensive efforts are currently underway to reduce the amount of Pt or replace Pt with non-precious nano-materials while maintaining or improving stability, durability, and performance. In this project we have focused on nano-metal catalysts of four different non-precious metals. Nano-metal particles of Nickel (Ni), Cobalt (Co), Copper (Cu), and Silver (Ag) were separately mixed in an ultrasonic bath with Vulcan XC72R carbon black as a catalyst support. Nafion was added to the mix as a binder. Each catalyst mix was prepared with a metal loading to catalyst support of 30% by weight. The electrochemical characterization for each catalytic mixed compound was studied by cyclic voltammetry using a rotating disk electrode. All nanoparticles showed a very small charge in the hydride region for hydrogen oxidation reaction, and for oxygen reduction reaction (ORR) the nanoparticles produced a potential of around 0 to 0.2 volts. Similar analysis was conducted on these metal catalysts after submerging it for 48 hours in liquid ammonia (NH₃). NH₃submerged nano-metal particles of Ni, Co, Cu, and Ag resulted in no charge in the hydride region and did not produce any potential for ORR.

Distribution of the Iridovirus in Eastern Box Turtles at Brookhaven National Lab. DANE BUENTEN (State University of New York at Fredonia, Fredonia, NY, 14063) VALORIE TITUS (Brookhaven National Laboratory, Upton, NY, 11973)

The Iridovirus is a family of pathogenic disease that affects reptiles, fish, and amphibians worldwide. Currently, there are four documented genera: The Chlorirdovirus and Iridovirus (which infects invertebrates) and the Lymphocystivirus and Ranavirus (which infects cold-blooded vertebrates). A recent outbreak of this Ranavirus had been detected on Brookhaven National Lab (BNL) property among the Eastern Box Turtle population. The symptoms of the Ranavirus in Eastern Box Turtles include conjunctivitis, lethargy, oral and nasal discharge, and death. Since New York State considers this species a Special Concern, a survey was needed to track and record the size and effect of this outbreak. A group of oral and cloacal samples of Eastern Box Turtles were collected on site for DNA. These DNA samples were removed from the swabs using the Dneasy tissue kit procedure. The samples were run through Polymerase Chain Reaction twice to enhance the DNA quantity, and then placed into an electrophoresis gel. Using Geographic Information Systems (GIS), the location of all turtles found was plotted so the distribution of the virus could be seen across BNL. The results came back inconclusive for this experiment. The majority of the testing came back negative, however there was reasonable doubt as to whether the outcome was reliable. Also, there was not enough consistency in the GIS plotting to be reasonably sure of the Ranavirus' movement.

Dynamic Modeling of Earthquake Ruptures. BRYANT PALMER (Shippensburg University, Shippensburg, PA, 17257) CHRISTOPHER R. BRADLEY, PH.D. (Los Alamos National Laboratory, Los Alamos, NM, 87545)

Geophysicists have invested considerable effort in understanding the physics involved in how earthquake ruptures fundamentally work. The driver of this investment is to provide early warning for safety, mitigate infrastructure damage, and posture critical infrastructure resources in less hazardous earth quake zones. If seismologists can more accurately predict the seismic magnitude, duration and location, infrastructure could be better designed to survive hazardous seismic zones. This poster focuses specifically on the dynamics involved in earthquake rupture. Tectonic outside forces creates stress and strain on the rocks which essentially stores energy like a spring. Once the strain exceeds the fault yield strength, the rock ruptures and this potential 'spring’ energy is released to the system. Based on conservation of energy and momentum, we show the elastodynamic equation of motion and how it is applied to our problem. Two methods have been used to dynamically model an actual earthquake rupture based on the 2000 Tottori, Japan earthquake. The two methods are the Finite Difference and the Finite Element Methods (FEM). This poster provides a short theoretical discussion about the two methods as it relates to earthquake ruptures. In our study, only the Finite Element method is presented to model the Tottori earthquake. A three-dimensional model of the fault was built in ABAQUS® (FEM) where the boundary conditions, such as friction and pre-stress, could be changed to alter the release of energy from the rupture of the fault. Based on these models, seismologists can better predict the energy and duration of seismic events. The more accurate the predictions, the better the community can prepare for these events.

Effects of Aerial Herbicide Application on Hanford’s Flora. BRIDGET TINSLEY (Washington State University, Pullman, WA, 99164) JANELLE DOWNS (Pacific Northwest National Laboratory, Richland, WA, 99352)

Herbicides (primarily Tordon 22K™) were applied aerially to approximately 10,599 hectares of shrub-steppe habitat located in the Hanford Site in southeastern Washington. These applications were conducted to control invasive weeds such as knapweed (Centaurea spp) and yellow starthistle (Centaurea solstitialis). Picloram is the active ingredient in Tordon 22k™. To understand the affects that picloram had on the native species vegetation surveys were conducted to measure the species richness, canopy cover and frequency of plants in growing in herbicide treated areas. These sites were compared to adjacent areas with similar species and soil composition. Sampling was stratified by year and soil series. Our results showed a significant difference between the canopy cover of forbs growing in treatment areas compared to control areas (P

Electricity Market Complex Adaptive System (EMCAS) for energy planning. LUIS RODRIGUEZ RUIZ (University of Puerto Rico at Mayaguez, Mayaguez, PR, 00794) GUENTER CONZELMANN (Argonne National Laboratory, Argonne, IL, 60439)

Energy has been one of the biggest concerns of modern times. This makes it imperative to use tools that can foresee the future need of electricity generating systems. In these tools, decision analysis techniques are used to help system planners to study future changes in energy systems. An example of a system planning software is the Wien Automatic System Planning (WASP) program, developed by the International Atomic Energy Agency (IAEA). This tool helps decision makers to study the development of an electric generation system and to predict appropriate technology for long term expansion. WASP has been used globally to aid decision makers working with energy systems for the last 30 years. However, recent changes in the power industry, notably privatization and restructuring, have altered the way investment decisions in new power plants are made. Therefore, a new tool has been developed at Argonne National Laboratory to study power system expansion, called Electricity Market Complex Adaptive System (EMCAS), in traditional as well as restructured power markets. EMCAS can help plan short-term operations and long-term system expansion. The EMCAS model simulates generation investment decisions of decentralized generating companies. This software uses a probabilistic 2 dispatch algorithm to calculate prices and profits for new candidate units in different future states of the system. The objective of this project is to analyze EMCAS. The goal is to produce results under a variety of scenarios and compare them with results from the WASP model in order to gain a deeper understanding of the interactions of generation companies and their impact on investment decisions. This will be particularly valuable, when studying a system’s long-term expansion. By presenting a simple case in both programs and comparing the results, the value of new insights provided by EMCAS can be demonstrated. Fuel prices were raised and it was found that it affects the decision making of the EMCAS results. In addition, the differences of the results when competition is taken into consideration are presented, to reflect that adding competition improves the representation of actual markets in EMCAS. As a future work, other sensitivity analyses will be done to further improve our insights into multi-agent investment decisions using the EMCAS software.

Examining the LC50 of Hyalella azteca When Exposed to Varied Concentrations of Silver Nanopartices in a Static Freshwater System. GREGORY BARCELLO (Heritage University, Toppenish, WA, 98948) AMORET BUNN (Pacific Northwest National Laboratory, Richland, WA, 99352)

The use of silver in consumer products is receiving renewed interest due to the increased effectiveness of silver as an anti-microbial agent when in nanoparticle form. Silver nanoparticles are an additive today in common items such as bandages, socks, underwear, and even items like electric razors and computer keyboards. With this renewed interest comes concern about the effects of silver nanoparticles on the environment. This study examined the effects of exposing the benthic, freshwater, amphipod Hyalella azteca to concentrations of silver nanoparticles during a 96 hour static test. The physical set-up for the experiment consisted of 125 mL containers with 7.5g of Accusand 20/30, 75 mL of groundwater/silver nanoparticle solution, and five amphipods. The silver nanoparticles ranged in size from 30-200 µm, and the concentrations of silver nanoparticles (measured as total Ag) tested were un-amended groundwater, 0.4, 4, 41 and 296 µg Ag L-1. The activity of the amphipods was noted every 24 hrs, and percent mortality was determined at the conclusion of the study. The only concentration where mortality was observed was in the highest concentration, 296 µg Ag L-1, where 20 of 25 amphipods were observed dead at 48 hours, and no additional mortality was recorded by 96 hrs. The lethal concentration killing 50% (LC50) of the amphipods was calculated to be 141 µg Ag L-1 using a graphical method. The results of this study showed that amphipods were tolerant to a higher concentration of silver nanoparticles than that reported in the literature for ionic silver exposures. The analysis of the silver nanoparticles in groundwater indicated that most of the silver was aggregated (between 14 and 45% of the silver was able to pass through a 0.45 µm filter) and not present in ionic form. The results of this study indicate that silver nanoparticles in the freshwater environment may not be as toxic as ionic silver to benthic aquatic organisms.

Exploring Global Climate Change Research Portfolios and Evaluations Methods. LINDSAY MENES (California State University Los Angeles, Los Angeles, CA, 90032) DAVE LEPOIRE (Argonne National Laboratory, Argonne, IL, 60439)

The US Strategic plan for responses to potential Global Climate Change includes mitigating emissions through non-energy sources, energy sources, direct CO2 capture, and adaptation. A subset of the Argonne National Laboratory research efforts to support this was identified along with current research progress and potential application. A Google Earth tour was programmed to provide identification of these research efforts, their locations, and their potential, prototype, and commercial applications. Since many Argonne research projects are concerned with increased energy efficiency, a real options model was adapted and simplified to understand the characteristics of the research and the market conditions necessary to assess a value for the research. A case was developed for the example of residential lighting where two technology transitions are concerned: one undergoing from incandescent bulbs to compact fluorescent bulbs (CFL), and one expected transition to light emitting diodes (LED). Data were collected through Internet sources on the relative production and operation costs, the variability of the price of electricity, the market size necessary, and adoption rates for the two lighting transitions. An alternative scenario was created using California’s data since the state is a leading indicator of environmental and energy changes for the country. The value of the research was explored as a function of the electricity market characteristics and research characteristics, e.g. time and results. This model could be applied to investigate other research efforts and be extended to include more options and realistic assumptions.

