Engineering Physics Commons^™

Improving The Structural And Physical Yield Of Aluminum By Repeated Additions Of Iron Carbide, Fayrooz K. Albasri

Al-Bahir Journal for Engineering and Pure Sciences

Aluminum suffers from low hardness and some ductility when thermal sintering which requires reinforcement with carbide or ceramic materials as Iron FeC with volumetric properties (2,4,6,8,10 )%. For purpose of the pressing process after mixing the two powder together, a scanning electron microscope examination performed for the prepared samples and found that there is a surface and structural consistency between aluminum and iron carbide and the best homogeneity is at10 % of carbide. Also some physical tests conducted for prepared samples and the results of the real density showed that the addition of iron carbide increases the density gradually and …

Using Powder Metallurgy Process To Produce Ceramic-Metal Composites, Ibrahim F. Abed, Salih, Y. Darweesh

Al-Bahir Journal for Engineering and Pure Sciences

Pressing powders and engineering materials is an innovative method for producing samples with a low cost and multiple industrial applications. In the current article, copper metal was added in different volume ratios to a ceramic material, alumina, for the purpose of improving the properties of alumina, by pressing with a hydraulic press. Where the results of the article showed that the percentage of true porosity after sintering is from (26-13)% with a copper content of (5%) to (25%). As for the apparent porosity after sintering, it decreased from (26-9)% at a copper content of (5-25)%, while the water absorption was …

Finite Element Analysis Of A Coconut (Cocos Nucifera L.) Climbing Mechanism, Arjay O. Afan, Omar F. Zubia, Adrian A. Borja, Ralph Kristoffer B. Gallegos

The Philippine Agricultural Scientist

A coconut climber mechanism was subjected to Finite Element Analysis (FEA) to improve its overall design and analyze its strength characteristics. The von Mises stress, total deformation, and factor of safety were evaluated using static structural analysis for the seat and pedal assemblies of the mechanism. The design has a minimum yielding factor of safety of 7.03 for the seat assembly and 12.09 for the pedal assembly. If aluminum is used as an alternative to steel, the prototype's weight can be reduced to at least 64.56% without compromising its strength properties. The weight reduction by using aluminum is expected to …

Effects Of Drying Temperature And Tempering Duration On Hybrid Rice Seed Germination, Thin-Layer Drying Characteristics, And Power Requirement, Rina A. Bawar, Joanne P. Foliente, Kevin F. Yaptenco, Mitchie Ann L. Cabiles

The Philippine Agricultural Scientist

This study presents the results of thin-layer drying tests for hybrid rice seeds. The independent factors were drying air temperature (45, 55, and 65 °C) and tempering duration (1, 2, and 4 h), while the dependent parameters were seed germination and drying characteristics, including drying rate, total and effective drying operation times, and power requirement. Considering one hybrid and 3 mo storage period after drying, the results showed that samples continuously dried at 45 and 55°C resulted in 91 and 86% germination percentages, respectively, which were above the acceptable Philippine national standard of at least 85%. However, when tempered for …

Air And Air-Steam Gasification Of Coconut Shell In A Fluidized Bed, Keynty Boy V. Magtoto, Rossana Marie C. Amongo, Sergio C. Capareda, Ronaldo B. Saludes

The Philippine Agricultural Scientist

Coconut shells’ abundance in tropical countries, along with its high volatile combustible matter (83.51%) and energy content (18.68 MJ kg^-1) make it a good biomass resource and a promising feedstock for gasification. In gasification, different mediums such as air, steam, oxygen, or their combinations can be used to react with the solid carbon and heavy hydrocarbons of biomass. Hence, the effects of using an air-steam mixture as a gasifying agent for the bench-scale fluidized bed gasification of coconut shells were studied. The steam-to-carbon ratio (SCR) was varied to evaluate its effect on the resulting syngas quality and gasification …

Development Of Spintronic Materials By Stoichiometric Engineering Of Cofeval, Gavin Baker, Matthew Wieberdink, Jax Wysong

The Journal of Undergraduate Research

We have carried out an experimental investigation of the Heusler Alloy CoFeVAl and its two variants Co_1.5Fe_0.5VAl and CoFeVAl_0.5Si_0.5 for their potential application in the field of spintronics. Heusler alloys are investigated for their many remarkable properties, including half-metallicity and spin-gapless semi-conductivity. Spintronic technology utilizes the intrinsic spin of an electron for information storage and manipulation in solid state devices. We synthesized these alloys using arc-melting and annealing. All three alloys were found to have cubic crystal structures with varying disorders. The parent alloy CoFeVAl shows a magnetic transition at 65 K. However, …

