A Plasma Gun for the Next Generation of Spallation Neutron Source H- Ion Sources. JUSTIN CARMICHAEL (Worcester Polytechnic Institute, Worcester, MA, 1609) ROBERT F. WELTON (Oak Ridge National
Laboratory, Oak Ridge, TN, 37831)
The ion source
for the Spallation Neutron Source (SNS) is required produce 40-50
mA of H- current depending on emittance with a duty factor of ~7%
for baseline facility operation. The SNS Power Upgrade Project
requires this current to be increased to 75-100 mA at the same
duty factor. In its present form, the baseline SNS ion source is
unable to deliver this performance over sustained periods of time.
A new generation of RF-driven, multicusp, ion sources based on
external antennas are therefore being designed to meet these requirements.
It was found that by injecting a stream of plasma particles from
a simple, steady-state, DC glow-discharge into the RF-plasma (i)
H- production can be dramatically increased and (ii) H- pulse rise
time can be significantly reduced. The design of a suitable plasma
gun is presented which features a hollow anode and mechanical compatibility
with the new ion sources. The Finite Element Method (FEM) has been
employed to optimize the design: coupled fluid dynamic, heat transfer,
mechanical stress and deformation, and ion/electron trajectory
simulations were performed. Several design improvements over earlier
versions were implemented such as the addition of an extraction
system. The FEM simulations showed that the design of the new plasma
gun is sufficient to handle the thermal stresses resulting from
a 1 kW load on the cathode face. The ion/electron simulations demonstrated
a high degree of control over the plasma beam, allowing for manipulation
of the intensity, mean energy, and divergence of the streaming
plasma. The extraction system also allows for selective emission
of electrons or ions. It is anticipated that the plasma beam can
be optimized with the extraction system to significantly increase
the H- current in the new ion sources.
Acoustic Doppler Measurement of High Speed Shearing Flow. DAVID
HUBBLE (University of Tennessee, Knoxville, TN, 37916) BRENNAN SMITH (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
The acoustic
Doppler velocimeter (ADV) is an innovative three-dimensional flow
measuring device that relates the phase shift between a transmitted
acoustic signal and its reflected counterpart to fluid velocity
through pulse-coherent processing. Its low cost and ruggedness
make it ideal for measuring in remote locations such as rivers
and tidal regions but its ability to measure high speed flow remains
in question. After analyzing data from an axisymmetric jet centerline
and the exit passage of a hydraulic turbine, it was determined
that an experiment was needed to improve understanding of how an
ADV responds in shearing turbulent flow and to quantify the bias
and errors in measurements from such flow fields. There are several
problems that occur when an ADV attempts to measure shearing turbulent
flow. First, due to range limitations on the speed settings, high
speed flows cannot be unambiguously measured. Second, due to probe
geometry, the vertical component of the velocity measurement is
biased, exhibiting higher variance than the other two flow directions.
To understand how an ADV reacts to shearing turbulent flow, experiments
are being conducted on an axisymmetric jet at the TVA’s Norris
Engineering Lab. The axisymmetric jet was chosen because it creates
a well understood, predictable flow field with areas of turbulence
strong enough to simulate those found in a hydraulic turbine exit
passage. The experimental design was determined by balancing probe
resolution against the flow capacity and geometric limitations
of the test flume. The geometric limitations caused concern due
to the risk of boundary influence. A four inch jet was chosen.
This allowed four probes to be located within the jet from 2 to
10 feet downstream with minimal flume boundary interference. There
is an inherent bias in the geometry of the ADV that causes vertical
measurements to contain less noise. Also, there is considerable
noise at high frequencies which indicates an inability to resolve
small extremely small scale turbulence. These data should help
engineers decide when an ADV is appropriate for flow measurement
in prototype settings.
Adaptively Improving Long Distance Network Transfers with Logistics. DAVID LABISSONIERE (East Tennessee State University, Johnson
City, TN, 37614) KENNETH ROCHE (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
The congestion
control mechanisms in the Transmission Control Protocol (TCP) severely
limit the bandwidth achieved by long distance data transfers. However,
it is regularly necessary to move data over great distances across
the Internet. The throughput of such transfers can be improved
by applying the logistical technique of breaking a single long
distance transfer into multiple shorter transfers. This technique
can result in significantly improved throughput while still working
with the TCP congestion controls and not attempting to circumvent
them. We have developed an algorithm that uses this technique to
traverse the network path that approximates the best available
bandwidth while the data is in flight. The algorithm couples graph
techniques with real-time latency and bandwidth measurements to
adaptively respond to network dynamics. The algorithm shows improvements
in speed and flexibility over standard data transfer methods such
as FTP. Future work includes algorithmic improvements to better
predict and model network bandwidths as well as a demonstration
of the algorithm as the data transfer mechanism for a production-scale
grid computation.
An Investigation of the Optical Detection of Cellular Metabolic Activity. KELLY CHRISTIAN (University
of Tennessee, Knoxville, TN, 37996) JUSTIN BABA (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
The clinical
challenge of preventing life-threatening vascular complications
after liver and other organ transplants necessitates a means for
continual post-operative monitoring for rejection, infection, and
normal function assessment. Current methods, which utilize crude
systemic measures such as volume of urine output and serum markers
for cellular injury, are woefully insufficient. At best, these
serve as indirect, time-delayed measures of tissue viability. Additionally,
these techniques do not provide continuous, real-time monitoring
and thus are inadequate for timely assessment that could enable
life saving interventions. To address these inadequacies, the development
of a device for continuous real-time tissue metabolic assessment
is underway. Currently, an investigation is in progress to determine
the appropriate equipment needed to produce a device that can track
the ratio of two fluorescent coenzymes that are involved in cellular
metabolic activity, NADH and FAD. It is anticipated that the NADH
/FAD ratio will stay constant for normal function and increase
considerably in the case of abnormal function. Therefore, the detection
of a noticeable increase would suggest an early change in tissue
viability, i.e. before irreversible organ damage occurs. Before
this can be explored, an optical probe must be developed that can
appropriately detect and measure the concentrations of NADH and
FAD. A device was designed and tested on a spectrophotometer with
several different light sources, such as a tungsten halogen, a
UV fluorescent lamp, and multiple LEDs (Light-Emitting Diodes),
to determine if one of the sources could detect high concentrations
of the coenzymes in vitro. A model probe was also constructed,
where the samples were tested with the photodiode detector. The
results presented show that NADH and FAD fluorescence was visibly
observed when the light sources simply illuminated the samples,
however the fluorescence was unable to be detected with all but
one of the light sources used. This indicates that the samples
were fluorescing, but the spectrophotometer and the probe were
unable to detect fluorescence due to low sensitivity in UV and
near visible range. Future work must be done to determine a proper
light source that can detect NADH and FAD suitably. Once the probe
is complete, it must be tested for the detection of anticipated
physiological concentrations in vitro and for conducting ex vivo
studies using excised organs before finally proceeding to live
in vivo studies.
Analysis of the Infrastructure That Will Support a Transition to a Hydrogen. TROY MITCHELL (Roane State Community College, Harriaman,
TN, 37748) JUAN FERRADA (Oak Ridge National Laboratory, Oak Ridge,
TN, 37831)
The transition
to a hydrogen economy is assumed to begin in 2020 with a total
of 2.5 million hydrogen cars in seven cities including: Atlanta,
Miami, San Francisco, Detroit, Houston, Chicago, and Los Angeles.
Factors that affect the transition to a hydrogen economy are production,
delivery, storage, and dispensing the hydrogen. Using data from
the Department of Energy’s Hydrogen Analysis (H2A) models, FLOW ©,
a simulation program developed at Oak Ridge National Laboratory,
can simulate the entire hydrogen economy for each one of the cities
used in the analysis. Sensitivity and uncertainty analysis are
applied to determine the affects of fluctuating feedstock prices
and demand for hydrogen. According to the results of the H2A models,
trucking of gaseous hydrogen was not a practical method of delivery.
During this research it was found that Python™ is a user friendly
object-oriented programming language. In terms of unit cost, natural
gas reforming was found to be an effective production method at
lower demands for hydrogen, and coal gasification was found to
be more effective with higher demands of hydrogen. Steam methane
reforming is an effective method of production and distribution,
in terms of unit cost. Piping is an effective method to distribute
hydrogen at low demands. Trucking is more cost effective when hydrogen
demand is higher. Results of the analysis will be used to provide
recommendations for the required infrastructure that will provide
a better transition to a hydrogen economy from the current fossil
fuel economy.
Aspen tree core mircro-cat analysis
and mutation detection. ASHLEY NEIL (Auburn University, Auburn, AL, 36830) LEE GUNTER (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
Among clonal
organisms the actual genetic mechanism used to maintain diversity
within the species is unknown; however they are suspected to have
a higher mutation rate than plants propagated by seed dispersal
alone. Populus tremuloides (aspen), with its wide distribution,
persistence in the environment and extensive clonal structure,
is a good model for studying this mechanism in plants. In this
project, its proposed using the number of estimated somatic mutations
to determine the absolute age of clonal aspen stands within Rocky
Mountain National Park (RMNP). Several parameters needed to be
examined in order to determine if aspen has a high somatic mutation
rate relative to other organisms, such as clone age, number of
somatic mutations, dominant genotype, as well as the geographic
distribution pattern correlated with the genetic structure. In
an effort to establish clone age, individual aspen ramets were
analyzed using an ultra high resolution x-ray computer tomography
system. The super resolution of this system generates a clear and
easily differentiated image of the rings of the collected cores.
