No abstract

The proposed study concerns the inclusion complexation of dimethoate (DMT) in the β-cyclodextrin (β-CD) molecule cage using a 1:1 stoichiometry. The interactions between DMT and -CD were evaluated using PM7 and DFT in water and gas with base 6-31G(d,p); using the CAMB3LYP functional. All approaches agree with the optimal 3D structure, which includes full DMT inclusion in the CD cavity. Complexation, LUMO, and HOMO energies were computed. The natural bond orbital (NBO) and UV- visible calculations were determined and discussed. Additionally, the non-covalent intermolecular interactions between dimethoate and β-cyclodextrin are investigated through: reduced density gradient (RDG), non-covalent interaction (NCI) and independent gradient model (IGM) that the main forces stabilizing the examined inclusion complex are H-bond and Van Der Waals interactions. Furthermore, the energy decomposition analysis (EDA) emphasizes the importance of the H-bond as attractive interactions.

The proposed study concerns the inclusion complexation of dimethoate (DMT) in the β-cyclodextrin (β-CD) molecule cage using a 1:1 stoichiometry. The interactions between DMT and -CD were evaluated using PM7 and DFT in water and gas with base 6-31G(d,p); using the CAMB3LYP functional.All approaches agree with the optimal 3D structure, which includes full DMT inclusion in the CD cavity. Complexation, LUMO, and HOMO energies were computed. The natural bond orbital (NBO) and UV-visible calculations were determined and discussed. Additionally, the non-covalent intermolecular interactions between dimethoate and β-cyclodextrin are investigated through: reduced density gradient (RDG), non-covalent interaction (NCI) and independent gradient model (IGM) that the main forces stabilizing the examined inclusion complex are H-bond and Van Der Waals interactions. Furthermore, the energy decomposition analysis (EDA) emphasizes the importance of the H-bond as attractive interactions.

Risk analysis and assessment are extremely important in the petrochemical sector to prevent potential risks. This study was carried out at Gas platform (unit No 30) of Skikda refinery Algeria, with the aim of predicting and estimating the effects of major explosions in the propane and butane Splitter column and estimating the possible human and environmental consequences of the containment loss. The methodology developed here is based on a combination of HAZOP presentation and PHAST tool. First, HAZOP is used to capture the responsible derivations of operating parameters to produce the worst consequences. Related Causes, safety barriers and some recommendations are carried out in a HAZOP sheet which represents all of that. Then the major scenarios detected by the worst consequences have been studied and modeled by PHAST software. The modeling process is completed by simulating the principal effects (Jetfire, BLEVE, UVCE) resulting from two scenarios in the form of two potential leaks on the bottom and the head of a gas separator column containing butane and propane respectively. The results are shown on the region map to indicate the exact threaten zones. Finally, a comparison in terms of effects between the two scenarios is performed and some conclusions are extracted.