Pabna University of Science and Technology
  • Pābna, Rajshahi, Bangladesh
Recent publications
First-principles-based DFT calculations have been carried out to analyze the structural, mechanical, elastic anisotropic, Vickers hardness, electronic, optical, and thermodynamic properties of TlBO 3 (B ¼ Cr, Mn) for the first time. We determined the lattice parameters, which are in good agreement with the previous results. The Born criteria was ensured by the elastic constants, which also confirms the ductility of the solid. The elastic constants were also used to evaluate and analyze some related physical properties. The values of Vickers hardness were calculated to determine the hardness and relative application of both TlCrO 3 and TlMnO 3. Though the metallic characteristics were evaluated via the investigation of the electronic band structure and density of states, both TlCrO 3 and TlMnO 3 reveal semiconducting behavior under spin-orbit polarization with up-spin and down-spin configurations. Significant constants such as absorption, conductivity, reflectivity, dielectric, loss function, and refractive index were also considered and determined without spin and with spin. As a result, various possible electronic, optical, and optoelectronic applications were predicted. TlBO 3 (B ¼ Cr, Mn) was also found to be reliable for thermal barrier coating (TBC) as indicated by the evaluated values of thermal conductivity and Debye temperature.
Through this article, we focus on the extension of travelling wave solutions for a prevalent nonlinear pseudo-parabolic physical Oskolkov model for Kevin-Voigt fluids by using two integral techniques. First of all, we explore the bifurcation and phase portraits of the model for different parametric conditions via a dynamical system approach. We derive smooth waves of the bright bell and dark bell, periodic waves, and singular waves of dark and bright cusps, in correspondence to homoclinic, periodic, and open orbits with cusp, respectively. Each orbit of the phase portraits is envisaged through various energy states. Secondly, with the help of a prevalent unified scheme, an inventive version of exact analytic solutions comprising hyperbolic, trigonometric, and rational functions can be invented with some collective parameters. The unified scheme is an excitably auspicious method to procure novel interacting travelling wave solutions and to obtain multipeaked bright and dark solitons, shock waves, bright bell waves with single and double shocks, combo waves of the bright-dark bell and dark-bright bell with a shock, dark bell into a double shock wave, and bright-dark multirogue type wave solutions of the model. The dynamics of the procured nonlinear wave solutions are also presented through 2-D, 3-D, and density plots with specified parameters.
Khulna City Corporation (KCC) has undergone rapid urban development and expansion in recent times. These changes, including the change in land surface temperature (LST) throughout the area, have significant long-term effects. This research analysed the effects of land cover changes on KCC’s LST. By using the maximum likelihood classification method, Landsat imagery investigation identified the land cover chart and determined the LST for the years 1999, 2009 and 2019. It was modelled for the simulation of land cover for the year 2029 by using the classification results and applying the multi-layer perceptron Markov (MLPM) models together. It then also modelled the LST for the year 2029 by using three thematic indices and multiple regression analysis. As a result, the KCC urban area grew by 49% between 1999 and 2019. Simulation results have shown that the KCC could possibly experience a temperature range of more than or equal to 26°C in 2029 if the recent pattern persists. For KCC, the average LST for the urban area is projected to be 27°C in 2029. The scenario shown in this article will assist urban planners in quantifying the impact of various LST change-related issues and, thus, in preparing proper strategic measures.
This research explores a (2 + 1)-D generalized Camassa–Holm–Kadomtsev–Petviashvili model. We use a probable transformation to build bilinear formulation to the model by Hirota bilinear technique. We derive a single lump waves, multi-soliton solutions to the model from this bilinear form. We present various dynamical properties of the model such as one, two, three and four solitons. The double periodic breather waves, periodic line rogue wave, interaction between bell soliton and double periodic rogue waves, rogue and bell soliton, rogue and two bell solitons, two rogues, rogue and periodic wave, double periodic waves, two pair of rogue waves as well as interaction of double periodic rogue waves in a line are established. Among the results, most of the properties are unexplored in the prior research. Furthermore, with the assistance of Maple software, we put out the trajectory of the obtained solutions for visualizing the achieved dynamical properties.
