Background and aim: The present study examined the in vitro effect of pure glycoside Stevioside hydrate on pH, growth and biofilm formation of Streptococcus mutans. Method: S. mutans were supplemented with different concentrations of Stevioside hydrate. Bacterial growth, metabolism and effect on biofilm formation were examined. Results: The presence of Stevioside hydrate had no significant effe...

Loss of stress support caused by hydrate dissociation may result in a significant reduction of rock strength. The strength of a hydrate-bearing sedimentary formation is a function of the strengths of inter-granular bonds and the interactions between the rock grains and the hydrates in the pore space. Myriads of such bonds and interactions define the macroscopic rock strength parameters. We expe...

In this study, we evaluated a two-step process for detoxification of waste roofing slate, involving cement hydrate removal and low temperature detoxification using oxalic acid. These treatments were conducted on raw material and intermediate product, respectively. Cement hydrate removal effectively eliminated most Ca-containing cement hydrate components from the raw material under the following...

To investigate the effect of particle size porous media on CO2 hydrate formation, formation experiments in with three sizes were performed. Three kinds mean diameters 2.30 μm (clay level), 5.54 (silty sand and 229.90 (fine level) used experiments. In experiments, temperature range was 277.15–281.15 K initial pressure 3.4–4.8 MPa. The final gas consumption increases increase decrease temperature...

The formation of hydrate plugs in oil and gas pipelines is a serious industrial problem and recently there has been an increased interest in the use of alternative hydrate inhibitors as substitutes for thermodynamic inhibitors like methanol. We show here that antifreeze proteins (AFPs) possess the ability to modify structure II (sII) tetrahydrofuran (THF) hydrate crystal morphologies by adherin...

The Michelsen stability and multiphase flash calculation by direct minimization of Gibbs free energy of the system at constant temperature and pressure, was used for systems containing gas hydrates. The solid hydrate phase was treated as a solid solution. The fugacities of all components of the hydrate phase were calculated as a function of compositions by the rearranged model of van der Wa...

Replacement of methane with carbon dioxide in hydrate has been proposed as a strategy for geologic sequestration of carbon dioxide (CO(2)) and/or production of methane (CH(4)) from natural hydrate deposits. This replacement strategy requires a better understanding of the thermodynamic characteristics of binary mixtures of CH(4) and CO(2) hydrate (CH(4)-CO(2) mixed hydrates), as well as thermoph...

Introduction: The composition of the martian polar caps has long been debated with a consensus opinion that the north is composed predominately of water ice and the south a combination of solid CO2 and water ice [1]. Smythe and Miller [2] suggested that the polar caps may be composed of at least some CO2 hydrate, aka. clathrate, or compound gas hydrates [3, 4, 5, 6, 7]. Durham [8] predicted tha...

Four different methanotrophs expressing soluble methane monooxygenase produced 2,2,2-trichloroacetaldehyde, or chloral hydrate, a controlled substance, during the oxidation of trichloroethylene. Chloral hydrate concentrations decreased in these cultures between 1 h and 24 h of incubation. Chloral hydrate was shown to be biologically transformed to trichloroethanol and trichloroacetic acid by Me...

The paper considers the process of hydrate-paraffin deposits formation in oil wells. Due to research with author's specially designed laboratory equipment – an experimental installation containing a technological unit and information-measuring system, most favorable pressure-temperature conditions hydrate wide range pressure (0.1–120 MPa) temperature (from –20 +80 °C) were determined. results m...