This research was aimed to study the compressive strength chloride binding capacity and chloride diffusion coefficient of concrete replaced by ground bottom ash (GBA) and limestone powder in ordinary Portland cement (OPC). The water to binder ratios were 0.55. The results showed that the compressive strength of concrete with GBA was lesser than that of OPC concrete at 28 days. Also the compressive strength of concrete with limestone powder was close to that of OPC concrete and compressive strength could develop of concrete with GBA 20% and 30% higher than that of OPC concrete at 56 days. Moreover the total chloride of the concrete containing GBA and limestone powder was less than that of OPC concrete. The chloride penetration of the concrete containing GBA and limestone powder was less than that of OPC concrete. The chloride binding capacity of the concrete made with ground bottom ash and limestone powder were higher than that of OPC concrete. Finally the chloride diffusion coefficient of the concrete containing GBA and limestone powder was less than that of OPC concrete.

This research aimed to study the optimum conditions for making raw lime from shells which consisted of 9 conditions: calcined at three levels of 700 800 and 900 degrees Celsius for 1 2 and 3 hours. Calcium element content in raw lime using X-ray fluorescence (XRF) measurement and structural analysis of calcium compounds by X-Ray Diffraction (XRD). The research results were found. 1. Optimal conditions for making lime mortar are temperature 800 degrees Celsius duration 2 hours. The physical characteristics of raw lime are white and porous. 2. The calcium content from the shells calcination at 800 degrees Celsius for 1 2 and 3 hours was 98.22% 96.70% 97.89%. 3. Changes in the calcium compounds of raw lime obtained by calcining the shell at 800 degrees Celsius for 1 hour were mainly found in the form of calcium carbonate (CaCO3). At 2 3 hours calcium carbonate (CaCO3) is mostly converted to form calcium hydroxide (Ca(OH)2)compound calcium oxide (CaO) compound is formed.

This research presents the development of ultrasonic scaler for mobile dental unit. The operation of the scaler uses a phase-locked loop circuit to generate high frequency electrical signal. Then the signal is amplified with a Darlington amplifier circuit to feed to the coil in the Hand Piece resulting in Magnetostriction. This phenomenon causes the stretching and shrinking of the magneto-strictive stack with high frequency which causes the tip of the scaling head to vibrate more than 20000 times/second. Traditional ultrasonic scaler for mobile dental unit has thermal problem of the amplifier circuit due to use of the transistors as the switching devices. When used for a period of time the scaler is necessary to stop working resulting in not much scaling per day. This research solved the problem by using MOSFETs as switching devices and adding cooling system to the amplifier circuit. The experiment was carried out using actual conditions. The experimental results show that the developed scaler has increased the number of scaling per day. In addition it will still remove plaque and dirt in the gumline around the base of the teeth similar to the scaler used by general dentists.

The purpose of this research was to study productivity rate in concrete plastering of interior brick wall by studying 2 construction projects in Bangkok. The researcher divided the methods of labor productivity into two categories: (1) direct labor production technique and (2) field rating technique. The direct labor productivity technique of project A is about 1.38 m2/person/hr. and project B is about 1.19 m2/person/hr. by field rating technique project A had 77.75 % of workers in work status project B had 73.75% of workers in work status. The error rate was 4.08 % and 4.31 % respectively at the 95% confidence level. Project A has higher productivity rate than project B because project manager A chooses ready-mixed plaster for plastering. Project B selects cement mix (silica cement) mixed with fine sand cement mixer and water which take longer to prepare than Project A resulted cost of materials increase for 28.21 %.Meanwhile the working time for wall plastering could take longer for 13.77 %. It can be concluded that the selection of material for work is another factor affecting labor productivity

The results of the study on the optimum temperature for baking soda extinguishers were investigated. B9R-3-EMERALD Using brass material in experiments. It was found that the temperature of 750˚C was good for 48% of the workpiece 52% was found that the workpiece was damaged at the surface of the work very porous at the surface. Caused by the heat of metal water pouring into contact with the moisture of the mold resulting in gas. High temperature of metal water Or eliminate gas in metal water is not exhausted. The workpiece is not suitable at a temperature of 800 ° C with a good workpiece of 76%. The workpiece loses 24%. The workpiece loses less punch at the lower porosity as well at 750˚C in temperature. 850˚C workpiece 96% workpiece 4% workpiece the workpiece is almost out. It is less than 750˚C and 800˚C at porosity. And at 900˚C the workpiece is 100% of the workpiece 0%. The workpiece is the best. Workpiece waste from the minimum. The test results make the temperature at 900 ° C is the cleanest casing temperature