New Journal of Glass and Ceramics

Journal Information
ISSN / EISSN : 2161-7554 / 2161-7562
Current Publisher: Scientific Research Publishing, Inc. (10.4236)
Total articles ≅ 111
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Latest articles in this journal

Zahid Hussain
New Journal of Glass and Ceramics, Volume 11, pp 1-33; doi:10.4236/njgc.2021.111001

Abstract:
The values of refractive index (n) for silicate glasses (silica, soda lime and borosilicate 7059) are decreased from 1.5119 to 1.5111, 1.5086 to 1.5065 and 1.5296 to 1.5281, respectively; and the optical band gap (Eg) is increased from 9.8 to 9.81 eV, 9.845 to 9.88 eV and 9.56 to 9.58 eV, respectively over the temperature range 295 - 473 K using ellipsometer at wavelength 632.8 nm. While n is decreased from 1.5276 to 1.5274, 1.5074 to 1.5070 and from 1.5283 to 1.5281, respectively; and Eg is increased from 9.59 to 9.592 eV, 9.862 to 9.870 eV, and 9.574 to 9.58 eV, respectively over the temperature range 297 - 322 K using Abbe refractometer at wavelength 589.3 nm. The values of oxide ion polarizability [αo2- (n) and αo2-(Eg)] regarding silica, soda lime and borosilicate 7059 glasses are decreased from 1.3427 to 1.3408, 1.6014 to 1.5941, 1.4329 to 1.4193, respectively over the temperature range 295 - 473 K using ellipsometer; and are decreased from 1.3786 to 1.3764, 1.5991 to 1.5969, 1.4297 to 1.4191, respectively over the temperature range 297 - 322 K using Abbe refractometer. Similarly, the values of optical basicity [A (n) and A (Eg)] of silica, soda lime, and borosilicate 7059 glasses are decreased from 0.4272 to 0.4245, 0.6271 to 0.6224, 0.5045 to 0.4933, respectively over the temperature range 295 - 473 K using ellipsometer; and are decreased from 0.4586 to 0.4567, 0.6256 to 0.6242, 0.5018 to 0.4930, respectively over the temperature range 297 - 322 K using Abbe refractometer. Further, we have found that for silica, soda lime and borosilicate 7059, the values of electronegativity (ξ1av) QUOTE ζ1av) using Zahidnumerical model [based on αO2- (n) and A (n)] are increased from 5.1035 to 5.5504, 4.0393 to 4.830, 4.8143 to 5.0111, respectively over the temperature range 295 - 473 K using ellipsometer; while these values are increased from 5.0657 to 5.2149, 5.0657 to 5.2149, 4.8357 to 5.0111, respectively over the temperature range 297 - 322 K using Abbe refractometer. It is very clear from this research report that both refractive index and optical band gap-based-oxide ion polarizability and optical basicity have the same decreasing trend as the temperature is increased, and this trend indicates that the reported glasses have a very small amount of electronic polarizability. Moreover, this decreasing trend occurs due to the decreasing amount of non-bridging oxygen (NBO) which in turn caused a decrease in refractive index within the silicate glass system at higher temperature. Since the calculated values of electronegativity are found to be in the range 4.0393 - 5.5504 for the reported silicate glasses, so all these glasses have an ionic character. Moreover, low values of optical basicity and of oxide ion polarizability suggest that the silicate glasses are not novel glasses (optical functional glasses) for non-linear optical (NLO) devices or for three dimensional displays.
Nada Elbaz, Gomaa El-Damrawi, Amr M. Abdelghany
New Journal of Glass and Ceramics, Volume 11, pp 34-43; doi:10.4236/njgc.2021.111002

Abstract:
A new type of cerium borate glass-ceramic is prepared and studied. The microstructure and crystallization behaviors of the glass samples were investigated by X-ray diffraction (XRD), electron diffraction (ED), and 31P NMR spectroscopy. The microstructures of samples contain 2 are amorphous in nature. More addition of CeO2 transforms the glass to glass-ceramics without thermal annealing. The morphological change of the microstructure of these materials was followed by transmission electron microscopy (TEM). The obtained results have revealed that the addition of more than 0.8 mol% CeO2 can promote nucleation and crystallization routes that are combined with the establishment of diverse crystalline phases. Glasses with lower contents of CeO2showed no tendency to crystallization. The crystals of CeO2 containing glasses were spheroid like morphology that was assigned to the three-dimensional fast growth of the well-formed structural species in the boro-apatite phase. In addition, the cerium free glass is characterized by particle-like morphology. Then the growth of spheroid species in three-dimension plays better compatibility and bioactivity behavior than that of the other types of morphology. This is may because the spherical shape has a higher surface area than that of the needle-like morphology. Accumulation and aggregation of small-sized spheres from cerium borate phases played the role of enhancing the hardness of the studied materials.
Monique Tohoue Tognonvi, Arezki Tagnit-Hamou, Léon Koffi Konan, Ablam Zidol, Wilfried Cyrille N’Cho
New Journal of Glass and Ceramics, Volume 10, pp 29-44; doi:10.4236/njgc.2020.103003

