NOPR Collection:

Uncertainty Measurements in Chemically Synthesized Stable Uniform Sized Gold Nanoparticles for TEM/HRTEM Calibration

Mon, 01 Feb 2021 00:00:00 GMT

Title: Uncertainty Measurements in Chemically Synthesized Stable Uniform Sized Gold Nanoparticles for TEM/HRTEM Calibration Authors: Singh, Sukhvir; Singh, Manjri; Arora, Manju; Singh, Dinesh; Singh, Surinder P Abstract: The accuracy of an electron microscope depends on the magnification and resolution of the microscope. Hence in order to achieve high accuracy measurement results from the electron microscopic examination, a standard specimen is required to calibrate the transmission electron microscope (TEM). In the present work, gold nanoparticles of uniform size with narrow particle size distribution were synthesized with an aim to use them as reference material (RM) for TEM/high resolution TEM calibration and then release them in market as Bhartiya Nideshak Dravya (BND). As synthesized gold nanoparticles at 20 ± 2 °C temperature and 45± 5% relative humidityand the standard sample were characterized by using HRTEM, model: FEI-Tecnai F30 G2 STWIN at suitable magnification and areas. Both images exhibit spherical shaped nanoparticles with size varying in the range from (15.35-20.15 nm) and (5.10 -7.70 nm) respectively. Stability in particles size of the chemically synthesized gold nanoparticles was studied for a period of one year time span using UV-Visible spectrometer. TEM/HRTEM measurements were carried out in automated mode under similar experimental and environmental conditions at different magnifications to get accurate particle size. Overall uncertainty is estimated in small and big size particles as per standard GUM document guidelines. Page(s): 83-91

Study on crystalline phases and degree of crystallinity of the melt compounded PVA/MMT and PVA/PVP/MMT nanocomposites

Mon, 01 Feb 2021 00:00:00 GMT

Title: Study on crystalline phases and degree of crystallinity of the melt compounded PVA/MMT and PVA/PVP/MMT nanocomposites Authors: Choudhary, Shobhna; Dhatarwal, Priyanka; Sengwa, R J Abstract: Polymer nanocomposite (PNC) films comprised poly(vinyl alcohol) (PVA) and also its blend with poly(vinyl pyrrolidone) (PVP) (i.e., PVA/PVP = 75/25 wt/wt%) as host matrices loaded with different amounts of montmorillonite (MMT) nanoclay up to 10 wt% were prepared by melt compounded method. X-ray diffraction (XRD) patterns of these PNC films were recorded in the appropriate angular range of 2θ values 3.8°–26° for their crystalline phase structural characterization. In comparison to the broader-type single diffraction peak for the aqueous solution cast prepared pure PVA film and that of the PVA/PVP blend film which is attributed to the hydrogen bonded isotactic and syndiotactic PVA crystals, five sharp diffraction peaks of different intensities corresponding to the evolution of various crystallites in the melt compounded PVA and PVA/PVP blend films were observed. Further, these peaks intensities were found significantly affected by the amounts of loaded MMT in these polymer matrices-based nanocomposites. It was observed that the prominent crystalline phase of the pure PVA converted into alternative tactic phases in the PVA/MMT films with the variation of MMT concentration. The prime crystalline phase of the PVA/PVP/MMT nanocomposites underwent alternative crystal structures formation abruptly on the initial loading of the 1 wt% amount of MMT in the PVA/PVP blend matrix reflecting a substantial alteration in the direction and nature of hydrogen bonding within the PVA crystal structures, and less changes were found with the further increase of MMT concentration up to 10 wt%. The effect of MMT loading on the crystallite sizes, degree of crystallinity, and the exfoliated and intercalated MMT structures in these PNC materials were analyzed in detail. Page(s): 92-102

Projectile Break-up Effect on Fusion in 16O + 156Gd Reaction at Energy Range 4.3-6.3 MeV/A

Mon, 01 Feb 2021 00:00:00 GMT

Title: Projectile Break-up Effect on Fusion in 16O + 156Gd Reaction at Energy Range 4.3-6.3 MeV/A Authors: Ali, Rahbar; Singh, D; Kumar, Harish; Tali, Suhail A; Khan, Asif; Ansari, M Afzal; Singh, R P; Muralithar, S Abstract: We discuss our present understanding of the incomplete fusion (ICF) reaction dynamics, the excitation function of six evaporation residues (ERs) have been measured in ¹⁶O + ¹⁵⁶Gd reaction at projectile energy range, E/A ~ 4.3-6.3 MeV/Nucleon. Some of the ERs are produced directly & indirectly (i.e. through pre-cursor), the pre-cursor contributions have been separated out from the measured cumulative cross-section with the help of Cavinato et al.¹. After correcting the pre-cursor contribution, the independent yield has been compared with the statistical model code PACE-2², which describes the fusion reaction cross section. In order to optimize the parameter of the code PACE-2 that reproduces the cross section of all the complete fusion (CF) channels like xn and /or pxn-channels. Using the same set of input parameters, cross section of the ERs populated via incomplete fusion (ICF) channels have been measured. The enhancement in the measured cross section of the ERs populated via ICF channels over the PACE-2 prediction have been measured, which indicates the occurrence of the break-up of projectile ¹⁶O into (¹²C+α) and/or (⁸Be+2α) leading to ICF reaction dynamics. Page(s): 103-108

Design and simulation of an infrared optical filter suitable for carbon dioxide and CO2 lasers

Mon, 01 Feb 2021 00:00:00 GMT

Title: Design and simulation of an infrared optical filter suitable for carbon dioxide and CO2 lasers Authors: Abdelbagi, Abdelrazig Mohamed; Kamal, Maha Abstract: The main objective of this study was to assess the molecular simulation of the design of carbon dioxide (CO₂) and to construct infrared optical filters for the transmission and absorption of the CO₂ laser and the emission of gaseous CO₂radiation. Semiconductor compounds used to determine the wavelength of infrared transmission and absorption infrared radiation (IR) to produce an IR filter for laser production and gas emission using the Fourier Transform infrared spectrometer (FT-RI) for research purposes. Carbon dioxide molecule simulation has been used based on Hyper 6 simulation programme in potential energy, and kinetic energy, which measures the infrared radiation spectrum. Infrared filters are constructed from the compounds of a semiconductor of Zinc Sulfide supplied (ZnS), Aluminum Oxide (Al₂O₃), Magnesium Oxide (MgO), Lead (II) Sulfide (PbS), and Potassium Chloride (KCl). The data used for evaluation of the optical elements in the IR region based on the transmission and absorption of radiation intensity effective for wavelength detection. The assessment of the detection is indicating transmission and absorption of the wavelengths of CO₂ laser and CO₂gas molecule under investigation. This study has identified the approach of the result of transmission and absorption of the peak intensities of 10.6, 2.7, 4.3 and 15μm of CO₂ laser and gas radiation emission of the filters in the IR region. The findings of this study have a number of important applications in the IR radiation region. Page(s): 109-115