Search Results for: glass

Total Search Results Found: 114

Analysis of composition dependence of some thermal transport properties in glassy Se80xTe20Snx (0 6 x 6 10) alloys using transient plane source measurements

This study measures the thermal conductivity, thermal diffusivity, and specific heat of selenium-tellurium-tin alloys at room temperature. Selenium-tin alloys have high photosensitivity, higher crystallization temperature and smaller aging effects then just selenium. However, without an extra element to act as a chemical modifier limited reversibility and low glass transmission are issues. The researchers hope that the addition of tin will produce an improved alloy. Investigations showed that there were structural changes in the alloy after the tin was added.

Compressive Creep and Thermophysical Performance of Mullite Refractories

The purpose of this study was to provide a comprehensive overview of compressive creep of mullite refractories, which are a potential replacement for more traditional silica refractories in harsh oxy-fuel environments. Tests performed included corrosion resistance, microstructure analysis, dimensional stability, phase content, and thermal properties. A thermal analyzer was used to perform thermal conductivity testing on 10 commercially available mullite refractories as part of the analysis.

Engineering thermal and mechanical properties of flexible fiber-reinforced aerogel composites

The authors present a method of fiber-reinforced aerogel composites by impregnation of four layers of aligned glass fibers into silica sol layer-by-layer. The effect of different fiber alignments, as well as the effect of fiber lamination on the mechanical strength of the silica aerogel composites was investigated. In addition to this, the thermal conductivity of each composite was determined. The objective of this work was to investigate whether it is possible to control the mechanical properties of the aerogel composites depending on the orientation of the layers in the composite. It was found that the addition of the glass fibers resulted in improved mechanical properties without significantly increasing the thermal conductivity.

The Effects of Thermophysical Properties and Environmental Conditions on Fire Performance of Intumescent Coatings on Glass Fibre-Reinforced Epoxy Composites

The reaction to fire properties of three commercial coatings designed for steel structures were investigated. The coatings in this study were covering a glass fiber-reinforced epoxy composite. It was determined that the thermal barrier effectiveness of these coatings was dependent on the degree of expansion and the thermal conductivity of the expanded char. Using these two parameters, the required thickness of a coating that can enable a structure to withstand fire conditions for a specified period of time. Two of the three coatings that were tested were epoxy based, while the third was water based. Minimal effects were observed when water was applied to the epoxy based coatings. The intumescing and thermal barrier properties of the water based coating were significantly altered.

Thermal conductivities of methane-methylcyclohexane and tetrabutylammonium bromide clathrate hydrate

The thermal conductivities of gas hydrates are well documented, but the thermal conductivities of structure H (sH) methane-methylcyclohexane (MCH) hydrate and type A tetrabutylammonium bromide (TBAB) semi clathrate hydrate have no experimental data. The purpose of this study was to determine the thermal conductivities of sH MCH hydrate and TBAB semi clathrate hydrate. The thermal conductivity was measured using a single sided transient plane source (TPS) method. Most gas hydrates increase in thermal conductivity when temperature is increased, but TBAB decreases with temperature. This could be caused by two things TBAB has a semi clathrate structure which is different from normal gas hydrates, or semi clathrate structure limits phonon free path, and increasing temperature decreases the free path further. The thermal conductivity of sH hydrated showed a glass like dependence on temperature (increasing temperature, increases thermal conductivity). The thermal conductivity of sH hydrate did not correlate with the values that were expected.