Other Physics Commons^™

Orbit Propagation And Determination Algorithms For Satellite Ground Stations, Shamma Esmaeel Jamali

Theses

The satellite orbital parameters are essential for satellite operations. With these parameters, it is possible to estimate the satellite position in the recent past and near future, which is essential to effectively plan satellite operations and associate satellite telemetry with geographical locations.
However, for small or medium satellite operators who do not possess the infrastructure required to track their satellites, the problem of determining the satellite orbit is problematic. To access the orbit for their satellites, these organizations have to rely on third parties such as Celestrak. These entities provide the service free of charge but do not provide orbital …

Assembly And Detection Of 3-D Qr Codes Through Additive Manufacturing And Terahertz Imaging, Patrick Dunn

Theses

Automatic identification and data capture, or AIDC, plays a substantial role in contemporary business, advertising, and military needs. The purpose of this study is to generate a potential alternative to current AIDC approaches by constructing three-dimensional plastic tags (or ‘3D QR codes’) using additive manufacturing techniques and interrogate them using Terahertz radiation. 3D Quick Response (QR) codes are designed in 3D computer-aided design software. The QR codes are 3D structures embedded in the printed plastic in which an air gap in the plastic (or an air gap filled in with another type of plastic) indicates a bit of information. Information …

Treated Hfo2 Based Rram Devices With Ru, Tan, Tin As Top Electrode For In-Memory Computing Hardware, Yuvraj Dineshkumar Patel

Theses

The scalability and power efficiency of the conventional CMOS technology is steadily coming to a halt due to increasing problems and challenges in fabrication technology. Many non-volatile memory devices have emerged recently to meet the scaling challenges. Memory devices such as RRAMs or ReRAM (Resistive Random-Access Memory) have proved to be a promising candidate for analog in memory computing applications related to inference and learning in artificial intelligence. A RRAM cell has a MIM (Metal insulator metal) structure that exhibits reversible resistive switching on application of positive or negative voltage. But detailed studies on the power consumption, repeatability and retention …

Passive Planar Terahertz Retroreflectors, Dhruvkumar Desai

Theses

As the application of the Terahertz (THz) band (0.1 - 10 THz) is investigated in various settings, wireless communication stands out as an important frontier to explore. The benefits of increased bandwidth and data rates it promises will only be realized if new technology is developed to support it. Specifically, since THz wireless communication links are typically line-of-sight (LoS), the LoS can be blocked by moving obstacles, thereby requiring alternative link paths. One proposed solution for indoor wireless communications involves systems of steerable antennas, reflective "wallpaper", and steerable mirrors which would redirect THz beams around a blocking obstacle.

As an …

Electrical Properties Of Metal Semiconductor Contacts - Metals On Mos2: A Case Study, Xiao Chang

Theses

Properties of monolayer semiconductor, MoS2, are presented in the research. Schottky barrier height and Schottky-Mott rules are discussed. The current-voltage measurement and capacitance-voltage measurement are analyzed considering the role of the work function. We mainly focus on metal semiconductor contacts on molybdenum disulfide (MoS2). The properties of bulk and monolayer molybdenum disulfide are discussed. The differences between the bulk and monolayer, based on band gap structure theory, are presented. Utilizing the data obtained in the literature, the influence of temperature on the electrical properties of monolayer molybdenum disulfide are analyzed. In particular, the electrical properties of metals on MoS2 such …

Inkjet Printing Polymerized Pcda As A Means Of Serialization, Constantino Stavrou

Theses

Polymerized PCDA, otherwise known as pentacosadiynoic acid, due to its color changing response to high temperatures, has been used as a means of indicating whether the material has been exposed to high temperatures. Quick-Response codes or Q-R codes have been used as means of serialization due to their two-dimensional design, allowing for the embedding of larger amounts of information than their one-dimensional barcode predecessors.

