2-D and 3-D resistivity in the area of the Menkaure Pyramid Giza, Egypt

An area 47 × 26 m adjacent to the Queens’ pyramids near the Menkaure Pyramid, Giza, was examined using 14 parallel Wenner-Schlumberger profiles at 2 m intervals with a 1 m electrode spacing. Most of the inverted 3-D models show moderate resistivity values at shallow depths. However, in two places higher resistivity values identified two elongate features. One may correspond to a 2 × 8 m solar boat placed near the pyramid while the other may indicate a 5 × 20 m N–S room with a mud brick roof.      

Electromagnetic design of folded‐waveguide resonator filter with single finite‐frequency transmission zero

This article presents electromagnetic (EM) design of a new folded‐waveguide resonator filter that uses an advanced coupling scheme to achieve the desired asymmetric frequency response with an attenuation pole of finite frequency on the high side of the passband. A filter of this type with a fraction bandwidth about 5% at a center frequency of 4.45 GHz has been successfully designed using a commercially available electromagnetic simulator. The designed filter has been fabricated and tested. Simulations and experimental results are presented to validate the design and to show the advantages of this type of filter. This filter also provides a compact size compared with conventional cavity resonator filters. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008.     

46—THE FORM TAKEN BY THREADS LAID ON A MOVING BELT. PART I: EXPERIMENTAL STUDY

An apparatus made to study the form taken by threads laid on a moving belt under different conditions is described. This mechanism of laying down the thread is a partial imitation of the mechanism of laying down the filaments emerging from the spinnerets during the manufacturing process of spun-bonded non-woven fabrics.

It is shown that the form of the laid-down thread can vary according to the type of thread, the height of the feed point, and the ratio of the feed speed to the belt speed. It is also shown that there is a critical value of the speed ratio at which the form changes its geometry considerably. The conditions for a homogeneous and controlled form of the laid thread are deduced.     

Sailfish Optimizer with EfficientNet Model for Apple Leaf Disease Detection

Recent developments in digital cameras and electronic gadgets coupled with Machine Learning (ML) and Deep Learning (DL)-based automated apple leaf disease detection models are commonly employed as reasonable alternatives to traditional visual inspection models. In this background, the current paper devises an Effective Sailfish Optimizer with EfficientNet-based Apple Leaf disease detection (ESFO-EALD) model. The goal of the proposed ESFO-EALD technique is to identify the occurrence of plant leaf diseases automatically. In this scenario, Median Filtering (MF) approach is utilized to boost the quality of apple plant leaf images. Moreover, SFO with Kapur's entropy-based segmentation technique is also utilized for the identification of the affected plant region from test image. Furthermore, Adam optimizer with EfficientNet-based feature extraction and Spiking Neural Network (SNN)-based classification are employed to detect and classify the apple plant leaf images. A wide range of simulations was conducted to ensure the effective outcomes of ESFO-EALD technique on benchmark dataset. The results reported the supremacy of the proposed ESFO-EALD approach than the existing approaches.     

Robust Image Watermarking Using LWT and Stochastic Gradient Firefly Algorithm

Watermarking of digital images is required in diversified applications ranging from medical imaging to commercial images used over the web. Usually, the copyright information is embossed over the image in the form of a logo at the corner or diagonal text in the background. However, this form of visible watermarking is not suitable for a large class of applications. In all such cases, a hidden watermark is embedded inside the original image as proof of ownership. A large number of techniques and algorithms are proposed by researchers for invisible watermarking. In this paper, we focus on issues that are critical for security aspects in the most common domains like digital photography copyrighting, online image stores, etc. The requirements of this class of application include robustness (resistance to attack), blindness (direct extraction without original image), high embedding capacity, high Peak Signal to Noise Ratio (PSNR), and high Structural Similarity Matrix (SSIM). Most of these requirements are conflicting, which means that an attempt to maximize one requirement harms the other. In this paper, a blind type of image watermarking scheme is proposed using Lifting Wavelet Transform (LWT) as the baseline. Using this technique, custom binary watermarks in the form of a binary string can be embedded. Hu’s Invariant moments’ coefficients are used as a key to extract the watermark. A Stochastic variant of the Firefly algorithm (FA) is used for the optimization of the technique. Under a prespecified size of embedding data, high PSNR and SSIM are obtained using the Stochastic Gradient variant of the Firefly technique. The simulation is done using Matrix Laboratory (MATLAB) tool and it is shown that the proposed technique outperforms the benchmark techniques of watermarking considering PSNR and SSIM as quality metrics.     

High-Performing Atomic Electrocatalyst for Chlorine Evolution Reaction

Electrocatalysts facilitating chlorine evolution reaction (ClER) play a vital role in chlor–alkali industries. Owing to a huge amount of chlorine consumed worldwide, inexpensive high-performing catalysts for Cl₂ production are highly demanded. Here, a superb ClER catalyst fabricated through uniform dispersion of Pt single atoms (SAs) in  C₂N₂ moieties of N-doped graphene (denoted as Pt-1) is presented, which demonstrates near 100% exclusive ClER selectivity, long-term durability, extraordinary Cl₂ production rate (3500 mmol h⁻¹ g_Pt⁻¹), and >140 000-fold increased mass activity over industrial electrodes in acidic medium. Excitingly, at the typical chlor–alkali industries’ operating temperature (80 °C), Pt-1 supported on carbon paper electrode requires a near thermoneutral ultralow overpotential of 5 mV at 1 mA cm⁻² current density to initiate the ClER, consistent with the predicted density functional theory (DFT) calculations. Altogether these results show the promising electrocatalyst of Pt-1 toward ClER.     

Macroscale assessment of low-velocity impact on hybrid composite laminates

Composites are usually brittle materials and have low impact properties. Structural dimensions, stacking sequence, ply materials, ply thicknesses and ply angles are standard variables that influence composite‘s performance against impact loads. Stacking sequence in hybrid laminates affects the failure and impact resistance. Failure mechanisms at the low-velocity impact of a rigid object in hybrid laminates are complex, and the subsurface damage in a composite laminate cannot be detected directly. However, various simulation platforms make it easy to see the impact damage between the plies of laminate. This paper numerically investigated the effect of stack sequence and hybridization of two fiber types against low-velocity impact. The current study adopted four-layer composite laminates of carbon and glass fiber layers with a stacking plan [C/C/C/C], [C/G/C/G] and [G/C/G/C], having lay-up angles as [0°/45°/−45°/90°]. Keeping the impactor mass and the incident velocity constant, the laminates were subjected to low-velocity impact. The damage contours for a failure mode were recorded and compared at the ply level. The numerical study resulted in impact imitations showing comparisons of the damage contours using Hashin failure criteria. Hybrid laminates display better performance in absorbing impact energies; however, hybrid laminates experienced more subsurface damage due to more impact energy absorption.     

Network Quality Assessment in Heterogeneous Wireless Settings: An Optimization Approach

The identification of an effective network which can efficiently meet the service requirements of the target, while maintaining ultimate performance at an increased level is significant and challenging in a fully interconnected wireless medium. The wrong selection can contribute to unwanted situations like frustrated users, slow service, traffic congestion issues, missed and/or interrupted calls, and wastefulness of precious network components. Conventional schemes estimate the handoff need and cause the network screening process by a single metric. The strategies are not effective enough because traffic characteristics, user expectations, network terminology and other essential device metrics are not taken into account. This article describes an intelligent computing technique based on Multiple-Criteria Decision-Making (MCDM) approach developed based on integrated Fuzzy AHP-TOPSIS which ensures flexible usability and maximizes the experience of end-users in miscellaneous wireless settings. In different components the handover need is assessed and the desired network is chosen. Further, fuzzy sets provide effective solutions to address decision making problems where experts counter uncertainty to make a decision. The proposed research endeavor will support designers and developers to identify, select and prioritize best attributes for ensuring flexible usability in miscellaneous wireless settings. The results of this research endeavor depict that this proposed computational procedure would be the most conversant mechanism for determining the usability and experience of end-users.     

Enhancement of the optical and mechanical properties of chitosan using Fe<Subscript>2</Subscript>O<Subscript>3</Subscript> nanoparticles

In this work, the optical and mechanical properties of Fe₂O₃ nanoparticles (NPs)/chitosan nanocomposite films have been investigated. Nanocomposite films of different weight ratios of Fe₂O₃ NPs/chitosan (0, 1, 5, 10, 20 and 30 wt%) were fabricated using casting technique. The optical properties of colloidal Fe₂O₃ NPs and Fe₂O₃ NPs/chitosan nanocomposite films were recorded using UV–visible spectrophotometer. As the ratio of Fe₂O₃ NPs to chitosan increases from 0 to 30%, the energy band gap of Fe₂O₃ NPs/chitosan films decreases from 3.16 to 2.11 eV. This decrease is due to quantum confinement effect. The mechanical properties of the nanocomposite films as a function of sweeping temperature were measured using a dynamic mechanical analyzer. An enhancement in storage modulus, stiffness and glass transition temperature (T_g) has been observed as the ratio of Fe₂O₃ NPs/chitosan increases. T_g of Fe₂O₃ NPs/chitosan nanocomposite film shifts towards higher temperature side with respect to pure chitosan film from 152.1 to 166.3?°C as the ratio of Fe₂O₃ NPs/chitosan increases from 0 to 30 wt%. The increase in T_g is mainly attributed to the decrease in free volumes and vacancies in the nanocomposite films as the weight ratio of Fe₂O₃ NPs/chitosan increases.     

Generalized fuzzy bi-ideals of semigroups

After the introduction of fuzzy sets by Zadeh, there have been a number of generalizations of this fundamental concept. The notion of (∈, ∈ ∨q)-fuzzy subgroups introduced by Bhakat is one among them. In this paper, using the relations between fuzzy points and fuzzy sets, the concept of a fuzzy bi-ideal with thresholds is introduced and some interesting properties are investigated. The acceptable nontrivial concepts obtained in this manner are the (∈, ∈ ∨q)-fuzzy bi-ideals and -fuzzy bi-ideals, which are extension of the concept of a fuzzy bi-ideal in semigroup.