Browse Items (11855 total)
Sort by:
-
Recent developments in bandwidth improvement of dielectric resonator antennas /
International Journal of RF And Microwave Computer-Aided Engineering, Vol.29, Issue 6, pp.1-17 -
Recent developments in bandwidth improvement of dielectric resonator antennas
This article shows a compressed chronological overview of dielectric resonator antennas (DRAs) emphasizing the developments targeting to bandwidth performance characteristics in last three and half decades. The research articles available in open literature give strong information about the innovation and rapid developments of DRAs since 1980s. The sole intention of this review article is to, (a) highlight the novel researchers and to analyze their effective and innovative research carried out on DRA for the furtherance of its performance in terms of only bandwidth and bandwidth with other characteristics, (b) give a practical prediction of future of DRA as per the past and current state-of-art condition, and (c) provide a conceptual support to the antenna modelers for further innovations as well as miniaturization of the existing ones. In addition some of the significant observations made during the review can be noted as follows; (a) hybrid shape DRAs with Sierpinski and Minkowski fractal DRAs seems comfortable in obtaining wideband as well as multiband, (b) combination of multiple resonant modes (preferably lower modes) can lead to wider impedance bandwidth, (c) at proper matching wider patch with slotted dielectric resonator can exhibit better bandwidth. 2019 Wiley Periodicals, Inc. -
Recent development on self-powered and portable electrochemical sensors: 2D materials perspective
Electrochemical sensors have attracted tremendous research interest due to their simplicity and compatibility to be integrated with standard electronic technologies and capability to produce electrical signals that can be effectively acquired, processed, stored, and analyzed. Due to the incredible electronic and physical properties derived from the 2D structure, two dimensional (2D) nanomaterials such as graphene, phosphorene black phosphorus, transition metal dichalcogenides (TMDCs), and others have proven to be attractive for the fabrication of high-performance electrochemical sensors. The book chapter is focused in the unique characteristics of 2D materials leading toward excellent sensing performance, the structural and molecular designing of various 2D materials, structure-property relationships, various sensing applications employing disparate 2D nanostructures with an emphasis on highlighting various prototypical and prominent research paths. 2023 Elsevier Inc. All rights reserved. -
Recent advances of MoO3 based materials in energy catalysis: Applications in hydrogen evolution and oxygen evolution reactions
This work mainly focuses on the hydrogen evolution reaction and oxygen evolution reaction of nanostructured molybdenum trioxide-based materials for energy catalysis. MoO3 is an n-type wide bandgap semiconductor and has the ability to replace noble metal catalysts. Here we summarize the crystal structure and properties of nanostructured MoO3. The work also highlights the recent advancement in electrocatalytic hydrogen evolution reaction, photocatalytic hydrogen evolution reaction, photoelectrochemical hydrogen evolution reaction, electrocatalytic oxygen evolution reaction, and photoelectrochemical oxygen evolution reaction in MoO3 based materials. 2022 Hydrogen Energy Publications LLC -
Recent advances in the development, design and mechanism of negative electrodes for asymmetric supercapacitor applications
Continuous technical advancements in a variety of industries, such as portable electronics, transportation, green energy, are frequently hampered by the inadequacy of energy-storage technologies. Asymmetric supercapacitors can expand their operating voltage window past the thermodynamic breakdown voltage of electrolytes by utilizing two distinct electrode materials, providing a workaround for the symmetric supercapacitors energy storage constraints. This evaluation offers a thorough understanding of this area. To comprehend the extensive research done in this field, we first examine the fundamental energy-storage mechanisms and performance evaluation standards for asymmetric supercapacitors. The most recent developments in the design and manufacture of electrode materials as well as the general structure of asymmetric supercapacitors. We have also discussed a number of significant scientific issues and offer our opinions on how to improve the electrochemical properties of future asymmetric energy storage devices. First, methods for designing high-performance electrode materials for supercapacitors must be developed; next, controllably built supercapacitor types must be attained (such as symmetric capacitors including double-layer and pseudocapacitors, asymmetric capacitors, and Li-ion capacitors). This review is timely because of the rapid expansion of research in this area. It summarizes recent developments in the study and creation of high-performance electrode materials with high supercapacitors. A number of crucial topics for enhancing the energy density of supercapacitors are examined, along with some reciprocal correlations between the main impacting parameters. Difficulties and prospects in this fascinating field are also covered. This offers a fundamental understanding