Abstract:
The reactivity of the recycled glass powder (GP) in a cementitious medium has been studied over time by means of X-ray diffraction and thermal gravimetric analysis. Two different mixtures based on cement/glass powder (0 or 20 wt% GP) and lime/glass powder (70 wt% GP) were considered. Analysis revealed the coexistence of both hydration and pozzolanic reaction during the hardening of the mortars. At young age, the cement hydration would prevail over the pozzolanic one resulting in a decrease of physico-chemical and mechanical properties of the material due to the dilution effect. The pozzolanic reaction that predominates from 91 days, would induce the formation of supplementary C-S-H leading to improve the material properties.
Vahdat Astani Chee, Junfeng Yang, Zuyuan Yu, Astani Che Vahdat, Yang Junfeng
New Journal of Glass and Ceramics, Volume 10, pp 1-13; doi:10.4236/njgc.2020.101001

Abstract:
The quality of a via hole on a multilayer stack of Low Temperature Co-fired Ceramic (LTCC) tape is of utmost importance to its functionality. This paper investigates a substitute for the commonly used circular shape hole to a more complex one and its implications when different parameters such as sheet thickness, punch speed, travel distance and tool clearance are changed. Fabrication of the punch tools and the punching process is carried out at the same machine, ensuring alignment. Two types of non-circular shape are chosen to carry out the experiment. Pre-sintered complex shape hole measurements show that while punch conditions such as speed and tool gap have little effect on the size, sheet thickness and travel depth play a vital role in the overall dimension. Albeit having only a slight effect on the size, those parameters are significant in other aspects of hole quality. Post-sintering investigation is also observed and discussed.<
Norhan Atef, Gomaa El Damrawi, Abdelmagud Hassan, Lobna Sharaf El-Deen
New Journal of Glass and Ceramics, Volume 10, pp 45-56; doi:10.4236/njgc.2020.104004

Abstract:
This work is aimed to shed light on the dielectric behavior of CuO containing glasses, since no publications concerning this issue have been presented before. Different glasses in the binary Na2O-B2O3 system were prepared by melt annealing technique. XRD spectra have shown that the amorphous structure is dominant in all glasses containing mixed concentrations from CuO and Na2O. The crystalline phases appeared only in glass free from Na2O. The dielectric spectroscopy is applied to shed some light on the conduction mechanisms in terms of changing both the dielectric constant and the electrical modulus of the investigated glasses. The ac conductivity increases with increasing frequency and decreases with increasing CuO concentration. Both the dielectric constant and dissipation loss is decreased with increasing frequency. Correlated barrier hopping (CBH) is considered an appropriate conduction mechanism results from the increase of frequency.
O. Ighere Jude, Alex Greaney P., Jude O. Ighere, P. Alex Greaney
New Journal of Glass and Ceramics, Volume 10, pp 15-27; doi:10.4236/njgc.2020.102002

Abstract:
Thermal storage potential and thermal expansion are characteristic properties for extreme applications. ZrB2 is a candidate for advanced applications in aircraft and fusion reactors. This article presents density functional theory calculations of its states, microstructure and quasi-harmonic levels calculations of thermophysical properties. Band structure highlighted dynamical instability with metallic impurities in ZrB2 structure based on frequency modes. The observed projected density of states (PDOS) appropriate 4d orbital of Zr dominated at low frequency both in perfect crystal in the presence or absence of covalent impurities while B 2s and 2p orbitals dominate higher frequency states. Temperature dependency and anisotropy of coefficient of thermal expansion (CTE) were evaluated with various impurities. Various thermodynamic properties like entropy and free energy were explored for degrees of freedom resulting from internal energy changes in the material. Computed results for heat capacity and CTE were compared to available numerical and experimental data.
Nissamuddeen Kunnath, Jacob Philip
New Journal of Glass and Ceramics, Volume 9, pp 1-14; doi:10.4236/njgc.2019.91001