Exposure Assessment of Second-Hand Smoke. YAZMIN CARRASCO (University of Texas at El Paso, El Paso, TX, 79902) LARA GUNDEL (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

Second-hand smoke (SHS) is a combination of sidestream and exhaled mainstream smoke, also referred to as environmental tobacco smoke (ETS). There are approximately 4,000 chemicals found in mainstream smoke, of which 250 are carcinogens. Exposure to SHS is responsible for approximately 53,000 deaths annually in nonsmokers, making it the third cause of preventable death in the United States. This project involves validating LBNL’s compact inexpensive sampler for measuring three tracers of smoking: nicotine, 3-ethenylpyridine (3-EP) and SHS particles. The new sampler has been operated in a room sized environmental chamber for 24-hour periods after smoking commercial cigarettes by a machine. This study has established the new sampler’s limits of detection for nicotine, 3-EP and SHS particles. Using two prototype active samplers for particles and a passive sampler for nitrogenated compounds, SHS was collected after smoking 6 cigarettes. To calibrate the measurements obtained from the active and passive samplers, previously established methods were used: four Teflon-coated glass-fiber filters and four tubes that sampled actively. The semi-volatile properties of nicotine appeared to have a role in its collection by the passive sampler. The nicotine:particle concentration ratio shows that nicotine was outgassing at the end of the 24 hour collection cycle. In contrast 3-EP appeared to have more stability than nicotine when comparing the 3-EP:particle concentration ratio to the nicotine:particle concentration ratio.

False Spring Occurrence over the Southeastern United States, 1901-2007. GARRETT MARINO (Massachusetts Institute of Technology, Cambridge, MA, 02139) DALE P. KAISER (Oak Ridge National Laboratory, Oak Ridge, TN, 37831)

Near-record warmth over much of the United States during March 2007 promoted early growth of vegetation and many agricultural and horticultural crops. A widespread arctic outbreak followed in early April, resulting in agricultural losses exceeding two billion dollars over the central and southeastern U.S. This "false spring" event also resulted in widespread damage to newly grown tissues of native deciduous forest species, shown by previous researchers to have affected the terrestrial carbon cycle. The current study models the historical occurrence of false springs for the southeastern United States (32-39 °N; 75-98 °W) from 1901-2007 using daily maximum and minimum temperature records from 176 stations in the Global Historical Climatology Network database, and Enhanced Vegetation Index (EVI) data derived from Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observations. A false spring index was introduced that considers the relative timing of the start of the growing season (SGS), or leaf emergence, to the timing of a potentially damaging last freeze (= -2.2 °C). SGS was modeled for the domain by combining EVI data with ground-based temperature "degree-day" calculations reflecting the rate of springtime warming. While interannual variability of the modeled SGS was large, no significant (0.2 days later/decade; p = 0.5) area-wide, long-term trend was found. However, the timing of the last freeze did occur significantly later (> 1 day/decade) over a contiguous region stretching from Mississippi eastward to the Carolinas. False spring risk also was found to be increasing over the same area, although a domain-averaged trend showed no change in risk since 1901. These results illustrate the complexity of observed climate change over the last century. In a generally warming world, the character of temperature changes in some regions does not result in decreasing risk of false spring, and may in fact pose increased risk if occurring during vulnerable plant growth stages.

Fecal Coliform Analysis of Marine Water Seeps in Dungeness Bay, Washington. RYAN RAYL (Monroe County Community College, Monroe, MI, 0) DANA WOODRUFF (Pacific Northwest National Laboratory, Richland, WA, 99352)

For over 15 years the Dungeness watershed, located on the Olympic Peninsula in Washington State, has experienced a steady decline in water quality due primarily to conversion of forested and farmed lands to residential development. The decline in water quality in the Dungeness River has lead to impaired water quality in the connecting estuary, Dungeness Bay, which has resulted in closure of commercial and recreational shellfish beds. The primary cause for the declining water quality and shellfish bed closures has been an increase in fecal coliform, a bacterial indicator associated with fecal contamination from both humans and other warm-blooded animals. A recent microbial source tracking study in the Dungeness watershed has confirmed the presence of human sources of fecal coliform as a partial source of contamination to the Bay. This project was conducted to collect additional fecal coliform data in areas not currently sampled, to determine if further microbial source tracking work is warranted in the Bay. Water samples from freshwater seeps to the Bay were collected at a low tide during the summer and analyzed for fecal coliform. Levels of fecal coliform found in the seep samples ranged from 52 to 1140 colony forming units (CFU)/100 ml. A majority of these concentrations are above state regulatory levels for bacteria in both fresh and marine waters. Although the actual loading from these seeps may not be significant (i.e. low flow), the relatively high concentration from some of the seeps would indicate further investigation to determine what the source of contamination might be (e.g. failing septic systems, animal sources). The overall goal is improved water quality in the Dungeness watershed, and a return of shellfish harvesting in Dungeness Bay.

Forecasting for the United States. BRITTANY ZILNICKI (Florida Institute of Technology, Melbourne, FL, 32901) VICTOR CASSELLA (Brookhaven National Laboratory, Upton, NY, 11973)

During the past several months, I have been learning how to forecast the weather. In order to forecast it was necessary to learn how to read MM5 models; an MM5 is a regional mesoscale model used for creating weather forecasts and climate projections. I also studied satellite imagery such as infared and visible imagery. In my case, I have been studying just the United States. I was also required to write a forecast for the Brookhaven National Laboratory community. The requirement of the forecast was to explain the current conditions, and then summarize the four twelve hour periods that followed. My mentor then evaluated my work forecast for the day as well as my accuracy for the prior day's forecast. These forecasts were then used by the BNL scientists.

Gravel-Corrected Kd Values for Radionuclides in the Hanford Reservation Pit 30 Area Soils. ELLWOOD GLOSSBRENNER (Washington State University, Tri-Cities, Richland, WA, 99352) DR. WOOYONG UM (Pacific Northwest National Laboratory, Richland, WA, 99352)

The standard measurement of a contaminants ability to adsorb to sediment is known as the distribution coefficient (K_d), and is usually determined by the _d has a direct influence on Rf. In this experiment, different gravel factions (0, 10, 30, 50, 80, and 100% gravel) were prepared from Pit 30-2 and 30-3 of the Hanford site in Richland, WA using synthetic groundwater spiked with a ⁹⁹Tc, ²³⁷Np, and ²³⁸U. The K_d, and K_{d,>2 mm} values were measured and then gravel-corrections calculated using two equations, one for K_d,gc,gc=0 where the gravel was simply assumed to be diluted K_d, and another for K_d,gc,gc=x where K_d,tot was a composite of both K_d, and K_{d,>2 mm}. ²³⁷Np had a lower sorption capacity than ²³⁸U, and ⁹⁹Tc did not sorb on any fractions. The K_d,gc,gc=0 for ²³⁸U underestimated K_d,tot by 37% and K_d,gc,gc=x underestimated K_d,tot by 5%. The gravel fractions had an adsorptive capacity, even it was significantly less than K_d, but larger than K_d,gc,gc=0 which assumed no reactive sorbent. The K_d,gc,gc=x was the best measurement of K_d,tot for ²³⁸U. However, because the ²³⁸U K_ds can be significantly influenced by several other factors, this empirically developed gravel correction equation should be used carefully to predict ²³⁸U K_ds.

Head injury assessment in juvenile Chinook using the αII-spectrin biomarker: Effects of pressure changes and passage through a removable spillway weir. CHRISTINE JONASON (Purdue University, West Lafayette, IN, 47906) ANN MIRACLE (Pacific Northwest National Laboratory, Richland, WA, 99352)

The cytoskeletal protein αII-spectrin has specific neurodegenerative mechanisms that allow the necrotic (injury-induced) and apoptotic (non-injury-induced) pathways of proteolysis to be differentiated in an immunoblot; consequently, αII-spectrin breakdown products (SBDPs) are potential biomarkers for diagnosing traumatic brain injury (TBI). The purpose of the following studies was to evaluate the utility of the αII-spectrin biomarker in diagnosing TBI in fish that travel through hydroelectric dams in the Columbia and Snake Rivers. The first investigation used hyperbaric pressure chambers to simulate the pressure changes that affect fish during passage through a Federal Columbia River Power System (FCRPS) Kaplan turbine. The second study correlated with a balloon-tag study conducted by the U.S. Army Corps of Engineers and tested the effect of a removable spillway weir (RSW) on passage of juvenile Chinook. Brain samples from fish were collected and analyzed using an immunoblot for SBDPs, and imaging software was used to quantify the protein band density and determine the ratio of cleaved protein to total protein. The biomarker analyses found higher SBDP expression levels in fish that were exposed to lower pressure nadirs and fish that passed through the RSW at a deep orientation. In general the incidence of injuries observed after treatment was positively correlated with expression levels, suggesting that the biomarker method of analysis is comparable to traditional methods of injury assessment. It was also found that, for some treatments, the 110 kDa spectrin fragment (SBDP 110) correlated more strongly with necrotic head injury incidence and mortality rates than the total cleaved protein or the 120 kDa fragment. These studies will be informative in future decisions regarding the design of turbines and fish passage structures in hydroelectric dams and will hopefully contribute to the development of faster and more accurate techniques for diagnosing TBI in fish.

