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University of Central Florida

Faculty Bibliography 2000s

2006

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Nuclear Spectra Of Comet 162p/Siding Spring (2004 Tu12), Humberto Campins, Julie Ziffer, Javier Licandro, Noemí Pinilla-Alonso, Yanga Fernández, Julia De León, Thais Mothé-Diniz, Richard P. Binzel Jan 2006

Nuclear Spectra Of Comet 162p/Siding Spring (2004 Tu12), Humberto Campins, Julie Ziffer, Javier Licandro, Noemí Pinilla-Alonso, Yanga Fernández, Julia De León, Thais Mothé-Diniz, Richard P. Binzel

Faculty Bibliography 2000s

We present visible and near-IR spectra of the nucleus of comet 162P/Siding Spring ( also known as 2004 TU12) obtained in 2004 December, while it had no detectable coma. This is the third object observed to have intermittent cometary activity even when relatively close to the Sun. The spectra show no strong features in this wavelength range. This paucity of deep absorptions is common among low-albedo asteroids and the few comet nuclei observed in this spectral region. Marginal spectral structure is observed in the visible spectrum, and beyond 2 mu m the flux from the nucleus is dominated by thermal …

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Time-Dependent Quantum Transport And Nonquasistatic Effects In Carbon Nanotube Transistors, Yupeng Chen, Yigian Ouyang, Jing Guo, Thomas X. Wu Jan 2006

Time-Dependent Quantum Transport And Nonquasistatic Effects In Carbon Nanotube Transistors, Yupeng Chen, Yigian Ouyang, Jing Guo, Thomas X. Wu

Faculty Bibliography 2000s

Nonquasistatic effects in ac characteristics of carbon nanotube field-effect transistors are examined by solving a full time-dependent, open-boundary Schrodinger equation. The nonquasistatic characteristics, such as the finite channel charging time, and the dependence of small signal transconductance and gate capacitance on the frequency, are explored. The validity of the widely used quasistatic approximation is examined. The results show that the quasistatic approximation overestimates the transconductance and gate capacitance at high frequencies, but gives a more accurate value for the intrinsic cutoff frequency over a wide range of bias conditions.

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On Value Distribution Theory Of Second Order Periodic Odes, Special Functions And Orthogonal Polynomials, Yik-Man Chiang, Mourad E. H. Ismail Jan 2006

On Value Distribution Theory Of Second Order Periodic Odes, Special Functions And Orthogonal Polynomials, Yik-Man Chiang, Mourad E. H. Ismail

Faculty Bibliography 2000s

We show that the value distribution (complex oscillation) of solutions of certain periodic second order ordinary differential equations studied by Bank, Laine and Langley is closely related to confluent hypergeometric functions, Bessel functions and Bessel polynomials. As a result, we give a complete characterization of the zero-distribution in the sense of Nevanlinna theory of the solutions for two classes of the ODEs. Our approach uses special functions and their asymptotics. New results concerning finiteness of the number of zeros (finite-zeros) problem of Besset and Coulomb wave functions with respect to the parameters are also obtained as a consequence. We demonstrate …

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Phase-And-Amplitude Regeneration Of Differential Phase-Shift Keyed Signals Using A Phase-Sensitive Amplifier, Kevin Croussore, Inwoong Kim, Cheolhwan Kim, Yan Han, Guifang Li Jan 2006

Phase-And-Amplitude Regeneration Of Differential Phase-Shift Keyed Signals Using A Phase-Sensitive Amplifier, Kevin Croussore, Inwoong Kim, Cheolhwan Kim, Yan Han, Guifang Li

Faculty Bibliography 2000s

DPSK phase- and- amplitude regeneration with a NOLM- based phase- sensitive amplifier is demonstrated experimentally. For a highly degraded input signal, maximum differential phase errors were reduced from 82 degrees to 41 degrees, while the SNR was improved by more than 5- dB. Differential phase Q- factor improvement was better than 6- dB. The PSA was operated free of excess noise due to stimulated Brillouin scattering by using a binary phase modulated pulse train as the pump. The impact of pump fluctuations on regeneration performance is clarified. The regenerated signal was characterized by measurement of the constellation diagram by linear …

