Analysis of a magnetic field and Hall effects in nanoliquid flow under insertion of dust particles

In this study, the two‐phase hydromagnetic flow of a viscous liquid through a suspension of dust and nanoparticles is considered. The influence of the Hall current is also taken into account. The similarity variables are utilized to transform the problem into one independent variable. The obtained expressions in one independent variable are solved through the Runge–Kutta–Fehlberg scheme connected with the shooting procedure. The computed results are sketched for employing multiple values of physical constraints on the temperature and velocity of the nanofluid and dust phase. The characterization of various nanoparticles like Cu, Al₂O₃, TiO_2, and Ag on velocities and temperatures of both phases is made through plots. A comparative analysis in the limiting approach is presented to justify the present solution methodology. The range of emerging parameters is taken as 0 ≤ l ≤ 3, 0.1 ≤ β_t ≤ 3, 0 ≤ m ≤ 2.5, 0 ≤ M² ≤ 2, 0.1 ≤ β_v ≤ 3, 0 ≤ ? ≤ 0.4, and ?0.8 ≤ λ ≤ 0.8. From the study, it is revealed that β_t has the opposite effect on the temperature of dust and nanofluid phases. The Hall parameter m raises the profiles of velocities in the nanoliquid and dust phases. Also, it is found that the transverse velocities h(η) and H((η) and temperatures θ(η) and θ_p(η) rise for larger ?.     

Coherent control of symmetric and asymmetric diffraction grating via relative phase

ABSTRACT

We present a theoretical model to realize the symmetric and asymmetric diffraction grating in a four-level atomic medium. The proposed atomic medium follows a double lambda configuration where four fields interact with it. We get control over symmetric and asymmetric behavior of the diffraction grating by manipulating the relative phase of the fields. Interestingly, the symmetric and asymmetric diffraction grating become prominent when the vortex beam is used instead of the plane wave. Enhanced first, second, and third-order diffraction gratings are achieved via the vortex beam. Further, we find control over asymmetric diffraction gratings by the relative phase of the fields. Coherent control of asymmetric diffraction grating in negative and positive diffracted angles is also achieved via the relative phase.     

Relationship of Water Stress and Flood Damage for Sustainable Development

Water Resources Management - Climate change leads to the extreme occurrence of events, water-related disasters, and pressure on existing water resources. The water resource is important for the...     

Chinese-Based Spearcons: Improving Pedestrian Navigation Performance in Eyes-Free Environment

This article presents nonspeech audio (i.e., English-based spearcons and Chinese-based spearcons) to represent distance, and forward-direction for pedestrian navigation in an eyes-free environment. Experiment in the field is carried out with the involvement of 10 participants (i.e., native Chinese) using within-subject design to evaluate English-based spearcons, Chinese-based spearcons, and Chinese text-to-speech (TTS). Results from the experiment suggest that Chinese-based spearcons are efficient in task completion compared to Chinese TTS. Moreover, Chinese-based spearcons are more effective in conveying distance and forward-direction compared to English-based spearcons in pedestrian navigation. Overall, participants have shown their satisfaction with Chinese-based spearcons as an auditory feedback in pedestrian navigation.     

Synthesis of Biaryls through Aromatic C?H Bond Activation: A Review of Recent Developments

This review describes recent progress made in the rapidly developing field of C H bond activation, in particular for syntheses of biaryls. The catalysts presented here provide convenient strategies for the direct arylation of arenes, via single or double C H bond activation, leading to inter‐, and intramolecular carbon‐carbon bond formation. The literature from mid‐2009 to December 2013 has been discussed.

     

Time Effects on Total Suction of Bentonites

This paper presents a study on time effects on total suction of bentonite-based materials under constant water content conditions. Three different types of bentonite (i.e., MX80, Calcigel I, and Calcigel II) and a natural expansive clay (i.e., London Clay) were used. Total suction was measured using chilled-mirror hygrometer technique. The measurements were performed on specimens aged 1 hour, 6 hours, 1 day, 2 days, 1 week, 2 weeks, 1 month, and 2 months. The results show that the true equilibrium state for two types of bentonite (i.e., MX80 and Calcigel I) used is time dependent. Total suction increases with time and this behaviour is controlled by the characteristics of the bentonites. Total suction of the other specimens (i.e., Calcigel II and London Clay) is not affected by curing time. The changes in total suction with time as the specimen's age are attributed to non homogeneity of the water content distribution in the micro- and macropores of the bentonites and inaccuracy of the device used.     

Synthesis of Biaryls via Ligand‐Free Suzuki–Miyaura Cross‐Coupling Reactions: A Review of Homogeneous and Heterogeneous Catalytic Developments

This review describes the recent developments in the field of Suzuki–Miyaura cross‐coupling reaction, in particular with regard to ligand‐free catalysis. The catalysts outlined here allow convenient and green synthetic pathways specifically for the construction of C–C bonds. They enable the synthesis of biaryls by the coupling arylboronic acids with aryl halides. The literature reporting ligand‐free synthesis of biaryls from 2010 to May 2015 has been reviewed.

     

A Novel Internet of Medical Thing Cryptosystem Based on Jigsaw Transformation and Ikeda Chaotic Map

Image encryption has attracted much interest as a robust security solution for preventing unauthorized access to critical image data. Medical picture encryption is a crucial step in many cloud-based and healthcare applications. In this study, a strong cryptosystem based on a 2D chaotic map and Jigsaw transformation is presented for the encryption of medical photos in private Internet of Medical Things (IoMT) and cloud storage. A disorganized three-dimensional map is the foundation of the proposed cipher. The dispersion of pixel values and the permutation of their places in this map are accomplished using a nonlinear encoding process. The suggested cryptosystem enhances the security of the delivered medical images by performing many operations. To validate the efficiency of the recommended cryptosystem, various medical image kinds are used, each with its unique characteristics. Several measures are used to evaluate the proposed cryptosystem, which all support its robust security. The simulation results confirm the supplied cryptosystem’s secrecy. Furthermore, it provides strong robustness and suggested protection standards for cloud service applications, healthcare, and IoMT. It is seen that the proposed 3D chaotic cryptosystem obtains an average entropy of 7.9998, which is near its most excellent value of 8, and a typical NPCR value of 99.62%, which is also near its extreme value of 99.60%. Moreover, the recommended cryptosystem outperforms conventional security systems across the test assessment criteria.     

Correction to: Deposition of bismuth sulfide and aluminum doped bismuth sulfide thin films for photovoltaic applications

Journal of Materials Science: Materials in Electronics -