Home Range and Population Estimation of Red and Gray Foxes at Brookhaven National Laboratory. RENEE FALLIER (Boston University, Boston, MA, 02215) JENNIFER HIGBIE (Brookhaven National Laboratory, Upton, NY, 11973)

Foxes play an important role in Long Island ecosystems as one of few remaining predatory animals in the area, yet little is known about their natural histories there. Non-invasive genetic studies in 2006 and 2007 identified the presence of red foxes (Vulpes vulpes) and gray foxes (Urocyon cinereoargenteus) at Brookhaven National Laboratory (BNL). A study performed in the summer of 2008 built upon this initial research by investigating the individual home ranges of these foxes and again testing for the presence of red and gray foxes. Two red fox kits were trapped, one of which was successfully collared and tracked. Additionally, scat was collected for DNA analysis over an eight-week period with a focus on areas with historic gray fox activity. The collared fox maintained a home range of 0.05 mi² but was only tracked for one week before he could no longer be found. It is likely that competition forced him out of his parents’ home range. Fecal DNA was extracted at a 17% success rate and analyzed using mitochondrial DNA markers. All tested samples were determined to be red foxes. Furthermore, no gray foxes were seen on an automated field camera, implying that there may no longer be a gray fox population at BNL. Trapping and radio collaring will resume next winter in order to track adult foxes with permanent home ranges at BNL, and continued fecal DNA analysis will verify the status of the gray fox population there.

Improved Pre-Treatment Process for Mercury Stabilization. XIAOSHAN HUANG (Stony Brook University, Stony Brook, NY, 11790) PAUL D. KALB (Brookhaven National Laboratory, Upton, NY, 11973)

The Sulfur Polymer Stabilization/Solidification (SPSS) process, developed by Brookhaven National Laboratory to effectively treat high concentrations of mercury contaminant waste, has been licensed to Newmont Mining Corporation, the largest gold mining company in the world. SPSS uses sulfur polymer cement and other reagents such as NaHS to treat mercury. This process is highly effective; however, testing by BNL and Newmont has found inconsistent leaching results that have been attributed to the presence of small quantities of unreacted mercury. The technical challenge was to design an improved SPSS process in which HgS is formed more effectively without leaving unreacted Hg that is susceptible to leaching. We proposed to improve the SPSS process by introducing a fluidized bed pre-treatment stage. We hypothesized that the reaction from Hg to HgS is predominantly a gas phase, and that reacting gaseous Hg with S powder with high surface area and rapid mixing will more effectively convert Hg to HgS and ultimately result in reduced Hg leaching from SPSS treated waste. We tested the application with a commercial fluidized bed dryer and an experimental fluidized bed column; however, the rapid accumulation of pressure in both test conditions prevents the generation of a sufficient quantity of mercury vapor from developing quickly enough to make this process efficient and cost-effective. We look forward to assembling a more efficient setup to improve the result.

In-Situ Monitoring of Trace Gases in a Non-Urban Environment. JOHN MIODUSZEWSKI (Edinboro University of PA, Edinboro, PA, 16412) XIAO-YING YU (Pacific Northwest National Laboratory, Richland, WA, 99352)

This paper describes the integration of a set of trace gas analyzers measuring carbon monoxide (CO), ozone (O₃), sulfur dioxide (SO₂), and nitrogen oxides (nitric oxide (NO), nitrogen dioxide (NO₂), and odd nitrogens (NO_x) ) into a single rack to facilitate study of various air chemistry problems. The first application of this system occurred between July 2, 2007 and August 7, 2007 in Richland, WA. The mixing ratios of all species were lower than in most rural-suburban environments, and strong diurnal patterns were observed. The characteristic anticorrelation between ozone and NO_x was observed. As photochemically-formed ozone depleted surrounding daytime NO₂, NO₂ was being replenished at night with ozone destruction. The highest ozone during these episodes was 45 ppb. The overall average was 15 ppb with readings dipping to near zero at times. This observation is low compared to average daytime summer readings of 60 - 80 ppb in highly populated and industrialized urban areas in the Pacific Northwest region. Four ozone episodes were observed. HYSPLIT analysis and prevailing weather conditions both indicated much of the ozone was transported locally or produced in-situ. Analysis of SO₂ as a tracer for ozone advection further indicated lack of long-range regional transport of pollutants to Richland. The results of this work could be a useful sample data set to study the historical record of air quality in rural eastern Washington.

Investigation of Nitrate Removal from Wetlands Receiving Agricultural Runoff. KRISTINA MINOR (University of California Berkeley, Berkeley, CA, 94701) WILLIAM STRINGFELLOW (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

Agricultural watersheds typically have excess amounts of nitrate-nitrogen in their drainage. High nitrate-nitrogen concentration in water is an environmental and health concern. Nitrate-nitrogen can act as a contaminant in drinking water and cause eutrophication that can deplete dissolved oxygen concentrations and thus endanger aquatic life. For this study, nontidal freshwater wetlands were tested for the treatment of nitrate-contaminated water. This study sought to identify relationships between laboratory microcosms and a full-scale treatment wetland, examine how nitrate-nitrogen load affects organic carbon production, and determine the relationship between influent load and concentration of nitrate-nitrogen in the microcosms. Results showed that the laboratory microcosms were very efficient in treating nitrate-contaminated water, with a range of 80-96% percent removal of nitrate-nitrogen. The laboratory microcosms compared to the field site showed a much higher percent removal at similar loads of nitrate-nitrogen. One potential reason that would explain the discrepancy in removal between the microcosms and the field site would be that the laboratory microcosms acted as an ideal, completely mixed system. Also, the plant biomass of the microcosms is predominantly composed of duckweed (Lemna valdiviana), which is not found at the field site. The flora at Ramona Lake is mostly comprised of tule (Schoenoplectus californicus). One plant species may have the ability to uptake NO3-N more effectively than another, thus affecting the removal percentage. Dissolved organic carbon results showed no measurable response to increased nitrate-nitrogen loads with consistent results and mean concentrations of 4.16 ± 0.51 mgC/L for Microcosm 1 and 4.08 ± 0.69 mgC/L for Microcosm 2. Total organic carbon results were highly variable and uncorrelated with increases in nitrate-nitrogen load; mean total organic carbon concentrations were 6.33 ± 3.98 and 11.34 ± 6.23 mgC/L for Microcosm 1 and 2 respectively. As expected, the data shows a strong linear relationship between nitrate-nitrogen influent load and concentration, with an r² value of 0.91 for both microcosms. We conclude that freshwater nontidal wetlands have the potential to treat agricultural runoff at highly efficient rates; however, further research is needed to investigate what factors specifically allowed the laboratory reactors to be much more efficient when compared to natural wetlands.

Isolation of Anaerobic Bacteria with Better Chromate Remediation Capabilities as Compared to Shewanella oneidensis MR1. KOJO WALLACE (CUNY Bronx Community College, Bronx, NY, 10453) DR. DEV. CHIDAMBARAM (Brookhaven National Laboratory, Upton, NY, 11973)

Exposure to hexavalent Chromium, Cr (VI), can lead to adverse health effects such as cancer and genetic mutations. Chromium (Cr) is used for hardening steel and extensively in the coating industry to fight corrosion. For example, all structural aluminum (such as in aircrafts) are coated with Cr (VI), based coating. However, due to its high solubility, hexavalent chromium used for the above-mentioned applications tends to solubilize and leads to contamination of underground water. Fortunately, the health hazards associated with Cr (VI) are related to its oxidation state; whereas Cr (VI) is a health hazard, Cr (III) is an important dietary trace element needed for the maintenance of a healthy heart and sugar metabolism. The health hazards associated with exposure to Cr (VI) have prompted research into methods of cleaning up chromium-contaminated sites. During growth and metabolism, bacteria oxidize organic carbon sources available to them and generate excess electrons which may be transferred to Cr (VI), and thus reducing it to the less harmful Cr (III). We have isolated an anaerobic bacterium (Bac 9) capable of removing soluble chromium. We have also investigated the well-known bioremediating capabilities of anaerobically grown Shewanella oneidensis MR-1 as a comparison to the Bac 9 bacterium. In our experiments, we used freshly grown (end of exponential phase), autoclaved (dead bacteria), and autoclaved and depressurized (hydrogen removed) microbial samples that were prepared in serum bottles. These samples were then inoculated with Cr (VI) solutions such that the total concentration of chromium in each serum bottle was 1mM. The concentration of Cr (VI) was analyzed spectrophotometrically using organic reagent diphenylcarbazide (DPC) and an UV-VIS spectrometer at various time intervals. A baseline for the reduction capabilities of the bacteria Shewanella oneidensis MR1 was generated and compared with that of Bac 9. Cr (VI) concentration was observed to decrease as early as fifteen minutes after the addition of chromium. Hence, these results show that the bacteria have a high potential for use in bioremediation of chromium (VI) contaminated sites.

Lattice Boltzmann Modeling of Reacting Flows. MICHAEL LEWIS (University of Alabama, Tuscaloosa, AL, 35486) SREEKANTH PANNALA (Oak Ridge National Laboratory, Oak Ridge, TN, 37831)

The objective of this study is to simulate flow and reactions in a tubular reactor. Tubular reactors are the basic building blocks of many catalytic devices, including those on cars to reduce emissions of carbon-monoxide (CO) and nitrogen oxide (NOx). Lattice Boltzmann Methods (LBM) have been applied to many areas where mesoscopic flows are encountered; our research focuses on using these methods for heterogeneous chemically reacting flows. Predictive models can be used to optimize tubular reactor designs and thus increase their energy efficiency and reduce operating costs. My summer project is that of debugging and developing a LBM Fortran 90 program, originally written by my mentors at Oak Ridge National Laboratory, namely Sreekanth Pannala and Srdjan Simunovic. I applied the program initially to simulate flow in a pipe with no chemical reactions, and compared the results to analytical solutions for fully developed and developing flows. To verify the approach, I simulated Poiseuille pipe flow with periodic boundary conditions and compared the predicted velocity profile to analytical results published by others. I also simulated Poiseuille pipe flow with inflow and outflow boundary conditions, and analyzed the entry-length effects. Now that the code has been verified for flow in the pipe, the chemistry has been “turned on” to simulate reactions within a tubular reactor. The net result of this research was a working Fortran 90 LBM program that accurately simulates flow in a tubular reactor in two dimensions; it still has limited capabilities for modeling chemical reactions. The ultimate objective of the research is to develop an efficient flow solving LBM program which can play a crucial role in solving reacting flow problems in energy applications that are important to the Department of Energy and the nation.

