scholarly journals Effect of crushed glass aggregate on the physico-mechanical properties of micro-concrete

2018 ◽  
Vol 19 (2) ◽  
pp. 210-228
Author(s):  
Maza Mekki ◽  
◽  
Naceri Abdelghani ◽  
Salim Zitouni ◽  
◽  
...  
Keyword(s):  
High Strength ◽  
Solid Wastes ◽  
Recycled Aggregates ◽  
Recycled Glass ◽  
A Value ◽  
Concrete Production ◽  
Glass Aggregate ◽  
Glass Wastes ◽  
Crushed Limestone

Demand for aggregates is growing considerably in line with the development of construction in Algeria. To overcome it, it will be necessary to ensure a rational exploitation of the aggregates available to the country by aevaluation of the existingresources. According to the statistics, the glass wastes accounted for 7% of the world’s solid wastes. The glass wastes can be used in concrete production in two forms: replacing part of aggregate or using as supplementary cementmaterial to replace cement. Using glass wastes to produce recycled aggregates for the production of new concrete reduces the consumption of natural resources as well as landfills.This work consists in formulating a micro-concrete with a substitution of 5 to 25% by weight of crushed calcareous aggregates of fraction 3/8 by glass aggregates of the same fraction 3/8. The incorporation of glass wastes as an aggregate in the micro-concrete plays a role of skeleton and improves its compressive mechanical strength.The compressive strength is considerably improved by substitution of crushed calcareous aggregates by recycled glass aggregates. The optimum has been reached for a value of around 46 MPa for a substitution of 10% of crushed limestone aggregates. The substitution of 10% crushed gravel by crushed glass allows improving the strength of more than 27%.The results obtained provedthat waste glass can be used as an aggregate for producing micro-concrete with a relatively high strength which will not deteriorate with time.

scholarly journals The Use of Fragmented, Worn-Out Car Side Windows as an Aggregate for Cementitious Composites

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1467 ◽  
Author(s):  
Maciej Szeląg ◽  
Bartosz Zegardło ◽  
Wojciech Andrzejuk
Keyword(s):  
Water Resistance ◽  
Microscopic Analysis ◽  
Hardened Concrete ◽  
Side Window ◽  
Recycled Glass ◽  
Air Content ◽  
Concrete Production ◽  
Concrete Mix ◽  
Glass Aggregate ◽  
Composite Samples

The paper describes a new model of concrete production, which contains a glass cullet. A worn-out car side window have been used for the production of recycled glass aggregate (RGA) and its properties were examined. The RGA was used in concrete as a 50% and 100% mass substitute of the traditional aggregate. Basic tests of fresh concrete mix and hardened concrete were carried out. The consistency, the air content in the concrete mix, the density of hardened concrete, water absorption, water resistance, frost resistance, and the compressive strength (after 9, 28, and 90 days) were evaluated. Composite samples were also subjected to microscopic analysis. The results showed that the RGA can be recommended as an aggregate for concretes, and the features of the RGA concrete are more favorable than those of traditional concrete. The microscopic analyses allowed us to identify the reasons for improving the properties of the RGA composites.

Studying the Effect of Tempering Temperature during Heat Treatment on the Corrosion Resistance of 13Mn6 Steel Samples

2021 ◽  
Vol 316 ◽  
pp. 203-207
Author(s):  
O.A. Nasibullina
Keyword(s):  
Heat Treatment ◽  
Rust Resistance ◽  
Mechanical Characteristics ◽  
High Strength ◽  
Tempering Temperature ◽  
A Value ◽  
Definition Of ◽  
Long Endurance ◽  
The Given

In the conditions of development of rates of the modern production the role of a heat treatment as a main way of receiving steels with the given structure and mechanical characteristics increases. The details applied on production have to have a long endurance not only at an ambient temperature, but also have high strength characteristics at low and high temperatures. In this regard, special attention is paid to the steel applied to manufacturing of such details. 13Mn6 steel concerns one of them. The definition of an influence of a heat treatment of steel - training at various temperatures, steel 13Mn6 on its rust resistance was the purpose of this work. For achievement of a goal such problems as a research of an influence of the various temperature of annealing of steel 13Mn6 on a value of hardness on Rockwell's method were solved; gravimetric researches after a heat treatment for identification of a temperature schedule of the annealing having the maximum indicators of corrosion were held. It is shown that, after spending vacation hardness of exemplars decreases with an increase in temperature. For assessment of corrosion aggression of the environment on the studied exemplars mass and deep indicators of corrosion were paid off. The maximum corrosion rate is observed when training, and the subsequent annealing at a temperature of 300°C, minimum at a temperature of annealing of 500°C.

Endangered Butterflies and their Non-Native Host Plants: Examining Shifting Values of Belonging in Restoration

2019 ◽  
Vol 3 (1) ◽  
pp. 1-9
Author(s):  
Robert M. Anderson ◽  
Amy M. Lambert
Keyword(s):  
Ecological Restoration ◽  
Native Species ◽  
Puget Sound ◽  
A Value ◽  
The Social ◽  
Remote Island ◽  
Scientific Truth ◽  
Native Host

The island marble butterfly (Euchloe ausonides insulanus), thought to be extinct throughout the 20th century until re-discovered on a single remote island in Puget Sound in 1998, has become the focus of a concerted protection effort to prevent its extinction. However, efforts to “restore” island marble habitat conflict with efforts to “restore” the prairie ecosystem where it lives, because of the butterfly’s use of a non-native “weedy” host plant. Through a case study of the island marble project, we examine the practice of ecological restoration as the enactment of particular norms that define which species are understood to belong in the place being restored. We contextualize this case study within ongoing debates over the value of “native” species, indicative of deep-seated uncertainties and anxieties about the role of human intervention to alter or manage landscapes and ecosystems, in the time commonly described as the “Anthropocene.” We interpret the question of “what plants and animals belong in a particular place?” as not a question of scientific truth, but a value-laden construct of environmental management in practice, and we argue for deeper reflexivity on the part of environmental scientists and managers about the social values that inform ecological restoration.

