Asian Journal of Research and Reviews in Physics最新文献

{"title":"Dzyaloshinskii-Moriya Interactions of Skyrmions for Memory and Logic Devices","authors":"Mosiori, Cliff Orori","doi":"10.9734/ajr2p/2022/v6i4122","DOIUrl":"https://doi.org/10.9734/ajr2p/2022/v6i4122","url":null,"abstract":"A skyrmion is considered to be a swirling quasi-particle that can exhibit nano-size disturbances similar to those by a knot of twisting magnetic field lines. The \"tangles\" observed in the magnetic field lines usually generate very strong localized magnetic fields. Thus, a stable skyrmion represent the smallest realizable ideal element with a magnetic texture while an antiskyrmion is considered to be a localized magnetic particle that represents a non-trivial magnetization texture with a specified magnitude with opposite topological charge to that of a skyrmion. The demand for novel memory and logic devices has grown in recent days with the advancement of communication and information technology. Particular attention has been drawn to the use of skyrmions and antiskyrmions in memory access and storage. The findings in most recent laboratory observation at room temperature further encourage more studies mainly covering transport and dynamic properties of both skyrmions and antiskyrmions. So far, some investigations have pointed on skyrmions for reservoir computing applications which in most applications require very large memory storages and fast access capabilities. To attain this scientific dream, a very careful ferromagnetic material re-engineering on the possibility of annihilating a skyrmion by an antiskyrmion (pairwise) to develop new concepts that may be useful for memory and logic applications. It is only recently that material physicists proposed skyrmions for ultra-dense magnetic memories though it has not been implemented. In this paper, we present the model, simulation and discuss the findings obtained by simulating a magnetic skyrmion model. These magnetic skyrmions were stabilized by Dzyaloshinskii-Moriya interaction. They were analyzed as tiny whirls of magnetic configurations that exhibit memory or logic element characteristics depending on complexity of their logical element geometry. The findings suggested that a magnetic skyrmion with antiskyrmion has a capacity to act as memory element. As a result, adopting them for memory applications can simplify the fabrication process of logic elements if their magnetic spin textures are taken into account. These findings form a promising pointer for future application of skyrmion and antiskyrmion for memory, logic and reservoir computing applications.","PeriodicalId":8529,"journal":{"name":"Asian Journal of Research and Reviews in Physics","volume":"11 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83612473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tropospheric Influence on Ultra-High Frequency (UHF) Radio Waves","authors":"J. Iloke, U. J. Ekah, Igwe O. Ewona","doi":"10.9734/ajr2p/2022/v6i3121","DOIUrl":"https://doi.org/10.9734/ajr2p/2022/v6i3121","url":null,"abstract":"This research investigates the effects of temperature and relative humidity on UHF signals. A spectrum analyzer was used in measuring UHF signals while a digital thermometer and hygrometer was used in measuring temperature and relative humidity, respectively. From results obtained, relative humidity had no significant effect on measured path loss while a positive correlation coefficient was obtained between temperature and measured path loss. This implies that an increase in temperature will lead to a decrease in received signal strength of UHF signals. Furthermore, a path loss propagation model for Calabar (PL = 37.920 + 2.796T + 0.290R + ) was obtained using multiple regression analysis and we believe that the obtained result will be useful to radio engineers for UHF signal propagation in the study terrain.","PeriodicalId":8529,"journal":{"name":"Asian Journal of Research and Reviews in Physics","volume":"55 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88854030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Universe before Big Bang","authors":"Deep Bhattacharjee","doi":"10.9734/ajr2p/2022/v6i3120","DOIUrl":"https://doi.org/10.9734/ajr2p/2022/v6i3120","url":null,"abstract":"The ghost condensation of the early universe in a pre-big bang phase has been presented in this paper through duration of a non-singular bounce. The undergoing universe contracts and passes smoothly in an expanding universe via a post-big bang phase. Initially developing and then taming any ghost like instabilities, the Null Energy Condition (NEC) is explicitly