In this study, density functional theory and time-dependent density functional theory are used to determine how the size of p-conjugated system influences the absorption spectra and non-linear optical (NLO) properties of dyes. Double and triple bonds, as well the benzene rings, are used in conjugated systems. The results of the theoretical computation show that the absorption spectra are gradually broadened and red-shifted with increases in the conjugation length. Theoretical examination of the NLO properties was performed on the key parameters of polarizability and hyperpolarizability. A notable increase in the non-linear optical response was observed with an increase in the conjugation length of the p-spacer.

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Non‐fused ring electron acceptors with different end‐capped substituents were designed to construct efficient organic solar cells (OSCs). End‐capped modification of acceptor materials is an efficient approach for developing high performance OSCs. In this report, five new S‐shaped fullerene‐free acceptor molecules (3P1 to 3P5) have been designed and examined through density function and time‐dependent density functional theories (TD‐DFTs). Designed molecules have twisted backbone with different out‐of‐plane rings that cause high solubility in dilute solvent. Different optoelectronic and photovoltaic properties of newly designed S‐shape molecules have been examined and explored through DFT tools. Orientation of frontier molecular orbitals (FMOs), light absorption range, exciton binding energy (Eb), oscillating strength (f), open circuit voltage (Voc), and transition density matrix (TDM) analysis have been performed for 3P1 to 3P5 molecules. Further, electron and hole reorganization energies are also estimated with excitation energy. Results of different computed parameters have recommended that these designed molecules are effective contributors for possible applications in the field of OSCs.

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In this research article, we reported solvent effects on non-linear optical (NLO) properties of 5,5 0 -disubstituted-2,2 0bipyridine complexes of ruthenium. The polarizability (a) and hyperpolarizability (b) were calculated in the gas phase. Benzene (e (dielectric constant) ¼ 2.3), THF (e ¼ 7.52), dichloromethane (e ¼ 8.93), acetone (e ¼ 21.01), methanol (e ¼ 33.00), and water (e ¼ 80.10) were used by density functional theory. These solvents cover a wide range of polarities. The results of theoretical investigation showed that the non-linear optical properties were significantly increased with the increase in solvent polarity. The results of this study also showed that similarly to structural modifications, polarity of the medium may play a significant role in modulating the NLO properties.

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We describe three cases of fracture of the titanium JRI-Furlong hydroxyapatite-ceramic (HAC)-coated femoral component. We have examined previous case reports of failure of this stem and conclude that fracture may occur in two places, namely at the neck-shoulder junction and at the conical-distal cylindrical junction. These breakages are the result of fatigue in a metallurgically-proven normal femoral component. All the cases of failure of the femoral component have occurred in patients with a body mass index of more than 25 in whom a small component, either size 9 or 10, had been used. In patients with a body mass index above normal size 9 components should be avoided and the femoral canal should be reamed sufficiently to accept a large femoral component to ensure that there is adequate metaphyseal fixation.

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