24Al Level Structure and the Corresponding 23Mg(p,) 24Al Astrophysical Reaction
Rate. CHRISTOPHER DEATRICK (Western Michigan University,
Kalamazoo, Mi, 49008) DARIUSZ SEWERYNIAK (Argonne National Laboratory,
Argonne, IL, 60439)
24Al Level Structure
and the Corresponding 23Mg(p,) 24Al Astrophysical Reaction Rate.
Christopher J. Deatrick (Western Michigan University, Kalamazoo,
MI 49008) Dariusz Seweryniak (Argonne National Laboratory, Argonne,
IL 60439) In order to better understand the processes involved
in heavy nuclide production in explosive stellar environments,
the breakout process from the CNO cycles to the NeNa cycle and
to the MgAl cycle must be quantified. Better numerical values of
proton capture rates are deduced for the 23Mg(p,) 24Al reaction
by studying nuclear energy levels in 24Al above the proton capture
threshold using high-resolution -ray spectroscopy and -ray angular
distribution analysis. 24Al nuclei were produced by colliding an
16O beam delivered by the Argonne Tandem-Linac Accelerator System
with a 10B target . Excited states in 24Al were populated after
evaporating two neutrons from the compound system. Gamma rays emitted
from these states were detected with the GAMASPHERE array of Compton-suppressed
Ge detectors. The Argonne Fragment Mass Analyzer was used to separate
reaction products from the beam and assign mass and atomic numbers.
As a result, states above and below the proton threshold were studied
in detail resulting in an improved 24Al level scheme. The analysis
of the first state above the proton threshold indicates that the
reaction rate contribution of this state could differ by a factor
of up to 9 from that of previous calculations in the 0.1-0.5 GK
temperature range.
A New Method for Protein Sequence Characterization Using Hidden Markov Models. HARSH SHAH (University of Illinois at Chicago, Chicago, IL, 60607) GYORGY BABNIGG (Argonne National Laboratory, Argonne, IL, 60439)
Predicted protein
sequences of newly sequenced species are normally analyzed for
similarity to existing protein sequences using BLAST. The sequences
are also characterized by searching with Hidden Markov Models (HMMs)
of existing protein families in order to assist function assignment.
While the BLAST searches are performed quickly, the more accurate
searches using HMMs are computation intensive and might take a
long time. Once new sequences are identified that belong to a certain
protein family, these sequences should be incorporated into family
profile (HMM) in order to represent these new members. The new
HMM in return should be used to search the protein space again
for inclusion of potential new members not found previously or
simply rebuilding statistical data for the existing family members.
While HMMs are very powerful for the detection of protein family
members, the dynamic construction of them is computationally prohibitive.
We have explored the possibility of constraining the protein space
and therefore speeding up searches with HMMs using two methods:
1) using a regular expression (REGEX) obtained from the HMM or
2) using PSI-BLAST with a position-specific scoring matrix generated
from the HMM to select candidate sequences from the protein space
(about 3.5 million sequences). The smaller proteins sequence database
was used for the more accurate search by the HMM. We have compared
execution times and the accuracy using a direct HMM search approach
with the two-step techniques. We have determined that while the
current implementation of the REGEX-based approach was resulting
in fast execution times, its accuracy was greatly affected by the
type of HMM and was only applicable for a small subset of cases.
The second, PSI-BLAST-based approach resulted in fast execution
times and high accuracy when compared to the HMMSearch standard.
Using the combination of PSI-BLAST and HMMSearch programs (PSI-HMMER)
improved accuracy even further with small impact on execution times.
The software developed during this project (PSI-HMMER) enables
the searches of protein sequences databases about 200 times faster
than traditional tools with negligible impact on search accuracy.
This tool will be incorporated into the currently used bioinformatics
pipelines.
A Study of Ion Exchange Resins for the Complete Separation of Cobalt, Nickel,
and Copper. TRACEY WILLIS (Texas Southern
University, Houston, TX, 77459) ASHLEY GARNER (Texas Southern
University, Houston, TX, 77004)
DR. MARGARET GOLDBERG (Argonne National Laboratory, Argonne, IL, 60439)
Age-dating of
60Co contained within "dirty" bombs can provide forensic
information about the time of irradiation and possible source that
leads to the constructor of the 60Co dirty bomb. The purpose of
this project is to develop an analytical method for separation
of transition metals, more specifically cobalt, copper, and nickel,
all of which are found in the contents of these "dirty" bombs.
Initial experiments will use non-radioactive metals for optimization.
Separation will be performed using ion exchange chromatography,
with an anionic and chelating resin using varied concentrations
of acid solvents (hydrochloric and nitric). Results using the Chelex
100 resin are incomplete. Analysis was performed using high resolution
inductively coupled plasma mass spectrometry (HR-ICPMS) to determine
eluted concentrations of each of the ions.
A Twin Ionization Chamber Arrangement for the Study of 12C(a,)16O Through
the ß-Delayed a Spectrum of 16N. ALESSANDRO
LAURO (University of Chicago, Chicago, IL, 60637) ERNST REHM
(Argonne National Laboratory, Argonne, IL, 60439)
The most fundamental
reactions that describe the complex process of helium burning during
stellar evolution include the 12C(a,)16O reaction and the 3 4He 12C + reaction. While the latter has been studied quantitatively
over the last decades, the properties of the 12C(a,)16O
are surrounded by a great deal of uncertainty due to its very small
cross section of 10-41 cm2.
Despite this restriction, the 12C(a,)16O reaction can be studied indirectly by observing the ß-delayed
a spectrum of 16N. While it is energetically impossible for ground state 16O
to a decay to 12C,
it is possible to examine 16O*,
excited states of 16O, that result from the ß-decay of 16N. Even though the branching ratio of this reaction favors
decay over a decay by a factor of about 105, a precise measurement of a-particles can be carried out by
a specially designed dual twin ionization chamber located at the
Argonne Tandem Linear Accelerator System (ATLAS) at Argonne National
Laboratory. An important step in this experiment involves the calibration
of the ionization chamber using a Pu-Be neutron source in order
to test the a emission produced by the 10B(n,a)7Li
and 6Li(n,a)t
reactions. It is from this procedure that a new method of obtaining
information about the emission angle of a-particles from the source
has been found.
ADDING FORWARD AND REVERSE MODE DIFFERENTIATION TOOLS TO NEOS. RACHEL
SISTERSON (University of Illinois, Champaign-Urbana, IL, 61820) PAUL HOVLAND (Argonne National Laboratory, Argonne, IL, 60439)
NEOS (Network-Enabled
Optimization Server) has optimization solvers that provide function
and/or gradient evaluations. This is offered freely to the public
and achieved with the help of automatic differentiation (AD) tools.
ADIC (Automatic Differentiation in C) and Tapenade are two types
of AD tools. NEOS has the ability to have more solvers and AD tools
added. A NEOS solver finds an x that minimizes f(x) for a user-defined
function and the AD tool finds the derivatives of the user-defined
function that are used by the solver algorithms for optimization.
Tapenade and a newer version of ADIC were to be made available
on NEOS through the BLMVM (Bound-Constrained Minimization Limited-Memory
Variable-Metric Algorithm) solver. In order to add these AD tools,
BLMVM's drivers, Makefiles, and XML (EXtensible Markup Language)
file had to be modified. Both AD tools have to be added as an option
in the XML file and pathways to the AD tools homes, libraries,
and environmental variables needed to be defined within the drivers
and Makefile. Future steps might be to have the ADIC upgrade and
Tapenade available on solvers other than BLMVM on NEOS.
Advanced Steam Reforming Catalysts for Generating H2 from Natural Gas. GINA FAZIO (University of Illinois at Urbana Champaign, Urbana-Champaign, IL, 61801) DR. MAGALI FERRANDON (Argonne National Laboratory, Argonne, IL, 60439)
Reforming of
natural gas at the point-of-application is one option being pursued
to provide H2 for use with fuel cell systems being developed for
distributed power applications. New reforming technologies will
be required for these integrated fuel processor-fuel cell systems.
A critical component of these fuel processors is the reforming
catalyst, which promotes the conversion of the natural gas to H2.
Rhodium supported on an oxide substrate, such as alumina or ceria,
is one of the most effective catalysts for reforming natural gas.
Unfortunately, Rh is an expensive precious metal and, hence, the
cost of a Rh based catalyst is an issue. Optimizing the Rh loading
is critical to minimizing catalyst cost. The objective of this
project is to investigate the effect of Rh loading on the performance
of Rh supported on a lanthana-modified alumina for the steam reforming
of methane, the primary component of natural gas. Three different
Rh loadings were investigated: 1, 2, and 5-wt%. The catalysts were
tested in a microreactor system using either a 3:1 mixture of H2O:CH4
or a reformate containing 1% CH4 at 600-950°C and gas-hourly space
velocities (GHSV) of 20,000-70,000 h-1. At a GHSV of 20,000 h-1,
similar CH4 conversions and H2 yields were observed for all three
Rh loadings for all conditions investigated. However, at a GHSV
of 60,000 h-1, a significant drop-off in performance were observed
with the 1 and 2-wt% but not the 5-wt% Rh catalysts.
