Student Abstracts: BNL

3 Inch Double GEM for X-Ray Fluorescent Detector. DERREK ANDERSON and JAMEL GRAY (Southern University, Baton Rouge, LA, 70813) DR. D. PETER SIDDONS (Brookhaven National Laboratory, Upton, NY, 11973)

Two 3-inch diameter gas electron multipliers (GEM) are used to build a high gain X-Ray gas detector for Extended X-Ray Absorption Fine Structures (EXAFS). The X-Ray ionizes the gas and the electrons are drifted towards the first GEM. The strong electric field in the GEM multiplies electrons by impact ionization. The second stage GEM further amplifies the electrons by the same process. The advantage of the double GEM is to provide two stages of electron amplification. This improves the signal magnitude without the introduction of noise. The charge collected from the second GEM is connected to a Keithley Amplifier. We have tested the Double GEM to detect dilute amounts of Mn and Fe in an arbitrary tree leaf.

9- THC Chronic Exposure in Adolescent Rats: Effects on Cocaine Conditioned Place Preference. YU FEN HWANG (State University of New York at Stony Brook, Stony Brook, NY, 11794) PETER THANOS (Brookhaven National Laboratory, Upton, NY, 11973)

Epidemiological studies have shown that use of marijuana during early adolescence is associated with a higher risk for other substance abuse disorders. The extent to which this represents neuroadaptation responses secondary to 9-THC (delta-9-tetrahydrocannbinol, main psychoactive ingredient of marijuana), exposure versus genetic vulnerability that underlies high risk with experimentation with drugs in general is unclear. In this study we investigated if chronic exposure of 9- THC during the adolescence period in the rat affected the reinforcing responses to cocaine (assessed with condition place preference). Male Sprague Dawley rats (age 3-4 weeks) were administered daily with either 9- THC (0.75 and 2 mg/kg) or saline for 21 days. The day after the last injection, we started the Conditioned Place Preference (CPP) segment of the study: [day 1: preconditioning; days 2-9 conditioning phase {cocaine (5 and 10mg/kg) and saline on alternate days}; day 10: test day]. The results showed that 9- THC pretreatment rats resulted in decreased CPP for cocaine (5mg/kg or 10mg/kg) On the other hand there were no differences between the group on cocaine induced dose-dependent increases in locomotor activity. These results provide evidence of that exposure to THC during the adolescent period changes the sensitivity to cocaine-induced conditioning. The extent to which this generalizes to conditioning to other drug but also non-drug reinforcers requires further investigation.

A Comparative Study of GEM Foils from Tech Etch and CERN. JONATHAN HERSTOFF (Muhlenberg College, Allentown, PA, 18104) CRAIG WOODY (Brookhaven National Laboratory, Upton, NY, 11973)

Gas Electron Multipliers (GEMs) were originally developed at CERN and are now being used in applications such as charged particle tracking. They consist of a thin polyimide foil which is copper clad on both sides and contain a large number of small holes extending through the foil. When high voltage is applied across the copper electrodes, a large electric field is developed inside the holes, which is used to produce gas gain. Different methods of manufacturing these GEMs can potentially be determinative of how the GEMs behave under high voltage. In this study, a company called Tech Etch produced three different batches of foils, each using a different chemical etching method. Although the measurements of gain versus time were varied widely from foil to foil, contrary to what was expected, there does appear to be a correlation between the size of the holes and the performance of the GEM. In general, foils with holes that have a larger polyimide area exposed tended to exhibit poorer gain stability than those with less exposed polyimide.

A Comparison between Sludge Sedimentation Rates and Dispersion Characteristics of No2 Oil and Biodiesel. CHRISTOPHER BROWN (Clarkson University, Potsdam, NY, 11787) THOMAS BUTCHER (Brookhaven National Laboratory, Upton, NY, 11973)

Biodiesel made to American Society for Testing and Material (ASTM) standards, D6751, is a renewable fuel source that within the fuel industry is criticized as being a solvent. When blended with petroleum-based fuels in tanks with contaminants such as carbon deposits, the Fatty Acid Methyl Esters (FAME or biodiesel) are accused of introducing contaminants into solution with the fuel. This leads to filter plugging and fuel starved equipment. In order to attain a greater knowledge of the fuel solvency characteristics of biodiesel, data was collected from testing sedimentation rates, particle size and particle distribution. To test sedimentation rates, clean fuel samples of biodiesel and No.2 oil were thoroughly mixed with sludge (carbon deposits from No.2 oil tank bottoms). After being uniformly mixed, each fuel sample was allowed to settle for set time intervals, and then centrifuged. To measure particle size and distribution a laser based optical probe measured the chord length of particles and distribution of particles in solution. When reviewing the sludge particle sedimentation rates, it was evident that the particles required a greater period of time to settle out of the biodiesel fuel sample compared to the No. 2 fuel oil sample. Furthermore, although the settling rate is longer for biodiesel, the same amount of sediment precipitated from the fuel. When analyzing the results from the laser based optical probe, the particle chord length and particle distribution was identical when comparing biodiesel to No. 2 fuel oil. The results that have been gathered imply a significant breakthrough on the industries diagnosis of biodiesel’s solvency. The data suggests that biodiesel has the same solvency characteristics as no. 2 fuel oil and that biodiesel is a better dispersant. Biodiesel disperses the sediment particles in the fuel and suspends them longer than No.2 fuel oil, allowing the contaminants a greater amount of time to be carried to the fuel filter. This finding will allow any necessary changes to be made to in-line fuel filtration.

A Computational Process to Locate IS elements and Study Horizontal Gene Transfer in Bacterial Genomes. WALTER LEWIS (Cheyney University of Pennsylvania, Cheyney, PA, 19319) SEAN MCCORKLE (Brookhaven National Laboratory, Upton, NY, 11973)

Currently there is a tremendous focus on studying how whole units of DNA are shared between species. These movable tracks of DNA, called transposons, are demarcated by shorter insertion sequence (IS) elements, which themselves are generally around 700 to 2500 bp in length, and code for proteins implicated in the transposition activity, such as transposase and intergrase. IS elements are bracketed by pairs of inverted repeats of variant length (approx. 10 -30 bp), and are further embedded in a pair of short direct repeats of approximately 3 – 7 bp. While there is a great deal of software to automatically annotate genes and regulatory regions, there are currently no programs to identify IS elements de novo. Hundreds of completed bacterial genomes are currently available and more are constantly being added to that list, which makes it increasingly important for the computational detection of IS elements. To this end, we have developed a C++ program to locate IS elements in bacterial genomes. The process was broken down into steps in order to make it more dynamic so that one could easily examine the data in each stage of the process to detect errors, or perhaps discover something unexpected. First, all repeats (within length constraints) are reported, then these are searched for pairs of inverted repeats which have the proper orientation and distance. Positions, paired inverted repeat sequences, and interior coding sequences are reported for these IS element candidates. Lastly the interior coding sequences are examined for homology with known transposition genes. Preliminary tests on the genome of Enterobacter strain 638, recently sequenced as part of the DOE biofuels initiative, revealed 9 putative IS candidates, 6 of which were confirmed by Blastx searches of Genbank, which yielded strong homology matches to transposase and intergrase in other organisms. Further testing on an IS-rich genome, now Cupriavidus metallidurans (CH34), will allow us to optimize program parameters to improve performance. Because this process reports direct and inverted sequence pairs, which travel along with the IS element as it moves, it can be used to trace horizontal gene transfer history within or between genomes for evolutionary studies.

A High Throughput Method of Screening Mutant Arabidopsis Plants for Improved Biofuel Capacity Using Infrared Microspectroscopy. SIMONE PARK (State University of New York at Stony Brook, Stony Brook, NY, 11794) LISA MILLER (Brookhaven National Laboratory, Upton, NY, 11973)

Acyl-esterification is one of the most common modifications that occurs within the plant cell wall, and contributes to the covalent cross-linked polymerizations found there. These cross-linkages are found between lignocelluloses, components found in the cell wall, and contribute to the recalcitrance and complexity of the overall plant and prevent effective degradation for conversion into bioethanol. In this study, stems from 12 mutant Arabidopsis thaliana plants representing 6 distinct mutant lines were analyzed with Fourier Transform Infrared (FTIR) microspectroscopy to develop a high-throughput method of screening and characterizing Arabidopsis lines. Cell wall components were extracted with ethanol in 2 ways and point spectra were taken to determine the extent of the 1740 cm-1 peak corresponding to the vibrational carbonyl group characteristic of esters. Results from cluster analysis and acyl content from the microspectroscopy revealed that samples presented variabilities inherent to the complexity of the cell wall structure and to those attributed with sample preparation. Imaging of cross-sectioned stems was also performed, and it was found that the acyl content in the section was radially heterogeneous. More careful sample preparation for microspectroscopy and use of synchrotron light for imaging to gain greater spatial resolution in the cell wall will be valuable in improving this high throughput screening method.

