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Solar energy is a promising replacement for rapidly depleting, non-renewable fossil fuel resources. For the efficient capture and use of solar energy, we fabricated new unconventional N719 dye-sensitized solar cells (DSSC) based on Tb2O3@TiO2 nanoparticles (NPs) with crystallite sizes in the range of 5–10 nm. The effect of loading concentrations of Tb2O3 (e.g., 0.001 to 0.010 M) on the photovoltaic performance of DSSC@Tb2O3-TiO2 complexes was assessed for comparison with that of a pristine TiO2 photoanode under simulated solar light (100 mW/cm2). Furthermore, the solar energy conversion of Tb2O3@TiO2 NPs was studied and explained in relation to their photoluminescence, photocatalytic, and surface properties. A 22% improvement in the efficiency was achieved for incident photon capture and electricity conversion in the DSSC-Tb2O3@TiO2 photoanode (at 0.001 M Tb2O3) as compared with the TiO2-based photoanode (η= 1.88 vs. 1.54). Tb2O3@TiO2 is thus demonstrated to have improved photoelectrochemical properties with enhanced charge carrier separation based on the high adsorption capability (against sensitized N719 dye: 1.74 × 10–7 mol/cm2) and photocurrent density (6.13 mA/cm2) (e.g., relative to pristine TiO2 (1.01 × 10–7 mol/cm2 and 4.66 mA/cm2, respectively). Therefore, the prepared Tb2O3@TiO2 NPs are recommended for use in photoanode applications to achieve highly efficient up-conversion of solar energy. [ABSTRACT FROM AUTHOR]

Present study portrays physicochemical investigations of aliovalent rare earth ion Tb3+ substitution of ZnO composition series [Zn(1−x)TbxO NPs, where x = 0, 0.05, 0.10] synthesized by sol-gel route. Rietveld refinement of X-ray diffraction (XRD) profiles of all the compositions revealed that the synthesized NPs exhibit hexagonal wurtzite type crystallinity with space group P63mc without any secondary phases or impurities. TEM images confirmed the formation of nanoscale particles with average particle diameter of 14.65 ± 1.28 nm, 18.39 ± 0.56 nm, 22.13 ± 1.17 nm for x = 0, 0.05, and 0.10, respectively. A red shift was observed in the optical band gap with the doping of Tb3+ ion in a UV-visible study. FTIR spectra showed a bend located at 491 cm−1 belonging to Zn-O stretching vibration, which confirmed the formation of pure and modified ZnO NPs. Pristine ZnO NPs [x = 0] showed negative susceptibility and diamagnetic character, and for the composition x = 0.05, paramagnetic nature was observed. Whereas, room temperature ferromagnetism (RTFM) behavior was observed in Tb3+ modified ZnO NPs [x = 0.10] with the rise in magnetic saturation by increasing doping concentration. Dielectric analysis revealed an increase of the dielectric constant of ZnO NPs with Tb3+-doping due to the formation of oxygen vacancies. AC conductivity increases with increasing Tb3+ content in the composition. Highlights: All the compositions exhibit hexagonal wurtzite symmetry. Diamagnetic to ferromagnetic transition was observed due to Tb3+ doping in ZnO. The energy band gap decreases with the intrusion of Tb3+ ions in the ZnO crystal lattice. Dielectric permittivity decreases with increasing Tb3+ concentration. [ABSTRACT FROM AUTHOR]

Dysprosium-doped ZnO nanoparticles [Zn1−xDyxO] were studied to enhance and control their multifunctional properties for various optoelectronic or magnetoelectrical properties. After synthesizing well-defined Dy-doped ZnO nanoparticles by Sol-Gel route, the evaluation of optical, magnetic, and electrical characteristics of synthesized ZnO nanoparticles was done. Formation of hexagonal wurtzite structure of Dy-doped nanoparticles was recognized by XRD studies and morphology, by transmission electron microscopy (TEM). The effect of the increase in dopant concentration on the bandgap was confirmed by UV-vis spectra. PL study was performed to show the presence of various types of defects in synthesized nanoparticles. In magnetic studies, room-temperature ferromagnetism (RTFM) behavior was observed. Four probe method showed the dependence of resistivity on dopant concentration. [ABSTRACT FROM AUTHOR]