Structural And Magnetic Properties Of Heusler Alloys: Fecrmn1-Xvxal (X = 0, 0.5, 0.75), Jax Wysong, Gavin Baker

The Journal of Undergraduate Research

Heusler alloys are important to investigate due to their multiple interesting properties including half-metallicity and spin-gapless semi conductivity. Materials exhibiting these properties are desired for spin-transport-based devices. These devices provide the storing and delivering of information through the utilization of the spin property of electrons. The magnetic and electronic band properties of these alloys can be modified by tuning the elemental composition. This work investigates structural and magnetic properties of the three Heusler alloys FeCrMnAl, FeCrMn_0.5V_0.5Al, and FeCrMn_0.25V_0.75Al. It was found that all three alloys crystallize in cubic crystal structure with an …

Smart Grid Control: Demand Side Management In Household Refrigerators As A Tool For Load Shifting, Anogh Utkalika Zaman, James Doyle

Macalester Journal of Physics and Astronomy

With improved supply of renewable sources of energy the focus has shifted away from simply producing clean energy to efficient consumption of energy. Until cheaper methods of energy storage are developed, Demand Side Management (DSM) is the best option for maximising energy efficiency. This paper proposes a method of turning regular refrigerators into smart demand response fridges. First, we develop an algorithm that accounts for small fluctuations in price and switches the device for optimal performance and lowered running cost. Then, we use longer price fluctuations to predict suitable times for pre-cooling and investigate the reduction in price as a …

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 …

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

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

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

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

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

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

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 …

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

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 …

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 …

Structure And Electrophysical Properties Of A Solid Solution (Gaas1-Δbiδ)1-X-Y(Ge2)X(Znse)Y, S.Z. Zainabidinov, I.N. Karimov, Hotamjon Mansurov, Akramjon Boboev, Dilkhayotjon Pulatjon Ugli Abdurakhimov

Scientific Bulletin. Physical and Mathematical Research

This paper shows the possibility of growing a single-crystal solid solution of substitution (GaAs1-δBiδ)1-x-y(Ge2)x(ZnSe)y on GaAs substrates by liquid-phase epitaxy from a bismuthcontaining solution-melt. The grown films had a ptype of conductivity with a current carrier concentration of 1,86·1017 сm-3, a mobility of р = 300 cm2/V·s, and a resistivity of 0,13 Ohms·cm. Structural studies have shown that the epitaxial films have a sphalerite structure of the ZnS type and are monocrystalline with an orientation of (100). The crystal lattice parameter of the film was af = 0,56697 nm. Studies of current-voltage characteris-tics of n-GaAs – p-(GaAs1-δBiδ)1-x-y(Ge2)x(ZnSe)y heterostructures at different …

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 …

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 …

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 …

Influence Of A Strong Magnetic Field On Fermi Energy Oscillations In Two-Dimensional Semiconductor Materials, Gafur Gulyamov, Ulugbek Inayatillyevich Erkaboev, Rustam Gulomzhonovich Rakhimov, Nozimjon Sayidov Sayidov, Jasurbek Mirzaev

Scientific Bulletin. Physical and Mathematical Research

This article discusses the effect of a quantizing magnetic field and temperature on Fermi energy oscillations in nanoscale semiconductor materials. A generalized mathematical expression is obtained for calculating the dependence of the Fermi energy oscillations on the magnetic field, temperature, and thickness of the quantum well. It is shown that the Fermi energy in nanoscale semiconductor materials under a quantizing magnetic field is quantized. The proposed theory explains the experimental results in two-dimensional semiconductor structures with a parabolic dispersion law.

