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In this methodology, the thiourea (TU) sensor was made-up by means of glassy carbon electrode (GCE) layered by the wet-chemically prepared binary SnO 2 /V 2 O 5 nanomaterials (NMs). The existence of SnO 2 and V 2 O 5 in prepared spherical NPs were categorized by X-ray photoelectron spectroscopy (XPS), Field Emission Scanning Electron Microscopy (FESEM), Energy-dispersive X-ray spectroscopy and X-ray Powder Diffraction (XRD). The TU sensor was displayed the linear responses in concentration range (LDR) of 0.1 nM ~ 0.01 mM. The calibration curve of TU sensor was made by plotting current verses concentration of TU, which was measured by electrochemical technique. The sensitivity and lower limit of detection (DL) for TU sensor were calculated from calibration curve, which are found as 17.0918 µAµM-1cm−2 and 95.40 ± 4.77 pM respectively. The analytical parameters of TU sensor such as reproducibility, response time and stability were measured and found efficient results. It also was validated in the detection of TU in presence of real bio-samples. Thus, this unique and prospective method is introduced to develop the selective biosensor by electrochemical approach, which might be a pioneer sensor probe for its simple and reliable approach for the safety of healthcare and biomedical fields in a large scales. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Fe/PVA/Chitosan and α-Fe 2 O 3 /PVA/Chitosan nanocomposites fabricated successfully. • At any concentration of nanoparticles, α-Fe 2 O 3 /PVA/Chitosan nanocomposite films showed best mechanical properties. • Fabricated novel nanocomposite may potentially be useful in various biomedical applications. Abstract Incorporation of nanoparticles into polymer matrix allows the development of new features that differs from the pure materials. In this research, magnetic nanoparticles reinforced organic biodegradable polymer matrix based biocompatible nanocomposite films were fabricated. This work covered, synthesis of Iron (Fe) and Iron oxide (α-Fe 2 O 3 ) nanoparticles by chemical reduction and sol-gel method respectively, fabrication of Fe/Polyvinyl alcohol (PVA)/Chitosan and α-Fe 2 O 3 /PVA/Chitosan nanocomposites by solvent casting method, and evaluation and comparison of their mechanical properties to find the superior biocompatible nanocomposite. The X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDX) analysis confirmed the size, structure, morphology and formation of Fe and α-Fe 2 O 3 nanoparticles. Magnetic study showed that, synthesized α-Fe 2 O 3 nanoparticle possess better magnetic properties than the Fe nanoparticle. The Fourier-transform infrared spectroscopy (FTIR) spectra confirmed the successful interaction of Fe and α-Fe 2 O 3 nanoparticles with the polymer matrix. The Iron oxide dispersed (16.67 wt%) nanocomposite α-Fe 2 O 3 /PVA/Chitosan showed highest tensile strength and elastic modulus that is respectively 45% and 40% higher than the PVA polymer alone. This novel nanocomposite may potentially be useful in various biomedical applications. [ABSTRACT FROM AUTHOR]

In this study, total concentrations of 16 trace elements (Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Sb, Hg, Pb, Th and U) in sediments of the rivers of the Sundarban mangrove forest, after the catastrophic oil spill accident in the Sela river of Sundarban, were determined. The overall mean concentrations of V, Cr, Fe and Cd in surface sediments of the Sundarban are remarkably higher than available literature data of those elements. Trace element contamination assessment, using different environmental contamination indices, reveals that As, Sb, Th and U are low to moderately contaminated while Cd is moderately to severely contaminated in the sediments of this area. The multivariate statistical analyses were applied to reveal the origin and behavior of the elements during their transport in the mangrove ecosystem. High Cr, Ni, Cu and As concentrations suggest the risk of potentially adverse biological effects in the ecosystem. [ABSTRACT FROM AUTHOR]