Measuring Airflow through Commercial Building HVAC Systems Using Air Velocity Sensors. SEBASTIAN COHN (Worcester Polytechnic Institute, Worcester, MA, 94563) MICHAEL APTE (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

In order to prevent buildup of indoor air contaminants within commercial buildings while avoiding excessive use of energy, it is necessary to monitor and control the flow of outdoor air into a building. Currently, for many applications, there are no accurate and economically feasible ways of measuring air intake flow rates in real time, and so many buildings are over-ventilated or under-ventilated. To solve this problem, a method of measuring outdoor air flow into a building that can become widespread is necessary. This study evaluated the accuracy of measurements of air intake flow rates when electronic velocity sensors were installed inside or at the down stream face of air intake louver systems. Louver systems are routinely used in buildings to limit water entry into the building during periods of rain snow. The study results indicate that this measurement approach, with sensors placed either inside the louver or at its outlet, can be reasonably accurate, with typical errors less than 10%, and may be practical because few sensors are required and calibrations are not necessary at the building site. Further study is needed to evaluate whether the high accuracy is maintained over time and the acceptability of system hardware and installation costs.

Microbial Community Fingerprinting. CHRISTINA COSENTINO (Suffolk County Community College, Brentwood, NY, 11717) VANESSA L. BAILEY (Pacific Northwest National Laboratory, Richland, WA, 99352)

Over the past two hundred years the concentrations of atmospheric carbon dioxide (CO₂) and greenhouse gases (GHG) have raised dramatically due to various activities, including agriculture, forestry and industrial activities. The United States Department of Energy (DOE) Office of Biological and Environmental Research (BER) established and formed the Consortium for Research on Enhancing Carbon Sequestration in Terrestrial Ecosystems (CSiTE) to perform the necessary investigations and the necessary research to see the impact of these activities on our climate systems. There are five scientific themes within CSiTE, and the focus of this research is within the theme of Microbial Community Function and Dynamics. This theme was investigated through looking at soil samples from different plots and depths located in Milan, TN during the different seasons. Deoxyribonucleic Acid (DNA) extraction, Polymerase Chain Reaction (PCR), and Ribosomal Intergenic Spacer Analysis (RISA) were the methods used for the investigation. The results for this part of the CSiTE project show there are differences between the samples during the different seasons of the year. They may only be slender differences, but there are still changes in the communities. Just by looking at any one of the samples and its banding patterns, you can see some differences. Some bands are missing or not present from one season to the other, and other bands go from darker and more defined to lighter and less defined, or lighter to darker. In the future for this project, there will be more work comparing the samples based on the different seasons to see if there are differences and how different they really are.

Microbial Community Mapping from Long Island’s Pine Barren Forest Soil. JEFFERY AMBROSE and NYESHA SMITH (Southern University at New Orleans, New Orleans, LA, 70126) MURTY KAMBHAMPATI (Brookhaven National Laboratory, Upton, NY, 11973)

Management of any ecosystem requires the information on the flora and fauna present in the environment. The current management plans for terrestrial ecosystems are mainly based on the macrofauna. While microorganisms are very critical for maintaining the balance in an ecosystem, no information is available on the types and behavior of microorganisms in the soil of the Long Island Pine Barren Forest. Thus, the existing management plan for an ecosystem does not consider the influence of the actions on the microbial diversity. In the first study of its kind, we mapped the Long Island Pine Barren Forest (LIPBF) soils based on their microbial, community-level, physiological profile (CLPP). Soil samples were collected from different parts of the forest and upon preparation of the inoculum, BIOLOG EcoPlates were inoculated. The clustering analysis based on color intensities illustrates that the entire LIBPF can be divided into four different clusters at every horizon. However, the physiological response of microbial community at each horizon and cluster was different. No correlation between sampling sites and the physiological profile was obtained based on vegetation or geographical location. In conclusion, comparing the physiological profile of the microbial community from each horizon, one can make a list of substrates that are utilized more throughout the LIPBF. However, further studies need to be carried out to test this hypothesis in the future.

Minimizing Optical Variability in Optical Measurements of Particles from Second Hand Tobacco Smoke. NICOLE LACOUNT (San Francisco State University, San Francisco, CA, 94114) LARA GUNDEL (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

Epidemiological studies show that exposure to Particulate Matter (PM) is linked to increased rates of respiratory disease. Currently, it is difficult to reliably measure concentration and nature of PM in a universal way. As a result, there is a need to develop an inexpensive miniature device that accurately measures concentration and content of PM in indoor and outdoor air. Prototype particle samplers have been developed to measure PM. The particle sampler employs the principle of thermophoresis to collect PM. Collected material (gas and PM) is analyzed using spectroscopy and gas chromatography. Due to the multi-step nature of determining particulate matter in the air, there are many possible sources of uncertainty in measurement in these experiments. Historically, these variables have been addressed through redesigning instruments and altering the procedures. Standard pre-tests and post tests of electrical power, baseline absorption, flow rate of the pumps, cleanliness, and accompanying devices (aethelometer) are conducted to minimize error. Despite these efforts, actual data still does not fully correlate with expected data. This summer, the experiments were designed to identify and correct sources of random error and/ or bias as a result of procedural and/or device malfunction or alteration. The objective this Summer was to determine the sources of random and systematic error in spectrometer data as a result of variables that effect light intensity (I) passing through the heat sinks. This experiment focuses on the effect of chipped quartz heat sink tips. chipping of the quartz rod reduces light intensity passing through the quartz. However, if the rod is chipped before the Reference Intensity (Io) measurement is taken, there is likely no change in the absorbance post experiment, as calculated with Beer’s Law (above). However, if the quartz is chipped during the experiment, the Intensity (I) of light will decrease, and thus provide increased absorbance readings. Findings suggest that with each consecutive chip (chip 1, chip 2, chip 3) of the same quartz, the intensity decreases within the ultraviolet light range and the visible light range by a difference of 200-1000 counts of intensity. To remedy this issue, we have ordered “quartz tip caps,” that will protect the tip and also prevent accidental PM collection.

Our Environment in Hot Water: Comparing Water Heaters. A Life Cycle Approach Comparing Tank and Tankless Water Heaters in California. ALISON LU LU (Yale University, New Haven, CT, 06520) JAMES MCMAHON (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

Residential water heating is a large source of energy use in California homes. This project took a life cycle approach to comparing tank and tankless water heaters in Northern and Southern California. Information about the life cycle phases was calculated using the European Union’s Methodology study for EcoDesign of Energy-using Products (MEEUP) and the National Renewable Energy Laboratory’s Life Cycle Inventory (NREL LCI) database. In a unit-to-unit comparison, it was found that tankless water heaters would lessen impacts of water heating by reducing annual energy use by 2800 MJ/year (16% compared to tank), and reducing global warming emissions by 175 kg CO2 eqv./year (18% reduction). Overall, the production and combustion of natural gas in the use phase had the largest impact. Total waste, VOCs, PAHs, particulate matter, and heavy-metals-to-air categories were also affected relatively strongly by manufacturing processes. It was estimated that tankless water heater users would have to use 10 more gallons of hot water a day (an increased usage of approximately 20%) to have the same impact as tank water heaters. The project results suggest that if a higher percentage of Californians used tankless water heaters, environmental impacts caused by water heating would be smaller.

Plant Species Diversity Relative to Surface Water Area in a Mitigation Wetland at Argonne National Laboratory, Illinois. MELISSA LANIOSZ (University of Illinois, Champaign, IL, 60558) KIRK LAGORY (Argonne National Laboratory, Argonne, IL, 60439)

When the Advanced Photon Source at Argonne National Laboratory in Illinois was constructed in 1990, 1.8 acres of wetland were destroyed. Because the Clean Water Act mandates a no-net-loss of wetland area, a mitigation wetland, Wetland R, was constructed. Wetland R has been monitored from 1992-1996 and 2002-2008 to determine if its plant diversity is comparable to that of the destroyed wetlands. The purpose of this study was to observe the annual change in plant species distribution, focusing on distribution relative to surface water area. Sampling occurred along 10 linear transects in 5 randomly located 0.25m2 quadrats per transect. Species name, percent cover, and the presence of standing water were recorded. Wetland status, native status, and the coefficient of conservatism were determined for each species. Three hydrology classes were determined based on species distribution in quadrats relative to the frequency of standing water. This year, 83 species were found, 14 more than last year. Native species increased from 73% to 77%. A non-native plant, Phalaris arundinacea, was the most abundant with a mean percent cover of 11.5, almost 4 times the percent cover from last year. It was found equally in quadrats not containing water and those with standing water >40% of the time. Boltonia latisquama, a native, obligate wetland species, was the second most abundant with a mean percent cover of 7.5. It was predominantly found in quadrats with standing water >40% of the time. Studies on the frequency and distribution of native versus non-native species should continue in Wetland R to ensure the wetland is comparable to those which were destroyed.

