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fundamental science and applied engineering problems |
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| Research is dedicated to the development of advanced diagnostic techniques and applications to a number of fundamental and applied problems. Research topics include traditional engineering problems in the general thermal-fluid sciences, such as combustion processes, thermal waste treatment, materials synthesis, and process monitoring. Emerging science and engineering problems of interest include biomedical applications such as laser ablation of tissue and laser- tissue interactions, real-time analysis of aerosols and nanoparticles, and novel biomedical diagnostics. Representative research projects, present and past, are summarized below. |
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fundamental science and applied engineering problems |
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Solar Thermal
Power
Solar thermal energy holds great promise for the production
of renewable and
zero-emission fuels such as hydrogen from water. Hydrogen-based
fuels are desirable as
a zero-emission energy source, with the added advantage of energy
storage over direct
solar-electric conversion. While there are many different approaches to
hydrogen generation, by far the most attractive means is to split water
molecules using solar energy. Such an
approach provides for a completely clean and renewable energy supply.
The current
approach is to develop highly reactive metal oxide materials to produce
intermediary reactions that result in the splitting of water to produce
hydrogen at moderate temperatures (<1000 K).
It is envisioned that the metal oxide reactors will ultimately be
mounted within a solar concentrating reactor, and irradiated via
heliostats. This Task is structured toward the overall
goals of solar-driven, thermochemical hydrogen production, with
associated
efforts toward the enabling surface science, catalysis, particle
science,
material synthesis, nano-structures, multiscale-multiphase physics
modeling,
and process simulation that will enable the realization of solar
hydrogen-based
fuels to power the transportation economy.
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Differential
Laser-induced Perturbation Spectroscopy:
A Novel Approach for Chemical and Biochemical Sensing The development of truly new methodologies that
provide improved sensitivity and/or specificity for rapid and accurate
biosensing is highly desirable for in
situ and in vivo
cancer
screening, detection of biological pathogens and/or explosives for
biodefense, as well as food
(e.g. pathogen detection) and building safety.
However, despite the need and motivation, to date the clinical
applicability of in vivo
cancer
sensing schemes has been limited by the large patient-to-patient
variations in
fluorescence properties, while biosensing for homeland defense has been
curtailed by the large variation in background signal levels combined
with a
lack of target specificity. The proposed
research seeks to develop a novel biosensing scheme that holds promise
to
significantly enhance both sensitivity and specificity as compared to
the
current state-of-the-art optical-based sensing methodologies.
This scheme is based on our recent research
showing that the biological matrix may be altered by low intensity
(i.e., below
the ablation threshold) ultraviolet radiation (primarily 193 to 213 nm)
such
that the intrinsic fluorescence or Raman scattering response is
perturbed. Our research uses a novel sequential combination of
optical probing (Raman or fluorescence), UV photochemical perturbation,
and
repeat optical probing to realize a powerful new spectral dimension
based on difference spectroscopy that will
be strongly coupled to the local biomolecular matrix. Since the
targeted material is optically probed
both before and after perturbation with the deep UV
light source, the resulting differential response will avoid the major
limitation of the current biosensing schemes, namely, the significant
variations in the absolute optical response, as generally observed in
patient-to-patient populations and real-world environments.
University of Florida Research & Graduate Programs (RGP) |
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Novel
Fluidized-bed Reactor for the Looping Process:
Coal to Hydrogen Production R&D The objective of the project is to research and develop
a novel chemical looping reactor concept for the ability to efficiently
and
effectively process coal gasification synthesis gas to generate
discrete
high-purity streams of hydrogen and sequestration-quality carbon
dioxide. The
research investigation will evaluate magnetically fluidized-bed reactor
configurations/concepts and the magnetic, chemical, thermal, and fluid
transport properties of various metal oxide particles for viability for
scale-up and integration into a coal gasification facility for
producing
commercial quantities of hydrogen.
