Quartzite Mining Waste: Diagnosis of ASR Alkali-Silica Reaction in Mortars and Portland Cement Concrete

The main objective was to determine the deleterious potential of quartzite mining tailings subjected to different ASR alkali–silica reaction tests. The studies included petrographic analysis, chemical analysis of cements, expansion tests in mortar bars and concrete prisms, and microstructural analysis. Petrographic analysis of quartzites indicated high percentages of deformed quartz (95%), and were classified as potentially reactive. Two types of HES high early strength cement with alkaline equivalents of 0.749% and 0.61%, respectively, were selected. Of the 8 samples analyzed by the accelerated method in mortars, only 2 quartzite samples and 1 diabasium sample indicated potentially reactive behavior. The accelerated and long-term methods in concrete prisms proved to be effective and were consistent with the deleterious potential of the samples. All analyzed samples were diagnosed with the ASR gel. In the microstructural analysis, in addition to the ASR products, other expansive products of late ettringite were detected. Reaction mitigation methods are proposed so that quartzite waste can be used as an alternative aggregate in concrete, and thus contribute to the reduction of mine tailings and, consequently, reduce the negative environmental impact from mining.

Axiomatic and Dynamic Processes for a Symmetric Allocation Rule

It has recently become imperative to analyze relevant issues to improve the efficiency of resource allocation by means of different perspectives and ways of thinking. There exist numerous decisive factors, such as changes in forms of allocation, reactive behavior, and the interaction and functional effectiveness of strategies, that need to be complied. In contrast to expert meetings, rules of thumb, or other existing concepts, this article aims to offer a different and efficient resource allocation approach by applying game-theoretical methods to resource-allocation situations. Our major investigative procedures are as follows: (1) after comparing our method with pre-existing allocation rules from pre-existing allocation rules, a symmetric allocation rule is proposed that considers both units and their energy grades; (2) based on the properties of grade completeness, criterion for models, unmixed equality symmetry, grade synchronization, and consistency, some axiomatic outcomes are used to examine the mathematical accuracy and the applied rationality of this symmetric allocation rule; (3) based on a symmetrical revising function, a dynamic process is applied to show that this symmetric allocation rule can be reached by units that start from an arbitrary grade completeness situation; and (4) these axiomatic and dynamic results and related meanings are applied to show that this symmetric allocation rule can present an optimal alternative guide for resource-allocation processes. Related applications, comparisons, and statements are also offered throughout this article.

The Neglected Nuclei

Since the nuclei in a molecule are treated as stationary, it is perhaps natural that interpretations of molecular properties and reactivity have focused primarily upon the electronic density distribution. The role of the nuclei has generally received little explicit consideration. Our objective has been to at least partially redress this imbalance in emphasis. We discuss a number of examples in which the nuclei play the determining role with respect to molecular properties and reactive behavior. It follows that conventional interpretations based solely upon electronic densities and donating or withdrawing tendencies should be made with caution.

Reactive behavior of isoquinoline alkaloid in a green reduction process assisted by ionic liquids and solvent-free techniques

Green reduction was assisted by ionic liquid and solvent-free technologies and a reaction in a tablet was realized for the first time.

Analysis of Green IT practices in technology-based organizations

Purpose: This paper aims to analyze Green IT practices adopted by technology-based organizations.Methodology: The study had a quantitative approach and the data were collected through a questionnaire, which was answered by 105 managers working in companies in the IT sector in BrazilFindings: Evidence collected showed that companies have a reactive behavior towards Green IT because they do not have, as their strategic objective, an increase in the general perception of value that consumers have about the company, nor do they seek competitivess based on sustainable development.Originality/value: In the Brazilian research scenario, the search for the keywords “Green IT”, “Green Information Technology”, “Green IT” and “Green Information Technology” on the Scielo search platform, found only five articles, on July 15th, 2020. In a search on the SPELL portal and CAPES Portal of Journals, also on July 15th, using the aforementioned keywords, four articles were found, in addition to those already found on the Scielo portal. Such results demonstrate how the topic is still little explored in the context of research in Brazil. It is important to note that Green IT comes up as a way of combining the available resources with the sustainability and economy policies in organizations, generating benefits for the environment and companies, providing opportunities for new business platforms.

Agent Adaptation in an Urban Coastal Scenario: Applying the VIABLE Framework

<p>An agent-based model (the VIABLE framework) of a coastal city is represented in Netlogo, describing adaptive dynamic agent behavior in a changing system. Rising sea levels and subsequent extreme sea level events incur damages to the city which an “urban planner” agent can mitigate through two adaptation pathways: developing coastal defenses, or as a more extreme measure, relocating vulnerable areas inland. Capital generated by the city can be directed as investments towards these pathways, with the remainder being consumed. The agent’s control variables are thus the amount of capital invested, and the ratio of investments allocated to the two pathways. As the simulation progresses and the system changes with rising sea levels, the agent alters these control variables to optimize its value, resulting in dynamic reactive behavior. Additionally, sea level rise is implemented in various modes, along with extreme sea level events that cause severe short-term damages.</p>

Children’s development of humour in everyday interactions: two case-studies in French and Brazilian Portuguese

In order to understand how children learn to recognize and use humor in their own cultural environment, we have chosen to study their production in two different languages and cultures. We studied a French-speaking monolingual child and a Brazilian Portuguese-speaking child, video-recorded once a month up to seven years old. The detailed multimodal linguistic coding of our data enabled us to draw the multimodal paths the two children followed from the first instances of shared amusement initiated by the adult, expressed mainly through reactive behavior such as laughing, to the children’s own verbal production of successful humor in dialogue. Our study demonstrates that the production of children’s humor is closely linked to the family input (their micro-culture), and to children’s multimodal linguistic and meta-cognitive development. We did not observe important differences between the two children at the macro-cultural level, but there were noticeable inter-individual differences.