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Texas A&M University
1.
Meng, Zhaokai.
Light Scattering Problem and its Application in Atmospheric Science.
Degree: 2011, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8914 
► The light scattering problem and its application in atmospheric science is studied in this thesis. In the first part of this thesis, light scattering theory…
(more)
▼ The light scattering problem and its application in atmospheric science is studied
in this thesis. In the first part of this thesis, light scattering theory of single irregular
particles is investigated. We first introduce the basic concepts of the light scattering
problem. T-matrix ansatz, as well as the null-field technique, are introduced in the
following sections. Three geometries, including sphere, cylinder and hexagonal column,
are defined subsequently. Corresponding light scattering properties (i.e., T-matrix and
Mueller Matrix) of those models with arbitrary sizes are simulated via the T-matrix
method.
In order to improve the efficiency for the algorithms of single-light scattering, we
present a user-friendly database software package of the single-scattering properties of
individual dust-like aerosol particles. The second part of this thesis describes this
database in detail. Its application to radiative transfer calculations in a spectral region
from ultraviolet (UV) to far-infrared (far-IR) is introduced as well. To expand the degree
of morphological freedom of the commonly used spheroidal and spherical models, triaxial
ellipsoids were assumed to be the overall shape of dust-like aerosol particles. The
software package allows for the derivation of the bulk optical properties for a given distribution of particle microphysical parameters (i.e., refractive index, size parameter
and two aspect ratios). The array-oriented single-scattering property data sets are stored
in the NetCDF format.
The third part of this thesis examines the applicability of the tri-axial ellipsoidal
dust model. In this part, the newly built database is equipped in the study. The precomputed
optical properties of tri-axial models are imported to a polarized addingdoubling
radiative transfer (RT) model. The radiative transfer property of a well-defined
atmosphere layer is consequently simulated. Furthermore, several trial retrieval
procedures are taken based on a combination of intensity and polarization in the results of
RT simulation. The retrieval results show a high precision and indicate a further
application in realistic studies.
Advisors/Committee Members: Yang, Ping (advisor), Kattawar, George W. (advisor), Fry, Edward (committee member).
Subjects/Keywords: Light Scattering; T-matrix; Aerosol; Database; Radiative Transfer
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APA (6th Edition):
Meng, Z. (2011). Light Scattering Problem and its Application in Atmospheric Science. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8914
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Meng, Zhaokai. “Light Scattering Problem and its Application in Atmospheric Science.” 2011. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8914.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Meng, Zhaokai. “Light Scattering Problem and its Application in Atmospheric Science.” 2011. Web. 08 Dec 2019.
Vancouver:
Meng Z. Light Scattering Problem and its Application in Atmospheric Science. [Internet] [Thesis]. Texas A&M University; 2011. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8914.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Meng Z. Light Scattering Problem and its Application in Atmospheric Science. [Thesis]. Texas A&M University; 2011. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8914
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
2.
Slanker, Julie Marie.
Radiance in the ocean: effects of wave slope and raman scattering near the surface and at depths through the asymptotic region.
Degree: 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2576
► Three investigations were conducted on the nature of the radiance field in clear ocean water. It is important to understand the sunlight intensity below the…
(more)
▼ Three investigations were conducted on the nature of the radiance field in clear ocean
water. It is important to understand the sunlight intensity below the sea surface because
this leads to an understanding of how ocean creatures navigate in shallow and deep
water. The nature of the radiance field is also gives an understanding of the living
environment for ocean animals. Hydrolight 4.1, a simulation software developed by
Curtis D. Mobley, was used to calculate the spectral radiance in clear ocean water for
multiple wavelengths from the surface down through the asymptotic region. The first
study found, as expected, that Raman scattering has little effect on wavelengths of light
that are less than 500 nm. The effect of Raman scattering increases with increasing
wavelength, and with increasing depth. The second study found the region of the water
column where the radiance field is asymptotic. The third investigation found the effect
of changing the mean square slope, or variance of the water-wave slope distribution.
This effect is greatest near the surface and for a more truncated mean square slope
integral. There are three peaks in percent difference to the ideal case, near the surface,
one in the solar beam and the others near the critical angle of water.
Advisors/Committee Members: Kattawar, George W. (advisor), Saslow, Wayne M. (committee member), Yang, Ping (committee member).
Subjects/Keywords: Raman Scattering; Asymptotic Region; Mean Square Slope
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APA (6th Edition):
Slanker, J. M. (2009). Radiance in the ocean: effects of wave slope and raman scattering near the surface and at depths through the asymptotic region. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2576
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Slanker, Julie Marie. “Radiance in the ocean: effects of wave slope and raman scattering near the surface and at depths through the asymptotic region.” 2009. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-2576.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Slanker, Julie Marie. “Radiance in the ocean: effects of wave slope and raman scattering near the surface and at depths through the asymptotic region.” 2009. Web. 08 Dec 2019.
Vancouver:
Slanker JM. Radiance in the ocean: effects of wave slope and raman scattering near the surface and at depths through the asymptotic region. [Internet] [Thesis]. Texas A&M University; 2009. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2576.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Slanker JM. Radiance in the ocean: effects of wave slope and raman scattering near the surface and at depths through the asymptotic region. [Thesis]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2576
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
3.
Chen, Guang.
Modeling of the optical properties of nonspherical particles in the atmosphere.
Degree: 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-1418
► The single scattering properties of atmospheric particles are fundamental to radiative simulations and remote sensing applications. In this study, an efficient technique, namely, the pseudo-spectral…
(more)
▼ The single scattering properties of atmospheric particles are fundamental to
radiative simulations and remote sensing applications. In this study, an efficient
technique, namely, the pseudo-spectral time-domain (PSTD) method which was first
developed to study acoustic wave propagation, is applied to the scattering of light by
nonspherical particles with small and moderate size. Five different methods are used to
discretize Maxwell?s equations in the time domain. The perfectly matched layer (PML)
absorbing boundary condition is employed in the present simulation for eliminating
spurious wave propagations caused by the spectral method.
A 3-D PSTD code has been developed on the basis of the five aforementioned
discretization methods. These methods provide essentially the same solutions in both
absorptive and nonabsorptive cases. In this study, the applicability of the PSTD method
is investigated in comparison with the Mie theory and the T-matrix method. The effects
of size parameter and refractive index on simulation accuracy are discussed. It is shown
that the PSTD method is quite accurate when it is applied to the scattering of light by spherical and nonspherical particles, if the spatial resolution is properly selected.
Accurate solutions can also be obtained from the PSTD method for size parameter of 80
or refractive index of 2.0+j0.
Six ice crystal habits are defined for the PSTD computational code. The PSTD
results are compared with the results acquired from the finite difference time domain
(FDTD) method at size parameter 20. The PSTD method is about 8-10 times more
efficient than the conventional FDTD method with similar accuracy. In this study, the
PSTD is also applied to the computation of the phase functions of ice crystals with a size
parameter of 50.
Furthermore, the PSTD, the FDTD, and T-matrix methods are applied to the study
of the optical properties of horizontally oriented ice crystals. Three numerical schemes
for averaging horizontal orientations are developed in this study. The feasibility of using
equivalent circular cylinders as surrogates of hexagonal prisms is discussed. The
horizontally oriented hexagonal plates and the equivalent circular cylinders have similar
optical properties when the size parameter is in the region about from 10 to 40.
Otherwise, the results of the two geometries are substantially different.
Advisors/Committee Members: Yang, Ping (advisor), Kattawar, George W. (committee member), North, Gerald (committee member), Wilheit, Thomas (committee member).
Subjects/Keywords: light scattering; FDTD; PSTD; single scattering; optical properties
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APA ·
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APA (6th Edition):
Chen, G. (2009). Modeling of the optical properties of nonspherical particles in the atmosphere. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-1418
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Chen, Guang. “Modeling of the optical properties of nonspherical particles in the atmosphere.” 2009. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-1418.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Chen, Guang. “Modeling of the optical properties of nonspherical particles in the atmosphere.” 2009. Web. 08 Dec 2019.
Vancouver:
Chen G. Modeling of the optical properties of nonspherical particles in the atmosphere. [Internet] [Thesis]. Texas A&M University; 2009. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1418.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Chen G. Modeling of the optical properties of nonspherical particles in the atmosphere. [Thesis]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1418
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
4.
You, Yu.
Applications of the Generalized DDA Formalism and the Nature of Polarized Light in Deep Oceans.
Degree: 2010, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2008-08-46
► The first part of this study is focused on numerical studies of light scattering from a single microscopic particle using the Discrete Dipole Approximation (DDA)…
(more)
▼ The first part of this study is focused on numerical studies of light scattering
from a single microscopic particle using the Discrete Dipole Approximation (DDA)
method. The conventional DDA formalism is generalized to two cases: (a) inelastic
light scattering from a dielectric particle and (b) light scattering from a particle with
magnetic permeability u /= 1. The first generalization is applied to simulations of
Raman scattering from bioaerosol particles, and the second generalization is applied
to confi rmation of irregular invisibility cloaks made from metamaterials.
In the second part, radiative transfer in a coupled atmosphere-ocean system is
solved to study the asymptotic nature of the polarized light in deep oceans. The rate
at which the radiance and the polarization approach their asymptotic forms in an
ideal homogeneous water body are studied. Effects of the single scattering albedo
and the volume scattering function are studied. A more realistic water body with
vertical pro files for oceanic optical properties determined by a Case 1 water model
is then assumed to study the e ffects of wavelength, Raman scattering, and surface
waves.
Simulated Raman scattering patterns computed from the generalized DDA formalism
are found to be sensitive to the distribution of Raman active molecules in the
host particle. Therefore one can infer how the Raman active molecules are distributed from a measured Raman scattering pattern. Material properties of invisibility cloaks
with a few irregular geometries are given, and field distributions in the vicinity of
the cloaked particles computed from the generalized DDA formalism con rm that the
designated material properties lead to invisibility. The radiative transfer model calculation
in deep oceans suggest that the underwater radiance approaches its asymptotic
form more quickly than the polarization does. Therefore, a vector radiative transfer
solution is necessary for asymptotic light field studies. For a typical homogeneous
water body whose scattering property is characterized by the Petzold phase function,
a single scattering albedo of w0 > 0:8 is required in order that the asymptotic regime
can be reached before there are too few photons to be detected.
Advisors/Committee Members: Kattawar, George W. (advisor), Yang, Ping (advisor), Agnolet, Glenn (committee member), Fry, Edward S. (committee member).
Subjects/Keywords: Light scattering; Raman scattering; Bioaerosol identification; Invisibility Cloak; Metamaterial; Radiative transfer
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APA ·
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APA (6th Edition):
You, Y. (2010). Applications of the Generalized DDA Formalism and the Nature of Polarized Light in Deep Oceans. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2008-08-46
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
You, Yu. “Applications of the Generalized DDA Formalism and the Nature of Polarized Light in Deep Oceans.” 2010. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-2008-08-46.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
You, Yu. “Applications of the Generalized DDA Formalism and the Nature of Polarized Light in Deep Oceans.” 2010. Web. 08 Dec 2019.
