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The effect of using citrate-gel auto combustion method to substitute erbium rare-earth ion on magnetism cadmium composition of chemicals formula Cd0.2Mg0.8ErxFe2-xO4 (CMEF) (x = 0.000, 0.005, 0.010, 0.015, 0.020, and 0.025). Synthesized powder were sintered for 4 h at 600 °C after the crushed powders were calcined. These CMEF nanoferrites' structural and magnetic properties were investigated using P-XRD, E-DAX, FE-SEM, HR-TEM, FT-IR, and VSM investigations. Analysis has been done on the benefits of the crystallite size, phase, and various structural features of CMEF using P-XRD data. The assessed crystalline size is within the range of 20.43 nm and 24.30 nm, while the lattice constant ranges from 8.34 to 8.37 Å. photos obtained with the HR-TEM showed that the Er3+ doped Mg-Cd nanoferrites had particle sizes between 10.5 and 20.7 nm, while the FE-SEM photos showed grain sizes between 19.3 nm and 40.3 nm. With the help of elemental analysis (%) from EDAX, and the CMEF of elements that comprise the given chemical composition were thoroughly analysed without interfering substances. The spinel structure was confirmed by the presence of two stretching bonds between metal nitrates and function groups, as shown by the FT-IR spectra that were obeyed. VSM generates the characteristic hysteresis loops of the synthesised sample at 300 K temperature in the magnetic experiments. The findings showed that at 300 K, all of the MCEF nanoferrites exhibited ferromagnetic behaviour. Substantial magnetization was reached at 300 K for 20–18.48 emu/g). The Hc values were determined to lie between 107.46 and 129.53 Oe, while the squareness or remanent ratio values at 300 K varied. [ABSTRACT FROM AUTHOR]

Thermal energy and its storage systems play an extensive role in day-to-day life. They store renewable energy and are capable of recovering generated heat from different systems. Storage of thermal energy can be classified into three types: sensible, latent and sorption heat storages. Thermal heat storages use different types of materials based on their capacity of heat storage, stability of duration and thermal conductivity. Various phase change materials (PCMs) that are suitable for thermal storage are reported. Low conversion ability limits their effectiveness. We reviewed some of the traditional materials synthesized recently that are used for thermal energy storage (TES). Recently developed TES materials exhibit high thermal conductivity, reduced super cooling and multiple phase change temperatures. Nano-enhanced PCMs produced an increase in thermal conductivity up to 32% with a reduction in latent heat by 32%. At this juncture, MXenes with high performance and extraordinary properties (thermal, mechanical, etc.) are of special significance. MXenes displayed an increased thermal conductivity up to 16% and 94% efficiency. In view of their structure and adaptability to be used in thermal storage systems, an attempt was made to review their role also in thermal storage applications. It is observed that MXenes highly impact storage and efficiency. Apart from MXenes, various types of PCMs along with their thermal characteristics are presented. [ABSTRACT FROM AUTHOR]

In the present work, we have synthesized rare-earth ion modified Bi4−xRExTi2Fe0.7Co0.3O12−δ (RE = Dy, Sm, La) multiferroic compounds by the conventional solid-state route. Analysis of X-ray diffraction by Rietveld refinement confirmed the formation of a polycrystalline orthorhombic phase. The morphological features revealed a non-uniform, randomly oriented, plate-like grain structure. The peaks evident in the Raman spectra closely corresponded to those of orthorhombic Aurivillius phases. Dielectric studies and impedance measurements were carried out. Asymmetric complex impedance spectra suggested the relaxation of charge carriers belonging to the non-Debye type and controlled by a thermally activated process. Temperature-dependent AC conductivity data showed a change of slope in the vicinity of the phase transition temperature of both magnetic and electrical coupling natures. Based on the universal law and its exponent nature, one can suppose that the conduction process is governed by a small polaron hopping mechanism but significant distortion of TiO6 octahedral. The doping of the A-sites with rare-earth element ions and changes in the concentrations of Fe and Co ions located on the B-sites manifested themselves in saturated magnetic hysteresis loops, indicating competitive interactions between ferroelectric and canted antiferromagnetic spins. The magnetic order in the samples is attributed to pair-wise interactions between adjacent Fe3+–O–Fe3+, Co2+/3+–O–Co3+/2+, and Co2+/3+–O–Fe3+ ions or Dzyaloshinskii–Moriya interactions among magnetic ions in the adjacent sub-lattices. As a result, enhanced magnetoelectric coefficients of 42.4 mV/cm-Oe, 30.3 mV/cm-Oe, and 21.6 mV/cm-Oe for Bi4−xDyxTi2Fe0.7Co0.3O12−δ (DBTFC), Bi4−xLaxTi2Fe0.7Co0.3O12−δ (LBTFC), and Bi4−xSmxTi2Fe0.7Co0.3O12−δ (SBTFC), respectively, have been obtained at lower magnetic fields (<3 kOe). The strong coupling of the Aurivillius compounds observed in this study is beneficial to future multiferroic applications. [ABSTRACT FROM AUTHOR]