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Tolerance Analysis Method For Shack-Hartmann Sensors Using A Variable Phase Surface, Costin Curatu, George Curatu, Jannick Rolland Jan 2006

Tolerance Analysis Method For Shack-Hartmann Sensors Using A Variable Phase Surface, Costin Curatu, George Curatu, Jannick Rolland

Faculty Bibliography 2000s

Even after good calibration, the measurement accuracy of a Shack-Hartmann sensor can be affected by the fabrication and alignment tolerances of the wavefront sensing optical system. The shifts of the Shack-Hartmann spots caused by misalignments correspond to ray intercept errors on the detector that typically have to be converted into a meaningful input wavefront measurement error. This conversion cannot be directly obtained from a conventional tolerance analysis using optical design software, because of the intrinsic wavefront sampling by the lenslet array. The tolerancing method proposed in this paper solves the problem of converting conventional merit function degradation into input wavefront …

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Sic-Based Optical Interferometry At High Pressures And Temperatures For Pressure And Chemical Sensing, Surendramohan Dakshinamurthy, Nathaniel R. Quick, Aravinda Kar Jan 2006

Sic-Based Optical Interferometry At High Pressures And Temperatures For Pressure And Chemical Sensing, Surendramohan Dakshinamurthy, Nathaniel R. Quick, Aravinda Kar

Faculty Bibliography 2000s

Crystalline silicon carbide is a chemically inert wide band gap semiconductor with good mechanical strength and oxidation-resistant properties at elevated temperatures, which make it a good sensor material for harsh environments such as combustion chambers and turbine systems. For such cases, optical sensors are generally superior to electrical sensors in many aspects such as responsivity, detectivity, and sensitivity. This paper presents a wireless technique for pressure and chemical sensing based on the pressure-and temperature-dependent refractive indices of silicon carbide. A helium-neon laser with a wavelength of 632.8 nm was used as a probe laser to obtain the complementary Airy pattern …

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E-Commerce And Caulerpa: Unregulated Dispersal Of Invasive Species, Linda J. Walters, Katherine R. Brown, Wytze T. Stam, Jeanine L. Olsen Jan 2006

E-Commerce And Caulerpa: Unregulated Dispersal Of Invasive Species, Linda J. Walters, Katherine R. Brown, Wytze T. Stam, Jeanine L. Olsen

Faculty Bibliography 2000s

Professional aquarists and hobbyists are thought to be the source of invasions of the aquarium strain of the green macroalga Caulerpa taxi folia in the Mediterranean, southern California, and Australia. The US Department of Agriculture, Animal and Plant Health Inspection Service (USDA-APHIS) restricted interstate commerce and importation of the Mediterranean clone of C taxi folia prior to the California invasion and is currently deciding if it should strengthen regulation of this genus as more species of Caulerpa are being described as invasive. Here we document the importance of e-commerce as a mode of dispersal for many species of Caulerpa in …

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Optical Breathers In Nonlinear Anisotropic And Dispersive Media, G. T. Adamashvili, D. J. Kaup Jan 2006

Optical Breathers In Nonlinear Anisotropic And Dispersive Media, G. T. Adamashvili, D. J. Kaup

Faculty Bibliography 2000s

Anisotropic crystals containing impurity atoms, when the principal optical axis of the uniaxial crystal and the vector of electrical dipole moment of the impurity atoms are perpendicular to each other and are directed along different crystallographic axes, are shown to have three different mechanisms of the formation of breathers depending on the direction of the wave propagation and on the symmetry of the medium. Explicit analytic expressions for the parameters of breathers and the effective nonlinear susceptibilities for extraordinary waves are obtained. All uniaxial crystals with quadratic susceptibilities can be divided into three different groups, according to the crystal classes. …

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Compact Low-Cost Detection Electronics For Optical Coherence Imaging, A. C. Akcay, K. S. Lee, L. R. Furenlid, M. A. Costa, J. P. Rolland Jan 2006

Compact Low-Cost Detection Electronics For Optical Coherence Imaging, A. C. Akcay, K. S. Lee, L. R. Furenlid, M. A. Costa, J. P. Rolland

Faculty Bibliography 2000s

A compact and low-cost detection electronics scheme for optical coherence imaging is demonstrated. The performance of the designed electronics is analyzed in comparison to a commercial lock-in amplifier of equal bandwidth. Images of a fresh-onion sample are presented for each detection configuration.