A Networked Control/Data Acquisition System Based On The ColdFire Microprocessor. ILYA SUKHANOV (State University of New York at Stony Brook, Stony Brook, NY, 11794) EDWARD KISTENEV (Brookhaven National Laboratory, Upton, NY, 11973)

Nose Cone Colorimeter Control (N3C) is a highly dynamic system used for slow data acquisition (DAQ), remote system control, and environmental monitoring. The N3C project utilizes an embedded ColdFire processor with the Quadros real time operating system (RTOS) which acts as a bridge between an array of hardware devices and remote-controlling machines over the TCP/IP network protocol. The requirements of this project were to build a network-capable device to program field-programmable gate array (FPGA) devices such as Xilinx and Altera. While such network-FPGA-programmers are available on the market they all only do one task, our specification called for a way to interface with other buses of the system and DAQ. N3C utilizes the feature rich ColdFire microprocessor which allows for easy access to a number of buses such as I²C, QSPI, UART, JTAG and GPIO. With the help of the N3C client one can quickly develop custom tools to remotely interface with devices via these buses. In the case of the Nose Cone Colorimeter, N3C is used to interface with most of the buses supported by ColdFire, JTAG is utilized for FPGA configuration and the systems slow control, I²C as a bridge to a Dallas 1-Wire bus which in turn is used for environmental monitoring and control, QSPI for slow DAQ read out. The N3C system is controlled via a simple control protocol over TCP and data-stream is transferred over UDP to reduce the network overhead at the cost of reliability. During the course of this project we've optimized Quadros RTOS supplied TCP/IP stack (a modified OpenTCP implementation) for our applications resulting in a ten-fold performance increase. This optimization makes it feasible to use N3C as a slow (2MBytes/s) DAQ system. For further improvement we plan to implement a compression schema into our DAQ system. While we have only tested compression on a desktop machine the results are promising. Utilizing a variant of Hashemian coding described in the paper entitled “Condensed Table of Huffman coding, a New Approach to Efficient Decoding” by Reza Hashemian, it is possible to compress data just as well as with Huffman coding but decompression requires less memory and time. Built with flexibility in mind, N3C was developed to work on two versions of the ColdFire processor, the MCF5282 and MCF523x. Such flexibility allows for easy integration of new features and utilization of this system in projects other than the Nose Cone Colorimeter Upgrade.

A Personality Profile of Cocaine Addicted Individuals. CATHERINE URBAN (State University of New York at Geneseo, Geneseo, NY, 14454) DR. RITA GOLDSTEIN (Brookhaven National Laboratory, Upton, NY, 11973)

Impairments in higher executive function, such as inhibitory control and decision-making, characterize cocaine addicted individuals; however, the contribution to these cognitive functions of personality traits is not well established. The current study therefore examined differences in personality traits between healthy control subjects and cocaine addicted individuals and the extent to which these differences may be affected by recent cocaine use. Sixty-six cocaine addicted individuals [20 testing negative (CUD-) and 46 testing positive (CUD+) for cocaine in urine, indicative of drug use within 72-hours] and 66 gender-, age-, and education-matched healthy control subjects were administered the Multidimensional Personality Questionnaire (MPQ) as part of a larger neuropsychological battery. The MPQ measures three trait super-factors, each comprised of 3-4 lower order subscales; differences between the groups were examined with four separate MANOVAs. Results revealed significant group differences on all three super-factors such that cocaine abuse was associated with lower positive emotionality [F(2, 131) = 3.8, p < .0001], higher negative emotionality [F(2,131) = 5.0, p < .0001], and decreased constraint [F(2, 131) = 3.1, p < .001]. These differences were driven by lower social closeness especially in the cocaine positive subgroup [Mean±SEM=12.3±0.6 for CUD+ vs. 14.0±0.8 for CUD- vs. 15.7±0.5 for controls], higher aggression especially in the cocaine negative subgroup [Mean±SEM=5.7±0.5 for CUD+ vs. 6.7±1.0 for CUD- vs. 3.4±0.4 for controls], and lower self-control in the cocaine positive subgroup [Mean±SEM=14.1±0.7 for CUD+ vs. 16.0±1.1 for CUD- vs. 17.7±0.5 for controls]. These effects remained significant after controlling (with ANCOVAs) for state depression and other demographic variables that differed between the groups. These results suggest significant differences between healthy control subjects and individuals addicted to cocaine in trait measures of personality. Together, the higher negative emotionality (aggression), lower positive emotionality (social closeness) and lower self-control may predispose the addicted individuals to relapse and compulsive drug use, especially under socially stressful situations. The underlying cognitive and neurobiological substrates remain to be elucidated.

A Systematic Study of the Effect of Magnetized Oxygen on a Photon Beam. ALISHIA FERRELL (Florida A & M University, Tallahassee, FL, 32307) DR. CAROL Y. SCARLETT (Brookhaven National Laboratory, Upton, NY, 11973)

A systematic study of the effects of oxygen oscillation on a laser beam propagating through an electromagnetic field (EMF) was deemed necessary due to the physical set up of the main experiment concerning space time curvature. The control or "shunt" measurements for the main experiment were made by propagating the laser outside of a vacuum chamber along side a super conducting magnet. However, this caused the beam to travel extremely close to the lead wires. This raised the question, "Was the oxygen movement being created by EMF deviating the laser beam enough to corrupt the control data". In order to see if the oxygen was significantly changing the data a systematic study had to be done. To perform this systematic study a 514 nm helium neon laser generator, several focusing and defocusing optical lenses, a quad cell photo-receiver, and a quadrapole magnet capable of oscillating its current were used. After doing a number of calibrations on the photo receiver we were able to ramp a 10 Amp electromagnetic field using alternating current through a quadrapole on the averages of events given. While the light was hitting the photo-receiver data was being collected from a data acquisition system. Once the data was done being colleted it was converted into text files. With these numbers a FORTRAN program was created using fast Fourier transforms (fft), which showed that there was a bit of movement in the X direction which caused a noticeable signal. Further studies must be done so that we can insure that this signal that we see is not just by coincidence.

A Systematic Study of the Effect of Magnetized Oxygen on a Photon Beam. JOSEPH HEARD (Community College of Philadelphia, Philadelphia, Pa, 19130) CAROL SCARLETT (Brookhaven National Laboratory, Upton, NY, 11973)

A systematic study of the effect of oxygen oscillation due to a paramagnetic effect has on a laser beam propagating through a electromagnetic field (EMF) was deemed necessary due to the physical set up of the experiment concerning space time curvature. The control or "shunt" measurements for the main experiment were taken by propagating the laser outside of the vacuum chamber along the side. However, this caused the beam to travel extremely close to the lead wires of the super conducting electromagnet. This raised the question, "was the oxygen movement being created by EMF of the lead wires deviating the laser beam enough to corrupt the control data." To perform a systematic study of this concern we used a 514 nm helium neon laser generator, several focusing and defocusing optical lenses, a quad cell photo receiver, and a Quadra-pole magnet capable of oscillating current. Also, FORTRAN computer programs containing FFT’s were used to accomplish the Fourier analysis necessary for data analysis. The systematic study was conducted by propagating the laser through an EMF field ramped at 80 MHz. Then different amounts of oxygen were exposed to the field. The photo receiver then tracked the laser beam movement. The results were then analyzed to see if the oxygen oscillation was visible in the data. We observed a large peak in the "x" (horizontal) direction. This might indicate that the signal seen may be partially due to magnetized oxygen. However, further studies must be conducted before conclusive results can be reached. Future studies would include: varying the type of magnet, adjusting the percentage of gaseous oxygen flowing through the magnet, and changing the position of the magnet in relation to the photon beam.

A Systematic Study of the Effect of Magnetized Oxygen on a Photon Beam. RACHAEL MILLINGS (Suffolk County Community College, Selden, NY, 11784) DR. CAROL SCARLETT (Brookhaven National Laboratory, Upton, NY, 11973)

When light is propagated through a ramped magnetic field into a photoreceiver in the presence of air, there exists a possibility that the observed laser beam deviation is due to the paramagnetic behavior of gaseous oxygen in the air. If the signal observed is not negligible, then the deviation cannot be used as a shunt for beam deviation due to light propagated in a vacuum. The purpose of this systematic study is to determine the significance of gaseous oxygen's magnetic susceptibility relative to the observed beam deviation. A photon beam from a 514 nm HeNe laser generator was propagated through a defocusing lens and a focusing lens to focus the beam; two mirrors were then used to reflect the beam through a quadrupole magnet and into a photoreceiver. As an alternating electric current of 10 amperes was directed through the magnet, the amount of light entering the photoreceiver was measured using a data acquisition system to interface with the photoreceiver and a computer. After the data was converted into text files, a programming language, FORTRAN, was used to write a code that analyzed the data by the method of fast Fourier transforms. On a graph of the amplitude of the light as a function of time, a signal was observed at the same frequency as that at which the current in the magnet was alternating, as expected. While the signal was relatively large, future studies must be conducted to yield conclusive results. This systematic study is part of a larger experiment researching the space-time curvature of light passing through a magnetic field in a vacuum as a possible validation of physical theory which postulates the existence of gravity in the absence of mass.

Amplification of Methylated DNA Sequences that Retains mCG Epigenetic Marks. DANNY KOHUT (New York University, New York, NY, 10003) JOHN J. DUNN (Brookhaven National Laboratory, Upton, NY, 11973)

It has been shown that tumor cells contain an extensive amount of methylated DNA, which could be used in finding cancer before the onset of symptoms or to monitor reoccurrence. By amplifying DNA in such a way that retains methylation patterns, a small amount of DNA can be used to detect cancer. The pGEM5 vector was methylated using HpaII Methyltransferase, an enzyme that recognizes CCGG sequences and adds a methyl group to the 2nd cytosine residue. The DNA was then cut with HpaII and MspI to check for complete methylation; the latter enzyme is able to cut methylated CmCGG sequence while the former cannot. An attempt was then made to amplify the methylated pGEM5 sequence using F29 amplification with dnmt1 Methyltransferase, but without success. Our second and novel method required HeLa DNA, which comes from a cancerous cell line, to be cut with MseI, gel purified and then joined to a synthetic DNA cassette. The purified ligation mixture was then bisulfite modified, which transforms all non-methylated cytosine residues into uracils. PCR amplification of the top strand with bisulfite-modified specific primers produced a large amount of DNA where the only remaining CG’s are those that were originally methylated. M.SseI Methyltransferase will then add a methyl group to these sites to re-form mCG’s, which are then affinity purified using the methyl-binding proteins MBD2b and MBD3L1 and then either hybridized to a microarray or sequenced.

