Influencing Factors of Reheating Shrinkage Rate of Glass Substrate on LTPS Process

Different heating treatments with the variation of heating rates,holding temperatures and holding time were used to simulate the LTPS procedure.The experimental results show that the reheating shrinkage rates of glass substrates are rarely changed with increasing the heating rate,but strongly enhanced by raising the holding temperature and time,which shows that the reheating shrinkage of glass is closely related to heat treatment and structural relaxation.The production process of glass is critical to the reheating shrinkage of glass.

High Alumina Fiber Composite SiO_2 Based Nanoporous Insulation Boards

The specimens were prepared with high alumina fiber accounting for 0. 5% , 10% or 15% by mass of the total amount of amorphous silica and high alumina fiber, using phenolic resin as binder, and extra-adding 0 or 0. 5% ZnO as sunscreen to cut the cost of SiO2 nanoporous insulation board. The hot volume stability and thermal conductivity （flat plate method ） of the specimens were tested and multi-Jimetion simulation equipment was used to study the thermal insulation performante. The results show that： （1） with high alumina fiber addition increasing, the linear shrinkage rate decreases, but thermal eonductivity changes a little; （2） adding ZnO can decrease thermal conductivity obviously; （3）for the specimen with ZnO and 15% of high alumina fiber, its cold face temperature hardly rises during the simulation experiment at 1 000 ℃ for 2 h, and the cold face temperature of the specimen with the smallest thickness of 2 cm doesn＇t exceed 180 ℃.

Effect of Alumina Micropowders on Properties of Calcium Hexaluminate

Calcium hexaluminate （ CA6 ） was synthesized by mixing light-weight calcium carbonate and Al2O3 mi- cropowder （calcined α-Al2O3, activated α-Al2O3 or α-Al2O3） according to the stoichimetric ratio of CA6, and reaction sintering at 1 200, 1 300, 1 400 and 1 500 ℃fin 3 h, respectiely. Efcts of the three alu- mina micropowders on the phase composition, micro- structure and properties of CA were investigated. The re- sults show that ： （ 1 ） for the three Al2O3 micropowders, the reaction to generate CA6 in specimens basically com- plete. at about 1 500 ℃ ; CA6 generated in all specimens is planar, bat the array modes are slightly different; （2） the specimel＇s prepared from, calcined α-Al2O3or ρ-Al2O3 shrink almost, while the specimens prepared from activated α-Al2O3 expand ; （ 3 ） the cold crushing strength of the specimen prepared from activated α-Al2O3 is the highest, reaching 42.5 MPa when only CA6 exists （ after firing at 1 500 ℃ ） ; （ 4 ） the specimen prepared from ρ-Al2O3 has the lowest generation temperature of CA6 and the highest apparent porosity, reaching 70. 1% when only CA exists （after firing at 1 500 ℃）; （5） the specimen prepared from calcined α-Al2O3 has the biggest bulk density.

Improving the Stability of the Inflatable Soil of Diamniadio by Using Typha Australis in Order to Value It in Partitioning Wall

The construction industry in Senegal is experiencing an upsurge in the development of residential housing units and administrative buildings within the new Diamniadio municipality, an area located just about 35 km from the capital city of Dakar. Laboratory oedometer or expansive-index tests, however, show poor density and compromised shear strength in the soil samples within the area -posing serious construction problems due to significant volume changes (swellings) that occur when subjected to moisture, thus, bringing into question the structural performance integrity of the soil, and the financial implications of substitute soil types used to compensate for its poor tensile strength. By way, the companies collect the soil of this location (Diamniadio) and throw it to make pile or micro-pile (pious) for their structures. This article demonstrates how we can value the soil of Diamniadio and the Typha Australis in residential building with a reasonable cost. Typha Australis is a plant generally luxuriant within the northern and central belts of Senegal but also known for its negative ecological impacts on the agricultural production of rice. The valorisation of the soil of Diamniadio will pass by the ability to increase its stability or to decrease its shrinkage/swelling rate. When we achieve it, the soil associate with Typha Australis will be used for small bricks which can be useful for partition wall and so the soil will not be ever thrown as a non-useful material. Tests results of soil specimens extracted from the site show a shrinkage rate of 29.19% with estimated cracking depths of 3.5 cm. But by adding gradually Typha Australis, the shrinkage rate will pass from 29.19% to 5.13% with the material treats with 10% by mass of Typha Australis. Moreover, the crackings in the cylindrical specimen disappear. That shows the increase of the stability;thus the composition will be used for building bricks. However, the densities will also be affected by the presence of Typha Australis. The density is decreased from 2032.28 Kg/m3 for the soil without Typha Australis to 937 Kg/m3 for the one with 10% of Typha Australis.