• Sm 2 O 3 based lead borate glasses were prepared. • The transparency and visibility were found similar to commercial window. • The HVL values found better than, red brick, concrete, commercial and X-ray windows. • All the shielding parameters varied with Sm3+ concentration. • These glasses can be a promising candidate for diagnostic X-ray shielding material. The impact of varying Sm 2 O 3 content on radiation shielding properties of 15PbF 2 : (65-x) B 2 O 3 : 20K 2 O:xSm 2 O 3 (where 0 ≤ x ≤ 1.5 mol %) glass samples, was investigated by studying their physical, radio-luminescence and X-ray-shielding characteristics. The density of glasses increased with an increase in Sm 2 O 3 contents. Evaluating the X-ray shielding parameters like mass and linear attenuation coefficients, half- and tenth- value layer, lead equivalent thickness and mean free path, it was found that the linear and mass attenuation coefficients decrease with a rise in Sm3+ concentration in the 70–120-kVp-energy range. The half- and tenth-value layers of the developed glasses increase with increasing energy and vary randomly with changing Sm 2 O 3 contents. Comparing the determined HVL data with that of the concrete, red brick, commercial window, and X-ray window at 120 keV, it is found that the developed glass performs better shielding. The obtained results revealed that this glass has excellent potential and could be used as a radiation-shielding material in various applications. [ABSTRACT FROM AUTHOR]

Copper oxide thin films are being considered in thin film solar cells for its unique photovoltaic properties. Electrodeposition is one of the cheapest processes to deposit copper oxide thin films. In this study, copper oxide was electrodeposited on the copper substrate and gold plated glass substrate in an electrolyte bath containing 0.2 M CuSO 4 .5H 2 O, 3 M lactic acid and NaOH. A Potentiostat/Galvanostat with silver chloride electrode (Ag/AgCl) as a reference electrode was used for elctrodeposition. During deposition, the bath temperature and pH were maintained 60 0 C and 12-12.5 respectively. Copper oxide was deposited at different potentials and deposition time. The films deposited at different electrodeposition conditions were characterized by Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDS). The optical band gap was determined from the films deposited on gold plated glass substrate using Ultraviolet-Visible Spectroscopy. From visual inspection it was found that copper oxide film was black and adherent on copper substrate. In gold coated glass substrate copper oxide film was also black but bonding between the substrate and copper oxide film was not good. The SEM study reveal that the films become more compact and grain sizes of copper oxide films decreases at more negative potentials in deposition potential range. EDS analysis shows that percentage of oxygen in the copper oxide films increases with more negative potentials at the deposition potential range. It was found that with increase of time more adherent and uniform film thickness occurs. The variation of the thickness of copper oxide films with different deposition parameters was analyzed. [ABSTRACT FROM AUTHOR]

Wood saw dust is being considerably used in reinforcing polymer both from a scientific and a commercial point of view over the last decades. In this study, three different types of wood saw dusts were treated with 10% NaOH solution separately. Both chemically treated and untreated wood saw dust particles reinforced polymer matrix composites were prepared and their tensile strengths and water absorption behaviour were studied. In order to know the water absorption behaviour, both chemically treated and untreated wood saw dust reinforced polymer matrix composites were weathered in water at ambient temperature for different time periods. Experimental results showed that the tensile strength of the composites substantially increases due to chemical treatment of the wood particles. After calculation of water uptake, plot of percentage of water absorption versus weathering period was obtained. It has been revealed that chemical treatment of the reinforcing wood particles increases the water absorption of the composites. Results also indicated that water absorption of the composites increases with increasing percentage of wood particles and weathering period. SEM micrograph of the composites exhibited large cavity and air bubble on the tensile fracture surfaces of the composites. The underlying reasons related to the experimentally observed tensile and water absorption behaviour of the developed composites have been discussed in this paper. [ABSTRACT FROM AUTHOR]

Wood dust reinforcing polymer matrix composites has been one of the epoch-making and pioneering study both from scientific and economical eye over the last decades, due to the eco-friendliness and aesthetical properties. Wood dust is suitable and beguiling filler for thermoset polymers due to its cost effectiveness, low density and high specific properties. It is biodegradable and nonabrasive during processing. The research was proceeded with the objective of evaluating the effect of different types of wood saw dust on the properties of composite materials. In this experiment, thermal behaviours of composites reinforced with wood dust particles of various woods (three types of woods) were investigated. Size was a viable parameter to control the properties of developed composites. As a result two different particle sizes as medium and coarse sized wood particles were used to develop the composites and characterize their thermal conductivities. The results of the experiment thus observed were quite interesting. Pure polyester has been found to have lower thermal conductivity compared to that of any wood reinforced polyester and that wood strength or true density has been found to influence the thermal conductivity of the as-received polymer. With increase in the dust particle content, thermal conductivities of all composites have been found to increase. [ABSTRACT FROM AUTHOR]