Combining the colorimetric response of PCDA polymer with the information coding powers of Q-R codes, an improved version of the Q-R Code is made, which was used not only for serialization purposes, but as a means …

Radiative Properties Of Silicon Related Materials, Scott Sanowitz

Theses

The objective of this thesis is to study the optical properties of silicon, as a function of temperature, in the infrared range of wavelengths. The wavelength range, considered in this study, is between 1 micron and 20 microns. The temperature range observed is from 50 degrees Celsius to 1000 degrees Celsius. Varying wafer thickness and doping are taken into account. The thickness of the native oxide, silicon dioxide, must be taken into account as well as its orientation (front side versus back side). The effect of layering wafers one onto another is investigated. It is shown that all these parameters …

Opto-Mechanical Design Of Synchrotron Radiation-Based Far-Infrared Spectroscopic Ellipsometer With Strong Magnetic-Field, Ahmad Abbas Chaudhry

Theses

The objective of this dissertation is to present opto-mechanical design of a synchrotron radiation based far-infrared spectroscopic ellipsometer with a strong external magnetic-field capability. Since high magnetic field has enabled major breakthrough in science such instrument will be highly important to the field of condensed matter physics and characterization of advanced electronic materials. This instrument will be installed at the multi-User facility with the most advanced synchrotron light source: Natonal Synchrotron Source (NSLS-II) at Brookhaven National Laboratory (BNL).The proposed here instrument is capable to measure full Mueller matrix spectroscopic ellipsometry spectra in high magnetic fields of up to 9 Tesla. …

Characterizing Alma For Solar Observation, Yi Chai

Theses

ALMA (Atacama Large Millimeter/submillimeter Array) is an antenna array of 66 antennas located in northern Chile at 5000 meters altitude. It is the largest ground-based array operated at millimeter/submillimeter wavelengths. In this thesis, the advantages of using ALMA for solar observation are presented, together with the introduction of a campaign to commission ALMA for solar observations. Observation modes of the solar campaign are reviewed in Chapter 2. Methods for constructing images from single dish data as well as the procedure for processing interferometer data, including calibration and imaging, are given in Chapter 3. The CLEAN algorithm that is used for …

Mems Approaches In Infrared Imaging, George Papavieros

Theses

The design and performance simulation of a novel Microelectromechanical System (MEMS) based infrared detector, that utilizes coefficient of thermal expansion, is discussed. The detector design uses a variety of thermal expansion coefficient materials, including alloys which are connected to ambient through a thermal conducting bridge. The thermal flux, due to the incident IR photons, is determined by the Extended Blackbody Calculator (BBC). These materials are physically interfaced with different types of piezoelectric resonators, constructed using the MEMS process. The expansion due to heating, applies stress to the piezoelectric resonator material. This thermally induced stress forces the resonator to alter its …

Solar Eclipse Observation On May 21, 2012 From Jvla, Shaheda Begum Shaik

Theses

The annular solar eclipse occurred on May 21, 2012 is studied using the radio data from the Jansky Very Large Array (JVLA), Sorrocco, Mexico. The eclipse is observed in the solar minimum activity period of solar cycle 24. The centimeter wavelength observation of the Sun's surface during the solar eclipse helps in determining the spatially well resolved features not obtained by the man made advanced technology. Even though, the activity on the Sun is observed to be low in the period of eclipse, the study provides a good opportunity to understand the quiet Sun features in the regions occulted by …

Validation Of Solar Flare Forecasting & Evolution Of Magnetic Helicity Of Two Active Regions, Qin Li

Theses

This thesis includes two components: (1) Validation of the NJIT flare-forecasting model that was established in recent years is carried out based on the statistical correlation between solar magnetic parameters and flare productivity of active regions (ARs). 378 ARs are examined, comparing observation with prediction. It is found that the accuracy rate to some extent decreases with the level of flares. (2) The temporal evolution of the relative magnetic helicity of two ARs, AR 11072 and 11158 is investigated. The former is flare-quiet while the latter is flare-productive over the 5-day observation period. It is found that for both regions, …

