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Modeling, Fabrication, And Characterization Of Rf-Based Passive Wireless Sensors Composed Of Refractory Semiconducting Ceramics For High Temperature Applications, Kavin Sivaneri Varadharajan Idhaiam 2022 West Virginia University

Modeling, Fabrication, And Characterization Of Rf-Based Passive Wireless Sensors Composed Of Refractory Semiconducting Ceramics For High Temperature Applications, Kavin Sivaneri Varadharajan Idhaiam

Graduate Theses, Dissertations, and Problem Reports

Real-time health monitoring of high temperature systems (>500oC) in harsh environments is necessary to prevent catastrophic events caused by structural failures, varying pressure, and chemical reactions. Conventional solid-state temperature sensors such as resistance temperature detectors (RTDs) and thermocouples are restricted by their operating environments, sensor dimensions and often require external power sources for their operation. The current work presents the research and development of RF-based passive wireless sensing technology targeting high temperatures and harsh environmental conditions. Passive wireless devices are generally classified as near-field and far-field devices based on the interrogation distance. Near-field sensors are placed at …


Sufficient Condition For The Possibility Of Completing The Pursuit, Nodirbek Umrzaqov 2021 Andijan State University named after Z.M. Babur, Andijan 170100 Uzbekistan.

Sufficient Condition For The Possibility Of Completing The Pursuit, Nodirbek Umrzaqov

Scientific Bulletin. Physical and Mathematical Research

In this paper, the problem of chase is represented by a system of linear differential equations of motion dynamics. In this case, there is an integral limit to the control parameter of the evader, and a geometric limit to the control parameter of the pursuer. The pursuer is allowed to use the control that the fugitive has used so far to build his control. There are enough conditions for the game to end even if it starts from any starting point. An algorithm for constructing the control function of the pursuer is defined. It should also be noted that the …


Intracavity Phase Interferometry Based Fiber Sensors, Luke Jameson Horstman 2021 University of New Mexico - Main Campus

Intracavity Phase Interferometry Based Fiber Sensors, Luke Jameson Horstman

Optical Science and Engineering ETDs

Intracavity Phase Interferometry (IPI) is a detection technique that exploits the inherent sensitivity of a laser's frequency to the parameters of its cavity. Intracavity interferometry is orders of magnitude more sensitive than its extracavity alternatives. This dissertation improves on previous free-space proof-of-concept designs. By implementing the technique in fiber optics, using optical parametric oscillation, and investigating non-Hermitian quantum mechanics and dispersion tailoring enhancement techniques, IPI has become more applicable and sensitive. Ring and linear IPI configurations were realized in this work, both operating as bidirectional fiber optical parametric oscillators. The benefit of using externally pumped synchronous optical parametric oscillation is …


Voltage Controlled Néel Vector Rotation In Zero Magnetic Field, Ather Mahmood, Will Echtenkamp, Mike Street, Jun Lei Wang, Shi Cao, Takashi Komesu, Peter Dowben, Pratyush Buragohain, Haidong Lu, Alexei Gruverman, Arun Parthasarathy, Shaloo Rakheja, Christian Binek 2021 University of Nebraska–Lincoln

Voltage Controlled Néel Vector Rotation In Zero Magnetic Field, Ather Mahmood, Will Echtenkamp, Mike Street, Jun Lei Wang, Shi Cao, Takashi Komesu, Peter Dowben, Pratyush Buragohain, Haidong Lu, Alexei Gruverman, Arun Parthasarathy, Shaloo Rakheja, Christian Binek

Peter Dowben Publications

Multi-functional thin films of boron (B) doped Cr2O3 exhibit voltage-controlled and nonvolatile Néel vector reorientation in the absence of an applied magnetic field, H. Toggling of antiferromagnetic states is demonstrated in prototype device structures at CMOS compatible temperatures between 300 and 400 K. The boundary magnetization associated with the Néel vector orientation serves as state variable which is read via magnetoresistive detection in a Pt Hall bar adjacent to the B:Cr2O3 film. Switching of the Hall voltage between zero and non-zero values implies Néel vector rotation by 90 degrees. Combined magnetometry, spin resolved inverse …


Sigesn Light-Emitting Devices: From Optical To Electrical Injection, Yiyin Zhou 2021 University of Arkansas, Fayetteville