Well-defined Dy-doped ZnO rods were synthesized by hydrothermal route. Various studies were carried out on the synthesized rods like x-ray diffraction to confirm their hexagonal wurtzite structure; TEM, HRTEM and selected area electron diffraction to establish their rodlike structure; energy-dispersive x-ray spectroscopy analysis confirming appropriate substitution of dopant; UV-Vis spectra, which showed decrease in band gap with dopant concentration and photoluminescence study furnishing information regarding the presence of various types of defects. Further, magnetic studies were done using VSM to confirm roomtemperature ferromagnetic behaviour of both for undoped and doped ZnO rods and, the electrical studies were performed using four probe method, which confirmed that the 'variation in resistivity with dopant concentration' was related to crystallinity of the samples. UV-Vis spectra showed effect of dopant concentration on band gap and photoluminescence study confirms induced ferromagnetic behaviour due to Dy doping. [ABSTRACT FROM AUTHOR]

The hydrothermally synthesised nanorods of Zn1 − xTbxO(x = 0.00, 0.02, 0.05, 0.1) were carried over here to analyse the changes in its optical, magnetic and electrical behavior on doping. Formation of hexagonal wurtzite structure with particle size in the range of 36 nm-22 nm was confirmed by X-Ray diffraction studies. The morphology of the samples was confirmed by SEM (Scanning electron microscope) images alongwith its TEM (transmission electron microscope) micrographs. SAED (Selected area electron diffraction) and HRTEM (High resolution transmission electron microscope) shows the clear formation of nanorods. The quantitative analysis of elemental composition was done by energy dispersive X-ray spectroscopy (EDAX). The effect of increase in dopant concentration on band gap was analysed by UV-vis spectra; the band gap was found to be 3.35, 3.31, 3.30, 3.28 eV for undoped and 2%, 5% and 10% Tb-doped ZnO nanorods respectively. The presence of various types of defects was verified by PL study. The room temperature ferromagnetism behavior was tested by VSM and saturation magentization varies from 0.004 emu/g to 0.05 emu/g for undoped to 10% tb-doped ZnO nanorods. The dependence of resistivity on dopant concentration was carried out by four probe method which shows rise in resistivity with increasing dopant concentration. [ABSTRACT FROM AUTHOR]

Tailoring of TiO2 properties by controlling W/T mole ratio (70, 140, 210 and 280) was carried out by sol-gel method using TTIP as Ti precursor and H2O as O2 precursor. The anatase phase evolution with Ti and O2 composition variations was verified, respectively, through X-ray diffraction and EDX analysis. The spherical topography of TiO2 particles was elucidated by FESEM, which was noticeably affected with W/T mole ratio. The quantitative measurement of particles’ size, shape and their distribution were directly observed at a scale approaching a bunch of atoms by HRTEM. The numerical values of crystallite size and particle size, as measured by the XRD peak broadening and TEM techniques, differ slightly. The optical study, by UV-Visible spectroscopy, registered blue shift in the absorption edge wavelength of TiO2 as well as increase in the band gap energy, with increase in W/T mole ratio. The presence of functional groups at the interface of TiO2 nanoparticles was confirmed by FTIR. Considering MB dye as a model pollutant, the characterization of photo-oxidation kinetics was also performed to assess the effect of pH and W/T mole ratio on removal efficiency of TiO2. Excellent photocatalytic performance of TiO2-70 R under UV light irradiation for 180 min was observed at a pH of 11; the corresponding photocatalytic kinetics, denoted by first order degradation rate constant (Kappa) was found to be approximately 0.00404 min−1. [ABSTRACT FROM AUTHOR]

CdTbS ( x = 0.00, 0.05, 0.10, 0.15) nanoparticles were synthesized by hydrothermal technique. The effect of Tb-doping on structural, optical and magnetic properties were studied. The X-ray diffraction (XRD) confirmed wurtzite phase without any impurity. HR-TEM micrographs revealed the particle size of ~ 18 nm with spherical morphology. Band gap calculated from UV-Visible absorption spectra showed an initial decrease from 2.49 eV ( x = 0) to 2.45 eV ( x = 0.10). Further, increasing Tb-doping to x = 0.15 band gap increased to 2.54 eV. Photoluminescence emission spectra showed peaks at 430 and 490 nm for x = 0 and 0.05 which corresponds to blue emission. Further increase in Tb doping, peaks found to be quenched. Peak at 530 nm is due to green emission and shifted to higher wavelength with Tb-doping. Magnetic analysis confirmed ferromagnetism in both undoped and Tb-doped nanoparticles. Saturation magnetization found to decrease upto x = 0.10 and increased for x = 0.15. [ABSTRACT FROM AUTHOR]