Utilization Of A Tropospheric-Stratospheric Lidar System To Study Mountain Induced Gravity Waves Over Jenny Jump State Forest, Anthony Teti

Theses

Gravity waves are a dominant driver of the middle and lower atmospheric circulation. Yet such waves have been difficult to study due to their inherent small spatial and temporal scales and synoptic occurrence, and thus require advanced experimental systems. In this thesis first results are presented from a newly constructed tropospheric-stratospheric lidar operating at the New Jersey Institute of Technology-United Astronomy Clubs of New Jersey site in Jenny Jump State Forest in northwest New Jersey. The system utilizes a 4-W 532-nm Nd:YAG laser transmitter and a 4-inch telescope receiver to collect backscattered photons from the lower atmosphere in order to …

Non-Destructive Evaluation Of Agglomerated Cork Products Using Thz Spectroscopy And Imaging, Han Zhang

Theses

Terahertz spectroscopy from 0.15 to 0.3 THz is used to classify agglomerated cork products. Position dependent scattering of radiation allows one to image the internal structure of cork products. Previous studies have focused on natural (solid) cork stoppers. In this study, the feasibility of classifying agglomerated cork structures using THz imaging and spectroscopy is investigated. Both THz images and spectra are used to classify the agglomerated cork samples. Classification of the samples used three methods: visible examination of the THz images, statistical analysis of the pixel intensities, and a polynomial regression of the THz spectral data averaged over all pixels. …

G-Factors For Ternary Crystals Of Groups Iii And V, Liviu Mateescu

Theses

The objective of this thesis is to present a method of calculating the g-factors of ternary crystals of III-V group elements.

There is an increasing interest in knowing the magnetic behavior of different semiconductor materials, due to advances in the domain of spintronics. The g-factors were calculated for the conduction electrons, since they have the greatest contribution to the magnetic properties of the crystal. The thesis presented here proposes a method to calculate the magnetic g-factor of whole families of crystals made of three elements, of the form A_1-xB_xC, for eleven values, x ε {0, 0.1, …

Synoptic Variability Of A Cir-Driven Open-Closed Boundary During Solar Minimum, Kevin Urban

Theses

The year 2008 marked a historically quiet period of solar activity during the declining phase of solar cycle 23. Such quiet time has permitted researchers to clearly distinguish the spectral signature of a corotating interaction region’s (CIR) impact on the open-closed boundary (OCB) of the magnetosphere in the southern hemisphere’s auroral zone. By using the PENGUIn AGOs network of ground-based magnetometers on the Antarctic continent, the synoptic behavior of the OCB during a CIR-driven magnetic storm has been studied. Observations were compared with results provided by the BATSRUS space weather model. It is shown that such synoptic magnetometer data sets …

Earthshine : Photometry, Modeling, And Spectral Observations, Jeffrey Patrick Hickey

Theses

The Earthshine group has been making sustained observations of the Earthshine from Big Bear Solar Observatory in California since late 1998. There have also been intermittent observations from 1994-5. High and low resolution Earthshine spectral observations have also been under taken at Palomar Observatory since 1999. The group has re-invigorated and modernized a nearly forgotten way of measuring the Earth's albedo, and hence its energy balance, previously studied by Danjon (and his followers) for about twenty-five years early in the last century, using their observations of the Earthshine from France. This is an overview paper covering observations, reductions, simulations, and …

Emissivity Of Patterned Silicon Wafers In Rapid Thermal Processing, Markus Rabus

Theses

The influence of patterns on emissivity in silicon wafers in rapid thermal processing systems has been investigated. In this study, two experiments with layered and patterned silicon wafers were conducted. The main difference in the experiments is the way in which the temperature was controlled. The first experiment was performed under Open Loop Intensity Control (OLIC). For OLIC, no feedback from the wafer is returned. It is assumed that supplying a certain power level will lead to the desired temperature. The other experiment used the Closed Loop Intensity Control. In this case, a feedback, in the form of temperature deviation …

An Analysis Of Changes In The Magnetic Field Of Active Region 9415 After The 2001 April 6 Solar Flare, Juli Marya Stoltz