Vancouver:
You Y. Applications of the Generalized DDA Formalism and the Nature of Polarized Light in Deep Oceans. [Internet] [Thesis]. Texas A&M University; 2010. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2008-08-46.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
You Y. Applications of the Generalized DDA Formalism and the Nature of Polarized Light in Deep Oceans. [Thesis]. Texas A&M University; 2010. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2008-08-46
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
5.
Ge, Wenchao.
Quantum States Preparation in Cavity Optomechanics.
Degree: 2015, Texas A&M University
URL: http://hdl.handle.net/1969.1/156398
► Quantum entanglement and quantum superposition are fundamental properties of quantum mechanics, which underline quantum information and quantum computation. Preparing quantum states in the macroscopic level…
(more)
▼ Quantum entanglement and quantum superposition are fundamental properties of quantum mechanics, which underline quantum information and quantum computation. Preparing quantum states in the macroscopic level is both conceptually interesting for extending quantum physics to a broader sense and fundamentally important for testing the validity of quantum mechanics. In this dissertation, schemes of preparing macroscopic entanglement and macroscopic superposition states in cavity optomechanics are studied using the unitary evolution method in the nonlinear regime or Lyapunov equation in the linearized regime. Quantum entanglement and quantum superposition states can be realized using experimentally feasible parameters with the proposals in this dissertation.
Firstly, a scheme of entangling two movable end mirrors in a Fabry-Perot cavity that are coupled to a common single photon superposition state is studied. It is shown that strong entanglement can be obtained either in the single-photon strong coupling regime deterministically or in the single-photon weak coupling regime conditionally.
Secondly, a scheme of entangling two movable end mirrors, that are coupled to two-mode entangled fields generated from a correlated-emission laser is investigated. By tuning the input driving laser frequencies at the Stokes sidebands of the cavity, the radiation-pressure coupling can be linearized as an effective beam-splitter-like interaction. Hence entanglement can be transferred from the two-mode fields to the two mechanical mirrors. Macroscopic entanglement between macroscopic mirrors persists at temperature ~ 1K.
Thirdly, a scheme of creating macroscopic quantum superpositions of a mechanical mirror via periodically flipping a photonic qubit is proposed. Quantum superposition states of a mechanical mirror can be obtained via the nonlinear radiation coupling with a single-photon superposition state. However, the difference between two superposed mechanical states is very small due to the weak single-photon coupling rate available in experiment. By periodically flipping the photonic qubit state, the difference can be magnified. It is shown in detail that this scheme is experimentally feasible under current technology.
Advisors/Committee Members: Zubairy, M. Suhail (advisor), Kattawar, George W. (committee member), Sokolov, Alexei (committee member), Klappenecker, Andreas (committee member).
Subjects/Keywords: Optomechanics; Quantum states
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APA (6th Edition):
Ge, W. (2015). Quantum States Preparation in Cavity Optomechanics. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/156398
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Ge, Wenchao. “Quantum States Preparation in Cavity Optomechanics.” 2015. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/156398.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Ge, Wenchao. “Quantum States Preparation in Cavity Optomechanics.” 2015. Web. 08 Dec 2019.
Vancouver:
Ge W. Quantum States Preparation in Cavity Optomechanics. [Internet] [Thesis]. Texas A&M University; 2015. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/156398.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Ge W. Quantum States Preparation in Cavity Optomechanics. [Thesis]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/156398
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
6.
Zhai, Pengwang.
A fourth-order symplectic finite-difference time-domain (FDTD) method for light scattering and a 3D Monte Carlo code for radiative transfer in scattering systems.
Degree: 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-1839
► When the finite-difference time-domain (FDTD) method is applied to light scattering computations, the far fields can be obtained by either a volume integration method, or…
(more)
▼ When the finite-difference time-domain (FDTD) method is applied to light scattering
computations, the far fields can be obtained by either a volume integration method,
or a surface integration method. In the first study, we investigate the errors associated
with the two near-to-far field transform methods. For a scatterer with a small
refractive index, the surface approach is more accurate than its volume counterpart
for computing the phase functions and extinction efficiencies; however, the volume
integral approach is more accurate for computing other scattering matrix elements. If
a large refractive index is involved, the results computed from the volume integration
method become less accurate, whereas the surface method still retains the same order
of accuracy as in the situation of a small refractive index.
In my second study, a fourth order symplectic FDTD method is applied to the
problem of light scattering by small particles. The total-field/ scattered-field (TF/SF)
technique is generalized for providing the incident wave source conditions in the symplectic
FDTD (SFDTD) scheme. Numerical examples demonstrate that the fourthorder
symplectic FDTD scheme substantially improves the precision of the near field
calculation. The major shortcoming of the fourth-order SFDTD scheme is that it
requires more computer CPU time than the conventional second-order FDTD scheme if the same grid size is used.
My third study is on multiple scattering theory. We develop a 3D Monte Carlo
code for the solving vector radiative transfer equation, which is the equation governing
the radiation field in a multiple scattering medium. The impulse-response relation for
a plane-parallel scattering medium is studied using our 3D Monte Carlo code. For a
collimated light beam source, the angular radiance distribution has a dark region as
the detector moves away from the incident point. The dark region is gradually filled
as multiple scattering increases. We have also studied the effects of the finite size of
clouds. Extending the finite size of clouds to infinite layers leads to underestimating
the reflected radiance in the multiple scattering region, especially for scattering angles
around 90 degrees. The results have important applications in the field of remote sensing.
Advisors/Committee Members: Kattawar, George W. (advisor), Yang, Ping (advisor), Hu, Chia-Ren (committee member), Zubairy, M. Suhail (committee member).
Subjects/Keywords: Symplectic FDTD; Monte Carlo; Light Scattering; Mueller Matrix
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APA ·
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APA (6th Edition):
Zhai, P. (2009). A fourth-order symplectic finite-difference time-domain (FDTD) method for light scattering and a 3D Monte Carlo code for radiative transfer in scattering systems. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-1839
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Zhai, Pengwang. “A fourth-order symplectic finite-difference time-domain (FDTD) method for light scattering and a 3D Monte Carlo code for radiative transfer in scattering systems.” 2009. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-1839.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Zhai, Pengwang. “A fourth-order symplectic finite-difference time-domain (FDTD) method for light scattering and a 3D Monte Carlo code for radiative transfer in scattering systems.” 2009. Web. 08 Dec 2019.
Vancouver:
Zhai P. A fourth-order symplectic finite-difference time-domain (FDTD) method for light scattering and a 3D Monte Carlo code for radiative transfer in scattering systems. [Internet] [Thesis]. Texas A&M University; 2009. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1839.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Zhai P. A fourth-order symplectic finite-difference time-domain (FDTD) method for light scattering and a 3D Monte Carlo code for radiative transfer in scattering systems. [Thesis]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1839
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
7.
Lee, Joonsuk.
Mixed-phase clouds, thin cirrus clouds, and OLR over the tropics: observations, retrievals, and radiative impacts.
Degree: 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-1897
► The tropics is a very important region in terms of earth?s radiation budget because the net radiative heating is largest in the tropics and that…
(more)
▼ The tropics is a very important region in terms of earth?s radiation budget
because the net radiative heating is largest in the tropics and that surplus energy is
redistributed by the circulations of oceans and atmospheres. Moreover, a large number
of clouds are formed by deep convection and convergence of water vapor. Thus, it is
very important to understand the radiative energy balance of the tropics and the effect of
clouds on the radiation field.
For mixed-phase clouds, error analyses pertaining to the inference of effective
particle sizes and optical thicknesses are performed. Errors are calculated with respect to
the assumption of a cloud containing solely liquid or ice phase particles. The analyses
suggest that the effective particle size inferred for a mixed-phase cloud can be
underestimated (or overestimated) if a pure liquid phase (or pure ice phase) is assumed
for the cloud, whereas the corresponding cloud optical thickness can be overestimated
(or underestimated). The analyses of optical depth and fraction of occurrence for thin cirrus clouds
showed that about 40% of pixels flagged as clear-sky contain detectible thin cirrus
clouds. The regions of high occurrence and large optical depth located around deep
convection showed seasonal variations. The thin cirrus clouds occur more frequently
with larger optical depth in the northern (southern) hemisphere during spring and
summer (autumn and winter). The net cloud radiative forcing by thin cirrus clouds is
positive at the top of atmosphere and is negative at the bottom of atmosphere.
The difference in OLR between measurement and model is 4.2 Wm-2 for
September 2005. The difference is smaller in moist regions and larger in drier regions.
OLR increases with increasing surface temperatures up to 300 K but decreases at surface
temperatures larger than 300 K due to the strong absorption of increased water vapor. In
summary, if the surface temperature is lower than the threshold of convection (300 K),
temperature is a dominant factor in OLR and if the surface temperature is larger than 300
K, OLR is strongly influenced by water vapor.
Advisors/Committee Members: Dessler, Andrew E. (advisor), Yang, Ping (advisor), Kattawar, George W. (committee member), North, Gerald R. (committee member), Platnick, Steven (committee member).
Subjects/Keywords: cirrus; OLR; raiative impacts
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APA (6th Edition):
Lee, J. (2009). Mixed-phase clouds, thin cirrus clouds, and OLR over the tropics: observations, retrievals, and radiative impacts. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-1897
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lee, Joonsuk. “Mixed-phase clouds, thin cirrus clouds, and OLR over the tropics: observations, retrievals, and radiative impacts.” 2009. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-1897.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lee, Joonsuk. “Mixed-phase clouds, thin cirrus clouds, and OLR over the tropics: observations, retrievals, and radiative impacts.” 2009. Web. 08 Dec 2019.
Vancouver:
Lee J. Mixed-phase clouds, thin cirrus clouds, and OLR over the tropics: observations, retrievals, and radiative impacts. [Internet] [Thesis]. Texas A&M University; 2009. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1897.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lee J. Mixed-phase clouds, thin cirrus clouds, and OLR over the tropics: observations, retrievals, and radiative impacts. [Thesis]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1897
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
8.
Cho, Hyoun-Myoung.
Studying Clouds and Aerosols with Lidar Depolarization Ratio and Backscatter Relationships.
Degree: 2012, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10606
► This dissertation consists of three parts, each devoted to a particular issue of significant importance for CALIPSO lidar observation of depolarization ratio (delta) and backscatter…
(more)
▼ This dissertation consists of three parts, each devoted to a particular issue of significant importance for CALIPSO lidar observation of depolarization ratio (delta) and backscatter (gamma?) to improve current understanding of the microphysical properties of clouds and aerosols. The relationships between depolarization ratio and backscatter allow us to retrieve particle thermodynamic phase and shape and/or orientation of aerosols and clouds.