Amphibians of Wetland R at Argonne National Laboratory, Illinois: A Comparison to Other Area Wetlands. VANESSA KONIECKI (Elmhurst College, Elmhurst, IL, 60126) DR. KIRK LAGORY (Argonne National Laboratory, Argonne, IL, 60439)
Wetlands are
considered to be the most productive ecosystem. In August 1990,
construction of the Advanced Photon Source began at Argonne National
Laboratory, destroying three small wetlands and posing potential
threats to a fourth. Wetland R, with an area of 1.8 acres, was
created to replace the three small wetlands. The purpose of this
baseline study was to assess and compare the amphibian diversity
in Wetland R to two other area wetlands. Wetland 302, a natural
wetland just northwest of Wetland R, and a retention pond behind
building 900 at Argonne National Laboratory were used for comparison
to Wetland R. Dipnetting, walk arounds of the standing water, tadpole
sweeps, and anecdotal observations were made. Captured individuals
were measured, weighed, and photographed. A timed walk around the
standing water, in which the number of amphibians observed was
tallied, was used to assess population size. Tadpole sweeps and
anecdotal observations were used to assess the species present
at each study area. Measurements of water surface area were taken
weekly at Wetland R. There were a total of seven species observed.
Four, possibly five, species were found at Wetland R, while only
four species were found at the retention pond, and three species
were found at Wetland 302. While numerous frogs were captured during
anecdotal observations, frog populations declined when water levels
receded. There was a correlation between water surface area and
the number of frogs present. Furthermore, there were significantly
more amphibians observed during walk arounds at the retention pond
than there were at Wetlands R and 302. It is recommended that annual
monitoring of Wetlands R and 302 and the retention pond be continued
to assess amphibian diversity within natural and artificial area
wetlands. More efficient methods for surveying will be needed to
more accurately assess the species present.
Analysis of the properties of particles emerging from Deep Inelastic Scattering
off a range of nuclei. SERERES JOHNSTON
(Andrews University, Berrien
Springs, MI, 49103) KAWTAR HAFIDI (Argonne National Laboratory, Argonne, IL, 60439)
Hadronization,
the process by which a struck quark evolves into a hadron, is not
well understood in the nuclear medium. Experiments done with medium
energy electron beams and multiple nuclear targets can investigate
hadronization at nuclear scales. Understanding this process would
provide insight into the confinement property of the nuclear strong
force. The data collected by the E02-104 Nuclear Semi Inclusive
Deep Inelastic Scattering experiment, performed at Jefferson Laboratory
with a 5 GeV electron beam, can be used to characterize hadronization
as a function of multiple variables. E02-104 ran with several solid
targets of differing atomic radius and the data taken is sensitive
to early hadronization processes. Programs were written which compared
the hadron attenuation and transverse momentum broadening in the
three nuclear targets, carbon, iron, and lead. Greater attenuation
is observed in large nuclei. Hadron attenuation is described by
the multiplicity ratio, RhM, which is a multivariable function. The high statistics of the
E02-104 data allowed its dependence on four different variables
to be examined in detail. The quark energy loss indicated by the
transverse momentum broadening is seen to increase with the square
of the nuclear distance traveled. This agrees with QCD predictions
based on quark energy loss through gluon radiation. There is also
some evidence that the transverse momentum broadening approaches
a limit in larger nuclei. Not enough nuclear targets were examined
for this last result to be definitive.
ARBUSCULAR MYCORRHIZAE INTERACTION
WITH ROOTS OF WILD QUININE (Parthenium integrifolium), SMOOTH
BLUE ASTER (Aster laevis) AND PRAIRIE DOCK (Silphium terebenthinaceum). MARY CARRINGTON (Governors State University, University Parkway, IL, 60466)
RAYMOND MICHAEL MILLER (Argonne National Laboratory, Argonne, IL, 60439)
We initiated
a field experiment for investigation of arbuscular mycorrhizal
(AM) colonization of roots and extramatrical for prairie dock (Silphium
terebenthinaceum), wild quinine (Parthenium integrifolium) and
smooth blue aster (Aster laevis), all prairie plant species in
the family Asteraceae, but with different root architectures. Soil
samples were collected, and fungal in-growth bags were buried,
near two-year-old individuals of each species in the field. Live
roots were separated from soil, and total root length was determined
for each root sample. Root samples were then stained and mounted
on microscope slides for determination of percent root length colonized
by AM. Results are forthcoming on percent root length colonization
by AM, and biomass of extramatrical fungi per unit soil volume. Both
variables are expected to vary inversely with degree of fine root
proliferation among the three plant species. Results from this
study will be an important step toward improving results and predictability
of prairie restoration efforts.
Atomic Layer Deposition of Tin (IV) Oxide and Indium Tin Oxide Using Tetrakis(Dimethylamino)Tin
Precursor. DAVID
BAKER (University of Illinois
at Urbana Champaign, Urbana, IL, 61802) GREGORY KRUMDICK (Argonne National Laboratory, Argonne, IL, 60439)
Thin films of
tin oxide were deposited on silicon wafers (001) and glass by Atomic
Layer Deposition (ALD) using alternating pulses of Tetrakis(Dimethylamino)Tin
and an oxidizing precursor. Doping tin oxide films with various
reagents, such as indium, can create smooth, optically transparent
and conductive coatings with applications in solar cell, gas sensor,
and flat panel display technologies. Using deposition temperatures
between 100oC - 400oC, and exposure times ranging from 0.5 to 8 seconds, growth of
a film was evident on Al2O3 coated substrates. For the silicon and glass substrates, measurements
from the spectroscopic ellipsometer showed the thickness of the
film increased with temperature and increased linearly with the
number of cycles (maximum of 1.5 Å per cycle) during the ALD growth.
At lower temperatures, extending the exposure times of each precursor
demonstrated a self-limiting reaction. Growth at higher temperatures
did not demonstrate a self-limiting reaction. This precursor was
also used to create Indium Tin Oxide (ITO) films also by ALD. As
evident from 4-point probe resistivity measurements, tin oxide
and ITO films are excellent conductors with good optical transmittance.
Characterization of the films was furthered by x-ray diffraction
(XRD), x-ray photoelectron spectroscopy (XPS), x-ray florescence
(XRF), and scanning electron microscope (SEM). Tetrakis(Dimethylamino)
tin precursor demonstrated consistent ALD growth on glass and silicon
surfaces coated with Al2O3.
Benchmark Report for Homeland Security: Standards, Guidelines and Fate. MEGAN
WILLIAMS (University of New Orleans, New Orleans, LA, 70148) MARGARET
MACDONELL (Argonne National Laboratory, Argonne, IL, 60439)
Because of the
rise in terrorist attacks throughout the world, pre-emptive and
response procedures are being identified to assure the safety of
Americans. Exposure guides are being developed to support health
protection of Americans for more than 150 threat contaminants that
could be released into the drinking water and air following a terrorist
attack. The contaminants evaluated are deemed a potential health
threat by the Environmental Protection Agency- National Homeland
Security Research Center (EPA-NHSRC). They consist of toxic industrial
chemicals (TIC), chemical warfare agents (CWA), radiochemical agents
and bacterial agents. Exposure guides which we develop are risk
based concentration (RBC) reports and provisional advisory levels
(PALs) reports. The RBC report identifies pre-existing benchmarks,
occupational limits, fate, toxicity use and degradation products
for the contaminants. The RBC report focuses on benchmarks for
chronic or repeat lifetime contaminant exposure. PALs are exposure
guides that answer the questions of how, what, when, where and
how a contaminant will effect the drinking water and air.
Biomarkers and Treatment for Potential Contamination Response. DANIEL
RAHILL (University of Notre
Dame, Notre Dame, IL, 46556) DR. MARGRET MACDONELL (Argonne National Laboratory, Argonne, IL, 60439)
The creation
of Provisional Advisory Levels (PALs) for specific chemicals of
possible threat was to compile valuable information regarding potential
risk in preparation for possible contaminations, including those
induced by terrorists. As there is risk of exposure to the PAL
chemicals, indicators of exposure and treatment outlines are of
great importance. Biomarkers to quickly identify a chemical contamination
event have been developed in this ongoing study. Once identified
either to a specific chemical or a family of chemicals, treatments
are available. Both immediate treatment and more extended medical
treatments have been provided. The treatments have been categorized
by both severity and symptom. The treatments account for sensitive
populations, children in particular. The treatments are most complete
for the organophosphates, which, for example, are treated with
intermittent doses of atropine and pralidoxime. The ultimate goal
of the biomarkers and treatment is to prepare all populations for
all severity levels in the event of a potential chemical release.
Another issue of importance was the quality assurance of the PAL
reports. Particularly PAL reports for methyl paraoxon and VX contained
errors that needed to be addressed and corrected. The methyl paraoxon
PAL required several components of fate and toxicity to be developed,
oral and inhalation PALs to be updated and corrected, and dermal
PALs to be created. The VX PAL contained inhalation PAL values
that should be revised. The VX document also contains improper
citations with several other documents that need clarification.
The corrections were flagged in this ongoing study.
