玻璃与陶瓷期刊(英文)Pub Date : 2019-06-05DOI: 10.4236/NJGC.2019.93004
H. Es-soufi, L. Bih, M. Benzineb
{"title":"Study of Tungsten Phosphate Glasses Containing Fe2O3","authors":"H. Es-soufi, L. Bih, M. Benzineb","doi":"10.4236/NJGC.2019.93004","DOIUrl":"https://doi.org/10.4236/NJGC.2019.93004","url":null,"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 < 1.","PeriodicalId":71698,"journal":{"name":"玻璃与陶瓷期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49664622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
玻璃与陶瓷期刊(英文)Pub Date : 2019-06-05DOI: 10.4236/NJGC.2019.93005
Kofi Asante-Kyei, A. Addae, Mercy Abaka-Attah
{"title":"Production of Clay Containers for Curbing Plantain Post-Harvest Losses in Ghana","authors":"Kofi Asante-Kyei, A. Addae, Mercy Abaka-Attah","doi":"10.4236/NJGC.2019.93005","DOIUrl":"https://doi.org/10.4236/NJGC.2019.93005","url":null,"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.","PeriodicalId":71698,"journal":{"name":"玻璃与陶瓷期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48322184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
玻璃与陶瓷期刊(英文)Pub Date : 2019-03-13DOI: 10.4236/NJGC.2019.92002
A. Behairy
{"title":"Characteristic Studies on Whisker-Reinforced Borosilicate Glasses","authors":"A. Behairy","doi":"10.4236/NJGC.2019.92002","DOIUrl":"https://doi.org/10.4236/NJGC.2019.92002","url":null,"abstract":"Glass composition of fixed values of the structural factor R(CdO/B2O3) = 0.5 and K(SiO2B2O3) = 0.5 in borosilicate glass modified by CdO has been studied by different techniques. The amorphous structure of as prepared glass was confirmed by both XRD and EDP spectroscopy. The amorphous samples were treated thermally to be transformed to suitable type of crystalline glass ceramic. Based on SEM and TEM data, the bulk crystallized network was developed by treating the glasses at high treatment route (950°C - 1100°C) for a specific time (8 hours). Crystalline Al4B2O9 and Al18B4O33 whisker phases are simply detected by X-ray diffraction spectroscopy. The scanning and transmission electron microscopes (SEM and TEM) have confirmed that aluminum borate crystalline phases in the form of whiskers (rods) species are the main formed type. Both size and concentration of the whisker species were increased with increasing temperature of thermal heat treatment. Formation of this type of crystals (whiskers) leads to interlocking microstructure and as a direct result, an increase in hardness number, glass transition temperature is simply evidenced. Glass-ceramics synthesized in this study can be applied as high temperature resistant materials because their microstructures can resist micro-cracking upon indentation. The crack length due to indentation process is reduced by increasing concentration of crystalline road or whisker like structure.","PeriodicalId":71698,"journal":{"name":"玻璃与陶瓷期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45069706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
玻璃与陶瓷期刊(英文)Pub Date : 2019-01-01DOI: 10.4236/NJGC.2019.91001
Nissamuddeen Kunnath, J. Philip
{"title":"Nanostructured Ceramics of Potassium Sodium Bismuth Titanate: Hydrothermal Synthesis and Piezoelectric Response at Morphotropic Phase Boundary","authors":"Nissamuddeen Kunnath, J. Philip","doi":"10.4236/NJGC.2019.91001","DOIUrl":"https://doi.org/10.4236/NJGC.2019.91001","url":null,"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.","PeriodicalId":71698,"journal":{"name":"玻璃与陶瓷期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70520390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}