Study on parameters on cutting AAC by wires

Autoclaved Aerated Concrete (AAC) is a Lightweight, Load-bearing, High-insulating, Durable building product, which is produced in a wide range of sizes and strengths. AAC Blocks is lightweight and when compared to the red bricks, AAC blocks are three times lighter. AAC block is rapidly developing in Vietnam. The block has more advantages such as precast, and easy installation. AAC is produced from the common materials: lime, sand, cement and water, and a small amount of rising agent. After mixing and molding, it is then autoclaved under heat and pressure to create its unique properties. Then, the AAC block will be cut into block brick by steel wire. When cutting the ACC block, the block brick surface must be smooth so that it is unnecessary to mortar. Furthermore, the roughness of the surface must be smaller than 0.1mm to paint the wall easily. The block dimension also need high precision so that the wall will be straight when blocks are superposed. However, in this paper, the roughness of the block surface will be only researched because the roughness will decide the cost, and the dimension decide the estheticism of wall. The block is made by using steel wires to cut big AAC blocks into small blocks. Effects of processing parameters on the performance of the steel wire sawing processes are wire speed, feed rate and tension. Each parameter will affect surface quality with different effects. In addition, these parameters affect each other, which causes scratches on the AAC surface. Experiments will be made to measure the height of roughness with the change of wire speed, feed rate and tension. The best parameters will be found, which helps the AAC manufacturer to obtain the higher quality.

Application of the Discrete Laguerre Wavelet Transform

In this work, Discrete Laguerre Wavelet Transform (DLWT) was used in the processing of images where they were divided into blocks and each block dimension is equal to matrix dimension obtained from DLWT. The concepts Peak Signal to Noise Ratio and Mean Squared Error were used. The examples used to prove the efficiency of the proposed method where good and convincing accounts were obtained.

Investigation of Heat Transfer Performances of Nanofluids Flow through a Circular Minichannel Heat Sink for Cooling of Electronics

Nanofluid is the suspension of nanoparticle in a base fluid. In this paper, the heat transfer performances of the nanofluids flow through a circular shaped copper minichannel heat sink are discussed analytically. Al2O3-water, CuO-water, Cu-water and Ag-water nanofluids were used in this analysis to make comparative study of their thermal performances. The hydraulic diameter of the minichannel is 500 μm and total block dimension is 50mm× 50mm× 4mm. The analysis is done at different volume fractions of the nanoparticle ranging from 0.5 vol.% to 4 vol.%. The results showed that the heat transfer performance increases significantly by the increasing of volume fraction of nanoparticle. Ag-water nanofluid shows the highest performance compared to the other nanofluids. So, this nanofluid can be recommended as a coolant flow through a circular minichannel for cooling of electronic heat sink.