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Color Appearance In High-Dynamic-Range Imaging, Ahmet Oguz Akyüz, Erik Reinhard Jan 2006

Color Appearance In High-Dynamic-Range Imaging, Ahmet Oguz Akyüz, Erik Reinhard

Faculty Bibliography 2000s

When viewing images on a monitor, we are adapted to the lighting conditions of our viewing environment as well as the monitor itself, which can be very different from the lighting conditions in which the images were taken. As a result, our perception of these photographs depends directly on the environment in which they are displayed. For high-dynamic-range images, the disconnect in the perception of scene and viewing environments is potentially much larger than in conventional film and photography. To prepare an image for display, luminance compression alone is therefore not sufficient. We propose to augment current tone reproduction operators …

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Two-Photon Resonance Fluorescence, Moorad Alexanian, Subir K. Bose Jan 2006

Two-Photon Resonance Fluorescence, Moorad Alexanian, Subir K. Bose

Faculty Bibliography 2000s

We present a theory of two-photon resonance fluorescence of an atom or molecule in which the excitation by an external electromagnetic field as well as fluorescence emission is mediated by two-photon processes. The treatment is based on first dressing the atom or molecule by the external field and then evaluating perturbatively the effect of the interaction with the vacuum or fluorescent field and so resonance fluorescence can be considered as spontaneous emission from the dressed atom. The introduction of the combined system of atom and external field via dressed states leads to simpler calculations and more transparent physics. The fluorescence …

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Strehl Ratio And Scintillation Theory For Uplink Gaussian-Beam Waves: Beam Wander Effects, Larry C. Andrews, Ronald L. Phillips, Richard J. Sasiela, Ronald R. Parenti Jan 2006

Strehl Ratio And Scintillation Theory For Uplink Gaussian-Beam Waves: Beam Wander Effects, Larry C. Andrews, Ronald L. Phillips, Richard J. Sasiela, Ronald R. Parenti

Faculty Bibliography 2000s

First-order weak-fluctuation Rytov theory predicts that the longitudinal (on-axis) component of the scintillation index of an uplink collimated beam will become significantly smaller as the size of the transmitter aperture increases up to around 100 cm. However, the results of recent computer simulations are at odds with this behavior, and we believe that this discrepancy is due to the fact that the conventional Rytov theory does not correctly account for the effects of beam wander on the scintillation index. We present a theoretical structure that accurately describes far-field irradiance fluctuations caused by uncorrected beam wander. This new theory is validated …

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Thermal Transport And Grain Boundary Conductance In Ultrananocrystalline Diamond Thin Films, Maki A. Angadi, Taku Watanabe, Arun Bodapati, Xingcheng Xiao, Orlando Auciello, John A. Carlisle, Jeffret A. Eastman, Pawel Keblinski, Patrick K. Schelling, Simon R. Phillpot Jan 2006

Thermal Transport And Grain Boundary Conductance In Ultrananocrystalline Diamond Thin Films, Maki A. Angadi, Taku Watanabe, Arun Bodapati, Xingcheng Xiao, Orlando Auciello, John A. Carlisle, Jeffret A. Eastman, Pawel Keblinski, Patrick K. Schelling, Simon R. Phillpot

Faculty Bibliography 2000s

Although diamond has the highest known room temperature thermal conductivity, k similar to 2200 W/m K, highly sp(3) amorphous carbon films have k < 15 W/m K. We carry out an integrated experimental and simulation study of thermal transport in ultrananocrystalline diamond (UNCD) films. The experiments show that UNCD films with a grain size of 3-5 nm have thermal conductivities as high as k=12 W/m K at room temperature, comparable with that of the most conductive amorphous diamond films. This value corresponds to a grain boundary (Kapitza) conductance greater than 3000 MW/m(2) K, which is ten times larger than that previously seen in any material. Our simulations of both UNCD and individual diamond grain boundaries yield values for the grain boundary conductance consistent with the experimentally obtained value, leading us to conclude that thermal transport in UNCD is controlled by the intrinsic properties of the grain boundaries.

