A5073329578- Stellar, planetary, and galactic studies
- Solar and Space Plasma Dynamics
- Superconducting and THz Device Technology
- Solar Radiation and Photovoltaics
- Calibration and Measurement Techniques
- Adaptive optics and wavefront sensing
- Carbohydrate Chemistry and Synthesis
- Spacecraft and Cryogenic Technologies
- Chemistry and Chemical Engineering
- Optical Polarization and Ellipsometry
- Superconducting Materials and Applications
- Chemical synthesis and alkaloids
- Astrophysics and Star Formation Studies
- Diet, Metabolism, and Disease
- Optical and Acousto-Optic Technologies
- Geomagnetism and Paleomagnetism Studies
- Fluorine in Organic Chemistry
- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Spectroscopy and Laser Applications
- Synthesis and Reactions of Organic Compounds
- Glycosylation and Glycoproteins Research
- solar cell performance optimization
- Advanced Measurement and Metrology Techniques
- Advanced Measurement and Detection Methods
Hindustan Institute of Technology and Science
2024
ETH Zurich
2022-2024
California State University, Northridge
2019-2022
Indian Institute of Science Bangalore
1980-2019
Indian Space Research Organisation
2019
Banaras Hindu University
1952
The Large Interferometer For Exoplanets (LIFE) is a proposed space mission that enables the spectral characterization of thermal emission exoplanets in solar neighborhood. designed to search for global atmospheric biosignatures on dozens temperate terrestrial and it will naturally investigate diversity other worlds. Here, we review status concept, discuss key parameters, outline trade-offs related mission's architecture. In preparation an upcoming concept study, define baseline based...
<i>Context</i> — The Large Interferometer for Exoplanets (LIFE) is a proposed space mission to characterise the atmosphere of terrestrial exoplanets, which planned operate in mid-infrared wavelength region from 6μm 16μm. A key requirement needed study feasibility this demonstrate broadband nulling at cryogenic temperatures (15K), flux levels comparable astronomical sources that LIFE will detect. Nulling Cryogenic Experiment (NICE) technology demonstrator built fulfil purpose....
Context. The inverse Evershed flow (IEF) is a mass motion towards sunspots at chromospheric heights. Aims. We combined high-resolution observations of NOAA 12418 from the Dunn Solar Telescope and vector magnetic field measurements Helioseismic Magnetic Imager (HMI) to determine driver IEF. Methods. derived line-of-sight (LOS) velocities spectra H α Ca II IR. HMI data were used in non-force-free extrapolation track closed lines near sunspot active region. determined their length height,...
Atmospheric retrieval studies are essential to determine the science requirements for future generation missions, such as Large Interferometer Exoplanets (LIFE). The use of heterogeneous absorption cross-sections might be cause systematic effects in retrievals, which could bias a correct characterization atmosphere. In this contribution we quantified impact differences line list provenance, broadening coefficients, and wing cut-offs an Earth twin exoplanet orbiting Sun-like star at 10 pc...
Abstract The use of trifluoroacetic anhydride as an NMR solvent for sugars has been explored. Dissolution carbohydrates in this is accompanied by trifluoroacetylation at the hydroxyl groups. Esterification results downfield shifts sugar protons yielding very well resolved 1 H spectra. analysis complex systems exemplified.
The Large Interferometer For Exoplanets (LIFE) is an envisioned nulling interferometry space mission to characterize the atmospheres of terrestrial exoplanets in mid-infrared (MIR) wavelength range (∼4-18.5 <i>μ</i>m.) star-to-planet flux contrast for Earth-twin exoplanet ≈ 10<sup>7</sup> at these wavelengths. Previous studies have shown that a "raw" null-depth 10<sup>5</sup> provided by interferometer sufficient as long residual starlight can be removed through signal modulation,...
This project presents a comprehensive solution for vehicle speed detection using an Infrared (IR) sensor and ESP32 camera module.The primary objective is to design efficient cost-effective system capable of accurately measuring monitoring the vehicles on road.The IR employed detect presence by interruption beam.Once detected, captures images log event provide visual evidence.The calculates time taken travel between two predefined points with known distance apart.The combination allows...
Abstract We present the properties of inverse Evershed flow (IEF) based on center-to-limb variation plasma speed and loop geometry chromospheric superpenumbral fibrils in eleven sunspots that were located at a wide range heliocentric angles from 12° to 79°. The observations acquired Dunn Solar Telescope spectral line H α 656 nm determine flows photospheric Si i 1082.7 estimate umbral magnetic field strength. All display opposite line-of-sight (LOS) velocities limb center side with distinct...
Abstract The effect of trifluoroacetylation on the 13 C chemical shifts 2‐acetamido‐2‐deoxyhexoses was examined. Studies 2‐acetamido derivatives glucose, galactose and mannose established that no regular trend in occurred trifluoroacetylation. This marked contrast to results obtained for 1 H shifts.
We propose a polarimeter, which is dedicated to Earth-like exoplanet imaging for future space missions. adopt minimum-polarization-component design philosophy, makes compact and robust system as well high-performance achievable in the real world. Our polarimeter consists of two polarization components liquid crystal variable retarders (LCVR) Wollaston prism. The can deliver an extra contrast better than 10−4.5. Combined with one currently available coronagraphs that are delivering on order...
Stokes V, the circular polarization of light, from solar corona is weak order <sup>10 − 4</sup> times intensity (Stokes <italic>I</italic>). Measuring source polarization, for a faint such as corona, difficult and requires long integration time. To obtain uninterrupted measurements, space-based polarimeter would be preferable over ground-based observatory. A full-Stokes designed that modulation matrix provides high efficiency in measuring V signal, while minimizing cross talk Q U. The...
We present a novel technique of imaging 2D region such that the image formed has both spectral and spatial information in single frame. This uses combination microlenslet array Fabry–Pérot etalon to generate multiple images at different wavelength positions. results formation hyperspectral snapshot. The instrument contains no moving parts property blueshift transmitted as angle incidence increases on an etalon. band covered, field view region, bands needed can be selected altered by simple...
The multislit spectro-polarimeter (MSSP) is a grating-based littrow spectrograph with five slits at the entrance aperture. polarimeter consists of nematic liquid crystal variable retarder as modulator and Savart plate an analyzer. It one facility instruments on Multiapplication Solar Telescope Udaipur Observatory, developed to measure magnetic fields Sun in photosphere chromosphere. MSSP currently operates only 630.2 nm (FeI), but will be upgraded cover CaII 854.2 nm, HeI 1083.2 FeI 1565.3...
Solar polarimetry aims at measuring the full set of Stokes vectors (I, Q, U, V) to extract magnetic field information solar atmosphere. During polarimetric observations, oblique reflections from telescope mirrors modify (crosstalk) or even produce polarization (instrumental polarization). For accurate measurements source, it is important correctly model and remove instrumental crosstalk introduced by telescope. The Multi-Application Telescope (MAST) Udaipur Observatory a Gregorian-Coude with...
An accurate metrology system is required to stabilize the differential path lengths in Nulling Interferometry Cryogenic Experiment (nice) within 0.45nm peak-to-peak achieve broadband mid-infrared nulls with long exposure times, which are for potential future space missions, such as Large Interferometer Exoplanets (life) mission, that aim directly image and characterize temperate terrestrial exoplanets. For this purpose, a heterodyne laser distance developed enable length measurements stable...