Soil-cement bricks produced from local clay brick waste and soft sludge from fiber cement production

Soil-cement bricks were produced using local clay brick waste (CBW) and soft sludge (SS) from fiber-cement industries, preserving raw resources by substituting with industrial wastes. The control formula to produce soil-cement bricks, is 15 wt% Portland cement, 15 wt% sand, and 70 wt% laterite. Clay brick waste was added with values from 10 to 50 % of laterite weight in the control formula. For SS, 5 and 10 % was used to replace the total weight of the dry mixture in the control formula. The samples were shaped by using a manual brick making machine. The results showed that the compressive strength of all by-product bricks exceeded industry standards. The maximum compressive strength was attained for 10 % replacement of laterite by CBW. When using both SS and CBW, thermal conductivity and weight of the bricks were further reduced. However, the percentage of water absorption incorporated into the by-product bricks was higher than that of the control formula but still within permissible limit of the industrial standard for load-bearing applications. All by-product bricks showed lower thermal conductivity compared with the control formula. Soil-cement bricks produced with industry by-products have improved or provided similar properties to control formula soil-cement bricks. The utilization of CBW and SS content in the brick samples can save natural resources, decreasing fuel consumption, and reduce CO2 emissions during delivery

Recycling of exhausted dust from regenerator of glass furnace in glass batch melting

In soda-lime glass manufacturing, evaporation of volatile compounds from glass melt is the origin of the dust emission from glass tank furnace. The exhausted dust then is deposited on the regenerator and is needed to be removed. Thus, this study focuses on using the dust from melting glass in glass production. The glass batches were prepared from 0 wt% to 10 wt% of the exhausted dust from soda-lime glass production as a substitution of the total raw materials. The analysis of phase and chemical composition of the dust by x-ray powder diffraction (XRD) and x-ray fluorescence technique (XRF) indicated that it consisted mainly sodium sulphate. Thermal analysis (TG/DSC) revealed that the addition of exhausted dust reduced the temperature of the melting reaction of the glass batches. The optimum amount of the exhausted dust, which made it possible to obtain the glass with the lowest number of remaining bubbles, was 2 wt%. From CIE lab and dilatometry results revealed that up to 2 wt% replacement of total raw materials by the exhausted dust in the glass batch did not affect the glass color, thermal expansion coefficient, glass transition temperature and dilatometric softening point of glass samples

Electrode surfaces based on multiwall carbon nanotubes-chitosan composites validated in the detection of homocysteine biomarkers for cardiovascular disease risk monitoring

This study aimed to modify screen-printed carbon micro-electrode surfaces by coating them with multiwall carbon-based nanotubes conjugated with chitosan and then validated the formed multiwall carbon-based nanotubes-chitosan coated screen printed carbon micro-electrode for the detection of homocysteine, a biomarker analyte known as a risk indicator in cardiovascular disease. The microstructure surface and crystallographic structure stability of the formed multiwall carbon-based nanotubes-chitosan obtained at formed multiwall carbon-based nanotubes per chitosan ratios of 1:1, 2:1, 3:1, and 4:1 were examined via field emission scanning electron microscopy, X-ray radiation, Raman spectroscopy, surface area and pore size, and thermogravimetric analyses. Homocysteine solutions at 30–100 µM were measured by cyclic voltammetry using the different formed multiwall carbon-based nanotubes-chitosan compositions as sensor electrodes. That with an optimal formed multiwall carbon-based nanotubes per chitosan ratio of 4:1 showed the highest crystallinity and electrical conductivity and gave a high coefficient of determination (R2 = 0.9036) between the homocysteine concentration and the oxidation current detection over an operating range of 30–100 µM. This new composite microelectrode for detecting homocysteine concentration makes it a promising candidate for clinical applications