Dye sensitized solar cells (DSSCs) have been fabricated using ZnO and CaCO 3-coated ZnO nanoparticles. The effect of CaCO 3 coating on the performance of DSSC has been investigated. CaCO 3-coated ZnO nanoparticles have been synthesized by hydrothermal method. X-ray diffraction patterns of synthesized nanoparticles reveal that the ZnO and CaCO 3-coated ZnO nanoparticles have respectively wurtzite and rhomb-centred structure and both having hexagonal phase. Transmission electron microscopy study reveal that ZnO and CaCO 3-coated ZnO nanoparticles possess spherical symmetry and have average particle size respectively 6.2 and 6.7 nm. In case of CaCO 3/ZnO nanoparticles, the quenching in photoluminescence emission intensity has been attributed to the decrease in recombination rate of photo-generated electron–hole pairs. UV–Vis absorption spectra, confirms that the electrodes fabricated from the CaCO 3-coated ZnO nanoparticles have higher absorbance that shows their higher dye adsorbing power. The use of CaCO 3 coating has been found to enhance the efficiency of DSSC by over 100 %. [ABSTRACT FROM AUTHOR]

We report here room temperature ferromagnetism in CdSe and Ni-doped CdSe nanorods. Pure and 3% Ni-doped CdSe nanorods are synthesized by using low temperature solvothermal process by using ethylenediamine as solvent. X-ray diffractogram depicts the wurtzite (hexagonal) structure of the CdSe nanorods. From Transmission Electron Microscopy analysis, it is found that the average diameter of the CdSe nanorods is about 4-5 nm having length of about 50 nm. Magnetic studies are made by the analysis of M-H curves, obtained by using Superconducting Quantum Interference Device. The room temperature ferromagnetic behaviour has been shown by both pure CdSe as well as Ni-doped CdSe nanorods. [ABSTRACT FROM AUTHOR]

Room temperature ferro-magnetism in Ni-doped CdSe nanoparticles (NPs) synthesized by a wet chemical precipitation method is reported. Transmission electron microscopy shows that the average particle size of Ni-doped CdSe NPs is about 8 nm. X-ray diffraction shows the zinc blende (cubic) structure of CdNiSe NPs. Superconducting quantum interference device was utilized to study the magnetic behavior of NPs. Magnetic studies revealed that pure CdSe NPs exhibit diamagnetic behavior at 300 K, whereas 5% Ni doped CdSe NPs shows the mixture of paramagnetic and ferromagnetic behavior. [ABSTRACT FROM AUTHOR]

We report the structural and magnetic properties of the Eu doped CdZnS nanoparticles synthesized by wet chemical method. The idea is to exploit the room temperature magnetic behavior of nanoparticles. The particles size as observed by Transmission electron microscopy (TEM) and X-ray diffraction (XRD) is about 5 nm. The magnetic loop observed at room temperature using SQUID indicates the ferromagnetic behaviour of doped particles. [ABSTRACT FROM AUTHOR]

Free standing powders of copper-doped Cd1− xZn xS (0 ≤ x ≤ 0.5) quantum dots (QDs) were synthesized using a simple chemical co-precipitation method. The copper concentration was varied from 0.01 to 10 at. wt% of Cd2+. X-ray diffraction and transmission electron microscope were used for crystallographic and morphological analyzes. Room temperature time resolved luminescence spectra were recorded using high peak power, pulsed N2-laser excitation. Decay time values for bluish green and yellow emission have been calculated from recorded luminescence decay curves. Decay time dependence on Cu2+ and Zn2+ concentrations have been studied in detail. These QDs will have wide applications as nanophosphors, solar cells, photocatalysts and chemical sensors. [ABSTRACT FROM AUTHOR]

Doped II–VI chalcogenide semiconductor nanostructures have recently attracted a lot of attention due to the possibility of their application in various modern era devices. In the present study, Cd(1− x)− y Zn x Mn y S {(0 ≤ x ≤ 0.5); (0.0001 ≤ y ≤ 0.1)} nanocrystals (NC) have been synthesized by facile wet chemical technique. Morphological and structural analyses of these synthesized quaternary NC have been done using X-ray diffraction (XRD) and transmission electron microscope (TEM) studies. Room temperature photoluminescence (PL) has been investigated using high peak power pulsed N2-laser. Important optical parameter; excited state lifetime values have been calculated from the recorded multi-exponential decay curves. These fast and efficient nanophosphors have wide applications in opto-electronic industry as futuristic displays, lasers, nanoelectronics and nanosensors. [ABSTRACT FROM AUTHOR]

