Sustainable design of self-consolidating green concrete with partial replacements for cement through neural-network and fuzzy technique

In order to achieve a sustainable mix design, this paper evaluates self-consolidating green concrete (SCGC) properties by experimental tests and then examines the design parameters with an artificial intelligence technique. In this regard, cement was partially replaced in different contents with granulated blast furnace slag (GBFS) powder, volcanic powder, fly ash, and micro-silica. Moreover, fresh and hardened properties tests were performed on the specimens. Finally, an adaptive neuro-fuzzy inference system (ANFIS) was developed to identify the influencing parameters on the compressive strength of the specimens. For this purpose, seven ANFIS models evaluated the input parameters separately, and in terms of optimization, twenty-one models were assigned to different combinations of inputs. Experimental results were reported and discussed completely, where furnace slag represented the most effect on the hardened properties in binary mixes, and volcanic powder played an effective role in slump retention among other cement replacements. However, the combination of micro-silica and volcanic powder as a ternary mix design successfully achieved the most improvement compared to other mix designs. Furthermore, ANFIS results showed that binder content has the highest governing parameters in terms of the strength of SCGC. Finally, when compared with other additive powders, the combination of micro-silica with volcanic powder provided the most strength, which has also been verified and reported by the test results

Microelectromechanical disk resonators for direct detection of liquid-phase analytes

a b s t r a c t This paper presents preliminary measurement results for real-time detection of biomolecules using rotational-mode MEMS resonant structures and capability of such to directly and specifically measure concentration of thiol-terminated DNA molecules in liquid. Thin film piezoelectric disk resonators with quality factors (Q) as high as ∼100 in aqueous solutions have been fabricated and utilized as direct biomolecular detectors that can address the problem of low Q for MEMS resonators when in direct contact with liquid. To adsorb thiol-terminated molecules, a gold layer is deposited on the top resonator surface. A gradual frequency shift of ∼10 kHz (3800 ppm) was recorded in real-time while forming monolayers of mercaptohexanol in aqueous solution, demonstrating the potential of such structures as highly sensitive biosensors. Over and above detection of target single-stranded-DNA (ssDNA) sequences using the disk resonators (with mass sensitivities as high as 19.3 ppm cm 2 /ng (65 Hz cm 2 /ng) in aqueous solution), the response of such devices has been characterized using different concentrations of thiol-terminated DNA molecules. For one order of magnitude change in concentration of functionalizing thiol-terminated-ssDNA solution, ∼2X difference in measured frequency shifts of the disk resonators was observed