Enhanced photocurrent in PbSe nanorod-quantum dot bulk nano-heterojunction solar cells

Journal of Materials Science: Materials in Electronics - Owing to their remarkable multiple exciton generation (MEG) yield, PbSe nanorods (NRs) have been considered as one of the most promising...     

Wavelet network-based classification of transients using dominant frequency signature

This paper presents a novel approach of classification of transients resulting from changes in circuit topology in a radial distribution system. The analysed data are obtained from experiments as well as simulated model based on Simulink in Matlab environment. Continuous wavelet transform-based dominant frequency signature (DFS) has been used as the key features for identification of circuit topological changes. Conclusions have been drawn after classification of the transients based on DFS using wavelet network.     

Ferrite ring loaded hybrid substrate design for gain enhancement of linearly and circularly polarized microstrip antennas

New design of compact high gain microstrip antennas (MSAs) by loading ferrite ring in the substrate has been proposed in this article. Gain enhancement in two compact wideband MSAs, one exhibiting linear polarization and the other featuring circular polarization, is demonstrated using hybrid substrate. The proposed hybrid substrate is a combination of Roger's 6002 (ε_r = 2.94, tan δ = 0.0012) and Ferrite ring having ε_r = 10, μ_r = 14, dielectric loss tangent tan δ_e = 0.0017 and magnetic loss tangent tan δ_m = 0.0391. This ferrite ring loaded composite antenna results in a peak gain enhancement of about 4.46 dBi in a linearly polarized E‐shaped MSA having bandwidth of 17.9%. In a similar fashion, a peak gain enhancement of about 3.61 dBi is exhibited on a standard dual‐fed circularly polarized square MSA (S‐MSA). Both E‐shaped MSA and S‐MSAs are fabricated and characterized for impedance and radiation pattern measurements exhibiting good corroboration with the simulated results.     

Crosslinked PVDF-HFP-based hydrophobic membranes incorporated with CNF for enhanced stability and permeability in membrane distillation

Over the past decades, numerous materials have emerged as promising amenities for the fabrication of novel membranes. The current study gives insight into a modest and effective method to fabricate a crosslinked poly-vinylidene fluoride-co-hexafluoropropylene membrane with better mechanical properties and permeability for desalination. Poly-vinylidene fluoride-co-hexafluoropropylene membrane was grafted with crosslinked collagen to enhance direct contact membrane distillation used for desalination. Stiffness, rigidity and mechanical properties of the membrane were intensified by incorporating collagen (extracted from eggshells) into the membrane matrix, with glutaraldehyde crosslinkers. Furthermore, to improve water vapor diffusion, immobilized carbon nanofibers (CNF) were integrated in the membrane, casted via phase inversion technique with an optimized controlled approach. The permeate flux of CNF incorporated membrane was as high as 8 LMH, 18% higher than the unmodified poly-vinylidene fluoride-co-hexafluoropropylene membrane at 60 °C, besides minimal salt leakage. The properties of the modified membrane were characterized from its contact angle, morphological structure, surface roughness, dynamic mechanical properties, and water flux. The overall performance of the modified membranes was better than the virgin membranes. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48021.     

Transport properties of I, Te and Xe in thoria-urania SIMFUEL

Diffusion properties for volatile fission products iodine and tellurium, and gaseous product xenon in a solid solution of thoria-2 mol% urania doped with fission products for simulating 2 at.% burnup were obtained by studying the release kinetics of the species from trace-irradiated fuel samples at different temperatures using post-irradiation annealing technique. Bulk diffusion coefficients for Xe, I and Te were evaluated in a well-defined powder sample of particle size in the range of 37-45 μm (25 m² kg⁻¹ BET surface area) with 97% of theoretical density. Temperature dependences of the apparent diffusion coefficients of Xe, I and Te derived from this study could be expressed in the form of Arrhenius equations for the respective cases as ln (s⁻¹) = −(19,480 ± 3300)/T − 9.3 ± 2.2 and ln (s⁻¹) = −(31,234 ± 3000)/T − 3.7 ± 2.0, (1273 ? T/K ? 1773) and ln (s⁻¹) = −(22,755 ± 1364)/T − 0.003 ± 0.775, 1700 ? T/K ? 1800. For Xe diffusion the activation energy and frequency factor are 189 kJ mol⁻¹ and 0.997 s⁻¹, respectively. For I and Te the activation energy values are 162 and 260 kJ mol⁻¹, respectively. The respective frequency factors for I and Te are 9.1 × 10⁻⁵ and 2.5 × 10⁻² s⁻¹. On comparison with the reported data in pure urania and thoria matrices a lowering of activation energy for all three species was observed in case of the fission product doped matrix. On the other hand the frequency factor has increased only in the case for diffusion of Xe. This suggests different mechanisms of transport for Xe and volatile fission products I and Te in the fuel matrix.     

