Cesium halides/Methylammonium double cation perovskite film for efficient and stable carbon-based perovskite solar cells

Journal of Materials Science: Materials in Electronics - The substitution with mixed cation in perovskite has advantages in improving the overall performance and stability of the perovskite solar...     

Estimation of magnetohydrodynamic radiative nanofluid flow over a porous non‐linear stretching surface: application in biomedical research

The present study investigates the effects of thermal radiation and chemical reaction on magnetohydrodynamic flow, heat, and mass transfer characteristics of nanofluids such as Cu–water and Ag–water over a non‐linear porous stretching surface in the presence of viscous dissipation and heat generation. Using similarity transformation, the governing boundary layer equations of the problem are transformed into non‐linear ordinary differential equations and solved numerically by the shooting method along with the Runge–Kutta–Fehlberg fourth–fifth‐order integration scheme. The influences of various parameters on velocity, temperature, and concentration profiles of the flow field are analysed and the results are plotted graphically. A backpropagation neural network is applied to predict the skin friction coefficient, Nusselt number, and Sherwood number and these results are presented through graphs. The present numerical results are compared with the existing results and are found to be in good agreement. The results of artificial neural network and the obtained numerical values agree well with an error <5%.Inspec keywords: silver, copper, transforms, nanofluidics, friction, backpropagation, heat radiation, water, external flows, partial differential equations, nonlinear differential equations, boundary layers, Runge‐Kutta methods, mass transfer, flow through porous media, magnetohydrodynamicsOther keywords: magnetohydrodynamic radiative nanofluid flow, nonlinear stretching surface, biomedical research, thermal radiation, chemical reaction, magnetohydrodynamic flow, nonlinear porous stretching surface, viscous dissipation, similarity transformation, governing boundary layer equations, nonlinear ordinary differential equations, shooting method, Runge–Kutta–Fehlberg fourth–fifth‐order integration scheme, flow field, backpropagation neural network, Cu–water nanofluid, Ag–water nanofluid, skin friction coefficient, Nusselt number, Sherwood number, artificial neural network, Ag‐H₂ O, Cu‐H₂ O     

Sulfonated polyethersulfone-based membranes for metal ion removal via a hybrid process

Membranes are being increasingly used as an economic alternative for wastewater treatment compared to conventional methods. Ultrafiltration membranes are widely used in metal ions’ rejection. Sulfonated Polyethersulfone (SPES)/polysulfone (PSf) blend flat sheet membranes are prepared using polar solvent N-methyl-2-pyrrolidone (NMP) by the dry–wet phase inversion technique. Polyethylene glycol (PEG-200) is used as a non-solvent additive in the casting solution. The effect of PSf/SPES blend ratio on the morphology, hydrophilicity, water content, porosity, hydraulic resistance, pure water flux, compaction, and molecular weight cut-off (MWCO) of the prepared membranes was studied and found to be improved significantly by the incorporation of SPES in the dope solution. Scanning electron microscopy (SEM) studies revealed that the membranes formed had an asymmetric structure with a thin skin layer and porous sublayer. The prepared membranes were used for rejection of Cu(II) and Zn(II) which are complexed with water-soluble chelating polymer polyethyleneimine. The results show that the order of rejection is Cu(II) ion > Zn(II) ion. Thus, it is worth mentioning that the PSf/SPES blend ultrafiltration membranes prepared in this study would offer immense potential in removal of toxic metal ion from industrial effluents.     

Chryseobacterium meningosepticum in a parapneumonic effusion in a chronic kidney disease patient on hemodialysis

Chryseobacterium meningosepticum is an uncommon human pathogen, which is an inhabitant of soil and water. It should be included in the list of suspected nosocomial infections, especially in patients with immunocompromised status. C. meningosepticum infections are not common but are clinically important because the organism is naturally resistant to multiple antibiotics. We report a case where the bacterium was isolated from the pleural fluid from a chronic kidney disease patient on hemodialysis, who developed pneumonia with complicated parapneumonic effusion. To the best of our knowedge, this is the first case where C. meningosepticum is isolated from the pleural effusion, from India.     

