Comparative study of multilayered ZnO/TiO<Subscript>2</Subscript>/ZnO and TiO<Subscript>2</Subscript>/ZnO/TiO<Subscript>2</Subscript> thin films prepared by sol–gel dip coating method

The aim of this research work is to represent the comparative study of ZnO/TiO₂/ZnO (ZTZ) and TiO₂/ZnO/TiO₂ (TZT) thin films deposited by sol–gel dip coating on FTO substrates. After deposition, the films were annealed at 500 °C for 1 h. Structural, surface morphology, optical and electrical properties of these films were studied by X-ray diffractrometer (XRD), Raman spectra, atomic force microscope (AFM), photoluminescence spectra (PL) and four point probe technique respectively. XRD and Raman spectra confirmed the anatase, brookite phases of TiO₂ and cubic phase of ZnO. AFM confirmed the formation of nano particles with average sizes of 18.4 and 47.2 nm of TZT and ZTZ films respectively. According to PL spectra, both the multilayer films slowdown the electron hole recombination rate and enhances the optoelectronic properties of the materials. Also it showed the peaks in the visible region of spectrum. The four point probe results showed that the average sheet resistivity of the films is 450 and 120 (ohm-m) respectively.     

Biomimetic production,characterisation, in vitro cytotoxic and anticancer assessment of aqueous extract‐mediated AgNPs of Teucrium stocksianum Boiss

Owing to the numerous biological applications, cost effectiveness and low cytotoxicity of the biomimetic nanoparticles (NPs), the authors optimised the production of silver NPs (AgNPs) using aqueous extract of Teucrium stocksianum Boiss. The NPs were characterised by ultraviolet‐visible (UV‐vis) spectroscopy, X‐ray diffraction (XRD), scanning electron microscopy (SEM), dynamic light scattering (DLS) and Fourier transform‐infrared spectroscopy (FTIR). The UV‐vis spectroscopy revealed a surface plasmon resonance (410‐440 nm) at an incubation temperature of 90°C when 1 mM Ag nitrate combined to 5 mg/ml extract concentration in the ratio of 1:10. DLS results show an average zeta size of ∼44.61 nm and zeta potential of −15.3 mV. SEM and XRD confirmed the high crystallinity and cubical symmetry with an average size below 100 nm. FTIR measurement shows the presence of various functional groups, responsible for the capping and reduction of Ag metal. The 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide cell viability assay shows that AgNPs are less cytotoxic to J774 and L929 cells as compared with enhanced anticancer activity with low IC50 concentrations (68.24 µg/ml) against Michigan Cancer Foundation‐7 (MCF‐7) cells. The ethidium bromide/acridine orange assay shows that the AgNPs kill the cell by apoptosis. Overall, the results show that AgNPs possesses potent anticancer activities.Inspec keywords: cellular biophysics, cancer, nanobiotechnology, nanomedicine, ultraviolet spectra, X‐ray diffraction, scanning electron microscopes, light scattering, patient treatmentOther keywords: anticancer assessment, in vitro cytotoxic assessment, aqueous extract‐mediated AgNPs, Teucrium stocksianum Boiss, nanoparticles, biological applications, biosynthesis, silver NPs, X‐ray diffraction, scanning electron microscopy, dynamic light scattering, Fourier transform‐infrared spectroscopy, UV‐vis spectroscopy, surface plasmon resonance, extract concentration, zeta potential, high crystallinity, FTIR measurement, amide molecules, viability assay, enhanced anticancer activity, potent anticancer activities     

An improved approach for determination of index positions on CNC magazines with cutting tool duplications by integrating shortest path algorithm

Optimisation of automatic tool changer (ATC) indexing problem, where cutting tools are allocated to the stations on a turret magazine of a CNC machine, is one of the challenging problems in machining. The aim of the problem is to minimise the total indexing time of ATC. This problem becomes even more challenging if duplication of cutting tools is allowed and a bidirectional ATC is used. The problem has a unique feature which has not been stressed yet by other researchers, that is, although ATC indexing (master problem) is the main optimisation problem, objective function evaluation of this problem is a standalone optimisation problem (sub problem) indeed. Although an approximation algorithm does not guarantee optimality for the master problem, the subproblem must be solved optimally; otherwise, deficiencies arising from ill-defined objective function might be encountered. Considering this interesting future, a novel methodology, which employs a shortest path algorithm, is developed. Thus, the subproblem of this complicated problem can be optimally solved. Moreover, two metaheuristics, based on threshold accepting and descent first improvement greedy methodologies, are proposed for generating efficient solutions. Finally, several benchmarking instances are generated and solved to test the proposed algorithms.     

An empirical investigation of knowledge management competence for enterprise resource planning systems success: insights from Jordan

The primary objective of the study reported herein is to empirically test the implicit, positive relationships between ERP-related Knowledge Management Competence (KM-competence; knowledge creation, knowledge retention, knowledge transfer, and knowledge application) dimensions and the extended Enterprise Resource Planning System Success construct (ERP system success; individual impact, workgroup impact, organisational impact, information quality, system quality, and vender/consultant quality). Data were collected from 173 of business and IT managers in 455 organisations in Jordan. Statistical techniques employed included confirmatory factor analysis to examine validity of the measurement model, and structural equation modelling using AMOS 16.0 is also utilised to test the hypotheses. The results of analysis show there is a positive significant impact of ERP knowledge creation on ERP success. Also, ERP knowledge retention positively and significantly affects ERP system success. Moreover, ERP knowledge transfer positively and significantly influence ERP system success. Furthermore, ERP knowledge application has positive effect on ERP system success. The results also indicate that ERP success construct is robust since all six observed variables are strongly loaded to the latent variable. Research limitations as well as implications for practice and research are discussed.     

