1. System and method for continuous wave low power laser based synthesis of metal nano particles : patent certificate IN 512589, 2024-02-20Sankaranarayana Iyer Sankararaman, Mohanachandran Nair Sindhu Swapna, Abdul Rahim Sajeela Beevi Ashik, Ramachandran Nair Amba Devi Krishnanunni, Vadakkedathu Parameswaran Narayanan Nampoori, 2024, patent Abstract: This disclosure relates to synthesis of metal nanoparticles (NPs). In particular, the invention relates to methods of synthesizing metal nanoparticles using Laser. The invention relates to Laser assisted synthesis of metal nanoparticles using continuous wave low laser power in a liquid medium. The system [100] for synthesis of metal nanoparticles, comprises of a laser source [101], a mechanical chopper [102], a lens [103], a target metal [104], a liquid medium [106] and a heat source [107]. Additionally the invention relates to laser assisted synthesis of metal nanoparticles with silver as the metal target and water as the liquid medium. The NPs produced are characterized by UV-Visible spectrophotometer, Field-emission Scanning Electron Microscope (FESEM), Energy Dispersive X-Ray Spectroscopy (EDS), and Transmission Electron Microscopy (TEM).Figure 1. Keywords: cw laser, nanoparticle, method Published in RUNG: 26.02.2024; Views: 1531; Downloads: 5 Link to file This document has many files! More... |
2. Satellite Data for Atmospheric Monitoring at the Pierre Auger ObservatoryA. Puyleart, Andrej Filipčič, Jon Paul Lundquist, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2022, published scientific conference contribution Abstract: Atmospheric monitoring over the 3000 km^2 of the Pierre Auger Observatory can be supplemented by satellite data. Methods for night-time cloud detection and aerosol cross-checking were created using the GOES-16 and Aeolus satellites, respectively. The geostationary GOES-16 satellite provides a 100% up-time view of the cloud cover over the observatory. GOES-13 was used until the end of 2017 for cloud monitoring, but with its retirement a method based on GOES-16 data was developed. The GOES-16 cloud detection method matches the observatory’s vertical laser cloud detection method at a rate of ∼90%. The Aeolus satellite crosses the Pierre Auger Observatory several times throughout the year firing UV-laser shots. The laser beams leave a track of scattered light in the atmosphere that can be observed by the light sensors of the observatory fluorescence telescopes. Using a parametric model of the aerosol concentration, the laser shots can be reconstructed with different combinations of the aerosol parameters. A minimization procedure then yields the parameter set that best describes the aerosol attenuation. Furthermore, the possibility of studying horizontal homogeneity of aerosols across the array is being investigated. Keywords: Pierre Auger Observatory, indirect detection, fluorescence detection, ultra-high energy, cosmic rays, atmospheric monitoring, satellite monitoring, cloud detection, aerosols, UV laser shots Published in RUNG: 04.10.2023; Views: 1722; Downloads: 7 Full text (2,92 MB) This document has many files! More... |
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4. Investigation of the effective transmittance of Mach-Zehnder interferometer in the multi-longitudinal-mode high-spectral-resolution lidarFei Gao, Fengjia Gao, Xiao Yang, Gaipan Li, Li Wang, Meng Wang, Dengxin Hua, Griša Močnik, Samo Stanič, 2022, original scientific article Abstract: Effective transmittance is an important parameter of Mach-Zehnder interferometer in the retrieval of aerosol optical properties using the multi-longitudinal-mode high-spectral-resolution lidar, which is a function of the complex degree of coherence. In this paper, we retrieve the parameter of the complex degree of coherence for the multi-longitudinal-mode laser from the theoretical analysis, optical simulation and experimental measurements, which are 0.726, 0.678 and 0.453 using the Mach-Zehnder interferometer with the optimal optical path difference of two times of laser optical cavity length (∼1000 mm) and under the light illumination of the high power Nd:YAG laser with the mode number of 101 and mode interval of 300 MHz under the condition of laser linewidth of 1 cm−1 (30 GHz). The preliminary measurement results of aerosol optical properties using the constructing multi-longitudinal-mode high-spectral-resolution lidar show that the difference of the complex degree of coherence retrieved from the presented methods results in the relative error of 40% in the aerosol backscattering coefficient with thin cloud layer and 90% with the presence of dense aerosol layer. Keywords: effective transmittance, Mach-Zehnder interferometer, Multi-logitudinal-mode laser, High-spectral-resolution lidar Published in RUNG: 20.09.2022; Views: 2299; Downloads: 0 This document has many files! More... |