Sigesn Light-Emitting Devices: From Optical To Electrical Injection, Yiyin Zhou

Graduate Theses and Dissertations

Si photonics is a fast-developing technology that impacts many applications such as data centers, 5G, Lidar, and biological/chemical sensing. One of the merits of Si photonics is to integrate electronic and photonic components on a single chip to form a complex functional system that features compact, low-cost, high-performance, and reliability. Among all building blocks, the monolithic integration of lasers on Si encountered substantial challenges. Si and Ge, conventional epitaxial material on Si, are incompetent for light emission due to the indirect bandgap. The current solution compromises the hybrid integration of III-V lasers, which requires growing on separate smaller size substrates …


Interplay Between The Lattice And Spin Degrees Of Freedom In Magnetoelectric And Magnetic Materials, Temuujin Bayaraa 2021 University of Arkansas, Fayetteville

Interplay Between The Lattice And Spin Degrees Of Freedom In Magnetoelectric And Magnetic Materials, Temuujin Bayaraa

Graduate Theses and Dissertations

This dissertation contains several investigations on the cross-coupling between structural and spin degrees of freedom in multiferroic and ferrimagnetic compounds by means of first-principles calculations and ab-initio-based Monte-Carlo simulations. We start with the reviews of magnetoelectricity, ferrimagnetism, strain engineering, followed by a brief introduction to first-principles computational methods, magnetic effective Hamiltonians, and other techniques that are utilized here. The results section of the dissertation can be divided into two parts. The first half focuses on magnetoelectric effects arising from different sources, while the second half is about the ferrimagnetic nature of materials. In the first part, we examine the epitaxial …


Theoretical Investigations Of The Structural, Dynamical, Electronic, Magnetic, And Thermoelectric Properties Of Corhysi (Y = Cr, Mn) Quaternary Heusler Alloys, Abdullah Hussain Hzzazi 2021 University of Arkansas, Fayetteville

Theoretical Investigations Of The Structural, Dynamical, Electronic, Magnetic, And Thermoelectric Properties Of Corhysi (Y = Cr, Mn) Quaternary Heusler Alloys, Abdullah Hussain Hzzazi

Graduate Theses and Dissertations

Thermoelectric materials have potential properties for utilizing waste heat. The computations are used to estimate the electronic structure of CoRhYSi (Y = Cr, Mn) Quaternary Heusler alloys, as well as their elastic and magnetic characteristics. The full-potential linearized augmented plane wave is used in the calculations. The exchange-correlations are addressed using Perdew–Burke and Ernzerhof's generalized gradient approximation (GGA-PBE). With the exception of CoRhCrSi and CoRhMnSi, which are simple ferromagnets that are approximately half metallic in nature, electronic structure calculations demonstrate that these compounds have a gap in the minority states band and are obviously half-metallic ferromagnets. The magnetic moments of …


Acoustic/Gravity Wave Phenomena In Wide-Field Imaging: From Data Analysis To A Modeling Framework For Observability In The Mlt Region And Beyond, Jaime Aguilar Guerrero 2021 Embry-Riddle Aeronautical University

Acoustic/Gravity Wave Phenomena In Wide-Field Imaging: From Data Analysis To A Modeling Framework For Observability In The Mlt Region And Beyond, Jaime Aguilar Guerrero

Doctoral Dissertations and Master's Theses

Acoustic waves, gravity waves, and larger-scale tidal and planetary waves are significant drivers of the atmosphere’s dynamics and of the local and global circulation that have direct and indirect impacts on our weather and climate. Their measurements and characterization are fundamental challenges in Aeronomy that require a wide range of instrumentation with distinct operational principles. Most measurements share the common features of integrating optical emissions or effects on radio waves through deep layers of the atmosphere. The geometry of these integrations create line-of-sight effects that must be understood, described, and accounted for to properly present the measured data in traditional …


Developing A Monte Carlo Simulation For Time- Series Analysis Of Actinium-225 Decay, Victoria Wood 2021 Agnes Scott College

Developing A Monte Carlo Simulation For Time- Series Analysis Of Actinium-225 Decay, Victoria Wood

The Journal of Advanced Undergraduate Physics Laboratory Investigations, JAUPLI-B

This report describes the development of a script programmed in the Python language designed to simulate radioactive decay using Monte Carlo methods. This is to conduct analysis on the equilibrium behavior of a specific radioactive decay chain, replacing the traditional method of deriving a mathematical representation via differential equations. The resulting script produces a stacked histogram illustrating the decay of Actinium-225 over time and more closely models the potential for irregularities in the natural phenomenon. The script has potential applications in nuclear imaging and medical physics.


