scholarly journals Tunning the Crystallization Behavior of B2O3 – SiO2 – Bi2O3 – TiO2 – Y2O3 Glasses

2021 ◽  
Author(s):  
kh. S. Shaaban
Keyword(s):  
Glass Ceramic ◽  
Xrd Analysis ◽  
Nucleating Agent ◽  
Thermal Parameter ◽  
Glass System ◽  
Present System ◽  
Increasing Trend ◽  
Parameter Values ◽  
Modifier Oxide ◽  
Quench Method

Abstract Glasses with the chemical composition of 52B2O3 – 12SiO2- 26Bi2O3 – (10-x)TiO2 -xY2O3, :(0 ≤ x ≥10)prepared using the melt-quench method. The goal of this study is to investigate the structural, thermal, and crystallization characteristics of these samples. XRD analysis has explored the nature of the glass system. Molar volume obtained reduced while the density denotes increased in the present system. FTIR analysis revealed that as Y2O3 replaced by TiO2, because of an increasing trend in bridging oxygens (BOs), structural units and interconnection of modifier oxide tetrahedral increment, while non-bridging oxygens (NBOs) reduce. These glasses' thermal stability investigated using DTA. As the concentration of Y2O3 increased, so the thermal parameter values. The glass-ceramic denoted prepared under controlled heat and investigated using XRD & SEM. Ultrasonic velocities and elastic moduli of glass-ceramic samples increase as internal energy increases. The significance of Y2O3 modifier in the glass system signifies proved. Y2O3 is a powerful nucleating agent that can cause crystallization, assisting in the formation of glass-ceramic phases.

Thermal and Crystallization Behavior of B2O3 – SiO2 – Bi2O3 – TiO2 – Y2O3 Glasses

2021 ◽  
Author(s):  
Kh. S. shaaban
Keyword(s):  
Glass Ceramic ◽  
Xrd Analysis ◽  
Nucleating Agent ◽  
Thermal Parameter ◽  
Glass System ◽  
Present System ◽  
Increasing Trend ◽  
Parameter Values ◽  
Modifier Oxide ◽  
Quench Method

Abstract Glasses with the chemical composition of 52B2O3 – 12SiO2- 26Bi2O3 – (10 - x ) TiO2 - xY2O3, : (0 ≤ x ≥ 10 )prepared using the melt-quench method. The goal of this study is to investigate the structural, thermal, and crystallization characteristics of these samples. XRD analysis has explored the nature of the glass system. Molar volume obtained reduced while the density denotes increased in the present system. FTIR analysis revealed that as Y2O3 replaced by TiO2, because of an increasing trend in bridging oxygens (BOs), structural units and interconnection of modifier oxide tetrahedral increment, while non-bridging oxygens (NBOs) reduce. These glasses' thermal stability investigated using DTA. As the concentration of Y2O3 increased, so the thermal parameter values. The glass-ceramic denoted prepared under controlled heat and investigated using XRD & SEM. Ultrasonic velocities and elastic moduli of glass-ceramic samples increase as internal energy increases. The significance of Y2O3 modifier in the glass system signifies proved. Y2O3 is a powerful nucleating agent that can cause crystallization, assisting in the formation of glass-ceramic phases.

scholarly journals Optical Properties of SiO2 – TiO2 – La2O3 – Na2O – Y2O3 glasses and A novel process of preparing the parent glass-ceramics

2021 ◽  
Author(s):  
A. F. Abd El-Rehim ◽  
E. A Abdel Wahab ◽  
M. M. Abou Halaka ◽  
Kh. S. shaaban
Keyword(s):  
Glass Ceramic ◽  
Room Temperature ◽  
Elastic Moduli ◽  
Glass Ceramics ◽  
Nucleating Agent ◽  
Thermal Parameter ◽  
Glass System ◽  
Ceramic Samples ◽  
Parameter Values