This article investigates the new results of three nonlinear conformable models (NLCMs). To study such varieties of new soliton structures, we perform the generalized Kudryashov (GK) method. The obtained new results are defined in the styles of the exponential and rational functions. The derived new soliton structures are stable, serviceable, and fitting to embrace the conformable dynamics, chaotic vibrations, global bifurcations, optimal control problems, fluid mechanics, plasma physics, system identification, local bifurcations, control theory and resonances, and so many. The outcomes declare that the process is hugely valuable and accessible for investigating nonlinear conformable order models treated in theoretical physics.
e connected and acyclic components contained in a network are identified by the computation of its complexity, where complexity of a network refers to the total number of spanning trees present within. e article in hand deals with the enumeration of the complexity of various networks' operations such as sum (), difference (K 2,n ⊖K 2), and the conjunction of S n with K 2. All our computations have been concluded by implementation of the methods of linear algebra and matrix theory. Our derivations will also be highlighted with the assistance of 3D plots at the end of this article.
This paper exhibits the confidentiality performance study of a cooperative multicast network consisting of K\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathcal {K}}$$\end{document} asymmetric relays over Nakagami-m fading channels, where the communication links face uneven signal-to-noise ratios (SNRs). Although, conventional symmetric deployment of relays are convenient for analysis purposes but this assumption is not always effective in real cooperative network applications. So in this analysis, a cooperative multicast network is considered where a group of asymmetric relays cooperate in communication between a base station and multiple destinations under the nose of multiple eavesdroppers. Based on the given probability density function (PDF) of SNR for a point-to-point communication system, the analytical expressions of the PDF of SNRs are developed for multicast and eavesdroppers channels. Then, using these PDFs, the analytical representations for the probability of non-zero secrecy multicast capacity and the secure outage probability are derived for analyzing the performance of the proposed model. Finally, analytical results are verified with Monte-Carlo simulations.
This study carried out DFT‐based simulation in order to observe the effect of pressure (up to 120 GPa) on the various physical properties of boron (B) containing new MAX compounds Hf2InB2 and Hf2SnB2. Structural parameters in ambient conditions show excellent concordance with prior experimental and theoretical data. A decreasing trend of lattice parameters with pressure was observed. The stability of the phases under pressure was determined by calculating the elastic constant using the Born stability criteria, and was found stable within the studied pressure range. Pressure’s effect on the various elastic moduli was considered, and a linear response with pressure was observed. The brittle/ductile behavior under pressure was investigated, and a brittle to ductile phase transition was found. An opposite trend of elastic moduli with pressure was observed for Vickers hardness. The non‐linear variation of Vickers hardness with pressure has been interpreted in terms of Pugh ratio and density of states (DOS). A decreasing trend of the anisotropic indices was observed for Hf2InB2, while an increasing trend was observed for Hf2SnB2. The electronic and optical properties were also significantly influenced by the pressure. The results obtained at zero GPa have been compared with previous results and show significant agreement. This article is protected by copyright. All rights reserved.
In this paper, optimized hybrid off-grid renewable energy systems (HRES) have been designed for two divisional locations in Dhaka and Khulna in Bangladesh. An analysis is conducted using five different load dispatch strategies to find the best dispatch strategy for a cost-effective and technically feasible Islanded hybrid microgrid that will support the growing power demand. A comparative analysis among the various dispatch strategies is also presented to find out the best and worst dispatch strategies for the proposed HRESs. The two HRESs consist of solar PV, a backup diesel generator, wind turbine, load demand of 23.31 kW, and a battery storage system. HOMER predictive strategy, Generator Order, Load Following, Combined Dispatch, and Cycle Charging dispatch strategy has been adopted for evaluation. The two HRESs are optimized for CO 2 emission, Levelized Cost of Energy, and Net Present Cost minimization along with a feasible and stable voltage-frequency response on basis of the five dispatch techniques. The techno-economic analysis of the two HRESs is conducted using the HOMER Pro software platform. For the power system response analysis, MATLAB/Simulink is used. This study provides a complete guideline for determining the optimum component sizing ensuring optimum operation and possible costing estimation for the optimized performance of the two HRESs for different dispatch techniques. Also, a comparative study among the designed HRESs, other hybrid systems, and conventional power plants is conducted to prove the significance of this research work.