Therefore, an estimate of the clone age will be determined based
on the rings reading from the image and the tree diameters. Thus
far approximately 300 ramets have been examined. A correlation
between the ramet ages and the diameters will need to be determined
in order to calculate the age of an individual tree from its diameter.
From earlier studies, it has been demonstrated that this technique
is the best one to yield satisfactory results. The major objective
in the genetic component of this study is to attempt to determine
the rate of somatic mutation, and, if successful, to use it to
estimate the absolute ages of several aspen clones in the RMNP.
Automatic Semantic Inference and Extraction of Textual Information from Internet
Resources. PHILLIP MARTIN (Clemson University, Clemson, SC, 29634) THOMAS E. POTOK (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
The Internet
is one of the largest available public collections of data. Current
methods of extracting the Internet’s copious amount of data by
hand in a timely manner have proved inadequate. To make the untapped
resources of the World Wide Web (WWW) more readily accessible,
it is necessary to automate the data extraction of several different
formats. Hyper Text Markup Language (HTML) is the most prevalent
data format for the World Wide Web. However, HTML is designed for
the visual presentation of data on a website and thus includes
little, if any, semantic information. The Resource Description
Framework (RDF) developed by the World Wide Web Consortium provides
a common format that enables a user to represent low-level semantic
information and structure. In addition, the Internet contains several
other data formats including documents generated using Microsoft
Office and Adobe PDF. The challenge is to gather HTML encoded documents
and generate basic semantic data using the RDF format and to expand
automatic data extraction to include other formats. To address
this challenge, an RDF document is automatically generated from
the basic syntax derived from an HTML document. This allows the
inference of some basic semantic information from any ordinary
HTML file. Text extraction is further expanded to include both
Microsoft Word documents and Adobe PDFs. The results demonstrate
how the methods described above can provide a broader and more
robust basis for automatically gathering information from the internet.
Characterization of Nano-particles in Mesophase Pitch Derived Graphite Foams. JENNIFER MUELLER (Virginia Polytechnic Institute and
State University, Blacksburg, VA, 24060) JAMES KLETT (Oak Ridge
National Laboratory, Oak Ridge, TN, 37831)
The addition
of nano-particles to a raw material can significantly alter the
structure and therefore properties of a material. A characterization
study was conducted to explore the effects of nano-particle additions
on graphite foam, a material that exhibits very high thermal conductivity
and low density. Carbon nano-particles were added to mesophase
pitch in varying amounts and processed to create graphite foam.
Image analysis was conducted on each sample by using an optical
microscope, Scanning Electron Microscope (SEM), and Transmission
Electron Microscope (TEM). Other analyses included density measurements,
compression tests, permeability tests, and flash diffusivity tests.
Results showed that there were overall trends of decreasing density,
thermal conductivity, and strength with an increasing amount of
carbon nano-particles, but the permeability increased. Through
optical image analysis, it was determined that the ligament size
of the graphitic matrix decreased and that there was a significant
disruption of graphitic plane alignment with greater additions
of carbon nano-particles. Additionally, it was seen with the SEM
that the number and size of open pores increased with an increasing
amount of carbon nano-particles. Overall, the decreased ligament
size and disruption of graphitic alignment explains the decreased
strength and thermal conductivity, respectively. Also, the addition
of the nano-particles increased the open porosity and, therefore,
increased the permeability of the foam. As a result, the graphite
foams characterized through this study are suitable for applications
where higher permeability foams are desired. Since the mixture
with the greatest amount of nano-particles had the highest permeability,
a further study should be conducted to determine what mixture results
in the maximum permeability of the graphite foam without a significant
loss in thermal and mechanical properties.
Characterization of Sub-diffusion within Benard-Rayleigh Advective Cells by
Examination of a Velocity Field with Additive Noise. MARSHA
LAROSEE (University of Michigan, Dearborn,
Mi, 48128) BEN CARRERAS (Oak Ridge National
Laboratory, Oak Ridge, TN, 37831)
Normal diffusion
worked out by Einstein and Taylor is modeled by averaged particle ‘Brownian
motion’ such that a given particle’s motion is determined by random collisions with surrounding particles. Less well understood is
the subject of anomalous diffusion, which is studied in many fields
where diffusion influences the system (e.g. heat, fluids, chemical
kinetics). The distinction between normal diffusion, a random mechanism
and anomalous diffusion, that is a mixture of random and deterministic processes, is the time scale at which the transport occurs. Both
diffusion and anomalous diffusion follow a power law relation < r s > 1/s ˜ t q(s),
where q(s) = 1/2, < 1/2, > 1/2 for diffusion, sub-diffusion,
and super-diffusion. Thus, sub-diffusion and super-diffusion scale
with time differently than random motion predicts. In order to
study sub-diffusion a deterministic model must be used while adding
randomness, or noise to the system. A model referred to as the
random walk with pauses or trapping events was investigated in
order to characterize sub-diffusion in a fluid system. The system
that was studied is an array of Benard Rayleigh advective cells
where the velocity fields cause 10,000 tracer particles to circulate
within a cell. Noise added to the velocity field causes diffusion
between cells. Moments of the displacement were calculated as a
function of time while varying the frequency and magnitude of noise
in order to magnify the region where sub-diffusion is observed.
Frequency of the additive noise extended the time frame in which
sub-diffusion was observed and appears to extend the time frame
non-linearly. Moments of the displacement show that the diffusive
exponent q(s) is the same for all higher moments which indicates
scale invariance, or q(s) = constant. This property is characteristic
of both anomalous and normal diffusion. The exponent observed q(s)
~ 0.4, was larger than the typical exponent of sub-diffusive systems
q(s) ~ 1/3. The reason for this is undetermined but may indicate
an influence of normal diffusion within the system and future investigation
is planned.
Characterization of Superconducting Splices. MEGAN
MALLETTE (Valparaiso University, Valparaiso, IN, 46383) CHRISTOPHER REY (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
High temperature
superconductors (HTS) are materials that have no resistance to
electrical current at temperatures below the transient temperature,
Tc, and are therefore able to conduct much higher currents than
traditional wire, in a much smaller area. HTS have the potential
to greatly increase electrical efficiency in a number of applications,
but it is necessary to first fully characterize the behavior of
splices (i.e. electrical joints) before incorporating HTS wire
into applications in order to minimize joint failure. During this
investigation, splices of superconductors to be tested were fabricated
by varying the type of solder, surface preparation, joint overlap
area, and thermal cycle. Each splice consists of a series of seven
lap joints. After fabricating each splice, a range of currents
are applied to the splice and voltage measurements across each
joint are used to calculate the resistance of each joint for the
range of currents tested. While holding all other variables constant,
the Sn60-Pb40 solder outperformed the In66.3-Bi33.7 solder in every
test. Testing splices with no surface preparation resulted in poor
mechanical joints that were unable to handle the stress of testing,
showing the importance of surface preparation and oxide removal.
Of the two types of fluxes tested, the paste flux outperformed
the ruby fluid flux with all other variables constant in every
test, except one splice in which the HTS was damaged by the temperature
of the soldering iron. Results from varying joint overlap areas
showed that larger contact areas decrease the joint resistance,
as expected. Surprisingly, there was little difference between
successive thermal cycles due to the stress of repeated temperature
changes. Further testing on additional types of solders, fluxes,
and joint overlap areas would result in a more comprehensive report
on splices of HTS. Other variables that need to be considered in
further testing of splices are the effects of varying magnetic
fields, temperature dependence, and different types of mechanical
stress.
Characterizing the Role of the Nell1 Gene in Cardiovascular Development. LEAH LIU (Pennsylvania State University, University
Park, PA, 16802) CYMBELINE CULIAT (Oak Ridge National Laboratory,
Oak Ridge, TN, 37831)
Nell16R is
a chemically-induced point mutation in a novel cell-signaling gene, Nell1,
which results in truncation of the protein and degradation of the Nell16R transcript. Earlier
studies revealed that loss of Nell1 function reduces
expression of numerous extracellular matrix (ECM) proteins required
for differentiation of bone and cartilage precursor cells, thereby
causing severe skull and spinal defects. Since skeletal and
cardiovascular development are closely linked biological processes,
this research focused on: a) examining Nell1 mutant
mice for cardiovascular defects, b) determining Nell1 expression in fetal and adult hearts, and c) establishing how
ECM genes affected by Nell1 influence heart development. Structural heart defects in Nell16R mutant
fetuses were
analyzed by heart length and width measurements on formalin-fixed
specimens and standard histological methods (haematoxylin and eosin
staining). Nell1 expression was assayed in fetal and adult hearts using reverse
transcription polymerase chain reaction (RT-PCR). A comprehensive
bioinformatics analysis using public databases (UCSC Genome Browser,
Mouse Genome Informatics, Integrated Cartilage Gene Database, PUBMED)
was undertaken to investigate the relationship between cardiovascular
development and each of the 28 ECM genes affected by Nell1. Nell1-deficient mice have significantly enlarged hearts (particularly
the heart width), dramatically reduced blood flow out of the heart
and unexpanded lungs. Isolation of total RNAs from hearts
of adult (control and heterozygote) and fetal (control and homozygous
mutant) mice have been completed and RT-PCR assays are in progress. The
bioinformatics analysis showed that the majority of ECM genes with
reduced expression in Nell1-deficient
mice are normally expressed in the heart (80%; 22/28), blood vessels
(71%; 20/28) and bone marrow (61%; 17/28). Moreover,
mouse mutations in seven of these genes (Col15a1, Osf-2, Bmpr1a, Pkd1, Mfge8, Ptger4, Notch3)
manifest abnormalities in cardiovascular development. These
data demonstrate for the first time that Nell1 has a role in early mammalian cardiovascular development, mediated
by its regulation of ECM proteins necessary for normal cardiovascular
growth and differentiation. In addition, the identification
of Nell1 and
its associated ECM genes can provide future targets for treatment
of heart and blood vessel defects.