Abstract Quaternary glasses with the composition 50SiO2 – 25TiO2 – 5La2O3 – (20-x) Na2O – xY2O3 where x: (0≤x≥10) were synthesized using the melt-quench technique. XRD examined the nature of prepared glasses. UV-spectroscopic of investigated glass system studied at room temperature. Both optical bandgap and refractive index of the present glass have been increased. The polarizability and basicity were determined. Thermal parameter values increased as Y2O3 increased. Under controlling heat, the glass-ceramic were prepared and confirmed using XRD. Glass-ceramics are examined using SEM to evaluate a microstructure. Ultrasonic velocities and elastic-moduli of glass-ceramic samples are increased because of the increase in internal energy. The role of Y2O3 modifier in the glass system is clearly demonstrated. Y2O3 also works as an excellent nucleating agent that can induce crystallizations, supporting in the creation of the sub-phase of glass-ceramics.

scholarly journals Synthesis, Crystallization, and Dielectric Behaviour of Lead Bismuth Titanate Borosilicate Glasses with Addition of 1% La2O3

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
C. R. Gautam ◽  
Abhishek Madheshiya ◽  
R. K. Dwivedi
Keyword(s):  
Glass Ceramic ◽  
Bismuth Titanate ◽  
Glass System ◽  
Glassy Matrix ◽  
Borosilicate Glasses ◽  
X Ray Diffraction ◽  
Mole Percent ◽  
Ceramic Samples ◽  
Donor Dopant ◽  
Quench Method

Lead bismuth titanate borosilicate glasses were prepared in the glass system 65[(PbxBi1-x)·TiO3]-34[2SiO2·B2O3]-1La2O3 (0.0≤x≤1.0) doped with one mole percent of La2O3 via conventional melt quench method. The amorphous nature of glass samples in this glass system is confirmed by using X-ray diffraction (XRD) study. Differential thermal analysis (DTA) has been employed to determine the glass transition temperature, Tg, as well as crystallization temperature, Tc. DTA measurements were recorded in temperature range from 30 to 1200°C. The prepared glasses were crystallized by regulated controlled heat treatment process on the basis of their DTA results. These samples are carried out for XRD measurements in the 2θ range from 20 to 80° to study the crystallization behaviour and phase formation of the glass ceramic samples. The scanning electron microscopy (SEM) of these glass ceramic samples has been carried out to explore the morphology through nucleation and growth of the crystallites in the glassy matrix. The values of dielectric constant as well as dielectric loss were increased with increasing the temperature within the frequency range from 20 Hz to 100 Hz. The addition of 1 mol% of La2O3 to the lead bismuth titanate glasses enhances the crystallization and acts as donor dopant for this glass system.

Tm3+/Yb3+ Codoped YAG Glass-Ceramic Formed in Silicate Glass System

2012 ◽  
Vol 455-456 ◽  
pp. 701-705
Author(s):  
Xiang Ling Zhang ◽  
Jie Zhang ◽  
Quan Shen ◽  
Hai Lin
Keyword(s):  
Glass Ceramic ◽  
Glass Formation ◽  
Heat Treating ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Glass System ◽  
Glass Formation Region ◽  
Formation Region ◽  
Internal Network ◽  
Crystal Grains

Based on the analysis of glass formation region of Y2O3-Al2O3-SiO2 glass system, the glass composition 5Li2O-18Y2O3-29Al2O3-48SiO2 (LYAS) in mol% central in the glass formation region of Y-Al-Si glass system was chosen for present work. The Tm3+ and Yb3+ were introduced as activators in LYAS glass. The glass samples were prepared by the high-temperature solid-state melting and then the derived YAG glass-ceramic was obtained by heat-treating the precursor glass. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis results indicate that the lattice constant of the obtained glass-ceramic is consistent with the pure YAG phase. The primary crystallite size is calculated to be 46nm and the crystal grains grow with excellent orientation (444) in the internal network. The secondary particle size is estimated to be ~8μm and the large grain size is owing to the particles aggregation. The crystal grains distributed uniformly in the glass matrix, and consistent well with the XRD analysis results.

scholarly journals Research on the Effects of Yttrium on Bismuth Titanate Borosilicate Glass System 