Building an Atomic Layer Deposition (ALD) System for the Coating of Ceramic
Rods. MATTHEW LEWIS (Iowa State University, Ames, IA, 50013)
GREGORY KRUMDICK (Argonne National Laboratory, Argonne, IL, 60439)
Many new types
of technology are being introduced in today’s world, but few of
them offer a wider variety of uses than Atomic Layer Deposition
(ALD). ALD makes it possible to deposit a layer of film as thin
as one atomic layer on a surface and allow maximum control of thickness.
With this type of layer control the technological possibilities
are virtually endless. The ALD system currently being built in
building 362 at Argonne National Laboratory needed to be designed
to coat ceramic rods so different materials could be tested on
them for strength and thermal efficiency. To accomplish this task
we used the existing ALD system as a template and scaled up the
new system. Many parts were fabricated by central shops using CAD
drawings from Microsoft Visio that were specialized to fit the
new system. The design and engineering phase of the new system
is nearly complete and the fabrication phase has already begun.
The system is scheduled to be finished in late January at which
time it will be leak checked and ready to coat materials. The system
is also being designed so that it is flexible, in that when ceramic
rod testing has been completed, the system will be able to be used
for many other types of applications.
Candidates for new transitions in 254No. DAVID
GRAYSON (University of Illinois
at Urbana Champaign, Urbana, IL, 61801) TENG LEK KHOO (Argonne National Laboratory, Argonne, IL, 60439)
Several candidates
for transitions in 254No have been observed in an experiment performed
at Argonne National Laboratory. The reaction 208Pb(48Ca,2n)254No
was used at beam energies of 219 and 223 MeV. In this report, gamma-gamma
matrices were examined to find candidates that were coincident
with previously known transitions in the ground state band of 254No.
The candidates found were only evident at 223 MeV, which suggests
that they come from parent states with high energies that are not
populated at the lower 219 MeV beam energy. The strongest candidate
was 469 keV. If this transition feeds in to the top of the previously
observed ground state band, then it breaks the pattern of transition
energies, which implies a change in structure at that energy. This
would have implications for the width of a specific neutron "magic
gap", and would help test theories of nuclear structure.
Cellulose Breakdown Using a Dry acid Catalyst. KEVIN
JACKSON (University of Illinios
at chicago, Chicago, IL, 60645) CHRISTOPHER MARSHALL (Argonne National Laboratory, Argonne, IL, 60439)
With the flux of current gas prices, energy security has become
top priority for the United States in recent months. Because
of current non-renewable fossil fuels located in unstable regions
of the world, America is now looking into renewable alternative
sources of energy to fuel our nation’s automotive fleet and provide
a means of cheap energy. A successful alternative energy source
would allow America to become independent of the unstable regions
of the world that currently produce over 80% of the worlds fossil
fuels. Ethanol and Hydrogen fuel cells are among the hopefuls
that will one day replace gasoline as the fuel that feeds our
gas tanks. Between those two, Ethanol production is disputed
to be the best option towards supplying our nation’s needs. In
Brazil, ethanol Production has already replaced 40% of their
fueling needs. However, ethanol production is much easier in
South America due to climate conditions. They use sugar cane,
which is highly made up of sugars like glucose, to produce ethanol.
To produce ethanol practically in the U.S. we will need a method
of converting the cellulose in corn into ethanol since sugar
cane can’t be grown in our climate. Methods: In
my experiments in the lab so far, I have worked with my supervisor
Chris Marshall to figure out a way to break the cellulose chain
into glucose. The current idea centers on the use of a dry-acid
Zeolite catalyst. The proposed catalyst is a three dimensional
molecule that has a monolithic structure. Inside the pores of
the zeolite is where the reaction takes place. However, the pore
size of the zeolite is too small for the large chain of cellulose
to fit through. So we have tried using partial acid hydrolysis
to break the cellulose into small enough fragments to fit inside
the zeolite. Then the reaction is observed and later analyzed
for Glucose. Results and Discussion: Trace
amounts of glucose was detected from the experiments. In each
case, the Glucose was produced at the last hour of extraction.
The Product also occurred only in runs that included dilute acid
solution as well. Whether or not the product is caused by the
catalyst itself is yet unknown. We have produced some glucose
and further refining of our methods is needed to further optimize
the conditions and possibly produce more. Conclusion: As
of yet, the dry acid catalyst has not produced any valuable amounts
of product to prove practical. Further study is needed.
CHEMICAL AND PHYSICAL RESPONSE OF NB-W-CR BASED ALLOYS TO HIGH TEMPERATURE
OXIDATION*. BRENDA MACHADO (University of Texas at El Paso, El
Paso, TX, 79968) KEN NATESAN (Argonne National Laboratory, Argonne,
IL, 60439)
Nickel-based
superalloys are the only high-temperature metallic materials known
at this time that can withstand temperatures up to 1000ºC. The
binary systems have not accomplished what is needed for the high-temperature
industry. Therefore, in order to develop an ultra-high temperature
metallic system for gas turbines, aircraft engines, and aerospace
materials, new ternary alloy systems are being explored. Using
Nb-W-Cr compositions with addition of Y, the oxidation performance
over 24 hours and the microstructural characteristics of the alloy
were evaluated. Oxidation curves have been plotted between weight
gain per unit area as a function of time for each temperature.
SEM (Scanning Electron Microscope) has been used to characterize
the surface of the alloys and EDS (Energy Dispersive Spectrometer)
to identify the elements and oxides. In the temperature range from
900 to 1300°C, Nb-W-Cr-Y shows a difference in microstructural
characteristics and oxidation resistance. The alloy turns into
complete powder at 700°C, 800°C and 1400°C, an unexpected result.
We were able to determine that the addition of Y lowered the temperature
range for formation of powder. Also it was found that Cr in the
alloy was good because it produces higher oxidation resistance
than for an alloy with a lower percentage of Cr in it. This alloy
must compete with nickel-based superalloys. The investigation performed
in this summer provides the basis for further work in the evaluation
of the oxidation resistance of the alloys from Nb-W-Cr.
Clay Synthesis and Platinum Loading for Catalytic Applications. LEAH PRANGER
(Rhodes College, Memphis, TN, 38112)
KATHLEEN CARRADO (Argonne National Laboratory, Argonne, IL, 60439)
Contributions
to the Catalyst Design Group were made concerning the development
of synthetic clays for eventual catalytic and materials applications
in three different areas. One project provides clay supports for
metal species activity in catalysis. The variety of clays prepared
includes silica-lithium-hectorite and tetraethoxysilane-hectorite
in various dilutions. In the past, the group has used such supports
in an array of projects, including loading cobalt-molybdenum-sulfide
species for hydrodesulfurization and Pt(0) metal nanoparticles
for oxidation catalysis. All of the samples prepared within this
project were determined to be suitable for further testing. Loading
of Pt(II) salts and reduction in H2/N2 atmospheres was performed.
It was found that only very slight temperatures (50oC) were needed
to effect reduction to Pt(0). Another task explored clay synthesis
under extreme dilutions in order to foster a phenomenon called “exfoliation”.
Such samples lose all their layer-to-layer registry and instead
the silicate layers are randomly distributed, similar to a “house
of cards” structure. These materials are useful for atomic layer
deposition experiments of catalytic species commonly used within
the research group. Finally, work on another layered porous material
was initiated. This involved reproduction of a literature synthesis
of a layered zeolite dubbed “ITQ-2”. Synthesis of these materials
was performed in an autoclave under controlled temperature conditions.
All materials were characterized by x-ray powder diffraction to
establish crystallinity and thermal gravimetric analysis to determine
water and organic contents. The Pt-loaded samples and dilute hectorites
were determined to be of value for future research, while the ITQ-2
project had only partial success in synthesis.
Collection and Interpretation of Teragrid Usage Statistics. JEFFREY
LEHEW (Milwaukee School
of Engineering, Milwaukee, WI, 53201) DANE SKOW (Argonne National Laboratory, Argonne, IL, 60439)
The TeraGrid
network, a multi-facility parallel computing resource allows researchers
to answer important questions that require large amounts of computing
power. The TeraGrid is relatively new, and coherent collections
of data on its usage are scarce. The goal of this project is to
create tools to view and interpret existing data sources to allow
developers to improve the TeraGrid infrastructure. To solve these
problems, two different types of receivers were setup. One receiver
was setup on a TeraGrid machine to listen for and store UDP (user
datagram protocol) packets sent at the completion of activities
using Globus software tools such as GridFTP and GRAM (Globus Resource
Allocation Manager). In addition, a second packet receiver was
started on the Juniper routers that make up the backbone of the
TeraGrid network. These receivers sampled the data flow through
the network, and once recorded, the data was sorted and output
using the Flow-Tools toolkit. The data from these receivers was
presented in a graphical format using Gnuplot, a graphing application.
The uniqueness of this project is in combining these various tools
to create an easily understandable metric of TeraGrid usage from
a large set of unorganized data. This study is part of a larger
project, and the tools developed at this stage will be integrated
into a long-term study of TeraGrid usage. Future work will involve
completing testing of these receivers, making some changes in the
way graphical data is presented, and presenting this information
in the form of a webpage.
Composition of Stainless Steel Slurries for Enhanced Structural Support of
the TuffCell. LAURA JANE ELGASS (College of DuPage, Glen Ellyn,
IL, 60517) J. DAVID CARTER (Argonne National Laboratory, Argonne,
IL, 60439)
The "TuffCell" is
a bipolar plate-supported solid oxide fuel cell that produces electrical
power by the galvanic combination of oxygen with hydrogen or other
fuel. The SOFC anode support must be both conducting and porous.