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Near-Field Characterization Of Effective Optical Interfaces, A. Apostol, D. Haefner, A. Dogariu Jan 2006

Near-Field Characterization Of Effective Optical Interfaces, A. Apostol, D. Haefner, A. Dogariu

Faculty Bibliography 2000s

The properties of many heterogeneous media depend on both the surface roughness and the local variations of the optical properties. An effective optical interface is usually invoked to describe the characteristics of such media. Using approaches specific to near-field optics, the two influences can be decoupled and a quantitative assessment of their contributions can be performed. It is also shown that a discrete random-walk model can be used to determine the magnitude of the dielectric constant fluctuations at subwavelength scales which, in turn, describe the morphology of optically inhomogeneous media.

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External Cavity Multiwavelength Semiconductor Hybrid Mode-Locked Laser Intracavity Gain Dynamics, Luis C. Archundia, Peter J. Delfyett Jr. Jan 2006

External Cavity Multiwavelength Semiconductor Hybrid Mode-Locked Laser Intracavity Gain Dynamics, Luis C. Archundia, Peter J. Delfyett Jr.

Faculty Bibliography 2000s

The intracavity gain dynamics of an external cavity semiconductor hybrid mode-locked laser is measured under multiwavelength operation. The results show a temporal skew between pulses corresponding to different wavelength channels. A measurement of the temporal evolution of the gain reveals a slow gain depletion, avoiding carrier heating and carrier cooling, and decreasing self-phase modulation effects and gain competition between wavelength channels, making multiwavelength operation possible.

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External Cavity Multiwavelength Semiconductor Mode-Locked Lasers Gain Dynamics, Luis C. Archundia, Peter J. Delfyett Jan 2006

External Cavity Multiwavelength Semiconductor Mode-Locked Lasers Gain Dynamics, Luis C. Archundia, Peter J. Delfyett

Faculty Bibliography 2000s

The gain dynamics of a semiconductor optical amplifier ( SOA) were measured using pump-probe techniques for the amplification of 750 fs pulses, 6.5 ps pulses and multiwavelength pulses, obtained from an external cavity semiconductor mode-locked laser. Furthermore, the intracavity gain dynamics of an external cavity semiconductor mode-locked laser was measured under multiwavelength operation. The experimental results show how the inherent chirp in pulses from external cavity semiconductor mode-locked lasers result in a slow gain depletion without significant fast gain dynamics. This mitigates gain competition between wavelength channels and nonlinearities in the gain media ( SOA), enabling the multiwavelength operation of …

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Preparation And Characterization Of Transparent Conducting Znte : Cu Back Contact Interface Layer For Cds/Cdte Solar Cell For Photoelectrochemical Application, Upendra S. Avachat, Neelkanth G. Dhere Jan 2006

Preparation And Characterization Of Transparent Conducting Znte : Cu Back Contact Interface Layer For Cds/Cdte Solar Cell For Photoelectrochemical Application, Upendra S. Avachat, Neelkanth G. Dhere

Faculty Bibliography 2000s

FSEC Photovoltaic Materials Laboratory has developed a photoelectrochemical (PEC) cell using multiple band gap tandem of thin-film photovoltaic (PV) cells and a photocatalyst for hydrogen production by water splitting. CdS/CdTe solar cell, a promising candidate for low-cost, thin-film PV cell, is used as one of the thin-film solar cells in a PEC cell. The back contact has been developed for a CdS/CdTe solar cell which involves the deposition of a primary p-type ZnTe:Cu back contact interface layer followed by the deposition of transparent and conducting ZnO:AI and Ni-Al outer metallization layer. This article presents preparation and characterization of ZnTe:Cu back …

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Subpixel Registration Directly From The Phase Difference, Murat Balci, Hassan Foroosh Jan 2006

Subpixel Registration Directly From The Phase Difference, Murat Balci, Hassan Foroosh

