Recent advances in terahertz imaging

We review recent progress in the field of terahertz “T-ray” imaging. This relatively new imaging technique, based on terahertz time-domain spectroscopy, has the potential to be the first portable far-infrared imaging spectrometer. We give several examples which illustrate the possible applications of this technology, using both the amplitude and phase information contained in the THz waveforms. We describe the latest results in tomographic imaging, in which waveforms reflected from an object can be used to form a three-dimensional representation. Advanced signal processing tools are exploited for the purposes of extracting tomographic results, including spectroscopic information about each reflecting layer of a sample. We also describe the application of optical near-field techniques to the THz imaging system. Substantial improvements in the spatial resolution are demonstrated. Received: 29 January 1999 / Published online: 7 April 1999     

Regulating the assembly and expansion of the silver cluster from the Ag37 to Ag46 nanowheel driven by heteroanions

Precise control over the shape and size of metal nanoclusters through anion template-driven self-assembly is one of the key scientific goals in the nanocluster community, however, it is still not understood comprehensively. In this work, we report the controllable synthesis and atomically precise structures of silver nanowheels Ag37 and Ag46, using homo (Cl⁻ ions) and heteroanion (Cl⁻ and CrO₄²⁻ ions) template strategies, along with macrocyclic p-phenyl-thiacalix[4]arene and small ⁱPrS⁻ ligands. Structural analyses revealed that in Ag37, Cl⁻ ions serve as both local and global templates, whereas CrO₄²⁻ ions function as local and Cl⁻ ions as global templates in Ag46, resulting in a pentagonal nanowheel (Ag37) and a hexagonal (Ag46) nanowheel. The larger ionic size and more negative charges of CrO₄²⁻ ions than Cl⁻ ions offer more coordination sites for the silver atoms and are believed to be the key factors that drive the nanowheel core to expand significantly. Also, by taking advantage of the deep cavity of thiacalix[4]arene with an extended phenyl group, Ag46 has been used as a host material for dye adsorption depending on the charge and size of organic dyes. The successful use of heteroanions to control the expansion of well-defined silver nanowheels fills the knowledge gap in understanding the directing role of heteroanions in dictating the shape and size of nanoclusters at the atomic level.

A heteroanion self-assembly strategy for regulating the shape and expanding the size of the silver cluster from Ag₃₇ to Ag₄₆ with a macrocyclic (p-phenyl-thiacalix[4]arene) ligand has been presented.     

Computational/In-Silico Methods: An Influential Approach for Drug Designing and Development

As the world is struggling with the pandemic. Various infectious diseases have become a threat to human health. Millions of deaths are caused by these microbial infections (bacterial, fungal, and viral infections). The process of designing and discovering new drugs is very expensive and it also consumes a good amount of time. As per available data, the process of discovery and designing takes 3–20 years to complete. There is a strong urge and demand to discover new methods to make the process of drug design and development more cost-effective. Computational methods are one the novel methods for designing and developing a drug. In this respect, in-silico parameters; ADME (Absorption, Distribution, Metabolism, and Excretion) models have been established with various levels of complication for the transmission of huge data of derivatives/ligands/drugs. Nowadays, in-silico tools are more cost-effective, faster, and simpler than transitional experimental trials. Currently, the pharmaceutical industry faces a huge erosion rate of preclinical and clinical applicants due to the unavailability of pharmacokinetics properties and huge toxicity. These can be minimized via structural modifications of drugs and can help medicinal chemists/pharmacists. In this report, various methodologies and steps have been explained via molecular docking that will lead to drug development in lesser time against various stains.     

MHD natural convection in inclined wavy annulus utilizing hybrid nanofluid with discrete wavy coolers

Journal of Thermal Analysis and Calorimetry - In the present framework, the combined effect of magnetic field (Hartmann number, Ha), angle of inclination $$(\alpha )$$ , nanoparticle volume...     

Optimization of Transducer Location for Novel Non-Intrusive Methodologies of Diagnosis in Diesel Engines

The health monitoring has been studied to ensure integrity of design of engine structure by detection, quantification, and prediction of damages. Early detection of faults may allow the downtime of maintenance to be rescheduled, thus preventing sudden shutdown of machines. In cylinder pressure developed, vibrations and noise emissions data provide a rich source of information about condition of engines. Monitoring of vibrations and noise emissions are novel non-intrusive methodologies for which positioning of various transducers are important issue. The presented work shows applicability of these diagnosis methodologies adopted in case of diesel engines. The effects of changing various fuel injection parameters was analyzed. Scope of using non-intrusive technique has been analyzed by changing locations of microphone. Novelty of this worklies in exploring signal processing methods for various locations around the engine test set up. Various frequency ranges of contributing noise and vibration sources were identified. Time-Frequency analysis showed the onset of various cyclic. Based on the identification of various frequency bands, it is possible to device suitable filters in order to extract more information.     

Raman and X-Ray Absorption Spectroscopy Investigations of the Structure and Ru–Mn Valence States of Li2Mn0.9Ru0.1O3

Journal of Applied Spectroscopy - We report the effect of the sintering temperature on the structure and valence states of Ru–Mn in Li2Mn0.9Ru0.1O3. These effects are explored by synchrotron...     

Crystal Structure of 3-[1-(4-Methylphenyl)-9,10-dihydro-4-azaphenanthren-3-yl]benzo[f]coumarin

Crystallography Reports - The crystal structure of the title compound is determined by single crystal X-ray structure analysis. The structure was solved by direct method and refined to a final...