Abstract: Nowadays, polyethylene (PE) and polypropylene (PP) based plastic materials are being extensively used for commercial and household purposes. However, these polymer based plastics are substantially resistant to biodegradation. Thus their increasing accumulation in the environment is proving to be an ecological threat to the world. Consequently, over the last couple of decades exhaustive studies on the biodegradation of plastics have been carried out in order to overcome the environmental problems associated with synthetic plastic waste. In this research, the improvement in the biodegradability of PP was observed by blending it with small additions (5%) of wood sawdust and wheat flour. The developed composites were then exposed to various environmental conditions namely; exposure to the open atmosphere, moist soil, water and brine solution for a period of 15 weeks. After exposure, the composites were visually inspected to find signs of crazing and discoloration that indicated the onset of biodegradation. The extent of the biodegradability of the composites was also observed by change in bonding nature by FTIR spectroscopy. In addition, the change in tensile properties of the composites after exposure was measured by tensile tests. The experimental results revealed that addition of both sawdust and wheat flour considerably improved the biodegradability of PP. The most pronounced biodegradation was exhibited by sam les exposed to brine solution and those buried under moist soil. [Copyright &y& Elsevier]

Abstract: Air process heater is one of the crucial equipment for many industries. Process heater is used in Baking, Drying, Laminating, Metal Working, Packaging, Plastic Welding, Preheating, Sealing, Soldering, Shrink Fitting, Synthetic Fabric Sewing and in other industries. But heating of air to a very high heat flux is sometimes impossible without the degradation of air quality, because many industries use combustion of gases for the purpose of heating the air to a very high heat flux. Electric heater can be alternative heating equipment, but it requires costly and long heating apparatus for the desired air temperature. In the present study, heat transfer enhancement in an air process heater was investigated both numerically and experimentally. A circular duct with 5 semi-circular hollow baffles and 4 cartridge electric heaters was designed for the process heating. Air was supplied from a wind tunnel at 3.17×104 Reynolds number. Total supplied electric power was 3kW. The results showed the temperature ratio (Ambient Temperature/Air Temperature) to be decreased up to 0.72 where in many electric air heaters the temperature ratio is about 0.9. The designed air process heater supplies air at velocity 19 m/s and temperature up to 147°C. The experimental results were also matched with the numerical simulation values of the designed heater. The results were also compared with some of the existing air process heater for investigating the enhancement of heat transfer. [Copyright &y& Elsevier]

Abstract: The present study focuses on the thermal response of a skin simulant material with a protective fabric (Kevlar 49) under a flame blast condition. This investigation has been conducted using a stream of hot air jet that has been impinged normally on the test surface with/without protective fabric to mimic the flame burst condition. The air jet temperature is 125°C and the jet velocity is 15 m/s and 19 m/s. The temperatures at various radial positions of the solid are measured using thermocouples and are used to calculate the surface heat flux to the skin simulant material. Subsequently, the local heat transfer coefficient and the local Nusselt Number for different radial positions of the base plate have been estimated, illustrated and analyzed for different longitudinal distance between nozzle and the test setup. The experimental results are then compared with Stoll Second Degree Burn Criterion of the ASTM Standard (F1060-01). The results show a significant reduction in heat transfer rate and exhibit an adequate protection due to the use of the protective fabric. [Copyright &y& Elsevier]

Abstract: ZnxCd1-xS thin films at low zinc content have been deposited on bare soda lime glass substrates using RF magnetron co-sputtering of CdS and ZnS for the first time to investigate annealing effect on the structural and optical properties of the thin films. The as-deposited films were annealed in O2/N2 ambient at annealing temperature ranging 200-500°C. The composition of the films was controlled by varying RF power of CdS and ZnS in such a ratio so that zinc content in the thin films was low. The composition, structural, optical and surface morphological properties of the films was investigated using EDX, XRD, UV-Vis spectrophotometer and FESEM. The annealed films were observed hexagonal wurtzite structure with strong preferential orientation along (002) diffraction peak. Crystallinity of the films increased with increasing annealing temperature below 400°C whereas beyond 400°C new peaks were observed along with decreasing trend of (002) diffraction peak. Optical absorption and transmission spectra were recorded within the range 300-900nm. With increasing annealing temperature, the band gap of the annealed films once decreased and then abruptly increased at around 400°C. The decreased bandgap may have been due to possible increase in the crystalline nature of the material. From SEM, it was observed that the thin films were formed by different clusters of grains which later changed to isolated grains as the annealing temperature increased. This work confirms that annealing temperature has overbearing influence on the ZnxCd1-xS thin film properties deposited by RF magnetron co-sputtering. [Copyright &y& Elsevier]