Energy storage and energy-storage devices have been a buzzword for long time as it is one of the essential needs in human life. These devices include mechanical systems, thermal systems, and batteries. These systems embedded with software can monitor the charging and discharging phenomena of energy. In this context, the role of rechargeable batteries needs to be reviewed. Even though novel types of rechargeable batteries are being continuously developed for storage of electricity, more attention and research towards supercapacitors is on the way. Huge number of researchers around the globe is involved in developing supercapacitors with improved performance making them more and more useful. The main aim is to improve their efficiency, energy density, operating voltage, miniaturization, optimization, economy, and environmental acceptance. For the last few years, lightweight and carbon-based novel wearable supercapacitors are developed. High durability, eco-friendliness, being non-volatile and electrostatic mechanism of supercapacitors make them advantageous than conventional batteries. In this regard, advances in microelectronics demand microsupercapacitors (MSCs). The selection of electrode in microsupercapacitor plays significant role in the fabrication. In this selection, MXenes as a family of 2D material play a vital role. Very high conductivity and high capacity of charge storage makes MXenes as one of the potential materials for electrodes in microsupercapacitors. This prompts us to review the role of MXenes in microsupercapacitors. This article reviews the recent advances of MXenes-based MSCs with emphasis on their fabrication techniques. [ABSTRACT FROM AUTHOR]

Liquid detection has been one of the buzzwords that refer to sensing of various liquids, which include water, chemicals, oils, etc. This detection gains more significance with the advent of metamaterials. Metamaterials are proved well suited in antenna designing, cloaking devices, solar cells, and sensors. Many papers reported metamaterial sensors, which can detect liquid chemicals, oils, etc. through shift in resonance frequency. Very few papers reported the applications of metamaterial sensors in water treatment. Water purification is one of the prime essentials for the existence of healthy humankind. It can be used to remove unwanted chemicals, contaminants and gases from water. The process of water purification can be done with various methods such as thermal, adsorption, distillation, desalination, reverse osmosis, etc. The main aim is to produce water required for specific purpose. In this context, role of metamaterials in water purification is of prime significance. Keeping this in view, an attempt is made to review the importance of metamaterial sensors in liquid detection along with water purification and its importance in comparison with earlier techniques already available. [ABSTRACT FROM AUTHOR]

MXenes are a class of 2D material produced from the MAX phase structure, e.g., 3D atomic laminate Ti3AlC2 ; they have a combination of layered carbides and nitrides. They belong to a distinctive type of structured materials with better conductivity than metals, increased ionic conductivity, flexible mechanical properties, and being hydrophilic. MXenes can be structured to form nanoparticles, multi- and single-layered nanosheets, which exhibit large specific surface areas enhancing their efficiency of sensing in MXene sensors. In addition, they are capable of forming composites with other materials with ease. Their morphology enhances their mechanical flexibility and stretchability enabling them to have wide applications in energy-storage devices, wearable sensors, and for electromagnetic shielding. Considering this, an attempt is made to review the recent advances in MXenes with emphasis on their applications in the area of wearable sensors that include pressure, strain, biochemical, temperature and gas sensing. [ABSTRACT FROM AUTHOR]

A field experiment was conducted at Regional Agricultural Research Station, Lam, Guntur, Andhra Pradesh during kharif, 2018 to evaluate the bio-efficacy of certain insecticides against Pectinophora gossypiella. The treatments under study were emamectin benzoate, flubendiamide, chlorantraniliprole, chlorantraniliprole + lambda cyhalothrin, deltamethrin, NSKE 5%, profenophos and cypermethrin along with one untreated control. Three sprays were given at 10 days interval and the data on larval population was collected at three, seven and ten days after spraying. The results of three sprays revealed that chlorantraniliprole + lambda cyhalothrin was effective in the control of P. gossypiella, which recorded 78.54, 85.24 and 94.36 per cent reduction larval population for 20 bolls over control at first, second and third sprays respectively followed by cypermethrin with per cent reduction of 74.03, 83.52 and 90.87 over control at first, second and third sprays respectively. Chlorantraniliprole + lambda cyhalothrin recorded highest number of good opened bolls per plant and seed cotton yield of 42.33 and 3786 kg ha-1, respectively followed by cypermethrin 25 EC (40.93 and 3662 kg ha-1) when compared to untreated control (22.40 and 2304 kg ha-1). [ABSTRACT FROM AUTHOR]

