Hesham Alhumyani^*

Intelligent Automation & Soft Computing, Vol.36, No.3, pp. 2933-2945, 2023, DOI:10.32604/iasc.2023.034689 - 15 March 2023

Abstract This paper introduces an efficient image cryptography system. The proposed image cryptography system is based on employing the two-dimensional (2D) chaotic henon map (CHM) in the Discrete Fourier Transform (DFT). The proposed DFT-based CHM image cryptography has two procedures which are the encryption and decryption procedures. In the proposed DFT-based CHM image cryptography, the confusion is employed using the CHM while the diffusion is realized using the DFT. So, the proposed DFT-based CHM image cryptography achieves both confusion and diffusion characteristics. The encryption procedure starts by applying the DFT on the image then the DFT More >

Adel Daoud^1,2,3,4,*, Ali Cheknane², Jean Michel Nunzi^3,4, Afak Meftah¹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.6, pp. 1569-1579, 2022, DOI:10.32604/fdmp.2022.022091 - 27 June 2022

Abstract A solubility model for Merocyanine-540 dye together with the interface's electron transfer kinetics of MC-540/TiO₂ has been investigated (Merocyanine 540-based dye has been used effectively in dye-sensitized solar cells). The highest absorption peaks were recorded at 489 nm and 493 nm in Water and Ethanol solvent, versus the vacuum phase which yielded 495 nm (associated with a modest electron injection-free energy value (ΔGinj) of -2.34 eV for both Water and Ethanol solvents). The time-dependent density functional theory (TD-DFT) method approach has been applied in this simulation. Additionally, the electronic structure and simulated UV-Vis spectra of the More > Graphic Abstract

Daniel Dodzi Yao Setsoafia¹, Kiran Sreedhar Ram¹, Hooman Mehdizadeh-Rad^1,2, David Ompong^1,2, Vinuthaa Murthy^1,2, Jai Singh^1,2,*

Journal of Renewable Materials, Vol.10, No.10, pp. 2553-2567, 2022, DOI:10.32604/jrm.2022.020967 - 08 June 2022

Abstract DFT and TD-DFT calculations of HOMO and LUMO energies and photovoltaic properties are carried out on four selected pentathiophene donor and one IDIC-4F acceptor molecules using B3LYP and PBE0 functionals for the ground state energy calculations and CAM-B3LYP functional for the excited state calculations. The discrepancy between the calculated and experimental energies is reduced by correlating them with a linear fit. The fitted energies of HOMO and LUMO are used to calculate the V_oc of an OSC based on these donors and acceptor blend and compared with experimental values. Using the Scharber model the calculated PCE… More >

S. Markkandan^1,*, S. Sivasubramanian², Jaison Mulerikkal³, Nazeer Shaik⁴, Beulah Jackson⁵, Lakshmi Naryanan⁶

Intelligent Automation & Soft Computing, Vol.32, No.1, pp. 361-375, 2022, DOI:10.32604/iasc.2022.021779 - 26 October 2021

Abstract The codebook design is the most essential core technique in constrained feedback massive multi-input multi-output (MIMO) system communications. MIMO vectors have been generally isotropic or evenly distributed in traditional codebook designs. In this paper, Gaussian mixture model (GMM) based clustering codebook design is proposed, which is inspired by the strong classification and analytical abilities of clustering techniques. Huge quantities of channel state information (CSI) are initially saved as entry data of the clustering process. Further, split into N number of clusters based on the shortest distance. The centroids part of clustering has been utilized for More >

SHYAM BADU¹, SANJAY PRABHAKAR^1,2, RODERICK MELNIK^1,3,*

BIOCELL, Vol.44, No.3, pp. 279-291, 2020, DOI:10.32604/biocell.2020.010916 - 22 September 2020

Abstract Photosynthesis is a fundamental process in biosciences and biotechnology that influences profoundly the research in other disciplines. In this paper, we focus on the characterization of fundamental components, present in pigment-protein complexes, in terms of their spectroscopic properties such as infrared spectra, nuclear magnetic resonance, as well as nuclear quadrupole resonance, which are of critical importance for many applications. Such components include chlorophylls and bacteriochlorophylls. Based on the density functional theory method, we calculate the main spectroscopic characteristics of these components for the Fenna-Matthews-Olson light-harvesting complex, analyze them and compare them with available experimental results. More >