Abstract: CdS thin films were deposited by three different processes; close spaced vapour transport (CSVT), chemical bath deposition (CBD), and sputtering technique on ITO coated glasses and their structural and optical properties were investigated through XRD, SEM, EDX and UV-Vis spectrometry, respectively. The as-grown films are annealed at 400°C and 500°C for 30 min in air and the change in structural properties with the thermal stress were also investigated. The crystallite grain size, lattice constant, microstrain and dislocation densities of the films are quite different in these processes as observed from XRD analysis. The highest crystallinity is observed for sputtered CdS thin films. However, the crystalline property of CBD and sputtered CdS increases with the thermal annealing, while CSVT-CdS loses its crystalline form. No significant grain changes are observed for thermally annealed CdS thin films but some cracked lines are observed in CBD and CSVT CdS thin films from SEM images. The absorbance in the visible wavelength decreased for annealed CdS thin films, which might be due to fact that films are becoming denser followed by thermal annealing. Significant blue shifts observed for thermally annealed CdS thin films have been found from all processes. The band gap found for as-grown CSVT-CdS is 2.44 eV, for CBD-CdS is 2.38 eV and for sputtered-CdS is 2.42 eV. The disorder of phonon states in the films are observed from Urbach's tail. The absorption edges due to the exciton–phonon interaction or electron-phonon interaction are also observed from the values of steepness parameter. [Copyright &y& Elsevier]

Bangladesh is encountering difficulties in supplying energy to maintain its economic growth. The gap between demand and supply is gradually increasing. Although it has some reserves of commercial energy resources (e.g., natural gas and coal), because of economic and technical constraints it is unable to supply sufficient energy. The dependence on imported fuel (oil and coal) is gradually increasing, and the rural population, which uses a fair amount of imported fuel (kerosene and diesel), is largely disadvantaged because of its low purchasing power. Most of the commercial energy used is derived from natural gas and imported oil, while the main consumers are power generation, transport and industry. The major share of the total energy consumption in Bangladesh is from biomass fuels comprising agricultural wastes, animal wastes and fuelwood. The biomass is mainly used in the rural households. Because of shortage of land there are limited prospects of increasing the supply from biomass sources. The emphasis is usually on commercial energy, which plays a decisive role in such aspects of development as industrialization, agricultural mechanization and urbanization. Efficiency of energy production and its utilization in Bangladesh is generally poor. The demand for energy exceeds the available resources and this gap is projected to increase significantly in the near future. There are significant opportunities for increasing energy efficiency and conservation by end-users in all sectors - domestic, industrial, commercial, transport and agriculture. The extent of energy conservation initiatives in the country has been limited. The Energy Monitoring and Conservation Centre of the government has almost no regulation-enforcing authority, and the National Energy Conservation Act is still under consideration by the legislators. Significant and concerted attempts to increase energy efficiency and conservation measures in the various sectors have not been widely applied in the country. Efforts have been made to increase energy efficiency and implement conservation measures in some industries such as sugar mills, spinning mills and fertilizer factories, and also in the rural domestic sector by the expansion of the use of improved cookers. The use of energy-efficient lighting and power-consuming devices can play a role in controlling the increasing demand. Among potential renewable resources solar and biomass have good prospects. Hydropower has already been utilized to a significant extent while the potential of wind energy is limited to coastal zones. In actual practice only a small number of solar photovoltaic devices are currently being used. In the existing scenario energy efficiency and renewable energy can play a more significant role in the energy sector of Bangladesh. This will require a proper and supportive government policy. Action plans to enhance commercialization of energy efficiency and renewable energy technologies have been suggested. [Copyright &y& Elsevier]

