Application of non-degradable waste as building material for low-cost housing

The history of diapers and their environmental impact

IMPACT

This article examines diaper practices around the world throughout history. This article reviews the innovation of the modern diaper and the environmental effects of disposable diapers.

An integrated multicriteria decision making framework for the selection of waste cement dust filled automotive brake friction composites

This work discusses selecting optimal brake friction composite alternatives based on an integrated MABAC (multi-attributive border approximation area comparison) and AHP (analytic hierarchy process) approach. Therefore, non-asbestos automotive brake friction composites containing varying proportions of cement dust (50 to 0 wt%) and barium sulfate (0 to 50 wt%) were developed and tribo-evaluated on a Krauss machine following European regulations. Composite made up of 30 wt% cement dust and 20 wt% barium sulfate had the highest friction coefficient (0.361), lowest variability coefficient (0.598), and maximum recovery (123.27%). The composite with the least fading (15.36%) included 50 wt% cement dust, whereas the composite with the lowest wear (9.10 g) and the least frictional fluctuations (0.271) contained 50 wt% barium sulfate. By AHP, the friction coefficient (0.1989), fade (0.1696), recovery (0.1551), and wear (0.1412) were selected as the essential criteria in the performance assessment. Based on the MABAC ranking evaluation, the composite comprises 20 wt% barium sulfate and 30 wt% cement dust has the best tribological profile, whereas the composites of solely cement dust or barium sulfate have the poorest tribological profile. The acquired ranking results were confirmed using other decision-making models and subjected to sensitivity analysis to demonstrate their robustness.

Optimizing the thermophysical qualities of innovative clay-rGO composite bricks for sustainable applications

This work concerned the development of a unique reduced graphene oxide (rGO) nano-filler to provide innovative opportunities in enhancing the thermophysical performance of clay composite bricks. Whereas, a series of clay-rGO composite bricks were produced, doped with various levels of rGO nanosheets (i.e., 0, 1, 2, 4, and 6 wt% clay). Each clay-rGO composite's microstructure, shrinkage, morphology, density, porosity, and thermophysical characteristics were carefully investigated, and the thermal conductivity performance was optimized. Incorporation of different levels of rGO NPs to the clay matrix allowed all the peaks intensity to rise relative to the untreated one in the XRD pattern. Meanwhile, the inclusion of these doping resulted in a grew in the crystallite sizes and apparent porosity within the compositions. In this vein, shrinkage fracture of fabricated brick composites varied depending on dopants type and levels during the drying and firing processes. Moreover, there are some changes in chemical compositions, as well as wave shifts, suggesting that functional groups of rGO may have contributed to partially introduce carbonyl groups in clay-rGO composites. Besides, the porous topography and bulk density improved rapidly with respect to the plane of the rGO nanosheets within the composites. The differ-dense microstructure displayed in the SEM micrographs supports these outcomes. Remarkably, clay-(4%)rGO compound not only has an optimum thermal conductivity value (0.43 W/mK), but it also has a high heat capacity (1.94 MJ/m3K). These results revealed the exceptional features of rGO sheets such as large surface area with high porosity within the modified clay composites.