scholarly journals Reinforcement of Recycled Aggregate by Microbial-Induced Mineralization and Deposition of Calcium Carbonate—Influencing Factors, Mechanism and Effect of Reinforcement

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 887
Author(s):  
Chunhua Feng ◽  
Buwen Cui ◽  
Haidong Ge ◽  
Yihong Huang ◽  
Wenyan Zhang ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Global Economy ◽  
Low Cost ◽  
High Water ◽  
Strengthening Mechanism ◽  
Recycled Aggregate ◽  
Strengthening Effect ◽  
Calcium Carbonate Precipitation ◽  
Environmental Friendliness ◽  
Advantages And Disadvantages

Recycled aggregate is aggregate prepared from construction waste. With the development of a global economy and people’s attention to sustainable development, recycled aggregate has shown advantages in replacing natural aggregate in the production of concrete due to its environmental friendliness, low energy consumption, and low cost. Recycled aggregate exhibits high water absorption and a multi-interface transition zone, which limits its application scope. Researchers have used various methods to improve the properties of recycled aggregate, such as microbially induced calcium carbonate precipitation (MICP) technology. In this paper, the results of recent studies on the reinforcement of recycled aggregate by MICP technology are synthesized, and the factors affecting the strengthening effect of recycled aggregate are reviewed. Moreover, the strengthening mechanism, advantages and disadvantages of MICP technology are summarized. After the modified treatment, the aggregate performance is significantly improved. Regardless of whether the aggregate was used in mortar or concrete, the mechanical properties of the specimens were clearly improved. However, there are some issues regarding the application of MICP technology, such as the use of an expensive culture medium, a long modification cycle, and untargeted mineralization deposition. These difficulties need to be overcome in the future for the industrialization of regenerated aggregate materials via MICP technology.

scholarly journals little-known facts about silicate bricks and fires

2019 ◽  
Vol 138 ◽  
pp. 01009
Author(s):  
Alexandr Ibragimov
Keyword(s):  
Thermal Conductivity ◽  
Frost Resistance ◽  
Low Cost ◽  
High Strength ◽  
High Water ◽  
Historical Background ◽  
Technical Diagnostics ◽  
Color Gamut ◽  
Environmental Friendliness ◽  
Wide Color Gamut

The article presents a brief historical background about the epistemology of silicate brick. Well-known facts about silicate brick are given: the technological scheme of manufacture, modern grades for strength and frost resistance, information about thermal conductivity, classification by species, size and purpose. Advantages are considered, among which are noted: relatively low cost, environmental friendliness, compatibility with masonry mortars, aesthetics, wide color gamut, good geometric parameters, high strength characteristics, good soundproof ability, relatively high frost resistance, ease of processing. Disadvantages are given, among which are noted: high thermal conductivity, high water absorption, brittleness, and instability to acidic and alkaline aggressive environments. Particular attention is given to the consideration of the behavior of silicate brick and masonry from it in a fire. References to works devoted to this problem are given. The research of high temperature effects on the brickwork of the silicate bricks in the fire was held. A model for the possible collapse of brickwork as a re-sult of reducing its bearing ability due to fire was designed. The conclusion is drawn about the need for technical diagnostics of the structures of buildings made of silicate brick exposed to fire, as well as the special tactics of extinguishing fires in such buildings.

Treadle pump: A low cost irrigation option for marginal farmers

2018 ◽  
Vol 5 (03) ◽  
Author(s):  
ATIQUR RAHMAN ◽  
ASHUTOSH UPADHYAYA ◽  
BP BHATT
Keyword(s):  
Low Cost ◽  
Water Productivity ◽  
High Water ◽  
Water Saving ◽  
Age Group ◽  
Male And Female ◽  
Human Power ◽  
Dry Spells ◽  
Supplementary Irrigation ◽  
Land Holdings