Climate Change Effects on Decomposition Mediated by Species Composition Versus
Plant Litter Quality. MARLENE TYNER (University
of Michigan, Ann Arbor, MI, 48109)
AIMEE CLASSEN (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
Global change is
rapidly modifying our planet, including altering ecosystem nutrient
cycling. Until recently, research has focused on manipulating single
climate change factors such as the effects of elevated carbon dioxide
(CO2) or elevated temperature on ecosystem processes. These factors,
however, will not occur independently and are likely to alter ecosystem
processes differently, perhaps mediating some of the effects. This
project investigated how multiple climate change factors may alter
decomposition in an old-field ecosystem. Specifically, it asked if
climate change (elevated [CO2] and temperature) would have a larger impact on decomposition
via indirect changes in community composition or direct changes in
litter quality. Three major findings resulted from this work: 1) Litter
chemical quality change due to elevated [CO2] or temperature does not alter decomposition rates; 2) Climate-driven
shifts in species composition has an effect on decomposition rates;
3) These effects occur primarily in the early stages of the decomposition
process, and decline over time. Taken together, these data suggest
that climate change will have a larger effect on ecosystems by causing
shifts in plant communities than it will by altering litter quality.
Further, these results suggest that the effects afflicted on ecosystems
by changing climates may be more varied and complex than previously
thought, and current databases on ecosystem process changes may need
to be expanded for more accurate modeling efforts.
Collection, Analysis, and Archiving Heavy Truck Driving Characteristics and
Duty Cycles to Support the Evaluation of Benefits of Energy Efficiency
Technologies. JOSEPH MASSIMINI (Purdue University, West
Lafayette, IN, 47906) GARY CAPPS (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
Despite common beliefs,
commercial vehicle energy performance on highways is not well known.
Ever changing hours of operation, anti-idling regulations, traffic situations
and construction work make it difficult for drivers to have a true situational
awareness of driving characteristics on highways. Understanding of these
characteristics is often obtained through qualitative means. A quantitative
profile of driving behavior of heavy trucks does not exist. Generation
of duty cycles that reflect real world driving would aide in creating
such a profile. Sensors, autonomous to the driver, mounted on active
fleet tractor trailers collecting kinetic, kinematics, human factor and
environmental information will provide the data necessary to generate
these duty cycles. Additionally, half the tractor-trailers will be fitted
with Next Generation Single Tires (NGSTs) as opposed to standard dual
tires to observe any improvements in fuel efficiency. This project involved
extracting and analyzing the duty cycle data collected during the Pilot
Test and creating and testing a prototype sensor suite for the Field
Test that includes both Controller Area Network (CAN) and RS-232 type
connections, requiring not only specific programming in the Data Acquisition
System (DAQ), but also special CAN cables, RS-232 connectors and signal
conditioning modules. ORNL worked with the DAQ vendor to specify and
create the necessary software and hardware needed for integration into
the prototype. This project also had to consider the fact that active
fleet tractor trailers with a single driver typically operate 11 hours
a day. Each channel collected and stored in the DAQ is collected at 16
bits per Hertz, thus a very large amount of data will be collected in
a very short period of time. Methods were developed for formatting, organizing
and archiving this large amount of data using custom Visual Basic software.
At vehicle launch duty cycle data will be collected with the custom sensor
suite, and will be archived and stored in an accessible location using
the created software and can be used for validation, research and development
of energy efficient technologies.
Comparing Predicted and Actual Energy Cost Escalation in Energy Savings Performance
Contracts. LARRU KISER (Ferrum College, Ferrum, VA, 24088)
JOHN A. SHONDER (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
Energy Savings Performance
Contracts (ESPC) are a method of financing energy conservation projects using
the energy and energy-related cost savings generated by the conservation measures
themselves. In Federal ESPC, an energy services company (ESCO) obtains financing
and installs energy conservation measures at no up-front cost to the government.
The government pays the ESCO from the cost savings generated, and the ESCO
uses these payments to repay the financing. Since energy prices are volatile,
ESPC contracts usually agree to escalate energy cost savings at fixed rates.
The most common source for escalation rates is the U.S. Energy Information
Agency (EIA), which publishes annual predictions for electricity and natural
gas price escalation for the four U.S. census regions. The purpose of this
project was to determine how well the predictions from the EIA matched the
actual escalation of electricity and natural gas prices from 1998 to 2004 for
the four census regions. It was discovered that the escalation of electricity
rates was overestimated, with the exception of region four (Western U.S.),
and the escalation of natural gas rates was underestimated. Based on statistics
from the U.S. Department of Energy’s Super ESPC program, a typical ESPC project
was defined, and the difference between actual and contracted cost savings
was calculated for each of the four regions.
Controlled Synthesis, Characterization,
and Properties of Tin Oxide Nanoparticles. JENNIFER CODDING (McMurry University, Abilene, TX, 79697) WEI WANG (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
Tin oxide nanoparticle
based materials have various applications as sensors, catalysts, pigments,
and electrode materials. Physical and structural properties, along
with crystallinity and particle size and morphology of the tin oxide
nanoparticles, depend on the method of synthesis. In this research,
tin oxide nanoparticles were synthesized by forced hydrolysis of Tin(IV)
chloride in a hydrochloric acid-alcohol aqueous solution. The use of
alcohols in the synthesis of tin oxide nanoparticles provided the ability
to correlate procedures of experimental synthesis with the properties
of the desired compound. A systematic study was performed to examine
nanoparticle formation at different conditions by varying the type
of alcohol, alcohol/water ratio, reaction temperature, and time. Dynamic
Light Scattering was used to verify the size and distribution of the
particles and a UV-visible spectrometer was used to measure absorption
to determine the temperature at particle appearance. Experiment shows
that tin oxide nanoparticles form in alcohol-water media with alcohol
volume fractions below thirty percent, and that particle size increases
with a decrease in alcohol percentage. In an ethanol-water mixture,
particle formation initiates at 84ºC in thirty percent alcohol, while
particles develop at 86ºC in twenty-five percent alcohol in a methanol-
or butanol-water mixture and at 85ºC in twenty percent alcohol in an
iso-propanol or n-propanol-water mixture. Particle size and concentration
also increase with an increase of reaction time above the formation
temperature. Under uniform conditions, the size of the nanoparticle
is directly proportional to the size of the alcohol molecule. Additional
experiments are needed to determine more precisely the required time
versus temperature ratio for the controlled synthesis of nanoparticles.
Ultimately, forced hydrolysis is a good method to control the size
and shape of discrete tin oxide colloidal nanoparticles.
Controls Engineering for a Compact Crystal Positioning System. PRISHANTHA
DUNSTAN (Columbia University, New
York, NY, 10027) CHRISTINA
HOFFMANN (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
The ability to manipulate
a sample for research and development has always been a basic essential.
When sample size shrinks to the micro-scale and the environment for
analysis proves unsuitable for direct human interference, the ability
to carefully and accurately control the sample becomes much more difficult.
In this case a positioning system for aligning and moving the samples
remotely is desired. Such a device was constructed by Square One Systems
in collaboration with the Spallation Neutron Source at Oak Ridge National
Laboratory. Based on a tri-sphere approach, a series of linear actuators
are employed to perform linear and spherical motions around a center
point. The scope of this project was multifold: The individual motors
of the instrument were calibrated and aligned. Once completed, the
instrument was hardwired into a computer for control through LabVIEW
software. The controls software was designed to mimic the operation
of a goniometer, such that the sample could be rotated through two
angles, the second angle being dependent upon the first. The equations
of motion used enable sample rotation such that the crystal’s position
remains fixed while the motors move around it. Since the samples will
be subject to neutron beam exposure with dimensions as small as 100m
x 100m, ensuring that the crystal does not leave the beam when rotating
will be essential to collect meaningful data. The controls also provide
numerous calibration functions, enabling re-centering and adjustment
of the sample after loading. The software calculates limits of rotation,
preventing over rotation and possible dropping of the sample. Virtual
images of the sample plate provide a visual for the scientist, due
to the fact that the sample chamber will prevent direct view of the
sample. This new instrument provides several advantages over the current
sample positioner on the market (the hexapod). Using innovative Piezo
motors, the instrument can manipulate the sample with zero backlash,
ensuring accurate manipulation. The instrument also allows for easy
sample changing, since the sample plate is not permanently fixed to
the instrument. Because the software allows for repositioning of the
sample, it provides much room for time-saving methods. For example,
if a sample pin were used, such that 3 samples were loaded (one at
the tip, one 1/3 from the tip, one 2/3 from the tip), the instrument
could manipulate 3 samples sequentially without the need to reload.