The first part is devoted to the investigation of the relationships between lidar backscatter and the corresponding depolarization ratio for different cloud classifications and aerosol types. For each cloud and aerosol types, layer-averaged backscatter and backscattering depolarization ratio from the CALIPSO measurements are discussed. The present results demonstrate the unique capabilities of the CALIPSO lidar instrument for determining cloud phase and aerosols subtypes.
In the second part, we evaluate the MODIS IR cloud phase with the CALIPSO cloud products. The three possible misclassifications of MODIS IR cloud phasealgorithm, which are studied by Nasiri and Kahn (2008) with radiative transfer modeling, are tested by comparing between MODIS IR phase and CALIOP observations. The current results support their hypotheses, which is that the MODIS phase algorithm may tend to classify thin cirrus clouds as water clouds or mixed phase clouds or unknown, and classify midlevel and/or mid-temperature clouds as mixed or unknown phase.
In the third part, we present a comparison of mineral dust aerosol retrievals from two instruments, MODIS and CALIPSO lidar. And, we implement and evaluate a new mineral dust detection algorithm based on the analysis of thin dust radiative signature. In comparison, three commonly used visible and IR mineral dust detection algorithms, including BTD procedure, D parameter method, and multi-channel image algorithm, are evaluated with CALIPSO aerosol classification. The comparison reveals that those dust detection algorithms are not effective for optically thin dust layers, but for thick dust storm. The new algorithm using discriminant analysis with CALIPSO observation is much better in detecting thin dust layer of optical thickness between 0.1 and 2.
Advisors/Committee Members: Yang, Ping (advisor), Nasiri, Shaima L. (advisor), North, Gerald R. (committee member), Kattawar, George W. (committee member).
Subjects/Keywords: lidar; CALIPSO; depolariization ratio
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APA (6th Edition):
Cho, H. (2012). Studying Clouds and Aerosols with Lidar Depolarization Ratio and Backscatter Relationships. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10606
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Cho, Hyoun-Myoung. “Studying Clouds and Aerosols with Lidar Depolarization Ratio and Backscatter Relationships.” 2012. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10606.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Cho, Hyoun-Myoung. “Studying Clouds and Aerosols with Lidar Depolarization Ratio and Backscatter Relationships.” 2012. Web. 08 Dec 2019.
Vancouver:
Cho H. Studying Clouds and Aerosols with Lidar Depolarization Ratio and Backscatter Relationships. [Internet] [Thesis]. Texas A&M University; 2012. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10606.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Cho H. Studying Clouds and Aerosols with Lidar Depolarization Ratio and Backscatter Relationships. [Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10606
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
9.
Wang, Chao.
Optimization of Two-photon Excited Fluorescence Enhancement between Tunable and Broadband Femtosecond Laser Pulse Excitations.
Degree: 2012, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10257
► This project explores optimization of two-photon excited fluorescence (TPEF) enhancement between tunable narrowband and un-tuned broadband femtosecond (fs) laser pulse excitations for two-photon microscopy (TPM).…
(more)
▼ This project explores optimization of two-photon excited fluorescence (TPEF) enhancement between tunable narrowband and un-tuned broadband femtosecond (fs) laser pulse excitations for two-photon microscopy (TPM). The research is conducted preliminarily in time domain and comprehensively in frequency domain to understand the physics behind TPEF enhancement by un-tuned sub-10 fs nearly transform-limited pulse (TLP) versus tunable 140 fs pulse. The preliminary study on inverse proportionality of TPEF yield to fs-pulse duration delimits a general lower-bound to narrowband fs-pulse regime (pulse duration > 40 fs) with assumption of dye-molecule frequency invariant response. Deviations from this inverse proportionality in broadband fs-pulse regime (pulse duration < 40 fs) highlights dye-molecule frequency variant response, necessity of group delay dispersion (GDD) compensation, and broadband TLP for TPEF enhancement.
The follow-up comparative study is made on un-tuned sub-10 fs TLP versus tunable 140 fs pulse excitations using three dye-phantoms (Indo-1, FITC, and TRITC) representative of fluorescent probes with similar TPEF characteristics. The integrated experimental system, with custom-designed GDD compensation, dispersion-less laser-beam expanding and focusing, and compound-lens for efficient fluorescence collection with good spectral resolution, ensures accurate TPEF measurements. Differentiated TPEF enhancements of Indo-1 (1.6), FITC (6.7), and TRITC (5.2) proportionally agree with calculated ones due to the overlap of fs-pulse second harmonic (SH) power spectrum with dye-molecule two-photon excitation (TPE) spectrum. Physically speaking, with broadband sub-10 fs TLP readily involved in both degenerate (v1 = v2) and non-degenerate (v1 ? v2) two-photon absorption (TPA), this un-tuned ultrashort fs-pulse excitation simultaneously allows for more accessibility to TPA-associated final states and diversely promotes population of thus excited dye-molecules with the three dye-phantoms. Under environmental influences (mutual quenching through one-photon absorption(s) and solvent effect), multicolor TPEF enhancement observed from a mixture of the three dyes shows promise of sub-10 fs TLP as simultaneous excitation for multiple-dye labeled samples in contrast to compromised excitation with narrowband fs-pulse tuning. Both single- and multicolor TPEF enhancements clarify tradeoff between tunability of narrowband fs-pulse and un-tuned broadband fs-pulse excitations, being instructive to further considerations on optimization of TPEF enhancement by strategic utilization of broadband fs-pulse for better performance of TPM.
Advisors/Committee Members: Yeh, Alvin T. (advisor), Kattawar, George W. (committee member), Meissner, Kenith (committee member), McShane, Mike (committee member).
Subjects/Keywords: two-photon excited fluorescence; femtosecond laser pulse
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APA ·
Chicago ·
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APA (6th Edition):
Wang, C. (2012). Optimization of Two-photon Excited Fluorescence Enhancement between Tunable and Broadband Femtosecond Laser Pulse Excitations. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10257
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Wang, Chao. “Optimization of Two-photon Excited Fluorescence Enhancement between Tunable and Broadband Femtosecond Laser Pulse Excitations.” 2012. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10257.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wang, Chao. “Optimization of Two-photon Excited Fluorescence Enhancement between Tunable and Broadband Femtosecond Laser Pulse Excitations.” 2012. Web. 08 Dec 2019.
Vancouver:
Wang C. Optimization of Two-photon Excited Fluorescence Enhancement between Tunable and Broadband Femtosecond Laser Pulse Excitations. [Internet] [Thesis]. Texas A&M University; 2012. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10257.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wang C. Optimization of Two-photon Excited Fluorescence Enhancement between Tunable and Broadband Femtosecond Laser Pulse Excitations. [Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10257
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
10.
Wagers, Andrew James.
The Diversity of Variations in the Spectra of Type Ia Supernovae.
Degree: 2012, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11528
► Type Ia supernovae (SNe Ia) are currently the best probe of the expansion history of the universe. Their usefulness is due chiefly to their uniformity…
(more)
▼ Type Ia supernovae (SNe Ia) are currently the best probe of the expansion history of the universe. Their usefulness is due chiefly to their uniformity between supernovae (SNe). However, there are some slight variations amongst SNe that have yet to be understood and accounted for. The goal of this work is to uncover relationships between the spectral features and the light curve decline rate, [delta]
m??. Wavelet decomposition has been used to develop a new spectral index to measure spectral line strengths independent of the continuum and easily corrected for noise. This new method yields consistent results without the arbitrary uncertainties introduced by current methods and is particularly useful for spectra which do not have a clearly defined continuum. These techniques are applied to SN Ia spectra and correlations are found between the spectral features and light curve decline rate. The wavelet spectral indexes are used to measure the evolution of spectral features which are characterized by 3 or 4 parameters for the most complicated evolution. The three absorption features studied here are associated with sulfur and silicon and all show a transition in strength between 1 to 2 weeks after B-band maximum. Pearson correlation coefficients between spectral features and [delta]
m?? are found to be significant within a week of maximum brightness and 3 to 4 weeks post-maximum. These correlations are used to determine the principal components at each epoch among the set of SN spectra in this work. The variation contained in the first principal component (PC1) is found to be greater than 60% to 70% for most epochs and reaching as high as 80% to 90% for epochs with the highest correlations. The same first principal component can be used to relate spectral feature strengths to the decline rate. These relations were used to estimate a SN light curve decline rate from a set of spectra taken over the course of the explosion, from a single spectrum, or from even a single spectral feature. These relationships could be used for future surveys to estimate spectral characteristics from light curve data, such as photometric redshift.
Advisors/Committee Members: Wang, Lifan (advisor), Suntzeff, Nicholas B. (committee member), Kattawar, George W. (committee member), McDeavitt, Sean (committee member).
Subjects/Keywords: Type Ia Supernova; supernova spectra; supernova subgroups; wavelet decomposition; principal component analysis
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Wagers, A. J. (2012). The Diversity of Variations in the Spectra of Type Ia Supernovae. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11528
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Wagers, Andrew James. “The Diversity of Variations in the Spectra of Type Ia Supernovae.” 2012. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11528.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wagers, Andrew James. “The Diversity of Variations in the Spectra of Type Ia Supernovae.” 2012. Web. 08 Dec 2019.
Vancouver:
Wagers AJ. The Diversity of Variations in the Spectra of Type Ia Supernovae. [Internet] [Thesis]. Texas A&M University; 2012. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11528.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wagers AJ. The Diversity of Variations in the Spectra of Type Ia Supernovae. [Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2012-08-11528
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
11.
Lu, Jianxu.
Simulation of Lidar Return Signals Associated with Water Clouds.
Degree: 2010, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2009-08-7138
► We revisited an empirical relationship between the integrated volume depolar- ization ratio, oacc, and the effective multiple scattering factor, -n, on the basis of Monte…
(more)
▼ We revisited an empirical relationship between the integrated volume depolar-
ization ratio, oacc, and the effective multiple scattering factor, -n, on the basis of Monte
Carlo simulations of spaceborne lidar backscatter associated with homogeneous wa-
ter clouds. The relationship is found to be sensitive to the extinction coefficient and
to the particle size. The layer integrated attenuated backscatter is also obtained.
Comparisons made between the simulations and statistics derived relationships of
the layer integrated depolarization ratio, oacc, and the layer integrated attenuated
backscatter, -n, based on the measurement by the Cloud-Aerosol Lidar and Infrared
Pathfinder Satellite Observations (CALIPSO) satellite show that a cloud with a
large effective size or a large extinction coefficient has a relatively large integrated
backscatter and a cloud with a small effective size or a large extinction coefficient
has a large integrated volume depolarization ratio. The present results also show
that optically thin water clouds may not obey the empirical relationship derived by
Y. X. Hu. and co-authors.
Advisors/Committee Members: Yang, Ping (advisor), Brooks, Sarah D. (advisor), Kattawar, George W. (committee member), Hu, Chia-ren (committee member).