Porosity is required to ensure that hydrogen gas can flow through
the anode support. SOFC anode supports have traditionally been
composed of nickel, but the use of stainless steel as a support
while also using a thinner anode will provide increased structural
integrity. The process for building the support layer starts with
making a stainless steel slurry. The slurry composition includes
stainless steel powder, binder, plasticizer, solvent, and in some
cases pore former. The slurry is allowed to mix thoroughly and
is then made into a tape cast using a doctor blade. The tape cast
is dried and then placed into the dilatometer for twenty hours
where it is exposed to air, nitrogen, and hydrogen to sinter. The
weight percent of each slurry component must be such that the slurry
meets certain criteria when cast and sintered. In casting, these
criteria include an even cast (i.e. the stainless steel cannot
separate from the other components during the cast), a strong and
flexible dried cast, and a slightly grainy texture. In sintering,
the stainless steel layer must not shrink more than the other layers
of the cell and must also be porous, with pores approximately 20
microns in diameter. An even cast is the result of optimal slurry
viscosity for the given components. Modification of flexibility
and strength is accomplished by varying the binder to plasticizer
ratio. Porosity can be achieved with a large stainless steel powder
particle size and no pore former, or with smaller particles plus
pore former (this method warrants varying the volume ratios of
stainless steel and pore former to find the optimal porosity).
In addition to finding the optimal weight percents of each of the
slurry components, it is necessary to determine which plasticizer/binder/solvent
trio best casts, sinters, and interacts with the other components
of the cell. When xylene/butanol is used for a solvent, compositions
with a combination of large stainless steel mesh size and smaller
stainless steel mesh size in conjunction with 12% solvent and a
plasticizer to binder ratio of 1:5 or 1:7 have proved most successful.
Creation of Exposure Advisory Levels via Standards and Guidelines, Toxicity,
and Fate Data. KATHLEEN METTEL (University
of Illinois at Urbana Champaign, Urbana, IL, 61801) MARGARET MACDONELL (Argonne National Laboratory, Argonne, IL, 60439)
The purpose of
this ongoing research project is to set provisional advisory levels
(PALs) for priority contaminants from a set of over 200 threat
contaminants that a terrorist could use to contaminate an air or
water supply. Responders to such an attack will be able to act
appropriately using the PAL levels set. PALs are set for various
time durations (<1 day, 1 day-30 days, 30 days-2 years) and
health threats (little/no effects, reversible effects, harmful/lethal
effects). Draft PAL documents for the initial priority set of four
contaminants with fate products were finalized for submission in
late June and work has begun on a new set of priority contaminants.
A major aspect of this project is to locate and assess the current
available standards and guidelines for each contaminant developed
for other programs. Various tables and figures were created to
describe each standard and guideline and also to compare each contaminant’s
newly set PAL values to the other available standards and guidelines.
Cumulative Risk Assessment: Environmental Fate, Physical-Chemical Properties,
and Contaminant Toxicity. JESSICA
ENGLEHART (University of Maine, Orono, ME, 4469) MARGARET MACDONELL (Argonne National Laboratory, Argonne, IL, 60439)
In the event
of a terrorist attack that utilizes chemical or biological weapons,
the emergency response team needs a way to find information about
the immediate risks and dangers present. In a scenario such as
this, Provisional Advisory Levels (PALs) currently undergoing preparation
by Argonne National Laboratory would be of great help. These PALs
are specifically designed to provide exposure guidelines for chemicals
that have been deemed potential homeland security threats. If one
of these chemicals were to be released to the water or air, a PAL
would help first responders (e.g. individuals without an extensive
scientific background) make a health-based decision about the level
of danger that is present. Each PAL report is chemical specific,
and multiple routes of exposure are analyzed in every document.
The values for each PAL are determined by using studies from medical
and scientific journals, government research, and other research
publications. When as much information as possible has been compiled
about each chemical, the most applicable material is used to develop
the calculated PAL values that regulate the exposure guidelines.
Although the derived PAL values are the designated purpose of the
PAL report, other important components of the document include
the chemical identification, physical-chemical properties, environmental
fate, and toxicology data. The environmental fate is especially
important to the report because many of the contaminants can rapidly
break down into other components and chemicals. The resulting byproducts
may be inert or even more toxic than the parent chemical. Specifically,
the environmental fate of the nematicide fenamiphos is undergoing
analysis. While examining the fate of a chemical, it is understood
that multiple chemicals may be present at any given time after
a contamination occurs. This topic leads into the study of cumulative
risk, which is an issue currently under national perusal. PALs
are an invaluable resource in a time when chemical and biological
warfare are legitimate fears; however, there is no guarantee that
only one chemical will be present during a contamination or release.
This is why it is vital to further investigate cumulate risk and
how exposure to multiple contaminants should be handled in a time
of crisis.
Data Analysis for Key Route Extrapolation
of Organophosphate Toxicity. SARAH
HODGINS (University of Maine, Orono, ME, 4469) MARGARET MACDONELL (Argonne National Laboratory, Argonne, IL, 60439)
With the threat
of chemical and biological warfare on the rise, the United States
government needs a way to inform citizens of any contaminants and
their potential health effects if released into the environment.
Exposure guidelines for these contaminants should be established
for the safety of all those who could be exposed and the possibility
of evacuating, cleaning-up, and/or reentering an area. Provisional
Advisory Levels, or PALs, are health-based exposure guides that
represent levels that humans can be exposed to on the basis of
the contaminant concentration, if introduced into the air or water,
and the length of exposure. PALs are derived from toxicity studies
of animals or humans that have been exposed to the contaminant
at different dosages and different lengths of time. In addition
to PALs importance to national security, they are also valuable
for natural disasters, such as Hurricane Katrina, where large areas
and water sources are contaminated with a multitude of substances
for long periods of time. Unfortunately, there are some possible
contaminants that do not have sufficient data for oral, inhalation,
and dermal exposure. The data gaps leave a lot of questions regarding
the ranges of exposure people can have to the contaminants. Organophosphates
are a group of contaminants that have this problem. This project
focuses on comparing each organophosphate with limited data to
help fill the gaps.
Design and Construction of an RF Plasma Source. JOHN CARR
(University of Illinois
at Chicago, Chicago, IL, 60601) RICHARD VONDRASEK (Argonne National Laboratory, Argonne, IL, 60439)
An RF plasma
source is being developed to provide a 1+ ion beam for the Californium Rare Ion Breeder Upgrade. The 1+ beam
will be injected into the Electron Cyclotron Resonance ion source,
at the Argonne Tandem Linear Accelerator System, and charge bred
to n+. An existing plasma source, no longer being used, was redesigned
and modified to conform to new specifications. The RF plasma source
consists of a 29 ml high-temperature quartz ion bottle. Gas is
admitted to the plasma chamber through the ion bottle using an
insulated tip and sealed with an o-ring. The bottle is mounted
to a 5 inch round base, also sealed with an o-ring. Beam extraction
is provided by a 30 kV puller mounted to the base opposite of the
ion bottle. The source is designed to use up to a 500 MHz RF signal
to ignite the plasma and create the ion beam. Redesigning and retrofitting
a currently available unit was a time and cost effective way to
construct a suitable plasma source.
Design Study of Temperature Stabilization of the Analyzer Array of the High
Energy Resolution Inelastic X-Ray Spectrometer of the Advanced
Photon Source. JUSTIN BUELL (Montgomery College, Rockville, MD, 20850) BRANISLAV BRAJUSKOVIC (Argonne National Laboratory, Argonne, IL, 60439)
Through the use
of the high energy resolution inelastic x-ray (HERIX) spectrometer
at the Advanced Photon Source (APS), vibrations in the lattice
structure of various materials can be studied. The instrument consists
of nine detector-analyzer pairs, a vacuum chamber, and a support
structure for the entire instrument. X-rays from the APS beamline,
scattered by a specimen through the vacuum chamber, are reflected
and focused by the analyzers through a collimator and into a series
of corresponding detectors which measure the properties of the
photons. Due to the high cost of vacuum compatible components,
it is more economical to place the analyzers outside of the chamber
than inside it. Because thermal expansion due to temperature fluctuations
in the hatch in which the spectrometer is located will compromise
the geometric alignment between the optical components of the spectrometer,
it is necessary to stabilize the temperature of the analyzers before
the instrument can be calibrated. Using SolidWorks, a model of
an enclosure and cooling channels for the analyzer array was developed.
Expanded Polystyrene, a type of Styrofoam, was the selected material
for the enclosure because of its optimal thermal properties. The
enclosure was designed to eliminate heat transfer by free convection
and minimize conduction to the analyzers. The cooling channels
will consist of a copper tube through which water at a controlled
temperature will flow and a series of copper pads, onto which the
tube will be brazed, that will be mounted onto the support plate
of the analyzers to improve thermal conduction between the analyzers
and the cooling water. Finite element analysis of transient heat
transfer was performed on the model assuming the hatch temperature
to be a sinusoidal function of time based on measurements from
a similar hatch. The results of the analysis indicated that the
enclosure alone would not sufficiently stabilize the temperature
of the analyzers, but that the enclosure and cooling infrastructure
would maintain an acceptable degree of stability in the temperature.