Preservation of Fluorescence in Transmission Electron Microscopy for Protein Localization. TIMOTHY CHUNG (University of California, Merced, Merced, CA, 95343) MANFRED AUER (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

The Department of Energy (DOE) faces the challenge of finding new efficient strategies for bioremediating toxic substances in the subsurface at over 5700 sites of contamination. One possible method is a microbial approach involving the sulfate reducing anaerobic bacterium Desulfovibrio vulgaris Hildenborough (DvH). DvH is important for its ability to reduce heavy metals such as uranium from its soluble state to an insoluble state thus confining it in the subsurface. Early attempts at using DvH to bioremediate contaminated sites demonstrated the lack of understanding of how a bacterium functions within a microbial community. This prompted the DOE to address bioremediation with a systems biology approach. Part of this approach is characterizing and understanding individual proteins and protein complexes as they function within DvH under normal and stressed conditions. In situ protein localization is a desirable method for the characterization of individual proteins as they function within the cell. A commonly used method to visualize individual proteins and track them inside a cell is fluorescent proteins and correlative microscopy. As fluorescent proteins require oxygen to function properly they are not suited for DvH, therefore we employed a novel tag based labeling technology called SNAP-Cell (Covalys Biosciences AG, Witterswil, Switzerland). The SNAP-Cell system has been widely used in eukaryotic systems and aerobic bacteria, however it has not been used in anaerobic bacteria. In order to proceed to correlative microscopy based protein localization studies, it was necessary to investigate whether the photostable SNAP-Cell fluorophore BG-505 would withstand transmission electron microscopy (TEM) processing. To determine whether the intensity of BG-505 maintained fluorescence throughout TEM processing, measurements were taken after each chemical treatment. The fluorescence intensity data was obtained by averaging 9 individual fluorescent cells per treatment. The overall conclusion of the data was that the fluorescence of the BG-505 fluorophore decreased during the fixation step, but was maintained at a detectable level and was therefore preserved throughout processing. Using this fluorophore and SNAP-Cell system, protein localization can proceed through correlative microscopy methods.

Principal Components Analysis of Aerosol Mass Spectra. MARGARET BROWN (Stony Brook University, Stony Brook, NY, 11794) ROBERT MCGRAW (Brookhaven National Laboratory, Upton, NY, 11973)

Earth’s climate is greatly affected by aerosols, small particles in the atmosphere, around which all cloud drops form. Our aim is to characterize and visualize the composition of aerosol particles so we can understand the effect they have on climate and represent them accurately in climate models. We are working with data obtained using the Aerodyne Aerosol Mass Spectrometer from a flight of a G-1 aircraft over Mexico City on March 19, 2006. The data set contains the concentrations of components of the aerosol particles in terms of mass-to-charge ratios. We analyzed the composition of aerosols from an urban plume of a mega-city, Mexico City, using Principal Components Analysis (PCA) on the covariance matrix of the data set, and used Singular Value Decomposition to obtain the principal vectors. We also analyzed projections upon the principal vectors of typical factors, like sulfate, nitrate, and hydrocarbon-like organic aerosols, oxygenated organic aerosols, and biomass burning organic aerosols, which are characterized by their spectra. We used Igor Pro software for computation and visualization of the data set. This analysis helped us to understand how the composition of the aerosol particles changes over time and distance from the city. Nitrates, which are produced from car exhaust, are representative of young aerosols. As the air mass moves away from the city and the aerosols age, the concentration of nitrates decreases, and the concentration of organics increases. The dimensionality of the aerosol - how many variables are needed to describe the aerosol in a statistical simulation for future use in climate models - was investigated. We found that the data set can be compressed into six principal components with 99% of the variance explained, and that it can be compressed very well using just three principal components, explaining 96% of the variance. We conclude that PCA is a powerful tool for analysis, compression, and visualization of an aerosol mass spectra data set. The method has been used here to determine how the composition of the aerosol changes with age during a field experiment. The compression studies suggest that statistical approaches based on PCA have the potential for greatly improving the efficiency of aerosol representation and tracking in climate models.

Production of Hydrogen Gas from Hydrogen Sulfide. DAVID SMITH (Shepherd University, Shepherdstown, WV, 25443) GREG KRUMDICK (Argonne National Laboratory, Argonne, IL, 60439)

Concerns over global climate change and the rising instability in oil producing regions of the Middle East have had major impacts on the global energy market. The United States has identified the need to transition from an energy strategy heavily dependent on fossil fuels to a more diversified alternative energy plan, including the use of hydrogen. Hydrogen can be used as a clean, efficient, transportable fuel source, emitting only water vapor as exhaust. However the cost of hydrogen is currently a prohibitive factor in the development of a hydrogen based energy plan. Identifying and developing means of efficient and cost effective hydrogen production is a crucial step in establishing hydrogen as a major energy source. The goal of this research is to test and develop techniques for recovering hydrogen gas from hydrogen sulfide (H2S) using molten copper as a reactant. H2S is a byproduct of the petroleum and natural gas refining industry. It is toxic to humans, destructive to industrial catalysts and a pollutant to the environment. This research tested methods for safely and efficiently recovering high purity hydrogen gas by reacting H2S with molten copper. The experimental design for this research is a scale up of the 2003 proof-of-principle system. Experiments were performed to determine maximum possible flow rates for varying melt sizes, effect of flow rate on purity of hydrogen produced, and effect of impurity gases on the process. Knowledge gained from this research may be instrumental in advancing a hydrogen based energy plan in the United States.

Quantifying the Infectious Period of Bean Leaf Beetles and the Latent Period of Bean Pod Mottle Virus in Soybean. BRITA KILBURG (Loras College, Dubuque, IA, 52060) DR. FORREST NUTTER, JR. (Ames Laboratory, Ames, IA, 50011)

Bean pod mottle virus (BPMV) can greatly impact soybean yields, with infections early in the season causing the greatest yield losses. The bean leaf beetle (BLB) is the primary insect vector for BPMV, but little is known about the length of time that the beetles remain infectious. In addition, there is scant information on the temporal and spatial dynamics of BPMV within soybean plants. Information on how long it takes from inoculation until a plant is infectious i.e., time from inoculation to the time that the beetles can feed and acquire the virus remains unknown. To quantify the infectious period of the BLB, 35 beetles were swept from grass borders near woodlots and allowed to feed on BPMV-infected plants for 48 hours. Individual plastic cages were used to house one beetle per plant and beetles were allowed a transmission period of 24 hours. This process was repeated until the 15th day, where upon beetles were collected and tested for the presence of BPMV using ELISA. Following a 21-day incubation period, the sap from each plant that the beetles had fed on was extracted and tested for BPMV by ELISA (Enzyme-linked immunosorbent assay). To determine the time needed for BPMV to become systemic throughout soybean plants, two sets of 225 plants were mechanically inoculated at the V2 and V5 growth stages. Following inoculation, 25 plants were destructively sampled each day and all leaves from each plant were individually extracted and tested for BPMV by ELISA. To determine if all leaf positions became infected with BPMV following inoculation, 25 plants inoculated at the V2 growth stage were allowed to grow for one month, and all leaves and branches of each plant were individually sampled, sap extracted, and tested for BPMV. The acquisition efficiency for beetles to acquire the virus was 54.3%, but just three of 19 beetles tested positive for BPMV at the end of the study. These results indicate that more than one day is necessary for the beetles to effectively acquire and transmit the virus. The percentage of BLB transmitting BPMV increased from day 1 (19.4 percent) to day 3 (25%). An average of 72.2% of the leaves from each BPMV-inoculated plant tested positive for BPMV 25 days after inoculation. In the V2 and V5 growth stage experiment, the youngest leaves on plants had the highest percentage of leaves testing positive for BPMV 5-7 days after inoculation.

Rates and Mechanisms of Radionuclide Fixation by Organo-Polyphosphates. CASEE LEMONS (University of Arkansas at Little Rock, Little Rock, AR, 72114) DAVID B. WATSON (Oak Ridge National Laboratory, Oak Ridge, TN, 37831)

Contaminants in radioactive wastewaters disposed of into the Y-12 Security Complex S-3 ponds for 32 years have migrated into the surrounding soil and groundwater. This experiment studied the potential role of organo-polyphosphates for uranium and thorium adsorption and immobilization. Phytate is a naturally occurring polyphosphate produced commercially for its utility as a metal chelating and precipitating agent. Polyphosphates can react with contaminants by adsorption, ion exchange, and/or coprecipitation. Forty small (5-10 g) permeable environmental leaching capsules (PELCAPs) were prepared to contain polyacrylamide, alone or in association with soil and polyphosphates. The PELCAPs were submerged in a contaminated groundwater then repeatedly retrieved and assayed using x-ray fluorescence spectrometry (XRF). Uranium and Th levels were compared to other elements (Sr, Rb, Fe, Mn, and Zr) which remained relatively constant. The small uptake of U and Th by polyacrylamide alone reflected the diffusion of dissolved ions into the gel. Thorium uptake was initially highest by soil only, but the final values of soil and soil + phytates were relatively similar. Uranium uptake values were initially highest in soil + Na phytate, but uptake was quickly dominated by soil + Ca phytate. Future studies will determine the mechanisms of attenuation and degree of leaching of the contaminant-laden PELCAPs. One-half of the PELCAPs will undergo sequential laboratory extractions to determine rates of ion diffusion by deionized water, weak ionic exchange by dissolved salts, and extraction of adsorbed soil oxides by dilute acid. The other half of the PELCAPs will be submerged in uncontaminated in situ groundwater. PELCAPs will be analyzed to determine which materials maintain radionuclide fixation longest relative to the contaminant uptake. As XRF data are insufficient to conclude the specific means of attenuation, the additional analytical methods of laboratory extractions and in situ leaching will assist in determining these mechanisms of radionuclide fixation.