DATABASE AND APPLICATION DESIGN FOR INTEGRATING RFID TRACKING METHODS INTO
THE COMMERCIAL SUPPLY CHAIN PROCESS FOR RADIOACTIVE MEDICAL ISOTOPES. JAMES HICE (Albion College, Albion, MI, 49224) DAVID RESSEGUIE (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
Current methods of
tracking use line of sight bar codes which encode a number, the package's
carrier tracking number, to identify each package. Each package is
tracked from when the package is shipped at a carrier through final
delivery. Progress of the package is marked when the bar code is manually
scanned at each of the carrier's facilities and when the delivery is
made. Tracking packages containing radioactive medical isotopes and
other sensitive materials beyond the standard shipping routes and carrier
facilities is becoming increasingly important. A test for tracking
sensitive packages using Radio Frequency Identification (RFID) tags
has been created to allow sensitive package tracking without requiring
manual, line of sight scanning. These RFID tags transmit a unique identification
number and will be placed inside packages on each radioactive medical
isotope container. Shippers register each package using a web application
which inserts the information into a database. RFID readers set up
at the shippers', carriers' and recipients' facilities read the packages
as they pass within range and update the database with the RFID identification
number, time, and location. No web application or database existed
for these tests, so extensive work was done to design and create the
database structure and required application. A relational database
design was used to store the package, RFID, and carrier provided tracking
data. The web application, which serves as the shippers' interface
for inserting and managing information in the database, consists of
multiple Java Server Pages. The main considerations in creating the
web application's design were ease of use for shippers as well as capturing
and managing the necessary data for packages of interest. Future applications
will use the database information to display package information, geographic
location, and compare tracking methods. Further work can be done to
display the web application more dynamically, providing real-time updates
from the database. The web application and database can also be used
for continued tracking of shipments beyond this test, including general,
non-sensitive RFID package tracking.
Density-Functional Theory Investigation of ß-SrRh2O4. GARETH
WILSON-SHORT (North Carolina State University, Raleigh, NC, 27606)
DAVID J. SINGH (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
There is a need of
better materials for direct photoelectrolytic hydrogen production.
Requirements are an appropriate band gap (ideally 1.8 eV), flat band
edges, photochemical and aqueous stability, and effective charge transfer
to water. Computational methods are appropriate for studying the band
structures of materials, allowing one to examine the first two of the
above requirements. This study is a theoretical treatment of (P-62c) ß-SrRh2O4 and its viability for direct photoelectrolysis. Straightforward
calculations are hampered by the disorder of strontium. Linearized-Augmented
Plane-Wave (LAPW) Density Functional Theory (DFT) calculations were
performed on supercells with different occupancies of these strontium
sites as well as virtual crystals that approximate the effect of Sr2+ by
substituting 2Rb+.
Independent DFT calculations, within either the local density approximation
(LDA) or the generalized gradient approximation, were performed in
order to calculate properties for these structures and relaxed structures
provided by a colleague. A result of interest for ß-SrRh2O4 is the flatness of the t2g band edge as well as the relative narrowness of the eg manifold.
The placement of strontium has a significant effect on the electronic
structures in both virtual crystal approximations and supercells. Despite
the strontium disorder, this study indicates that the bulk electronic
structure of ß-SrRh2O4 is
excellent for the for the direct photoelectrolytic production of hydrogen.
LAPW DFT within the LDA calculates band gaps (1.0-1.2 eV) in these
supercells, lower than those for the virtual crystal approximations
(1.5-1.7 eV). However, this method traditionally underestimates semiconductor
band gaps. A good example being the prediction of a 0.6 eV band gap
in ZnRh2O4 using the same computational methods employed here, while experiment
revealed a 1.2 eV band gap. This study does make two significant assumptions,
namely that the compound is stable in water due to low ionic mobility
of Sr, and that effective charge transfer to water can occur. These
can both be addressed with experiments.
Detection and Quantification of Dehalococcoides Strains from a Chloroethene-Contaminated. ALMA ZHOLI (University of Michigan Dearborne, Dearborne,
MI, 48128) CHRISTOPHER SCHADT, SONIA TIQUIA (Oak Ridge National Laboratory,
Oak Ridge, TN, 37831)
Detection and Quantification
of Dehalococcoides Strains from a Chloroethene-Contaminated Aquifer
Using Quantitative Real-Time PCR (qPCR) Alma Zholi and Kelly Cho The
University of Michigan, Dearborn, MI PROGRAM NAME (FaST Program) Faculty
Adviser: Sonia M. Tiquia Mentor: Christopher W. Schadt Department of
Natural Sciences Environmental Sciences Division The University of
Michigan-Dearborn Oak Ridge National Laboratory Dearborn, MI 48128
Oak Ridge, TN 37128 ABSTRACT Chlorinated solvents such as tetrachloroethene
(PCE) and trichloroethene (TCE) are some of the most prevalent contaminants
in groundwater in the United States. Recent studies have revealed that
PCE and TCE can be reductively chlorinated to non-toxic ethene by specific
dehalo-respiring bacteria from the genus Dehalococcoides. While Dehalococcoides
have been found at a significant number of sites, these microbes may
not be present in all groundwater environments. Hence, to promote complete
dehalogenation of TCE and PCE, Dehalococcoides are often added to contaminated
sites in a process known as bioaugmentation. The present study aims
to determine the presence and abundance of Dehalococcoides strains
in TCE/PCE-contaminated aquifer samples from Dover Air Force Base (DAFB)
in Delaware that have underwent various treatment strategies, including
bioaugmentation. Five samples were tested for the presence and abundance
of Dehalococcoides 16S rRNA genes using real-time PCR (qPCR). The composition
of Dehalococcoides in the samples were also determined by cloning and
sequencing using PCR primers directed toward conserved regions of the
gene within the group Dehalococcoides. Results of the qPCR experiment
revealed an abundance of Dehalococcoides in all aquifer samples examined,
indicating that this microbe may be wide spread in groundwater from
DAFB, and perhaps active under each of the remediation strategies.
Database searches of 16S rRNA-Dehalococcoides partial sequences indicated
that the samples were dominated by gene sequences related to Dehalococcoides
ethenogenes, Dehalococcoides sp. CBDB1, and several uncultured Dehalococcoides
spp. This project is part of a larger effort to contribute to research
and development of microbiological systems that influence parameters
important to the clean up environmental contaminants such as PCE and
TCE.
Detection of Concentration Variations of Matrix Metalloproteases. CASSANDRA ARMSTEAD-WILLIAMS (Stanford University, Stanford, CA, 94305)
KARA KRUSE (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
In recent years the
Nanoscale Science and Devices group at Oak Ridge National Laboratory
has developed and continues to study how micocantilever technology
can be used to create high-throughput, label-free tests for biological
macromolecules. The Vascular Research Laboratory at the University
Of Tennessee Medical Center of Knoxville is studying the effects of
certain drugs on the concentrations of Matrix Metalloproteases (MMP’s)
in the blood. The Vascular Research Laboratory and the Nanoscale Devices
and Sciences group are working together to create a dependable, high-throughput,
label-free system for quantitatively measuring concentrations of MMP’s.
Microcantilevers bend due to a change in the entropy and energy on
one side of the cantilevers and not the other. This bending can be
monitored optically by reflecting a laser beam off of the cantilevers
and onto a position sensitive detector (PSD). The PSD translates the
optical signal into an electronic signal for real-time monitoring of
microcantilever bending. For this experiment, gold-coated silicon microcantilevers
were immobilized with 3,3-Dithiobis(sulfosuccinimidylpropionate) (DTSSP)-a
homobifunctional, amine reactive cross linking agent. Immobilizing
the cantilevers with a DTSSP monolayer allows selective attachment
of biochemical molecules onto the gold and silicon/silicon nitride
microcantilever substrate. MMP specific probe antibodies were then
attached to the microcantilevers via a captavidin-biotin linkage system.
Surface amine groups of captavidin were reacted with the succinimide
terminals of DTSSP. The biotin-conjugated, MMP specific probe antibodies
selectively adsorbs onto the captividin protein layer. After functionalization
(immobilization), solutions containing unknown concentrations of MMP’s
are introduced to the microcantilevers while bending is being monitored.
Using a model antibody system, current tests indicate that DTSSP and
antibodies can reliably be immobilized on the cantilever surfaces.
However, we have not been able to determine the antibodies’ range of
sensitivity for protein concentration detection. The reliability of
the DTSSP and antibody immobilization shows that this detection system
can work. We are currently modifying our detection system and probe
immobilization procedures to find the optimal working range for this
technology.