violated through the curvature mechanism of an adiabatic perturbed metric. The vacuum state of the ongoing phase is stabilized via a Lagrangian that in essence stabilizes the vacuum state under the higher order derivatives. The violation of the NEC regards a catastrophic vacuum instability, which re-emerges with a correction valid at small energies and momenta, below the UV-cut-off scale that, could potentially be problematic if one tries to construct a UV-completed theory of this Ekpyrotic model. The scale-invariant curvature perturbation, that arises and is sourced out of the scale-invariant entropy perturbations sourced by 2-Ekpyrotic scalar fields, that, in contrast, becomes constant on the super-horizon limits, due to the non-singular nature of the background geometry. Apart, from the ghost condensates, this theory addresses the new Ekpyrotic theory which in order becomes a distinguishable alternative to inflation theory for the birth of the universe. As per the recent WMAP data, the Ekpyrotic model has a spectral red tilt that shows the bounced scalar potential falling through a negative phase shift during the matter-fluid fluctuations in the hot big bang phase.","PeriodicalId":8529,"journal":{"name":"Asian Journal of Research and Reviews in Physics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91528601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance Analysis of Three-Phase Shunt Active Power Filter for Harmonic Mitigation","authors":"S. D. Yusuf, A. Loko, Jibrin Abdullahi, A. Abdulhamid","doi":"10.9734/ajr2p/2022/v6i3118","DOIUrl":"https://doi.org/10.9734/ajr2p/2022/v6i3118","url":null,"abstract":"Aims: To carried out performance analysis of a shunt active power filter (SAPF) for harmonics mitigation. \u0000Study Design: Experimental design through simulation studies using P-Q Theory and proportional integral controller. \u0000Place and Duration of Study: Department of Physics, Nasarawa State University Keffi, main campus, Nigeria, between October 2020 and September 2021. \u0000Methodology: Primary and secondary data were obtained using AVO Digital Multimeter and manufacturers’ datasheets from Schneider electric website to capture required system parameters, SAPF was designed using a Voltage Source Inverter model to represent the Three-Phase source, and P-Q Theory with PI Control was used for reference current extraction. The SAPF was modeled, designed and simulated using MATLAB-Simulink and analyzed under different nonlinear load conditions and harmonic spectrum to achieve low Total Harmonic Distortion (THD). \u0000Results: The THD in the unbalanced system voltages before the application of SAPF was found to be 12.6%, 11.4% and 11.2%, while after the application of SAPF was 2.2%, 2.5% and 2.5% for phase voltages a, b and c respectively. The grid currents indicated THD of 27.2%, 30.9% and 31% before application of SAPF and 2.2%, 2.2% and 2.1% after application. \u0000Conclusion: The use of non-linear loads; has adverse effects on the quality of electric power as well as phase voltage and frequency waveforms. The use of SAPF is of vital importance in improving electric power quality for reliable power supply and quality service delivery.","PeriodicalId":8529,"journal":{"name":"Asian Journal of Research and Reviews in Physics","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85854428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Theoretical Study on the Information Theoretic Inequalities and Fisher-Shannon Product of a Free Particle","authors":"Sudin Singh","doi":"10.9734/ajr2p/2022/v6i3119","DOIUrl":"https://doi.org/10.9734/ajr2p/2022/v6i3119","url":null,"abstract":"In this article, the plane wave solution for a free particle in three dimensions is considered and the wave function is normalized in an arbitrarily large but finite cube. The momentum space wave function is obtained by taking the Fourier transform of the coordinate space wave function. The probability densities are employed to compute the numerical values of the information theoretic quantities such as Shannon information entropy (S), Fisher information entropy (I), Shannon power (J) and the Fisher–Shannon product (P) both in coordinate and momentum spaces for different values of the length (L) of the cubical box. Numerical values so found satisfy the Beckner, Bialynicki-Birula and Myceilski (BBM) inequality relation; Stam-Cramer-Rao inequalities (better known as the Fisher based uncertainty relation) and Fisher-Shannon product relation. This establishes the validity of the information theoretic inequalities in respect of the motion of a free