Search

The present study evaluates the surface settlement due to the construction of twin tunnels using small-scale physical modeling. Extensive numerical modeling has also been conducted to investigate the surface settlement and change of stresses in the surrounding soil medium. The accuracy of the numerical model has been benchmarked, and a parametric study considering the prototype dimensions of the tunnel, level of water table, surcharge loading, and spacing between the tunnels has been investigated. The surface settlement was found to be the maximum for the location of the water table at the crown of twin tunnels. The surface settlement typically decreased with the decreasing ratio of clear spacing (X) to tunnel diameter (D). A sharp decrease in settlement was observed for the range of X/Dratio between 0.75 and 2.25.

The dissociative ionization of 13 nitro derivatives of 2(4)-azafluorenes and 2(4)-azafluorenones was investigated. The introduction of an electron-acceptor nitro group into the molecule markedly reduces the stability of the molecular ions and suppresses the fragmentation pathways that are characteristic for azafluorenes. Nitro-nitrite rearrangement proceeds more readily in nitro-substituted 4-azafluorenes than in nitro-substituted 2-azafluorenes. A characteristic feature of the fragmentation of azafluorenes that do not contain nitro and methyl groups in a vicinal orientation is elimination of a OH particle by the molecular ions. It was established by deuterium labeling that in this case the formation of an [M — OH]+ ion is due to the presence of a methylene group attached to the C9 atom in the molecule.

Paracetamol or acetaminophen is a medication commonly used in pain and fever. It is typically used for mild to moderate pain relief. It can produce selective inhibition to the prostaglandin synthesis. We envisage the density functional theory (DFT) with B3LYP/6-31G+(d,p) basis set to optimize the newly modified derivatives. Thermodynamic properties, molecular orbital features, dipole moment, atomic partial charge and electrostatic potential have been calculated in order to compare their physicochemical and biological properties. Molecular docking, nonbonding interactions, and dynamics simulation have been performed against prostaglandin H2 (PGH2) synthase protein 5F19 to investigate their binding affinity, binding modes, and stability of the protein-drug complex. ADMET prediction has been utilized to compare the absorption, metabolism, and carcinogenic properties of new derivatives with parent drug (PCT). From physicochemical data, all modified structures are thermodynamically stable; most of them are chemically more reactive and show better binding affinity than the parent drug. ADMET calculations predict the improved pharmacokinetic properties of modified derivatives. Based on physicochemical, docking, dynamics simulation and ADMET prediction results, this study can be helpful to design a new analgesic and antipyretic drug.