Determination of Binding Constants Between Thiourea Anion Receptors and Selected
Monovalent Anions. ALICIA POWERS (Georgia Institute
of Technology, Atlanta, GA, 30332) LÆTITIA DELMAU (Oak Ridge National
Laboratory, Oak Ridge, TN, 37831)
The selective extraction
of anions, particularly those in nuclear waste, is desirable because
some anions hinder waste processing. Anion receptors can increase anion
extraction and can possibly exhibit selectivity when designed from
ligand modeling calculations. In this project, three thioureas, chosen
for their geometry and ability to develop hydrogen bonds with anions,
are compared as anion receptors for several monovalent anions—nitrate,
chloride, bromide, iodide, bicarbonate, and perchlorate—by measuring
the binding constants between each thiourea and anion. Radiotracer
experiments are used to measure the distribution of cesium between
the organic and aqueous phases at varying initial concentrations of
cesium for systems with and without anion receptors. Data from these
experiments is modeled using the Fortran modeling program SXLSQI. In
this program the predicted species formed in the organic phase are
entered and the binding constants are calculated. The stoichiometry
of the predicted species is varied in order to determine which model
best fits the obtained data. Electrospray mass spectrometry (ESMS)
is used to provide further evidence that the species used in the model
are the actual species formed. Results show that all of the thioureas
increased cesium extraction for all anions except perchlorate, although
the order of the amount by which the thioureas increased extraction
varied by anion. Most of the systems were best modeled with one thiourea
binding to each monovalent anion although some were best modeled by
both one and two thioureas binding to each anion. ESMS results for
the nitrate anion with one of the thioureas showed that nitrate did
bind to one thiourea although some nitrate also bound to two thioureas.
These results show that thioureas were successful both in increasing
anion extraction and in selectively extracting certain anions.
Determining Cellular Localization of Candidate Cilia Proteins in Transgenic
Caenorhabditis elegans. SANDRA MCGILL (Clayton State University, Morrow, GA, 30281) EDWARD
J. MICHAUD (Oak Ridge National Laboratory, Oak Ridge, TN, 37831)
Primary cilia are
small organelles that protrude from cell surfaces and are conserved
in most eukaryotes, including nematodes, mice, and humans. In humans
primary cilia have vital sensory functions; flaws in these organelles
lead to many diseases. Based on comparative genomics and proteomics
studies it has been estimated that the cilia proteome consists of 300-500
proteins, but the functions of most are unknown. Disruption of the
homologous genes in mice is an effective approach for determining function.
However, prior to performing lengthy and costly experiments in mice,
it is desirable to verify that these candidate genes do indeed localize
to primary cilia. An efficient method for determining the in
vivo cellular
localization of candidate cilia proteins is to perform translational
GFP assays in transgenic nematodes. In a previous project, translational
fusion vectors were constructed in which two nematode candidate cilia
genes, E02H1.5 and R148.1,
were cloned in-frame with the Green Fluorescence Protein (gfp) reporter gene in a plasmid vector, pPD95.81. In this project,
the two vectors are being microinjected into the gonads of nematodes,
where transcription and translation of the fusion vector results in
the nematode protein being tagged with the GFP protein. Visualizing
the GFP marker under a fluorescent microscope reveals the locations
of the fusion proteins in nematodes. Three independent lines of transgenic
nematodes were established for E02H1.5,
but examination of the transgenic nematodes did not reveal any GFP
expression. Based on this result, and on further examination of the
genomic locus encompassing the E02H1.5 gene,
it appears that E02H1.5 may be one gene in a four-gene operon. Approximately 10% of
all worm genes exist in operons, where one promoter region directs
the expression of all genes in the operon. The entire E02H1.5 operon
is now being cloned into the pPD95.81 vector and will be used to generate
new lines of transgenic nematodes. Microinjection of the R148.1 vector into nematodes is under way. Additionally, translational
fusion vectors are being made for two other candidate cilia genes, K07G5.3 and C02H7.1,
which will also be used to generate transgenic nematodes to determine
protein localization. If these four proteins are shown to localize
to cilia in nematodes, the stage will be set for analysis of the functions
of the homologous proteins in mice and humans.
Development of a Biosensor for Measuring Antibody-Antigen Interactions. CASSANDRA ARMSTEAD-WILLIAMS (Washington University
School of Medicine, St. Louis, MO, 63110) KARA KRUSE (Oak Ridge National
Laboratory, Oak Ridge, TN, 37831)
In recent years the
Nanoscale Science and Devices group at Oak Ridge National Laboratory
has developed and continues to study how microcantilever technology
can be used to create high-throughput, label-free tests for biological
macromolecules. The Vascular Research Laboratory at the University
Of Tennessee Medical Center of Knoxville is studying the effects of
certain drugs on the concentrations of Matrix Metalloproteases (MMP’s)
in the blood. The Vascular Research Laboratory and the Nanoscale Devices
and Sciences group are working together to create a dependable, high-throughput,
label-free system for quantitatively measuring concentrations of MMP’s.
Microcantilevers bend due to a change in the entropy and energy on
one side of the cantilevers and not the other. This bending can be
monitored optically by reflecting a laser beam off of the cantilevers
and onto a position sensitive detector (PSD). The PSD translates the
optical signal into an electronic signal for real-time monitoring of
microcantilever bending. For this experiment, gold-coated silicon microcantilevers
were immobilized with 3,3-Dithiobis(sulfosuccinimidylpropionate) (DTSSP)-a
homobifunctional, amine reactive cross linking agent. Immobilizing
the cantilevers with a DTSSP monolayer allows selective attachment
of biochemical molecules onto the gold and silicon/silicon nitride
microcantilever substrate. MMP specific probe antibodies were then
attached to the microcantilevers via a captavidin-biotin linkage system.
Surface amine groups of captavidin were reacted with the succinimide
terminals of DTSSP. The biotin-conjugated, MMP specific probe antibodies
selectively adsorbs onto the captividin protein layer. After functionalization
(immobilization), solutions containing unknown concentrations of MMP’s
are introduced to the microcantilevers while bending is being monitored.
Using a model antibody system, Current tests indicate that DTSSP and
antibodies can reliably be immobilizing on to the cantilevers surfaces.
However, we have not been able to determine the antibodies’ range of
sensitivity for protein concentration detection. The reliability of
the DTSSP and antibody immobilization shows that this detection system
can work. We are currently modifying our detection system and probe
immobilization procedures to find the optimal working range for this
technology.
Development of a Long Ion Chamber Electrometer for Particle Accelerator Beam
Containment. NICHOLAS PATE (Tennessee Technological
University, Cookeville, TN, 38505)
PAUL WRIGHT (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
A common problem
in cavity-coupled linear particle accelerators is misalignment of cavity
phases resulting in particle beam loss over a short distance; when
an intense beam is lost in this manner, high levels of ionizing radiation
are developed that can pose a danger to both personnel and the machine
itself. Long Ion Chambers (LIONs) provide a low-cost and -complexity
method of monitoring radiation levels along a length such as an accelerator,
potentially allowing a control system to take beam containment measures
if a radiation threshold is exceeded. LION implementation in machine
protection systems at the Spallation Neutron Source (SNS) requires
that a standard electrometer design be developed, validated, and calibrated
against other beam-loss and radiation detector systems. Circuit analysis
of an existing prototype electrometer was performed to determine ideal
characteristics of the design, and an experimental frequency analysis
was performed to verify suitability for use under the expected measurement
conditions. Because a vital piece of measurement equipment was unavailable,
it was not possible to conduct a more detailed characterization of
the circuit. It was determined that the maximum input signal before
output clipping occurs is an order of magnitude higher than necessary,
that gain drops off significantly for signals above 10KHz, and that
the circuit operates as expected for relatively high input and offset
currents. Further work will include a more detailed spectrum analysis,
especially for small signals, determination of signal-to-noise ratio,
and investigation of a small interference source that was observed
during testing. This work is part of an ongoing effort to evaluate
and implement LION-based radiation monitoring and beam containment
in the SNS accelerator system.
Development of a Low-Cost Pitch-Based Carbon-Carbon Composite for Friction
Applications. ANDREW MELO (The University of the South, Sewanee, TN, 37383)
DR. JAMES KLETT (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
Carbon-Carbon (C/C)
composites are materials containing a carbon fiber preform impregnated
with a graphite matrix. These composites have many important physical
characteristics such as excellent specific strength, wear resistance
and low thermal expansion coefficients. Current C/C composites are
often produced by forcing pitch under high pressures and temperatures
into the preform. The pitch fills the voids between the preform fibers,
and the high heat carbonizes the pitch simultaneously. A second step,
called graphitization, involves heating the sample to 2800°C under
an inert atmosphere which causes the carbon within the sample to form
a graphite matrix. Due to the pitch’s viscosity, this process takes
several month-long cycles to conduct. Because of the time and cost
currently required to produce C/C composites, they have seen limited
use outside of aerospace and military applications. A novel proprietary
process for the fabrication of C/C which obviates the need for high
pressure processing has been developed at ORNL. In the present project,
this process was used to fabricate samples made of a chopped carbon
fiber technology called P4 and samples made from a three dimensional
fiber weave. These samples were processed (impregnated, carbonized
and graphitized at least two times) in under a month to create samples
with an average density of 1.3 g/cc compared with a density of approximately
1.7 g/cc with the old method. Optical microscogy, scanning electron
microscopy, thermal conductivity, flexural strength, tensile strength,
wear testing, and density measurements were performed on the samples
to characterize their properties. Currently, these parts demonstrate
a thermal conductivity of 12.5 W/m K as well as a flexural strength
and modulus of 30.3 MPa and 76 GPa, respectively. It is hoped that
this new process will produce parts with nearly the same physical characteristics
as the old method while dramatically reducing cost.
