Open Access Original Research Article

Impacts of the Variations of Aerosols Components and Relative Humidity on the Visibility and Particles Size Distribution of the Desert Atmosphere: Validating Results Obtained from OPAC 4.0 using MERRA-2 Model (Angstrom Exponent and Extinction Coefficient) Data

S. U. Yerima, B. I. Tijjani, U. M. Gana

Asian Journal of Research and Reviews in Physics, Page 1-15
DOI: 10.9734/ajr2p/2022/v6i230179

In this work, data extracted from OPAC 4.0 was compared and validated with 11 years data record from MEERA-2 model (average Angstrom Exponent and average Extinction Coefficient). The 11 years MEERA-2 model data for 10 selected deserts was extracted at an average relative humidity (RH) condition of 78%RH while OPAC considers eight different (RH) levels (00% to 99%RH). Based on the investigation, MEERA-2 model has the highest angstrom exponent (a) values for (Arabian, Danakil, Ferlo, Lompoul, Patagonian, Registan and Syrian deserts), which is greater than 1, and this signifies the dominance of fine mode particles over coarse mode particles when compared to OPAC 4.0. It can be seen that Chalbi (0.845), Karoo (0.482) and Sahara (0.417) deserts have an a values which is less than 1(indicating the dominance of coarse mode particles over fine mode particles). It can also be said that, MEERA-2 (a) is still greater than that of OPAC and this shows that the deserts atmosphere can be dominated by fine mode particles. The angstrom exponent (a) for OPAC 4.0 fluctuate all through the four studied components except for WASO which increases with the increase in RH and particles concentration (and this signifies that the particles dissolved as they uptake water and reach their saturation level). Based on the results of the investigation (time series analysis), it was found that the model’s significance (b) level are very high, and this shows that the aerosols distribution fluctuates around a reasonable stable, which signifies that the models are very significant. The analysis further found that, the significance (d) from the seasonal aspect is very poor except for Ferlo and Lompoul deserts, this signifies that season effect is consistent over time. It was also found that, the MEERA-2 has the highest visibility (km) over (OPAC 4.0). The investigation further revealed that the Arabian, Syrian and Patagonian deserts have the highest visibility (km) in the months of January, February, June, November and December. OPAC model underestimated the visibility when compared to MEERA-2 model.

Open Access Original Research Article

Students’ Perception of Their Physics Teachers’ Classroom Practices

Maxwell, Dah

Asian Journal of Research and Reviews in Physics, Page 16-24
DOI: 10.9734/ajr2p/2022/v6i230180

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.  

Open Access Original Research Article

Domain Structure in Ferroelectric Thin Films

Nyanga Bernard Yunga, Alain Moise Dikande

Asian Journal of Research and Reviews in Physics, Page 41-49
DOI: 10.9734/ajr2p/2022/v6i230182

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.

Open Access Original Research Article

Modulational Instability of the Second-order Bright Solitary Wave in Flattened Optical Fiber

J. R. Bogning, C. R. Ngouo Tchinda

Asian Journal of Research and Reviews in Physics, Page 50-58
DOI: 10.9734/ajr2p/2022/v6i2116

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.

Open Access Review Article

M-Theory and F-Theory over Theoretical Analysis on Cosmic Strings and Calabi-Yau Manifolds Subject to Conifold Singularity with Randall-Sundrum Model

Deep Bhattacharjee

Asian Journal of Research and Reviews in Physics, Page 25-40
DOI: 10.9734/ajr2p/2022/v6i230181

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.

Topics: 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.

Methods: 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.

Results: 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.