Subjects/Keywords: lidar; multiple scattering; Stokes parameter; Mueller matrix
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Manager
APA (6th Edition):
Lu, J. (2010). Simulation of Lidar Return Signals Associated with Water Clouds. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2009-08-7138
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lu, Jianxu. “Simulation of Lidar Return Signals Associated with Water Clouds.” 2010. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-2009-08-7138.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lu, Jianxu. “Simulation of Lidar Return Signals Associated with Water Clouds.” 2010. Web. 08 Dec 2019.
Vancouver:
Lu J. Simulation of Lidar Return Signals Associated with Water Clouds. [Internet] [Thesis]. Texas A&M University; 2010. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2009-08-7138.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lu J. Simulation of Lidar Return Signals Associated with Water Clouds. [Thesis]. Texas A&M University; 2010. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2009-08-7138
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
12.
Gao, Meng 1981-.
Physics of the Structural Color on the Skin of Cephalopods.
Degree: 2012, Texas A&M University
URL: http://hdl.handle.net/1969.1/148161
► The structural colors, produced by leucophore and iridophore cells, are important for cephalopod camouflage; however, their scattering properties have not been very well studied. These…
(more)
▼ The structural colors, produced by leucophore and iridophore cells, are important for cephalopod camouflage; however, their scattering properties have not been very well studied. These colors are mainly due to the scattering of the specific small scatterers inside of the cell. In this work we will summarize the theories and the numerical methods used to solve both the scattering problems for one scatterer and a collection of such scatterers. The reflection spectrum of iridophores is shown to depend on both particle orientation and incident angle of the light. The leucophores are shown to be a white Lambertian surface. Therefore, starting from the structure of the cells, we can predict their color appearance in the skin. This work provides a general framework for the study of the structural color of cephalpods, and can be applied to many species with different cell structures.
Advisors/Committee Members: Kattawar, George W (advisor), Allen, Roland E (committee member), Fry, Edward S (committee member), Yang, Ping (committee member).
Subjects/Keywords: structural color; iridophore; leucophore; cephalopod; scattering
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APA (6th Edition):
Gao, M. 1. (2012). Physics of the Structural Color on the Skin of Cephalopods. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/148161
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Gao, Meng 1981-. “Physics of the Structural Color on the Skin of Cephalopods.” 2012. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/148161.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Gao, Meng 1981-. “Physics of the Structural Color on the Skin of Cephalopods.” 2012. Web. 08 Dec 2019.
Vancouver:
Gao M1. Physics of the Structural Color on the Skin of Cephalopods. [Internet] [Thesis]. Texas A&M University; 2012. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/148161.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Gao M1. Physics of the Structural Color on the Skin of Cephalopods. [Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/148161
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
13.
Huang, Xin.
Retrieval of Non-Spherical Dust Aerosol Properties from Satellite Observations.
Degree: 2013, Texas A&M University
URL: http://hdl.handle.net/1969.1/151193
► An accurate and generalized global retrieval algorithm from satellite observations is a prerequisite to understand the radiative effect of atmospheric aerosols on the climate system.…
(more)
▼ An accurate and generalized global retrieval algorithm from satellite observations is a prerequisite to understand the radiative effect of atmospheric aerosols on the climate system. Current operational aerosol retrieval algorithms are limited by the inversion schemes and suffering from the non-uniqueness problem. In order to solve these issues, a new algorithm is developed for the retrieval of non-spherical dust aerosol over land using multi-angular radiance and polarized measurements of the POLDER (POLarization and Directionality of the Earth?s Reflectances) and wide spectral high-resolution measurements of the MODIS (MODerate resolution Imaging Spectro-radiometer).
As the first step to account for the non-sphericity of irregularly shaped dust aerosols in the light scattering problem, the spheroidal model is introduced. To solve the basic electromagnetic wave scattering problem by a single spheroid, we developed an algorithm, by transforming the transcendental infinite-continued-fraction-formeigen equation into a symmetric tri-diagonal linear system, for the calculation of the spheroidal angle function, radial functions of the first and second kind, as well as the corresponding first order derivatives. A database is developed subsequently to calculate the bulk scattering properties of dust aerosols for each channel of the satellite instruments.
For the purpose of simulation of satellite observations, a code is developed to solve the VRTE (Vector Radiative Transfer Equation) for the coupled atmosphere-surface system using the adding-doubling technique. An alternative fast algorithm, where all the solid angle integrals are converted to summations on an icosahedral grid, is also proposed to speed-up the code. To make the model applicable to various land and ocean surfaces, a surface BRDF (Bidirectional Reflectance Distribution Function) library is embedded into the code. Considering the complimentary features of the MODIS and the POLDER, the collocated measurements of these two satellites are used in the retrieval process. To reduce the time spent on the simulation of dust aerosol scattering properties, a single-scattering property database of tri-axial ellipsoid is incorporated. In addition, atmospheric molecule correction is considered using the LBLRTM (Line-By-Line Ra- diative Transfer Model). The Levenberg-Marquardt method was employed to retrieve all the interested dust aerosol parameters and surface parameters simultaneously. As an example, dust aerosol properties retrieved over the Sahara Desert are presented.
Advisors/Committee Members: Kattawar, George W. (advisor), Yang, Ping (advisor), Allen, Roland E. (committee member), Fry, Edward S. (committee member).
Subjects/Keywords: Light scattering; Radiative transfer; Aerosol retrieval; Spheroidal wave functions; Adding-doubling; Surface BRDF; Fast model; POLDER/PARASOL; Saharan dust
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APA ·
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APA (6th Edition):
Huang, X. (2013). Retrieval of Non-Spherical Dust Aerosol Properties from Satellite Observations. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/151193
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Huang, Xin. “Retrieval of Non-Spherical Dust Aerosol Properties from Satellite Observations.” 2013. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/151193.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Huang, Xin. “Retrieval of Non-Spherical Dust Aerosol Properties from Satellite Observations.” 2013. Web. 08 Dec 2019.
Vancouver:
Huang X. Retrieval of Non-Spherical Dust Aerosol Properties from Satellite Observations. [Internet] [Thesis]. Texas A&M University; 2013. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/151193.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Huang X. Retrieval of Non-Spherical Dust Aerosol Properties from Satellite Observations. [Thesis]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/151193
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
14.
Liu, Jianping.
Effects of Chirality and Coherence on Light Scattering.
Degree: 2014, Texas A&M University
URL: http://hdl.handle.net/1969.1/153505
► In the first part of this dissertation, we study the light scattering properties of particles with chiral structures. Special attention is paid to the dinoflagellates,…
(more)
▼ In the first part of this dissertation, we study the light scattering properties of particles with chiral structures. Special attention is paid to the dinoflagellates, known for their circular polarization effects and as a causative agent of the red tide. Based on experimental observations and previous works, we build a helical plywood liquid crystal model for the nucleus of dinoflagellates, and apply the Discrete Dipole Approximation (DDA) method to investigate the light scattering properties of dinoflagellates. The backscattering signals display strong sensitivity to the wavelength of the incident beam, and they are most prominent when the wavelength matches the pitch of the chromatic helix. Our results indicates a promising means to monitor and detect the specific species of dinoflagellates.
In the second part of the dissertation, we investigate the the problem of light scattering when the incident light has finite coherence length. The conventional Lorenz-Mie theory and DDA method are generalized to include a partially spatially coherent source. The formalism is applied to atmospheric particles such as water droplets and hexagonal ice crystals. Given that the solar source is partially coherent, our results have practical implications in remote sensing. Using the same technique, we also study the effects of incoherence on particle characterization using digital holographic microscopy. We show that holography is rather robust against incoherence and demonstrate the possibility of retrieving the coherence length of the illumination.
Advisors/Committee Members: Kattawar, George W. (advisor), Allen, Roland E. (committee member), Fry, Edward (committee member), Yang, Ping (committee member).
Subjects/Keywords: Light scattering; chirality; coherence; holography
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APA ·
Chicago ·
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Manager
APA (6th Edition):
Liu, J. (2014). Effects of Chirality and Coherence on Light Scattering. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/153505
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Liu, Jianping. “Effects of Chirality and Coherence on Light Scattering.” 2014. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/153505.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Liu, Jianping. “Effects of Chirality and Coherence on Light Scattering.” 2014. Web. 08 Dec 2019.
Vancouver:
Liu J. Effects of Chirality and Coherence on Light Scattering. [Internet] [Thesis]. Texas A&M University; 2014. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/153505.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Liu J. Effects of Chirality and Coherence on Light Scattering. [Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/153505
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
15.
Sun, Bingqiang.
Simulation and Application of Light Scattering Properties for Scatterers with Large Aspect Ratios.
Degree: 2014, Texas A&M University
URL: http://hdl.handle.net/1969.1/154191
► For scatterers with axial or N-fold rotational symmetry, the T-matrix is one of the most efficient techniques to obtain the scattering properties. Extended boundary condition…
(more)
▼ For scatterers with axial or N-fold rotational symmetry, the T-matrix is one of the most efficient techniques to obtain the scattering properties. Extended boundary condition method (EBCM) and invariant imbedding T-matrix method (II-TM) are currently two of the most effective realizations of the T-matrix. The T-matrix of the scatterers with the rotational symmetry will be fully or partially decoupled between different azimuthal components, which can dramatically increase calculation efficiencies.
However, the ill-conditioned problem will occur for the EBCM whereas memory requirements and time consumption will be exponentially increased for the II-TM when scatterers have large aspect ratios (the ratios of the heights to the characteristic widths of the scatterers). The many-body iterative T-matrix method (MBIT), which uses the T-matrix and many-body techniques, is developed and generalized to target the homogeneous and inhomogeneous scatterers with large aspect ratios.
For infinite scatterers with one dimension periodicity, a semi-analytical solution instead of the iterative technique has been obtained by extending the application of the MBIT method to infinite number of sub-units. The semi-analytical solution of a scatterer with 1-D periodicity can be treated as an proxy and the limit of the corresponding finite scatterer with extreme large aspect ratios. For oceanic diatom scatterers, which have chain structures in preferential orientations, the MBIT method is applied to get the scattering properties, which can be the indicators of scatterer orientations, compositions, and shapes.
Advisors/Committee Members: Kattawar, George W (advisor), Yang, Ping (advisor), Fry, Edward S (committee member), Sokolov, Alexei V (committee member).
Subjects/Keywords: T-matrix; EBCM; II-TM; Large Aspect Ratios; MBIT; 1-D Periodicity.