The electrochemical template synthesis of high aspect-ratio nickel nanorods in the track-etch membranes of polycarbonate having nominal pore size of 80, 50 and 30 nm is considered. The morphological and structural analyses have been carried out through scanning electron microscopy and X-ray diffraction respectively. The synthesized nanorods possess FCC lattice structure with texturing for {220} planes. When excited with UV radiation pulse, the structures exhibited weak photoluminescence with exponential decay, which is attributed to the presence of some adsorbed metal hydroxide. [ABSTRACT FROM AUTHOR]

The electrochemical template synthesis of high aspect ratio copper microcylinders in the track-etch membranes of polycarbonate having nominal pore size of 800, 600 and 200 nm is considered. The morphological and structural analyses have been carried out through scanning electron microscopy and X-ray diffraction, respectively. The X-ray diffraction studies reveal that the material has FCC lattice structure with a high texture coefficient for (200) planes. Regardless of the nominal pore-size of the template membrane, the texturing has been found to decrease significantly when the electrolyte temperature during fabrication is increased from 30 to 60 °C. [ABSTRACT FROM AUTHOR]

Aims/hypothesis: Miltefosine, the first oral anti-leishmanial drug, is reported to inhibit phosphatidy-linositol 3-kinase (PI3K)/Akt activity in carcinoma cell lines. Inhibition of the PI3K/Akt pathway is known to result in insulin resistance. Therefore, we investigated whether miltefosine has any deleterious effect(s) on insulin sensitivity in L6E9 skeletal muscle cells. Materials and methods: L6E9 myotubes were treated with miltefosine and its effect was observed on insulin-signalling proteins such as Akt, PI3K, insulin receptor-β, IRS-1, c-Jun N-terminal kinase, p38 and glycogen synthase kinase β, as well as on glucose uptake. Results: Miltefosine caused skeletal muscle insulin resistance in vitro by interfering with the insulin-signalling pathway and inhibiting insulin-stimulated glucose uptake. Conclusions/interpretation: Miltefosine may contribute to the risk of type 2 diabetes and needs further clinical exploration [ABSTRACT FROM AUTHOR]

The electrochemical template synthesis of high aspect ratio copper microcylinders in the track-etch membranes of polycarbonate having nominal pore size of 800 nm is considered. Effect of various parameters during electrodeposition is studied. It is found that only a narrow range of current densities yields good quality crop. Proper wetting of the membrane prior to electrodeposition is found to make significant contribution towards simultaneous start and uniform growth of the microstructures. The morphological and structural analyses have been carried out through scanning electron microscopy and X-ray diffraction respectively. It is observed that the actual diameter of the cylinders is slightly larger than the nominal pore-size. X-ray diffraction studies reveal that the material has FCC lattice structure with a high texture coefficient for (200) planes. Finally, the voltage-current studies have been carried out and the microstructures are found to obey ohm’s law. [ABSTRACT FROM AUTHOR]

Three VA-mycorrhizal fungi; Glomus occultum, Glomus aggregatum (local isolates) and G. mosseae (strain from Bangalore, India) were inoculated to assess their effect on growth of Acacia mangium in lateritic soil. All inoculations enhanced growth with respect to shoot height, root diameter, leaf area, chlorophyll content and biomass of A. mangium significantly compared to uninoculated control seedlings. G. occultum proved most efficient among the three. The mycorrhizal dependency factor indicated that the growth of A. mangium was 57% dependent on G. occultum, 47% on G. mosseae and 46% on Glomus aggregatum. [ABSTRACT FROM AUTHOR]

Reference materials development activities in India started during the period 1955–1960 for quality control in the production and use of drugs and pharmaceuticals. While the practice of import and distribution gradually accelerated in some areas, including medical, environment etc., the earliest known development of Certified Reference Materials (CRMs) within the country began with the preparation of metallurgical CRMs somewhere around 1965. A few more area-specific programs involving preparation of CRMs for quality control in the electronic industries, food and food products etc., began in the past decade. A common national program covering these activities was initiated in 1996, through organization of a national workshop on the subject and formation of a National Task Force for the development and use of reference materials in the country. The existing status and the priority needs of reference materials have been compiled by the Task Force, and a program has also been prepared for development of some of the urgently required CRMs within the country. [ABSTRACT FROM AUTHOR]

Reports an indirect method for estimating qualitative change in the resistivity of thermally annealed silver microstructures. Irradiation of polycarbonate samples; Etching in electrolytically controlled etching cell; Emission wavelengths for unannealed microstructures; Emission wavelengths upon annealing.