Determination Of The Specific Thermo Emf Of Granulated Silicon Doped With Alkaline Metals., B.M. Abdurakhmanov, Zarnigor Sohibova, M.M. Adilov

Scientific Bulletin. Physical and Mathematical Research

The value of the specific thermo EMF is one of the most important thermoelectric parameters of a material and in practice is estimat-ed mainly by two well-known methods - integral and differential. To measure the thermo EMF of granular silicon, we used a differential method. In this work, the thermoelectric properties of granular silicon containing alkali metal atoms have been studied, the presence of which, for example, in single-crystal structures makes it possible to improve the characteristics of a number of devices, and in polycrystalline ones, the effect of grain boundaries on the electrical properties, in particular, to reduce the …

The State Of Solar Energy In Uzbekistan In The Framework Of The Devel-Opment Of Renewable Energy Sources, E.Z. Imamov, Ramizulla Abdullaevich Muminov, Temur Asfandiyarovich Djalalov, I.Sh. Abdullaeva

Scientific Bulletin. Physical and Mathematical Research

The paper analyzes the possibilities of renewable energy sources to become the main sources of ener-gy that can in the future replace traditional technologies for the production of thermal and electrical energy based on the use of fossil fuels and nuclear energy.

Technological approaches are considered that make it possible to significantly increase the efficiency of solar energy, and it is also shown that such a possibility can be realized by using weakly crystalline and cheap modifications of silicon, which have previously passed the corresponding nanotechnological effect.

Properties And Applications Of Metal-Oxide Thin Films In Converters Of En-Ergy (Review), Shakhriyor Kh. Yulchiev, Akramjon Boboev, Xushruybek Mahmudov

Scientific Bulletin. Physical and Mathematical Research

Metal-oxide semiconductors (SnO2, ZnO, TiO2, etc.) have a wide band gap (~3 eV) and are trans-parent in the visible range of the optical spectrum. Therefore, transparent semiconductor devices (diodes, transistors, integrated circuits, etc.) can be made based on them. There are two peaks in the emission spectrum of the LED. One of the peaks (3.3 eV), apparently, is as-sociated with exciton recombination, and the other peak is associated with recombination through a deep impuri-ty level. The emission spectrum of the LED was ob-served at a direct current of 40 mA. The electrolumines-cence spectrum obtained on the heterostructure at room temperature …

Development And Implementation Of A Photovoltaic Power Plant With A Capacity Of 3-6 Kw With “Smart Greed” Elements In The Conditions Of The Fergana Valley, Райимжон Алиев, Жамшидбек Каххоров, Авазбек Мирзаалимов, Наврузбек Мирзаалимов, Бобур Рашидов

Scientific Bulletin. Physical and Mathematical Research

Today, solar cells are manufactured at the industrial level mainly from polycrystalline and monocrystalline silicon. Solar elements made of silicon make up more than 90% of the solar elements that are produced worldwide. Depending on the seasons of the year in the Ferghana Valley, the movement of the Sun, geographical location, air humidity, temperature changes, the intensity of light falling on the surface of solar panels and other parameters, the characteristic (I-V) of solar panels was studied. The installation of solar panels installed at Andijan State University consists of the installation, commissioning and analysis of the results obtained on sunny, …

A Cauchy-Goursat Problem For A Second Kind Degenerated Equation Of Hyperbolic Type, Doniyor Usmonov

Scientific Bulletin. Physical and Mathematical Research

In the work a Cauchy-Goursta problem has been formulated and investigated for a second kind degenerated equation of hyperbolic type. During the investigation, it was used properties of Gauss’s hyper geometric function and symbol of Pochhammer, the considered problem equivalently reduced to an integral equation with respect to trace of unknown function. Properties of Riemann-Liuvill integral-differential and generalized integral-differential operators have found solution of the taken integral equation. To find solution of the problem it was used general solution of the equation. A class of generalized solutions was introduced for the correctness of the problem. It was found necessary conditions …

Evolution Of Quantum Systems Consisting Of Mul-Tiple Various Particles Interacting With General-Ized Yukasha Potential, N.N. Bogolyubov, Rasulova Mukhayo, U.O. Avazov

Scientific Bulletin. Physical and Mathematical Research

In this paper, multi-variety densely packed par-ticle dynamic systems with the ability to interact with the shielded Yukawa potential were studied. Also, in order to study more widely the dynamics of systems containing particles interacting via shielded potential, the theoretical foundations of the dynam-ics of systems consisting of an arbitrary number of bounded - sorted multi-particles are analyzed. The dynamics of an arbitrary number of interacting par-ticle systems on a screening potential was studied using the Bogolyubov-Born-Green-Kirkwood-Yvon (BBGKY) chain of quantum kinetic equations. The BBGKY chain of quantum kinetic equations has solutions for the case that characterizes the evo-lution of …