Cracks in concrete cause initial structural damage to civil infrastructures such as buildings, bridges, and highways, which in turn causes further damage and is thus regarded as a serious safety concern. Early detection of it can assist in preventing further damage and can enable safety in advance by avoiding any possible accident caused while using those infrastructures. Machine learning-based detection is gaining favor over time-consuming classical detection approaches that can only fulfill the objective of early detection. To identify concrete surface cracks from images, this research developed a transfer learning approach (TL) based on Convolutional Neural Networks (CNN). This work employs the transfer learning strategy by leveraging four existing deep learning (DL) models named VGG16, ResNet18, DenseNet161, and AlexNet with pre-trained (trained on ImageNet) weights. To validate the performance of each model, four performance indicators are used: accuracy, recall, precision, and F1-score. Using the publicly available CCIC dataset, the suggested technique on AlexNet outperforms existing models with a testing accuracy of 99.90%, precision of 99.92%, recall of 99.80%, and F1-score of 99.86% for crack class. Our approach is further validated by using an external dataset, BWCI, available on Kaggle. Using BWCI, models VGG16, ResNet18, DenseNet161, and AlexNet achieved the accuracy of 99.90%, 99.60%, 99.80%, and 99.90% respectively. This proposed transfer learning-based method, which is based on the CNN method, is demonstrated to be more effective at detecting cracks in concrete structures and is also applicable to other detection tasks.
Traveling wave solutions have played a vital role in demonstrating the wave character of nonlinear problems emerging in the field of mathematical sciences and engineering. To depict the nature of propagation of the nonlinear waves in nature, a range of nonlinear evolution equations has been proposed and investigated in the existing literature. In this article, solitary and traveling periodic wave solutions for the (2 + 1)‐dimensional modified KdV‐KP equation are derived by employing an ansatz method, named the enhanced (G′/G)‐expansion method. For this continued equation, abundant solitary wave solutions and nonlinear periodic wave solutions, along with some free parameters, are obtained. We have derived the exact expressions for the solitary waves that arise in the continuum‐modified KdV‐KP model. We study the significance of parameters numerically that arise in the obtained solutions. These parameters play an important role in the physical structure and propagation directions of the wave that characterizes the wave pattern. We discuss the relation between velocity and parameters and illustrate them graphically. Our numerical analysis suggests that the taller solitons are narrower than shorter waves and can travel faster. In addition, graphical representations of some obtained solutions along with their contour plot and wave train profiles are presented. The speed, as well as the profile of these solitary waves, is highly sensitive to the free parameters. Our results establish that the continuum‐modified KdV‐KP system supports solitary waves having different shapes and speeds for different values of the parameters.
The variant Boussinesq equation has significant application in propagating long waves on the surface of the liquid layer under gravity action. In this article, the improved Bernoulli subequation function (IBSEF) method and the new auxiliary equation (NAE) technique are introduced to establish general solutions, some fundamental soliton solutions accessible in the literature, and some archetypal solitary wave solutions that are extracted from the broad-ranging solution to the variant Boussinesq wave equation. The established soliton solutions are knowledgeable and obtained as a combination of hyperbolic, exponential, rational, and trigonometric functions, and the physical significance of the attained solutions is speculated for the definite values of the included parameters by depicting the 3D profiles and interpreting the physical incidents. The wave profile represents different types of waves associated with the free parameters that are related to the wave number and velocity of the solutions. The obtained solutions and graphical representations visualize the dynamics of the phenomena and build up the mathematical foundation of the wave process in dissipative and dispersive media. It turns out that the IBSEF method and the NAE are powerful and might be used in further works to find novel solutions for other types of nonlinear evolution equations ascending in physical sciences and engineering.