particle.","PeriodicalId":8529,"journal":{"name":"Asian Journal of Research and Reviews in Physics","volume":"224 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77790264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Mathematical Relationship between Hydrogenic Periodic Property and Nuclear Properties in Furtherance of Bohr’s Theory","authors":"Ikechukwu Iloh Udema","doi":"10.9734/ajr2p/2022/v6i3117","DOIUrl":"https://doi.org/10.9734/ajr2p/2022/v6i3117","url":null,"abstract":"Background: Atomic physics and nuclear matter physics are often exclusively studied. However, atomic properties are a direct function of nuclear properties. Establishing a mathematical relationship between nuclear and atomic properties could serve the interest of nuclear and atomic engineers. Nuclear - and atomic-based instrumentation engineering and nuclear medicine (and perhaps atomic medicine) applications could be the benefits. \u0000Objectives: The research is undertaken to 1) link nuclear property, the mass-radius of the nucleon, and ionization energy of hydrogen via the derivation of appropriate equation and 2) determine the mass-radii of the nucleons and some leptons. \u0000Methods: Theoretical and computational methods. \u0000Results and Discussion: As applicable to the previous results in the literature, the larger the mass of the elementary particles, the longer the radii. For the particles investigated, the order of the radius is muon (m-)<proton (p+)< neutron (n)< tauon (t-) corresponding to increasing mass, m-<p+< n<t-. The values of the mass radii were respectively » 0.1240, 1.1012, 1.1027, and 2.0855 fm. \u0000Conclusion: Nuclear properties such as the radius of any nucleon (ΓN) can be mathematically linked to atomic properties such as the ionization energy of hydrogen via equation which shows that ΓN is inversely proportional to the ionization energy of hydrogen and directly proportional to the rest-mass of the particle.","PeriodicalId":8529,"journal":{"name":"Asian Journal of Research and Reviews in Physics","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80605244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modulational Instability of the Second-order Bright Solitary Wave in Flattened Optical Fiber","authors":"J. R. Bogning, C. N. Tchinda","doi":"10.9734/ajr2p/2022/v6i2116","DOIUrl":"https://doi.org/10.9734/ajr2p/2022/v6i2116","url":null,"abstract":"The criterion of modulational instability of the second order bright solitary wave is studied in this article. The Principle consists initially in seeking all solitary wave solutions of the bright type which verify the nonlinear partial differential equation which governs the dynamics of propagation in flattened optical fibers. When the reference solution to be subjected to a disturbance is identified, the next step consists in establishing the condition of modulational stability/instability.","PeriodicalId":8529,"journal":{"name":"Asian Journal of Research and Reviews in Physics","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74926311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Domain Structure in Ferroelectric Thin Films","authors":"N. Yunga, A. M. Dikandé","doi":"10.9734/ajr2p/2022/v6i230182","DOIUrl":"https://doi.org/10.9734/ajr2p/2022/v6i230182","url":null,"abstract":"At low temperatures, uniaxial perovskites exhibit a spontaneous polarization with a permanent dipole moment. The broken symmetry state involves an order parameter and dielectric properties of the materials which are strongly dominated by a one-dimensional physics. For the last sixty years there has been growing interest in these crystals for potential applications in communication technology. Very recently, renewed interest to ferroelectric memory devices has been remarkable with particular emphasis on miniaturized devices. This new perspective comes along with great challenges, one of which is the critical size for stable domains in thin ferroelectric crystals. Since the polarization switching involves a pre-existing spontaneous polarization, it is of fundamental importance to address the question of conditions under which polarized domains can develop in a ferroelectric thin film. From previous articles, it has been observed that most studies focus on numerical simulations which is a good approach but for the fact that numerical simulations involve approximation of physical quantities, which is limitation to comparing experimental with theoretical studies. This motivated the authors to look purely at an analytical approach taking advantage of the new mathematical approach in the study of nonlinear systems. In this work, the authors have considered