Effect of some nucleating agents on thermal expansion behaviour of Li2O-BaO-Al2O3-SiO2 glasses and glass-ceramics

The thermal expansion behaviour of some glasses and glass-ceramics within the system spodumence (LiAlSi2O6)-celsian (BaAl2Si2O8) containing LiF, TiO2 and Cr2O3 as nucleation catalysts was described. LiF and TiO2 were found to increase the thermal expansion of the glasses investigated, whereas Cr2O3 slightly lowered the expansion coefficient. The dilatometric transition and softening points of the glasses showed the reverse behaviour. The thermal expansion of the glass-ceramics was a function of type and amount of nucleating agent and heat treatment which greatly affected the mineralogical constitution of the materials

Effect of the nucleating agents Cr2O3 and LiF on crystallizing phases and microstructures of glass-ceramics prepared by using some industrial wastes

Glass-ceramics in the system diopside-anorthite-orthoclase were prepared using the waste known as the by-pass cement dust in the amount of 36 % of the batch constituents. The effects of addition of the nucleating agents Cr2O3, LiF, and mixtures of them on the crystallizability, phase assemblages, and the resultant microstructures were investigated. Low concentration of Cr2O3 (0.5 wt%) causes volume crystallization and formation of fine-grained microstructures of microcline, anorthite and aluminous pyroxene. Higher concentrations of Cr2O3 favor formation of leucite and aluminous pyroxene and inhibit crystallization of anorthite. LiF causes the formation of microcline and its transformation into orthoclase. It also increases the crystallizability with the formation of nonuniform coarse-grained texture. Α mixture of 0.5 % Cr2O3 and 1.5 % LiF causes a synergistic effect, where fine-grained microstructure is formed (due to Cr2O3) with orthoclase formation (due to LiF) in addition to aluminous pyroxene and anorthite. The effects of various Cr2O3 concentrations were discussed on the bases of the increased viscosity and separation of Cr2O3 and/or chromiumspinel phases. The effects of LiF were attributed to the role of fluorine ions in reducing the viscosity of the glasses, consequently facilitating crystallization of the structurally more complex silicate in addition to favoring reaching thermodynamic equilibrium

Subclinical pulmonary pathogenic infection in camels slaughtered in Cairo, Egypt

Introduction: Camels migrate between the open boundaries of Sudan and Egypt either for grazing or for slaughtering. Bad hygiene and stress is often related to pulmonary diseases in camels. This study investigated whether camels slaughtered in Cairo carried pulmonary infections. Methodology: Five hundred lung tissues of slaughtered camels were examined and 100 samples suspected for pulmonary infection were subjected to microbial identification and histopathology. Results: A total of 70 lung tissues revealed 97 bacterial isolates of 8 species, including Staphylococcus aureus (37.14%), Escherichia coli (27.14%), Klebsiella pneumoniae (26.71%), Bacillus spp. (25.72%), Streptococcus pyogenes (10%), Corynebacterium spp. (8.85 %), Pasteurella spp. (2.85%), and Arcanobacterium pyogenes (1.4%). Some of these species were earlier reported to be associated with pulmonary infection. Histopathology revealed different types of pneumonia in 50% of the investigated lungs. Conclusions: A considerable number of apparently healthy camels carry pathogenic agents in their lower respiratory tracts. Immunosuppression and stressful conditions might influence these pathogens to induce respiratory diseases in camels. Thus, the infected camels might act as reservoir of these infections agents. If adequate care is not taken, this might be a threat to abattoir workers and may spread infections to humans

Assessment of 25 (OH) Vitamin D in Neonates with Hypoxic Ischemic Encephalopathy

Background: Vitamin D is a hormone that affects a wide range of functions within the body. Neonatal hypoxic ischemic encephalopathy (HIE) is a serious disease that may lead to permanent brain injury.Objective: The present study aimed to study vitamin D status in hypoxic ischemic in encephalopathy.Patients and methods: A case control study carried out in newborn intensive care unit (NICU) of Zagazig University Children Hospitals. Total number of cases that met the inclusion and exclusion criteria was 49 full term neonates with HIE divided according to Sarnat stages: stage I; 20 full term neonates, stage II; 15 full term neonates and stage III; 14 full term neonates. Cases were compared to 16 healthy controls. Results: There was a statistical significant increase in Apgar score 1, 5, 10 in control group compared to all cases groups. There were no statistical significant differences between the studied groups in relation to CBC results. There was a statistical significant difference between the different stages of HIE in CRP and pH. There was a statistical significant increase in frequency of hypoxic change in stage III compared to stage II and I. All stages of HIE showed statistical significant increase in frequency of vitamin D deficiency compared to control group. Stage III had statistical significant increase in frequency of vitamin D deficiency compared to stage I and II.Conclusion: Serum 25(OH) vitamin D insufficiency is present in the majority of term HIE neonates. 25 (OH) vitamin D was significantly deficient in stage III more than stage I and II