Research on the Effects of Dioxin on the Hepatic System. AMY GREEN (Monroe County Community College, Monroe, MI, 48161) MARGARET MACDONELL (Argonne National Laboratory, Argonne, IL, 60439)

Dioxin, in specific 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) is currently believed to have a number of adverse health effects on people, but due to the inability to perform dioxin testing on humans, researchers must rely on past human data and current observations collected from animal research. At this time the project is centered on reviewing and evaluating recent articles focused on discovering the effects of dioxin on the human system in order to assist the Environmental Protection Agency (EPA) in compiling adequate and reputable research to support the development of health base levels to provide to the general public. Each member of the research team has a specific endpoint or body system that they will be researching. For example, this specific focus was to find information on the effects of TCDD on the hepatic system. In order to find articles, the research team compiled a database of systematic search terms which were used to conduct online searches on PubMed, and the abstracts acquired from these searches were coded according to their level of relevance to the goal of the project. After retrieving the full articles of the higher order abstracts, the information in the articles was read and thoroughly evaluated, and that information was used to build a database of dose-response data to be used by the EPA for plotting and modeling the effects of TCDD in lower doses. The research will continue as more information is collected allowing the database to grow.

Statistical Variations in Bird Survey Data From 2000 to 2007. RACHAEL MILLINGS (Stony Brook University, Stony Brook, NY, 11722) JENNIFER HIGBIE (Brookhaven National Laboratory, Upton, NY, 11973)

Since 2000, the Environmental & Waste Management Services (EWMS) Division at Brookhaven National Laboratory (BNL) has conducted monthly bird surveys from March through October using a point-count method. The purpose of these surveys is to identify new species in the area; monitor changes in species populations, as well as changes in parasitic species populations; create accurate habitat models; and evaluate the effect of land management on various species. To accomplish this, statistical analysis of the data collected from 2000 through 2007 was performed using Statistix 9, an analytical statistics program. The data were organized into smaller files by year, family, and species. Biodiversity indices were calculated for each year. Next, descriptive statistics files, such as scatter plots and pie charts were created to gain a visual perspective of how the number of birds observed varied with respect to weather and temporal variables, as well as how biodiversity indices varied by year. A one-way analysis of variance (ANOVA) test and/or a Kruskal-Wallis nonparametric ANOVA test was then performed on selected data sets to determine the significance of any variation from the mean. Finally, a Geographical Information System was used to identify any correlation between species population variations and habitat availability. The results showed that the brown-headed cowbird (Molothrus ater) and the ovenbird (Seiurus aurocapillus) experienced population changes during the 2000-2007 period (α - 0.05). Both increases and decreases in the total sum of birds and bird species observed with respect to season were determined. ANOVA testing also showed that the diversity of the Biology Fields and Peconic River transects was greater than that of the South and Z-Path transects (α - 0.05). According to the Pearson correlation test, a strong correlation of 0.6581 exists between the species richness of a transect and vegetation type representing more that 30 percent of the station area. Using these results, the EWMS division at BNL can make informed management decisions concerning the experimental design of the survey method and the oversight of bird species populations and habitats.

System Dynamics: Water Use and Crops. LESLIE WEEKS (Brigham Young University-Idaho, Rexburg, ID, 83440) JACOB J. JACOBSON (Idaho National Laboratory, Idaho Falls, ID, 83415)

As demand rises for a renewable, more environmentally friendly energy source, many people are turning to biofuels like ethanol. The production of biomass and feedstock, which can be used to make ethanol, has risen to try and meet the increasing demand. In order to meet biofuel production goals set forth by President Bush’s State of the Union Address (2007), many factors must be included and evaluated over an extensive period of time to ensure sustainable, renewable energy. System dynamics incorporates these factors in a synergistic way, allowing the relationships between multiple factors to be accounted for when analyzing biofuel sustainability. The model studies the long term effects on water sources due to an increase in growing biomass and feedstock. The model allows the user to see the long term effects on water as factors such as crop rotations, fertilizer practices and location of the farm changes. The model tracks both the quality and quantity of a local river and fertilizer in the ocean, as the water eventually drains to the Gulf of Mexico or other areas on the coast. The model can be used by user groups trying to determine the effects of farming practices on water and fertilizer contaminants, helping to bring the changing demand into perspective and allowing realistic expectations for its future.

The Biodegradation of Ionic Liquids. TRISHA RAMDIHAL (Queensborough Community College, Bayside, NY, 11364) DR. CLEVELAND DODGE (Brookhaven National Laboratory, Upton, NY, 11973)

Ionic liquids (ILs) are organic salts with melting points below 100°C. Owing to their attractive properties such as non-volatility, non-flammability, high thermal stability, high conductivity, and recyclability, ILs have received considerable attention as environmentally friendlier alternatives to conventional solvents. However, the toxicity of ILs and their fate after entering the environment is not clearly understood. Understanding the effect of the structure of ILs on their biodegradability is important for the success of their large scale application and gives insight into possible waste management procedures for spent ILs. The overall goal of this project is to design ionic liquids that will have a minimum negative impact on the environment. Results in the literature indicate that incorporation of ether, hydroxyl, and ester linkages in the cation of ILs is favorable for biodegradation. Halide salts based on the 1-methylimidazolium cation bearing alkyl, hydroxyalkyl, and ethoxyethyl substituents have been successfully synthesized. The halide salts were converted to phosphate containing ILs. H-1, C-13 and P-31 NMR spectra were used to confirm the structures of these compounds. The biodegradation of the ILs is being assessed by incubating a fixed volume in a mineral salt medium with the soil microorganisms. After several dilutions at periodic intervals the fate of the IL will be determined by comparing the NMR spectra of the ILs before and after contact with the microorganisms. Preliminary results for hydroxyalkyl imidazolium bromide ILs indicate that the IL was not degraded by the soil microorganisms. Future work will include investigating the ethoxyethyl and alkyl containing ILs in a similar manner.

The Cultivation of Clostridium acetobutylicum and Clostridium pasteurianum for the Production of Ethanol in a Synthetic Medium. CLARIBEL NUNEZ (Brooklyn College, Brooklyn, NY, 11213) CLEVELAND DODGE (Brookhaven National Laboratory, Upton, NY, 11973)

Due to atmospheric pollution and the need to reduce the release of harmful gases to the ozone layer, there has been ongoing research for alternative fuel sources. Ethanol is a source that has been discovered to reduce the ground-level formation of ozone layer when added to gasoline. 50Consequently, it has been of great importance to study efficient ways to produce this alcohol. Therefore, the production of ethanol fermentation by Clostridium acetobutylicum and Clostridium pasteurianum was investigated. These two bacteria were studied under Four Mineral Salts medium. The growth of the bacteria in these mediums depended on Mg, Fe, and K. In order to maintain the best cell growth and alcohol production both bacteria needed to be kept in neutral pH and in anaerobic conditions. The mediums were neutralized with 1N of Sodium Hydroxide and placed into 150-ml bottles. The mediums were then sparged with nitrogen, autoclaved, and inoculated. Due to time constraints a proper growth curve of the four mineral salts medium was not obtained. The cultures were growing slowly and so it was difficult to obtain accurate data on the optical density and pressure as the cultures grew. Because of this it was also difficult to obtain accurate data on the pH of each medium as the cultures of C. acetobutylicum and C. pasteurianum continued to grow. Glucose provided to be a better carbon source for C. acetobutylicum and C. pasteurianum than glycerol. The cultures grew at a more rapid pace when maintained in glucose. Increasing the amount of salts (such as potassium sulfate) and carbon sources (such as yeast extract) showed to increase the production of ethanol in both cultures. However, even though ethanol increased in both cultures, C. pasteurianum showed the most ethanol production when kept in any of the four mineral salts medium. Further tests were unable to be made due to time constraints and so the experiment could not be concluded.

The Development and Testing of a Novel Thermodenuder for Internal Combustion Engine Emissions Analysis. BRADLEY LANDGRAF (Allegheny College, Meadville, PA, 16335) MENG-DAWN CHENG (Oak Ridge National Laboratory, Oak Ridge, TN, 37831)

A thermodenuder is an instrument that removes vapor from an aerosol via heat and diffusive transport, leaving behind solid aerosol particles that can be characterized in terms of particle size, number of particles, and other physico-chemical properties. The objective of this study was to examine the effects of temperature on the performance of two thermodenuders - one commercially available from TSI^® Inc. and one being developed in-house at ORNL. I compared the performance of the in-house developed thermodenuder (referred to hereafter as the ORNL-TD) to that of the TSI Model 3065 thermodenuder using laboratory-generated aerosol particles. A 1% solution of ammonium sulfate [(NH₄)₂SO₄] was aerosolized by an atomizer, conditioned by removing water vapor in a diffusion dryer, and flowed through a bypass line, the TSI 3065, or the ORNL-TD. Both thermodenuders were operated at each of six temperatures - 25, 50, 100, 130, 160, and 200ºC - in separate experiments. The ammonium sulfate aerosol particles were size-classified by an electrostatic classifier and counted using an ultrafine condensation particle counter. Particle losses were compared between the TSI 3065, ORNL-TD, and the bypass line. Results show that the size distributions of the ammonium sulfate particles did not change over the range from room temperature to 160ºC. Above 160ºC, the peak particle size declined significantly, and the number of particles increased, possibly due to decomposition of the chemical forming smaller particles by nucleation. The TSI thermodenuder had a particle loss of 20% or more depending on the operating temperature. The ORNL-TD had a particle loss of 7% under the same conditions used in experiments with the TSI thermodenuder. These results indicate that the ORNL-TD is a promising technology for analyzing aerosols. Additional tests are expected to support these preliminary findings.

The Effect of Phragmite australis Invasion on Southern Leopard Frog Tadpole Survival on Long Island. KAITLIN FRIEDMAN (University of Vermont, Burlington, VT, 05405) JEREMY FEINBERG (Brookhaven National Laboratory, Upton, NY, 11973)

Phragmites australis is a type of invasive plant whose destructive ecological effects include displacing native species and altering the structure of wetlands. Our research explored the possibility that P. australis has a detrimental impact on the survival of the southern leopard frog (Rana sphenocephala) and is a factor in the decline of the frog on Long Island. We raised southern leopard frog tadpoles at six different sites with three different levels of invasion: none, medium, and heavy. The tadpoles were raised in mesh enclosures in situ and their growth and survival was monitored. Basic aspects of water quality were evaluated to determine if the presence of P. australis made a notable difference. Results indicate that P. australis alone does not have a detrimental impact on tadpole survival, but may be harmful in conjunction with other stress factors such as disease. Water temperature tended to be lower as invasion levels increased, presumably due to an increase in shade. It is possible that the decreased water temperature slows tadpole development. Further research could explore the possibility that P. australis does not prevent tadpoles from surviving physically, but affect the adults behaviorally by altering the structure of wetlands. It is possible that sites with heavy P. australis invasion are not seen as suitable breeding habitat.