• Pr 0.55 Ca x Sr 0.45-x MnO 3 (x = 0.00, 0.05, 0.1, 0.2, 0.25.) have been prepared by the conventional solid-state reaction technique. • Orthorhombic structure with space group Pnma of all the samples are confirmed. • The lattice parameters, cell volume and Mn-O-Mn bond angle decreases. • Curie temperature decreases from 290 K to 240 K. • The Arrott plots of the samples reveal second-order FM-PM phase transitions of all the samples. • The mean field model explains the existence of long range ferromagnetic interactions in the studied samples. The polycrystalline manganite Pr 0.55 Ca x Sr 0.45-x MnO 3 (x = 0.00, 0.05, 0.1, and 0.2) has been prepared by the solid state reaction technique to investigate its crystal structure, magnetic, and magnetocaloric properties. Critical behaviour around PM-FM phase transition has also been analyzed through various methods including modified Arrott plots (MAP), and critical isotherm analysis of Pr 0.55 Ca x Sr 0.45-x MnO 3 (x = 0.00, 0.05, 0.1, and 0.2). XRD analysis reveals that all the samples are found to be crystallized in the orthorhombic system with Pnma space group and lattice parameters a, b and c as well as the cell volume are found to decrease with increasing Ca (x) content. Microstructure is observed with the field emission scanning electron microscopy (FESEM) photograph and elemental compositions are determined by energy dispersive X-ray diffractometer (EDX). Temperature and field dependent magnetization measurement disclose that all the samples undergo second-order FM to PM phase transition but the Curie temperature (T C) value decreases from 290 K to 245 K with the increase in Ca (x) content from 0.00 to 0.20. The magnetocaloric effect (MCE) in terms of maximum entropy change, (-ΔS m) max and relative cooling power (RCP) was calculated from isothermal magnetization measurements around T C , using Maxwell's thermodynamic relations. Both (−ΔS m) max and RCP increases with increasing Ca content suggests the suitability of this compound as a potential solid state refrigerent. Contribution of itinerant electron in the entropy change is found from modulating MCE with Landau theory of phase transition. [ABSTRACT FROM AUTHOR]

• Structural and magnetic properties of La 0.55 Ca x Sr 0.45−x MnO 3 (x = 0.0, 0.1, 0.2) have been investigated to find the effect of calcium doping on the D.C. and A.C. magnetic properties. • Rhombohedral structure with space group R-3c for all the samples is confirmed. • All the samples undergo paramagnetic (PM) to ferromagnetic (FM) phase transition but the FM state coexists with the residual canted anti-ferromagnetic state rather than a pure FM state. • The saturation magnetization and T C values depends on Ca(x) content of the samples. • The values of A.C. permeability (μʹ) also depend on Ca(x) content as well as grain size. However, μʹ values of the samples remain almost constant over a wide range of frequency which indicates the compositional stability of the perovskites. • The magnetic modulus demonstrates the dynamics of their A.C. permeability by screening out the stray/any other effects in them. The Nyquist plots of magnetic modulus of the samples show the type of their magnetic relaxation. Conventional solid-state reaction technique was used to prepare the studied samples La 0.55 Ca x Sr 0.45−x MnO 3 (x = 0.0, 0.1, 0.2). Their structural and magnetic properties have been investigated to find the effect of calcium doping on the D.C. and A.C. magnetic properties of the compounds. Room temperature XRD investigations confirm rhombohedral structure with space group R-3c for all the samples. Lattice parameter is found to decrease with increase in Ca(x) content. Microstructure was examined from the images taken by Scanning Electron Microscopy (SEM) and chemical compositions were determined by an energy dispersive X-ray diffractometer (EDX). The zero-field cooled (ZFC) and field cooled (FC) DC magnetization measurements reveal paramagnetic (PM) to ferromagnetic (FM) transition in them upon cooling through their Curie temperature (T C). But the FM state coexists with the residual canted anti-ferromagnetic state rather than a pure FM state in the samples. The T C values are dependent on Ca(x) content of the samples. Moreover, XRD analysis and EDX data reveals the presence of Mn deficiency in the studied samples. Presence of minor secondary Mn 3 O 4 phase creates this deficiency resulting a significant decrease in T C and strongly influences the magnetic properties. The values of A.C. permeability (μʹ) also depend on Ca(x) content as well as grain size that can be explained by Globus equation. However, μʹ values of the samples remain almost constant over a wide range of frequency which indicates the compositional stability of the perovskites. The magnetic modulus demonstrates the dynamics of their A.C. permeability by screening out the stray/any other effects in them. The Nyquist plots of magnetic modulus of the samples show the type of their magnetic relaxation. [ABSTRACT FROM AUTHOR]

