Mechanical and microstructural properties of alkali-activated slag and slag?+?fly ash mortars exposed to high temperature

In this study, changes in the mechanical and microstructural properties of alkali-activated blast furnace slag (BFS) and BFS + fly ash (FA) blended mortars exposed to 25, 400, 600 and 800 °C temperatures are investigated. The alkali-activated mortars using the replacement ratios of 0, 25 and 50% FA by weight of BFS together with the activators are produced in addition to the control mortars produced by only cement. Three different optimum Ms (SiO2/Na2O ratio of activators) values of 0.50, 0.75 and 1.00 are determined for the alkali-activated mortars. The FA substitution by BFS increases the high temperature resistance of alkali-activated BFS mortars. © 2019 Elsevier LtdÖmer Halisdemir ÜniversitesiThe SEM, EDS and XRD analyses of this research were performed by using the devices in Central Laboratory of Niğde Ömer Halisdemir University. This research study was supported by Niğde Ömer Halisdemir University project “Investigation of the properties of alkali-activated lightweight concretes”, project code FEB2008/10-BAGEP

Numerical and experimental investigation of CI engine behaviours supported by zinc oxide nanomaterial along with diesel fuel

Zinc oxide nano additives of 250 ppm, 500 ppm, and 1000 ppm were blended with diesel fuel. The prepared fuels which were designated as DF-250 ppm ZnO, DF-500 ppm ZnO, and DF - 1000 ppm ZnO were tested for engine characteristics along with diesel fuel (DF) in a standard bench-scale engine. All the tests were carried out at different speeds of the engine ranging between 2000 and 3000 rpm with unvarying engine load and advanced injection timing. The outcomes from these experiments exhibited higher brake thermal efficiency and cylinder pressure for fuels with ZnO nano additives than that of diesel fuel. The emission gas temperature and brake-specific fuel consumption were noticed to be lower for fuels blended with ZnO nano additive than those of diesel fuel. The level of SPM emissions also increased in compression ratio from CR = 15.5 to CR = 16.5, but starting from CR of 17.5, the SPM emissions for all the investigated fuels were relatively constant with a slight decrease at the maximum compression ratio. In addition, at all test conditions, NO and SO2 emissions from the engine tail pipe were higher with ZnO mixed diesel fuel. © 2021 Elsevier Ltd2-s2.0-8511857436