Synthesis and characterization of potassium metal/graphitic carbon nanofiber intercalates

Direct reaction of herringbone, platelet, or narrow, tubular herringbone graphitic carbon nanofibers (GCNFs) with molten potassium gives K/GCNF intercalates with stoichiometric control of potassium loading. Intercalate formation is confirmed by powder X-ray diffraction and micro-Raman spectroscopy. K/GCNF intercalates act as radical-anion alkene polymerization catalysts and reduce water with stoichiometric formation of hydrogen gas. Stage-1 K/narrow, tubular GCNF intercalate exhibits thermionic emission at 300 degrees C. Stage-1 K/herringbone GCNF intercalate is an excellent thermionic emitter having high thermal stability up to 1000 degrees C. K/GCNF intercalates have much reduced work functions of ca. 2.2 eV with localized emission showing a work function of 1.6 eV.     

Dye-sensitized solar cells with natural dyes extracted from rose petals

Nanocrystalline TiO₂ dye-sensitized solar cells have been fabricated using TiO₂ photoelectrode sensitized using the extracts of red rose and table rose as natural sensitizers and their characteristics have been studied. The extracts having anthocyanin pigment (pelargonidin, peonidin and cyanidin), which have hydroxyl and carboxylic groups in the molecule can attach effectively to the surface of TiO₂ film. The solar cell constructed using the red rose sensitized TiO₂ photo-electrode exhibited a short-circuit photocurrent of 4.57 mA/cm² and a power conversion efficiency of 0.81 % and that of table rose sensitized TiO₂ photo-electrode exhibited a short-circuit photocurrent of 4.23 mA/cm² and a power conversion efficiency of 0.67 %. Natural dye sensitized TiO₂ photo electrodes present the prospect to be used as an environment-friendly, low-cost alternative system.     

The growth of benzophenone crystals by Sankaranarayanan–Ramasamy (SR) method and slow evaporation solution technique (SEST): A comparative investigation

Longest unidirectional〈1 0 0〉 benzophenone (BP) crystal having dimension of 1060 mm length and 55 mm diameter was grown by Sankaranarayanan–Ramasamy method. The growth rate was measured by monitoring the elevation of the crystal–solution interface at different temperatures. The high resolution X-ray diffraction and etching measurements indicate that the unidirectional grown benzophenone crystal has good crystalline perfection and less density of defects. The optical damage threshold of SEST and SR grown BP crystals has been investigated and found that the SR grown benzophenone crystal has higher laser damage threshold value than the conventional method grown crystal. Microhardness measurement shows that crystals grown by SR method have a higher mechanical stability than the crystals grown by SEST method. Dielectric permittivity and birefringence are high in SR grown crystal compared to SEST grown BP crystal. The UV–vis-NIR results show that SR method grown crystal exhibits 7% higher transmittance as against crystals grown by conventional method.     

The effect of AlN and flux addition on luminescence properties of Ce doped TAG phosphor for white light emitting diodes

A series of Ce³⁺-activated Tb₃Al₅O₁₂ green-yellow phosphors were synthesized using solid state reaction method. The X-ray diffraction peaks of the synthesized phosphor were well matched to the Tb₃Al₅O₁₂ reference peak data. As the addition amount of AlN increase, the relative intensity of diffraction peak increase. But, the addition amount of AlN is over 0.3 mol, the second phase TbAlO₃ diffraction peaks increase. When the addition amount of AlN is 0.3 mol, PL shows the highest emission efficiency. These results were explained by the reducing atmosphere made using AlN. The highest emission intensity was observed when the Ce³⁺ concentration is 0.25 mol. The emission intensity of the Tb_2.75Al₅O₁₂:Ce_0.25³⁺ phosphors were increased by adding BaF₂ and KNO₃ as a flux. The yellow emitting Tb₃Al₅O₁₂:Ce³⁺ phosphors obtained could be applied as white LEDs.