This article reports on the scattering of unpolarized and spin polarized electrons and positrons from 28Ni58,29Cu63,46Pd108, and 78Pt196, covering light to heavy precious metal targets. To cover the wide energy domain of 1 eV ≤Ei≤300 MeV, Dirac partial-wave phase-shift analysis is employed, using a complex optical potential for Ei≤1 MeV and a potential derived from the nuclear charge distribution for Ei>1 MeV. Results are presented for the differential and integral cross-sections, including elastic, momentum transfer, and viscosity cross-sections. In addition, the inelastic, ionization, and total (elastic + inelastic) cross-section results are provided, together with mean free path estimates. Moreover, the polarization correlations S,T, and U, which are sensitive to phase-dependent interference effects, are considered. Scaling laws with respect to collision energy, scattering angle, and nuclear charge number at ultrahigh energies are derived using the equivalence between elastic scattering and tip bremsstrahlung emission. In addition, a systematic analysis of the critical minima in the differential cross-section and the corresponding total polarization points in the Sherman function S is carried out. A comparison with existing experimental data and other theoretical findings is made in order to test the merit of the present approach in explaining details of the measurements.
This paper presents a performance evaluation of an off-grid PV-wind-biomass hybrid energy system for a remote area named Kuakata in Bangladesh considering dispatch strategy-based control, power system response, and reliability analysis-based stability and feasibility study. The simulation and optimization of operations of the system have been done by the HOMER software using the real-time field data of solar radiation, wind speed, and biomass of that particular area for ensuring economical and environmental feasibility offering the least net present cost (NPC), cost of energy (COE), and CO2 emission. The result shows that NPC has been reduced by 88 percent, CO2 emissions have been reduced by 99 percent, the operating cost has been lowered by 99 percent, and COE has been reduced by 92 percent than another available work. Besides, in comparison to traditional power sources, COE has been reduced by 40 percent, NPC has been lowered by 90 percent, and CO2 emissions have been reduced by 99 percent. The proposed system has also been analyzed utilizing DIgSILENT PowerFactory software to find the power system responses, i.e., active, reactive powers, voltage, and frequency responses of the proposed microgrid in a per unit fashion on the occurrence of a three-phase fault. To establish the feasibility of the microgrid, a reliability study considering different reliability indices has also been done. The analyzed hybrid energy system might be applicable to other regions of the world where there are similar climatic conditions
Objectives: Recently, suicide among Bangladeshi university students has become a serious problem. However, to date, there have been no studies assessing suicidal behaviors among Bangladeshi students. Therefore, the present study investigated suicidal ideation (SI) and its risk factors among this population. Methods: A classroom-based convenience sampling method was utilized to survey among 665 students of a university in Bangladesh (67.5% males; aged 21.16±1.6 years). In addition to socio-demographic questions, the survey also included the Smartphone Application-Based Addiction Scale, Bergen Facebook Addiction Scale, and Depression Anxiety Stress Scale–21. Results: Results showed that the prevalence of suicidal ideation was 2.3% in the past 24 hours, 4.8% in the past 15 days, 6.9% in the past month, 14.7% in the past year, and 61.1% in the lifetime. The unadjusted regression model showed that being divorced (or separated) from a partner (OR=4.486, 95% CI=1.972-10.207, p<0.0001), social media addiction (OR=1.550, 95% CI=1.006-2.388, p=0.047), depression (OR=1.657, 95% CI=1.677-4.211, p<0.0001), anxiety (OR=2.649, 95% CI=1.624-4.320, p<0.0001), and stress (OR=2.626, 95% CI=1.673-4.122, p<0.0001) were the risk factors of past-year SI. Conclusion: Compared to global prevalence rates, the present study reported higher levels of SI prevalence. Therefore, supportive suicide prevention programs are needed to tackle SI and alongside comorbid psychopathology.
