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Full-Text Articles in Physics

Optical Cryoimaging Of Celular Redox In Kidneys From Diabetic Mice, Sepideh Maleki Aug 2012

Optical Cryoimaging Of Celular Redox In Kidneys From Diabetic Mice, Sepideh Maleki

Theses and Dissertations

Diabetic Nephropathy (DN) is the major single cause of end stage renal diseases (ESRD) in the United States. Diabetes is the third leading fatal disorder after cancer and heart disease. It is affecting 8.3% of the residents of the United States, with a total healthcare cost of $174 billion/yr by 2010.

There currently exists a need for a sensitive and specific diagnosis for temporal detection of oxidative stress (OS) in cellular metabolic levels, which plays an early role in the development of DN. The objective of this research is to use a fluorescence optical imaging technique in order to delineate …


Spectral Analysis Of Encrypted Chaotic Signals Using Fast Fourier Transforms And Laboratory Spectral Analyzers, Monish Ranjan Chatterjee, Abhinay Kundur Aug 2012

Spectral Analysis Of Encrypted Chaotic Signals Using Fast Fourier Transforms And Laboratory Spectral Analyzers, Monish Ranjan Chatterjee, Abhinay Kundur

Electrical and Computer Engineering Faculty Publications

The use of acousto-optic chaos, as manifested via first-order feedback in an acousto-optic Bragg cell, in encrypting a message wave and subsequently recovering the message in the receiver using a chaotic heterodyne strategy, has been reported recently [1-3]. In examining the dynamical system analytically using computer simulation, (expected) modulated chaos waveforms are obtained within specified observation windows.

Because of the relatively random nature inherent in chaos waveforms, it is essentially impossible to ascertain from the visual display of the chaotic wave whether a given message signal has in fact modulated the chaotic "carrier". In fact, it has been observed from …


Adaptive Circuits Using Pfet Floating-Gate Devices, Paul Hasler, Bradley Minch, Chris Diorio Jul 2012

Adaptive Circuits Using Pfet Floating-Gate Devices, Paul Hasler, Bradley Minch, Chris Diorio

Bradley Minch

In this paper, we describe our floating-gate pFET device, with its many circuit applications and supporting experimental measurements. We developed these devices in standard double-poly CMOS technologies by utilizing many effects inherent in these processes. We add floating-gate charge by electron tunneling, and we remove floating-gate charge by hot-electron injection. With this floating-gate technology, we cannot only build analog EEPROMs, we can also implement adaptation and learning when we consider floating-gate devices to be circuit elements with important time-domain dynamics. We start by discussing non-adaptive properties of floating-gate devices and we present two representative non-adaptive applications. First, we discuss using …


Switch Yard Operation In Thermal Power Plant(Katpp Jhalawar Rajasthan), Radhey Shyam Meena Er. Jul 2012

Switch Yard Operation In Thermal Power Plant(Katpp Jhalawar Rajasthan), Radhey Shyam Meena Er.

Radhey Shyam Meena

Switchyard Provides the facilities for switching ,protection & Control of electric power. To handle high Voltage power with proper Safety measures. To isolate the noises coming from the grid with true 50Hz power SWITCH YARD IS IMPORTANT PART IN THERMAL PLANT. IN KALISINDH THERMAL 400KV AND 220KV SWITCH YARD LOCATED.


The Double Pendulum: Construction And Exploration, Benjamin J. Knudson Jul 2012

The Double Pendulum: Construction And Exploration, Benjamin J. Knudson

Physics

The exploration of a nonlinear mechanical system, the Double Pendulum, a physical pendulum on the end of a physical pendulum, using analytic and experimental approaches. Also included discussion of the design and construction of the Double Pendulum apparatus to work with Vernier LabPro and LoggerPro. The apparatus outputs live data of the angles to a LoggerPro which collects and produces time evolution graphs as well as a corresponding animation lending itself to comparison with theoretical models. Normal mode frequencies are found both analytically and experimentally for the the general (real) double pendulum. Examples of both simple (periodic) and complex (chaotic) …


Size-Dependent Metal-Insulator Transition In Pt-Dispersed Sio2 Thin Film: A Candidate For Future Non-Volatile Memory, Albert B. Chen Jun 2012

Size-Dependent Metal-Insulator Transition In Pt-Dispersed Sio2 Thin Film: A Candidate For Future Non-Volatile Memory, Albert B. Chen