Perempuan dan Liminalitas dalam Tradisi Perkawinan Adat di Timor Tengah Selatan

2020 ◽  
Vol 6 (1) ◽  
pp. 114
Author(s):  
Marsel Eliaser Liunokas
Keyword(s):  
Qualitative Research ◽  
Research Method ◽  
Literature Study ◽  
Qualitative Research Method ◽  
South Central ◽  
A Value ◽  
Traditional Marriage ◽  
The Village ◽  
As If

Timorese culture is patriarchal in that men are more dominant than women. As if women were not considered in traditional rituals so that an understanding was built that valued women lower than men. However, in contrast to the article to be studied, this would like to see the priority of women’s roles in traditional marriages in Belle village, South Central Timor. The role of women wiil be seen from giving awards to their parents called puah mnasi manu mnasi. This paper aims to look at the meaning of the rituals of puah mnasi maun mnasi and the role and strengths that women have in traditional marriage rituals in the village of Belle, South Central Timor. The method used for this research is a qualitative research method using interview techniques with a number of people in the Belle Villa community and literature study to strengthen this writing. Based on the data obtained this paper shows that the adat rituals of puah mnasi manu mnasi provide a value that can be learned, namely respect for women, togetherness between the two families, and brotherhood that is intertwined due to customary marital affrairs.

Influence of social networks on business processes’ development

2020 ◽  
Vol 19 (12) ◽  
pp. 2225-2252
Author(s):  
E.V. Popov ◽  
V.L. Simonova ◽  
O.V. Komarova ◽  
S.S. Kaigorodova
Keyword(s):  
Social Networks ◽  
Social Media ◽  
Business Models ◽  
Business Processes ◽  
Digital Economy ◽  
Theoretical Understanding ◽  
Sales Channels ◽  
A Value ◽  
The Impact

Subject. The emergence of new ways of interaction between sellers and buyers, the formation of new sales channels and product promotion based on the use of digital economy tools is at the heart of improving the business processes. Social networks became a tool for development; their rapid growth necessitates theoretical understanding and identification of potential application in enterprise's business process digitalization. Objectives. We explore the role of social media in the digitalization of business processes, systematize the impact of social networks on business processes of enterprises in the digital economy. Methods. The theoretical and methodological analysis of social networks as a tool for digitalization of company's business processes rests on the content analysis of domestic and foreign scientific studies, comparison, generalization and systematization. Results. We highlight the key effects of the impact of social networks on the business processes of the company; show that the digitalization of business processes should be considered in the context of a value-based approach, aimed at creating a value through the algorithmization of company operations. We determine that social networks are one of the most important tools for digitalization of company's business processes, as they have a high organizational and management potential. We also systematize the effects of social media on company's business processes. Conclusions. We present theoretical provisions of the impact of social networks on business processes of enterprises, which will enable to model and organize ideas about the development of digital ecosystems and the formation of business models.

scholarly journals Determining the Role of Acidity, Fate and Formation of IEPOX-Derived SOA in CMAQ

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 707
Author(s):  
Petros Vasilakos ◽  
Yongtao Hu ◽  
Armistead Russell ◽  
Athanasios Nenes
Keyword(s):  
Significant Influence ◽  
Organic Aerosol ◽  
Liquid Water Content ◽  
Anthropogenic Emissions ◽  
So2 Emissions ◽  
Aerosol Acidity ◽  
A Value ◽  
Future Emission ◽  
The Impact

Formation of aerosol from biogenic hydrocarbons relies heavily on anthropogenic emissions since they control the availability of species such as sulfate and nitrate, and through them, aerosol acidity (pH). To elucidate the role that acidity and emissions play in regulating Secondary Organic Aerosol (SOA), we utilize the 2013 Southern Oxidant and Aerosol Study (SOAS) dataset to enhance the extensive mechanism of isoprene epoxydiol (IEPOX)-mediated SOA formation implemented in the Community Multiscale Air Quality (CMAQ) model (Pye et al., 2013), which was then used to investigate the impact of potential future emission controls on IEPOX OA. We found that the Henry’s law coefficient for IEPOX was the most impactful parameter that controls aqueous isoprene OA products, and a value of 1.9 × 107 M atm−1 provides the best agreement with measurements. Non-volatile cations (NVCs) were found in higher-than-expected quantities in CMAQ and exerted a significant influence on IEPOX OA by reducing its production by as much as 30% when present. Consistent with previous literature, a strong correlation of isoprene OA with sulfate, and little correlation with acidity or liquid water content, was found. Future reductions in SO2 emissions are found to not affect this correlation and generally act to increase the sensitivity of IEPOX OA to sulfate, even in extreme cases.

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