Papers by Keyword: Ruby

Abstract: Silica-coating is one of simple methods to colloidally stabilize particles. The present work proposed a method for fabricating silica-coated ruby particles having a particle size of ca. 1 µm (ruby/SiO₂) by a process based on a Stöber method. Two systems were examined, which were the systems using sodium hydroxide (NaOH) and aqueous ammonia (NH₄OH) as base catalysts for a sol-gel reaction. In the NaOH system, not only the ruby/SiO₂ particles with silica shells with a thickness of ca. 61 nm but also core-free SiO₂ particles were produced by adding tetraethyl orthosilicate/ethanol solution and NaOH aqueous solution to ethanol dispersing the ruby particle powder. In the NH₄OH system, it was demonstrated that it was possible to increase the shell thickness to 132 nm by repeating addition of TEOS and NH₄OH to a mixture of ruby particles, water, and ethanol, which meant that it was found to vary the shell thickness. The ruby particles emitted luminescence even after the silica-coating, which found that the silica-coating did not deteriorate luminescence property of ruby particles.

Abstract: Glass filled ruby is one of the treated rubies that consist of the additive substance to improve the clarity of ruby. There are many variations of glass filled rubies based on their chemical additives to fulfill the fractures during heat treatment process. However, the quality and the price of ruby are related to the different types of glass materials. Thus, the aim of this study is important to classify the type of glass materials inside the ruby samples by a non-destructive property such as their internal features. In this research, the glass filled ruby samples were collected including lead-glass filled rubies and high alumina-glass filled rubies. The surface and internal features in macro scale of the samples were observed by gem microscope. Moreover, their internal features were magnified to detect the chemical content of fractures and groundmass using electron probe micro analyzer (EPMA). As the results, there are high PbO and SiO₂ in the fractures of lead-glass filled rubies. Besides, there are high Al₂O₃ mixing with SiO₂ in the fractures of high alumina-glass filled rubies. It could be summarized that the varieties of glass filled ruby samples have been classified by the glass materials in their fractures.

Abstract: The mass attenuation coefficients and effective atomic numbers of ruby from Vietnam were measured at the different energy of γ-rays using the Compton scattering technique. The compositions of ruby were analyzed by energy dispersive x-rays fluorescence spectrometer and showed the Al₂O₃ is major composition. The results of the experimental values of mass attenuation coefficients and effective atomic numbers showed the good agreement with the theoretical values. The mass attenuation coefficients decreased with the increasing in gamma rays energies, due to the higher photon interaction probability of ruby at lower energy. The effective atomic numbers found to be constant around 10.0 electrons/atom.

Abstract: This research aims to investigate the effects of heat treatment on color and clarity of ruby. The ruby were heated at 1200, 1300, 1400, 1500 and 1600°C in oxygen atmosphere for 40 hours, respectively. Each ruby before heated and after heated, the color measurement by spectrophotometer, to observe color changing and clarity. Found that, the samples had beautiful red and clarity more than before heated. So that, heat treatment of ruby at high temperature in oxygen atmosphere, could to increment valuated of natural ruby.

Abstract: The correlations between of lightness, chroma, Cr3+ and color index were studied to analyze the impact of all these three elements on ruby red color; and with the color difference research, the lightness difference is testified to be the key affecting color appearance. Based on the uniform color space CIE 1976L*a*b*, the ruby displays the best red color when the content of Cr3+ is within (1555, 5183ppm), L* (32.64, 44.25) and ho  (354.14, 0.7). With the help of partial correlation analysis of color difference, it is illustrated that the correlation between L* and E* (r=0.999) is relatively higher than that between L* and E* (r=0.948); and with high significance level ( = 0.129) of H* and E*, it shows that H* has little impact on E*. It is concluded that the color change of ruby from red to purple are mostly affected by lightness change; lightness difference should be considered as the most important factor when evaluating the red color of ruby, and then followed by the chroma and hue jointly.

Abstract: With the development of the Internet, the online shopping was increasingly into people's life. In order to provide convenient search and price comparison service for shopping online, this article designs and implements automatic search and comparison system based on Deep web. To overcome the difficulties of data capture from the current dynamic webpage, the background’s data capture of this system implements by watir. The search module for end-users implements by JavaEE. The practical application shows that this system can fully satisfy people’s needs in search and comparison.

Abstract: Advanced engineering ceramic technology has very remarkable reputation in the high-tech fields such as semiconductor device manufacturing. ZTA (Zirconia Toughened Alumina), ruby and alumina is applied in the manufacturing of the capillaries that demonstrate high strength, fracture toughness and long life. The advantages of the new composite material over the standard ultra-fine grain high-density material have been proven in many applications especially for packages requiring less than 50μm capillary tip diameter. In this work, micro-structural evolution of ceramic composites and its correlation with important criteria in the selection of the suitable capillary material either ZTA composites or high-density ruby ceramics for a specific package applications will be discussed.

Abstract: Electro-stimulated piezo-spectroscopy (PS) can be quantitatively used for obtaining information about applied and residual stress fields piled up in ceramic materials and devices. PS experiments can be conducted in a field-emission-gun scanning electron microscope (FEG-SEM) equipped with a high spectral resolution cathodoluminescence (CL) spectrometer. Micromechanical information can be thus added to the microscopic crystallographic and chemical information already available in conventional SEM devices. Independent of the physical mechanisms behind CL emission, the spectral position of selected bands in ceramics is shown to possess high stress sensitivity. In addition, given the high scanning flexibility and spatial resolution of the electron beam, residual stress assessments can be performed on relatively large areas with significantly improved spatial resolution as compared with the more popular photo-stimulated PS approach (i.e., using a laser beam as the excitation source). In this paper, we first quantitatively characterize the stress dependence of the spectroscopic bands observed in ruby. Then, based on this knowledge, an application is shown of bi-dimensional residual stress mapping around an indentation print.

Abstract: Laser scanning confocal microscopy (LSCM) is a microscopic technique which allows for height discrimination. The ability to gather 3D data, along with adequate resolution (around 400 nm), makes the technique suitable for fractography; however, its applications in this area are not sufficiently explored. In this work, LSCM and SEM are applied to the study of fracture surfaces in sapphire and ruby fibers submitted to tensile stress in high-temperature conditions. The obtained qualitative and quantitative information demonstrates the validity of LSCM as a fractographical technique, allowing for clear identification of fractographical features and providing novel insight in the phenomenon of subcritical crack growth (SCG).