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Solving the
Plasma-Analyte Interaction Problem
Plasmas are a
central
component of many of today’s leading analytical methods for chemical
analysis,
microanalysis and materials characterization, including laser-ablation
inductively-coupled plasma mass spectrometry (LA-ICP-MS),
inductively-coupled
plasma atomic emission spectroscopy (ICP-AES), and laser-induced
breakdown
spectroscopy (LIBS). In all of these, the complex plasma-analyte
interactions
are directly related to the ultimate analyte response and to the
quality of the
results provided by the techniques. This research seeks to transform
these
analytical methods by solving the problems associated with the
plasma-analyte
interface, thereby providing an essential step forward in quantitative
plasma-based and plasma-assisted analysis that is necessary to support,
for
example, larger research efforts in microanalysis, the nanosciences,
novel
materials development, and the biosciences. Rapid, local, accurate,
direct quantitative
solid sample analysis will be the outcome of the collaborative studies
envisaged in this proposal. The overall plan of research involves
an
integrated approach to understand and control plasma-analyte and mutual
analyte-analyte interactions through a combination of theoretical
modeling and
innovative experimental methods. Each aspect of the program is designed
to
promote true synergy between the US and German research groups.
Plasma-Analyte Interaction Working Group (PAIWG), a collaborative effort of the University of Florida, Federal Institute of Materials Research and Testing (BAM) in Berlin, and the Institute for Analytical Sciences (ISAS) in Dortmund, jointly funded by the NSF and DFG. |
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Plasma-Particle
Interactions
Research to understand the
physical
processes associated with the interactions of laser-induced plasmas
with
aerosol particles, including particle vaporization/dissociation, atomic
diffusion of aerosol constituent atoms, and ensuing plasma optical
emission. The emphasis is on the basic plasma-particle interactions, a
complex
problem
given the highly transient nature of the laser-induced plasma, plasma
non-homogeneity,
and the uncertainty as to the exact mechanisms of aerosol particle
dissociation. An overall project goal is to advance laser-induced
plasma spectroscopy
as a contemporary analytical tool, particularly for quantitative
aerosol
analysis.
National Science Foundation (CTS-0317410) |
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Catalytic
Combustion
Catalytic combustion can
play
an important role in emissions reduction strategies, including
reduction
of NOx. Research efforts support the understanding of
heterogeneous
reactions from hydrocarbon fuels over noble-metal catalysts.
Program
involves in situ diagnostic
schemes for species measurements in
coordination
with development of kinetic models.
In collaboration with Siemens Power Generation |
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Methanol
Reformation for Hydrogen Production
Research is focused on
measurement
of the evolution of reformate gases during the catalytic reformation of
methanol.
Experiments are performed in a laboratory-scale reformer that
utilizes in situ Raman spectroscopy. The optical access
reactor
provides a clear picture of the progression of the reforming/reaction
progress.
In collaboration with NASA |
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Portable
LIBS System for Field Measurements
Research efforts support the development of a
new instrument based on the technique
of laser-induced breakdown spectroscopy (LIBS). A prototype
LIBS-based
instrument is being developed to provide field-deployable, rapid
analysis
of a range of compounds relevant to national security, including
biological
compounds and explosives. Research issues to be addressed at the
University of Florida include optimization of the LIBS technique for
compounds of interest, real-time analysis using chemometrics, and
spectral normalization.
In collaboration with
Ocean Optics, Inc., U.S. Army Research Laboratory, |
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Research is focused on the interactions of 193-nm ArF excimer laser beams with corneal tissue during ablation processes. Topics include quantifaction of the absorption properties (e.g. exact chromphores and cross-sections), development of dynamic ablation models, assessment of corneal transport properties, and development of real-time diagnostics. Fundamental understanding of the corneal ablation process can lead to better therapeutic and refractive procedures. ALCON Research, Ltd. |
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Advanced
Measurement Techniques for Emerging
Technologies
The primary objective of this program
was to develop an integrated curriculum and research program to address
the
needs for advanced measurement techniques applicable to current and
emerging
technologies within the overall sphere of thermal sciences and
engineering. Relevant technology
applications include several emerging areas in engineering education
such as
microelectronics, micro-electro-mechanical systems (MEMS),
biotechnologies and
bioengineering. Our curriculum
functioned to educate and train engineers in these much-needed fields
by
focusing on innovative, technology crosscutting measurement techniques
and
emphasizing relevant applications.
