Engineering Physics Commons^™

Method Of Characteristics For Solving The Problem Of Gas Outflow From An Elementary Sec-Tion Of A Gas Pipeline, Madaminjon K. Mahkamov, S.S. Akhmadjonov, I.K. Khujaev

Scientific Bulletin. Physical and Mathematical Research

Numerous problems based on equations of hyperbolic type are solved by the method of characteristics when boundary conditions of the first, second and third kinds are set on the boundary. These include, in particular, the problems of pipeline transportation of various media. The quasi-one-dimensional equations of conservation of mass and momentum are linearized and separate equations are drawn up for a specific indicator (flow rate, gas pressure) of the process. This approach is associated with the tradition of forming boundary conditions and solving problems only with respect to a specific indicator, in particu-lar, with respect to pressure, velocity, and flow …

Measurement Of Geometric Fractals On The Basis Of Hausdorf-Bezikovich And Minkovsky-Buligan Measurements, Anorova Amanbaevna Shaxzoda, Jabborov Sindorovich Jamoliddin, Meliyev Fattoevich Farxod

Scientific Bulletin. Physical and Mathematical Research

This article is devoted to the study of the future position of fractal measurements. Different methods of computer modeling of a wide range of classes of fractal geometric objects are described in detail, as well as the main methods of mathematical analysis of fractal size of virtual and real fractals are described. The article explains the differences between the concept of fractals, their properties, B. Mandelbrot's tariff, Hausdorf-Bezikovich scale, Minkowski-Buligan scale, topological measurement, the concept of fractal measurement and measurement in Euclidean geometry. This article provides basic information about fractals. A detailed description of the various methods of computer modeling …

Effect Of Excess Tellurium And Lead On Defor-Mation - Characteristics Of Polycrystalline Pbte Films, Yu.Yu. Vaitkus, Otajonov Salimjon

Scientific Bulletin. Physical and Mathematical Research

In this work, we studied the ef-fect of excess tellurium and lead on the defor-mation characteristics of polycrystalline PbTe films obtained on different substrates. It was found that the resistance of the films first increases and reach-es a maximum, and with a further increase in the level of deformation, it decreases and the sign of the tensile resistance begins to change, which are associated with the presence of internal stresses in the films. It was also shown that with an increase in the amount of lead in the composition of the PbTe film, the electrical conductivity increases in com-parison with …

Simulation Of Self-Heating Effect In Mosfet Based On 2d Mos2, Atabek E. Atamuratov, Xushnudbek Sh. Saparov, A Yusupov, Frank Schwierz

Scientific Bulletin. Physical and Mathematical Research

One of the main trends of today's electronics is the decreasing the sizes of MOSFET up to nanometer scale. In this connection there are two main views to the perspective of scaling. According to one of them limit of scaling is reached at sizes 10 nm order, however according to second view, still there are opportunity to decrease transistor to more lower sizes. In accordance with second approach it is suggested to continue the size scaling by modification the transistor structure or by using the new materials, particularly one or two dimensional materials. One of such suggestions is the designing …

Electrophysical Properties Of Supercapacitor On The Basis Of New Gel Polymer Electrolyte, J.A. Shodmanov, Azamat Boymirzaev

Scientific Bulletin. Physical and Mathematical Research

The results showed a slight increase in internal resistance under the influence of bending and confirmed that the equivalent circuit model of electrons did not change under bending conditions as indicated in graphically illustrated the results by cyclic voltamperometry (TsV) at a scanning speed of 10 mV / s under the above bending angles of the SK prepared on the basis of PG 10 GPE. From ex-periments we found that the shapes are almost rec-tangular, with no redox peaks observed. We can see that the area of the TsV curves changes slightly as the bending angle increases, but this does …

Lessons From The Classroom – Assessing The Work Of Postgraduate Students To Support Better Hygrothermal Risk Assessment, Joseph Little, Benat Arregi, Christian Bludau

Conference papers

The widespread adoption of transient simulation modelling tools by building design professionals to support hygrothermal risk assessment of building design specifications is a crucial component in a multi-pronged drive to reduce moisture risk in buildings. Structured upskilling is essential. Much can be learnt about the ways practitioners use such tools by reviewing the work of professional postgraduate student groups. Such review could inform the creation of a user protocol. Peer-review under the responsibility of the organizing committee of the ICMB21.

