Advanced Journal of Chemistry, Section A
Volume:4 Issue: 3, Summer 2021

The production of phosphoric acid in the world generates an enormous amount of a by-product named phosphogypsum (PG). A large quantity of this PG is stockpiled or dumped into environment, causing several environmental problems. This research study proposes an attractive process for transforming the PG into calcite (CaCO3) and thenardite (Na2SO4). A parallel study of the conversion of pure gypsum (GRH) was also realized to compare their reactivity with that of PG. The following of the PG and GRH conversion reaction was evaluated using by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). While, the quality of the products obtained under the optimum condition were proved by scanning electron microscopy (SEM), flame photometer (FP), inductively coupled plasma mass spectrometry (ICP-MS) and thermogravimetric analysis (TGA-DTA). A result revealed that, PG rest more reactive than GRH and yields the desired results at short reaction time under room temperature.

The present study deals with the theoretical investigation of structural, molecular, electronic, and chemical reactivity details of (E)-7-((1H-indol-3-yl)methylene)-1,2,6,7-tetrahydro-8H-indeno[5,4-b]furan-8-one (ITHF). The ITHF molecule is characterized by proton nuclear magnetic resonance (1H NMR) and carbon nuclear magnetic resonance (13C NMR) spectral techniques. The Becke-3-Lee-Yang-Parr functional (B3LYP) level of theory at the 6-311G(d,p) basis set was used for the density functional theory (DFT) investigation. Bond lengths were predicted from the optimized molecular structure, and the physical and chemical properties of the molecules were inferred as a consequence. The HOMO and LUMO are computed and their energies were established. The calculated HOMO-LUMO energy gap is 3.67 eV indicating inevitable electron transfer phenomenon within the ITHF molecule. Amongst all carbon atoms, the C6 carbon as more positive and C21 as more negative carbon atoms. The molecular electrostatic surface potential revealed that the negative electrostatic potential is present over oxygen atoms and the positive, on the other hand, is located over two aromatic rings' hydrogen atoms in the ITHF molecule.  Importantly, the ITHF compound were evaluated for antibacterial activities against two Gram positive bacteria namely Bacillus subtilis and Staphylococcus aureus and two Gram negative bacteria namely Escherichia coli and Proteus vulgaris and two fungal agents namely Aspergillus niger and Candida albicans. The ITHF compound was found to show good antimicrobial action.

A magnetically separable catalyst n-butylpyridinium tetrachloroferrate ([C4py]FeCl4) was designed for the removal of  trace olefins from aromatic hydrocarbons. The magnetic ionic liquid was prepared via a facile synthetic route and well characterized by FTIR, TGA/DTG, DTA, UV–Visible, and Raman techniques. Then, the effects of different reaction parameters such as molar ratio, reaction temperature, reaction time, and the reusability of the ionicliquid were investigated. It was found that the ionic liquid ([C4py] FeCl4) with 5 wt% of the catalyst at 70 °C for 12 min., exhibited a better performance for olefin removal.The magnetic IL was easily removed from solution using an external magnet, allowing efficiently recovery and without work-up or purification processes.

A green synthesis of gold nanoparticles (GNPs) was accomplished by aqueous medium of the Tribulus terrestris (T. terrestris)extract, without the addition of any external chemical reducing agent. Several factors such as pH of the solution, temperature, and concentration of the added extract greatly influence the synthesized nanoparticles. The reduced GNPs were characterized by energy dispersive X-ray (EDX), ultra-violet–visible absorption spectroscopy (UV–Vis), fourier transform–infrared spectroscopy (FT–IR), and scanning electron microscopy (SEM). Formation of GNPs was approved from the change in color of colorless to violet and strong surface plasmon resonance (SPR) was observed at 555 nm using UV-Vis spectroscopy. The size distribution of the GNPs was also revealed by SEM analysis. The size range of the GNPs was from 6 to 25 nm. Similarly, particles with a distinctive peak of gold were examined with EDX. Moreover, the potential of the nanoparticles for biomedical applications have also been confirmed by their antimicrobial activity against Gram positive and negative bacteria. Actualy, this study provides new possibilities of using T. terrestris extract as a capping and reducing agent for the synthesis of GNPs, which may be applicable for the future diagnostic and therapeutic fields.

Naphtha isomerization is one of the reactions present in catalytic conversion process of heavy naphtha. The catalyst is highly active at 80-100 °C; however, due to corrosion, environmental issues, and the lack of appropriate selectivity, it has not been commonly used. In addition, since naphtha conversion catalysts act at 320-450 °C and at this temperature isomerization is not appropriately done, the catalyst did not show good activity in isomerization of light alkanes. The presence of a known concentration of HCl on the catalyst surface will cause the Bronsted places to have stability and maintain the catalytic activity during the reaction. In this research study, the conditional contract arrangement was utilized to extract the relevant knowledge in isomerization for 3 major factors: H2/HC, optimum pH and acidic site in catalyst. Results revealed that, the best range of temperature of light Naphtha in feed was less 30 °C, pressure of recycle gas was more than 35 bar, the H2/HC was less than 0.05, conditions of feed (temperature was less than 35 °C, pressure was more than 19 bar), optimum pH was less than 5.5 and the ratio of metal and acidic site in catalyst was under 6.

In the present work, synthesis and DFT study of 2-(4-fluorophenyl)-5-phenyl-1,3,4-oxadiazole is reported. The 6-311++G (d,p) basis set was used to optimize the molecular structure of the title compound using the DFT/B3LYP method.The structural parameters, bond length, and bond angle were studied. The fundamental vibrational wavenumbers and intensities were computed, and the observed and calculated wavenumbers were found to be in excellent agreement.  In order to decide the reactivity and possible site for electrophilic and nucleophilic, Frontier molecular orbital (HOMO-LUMO) energies, global reactivity descriptors, molecular electrostatic potential as well as Mulliken charges were calculated using the same theory. The obtained results indicates that the compound possess good kinetic stability. The molecular electrostatic potential surface analysis shows that the nitrogen atom oxadiazole ring is the binding site for electrophilic attack.

The present study is a combined research because it uses qualitative and quantitative methods in order to collect and analyze data by identifying indices and indigenous components of professional competence of hotel, oil and gas industry hotel managers. The qualitative and meta-analysis approach has been used. In a quantitative approach, he has used the fuzzy structural equation modeling method. Finally, based on the data, a new model of sustainable development in the oil, gas and energy industry has been reached. These components are: general professional performance, analytical skills, specific professional skills, general professional skills, job information and awareness, psychological abilities, innovative personality, basic specialized knowledge, job commitment, professional attitude, desire to Job development, intrinsic personal characteristics, and increasing factors that psychological abilities and increasing factors of competence are placed in the fourth level and were identified as the main and most effective dimensions in the development of sustainable development of oil, gas and energy industry. And the element of general professional performance is the least important among the studied dimensions.