An Assessment of the Implications of 10CFR851 on the Vacuum Systems at the National Synchrotron Light Source. MICHAEL ESPINOZA (State University of New York at Stony Brook, Stony Brook, NY, 11790) ED HAAS (Brookhaven National Laboratory, Upton, NY, 11973)

As of February 9, 2007, the U.S. Department of Energy required that its’ facilities are compliant with Section 10 of the Code of Federal Regulations, part 851 (10CFR851). One of the new rules is the requirement to treat vacuum vessels as pressure vessels due to their susceptibility to backfill pressurization. The consequence of treating vacuum vessel as pressure vessels is that they must potentially comply with the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Codes which formerly were not used for vacuum systems, specifically Section VIII of the B&PV code. At the National Synchrotron Light Source, electrons circulating in the accelerators produce photons in the beam lines for research. The electrons and photons are contained within vacuum chambers and beam pipes. Most beam line segments having sources of pressure, such as water or a gas, and were inspected to see if added safety devices were needed. If needed, ASME-compliant safety devices shall be identified, sized, and located according to ASME code. All of these codes are divided into smaller sub-sections, in which only some are applicable to vacuum systems. These codes require safety pressure relief devices on vessels where over-pressurization could result in a failure mode. After developing and programming the necessary equations using Excel spreadsheets, a study of each beam line was undertaken. Of highest concern were pressure sources that penetrated into the vacuum space within components such as monochromators, slits, and beryllium windows. Cooling water sources connected to make-up water, nitrogen, helium, and process gas sources were examined and the pressure and flow information was calculated. Each isolatable section with a potential pressure source required a pressure relief device. Within each segment, the weakest component was generally identified. Glass view ports and beryllium windows for example were usually the components which would be expected to fail at the lowest internal pressure. The spreadsheet calculated the pressure relief requirements and output graphs of flow rate and pressure verses time. This effort assures that NSLS is compliant with 10CFR851 and its vacuum systems are safe.

An Enclosure Study to Investigate the Causes of the decline of Southern Leopard Frogs (Rana sphenocephala) on Long Island. DUNCAN ADAMS (Earlham College, Richmond, IN, 47374) JEREMY FEINBERG (Brookhaven National Laboratory, Upton, NY, 11973)

Around the world amphibian species are declining at unprecedented rates due to a variety of causes. Some, such as habitat loss, are readily observable, while some amphibian declines are not as well understood. The southern leopard frog (Rana sphenocephala) is an anuran native to much of the eastern United States, including Long Island, New York. Formerly one of the most visible and abundant frog species on Long Island, it has declined over the last 30 to 50 years to the point that there has not been a confirmed sighting since 1998. This possible extirpation could be due to habitat loss, environmental contamination, disease, invasive vegetation, interspecific competition, or any combination of these factors. In order to test these hypotheses leopard frog tadpoles were used as bio indicators. Leopard frog eggs were collected from southern New Jersey and placed in screen enclosures located in Long Island wetlands. Measurements of the tadpoles will be collected weekly and dead tadpoles tested for disease and toxicity. Tadpole growth and survival rates for the different conditions will indicate the relative importance of competition, disease, and plant community to the leopard frog. In following years similar experiments will be done to test the same and other factors in southern leopard frog decline on Long Island. The use of leopard frog tadpoles as bio-indicators this year and subsequent findings will help to identify possible sites of relic populations, as well as allowing the design of more effective conservation efforts for southern leopard frogs and similar species.

Analysis of Some Near-Infrared Spectra of C2Br. ELIZABETH MILLINGS (Suffolk County Community College, Selden, NY, 11784) DR. TREVOR SEARS (Brookhaven National Laboratory, Upton, NY, 11973)

In combustion chemistry, the C₂H molecule has been studied extensively because it is an important intermediate and provides an example of the breakdown of the Born-Oppenheimer approximation. A related molecule, C₂Br, supplies a different view of the Born-Oppenheimer breakdown, and its rotational, vibrational, and electronic structure can be compared to C₂H. Previously, only computational studies have been reported regarding C₂Br. Its energy states and spectra were theoretically determined, and a model equation was developed to describe its rotational energy levels. Recently, a spectrum of C₂Br was accidentally detected at Brookhaven National Laboratory, and a portion of it was tentatively assigned to some P-branch rotational transitions. In this project, the spectroscopic data were further examined in an attempt to confirm the assignments, determine the rotational constants, identify spectral lines corresponding to the two bromine isotopes, and identify the band origins. To accomplish this, a LabVIEW computer program was developed and used to calculate the energy levels and predict spectra, which were then compared to the experimental near-infrared (NIR) spectra. The error between the data and the calculations was minimized by adjusting the modeling constants and testing possible assignments. A simulated spectrum was created with each new calculation enabling a set of "best fit" values to be determined. This analysis is part of a larger work investigating the chemical processes of combustion by studying the structure and dynamics of intermediate reactive species.

Analyzing the Response of Frisch-Ring CdZnTe Radiation Detectors. NAJEB ABDUL-JABBAR (University of Michigan, Ann Arbor, MI, 48104) ALEKSEY BOLOTNIKOV (Brookhaven National Laboratory, Upton, NY, 11973)

Cadmium zinc telluride (CdZnTe or CZT) is a direct band gap semiconductor that has very promising qualities as a material for gamma-ray radiation detectors. Unlike the traditional high purity Germanium detectors, which require cryogenic cooling, CZT devices have yielded high detection efficiency and exceptional energy resolution while operating at ambient temperatures. This makes them particularly appealing for national security applications such as explosives detection. It is known that CZT detector performance is dependent on two common factors: CZT crystal defects (mainly Te inclusions present in the crystal structure) and surface irregularities that may cause polarization or electric field defocusing. Using infrared microscopy (with magnification up to x10), Te inclusions on the order of micrometers can be identified. X-ray mapping techniques at Brookhaven’s National Synchrotron Light Source (NSLS) are utilized to analyze CZT surface irregularities at a maximum resolution of 10 µm steps. To determine CZT detector performance, pulse height spectra and correlation curves are obtained using Cs-137 and Ge-68 sources. Results show that CZT crystals with a low concentration of Te inclusions measuring greater than ~10-20 µm in diameter consistently yielded excellent spectral response (the best detector tested had an energy resolution of ~1.1%). Polarization was not observed in any of the samples; however an aberrant defocusing effect was discovered that diminished detector energy resolution by roughly 25%. The research involved in this project is part of a general effort to correlate CZT detector performance with the material properties of CZT.

Assessing Benthic Macroinvertebrate Sampling Procedures for the Development of the Freshwater Wetland Health Monitoring Protocols of Long Island’s Central Pine Barrens. SARAH MILOSKI (State University of New York at Brockport, Brockport, NY, 11420) ARIANA BREISCH (Brookhaven National Laboratory, Upton, NY, 11973)

While wetlands, among the most productive ecosystems in the world, are often called the nurseries of life, little is known about the current health status of Long Island’s freshwater wetlands. Such vital systems should be monitored over time to determine the health of the wetlands. However, before gathering data in the field, it is necessary to assess and choose methods that will obtain the most representative results. Appropriately designed protocols will achieve the goals of establishing baseline data of the current wetland health and provide land managers with the data they require to make management decisions to optimize the health of the wetlands under their supervision. Monitoring methods need to be consistent, informative, and replicable in order to be comparable to future data. Benthic macroinvertebrates are crucial indicators of wetland health, since the number and type of species present yield significant information regarding water quality. In this research, appropriate procedures for sampling these organisms were reviewed and assessed using protocols developed by other states, such as Ohio and Florida. These protocols were adjusted to accommodate the unique conditions of the wetlands of Long Island’s Central Pine Barrens. To test the protocols, invertebrates were acquired using a d-frame dip net to sweep various wetland habitats. Invertebrates were then randomly chosen from an observation tray and identified in the field. Several protocols called for a sample total of 100 organisms. This task consumed time that could have been allotted to other aspects of the protocol. Therefore, the benthic macroinvertebrates encountered were noted as present, thus providing a list of organisms that existed in the wetland. When this list is compared to data collected during the revisit of a site, the absence of a formerly present organism provides information about the current state of the wetland and how it has changed. Despite a low amount of diversity while sampling, there was a plethora of adult Odonates in the wetland. This occurrence would support the existence of a substantial supply of microorganisms, such as algae and periphyton. It was concluded that simply monitoring benthic macroinvertebrates may not be an informative way of monitoring the aquatic organisms. Therefore, for the wetland protocol of Long Island’s Central Pine Barrens, further analysis should delve into a smaller scale of aquatic biota, such as periphyton and algae.

Assessment of a Residential Style Oil-Fired Boiler as a host for a Thermophotovoltaic Combined Heat and Power System. JULIAN CARPENTER (Alfred State College, Alfred, NY, 14802) THOMAS BUTCHER (Brookhaven National Laboratory, Upton, NY, 11973)

Combustion of number 2 heating oil is intrinsically emissive, more so than natural gas, propane or butane. Therefore, oil combustion is a good candidate for power generation using thermophotovoltaic (TPV) cells. In order to test the viability of current residential oil heat technology as a host for TPV combined heat and power generation (CHP), a prototype oil fired TPV CHP system must be built, tested, and characterized. Previous work has shown potential for sufficient power densities using a small 1 cm2 GaSb TPV array with a residential boiler, however, the effects of the much larger array (99 cm2) on achievable power density, and the effects of system geometry, firing rate, combustion conditions and the use of silicon carbide (SiC) emitters is not known. One small and one large (99 cm2) GaSb TPV arrays were tested with various configurations in a modified residential style boiler capable of firing at 0.5 to 0.85 gallon per hour (gph). The use of a reticulated SiC emitter as well as the effect of firing conditions, burner output, and system geometry were varied and measurements of short circuit current (Isc) and open circuit voltage (Voc) were taken to measure power output. It was determined that a large pore SiC foam emitter improved power output, although the pressure drop across the foam plate was problematic. Varying the distance from cell to emitter, the size of the cell, boiler combustion chamber insulation, amount of excess air, and firing rate were found to substantially impact the power output of the TPV cell. Power densities of approximately 1.3 w/cm2 were achieved with the single cell array, and 0.85 W/cm2 with the 99 cell array. Future work should investigate ways to boost power output to over 2 W/cm2, in an effort to provide more than enough power for a stand-alone oil fired boiler TPV CHP system.