of supercapacitors and serves as a crucial design rule for enhanced next-generation supercapacitors that will be used in both industrial and consumer applications. In this context, we extensively reviewed the classification of supercapacitor, EDLC (activated carbon, carbon aerogel, carbon nanotube), Pseudocapacitors, conducting polymers, metal oxides, hybrid materials, composite hybrids, rechargeable batteries, asymmetric devices and its design, aqueous solid state, fiber based asymmetric device, graphene based asymmetric device, terminologies used during the electrode selection, positive and negative electrodes in asymmetric device, material used for fabrication of negative electrodes, electrochemical performance of various devices which are fabricated by different electrode materials. Performance of material for various asymmetric device applications, conclusions outlook, recent developments in asymmetric devices. The current review may offer a thorough understanding and future prospects for developing negative electrodes to enhance asymmetric supercapacitor performance. 2023 Taylor & Francis Group, LLC. -
Recent advances in polyethylene glycol as a dual-functional agent in heterocycle synthesis: Solvent and catalyst
Reactant solubility, which dictates achievable concentrations, and the stability of reaction intermediates (excited states), solvents modulate the potential energy landscape and influence reaction rates. Consequently, solvent selection is pivotal in optimizing process productivity, economic feasibility, and environmental footprint. At present, organic synthesis pivots around the idea of sustainability. In particular, PEG-400, a popular solvent and phase transfer catalyst, is considered greener as it can be reused several times without significant loss in its catalytic activity, which checks the box regarding sustainability. This review highlights the emerging potential of Polyethylene Glycol 400 (PEG-400) as a dual-threat agent in sustainable organic synthesis. We explore its efficacy as a catalyst, promoting various reactions under mild conditions and often eliminating the need for traditional metal catalysts. Additionally, PEG-400's role as a green solvent is addressed, emphasizing its biodegradability, low toxicity, and ability to facilitate reactions without hazardous Volatile Organic Compounds (VOCs). The review examines recent research on PEG-400 mediated reactions, showcasing its effectiveness in diverse transformations, thus exploring the potential of PEG 400 as a facilitator for heterocycle synthesis in both multicomponent reactions and stepwise approaches. It identifies exciting research directions that promise to expand the boundaries of polymer-based solvents in heterocyclic chemistry. 2024 The Author(s). Polymers for Advanced Technologies published by John Wiley & Sons Ltd. -
Recent Advances in Pedestrian Identification Using LiDAR and Deep Learning Methods in Autonomous Vehicles
The myriad benefits of autonomous vehicles (AVs) encompassing passenger convenience, heightened safety, fuel consumption reduction, traffic decongestion, accident mitigation, cost-efficiency and heightened dependability have underpinned their burgeoning popularity. Prior to their full-scale integration into primary road networks substantial functional impediments in AVs necessitate resolution. An indispensable feature for AVs is pedestrian detection crucial for collision avoidance. Advent of automated driving is swiftly materializing owing to consistent deployment of deep learning (DL) methodologies for obstacle identification coupled with expeditious evolution of sensor and communication technologies exemplified by LiDAR systems. This study undertakes exploration of DL-based pedestrian detection algorithms with particular focus on YOLO and R CNN for purpose of processing intricate imagery akin to LiDAR sensor outputs. Recent epochs have witnessed DL approaches emerge as potentially potent avenue for augmenting real-time obstacle recognition and avoidance capabilities of autonomous vehicles. Within this scholarly exposition we undertake exhaustive examination of latest breakthroughs in pedestrian detection leveraging synergy of LiDAR and DL systems. This discourse comprehensively catalogues most pressing unresolved issues within realm of LiDAR-DL solutions furnishing compass for prospective researchers embarking on journey to forge forthcoming generation of economically viable autonomous vehicles. The Author(s), under exclusive license to Springer Nature Switzerland AG 2024. -
Recent Advances in Nanomaterials Based Molecularly Imprinted Electrochemical Sensors
Nanotechnology and molecular imprinting both are omnipresent in the modern scientific world. Molecular recognition in the biological systems was mimicked to an extreme extent with its difficulties through molecular imprinting. Solving the problems related to this mimicking was the goal of science and technology. Some challenges like difficulties with the imprinting of protein, poor compatibility with aqueous environments, template leakage, and heterogeneous populations of binding sites in the polymers that contribute to a high level of nonspecific binding sites were addressed with recent advancement in the modern era. These issues were solved later with nano level instrumentations and inventions. Different types of nanomaterials were employed for this research on molecular recognition through MIPs to enhance selectivity, sensitivity and stability to specific systems such as sensors. This review paper attempts to give all the recent advances in molecular imprinting and the potential of nanomaterials in electrochemical sensors. 2021 Taylor & Francis Group, LLC. -