Faculty Bibliography 2000s

This paper proposes a new approach to subpixel registration, under local/global shifts or rotation, using the phase-difference matrix. We establish the exact relationship between the continuous and the discrete phase difference of two shifted images and show that their discrete phase difference is a 2-dimensional sawtooth signal. As a result, the exact shifts or rotations can be determined to subpixel or subangle accuracy by counting the number of cycles of the phase-difference matrix along the frequency axes. The subpixel portion is represented by a fraction of a cycle corresponding to the noninteger part of the shift or rotation. The rotation …

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The Complete Chloroplast Genome Sequence Of Citrus Sinensis (L.) Osbeck Var 'Ridge Pineapple': Organization And Phylogenetic Relationships To Other Angiosperms, Michael G. Bausher, Nameirakpam D. Singh, Seung-Bum Lee, Robert K. Jansen, Henry Daniell Jan 2006

The Complete Chloroplast Genome Sequence Of Citrus Sinensis (L.) Osbeck Var 'Ridge Pineapple': Organization And Phylogenetic Relationships To Other Angiosperms, Michael G. Bausher, Nameirakpam D. Singh, Seung-Bum Lee, Robert K. Jansen, Henry Daniell

Faculty Bibliography 2000s

Background: The production of Citrus, the largest fruit crop of international economic value, has recently been imperiled due to the introduction of the bacterial disease Citrus canker. No significant improvements have been made to combat this disease by plant breeding and nuclear transgenic approaches. Chloroplast genetic engineering has a number of advantages over nuclear transformation; it not only increases transgene expression but also facilitates transgene containment, which is one of the major impediments for development of transgenic trees. We have sequenced the Citrus chloroplast genome to facilitate genetic improvement of this crop and to assess phylogenetic relationships among major lineages …

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Interfacial Phonon Scattering In Semiconductor Nanowires By Molecular-Dynamics Simulation, Brian Becker, Patrick K. Schelling, Simon R. Phillpot Jan 2006

Interfacial Phonon Scattering In Semiconductor Nanowires By Molecular-Dynamics Simulation, Brian Becker, Patrick K. Schelling, Simon R. Phillpot

Faculty Bibliography 2000s

We use molecular-dynamics simulations of vibrational wave packets to study the scattering of longitudinal-acoustic modes from interfaces in semiconductor nanowires of varying diameters. The energy transmission coefficient at the interface is found to depend strongly on both the nanowire diameter and the frequency of the incident wave. By analyzing the scattering events, we determine the selection rules for nanowire scattering that can be understood in terms of the representations of the point-group symmetry of the nanowire. Using such symmetry arguments, we predict that the presence of gaps in the phonon spectrum of thin high-symmetry nanowires will result in a complete …

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Elusive Equity: Education Reform In Post-Apartheid South Africa, Karen L. Biraimah Jan 2006

Elusive Equity: Education Reform In Post-Apartheid South Africa, Karen L. Biraimah

Faculty Bibliography 2000s

No abstract provided.

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Crossover In Thermal Transport Mechanism In Nanocrystalline Silicon, Arun Bodapatil, Pawel Keblinski, Patrick K. Schelling, Simon R. Philpot Jan 2006

Crossover In Thermal Transport Mechanism In Nanocrystalline Silicon, Arun Bodapatil, Pawel Keblinski, Patrick K. Schelling, Simon R. Philpot

Faculty Bibliography 2000s

Using vibrational mode analysis, we demonstrate that lattice vibrations in small grain (less than or similar to 3 nm) structurally inhomogeneous nanocrystalline silicon are almost identical to those in homogeneous amorphous structures with the majority of the vibrations delocalized and unpolarized. As a consequence the principal thermal conductivity mechanism in such a nanocrystalline material is the same as in the amorphous material. With increasing grain size the ability of vibrations to homogenize over the nanocrystalline structure is gradually lost and the phonon spectrum becomes progressively more like that of a crystalline material; this is reflected in a crossover in the …

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Biodiversity Of Sessile And Motile Macrofauna On Intertidal Oyster Reefs In Mosquito Lagoon, Florida, Michelle L. Boudreaux, Jennifer L. Stiner, Linda J. Walters Jan 2006

Biodiversity Of Sessile And Motile Macrofauna On Intertidal Oyster Reefs In Mosquito Lagoon, Florida, Michelle L. Boudreaux, Jennifer L. Stiner, Linda J. Walters