The Effects of Physical and Chemical Water Quality Parameters on the Distribution of Aquatic Invertebrates within the Carmans River on Long Island, New York. GLEN BORNHOFT, VICKY GIESE, and MELLISSA WINSLOW (California Polytechnic University, San Luis Obispo, CA, 93407) TIMOTHY GREEN, PHD. (Brookhaven National Laboratory, Upton, NY, 11973)

While the Carmans River is one of a few pristine aquatic ecosystems on Long Island, roadside run-off, fertilizers, septic systems and groundwater contaminants all threaten to degrade its condition. All of these factors directly affect water quality and the distribution of aquatic invertebrates, which, in turn, affect higher trophic levels. Sensitive populations such as invertebrate species serve as indicators of biological integrity and can be useful for identifying problems in water quality. This research is the initial investigation of a longitudinal study and will be used for planning mitigation projects. The physical and chemical variations in water quality were compared for six different locations and among three habitat types selected along the Carmans River. Water samples taken at each location were then tested in areas of varying water velocities. A Yellow Spring Instruments, Inc. (YSI) 650 MDS water quality meter was used to measure the real-time data for temperature, pH, dissolved oxygen, conductivity, and turbidity. Water samples were analyzed using a HACH Company Digital Titrator and colorimeter. Using a Surber sampler, aquatic invertebrate samples were collected, preserved, and then sorted and identified using a compound light microscope and taxonomic keys. Rapid bioassessment, another technique used to assess invertebrate diversity, provided supplementary data needed to create a more accurate biodiversity index. By comparing the data collected from each site, invertebrate distributions were correlated with environmental parameters. The Carmans River, and the biodiversity that it supports, is identified as a key natural resource on Long Island by several groups including the U.S. Fish & Wildlife Service, the Environmental Defense Fund, the Nature Conservancy, and the New York State Department of Environmental Conservation. The results from this experiment showed that with movement downstream, the diversity of invertebrates increases with increasing habitat complexity, as expected. Also, from our data it can be concluded that upstream locations are more affected by runoff and other sources of contaminants than downstream locations. Using data from this initial investigation, areas of concern can be targeted for future projects to improve the water condition of the Carmans River.

The Use of Visual Surveys To Determine Odonate Species and Abundance at Vernal Pools At Brookhaven National Lab. DIANNA RODRIGUEZ (State University of New York at Old Westbury, Old Westbury, NY, 11568) DR. TIMOTHY GREEN (Brookhaven National Laboratory, Upton, NY, 11973)

Dragonflies and damselflies are insects of the order Odonata, suborders Anisoptera and Zygoptera, respectively. In the state of New York there are over 170 known, documented species of odonates of the over 5000 species known worldwide. Odonates play an important role in maintaining the delicate ecosystems of vernal pools and other bodies of water such as marshes, streams, and wetlands. Determining the species present and their abundance at a site can be difficult due to their incredible flight speed, their temperamental habits, and the surrounding weather conditions. Visual surveys are the simplest way to document the species and their abundance. Specific ponds onsite at Brookhaven National Laboratory (BNL) were each surveyed once every five to nine days at the same designated time. The survey was conducted for a full hour and the odonates present were marked as being present at intervals of ten minutes using a number system that denotes a range of 1 to 5, 6 to 20, 21 to 100, or 100 + individuals. The study was conducted for ten weeks. The surveys have shown the strong presence of some odonates while others have very weak presence or none at all. The surveys have also shown that at certain ponds overall species abundance was declining at an alarming rate unrelated to flight season; hydroperiode may have had a significant effect on certain Odonate species. Through these surveys we have added to the Odonate Atlas, an existing study that is identifying all odonates of the United States by identifying all Odonates present at BNL.

Translocation of Radio-implanted Eastern Tiger Salamanders (Ambystoma tigrinum tigrinum). SARAH MILOSKI (State University of New York at Brockport, Brockport, NY, 11951) VALORIE TITUS (Brookhaven National Laboratory, Upton, NY, 11973)

A way to combat degrading upland habitat that surrounds amphibian breeding ponds is the translocation of jeopardized species to other wetlands. Information on movement patterns of translocated individuals is crucial to comprehending the ecology of a species by detecting any adverse effects the translocation has on the individual. This type of knowledge is vital when making management decisions regarding land use. Although the historic range stretches from Long Island down to northern Florida, the eastern tiger salamander is a New York state endangered amphibian found on New York’s Long Island. This amphibian species is affected by increased urbanization that threatens its breeding habitat. This status makes this species a candidate for translocation to suitable habitat. In an effort to determine the impact of translocation on this species, eleven Eastern tiger salamander juveniles were collected from two different ponds, Pond A and Pond B, and implanted with radio transmitters. This allowed for the tracking of movement patterns after pond emergence. Five individuals from Pond A were translocated to Pond B, while five were returned to Pond A. The individual collected from Pond B was implanted and returned to its collection site. All individuals were tracked for four weeks to determine movement patterns and habitat selection through the recording of vegetation in a plot surrounding the individual’s location. Of the five individuals returned to their native pond, three were lost to predation, one died in the field, and one was lost when its signal became untraceable. The greatest distance traveled occurred by the salamanders placed at pond of original collection. Of the translocated individuals, four were preyed on. This indicates that translocated individuals are more susceptible to predation. Translocated individuals at Pond B moved a shorter distance, in comparison to individuals at Pond A. This is indicative of stress and unfamiliarity with the area. Due to a very dry summer, Pond A dried up completely, prompting an early emergence of the salamanders at a smaller size, making these individuals more vulnerable to mortality. Although transience existed at both ponds it appears that eastern tiger salamanders fare better when they are not translocated. With the abiotic and biotic factors at the study sites, more research is necessary to deem translocation a worthy way to manage the eastern tiger salamander population of Long Island.

Understanding Aerosol-Cloud Interactions From Satellite Data. BANGLUN ZHENG (Contra Costa College, San Pablo, CA, 94806) SURABI MENON (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

Emissions of greenhouse gases (GHG) and small particles, aerosols, affect global climate. The interaction of aerosols with clouds (indirect effect) can increase cloud fraction (CF), cloud optical thickness (COT) and reduce cloud effective radius (Reff) if aerosols increase and cloud water stays the same. Thus cloud reflectivity is enhanced and leads to cooling of the surface. This counteracts GHG effects. The correlation between these variables to aerosol optical thickness (AOT is a measure of the amount of aerosols in an atmospheric column) is studied using satellite (MODIS, Moderate Resolution Imaging Spectroradiometer) retrieved data to understand aerosol-cloud interactions in specific regions which have seemingly different characteristics. In this study, the data is filtered such the AOT value is less than 0.6 (due to possible errors reported by MODIS), Cloud Top Temperature (CTT) greater than 273 K (liquid-phase cloud), and Cloud Top Pressure (CTP) greater than 640 hPa (low level cloud). In our analyses, we find that clear signals of cloud properties changes to AOT in clean regions. In polluted regions, meteorology usually plays a larger role in the changes of these properties, and obscure signals can be found.

Understanding Gas Absorbance and Background Emissivity Effects on Gas Detection Sensitivity Using Hyperspectral Imagery. MARIE CHILTON (Brigham Young University, Provo, UT, 84604) DON S. DALY (Pacific Northwest National Laboratory, Richland, WA, 99352)

A natural or anthropogenic process often generates a signature gas plume whose chemical constituents may be identified using hyperspectral imagery. A hyperspectral image is a pixel-indexed set of spectra where each spectrum reflects the chemical constituents of the plume, the atmosphere, the bounding background surface, and instrument noise. This study explored the effect of gas absorbance and background emissivity on relative gas detection sensitivity across the long-wave infrared (LWIR) spectrum. A physics-based model for the observed radiance shows that high gas absorbance coupled with low background emissivity results in a higher recorded radiance due to the chemical effluent. Two metrics were developed to predict relative detectability using chemical absorbance and background emissivity: one focused on a single wavenumber while the other spanned the entire spectrum. Their predictions were compared to synthetic image analysis. This study simulated images with each of 499 distinct gases at each of 6 concentrations over 6 different background materials with the atmosphere and level of instrument noise held constant. The Whitened Matched Filter (WMF) was used to detect the presence of a gas within a spectrum. A chemical’s probability of detection at a given concentration over a specific background was estimated by the proportion of WMF detections in 500 trials. For the 223 chemicals with detection proportions greater than 0.2, the single wavenumber metric correctly predicted the background over which the chemical had the largest relative detection probability for 92.8% of the chemicals. Further, the metric which accounted for information across all wavenumbers correctly predicted the background over which the chemical had the largest relative probability of detection for 93.3% of the 223 chemicals. These results suggest that the wavenumber with largest gas absorbance has the most influence over gas detection. By furthering the in-silico experimentation, these conclusions may be confirmed and generalized to more gases. This methodology of simulation coupled with detector-motivated sensitivity metrics will help simplify image acquisition planning and the identification of unknowns in field-collected images.

