Growth and characterization of urea-oxalic acid crystals by solution growth technique

Single crystals of urea-oxalic acid (UOA) have been grown from aqueous solution by slow evaporation technique. Single crystal X-ray diffraction analysis confirmed that the grown crystals belong to monoclinic system having space group P21/C. The presence of functional groups was confirmed by using Fourier transform infrared (FTIR) spectroscopy. Optical absorption studies show very low absorption in entire visible region and the UV cut-off is found to be around 240 nm. Thermal analysis studies were carried out using TG/DTA analysis and the grown crystal is thermally stable up to 180 °C. Dielectric constant studies confirm the ferroelectric property of the materials and very low dielectric loss reveals very high purity of the crystal

Synthesis and characterization of L-threonine ammonium bromide: grown on single crystal with experimental studies on NLO

L-threonine ammonium bromide (LTAB) is a significant nonlinear optical (NLO) material. The crystal has been grown by the slow evaporation technique (SET). Ammonium bromide has properties, which are that of chiral molecules and zwitterions environmental benefits due to advance NLO properties of LTAB. L-threonine-doped ammonium bromide crystals are grown using SET at ambient temperature. In this study, the unit cell factors are derived from X-ray diffraction (XRD) studies. The powder XRD spectra suggests the formation of orthorhombic crystal system. Fourier transform infrared spectroscopy (FTIR) analysis depicts the different functional groups offered in the grown crystals. The study of optical transmittance was done by crystals utilizing ultraviolet, visible, spectral analytical methods. Further, the minimum cutoff wavelength of the grown crystal has been recognized as 220 nm. The overall result of the second harmonic generation (SHG) efficiency is depicted higher and nearly around LTAB obtained crystal which is greater than potassium dihydrogen phosphate (KDP). It proves the potential application of LTAB crystal in optoelectronic industries.We would like to acknowledge the Department of Science and Technology (DST, Delhi), Government of India, for the award of DST-FIRST Level-1(SR/FST/PS-1/2018/35) scheme to the Department of Physics. We appreciate the KLEF for offering infrastructure, facilities, basic found (Perform basic instruments) and support for the current investigation.Scopu

Thermal investigation of a solar box-type cooker with nanocomposite phase change materials using flexible thermography

In this study, three SBCs are developed as (i) SBC with phase change material (PCM: waste cooking oil and C4H4O3), (ii) a novel SBC with nanocomposite PCM (NPCM), and (iii) a SBC without NPCM. The novel proposed cooker integrated with NPCM (MgAl2O4/Ni/Fe2O3-PCM) was experimentally developed and its performance was evaluated using fuzzy logic and Cramer's rules, and image processing techniques. The results indicated that the implementation of a bar plate absorber coated with MgAl2O4/Ni-doped, Fe2O3 nanoparticles, and integrated with PCM increases the cooker's internal temperature up to 164.12 °C. The used nanocomposite materials were in the average particle size of 20 μm. The cooking materials were verified with the temperature in the segmentation process. The NPCM indicated the SBC's thermal performance enhancement of 11% in comparison with the SBC with PCM and without NPCM. Additionally, the overall thermal performance of SBCs without NPCM, with PCM, and with NPCM was obtained as 24.90–33.90%, 24.77–45.20%, and 31.77–56.21%, respectively. Moreover, the temperature of the bar plate absorber was achieved as 163.74 °C, 147 °C, and 113.34 °C for the SBC with NPCM, PCM, and without NPCM, respectively, under the solar radiation of 1,037 W/m2