Modeling The Motion Of A Volleyball With Spin, Julian Ricardo 2021 Amherst College

Modeling The Motion Of A Volleyball With Spin, Julian Ricardo

The Journal of Advanced Undergraduate Physics Laboratory Investigations, JAUPLI-B

Though a qualitative understanding of how spin affects a ball’s trajectory can be easily developed, a quantitative one is relatively difficult to hone. Additionally, although projectile motion is an extensively covered topic in introductory physics courses, friction and drag—let alone spin—receive little to no attention. Here we use a volleyball and video modeling software to compare the behavior of a non-spinning ball with one that has topspin in order to assess the accuracy of our various models incorporating drag and the Magnus effect.


Electrical And Magnetic Properties Of High Temperature Superconductors Using Varying Forms Of Data Acquisition, Aryn M. Hays, Lindsay Bechtel, Colton Turbeville, Anthony Johnsen, Chris A. Tanner 2021 Austin College

Electrical And Magnetic Properties Of High Temperature Superconductors Using Varying Forms Of Data Acquisition, Aryn M. Hays, Lindsay Bechtel, Colton Turbeville, Anthony Johnsen, Chris A. Tanner

The Journal of Advanced Undergraduate Physics Laboratory Investigations, JAUPLI-B

High temperature superconductors (HTS) are materials that display superconducting properties at temperatures above that of liquid nitrogen. Possible applications and ease of use in a typical physics laboratory make them interesting systems to study. In this experiment we measured the critical temperatures of two samples made of different HTS materials. We also devised a method that makes taking data automated.


Shape And Size Matter For Projectile Drag, Daniel Gordon Ang 2021 Harvard University

Shape And Size Matter For Projectile Drag, Daniel Gordon Ang

The Journal of Advanced Undergraduate Physics Laboratory Investigations, JAUPLI-B

Newtonian mechanics is a fundamental building block of physics education, allowing us to characterize the motion of various objects in every day life. Here, we set out to investigate the effect of air resistance on projectile motion. We use high-speed cameras to record the flight of three different projectiles and compare this motion to a trajectory generated based on our theoretical model. We find that we are able to fit our model to the actual trajectory reasonably well, and find evidence that drag depends on the size and shape of the projectile.


Modeling A Swinging Atwood Machine, Parker W. Moody 2021 Amherst College

Modeling A Swinging Atwood Machine, Parker W. Moody

The Journal of Advanced Undergraduate Physics Laboratory Investigations, JAUPLI-B

The motion of a Swinging Atwood Machine is a difficult to solve for using Newtonian Mechanics. Lagrangian Mechanics, on the other hand, is extremely useful tool for a system that can seem overwhelmingly difficult to solve in Newtonian Mechanics. In this Lab we find the Lagrangian for this Swinging Atwood system, solve for the equation of motion, and compare our model to that of the observed motion of the system. Our model provides a good approximation of the motion, with small discrepancies due to the unknown mass of our pulley and dissipative forces.


Atomic Force Microscopy, Tyler Lane 2021 Minnesota State University - Moorhead

Atomic Force Microscopy, Tyler Lane

The Journal of Advanced Undergraduate Physics Laboratory Investigations, JAUPLI-B

The goal of this experiment is to use the Atomic Force Microscope (AFM) to get images of selected items and determine some distances of the characteristics of each sample. The ultimate goal is to measure the length of a nanotube, but unfortunately there were none left on the slide that was supposed to contain them. From the results of the lab and the lab manual of “companies” with possible lengths for each sample, Lindaas-Lahti Industries seems to have the best fit overall.


Decay Time Of A Damped Pendulum, Scott D. Froehle 2021 Minnesota State University - Moorhead

Decay Time Of A Damped Pendulum, Scott D. Froehle

The Journal of Advanced Undergraduate Physics Laboratory Investigations, JAUPLI-B

A number of labs have been conducted to find the equation for a damped pendulum. A damped pendulum's behavior will be analyzed and fit to this equation. This lab focused on tau, the decay constant. It was hypothesized that the decay constant would be greater with increasing initial angles, ultimately because of the pendulum's greater velocity. A pendulum was hung on a rotary motion sensor to detect its activity when released from different angles from the vertical. Its behavior was observed and fit to the equation for the behavior of a damped pendulum. It was found that decay time and …


Magnetic Field Perturbations To A Soft X-Ray-Activated Fe (Ii) Molecular Spin State Transition, Guanhua Hao, Alpha T. N’diaye, Thilini K. Ekanayaka, Ashley S. Dale, Xuanyuan Jiang, Esha Mishra, Corbyn Mellinger, Saeed Yazdani, John W. Freeland, Jian Zhang, Ruihua Cheng, Xiaoshan Xu, Peter Dowben 2021 University of Nebraska - Lincoln

