Extraction, optical properties, and aging studies of natural pigments of various flower plants

In this paper, we reported the extraction process of five different flowering plants utilizing different dye extraction methods and solvents (ethanol and water) to choose the best dye removal process. The FTIR spectra revealed the presence of several clear functional groups for all five natural dyes. The analytical studies such as UV spectroscopy, column chromatography, and vacuum evaporation were performed to isolate the dyes from their solutions. The UV-Vis studies on the pigments of flower extracts indicated broad absorption peaks in the visible region including clear bandgaps. Among the studied pigments, Alternanthera ficoidea showed the lowest direct bandgap of 1.69 eV and an Urbach energy value of 6.33 meV. The dye extraction yield rate improvement was extended from 11.7 to 24.7% (water solvent) and 11.3–32.4% (ethanol solvent). Throughout the studies, it was observed that ethanol produced a better extraction for organic dyes than water as a solvent. Aging studies revealed that all the dyes at the room temperature showed better stability with minor changes in the observed optical parameters in oxygen-rich conditions; however, these parameters have shown significant variations at a 60 °C temperature

Studies of dose distribution to Lung and Stomach and Estimation of Second Cancer Risk due to Outfield Dose in Radiotherapy with 60Co Teletherapy Beam

A critical component of the radiation regimen for treating cancer patients is the precise dose delivery to the treatment organ while minimizing the dose to the healthy tissue. This study aims to evaluate in-field organ dose and dose distribution outside the target organs to estimate the excess lifetime risk of second cancer. The study was carried out with a male Alderson Rando Phantom. 20 sets of thermoluminescence dosimeters (MTS-100) were used in this study. The in-field organs absorbed dose was measured by inserting TLDs at different geometrical depths of the left lung, right lung, and stomach, and for peripheral organs skin dose TLDs were placed at the surface of the corresponding organs. Target organs were irradiated at 100 cGy and 200 cGy by a 60Co teletherapy unit, and irradiated TLDs were read out by a RE-2000 TLD reader. For precise dose delivery to the cancerous organs by 60Co teletherapy, the depth dose correction factor for lung cancer treatment is 0.8667 ± 0.01, and for the stomach is 0.7856 ± 0.017. In the case of the treatment for the lung and stomach, the closest organs received significant doses compared to the other distant organs. Thus, the risk of second cancer due to the peripheral dose is obtained. The stomach is at the highest risk when the lung is the target and the liver is at the highest risk when the stomach is the targeted organ

Structural, surface electronic bonding, optical, and mechanical features of sputtering deposited CrNiN coatings with Si and Al additives

Herein, the closed field unbalanced magnetron sputtered CrNiN, CrNiSiN, and CrNiAlN coatings are studied to gain insights into their structural, morphological, optical, and mechanical properties. Detailed characterizations of the thin films have been carried out through X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible–near infrared (UV–Vis) spectroscopy, nanoindentation, finite element modeling (FEM), and water contact angle measurements. XRD confirmed the hexagonal close-packed hcp-Cr2N (211) phase and face-centered cubic fcc-CrN (200) phase. The SEM images confirmed the compact, dense, and uniform distribution of gains in the coating structures. The average crystallite size of CrNiN coatings was 515 nm. The addition of substituents (Si and Al) to the CrNiN coatings resulted in increasing the crystallite sizes to 605 nm (for CrNiSiN) and 811 nm (for CrNiAlN) as well as grain size from 1.32 to 2.335 μm. XPS analysis was conducted to estimate the atomic constituents and measure the high-resolution XPS spectra of Ni2p photoelectron lines. The elastic modulus and hardness of the coatings are between 361 and 459 GPa, and 23.1–26.8 GPa, respectively. The Si, and Al additions enhanced both Young's modulus and the hardness of the coatings. Results of FEM modeling demonstrated the stress distribution within the coatings on steel and silicon substrates at different film thicknesses. The maximum stress level was increased by 30% at the coatings' upper portion, while that of the interface was reduced by 60%. The water contact angle values lay within the range of 102.4°–112.4°

A holistic framework towards understanding the optical and dielectric behaviors of CH3NH3PbCl3 perovskites/graphene oxide hybrid films for light absorbing active layer

In this work methylammonium trichloride CH3NH3Cl3 (MACl), methylammonium lead trichloride CH3NH3PbCl3 (MAPbCl), and graphene oxide (GO) doped methylammonium lead trichloride GO-CH3NH3PbCl3 (MAPbCl:GO) perovskite based thin film coatings deposited onto glass substrates using wet-chemical based spin coating technique at varying GO concentrations (0.025, 0.050, 0.075 ​g/ml), were investigated for their structural, compositional, optical, and dielectric characteristics. Characterizations of the coatings were carried out using XRD, SEM, FTIR, and UV–Vis spectroscopic methods. The XRD patterns and scanning electron microscope images revealed the cubic and regular constructions of MAPbCl and MAPbCl:GO with higher degree of crystallinity. FTIR studies demonstrated different vibrational modes mainly dominated by the organic salt (MACl) in both structures and a few new bonds such as Cdouble bondC stretching, C–H (methyl) bending, CH3–NH3 rocking were observed. Effective changes in the band-gap values were observed due to GO incorporation. A good correlation among different optical parameter such as absorption coefficient, refractive index, extinction coefficient, and dielectric function was also pragmatic. A very high value of the optical conductivity of 2.02 ​× ​1014 ​Ω/nm was shown by MAPbCl:GO (0.05 ​g/ml) perovskite composite. Hence, MAPbCl:GO coatings could be successfully used as a good light absorbing layer in perovskite solar cell (PSC) in an open-air environment and may be explored for further development to achieve a stable structure