Iranian Journal of Science and Technology, Transactions A: Science最新文献

The isothermal equation of state has been commonly used to determine the compression-dependent pressure of semiconductors like Ge, FeSi2, SiC, AIN, SnS, MoN, and GaN. Progress in this field has been achieved through the application of Murnaghan, Kholiya, and newly developed equations of state. While the Murnaghan and Kholiya equations yielded comparable results to experimental data at low compression, the Kholiya equation had to reduce results at high compression, while the Murnaghan equation had increasing results. However, the newly developed equation of state displayed a striking similarity to experimental values with only minor deviations, revealing its potential to forecast the thermos-elastic properties of semiconductors at both low and high compressions.

This paper thoroughly examines the Local Integrated Radial Basis Function (LIRBF) method’s performance in addressing linear systems and first- to higher-order Fredholm integro-differential problems. Utilizing a meshless approach with Gauss–Lobatto quadrature points for spatial discretization, we rigorously assess the method’s accuracy and efficiency across various numerical problems from the existing literature. Evaluation criteria, including maximum absolute errors and rates of convergence, validate the method’s effectiveness. To gauge the proposed LIRBF method’s efficacy, we benchmark it against well-established numerical techniques like Multi-Scale-Galerkin’s, Alpert Multiwavelets, Legendre multi-wavelets collocation, Legendre–Galerkin, Legendre polynomial approximation, and variational iteration methods. A comparative analysis based on criterion norms assesses the numerical results obtained by each method. The findings reveal that the proposed method demonstrates a significant reduction in sensitivity to the shape parameter compared to the RBF method. This observation establishes the robustness and stability of the proposed method, highlighting its ability to maintain accuracy and efficiency across diverse conditions. Results from numerical experiments and comparisons with other established techniques affirm the efficiency and accuracy of the LIRBF method in solving Fredholm integro-differential problems. The outcomes demonstrate promising performance, emphasizing the LIRBF method’s potential as a compelling alternative for addressing similar problems with high precision and computational efficiency.

In this study we develop a q-Fibonacci matrix (mathcal {F}(q)=(f^q_{nv})_{n,vin mathbb {N}_0}) given by

where (left( f_v(q)right)) represents a sequence of q-Fibonacci numbers. By utilizing the matrix (mathcal {F}(q)), we define matrix domains (ell _p (mathcal {F}(q)):=(ell _p)_{mathcal {F}(q)}) ((0<p< infty )) and (ell _infty (mathcal {F}(q)):=(ell _infty )_{mathcal {F}(q)}) also known as q-Fibonacci sequence spaces. We obtain Schauder basis for the space (ell _p (mathcal {F}(q))) and determine Alpha-((alpha)-), Beta-((beta)-) and Gamma-((gamma)-) duals of the newly defined spaces. We obtain some results related to matrix transformations from the spaces (ell _p(mathcal {F}(q))) and (ell _infty (mathcal {F}(q))) to classical sequence spaces (ell _infty ,) c and (c_0). We also examined some of the geometric properties like approximation property, Dunford–Pettis property, Hahn–Banach extension property, and rotundity of the spaces (ell _p(mathcal {F}(q))) and (ell _infty (mathcal {F}(q))).

This paper addresses Bazykin’s prey predator system, which is an ecological model comprising two differential equations for prey and predator species including predator intra-species competition. We study the solution of Bazykin’s predator–prey model of fractional order utilizing the Homotopy Perturbation Method (HPM). Here, the fractional order Bazykin’s model is developed from the integer order counterpart. Additionally, the Holling type-II response function is included in Bazykin’s model, which we have approximated employing Taylor’s polynomial in order to utilise HPM. Extensive numerical simulations are performed for various scenarios. Our numerical findings suggest that few terms of the series solution yield a precise approximate solution. Discussion is held regarding the solutions’ dependence on fractional orders. This method is highly efficient as well as straightforward in analysing this ecological system.