Recent advances in lightweight epoxy-based composites for X-Ray and y-Ray shielding applications
Rapidly advancing technologies in the nuclear industry have led to the increased use of X-rays and ?-rays in our day-to-day life. They have emerged to be an integral part of several industries including medical diagnostics and imaging, nuclear medicine, reactor research facilities, industrial gauging, agricultural irradiation, geological exploration and security purposes. However, considering the adverse effects of prolonged exposure to these radiations on human health, this is also a cause of concern for mankind and radiation shielding and protection have become issues of paramount importance. In the search for alternatives to conventional shielding materials such as lead, metals, glass composites, ceramics and concretes, epoxy-based composites have emerged as promising X-ray and ?-ray shields. Material properties like high mechanical and bonding strength, high temperature resistance, low electrical conductivity and thermal expansion coefficients, dielectric constant with minimal shrinking stress and lightweight structure render epoxy composites to be particularly suitable for structural applications. Epoxy composites incorporated with fillers/additives such as inorganic metal oxides, carbon fibers, clay and carbon nanotubes are an emerging class of high-performance materials. The primary focus of this article is to present a detailed review on the recent research directed towards developing epoxy-based materials for radiation shielding applications. Influence of filler loading, filler size and interfacial adhesion on microstructural, thermo-mechanical and radioprotective efficacy of epoxy composites are discussed. We present a general overview and propose new possibilities for further research in this direction. 2022 Nova Science Publishers, Inc. -
Recent Advances in Hydrogenation Reactions Using Bimetallic Nanocatalysts: A Review
Hydrogenation reactions have been studied for many decades now and have developed from reactions that appear simple to now being recognized for their many complexities. These reactions are generally catalyzed using monometallic and more recently, with bimetallic nanocatalysts. Hydrogenation plays a vital role in food, chemical, petrochemical, pharmaceuticals, and dye industries to name a few. The hydrogenated products derived from several biomass-based compounds are potential fossil fuels. Such products when employed in daily life, can help conserve natural resources. While hydrogenation of alkynes and alkenes are among the simplest of hydrogenation reactions, the most extensive and elegant manifestation of this reaction is seen in polymerization. Polymers like polythene, polypropylene (plastic) have replaced materials like glass, stainless steel, etc., in making daily use items for the obvious advantages of the former. Purification of alkenes is achieved by partially hydrogenating the respective alkynes present in trace amounts. This serves as an important step in the polymerization process. The presence of nitro group on aromatic rings makes them carcinogenic in nature which harms living organisms. For a safe environment, the elimination or modification of this nitro group becomes imperative. The products of hydrogenation of nitroaromatics and amino aromatics form the basis of pharmaceuticals and dyestuffs. A plethora of bimetallic catalysts have been used to catalyze these hydrogenation reactions. These catalysts are evaluated based on their selectivity and efficiency. This review highlights the recent advancements in the field of hydrogenation of nitro compounds, carbonyl compounds, and unsaturated hydrocarbons catalyzed by bimetallic nanoparticles. 2021 Wiley-VCH GmbH -
Recent advances in functionalization of carbon nanosurface structures for electrochemical sensing applications: tuning and turning
Carbon nanomaterial has garnered interest in the research fraternity owing to the multiple advantages which includes its earth abundance, good electronic conductivity, excellent tolerance to acidic/alkaline media, and very good biocompatibility. Because of the above-mentioned advantages, they have found their way through applications in catalysis, sensing environmental remediation, and biological application. Heteroatom doping and organo-functionalization of carbon materials greatly extends the arsenal of these materials and their potential for a spectrum of application particularly in the field of electrochemical sensing. This review focusses on the creation and development in the design of electrochemical sensors based on the usage of doped and organo-functionalized carbon materials. Emphasis is given on the distinct properties and synergistic effects resulting from functionalization and doping. We hope that this review would throw light into the minds of researchers who would like to tune and turn their work, such that it promotes further activities in this particular field of research. 2021, Islamic Azad University. -
Recent advances in electrochemical synthesis of nitriles: A sustainable approach /
ChemistrySelect, Vol.7, Issue 12, ISSN No: 2365-6549.