• The eddy-current loss as heat radiation becomes selectable over the conductive frequency bands. • The Joule's heat and Joule's heat per unit time have been calculated corresponding to the eddy-current loss. This paper reports on the experimental findings of ac conductivity as determined from the measurement of conductance by using the Waynekerr 6500B impedance analyzer for the stoichiometric and non-stoichiometric manganese doped cobalt ferrite nanoparticles. In the dispersion of ac conductivity over the frequency band 100 Hz–1 MHz, two distinct conductive bands 100 Hz–1 kHz and 1 kHz–1 MHz for stoichiometric compositions, and 100 Hz–3 kHz and 3 kHz–1 MHz for non-stoichiometric compositions are observed. On the other hand, well-resolved peaks are observed in the dispersion of ac conductivity over the frequency band 1–120 MHz that corresponds to the hopping resonance for both the compositions. The ac conductivity is found to be tunable by the Mn content and selectable by the frequency between cutoff frequencies for both the compositions. A comparatively higher magnitude of ac conductivity is observed for the representative sample of non-stoichiometric composition and a lower magnitude for the stoichiometric compositions. The presence of tunability of ac conductivity in the studied samples is, therefore, a concern on which basis, the Joule's heat and Joule's heat per unit time have been determined for the studied samples by using the usual formula and also found to be tunable by the manganese content. This tunability of the generated Joule's heat may make these possible to use in the temperature switching/sensing, and/or thermoelectric/thermomagnetic devices. [ABSTRACT FROM AUTHOR]

• Hump region observed in the dispersion of ac conductivity. • A rightward shift of resonance frequency observed with increased sintering temperature. • Maximum magnetic loss tan δ m is observed at the resonance frequency in the spectra of the imaginary part of magnetic modulus that corresponds to the residual magnetic loss. This paper reports on the effects of magnetic and electric properties of a non-stoichiometric composition of cobalt ferrite nanoparticles doped with manganese content at the weight percent 0.25. Its toroid and disc-shaped samples were sintered at two different temperatures 750 °C and 1050 °C. The studied results show the dependence of the permittivity and permeability on the microstructural features, particularly crystallite/grain size that change with the sintering temperature. The anomalous behavior of ac conductivity is marked outside a hump region with a decreased sintering temperature. A rightward shift of the characteristic frequency in the absorption of electric modulus is observed with the increased sintering temperature. Similarly, a rightward shift of the resonance frequency in the spectra of the imaginary part of the magnetic modulus is marked with the increased sintering temperature. The higher magnitude of the imaginary part of the electric modulus at the characteristic frequency is expected to dissipate as eddy current loss. Similarly, the higher magnitude of the imaginary part of the magnetic modulus at the resonance frequency is assumed to dissipate as a residual loss. Both of them are selectable by the sintering temperature. This behavior may make this material suitable to be used in thermoelectric and thermomagnetic sensors/switches. [ABSTRACT FROM AUTHOR]

• Structural correlation with electric and magnetic properties. • Identification of grain and grain boundaries in the conduction mechanism of material. • Understanding the formation of spin-glass state. The investigated samples of manganese doped cobalt nanoferrites were prepared by the conventional solid-state reaction route using a planetary ball milling technique. The XRD patterns confirm their crystallinity and single-phase formation of spinel structure. The average particle size is obtained in the nanoscale range from their field emission scanning micrographs. Their spectroscopic analysis was performed from the measurement of dielectric constant and permeability for microstructural correlation. In the spectra of the modulus, the appeared peaks at a particular frequency set the boundary between long-range and short-range mobility of charge carriers in the material. The enumerated dielectric relaxation time constant is found to be a maximum at a characteristic temperature, which signifies the ferromagnetic-to-spin-glass state transition. The activation energy in the long-range mobility wing is found to be greater than that at the short-range mobility wing. The observed increasing trend in the real part of the magnetic modulus with the concentration level may be attributed to the dominance of dipolar orientations across the grain boundaries whereas it's decreasing trend is correlated with the decreasing trend in the crystallite/grain size. The temperature response of relaxation time constant, determined from the well-resolved peaks of the dispersion of imaginary part of magnetic modulus, exhibits the transformation of ferromagnetic phase to the glass transition at a particular temperature in the low-temperature regime due to ceasing of wall motion and spatially randomized spins by the freezing effects. [ABSTRACT FROM AUTHOR]