2021 ◽  
Author(s):  
Kh. S. shaaban
Keyword(s):  
Molar Volume ◽  
Glass Structure ◽  
Effective Atomic Number ◽  
Mean Free Path ◽  
Xrd Analysis ◽  
Mass Attenuation Coefficient ◽  
Radiation Shielding ◽  
Glass System ◽  
Present System ◽  
Gamma Photon

Abstract Glasses with the chemical composition of 52B2O3 – 12SiO2- 26Bi2O3 – (10 - x)TiO2 - xY2O3, (0 ≤ x ≥ 10)prepared using the melt-quench method. The goal of this study is to investigate the structural, mechanical, and radiation shielding characteristics of these samples. XRD analysis has explored the nature of the glass system. Molar volume obtained reduced while the density denotes increased in the present system. As the molar volume decrease inter-ionic distance, polaron radius, inter-nuclear distance, and Y-Y separation of the investigated glasses decreased. The mechanical characteristics depend on the glass structure of the current glasses sample. Ultrasonic velocities and elastic moduli (experimental and theoretical) for these glasses obtained observed to get enhanced. The radiation shielding efficiency investigated by Phy-X/PSD software. The mass attenuation coefficient (μ/ρ) mean free path (MFP), half-value layer (HVL), tenth value layer (TVL), and effective atomic number (Zeff), of glasses, have designed to simulate for gamma photon energies between 0.015 and 15 MeV.

scholarly journals Fabrication and characterization of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) modified with nano-montmorillonite biocomposite

e-Polymers ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 038-046
Author(s):  
Xu Yan ◽  
Wanru Zhou ◽  
Xiaojun Ma ◽  
Binqing Sun
Keyword(s):  
Thermal Stability ◽  
Oxygen Permeability ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Nucleating Agent ◽  
Vapor Permeability ◽  
Casting Method ◽  
Increasing Trend ◽  
Solution Casting Method

Abstract In this study, a poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) modified with nano-montmorillonite biocomposite (MMT/PHBH) was fabricated by solution-casting method. The results showed that the addition of MMT increased the crystallinity and the number of spherulites, which indicated that MMT was an effective nucleating agent for PHBH. The maximum decomposition peak of the biocomposites moved to a high temperature and residue presented an increasing trend. The biocomposites showed the best thermal stability at 1 wt% MMT. Compared with PHBH, 182.5% and 111.2% improvement in elastic modulus and tensile strength were obtained, respectively. Moreover, the oxygen permeability coefficient and the water vapor permeability of MMT/PHBH biocomposites decreased by 43.9% and 6.9%, respectively. It was also found that the simultaneous enhancements on the crystallizing, thermal stability, mechanical, and barrier properties of biocomposites were mainly caused by the formation of intercalated structure between PHBH and MMT.

MODELING THE TRANSMISSION DYNAMICS OF DAIRY CATTLE BRUCELLOSIS IN JILIN PROVINCE, CHINA

2014 ◽  
Vol 22 (04) ◽  
pp. 533-554 ◽  
Author(s):  
JING NIE ◽  
GUI-QUAN SUN ◽  
XIANG-DONG SUN ◽  
JUAN ZHANG ◽  
NAN WANG ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Rapid Development ◽  
Real Data ◽  
Jilin Province ◽  
Annual Number ◽  
Bacterial Disease ◽  
Increasing Trend ◽  
Milk Cows ◽  
Parameter Values ◽  
Globally Stable

Dairy cattle brucellosis is a chronic bacterial disease, which is caused by Brucella abortus and mainly characterized by abortion in dairy cattle. With the rapid development of breeding industry of milk cows in China, the infectious cases of dairy cattle brucellosis show an increasing trend. Particularly in Jilin province, the annual number of the positive cases of dairy cattle was only 3 cows in 1987, and went up to 168 cows in 2005. Based on the situation of the brucellosis infection in Jilin province, we propose an Susceptible-Exposed-Infected-Virus (SEIV) dynamical model with outside transferred amount to describe the transmission of brucellosis amongst dairy cattle in this paper. We calculate the basic reproduction number R0 and prove that the equilibria are globally stable. Moreover, using the real data of nearly 20 years in Jilin province, we estimate the parameter values in the system. As a result, we can predict the number of infections as time increases. According to the prediction for the next 30 years, we can conclude that the disease will persist if we just take existing measures. If culling, sterilizing and decreasing the number of outer importing are used together, dairy cattle brucellosis will be well controlled.