Nitriles unveil widespread applications in pharmaceuticals, agrochemicals, textiles, rubber, polymers, and constitute a significant intermediate in several organic transformations, necessitating the design of simple and environmentally benign pathways for their synthesis. Over the recent years, electro-organic reactions have found widespread attention in developing effective and selective organic synthesis. They possess several advantages: high atom economy, selectivity, minimal waste production, and shorter routes to multistep traditional organic reactions. The development of novel strategies for greener and sustainable electro-organic synthesis of nitriles is therefore commendable. -
Recent Advances in Electrochemical Synthesis of Nitriles: A Sustainable Approach
Nitriles unveil widespread applications in pharmaceuticals, agrochemicals, textiles, rubber, polymers, and constitute a significant intermediate in several organic transformations, necessitating the design of simple and environmentally benign pathways for their synthesis. Over the recent years, electro-organic reactions have found widespread attention in developing effective and selective organic synthesis. They possess several advantages: high atom economy, selectivity, minimal waste production, and shorter routes to multistep traditional organic reactions. The development of novel strategies for greener and sustainable electro-organic synthesis of nitriles is therefore commendable. This review focuses on analyzing various methods and strategies used in the electrochemical synthesis of nitriles using phase transfer catalyst, N-oxoammonium salts mediated electrocatalysis, iodine-mediated electrocatalysis, and anodic oxidations of aldoximes. In addition, the recent trends including the synthesis of nitriles via C?H cyanation, domino oxidation, bio electrocatalysis, and metal-ligand cooperative synthesis have been discussed. 2022 Wiley-VCH GmbH. -
Recent advances in electrochemical and optical sensing of the organophosphate chlorpyrifos: A review /
Critical Reviews in Toxicology, Vol.52, Issue 6, ISSN No: 1040-8444.
Chlorpyrifos (CP) is one of the most popular organophosphorus pesticides that is commonly used in agricultural and nonagricultural environments to combat pests. However, several concerns regarding contamination due to the unmitigated use of chlorpyrifos have come up over recent years. This has popularized research on various techniques for chlorpyrifos detection. Since conventional methods do not enable smooth detection, the recent trends of chlorpyrifos detection have shifted toward electrochemical and optical sensing techniques that offer higher sensitivity and selectivity. -
Recent advances in electrochemical and optical sensing of the organophosphate chlorpyrifos: a review
Chlorpyrifos (CP) is one of the most popular organophosphorus pesticides that is commonly used in agricultural and nonagricultural environments to combat pests. However, several concerns regarding contamination due to the unmitigated use of chlorpyrifos have come up over recent years. This has popularized research on various techniques for chlorpyrifos detection. Since conventional methods do not enable smooth detection, the recent trends of chlorpyrifos detection have shifted toward electrochemical and optical sensing techniques that offer higher sensitivity and selectivity. The objective of this review is to provide a brief overview of some of the important and innovative contributions in the field of electrochemical and optical sensing of chlorpyrifos with a primary focus on the comparative advantages and shortcomings of these techniques. This review paper will help to offer better perspectives for research in organophosphorus pesticide detection in the future. 2022 Informa UK Limited, trading as Taylor & Francis Group. -
Recent advances in carbon nanotubes-based biocatalysts and their applications
Enzymes have been incorporated into a wide variety of fields and industries as they catalyze many biochemical and chemical reactions. The immobilization of enzymes on carbon nanotubes (CNTs) for generating nano biocatalysts with high stability and reusability is gaining great attention among researchers. Functionalized CNTs act as excellent support for effective enzyme immobilization. Depending on the application, the enzymes can be tailored using the various surface functionalization techniques on the CNTs to extricate the desirable characteristics. Aiming at the preparation of efficient, stable, and recyclable nanobiocatalysts, this review provides an overview of the methods developed to immobilize the various enzymes. Various applications of carbon nanotube-based biocatalysts in water purification, bioremediation, biosensors, and biofuel cells have been comprehensively reviewed. 2021 Elsevier B.V. -
Recent advances in cancer nanotheranostics