The population of marginal farmers in India is bound to increase due to continued division of farm holdings. Characteristically, marginal farmers are having more family labours but the production and productivity of their land holdings is low. The foremost reason behind this is the erratic rainfall and lack of assure supplementary irrigation during long dry spells. This paper presents the scope and applicability of a diaphragm based treadle pump in Bihar where groundwater is abundant and available at shallow depths round the year. Therefore, this pump could be very useful for marginal farmers in improving production and productivity of their tiny piece of land, as it uses human power and can be operated by male and female of age group 32- 45 years and lifts water from a depth ranging from 0- 30 feet. The water saving technologies such as bucket kit drum kit etc. could be used with this pump to irrigate the crops with high water productivity.

scholarly journals A review of biomass materials for advanced lithium–sulfur batteries

2019 ◽  
Vol 10 (32) ◽  
pp. 7484-7495 ◽  
Author(s):  
Huadong Yuan ◽  
Tiefeng Liu ◽  
Yujing Liu ◽  
Jianwei Nai ◽  
Yao Wang ◽  
...  
Keyword(s):  
Recent Progress ◽  
Low Cost ◽  
High Abundance ◽  
Chemical Adsorption ◽  
Environmental Friendliness ◽  
Lithium Sulfur Batteries ◽  
Biomass Materials ◽  
Physical And Chemical ◽  
Lithium Sulfur

This review summarizes recent progress of biomass-derived materials in Li–S batteries. These materials are promising due to their advantages including strong physical and chemical adsorption, high abundance, low cost, and environmental friendliness.

Green water-based binders for LiFePO4/C cathode in Li-ion batteries: a comparative study

2021 ◽  
Author(s):  
Xiaojing Zhang ◽  
xinyi Ge ◽  
Zhigang Shen ◽  
Han Ma ◽  
Jingshi Wang ◽  
...  
Keyword(s):  
Comparative Study ◽  
Polyvinylidene Fluoride ◽  
Low Cost ◽  
Green Water ◽  
Li Ion Batteries ◽  
Environmental Friendliness ◽  
Water Based ◽  
Li Ion

Compared with environmentally harmful binder polyvinylidene fluoride (PVDF) in Li-ion batteries (LIBs), water-based binders have many advantages, such as low cost, rich sources and environmental friendliness. In this study, various...

scholarly journals Kaolin-Enhanced Superabsorbent Composites: Synthesis, Characterization and Swelling Behaviors

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1204
Author(s):  
Mengna Chen ◽  
Xuelong Chen ◽  
Caiyan Zhang ◽  
Baozheng Cui ◽  
Zewen Li ◽  
...  
Keyword(s):  
Water Absorption ◽  
Low Cost ◽  
High Water ◽  
Kinetic Mechanism ◽  
Swelling Kinetics ◽  
Synthesis Conditions ◽  
Ph Tolerance ◽  
Monovalent Salt ◽  
Infrared Spectrometer ◽  
Pseudo Second Order

One type of low-cost and eco-friendly organic‒inorganic superabsorbent composite (SAPC) was synthesized by free radical polymerization of acrylic acid (AA), starch (ST), sodium alginate (SA) and kaolin (KL) in aqueous solution. The structure and morphology of the SAPC were characterized by Fourier transform infrared spectrometer (FT-IR), scanning electron microscope (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The influence of different reaction conditions on water absorption of SAPC, i.e., SA and KL contents, AA neutralization degree (ND), potassium persulfate (KPS) and N, N′-methylenebisacrylamide (MBA) loading were systematically studied. Under the optimal synthesis conditions, very high water absorption of 1200 g/g was achieved. The swelling kinetic mechanism of SAPC was studied by pseudo-second order swelling kinetics model and Ritger‒Peppas model. The performances of SAPC under different environments were tested and results revealed that this new SAPC had excellent swelling capacity, high water retention, good salt tolerance in monovalent salt solution (NaCl solution) and good pH tolerance between 4 and 10.

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