This paper reports on the structural and electrical properties of copper doped lanthanum manganite nanoparticles (NPs). The investigated samples were prepared via a standard solid state reaction route using the planetary ball milling technique. The X-ray diffraction patterns confirm their crystallinity and formation of single phase perovskite structure. The micrographs of field emission scanning electron microscopy shows the particles of almost non-spherical shape and a little agglomerated. The average particle sizes' are in the nanorange. The energy dispersive spectroscopy marks the presence of the compositional constituents. A second order magnetic phase transition from paramagnetic to diamagnetic is observed from the dispersion of dielectric constant. The peaks are found in the loss tan δ spectra that correspond to energy loss as heat radiation. The higher energy loss as heat radiation is obtained for the composition with Cu content (x) = 0.2 and is assumed it to be more suitable in the dielectric heating as well as heat generating applications. The peaks are observed at around 10 kHz in their M″ spectra, which indicate the transition from short-range to long-range mobility of ions. However, the peak position in the dispersion of M′ are detected to shift rightward with the Cu content (x). [ABSTRACT FROM AUTHOR]

• The properties of ZTO films deposited by the reactive co-sputtering process has been investigated. • Film's optoelectronic properties are significantly affected by the substrate temperature. • All the secured high transmittance (above 85%) in the visible region. • The carrier mobility is as high as 14.5 cm2/Vs found in this study. • The highest conversion efficiency of 24.07% has been achieved for PSC via SCAPS-1D using ZTO as ETM. Thin-films of Zinc Tin Oxide (ZTO) with high charge carrier mobility and superior optical transmittance has been prepared by the rf-reactive co-sputtering technique in argon-oxygen (99:01) ambient. These deposited films have been systematically studied to determine the effect of deposition temperature on film structure, composition, and optoelectronic properties. X-ray diffraction (XRD) spectra indicated that the ZTO films remain amorphous even growth temperature increased to 400 °C. The films deposited at room temperature (RT) and 100 °C were slightly tin-rich found in Energy-dispersive X-ray (EDX) spectroscopy compared to the films deposited over 100 °C. It was found that growth temperature played a crucial role in carrier concentration and mobility of the films and such properties are controlled by the grain boundary scattering over the Sn dopant concentration. The transmittance of the films was found above 85% in the visible range regardless of substrate temperature. The complete perovskite solar cell has been numerically analyzed by employing SCAPS-1D software and the effect of ZTO's optoelectrical properties on cell performance has been revealed. [ABSTRACT FROM AUTHOR]

This paper reports a series of investigations on the frequency and temperature dependent intrinsic electric properties of manganese doped cobalt ferrite nanoparticles. The investigated samples were prepared via solid state reaction route using the planetary ball milling technique. The XRD patterns confirm their crystallinity and single phase spinel structure. The Field Emission Electron Scanning Microscopic (FE-SEM) micrographs show the agglomerated particle with a nearly spherical shape. The estimated lattice constant is found to decrease but the crystallites size to increase with the Mn content. The ac resistivity is found to decrease exponentially with the increase of frequency due to the effect of multilayer capacitance. Conversely, the ac conductivity is observed to increase exponentially with the frequency due to increased hopping between metallic cationsFe2+and Fe3+. The temperature dependent ac resistivity exhibits the semiconducting behavior of the materials above room temperature. The variation in both the resistivity and conductivity is assumed to follow the Arrhenius equation at a selected frequency of 10 kHz. The estimated activation energy using the Arrhenius equation of ac conductivity in the ferro region is found to increase with the Mn content. This increasing trend in activation energy signifies ferrimagnetic-to-paramagnetic phase transition. Besides, the electric modulus shows the contributions of both the grain and grain boundaries to the conduction mechanism in the materials. This nature of temperature dependent resistivity is as usual for the majority of nanoferrite materials. [ABSTRACT FROM AUTHOR]

The determination of mineral compositions of Japanese green tea leaves was carried out using a combination of PGA (neutron-induced prompt gamma-ray analysis) and INAA (instrumental neutron activation analysis). Due to the nondestructive, multi-element analytical capability and minimal sample preparation, these techniques can easily be used to determine a wide range of elemental contents (from 7.4% of H to 7.1 ng/g of Sc) in tea leaves. The extraction efficiencies of the elements in tea infusion were evaluated by comparing average elemental concentrations of the tea leaves before and after infusion, which show that Cl (93%), Br (80%), K (71%), Rb (66%), Cs (60%), Na (59%) and Co (51%) are highly extracted, whereas Fe (9%), La (7%) and Mn (5%) are poorly extracted by a 6 min hot water infusion process. Although K has a high content in green tea leaves with high extraction efficiency, as much as seven cups (250 mL each cup) of green tea infusion need to be consumed to get a source of 10% daily value of this mineral. [ABSTRACT FROM AUTHOR]