Ecological Silicate Glasses

2008 ◽  
Vol 39-40 ◽  
pp. 667-670 ◽  
Author(s):  
Bogdan Alexandru Sava ◽  
Adriana Diaconu ◽  
Luminita Daniela Ursu ◽  
Lucica Boroica ◽  
M. Elisa ◽  
...  
Keyword(s):  
Borosilicate Glass ◽  
Raw Materials ◽  
Structural Data ◽  
Refraction Index ◽  
Titanium Oxides ◽  
Glass Waste ◽  
Oxide Systems ◽  
High Annealing ◽  
Fluorine Compounds

The investigated ecological glasses with no toxic compounds, such as BaO, PbO, As2O3, As2O5, fluorine, CdS and CdSe in their composition are located in ternary and quaternary oxide systems: ZnO-SiO2-TiO2 and SiO2-R'2O-R''O-R'''O2, where R' is Na or K, R'' is Ca or Mg and R''' is Zr or Ti. The first system contains P2O5, ZnO and TiO2 in order to obtain opal glasses, without fluorine compounds. The second system replaces the barium oxide and lead oxide with potassium, magnesium, zirconium and titanium oxides, for materials like lead free crystals. The raw materials can be replaced by silicate or borosilicate glass waste. The advantages of borosilicate glass waste are: bringing valuable components into recipes (B2O3, CaO, Al2O3), saving raw materials and energy, creating an ecological environment The characteristic temperatures (vitreous transition point, low and high annealing points, softening point) and the thermal expansion coefficient of the glass are presented. The FTIR and Raman spectroscopy provided structural data, such as characteristic vibration maxima for silicon and titanium oxide, and revealed the role of zinc oxide in the vitreous network. The refraction index and UV-VIS transmission are discussed.

scholarly journals Environmentally Clean Ceramics Manufacturing With Application of Hazardous Car Production Mud and Galvanic Process Glass Waste

2021 ◽  
Author(s):  
Vsevolod Mymrin ◽  
Kirill Alekseev ◽  
Monica A. Avanci ◽  
Paulo H.B. Rolim ◽  
Cleber L. Pedroso ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Raw Materials ◽  
Linear Shrinkage ◽  
Formation Processes ◽  
Glassy Material ◽  
Glass Waste ◽  
Similar Materials ◽  
Flexural Resistance ◽  
Red Ceramics

Abstract It was developed new ceramics composites with hazardous car production mud (CPM) and galvanic process glass waste with high content of heavy metals. They were applied as valuable components of red ceramics sintered at 700°, 750°, 800°, 850°, 900°, and 950°C to provide flexural resistance of up to 17.6 MPa, water absorption at 950°C 6.53 -10.45%, linear shrinkage – 5.24-6.29%, density 2.7 – 3.2 g/cm³, and dilatation coefficient 5.3 -13.8%. Structure formation studies by the XRD, SEM, EDS, and LAMMA methods demonstrated the synthesis of amorphous glassy material with small inclusion of mullite Al6Si2O13. Car production mud and galvanic process glass waste play the role of the intensifiers of the ceramics’ structures formation processes. The ceramics' leaching and solubility tests by the atomic absorption spectroscopy method showed strong chemical bond of heavy metals of the hazardous raw materials in insoluble structures. According to Brazilian standards, they can be used to produce tiles, bricks, blocks, and similar materials with high environmental eficiency.

The Role of Boron in Monitoring the Leaching of Borosilicate Glass Waste Forms

1984 ◽  
Vol 44 ◽  
Author(s):  
Barry E. Scheetz ◽  
W. Phelps Freeborn ◽  
Deane K. Smith ◽  
Christine Anderson ◽  
Michael Zolensky ◽  
...  
Keyword(s):  
Borosilicate Glass ◽  
Solid Phase ◽  
Waste Form ◽  
Direct Measure ◽  
Glass Waste ◽  
Worst Case ◽  
Waste Forms

AbstractIn the absence of any identified solid phase host (other than the original glass), boron has been assumed to accumulate in the fluid during the reaction of borosilicate glass waste forms with aqueous fluids. Using this assumption, it is possible to define a boron index which can be used to monitor the amount of glass that has been dissolved and to provide a worst-case measure of the degradation of the primary glass waste form. Several boron-containing silicate phases have been identified thus invalidating the assumption that boron does not precipitate. The effect is apparently small and the assumption that boron release is a direct measure of degree of alteration of borosilicate glass is still probably a good one.

