Papers by Keyword: Glass

Abstract: The purpose of this study was to achieve grooving on glass substrates with high levels of efficiency and precision with the use of a diamond grindstone with a small diameter in the range of 1.0-1.8 mm. Mechanical material removal by grinding has high efficiency and enables process control for creating complicated forms, but has a drawback of generating chippings on the processed surface of the brittle glass material. The study gave ultrasonic vibration of 10 μm at 20 kHz in the thrust direction to the rotating small-diameter diamond grindstone in the grinding process, in order to attain high levels of efficiency and precision in micro-grooving of glass. The grooving approach with ultrasonic vibration did create some minor chippings, but succeeded in meeting the target of reducing the average size of chippings around the groove to 0.1 mm or less.

Abstract: The linear and non-linear properties of material have gained in both scientific interest and technological importance. Over the last few years, there has been much interest in developing materials with large nonlinearities in order to exploit their potential for use in ultrafast nonlinear optical devices. The different factors that play a role for controlling the refractive indices such as density, molar refraction, photon energy, coordination number, electronic polarizability, field strength of cations, bridging and nonbridging oxygen, and optical basicity are discussed in accordance with the obtained linear refractive index data. The nonlinear phenomena which include intensity dependent on refractive index, excitation energy, dispersion energy, optical energy, metallization criterion, second and third harmonic generations have been discussed. Finally, the optical application, viz. photonics, electro-optics, photo chromic and magneto-optics of the material have been studied. Keywords: Glass; linear; nonlinear indices; optical application

Abstract: The temperature field is an important aspect to study the interaction mechanism between the laser and glass. The temperature distribution on the surface of the glass that illuminated by the CO laser is numerical simulated by using the finite element method. The change of the temperature field of the target, irradiated by the laser in different time or different power, is simulated respectively, get the curve of the temperature field which reflects the temperature at the center spot changing with the action time and power.

Abstract: To investigate the effects of sol pH value and water content on photocatalytic activity of TiO₂ prepared with sol-gel auto-igniting synthesis (SAS) method, TiO(NO₃)₂ was prepared with TiCl₄ as raw material and used as precursor of TiO₂. By changing sol pH value and water content, different TiO₂ powders were prepared and characterized with XRD, SEM and photodegradation of methylene blue (MB). Results indicated that TiO₂ presented the highest photocatalytic activity while sol pH value and mass fraction of water were adjusted to 7 and 50% respectively while the mole ratio of n (TiCl₄): n (citric acid): n (ammonium nitrate) was fixed as 1: 1: 3. The TiO₂ powders were confirmed as loose and porous anatase type with particle size of 15 nm by SEM and XRD.

Abstract: In this work, effects of Ni²⁺ ions on soda lime silicate glasses have been investigated. Glasses were prepared in formula (65-x)SiO₂ : 25Na₂O : 10CaO: xNiO (where x is 0.00, 0.02, 0.04, 0.06, 0.08 and 0.10 mol%). The densities of glasses not depend on Ni²⁺ concentration. The refractive indices decreased with increasing of NiO concentration. The optical absorption spectra were measured by uv-visible spectrophotometer and show peaks correspond with Ni²⁺ in glass matrices. Both of octahedral transitions and tetrahedral transition from Ni²⁺ ion were found around 450 and 625 nm respectively. The color of glasses were also measured in CIE L* a* b* system.

Abstract: Bismuth borate glasses doped with cerium in the composition 50Bi₂O₃:(50-x)B₂O₃:xCeF₃ were prepared for the composition range 0x2.5 (in mol%). The glass samples have been fabricated by the conventional melt quenching technique. The physical and optical properties of glass samples were investigated. The optical absorption spectra of the glasses have been measured in the wavelength range 190-1100 nm and no absorption peak was obtained in this region. The absorption spectra of all samples were shifted to longer wavelength with increasing of CeF₃ concentrations. Optical band gap decreased and refractive index increased with increasing of CeF₃ concentrations.

Abstract: This research is intended to study and construct a two doors electrical furnace. Two line of Kanthal AF wire were used as a heat source furnace. Insulator of furnace was constructed from light brick C-2. The volume of furnace was about 25x30x45 cm³. Quantity of current flow through heating element was controlled by solid state relay. Temperature of the furnace is measured by thermocouple type K. The result of test performance of the furnace show that the temperature of 1200 °C was obtained at 220 volt and current in heating elements of 15 A.

Abstract: Soda-lime-silicate glasses in the compositions of (65-x)SiO₂-25Na₂O-10CaO-xHo₂O₃ (where x = 0.0, 0.50, 1.00, 1.50, 2.00 and 2.50 mol % ) were prepared by melt-quenching technique and characterized. The results show that, the absorption spectra of Ho³⁺ doped in soda-lime-silicate glass correspond with several bands, which are assigned from the ground state, ⁵I₈ to ³H₆ (360 nm), ⁵G₄ (380 nm), ⁵G₅ (417 nm), ⁵G₆ (453 nm), ⁵F₃ (479 nm), ⁵F₄ (538 nm), ⁵F₅ (639 nm), and ⁵I₅ (880 nm). The refractive index and density of glasses were increase with increasing of Ho₂O₃ concentration. The color of glass samples is light amber with doped Ho₂O₃ in glass matrix.

Abstract: The soda-lime glass with the composition of 74SiO₂-18Na₂O-6CaO-B₂O₃-Al₂O₃ thermodynamically requires the exploited heat of 557 kW/ ton of glass to transform raw materials into glass. The objective of this project is to modify the soda-lime glass batch by using wollastonite instead of limestone and pyrophyllite instead of aluminium hydroxide. The exploited heat of the batch with wollastonite is reduced to 546 kW/ton of glass while the batch with wollastonite and pyrophyllite is decreased to 550 kW/ton of glass. According to Batch-Free Time testing, it is found that the melting ability of both modified batches is higher than of the original batch, while the properties of glass are slightly changed. This implies that the modified batch requires a lower melting energy than the original batch.

Abstract: Bismuth titanium borate glasses in compositions xTiO₂ : (30-x)Bi₂O₃ : 70B₂O₃ (with x is in mol%, varying from 0% to 10%) were fabricated by the conventional melt quenching technique. The effect of TiO₂ on the physical and spectroscopic properties of bismuth borate glasses have been carried out by means of density and UV-Visible spectroscopy measurement techniques. The density and molar volume of all glasses are found to change depend on TiO₂ substitution. The fundamental absorption edges for all glasses have been identified using the theory proposed by Davis and Mott. The optical band gap (E_g) is found to decrease with increase in TiO₂ content.