Corrigendum: Surface Termination And Schottky-Barrier Formation Of In4Se3(001) [Semiconductor Science And Technology (2020) 35 (065009) Doi: 10.1088/1361-6641/Ab7e45], Archit Dhingra, Pavlo V. Galiy, Lu Wang, Nataliia S. Vorobeva, Alexey Lipatov, Angel Torres, Taras M. Nenchuk, Simeon J. Gilbert, Alexander Sinitskii, Andrew J. Yost, Wai-Ning Mei, Keisuke Fukutani, Jia Shiang Chen, Peter Dowben

Peter Dowben Publications

Through the description of various surface terminations, the chain direction of In4Se3 in this paper [1] is implied to be in the plane of its surface. Even though the common convention for photoemission spectroscopy is to place z-axis along the surface normal, the axis perpendicular to the growth direction for this indium selenide is the crystallographic a-axis (and not the c-axis) [2–4]. Therefore, in our work the surface of In4Se3 should have been labeled (100), and not (001), to prevent any confusion that may have resulted from a less than conventional index notation. Data availability statement The data that support …

Colossal Intrinsic Exchange Bias From Interfacial Reconstruction In Epitaxial Cofe2 O4/Al2 O3 Thin Films, Detian Yang, Yu Yun, Arjun Subedi, Nicholas E. Rogers, David M. Cornelison, Peter Dowben, Xiaoshan Xu

Peter Dowben Publications

We have studied the epitaxial CoFe₂O₄ (111) films grown on Al₂O₃ (0001) substrates of different thickness at various temperature and discovered colossal intrinsic exchange bias up to 7 ± 2 kOe. X-ray and electron diffraction clearly indicate an interfacial layer about 2 nm of different crystal structure from the “bulk” part of the CoFe₂O₄ film. The thickness dependence of the exchange bias suggests a hidden antiferromagnetic composition in the interfacial layer that couples to the ferrimagnetic “bulk” part of the CoFe₂O₄ film as the origin of the exchange …

Design And Characterization Of Standard Cell Library Using Finfets, Phanindra Datta Sadhu

Master's Theses

The processors and digital circuits designed today contain billions of transistors on a small piece of silicon. As devices are becoming smaller, slimmer, faster, and more efficient, the transistors also have to keep up with the demands and needs of the daily user. Unfortunately, the CMOS technology has reached its limit and cannot be used to scale down due to the transistor's breakdown caused by short channel effects. An alternative solution to this is the FinFET transistor technology, where the gate of the transistor is a three dimensional fin that surrounds the transistor and prevents the breakdown caused by scaling …

Realization Of Bsu First Magneto-Optical Trap For The Spatial Confinement Of Rb Atoms Using Next Generation Fiber Optic Capabilities With Minimot, Brahmin Thurber-Carbone

Honors Program Theses and Projects

This paper will be a combination of my theoretical and experimental work toward Bridgewater State Universities first Magneto-Optical Trap (MOT) for laser cooling and trapping of neutral atoms in order to study fundamental quantum mechanical behavior of Rubidium (Rb) atoms. The goal of the theoretical aspect is to complete details of well-established works on how the complicated quantum, atomic, and electromagnetic (laser) interactions required to understand the design and operation of the MOT reduce to the physics and mathematics of a damped oscillator. This is made explicitly clear using familiar damped oscillator systems, such as a spring/mass/damping or pendulum/mass/damping (ie …

Magnetism And Topological Hall Effect In Antiferromagnetic Ru2Mnsn-Based Heusler Compounds, Wenyong Zhang, Balamurugan Balasubramanian, Yang Sun, Ahsan Ullah, Ralph Skomski, Rabindra Pahari, Shah R. Valloppilly, Xingzhong Li, Cai-Zhuang Wang, Kai-Ming Ho, David J. Sellmyer

Faculty Publications from Nebraska Center for Materials and Nanoscience

Heusler compounds and alloys based on them are of great recent interest because they exhibit a wide variety of spin structures, magnetic properties, and electron-transport phenomena. Their properties are tunable by alloying and we have investigated L2₁-ordered compound Ru₂MnSn and its alloys by varying the atomic Mn:Sn composition. While antiferromagnetic ordering with a Néel temperature of 361 K was observed in Ru₂MnSn, the Mn-poor Ru₂Mn_0.8Sn_1.2 alloy exhibits properties of a diluted antiferromagnet in which there are localized regions of uncompensated Mn spins. Furthermore, a noncoplanar spin structure, evident from …

Virtual Prototyping Of Liquid Lithium Divertor Concepts, Brennan Arnold

Macalester Journal of Physics and Astronomy

A tokamak divertor must withstand power deposition in excess of 10 MW/m^2 in steady state and much higher in disruptions, enough to destroy nearly any material. In order to handle this extreme heat, there is some interest in using liquid metal flows to continually renew the divertor surface. In this paper, we examine an idea for a divertor with a porous surface that allows liquid lithium flowing through the divertor to percolate to the plasma facing surface. This idea is complicated by magnetohydrodynamic drag, where the stong magnetic fields in the tokamak cause the lithium to flow too slowly to …

Radiosonde High Altitude Measurements Of Radiation Levels And Cosmic Ray Events, Ayodeji Opeyemi Akinuliola

Electronic Theses and Dissertations

Just above us, cosmic rays are hurtling in from space. These fast moving particles crash uncontrollably into molecules in the atmosphere, causing spontaneous decays of these particles. Despite the fact that we are broadly shielded from this radiation on earth, these particles can still disturb humans and electronics alike. Therefore, this research focuses on expanding the use of long-range radio transmitters such as radiosondes to transmit valuable data such as cosmic ray flux, geographical position, atmospheric temperature, pressure, etc. This can improve real-time radiation monitoring for aviation industry crew and passengers working in potentially higher radiation environments. On March 11, …

Structural Origin Of Thermal, Mechanical Properties And Morphological Behaviors Of Semiconducting Polymers, Song Zhang

Dissertations

The past decades have witnessed a surging exploration of semiconducting polymers for the application of wearable and flexible organic electronic devices. Despite the increased amounts of molecular engineered polymers and their much-improved electrical performances, a systematic study of the structure-thermal/mechanical property-morphology relationship of semiconducting polymers is still less investigated.