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APA (6th Edition):
Sun, B. (2014). Simulation and Application of Light Scattering Properties for Scatterers with Large Aspect Ratios. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/154191
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Sun, Bingqiang. “Simulation and Application of Light Scattering Properties for Scatterers with Large Aspect Ratios.” 2014. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/154191.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Sun, Bingqiang. “Simulation and Application of Light Scattering Properties for Scatterers with Large Aspect Ratios.” 2014. Web. 08 Dec 2019.
Vancouver:
Sun B. Simulation and Application of Light Scattering Properties for Scatterers with Large Aspect Ratios. [Internet] [Thesis]. Texas A&M University; 2014. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/154191.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Sun B. Simulation and Application of Light Scattering Properties for Scatterers with Large Aspect Ratios. [Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/154191
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
16.
Chun, Hye Jin.
Vibrational Spectra, Theoretical Calculations, and Structures of Cyclic Silanes, 2,4,7-Trioxa(3.3.0)Octane and Botryococcenes.
Degree: 2014, Texas A&M University
URL: http://hdl.handle.net/1969.1/154198
► The vibrational spectra and structures of several cyclic silanes and a bicyclic molecule have been investigated with high-level ab initio and density function theory (DFT)…
(more)
▼ The vibrational spectra and structures of several cyclic silanes and a bicyclic molecule have been investigated with high-level ab initio and density function theory (DFT) calculations. In addition, the Raman spectra of botryococcene hydrocarbons have been studied to help with their identification.
Infrared and Raman spectra and ab initio and DFT calculations have been utilized to study 1,3-disilacyclopent-3-ene, 1,3-disilacyclopentane, 1-silacyclopent-3-ene, silacyclopentane and their derivatives. In each case the agreement between observed and calculated infrared and Raman spectra was very good.
Theoretical computations have also been used to calculate the potential energy surfaces (PES) for four cyclic silanes. The calculated ring-puckering potential energy functions of 1-silacyclopent-3-ene and 1,3-disilacyclopent-3-ene had barriers of 3.8 cm^-1 and 0 cm^-1, respectively, in good agreement with experimental results. The calculated results for and 1,3-disilacyclopentane predicted ring-twisting barriers of 2493 cm^-1 (vs. 2110 cm^-1 observed) and 1395 cm^-1, respectively. The conformational energies for the bent forms were calculated to be 1467 cm^-1 (vs. 1509 cm^-1 observed) for the former and 878 cm^-1 for the latter relative to the energy of the twist minima.
The vibrational assignments of 2,4,7-trioxa(3.3.0)octane have been made based on its infrared and Raman spectra and theoretical DFT calculations. The two ring-puckering motions (in-phase and out-of-phase) were observed in the Raman spectrum of the liquid at 249 and 205 cm^-1 and these values correspond well to the DFT values of 247 and 198 cm^-1. Ab initio calculations were utilized to calculate the structures and conformational energies for the four energy minima and the barriers to interconversion and the data were utilized to generate a two-dimensional PES for the two ring-puckering motions.
The Raman and infrared spectra of liquid squalene, which is a building block molecule for the production of essential cellular molecules, have been collected and assigned using DFT calculations. This was helpful for analyzing the Raman spectra of botryococcus braunii. DFT calculations also assisted in understanding the Raman spectra of the botryococcenes. The spectral region from 1600-1700 cm^-1 shows C=C stretching bands specific for botryococcenes, and this is of great value for identifying the specific molecules.
Advisors/Committee Members: Laane, Jaan (advisor), Lucchese, Robert R (committee member), Wheeler, Steven E (committee member), Kattawar, George W (committee member).
Subjects/Keywords: Potential energy surface; wavefunctions; infrared and Raman spectra; molecular structure; theoretical calculations
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APA (6th Edition):
Chun, H. J. (2014). Vibrational Spectra, Theoretical Calculations, and Structures of Cyclic Silanes, 2,4,7-Trioxa(3.3.0)Octane and Botryococcenes. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/154198
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Chun, Hye Jin. “Vibrational Spectra, Theoretical Calculations, and Structures of Cyclic Silanes, 2,4,7-Trioxa(3.3.0)Octane and Botryococcenes.” 2014. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/154198.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Chun, Hye Jin. “Vibrational Spectra, Theoretical Calculations, and Structures of Cyclic Silanes, 2,4,7-Trioxa(3.3.0)Octane and Botryococcenes.” 2014. Web. 08 Dec 2019.
Vancouver:
Chun HJ. Vibrational Spectra, Theoretical Calculations, and Structures of Cyclic Silanes, 2,4,7-Trioxa(3.3.0)Octane and Botryococcenes. [Internet] [Thesis]. Texas A&M University; 2014. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/154198.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Chun HJ. Vibrational Spectra, Theoretical Calculations, and Structures of Cyclic Silanes, 2,4,7-Trioxa(3.3.0)Octane and Botryococcenes. [Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/154198
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
17.
Echeverria, Francesco Jozac.
Nonlinear Optical Effects on Retinal Damage Thresholds in the 1200-1400 nm Wavelength Range.
Degree: 2015, Texas A&M University
URL: http://hdl.handle.net/1969.1/155191
► Recent changes in the maximum permissible exposure (MPE) limits for near-infrared (NIR) laser exposures are analyzed in light of nonlinear optical phenomena. We have evaluated…
(more)
▼ Recent changes in the maximum permissible exposure (MPE) limits for near-infrared (NIR) laser exposures are analyzed in light of nonlinear optical phenomena. We have evaluated the thresholds for supercontinuum (SC) generation for ultra-short (femtosecond) laser exposures in the NIR region and compared these values with the MPEs listed in the American National Standard for Safe Use of Lasers 2014 Edition (ANSI Z136.1-2014). Due to the strong increase in ocular absorption in the 1.2 to 1.4 micrometer (i.e. 1200-1400 nm) range, evaluation of the SC generation phenomenon is necessary because any shift in laser energy within the eye to shorter wavelengths (i.e. greater frequency) could lead to unforeseen increases in hazards to the retina. The findings of this research do in fact indicate a shift in laser energy to shorter wavelengths for femtosecond pulsed lasers. In addition, an analysis involving spectral measurements through a water cuvette leads to estimations involving the eye configuration that show radiant exposures exceeding the ANSI thresholds for visible wavelengths. The implications of these findings are such that enough NIR energy is converted to visible energy near the retina when dealing with femtosecond pulsed lasers, warranting further studies in examining what the effects caused by nonlinear optical phenomena due to ultrashort pulsed lasers have on MPE thresholds established for eye safety.
Advisors/Committee Members: Sokolov, Alexei (advisor), Kattawar, George W. (committee member), Fry, Edward (committee member), Wherley, Benjamin G. (committee member).
Subjects/Keywords: Retinal Damage Threshold; Nonlinear Optical Effects; Self-Phase Modulation; Supercontinuum Generation; Spectral Broadening; Ocular Transmission; Maximum Permissible Exposure; ANSI Changes; White Light Radiant Exposures
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APA (6th Edition):
Echeverria, F. J. (2015). Nonlinear Optical Effects on Retinal Damage Thresholds in the 1200-1400 nm Wavelength Range. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/155191
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Echeverria, Francesco Jozac. “Nonlinear Optical Effects on Retinal Damage Thresholds in the 1200-1400 nm Wavelength Range.” 2015. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/155191.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Echeverria, Francesco Jozac. “Nonlinear Optical Effects on Retinal Damage Thresholds in the 1200-1400 nm Wavelength Range.” 2015. Web. 08 Dec 2019.
Vancouver:
Echeverria FJ. Nonlinear Optical Effects on Retinal Damage Thresholds in the 1200-1400 nm Wavelength Range. [Internet] [Thesis]. Texas A&M University; 2015. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/155191.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Echeverria FJ. Nonlinear Optical Effects on Retinal Damage Thresholds in the 1200-1400 nm Wavelength Range. [Thesis]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/155191
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
18.
Mason, John David.
Applications of Fumed Silica Integrating Cavities.
Degree: PhD, Physics, 2016, Texas A&M University
URL: http://hdl.handle.net/1969.1/174273
► Integrating cavities have been used in radiometric and photometric measurements since their creation by Frederick Ulbricht in 1900. Modern commercial integrating cavities use Spectralon, a…
(more)
▼ Integrating cavities have been used in radiometric and photometric measurements since
their creation by Frederick Ulbricht in 1900. Modern commercial integrating cavities use
Spectralon, a PTFE-based diffuse reflector with a reflectivity > 97.5% from 350-1600
nm, as a diffuse reflector. However, Spectralon’s reflectivity diminishes in the ultraviolet
which limits the potential for short wavelength experiments. The high reflectivity of a
recently characterized diffuse reflector, fumed silica, in the UV, as well as the VIS-NIR,
has improved the sensitivity of integrating cavity based measurements.
With the increased ultraviolet reflectivity, measurements of the optical absorption coefficient
of pure water were performed using an improved version of the Integrating Cavity
Absorption Meter (ICAM), the ICAM-II. The ICAM-II replaces Spectralon of the inner
and outer cavity from the original ICAM with fumed silica powder. The fumed silica
diffuse reflector, along with increased volume in the sample region, extended the optical
pathlength by a factor of 2.5 at 532 nm and much more in the UV at 250 nm. Scattering independent
measurements of the absorption coefficient of pure water from 250-550 nm
were made with this instrument.
Furthermore, the increased reflectivity of fumed silica, the new scattering-independent
integrating cavity ring-down spectroscopy technique can be applied to measuring the absorption
coefficient of highly scattering media. ICRDS measurements were made of various
biological cells and tissues. The results from these measurements were compared with
the well-established Inverse Adding-Doubling (IAD) technique.
Advisors/Committee Members: Fry, Edward S (advisor), Yakovlev, Vladislav V (committee member), Zheltikov, Aleksei M (committee member), Kattawar, George W (committee member).
Subjects/Keywords: Fumed Silica; Absorption; Water; Integrating Cavity Ring Down
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APA (6th Edition):
Mason, J. D. (2016). Applications of Fumed Silica Integrating Cavities. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/174273
Chicago Manual of Style (16th Edition):
Mason, John David. “Applications of Fumed Silica Integrating Cavities.” 2016. Doctoral Dissertation, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/174273.
MLA Handbook (7th Edition):
Mason, John David. “Applications of Fumed Silica Integrating Cavities.” 2016. Web. 08 Dec 2019.
Vancouver:
Mason JD. Applications of Fumed Silica Integrating Cavities. [Internet] [Doctoral dissertation]. Texas A&M University; 2016. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/174273.
Council of Science Editors:
Mason JD. Applications of Fumed Silica Integrating Cavities. [Doctoral Dissertation]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/174273
Texas A&M University
19.
Hokr, Brett Harrison.
Random Raman Lasing.
