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Surface integrity parameters are the major aspect in the extension of the fatigue life of aero- engine components. In this study, a modified burnishing surface treatment (low plasticity burnishing) with reduced cold work was proposed to improve surface integrity characteristics such as surface finish and hardness, and to induce stable, advantageous compressive residual stress in a cylindrical Ti-6Al-4 V specimen (as-received). In this process, a rolling rigid spherical tungsten carbide ball is pressed across a Ti-6Al-4 V specimen at an appropriate fluid pressure generated by the hydraulic unit. The low plasticity ball burnishing tooling system supported by a hydraulic unit of capacity 30 MPa is designed and developed in this study. By using a suitable specimen holding fixture, the ball burnishing with a small amount of plastic strain was carried out on the Ti-6Al-4 V cylindrical specimen. This research examined the effect of burnishing process variables namely tool pass and burnishing fluid pressure on compressive residual stresses, surface roughness, and hardness in Ti-6Al-4 V. The explicit dynamic analysis was carried out by using FE-Analysis software ABAQUS 6.17 as a part of numerical simulation. Hydraulic burnishing pressure and burnishing passes are the most influential parameters in generating favourable compressive residual stress, qualitative surface finish with less cold work in Ti-6Al-4 V turned specimen. [ABSTRACT FROM AUTHOR]

ZnO nanoparticles (nps) have wide range of applications and improve the optical parameters of molecules of soft liquid crystalline (LC) materials. The present paper mainly discusses the optical studies on LC materials regarding p-n-butyloxybenzoic acid (4oba) and p-n-butylbenzoic (4ba) compound along with homogeneous dispersion of ZnO nps in lower weight concentration, i.e., 1, 1.5, 2 and 2.5 wt%. The existence and size of ZnO nps in LC compounds are well determined through spectroscopic techniques such as scanning electron microscopy (SEM) and X-ray diffraction (XRD). The temperatures of LC compounds and phase transitions are determined by using polarizing optical microscopy (POM) and differential scanning calorimetry (DSC) which is found to decrease with increasing concentration of dispersed ZnO nps. Image enhancement with visual quality matrix method is used to improve the quality of the image. Specially designed wedge-shaped modified spectrometer is used to determine the refractive indices with different wavelengths (460, 500, 570 and 635 nm). The refractive indices measured are fitted with two and three coefficient Cauchy model. Further, the order parameter S of the molecules of 4ba and 4oba with dispersed ZnO nps are determined by molecular field models namely Kuczynski, Vuks and effective geometry model, respectively. From the data, it is found that the values of birefringence (δn) and order parameter (S) of the molecules of 4oba and 4ba are enhanced with the dispersion of ZnO nps with increasing weight concentrations in the stabilized nematic thermal region. [ABSTRACT FROM AUTHOR]

The synthesis and characterisation are carried on liquid crystalline (LC)p-dodecyloxy benzoic acid (12OBA) with 1 and 2 wt% for PdCl2nanoparticles dispersion. Further, characterizations are carried out by different spectroscopic techniques like X-ray diffraction spectrometric studies, scanning electron microscopy, Fourier transform infrared and differential scanning calorimetry (DSC). Textural determinations of the synthesised compounds are recorded by using polarising optical microscope (POM) attached with a hot stage and camera. The results show that the dispersion of PdCl2nanoparticles in 12OBA exhibits Nematic phases as same as the pure 12OBA with reduced clearing temperature as expected. Further, the nematic thermal ranges are quenched and the smectic C thermal range has been increased while performing both DSC and POM with the dispersion of 1 wt% PdCl2nanoparticles. Size dependence on bonding nature with LC compounds is established. [ABSTRACT FROM AUTHOR]

In this work we synthesized SrO-ZnO-P2O5 glasses mixed with Pb3O4 (heavy metal oxide) and doped with different amounts of Dy2O3 (0.1 to 1.0 mol%). Subsequently their emission and decay characteristics were investigated as a function of Dy2O3 concentration. The emission spectra exhibited three principal emission bands in the visible region corresponding to 4F9/2 → 6H15/2 (482 nm), 6H13/2 (574 nm) and 6H11/2 (663 nm) transitions. With increase in the concentration of Dy2O3 (upto 0.8 mol%) a considerable increase in the intensity of these bands was observed and, for further increase, quenching of photoluminescence (PL) output was observed. Using emission spectra, various radiative parameters were evaluated and all these parameters were found to increase with increase in Dy2O3 concentration. The Y/B integral emission intensity ratio of Dy3+ ions evaluated from these spectra exhibited a decreasing trend with increase in the Dy2O3 concentration up to 0.8 mol%. Quenching of luminescence observed in the case of the glasses doped with 1.0 mol% is attributed to clustering of Dy3+ ions. The quantitative analysis of these results together with infra-red (IR) spectral studies indicated that 0.8 mol% is the optimum concentration of Dy3+ ions needed to achieve maximum luminescence efficiency. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this paper, 20 µl citrate capped Gold (Au) nanoparticles are dispersed in Schiff base Liquid Crystalline compounds 6O.Om (m = 7 and 9) and characterizations are carried-out to observe the changes occurred with the dispersion of nanoparticles in Liquid Crystalline compounds. The Polarizing Microscopy (POM) technique is used to measure the phase transition temperatures. Differential Scanning Calorimetry (DSC) is used to determine the transition temperatures and enthalpy values. Further characterization is carried-out by Scanning Electron Microscopy (SEM). The nematic transition temperature is decreased by 1 °C with the dispersion of citrate capped Au nanoparticles into the Liquid Crystalline compounds. Image processing technique of textural analysis is also carried-out to identify the statistical parameters of the images and their transition temperatures. [ABSTRACT FROM AUTHOR]

