Comparison of different sintering aids in cold sinter-assisted densification of lead zirconate titanate

Ceramics such as lead zirconate titanate (PZT) tend to dissolve incongruently, and thus pose a challenge in the cold sintering process. Moist lead nitrate has previously been shown to enable a cold sinter-assisted densification of PZT by a viscous phase sintering mechanism. In this paper, lead acetate trihydrate is demonstrated to lower the required temperature of the cold sintering step to 200°C. This densification process was described as a two-step process: cold sintering of PZT with lead acetate trihydrate and post-annealing the as-cold sintered PZT ceramics. Unlike in the case of lead nitrate, PZT densification with lead acetate trihydrate occurs by a liquid phase assisted sintering mechanism, leading to an as-cold sintered relative density of 84% at 200°C. After performing a post-anneal step at 900°C, >97% relative densities were achieved in samples that were cold sintered with lead acetate trihydrate. This step not only densified PZT but also refined the grain boundaries. In the post-annealed samples, the room-temperature relative permittivity at 100 Hz was ~1600, slightly higher than that reported in samples that used lead nitrate as a sintering aid; the loss tangent was about 3.8%. For measurements at 10 Hz, the remanent polarization in both cases was ~28 µC/cm². Both Rayleigh analysis and aging studies showed that a higher irreversible contribution to the permittivity exists in samples that used lead nitrate as a cold sintering aid.     

Solution of an imperfect‐quality EOQ model with backorder under fuzzy lock leadership game approach

This paper considers an economic order quantity (EOQ) inventory model for items with imperfect quality and shortage backordering under several styles of managerial leadership via lock fuzzy game theoretic approach. The decision maker (DM) controls several cost components by playing as Player 1 on the one side and the consumers who may accept/reject those items (unwilling to buy those commodities) stands as Player 2 on the other side. First of all, we develop a profit maximization backlogging EOQ model where the imperfect items are screened out batchwise. Because of the fuzzy flexibility of the model parameters we also develop a fuzzy mathematical model by considering the demand, all cost parameters, and other input parameters of the inventory system as triangular lock fuzzy numbers. Then we develop a 3 × 3 matrix game by applying a five‐stage leadership theory employing several key vectors in the model itself. The problem has been solved for crisp, general fuzzy models of several leadership styles also. Numerical results show that for a cooperative game, inventory profit function reaches its maximum rather than the noncooperative game by the use of proper keys. Finally, comparative study, sensitivity analysis, and graphical illustrations are made to justify the new approach.     

Humidity sensor properties of hydrothermally grown rutile-TiO2 microspheres on interdigital electrodes (IDEs)

Journal of Materials Science: Materials in Electronics - Rutile-TiO2 microspheres were synthesized by the single-step hydrothermal method and were subsequently annealed in an argon environment at...     

Plasmonic Charge Transfers in Large-Scale Metallic and Colloidal Photonic Crystal Slabs

The challenges in plasmonic charge transfer on a large-scale and low losses are systematically investigated by optical designs using 1D-plasmonic lattice structures. These plasmonic lattices are used as couplers to guide the energy in an underneath sub-wavelength titanium dioxide layer, resulting in the photonic crystal slabs. So far, photodetection is possible at energy levels close to the semiconductor bandgap; however, with the observed hybrid plasmonic–photonic modes, other wavelengths over the broad solar spectrum can be easily accessed for energy harvesting. The photo-enhanced current is measured locally with simple two-point contact on the centimeter-squared nanostructure by applying a bias voltage. As lattice couplers, interference lithographically fabricated conventional gold grating provides an advantage in fabrication; this optical concept is extended for the first time toward colloidal self-assembled nanoparticle chains to make the charge injection accessible for large-scale at reasonable costs with possibilities of photodetection by electric field vectors both along and perpendicular to the grating lines. To discuss the bottleneck of unavoidable isolating ligand shell of nanoparticles in contrast to the directly contacted nanobars, polarization-dependent ultrafast characterizations are carried out to study the charge injection processes in femtosecond resolution.     

Gyrase ATPase Domain as an Antitubercular Drug Discovery Platform: Structure‐Based Design and Lead Optimization of Nitrothiazolyl Carboxamide Analogues

In this study, we explored the pharmaceutically underexploited mycobacterial gyrase ATPase (GyrB) domain as a template for a structure‐based virtual screening of our in‐house (BITS Pilani) compound collection to discover new inhibitors targeting Mycobacterium tuberculosis (M.tb.) The hit identified was further customized by using a combination of molecular docking and medicinal chemistry strategies to obtain an optimized analogue displaying considerable in vitro enzyme efficacy and bactericidal properties against the M.tb. H₃₇Rv strain. The binding affinity of the ligand toward the GyrB domain was reascertained by differential scanning fluorimetry experiments. Further evaluation of the hERG toxicity (a major limitation among the previously reported N‐linked aminopiperidine analogues) indicated these molecules to be completely devoid of cardiotoxicity, a significant achievement within this class.     

Determination of biogenic amines and total aflatoxins: Quality index of starter culture soy sauce samples

Food Science and Biotechnology - This study deals with understanding the effects of starter cultures on the safety aspects of soy sauce fermentation and their application to compensate undesirable...     

Study and explanation about the morphological,electrochemical and structural properties of differently synthesized polypyrrole

Polypyrrole (ppy), a conducting polymer was synthesized by four different polymerization methods viz. electrochemical polymerization (EP), interfacial polymerization (IP), chemical oxidative polymerization (COP) and template-assisted polymerization (TAP). The change in morphology that occurred due to the variation of polymerization method used was studied with scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The samples were analyzed by Fourier transform infrared (FT-IR) spectroscopy to confirm the successful polymerization of pyrrole to polypyrrole with the appearance of characteristic bands for N–H stretching, C–N stretching, ppy ring stretching, C–H and C–C bending vibrations. Optical studies were done by UV–Vis absorption spectroscopy that displayed π→π^* and polaronic/bipolaronic transitions of ppy. XRD analysis revealed amorphous nature of ppy. Examination of SEM micrographs disclosed that ppy synthesized by EP had the typical cauliflower structure while ppy formed by IP were in the form of chain like network with a thickness of 250–290 nm, COP resulted in the formation of interlinked microspheres of polypyrrole and TAP formed polypyrrole nanofibers. Electrochemical characterization showed that ppy prepared by EP had the lowest redox activity and the samples were also tested to detect Pb²⁺.