Degree: PhD, Physics, 2016, Texas A&M University
URL: http://hdl.handle.net/1969.1/156873
► The propagation of light in turbid media is something that is experienced by everyone, everywhere, everyday. These dynamics play an essential role in everything from…
(more)
▼ The propagation of light in turbid media is something that is experienced by everyone, everywhere, everyday. These dynamics play an essential role in everything from the color of a material, to the multitude of colors present during a sunset. Considering the central role of these dynamics, there are still a great deal of outstanding questions that remain to be answered. Nonlinear light propagation in turbid media is one such question, with far ranging applications in biomedical imaging where it has potential to elucidate many biological processes label-free and in vivo. Conventional wisdom suggests that nonlinear effects, such as stimulated Raman scattering (SRS), should not play a significant role in the propagation of light through random media. The diffusive nature of elastic scattering restricts the interaction distance by limiting the depth at which high intensities can be delivered, thus reducing the efficiency of nonlinear optical effects. However, light scattering can dramatically increase the interaction length by multiply scattering the photons in a random walk type motion, making the overall outcome somewhat hard to predict.
Random Raman lasing uses SRS as the primary gain mechanism for a lasing process that receives feedback through multiple elastic scattering in the material. This is a fundamentally new optical system that pushes the boundaries of the understanding of light propagation in turbid media. The discovery of this lasing system will be presented along with several fundamental measurements of the process, some of which contrast with classical light transport theory and point towards exciting new physics. Furthermore, random Raman lasing opens the door to many exciting applications ranging from remote chemical identification at unprecedented range, in a single laser pulse, to a revolutionary new light source for imaging microscopy 10,000 times brighter than conventional sources while maintaining the low spatial coherence required for speckle-free imaging.
Advisors/Committee Members: Scully, Marlan O (advisor), Yakovlev, Vladislav V (advisor), Kattawar, George W (committee member), Fry, Edward S (committee member), Sokolov, Alexei V (committee member), Zheltikov, Aleksei M (committee member).
Subjects/Keywords: random Raman lasing; stimulated Raman scattering; nonlinear optics; turbid media
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APA ·
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to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Hokr, B. H. (2016). Random Raman Lasing. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/156873
Chicago Manual of Style (16th Edition):
Hokr, Brett Harrison. “Random Raman Lasing.” 2016. Doctoral Dissertation, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/156873.
MLA Handbook (7th Edition):
Hokr, Brett Harrison. “Random Raman Lasing.” 2016. Web. 08 Dec 2019.
Vancouver:
Hokr BH. Random Raman Lasing. [Internet] [Doctoral dissertation]. Texas A&M University; 2016. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/156873.
Council of Science Editors:
Hokr BH. Random Raman Lasing. [Doctoral Dissertation]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/156873
20.
Tang, Guanglin.
Application of the discontinuous Galerkin time domain method in the simulation of the optical properties of dielectric particles.
Degree: 2012, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7948
► A Discontinuous Galerkin Time Domain method (DGTD), using a fourth order Runge-Kutta time-stepping of Maxwell's equations, was applied to the simulation of the optical properties…
(more)
▼ A Discontinuous Galerkin Time Domain method (DGTD), using a fourth order Runge-Kutta time-stepping of Maxwell's equations, was applied to the simulation of the optical properties of dielectric particles in two-dimensional (2-D) geometry. As examples of the numerical implementation of this method, the single-scattering properties of 2D circular and hexagonal particles are presented. In the case of circular particles, the scattering phase matrix was computed using the DGTD method and compared with the exact solution. For hexagonal particles, the DGTD method was used to compute single-scattering properties of randomly oriented 2-D hexagonal ice crystals, and results were compared with those calculated using a geometric optics method. Both shortwave (visible) and longwave (infrared) cases are considered, with particle size parameters 50 and 100. Ice in shortwave and longwave cases is absorptive and non-absorptive, respectively. The comparisons between DG solutions and the exact solutions in computing the optical properties of circular ice crystals reveal the applicability of the DG method to calculations of both absorptive and non-absorptive particles. In the hexagonal case scattering results are also presented as a function of both incident and scattering angles, revealing structure apparently not reported before. Using the geometric optics method we are able to interpret this structure in terms of contributions from varying numbers of internal reflections within the crystal.
Advisors/Committee Members: Panetta, Richard L. (committee member), Yang, Ping (committee member), Kattawar, George W. (committee member).
Subjects/Keywords: discontinuous Galerkin method; radiative transfer; single scattering
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APA (6th Edition):
Tang, G. (2012). Application of the discontinuous Galerkin time domain method in the simulation of the optical properties of dielectric particles. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7948
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Tang, Guanglin. “Application of the discontinuous Galerkin time domain method in the simulation of the optical properties of dielectric particles.” 2012. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7948.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Tang, Guanglin. “Application of the discontinuous Galerkin time domain method in the simulation of the optical properties of dielectric particles.” 2012. Web. 08 Dec 2019.
Vancouver:
Tang G. Application of the discontinuous Galerkin time domain method in the simulation of the optical properties of dielectric particles. [Internet] [Thesis]. Texas A&M University; 2012. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7948.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Tang G. Application of the discontinuous Galerkin time domain method in the simulation of the optical properties of dielectric particles. [Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-05-7948
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
21.
Byeon, Joong-Hyeok.
ULTRASHORT LASER PULSE PROPAGATION IN WATER.
Degree: 2010, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2008-08-60
► We simulate ultrashort pulse propagation through water by numerical methods, which is a kind of optical communication research. Ultrashort pulses have been known to have…
(more)
▼ We simulate ultrashort pulse propagation through water by numerical methods, which
is a kind of optical communication research. Ultrashort pulses have been known to have
non Beer-Lambert behavior, whereas continuous waves (CW) obey the Beer-Lambert
law. People have expected that the ultrashort pulse loses less intensity for a given
distance in water than CW which implies that the pulse can travel over longer distances.
In order to understand this characteristic of the pulse, we model numerically its spectral
and temporal evolution as a function of traveling distance through water. We achieve the
pulse intensity attenuation with traveling distance, obtain the temporal envelope of the
pulse and compare them with experimental data. This research proves that the spectral
and temporal profile of a pulse can be predicted knowing only the intensity spectrum of
the input pulse and the refractive index spectrum of water in the linear regime. The real
feasibility and the advantage of using an ultrashort pulse as a communication carrier will
also be discussed.
Advisors/Committee Members: Kattawar, George W. (advisor), Sokolov, Alexei (committee member), Yang, Ping (committee member).
Subjects/Keywords: ultrashort pulse propagation simulation water beer-lambert law
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APA (6th Edition):
Byeon, J. (2010). ULTRASHORT LASER PULSE PROPAGATION IN WATER. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2008-08-60
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Byeon, Joong-Hyeok. “ULTRASHORT LASER PULSE PROPAGATION IN WATER.” 2010. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-2008-08-60.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Byeon, Joong-Hyeok. “ULTRASHORT LASER PULSE PROPAGATION IN WATER.” 2010. Web. 08 Dec 2019.
Vancouver:
Byeon J. ULTRASHORT LASER PULSE PROPAGATION IN WATER. [Internet] [Thesis]. Texas A&M University; 2010. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2008-08-60.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Byeon J. ULTRASHORT LASER PULSE PROPAGATION IN WATER. [Thesis]. Texas A&M University; 2010. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2008-08-60
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
22.
Haubrich, David.
Instrumentation to Measure the Backscattering Coefficient bb for Arbitrary Phase Functions.
Degree: 2011, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8246
► The backscattering coefficient bb is one of the inherent optical properties of natural waters which means that it is independent of the ambient light field…
(more)
▼ The backscattering coefficient bb is one of the inherent optical properties of natural
waters which means that it is independent of the ambient light field in the water.
As such, it plays a central role in many problems of optical oceanography and is used
in the characterization of natural waters. Essentially, any measurement that involves
sending a beam of light into water must account for all inherent backscattering. Some
of the applications that rely on the precise knowledge of the backscattering coefficient
include studies of suspended particle distributions, optical bathymetry, and remote
sensing. Many sources contribute to the backscattering, among them any suspended
particles, air bubbles, and the water molecules themselves. Due to the importance of
precise measurements and the ease with which water samples can be contaminated,
an instrument to determine directly and quickly the backscattering coefficient in situ
is highly desirable.
We present such an instrument in both theory and experiment. We explain the
theory behind our instrument and based on measurements made in the laboratory
we demonstrate that our prototype shows the predicted behavior. We present data
for increased extinction in the water, and show how measuring the extinction and
taking it into account improves the quality of our measurements. We present calibration
data obtained from three different particle sizes representing differently shaped
volume scattering functions. Based on these measurements we demonstrate that our
prototype has the necessary resolution to measure the backscattering coefficient bb over the whole range found in natural waters. We discuss potential improvements
that should be made for a commercial version of the instrument.
Advisors/Committee Members: Fry, Edward S. (advisor), Bevan, John W. (committee member), Kattawar, George W. (committee member), Welch, George R. (committee member).
Subjects/Keywords: Physics; Optics; Ocean Optics
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Haubrich, D. (2011). Instrumentation to Measure the Backscattering Coefficient bb for Arbitrary Phase Functions. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8246
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Haubrich, David. “Instrumentation to Measure the Backscattering Coefficient bb for Arbitrary Phase Functions.” 2011. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8246.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Haubrich, David. “Instrumentation to Measure the Backscattering Coefficient bb for Arbitrary Phase Functions.” 2011. Web. 08 Dec 2019.
Vancouver:
Haubrich D. Instrumentation to Measure the Backscattering Coefficient bb for Arbitrary Phase Functions. [Internet] [Thesis]. Texas A&M University; 2011. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8246.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Haubrich D. Instrumentation to Measure the Backscattering Coefficient bb for Arbitrary Phase Functions. [Thesis]. Texas A&M University; 2011. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8246
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
23.
Bi, Lei.
Light Scattering by Ice Crystals and Mineral Dust Aerosols in the Atmosphere.
Degree: 2012, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2011-05-9319
► Modeling the single-scattering properties of nonspherical particles in the atmo?sphere (in particular, ice crystals and dust aerosols) has important applications to climate and remote sensing…
(more)
▼ Modeling the single-scattering properties of nonspherical particles in the atmo?sphere (in particular, ice crystals and dust aerosols) has important applications to climate and remote sensing studies. The ?rst part of the dissertation (Chapters II?V) reports a combination of exact numerical methods, including the ?nite-di?erence time-domain (FDTD), the discrete-dipole-approximation (DDA), and the T-matrix methods, and an approximate method-the physical-geometric optics hybrid (PGOH) method-in the computation of the optical properties of the non-spherical particles in a complete range of size parameters. The major advancements are made on the modeling capabilities of the PGOH method, and the knowledge of the electromag?netic tunneling e?ect ? a semi-classical scattering e?ect. This research is important to obtain reliable optical properties of nonspherical particles in a complete range of size parameters with satisfactory accuracy and computational e?ciency.