The innovative synthetic approaches coupled with bioengineering aptitude created multiple functional materials in the nanoscale dimension aiming for a combination of therapeutic and diagnostic capacities, often referred to as nanotheranostics. The diverse role played by nanomaterials has been broadly examined in biomedicine, especially in the disciplines of imaging and drug delivery. In this view, cancer is an intimidating foe to the entire human species by adopting various survival skills. Conventional therapies remain to be a failure in meeting the anticipations of the entire medical community. Stepping to the emphasis on cancer nanotheranostics, which requires more advancement to amalgamate and fine-tune diagnosis and therapy, has already attracted significant research interest among researchers in chemistry, material science, life science, and clinicians. Monitoring the therapeutic response in a real-time manner with the intelligent fabrication of nanotheranostic agents could strike down the daunting claws of cancer by facilitating personalized treatment approaches. Here, we aimed to portrait the key approaches and recent developments in nanotheranostics with a focus on its clinical impact in oncology. 2024 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies. -
Recent advances in bimetallic based nanostructures: Synthesis and electrochemical sensing applications
Detection of biomolecules is paramount for the diagnosis of various health conditions in humans for improving the quality as well as the standard of living. Many of the existing analytical detection methods being used have one or the other drawbacks. This has led to revolutionary paradigms in research and development in the electrochemical sensing of biomolecules. Nanoparticles have enhanced surface area to volume ratio and are highly effective as sensors due to their improved electrocatalytic properties. Bimetallic nanoparticles such as platinum, nickel, iron, palladium, and gold-based nanoparticles in combination with other metals are being extensively used for electrode modification owing to their unique electrocatalytic characteristics. The synergistic effect of two metals provides us with highly sensitive electrodes. Over a while, there has been a significant increase in research carried out in this field, which encouraged us to carry out a thorough survey of the development of bimetallic nanoparticle-based electrochemical sensors for the sensing of glucose, hydrogen peroxide, ascorbic acid, dopamine, and uric acid. We have also mentioned the different types of electrode modifications for developing electrochemical sensors. This review provides readers a comparative study of the analytical parameters of the various electrochemical sensors for linear range, detection limit, and sensitivity. 2020 Elsevier B.V. -
Recent Advances in Analytical Techniques for Antidepressants Determination in Complex Biological Matrices: A Review
Depression is one of the most prevalent but severe of mental disorders, affecting thousands of individuals across the globe. Depression, in its most extreme form, may result in self-harm and an increased likelihood of suicide. Antidepressant drugs are first-line medications to treat mental disorders. Unfortunately, these medications are also prescribed for other in- and off-label conditions, such as deficit/hyperactivity disorders, attention disorders, migraine, smoking cessation, eating disorders, fibromyalgia, pain, and insomnia. This results in an increase in the use of antidepressant medications, leading to clinical and forensic overdose cases that could be either accidental or deliberate. The findings revealed that people who used antidepressants had a 33% greater chance of dying sooner than expected, compared to those who did not take the medications. Analytical techniques for precisely identifying and detecting antidepressants and their metabolic products in a variety of biological matrices are greatly needed to be developed and made available. Hence, this study attempts to discuss various analytical techniques used to identify and determine antidepressants in various biological matrices, which include urine, blood, oral fluid (saliva), and tissues, which are commonly encountered in clinical and forensic science laboratories. The Author(s) 2023. -
Recall of advertisements placed during Indian crime shows /
Brad J. Bushman conducted a study in 1998 that studied the effects of watching televised violence on memory. Bushman conducted experiments to find out if the viewers remembered the advertisements after watching violence on television. Results showed that violence had a negative effect on recall of the brand and the advertisement message. The present research sought to study the effect of violence in Indian crime shows on the recall of the brand, the product category and the tag lines used in the advertisements.