Aqueous dissolution of silicate glasses and minerals plays a critical role in global biogeochemical cycles and climate evolution. The reactivity of these materials is also important to numerous engineering applications including nuclear waste disposal. The dissolution process has long been considered to be controlled by a leached surface layer in which cations in the silicate framework are grad...

The Lafayette meteorite is an olivine clinopyroxenite that crystallized on Mars ~1300 million years ago within a lava flow or shallow sill. Liquid water entered this igneous rock ~700 million years later to produce a suite of secondary minerals, collectively called ‘iddingsite’, that occur as veins within grains of augite and olivine. The deuterium/hydrogen ratio of water within these secondary...

Introduction: Volcanic and hydrothermal supply of reducing gases to the early atmosphere of Mars likely surpassed the slow supply of oxidizing power from hydrogen escape to space, resulting in a neutral or mildly reducing atmosphere and in geochemical cycles that operated very differently than they do on the modern Earth. We have recently suggested that one such difference between the modern an...

Carbonation of magnesiumand calcium-silicate minerals to form their respective carbonates is one method to sequester carbon dioxide. Process development studies have identified reactor design as a key component affecting both the capital and operating costs of ex-situ mineral sequestration. Results from mineral carbonation studies conducted in a batch autoclave were utilized to design and const...

OBJECTIVES Tricalcium silicate is the major constituent phase in mineral trioxide aggregate (MTA). It is thus postulated that pure tricalcium silicate can replace the Portland cement component of MTA. The aim of this study was to evaluate bond strength of methacrylate-based (MB) composites, silorane-based (SB) composites, and glass ionomer cement (GIC) to Biodentine® and mineral trioxide aggreg...

Near-surface reaction of CO2-bearing fluids with silicate minerals in peridotite and basalt forms solid carbonate minerals. Such processes form abundant veins and travertinedeposits, particularly in associationwith tectonically exposed mantle peridotite. This is important in the global carbon cycle, in weathering, and in understanding physical-chemical interaction during retrograde metamorphism...

Abstract The article deals with a laboratory preparation of triclinic modification clinker mineral tricalcium silicate. A substantial part the is devoted to technology and technique firing sample silicate, which would in future allow study development crystal lattice structure this at short isothermal durations, order minutes. As research, small high-temperature experimental furnace was designe...

OBJECTIVE The purpose of this study was to investigate and compare the crystalline structures of recently released MTA Plus (MTA-P), MTA Angelus (MTA-A), DiaRoot BioAggregate (BA) by X-ray diffraction (XRD) analysis. MATERIALS AND METHODS Phase analysis was carried out on powder and set forms of tested materials. The powder specimens placed into sample holders that were packed with a glass sl...

The aim of the study was to determine if the increase in radiopacity provided by bismuth oxide is related to the color alteration of calcium silicate-based cement. Calcium silicate cement (CSC) was mixed with 0%, 15%, 20%, 30% and 50% of bismuth oxide (BO), determined by weight. Mineral trioxide aggregate (MTA) was the control group. The radiopacity test was performed according to ISO 6876/2001...

a total of 148 groundwater samples were collected from bore wells from thirumanimuttar sub-basin for two seasons to identify major geochemical process activated to alter groundwater chemistry. the study revealed relationships with the lithology and anthropogenic process. groundwater in the region was dominated by na – ca – mg and cl and hco3 types. the (ca +mg) versus tz+ plot for both seas...