In this study, the Biswas-Arshed equation (BAE) is handled with the beta time derivative. This model compensates for the group velocity dispersion (GVD) by the dispersion of time and space. Optical soliton and other solutions of BAE are obtained by the modified extended auxiliary equation mapping and improved F-expansion methods. Based on the used methods, we reduced the model nonlinear ordinary differential equation with the help of the wave transformation. Obtained solutions are expressed as hyperbolic, trigonometric and rational function solutions. Discussed methods are useful and powerful for deriving the exact solutions of nonlinear differential equations with beta derivatives. All obtained solutions are checked by Maple.
In this study, we have considered the (2+1)-dimensional paraxial nonlinear Schrödinger (NLS) equation in Kerr media and used the (w/g) -expansion method. The g′ and (g′/g2)-expansion techniques have been customized from the (w/g)-expansion method. We applied these two techniques to the paraxial NLS equation and found the optical soliton solutions. The optical soliton solutions are attained as the flat kink, kink, singular kink, peakon, anti-parabolic, W-shape, M-shape, bell, and periodic wave solitons in terms of free parameters. We have presented three-dimensional (3D), two-dimensional (2D) and contour plots of the obtained results and discussed the effect of the free parameters and nonlinearity of the equation by determining different parametric values, which have not been discussed in the previous literature. We have studied the impact of the Kerr nonlinearity and wavenumber on the travelling wave solutions. Moreover, we also analyze the streamlines pattern and instantaneous local directions of the wave profile. All wave phenomena are applied to signal transmission, magneto-acoustic waves in plasma, optical fiber art, coastal engineering, quantum mechanics, hydro-magnetic waves, nonlinear optics and so on. The achieved solutions prove that the proposed methods are very powerful and effective for modern science and engineering for scrutinizing nonlinear evolutionary equations.
We apply the unified method to retrieve optical soliton solutions of the Biswas-Arshed model (BAM) with the Kerr law nonlinearity in this paper. We first derive the ordinary differential form of this model from its partial differential form via a variable transformation. Then we add many new dynamical solitons of combo trigonometric, hyperbolic, and rational function solutions by Maple-18 package in this literature. The derived solutions exhibit some dynamics as singular solitons with exponentially increasing and decreasing amplitudes, singular solitons with gradually increasing and decreasing amplitudes, and singular solitons with constant amplitudes. Moreover, W-shaped solitons with multiple bright and dark waves, double periodic optical solitons with exponentially increasing and decreasing amplitudes, and double periods with symmetric and asymmetric amplitudes are obtained. Besides this, various dynamical properties of the obtained solutions are presented graphically.
In mathematical chemistry, molecular structure of any chemical substance can be expressed by a numeric number or polynomial or sequence of number which represents the whole graph is called topological index. An important branch of graph theory is the chemical graph theory. As a consequence of their worldwide uses, chemical networks have inspired researchers since their development. Determination of the expressions for topological indices of different derived graphs of graphs is a new and interesting problem in graph theory. In this article, some graphs which are derived from honeycomb structure are studied and obtained their exact results for sum degree-based indices. Additionally, a comparison is shown graphically among all the indices.
The present study investigates the impact of macroeconomic factors on the performance of banks in Bangladesh. The study analyzed 35 commercial banks consisting of both Islamic and conventional banks in Bangladesh from 2015 to 2020. The data was analyzed using the random effect regression model. Return on assets (ROA) is the dependent variable while macroeconomic variables such as GDP growth (GDPG), inflation (INF), and unemployment (UNEP) are the independent variables. The regression results showed that GDP growth and unemployment rate have a significant impact on the return on assets for banks in Bangladesh banks. There was no significant impact between inflation and return on assets.
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575 members
Md. Nur Alam
  • Department of Mathematics
Liton Chandra Paul
  • Department of Electrical Electronic and Communication Engineering
Pretam Kumar Das
  • Department of Physics
M. S. Ali
  • Department of Physics
Dhaka-Pabna Highway, 6600, Pābna, Rajshahi, Bangladesh
Head of institution
Prof. Dr. M. Rostom Ali
+88 0731 66742