Effects due to body-forces and body-couples in the interior of a micropolar elastic half-space—I

A general solution of the equilibrium equations is obtained for a half-space with a fixed boundary and arbitrary but axisymmetric distribution of body forces and body couples in the interior of the half-space. Few particular cases have been investigated in detail. The stresses have been obtained at the boundary and the displacements have been obtained in the interior of the half-space. Numerical results have been displayed graphically.

---

Zusammenfassung Eine allgemeine lösung für Gleichgewicht eines Halbraums mit festem Rand und einer beliebigen, aber antisymmetrischen Verteilung von Körperkräften und Körpermomenten im Inneren wird gefunden. Einige Spezialfälle wurden ansführlich erforscht. Die Spannungen am Rand und die Verschiebungen im Inneren des Halbraums wurden erhalten. Numerische Resultate wurden graphisch dargestellt.

     

Synthesis, characterization and antimicrobial studies of mixed ligand silver(I) complexes of triphenylphosphine and heterocyclic thiones: Crystal structure of bis[{(μ-diazinane-2-thione)(diazinane-2-thione)(triphenylphosphine)silver(I) nitrate}]

Mixed ligand silver(I) complexes of triphenylphosphine and heterocyclic thiones (imidazolidine-2-thione (Imt), diazinane-2-thione (Diaz) and 2-mercaptopyridine (Mpy)) having the general formulae [(Ph₃P)Ag(thione)₂]NO₃ and [(Ph₃P)₂Ag(thione)]NO₃ were prepared and characterized by elemental analysis, IR and NMR (¹H, ¹³C and ³¹P) spectroscopic methods. The crystal structure of one of the complexes, [Ag(Ph₃P)(Diaz)₂]₂(NO₃)₂ (1) was determined by X-ray crystallography. The title complex (1) is dinuclear, having each silver atom coordinated to three thione sulfur atoms of Diaz and to one phosphorus atom of PPh₃ in a nearly tetrahedral environment, with an average P-Ag-S bond angle of 108.5°. The spectral data of the complexes are consistent with sulfur coordination of the thiones to silver(I). Antimicrobial activities of the complexes were evaluated by minimum inhibitory concentrations and the results showed that the complexes exhibit a wide range of activity against two gram-negative bacteria (E. coli, P. aeruginosa) and molds (A. niger, P. citrinum), while the activities were poor against yeasts (C. albicans, S. cerevisiae).     

FT-Raman, FT-IR spectra and total energy distribution of 3-pentyl-2,6-diphenylpiperidin-4-one: DFT method

FT-Raman and FT-IR spectra were recorded for 3-pentyl-2,6-diphenylpiperidin-4-one (PDPO) sample in solid state. The equilibrium geometries, harmonic vibrational frequencies, infrared and the Raman scattering intensities were computed using DFT/6-31G(d,p) level. Results obtained at this level of theory were used for a detailed interpretation of the infrared and Raman spectra, based on the total energy distribution (TED) of the normal modes. Molecular parameters such as bond lengths, bond angles and dihedral angles were calculated and compared with X-ray diffraction data. This comparison was good agreement. The intra-molecular charge transfer was calculated by means of natural bond orbital analysis (NBO). Hyperconjugative interaction energy was more during the π–π* transition. Energy gap of the molecule was found using HOMO and LUMO calculation, hence the less band gap, which seems to be more stable. Atomic charges of the carbon, nitrogen and oxygen were calculated using same level of calculation.     

Molecular structure, vibrational spectroscopic (FT-IR, FT-Raman), UV and NBO analysis of 2-chlorobenzonitrile by density functional method

In this work, we will report a combined experimental and theoretical study on molecular structure, vibrational spectra, NBO and UV spectral analysis of 2-chlorobenzonitrile (2-ClBN). The FT-IR solid phase (4000-400 cm(-1)), and FT-Raman spectra (3500-50 cm(-1)) of 2-ClBN was recorded. The molecular geometry, harmonic vibrational frequencies and bonding features of 2-ClBN in the ground state have been calculated by using the density functional methods (BLYP, B3LYP) with 6-31G(d,p) as basis set. The assignments of the vibrational spectra have been carried out with the help of normal co-ordinate analysis (NCA) following the Scaled Quantum Mechanical Force Field Methodology (SQMFF). Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The results show that charge in electron density (ED) in the σ* and π* anti bonding orbitals and E2 energies confirms the occurrence of ICT (Intra molecular Charge Transfer) within the molecule. The UV spectrum was measured in ethanol solution. The energy and oscillator strength calculated by Time-Dependent Density Functional Theory (TD-DFT) results complements with the experimental findings. The calculated HOMO and LUMO energies also confirm that charge transfer occurs within the molecule. Finally calculated results were applied to simulated Infrared and Raman spectra of the title compound which show good agreement with observed spectra.     

Structural studies on fullerenes

Amongst the other physical properties, the structure of fullerene solids, and the structural transformations with temperature, pressure and doping have all evoked considerable interest and during the last two years tremendous progress has been made in this area. This paper provides a brief review of the studies on the structural properties of pristine and doped fullerenes. The results of our own investigations are also presented.     

Pion-proton elastic scattering at 200 GeV/c

Recent measurements of differential and elastic cross-sections, slope parameters and ratios of the real and imaginary parts of the forward scattering amplitudes for pion-proton elastic scattering at 200 GeV/c have been fitted by using a simple Regge pole model with phenomenological residue functions. The computed results for total cross-sections have also been compared with the experimental data.     

Microdetermination of spermidine, 1,3-diaminopropane,and p-phenylenediamine with chloranil

Spermidine, 1,3-diaminopropane, and p-phenylenediamine form molecular complexes with chloranil at pH 9. The composition and stability of these complexes have been studied spectrophotometrically. The results indicate that complexes were of 1:1 type and their stability increases with the basicities. The method of complexation was used to determine spectrophotometrically a ppm amount of SD, DAP, and PhDA in solution. The accuracy and precision of the method were found to be very high.     

Principle of massive support in the opposed anvil high pressure apparatus

The Bridgman anvil technique offers a simple and versatile means of generating very high pressures required in solid state studies. The opposed anvil technique is based on the principle of massive support. The practical case of a gasketted anvil is considered, and an expression for the maximum pressure generated under massive support is derived in terms of the geometric parameters, the strength of the anvil material and the gasket properties. In particular, for a given maximum pressure, it is possible to calculate the taper angle, the taper height and the gasket thickness from this expression. The anvil is assumed to be in the elastic region under load. Good agreement is obtained between the calculated and the experimental values for the massive support factor (msf) for various taper angles. By choosing the proper geometry, it is possible to achieve a pressure as high as 130 kbar in an alloy steel anvil. It has been clearly found that the straight portion, where the taper ends, does not really take any part in changing the stress pattern. Thus the minimum straight portion can serve the purpose, and will result in material saving. Anvils exhibit yielding at very high pressure. It is also pointed out that a further strengthening of the anvil can extend the ultimate pressure. Several methods of further strengthening the anvils are discussed.