Investigation of the Fluxing Additives Effect on the Foaming of Different Silicate Raw Materials

2021 ◽  
Vol 1037 ◽  
pp. 767-774
Author(s):  
Boris M. Goltsman ◽  
Elena A. Yatsenko ◽  
Lyubov A. Yatsenko ◽  
Natalia S. Goltsman ◽  
Dmitriy M. Kuzmenkov
Keyword(s):  
Porous Structure ◽  
Sodium Fluoride ◽  
Energy Intensity ◽  
Raw Materials ◽  
Sodium Tetraborate ◽  
Insulating Materials ◽  
Narrow Temperature Range ◽  
Modifying Additives ◽  
Melting Effect

The main trends in the use of silicate raw materials for the production of heat-insulating materials are considered. It is shown that the introduction of modifying additives-fluxes is promising to reduce the energy intensity of the technology. The substances that play the role of fluxes in the silicate industry are selected. The most active fluxes were chosen - sodium tetraborate Na2B4O7 (borax) and sodium fluoride NaF. The mechanism of their melting effect on the silicate mass is investigated. It is shown that both borax and sodium fluoride are active fluxes, intensifying the melting of silicate raw materials of all types. The use of fluoride is hampered by a narrow temperature range, in which the formation of a stable porous structure is possible.

Study of structures of tillage working bodies with overhead chisel

2021 ◽  
pp. 10-15
Author(s):  
A. A. Kazubov ◽  
D. A. Mironov
Keyword(s):  
Wear Resistance ◽  
Energy Intensity ◽  
Raw Materials ◽  
High Strength ◽  
Its Regions ◽  
Land Cultivation ◽  
Strength Material ◽  
Working Bodies ◽  
Important Branch

Agriculture is the most important branch of the national economy, providing the population of our country with food and obtaining raw materials for a number of industries. The role of agriculture in the economy of Russia and its regions shows the structure and level of development of the state. It is impossible to get a good harvest without proper cultivation of the land. Cultivation of any crops begins with basic tillage, which is one of the most time-consuming operations. For this purpose, mounted and semi-mounted ploughshares are used. One of the effective ways to reduce the energy intensity of the main tillage process is chisel-shaped ploughshares with a protruding toe (chisel), which is located below the blade by 20 … 25 mm. Due to this, the sinking capacity of the hull and its resource are improved. To achieve this goal, such methods are used as the influx of metal in the field-cut zone, which increases its thickness, the surfacing of the nose part, which increases wear resistance and, accordingly, reduces wear of the sock in thickness, welding to the sock with a plate made of a more high-strength material [1].

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.

Fabrication of poly (1, 8-octanediol-co-Pluronic F127 citrate)/chitin nanofibril/bioactive glass (POFC/ChiNF/BG) porous scaffold via directional-freeze-casting

2020 ◽  
Vol 40 (7) ◽  
pp. 591-599
Author(s):  
Yaling Tian ◽  
Kai Liang ◽  
Yali Ji
Keyword(s):  
Bioactive Glass ◽  
Porous Structure ◽  
Pore Structure ◽  
Porous Scaffold ◽  
Pluronic F127 ◽  
Porous Scaffolds ◽  
Freeze Casting ◽  
Promising Candidate ◽  
Complete Replacement

AbstractThe citrate-based thermoset elastomer is a promising candidate for bone scaffold material, but the harsh curing condition made it difficult to fabricate porous structure. Recently, poly (1, 8-octanediol-co-Pluronic F127 citrate) (POFC) porous scaffold was creatively fabricated by chitin nanofibrils (ChiNFs) supported emulsion-freeze-casting. Thanks to the supporting role of ChiNFs, the lamellar pore structure formed by directional freeze-drying was maintained during the subsequent thermocuring. Herein, bioactive glass (BG) was introduced into the POFC porous scaffolds to improve bioactivity. It was found the complete replacement of ChiNF particles with BG particles could not form a stable porous structure; however, existing at least 15 wt% ChiNF could ensure the formation of lamellar pore, and the interlamellar distance increased with BG ratios. Thus, the BG granules did not contribute to the formation of pore structure like ChiNFs, however, they surely endowed the scaffolds with enhanced mechanical properties, improved osteogenesis bioactivity, better cytocompatibility as well as quick degradation rate. Reasonably adjusting BG ratios could balance the requirements of porous structure and bioactivity.

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.

Pots on mats: mat-impressed salt-extraction pottery at Chalcolithic Provadia-Solnitsata, Bulgaria

Antiquity ◽  
2021 ◽  
pp. 1-16
Author(s):  
Mila Andonova ◽  
Vassil Nikolov
Keyword(s):  
Material Culture ◽  
Large Scale ◽  
Raw Materials ◽  
Salt Production ◽  
Production And Consumption ◽  
Late Chalcolithic ◽  
South Eastern Europe ◽  
Materials Used ◽  
The Relationship

Evidence for both basket weaving and salt production is often elusive in the prehistoric archaeological record. An assemblage of Middle–Late Chalcolithic pottery from Provadia-Solnitsata in Bulgaria provides insight into these two different technologies and the relationship between them. The authors analyse sherds from vessels used in large-scale salt production, the bases of which bear the impression of woven mats. This analysis reveals the possible raw materials used in mat weaving at Provadia-Solnitsata and allows interpretation of the role of these mats in salt production at the site. The results illustrate how it is possible to see the ‘invisible’ material culture of prehistoric south-eastern Europe and its importance for production and consumption.

Development of two dosimetry systems based on basic violet dye for possible use as radiation dosimeters

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nehad Magdy ◽  
Sameh Gafar
Keyword(s):  
Gamma Ray ◽  
Raw Materials ◽  
Absorbed Dose ◽  
Chemical Yield ◽  
Radiation Sensitivity ◽  
Vital Role ◽  
Radiation Chemical ◽  
Content Type ◽  
Before And After

Purpose The purpose of this research paper is to study a comparison between two dosimetry systems, both of them based on basic violet dye (BV). Design/methodology/approach The first system depends on (BV) (incorporating polyvinyl alcohol) as a thin-film dosimeter. The second system also relies on (BV) as a solution dosimeter, which is more sensitive to gamma rays. The two prepared film/solutions have a considerable signal that decreases upon irradiation and the strength of the signal decreases with increasing radiation dose. Findings The gamma ray absorbed dose for these dosimeters was found to be up to 35 kGy for films and 1 kGy for the liquid phase. All dosimetric characteristics as radiation chemical yield, additive substance, dose-response function, radiation sensitivity, also before and after-irradiation stability under various conditions were considered. Practical implications It is expected the vital role of gamma radiation on this dye in its two forms or two media. This reveals their wide applications in the field of gamma irradiation processing. Originality/value These two dosimetry systems which depend upon the same dye are safe to handle, inexpensive, available raw materials and can be applied in various dosimetry applications as mentioned above.

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