GREEN BONDS AS A NEW FINANCIAL INSTRUMENT

2020 ◽  
Vol 3 (7) ◽  
pp. 98-102
Author(s):  
M. V. DUBROVA ◽  
◽  
N. N. ZHILINA ◽  
Keyword(s):  
Raw Materials ◽  
Financial Burden ◽  
Environmental Problems ◽  
Green Economy ◽  
Non Profit ◽  
The Public ◽  
Economic Problems ◽  
Green Finance ◽  
Non Profit Organizations

The relevance of the article is determined by the fact that in Russia there is no effective mechanism of state support for the activities of non-profit organizations in the field of “green Finance”. The role of non-profit organizations is leveled, which can become a serious help in solving economic problems, in particular, the problems of recycling and processing of secondary raw materials, the placement of industrial waste and household garbage, and landscaping of large megacities. The main financial burden in the field of “green economy” falls on States and large enterprises. Meanwhile, we cannot ignore the important role of non-profit organizations that can not only draw attention to environmental problems to the public, but also offer their own measures to solve environmental problems. In this regard, it becomes relevant to consider the participation of non-profit organizations in the implementation of environmental projects by attracting “green Finance”.

POTENTIAL DEVELOPMENT OF «GREEN BONDS» IN THE RUSSIAN ECONOMY

2020 ◽  
Vol 1 (8) ◽  
pp. 119-123
Author(s):  
M. V. DUBROVA ◽  
◽  
N. N. ZHILINA ◽  
Keyword(s):  
Raw Materials ◽  
Financial Burden ◽  
Environmental Problems ◽  
Green Economy ◽  
Non Profit ◽  
Russian Economy ◽  
Green Finance ◽  
Potential Development ◽  
Non Profit Organizations

he relevance of the article is determined by the fact that in Russia there is no effective mechanism of state support for the activities of non-profit organizations in the field of «green Finance». The role of non-profit organizations is leveled, which can become a serious help in solving economic problems, in particular, the problems of recycling and processing of secondary raw materials, the placement of industrial waste and household garbage, and landscaping of large megacities. The main financial burden in the field of «green economy» falls on States and large enterprises. Meanwhile, we cannot ignore the important role of non-profit organizations that can not only draw attention to environmental problems to the public, but also offer their own measures to solve environmental problems. In this regard, it becomes relevant to consider the participation of non-profit organizations in the implementation of environmental projects by attracting «green Finance».

scholarly journals Recent Advances in Fabrication of Non-Isocyanate Polyurethane-Based Composite Materials

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3497
Author(s):  
Piotr Stachak ◽  
Izabela Łukaszewska ◽  
Edyta Hebda ◽  
Krzysztof Pielichowski
Keyword(s):  
Raw Materials ◽  
Synthesis Method ◽  
Polymeric Materials ◽  
Original Research ◽  
Significant Group ◽  
Oh Groups ◽  
New Class ◽  
Hazardous Chemical ◽  
Wide Range

Polyurethanes (PUs) are a significant group of polymeric materials that, due to their outstanding mechanical, chemical, and physical properties, are used in a wide range of applications. Conventionally, PUs are obtained in polyaddition reactions between diisocyanates and polyols. Due to the toxicity of isocyanate raw materials and their synthesis method utilizing phosgene, new cleaner synthetic routes for polyurethanes without using isocyanates have attracted increasing attention in recent years. Among different attempts to replace the conventional process, polyaddition of cyclic carbonates (CCs) and polyfunctional amines seems to be the most promising way to obtain non-isocyanate polyurethanes (NIPUs) or, more precisely, polyhydroxyurethanes (PHUs), while primary and secondary –OH groups are being formed alongside urethane linkages. Such an approach eliminates hazardous chemical compounds from the synthesis and leads to the fabrication of polymeric materials with unique and tunable properties. The main advantages include better chemical, mechanical, and thermal resistance, and the process itself is invulnerable to moisture, which is an essential technological feature. NIPUs can be modified via copolymerization or used as matrices to fabricate polymer composites with different additives, similar to their conventional counterparts. Hence, non-isocyanate polyurethanes are a new class of environmentally friendly polymeric materials. Many papers on the matter above have been published, including both original research and extensive reviews. However, they do not provide collected information on NIPU composites fabrication and processing. Hence, this review describes the latest progress in non-isocyanate polyurethane synthesis, modification, and finally processing. While focusing primarily on the carbonate/amine route, methods of obtaining NIPU are described, and their properties are presented. Ways of incorporating various compounds into NIPU matrices are characterized by the role of PHU materials in copolymeric materials or as an additive. Finally, diverse processing methods of non-isocyanate polyurethanes are presented, including electrospinning or 3D printing.