Uranium Extraction from Ores the Green Way. WILLIAM KWOK (Housatonic Community College, Bridgeport, CT, 06606) CLEVELAND J. DODGE (Brookhaven National Laboratory, Upton, NY, 11973)

Extraction of uranium from naturally-occurring ores is gaining renewed interest because of the worldwide increase in demand for uranium and the recent increase in the cost of petroleum fuels. In this study, we examined the use of citric acid, which is a cheaper and more environmentally friendly method to extract uranium from ores than the current method. In this process, we mixed various concentrations of citric acid with uranium samples and analyzed the extraction efficiency for each concentration of citric acid. We used uranium ores obtained from Moab, Utah and Cigar Lake, Canada. The ore samples were ground to <0.2 mm and analyzed for uranium content using a spectrophotometric method. Micro-XANES analyses at the Brookhaven National Laboratory National Synchrotron Light Source (NSLS) confirmed the uranium was present in hexavalent form in the Moab ore and tetravalent form in the Cigar Lake mineral. Elemental mapping was done to determine the association of iron, manganese, calcium and other metals with the uranium. X-ray diffraction performed at Stony Brook University showed the Moab uranium ore was composed of silicon oxide and calcium carbonate. The results of this study will be useful for the optimum extraction from both low and high grade ores. The most efficient concentration for uranium extraction with both Moab and Cigar Lake uranium was 0.8M citric acid. The efficiencies in extracting uranium for Moab was 72.5% ± 0.02%, for Cigar Lake it was 16.95% ± 0.24%, and for Cigar Lake with hydrogen peroxide and 0.8M citric acid it was 35.73% ± 0.00%. Though the results didn’t show extraction of uranium using citric acid to be as efficient as the current method, the method is still more environmentally friendly than the current method. Due to lack of time there was no trial involving photodegradation which was originally planned, but that will be accomplished at a future date.

Using RNA Interference to Study the Effect of Silencing Aux/IAA Genes on Populus Root Growth. BROOKS BOWERS (Middle Tennessee State university, Murfreesboro, TN, 37013) LEE GUNTER (Oak Ridge National Laboratory, Oak Ridge, TN, 37831)

The objective of this study was to identify the effect of silencing genes belonging to the Auxin/Indole-3-Acetic Acid (Aux/IAA) gene family on Populus root growth through RNA interference (RNAi). The Aux/IAA family consists of genes which are either suppressed or expressed as early as 2 to 3 minutes after auxin application and are referred to as early auxin response genes, regulating several plant growth and developmental processes. By down-regulating Aux/IAA in Populus transformants, carbon allocation and partitioning to roots may increase carbon sequestration potential. Increasing the amount of carbon belowground could have a global impact by increasing the amount of CO₂ stored in underground biomass. I used quantitative real-time polymerase chain reaction (qRT-PCR) to measure the level of gene expression for Aux/IAA in multiple transformants from 6 different gene constructs- Aux 3-1, Aux 3-2, Aux 3-4, Aux 7, Aux 16-1, and Aux 17. RNA was extracted and treated with DNase enzyme to get rid of any remaining genomic DNA (gDNA) that might cause contamination prior to complementary DNA (cDNA) synthesis. Using the cDNA, qRT-PCR was performed to measure the degree of fluorescence emitted by the SYBR® Green molecule when it attaches itself to the double stranded DNA during amplification. The level of fluorescence is then correlated into relative expression for the target genes. The results of the experiment revealed that the relative gene expression of Aux/IAA in all transformant plants is down-regulated from the transformant control. Aux 16-1 primers consistently produced dimers despite changing primers or reducing primer concentration. Additionally, the transformant control expressed up-regulation from the wild-type control in the Aux 3-1, Aux 3-2, and Aux 16-1 gene constructs; however, the opposite is true of Aux 3-4, Aux 7, and Aux 17 gene constructs. This study concludes that RNAi is an effective method for down-regulating AUX/IAA genes in order to investigate root proliferation in Populus, and therefore maybe useful in other applications for silencing gene expression. Suggestions for future research include mutant complementation studies, optimizing Aux 16-1 primers, and research for the effect of environmental factors on gene expression between transformant and wild-type controls.

Validation of Cigarette Smoke Passive Sampling Techniques. KRISTOPHER POHLMAN (Contra Costa College, San Pablo, CA, 94806) LARA GUNDEL (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

The primary method for detecting ambient secondhand smoke levels is to test for nicotine and its metabolites, such as cotinine, in human urine. However, as nicotine is very sticky on surfaces, it behaves very differently from the other constituents of smoke, and this makes nicotine a poor tracer for secondhand smoke exposure. This makes it so that determining the nicotine content in air through sampling presents its own host of problems. A popular way to determine the nicotine content in air is the Hammond method. This method involves trapping nicotine that diffuses to an acid-treated substrate, and then treating the sample with solvents. This passive sampling method is easy to deploy in the field, but preparing and processing the samples is rather complex and time-consuming, and it is limited to determination of nicotine. This project seeks to design and implement a sampler that is both inexpensive and small, without sacrificing precision. More specifically, the sampler must be able to fit reasonably in a home or office and collect gas and particle samples over an extended period of time. Furthermore, it must do so in a way which does not necessitate the loss of significant quantities of gathered material. While this sampler is being designed specifically to detect the constituents of cigarette smoke, it should also be able to detect several other particles and gasses, such as vehicle exhaust. This project explored the influence of several characteristics of the sampler on the sampling rate for nicotine. We are attempting to explain and then minimize variation that has been consistently reoccurring in results generated by the passive sampler. It was found that variation in the distance from the top of the opening to the Tenax bed would cause up to 15% variation in the predicted sampling rates for nicotine. Variability in recovery of nicotine from the tubes was measured by simultaneously exposing two dozen Tenax sampling tubes to the same concentration of secondhand tobacco smoke. Results analyzed so far show that the nicotine variability was somewhat less than that predicted from the geometry.

Vanadium Reduction by Clostridium. PATRYCJA CHODNICKA (CUNY Brooklyn College, Brooklyn, NY, 11210) DEV CHIDAMBARAM (Brookhaven National Laboratory, Upton, NY, 11973)

Vanadium, found in carbon deposits, is one of the major contaminants in groundwater. Its excessive mobility also allows it to infiltrate the surrounding soil, later to be taken up by plants. Anaerobic bacterium of the Genus Clostridium, with known bioremediation capabilities was tested for its potential use in remediating vanadium. After growing the bacteria in a glucose based medium for about 18 hours, the culture was inoculated with vanadium(V). The Clostridium oxidized the glucose and transferred the electron to vanadium(V), reducing it to vanadium(IV) and possibly lower oxidation states as well. After 28 hours, only 7.6% of the original concentration of vanadium(V) remained in solution while 26.5% remained in the control containing dead bacteria. The amount of vanadium(IV) in solution fluctuated throughout the experiment, but remained at zero in the controls. This data suggests that much of the vanadium had been absorbed by the bacteria but without further testing it is impossible to tell how much of the vanadium(V) had actually been reduced to vanadium(IV) or other lower oxidation states. Once further research is done on this method it can become an efficient and cost effective way to remove vanadium from groundwater and prevent it from contaminating the surrounding environment.

Velocity Models Along 12th Street of the 200 East Area, Hanford Site, Washington. NICOLE MCMAHON (The University of Oklahoma, Norman, OK, 73019) GEORGE V. LAST (Pacific Northwest National Laboratory, Richland, WA, 99352)

Accurate vadose zone and hydrogeological models are essential for remediation at the Hanford Site. Seismic reflection and refraction techniques have the potential to improve our understanding of the subsurface hydrogeological framework, but lack of velocity information has limited the use of these techniques. Velocity models are needed in order to process seismic data correctly. A 4.6 km transect was identified that incorporates eighteen wells coincident with a seismic reflection survey along 12th Street of the 200 East area. Borehole data were standardized and a geologic cross-section was constructed to portray the surface structure of geologic formations and subunits. This cross-section was then projected onto the newly acquired (2008) seismic reflection line for special comparison. Three different velocity model approaches were evaluated for processing of the seismic data to better reflect the borehole data. These velocity model approaches used Gardner’s Equation relating compressional wave velocity and density to estimate the velocities by facies, analog velocity values for specific stratigraphic units obtained from literature, and by studying the relationship between increasing velocity and depth. Inconsistencies between the three different modeling approaches are thought to arise from differences in density measurement methods, the potential inapplicability of Gardner’s Equation, and the scales of the model constructs. The velocity models are quite different and need to be further evaluated during seismic data processing. Another velocity model approach to evaluate would be a combination of the velocity models used in this study. Other improvements may include additional data collection and/or accounting for additional factors.

Water Management in the Hydrogen Polymer Electrolyte Membrane (PEM) Fuel Cells. HENSLEY FEELEY (Farmingdale Staate College, Farmingdale, NY, 10974) HAZEM TAWFIK (Brookhaven National Laboratory, Upton, NY, 11973)

The appropriate Relative Humidity (RH) level of the reactant gases inside a fuel cell are required to optimize its electrochemical reaction. The purpose of this research project is to determine the RH levels of the reactants that produce the fuel cell’s maximum power output without flooding or drying the membranes. These two extreme conditions must be avoided during operation due to their adverse effect on the catalyst inside the membrane. This research will enable the development of a correlation between the load and the main parameters; namely, reactants RH and temperature. This correlation will be incorporated into the development of a humidity and water management control system which is necessary for the fuel cell to operate optimally at various loading conditions. Accordingly, an experimental setup was built with four humidity and temperature sensors installed on the inlets and outlets of the hydrogen and oxygen and to the five-cell power stack. This system also incorporated two heated humidifiers, one for each reactant gas, to manage the humidity level inside the fuel cell. All humidity and temperature sensors as well as reactant gas flow meters were connected to Lab View software as a data acquisition system. The experimental setup was operated and tested at four relative humidity levels; namely, 60%, 70%, 80%, and 90%. As a result of our experimentation, it is apparent that the optimum relative humidity is 95%. The experimental evidence proves that at this humidity level the fuel cell will have the maximum power output.

Environmental Science Abstracts: