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Synthesis of Ce3+ substituted Ni-Co ferrites for high frequency and memory storage devices by sol-gel route
Get PDFYesCerium (Ce3+) substituted Ni-Co ferrites with composition Ni0.3Co0.7CexFe2−xO4 (x = 0.0–0.20, with step size
0.05) were synthesized by sol-gel method. Face-centered cubic (FCC) spinel structure was revealed by X-ray
analysis. The crystalline size was calculated ranging between 17.1 and 18.8 nm, lattice constant showed a
decreasing trend with increase of Ce3+ contents, furthermore, X-ray density was calculated between 5.30
and 5.69 g/cm3. The two characteristic spinel ferrites absorption bands were seen around 550 (cm−1) and
415 (cm−1) in Fourier transform infra-red (FTIR) spectroscopy. The microstructural and elemental studies
were carried out by field emission transmission electron microscopy (FE-TEM) and energy dispersive X-ray
(EDX) respectively, the average particle size was calculated around 21.83 nm. Magnetic studies were per-
formed by vibrating sample magnetometer (VSM), which showed that saturation magnetization Ms and
remanence Mr decreased with substitution up to x = 0.10 due to small magnetic moment of Ce3+ than Fe3+.
The coercivity Hc increased with substitution up to 908.93 Oe at x = 0.05, then it decreased following the
trend of anisotropy constant. The dielectric studies exhibited decrease in dielectric parameters with fre-
quency due to decreasing polarization in material. The dielectric loss was significantly decreased in material
at high frequency. The Cole-Cole interpretation exhibited conduction mechanism being caused by grain
boundary density. These attributes of Ce3+ substituted Ni-Co ferrites suggest their possible use in memory
storage, switching and high frequency devices like antenna and satellite systems.The authors would like to acknowledge the Researcher's Supporting Project Number (RSP-2021/269) King Saud University, Riyadh, Saudi Arabia, for their support in this work
Dependability of the Internet of Things: current status and challenges
Get PDFYesThe advances in the Internet of Things (IoT) has substantially contributed to the automation of modern societies by making physical things around us more interconnected and remotely controllable over the internet. This technological progress has inevitably created an intelligent society where various mechatronic systems are becoming increasingly efficient, innovative, and convenient. Undoubtedly, the IoT paradigm will continue to impact human life by providing efficient control of the environment with minimum human intervention. However, despite the ubiquity of IoT devices in modern society, the dependability of IoT applications remains a crucial challenge. Accordingly, this paper systematically reviews the current status and challenges of IoT dependability frameworks. Based on the review, existing IoT dependability frameworks are mainly based on informal reliability models. These informal reliability models are unable to effectively evaluate the unified treatment safety faults and cyber-security threats of IoT systems. Additionally, the existing frameworks are also unable to deal with the conflicting interaction between co-located IoT devices and the dynamic features of self-adaptive, reconfigurable, and other autonomous IoT systems. To this end, this paper suggested the design of a novel model-based dependability framework for quantifying safety faults and cyber-security threats as well as interdependencies between safety and cyber-security in IoT ecosystems. Additionally, robust approaches dealing with conflicting interactions between co-located IoT systems and the dynamic behaviours of IoT systems in reconfigurable and other autonomous systems are required
Chemoselective solution- and solid-phase synthesis of disulfide-linked glycopeptides
Get PDFYesGlycosylation of peptides and proteins is a widely employed strategy to mimic important post-translational modifications or to modulate the physicochemical properties of peptides to enhance their delivery. Furthermore, glycosylation via a sulfur atom imparts increased chemical and metabolic stability to the resulting glycoconjugates. Herein, we report a simple and chemoselective procedure to prepare disulfide-linked glycopeptides. Acetate-protected glycosylsulfenyl hydrazines are shown to be highly reactive with the thiol group of cysteine residues within peptides, both in solution and as part of conventional solid-phase peptide synthesis protocols. The efficiency of this glycosylation methodology with unprotected carbohydrates is also demonstrated, which avoids the need for deprotection steps and further extends its utility, with disulfide-linked glycopeptides produced in excellent yields. Given the importance of glycosylated peptides in structural glycobiology, pharmacology, and therapeutics, the methodology outlined provides easy access to disulfide-linked glycopeptides as molecules with multiple biological applications.A.P. and G.R.M. were supported by the Institute of Cancer Therapeutics Doctoral Training Centre. K.A.F.B. was supported by a Jadara University scholarship and F.M.B. was supported by the Ghana Education Trust Fund
Mothers’ and fathers’ views on the importance of play for their children’s development: gender differences, academic activities, and the parental role
No full textYesBackground: Play is a main driver of children’s cognitive and social development and is crucial for educational success (Ginsburg, 2007). In recent years however, parents and schools are under pressure to prioritise academic targets over play. Aims: The current research investigated parents’ views about three aspects of their children’s play and academic activities. Sample: Predominantly highly educated UK parents (109 mothers and 49fathers) were recruited via social media. Method: Participants were asked to complete an amended online version of the Preschool Play and Learning Questionnaire (Parmar, Harkness, & Super, 2004). The questionnaire consisted of 25 items covering three themes: the importance of play for children’s development, the importance of academic activities, and the importance of parents’ role in their children’s development. The independent variables were the gender of the parent, the gender of their child, and the age group of their child (4 to 7 years, or 8 to 11 years). Results: Parents rated play higher than academic activities or their own roles, but the difference was not noteworthy. However, fathers rated academic activities and the parents’ role significantly higher than mothers did. In addition, parents of girls rated academic activities and their own role, significantly higher than parents of boys.
Conclusions: The findings of the current research highlight gender divisions between parents and towards boys and girls regarding the importance of education. Gender roles appear to influence the way parents think about the academic activities their children partake in
Solid state orientation of thermoplastic vulcanizates
No full textYesDie drawing has been used to produce polymeric products with superior mechanical properties by orientation of polymer chains. Although this process has been studied for a variety of thermoplastics and composites, there are no current publications exploring its efficacy to enhance thermoplastic vulcanizates (TPVs). TPVs combine the elasticity and high elongation at break of thermosets while maintaining the processability of a thermoplastic. For the first time, TPVs are die drawn and the effect upon their mechanical and thermal properties is investigated. TPVs based upon ethylene propylene diene monomer (EPDM) and polypropylene (PP) as well as ground tyre rubber (GTR) and PP are prepared by dynamic vulcanization using a twin-screw extruder. In all cases, die drawing leads to an increase in tensile strength and modulus of the material along the drawing direction, often at the cost of elongation at break. At a draw ratio of 2, EPDM/PP TPVs exceed the strength and modulus of neat polypropylene whilst maintaining an elongation at break in excess of 200%. For EPDM/PP, tensile strength increases from ≈21 MPa to over 90 MPa using a draw ratio of 4, whilst for GTR/PP this increases from ≈15 to ≈57 MPa.EPSRC and NSFC funding of this work through the Joint UK-China Low Carbon Manufacturing Grant, Grant number EP/S018573/1
The Novel Coronavirus Causes Impairment of Blood Vessels and Respiratory System with Head-to-Toe Symptoms and Vaccine Development: An Overview
Get PDFYesBlood clotting was reported in April 2020 [1] as another serious symptom due to COVID-19, but also came other reports such as young adults dying due to strokes and heart attacks [2]. The currently known head-to-toe symptoms of COVID-19, seem to indicate vascular as well as respiratory diseases and that 40% of related death are due to cardiovascular complications [2]. In a recently published journal paper in Lancet [3], the authors found that SARS-CoV-2 virus can infect the endothelial cells that line the inside of blood vessels noting that endothelial cells protect the cardiovascular system and release proteins that influence everything from blood clotting to the immune response. In the same paper, the authors showed damage to endothelial cells in the lungs, heart, kidneys, liver, and intestines in patients with Covid-19. Therefore, the emerging belief is that the novel coronavirus is a respiratory illness to begin with, but as it spreads further into blood vessels it becomes a vascular illness that is capable of killing patients via vascular system
Axial-load response of CFST stub columns with external stainless steel and recycled aggregate concrete: Testing, mechanism analysis and design
Get PDFYesRecycled aggregate concrete filled stainless steel tube (RAC-FSST) is a new type of composite member combining the advantage of stainless steel and RAC. In this paper, a total of twenty-four RAC-FSST stub columns were tested under axial load, considering the influences of coarse recycled aggregate (CRA) content, steel ratios and compressive strengths of RAC. The obtained results, including the failure patterns, responses of axial load vs. deformation, stress states of external stainless steel tube and inner RAC and confinement effects, were systematically analyzed. Results indicated that all specimens presented good ductility and high residual strengths after reaching the maximum axial load. The elastic stiffness of RAC-FSSTs obviously declined with the increasing CRA content, while the strain at the ultimate load was larger. The inclusion of CRA could advance the occurrence of the confinement and lead to lower confining stress. Based on the experimental results, an analytical model with consideration of confinement action was developed to predict the axial response of RAC-FSST stub columns. Besides, the current design provisions for the normal CFST and RAC-FST members were employed to evaluate their applicability to RAC-FSSTs. In general, the design rules EN 1994-1-1:2004, GB 50936-2014 and T/CECS 625-2019 gave a conservative and relatively accurate prediction on ultimate strength of RAC-FSST stub columns.This work was supported by the National Natural Science Foundation
Towards Autonomous Health Monitoring of Rails Using a FEA-ANN Based Approach
Get PDFYesThe current UK rail network is managed by Network Rail, which requires an investment of £5.2bn per year to cover operational costs [1]. These expenses include the maintenance and repairs of the railway rails. This paper aims to create a proof of concept for an autonomous health monitoring system of the rails using an integrated finite element analysis (FEA) and artificial neural network (ANN) approach. The FEA is used to model worn profiles of a standard rail and predict the stress field considering the material of the rail and the loading condition representing a train travelling on a straight line. The generated FEA data is used to train an ANN model which is utilised to predict the stress field of a worn rail using optically scanned data. The results showed that the stress levels in a rail predicted with the ANN model are in an agreement with the FEA predictions for a worn rail profile. These initial results indicate that the ANN can be used for the rapid prediction of stresses in worn rails and the FEA-ANN based approach has the potential to be applied to autonomous health monitoring of rails using fast scanners and validated ANN models. However, further development of this technology would be required before it could be used in the railway industry, including: real time data processing of scanned rails; improved scanning rates to enhance the inspection efficiency; development of fast computational methods for the ANN model; and training the ANN model with a large set of representative data representing application specific scenarios
Effect of solid-state shear milled natural rubber particle size on the processing and dynamic vulcanization of recycled waste into thermoplastic vulcanizate
Get PDFYesNatural rubber (NR) and crosslinked polyethylene (XLPE) waste streams were devulcanized by solid state shear milling (S3M), producing a fine powder that may be more easily reprocessed. Understanding devulcanization and the nature of decrosslinked thermoset materials is of utmost importance for turning these waste steams into functional products. It was found that the devulcanized powders contained significant concentrations of radicals, which may be active in the subsequent revulcanization process. The produced devulcanized powders were converted into recyclable thermoplastic vulcanizates (TPVs) by twin screw extrusion. Reprocessing of these powders into value-added products is an important step in recycling and the use of extrusion allows for high throughput and industrial viability. Herein, we demonstrate that the optimal conditions for reprocessing are dependent upon the particle size of the devulcanized powder. Furthermore, dynamic vulcanization is affected by the nature of these recyclate powders. The successfully prepared TPVs showed similar properties to virgin materials, with a high elongation to failure. Therefore, the conversion of waste rubber into the rubber phase of a TPV shows significant promise in moving towards sustainable products, providing the revulcanization step can be well controlled.EPSRC and NSFC for their funding of this work through the Joint UK-China Low Carbon Manufacturing Grant, Grant number EP/S018573/1
Artificial intelligence and blockchain integration in business: Trends from a bibliometric-content analysis
Get PDFYesArtificial intelligence (AI) and blockchain are the two disruptive technologies emerging from the Fourth Industrial Revolution (IR4.0) that have introduced radical shifts in the industry. The amalgamation of AI and blockchain holds tremendous potential to create new business models enabled through digitalization. Although research on the application and convergence of AI and blockchain exists, our understanding of the utility of its integration for business remains fragmented. To address this gap, this study aims to characterize the applications and benefits of integrated AI and blockchain platforms across different verticals of business. Using bibliometric analysis, this study reveals the most influential articles on the subject based on their publications, citations, and importance in the intellectual network. Using content analysis, this study sheds light on the subject’s intellectual structure, which is underpinned by four major thematic clusters focusing on supply chains, healthcare, secure transactions, and finance and accounting. The study concludes with 10 application areas in business that can benefit from these technologies