EFFICIENT SYNTHESIS OF 2,4,5-TRISUBSTITUTED IMIDAZOLES USING SILICOTUNGSTIC ACID AS CATALYST

Objective: One-pot multicomponent reactions (MCRs) that convert more than two reactants directly into their products are of interest to chemists, owing to conserving atom economy and fostering the benign synthesis of organic compound like 2,4,5-trisubstituted Imidazoles derivatives. were efficiently synthesized by the reaction of benzyl/benzoin, ammonium acetate, and aromatic aldehydes in the presence of Silicotungstic acid as catalyst in ethanol. Materials and Methods: 2,4,5-trisubstituted Imidazoles derivatives were efficiently synthesized by the reaction of benzyl/benzoin, ammonium acetate, and aromatic aldehydes in the presence of Silicotungstic acid as catalyst in ethanol under reflux. Result: The syntheses of 2,4,5-triarylimidazoles using various benzaldehyde, benzil, ammonium acetate in the presence of a catalytic amount of silicotungstic acid (7.5 % ) under reflux using ethanol as solvent. Conclusion: The attractive features of this process are mild reaction conditions, short reaction times, easy isolation of products, and excellent yields

Coated dielectric lens design, modelling and measurements for future CMB polarimetry missions

We present an ongoing programme of work to investigate the use of large dielectric lenses with coating layers for future satellite-based cosmic microwave background (CMB) polarimetry missions. The primary purpose of this study is to validate modelling and manufacturing techniques. We present details of the study, and preliminary results of material and lens testing

Coated dielectric lens design, modelling and measurements for future CMB polarimetry missions

We present an ongoing programme of work to investigate the use of large dielectric lenses with coating layers for future satellite-based cosmic microwave background (CMB) polarimetry missions. The primary purpose of this study is to validate modelling and manufacturing techniques. We present details of the study, and preliminary results of material and lens testing

Tides in colliding galaxies

Long tails and streams of stars are the most noticeable upshots of galaxy collisions. Their origin as gravitational, tidal, disturbances has however been recognized only less than fifty years ago and more than ten years after their first observations. This Review describes how the idea of galactic tides emerged, in particular thanks to the advances in numerical simulations, from the first ones that included tens of particles to the most sophisticated ones with tens of millions of them and state-of-the-art hydrodynamical prescriptions. Theoretical aspects pertaining to the formation of tidal tails are then presented. The third part of the review turns to observations and underlines the need for collecting deep multi-wavelength data to tackle the variety of physical processes exhibited by collisional debris. Tidal tails are not just stellar structures, but turn out to contain all the components usually found in galactic disks, in particular atomic / molecular gas and dust. They host star-forming complexes and are able to form star-clusters or even second-generation dwarf galaxies. The final part of the review discusses what tidal tails can tell us (or not) about the structure and content of present-day galaxies, including their dark components, and explains how tidal tails may be used to probe the past evolution of galaxies and their mass assembly history. On-going deep wide-field surveys disclose many new low-surface brightness structures in the nearby Universe, offering great opportunities for attempting galactic archeology with tidal tails.Comment: 46 pages, 13 figures, Review to be published in "Tidal effects in Astronomy and Astrophysics", Lecture Notes in Physics. Comments are most welcom

Coated dielectric lenses for applications in high purity THz electromagnetic wave polarization detection

A comprehensive test programme has been implemented to enable the consideration of large refractive components with coating layers in the design of future satellite-based cosmic microwave background polarimetry missions. This requires understanding of systematic effects to an unprecedented level of precision, and validation of modelling tools and manufacturing techniques. We present the details of this study, and key results of the material and lens testing programme

Coated dielectric lens design, modelling and measurements for future CMB polarimetry missions

We present an ongoing programme of work to investigate the use of large dielectric lenses with coating layers for future satellite-based cosmic microwave background (CMB) polarimetry missions. The primary purpose of this study is to validate modelling and manufacturing techniques. We present details of the study, and preliminary results of material and lens testing

Coated dielectric lens design, modelling and measurements for future CMB polarimetry missions

We present an ongoing programme of work to investigate the use of large dielectric lenses with coating layers for future satellite-based cosmic microwave background (CMB) polarimetry missions. The primary purpose of this study is to validate modelling and manufacturing techniques. We present details of the study, and preliminary results of material and lens testing