National Science Foundation
(EEC-0080453)
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Real-time
Aerosol Analysis
Research has led to the
development
of a novel technique for the quantitative analysis of individual
submicron-sized
aerosol particles. The technique uses laser-induced breakdown
spectroscopy
(LIBS) to dissociate single aerosol particles in a laser-induced
plasma.
Analysis of the resulting plasma emission is used to quantify the mass
and composition of aerosols. The technique has been applied in
real-time
for the analysis of ambient air particles. Single particles have
been measured with sizes as small as 100 nm with corresponding mass of
about 1 femtogram. This research is promising for the real-time
monitoring
of fine particulate matter in ambient air. Fine particulate
matter
(PM) is an air pollutant that has been increasingly associated with
risks
to human health.
In collaboration with Sandia National Laboratories, Livermore, California |
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Using Fuel Additives Technologies The research goal is to
characterize particulate matter (PM) emissions from naval engines, and
explore control stratagies, including metallic-based fuel
additives. In situ
diagnostic techniques (RDG light scattering, LIF and laser-induced
incandescence) are used to enhance
understanding of the sources and mechanisms of PM formation, and the
roles and mechanisms of fuel additive compounds in soot
suppression. The integrated
research program is designed to realize effective and optimal control
of emissions from aircraft and shipboard engines. Office of
Naval
Research |
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Remote
Hydrogen Leak Detection
Research efforts are
focused
on the remote detection of hydrogen leaks under ambient air conditions.
The technological approach uses the integration of Raman
spectroscopy
and Rayleigh light scattering using temporal and spectral data analysis
in combination with pulsed laser excitation to discriminate from
background
contaminants and to optimize leak detection at the leak source. A
long-term project goal is the development robust detection schemes with high species sensitivity.
In collaboration with NASA |
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Analysis
of in vivo Generated Implant Wear Debris
Advanced measurement
techniques
have been applied to the analysis of wear debris particles generated
within
patients with artificial knee implants. Polyethylene particles
were analyzed using laser light scattering and micro-Raman
spectroscopy.
Metallic particles were analyzed using laser-induced breakdown
spectroscopy. Research to date has produced data regarding the
concentration of wear
debris particles, the chemical composition of polyethylene particles,
and
the size and alloy composition of metallic particles. This
research
is important for understanding and ultimately reducing premature
implant
failures, notably implant failures associated with tissue inflammatory
response and osteolysis.
In collaboration with
the College of Medicine, University of Florida |
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LIBS-based
Analysis of Toxic Metals
Research activities are
focused
on understanding fundamental processes associated with atomic emission
from metal atoms in laser-induced plasmas. Specific studies have
focused on emission from mercury, elucidating the complex interactions
between mercury and oxygen species during the plasma decay
process. Additional research has focused on optimization for
simultaneous detection of multiple metals, and signal enhancements
using a novel conditional data analysis routine.
In collaboration with Sandia National Laboratories, Livermore, California |
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Research activities are
focused on the design and implementation of rapid,
real-time process monitoring techniques using laser-induced breakdown
spectroscopy (LIBS). Applications include the identification and
sorting of wood products treated with chromated copper arsenate (CCA)
from construction
and demolition debris waste streams. Such real-time sorting
capabilities provide additional options for waste management strategies.
In collaboration with
Environmental Engineering Department, University of Florida |
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Biomedical
Diagnostics
Research is focused on the
development of non-invasive laser-based diagnostic techniques for
applications
to both humans and animals. Recent activities have focused on the
assessment of corneal haze in animal models. The presence of corneal
haze
is associated with structural changes or remodeling of the corneal
stroma, and in general produces a detrimental impact on visual
acuity. This research supports the long term goal of advancing
the knowledge base regarding the role of corneal haze in the human
vision system.
In collaboration with the College of Medicine, University of Florida |
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