Development of a System to Test Internal Pressurizer Dynamics. IRENE
BERRY (Virginia Polytechnic Institute and State University, Blacksburg, VA, 24060)
EMILIAN POPOV (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
The International
Reactor Innovative & Secure (IRIS) is a next generation pressurized
water reactor (PWR) that utilizes an integral coolant loop. The coolant
loop is inside the reactor vessel; the loop pressurizer is in the upper
head of the vessel and has larger liquid surface area and volume than
traditional PWR pressurizers. Because of this, the internal pressurizer
will respond differently to changes in coolant volume and level. Its
response to these dynamics must be tested and characterized to optimize
IRIS design and control. A facility is being built at Oak Ridge National
Laboratory to test internal pressurizer dynamics. This project focused
on preparing the facility for operation and involved the completion
of three main tasks: designing the facility’s detailed layout and instrument
placements, developing operating procedures, and creating a Supervisory
Control and Data Acquisition (SCADA) system. To aid in designing facility
layout, a 3d model of the facility was created using AC3D design software.
This model was used to determine instrument placements and pipe dimensions.
Facility constraints and test requirements posed many concerns that
had to be addressed in the operating procedures. To develop these procedures,
facility geometry and conditions, including temperature, pressure,
coolant density, and liquid level, were analyzed at start-up, operating,
and test states. Methods were then developed to safely and consistently
bring the facility to pre-test conditions, run tests, and shutdown
the facility. These procedures were automated as part of SCADA system
design. The SCADA system developed monitors the facility and automates
all start-up and test procedures. It was created using Intellution
FIX, an industrial automation software, and consists of over 100 database
blocks and five control panels. These panels display instrument readings
and allow the user to enter set points and commands. A simple numerical
model of the facility was also created for use with TRAC/RELAP Advanced
Computational Engine (TRACE). TRACE is a computer code designed to
model and evaluate thermal and hydraulic transients in nuclear reactors.
The model developed will be used to approximate start-up and test procedures
and predict facility response. As a direct result of this project,
the internal pressurizer dynamics test facility is nearing completion.
Tests will begin as soon as all equipment is assembled.
Development of Emittance Analysis Software for Ion Beam Characterization. MARIANO PADILLA (Fullerton College, Fullerton, CA, 92832) YUAN LIU (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
Transverse beam emittance
is a crucial property which describes the angular and spatial spread
of charged particle beams. It is a figure of merit frequently used to
determine the quality of ion beams, the compatibility of an ion beam
with a given beam transport system, and the ability to suppress neighboring
isotopes at on-line mass separator facilities. Generally a high quality
beam is characterized by a small emittance. In order to determine and
improve the quality of ion beams used at the Holifield Radioactive Ion
beam Facility (HRIBF) for nuclear physics and nuclear astrophysics research,
the emittances of the ion beams are measured at the off-line Ion Source
Test Facilities. In this project, an emittance analysis software was
developed to perform various data processing tasks for noise reduction
and to evaluate root-mean-square emittance, Twiss parameters, and area
emittance of different beam fractions. The software also provides 2D
and 3D graphical views of the emittance data, beam profiles, emittance
contours, and ellipses. Noise exclusion is essential for accurate determination
of beam emittance values. A Self-Consistent, Unbiased Elliptical Exclusion
(SCUBEEx) method is employed. Numerical data analysis techniques such
as interpolation and nonlinear fitting are also incorporated into the
software. The software will provide a simplified and fast tool for comprehensive
emittance analyses. The main functions of the software package have been
completed. In preliminary tests with real experimental emittance data,
the analysis results using the software were proven to be correct.
Does an Indentation Size Effect Exist in Nickel Titanium Shape Memory Alloy?. ERIN DONOHUE (Brown University, Providence, RI,
2912) EASO P. GEORGE (Oak Ridge National Laboratory, Oak Ridge, TN, 37831)
Hardness is usually
measured by indentation and is considered to be an intrinsic property
of a material. Recently, however, an indentation size effect (ISE) has
been observed, which is manifested as an increase in a material’s hardness
with a decrease in the volume of material probed. This phenomenon has
previously been studied in a variety of materials and is due to the creation
of geometrically necessary dislocations (GND) and work hardening. In
this new work, shape memory alloys (SMA) are examined to determine if
they demonstrate an ISE. After elastic deformation, instead of going
directly into the plastic regime, deformation in a SMA occurs by the
reorientation of the variants of the martensite phase. As a result, when
the SMA is heated above its martensite-to-austenite transformation temperature,
the material returns to its original shape. Nickel titanium (NiTi), a
common SMA, is the material chosen for this study. Using an Instron machine,
a uniaxial compression test is performed to determine the stress-strain
behavior of a bulk sample of NiTi. Another NiTi sample is tested with
spherical indenters in the Nano Indenter XP. By making indents at a variety
of maximum depths for each of the five indenters of different radii,
it is possible to characterize the size dependence of hardness in NiTi.
Fused silica, a material whose elastic properties are well known, is
used to calibrate the size of each indenter. The indents are also imaged
and measured by the MicroXAM Interferometric Surface Profiler. Finally,
the sample is placed in hot water to see which indents are able to recover.
There is a clear trend of increasing hardness with decreasing radii of
the indenters, i.e., an indentation size effect. However, the hardness
values obtained with the two smallest spheres were similar, indicating
that the size effect breaks down at small length scales. The hardness
values obtained with the two largest spheres agree with the hardness
deduced from uniaxial compression, indicating that they correspond to
the macroscopic hardness of the material. Indent sizes measured with
the Nano Indenter and the Profiler correlate well and there is no time-dependent
shape recovery. When placed in hot water, all of the indents experience
some degree of recovery, with some of the smaller indents disappearing
completely. These results indicate that the observed ISE cannot primarily
be due to a dislocation mechanism.
Effects of Annealing on DC Sputtered Gold Catalyst for Growth of Pinning-Effective
Nanostructures in YBCO Film. JONATHAN
HEBERT (University of South Alabama, Mobile, AL, 36688) DAVID CHRISTEN (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
As high temperature
superconductors move more from the laboratory to industry, it is critical
to improve the current carrying capacity. One way to do this is to introduce
controllable flux pinning sites, which prevent the dissipative motion
of superconducting vortices. A method for this of current interest at
ORNL is to embed an ordered array of nanorods within a superconducting
film. In order to be effective, this method should produce pinning sites
with appropriate sizes in densities comparable to important flux densities,
which for most applications is on the order of one tesla. Also, the nanorod
material must be nonreactive to the superconductor and, in order to be
grown perpendicular to the substrate, have a similar crystal structure
to the substrate material. Magnesium oxide (MgO) is an ideal material
for these nanorods for use with the superconductor yttrium barium copper
oxide (YBCO). Another prerequisite for nanorod growth is the presence
of a catalyst, from which the nanorods will nucleate. One such catalyst
for MgO is gold. Through the method of DC sputtering, thin films of gold
have been fabricated, and by annealing these films, "nanodots" were
created. It is known that four main factors affect the size and density
of these nanodots: film thickness, substrate material, annealing time,
and annealing temperature. In this project the effect of different annealing
times was studied for a sputtering time of eight seconds, a sufficient
time for the growth of a continuous film, and an annealing temperature
of 900°C, the processing temperature of MgO nanorods. Interestingly,
the as-deposited film appears to consist of layers of nanoparticles,
each around 100 nm in size, implying that the gold is deposited as fairly
uniformly sized particles instead of atomically. Analysis of the films
and nanodots is carried out using atomic force microscopy and scanning
electron microscopy. The results show that an annealing time on the order
of tens of minutes is needed for nanostructures to agglomerate from continuous
film. In addition, the smallest particles were obtained with an annealing
time of 60 minutes, while annealing for 30 minutes produced the most
uniformly sized particles.
Effects of Reaction Time upon Mesoporous Carbon Self Assembly. LAURA
WANAMAKER (Middle Tennessee State University, Murfreesboro, TN, 37132)
SHENG DAI (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
Mesoporous carbon materials,
which have a wide range of applications, have previously been synthesized
using silica scaffolds, which are fabricated from surfactant templates.
This method, however, is very inefficient as it involves the waste of
silica scaffolds and surfactant templates and the use of toxic chemicals
for silica removal. Thus, a method has been developed using surfactants
as direct templates for the synthesis of the carbon materials. As prescribed
by this method, triblock copolymers were used as the surfactant templates
and a phloroglucinol/formaldehyde copolymer was used as a carbon precursor.
These triblock copolymers are ideal for use in this process as they provide
for carbon through self-assembly under mild conditions. Also, they permit
the production of carbon materials as monoliths, fibers, sheets, and
films. In addition, this method allows for the management of pore size
and structure of the carbon materials by regulation of concentration
and the specific surfactant used, respectively. The purpose of the current
research was to determine the optimal reaction time to produce carbon
materials composed of polymers of predetermined sizes and of uniform
pore size. Reaction times were varied between 20 minutes and 2 hours
to determine the dependence of the self-assembly process. This process
of polymerization of phloroglucinol/formaldehyde copolymers induced phase
separation into an aqueous, inorganic layer, which was discarded, and
an organic layer. The organic layer was separated out and dried at 80°C
overnight and then at 140°C overnight prior to carbonization. Nitrogen
absorption/adsorption measurments, although pending, will provide pore
size, pore volume, and surface area of the produced carbon material.