The second part (Chapters VI-VII) of the dissertation is to investigate the de?pendence of the optical properties of ice crystals and mineral dust aerosols in the atmosphere on the spectrum, the particle size and the morphology based on compu?tational models. Ice crystals in the atmosphere can be classi?ed to be simple regular faceted particles (such as hexagon columns, plates, etc.) and imperfect ice crystals. Modeling of the scattering by regular ice crystals is straightforward, as their morphologies can be easily de?ned. For imperfect ice crystals, the morphology is quite diverse, which complicates the modeling process. We present an e?ective approach of using irregular faceted particle to characterize the imperfectness of ice crystals. As an example of application, less-than-unity backscattering color ratio of cirrus clouds is demonstrated and explained theoretically, which provides guidance in the calibra?tion algorithm for 1.064-?
m channel on the Calipso lidar. Dust aerosols have no particular morphology. To develop an approach to modeling the optical properties of realistic dust particles, the principle of using simple shapes (triaxial ellipsoids and nonsymmetric hexahedra) to represent irregular dust particles is explored. Simulated results have been compared with those measured in laboratory for several realistic aerosol samples. Agreement between simulated results and measurement suggests the potential applicability of the two aforementioned aerosol models. We also show the potential impact of the present study to passive and active atmospheric remote sensing and future research works.
Advisors/Committee Members: Kattawar, George W. (advisor), Yang, Ping (advisor), Hu, Chia-Ren (committee member), Ko, Che-Ming (committee member).
Subjects/Keywords: Light Scattering; Ice Crystals; Mineral Dust Aerosols; Physical-Geometric Optics Hybrid Method; Electromagnetic Edge Effect
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APA (6th Edition):
Bi, L. (2012). Light Scattering by Ice Crystals and Mineral Dust Aerosols in the Atmosphere. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2011-05-9319
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Bi, Lei. “Light Scattering by Ice Crystals and Mineral Dust Aerosols in the Atmosphere.” 2012. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-2011-05-9319.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Bi, Lei. “Light Scattering by Ice Crystals and Mineral Dust Aerosols in the Atmosphere.” 2012. Web. 08 Dec 2019.
Vancouver:
Bi L. Light Scattering by Ice Crystals and Mineral Dust Aerosols in the Atmosphere. [Internet] [Thesis]. Texas A&M University; 2012. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-05-9319.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Bi L. Light Scattering by Ice Crystals and Mineral Dust Aerosols in the Atmosphere. [Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-05-9319
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
24.
Qu, Xinmei.
Mercury dimer spectroscopy and an Einstein-Podolsky-Rosen experiment.
Degree: 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-3041
► The dissociation of a 199Hg2 dimer prepares an entangled state of two spatially separated 199Hg atoms, each with nuclear spin 1/2, and with zero total…
(more)
▼ The dissociation of a 199Hg2 dimer prepares an entangled state of two spatially separated
199Hg atoms, each with nuclear spin 1/2, and with zero total electron and nuclear spin
angular momenta. This is identical to the entangled state of the two spin 1/2 particles in
Bohm?s classic version of the EPR gedankenexperiment. An analysis of the rotational
structure of the CD=57HCI=0 band of the D3K+
u (1u)HX1Kg
+ (0+
g ) transition in Hg2 (natural
abundance) is presented. The analysis of the fluorescence excitation spectrum using a dye
laser gives the values of the constants BCD=57 and BCI=0 for the excited and ground electronic
energy states involved in the transition, respectively. To increase the accuracy of the
rotational constants and resolve the fine spectrum of the Hg2, a continuously tunable single
longitudinal mode laser with ultra-narrow line-width is needed. Measurements using a
narrow line-width alexandrite laser had been attempted and the values of BCD=57 and BCI=0
were determined. To improve the quality of the laser beam and hence the precision of the
rotational constants, modifications have been made to the cavity of the alexandrite laser.
This provides a possibility for further investigation.
Advisors/Committee Members: Fry, Edward S. (advisor), Kattawar, George W. (committee member), Laane, Jaan (committee member), Sokolov, Alexei (committee member).
Subjects/Keywords: SPECTROSCOPY
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APA (6th Edition):
Qu, X. (2009). Mercury dimer spectroscopy and an Einstein-Podolsky-Rosen experiment. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-3041
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Qu, Xinmei. “Mercury dimer spectroscopy and an Einstein-Podolsky-Rosen experiment.” 2009. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/ETD-TAMU-3041.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Qu, Xinmei. “Mercury dimer spectroscopy and an Einstein-Podolsky-Rosen experiment.” 2009. Web. 08 Dec 2019.
Vancouver:
Qu X. Mercury dimer spectroscopy and an Einstein-Podolsky-Rosen experiment. [Internet] [Thesis]. Texas A&M University; 2009. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-3041.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Qu X. Mercury dimer spectroscopy and an Einstein-Podolsky-Rosen experiment. [Thesis]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-3041
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
25.
Springer, Matthew M.
Time-resolved Characterization of Ultrashort Pulse Propagation.
Degree: 2013, Texas A&M University
URL: http://hdl.handle.net/1969.1/151868
► The propagation of ultrashort femtosecond laser pulses in linear dielectric materials is determined in the time, space, and frequency domains by linear Maxwell optics through…
(more)
▼ The propagation of ultrashort femtosecond laser pulses in linear dielectric materials is determined in the time, space, and frequency domains by linear Maxwell optics through dispersion and di?raction. For intense pulses, pulse propagation is additionally modi?ed by nonlinearities in the medium such as the optical Kerr e?ect, plasma generation, and self-phase modulation.
In this work we report the results of several experiments on the propagation of ultrashort pulses. In the linear regime, we characterize the temporal evolution of an ultrashort pulse during propagation through a linear dielectric under anomalous dispersion. Under these conditions the pulse evolution departs from the group velocity and group delay dispersion approximations, which leads to the formation of optical precursors. We describe an experiment which observes the propagation of optical precursors in a bulk condensed-matter dielectric. We generate ultrashort laser pulses and propagate the pulses through a bulk dye with an absorption resonance turned to the center wavelength of the femotsecond pulse. The pulse is then characterized in the time domain before and after propagation. Through numerical simulation we verify that the behavior of the precursors in the temporal pulse pro?le corresponds with the classical model.
Under very high intensity laser pulses, the nonlinearities induced by the propagation of the intense ultrashort pulse produce changes in the complex refractive index of the nonlinear material. We report the results of experiments involving time- resolved imaging of the propagation of ultrashort pulses in dielectric materials. We experimentally observe and characterize these e?ects through a weak-probe imaging e?ect which directly measures the nonlinearity in a time-resolved manner. In these experiments an intense femtosecond laser pulse is propagated in a nonlinear intensity regime while an unfocused low-intensity femtosecond pulse is used as to probe the nonlinear pulse. We use this technique to characterize femtosecond pulses in air and liquid, especially in the regime of optical ?lamentation. We subsequently calculate parameters such as the plasma density, the transverse extent, and the instantaneous refractive index within the femtosecond laser ?lament under conditions which are not accessible through most standard pulse measurement techniques.
Advisors/Committee Members: Sokolov, Alexei V (advisor), Kattawar, George W (committee member), Fry, Edward S (committee member), Hemmer, Phillip R (committee member).
Subjects/Keywords: Femtosecond Filamentation; Optical Precursors
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APA ·
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CSE |
Export
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APA (6th Edition):
Springer, M. M. (2013). Time-resolved Characterization of Ultrashort Pulse Propagation. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/151868
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Springer, Matthew M. “Time-resolved Characterization of Ultrashort Pulse Propagation.” 2013. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/151868.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Springer, Matthew M. “Time-resolved Characterization of Ultrashort Pulse Propagation.” 2013. Web. 08 Dec 2019.
Vancouver:
Springer MM. Time-resolved Characterization of Ultrashort Pulse Propagation. [Internet] [Thesis]. Texas A&M University; 2013. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/151868.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Springer MM. Time-resolved Characterization of Ultrashort Pulse Propagation. [Thesis]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/151868
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
26.
Mershin, Andreas.
Tubulin in vitro, in vivo and in silico.
Degree: 2005, Texas A&M University
URL: http://hdl.handle.net/1969.1/1635
► Tubulin, microtubules and associated proteins were studied theoretically, computationally and experimentally in vitro and in vivo in order to elucidate the possible role these play…
(more)
▼ Tubulin, microtubules and associated proteins were studied theoretically, computationally and experimentally in vitro and in vivo in order to elucidate the possible role these play in cellular information processing and storage. Use of the electric dipole moment of tubulin as the basis for binary switches (biobits) in nanofabricated circuits was explored with surface plasmon resonance, refractometry and dielectric spectroscopy. The effects of burdening the microtubular cytoskeleton of olfactory associative memory neurons with excess microtubule associated protein TAU in Drosophila fruitflies were determined. To investigate whether tubulin may be used as the substrate for quantum computation as a bioqubit, suggestions for experimental detection of quantum coherence and entanglement among tubulin electric dipole moment states were developed.
Advisors/Committee Members: Nanopoulos, Dimitri V. (advisor), Kattawar, George W. (committee member), Schuessler, Hans A. (committee member), Zoran, Mark J. (committee member).
Subjects/Keywords: tubulin; microtubules; dielectric; spectroscopy; surface; plasmon; resonance; simulation; drosophila; memory; olfactory; quantum; brain; qubit; biobit; bioqubit; teleportation; refractometry; dipole; moment; protein
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APA ·
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APA (6th Edition):
Mershin, A. (2005). Tubulin in vitro, in vivo and in silico. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/1635
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Mershin, Andreas. “Tubulin in vitro, in vivo and in silico.” 2005. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/1635.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Mershin, Andreas. “Tubulin in vitro, in vivo and in silico.” 2005. Web. 08 Dec 2019.
Vancouver:
Mershin A. Tubulin in vitro, in vivo and in silico. [Internet] [Thesis]. Texas A&M University; 2005. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/1635.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Mershin A. Tubulin in vitro, in vivo and in silico. [Thesis]. Texas A&M University; 2005. Available from: http://hdl.handle.net/1969.1/1635
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
27.
Cone, Michael Thomas.
A New Diffuse Reflecting Material with Applications Including Integrating Cavity Ring-Down Spectroscopy.
Degree: 2014, Texas A&M University
URL: http://hdl.handle.net/1969.1/152759
► We report the development of a new diffuse reflecting material with measured diffuse reflectivity values as high as 0.9992 at 532 nm, and 0.9969 at…
(more)
▼ We report the development of a new diffuse reflecting material with measured
diffuse reflectivity values as high as 0.9992 at 532 nm, and 0.9969 at 266 nm. These
values are, to the author?s best knowledge, the highest diffuse reflectivity values
ever produced. The material is a high-purity fumed silica, or quartz powder. We
demonstrate the application of this new material to several areas of integrating cavity
enhanced spectroscopy, including absorption, Raman, and fluorescence spectroscopy.