Albert B Chen

Non-volatile random access memories (NVRAM) are promising data storage and processing devices. Various NVRAM, such as FeRAM and MRAM, have been studied in the past. But resistance switching random access memory (RRAM) has demonstrated the most potential for replacing flash memory in use today. In this dissertation, a novel RRAM material design that relies upon an electronic transition, rather than a phase change (as in chalcogenide Ovonic RRAM) or a structural change (such in oxide and halide filamentary RRAM), is investigated. Since the design is not limited to a single material but applicable to general combinations of metals and insulators, …


Inductive Metal Identification, Paul Maggi Jun 2012

Inductive Metal Identification, Paul Maggi

Electrical Engineering

This project focuses on creating a device to differentiate between various types of metals via magnetic induction. Magnetic induction is used because it is both non-optical and non-contact. It achieves this by generating a varying magnetic field, which induces eddy currents in the metal. These eddy currents produce small disturbances in the surrounding magnetic field, which can be sensed with Hall Effect Sensors (HES). The primary challenge in this project was generating a sufficiently strong magnetic field to detectable disturbances. In order to achieve better results, a stronger magnetic field must be used as well as more sensitive Hall Effect …


Day/Night Band Imager For A Cubesat, Eric Stanton Jun 2012

Day/Night Band Imager For A Cubesat, Eric Stanton

Electrical Engineering

Day/Night Band (DNB) earth sensing and meteorological systems like the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) provide visible wavelength imagery 24 hours a day that is used primarily for cloud imaging in support of weather forecasting. This paper describes a compact push-broom imager that meets low light imaging requirements for DMSP OLS and the NOAA/NASA Joint Polar Satellite System (JPSS) as documented in the Integrated Operational Requirements Document [1] (IORD) including the imager design, system level concepts of operation for data collection, radiometric and spatial calibration, and data transmission to Earth. This small, lightweight imager complies with …


Emp And Geomagnetic Storm Protection Of Critical Infrastructure, George H. Baker Iii May 2012

Emp And Geomagnetic Storm Protection Of Critical Infrastructure, George H. Baker Iii

George H Baker

EMP and solar storm wide geographic coverage and ubiquitous system effects beg the question of “Where to begin?” with protection efforts. Thus, in addressing these “wide area electromagnetic (EM) effects,” we must be clever in deciding where to invest limited resources. Based on simple risk analysis, the electric power and communication infrastructures emerge as the highest priority for EM protection. Programs focused on these highest risk infrastructures will go a long way in lessoning societal impact. Given the national scope of the effects, such programs must be coordinated at the national level but implemented at local level. Because wide-area EM …


Dynamical Model Of Harmonic Generation In Centrosymmetric Semiconductors At Visible And Uv Wavelengths, Michael Scalora, Maria Antonietta Vincenti, Domenico De Ceglia, N. Akozbek, Vito Roppo, M. J. Bloemer, Joseph W. Haus May 2012

Dynamical Model Of Harmonic Generation In Centrosymmetric Semiconductors At Visible And Uv Wavelengths, Michael Scalora, Maria Antonietta Vincenti, Domenico De Ceglia, N. Akozbek, Vito Roppo, M. J. Bloemer, Joseph W. Haus

Electrical and Computer Engineering Faculty Publications

We study second and third harmonic generation in centrosymmetric semiconductors at visible and UV wavelengths in bulk and cavity environments. Second harmonic generation is due to a combination of spatial symmetry breaking, the magnetic portion of the Lorentz force, and quadrupolar contributions from inner core electrons. The material is assumed to have a nonzero, third-order nonlinearity that gives rise to most of the third harmonic signal. Using the parameters of bulk silicon we predict that cavity environments modify the dependence of second harmonic generation on incident angle, while improving third harmonic conversion efficiency by several orders of magnitude relative to …


Information Encryption And Retrieval In Mid-Rf Range Using Acousto-Optic Chaos, Monish Ranjan Chatterjee, Abhinay Kundur Apr 2012

Information Encryption And Retrieval In Mid-Rf Range Using Acousto-Optic Chaos, Monish Ranjan Chatterjee, Abhinay Kundur

Electrical and Computer Engineering Faculty Publications

In recent work, low-frequency AC signal encryption, decryption and retrieval using system-parameter based keys at the receiver stage of an acousto-optic (A-O) Bragg cell under first-order feedback have been demonstrated [1,2]. The corresponding nonlinear dynamics have also been investigated using the Lyapunov exponent and the so-called bifurcation maps [3]. The results were essentially restricted to A-O chaos around 10 KHz, and (baseband) signal bandwidths in the 1-4 KHz range. The results have generally been satisfactory, and parameter tolerances (prior to severe signal distortion at the output) in the ±5% - ±10% range have been obtained.