Theses

The objective of this study was to further the current understanding of the correlation between solar flares and magnetic flux change. The average gradient of the magnetic flux around the neutral line of Active Region 9415 and the locations of the magnetic flux centers-of-mass in both polarities in AR 9415 were determined. Subsequent to the 2001 April 6 flare, there was a statistically significant mean increase of 0.00208 G/km in the average gradient. Prior to the flare, the magnetic flux centers-of-mass became increasingly sheared along the neutral line. After the flare, this shear suddenly decreased and the magnetic flux centers-of-mass …

Production Of Pulsed Low Energy Electron Beams, Shyam Das

Theses

In this thesis, an experimental setup for the production of low energy electron beams based on Explosive Electron Emission (EEE) is used to study the transmission of pulsed low energy electron beams through silicon nitride foils. The electron beam density before and after the foil are measured. The experimental values fully agree with the theoretical estimates. Work done in this thesis is a judicious combination of vacuum technology, pulsing of high voltage sources, thermal physics and electronics. Dia rams and -photo uaphs of the experimental setup arl-I presented. A paper was 9 presented at the American Vacuum Society (AVS) symposium …

Surface Phenomena On The Tin-Dioxide Polycrystalline Layers, Andrei A. Fluerasu

Theses

Polycrystalline tin-dioxide is widely used in the detection of reducing gases (such as H₂, CO, CH₄, C₂H₅OH,...) in air by measuring its conductivity changes. The advantage of gas sensors based on such sensing devices is low cost and high sensitivity. In contrast to their widespread applications and to their successful empirical research and development work, the present understanding of the chemical sensing mechanisms is still immature.

In this thesis, for gas sensors based on thick and porous tin-dioxide layers, a study of the response function upon variation of the partial pressure of …

Degradation And Breakdown In Ultra-Thin Silicon Oxides, Christopher Franck

Theses

Emerging trends in the semiconductor device industry call for detailed knowledge of the properties of devices whose dimensions are small enough to exploit Quantum Mechanical effects. This thesis presents a complete picture of oxide degradation in MOS direct tunnel diodes (t0 <3.4 nm). It is demonstrated that for structures fabricated at different facilities and stressed with either gate or substrate injection, a universal degradation mode is revealed which is manifested as the build up of positive charge in the oxide. The data gathered demonstrates that the positive charging phenomena in sub-3.5 nm oxides is independent of oxide thickness, and is characterized by a voltage threshold and two-regime temperature dependence. Further, the catastrophic failure, or breakdown, of these oxides was studied and the strongest evidence to date is presented which links the positive charging phenomena to the oxide breakdown. This thesis concludes with the presentation of a novel device design which can exploit the properties of degradation and breakdown, in thin oxides, to achieve an EEPROM memory cell of superior endurance.

Design And Fabrication Of A Miniature Pressure Sensor Head Using Direct Bonded Ultra-Thin Silicon Wafers, Chad Eugene Statler

Theses

A miniature pressure sensor head is designed and fabricated using an ultra-thin silicon membrane directly bonded to an excimer laser micromachined substrate. The pressure sensor head has its intended implementation as part of an optically interrogated device with sensitivity to pressures ranging from 0.5 to 4.0 MPa. The pressure range design is shown to be easily adjusted by tailoring the thickness of the membrane wafer. The fabrication process features numerous advantages over existing pressure sensor construction technology including a maskless procedure and no chemical etching or mechanical thinning necessary to form the membrane after bonding. An optic lever is constructed …

Investigation Of Potential Oxygen Defect Mechanism Of Persistent Photoconductivity And Photoinduced Superconductivity In Yba2cu3ox, Denise Catherine Chew