Designing a Mobile Application for Purification Database
Systems. PAMILA
NELSON (Governor State University, University Park, IL, 60466)
SOON-OK PARK (Governors State University, University Parkway, IL, 60466)
RAKEYA SMITH (Governors State University, University Park, IL, 60466)
DR.ANDRZEJ JOACHIMIAK (Argonne National Laboratory, Argonne, IL, 60439)
The Midwest Center
for Structural Genomics at Argonne National Laboratory develops
and optimizes integrated methods for determination of protein structures
through x-ray crystallography. Scientists at the center traditionally
have written down their experimental results on paper, later returning
to their desktop computer to enter the data on a Web page. The
objective of this project was to design and develop a personal
digital assistant (PDA) exhibiting the same functionality as the
Web page but providing much greater convenience and accuracy. The
PDA application was developed by using Microsoft .NET technology.
Specifically, user interfaces were developed with Mobile ASP.NET
forms, HTML, and JavaScript. The scientific logics were implemented
with C# programming language. Like the Web page, the PDA application
uses Oracle 9i database for data storage. With the PDA, however,
scientists can scan bar-coded purification instruments and enter
the experimental values directly, updating the database in real
time and comparing values with prerecorded information about volume,
temperature, and concentration ranges for proteins. The PDA thus
increases the efficiency of data collection and analysis and minimizes
the errors inherent in transposing data from paper to computer.
In order to assist the scientists, an online user manual was also
developed as part of this project. The PDA application is now available
for use at Argonne. This application enables scientists to access
and modify the data, in the lab or almost anywhere, while preserving
the sophistication of the Web application. Moreover, the PDA provides
an important step toward automation of biochemical laboratory and
integration with databases.
Determination of Forcefield Parameters
to Evaluate the Binding of Porphyrin Structures to c-type Cytochrome
Architectures. ADRIENNE EASTLAND (Chicago State University, Chicago, IL, 60628)
DR. DAVID TIEDE (Argonne National Laboratory, Argonne, IL, 60439)
The binding of
porphyrin-like molecules to the surface of c-type cytochrome proteins
allows the initiation of electron transport. In order to develop
biomimetic photosynthetic devices, the initiation step must be
tuned by the choice of substituents on the porphyrin molecules.
Computational docking studies combined with experimental fluorescence
studies allow the evaluation of the effects of substituent changes
on electron transport rates. The aim of this work is to develop
a scoring function that is fast enough to be successfully applied
to the prediction of the binding energy of a c-type cytochrome
to a porphyrin-like ligand. Docking studies depend heavily on the
scoring function employed. By using ab initio calculations at the
Hartree Fock//6-31G* level, bond, angle, and dihedral parameters
for the CHARMM scoring function were developed for a series of
small molecules, representative of functional groups found in organic
and biochemical systems. Upon parameterization, the dihedral force
constant, k, for the CA-CC-OC-OC dihedral in carboxybenzene was
determined to be 3.66 kcal/mol/degree with n = 2 (n is the multiplicity
of the function). For naphthalene dicarboxylate k = 1.16 kcal/mol/degree
with n = 4. The magnitudes of the k values are in good agreement
with existing CHARMM forcefield parameters. Furthermore, these
values reproduce the quantum mechanical energy profiles as a function
of angle with R2 values of 0.97 and 0.94 for the carboxybenzene
and naphthalene dicarboxylate molecules, respectively. A successful
method will bridge the gap between expensive free-energy simulations
and empirical scoring functions that are currently used to predict
binding energy.
Determination of the Effect of Interlayer Porosity on the Performance of Oxygen
Electrodes for Solid Oxide Electrolysis Cells. PATRICK
DRIEMEYER (University of Missouri
- Rolla, Rolla, MO, 65401) JENNIFER MAWDSLEY (Argonne National Laboratory, Argonne, IL, 60439)
Currently work
is being done on the thermochemical cycle known as the "Westinghouse
Process" in which hydrogen is produced. The step of interest
in the Westinghouse Process is the decomposition of SO3 to SO2
using electrolysis to lower the temperature at which this reaction
occurs. This step is considered a hybrid of thermochemical and
electrochemcical processes and reduces the highest temperature
of any step to 500-600°C from 850°C. The lower temperature range
opens the door for a wider array of materials to be used in construction
of a hydrogen production plant. The development of an oxygen ion
conducting cathode for the electrolyzer cell which exhibits low
resistance is desired since it would allow free exchange of oxygen
and electrons, thereby improving the performance and output of
the electrolyzer cell. The production and testing of various cathode
compositions along with an examination into the effect of porosity
in the doped-ceria interlayer will be examined and reported on.
The compositions that will be tested include La0.5Sr0.5CoO3-d;
Nd0.5Sr0.5CoO3-d; Ba0.5Sr0.5CoO3-d. These compositions will be
produced on site and tested in air within the temperature range
of 900°C to 500°C. Their performance will be measured using electrochemical
impedance spectroscopy (EIS) in which the area specific resistance
(ASR) will be calculated and compared to determine the most appropriate
design path. We have found that the incorporation of porosity in
the doped-ceria interlayer between the oxygen electrode and the
stabilized-zirconia electrolyte improves performance.
Determination of the Electrostatic Potential of Cytochrome c7. BRIAN
WRIGHT (Chicago State University, Chicago, IL, 60426) DAVID TIEDE (Argonne National Laboratory, Argonne, IL, 60439)
Assemblies of
c-type cytochromes may be capable of long-range electron transport
and thus are being considered as components of electron transfer/energy
storage devices. The electron transport mechanism requires the
binding of a small porphyrin-like molecule to initiate the electron
transfer. In order to determine the likely binding sites on the
surface of c-type cytochromes, the electrostatic potential of cytochrome
c7 taken from Geobacter sulfurreducens (Protein Data Bank entry
1OS6) and horse heart cytochrome c7 (Protein Data Bank entry 1HRC)
were calculated by solving the Poisson-Boltzmann equation using
Delphi, a program that is integrated into the Chimera molecular
modeling program. These calculations allow the identification of
electron-rich or electron-poor sites that should contribute to
binding. Results with model 1HRC showed good agreement with literature
values, validating the charge and radii parameters chosen for the
calculation. The overall surface of cytochrome c7 in model 1OS6
is positively charged by the amino acid lysine (Lys) (electron
poor). The amino acids aspartic acid and glutamic acid contribute
to the negative charge (electron rich) of the 1OS6 model. One possible
binding site is located near Lys-64, Lys-52, and Lys-9. Another
possible binding site is near Lys-37, Lys-33, and Lys-29. These
areas are been considered as binding sites because the surface
may provide prophyrin-like molecules large enough areas to bind.
The ability to determine which parts of the c-type cytochrome are
involved in the binding will lead to an improved understanding
and control of the electron transfer process.
Development of a Web-Based Report Tool for User Queries Made of the Integrated
Relational Model of Installed Systems (IRMIS) Control System
Database at the Advanced Photon Source Accelerator. DAWN CLEMONS
(Purdue University
Calumet, Hammons, IN, 46321) DEBBY QUOCK (Argonne National Laboratory, Argonne, IL, 60439)
The Advanced
Photon Source (APS) accelerator is run by a complex and specialized
control system. IRMIS, a descriptive control system relational
database application, allows accelerator operations to be more
easily monitored and maintained. Several IRMIS viewers (user interfaces
for querying the database) present information in ways that are
comprehensible and useful to those who support the accelerator.
However, lacking in the viewers was the mobility of their results
separate from the web interface; thus, a reporting tool was necessitated.
The main achievement of this project is to provide a means for
easily saving queried results. Results can be saved as text files,
comma-separated (CSV) files, or viewed as printer-friendly HTML
pages. Methods of software architecture were employed, as well
as code qualities useful to it, such as adaptability, readability,
and appropriate documentation. Because the report tool was to be
adapted to an established database project, the tool required an
interface design that merged with one already existing, and the
code needed to be integrated into hierarchically structured viewer
source code. Resources included the languages PHP 4, HTML, and
JavaScript; the Zend scripting engine; and the Apache web server.
The IRMIS report tool aids with APS control system troubleshooting
and diagnostics. It also is a step towards providing a unified
PHP viewer framework. Because the tool adds to the descriptiveness
of IRMIS, it also lends itself to a desired future prescriptiveness
of the database.
DEVELOPMENT OF PRELIMINARY ACUTE ORAL PROVISIONAL ADVISORY LEVELS (PALs) FOR
PHORATE. JENNIFER MATTLER (University
of Florida, Gainesville, FL, 32611) MARGARET MACDONELL (Argonne National Laboratory, Argonne, IL, 60439)
Phorate is a
highly toxic organophosphorus pesticide that inhibits acetylcholinesterase,
an enzyme that degrades neurotransmitters that stimulate depolarization
of nerves and muscles. Because it has been identified as a possible
threat agent, concentration-based guidelines called Provisional
Advisory Levels (PALs) have been developed for phorate. Draft PALs
were developed using data such as the environmental fate, toxicokinetics,
toxicodynamics, and symptoms of exposure in humans and animals.