MINGHAO LI¹, YOULI QIU², WENHUI ZHANG¹, RUIHAO SUN¹, MEIJIN DU¹, LUZE YANG³, YU LI^1,*

BIOCELL, Vol.44, No.2, pp. 247-255, 2020, DOI:10.32604/biocell.2020.08835 - 27 May 2020

Abstract While phthalate acid esters (PAEs) cannot fluoresce alone, they can be detected by fluorescence spectroscopy after chelation with bovine serum albumin (BSA). In this study, the types of amino acid residues at the active site of PAEs chelated with BSA were determined using molecular docking technology. A modification scheme of BSA with higher detection sensitivity fluorescence spectroscopy for PAEs was proposed based on the docking results and constructed for a novel BSA structure with a higher detection sensitivity of fluorescence spectroscopy using a homologous modeling method. Density functional theory (DFT) was employed to explore the… More >

Yuan Chen¹, Liangtao Duan¹, Weize Sun^{2, *}, Jingxin Xu³

CMC-Computers, Materials & Continua, Vol.62, No.2, pp. 849-859, 2020, DOI:10.32604/cmc.2020.07115

Abstract In this paper, we address the frequency estimator for 2-dimensional (2-D) complex sinusoids in the presence of white Gaussian noise. With the use of the sinc function model of the discrete Fourier transform (DFT) coefficients on the input data, a fast and accurate frequency estimator is devised, where only the DFT coefficient with the highest magnitude and its four neighbors are required. Variance analysis is also included to investigate the accuracy of the proposed algorithm. Simulation results are conducted to demonstrate the superiority of the developed scheme, in terms of the estimation performance and computational More >

Brian Schwarz, Patrick McHargue, Mark Richardson

Sound & Vibration, Vol.52, No.2, pp. 1-6, 2018, DOI:10.32604/sv.2018.03637

Abstract In this paper, we show how Operating Deflection Shapes (ODS’s) and mode shapes can be obtained experimentally from measurements that are made using only two sensors and two short wires to connect them to a multi-channel acquisition system. This new test procedure is depicted in Figure 1. Not only is the equipment required to do a test much more cost effective, but this method can be used to test any sized test article, especially large ones.
The testing method introduced here involves moving a pair of sensors along together in a prescribed manor, and calculating the Transmissibility between them. More >

Jan Badorrek^1,2, Michael Walter^3,4,*, Marie-Pierre Laborie^1,2,*

Journal of Renewable Materials, Vol.6, No.3, pp. 325-335, 2018, DOI:10.7569/JRM.2017.634183

Abstract Doping lignin with carbon nanotubes is a promising strategy for cost-effective high-performance carbon fibers. We investigate the intermolecular interaction potential of CNT and organosolv lignin with two main approaches. Experimentally, oxidized purified multiwalled carbon nanotubes (MWCNTs) and beech organosolv lignins and derivatives are analyzed with their Hansen solubility parameters (HSPs) to assess their mutual compatibility. Theoretically, dispersion-corrected density functional theory simulations of the interaction between model molecules and single-walled carbon nanotubes reveal the source of interactions. We find that oxidation enables and enhances the interaction between carbon nanotubes and organosolv lignin experimentally, which is in More >

Fengjuan Wang^1,2, Shengping Wu^1,2,*, Jinyang Jiang^1,2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.1, pp. 1-10, 2018, DOI:10.31614/cmes.2018.03834

Abstract Corrosion inhibition performances of three purine derivatives were investigated systematically by employing DFT and molecular modeling. The relationship between macroscopic inhibition efficiency and quantum chemical properties was discussed from multiple perspectives, based on frontier orbital theory, and Fukui function theories. Comparative experimental and theoretical studies were taken, indicating the inhibition efficiency could be analyzed in the order of guanine <2,6-diaminopurine <2,6-dithiopurine. The sulphur atom (S5) was validated to be the most susceptible site for electrophile via quantitative surface analysis. More >