Auto-ADL (Automatic Generation of MEDM Displays Depicting Collider-Accelerator Components). JONATHAN BECK (Binghamton University, Vestal, NY, 13850) TED D'OTTAVIO (Brookhaven National Laboratory, Upton, NY, 11973)

A software program called Auto-ADL was developed for use by the Collider-Accelerator Department (C-AD) at Brookhaven National Laboratory (BNL). The goal of this program is to use software automation to greatly decrease the time and tedium required to create displays using the program Motif-Based Editor & Display Manager (MEDM). Previously, the displays could take a member of the C-AD several hours to generate, as each element would have had to been added manually and each portion of the Collider-Accelerator complex can contain hundreds of magnets, detectors, and other devices of interest. To accomplish this, the user inputs the beamline section and element types of interest. This input is turned into an SQL query and data is extracted from a Sybase database using the DB_request library available at BNL, then converted to an Extensible Mark-up Language (XML) file using the XMLDom library, also available at BNL. This XML file is then converted to MEDM's native file format (ADL) and the data is displayed using MEDM. Using Auto-ADL, the user only needs to take a few seconds to select the areas and device types they would like to view, and the appropriate ADL files are produced in less than a minute, saving the C-AD hours of tedious work. Future improvements on Auto-ADL may include making the displays produced dynamic, so that new files do not need to be produced every time a new set of device types are to be displayed. This would significantly improve the speed at which a user can switch between different displays. The XML files produced by Auto-ADL may also be put to use in other programs whose development has not yet started.

Best Educational Practices for Modern Day Teachers. MEGAN REBEN (St. Joseph's College, Patchogue, NY, 11772) GAIL DONOGHUE (Brookhaven National Laboratory, Upton, NY, 11973)

For as long as there have been teachers, there have been those who sought the best ways to educate our children. In order to stay ahead in this changing world, it is increasingly important to provide quality education to as many students as possible. In order to find or develop the most effective method of introducing educational material to students at the elementary level, this study intends to use peer reviewed articles and subsequent results concerning the types of teaching methods in question. By referencing the conclusions of previously published studies, the results are meant to show a complete and accurate detailing of each of the methods strong and weak points. Presently, the results are not conclusive due to several factors, including cost effective versus educational effectiveness issues. The success of any particular method is interpretive because the techniques used to teach are not solely judged by their ability to allow the student to retain the most knowledge. Some examples of practices that are proven to give students an edge up are cooperated learning and even outreach programs like the one Brookhaven Nation Laboratory provides. The purpose of this study is to uncover the most effective method to be used in classrooms which will allow each and every student to reach his or her full potential. That being the case, it is important to develop some kind of progress report to correlate the techniques used and the advancement of the students.

Biodistribution and Metabolism Studies of 14C-Ethanol in Mice. MEL PILAR ESPAILLAT (Farmingdale State College, Farmingdale, ny, 11735) ANDREW GIFFORD (Brookhaven National Laboratory, Upton, NY, 11973)

Ethanol acts as a central nervous system depressant; it is rapidly absorbed by the body and approximately 90% is metabolized, almost entirely in the liver. The intermediate metabolites of ethanol are believed to be involved in its toxicological properties. The mechanism of ethanol toxicity and its interaction with tissue have not been well understood because of lack of fundamental knowledge about both the pharmacokinetics of ethanol and its metabolism in the human body. This work seeks to study the rate of metabolism of ethanol in different tissues and provide preliminary data for future PET studies to directly measure the distribution and pharmacokinetics of ethanol in human subjects. Mice were injected with approximately 2.0x10-¬¬3 microcuries of 14C-Ethanol and then were sacrificed at 5, 15, and 60 minute intervals after injection. Plasma and various organs were collected and assayed for carbon-14 under acidic and basic conditions. In the present study a high concentrations non-volatile material was found in the liver, consistent with the role of this organ in metabolizing ethanol. However it is notable that other organs were also found to accumulate both ethanol and non-volatile metabolites although it is not possible to say whether this represents accumulation of circulating radiolabeled metabolites from liver metabolism of ethanol or is due to local metabolism of the radiolabeled ethanol. This work is a small portion of a much larger project being researched to investigate the distribution and pharmacokinetics of ethanol in human subjects.

BOB Ionic Liquids: Preparation and Properties. ALEJANDRA CASTANO (Queens College, Flushing, NY, 11367) JAMES WISHART (Brookhaven National Laboratory, Upton, NY, 11973)

Ionic liquids (ILs) are salts that melt below 100 0C. ILs are ideal alternative solvents to work with because they exhibit properties such as thermal stability, non-volatility, combustion resistance, high conductivity, and wide electrochemical windows. Owing to their non-volatility ILs do not contribute to air pollution and they are being investigated for a variety of applications as alternative solvents, including use in nuclear processes. The potential utility of ionic liquids for the processing of radioactive material is being investigated through the use of pulse radiolysis techniques. Ionic liquids containing the Bis(Oxalato)Borate (BOB-) anion are being investigated for this application, because of the neutron scavenging ability of 10boron. Calculations by others have shown that ILs containing boron can be used to handle higher concentrations of fissile material than conventional solvents without the risk of criticality. Halide salts such as 1-methyl-3-pentylimidazolium bromide (C5MIM Br) and a homologous series of pyrrolidinium, and pyridinium types were synthesized using both thermal and microwave-assisted techniques. The halide salts were prepared by reacting the amines with their corresponding alkyl halides. Boron containing ILs were prepared by metathesis reactions with sodium BOB (NaBOB). NaBOB was synthesized by reacting boric acid, oxalic acid and sodium hydroxide in water under reflux conditions. Preliminary results of pulse radiolysis experiments indicate that BOB anion scavenges radiolytically-generated solvated electrons too efficiently for BOB ILs to be stable as neat solvents for processes under ionizing radiation, as in nuclear separations. Thus, only small concentrations of borated ILs such as the BOB salts may be necessary to achieve inherent criticality protection. The salts would be most effective when dissolved in a IL co-solvent such as N-butyl-N-methylpyrrolidiunium bis(trifluoromethylsulfonyl)imide. Further characterizations such as viscosity, melting points, glass transitions, and electrochemical windows are also being investigated. Such data will provide valuable information to facilitate the broader applications of the BOB ILs.

Characterization of Actin as a Cofactor for the Adenovirus Proteinase. HAN ZHU (Massachusetts Institute of Technology, Cambridge, MA, 2139) WALTER F. MANGEL (Brookhaven National Laboratory, Upton, NY, 11973)

A good model system for the development of effective protease-inhibition based anti-viral agents (drugs) is human adenovirus (AVP), because AVP is essential for the production of infectious viruses. AVP is found to require viral cofactors, which regulate the activity of AVP in time and space, for maximal activity. Actin, one of the most abundant proteins in the cell and a major component of the cytoskeleton, is believed to be an AVP cofactor due to the high homology of its c-terminus with the 11 amino acid peptide viral cofactor pVIc. The binding of monomeric actin to AVP allows for its activation and the cleavage and degradation of the cytokeratin-18 network of a host cell, releasing newly formed virions. Using a spectrofluorometric assay with optimized buffer conditions to preserve the native structure and monomeric form of actin, insights can be gained by characterizing the binding interaction between actin and AVP. Although the reaction rates were lower than expected, assays varying the actin concentration with constant concentrations of AVP suggest tight binding between actin and AVP. The KM of the AVP-actin complex was measured to be 7 µM, very similar to the measured KM of the AVP-pVIc complex, suggesting that the binding of actin does not change substrate affinity. Rather, the binding of actin changes the properties of the enzyme itself, or the kcat (determined by VMAX). In addition, actin stimulates AVP in the presence of either one of the two viral cofactors (DNA and pVIc), allowing us to conclude that actin binds to two independent sites on AVP. Furthermore, through the use of competition assays with DNA, we were able to begin to estimate the binding affinity between actin and AVP with and without its viral cofactor pVIc. A better understanding of the interaction between actin and AVP should reveal new targets for anti-viral drug development.

Chronic THC Exposure: Effects on Sucrose Conditioned Place Preference in Adolescent Rats. ANNA VERDE (State University of New York at Stony Brook, Stony Brook, NY, 11790) PANAYOTIS (PETER) THANOS (Brookhaven National Laboratory, Upton, NY, 11973)

The psychoactive constituent in marijuana 9-tetrahydrocannabinol (THC) pharmacologically activates the mesolimbic reward pathways. Similarly highly palatable foods also activate the reward circuitry of the brain. Specifically, administration of THC has been shown to influence the intake of sweet foods. The effect of THC in adolescence hasn’t been looked at yet. Adolescence may be characterized as a period when a significant amount of neurobiological and development changes occur. Drug abuse during an early neurodevelopmental period may impact the reward potential and consumption of foods or drugs later in life. Therefore, the goal of the present study was to examine the effect of chronic THC administration during adolescence on the reward potential of sucrose using a conditioned place preference (CPP) paradigm. During the exposure period, 4 week old male Sprague Dawley rats were divided into 3 groups to receive a daily i.p. injection for 3 weeks of either: 1) vehicle (saline) 2) low dose THC (0.75 mg/kg) 3) high dose THC (2 mg/kg). Next, all rats started CPP after the last day of treatment. The CPP timeline encompassed the following: Day 1: Habituation, Days 2-9: Conditioning Phase (10 sucrose pellets on even days and no sucrose on odd days), and Day 10: Test Day. These findings will help gain insight on the impact of chronic THC exposure during a neurodevelopmental period on the subsequent reward potential of natural rewards. Finally these sucrose CPP results will be compared to CPP results to drugs in similar THC pretreated rats (Hwang et al. 2006).