The preliminary PALs discussed were developed for oral exposure
at three effect levels (no effect, moderate reversible effects,
and lethality) for the acute (<24 hours) duration. Once a specific
study dose was selected as the basis for the PAL, based on appropriateness
for the given effect level it was scaled for a 70 kg adult who
drinks 2 L of water per day and uncertainty factors (UFs) were
applied to account for interspecies and human variation, database
adequacy, exposure duration, and effect severity. The preliminary
acute oral PALs 1, 2, and 3 for phorate were determined to be 0.3,
0.5, and 1.0 mg/L, respectively. These preliminary PALs are somewhat
lower than the PALs for other organophosphorus (OP) compounds,
which share a mechanism and general level of toxicity with phorate,
indicating either possible over-conservatism in the preliminary
PALs or greater toxicity for phorate compared to other OPs. With
further study, the internal draft phorate PALs can be refined and
also used to support extrapolations to determine PALs for other
organophosphorus compounds that lack the necessary toxicological
data.
Development of Thin Film Diamond Coatings for Mechanical Rotary Pump Shaft
Seals. ELIZABETH ROLLINGS (University of California, Berkeley,
Berkeley, CA, 94720) GREG KRUMDICK (Argonne National Laboratory,
Argonne, IL, 60439)
The key materials
properties necessary for long-term, reliable operation of rotary
pump shaft seals include high hardness, high thermal conductivity,
low coefficient of friction, and high resistance to corrosion.
Given this list of properties, it is clear that diamond is an ideal
candidate material for pump seal surfaces. In this work, three
varieties of diamond thin films grown by hot-filament chemical
vapor deposition are investigated for their viability as smooth,
wear resistant coatings for silicon carbide pump seal surfaces.
Scanning electron microscopy is employed to characterize film surface
morphology, and Raman spectroscopy is developed as a tool to monitor
film composition. Signature Raman spectra are associated with diamond
grain size via the relative intensity of spectral features associated
with sp2-bonded carbon versus sp3-bonded carbon in the polycrystalline films. Finally, surface
profilometry measurements are used to quantify the average surface
roughness of the coated seals. It is found that nanoscale grain
size is an essential feature of high-performance diamond pump seal
coatings.
Dialysis or Column Exchange: Developing an Efficient and Quantifiable Protocol
for Detergent Exchange Prior to Crystallization of Membrane Proteins. NICK IMPELLITTERI (UW Stevens
Point, Stevens Point, WI, 54481) PILIP D. LAIBLE (Argonne National Laboratory, Argonne, IL, 60439)
The goal of this
study was to develop quantitative methods to replace detergents
used for the solublization and purification of a membrane protein
with a diverse range of detergents that could potentially increase
the success rate of the proteins characterization and crystallization.
Previously it has been anecdotally perceived that detergent exchange
could be accomplished either by dialysis or by extensively washing
and eluting column bound membrane protein with an alternate buffer
containing a different, yet desired, detergent. Rhodobacter sphaeroides
reaction centers (RCs), as well as foreign affinity-tagged Escherichia
coli membrane protein APC00809 (809) were solublized, concentrated,
and purified using the detergents N,N-Dimethyldodecylamine-N-Oxide
(LDAO) and deriphat-160, respectively. These two membrane protein’s
detergents were exchange into the following detergents using both
on column exchange and dialysis: LDAO, Triton X-100, n-Octyl-B-D-Glucopyranoside
(OG), Tetraethylene Monooctyl Ether (C8E4), Deriphat-160, and CHAPS.
Column-bound membrane proteins were eluted and analyzed after being
washed with 1, 5, 10, and 20 column volumes of buffer containing
the desired detergent, while membrane proteins were left in dialysis
tubing with large reservoirs for 1,2,5, or 7 days. After concentrating
all samples to ~10 mg\mL and analyzing them using thin layer chromatography
(TLC), iodine staining and Image J software, the results of this
experiment explicitly show the superiority of column exchange over
dialysis in terms of accomplishing complete exchange of detergents
with every combination attempted. For every trial, detergent exchange
for RCs is more complete after 20 column volumes of detergent buffer
than after 7 days of dialysis. Column exchange yielded a complete
detergent exchange for all detergents except deriphat, which did
not exchange well with LDAO in RCs in either column exchange or
dialysis. Though all dialysis and most column exchange samples
for 809 were lost in concentration, the column exchange samples
that were concentrated and analyzed clearly showed that column
exchange was fast and effective. In this experiment it clearly
shows that column exchange is the most suitable means by which
to exchange one detergent with many others of varying CMC. Dialysis,
as this experiment shows, can only yield up to a 90% exchange after
7 days when exchanging with detergents of extremely low CMC. These
results or this experiment will lead to more defined and reproducible
protein-detergent complexes for input into structural and functional
studies.
Diffusion-controlled Apparatus' for Microgravity. PRADEEP
RAJENDRAN (Stanford University, Stanford, CA, 94305) DR. P. THIYAGARAJAN (Argonne National Laboratory, Argonne, IL, 60439)
Large photoactive
yellow protein (PYP) crystals are being grown using diffusion-controlled
apparatus’ for microgravity (DCAMs) for proposed neutron crystallography
experiments. The basis for this experiment is that a short strong
hydrogen bond (SSHB) appears to play an important role in the function
of PYP in the photocycle. In order to fully understand the structure
and dynamics of the SSHB, it is necessary to accurately locate
the nuclear position of the proton (or deuteron) with respect to
the heavy atoms involved in the hydrogen bond. Pervious attempts
to grow PYP crystals using the batch and hanging drop method have
had limited success. The resolution of diffraction data collected
from PYP crystals grown using these methods was determined to be
between 0.95 to 1.40 . PYP crystallizes best between a concentration
range of 2.3 M to 2.5 M. Two DCAM units have been set up. The units
have a concentration of 1.6 M and 2.0 M (ND4)2SO4 in
the small chamber, respectively, and a concentration of 3.0 M (ND4)2SO4 in the large chambers. As the higher concentration solution
in the large chamber equilibrates with the lower concentration
solution in the small chamber through the diffusion control plug,
the concentration increases within the "button" containing
the PYP sample, causing crystallization to begin. Large PYP crystals
have been grown following these procedures using DCAMs.
DIRECTED LONG RANGE
THERMAL NEUTRON DETECTION SYSTEM. JEFFREY MAGEDANZ (Oregon State University, Corvallis, OR, 97333)
DR. RAYMOND KLANN (Argonne National Laboratory, Argonne, IL, 60439)
A long range
thermal neutron detection system could be useful for determining
whether a suspected location contains a neutron source. At long
ranges, the flux of neutrons from the source becomes small compared
to the flux of background neutrons. A bundle of collimator tubes
made of a neutron absorbing material could be used to minimize
the effect of background neutrons by only allowing neutrons coming
from the direction of the source to reach the detector. Monte Carlo
N-Particle transport code (MCNP) version 4c was used to simulate
a detector with such a collimator bundle in order to study its
potential and optimize the design. The simulations determined the
response to a moderated californium-252 source at several distances
as well as the response to background neutrons. It was determined
that cadmium was not an adequate shielding material while materials
containing boron, particularly enriched boron, performed well.
A 100 cm2 detector with a collimator was found to be reasonably
certain to detect a source producing 105 neutrons per second at
30 meters in less than a half hour. However, for greater distances,
the time required for detection becomes large. Further research
will compare the simulation results to experimental results.
Distribution coefficients of several ion-exchange resins for the separation
of cobalt, nickel, and copper. JILLIAN
SMITH (East Stroudsburg University, East Stroudsburg, PA, 18301)
MARGARET GOLDBERG (Argonne National Laboratory, Argonne, IL, 60439)
A method for
the separation and accurate quantification of cobalt, nickel and
copper is needed for the age dating of certain irradiated substances.
The separation will be completed by using ion-exchange chromatography.
The objective of this project was to measure the distribution coefficients
for cobalt, nickel, and copper as a function of acid concentration
and resin (Chelex 100, AG 1-X8, AG MP-1 and AG 50W-X8) using batch
ion-exchange. The equilibrium of the metal ions between the aqueous
phase and the ion-exchange resin is represented by the distribution
coefficient (KD). Initial and final concentrations of the cations
were measured by using high resolution inductively coupled plasma-mass
spectrometry. The project, however, was halted when the results
showed an apparent contamination of the analyzed final concentrations.
With only one quarter of the samples run, further research is necessary
to correct the calibration curve and to account for the interferences
of the matrix before any more quantification is performed.
Effects of Low-Level Cadmium on Cyr61 Expression in pre-Osteoclastic Cells. KATHRYN TORMOS (Benedictine University, Lisle, IL, 60532) MARYKA H. BHATTACHARYYA (Argonne National Laboratory, Argonne, IL, 60439)
Cadmium is a
heavy-metal element that is a major component of orange or red
pigments and is naturally occurring in trace amounts in air, water,
and soil. It is well known that high, unnatural exposures to cadmium
can result in toxic effects in human beings, in particular in the
kidneys, liver, and lungs. However, the discovery that cadmium
is linked to the severe bone-breaking Itai-Itai disease has shed
light on the potential impact of cadmium on bone systems as well.