Electrodeposition of Cobalt and Cobalt-Vanadium Alloy Films on Copper and Iron
Substrates. BENJAMIN TAYLOR (Tennessee Technological
University, Cookeville, TN, 38505)
MARIAPPAN PARANS PARANTHAMAN (Oak Ridge National
Laboratory, Oak Ridge, TN, 37831)
Cobalt (Co) and its
alloys have magnetic and electrical properties that are very attractive
for technological applications. Low coercivity, high magnetic permeability
and relatively high saturation magnetization and electrical resistivity
allow these materials to be used in technical devices such as transformers,
thin film inductors, giant magneto-impedance sensors, etc. One of the
major advantages of Cobalt-Vanadium (Co-V) alloys is that they can be
prepared on different shaped substrates with controlled composition and
magnetic properties by electrodeposition methods. This study concentrates
on developing successful electrodeposition techniques to grow thin films
of Co and Co-V alloys on flat Copper and Iron substrates and transform
the techniques to round wires. The controlling parameters for electrodeposition
of Co and Co-V alloys on Copper and Iron substrates were investigated;
these are temperature, pH, current density, electrolyte composition,
and time. The compositional, magnetic, electrical, and structural properties
of the electrodeposited films were studied. The electroplated samples
were characterized using x-ray diffraction (XRD), x-ray fluorescence,
scanning electron microscopy (SEM), optical microscopy, atomic force
microscopy, and energy dispersive x-ray diffraction. XRD analysis shows
that electrodeposited Co forms hexagonal close packed (h.c.p.) and face
centered cubic (f.c.c.) structures under the various deposition conditions
used in this study. The addition of vanadium (V) and a divided electrolytic
cell with very negative current densities forms slightly textured Co
films in the (110) and (100) orientations. The division of the cell increases
the current efficiency in solutions containing V. Co film thickness is
found to have linear relationships with both current density and time.
SEM images show dense, uniform Co films without cracks or porosity. Grain
size variation is observed with changes in current density and time.
More negative current density causes the electrodeposited Co to be deposited
f.c.c., which is more magnetically reversible than the h.c.p. structured
Co. The coercive field is also significantly less in the f.c.c. electrodeposited
cobalt than in the h.c.p. The electrical and magnetic performances of
the electrodeposited wires will be compared with commercially available
Copper and Iron wires. Research efforts are underway to optimize the
growth of Co film alloyed with 2-3 atomic % V.
Enhancing Javapeño. AARON FLECKENSTEIN (Western Michigan University, Kalamazoo, MI, 49093) DR. BRADLEY T. REARDEN (Oak Ridge National
Laboratory, Oak Ridge, TN, 37831)
Javapeño is a Java-based
data visualization package that is part of Oak Ridge National Laboratory’s
SCALE software suite. Javapeño provides a graphical interface that allows
the user to visualize data in customizable plots. Javapeño was created
by Dr. Bradley Rearden in 2001 as a port from plotting software called
SenPlot. Originally supporting only sensitivity data from the TSUNAMI
modules of SCALE, Javapeño has been improved to support additional data
types. Currently, Javapeño enables visualization of data generated from
SCALE modules: TSUNAMI, SMORES, KMART, and XSDRN-PM, as well as a generic
2D data type. Sponsors of SCALE development have requested that Javapeño
be expanded to support visualizing neutron and gamma cross-section data
in the AMPX format and cross-section-covariance data in the COVERX format.
For this project these new data types required adding three dimensional
(3D) plotting capabilities to Javapeño. To maintain cross-platform compatibility
Javapeño’s 3D plotting engine uses the OpenGL version of Java 3D, an
open source Java extension. Javapeño’s 3D engine is an extensively modified
version of FreeHEP’s Lego Plot application. After developing the 3D engine,
support was added for the COVERX data type. There were conflicts with
the existing methods implemented in Javapeño and the way Java handles
Java 3D objects. Java 3D objects are treated as heavy-weight objects,
while the rest of Javapeño is light-weight. In Java, heavy-weight objects
are always placed on top of light-weight objects, even when they are
not active. Thus, unless modified, the new 3D plotting capability would
prevent using the existing 2D plotting capabilities of Javapeño. To address
this conflict, a new interface and window manager was created. Planned
future enhancements include support for AMPX data files, saving plots,
and configuration files.
Evaluation of a 4.5 kW Air-Cooled Lithium Bromide/water Solar Powered (Hot
Water-Fired) Absorption Unit. DAVID GOODNACK (Pennsylvania
State University, University Park, PA, 16802) ABDOLREZA ZALTASH (Oak
Ridge National Laboratory, Oak Ridge, TN, 37831)
During the summer months,
air-conditioning (cooling) is the single largest use of electricity in
both residential and commercial buildings with the major impact on peak
electric demand. Improved air-conditioning technology has by far the
greatest potential impact on the electric industry compared to any other
technology that uses electricity. Thermally activated absorption air-conditioning
(absorption chillers) can provide overall peak load reduction and electric
grid relief for summer peak demand. This innovative absorption technology
is based on integrated rotating heat exchangers to enhance heat and mass
transfer resulting in a potential reduction of size, cost, and weight
of the "next generation" absorption units. Rotartica Absorption
Chiller (RAC) is a 4.5 kW air-cooled lithium bromide (LiBr)/water unit
powered by hot water generated using the solar energy and/or waste heat.
Typically LiBr/water absorption chillers are water-cooled units which
use a cooling tower to reject heat. Cooling towers require a large amount
of space, increase start-up and maintenance costs. However, RAC is an
air-cooled absorption chiller (no cooling tower). The purpose of this
evaluation is to verify RAC performance by comparing the Coefficient
of Performance (COP or ratio of cooling capacity to energy input) and
the cooling capacity results with those of the manufacturer. The performance
of the RAC was tested at Oak Ridge National Laboratory (ORNL) in a controlled
environment at various hot and chilled water flow rates, air handler
flow rates, and ambient temperatures. Temperature probes, mass flow meters,
rotational speed measuring device, pressure transducers, and a web camera
mounted inside the unit were used to monitor the RAC via a web control-based
data acquisition system using Automated Logic Controller (ALC). Results
showed a COP of approximately 0.58 at 35°C design condition for ambient
temperature with 40°C cooling water temperature and approximately 3.7
kW capacity. This is in close agreement with the manufacturer data of
0.60 for COP and 3.9 kW capacity. This study resulted in a complete performance
map of RAC which will be used to evaluate the potential benefits of rotating
heat exchangers in making the "next-generation" absorption
chillers more compact and cost effective without any significant degradation
in the performance. In addition, the feasibility of using rotating heat
exchangers in other applications will be evaluated.
Evaluation of Long-Term Brake Performance Using Performance-Based Brake Testers
(PBBT). JESSICA JOSEPH (Southern
University A&M of Baton Rouge, Baton Rouge, LA, 70816) GARY J.
CAPPS (Oak Ridge National Laboratory, Oak Ridge, TN, 37831)
Performance-Based Brake
Testers (PBBTs) are devices that can evaluate the current braking capabilities
of a vehicle through the measurement of brake forces developed as a vehicle
engages in a braking event while on a PBBT. They are widely used for
brake inspection in Europe and Australia and are beginning to emerge
as both an enforcement tool and diagnostic aid for private sector maintenance
and repair shops. Because of the significant benefits of utilizing PBBT
technologies (time/labor savings, error reduction, objective measures,
consistency, enhanced fleet safety), Federal Motor Carrier Safety Administration
(FMCSA) has an interest in assessing a vehicle’s long-term brake performance
using PBBT technology over time in a real-world testing environment.
This will be done in conjunction with volunteer fleets (including a motor-coach),
over a sufficiently long period of time, to measure (for each vehicle
in the test fleet) the brake force for the overall vehicle, and for each
individual wheel-end. Such an effort would provide experiential data,
and would quantitatively assess benefits from long-term brake performance
data. A market search was done to find manufactures or sole distributors
of PBBT devices that offer artificial axle loading (AAL) capability and
research was done to understand the theory of operation of the PBBT.
The different types of PBBT (roller, in-ground, portable) were evaluated
to decide which PBBT with AAL would be best for research based on meeting
FMCSA’s Functional Specifications. An evaluation was completed for three
possible vendors to determine which vendor would provide the best PBBT
for research applications and a training module for use by the Tennessee
Department of Safety Personnel. The vendor’s PBBT must be certified and
meet the FMCSA criteria in order to be a candidate to provide a PBBT.
A survey and location matrix was done to compare and decide which one
of three possible locations would accommodate the needs for the State
of Tennessee and Oak Ridge National Lab.
Expression of Type I Cohesin and Type I Dockerin Domains from Clostridia thermocellum
for Nano Patterning. CATHEIRNE
COFFMAN (University of Tennessee Chattanooga, Chattanooga, TN, 37403)
JENNIFER MORRELL-FALVEY (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
Cellulosomes are multienzymatic
complexes from bacteria that have been studied for their ability to break
down the cellulose in plant walls yielding ethanol as a byproduct. The
scaffoldin protein is a significant component of the cellulosome structure
because it binds to both the cellulose and cellulose degrading enzymes
in the most advantageous manner for hydrolysis. In the assemblage of
scaffoldin, nine Cohesin domains, in the presence of Calcium, mediate
binding to enzymes that contain a Dockerin domain. This investigation
examines the specific binding of the Type I Cohesin (CohI) and Type I
Dockerin (DocI) molecules, which are components of the scaffoldin in
the cellulosome. The objective is to artificially generate and assemble
CohI and DocI using their unique binding specificity as an affinity pair.