Climatological Impacts of Extreme Naturally Occurring Fire Events Associated with the Alaskan Summer of 2004. JESSICA RAGAZZI (St. Joseph's College, Patchogue, NY, 11772) RICHARD WAGENER (Brookhaven National Laboratory, Upton, NY, 11973)

Besides their important role in the forest ecology, fires are also expected to have a large impact on weather and climate. Climatotological impacts are expected to be the largest in the arctic regions due to these high intensity fires. Previous studies have shown that the composition of smoke particles produced by the fires depends on the type of fire and its temperature. Fires create their own local weather and the most intense fires lift smoke particles high into the atmosphere where they can reside a long period of time and are transported great distances by high altitude winds. The summer of 2004 in Alaska had been a most unusual season, characterized by dry spells and various periods of intense lightning strikes. In two days alone, seventeen thousand strikes were recorded. These events triggered tremendous fires across the state, in the end leaving six million acres burned. This study Used Moderate Resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging Spectro-radiometer (MISR) satellite data to calculate the area of these fires. An analysis of the trajectories of these smoke plumes using an atmospheric transport model (HYSPLIT- HYbrid Single- Particle Lagrangian Integrated Trajectory) needed to be enacted in order to select those fires whose plumes pass over the in-situ Aerosol Observation System (AOS) operated by National Oceanic and Atmospheric Administration in Barrow, AK. The site is collocated with the DOE’s Atmospheric Radiation Measurement’s Climate Research Facility whose complement of instruments allows ground-based aerosol measurements. These in-situ and ground-based remote sensing measurements are combined with the MODIS aerosol retrieval products to estimate the direct radiative impact of these high intensity wild-fires. Several potential indirect effects investigated include the effects of smoke particles on cloud formation, cloud properties (droplet size, life-time), and the effect of soot particles on surface albedo by direct modification of the albedo of Alaskan glaciers and the potential for accelerated melting. This project explored only some of the effects of fires on climate. Further research may be done in order to obtain information on additional short or long term effects.

Comparative Ecological Study: Long Island Pine Barren Ponds, NY. LATONYA STEMLEY (Southern University at New Orleans, New Orleans, LA, 70126) MURTY KAMBHAMPATI (Brookhaven National Laboratory, Upton, NY, 11973)

The purpose of this research was to collect scientific ecological data on water and sediments from the Long Island Pine Barren Ponds including the ponds on Brookhaven National Laboratory (BNL) site and to compare results between the on-site (Zone-I) and off-site (Zone-II) ponds. The specific objectives were to: (a) analyze samples for physico-chemical factors; (b) compile and analyze data statistically; and (c) to identify the interrelationships between abiotic factors in ponds of two zones. We have collected 99 surface water and sediment samples (<15cm deep at 50 - 200m intervals, depending on size of each pond) randomly from 5 experimental sites (Groups 1-5). Experimental sites were plotted using eXplorist 200 Global Positioning System (GPS) and ArcInfo Geographic Information Systems (GIS). Field data were obtained on dissolved oxygen (DO), temperature, pH, turbidity, and conductivity using Yellow Spring Instruments, Inc. (YSI) probe. Water samples were analyzed using HACH DR890 colorimeter. Filtered and acidified water samples (pH<2) were used to estimate metal content using Direct Coupled Plasma Spectrometer (DCP). Sediment samples were air dried, sieved, and saved for elemental analysis using DCP. Macro and micronutrients were analyzed using LaMotte Soil Test Kits. Samples were also dried in an oven at 650C for 36-48 hr to obtain moisture. Water was acidic (5.31±0.35 to 6.84±0.13 at CP and GP, respectively) and low in DO (4.12±0.89 to 6.92±0.55 ppm at CP and SBP, respectively). Alkalinity ranged from 27.71.1±60 ppm in BNL ponds to 82.9332±0.50 ppm in GP. One-way ANOVA results indicated mean differences between groups (df = 4) and within groups (df = 28). Soil texture is mostly either sand or silt. Moisture content varied between 20.98±10.35 to 50.02±6.13% in NRP and BNL samples, respectively. Sediment ANOVA results indicated positive and negative significances (P<0.05 and P<0.01) between elements, aluminum (Al), iron (Fe), lead (Pb), and chromium (Cr). In conclusion, the Long Island Pine Barren pond water and sediments are acidic and nutrient poor.

Comparative Ecological Study: Long Island Pine Barren Ponds, NY. HA'WANNA ST.CYR (Southern University at New Orleans, New Orleans, LA, 70126) DR. TIM GREEN (Brookhaven National Laboratory, Upton, NY, 11973)

The purpose of this research was to collect scientific ecological data on water and sediments from the Long Island Pine Barren Ponds including the ponds on Brookhaven National Laboratory (BNL) site and to compare results between the on-site (Zone-I) and off-site (Zone-II) ponds. The specific objectives were to: (a) analyze samples for physico-chemical factors; (b) compile and analyze data statistically; and (c) to identify the interrelationships between abiotic factors in ponds of two zones. We have collected 99 surface water and sediment samples (<15cm deep at 50 - 200m intervals, depending on size of each pond) randomly from 5 experimental sites (Groups 1-5). Experimental sites were plotted using eXplorist 200 Global Positioning System (GPS) and ArcInfo Geographic Information Systems (GIS). Field data were obtained on dissolved oxygen (DO), temperature, pH, turbidity, and conductivity using Yellow Spring Instruments, Inc. (YSI) probe. Water samples were analyzed using Hach DR890 colorimeter. Filtered and acidified water samples (pH<2) were used to estimate metal content using Directly Coupled Plasma Spectrometer (DCP). Sediment samples were air dried, sieved, and saved for elemental analysis using DCP. Macro and micronutrients were analyzed using LaMotte Soil Test Kits. Samples were also dried in an oven at 650C for 36-48 hr to obtain moisture. Majority of the water and sediments were acidic and nutrient poor. Soil texture is mostly either sand or silt. Moisture content varied between 20.98±10.35 to 50.02±6.13% in NRP and BNL samples, respectively. Sediment ANOVA results indicated positive and negative significances (P<0.05 and P<0.01) between elements, aluminum (Al), iron (Fe), lead (Pb), and chromium (Cr). In conclusion, the Long Island Pine Barren pond water and sediments are acidic and nutrient poor. Sediments have higher concentrations of metals (Al and Fe), in general.

Comparing the properties of pyridinium and 4-dimethylaminopyridinium ionic liquids. JASMINE HATCHER (Queens College, Queens, NY, 11590) JAMES WISHART (Brookhaven National Laboratory, Upton, NY, 11973)

Ionic liquids, organic salts that melt below 100°C, are generally composed of a large organic cation and a relatively small inorganic anion. They have generated much interest due to their potential as alternative reaction media for a variety of applications including use in batteries, fuel cells, and for the storage and processing of nuclear waste. Ionic liquids can be designed to incorporate specific functionalities for certain uses ("task-specific ionic liquids"). The physical characterization and properties of 4 dimethylaminopyridnium (DMAP) based ionic liquids with varying functionalities in comparison to their pyridinium (py) analogues are reported here. In addition, this study examines the effect of the dimethylamino group of DMAP on the physical properties of these two series of ionic liquids. The dimethylamino group of DMAP is known to have catalytic properties and DMAP based ionic liquids are expected to have similar properties. The DMAP and pyridinium salts were synthesized using various alkylating agents such as 3-chloropropanol and 2-bromoethyl ethyl ether. The resultant halide salts were converted to ionic liquids bearing bis(trifyl)imide anion. Physical properties investigated include: viscosity, conductivity, and thermal profile. Preliminary results indicate that for both the DMAP and py systems, the ionic liquids containing alkyl groups have lower viscosities and higher conductivities at room temperature compared to those bearing hydroxyl groups. Results also suggest the presence of the dimethyl amino group on the pyridine ring has minimal effect on the conductivity and viscosity. The Butyl DMAP and Butyl Pyridinium ionic liquids had almost the same conductivity (2.12 mS/cm and 2.22 mS/cm respectively) and viscosity (9.950 cP and 9.122 cP at 850C respectively). Future work will focus on the effect of the position of the dimethylamino group on the pyridine ring on the same properties.

Conflict Resolution is Impaired in Currently Withdrawn Cocaine Addicted Individuals. BAABA BLANKSON (State University of New York at Stony Brook, Stony Brook, NY, 11790) RITA GOLDSTEIN (Brookhaven National Laboratory, Upton, NY, 11973)

Individuals with cocaine use disorders (iwCUD=CUD) experience neuropsychological impairments that encompass attention and executive function deficits, possibly due to structural and functional changes in prefrontal cortical brain regions. The Attention Network Test (ANT), a computerized reaction time task, has been developed to measure three of these attention and executive function networks: alerting (associated with right hemisphere frontal and parietal regions), orienting (associated with subcortical regions), and executive control (associated with the prefrontal cortex, particularly the anterior cingulate cortex). Our study used the ANT to examine 1) differences between CUD and healthy control subjects in attention and executive function; and 2) the effect of urine status (positive or negative for cocaine use within 72 hours) on attention and executive function in the CUD group. The ANT was administered as part of a larger neuropsychological battery to 84 individuals with current CUD [55 positive (CUD+), 29 negative (CUD-)] and 75 healthy control subjects matched on gender, age, and years of education, but not on race, general intellectual functioning, socioeconomic status, state depression and history of cigarette smoking. Results of 3 separate ANOVAs revealed a significant group difference in executive control [[F (2, 156) = 5.8, p < 0.004; pairwise comparisons: controls faster than both cocaine subgroups, an effect that reached significance for CUD-, p < .004, M±SD = 127.5±47.8 for controls vs. 149.4±64.5 for CUD+ vs. 169.8±76.5 for CUD-], but not in orienting [F (2, 158) = 1.0, p > 0.4] or alerting [F (2, 157) = 0.2, p > 0.8]. The executive control effect remained significant after controlling (with ANCOVA) for general intellectual functioning, the only non-matched variable that correlated with executive control (p < 0.03). The current results suggest that the ability to resolve a cognitive conflict may be uniquely impaired in CUD and expressed primarily during acute withdrawal. Possible explanations may encompass the self-medicating hypothesis (i.e., where cocaine use ameliorates an underlying cognitive deficit in CUD) or the effects of acute withdrawal symptoms on neuropsychological function. The effects of longer abstinence periods and other drug use variables on ANT conflict in CUD remain to be established. Future studies need to also explore the role of the anterior cingulate cortex in underlying this cognitive conflict resolution performance deficit in drug addiction.