Previous microarray experimentation of cadmium’s effects on genes
expressed in bone cells in vivo in mice has shown the most up regulated
gene early after cadmium treatment to be cyr61. The Cyr61 protein
has been linked to such molecular processes as angiogenesis, ossification,
embryogenesis, and cell migration. Preliminary immunohistochemistry
staining and RNA isolation in bone cell cultures have shown potential
Cyr61 protein expression in osteoclasts (bone resorbing cells);
this expression appeared to be greater than in cultured osteoblasts
(bone matrix excreting cells). This summer, we continue to test
the hypothesis that cadmium triggers osteoclastic precursors cells
to secrete Cyr61, increasing their migration, aggregation, and
fusion into mature osteoclasts. Using the pre-osteoclastic RAW264.7
cell line, Cyr61 protein expression is being analyzed using Western
blotting and immunoprecipitation, and cyr61 gene expression is
being analyzed using RT-PCR technology. We aim to conclusively
demonstrate whether the Cyr61 protein is significantly up regulated
in cadmium’s presence in RAW 264.7 cells. Showing Cyr61’s role
in osteoclastic precursors in the presence of cadmium will pinpoint
a new, previously unresearched, role for the protein, and will
also help our laboratory continue to construct a hypothetical pathway
proving cadmium’s central role in bone resorption.
Electrochemical Characteristics of Composites Containing (x)LiNi0.5Mn0.5O2 • (1
- x)LiNi0.5Mn1.5O4 as the Active Material in the Cathode. JONATHAN
BREITZER (Fayetteville State University, Fayetteville, NC, 20835)
CHRISTOPHER JOHNSON (Argonne National Laboratory, Argonne, IL, 60439)
Our FaST team
from Fayetteville State University, a constituent institution of
the University of North Carolina, synthesized and evaluated cathode
materials for use in high-energy lithium-ion batteries. These cathode
materials were composites of lithium nickel manganese oxides in
different stoichiometric ratios that adopt either a spinel or an
ordered rocksalt structure. Working in conjunction with CMT scientist
Dr. Christopher Johnson, this team functioned well in generating
useful data, dividing the labor by mutual agreement. Over the course
of this research, the team was introduced to a wide variety of
other summer researchers and regular employees of Argonne National
Laboratory, and was educated in many ways about the safety culture
of the Laboratory. The results of our research were useful in guiding
the direction of further inquiry, and the experience we gained
from the FaST program has led us to desire further collaboration.
This will advance research in a critical field, promote our University
through grant-writing activities, and provide a valuable opportunity
to more undergraduate students.
Electrochemical Characteristics of Secondary Lithium Metal Batteries Containing
(x)LiNi0.5Mn0.5O2•(1-x)LiNi0.5Mn1.5O4 as the Active Material
in the Cathode. JACOB HENDRICKS-HOLTZ (Fayetteville State University,
Fayetteville, NC, 28301) CHRISTOPHER JOHNSON (Argonne National
Laboratory, Argonne, IL, 60439)
As technology
progresses, a search for improved batteries that have higher energy
content is needed to implement Li-ion chemistry in hybrid electric
vehicles. The (x)LiNi0.5Mn0.5O2 (layered)•(1-x)LiNi0.5Mn1.5O4(spinel)
(0 <= x <= 1) composite-structure materials were synthesized
and evaluated as cathodes in lithium metal secondary cells. Various
lithium metal oxides were synthesized and optimized for phase purity
and structure. Electrochemical characteristics are being studied
such as current rate, cycle life, stability, capacity, and safety
in "coin cells". The synthesis method used was precipitation
of the metal hydroxide salts in basic solution, followed by heating
the solid with Li2CO3 to 900°C in air. For the battery testing
the anode was lithium metal, and the electrolyte was a 1.2M of
LiPF6 in ethylene carbonate (EC) and ethyl methyl carbonate (EMC)
in a ratio of 3:7 respectively as the solvent. Ten charge/discharge
cycles were used, with a fully-charged voltage of 4.8V and a fully
discharged voltage of 2.8V. The current drawn was 0.16mA with and
has a current density of 0.10 mA/cm2. We used X-Ray Diffraction
(XRD) of each metal oxide, (x) LiNi0.5Mn0.5O2 (layered) • (1-x)
LiNi0.5Mn1.5O4 (spinel) (0 <= x <= 1), indicated that composites
were formed. The composites have broad peaks showing crystal strain
in their structure.
Energizing a Superconducting Solenoid for Applications in Precise Mass Measurements. DAVID DANAHER (Monmouth College, Monmouth, IL, 61462)
GUY SAVARD (Argonne National Laboratory, Argonne, IL, 60439)
The precise mass
measurement of ions is the main objective of the Canadian Penning
Trap (CPT) collaboration at Argonne National Laboratory. The mass
measurements require a beam from the Argonne Tandem Linear Accelerator
System (ATLAS) to fuse with a target to create the desired reaction
products. A new beamline has nearly been completed in Area II of
ATLAS for the purpose of taking mass measurements of ions with
greater divergence angles that were previously hard or nearly impossible
to measure, which diverge due to alpha decay and are refocused
for later measurement. A solenoid can be used to refocus the ions
before they can be sent through the rest of the system and, consequently,
measured. This component of the new beamline in Area II is a superconducting
solenoid with a 68 centimeter inner bore and a central field of
1.5 Tesla, weighing over 10 tons with all of the necessary shielding
and support in place. For the solenoid to produce a magnetic field,
it must be energized and continually carry a current of about 200
Amps within its coils. The process of energizing such a device
is a subtle exercise and requires creating a vacuum within the
solenoid, pre-cooling of the cryostat with liquid Nitrogen, filling
the cryostat with liquid Helium, running a cryo-compressor to limit
Helium boil-off, and well-regulated power sources to bring the
solenoid to maximum field. Once carefully assembled, however, the
components of the energization process may be used to safely energize
and de-energize the system time and time again. My project was
to help locate all the components of the energization process,
facilitate the interconnections between components, and, finally,
to aide with the powering of the magnet.
Engineering Development of the Solid Oxide Electrolysis Cell by Computational
Fluid Dynamics: Restricted Flow. JEFFREY
SMITH (Kansas State University, Manhattan, KS, 66502) DAVID POINTER, BILGE YILDIZ (Argonne National Laboratory, Argonne, IL, 60439)
With the continuing
demand for energy supply and current desire to critical production
of green house gases, there is a call for alternative fuel development.
There is now considerable interest in research on producing alternative
fuels such as bio-fuels, wind power and H2 production. Some 50
million metric tons of H2 with an estimated worth of about $140
B was produced last year, and is expected to increase in years
to come. Several ways of H2 production are used or under conclusion
today such as thermo-chemical processing of hydrocarbons and electrolysis.
With an increased emphasis on nuclear power based technologies
and via the Global Nuclear Energy Partnership, we are considering
advanced nuclear system design that produce high enough temperatures,
to facilitate for example electrolysis to produce hydrogen. Steam
electrolysis to yield H2 and O2 is (electro-chemically) kinetically
and thermodynamically favorable at high temperatures (e.g. 800?C).
The analysis of a steam electrolysis device is the focus of this
work. Engineering analysis of a high temperature steam electrolytic
(HTE) cell is needed to better understand the factors that influence
cell design. The solid oxide fuel cell (SOEC) used to host the
electrolytic process must withstand high temperatures while equally
being reliable, economical and with a practical life cycle. The
DOE’s current goals are to realize a cell lasting a minimum of
5 years of operation with little degradation of the structural
integrity and efficiency of the cell. Via use of computational
fluid dynamic (CFD) software (STAR-CD) and ANL’s electrochemical
model for SOECs that runs coupled with STAR-CD, and experimental
data, determination of the cell’s desirable performance characteristics
were undertaken. In collaboration with Idaho National Labs (INL),
experimental data were obtained to facilitate refinement of the
CFD model of the SOEC. By using this data, ANL’s electrochemical
model of the SOEC was tailored such that further analysis on the
SOEC characteristics, such as material engineering consideration,
geometry and flow configuration (parallel versus cross), beyond
the experimental parameter range could be assessed. A model of
the SOEC was created to simulate restricted flow conditions of
the steam to model the bipolar supported TuffCell design of Argonne
National Laboratory. The TuffCell design has the advantage of overcoming
the sealing issues of SOECs, while imposing restricted flow path
on the steam/hydrogen side of the SOEC. Our analysis found that
the flow restrictions of the TuffCell design created large temperature
and current density gradients that can lead to the structural and
electrochemical degradation of the cell. In prior analysis of ANL,
it was found that the thermodynamic efficiencies of the cell do
vary slightly with parallel or cross flow, while the temperature
profile and gradients are more uniform, symmetric and smaller in
magnitude (gradients) for parallel flow. Our current analysis shows
that, in spite of the mechanical advantages of the TuffCell geometry,
the large thermal and electrical gradients it leads to at the SOEC
is not favorable. In the further design engineering of the SOEC,
we must minimize the possibility of restricted flow or reduced
flow across the cell, and the mechanical sealing advantages of
the TuffCell should be evaluated against its possible degradation
due to large thermal and electrical gradients compared to the base
parallel or counter flow.
