Recycled concrete aggregates and mixed recycled aggregates are specified as types of aggregates with lower densities, higher water absorption capacities, and lower mechanical strength than natural aggregates. In this paper, the mechanical behaviour and microstructural properties of natural aggregates, recycled concrete aggregates and mixed recycled aggregates were compared. Different specimens ...

The structure of biofilms in drinking water systems is influenced by the interplay between biological and physical processes. Bacterial aggregates in bulk fluid are important in seeding biofilm formation on surfaces. In simple pure and co-cultures, certain bacteria, including Methylobacterium, are implicated in the formation of aggregates. However, it is unclear whether they help to form aggreg...

The extensive use of titanium dioxide nanoparticles (nano-TiO2) in many consumer products has raised concerns about possible risks to the environment The magnitude of the threat may depend on whether nano-TiO2 remains dispersed in the environment, or forms much larger-sized aggregates or clusters. Currently, limited information is available on the issue. In this context, the purpose of the pres...

Stable hairy lanthanum hydroxide nanoparticles were synthesized in water by performing hydrolysis and condensation reactions of lanthanum cations in the presence of double hydrophilic polyacrylic acid-b-polyacrylamide block copolymers (PAA-b-PAM). In the first step, the addition of asymmetric PAA-b-PAM copolymers (Mw,PAA o Mw,PAM) to lanthanum salt solutions, both at pH = 5.5, induces the forma...

Gelfond and Zhang recently proposed a new stable model semantics based on Vicious Circle Principle in order to improve the interpretation of logic programs with aggregates. The paper focuses on this proposal, and analyzes the complexity of both coherence testing and cautious reasoning under the new semantics. Some surprising results highlight similarities and differences versus mainstream stabl...

Physical properties of interfacial layers formed at the xylene-water interface by the adsorption of a polyaromatic organic compound, N-(1-hexylheptyl)-N'-(5-carbonylicpentyl) perylene-3,4,9,10-tetracarboxylic bisimide (in brief, C5Pe), were studied systematically. The deprotonation of the carboxylic group of C5Pe at alkaline pH made it highly interfacially active, significantly reducing the xyl...

A novel concept in internal curing of High Performance Concrete is based on dispersing very small, saturated lightweight aggregates (LWA) in the concrete, containing sufficient water to counteract self-desiccation. With this approach, the amount of water in the LWA can be minimized, thus economizing on the amount of the LWA. In this study, the pore structure of different size fractions of pumic...

Arbuscular Mycorrhizal (AM) fungi form mutualistic symbiotic relationships with approximately 80% of terrestrial plant species, while producing the glycoprotein glomalin as a structural support molecule along their mycelial network. Glomalin confers two benefits for soils: (1) acting carbon and nitrogen storage molecule; (2) binding soil microaggregates (<250 µm) to larger, more stable struc...

Diatom-bacteria aggregates are key for the vertical transport of organic carbon in the ocean. Sinking aggregates also represent pelagic microniches with intensified microbial activity, oxygen depletion in the center, and anaerobic nitrogen cycling. Since some of the aggregate-forming diatom species store nitrate intracellularly, we explored the fate of intracellular nitrate and its availability...