A large part of the global brick manufacturing industry has evolved based on knowledge transmitted from generation to generation without developing a consistent scientific approach. The purpose of this article is to contribute to this approach by discussing the state-of-the-art and future trends of the design and construction of artisan brick kilns (ABK). The methodology proposed for this study is based on a systematic literature review whereby main question is: What research exists on brick kilns? Based on the results of this review, it is recommended that appropriate emerging technologies that should be incorporated to ABKs for either medium or small enterprises should be: mechanical fans, envelope thermal insulation, organic waste of uniform size as fuel, automatic control of process variables and computer simulations of phenomenological processes. This should be accompanied by technical training for the brick-makers and greater access to financing funds. The technologies reviewed throughout the paper will allow for a more thermally efficient design of kilns, which will emit less hazardous greenhouse gases and atmospheric pollutants.

Traditional nixtamalization is performed to produce corn flour and tortillas. This process has undergone several modifications for industrialization purposes. Extrusion is an industrially used process for nixtamalization and ohmic heating may be considered an alternative. For this study, a continuous ohmic heater was used to produce nixtamalized corn flour and the effects of the process parameters – process temperature, feed moisture, and screw speed – on the physicochemical and textural properties of dough and tortilla were reviewed. Data showed that the process temperature had a greater effect than the feed moisture on the resulting product, while screw speed did not appear to have any significant influence on this. Tortillas showed good quality characteristics because of good water absorption and retention during the process. The products obtained by continuous ohmic heating process show quality characteristics similar to those present in traditional corn flour products.

Nanoporous materials show a promising combination of mechanical properties in terms of their relative density; while there are numerous studies based on metallic nanoporous materials, here we focus on amorphous carbon with a bicontinuous nanoporous structure as an alternative to control the mechanical properties for the function of filament composition.Using atomistic simulations, we study the mechanical response of nanoporous amorphous carbon with 50% porosity, with sp${}^3$ content ranging from 10% to 50%. Our results show an unusually high strength between 10 and 20 GPa as a function of the $\%s{p}^3$ content. We present an analytical analysis derived from the Gibson–Ashby model for porous solids, and from the He and Thorpe theory for covalent solids to describe Young’s modulus and yield strength scaling laws extremely well, revealing also that the high strength is mainly due to the presence of sp${}^3$ bonding. Alternatively, we also find two distinct fracture modes: for low $\%s{p}^3$ samples, we observe a ductile-type behavior, while high $\%s{p}^3$ leads to brittle-type behavior due to high high shear strain clusters driving the carbon bond breaking that finally promotes the filament fracture. All in all, nanoporous amorphous carbon with bicontinuous structure is presented as a lightweight material with a tunable elasto-plastic response in terms of porosity and sp${}^3$ bonding, resulting in a material with a broad range of possible combinations of mechanical properties.

The behaviour of mussel shell particulate as fine aggregate for mass concrete has been analysed. The shells were washed and mechanically crushed to obtain a particle size similar to that of the natural aggregate (fine) to be replaced, which was dried at 140 °C. The Faury-Joisel method was used to design the H-35(95)-20-6 structural mass concrete sample, with 0%, 10%, 30% and 60% replacements of fine aggregate by mussel shell particulates, performing compressive strength and thermal conductivity analyses at 7 and 28 days. The results indicate that in order to maintain the compressive strength of H-35(95)-20-6 structural mass concrete, the replacement percentage should not exceed 40%. On the other hand, as the mussel shell particulates in the concrete increase, the thermal conductivity decreases, turning into a material with a tendency to increase thermal insulation, which would help to improve the new demands on energy saving and efficiency in households, if used as coating. Hence, it can be concluded that it is feasible to replace fine aggregate with mussel shell particulate matter, which would be useful in increasing the recycling of this residue and in reducing its natural exploitation.