Versatile CAD formulation for estimation of the resonant frequency and magnetic polarizability of circular split ring resonators

In this article, we propose a theoretical formulation to estimate the resonant frequency and magnetic polarizability of a circular split ring resonator (SRR). The computed results are compared with experimental and simulation results revealing excellent agreement for a wide range of frequencies. The proposed theory was compared with simulation for different parametric variation of the SRR. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011.     

Synthesis and characterization of elastomeric polyurethane and PU/clay nanocomposites based on an aliphatic diisocyanate

This investigation reports preparation of polyurethane and polyurethane/clay nanocomposites based on polyethylene glycol, isophorone diisocyanate (IPDI), an aliphatic diisocyanate and 1,4‐ Butanediol as chain extender by solution polymerization. In this case PU/clay nanocomposites were prepared via ex‐situ method using 1, 3, and 5 wt % of Cloisite 30B. Thermogravimetric analysis showed that the maximum decomposition temperature (T_max) of the PU/clay nanocomposite is much higher than the pristine PU. The tensile properties improved upon increasing the organoclay (Cloisite 30B) content upto 3 wt %, and then decreased to some extent upon further increasing the nanoparticle loading to 5 wt %. Optical properties of the nanocomposites were studied by UV‐vis spectrophotometer. X‐ray diffraction (XRD) and transmission electron microscopy (TEM) were used to study the morphology of the nanocomposites. It was observed that with the incorporation of 3 wt % nanoclay the crystallinity in PU nanocomposite increases, then diminishes with further loading. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3328–3334, 2013     

Efficiency of nutrient utilization and reproductive performance of pre‐pubertal anestrous dairy heifers supplemented with inorganic and organic chromium compounds

An on‐farm trial was conducted to ascertain the effects of chromium supplementation on the nutrient utilization and reproductive performance of cross‐bred (Bos taurus × Bos indicus) pre‐pubertal anestrous dairy heifers. Chromium was supplemented (0, 0.25, 0.5 and 1.0 mg kg^?1 diet dry matter) as chromium chloride hexahydrate or chromium–yeast complex. The intake of the total digestible nutrients (P < 0.01) and body weight gain (P < 0.05) increased with supplementation of chromium. Chromium–yeast supplementation resulted in a dose‐dependent increment (P < 0.01) in the total digestible nutrient intake. Intake and apparent absorption of chromium increased linearly (P < 0.001) with the dose. Chromium chloride tended to be better absorbed (P < 0.10) than the chromium–yeast complex. The source of supplemental chromium did not affect the plasma concentrations of glucose, cholesterol, total protein and albumin. The postprandial plasma glucose concentration in the control group increased by 38% versus 0.27 and 1.1% in the heifers supplemented with 1.0 mg Cr kg^?1 dry matter as chromium chloride and chromium–yeast complex, respectively. The postprandial increment in the plasma cholesterol was also generally lower in the supplemented heifers. The plasma chromium concentration varied (P < 0.05) between the groups, although it was difficult to correlate these changes with the sources and doses of supplemental chromium. Chromium chloride and chromium–yeast supplementation resulted in similar changes in the plasma concentrations of copper, zinc, iron and manganese (P > 0.05). Plasma concentrations of copper and zinc, which increased (P < 0.001) with chromium supplementation, declined quadratically (P < 0.05) as the dose of supplemental chromium increased. At the end of the supplementation, two, four and three heifers fed with 0.25, 0.5 and 1.0 mg Cr kg^?1 dry matter (as chromium chloride), respectively, developed Graffian follicles and showed estrus; the numbers were one, three and four in the corresponding groups fed with chromium–yeast complex and one, two and three heifers amongst them showed estrus. All the supplemented animals showing estrus conceived and no abortion was reported during the first trimester of their pregnancy. It was concluded that chromium supplementation could appreciably enhance the nutrient utilization and the reproductive performance in anestrous dairy heifers and inorganic trivalent chromium (CrCl₃.6H₂O) supplementation might be as useful as a chromium–yeast complex for this purpose. Copyright © 2006 Society of Chemical Industry