To understand the thin-film mechanical properties, a pseudo-free standing tensile tester was self-built and utilized to obtain their real-time stress-strain behaviors through uniaxial stretching on top of the water surface. It also enables the first quantitative measurement of fracture energy on ultrathin polymeric films. Through multiple mechanical testing methods (i.e., strain-rate …

Voltage-Controlled Magnetic Anisotropy In Antiferromagnetic Mgo-Capped Mnpt Films, P. H. Chang, Wuzhang Fang, T. Ozaki, Kirill Belashchenko

Kirill Belashchenko Publications

The magnetic anisotropy in MgO-capped MnPt films and its voltage control are studied using first-principles calculations. Sharp variation of the magnetic anisotropy with film thickness, especially in the Pt-terminated film, suggests that it may be widely tuned by adjusting the film thickness. In thick films the linear voltage control coefficient is as large as 1.5 and -0.6 pJ/Vm for Pt-terminated and Mn-terminated interfaces, respectively. The combination of a widely tunable magnetic anisotropy energy and a large voltage-control coefficient suggest that MgO-capped MnPt films can serve as a versatile platform for magnetic memory and antiferromagnonic applications.

Designing Cryogenic Strain Device For 2d Materials, Jake Carter

Mechanical Engineering Undergraduate Honors Theses

The Churchill lab working within the Physics Department at the University of Arkansas is working to create important quantum states including weak topological insulators (TIs) through the use of symmetry engineering and topological electronic states in two-dimensional (2D) crystals of WHM materials. Experimental results of these topological states have been obstructed due to the difficulty to perform controlled in situ strain. This project strives to create a mount to utilize a piezoelectric nanopositioner within cryostats achieving an in situ strain that creates the quantum states the lab is looking to observe. This report also examines the necessary equations to determine …

Direct Drive Solar Panel Control Circuit, Marcorios Bekheit

Physics

A control circuit is built for insulated solar electric cookers (ISEC). Power delivery and temperature safety are the focus. Using a maximum power point tracking (MPPT) algorithm, Arduino Nano, voltage and current sensors, and a buck converter, the solar panel’s output power was maximized for a direct load heat resistor with 3.5Ω for a range of solar intensities. Using a resistance temperature detector, a temperature sensor is built for safety shutoff.

Memory Module Design For High-Temperature Applications In Sic Cmos Technology, Affan Abbasi

Graduate Theses and Dissertations

The wide bandgap (WBG) characteristics of SiC play a significant and disruptive role in the power electronics industry. The same characteristics make this material a viable choice for high-temperature electronics systems. Leveraging the high-temperature capability of SiC is crucial to automotive, space exploration, aerospace, deep well drilling, and gas turbines. A significant issue with the high-temperature operation is the exponential increase in leakage current. The lower intrinsic carrier concentration of SiC (10-9 cm-3) compared to Si (1010 cm-3) leads to lower leakage over temperature. Several researchers have demonstrated analog and digital circuits designed in SiC. However, a memory module is …

Simulation Of Optical Properties Of Dielectric Layers From Visible To Near Infrared Spectral Range, Andrew Cochran, Cory Conkel

ONU Student Research Colloquium

Optical properties of dielectrics play a critical role in various applications including the design and manufacture of optical components & devices such as detectors, filters, imagers, lenses, optical coatings, photonic crystals, sensors and waveguides, and solar cells. Radiative properties of varying thicknesses of different dielectrics such as Aluminum Oxide (Al2O3), Silicon Dioxide (SiO2), Indium Tin Oxide (ITO), Magnesium Fluoride (MgF2) and Silicon Nitride (Si3N4) have been simulated and compared in the range of visible to near infrared by mathematical modelling using MATLAB simulations. The results of the evolution of the radiative properties, as a function of dielectric material thickness, on …

Monitoring Chlorophyll A And Pheophytin At Crabtree Swamp, James Blankenship

Undergraduate Research Competition

The two chemicals compound we will be looking at include Chlorophyll A and Pheophytin. These two chemicals are common in most waters around the world. While they are helpful for the ecosystem, like most everything, having too much can also be harmful. Having a high concentrate of Chlorophyll A can result in foul smell and green scum on the bottom and surface of water. Likewise, pheophytin can be harmful when it comes to dissolving oxygen in water. This can result in erosion around the water source and can lead to unwanted chemicals in water (4). The results discussed will show …