Faculty Bibliography 2000s

Our research focused on determining the diversity and abundance of sessile and motile macrofauna that use intertidal reefs of the eastern oyster Crassostrea virginica for feeding, settlement space or refuge in Mosquito Lagoon, Florida. Five replicate lift nets were deployed at six sites (three impacted reefs with seaward margins of disarticulated shells, three reference reefs Without dead margins) to determine the species composition and numbers present on these reef types. All nets were deployed intertidally on backreef areas on living oyster reefs, just above mean low water. One and a half liters of live oysters and oyster shells were placed …

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A Hubble Space Telescope Advanced Camera For Surveys Search For Brown Dwarf Binaries In The Pleiades Open Cluster, H. Bouy, E. Moraux, J. Bouvier, W. Brandner, E. L. Martin, F. Allard, I. Baraffe, M. Fernández Jan 2006

A Hubble Space Telescope Advanced Camera For Surveys Search For Brown Dwarf Binaries In The Pleiades Open Cluster, H. Bouy, E. Moraux, J. Bouvier, W. Brandner, E. L. Martin, F. Allard, I. Baraffe, M. Fernández

Faculty Bibliography 2000s

We present the results of a high-resolution imaging survey for brown dwarf binaries in the Pleiades open cluster. The observations were carried out with the Advanced Camera for Surveys (Pavlovsky and coworkers) on board the Hubble Space Telescope. Our sample consists of 15 bona fide brown dwarfs. We confirm two binaries and detect their orbital motion, but we did not resolve any new binary candidates in the separation range between 5.4 and 1700 AU and masses in the range 0.035-0.065 M-circle dot. Together with the results of our previous study (Martin and coworkers), we can derive a visual binary frequency …

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Characterization Of The Ifn-Gamma T-Cell Responses To Immediate Early Antigens In Humans With Genital Herpes, Ralph P. Braun, Lendon G. Payne, Lichun Dong Jan 2006

Characterization Of The Ifn-Gamma T-Cell Responses To Immediate Early Antigens In Humans With Genital Herpes, Ralph P. Braun, Lendon G. Payne, Lichun Dong

Faculty Bibliography 2000s

Background: The IFN-gamma ELISPOT assay has been used to examine the T-cell repertoire for many disease states in humans but, as yet, not genital herpes. Using overlapping synthetic peptide libraries, an IFN-gamma ELISPOT assay was established that could measure CD4 and CD8 T-cell responses to HSV-2 antigens in patients with genital herpes. Results: In unexpanded T-cells isolated from peripheral blood, CD4 responses were readily measured against four immediate early antigens (ICP0, ICP4, ICP22 and ICP27), VP22 and gD. The CD4 responses were characterized by a low number of positive cells which produced large ELISPOTs. CD4 responses had a broad specificity …

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High Efficiency Sio2-Tio2 Hybrid Sol-Gel Antireflective Coating For Infrared Applications, E. Brinley, S. Seal, R. Folks, E. Braunstein, L. Kramer, S. Seal Jan 2006

High Efficiency Sio2-Tio2 Hybrid Sol-Gel Antireflective Coating For Infrared Applications, E. Brinley, S. Seal, R. Folks, E. Braunstein, L. Kramer, S. Seal

Faculty Bibliography 2000s

Sol-gel derived antireflective thin films were created for chalcogenide glass substrates in the 1.5-5 mu m wavelength range of infrared region. Presented herein is a preparation and characterization of the hybrid sol-gel created including particle size, refractive index, pH, and Fourier transform infrared FTIR transmission spectra. It is shown that an increase of not less than 8% and up to 25.1% transmission is achieved using sol-gel derived antireflective coatings.

