Spectral line shapes of collision-induced light scattering (CILS) and collision-induced absorption (CIA) using isotropic intermolecular potential for H2-Ar

Quantum mechanical line shapes of collision-induced light scattering at room temperature (295 K) and collision-induced absorption at T = 195 K are computed for gaseous mixtures of molecular hydrogen and argon using theoretical values for pair-polarisability trace and anisotropy and induced dipole moments as input. Comparison with other theoretical spectra of isotropic and anisotropic light scattering and measured spectra of absorption shows satisfactory agreement, for which the uncertainty in measurement of its spectral moments is seen to be large. Ab initio models of the trace and anisotropy polarisability which reproduce the recent spectra of scattering are given. Empirical model of the dipole moment which reproduce the experimental spectra and the first three spectral moments more closely than the fundamental theory are also given. Good agreement between computed and/or experimental line shapes of both absorption and scattering is obtained when the potential model which is constructed from the transport and thermo-physical properties is used

Morphological, structural and antibacterial behavior of eco-friendly of ZnO/TiO₂ nanocomposite synthesized via Hibiscus rosa-sinensis extract

An eco-friendly preparation technique was used to synthesize zinc oxide (ZnO) from Hibiscus rosa-sinensis extract. In addition, titanium dioxide (TiO2) was combined with ZnO in a nanocomposite. The structural investigation was done by x-ray diffraction (XRD) and the hexagonal symmetry of ZnO was detected. The calculated crystallite size of ZnO increased from 31.3 to 34.4 nm. Furthermore, functional groups of organic residues were detected by chemical analysis of Fourier transform infrared spectroscopy (FTIR). The rod grains of ZnO and TiO2 were detected by scanning electron microscope (SEM). Further, ZnO grains increased in length from 0.87 to 4.5 μm. Besides, the width increased from 0.27 to 2 μm (from ZnO to ZnO/TiO2 respectively). Furthermore, TiO2 grains decreased in length from 536 to 337 nm, while the width decreased from 136 to 122 nm. A transmission electron microscope (TEM) was used to investigate the particles of ZnO/TiO2 composite. ZnO particles were detected as ellipsoidal with length and width around 123 and 91 respectively. Besides the sphere particles of TiO2 with a diameter around 25 nm. The eco-friendly composites without harmful chemicals could be suggested for biological applications. The inhibition zone values of E. coli and S. aureus microorganisms was 61.4 ± 3.6 and 39.6 ± 4.4 and has been increased by by doping by TiO2 to 82.3 ± 6.7 and 54.3 ± 2.8

Structural, morphological features, and antibacterial behavior of PVA/PVP polymeric blends doped with silver nanoparticles via pulsed laser ablation

Polyvinyl alcohol (PVA)/polyvinylpyrrolidone (PVP) blends doped with silver nanoparticles (AgNPs) have been fabricated using laser ablation technique in one spot. The physical features of AgNPs@PVA/PVP layers were detected by XRD, FTIR, and FESEM techniques. Regarding XRD analysis upon different laser ablation times, and silver content induces a variation of PVA/PVP peaks intensities. The surface morphology was exhibited as well size and particle distribution of AgNPs through the blend surfaces. Further, the particle size of AgNPs increases with ablation time from 45.3 nm to 55.4–81.3 nm for the t = 5.0 and 20.0 min, respectively. Besides, the roughness average increased from 60.99 nm at t = 0 min to 102.4 nm at t = 20 min. Besides, the highest contact angle of 61.3 ± 3.1° was detected for pristine PVP/PVP, which decreased with increasing silver content, reaching 38.1 ± 2.1° at t = 20 min. Moreover, the highest cell viability percentage is recorded by the highest silver content composite by 97.1 ± 3.2%. Further, the antibacterial activity was examined and showed that the inhibition zone reached around 17.3 ± 1.9 and 17.1 ± 2.1 mm against Escherichia coli and Staphylococcus aureus, receptively. The fabricated AgNPs@PVA/PVP films could be suggested to be utilized for wound healing/dressing application

Synthesis and optical properties studies

4-(4-Amino-1,5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-ylideneamino)-phenol (L1) and 4-(4-Amino-1,5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-ylideneamino)-benzoic acid (L2) have been synthesized by the condensation reaction of 4-aminoantipyrine (4-AAP) and 4-aminophenol or 4-aminobenzoic acid in ethanolic solution and are characterized by various physico-chemical techniques. Thin films of L1 and L2 have been prepared by the conventional spin coating technique. X-ray diffraction patterns (XRD) show an amorphous nature for both powder and thin films for L1 and L2 ligands. The optical absorption and refraction properties of L1 and L2 are investigated by spectrophotometric techniques at normal incidence of light in the wavelength range of 200–2500 nm. The absorption spectra show two peaks in the UV region which correspond to π → π∗ transition and a peak in UV–Vis region which may correspond to n → π∗ transition. The values of dispersion parameters Eo, Ed, εL, ε∞ and N/m* are calculated according to the single oscillator model. The presence of the OH group increases the value of ε∞ from 3.21 to 3.32 and the value of N/m* from 7.38 × 1053 to 2.08 × 1054 m−3Kg−1. The optical band transition is found to be indirect allowing fundamental energy gap values of 3.4 and 3.9 eV and onset energy gap values of 2.1 and 2.6 eV for L1 and L2, respectively

Armazenamento de maçã 'gala' em atmosfera controlada com remoção de etileno Storage of 'gala' apple in controlled atmosphere with removal of ethylene

O objetivo deste trabalho foi avaliar o efeito de diferentes níveis de etileno na câmara sobre a manutenção da qualidade da maçã cv. Gala, durante o armazenamento em AC. O delineamento experimental utilizado foi inteiramente casualizado com quatro repetições e a unidade experimental composta por 50 frutos. Os tratamentos utilizados foram: >10µl L-1 (sem absorção); < 0,4µl L-1 e < 0,04µl L-1, cujos níveis mais baixos foram obtidos por absorção química. Após oito meses de armazenamento, na abertura das câmaras e após sete dias a 20&ordm;C, verificou-se maior firmeza de polpa, maior acidez titulável e menor ocorrência de podridões e degenerescência senescente nos frutos armazenados com remoção do etileno. Quanto aos teores de sólidos solúveis totais, não houve diferença estatística entre os tratamentos, em ambas as avaliações. A coloração da epiderme apresentou-se mais verde nos frutos armazenados sob remoção de etileno, após sete dias de exposição dos frutos a 20&ordm;C. A incidência de polpa farinhenta foi menor nos tratamentos com eliminação do etileno, na abertura das câmaras.<br>The objective purpose of this work was to evaluate the effect of different ethylene levels on the quality of cv. Gala apples during CA storage. The experimental design was completely randomized with 4 replications of 50 fruits. The treatments were: >10µl L-1 (without absorption); < 0.4µl L-1 and < 0.04µl L-1. After 8 month storage, at the chambers opening and after 7 days shelf life at 20&ordm;C fruits with ethylene absorption had higher firmness and titratable acidity and lower rot and senescent breakdown incidence. There was no statistic difference between treatments for TSS. After 7 days shelf life ground color was greener on the fruits stored with ethylene absorption. Mealy fruits incidence was lower with ethylene absorption, at the chambers opening