Periodic AC waveforms, and a …


A Threshold-Based Approach To Calorimetry In Helium Droplets: Measurement Of Binding Energies Of Water Clusters, William K. Lewis, Barbara A. Harruff-Miller, Michael A. Gord, Joseph R. Gord, Elena A. Guliants, Christopher E. Bunker Jan 2012

A Threshold-Based Approach To Calorimetry In Helium Droplets: Measurement Of Binding Energies Of Water Clusters, William K. Lewis, Barbara A. Harruff-Miller, Michael A. Gord, Joseph R. Gord, Elena A. Guliants, Christopher E. Bunker

Electrical and Computer Engineering Faculty Publications

Helium dropletbeam methods have emerged as a versatile technique that can be used to assemble a wide variety of atomic and molecular clusters. We have developed a method to measure the binding energies of clusters assembled in helium droplets by determining the minimum droplet sizes required to assemble and detect selected clusters in the spectrum of the dopeddropletbeam. The differences in the droplet sizes required between the various multimers are then used to estimate the incremental binding energies. We have applied this method to measure the binding energies of cyclic waterclusters from the dimer to the tetramer. We obtain measured …


Time Dynamics Of Self-Pumped Reflection Gratings In A Photorefractive Polymer, Partha P. Banerjee, S. H. Buller, C. M. Liebig, S. A. Basun, Gary Cook, Dean R. Evans, Pierre-Alexandre Blanche, J. Thomas, Cory W. Christenson, N. Peyghambarian Jan 2012

Time Dynamics Of Self-Pumped Reflection Gratings In A Photorefractive Polymer, Partha P. Banerjee, S. H. Buller, C. M. Liebig, S. A. Basun, Gary Cook, Dean R. Evans, Pierre-Alexandre Blanche, J. Thomas, Cory W. Christenson, N. Peyghambarian

Electrical and Computer Engineering Faculty Publications

The time dynamics of self-pumped reflection gratings in a commonly used photorefractive polymer PDCST:PVK:ECZ-BBP:C60 with no additional electron sources or traps is investigated. While holes are normally the mobile charges and responsible for grating formation, our experimental observations, analyzed using multi-exponential fitting curves, show evidence of electrons in addition to holes as charge carriers, particularly above an applied field of 40 V/μm.

The dependence of effective carrier mobilities on the applied electric field, deduced from experimental results, show stronger field dependence of electron mobility at high electric fields. At an applied field of 70 V/μm, electron and hole mobilities become …


Examination Of The Nonlinear Dynamics Of A Chaotic Acousto-Optic Bragg Modulator With Feedback Under Signal Encryption And Decryption, Mohammed A. Al-Saedi, Monish Ranjan Chatterjee Jan 2012

Examination Of The Nonlinear Dynamics Of A Chaotic Acousto-Optic Bragg Modulator With Feedback Under Signal Encryption And Decryption, Mohammed A. Al-Saedi, Monish Ranjan Chatterjee

Electrical and Computer Engineering Faculty Publications

An acousto-optic Bragg cell with first-order feedback, which exhibits chaotic behavior past the threshold for bistability, was recently examined for possible chaotic encryption and recovery of simple messages (such as low-amplitude periodic signals) applied via the bias input of the sound cell driver. We carry out a thorough examination of the nonlinear dynamics of the Bragg cell under intensity feedback for (i) dc variations of the feedback gain (β˜) and the phase shift parameter (α^ 0) and (ii) ac variations of α^ 0; total under signal encryption, investigating both from two different perspectives: (i) examining chaos in view of the …


Commentary And Interpretations Of Tagore’S 'Ode To Africa', Monish Ranjan Chatterjee Jan 2012

Commentary And Interpretations Of Tagore’S 'Ode To Africa', Monish Ranjan Chatterjee

Electrical and Computer Engineering Faculty Publications

This is a commentary/interpretation of Rabindranath Tagore's poem "Ode to Africa."


Optical Mode Pattern Study Of Gan Based Leds With And Without Nanoscale Top Grating, Gregory Chavoor Jan 2012

Optical Mode Pattern Study Of Gan Based Leds With And Without Nanoscale Top Grating, Gregory Chavoor

Electrical Engineering

This study analyzes optical confinement factor and light emitting mode order for three different GaN LEDs: a conventional LED, thin Film LED, and thin Film LED with a photonic crystal (PhC) grating. For the first structure, we increase the thickness of AlxGa1-xN from 0 to 600nm, alter the x composition in AlxGa1-xN from 0.05 to 0.2 in steps of 0.05, and adjust the p-GaN and n-GaN thicknesses each from 0 to 200nm. For the second structure, we alter the n-GaN substrate thickness from 300-1000nm in steps of 100nm and 1000-4000nm in steps …