In addition, we demonstrate a new spectroscopic technique based on cavity ring-down
spectroscopy using an integrating cavity made of our new diffuse reflector.
This technique, which we call integrating cavity ring-down spectroscopy (ICRDS),
has tremendous potential for sensitive absorption measurements of low-absorbing
samples, even when there is strong scattering. Results for measurements of the
absorption coefficient of retinal pigment epithelium cells using this ICRDS technique
are also presented. Finally, we discuss the importance of the ?wall-time? when
considering the temporal response of an integrating cavity. Light reflecting off the
inner wall of an integrating cavity actually penetrates into the diffuse reflecting
material. Therefore, the light spends some time inside the cavity wall. We measure
this wall-time via two independent methods, and show that it can be on the order
of several picoseconds.
Advisors/Committee Members: Fry, Edward S (advisor), Kattawar, George W (committee member), Welch, George R (committee member), Bevan, John W (committee member).
Subjects/Keywords: integrating cavity; diffuse reflector; silica
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APA ·
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Export
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APA (6th Edition):
Cone, M. T. (2014). A New Diffuse Reflecting Material with Applications Including Integrating Cavity Ring-Down Spectroscopy. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/152759
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Cone, Michael Thomas. “A New Diffuse Reflecting Material with Applications Including Integrating Cavity Ring-Down Spectroscopy.” 2014. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/152759.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Cone, Michael Thomas. “A New Diffuse Reflecting Material with Applications Including Integrating Cavity Ring-Down Spectroscopy.” 2014. Web. 08 Dec 2019.
Vancouver:
Cone MT. A New Diffuse Reflecting Material with Applications Including Integrating Cavity Ring-Down Spectroscopy. [Internet] [Thesis]. Texas A&M University; 2014. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/152759.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Cone MT. A New Diffuse Reflecting Material with Applications Including Integrating Cavity Ring-Down Spectroscopy. [Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/152759
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
28.
Zhang, Zhibo.
Computation of the scattering properties of nonspherical ice crystals.
Degree: 2004, Texas A&M University
URL: http://hdl.handle.net/1969.1/1267
► This thesis is made up of three parts on the computation of scattering properties of nonspherical particles in the atmosphere. In the first part, a…
(more)
▼ This thesis is made up of three parts on the computation of scattering properties of nonspherical
particles in the atmosphere. In the first part, a new crystal type-droxtal-is introduced to make a better
representation of the shape of small ice crystals in the uppermost portions of midlatitude and tropical cirrus
clouds. Scattering properties of droxtal ice crystals are investigated by using the Improved-Geometric Optic
(IGO) method. At the visible wavelength, due to the presence of the hexagonal structure, all elements of the
phase matrix of droxtal ice crystals share some common features with hexagonal ice crystals, such as 220
and 460 halos. In the second part of this thesis, the possibility of enhancing the performance of current
Anomalous Diffraction Theory (ADT) is investigated. In conventional ADT models, integrations are
usually carried out in the domain of the particle projection. By transforming the integration domain to the
domain of scaled projectile length, the algorithm of conventional ADT models is enhanced. Because the
distribution of scaled projectile length is independent of the particle's physical size as long as the shape
remains the same, the new algorithm is especially efficient for the calculation of a large number of particles
with the same shape but different sizes. Finally, in the third part, the backscattering properties of
nonspherical ice crystals at the 94GHz frequency are studied by employing the Finite-Difference Time-
Domain (FDTD) method. The most important factor that controls the backscattering cross section is found
to be the ratio of the volume-equal radius to the maximum dimension of the ice crystal. Substantial
differences in backscattering cross sections are found between horizontal orientated and randomly oriented
ice crystals. An analytical formula is derived for the relationship between the ice water (IWC) content and
the radar reflectivity ( e Z ). It is shown that a change to the concentration of ice crystals without any
changes on the size distribution or particle habits leads only to a linear e Z IWC - relationship. The famous
power law e Z IWC - relationship is the result of the shift of the peak of particle size distribution.
Advisors/Committee Members: Yang, Ping (advisor), Kattawar, George W. (committee member), Wilheit, Thomas (committee member).
Subjects/Keywords: Scattering; nonspherical ice crystals; FDTD; GOM; ADT; radar remote sensing
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APA ·
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CSE |
Export
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Manager
APA (6th Edition):
Zhang, Z. (2004). Computation of the scattering properties of nonspherical ice crystals. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/1267
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Zhang, Zhibo. “Computation of the scattering properties of nonspherical ice crystals.” 2004. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/1267.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Zhang, Zhibo. “Computation of the scattering properties of nonspherical ice crystals.” 2004. Web. 08 Dec 2019.
Vancouver:
Zhang Z. Computation of the scattering properties of nonspherical ice crystals. [Internet] [Thesis]. Texas A&M University; 2004. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/1267.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Zhang Z. Computation of the scattering properties of nonspherical ice crystals. [Thesis]. Texas A&M University; 2004. Available from: http://hdl.handle.net/1969.1/1267
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
29.
Lawless, Ryan Lee.
Sensitivity of the Mueller matrix to the optical and microphysical properties of cirrus clouds.
Degree: 2006, Texas A&M University
URL: http://hdl.handle.net/1969.1/4323
► An adding-doubling method is employed to calculate the reflected Stokes parameters for cirrus cloud layers composed of different habits and effective sizes. The elements of…
(more)
▼ An adding-doubling method is employed to calculate the reflected Stokes
parameters for cirrus cloud layers composed of different habits and effective sizes. The
elements of the Mueller matrix are determined from the reflected Stokes parameters by
considering four different incident polarization states. The sensitivity of these elements is
observed by comparing different ice crystal habits, effective sizes, and optical depth. The
Mueller elements are strongly dependent on habit. The three habits, aggregate, bullet
rosette, and plate, are observed and the
M12/M11,M43/M11 and M44/M11 elements are discussed. The wavelength used is 0.532????
m, which is the lidar wavelength used on
the CALIPSO satellite. The linear depolarization ratio is also discussed. The method of
subtracting the two depolarization ratios, is noted as another way to possibly better distinguish ice crystal habits.
The sensitivity of the Mueller matrix to effective size is also observed. For three
size distributions, the Mueller elements indicate no strong dependence. This may be due
to the assumption of randomly oriented ice. Also, using an absorbing wavelength might
provide dependence. Finally, the Mueller elements are dependent on optical depth. For a
greater optical depth, the strength of reflection increases while the polarization decreases.
As the optical depth increases, any peak-like features become non-existent.
Advisors/Committee Members: Yang, Ping (advisor), Kattawar, George W. (committee member), North, Jerry R. (committee member), Wilheit, Thomas (committee member).
Subjects/Keywords: polarization; radiative transfer; Mueller matrix; cirrus clouds
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CSE |
Export
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Manager
APA (6th Edition):
Lawless, R. L. (2006). Sensitivity of the Mueller matrix to the optical and microphysical properties of cirrus clouds. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/4323
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lawless, Ryan Lee. “Sensitivity of the Mueller matrix to the optical and microphysical properties of cirrus clouds.” 2006. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/4323.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lawless, Ryan Lee. “Sensitivity of the Mueller matrix to the optical and microphysical properties of cirrus clouds.” 2006. Web. 08 Dec 2019.
Vancouver:
Lawless RL. Sensitivity of the Mueller matrix to the optical and microphysical properties of cirrus clouds. [Internet] [Thesis]. Texas A&M University; 2006. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/4323.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lawless RL. Sensitivity of the Mueller matrix to the optical and microphysical properties of cirrus clouds. [Thesis]. Texas A&M University; 2006. Available from: http://hdl.handle.net/1969.1/4323
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
30.
Lu, Zheng.
Optical absorption of pure water in the blue and ultraviolet.
Degree: 2007, Texas A&M University
URL: http://hdl.handle.net/1969.1/5828
► The key feature of the Integrating Cavity Absorption Meter (ICAM) is that it produces an isotropic illumination of the liquid sample and thereby dramatically minimizes…
(more)
▼ The key feature of the Integrating Cavity Absorption Meter (ICAM) is that it produces an
isotropic illumination of the liquid sample and thereby dramatically minimizes scattering
effects. The ICAM can produce an effective optical path length up to several meters. As a
consequence, it is capable of measuring absorption coefficients as low as 0.001
m-1. The
early version of the ICAM was used previously to measure the absorption spectrum of pure
water over the 380-700 nm range. To extend its range into the ultraviolet, several
modifications have been completed. The preliminary tests showed that the modified ICAM
was able to measure the absorption of pure water for the wavelength down to 300 nm. After
extensive experimental investigation and analysis, we found that the absorption of
Spectralon???? (the highly diffusive and reflective material used to build the ICAM) has a
higher impact on measurements of absorption in the UV range than we had expected.
Observations of high values for pure water absorption in the UV, specifically between 300
and 360 nm, are a consequence of absorption by the Spectralon????. These results indicated
that even more serious modifications were required (e.g. Spectralon???? can not be used for a
cavity in the UV). Consequently, we developed a new diffuse reflecting material and used
fused silica powder (sub-micron level) sealed inside a quartz cell to replace the inner Spectralon???? cavity of the ICAM. The new data is in excellent agreement with the Pope and
Fry data (380-600 nm) and fills the gap between the 320 nm data of Quickenden and Irvin
and 380 nm data of Pope and Fry. We present definitive results for the absorption spectrum
of pure water between 300 and 600 nm.
Advisors/Committee Members: Fry, Edward S. (advisor), Eknoyan, Ohannes (committee member), Kattawar, George W. (committee member), Kenefick, Robert A. (committee member).
Subjects/Keywords: Absorption; Pure water; Ultraviolet
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APA (6th Edition):
Lu, Z. (2007). Optical absorption of pure water in the blue and ultraviolet. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/5828
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lu, Zheng. “Optical absorption of pure water in the blue and ultraviolet.” 2007. Thesis, Texas A&M University. Accessed December 08, 2019.
http://hdl.handle.net/1969.1/5828.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lu, Zheng. “Optical absorption of pure water in the blue and ultraviolet.” 2007. Web. 08 Dec 2019.
Vancouver:
Lu Z. Optical absorption of pure water in the blue and ultraviolet. [Internet] [Thesis]. Texas A&M University; 2007. [cited 2019 Dec 08].
Available from: http://hdl.handle.net/1969.1/5828.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lu Z. Optical absorption of pure water in the blue and ultraviolet. [Thesis]. Texas A&M University; 2007. Available from: http://hdl.handle.net/1969.1/5828
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
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