the question from an analytical point of view, focusing on an interesting model introduced by Lu and Cao. We propose an analytical counterpart of the numerical simulations done in this previous study.","PeriodicalId":8529,"journal":{"name":"Asian Journal of Research and Reviews in Physics","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87992126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"M-Theory and F-Theory over Theoretical Analysis on Cosmic Strings and Calabi-Yau Manifolds Subject to Conifold Singularity with Randall-Sundrum Model","authors":"Deep Bhattacharjee","doi":"10.9734/ajr2p/2022/v6i230181","DOIUrl":"https://doi.org/10.9734/ajr2p/2022/v6i230181","url":null,"abstract":"String theory always comes with heavy mathematical rigor as it questions the most significant and impossible attempt to make a scale-invariant phenomenology between general relativity and quantum theory. Thus, steps have been taken to simplify the theory a bit thereby making it accessible to general yet enthusiastic readers of physics. However, as there is numerous mathematics involved in the modeling of this theory, thus, any chance to make a purely non-mathematical approach towards strings would prove vacuous and intimidating making the pathway of this marvelous theory chocked with unnecessary assumptions resulting in false analogies (or hopes) relating to this theory. Thus, where it’s almost impossible to proceed without any equations, we have given a few just to wipe out some logical confusion arising to the first readers of strings. Few necessary diagrams are included along with intense theory and least mathematics for making this significant approach of theoretical physicists accessible to general learners or readers. \u0000Topics: Bosonic string theory, supersymmetric string theory, M – theory, F – theory, dualities and interconnectedness, viability, Randall – Sundrum model for tackling the hierarchy problem of particle physics, conifold singularities, Branes, Bulks, Extremal black holes, Ekpyrotic cosmology, topological aspects of Calabi – Yau (CY) manifolds, A and B models, Mirror Symmetries; AdS/CFT, cosmic strings, all in a way accessible to every reader. \u0000Methods: Theoretical analogies, deductions, principles behind the origin, development along with the probable conclusion of this theory, the roots of its origin, the necessary difficulty for detecting those strings, and approaches done by theorists to work out the pathway of achieving Einstein’s dream of unification irrespective of several hindrances. \u0000Results: String theory itself is not a complete theory. Rather it’s in the process of further development through the increment of time resulting in more applications of mathematics by developing or incorporating them in due needs. Thus, without stating any concrete results, the theory has been tackled in this paper with a viable hypothesis based on the current understanding, and previous attempts are stated to have been made for its success.","PeriodicalId":8529,"journal":{"name":"Asian Journal of Research and Reviews in Physics","volume":"57 4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73293285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Students’ Perception of Their Physics Teachers’ Classroom Practices","authors":"Maxwell Dah","doi":"10.9734/ajr2p/2022/v6i230180","DOIUrl":"https://doi.org/10.9734/ajr2p/2022/v6i230180","url":null,"abstract":"The purpose of the study was to investigate students’ perception of their physics teachers’ classroom practices. The study was conducted in eight (8) senior high schools in the Hohoe Municipality in the Volta Region of Ghana. Descriptive cross-sectional survey design was employed in carrying out the study. A total sample of 200 senior high school physics students were involved in the study. A questionnaire consisting mainly of closed ended items was used in collecting data from respondents. Data collected was analysed using frequencies, percentages, mean and standard deviation. It was found that physics teachers do not often motivate students and make them appreciate the fact that the things they learn in physics are important. Based on the findings, it was recommended that physics teachers make learning of physics interesting by making students appreciate the importance of what they teach, often encourage students to study physics and also show interest in the overall success of their students.  ","PeriodicalId":8529,"journal":{"name":"Asian Journal of Research and Reviews in Physics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89869748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}