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7. Evolution of fractal dimension in pulsed laser deposited MoO3 film with ablation time and annealing temperatureMohanachandran Nair Sindhu Swapna, 2021, original scientific article Abstract: The multifractal analysis is a potential method for assessing thin flm surface morphology and its changes due to diferent
deposition conditions and post-deposition treatments. In this work, the multifractal analysis is carried out to understand the
surface morphology—root mean square (RMS) surface roughness—of nanostructured MoO3 flms prepared by pulsed laser
deposition technique by varying the ablation time and post-deposition annealing. The XRD analysis shows the evolution of
crystalline nature with annealing temperature. The XRD pattern of all the annealed flms shows the characteristic peak of
the orthorhombic MoO3 phase. The FESEM and AFM analysis reveals the morphological modifcation with ablation time
and annealing temperature. The multifractal analysis of the AFM images shows that the box—counting, information and
correlation dimension varies with the annealing temperature. The study also reveals the inverse relation between the fractal
dimension and the RMS surface roughness due to the annealing induced particle size variation and reorientation. The fractal
dimension’s evolution in the pulsed laser deposited MoO3 flm with ablation time and annealing temperature is also investigated. Thus, the study reveals the potential of multifractal analysis in the thin flm surface characterizatio Keywords: Multifractal analysis · Pulsed laser deposition · Molybdenum oxide · Atomic force microscopy · Fractal
dimension Published in RUNG: 04.07.2022; Views: 1961; Downloads: 0 This document has many files! More... |
8. Study of Drug Diffusion rate by beam deflection techniqueMohanachandran Nair Sindhu Swapna, 2017, original scientific article Abstract: Drug administration is an unavoidable part of treatment. When a drug is administered orally or intravenously, it gets absorbed into the blood stream. The rate and efficiency of absorption depend on the route of
administration. When a drug is administered through the oral route, it penetrates the epithelial cells of the intestinal mucosa. The diffusion of the drug into the blood stream depends on various parameters, such as concentration, temperature, and the nature of the mucous membrane. The passive diffusion of drugs is found to obey
Fick’s law. Water soluble drugs penetrate the cell membrane through aqueous channel or pores. Hence, the
study of diffusion of drugs into the water and finally into the blood stream is important. An attempt has been made
to study the diffusion of the drug in water as 60% to 80% of human body is water. For the study of drug diffusion in
water, a commonly used cough syrup of specific gravity 1.263 is used. It is found that the diffusion rate increases
with the concentration of the drug. Keywords: laser beam deflection, diffusion coefficient, Fick’s law, sodium chloride, syrup Published in RUNG: 30.06.2022; Views: 1768; Downloads: 0 This document has many files! More... |
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10. Ultrafast relaxation of photoexcited superfluid He nanodropletsM. Mudrich, A.C. LaForge, A. Ciavardini, P. O'Keeffe, C. Callegari, M. Coreno, A. Demidovich, M. Devetta, M. Di Fraia, M. Drabbels, P. Finetti, O. Gessner, C. Grazioli, A. Hernando, D.M. Neumark, Y. Ovcharenko, P. Piseri, O. Plekan, K.C. Prince, R. Richter, M.P. Ziemkiewicz, T. Moller, J. Eloranta, M. Pi, M. Barranco, F. Stienkemeier, 2020, original scientific article Keywords: helium, helium nanodroplet, nanomaterial, density functional theory, dipole, excitation, ionization, photoelectron spectroscopy, photoexcitation, photon, simulation, ultraviolet radiation, ultrafast photoemission, free electron laser, ultrafast spectrscopy Published in RUNG: 20.01.2022; Views: 2462; Downloads: 0 This document has many files! More... |