Green fabricated CuO nanobullets via Olea europaea leaf extract shows auspicious antimicrobial potential

In present investigation, copper oxide (CuO) nanostructures have been prepared via green chemistry. Olea europaea leaf extract act as strong chelating agent for tailoring physical as well as bio‐medical characteristics of CuO at the nano‐size. Physical characterisation such as scanning electron microscope analysis depicts the formation of homogenised spherical shape nanoparticles (NPs) with average size of 42 nm. X‐ray diffraction and Fourier transform infrared spectroscopy further confirmed the crystalline pure phase and monoclinic structure. High performance liquid chromatography (HPLC) testing is performed to evaluate the relative concentration of bioactive molecules in the O. europaea leaf extract. From HPLC results capping action of organic molecules around CuO‐NPs is hypothesised. The antimicrobial potency of biosynthesised CuO‐NPs have been evaluated using colony forming unit (CFU) counting assay and disc diffusion method which shows a significant zone of inhibition against bacterial and fungal strains may be highly potential for future antimicrobial pharmaceutics. Furthermore, reduction of various precursors by plant extract will reduce environmental impact over chemical synthesis.Inspec keywords: copper compounds, antibacterial activity, biochemistry, nanoparticles, nanomedicine, biomedical materials, chromatographyOther keywords: CuO, size 42 nm, chemical synthesis, antimicrobial pharmaceutics, bacterial strain, fungal strain, disc diffusion method, colony forming unit counting assay, biosynthesised CuO‐NP, bioactive molecules, high‐performance liquid chromatography testing, monoclinic structure, crystalline pure phase, Fourier transform infrared spectroscopy, X‐ray diffraction, homogenised spherical shape nanoparticles, scanning electron microscope analysis, CuO biomedical characteristics, chelating agent, green fabricated CuO nanobullets, green chemistry, copper oxide nanostructures, antimicrobial potential, Olea europaea leaf extract     

Strain-Mediated Lattice Rotation Design for Enhancing Thermoelectric Performance in Bi2S2Se

A unique strain-mediated lattice rotation strategy is introduced via nanocompositing to upsurge the optimized limits in the composition-to-structural pathway on rationally engineering the efficient thermoelectric material. In this study, a special lattice rotation via strain engineering is realized to optimize the desired electronic and chemical environment for enhancing thermoelectric properties in n-type Bi₂S₂Se. This approach results in a unique transport phenomenon to assist high-energy electrons in transferring through the optimized transport channels, and appropriate structure disparity to significantly localize phonons. As a result, Sb over Cl doping in Bi₂S₂Se gently reduces E_g and introduces defect states in bandgap with shifting down the Fermi level, thus causing increase in carrier concentration, which contributes to a higher power factor of ≈7.18 µW cm⁻¹ K⁻² (at T = 773 K). Besides, a lower thermal conductivity of ≈0.49 W m⁻¹ K⁻¹ is driven through lattice strain and defect engineering. Consequently, an ultra-high ZT_max = 1.13 (at T = 773 K) and a high ZT_ave = 0.54 (323 K-773 K) are realized. This study not only leads to an extraordinary thermoelectric performance but also reveals a unique paradigm for electron transportation and phonon localization via lattice strain engineering.     

Efficient JPEG Encoding Using Bernoulli Shift Map for Secure Communication

To ensure confidentiality and efficient network bandwidth, digital data must be compressed and encrypted. In most communication systems, these two factors are critical for information processing. Image compression and encryption may result in lower restoration quality and performance. Secure-JPEG is an effort to create a compression and encryption technique for digital data. This approach is based on the JPEG compression standard, which is the most extensively used lossy compression scheme. It enhances the usual JPEG compression algorithm to encrypt data during compression. The Secure-JPEG approach encrypts the data while it is compressed, and it may be easily modified to offer near lossless compression. Lossless compression, on the other hand, has a lower compression ratio and is only useful in certain situations. The paper addresses the issue of insufficient security as a result of the usage of a simple random number generator that is not cryptographically safe. The enhanced security characteristics are provided via the Generalized Bernoulli Shift Map, which has a chaotic system with proven security. Several cryptographic tests are used to validate the algorithm's security, and the chaotic system's behavior is also examined.

     

Automatic COVID-19 detection mechanisms and approaches from medical images: a systematic review

Multimedia Tools and Applications - Since early 2020, Coronavirus Disease 2019 (COVID-19) has spread widely around the world. COVID-19 infects the lungs, leading to breathing difficulties. Early...     

Optimal Modulation Technique for MIMO FSO Link

Wireless Personal Communications - Full duplex (FD) and device-to-device (D2D) communications are being considered in urban small cell deployment to meet the increasing mobile data traffic. Though...     

Adaptive intelligent cascade control of a ball-riding robot for optimal balancing and station-keeping

This paper presents an adaptive intelligent cascade control strategy to maintain the dynamic stability of a ball-riding robot (BRR). The four-wheeled mechanism beneath the robot body balances it on a spherical wheel. The BRR is modeled as a combination of two decoupled inverted pendulums. Therefore, two independent controllers are used to control its pitch and roll rotations. An incremental proportional–integral–derivative (PID) is implemented in the inner loop of the cascade to maintain the vertical balance. A generic PD controller is used in the outer loop to keep the station by controlling its spatial position. The controller parameters are automatically tuned via a fuzzy adaptation mechanism. The centers of fuzzy output membership functions are dynamically updated via an extended Kalman filter (EKF). The proposed controller quickly responds to changes in system’s state and effectively rejects the exogenous disturbances. The results of real-time experiments are presented to validate the effectiveness of the proposed hybrid controller over the conventional classical controllers.