Effect of metal ion on optical, photoluminescence, morphological, and photocatalytic properties of ZnS nanoparticles.

The semiconducting materials of pure zinc sulfide (ZnS), 2.5 wt%, 5.0 wt%, 7.5 wt%, and 10 wt% of Ag-doped ZnS nanoparticles were prepared using the sol-gel technique. The prepared nanoparticles were analyzed by powder X-ray diffraction (PXRD), Fourier transformed infrared (FTIR), UV-visible absorption, diffuse reflectance photoluminescence (PL), high-resolution transmission electron microscope (HRTEM), and field emission scanning electron microscope (FESEM) to study the properties of pure ZnS and Ag-doped ZnS nanoparticles (NPs). The Ag-doped ZnS nanoparticles have a polycrystalline nature, which is confirmed by PXRD analysis. The functional groups were identified by the FTIR technique. The bandgap values decrease with increasing Ag concentration compared to pure ZnS NPs. The crystal size lies between 12 and 41 nm for pure ZnS and Ag-doped ZnS NPs. The presence of Zn, S, and Ag elements was confirmed by EDS analysis. Using methylene blue (MB), the photocatalytic activity of pure ZnS and Ag-doped ZnS NPs was performed. The highest degradation efficiency was observed for 7.5 wt% Ag-doped ZnS NPs.

Enhanced photodegradation of methylene blue from aqueous solution using Al-doped ZnS nanoparticles.

The post-transition semiconducting material of pure zinc sulfide (ZnS) and various concentrations of aluminum (Al) (2.5 wt%, 5.0% wt, 7.5 wt%, and 10% calcined at 200 °C) doped ZnS nanoparticles (NPs) were synthesized by sol-gel procedure. The crystal-like nature and phase structure of the product were examined by powder XRD analysis. This analysis shows that the pure ZnS nanoparticle does not form any secondary phase. The functional group of synthesized materials was analyzed by FTIR examination. The energy gap of the materials is calculated using electro-optic analysis and the Kubelka-Munk equation varies from 3.04 nm to 3.63 nm. The photoluminescence studies show the wide emissions (blue to green) for pure ZnS and Al-doped ZnS nanomaterials. The SEM images show the spherical structure and the agglomerated nanostructures. The presence of Zn, S, and Al are confirmed by EDAX spectra. From HR-TEM studies, pure ZnS and Al-doped ZnS nanoparticles exhibit uniform particle sizes. The rate of degradation was observed using MB dye. MB dye has maximum wavelength (λmax) of 664 nm. The dye degradation efficiency was improved as the dye ratio increased. Photocatalytic activities studies show the intensity of photocatalytic activities decreased for the maximum time interval. Doping of Al in ZnS boosts the photocatalytic activity. Hence, Al-doped ZnS appears to be better decomposing MB dye when exposed to visible light.

Multivariate polynomial fit: Decay heat removal system and pectin degrading Fe3 O4 -SiO2 nanobiocatalyst activity.

Herein, multivariate Lagrange's interpolation polynomial (MLIP) and multivariate least square (MLS) methods are used to derive linear and higher-order polynomials for two varied applications. (1) For an effective fabrication of Pectin degrading Fe3 O4 -SiO2 Nanobiocatalyst activity (IU/mg). Here, the three parameters namely: pH value, pectinase loading and temperature as independent variables are optimized for the maximal of anobiocatalyst activity as a dependent variable. (2) For a passive system reliability estimation of decay heat removal (DHR) of a nuclear power plant. The success criteria of the system depend on three types temperature that do not exceed their respective design safety limits and are considered as dependent variables and 14 significant parameters were used as independent variables. Statistically, the validation of these multivariate polynomials are done by testing of hypothesis. Comparative study of the proposed approach gives significance results in the first application have the optimum conditions for maximum activity using linear MLIP method is: 58.64 with pH = 4, pL = 250 and Temp = 4°C. The maximum activity using second order MLIP method is 59.825 and method of MLS is 59.8249 with the optimized values of an independent variables pH = 4, pL = 300 and Temp = 8°C depicted in Table 1. In DHR system, the significance results are obtained and depicted in Table 2.

Alkaptonuria in an adolescent boy.

Alkaptonuria is a rare genetic disorder resulting in abnormality of tyrosine metabolism. It is one of the Garrod's tetrad of 'inborn errors of metabolism' proposed to have Mendelian recessive inheritance. The disorder is characterised by deposition of homogentisic acid leading to ochronosis and ochronotic osteoarthropathy; however, blackish discoloration of urine is the only childhood manifestation. Other manifestations present only after third decade. A 13-year-old boy presented to paediatric nephrology clinic with blackish discolouration of urine since infancy. Examination revealed bluish black discolouration of bilateral sclera and ear cartilage; however, he had no symptoms of ochronotic osteoarthropathy. Genetic test pointed towards alkaptonuria. Currently, he is on regular follow-up and is being treated with vitamin C to delay the progression of the disease. Early diagnosis with appropriate intervention delays the onset of complications and preserves the quality of life of the patient.

Crystal growth, spectral, optical, laser damage, photoconductivity and dielectric properties of semiorganic L-cystine hydrochloride single crystal.

The semiorganic single crystals of l-cystine hydrochloride have been grown by slow evaporation solution growth technique at 40°C. The grown crystals were subjected to single crystal XRD, FTIR, optical absorbance, laser damage threshold, photoluminescence, photoconductivity and dielectric studies. Single crystal XRD studies reveal that the crystal belongs to monoclinic system with space group C2 and the lattice parameters are a=18.63 (Å), b=5.28 (Å), c=7.26 (Å), α=90°, ß=103.70°, γ=90° and V=696 (Å(3)). FTIR spectroscopy confirms that a band at 1731 cm(-1) represents characteristic of α-amino acid hydrochlorides. The UV-Vis-NIR absorption spectrum was analyzed and the optical band gap energy was found to be 3.8eV. The crystal exhibits sharp emission peak at 388 nm. The thermal characteristics of crystals were studied by TG-DTA, which indicate that there is no weight loss up to 201°C. Surface laser damage threshold value of title compound was estimated using high power Q-switched Nd:YAG laser operating at 1064 nm. Dielectric and photoconductivity studies were also carried out for the grown crystals.