scholarly journals Reddish-Orange Luminescence from BaF2:Eu3+ Fluoride Nanocrystals Dispersed in Sol-Gel Materials

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3735 ◽  
Author(s):  
Natalia Pawlik ◽  
Barbara Szpikowska-Sroka ◽  
Joanna Pisarska ◽  
Tomasz Goryczka ◽  
Wojciech A. Pisarski
Keyword(s):  
Glass Ceramic ◽  
Structural Changes ◽  
Sol Gel ◽  
Ceramic Materials ◽  
Xrd Analysis ◽  
Luminescence Spectra ◽  
Silica Network ◽  
Scanning Calorimetry ◽  
Glass Ceramic Materials ◽  
Reddish Orange

Nanocrystalline transparent BaF2:Eu3+ glass-ceramic materials emitting reddish-orange light were fabricated using a low-temperature sol-gel method. Several experimental techniques were used to verify structural transformation from precursor xerogels to sol-gel glass-ceramic materials containing fluoride nanocrystals. Thermal degradation of xerogels was analyzed by thermogravimetric analysis (TG) and differential scanning calorimetry method (DSC). The presence of BaF2 nanocrystals dispersed in sol-gel materials was confirmed by the X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM). In order to detect structural changes in silica network during annealing process, the infrared spectroscopy (IR-ATR) was carried out. In particular, luminescence spectra of Eu3+ and their decays were examined in detail. Some spectroscopic parameters of Eu3+ ions in glass-ceramics containing BaF2 nanocrystals were determined and compared to the values obtained for precursor xerogels. It was observed, that the intensities of two main red and orange emission bands corresponding to the 5D0→7F2 electric-dipole transition (ED) and the 5D0→7F1 magnetic-dipole (MD) transition are changed significantly during transformation from xerogels to nanocrystalline BaF2:Eu3+ glass-ceramic materials. The luminescence decay analysis clearly indicates that the measured lifetime 5D0 (Eu3+) considerably enhanced in nanocrystalline BaF2:Eu3+ glass-ceramic materials compared to precursor xerogels. The evident changes in luminescence spectra and their decays suggest the successful migration of Eu3+ ions from amorphous silica network to low-phonon BaF2 nanocrystals.

scholarly journals Effects of Sintering Temperature Variation on Synthesis of Glass-Ceramic Phosphor Using Rice Husk Ash as Silica Source

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5413
Author(s):  
Rabiatul Adawiyah Abdul Wahab ◽  
Mohd Hafiz Mohd Zaid ◽  
Sidek Hj. Ab Aziz ◽  
Khamirul Amin Matori ◽  
Yap Wing Fen ◽  
...  
Keyword(s):  
Rice Husk ◽  
Glass Ceramic ◽  
Rice Husk Ash ◽  
Glass Ceramics ◽  
Xrd Analysis ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Silica Source ◽  
Quenching Method

In this study, the authors attempted to propose the very first study on fabrication and characterization of zinc-boro-silicate (ZBS) glass-ceramics derived from the ternary zinc-boro-silicate (ZnO)0.65(B2O3)0.15(RHA)0.2 glass system through a conventional melt-quenching method by incorporating rice husk ash (RHA) as the silica (SiO2) source, followed by a sintering process. Optimization of sintering condition has densified the sintered samples while embedded beta willemite (β-Zn2SiO4) and alpha willemite (α-Zn2SiO4) were proven in X-ray diffraction (XRD) analysis. Field emission scanning electron microscopy (FESEM) has shown the distribution of willemite crystals in rhombohedral shape crystals and successfully form closely-packed grains due to intense crystallization. The photoluminescence (PL) spectra of all sintered ZBS glasses presented various emission peaks at 425, 463, 487, 531, and 643 nm corresponded to violet, blue, green, and red emission, respectively. The correlation between the densification, phase transformation, microstructure, and photoluminescence of Zn2SiO4 glass-ceramic phosphor is discussed in detail.

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