Construction of a Monitoring System for the Solenoidal Tracker At RHIC (STAR) Forward Meson Spectrometer (FMS). SHAWN PEREZ (State University of New York at Stony Brook, Stony Brook, NY, 11794) LES BLAND (Brookhaven National Laboratory, Upton, NY, 11973)

The Forward Meson Spectrometer (FMS) at Brookhaven National Lab, consists of a matrix of lead-glass bars viewed by photomultiplier tubes that surround the colliding beam axis. The FMS detects the two photons associated with the decay of a p⁰ meson, or other photons, electrons or positrons produced in the collisions. The pseudo rapidity -ln(tan(/2) dependence of particle production can be analyzed to explore parton distributions within the proton. We are currently designing an LED light pulsing system which will be used to monitor the performance of these 1264 lead-glass detectors. Using Very High Speed Integrated Circuit (VHSIC) Hardware Description Language (VHDL) to program the Field Programmable Gate Array (FPGA) via the Xilinx ISE WebPack development environment, the goal is to have the LED Panel mimic events generated from the proton–proton collisions by pulsing different patterns of light with amplitude control into the FMS. The aspect of this project that I have been assisting with is the PC Board design, which integrates the electronic components with the necessary circuitry and mechanics for the monitoring system to function. The software required for this design are Microsoft Office Visio 2007 to generate the block diagram of the processes between the electronics, Cadence OrCAD Capture Schematic to represent the systems circuitry, and PADS – PCB 2007 which is the PC board layout tool manufactured by Mentor Graphics. The LED monitoring system once completed, will provide a means of testing the FMS and monitoring its performance during RHIC operations.

Conversion of Geothermal Silica into Value-added Nano-sized Materials. ZHAN HANG YANG (State University of New York at Stony Brook, Stony Brook, NY, 11790) DEVINDER MAHAJAN (Brookhaven National Laboratory, Upton, NY, 11973)

Geothermal brines store natural heat that can be harnessed to produce thermal and electrical power. Unlike fossil fuels, it is a promising, sustainable natural resource with negligible CO₂, SO₂ and NO_x emissions. The circulating hot fluids below the Earth’s surface dissolve minerals and metals like silica, lithium, zinc and manganese from the rocks they travel through. The presence of silica (SiO₂) and other chemicals is a major concern during power production from geothermal brines because it causes scaling and corrosion. The recovery of silica is highly desirable to reduce scaling and to offset the cost of power production. This research project is undertaken to investigate the conversion of silica of high purity into nano-sized, value-added materials such as silicon carbide (SiC) and silicon nitride. Sonication or ultrasound irradiation is employed since this technique is known to produce nanoparticles in-situ. The method involves cavitations, and within the cavities high pressures and high temperatures are generated that can be harnessed to drive chemical reactions. A carbonaceous source, dextrose or graphite, was sonicated with silica to yield silicon carbide. The product was characterized by X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). The XRD patterns of collected solids suggested the presence of three different polytypes of silicon carbide, along with unreacted starting materials. The FTIR measurements showed the appearances of two new peaks at 1015 and 815 cm^- that are probably due to v(Si-O-C) and v(Si-C) stretching, respectively. The vibrations are tentative evidence of silicon carbide formation and possible indicator of the extent of reaction.

Crystallization and Crystallography Analysis of Amidohydrolase Enzyme from the Structure Genomic Project. ARSHAD MEHMOOD (Medgar Evers College, Brooklyn, NY, 11226) D. KUMARAN (Brookhaven National Laboratory, Upton, NY, 11973)

Designing an LED Monitoring System for the FMS. JONATHAN LANGDON (State University of New York at Stony Brook, Stony Brook, NY, 11794) LES BLAND (Brookhaven National Laboratory, Upton, NY, 11973)

The Forward Meson Spectrometer (FMS) at Brookhaven National Laboratory’s STAR Experiment is composed of lead glass cells which are used to detect photons produced in high energy collisions of gold nuclei or protons. In past iterations of the FMS, panels of fiber optics were used to provide light from light emitting diodes (LEDs) as a calibration signal. This test signal could be observed as an event distribution within the data, far removed from other physical events. For the FMS, the goal is to create a more comprehensive and adaptable LED testing system. Unlike previous iterations, the goal is provide variable light sources to cell clusters allowing for patterns of light to be used instead of simply pulses of light. This would provide a means for proofing the functionality of the FMS’s triggering system. To accomplish this, a type of microchip, known as a Field Programmable Gate Array (FPGA), will be installed to control the LED output. FPGAs are also known as programmable logic chips, since one can use a computer to define its behavior after it has been implemented. Making use of an FPGA development kit in conjunction with an "integrated software environment" (ISE), known as Xilinx ISE Webpack, a functioning system for controlling the light panels has been developed. However, in addition to the hardware aspect, it has also been necessary to develop graphical interface tools for loading light pattern instructions in real time. This was accomplished by way of Microsoft’s "Visual Basic.NET 2005 Express" interactive development environment (IDE). The final product, known as the "Light Panel Control System," is the product of by directional development, starting from the computer out to the development board and from the FPGA back.

Designing the Gamma Calorimeters for the Future International Linear Collider. ERIC JONES (State University of New York at Stony Brook, Stony Brook, NY, 11790) WILLIAM MORSE (Brookhaven National Laboratory, Upton, NY, 11973)

The electron-positron beams of the future International Linear Collider (ILC) must be monitored by utilizing feedback measurements of the bunch characteristics in order to keep them properly aligned for the optimum resulting luminosity once they collide. The Gamma Calorimeter (GamCal) is one of the proposed calorimeter designs to be placed in the very-forward region of the ILC that will be used to gather information about the beam interactions in order to maintain this alignment. It will measure the energy of photons produced by so-called beamstrahlung, a process which results from the intensification of the electromagnetic fields of the bunches as they pass through each other; however, their energy will not be measured directly. The beamstrahlung photons will first be converted into electron-positron pairs by directing them into a 10^-5 m thick diamond foil, and then the positrons will be magnetically deflected into a detector grid that will measure their energy. In order to obtain a quantity proportional to the luminosity, this information will then be combined with information from the Beam Calorimeter (BeamCal) that will detect the pair particles produced in the collisions. We have used Daniel Schulte’s simulation program, the Generator of Unwanted Interactions for Numerical Experiment Analysis Program, Interfaced with Geometry and Tracking (GEANT) (GUINEA-PIG), in order to understand the effects of changing important collision parameters such as the beam offset, the incoming beam angles, and the bunch lengths on the produced pair particles and beamstrahlung photons. The resulting GUINEA-PIG data were analyzed using the program Physics Analysis Workstation (PAW) and Excel. The photon energy and angular distributions will be used to optimize the detector placement in the GamCal, while other output data shall be used to determine if the luminosity can be optimized without data from the BeamCal during preliminary runs of the beams. Future studies shall also determine how well the converting foil will survive when the beams fail to interact, as the electron-positron beams are intense enough to punch holes through the foil, and these holes will decrease the acceptance of our detector. What we understand now are the number and energy acceptances for nominal bunch parameters with varying offsets and incoming angles, and that the foil should remain reliable to about 1% error.

Detection of Ultra High Energy Cosmic Rays Using Radar. STEVEN HICK (State University of New York at Stony Brook, Stony Brook, NY, 11794) HELIO TAKAI (Brookhaven National Laboratory, Upton, NY, 11973)

Ultra High Energy Cosmic Rays (UHECR) are constantly bombarding our planet from unknown sources outside the solar system and uncovering their mysteries can provide insight into the origins and evolution of the universe. The Mixed Apparatus for Radar Investigation of Cosmic-rays of High Ionization (MARIACHI) project is a collaborative effort between research scientists, educators, and students that will explore UHECR. Understanding UHECR will be a major accomplishment in the physics community since the energies they produce are orders of magnitude higher than energies we can produce on earth with current particle accelerators. MARIACHI will scatter radio waves off ionization trails that are created when UHECR interact with our atmosphere, and will be detecting these signals using scintillator arrays that are strategically located across Long Island. Along with the scintillator arrays, antennas will be constructed and used for the detection of UHECR, and calibrating these antennas will be a major step forward for MARIACHI. The design for an antenna is a simple double dipole, which we have been experimenting with all summer. Designing, calibrating, and implementing the antennas as a compliment to the scintillator arrays is a main goal for the project. Furthermore, MARIACHI will be developing ways to subtract unwanted background information from meteors and other sources that try and mask the detection of UHECR. The MARIACHI project is still in its initial phases and there is a high risk involved since it is unknown whether or not it’s possible to use radar for UHECR detection. Although there is this risk factor the concept of MARIACHI is highly seductive since the forward scattering technique is extremely inexpensive, which allows for a wide range of users to participate. The project is mainly concerned with pure scientific research, but is unique in the fact that research scientists, educators, and students are all participants. Detecting UHECR and extracting maximal information from the MARIACHI project has promise and potential for opening many new doors in physics and education.

