The Application of a New Oxidation Mortar Bar Test to Mixtures containing Different Cementing Systems

The effects of different cementing systems on the expansion of mortars containing iron sulphide-bearing aggregate was studied. Using a recently developed oxidation mortar bar test, the results showed that cementing systems containing low-calcium fly ash, metakaolin, slag, high-sulphate resisting Portland cement, or low heat of hydration Portland cement could reduce the expansion by 50–85%. The main suggested mechanisms behind the reduced expansion is the more refined pore structure of samples with SCMs, and the reduced C3A of low heat of hydration Portland cement. The refined pore structure reduces the permeation of the oxidizing solution into the samples. The similarity of this to penetration of oxygen into concrete under field exposure needs to be determined. Soaking the samples for >3 h in the oxidizing agent can produce excessive expansion – not related to oxidation of iron sulphide phases – in samples with cementing blends containing reactive alumina such as metakaolin.

The Application of a New Oxidation Mortar Bar Test to Mixtures containing Different Cementing Systems

The effects of different cementing systems on the expansion of mortars containing iron sulphide-bearing aggregate was studied. Using a recently developed oxidation mortar bar test, the results showed that cementing systems containing low-calcium fly ash, metakaolin, slag, high-sulphate resisting Portland cement, or low heat of hydration Portland cement could reduce the expansion by 50–85%. The main suggested mechanisms behind the reduced expansion is the more refined pore structure of samples with SCMs, and the reduced C3A of low heat of hydration Portland cement. The refined pore structure reduces the permeation of the oxidizing solution into the samples. The similarity of this to penetration of oxygen into concrete under field exposure needs to be determined. Soaking the samples for >3 h in the oxidizing agent can produce excessive expansion – not related to oxidation of iron sulphide phases – in samples with cementing blends containing reactive alumina such as metakaolin.

Biocompatible Iron Sulphide Nanoparticles Against Neuroinflammation for Intracerebral Haemorrhage and Long-term Neurological Functional Recovery

BackgroundMass effects of haematoma, neuroinflammation, oxidative stress, and neuronal apoptosis are the major causes of poor prognosis of intracerebral haemorrhage (ICH). Our previous study suggests that biocompatible iron sulphide nanoparticles possess peroxidase-like activity and can release hydrogen polysulfanes, which may inhibit brain injury. The purpose of this study was to investigate the neuroprotective efficacy of diallyl disulfide (DADS)-nFeS in mice after ICH and preliminarily illustrate the potential mechanism. MethodsAdult male C57BL/6 mice (n = 176) were injected with bacterial collagenase in the striatum. In the first part, DADS-nFeS at different doses (25, 50, or 100 mg/kg) was intragastrically administered 2 h, 26 h, and 50 h before ICH. In the second and third parts, DADS-nFeS (50 mg/kg) was administered 2 h, 26 h, and 50 h before and after the induction of ICH in the pre-treatment group and post-treatment group, respectively. H&E staining was performed to detect drug toxicity. Haematoma volume measurement, Fluoro-Jade C (F-JC) staining, Nissl staining, immunofluorescence staining, western blotting, terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) staining, malondialdehyde (MDA) and superoxide dismutase (SOD) assays, and neurobehavioural tests were performed. ResultsAll three doses of DADS-nFeS had neuroprotective effects, and 50 mg/kg resulted in the best outcome. DADS-nFeS reduced the haematoma volume and MDA content, inhibited the activation of microglia and astrocytes, progressive neuronal degeneration, and apoptosis, increased SOD activity and neuronal survival, and improved both short-term and long-term neurological functions in perihaematomal areas after ICH. Moreover, DADS-nFeS was associated with the downregulation of Iba-1, GFAP, TNF-α, IL-1β, 4-hydroxynonenal (4-HNE), and Bax/Bcl-2 levels in perihaematomal areas after ICH. Finally, post-treatment with DADS-nFeS had a better effect than pre-treatment with DADS-nFeS. ConclusionsOur study indicated that gavage administration of DADS-nFeS decreased the haematoma volume, suppressed neuroinflammation, oxidative stress, and neuronal apoptosis, and improved short- and long-term neurological functions, which was, at least in part, realized by inhibiting the activation of microglia and astrocytes, enhancing local SOD activity, and decreasing the recruitment of reactive oxygen species. Therefore, DADS-nFeS may serve as a potential therapeutic strategy via the diet against central nervous system diseases.

The Application of a New Oxidation Mortar Bar Test to Mixtures containing Different Cementing Systems

The effects of different cementing systems on the expansion of mortars containing iron sulphide-bearing aggregate was studied. Using a recently developed oxidation mortar bar test, the results showed that cementing systems containing low-calcium fly ash, metakaolin, slag, high-sulphate resisting Portland cement, or low heat of hydration Portland cement could reduce the expansion by 50–85%. The main suggested mechanisms behind the reduced expansion is the more refined pore structure of samples with SCMs, and the reduced C3A of low heat of hydration Portland cement. The refined pore structure reduces the permeation of the oxidizing solution into the samples. The similarity of this to penetration of oxygen into concrete under field exposure needs to be determined. Soaking the samples for >3 h in the oxidizing agent can produce excessive expansion – not related to oxidation of iron sulphide phases – in samples with cementing blends containing reactive alumina such as metakaolin.

Chemical composition of iron sulphides contained in dust from pyrometallurgical Zn and Pb production

The paper presents results of investigations of the chemical composition of iron sulphides contained in dust from the pyrometallurgical production process of zinc and lead. The main mineral components of these dusts are sphalerite, galena, iron sulphide – pyrite, zincite, anglesite and probably kirchsteinite. The tests performed have demonstrated that the chemical composition of iron sulphide grains was not close to stoichiometric, the grains were non-uniform in terms of phase composition, and they always included admixtures in the form of inclusions of other sulphides, i.e. zinc sulphide and lead sulphide, and accompanying elements (Ca, Mn, Se, As, Ag, Cu, Cd).

Preparation and anti-coking application of sol–gel SiO2 coating in a delayed coking furnace

To isolate iron sulphide and reduce coke adhesion reactions that occur on the surface of a delayed coking furnace, a SiO2 coating was developed on Cr9Mo alloy by employing the sol–gel method.

Iron Sulphide Rice Grain Nanostructures as Potential Electrocatalysts for Improved Oxygen Evolution Reaction

Iron based chalcogenides are considered as the promising group of electro-active materials for various electrochemical technologies. Herein we demonstrate a facile fabrication of various iron sulphide (FeS) nanostructures, including rice...