Theses

In this thesis work, we conclude that oxygen vacancy defects play a fundamental role in the PPC/PISC mechanism and identify the oxygen defects as F centers (an oxygen vacancy which traps two electrons) or F⁺ centers. Also, the correlation between the peaks observed in the luminescence spectra and those observed in the wavelength dependence of PPC suggest that the photogeneration of charges and their annihilation via luminescent recombination occur in the same level (Cu-O chains) of the YBa₂Cu₃O_x crystal. Previous models had assigned the peaks in the PPC excitation spectrum to charge transfer in …

Microaccelerometer With Mechanically-Latched Memory, Zhenyu Ma

Theses

A new mechanically-latching micromachined accelerometer is designed in this thesis based on the large deflection of a microcantilever beam. This surface micromachined device moves in the plane of the substrate surface. This device is surface micromachined with no backside etching needed. The interaction of the friction tether and the dimensions of the cantilever beam have been modeled and calculated. The design acceleration sensitivity range is from 100G to 1000G. The photomask set has been designed by using the Mentor Graphics system. The dimension of individual accelerometers ranges from 100 to 1000 micrometers in length to tens of micrometers in width. …

Silicon Optical Fiber Pressure Sensor, Jian Pan

Theses

A novel optical fiber pressure sensor based on a micromachined thin silicon diaphragm is proposed. Detail descriptions of the sensor structure, modulation principle and fabrication process are given.

The device operates on the following principle: Pressure deflects a silicon diaphragm which moves the output end of a light source fiber. The emitted light intensity is picked up and shared by two receiving fibers placed side by side. The variation of the intensity ratio in the receiving fibers caused by the relative motion of the emitting fiber can be easily converted to a linear signal versus the deflection of the silicon …

A High Temperature Pressure Sensor Based On Magnetic Coupling And Silicon Wafer Bonding, Deguang Zhu

Theses

In this thesis, the design and fabrication of a bulk micromachined and wafer bonded pressure sensor for high temperature applications is described. The device design is based on the magnetic coupling principle as described by the Biot-Savart law. By combining the mechanical properties of single crystal silicon with magnetic coupling, the designed sensor can be operated up to 600°C. The key components within the sensor are two inductive coils, a silicon diaphragm and a hermetic vacuum cavity.

The modeling based on a nine-turn single level coil device and a 300 μm x 300 diaphragm indicates an output rms voltage range …

Ultra-Thin Silicon Wafer Bonding, Diyu Yan

Theses

In this thesis the history and recent developments on the silicon direct bonding technique are reviewed. The growing applications of this technique in SOI, SOS and MEMS areas, difficulties and disadvantages of various bonding processes are discussed. A direct bonding procedure for attaching ultra-thin wafers less than 200 μm thick to substrate wafers is developed and described in detail. Difficulties in handling, aligning and annealing ultra-thin wafers are reported. Wafers of different doping concentration, thickness, surface roughness and chemical characteristics are tested for bondability. Methods to minimize voids and other failure mechanisms are proposed. A photodetector is designed based on …

Subthreshold Channel Leakage Current In Gaas Mesfet's, Wei Long

Theses

In this thesis, a physical model including the subthreshold conpensation properties is presented. The Poisson equation is solved analytically in one dimension for GaAs MESFET's with undoped substrates in the subthreshold region. The solution is then used to derive expressions for subthreshold drain current and subshreshold swing in MESFET's with undoped substrates. Very good agreement between experimental and analytical results is achieved.

Two key parameters (Nilo and Iso) that determine the subthreshold Characteristics have been analyzed as a function of residual acceptor concentration Na, deep level EL2 concentration Nt, channel doping concentration Nd and threshold voltage Vt. It is shown …

Measurement Of The Hall Coefficient And Electron Mobility Using Van Der Pauw Type Hall Effect Measurements, Hong-Sheng Luo

Theses

Hall effect measurement in the electrical characterization of semiconductor materials is very important. We set up the Hall effect measurement system and examined the system with a standard sample. The experimental results show that this Hall measurement system worked as well as expected. We also used this system to study the GaAs/GaAs and InGaAs/GaAs which grown by MBE. Finally, we disscussed and consided some common problems of Hall measurement. Some useful formulas and plots are presented.