A 6x Histadine (His) tag will be added to the CohI so that it can bind
to a nickel surface. Green florescent protein (GFP) and a strep tag are
added to DocI. The interaction between the CohI and DocI would be visible
through the GFP, and the strep tag allows for purification of the DocI
fusion protein. Thus far, the CohI and DocI domains have been identified
in the sequences of CipA and CelS respectively in Clostridia thermocellum.
Using genomic material from C. thermocellum, the CohI and DocI domains
were PCR amplified. Expression vectors were constructed with the CohI
and DocI inserts. A GFP with no stop codon was also ligated into the
vector containing DocI so that, when expressed, the GFP forms a fusion
protein with DocI. The ligated plasmids were transformed into E. coli
strain BL21(DE3) where the CohI and DocI-GFP can be expressed. After
the cell produces the proteins, they can be purified using the attached
His and strep tags. This affinity pair can potentially be useful in nano
patterning as CohI can be positioned using nickel beads and binding events
can be mediated through the Cohesin-Dockerin specificity. Binding can
also be controlled since the CohI and DocI do not bind unless calcium
is present in the system.
Finding Multiple Alignments and Common Motifs for Orthologous Rhodopseudomonas
palustris genes. ARIELLA BARHEN (Miami University, Oxford, OH, 45056) LOREN HAUSER (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
There is an ongoing
problem of being able to find consistent regulatory motifs in unaligned
DNA sequences, including MEME, PhyloCon, and ClustalW. In one approach,
orthologous input sequences are used to identify well conserved regions
by phylogenetic footprinting. When numerous genomes are available, orthologous
sequences can be aligned and conserved regions can be identified. These
results are then submitted to various motif finders. To obtain a multiple
alignment, ClustalW was used. ClustalW is a multiple sequence alignment
program for DNA or proteins, and it calculates the best match for specific
sequences and lines them up so that the sequences can be compared and
contrasted. Phylogenetic trees were also constructed from the multiple
alignments. ClustalW was used to provide multiple alignment sequences
for specific genes from four different Rhodopseudomonas palustris strains.
Based on the results, conserved sequences can be identified and motifs
can be found. The complete sequences genome of Rhodopseudomonas palustris
was used to compare R. palustris BisA53, R. palustris BisB18, R. palustris
BisB5, and R. palustris HaA2. FASTA files were collected from Artemis
(they contained an average of about 200 base pairs upstream from the
start codon of the specific genes) and compiled using the editor “Kate.” ClustalW
lines up the specific sequences and similarities and differences can
be seen between the orthologous genes. Common motifs were able to be
identified as well as possible promoter sequences. These identifications
can be of high importance when trying to verify evolutionary relationships.
Further work could be done to compare the actual transcription factors
for the orthologous genes.
Generation of Translational Fusion Vectors for Candidate Cilia Genes. SANDRA MCGILL (Clayton State University, Morrow, GA, 30260) EDWARD J. MICHAUD, III (Oak
Ridge National Laboratory, Oak
Ridge, TN, 37831)
Cilia are small organelles
that protrude from the surfaces of cells and are conserved in most eukaryotes,
including nematode worms, laboratory mice, and humans. Cilia fall into
two broad classes: motile cilia, which occur in clusters on mammalian
cells and move fluids over cell surfaces; and primary cilia, which are
found singly on virtually all cell types in mammals. It was recently
discovered that primary cilia have vital sensory functions in many human
tissues, and that flaws in these organelles lead to numerous human diseases.
Comparative genomics and proteomics studies have determined that the
cilia proteome consists of some 300-500 proteins. However, the functions
of most of these candidate cilia proteins are unknown. The goal of this
project was to select two of these candidate proteins identified by computational
methods and to construct plasmid vectors in which the worm genes are
cloned in-frame with the green fluorescence protein (gfp) reporter gene. Two candidate cilia genes in C. elegans nematodes, E02H1.5 and R148.1,
were selected for cloning into the GFP reporter vector, pPD95.81. The
DNA sequence of each gene was obtained from the University of California
at Santa Cruz Genome Browser, and polymerase chain reaction (PCR) primers
were chosen using the MacVector 6.5.3 sequence analysis program. These
primers were used to amplify the promoter and coding regions of each
gene from C.
elegans DNA. Each gene was amplified by PCR and cloned in-frame with gfp in
the pPD95.81 vector, resulting in two translational vectors, E02H1.5::GFP
and R148.1::GFP. The E02H1.5::GFP and R148.1::GFP translational vectors
were subjected to restriction enzyme digestions and DNA sequence analysis,
which confirmed that the two C.
elegans genes
were cloned into the pPD95.81 vector in the correct orientation and in-frame
with gfp.
Future work will involve microinjection of these generated transgene
vectors into the gonads of nematodes to produce transgenic worms, which
will be used to determine experimentally if these proteins localize to
primary cilia. These worms will be examined under a fluorescence microscope
to determine if the E02H1.5::GFP and R148.1::GFP fusion proteins localize
only to ciliated cells. If they do localize to ciliated cells exclusively,
E02H1.5 and R148.1 will be confirmed as cilia proteins. This will set
the stage for analysis of the functions of the homologous proteins in
mice and humans.
Genome-Enabled Discovery of Carbon Sequestration Genes in Populus. KEVIN JARBOE (George Mason University, Fairfax, VA, 22030)
LEE GUNTER/UDAYA KALLURI (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
As atmospheric levels
of carbon dioxide rise along with the demand for fossil fuels a difficult
problem arises to which there is no simple solution. Using less energy
as well as taking advantage of low carbon and carbon-free fuels are two
ways which can help control atmospheric carbon concentrations, however
current research shows this is simply not enough. Additional methods
must be developed and employed to control atmospheric carbon concentrations
and avoid the potential side effects that may accompany a state of highly
elevated carbon levels. Plants have a natural ability to fix atmospheric
carbon dioxide through photosynthesis. Allocation of photosynthetic products
to quantitatively important recalcitrant plant components contributes
towards terrestrial carbon sequestration. There is a genetic aspect to
the plant processes controlling carbon allocation to sink tissues. Present
work explores the functional roles of candidate carbon allocation genes,
Aux/IAAs, in determining Populus plant structure as well as biomass distributions.
Preliminary phenotyping of transgenic Aux/IAA plants have shown differences
in above- and belowground biomass distributions when compared to that
of control plants. Results from real-time RT-PCR studies and morphological
characterization of transgenic Aux/IAA plants will be presented.
Global Analysis of Iron Response and Fur Regulon in Shewanella oneidensis MR-1. DANIEL HARRIS (Albion College, Albion, MI, 49224) JIZHONG ZHOU (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
Iron is an essential
micronutrient for both prokaryotic and eukaryotic organisms. In addition
to structural roles in proteins, the iron redox potential makes it a
useful cofactor for proteins functioning in respiration, electron transport,
photosynthesis, nitrogen fixation, DNA biosynthesis and other important
processes. However, accumulation of free Fe(II) will catalyze Fenton
reactions, which produce highly reactive oxygen species that damage cellular
components. Levels of intracellular iron must therefore be precisely
regulated to meet metabolic needs while minimizing risk of iron toxicity.
Most bacteria moderate iron though the use of the Ferric Uptake Regulator
(Fur), an iron-responsive global transcriptional factor that represses
transcription when iron is present. In this study, the iron response
network was analyzed in Shewanella oneidensis MR-1, and in a fur deletion
mutant derived from MR-1. Cells were harvested at various intervals after
addition of iron chelator (2,2’-dipyridyl), and then after iron repletion
with iron sulfate (FeSO4). Total RNA from extracted from each strain
at 13 time intervals, reverse transcribed, fluorescently labeled, and
hybridized to DNA microarray slides. Four biological replicates were
collected for each mutant for a total of 102 microarray hybridizations.
Our results indicate that transcription of proteins involved in iron
uptake and storage are mediated by Fur, and that these proteins are highly
sensitive to iron availability. Proteins involved in energy metabolism
are also regulated by iron availability and Fur, though to a lesser extent.
Interestingly, Fur not only acts globally as a repressor, but also activates
certain genes in response to fluctuations in extracellular iron concentration.
Most of these genes have unknown function. In addition, we also identified
regulatory genes controlled by Fur. Further investigations into the interaction
between regulatory genes and Fur would be interesting and significantly
increase our understanding of transcriptional regulation in S. oneidensis,
an important metal-reducing bacterium with potential in the bioremediation
of contaminated sites.
Heavy Truck Duty Cycle Study. MARY LASCURAIN
(Pensacola Christian College, Pensacola, FL, 32503)
GARY CAPPS (Oak Ridge National Laboratory, Oak
Ridge, TN, 37831)
To date, little real-world
scientific data regarding long-haul, Class-8 tractors and their engine
and drive train components has been collected for analysis. Of great
importance to the study of this class of commercial vehicle is the
understanding of how factors such as tire type and vehicle loading
influence fuel efficiency. Because many variables cannot be controlled