A true gift of mother earth: the use and significance of obsidian at Çatalhöyük

2011 ◽  
Vol 61 ◽  
pp. 1-19 ◽  
Author(s):  
Tristan Carter
Keyword(s):  
Raw Materials ◽  
Daily Practice ◽  
Social Identities ◽  
Raw Material ◽  
Central Anatolia ◽  
Social Significance ◽  
Key Issues ◽  
Raw Material Variability ◽  
Mother Earth

AbstractThis paper reviews 50 years of obsidian studies at Neolithic Çatalhöyük in the Konya plain, central Anatolia. A number of key issues are addressed: (1) the source of the site's raw materials, the means and forms by which the obsidian was introduced to the site and the role of Çatalhöyük in the supra-regional dissemination of these raw materials; (2) the alleged gender associations of certain obsidian goods in the burial record and beyond; (3) a more general consideration of the social significance of the circulation and consumption of obsidian at the site, including the phenomena of hoarding and gifting, plus the important role of projectiles in the creation of social identities and various forms of ritual behaviour, not least the termination of the life of a building/individual; (4) the technotypological and raw material variability through time; (5) the use of obsidian in daily practice and craft-working.

Glass-Ceramic Foams from Borosilicate Glass Waste

2014 ◽  
Vol 5 (2) ◽  
pp. 136-145 ◽  
Author(s):  
Rosa Taurino ◽  
Isabella Lancellotti ◽  
Luisa Barbieri ◽  
Cristina Leonelli
Keyword(s):  
Borosilicate Glass ◽  
Glass Ceramic ◽  
Glass Waste ◽  
Ceramic Foams

Ionic transport of alkali in borosilicate glass. Role of alkali nature on glass structure and on ionic conductivity at the glassy state

2015 ◽  
Vol 410 ◽  
pp. 74-81 ◽  
Author(s):  
Muriel Neyret ◽  
Marion Lenoir ◽  
Agnès Grandjean ◽  
Nicolas Massoni ◽  
Bruno Penelon ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Borosilicate Glass ◽  
Glassy State ◽  
Glass Structure ◽  
Ionic Transport

Crystal structure of the wild-type and D30A mutant thioredoxin h of Chlamydomonas reinhardtii and implications for the catalytic mechanism

2001 ◽  
Vol 359 (1) ◽  
pp. 65-75 ◽  
Author(s):  
Valeria MENCHISE ◽  
Catherine CORBIER ◽  
Claude DIDIERJEAN ◽  
Michele SAVIANO ◽  
Ettore BENEDETTI ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Proton Transfer ◽  
Chlamydomonas Reinhardtii ◽  
Catalytic Mechanism ◽  
Structural Data ◽  
Careful Analysis ◽  
Wild Type ◽  
Thioredoxin H ◽  
Dynamics Simulations

Thioredoxins are ubiquitous proteins which catalyse the reduction of disulphide bridges on target proteins. The catalytic mechanism proceeds via a mixed disulphide intermediate whose breakdown should be enhanced by the involvement of a conserved buried residue, Asp-30, as a base catalyst towards residue Cys-39. We report here the crystal structure of wild-type and D30A mutant thioredoxin h from Chlamydomonas reinhardtii, which constitutes the first crystal structure of a cytosolic thioredoxin isolated from a eukaryotic plant organism. The role of residue Asp-30 in catalysis has been revisited since the distance between the carboxylate OD1 of Asp-30 and the sulphur SG of Cys-39 is too great to support the hypothesis of direct proton transfer. A careful analysis of all available crystal structures reveals that the relative positioning of residues Asp-30 and Cys-39 as well as hydrophobic contacts in the vicinity of residue Asp-30 do not allow a conformational change sufficient to bring the two residues close enough for a direct proton transfer. This suggests that protonation/deprotonation of Cys-39 should be mediated by a water molecule. Molecular-dynamics simulations, carried out either in vacuo or in water, as well as proton-inventory experiments, support this hypothesis. The results are discussed with respect to biochemical and structural data.

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