Synthesis and characterization of Liquid Crystalline p-n-decyloxy benzoic acid (10OBA) compound with thiolcapped Ag nanoparticle dispersion was carried out by chemical reduction method. The Polarizing Microscopy (POM), Differential Scanning Calorimeter (DSC) technique are used to measure the Glass transition temperature (Tg) and melting temperature (Tm) of the prepared samples. Spectroscopic techniques like X-ray Diffraction spectrometric studies (XRD), Scanning Electron Microscopic studies (SEM), Ultra-Violet Visible (UV) spectroscopy, Fourier Transform Infra Red Spectroscopy (FTIR) were also carried out on to the samples. Textural determinations of the synthesized compounds are recorded by using POM connected with a hot stage and camera. The results showed that the dispersion of thiol-capped Ag nanoparticles in 10OBA exhibited NC phases as that of the pure 10OBA with reduced clearing temperature as expected. The order parameter is estimated from birefringence anisotropy data without considering any internal field model to liquid crystal molecule and with dispersed thiol-capped Ag nanoparticles. It is found that the birefringence anisotropy as well as orientational order parameter of 10OBA increased with dispersed 1 wt% thiol-capped Ag nanoparticles. [ABSTRACT FROM AUTHOR]

In the present paper synthesis and characterization are carried on citrate capped Gold (Au) nanoparticles dispersed in Liquid Crystalline p-n-Hexyloxycyanobiphenyl (6OCB) compound. We have reported citrate capped Au nano particles are synthesized by chemical reduction method which is having a broad range of applications and dramatically effects the birefringence properties of 6OCB when dispersion with low concentration. The Polarizing Microscopy (POM) technique is used to measure the phase transition temperatures. Further characterization is carried out by various spectroscopic techniques like X-ray Diffraction Studies (XRD), Scanning Electron Microscopic studies (SEM), Ultra Violet Visible (UV) spectroscopy. Textural determinations of the synthesized compounds are recorded by using POM connected with a hot stage and camera. The results showed that the dispersion of citrate capped Au and in 6OCB exhibit nematic phase as same as the pure 6OCB with slightly reduced clearing temperature as expected. Further, the birefringence anisotropy of 6OCB with dispersed citrate capped Au nanoparticles increases by 14%. It is found that the birefringence anisotropy as well as orientation order parameter of 6OCB increases with dispersed citrate capped Au nanoparticles. [ABSTRACT FROM AUTHOR]

Liquid crystalline compounds exhibit more enhanced optical properties with dispersed ZnO nanoparticles. In the present work 1wt% ZnO nanoparticles are dispersed in liquid crystalline Schiff base 10O.Om compounds (m=3,4 and 5). The Differential Scanning Calorimetry (DSC) technique is used to measure the phase transition temperatures. The characterization of nanoparticles is carried out by various spectroscopic techniques like Ultra-Violet Visible Spectroscopy(UV), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier Transform Infra Red Spectroscopy (FTIR). Textural determinations of the synthesized compounds are recorded by using Polarizing Optical Microscope (POM) connected with hot stage and camera. The results show that the dispersion of 1wt%ZnO nanoparticles in 10O.Om compounds exhibit NC phases as same as the pure compounds with reduced clearing temperatures as expected and the nematic thermal ranges are increased slightly. [ABSTRACT FROM AUTHOR]

The synthesis is carried on liquid crystalline (LC)p-decyloxy benzoic acid (10OBA) and p-undecyloxy benzoic acid (11OBA) with 0.5wt % and1wt% for Fe3O4 nanoparticles dispersion. The prepared samples are characterized by different spectroscopic techniques like X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infra Red (FTIR) and Differential Scanning Calorimetry (DSC). Textural determinations of the synthesized compounds are recorded by using Polarizing Optical Microscope (POM) attached with a hot stage and camera. The results show that the dispersion of Fe3O4 nanoparticles in 10OBA and 11OBA exhibits NC phases as same as the pure 10OBA and 11OBA with reduced clearing temperature as expected. Further, the nematic thermal range is increased in both 10OBA and 11OBA with Fe3O4 nanoparticles dispersion. [ABSTRACT FROM AUTHOR]