Abstract:
Potassium Sodium Bismuth Titanate (KNBT) ceramics, with the general formula (1 - x)K0.5Bi0.5TiO3 -xNa0.5Bi0.5TiO3, have been synthesized following hydrothermal route, starting with solid solutions of pure perovskite nanoceramics of KBT and NBT in desired stoichiometric weight ratios, followed by sintering between 850°C and 1000°C for few hours. Pure KNBT nanoceramics with perovskite structure, having mean particle size around 30 nm, could be obtained. Morphology of the samples is found to depend strongly on composition. A change of composition results in a phase change, as evident from X-ray structure analysis. This phase change is a result of rhombohedral to tetragonal morphotropic phase boundary (MPB) in the sample with x around 0.80. Composition dependent occurrence of MPB leads to formation of needle like structures with micrometer length scales. These are typical of tetragonal lamellar structures, suggesting partial induction of tetragonal polar order from rhombohedral structure at MPB. Dielectric and piezoelectric properties, such as dielectric constant and loss, piezoelectric coefficients and figures of merit, exhibit threshold maxima in their values at the composition corresponding to MPB. These values reported for a lead-free piezoceramic, synthesized by a comparatively simple hydrothermal route, are highly promising, and comparable to well-known PZT.
Hicham Es-Soufi, Lahcen Bih, Meyrem Benzineb
New Journal of Glass and Ceramics, Volume 9, pp 33-49; doi:10.4236/njgc.2019.93004

Abstract:
Glasses of the compositions 20Li2O-(50 - x)Li2WO4-xFe2O3-30P2O5 where (x = 0, 1, 5, 8, 10, 15 mol%) were elaborated by the melt-quenching route. Synthesized glasses are characterized using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), differential scanning calorimetric (DSC), and density determination. The XRD patterns confirmed the amorphous nature of samples, and IR spectra showed the structural groups and highlight the depolymerization of phosphate network with the introduction of iron oxide. It is found that the structural unit Q2 converts to Q1 and Q0 as Fe2O3 replaces Li2WO4. Chemical durability tests on the glasses have shown that the compositions containing pyrophosphate (Q1) and orthophosphate (Q0) units are more water-resist. The electrical conductivity measurements were performed by complex impedance spectroscopy in the frequency range of 20 - 106 Hz at various temperatures from ambient to 400°C. It is found that the conductivity is activated thermally and follows an Arrhenius law. The obtained electrical data were analyzed by the modulus formalism and dielectric formalism. The determined asymmetric nature of spectra suggested that the relaxation behavior is non-Debye and characterized by the stretched exponent parameter β
Kofi Asante-Kyei, Alexander Addae, Mercy Abaka-Attah
New Journal of Glass and Ceramics, Volume 9, pp 50-65; doi:10.4236/njgc.2019.93005

Abstract:
In Ghana, most farmers are peasants and at times foodstuffs produced get rotten either through transportation or market places. This normally affects the meager income that farmers earn through hard work. Available statistics indicate that each year, food crops worth several hundreds of dollars go waste in the country due to poor harvest losses and it represents 70% of total food production in Ghana. Again, in the country, there is abundant of clay as a natural resource. Geological study has revealed that it is found in almost every part of the country. As a means of finding solution to the rate at which local foodstuffs especially plantain rot, the study sought to design and compose clay container purposefully for storing plantain to prolong its lifespan. The study focused on 5 clay body compositions (C1 to C5) and fired at 950°C. Composition C1 consisted of 50% of Abonko clay and 50% of Daboase clay. Composition C2 was made up of 40% Abonko clay, 50% Daboase clay and 10% of smooth sawdust. Composition C3 composed of 45% of Abonko clay, 45% of Daboase clay and 10% of smooth sawdust. Composition C4 was made up of 90% Daboase clay and 10% rough sawdust. The last composition C5 comprised mainly 100% Abonko clay. Fresh plantains obtained from Takoradi market circle were stored in the containers and weekly recordings of states of plantain for five consecutive weeks were carried out. It was revealed that C4 was successful in storing fresh plantains to ripe stage after the five weeks. It is recommended among others that, the technique should be made available to stakeholders such as Ministry of Food and Agriculture (MOFA), plantain farmers and market plantain sellers through seminars, public education and symposia in order to minimize post-harvest losses.
A. Behairy
New Journal of Glass and Ceramics, Volume 9, pp 15-24; doi:10.4236/njgc.2019.92002

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