Preparation and properties of Li2O-BaO-Al2O3 -SiO2 glass-ceramic materials

The crystallization of some glasses, based on celsian-spodumene glass-ceramics, was investigated by different techniques including differential thermal analysis, optical microscope, X-ray diffraction, indentation, microhardness, bending strengths, water absorption and density measurement. The batches were melted and then cast into glasses, which were subjected to heat treatment to induce controlled crystallization. The resulting crystalline materials were mainly composed of β-eucryptite solid solution, β-spodumene solid solution, hexacelsian and monoclinic celsian, exhibiting fine grains and uniform texture. It has been found that an increasing content of celsian phase in the glasses results in increased bulk crystallization. The obtained glass-ceramic materials are characterized by high values of hardness ranging between 953 and 1013 kg/mm2, zero water absorption and bending strengths values ranging between 88 and 126 MPa, which makes them suitable for many applications under aggressive mechanical conditions

Evaluation of Saudi pegmatite and its use in porcelain industry

Pegmatite is the main source of feldspar for ceramics industry. Usage of pegmatite in ceramic industry causes some problems due to the presence of mica and iron oxides. These materials reduce tile strength, hardness and density of the final product leading to low quality ceramic products. Southern Saudi pegmatite separation treatment was carried out in two phases in order to improve the ceramic quality of the feldspar obtained from this pegmatite. The first phase consists of gravitational separation to remove the heavy impurities and in the second phase magnetic separation was carried out to further minimize iron content. Porcelain ceramic batches were prepared by wet-mixing, drying, pressing (semi-dry press) and fired at temperatures from 1000 to 1350 °C. The porcelain ceramic bodies were prepared and examined by DTA, X-ray diffraction, SEM and tested for bulk density, linear shrinkage, water absorption and flexural strength. These results indicated that, after treatment (gravity and magnetic separation), the pegmatite can be considered as a good source of potash feldspar. The present study provides a positive indication for using of Southern Saudi pegmatite after treatment in ceramic industries

WITHDRAWN: Deep Learning Classification For Diagnosis COVID-19 Between Bacterial Pneumonia and Viral Pneumonia in Chest X-Ray Images

This article has been withdrawn due to reported author misconduct. Further, The author also reported scientific error however, the author fails to update the article with an acceptable improved version. Refer to about section for more detail on withdrawal policy

Augite-anorthite glass-ceramics from residues of basalt quarry and ceramic wastes

Dark brown glasses were prepared from residues of basalt quarries and wastes of ceramic factories. Addition of CaF2, Cr2O3 and their mixture CaF2-Cr2O3 were used as nucleation catalysts. Generally, structures with augite and anorthite as major phases and small amount of magnetite and olivine phases were developed through the crystallization process. In the samples heat treated at 900 °C the dominant phase is augite, whereas the content of anorthite usually overcomes the augite at higher temperature (1100 °C). Fine to medium homogenous microstructures were detected in the prepared glass-ceramic samples. The coefficient of thermal expansion and microhardness measurements of the glass-ceramic samples were from 6.16×10-6 to 8.96×10-6 °C-1 (in the 20–500 °C) and 5.58 to 7.16 GP, respectively

Synthesise and Characterization of Cordierite and Wollastonite Glass—Ceramics Derived from Industrial Wastes and Natural Raw Materials

Industrial waste is one of the primary sources that harm the environment, and this topic has occupied many scientists on how to take advantage of these wastes or dispose of them and create a clean environment. By-pass cement dust is considered one of the most dangerous industrial wastes due to its fine granular size and its volatilization in the air, which causes severe environmental damage to human and animal health, and this is the reason for choosing the current research point. In this article, eight samples of glass–ceramics were prepared using by-pass cement dust and natural raw materials known as silica sand, magnesite, and kaolin. Then melted by using an electric furnace which was adjusted at a range of temperatures from 1550 to 1600 °C for 2 to 3 h; the samples were cast and were subjected to heat treatment at 1000 °C for 2 h based on the DTA results in order to produce crystalline materials. Various techniques were used to study the synthesized glass–ceramic samples, including differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscope (SEM), and thermal expansion coefficient (CTE). X-ray analysis showed that the phases formed through investigated glass–ceramic samples consisted mainly of β- wollastonite, parawollastonite, diopside, anorthite, and cordierite. It was noticed that β- the wollastonite phase was formed first and then turned into parawollastonite, and also, the anorthite mineral was formed at low temperatures before the formation of the diopside mineral. SEM showed that the formed microstructure turned from a coarse grain texture to a fine-grained texture, by increasing the percentage of cordierite. It also showed that the increase in time at the endothermic temperature significantly affected the crystalline texture by giving a fine-grained crystalline texture. The linear thermal expansion measurements technique used for the studied glass–ceramic samples gives thermal expansion coefficients ranging from 6.2161 × 10−6 to 2.6181 × 10−6 C−1 (in the range of 20–700 °C), and it decreased by increasing cordierite percent