Evaluation of Friction and Wear of Steel Sliding Surfaces Lubricated by Various
Types of Gear Oils. UTHAM BALACHANDRAN (University
of Illinois at Urbana Champaign, Urbana-Champaign, IL, 61820) GEORGE FENSKE (Argonne National Laboratory, Argonne, IL, 60439)
A vast majority
of critical components in diesel engines and automobiles are lubricated
by oil. Satisfactory performances of these critical components
are achieved through a combination of materials, surface finish,
and lubricant oil formulations. An empirical trial and error approach
is commonly used to formulate lubricants and select materials and
surface treatment strategies. The Tribology Section within the
Energy Systems Division at Argonne National Laboratory is doing
research to progress to a knowledge-based lubricant formulation
and component performance prediction methodology using expertise
and unique experimental capabilities available at Argonne. As part
of this on-going activity we have evaluated the friction and wear
of steel sliding surfaces lubricated by various types of additized
gear oils provided by Caterpillar and Eaton industries. A total
of 13 oils were evaluated using a ball-on-disk tribometer. Friction
coefficient as a function of sliding speed and time using various
types of oils are reported in this research paper.
Evaluation of Various New Anode and Cathode Materials for High Power Li-Ion Battery
Applications. STEPHANIE
TRAN (Michigan State University, East Lansing, MI, 48823)
JUN LIU (Argonne National Laboratory, Argonne, IL, 60439)
Since the establishment
of the Partnership for a New Generation of Vehicles Program (PNGV)
between the US government and the US Council for Automotive Research
in 1993, much research has been invested into developing more efficient
high power and high energy density hybrid electric vehicles (HEV).
The power and performance properties of a Li-ion battery system
make it an efficient source of energy for the automobile. However,
high production costs of the Li-ion battery make them difficult
to be accepted by automobile manufacturers. LiMn2O4 Spinel and
LiFePO4 Olivine active cathode materials are cheaper to produce
and may still maintain the performance characteristics of the Li-ion
system. Cycling performance tests for these materials have shown
a stable battery capacity over many charge-discharge cycles in
room temperature and high temperature conditions. Potential hard
carbon anode materials also display the prevention of capacity
loss at elevated temperatures and long term battery usage. Cost
efficient battery components that can still uphold the high power
and high energy qualities of a lithium-ion battery system are promising
to the new generation of hybrid vehicles.
Evaluation of Water-Based Diamond Seeding for UNCD™ Thin Film Growth on Silicon
Wafers. BRENT HAYNAM (University of Missouri - Columbia, Columbia, MO, 65211)
GREG KRUMDICK (Argonne National Laboratory, Argonne, IL, 60439)
Ultrananocystalline
Diamond™ (UNCD™) films are grown on silicon wafers via chemical
vapor deposition (CVD). In preparation for the CVD process the
wafers are seeded with diamond powder. The seeding of each wafer
consumes organic solvents, which are costly and designated by the
EPA as hazardous. The objective of this project is to investigate
a viable alternative method in which the organic solvent based
process is replaced with a low cost water-based process. In order
to evaluate the effectiveness of the proposed method two wafers
were seeded using each method. These wafers then underwent the
remainder of the UNCD™ growth process together in one deposition
in the CVD reactor. Four sets of wafers were coated resulting in
8 UNCD™-coated wafers. These wafers were characterized to determine
whether the proposed method of seeding wafers yields a diamond
film that meets specifications. To accurately evaluate the quality
of films created using the proposed method the samples underwent
optical inspection, profilometry, Raman spectroscopy, scanning
electron microscopy, and nucleation density analysis. Based on
this data, the proposed water-based seeding method produced UNCD™ thin
films that were comparable to the films produced using organic
solvent seeding. The diamond films produced using the alternate
seeding method met specifications. Further research could analyze
water-based ultrasonic seeding of Si wafers.
Expression of Cyr61 in pre-Osteoclastic cells as a result of Cadmium exposure? MARYN VALDEZ
(University of Maryland, College
Park, MD, 20742) MARYKA BHATTACHARYYA (Argonne National Laboratory, Argonne, IL, 60439)
Cadmium (Cd)
is a natural metal commonly present in paint, plastics, batteries,
the protective coating of steel, fertilizers, and in cigarettes.
Cd has been shown to start having adverse effects on bone organ
and cell culture systems at levels ranging from 10nM-100nM. However,
the mechanism by which Cd acts on the bone system to cause bone
loss has yet to be deciphered and thus needs to be further studied.
This is the ultimate goal of our research. Past experiments and
the literature have led us to think that Cry61 plays a pivotal
role in the pathway. Cyr61 is a ligand to the integrins aVß3. We
hypothesize that Cd provokes expression of Cry61 in Osteoblast(OB)
or Osteoclast(OC) cells, which binds to aVß3 located on the surface
of OC precursors. The binding eventually leads to responses that
lead to bone resorption. Specifically in this paper we are trying
to determine whether Cd triggers OC precursor cells to secrete
elevated levels of Cry61. Total Cell lysate(TL), extracellular
matrix(ECM), and concentrated media(CM) samples collected after
exposure to 100nM Cd for 2-48hrs, were analyzed for Cry61 expression
using western blots. Most of our time was spent working out the
proper protocol and we feel it has been developed to the best of
our ability. We concluded that fetal calf serum (FCS ) does indeed
cause Cry61 expression, as reported by others. We tentatively concluded,
that at 24 hours and possibly at 48 hours, Cd is causing an increase
in Cry61 expression in the media, but we can not say Cd is inducing
Cry61 expression in TL or ECM. Perhaps a different cell line needs
to be used-- One in which Cry61 is overexpressed to begin with,
or perhaps we need to look at the pre-OB cell lines. More experiments
that include more than 0.1% serum and more negative controls also
need to be done. Immunhistochemical staining experiments may also
be needed. Thus we made progress, but much more work needs to be
done.
Froth Flotation and Other Means of Separation of Plastics of Equal Density
and/or Similar Characteristics. MICHAEL
MAJEWSKI (University of Pittsburgh, Pittsburgh, PA, 15213) BASSAM JODY (Argonne National Laboratory, Argonne, IL, 60439)
Froth flotation
is a method of using the hydrophobic and hydrophilic properties
of materials to selectively attach air bubbles to one type of polymer
in a mix, allowing for separation. By manipulating surface tension,
acidity/basicity and specific gravity of solutions, it is possible
to isolate, purify, and clean polymers from various shredder residues
into high value resin streams. Plastics that are of interest include
polypropylene (PP), talc-filled polypropylene (PP w/Talc), polyethylene
(PE), acrylonitrile-butadiene-styrene copolymer (ABS), and ABS-polycarbonate
alloys (ABS-PC). After submersion in successive solutions in which
some plastics float and others sink due to the previously mentioned
parameters and froth flotation, individual fractions form, each
with a high purity in one or more thermoplastics. After experimentation,
FTIR spectroscopy, as well as some FT-Raman, is used to identify
the polymers. Difficulty arises in the isolation of polymers from
shredder residue, as numerous contaminants include oils, gasoline,
other automotive and appliance fluids, foam, and metals. What is
received as bulk shredder residue destined for a landfill can be
processed, cleaned, pelletized, and re-molded. A PP/PE product
has been isolated. Interior automotive plastic components, such
as battery trays and knee bolsters, have been molded from the recycled
material. I have spent time in the lab doing wet chemistry, including
froth flotation and density separation, on various polymers, air
classification using air columns, FTIR analysis to identify plastics,
and measurements of the surface tension and specific gravity of
solutions.
Functionalization of a Ceramic Membrane for Liquid-Liquid Extraction. DERRICK WHITLOCK (Texas Southern
University, Houston, TX, 77095)
SETH SNYDER (Argonne National Laboratory, Argonne, IL, 60439)
Ethanol,
a product available in large quantity from corn fermentation,
has been proposed as a viable alternative for gasoline. However,
major barriers to the successful implementation of ethanol as
a major fuel source are high costs and energy consumption associated
with routine distillation of aqueous mixtures. Hydrophobic membranes,
which have been employed successfully in liquid-liquid extraction,
should offer a viable alternative to distillation. Herein, we
disclose a process using ethyltrimethoxysilane (EtTMS) to functionalize
ceramic membranes capable of separating ethanol from water with
high flux and minimal energy costs. Overall hydrophobicity analyses
conducted on functionalized ceramic test membranes indicated
the development of successful and versatile hydrophobic functionalization
protocol and the measurement of negligible H2O
flux.
Gain Mapping and Response Uniformity Testing of the Hamamatsu R8900 Multianode
Photomultiplier Tube and the Burle Planacon Microchannel Plate
Photomultiplier Tube for the Picosecond Timing Project. MELINDA
MORANG (University of Chicago, Chicago, IL, 60637) KAREN BYRUM (Argonne National Laboratory, Argonne, IL, 60439)
Research is currently
underway for the development of a microchannel plate photomultiplier
tube with picosecond timing capabilities, a property that would
be extremely useful in many fields of physics and in radiology.
It is important in a research and development study such as this
one to fully understand the currently available technology, and
the study presented in this paper focuses on characterizing gain
and response uniformity in the Hamamatsu R8900-00-M16 multianode
photomultiplier tube (R8900) and the Burle Planacon 85011-501 microchannel
plate photomultiplier tube (MCPPMT). The tubes were tested using
a dark b
