Effect of the TMCS/hydrogel volume ratio on physical properties of silica aerogels based on fly ash acid sludge

ABSTRACTRefuse-derived-fuel (RDF) consisting mainly of waste paper and plastics is a viable fuel source for the production of power. An experimental test burn partially substituting coal with RDF was undertaken by the Public Service of New Hampshire at the Merrimack Power Station.Five percent and ten percent RDF were substituted, on a BTU basis, for coal in the test bums. The chemical and physical properties of the resulting fly ash were determined. Twelve test burn days were run with 4 days of 5% RDF and 8 days of 10% RDF. Emphasis was placed on investigating the effect of the RDF fly ash on Portland cement concrete.Most of the chemical and physical properties of the coal-RDF fly ash were found to be comparable with ordinary coal fly ash except for the amount of cadmium and lead, the pozzolanic activity index and the compressive strength of fly ash concrete. Cadmium and lead were at average levels of 5.1 ppm and 102.6 ppm for the 5% RDF, and 7.8 ppm and 198.3 ppm for the 10% RDF, respectively. Although the pozzolanic activity index of coal-RDF fly ash increases over normal coal fly ash, preliminary results show that the 28-day compressive strength of concrete with direct replacement of cement and sand decreases by up to 30%. Leaching tests on crushed concrete were conducted to evaluate the environmental effect of acid rain.

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00/00165 Laboratory-produced high-volume fly ash blended cements: physical properties and compressive strength of mortars

Fuel and Energy Abstracts ◽

10.1016/s0140-6701(00)94958-0 ◽

2000 ◽

Vol 41 (1) ◽

pp. 17

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Physical Properties ◽

High Volume ◽

Blended Cements ◽

High Volume Fly Ash

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Study on the Physical Properties of a SiNW Biosensor to the Sensitivity of DNA Detection

Materials ◽

10.3390/ma14195716 ◽

2021 ◽

Vol 14 (19) ◽

pp. 5716

Author(s):

Siti Noorhaniah Yusoh ◽

Khatijah Aisha Yaacob

Keyword(s):

Surface Roughness ◽

Physical Properties ◽

Limit Of Detection ◽

Silicon Nanowire ◽

Volume Ratio ◽

Silicon Nanowire Arrays ◽

Atomic Force ◽

Local Anodic Oxidation ◽

Wet Chemical ◽

Biosensor Device

SiNW (silicon nanowire) arrays consisting of 5- and 10-wires were fabricated by using an atomic force microscope—the local anodic oxidation (AFM-LAO) technique followed by wet chemical etching. Tetramethylammonium hydroxide (TMAH) and isopropyl alcohol (IPA) at various concentrations were used to etch SiNWs. The SiNWs produced were differed in dimension and surface roughness. The SiNWs were functionalized and used for the detection of deoxyribonucleic acid (DNA) dengue (DEN-1). SiNW-based biosensors show sensitive detection of dengue DNA due to certain factors. The physical properties of SiNWs, such as the number of wires, the dimensions of wires, and surface roughness, were found to influence the sensitivity of the biosensor device. The SiNW biosensor device with 10 wires, a larger surface-to-volume ratio, and a rough surface is the most sensitive device, with a 1.93 fM limit of detection (LOD).

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