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Cellular Response Of Shewanella Oneidensis To Strontium Stress, Steven D. Brown, Madhavi Martin, Sameer Deshpande, Sudipta Seal, Katherine Huang, Eric Alm, Yungfeng Ynag, Liyou Wu, Tingfen Yan, Xueduan Liu, Adam Arkin, Karuna Chourey, Jizhong Zhou, Dorothea K. Thompson Jan 2006

Cellular Response Of Shewanella Oneidensis To Strontium Stress, Steven D. Brown, Madhavi Martin, Sameer Deshpande, Sudipta Seal, Katherine Huang, Eric Alm, Yungfeng Ynag, Liyou Wu, Tingfen Yan, Xueduan Liu, Adam Arkin, Karuna Chourey, Jizhong Zhou, Dorothea K. Thompson

Faculty Bibliography 2000s

The physiology and transcriptome dynamics of the metal ion-reducing bacterium Shewanella oneidensis strain MR-1 in response to nonradioactive strontium (Sr) exposure were investigated. Studies indicated that MR-1 was able to grow aerobically in complex medium in the presence of 180 mM SrCl2, but showed severe growth inhibition at levels above that concentration. Temporal gene expression profiles were generated from aerobically grown, mid-exponential-phase MR-1 cells shocked with 180 mM SrCl2, and analyzed for significant differences in mRNA abundance with reference to data for nonstressed MR-1 cells. Genes with annotated functions in siderophore biosynthesis and iron transport were among the most highly …

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Structural Health Monitoring Of Bridges For Improving Transportation Security, F. Necati Catbas, Melih Susoy, Naim Kapucu Jan 2006

Structural Health Monitoring Of Bridges For Improving Transportation Security, F. Necati Catbas, Melih Susoy, Naim Kapucu

Faculty Bibliography 2000s

Structural health monitoring (SHM) is a promising technology for determining the condition of significant transportation structures objectively for efficient management and preservation of transportation assets. In addition to identifying, locating, and quantifying damage and deterioration due to effects of operation, aging, and natural hazards, the need for taking terrorism-related hazards into account has become evident after 9/11 terrorist attacks. Key transportation facilities like major bridges were identified by Department of Homeland Security (DHS) as possible terrorist targets since their loss or even temporary deficiency could lead to major impacts on economy and mobility. Several governmental, local, and private organizations have …

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Mitochondrial Uncoupling Protein-4 Regulates Calcium Homeostasis And Sensitivity To Store Depletion-Induced Apoptosis In Neural Cells, Sic. L. Chan, Dong Liu, George A. Kyriazis, Pamela Bagisyao, Xin Ouyang, Mark P. Mattson Jan 2006

Mitochondrial Uncoupling Protein-4 Regulates Calcium Homeostasis And Sensitivity To Store Depletion-Induced Apoptosis In Neural Cells, Sic. L. Chan, Dong Liu, George A. Kyriazis, Pamela Bagisyao, Xin Ouyang, Mark P. Mattson

Faculty Bibliography 2000s

An increase in the cytoplasmic-free Ca2+ concentration mediates cellular responses to environmental signals that influence a range of processes, including gene expression, motility, secretion of hormones and neurotransmitters, changes in energy metabolism, and apoptosis. Mitochondria play important roles in cellular Ca2+ homeostasis and signaling, but the roles of specific mitochondrial proteins in these processes are unknown. Uncoupling proteins (UCPs) are a family of proteins located in the inner mitochondrial membrane that can dissociate oxidative phosphorylation from respiration, thereby promoting heat production and decreasing oxyradical production. Here we show that UCP4, a neuronal UCP, influences store-operated Ca2+ entry, a process in …

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Ultralow Noise Optical Pulse Generation In An Actively Mode-Locked Quantum-Dot Semiconductor Laser, Myoung-Taek Choi, Ji-Myung Kim, Wangkuen Lee, Peter J. Delfyett Jan 2006

Ultralow Noise Optical Pulse Generation In An Actively Mode-Locked Quantum-Dot Semiconductor Laser, Myoung-Taek Choi, Ji-Myung Kim, Wangkuen Lee, Peter J. Delfyett

Faculty Bibliography 2000s

We report excellent noise performance of an external-cavity actively mode-locked laser based on quantum-dot gain medium. Optical pulse trains with less than 7.5 fs residual timing jitter (1 Hz to 10 MHz) for a 12.8 GHz harmonically mode-locked ring laser were obtained. This result represents, to our knowledge, the lowest residual jitter reported from actively mode-locked semiconductor lasers, and shows that quantum-dot mode-locked lasers are promising as sources of ultralow noise optical pulse trains.

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