Some of the insect pests developed resistance to conventional insecticides like organochlorine, organophosphate, and carbamates. Synthetic pyrethroids and some of the molecules were restricted to use which has an undesirable effect on beneficial organisms, natural enemies and mammals, which lead to the development of novel insecticides with a unique mode of action like Chordotonal organ TRPV channel modulators nerve action GABA gated chloride channel allosteric modulators, Nicotinic acetylcholine receptor (nAchR) competitive modulators; Insect growth regulator with contact activity; Nicotinic acetylcholine receptor allosteric modulator site I; Nicotinic acetylcholine receptor allosteric modulator site II; Ryanodine receptor modulators; Inhibitors of acetyl CoA carboxylase; calcium-activated potassium channel modulator; Voltage-dependent sodium channel blockers; Chordotonal organ TRPV channel modulators – undefined target site; Inhibitors of mitochondrial ATP synthase and Mitochondrial complex III electron transport inhibitors-Qi site. Pest management now requires knowledge for agricultural production among the farmers in an economically successful manner. The major approach is to manage the insecticide resistance in insect pests by following an integrated control strategy, alternation of insecticides with a unique mode of action, application of insecticides at the correct time with the recommended dosage and targeting vulnerable stages of insect pests. [ABSTRACT FROM AUTHOR]

Anthropogenic activity in terms of urbanization, industrialization, and modern agricultural techniques challenges the natural environment in terms of compromise in air pollution and water quality, which lead to hazardous health impacts on human beings. In this context, it is very essential to monitor the air and water quality to a maximum possible extent with maximum accuracy, which is of utmost significance. A significant effect on human health due to pollutants makes their detection in water and air essential. Even though various techniques of monitoring these pollutants are available, proven advantages of electrochemical techniques attract more attention. Because of this, an attempt is made to review some of the latest advances in electrochemical sensing of environmental contaminants, which include heavy-metal ions and pesticides. Electrochemical sensing has been done by using sensors designed with various materials. However, sensors designed with carbon and its allotropes such as carbon nanotubes, graphene derivatives, carbon nanodots, active carbon, screenprinted carbon electrode, and others are reviewed. Even though these sensors are capable of being used in medical analysis, food safety, soil quality, drug detection, etc., the review paper highlights only applications related to environmental monitoring. This review is mainly meant to come up with an understanding of the present-day progress in electrochemical applications based on carbon and its allied materials towards environmental pollutants. This review highlights some of the synthesis techniques of graphene (an allotrope of carbon) and sensor designing along with their performance. This review has established the compatibility in the published literature that graphene and related materials play a significant role in electrochemical sensing of pollutants. [ABSTRACT FROM AUTHOR]

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Magnetic properties and structural analysis of Nd(Neodymium) doped Ni0.65Zn0.35Fe2O4 using XRD, Rietveld Analysis, FTIR Spectroscopy and VSM are reported. Confirmation of secondary phase formation with increased Nd content is established. Cation distribution for neodymium substituted nickel-zinc ferritesis proposed by considering the deficiency of Fe3+ in NiZnFe2O4 due to secondary phase formation of NdFeO3. The quality of present cation distribution was confirmed through close agreement of experimentally calculated lattice constant and Rietveld refinement. Changes in saturation magnetization with increased Nd content are explained on the basis of intensifying effect on energy exchange (inter-sublattice) between Ni-O-Nd and Ni-O-Fe concnerning Fe-O-Fe interaction, effect of replacing lower magnetic moment Nd3+ (3.62 μB) in place of Fe3+ (5 μB) and exchange developed between the cations existing at B-sites due to creation of oxygen vacancies. [ABSTRACT FROM AUTHOR]

Back electromotive force (EMF)-based sensorless vector control of permanent magnet synchronous motor (PMSM) drives provides a simple, robust, and low-cost solution for applications requiring only medium- and high-speed control. However, during the low-speed operation, back EMF is nearly zero, and hence, for starting and speed ramp-up, open-loop I−ƒ control is used. Once the motor attains a sufficient speed, the control is transferred to sensorless vector control. However, an arbitrary choice of the slope of frequency ramp leads to pole slipping. Pole slipping is usually prevented by fixing the frequency ramp slope to a minimum value, which deteriorates the dynamic performance during starting. In this article, a torque controller is proposed to dynamically vary the frequency slope depending on the moment of inertia and load torque present in the system, achieving fast and reliable starting. A reference frequency modulation algorithm for overcoming the inherent mid-frequency instability of the open-loop control is also included. An additional slope attenuator is proposed to minimize the torque oscillations caused by the reference frequency modulation during the transition from a ramp-up interval to a constant-speed interval with I−ƒ control. The proposed methods are experimentally verified on a 25-kW PMSM drive, which is started using open-loop I−ƒ control. [ABSTRACT FROM AUTHOR]