Determining the Components of an Iron Beam at the NASA Space Radiation Laboratory. JENNIFER MABANTA (St. Joseph's College, Patchogue, NY, 11772) MICHAEL SIVERTZ (Brookhaven National Laboratory, Upton, NY, 11973)

Before extended space missions can occur, protective measures must be put in place for astronauts since prolonged exposure to radiation fields can have adverse effects. The purpose of the research done at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL) is to gain a better understanding of the cosmic rays in space and develop the most efficient countermeasure for the voyagers. Proton and heavy-ion beams from the BNL Booster accelerator are directed along a beam line to NSRL. These beams mimic cosmic rays providing a controlled area in which to study the effects of the rays. The most harmful of the rays is iron and the least destructive and most abundant is hydrogen. Of particular interest to NASA are the iron beams as they are the most destructive form of radiation facing astronauts. Since completely shielding them from these heavy beams would not be feasible given the constraints in space, scientists are seeking to utilize the process of fragmentation in their shielding methods. Fragmentation is the way in which heavy ions break up into lighter less dangerous ions. In order to study this process, it is necessary to measure the components within the beam. To achieve this, a scintillator detector is placed within the beam. However, the response of this scintillator is not linear with the deposited energy; it follows a relation known as Birk’s Law. In order to study the different components of the beam, the response function of the scintillator must be determined. Once this response function is made linear, each elemental ion within the iron beam is more easily identified. To create the best fit, the fewest number of parameters must be used while still keeping the value of chi squared at a minimum. Using the spreadsheet software Excel, a fitting routine was created that could be implemented on each of the components of the iron beam from hydrogen to iron. Using this routine, the centroids for the peak of each element was determined and used to develop the response function. A second order polynomial was found to be adequate to fit the response of the scintillator, y = 0.000121x^2 +1.0x. A comparison of the scintillator response function before and after unfolding shows that the response can be portrayed as a linear function within a given range. Using this function, scientists will be better able to characterize the iron beam in order to develop the best shielding methods for harmful space radiation.

Dose-Dependent Conditioned Place Preference Response and Locomotor Activity in Methamphetamine-Treated Animals. REEMA DALAL (New York University, New York, NY, 10003) DR. STEPHEN DEWEY (Brookhaven National Laboratory, Upton, NY, 11973)

Previous behavioral studies indicate that animals exposed to methamphetamine (METH) often associate and prefer specific environments with their exposure, a behavior termed conditioned place preference. The conditioned place preference (CPP) paradigm is a commonly used technique to evaluate the positive or negative reinforcement values of different drugs. These studies closely parallel behavioral responses reported by human substance abusers. In the present study, the procedure involved several drug pairings where the animals, adolescent male Sprague-Dawley rats, were exposed to different doses of METH in distinct chambers containing well-defined tactile, visual, and/or olfactory cues. Following randomization of the animals, the goal was to expand previous studies, demonstrating that rats will express a CPP to METH exposure by determining a dose-response. For these CPP studies, three groups of animals were exposed to METH at concentrations of 2.5, 5.0, or 10.0 mg/kg. Following twenty consecutive days of pairings (alternating with saline), animals were given access to both chambers in a drug-free state (saline injection). The amount of time spent in the METH-paired chamber was recorded, and was used as an indicator of preference. Further, the locomotor activity was monitored each day and the values obtained on the test day were compared against those obtained for the pre-test. This analysis indicated a significant increase from low-dose to high-dose administration, demonstrating that methamphetamine produced a significant, dose-dependent CPP. Further studies using different concentrations are currently ongoing in a continuing effort to better understand the locomotor and behavioral effects of METH.

Dynamics of Fast Reactions in Ionic Liquids. KATHRYN SIMS and KANDIS STUBBLEFIELD (Howard University, Washington, DC, 20059) DR. JAMES WISHART (Brookhaven National Laboratory, Upton, NY, 11973)

Ionic liquids (ILs) are liquids consisting of ions and have melting points below 100 °C. Used in technologies and green chemistry they are being considered as processing media in the advanced nuclear fuel cycles needed to support a sustainable nuclear power industry for the world’s future energy needs. It is important to understand the radiation-induced chemistry of ILs and how it may affect the chemistry of nuclear fuel separation. The unique reactivity of the "pre-solvated" electron surfaces as an important aspect of radiation chemistry due to the slower response to charge movement in ionic liquids relative to ordinary solvents. This study explores the reactivity of pre-solvated electrons in the ionic liquid N-methyl N-butylpyrrolidinium NTf2 (P14NTf2) by measuring the kinetics of their reactions with cadmium, nitrate and selenate ions. These ions were selected because they show a wide range of reactivities with electrons in conventional solvents. The process of electron solvation, which competes with pre-solvated electron capture, is estimated by measuring the benzophenone anion solvation process because its spectroscopic properties are better suited to the available detection equipment than those of the electron. The Brookhaven National Laboratory (BNL) Laser Electron Accelerator Facility (LEAF) was used for all of the kinetics measurements performed by pulse radiolysis transient absorption spectroscopy. The C37 parameter was obtained to look at the lower concentration of benzophenone. Higher concentrations were also analyzed to allow us to look at the spectral shifts and compare them to that of the selected ions in the IL. In conclusion, we have determined the reaction kinetics of fast reactions in the IL.

Effect of Biotin Density on 2D Streptavidin Crystallization on Lipid Monolayers at the Liquid-Vapor Interface. MATTHEW LOHR (Pennsylvania State University, University Park, PA, 16802) MASAFUMI FUKUTO (Brookhaven National Laboratory, Upton, NY, 11973)

Phospholipid monolayers at the gas-liquid interface are interesting because of their ability to act as templates for two-dimensional (2D) crystallization of various proteins. Such behavior could lead to utilization for assembly of practical bio-nanostructures. Previously studied examples of this phenomenon include the crystallization of streptavidin through binding with biotinylated phospholipids. In this study, we examine the effect of biotin surface density on streptavidin crystallization by observing the behavior of streptavidin at an ionic subphase-vapor interface coated with a phospholipid monolayer comprised of a binary mixture of dimyristoylphosphatidylcholine (DMPC) and biotin-capped dipalymitoylphosphotidylethanolamine (DPPE-x-Biotin). We monitor the formation of 2D streptavidin domains on lipid surfaces using Brewster-angle microscopy (BAM) over 20 hours. The mean molecular area of lipids is fixed at 75 Å2/lipid, and the mole fraction of DPPE-x-Biotin ranges from 100% to 0.01%. These observations have yielded several distinct regimes for crystallization behavior. At 8% DPPE-x-Biotin composition and above (937.5 Å2 per biotin and below), bowtie-shaped crystal domains form almost immediately after injection of streptavidin, grow with time, and eventually cover the entire surface of the sample. At 5% and 4.3% DPPE-x-Biotin composition (1500 and 1744 Å2 per biotin), crystal domains only partially cover the available sample surface. At 3.9% and 3.5% DPPE-x-Biotin composition (1923 and 2142 Å2 per biotin), several crystal domains are observed, but they are not uniformly distributed over the entire surface. At 3% DPPE-x-Biotin and below (2500 Å2 per biotin or larger), the surface shows no crystal domains that can be discerned by BAM (=10 m). According to previous diffraction studies of streptavidin crystals under similar conditions, the proteins arrange in two-dimensional unit cells with an average of 1610 Å2 per biotin binding site. This observation and our BAM studies provide strong evidence that in order for the 2D crystallization of streptavidin to take place, the surface density of biotin linkers must be comparable to or larger than the binding site density in the 2D crystal. This observation may be key to understanding the mechanisms behind streptavidin’s crystallization behavior. These results supplement ongoing studies of streptavidin crystallization, including x-ray and optical studies of the effects of subphase pH.

Effect of stroke on regional distribution of aromatase and NMDA receptors in the female rat brain. CANDACE GIRARD (Mount Holyoke College, South Hadley, MA, 1075) ANAT BIEGON (Brookhaven National Laboratory, Upton, NY, 11973)

The production of estrogens from precursor androgens is catalyzed by the enzyme aromatase (AR), which under normal circumstances, is restricted to specific neuronal locations. The N-methyl-D-aspartate receptor (NMDAR) is one of the three major subtypes of glutamate receptors, which under normal circumstances, plays a critical role in synaptic plasticity mechanisms. Experimental data suggests that AR activity and NMDARs may be involved in neurodegenerative processes following brain injury. Recent studies have indicated that brain insults can induce brain AR expression and decrease brain NMDAR’s. However, the long term effect of stroke w/respect to AR and NMDAR distribution has not been investigated. Middle cerebral artery occlusion (MCAo) in female rats induced stroke and was confirmed in the left hemisphere by MRI and histology. Stroke rats were sacrificed 2 or 4 weeks post MCAo and brain tissue processed for autoradiography. Five control brains (w/surgery; w/o stroke) and five experimental brains (w/surgery; w/stroke) were used in these experiments. Using quantitative in vitro autoradiography, AR distribution was investigated with [11C]-vorozole and NMDA distribution with [3H]-MK-801. Regional densities of autoradiograms were quantified with standard image analysis software. The [11C]-vorozole autoradiograms did not show specific or increased binding in our stroke animals. This may be due to the low AR expression in young females and/or a short-lived (<2wks) increase in aromatase. The [3H]-MK-801 autoradiograms showed similar regional binding density in control rats at 2 and 4 weeks. In stroke animals, binding density was decreased at 2wks after surgery compared to controls as well as to stroke rats 4wks after surgery. These effects were more pronounced in brain regions adjacent to the stroke. The most significant increase in binding between 2 and 4wks after stroke was found to be in the frontal cortex (~20%) and denate gyrus (~28%). Binding in the left caudate putamen was significantly lower in experimental rats (~18%). These results, if upheld in a larger series, suggest that hippocampal and cortical NMDAR reduction induced by MCAo is transient, which is in line with the transient nature of many cognitive symptoms often seen in the acute phase after a stroke. This also suggests that damage to the caudate putamen may be sustained or irreversible, in line with the long term nature of motor deficits among MCAo stroke patients.