Magnetic Field Perturbations To A Soft X-Ray-Activated Fe (Ii) Molecular Spin State Transition, Guanhua Hao, Alpha T. N’Diaye, Thilini K. Ekanayaka, Ashley S. Dale, Xuanyuan Jiang, Esha Mishra, Corbyn Mellinger, Saeed Yazdani, John W. Freeland, Jian Zhang, Ruihua Cheng, Xiaoshan Xu, Peter Dowben

Peter Dowben Publications

The X-ray-induced spin crossover transition of an Fe (II) molecular thin film in the presence and absence of a magnetic field has been investigated. The thermal activation energy barrier in the soft X-ray activation of the spin crossover transition for [Fe{H2B(pz)2 }2 (bipy)] molecular thin films is reduced in the presence of an applied magnetic field, as measured through X-ray absorption spectroscopy at various temperatures. The influence of a 1.8 T magnetic field is sufficient to cause deviations from the expected exponential spin state transition behavior which is measured in the field free case. We find …


Ultra-Low Frequency Waves At Middle Latitudes During Substorms: Observations And Modeling, Mergen Alimaganbetov 2021 Embry-Riddle Aeronautical University

Ultra-Low Frequency Waves At Middle Latitudes During Substorms: Observations And Modeling, Mergen Alimaganbetov

Doctoral Dissertations and Master's Theses

This doctoral dissertation presents the results of investigation of the Ultra-Low Frequency (ULF) waves at middle latitudes during substorms. The dissertation consists of two major parts, observations and simulations. The research in this dissertation proposes that the main role in the generation of ULF waves at middle latitudes during substorm belongs to the plasmapause.

The first part of the dissertation presents results of the data analysis of 84 intense substorm events as well as an overview of space observation programs such as CRRES, Van Allen Probes and DMSP. Data used in this study are from the ACE satellite taken measurements …


High Speed Impact On Graphene Composites, Giovanny A. Espitia 2021 Kennesaw State University

High Speed Impact On Graphene Composites, Giovanny A. Espitia

Symposium of Student Scholars

Since the isolation of Graphene occurred in 2004, numerous studies attempting to exploit the properties of this carbon allotrope have been conducted. Graphene exists in a 2-D manner with sp2 bonds, which provides the allotrope with great electrical, conductive, and mechanical properties. In this paper however, we will focus on the latter in order to examine the feasibility of graphene composites for bulletproof material in the military. Pure graphene sheets count with high porosity density that leads to structural defects as well as poor mechanical properties due to physical contact being sole retainer. For this reason, the selected composite is …


Photoluminescence Spectra Of Silicon Doped With Cadmium, N A. Sultanov, E T. Rakhimov, Z Mirzajonov, F T. Yusupov 2021 Fergana Polytechnic Institute

Photoluminescence Spectra Of Silicon Doped With Cadmium, N A. Sultanov, E T. Rakhimov, Z Mirzajonov, F T. Yusupov

Scientific-technical journal

Cadmium and zinc, as transition metals, are deep-level impurities (DL) and have a significant effect on the electrical, photoelectric, recombination, and other properties of semiconductor crystals.This paper presents the results of experimental studies of the optical and electrical properties of silicon crystals containing impurity atoms of cadmium and zinc using DLTS and low-temperature photoluminescence (PL).


Infinite Peirce Distribution In The Algebra Of Compact Operators And Description Of Its Local Au-Tomorphisms, Farhodjon N. Arzikulov, Rejabboy Qo’shaqov 2021 Andizhan State University

Infinite Peirce Distribution In The Algebra Of Compact Operators And Description Of Its Local Au-Tomorphisms, Farhodjon N. Arzikulov, Rejabboy Qo’Shaqov

Scientific Bulletin. Physical and Mathematical Research

In the present paper the infinite Peirce decomposition of the algebra 𝐾(𝐻) of com-pact operators on an infinite dimensional separable Gilbert space 𝐻 is constructed, using the norm of the algebra 𝐾(𝐻) and a maximal family of mutually or-thogonal minimal projections, i.e., self-adjoint,idempotent elements. The infinite Peirce decompo-sition on the norm of a 𝐶∗-algebra is also con-structed in 2012 by the first author. But, it turns, the condition, applied then, is not sufficient for the infi-nite Peirce decomposition on the norm constructed in 2012 to be an algebra. Therefore, in the present paper, the infinite Peirce decomposition on the norm …


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