The study provides a thorough examination of the biofuel potential of three unique lignocellulosic crop residues, including rice straw (Oryza sativa), corn stalk (Zea mays), and sugarcane bagasse (Saccharum officinarum) of Odisha. In the investigation, we explored the compositional, thermal, and structural characteristics of these biomass sources to make clear their application for sustainable bioenergy production. Proximate analysis indicated variances in critical factors ranging from 5.9–14.8% (moisture content), 1.8–19.4% (ash content), 60–72.4% (volatile matter), and 9.6–14.7% (fixed carbon). Proximate analysis contributes to the various energy-generating capacities of these materials. An in-depth investigation of cellulose, hemicellulose, and lignin concentration revealed the promise of sugarcane bagasse as a cellulose-rich option for bioethanol synthesis. Thermochemical profiling using thermogravimetric and FTIR analysis revealed information about thermal stability and chemical changes, with pretreatment essential in increasing biomass accessibility and crystallinity. The significance of pretreatment-induced crystallinity for effective enzymatic hydrolysis and fermentable sugar generation was highlighted by X-ray diffraction (XRD). Overall, this study advances our understanding of the intricate relationships between biomass composition, structure, and bioenergy potential, offering valuable insights for developing sustainable biofuel production strategies.

In the present study, we have calculated the energy band gap of some chalcogenides viz. Na₂S and Na₂Se, using the equation from Angilella et al. (JPCS 121:032006, 2008) to analyze the variation of energy band gap under high pressure with respect to the lattice constant. To determine the pressure, we using some different equation of state viz. Murnaghan EOS, Hama-Suito EOS, Vinet-Rydburg EOS, Birch-Murnaghan EOS and Shanker EOS. The energy band gap of chalcogenide materials similarly behaves like other semiconductors when influenced by high pressure. The result of our calculations for the lattice constant under high pressure indicate that the lattice constant decreases as pressure increases. Furthermore for, Na₂S and Na₂Se materials at high pressure, our results show that the energy band gap increases as pressure increases for all EOSs.

The current study explores the concept of generalization of multi-switching synchronization. It contains designing the various orders of switches based on the number of state variables in the drive and response subsystems. The proposed theme is demonstrated using two hyper chaotic systems, namely Chen and Lorenz, with the aid of nonlinear active control. Prior to achieving synchronization, a chaotic analysis is conducted, including the Lyapunov characteristics exponents, fractional dimensions, and dissipativity. The study presents four distinct orders of switches (heterogeneous) and validates the computational results using Mathematica. This research contributes to the understanding of the multi-switching synchronization in broad sense and its potential applications in synchronizing the chaotic systems.

Inertial Confinement Fusion (ICF) is a promising approach to addressing global energy challenges through controlled nuclear fusion. This study investigates the impact of incorporating a gold pusher layer in laser-driven ICF target design. Numerical simulations with the MULTI-IFE code reveal that the gold pusher enhances confinement and energy deposition, resulting in a 9% increase in laser energy absorption and a 5% augmentation in total energy produced by alpha particles. Notably, these improvements amplify fusion reactions in the core and elevate the radiation temperature from 2.6 to 3.7 keV, creating more favorable conditions for ignition and burn. Furthermore, this study quantifies the gold pusher’s effect on fusion gain, a crucial metric for ICF feasibility, revealing a notable enhancement from 84 to 102. This significant boost underscores the gold pusher’s potential to optimize ICF target configurations, thereby advancing progress toward practical and efficient laser-driven inertial confinement fusion.

Thin film techniques and layers are essential in many industrial applications such as solar cells, gas sensors, photodetectors, etc. In this study, the impact of the annealing process on the structural and optical characteristics of tin sulfide and cuprous oxide (Cu₂O NPs/SnS) thin films prepared by thermal evaporation technique onto glass substrates, then annealed at 200 °C was studied to a candidate the layers for solar cell fabrication. X-ray diffraction, surface morphology, and UV–visible measurement characterized the films. After annealing, the average crystal size of Cu₂O/SnS nanostructure films decreased from 14 to 12 nm, while the dislocation and micro-strain increased. The SEM images show a uniform and homogeneous distribution after the annealing process and EDX analysis confirmed the elemental stoichiometry of the films. The obtained values of average roughness increased from 0.458 to 0.678 nm, and the root mean square increased from 0.579 to 0.875 nm. The evaluated energy gap of thin films was 1.75 eV for as-deposited and 1.8 eV for annealed films. The surface homogeneity and appropriate energy band gap refer to suitable films for optoelectronics applications.