Effects of Humidity in Inlet Air on a Proton Exchange Membrane (PEM) Fuel Cell. ANDREW FASANO (Farmingdale State College, Farmingdale, NY, 11735) DEVINDER MAHAJON (Brookhaven National Laboratory, Upton, NY, 11973)

Air humidification plays a crucial role in the performance of Polymer Electrolyte Membrane (PEM) fuel cells. The present study aims to determine the effect of relative humidity on the cathode side that will produce optimal fuel cell performance at various power levels. Usually, increasing air humidity improves fuel cell performance until it reaches an optimal operating condition. If humidity continues to increase beyond this point, the fuel cell experiences flooding due to the isolation of the catalyst surface from the reactant gases which causes considerable power degradation of the fuel cell. The recorded data shows that air humidification at relatively low temperature levels tends to hinder the cell performance due to its saturation with water. When current levels are increased, an increase in inlet air humidity causes the cell to initially drop in performance due to a certain degree of catalyst flooding at low temperature. However, as the cell begins to increase in temperature, the humidification of inlet air results in a slight recovery of power in the cell output. In conclusion, at room and low temperatures humidification of the inlet air to the PEM fuel cell exhibits a negative effect on the cell power output due to partial flooding. But as the fuel cell continued to operate, the temperature increased that allowed the initial flooding to subside and power escalation was observed.

Electrical Systems Analysis of Off-Site Groundwater Treatment Facilities to Determine Arc Flash Hazard. JOHN BOUCHER (Middlebury College, Middlebury, Vermont, 5753) ALAN RAPHAEL (Brookhaven National Laboratory, Upton, NY, 11973)

Before an arc flash accident prompted Brookhaven National Laboratory (BNL) to devise the Arc Flash Analysis Project, a project designed to achieve a complete electrical systems analysis of all BNL systems and buildings, many of BNL’s older facilities had not been inspected to determine if they satisfied the National Fire Protection Association’s "Standard for Electrical Safety in the Workplace" (NFPA 70E - 2004). The following study examined the electrical systems of BNL’s Off-Site Water Treatment Facilities for their compliance with NFPA 70E - 2004 and so was only a piece of the comprehensive Arc Flash Analysis Project. Electrical information such as equipment layout, manufacturing, and operating information for all electrical components such as panels, fuses, and circuit breakers, as well as cable sizes, types, and approximate lengths was obtained by manually inspecting and tracing out the water treatment facilities’ electrical systems. Using SKM PTW Power Tools Software (PTW), this information was organized, illustrated, and then analyzed to establish the electrical systems’ susceptibility to and energy available for arc flash. The work done for this study produced single-line electrical diagrams via PTW containing all electrical equipment down through the lowest rated panels (480 Volt or 208 Volt) to any 3 phase 480 Volt or 3 phase 208 Volt / 225 Amp or greater equipment for the facilities. With the supplied information in the single-line diagrams, PTW was used to compute information such as arc flash incident energy level at each equipment location, the flash protection boundary, and the recommended Personal Protective Equipment (PPE) at these locations. This study sought to achieve greater safety for those working on the concerned electrical systems by providing recommendations for necessary PPE for electrical workers, collecting data to be archived, managed, updated as necessary, and made accessible to facility engineers for future electrical work, and affixing up-to-date arc flash warning labels to all appropriate electrical equipment.

Electron Transfer in Molecular Wires. ELICIA SELVAGGIO (Dowling College, Oakdale, NY, 11767) JOHN MILLER (Brookhaven National Laboratory, Upton, NY, 11973)

Conjugated oligofluorenes with two to ten monomer units (F2 to F10) were used to address fundamental questions regarding eletron capture capacity and delocalization of charge. The oligofluorenes were reacted with sodium metal in tetrahydrofuran (THF) under vacuum, and ultraviolet/visible/near infrared (UV-vis-NIR) spectroscopy was used to measure the formation of anions, dianions, trianions, and tetranions. When reacted with sodium, F2 through F10 formed anions and dianions. Trianions and tetranions were observed in F4 and larger oligofluorenes. The absorption maxima, wavelengths at the maximum absorbances, and extinction coefficients were determined for each species formed. The study indicates that oligofluorenes can capture and store multiple electrons from sodium metal, and that the negatively-charged molecules are stable in the absence of air. Results for the series indicate that the length occupied by an electron is three to five monomer units. These results are consistent with the value obtained in polyfluorene by a different method in this lab. This challenges the notion that electrons are delocalized over the entire length of a conjugated molecule, and it has implications for understanding the fundamental nature of charged molecules in conjugated systems.

Electronic Structure of Nanowire Arrays. SAM OCKO (Brown University, Providence, RI, 2912) WEI KU (Brookhaven National Laboratory, Upton, NY, 11973)

It has recently been proposed that electrons will localize in the intersections of nanowires. This is purely a quantum effect, originating from the wave nature of electrons, as there is no attractive potential to keep them in the intersection. This phenomenon of localization is very important because it might provide the basis for a functional device which uses localization to exhibit useful properties such as ferromagnetism, anti-ferromagnetic insulation, and perhaps even superconductivity. We investigate the electronic structure of an array of nanowires using a piece of software we have written, which uses self-adaptive bi-orthogonal wavelet basis to model the electrons’ wave functions. Instead of trying to solve Schrödinger’s equations directly and treating the problem as an eigen-value equation, we use a functional minimization method which uses conjugate gradient and steepest descent methods. The program we have developed is easily extensible, as other systems can be applied simply through changing the energy functional, which makes our program able to model many-body effects and solve other Quantum Mechanical systems. Our program has successfully demonstrated phenomena of localization and showed that the strength of localization is inversely proportional to the diameter of the wires. In application, a grid of nanowires could be possibly be printed on a piece of silicon, with complete control over the properties of the grid. Through properly choosing the diameter of the nanowires and the density of the grid, we could control the kinetic energy and electron interaction of the nanowires. Through modulating the gate voltage, we can tune the number of electrons in the grid. A grid of nanowires whose properties are chosen carefully might show many interesting electrical properties, including ferromagnetism, anti-ferromagnetic insulation, and perhaps even superconductivity, which we hope to investigate further.

Energetics of Electron Transfer and Charge Separation in Moderate to Low Polarity Solvents. BRIAN ALBERT (Columbia University, New York, NY, 10027) JOHN MILLER (Brookhaven National Laboratory, Upton, NY, 11973)

Because photosynthesis occurs in a region of low polarity so that photoelectrons store their absorbed energy in new chemical bonds instead of emitting it as heat through interaction with the solvent, studying electron transfer and charge separation in low polarity solvents will have applications in new solar energy storage. These experiments combine strong electron donors (metallocenes) and strong electron acceptors (quinones) to obtain ion formation by thermal equilibria in media of moderate to low polarity. In solvents of a range of dielectric constants, the extent to which cobaltocene and various quinones formed ion pairs and separated to form free ions was measured via conductivity and UV-Vis spectroscopy. Gibbs free energy changes were calculated for both the electron transfer and charge separation reactions in various solvents using acetonitrile as a standard highly polar solvent. With known values for the ionization potential of cobaltocene and the electron affinities of the quinones, Gibbs free energy changes observed in the moderately polar solvent, tetrahydrofuran (THF), were fit to the theoretical Born solvation energy and Coulomb potential models. Predictions made for free energy changes in solvents of very low dielectric constants disagreed with experimental data because a fourth species, charge transfer complex, becomes more significant in relative concentration, thus introducing a third equilibrium. Also, molecule structure of the solvent molecule was found to affect Gibbs free energy changes of ion formation. Approximations of neutral specie, ion pair, and free ion concentrations became more difficult in low polarity solvents because of charge transfer complexes that appear as broadened peaks in UV-Vis absorption spectra as well as extremely low conductivity measurements. Observed Gibbs free energy changes were found to be significantly more unfavorable compared to redox potentials of the same reactions determined electrochemically. The difference is attributed to the stabilization caused by salt in solution required for the electrochemical method.

Ensuring Co-planarity of Tiled Optical Surfaces. MICHAEL DAWSON-HAGGERTY (Tufts University, Medford, MA, 2155) PAUL O'CONNOR (Brookhaven National Laboratory, Upton, NY, 11973)

The Large Synoptic Survey Telescope (LSST) is designed to have an extremely large field of view, 9.62 square degrees, nearly 50 times the area of the full moon. The digital camera used to record the images provided by such a large field needs to be enormous. The focal plane of the camera is a circular area 60 cm in diameter, covered in a tiled surface of 4cm square CCD imaging chips, which provide the digital image for analysis. Although the area is large, the tiled sensors need to be coplanar to within plus or minus five microns, as the light is converging on a very specific, precise point. To do this, the tiles are grouped into 3x3 arrays called 'rafts' which can be constructed individually. The rafts are scanned with a laser confocal displacement meter mounted onto an x-y gantry system. The displacement meter is scanned over the raft surface, and a 3D model can be made of the raft. Tilt and vertical displacement of each CCD can be assessed, and extremely thin foil shims of known thickness can be inserted to compensate. The scan is repeated until all silicon sensor surfaces are within tolerances. This allows the effectiveness of thin- foil spacers to be assessed, as well as the overall feasibility of the precision requirements for the tiled surface, a greater precision then has been attempted previously. This work is a small portion of a much larger project being researched to develop the LSST optical and mechanical systems, and once completed will play a large part in ensuring a clear and focused image.

Evaluation of Operating Conditions When Measuring Gaseous Ammonia Using A Tunable Diode Laser Absorption Spectrometer (TDLAS). KHATERA RAHMANI (Brooklyn College, Brooklyn, NY, 11210) ARTHUR SEDLACEK (Brookhaven National Laboratory, Upton, NY, 11973)

Ammonia (NH₃) is the only alkaline in the atmosphere. It is highly-reactive and is commonly found in concentrations of 1ppb in ambient air (but can readily approach concentrations in the 1000s of ppb when near sources). In addition to the role that NH₃ plays in the biochemical cycles of nitrogen, it also plays a role in aerosol formation by reacting with atmospheric NOx and SOx. The resulting aerosols have been observed to play a role in global climate change. The high sensitivity and fast response time of the TDLAS makes it a good candidate for measuring gaseous NH₃. Although the TDLAS is highly sensitive and can measure concentrations of NH₃

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