จำนวน Repository ( 29 )
กำลังและความต้านทานการกัดกร่อนของมอร์ต้าร์ที่ใช้วัสดุประสานกระตุ้นด้วยด่างจากเถ้าถ่านหินแคลเซียมสูง
The aim of this study is developed of alkali activated high calcium fly ash to use as cementitious material to replace Portland cement. The mixture of mortar made from fly ash and sodium hydroxide solution (NaOH) was used to activate strength at concentrations of 2 4 6 and 8 molars. Superplasticizer was used to control the flow of mortar in the rage of 105 – 110. The compressive strength of mortar was determined at 7 28 45 and 60 days. The acid resistance of mortars due to sulfuric at a concentration of 3% were also investigated. The results showed the mortar made from high calcium fly ash with sodium hydroxide of 6 molar obtained the highest compressive strength which could be developed compressive strength up to 189 ksc at 60 days. For the acid resistance of mortar it was found that the of use 6 molar of NaOH activated high calcium fly ash binder had the least weight loss due to sulfuric acid attack.
กำลังอัดความสามารถเก็บกักคลอไรด์และสัมประสิทธ์การแพร่คลอไรด์ของคอนกรีตผสมเถ้าก้นเตาบดละเอียดและผงหินปูน
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.
การปรับปรุงเครื่องขูดหินปูนแบบอัลตร้าโซนิคสาหรับชุดทันตกรรมเคลื่อนที่
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.
ผลของน้ำมันเครื่องใช้แล้วต่อสมบัติของมอร์ต้าร์หินพัมมิซผสมเถ้าไม้ยางพารา
Properties of pumice aggregate mortar blended with para rubber wood fly ash (PRWFA) replaced type 1 ordinary Portland cement (OPC) in different proportions of 020 and 40 wt.% OPC and dosed with used engine oil (UEO) in proportions of 00.2 and 0.3 wt% water were investigated. Whole mix type specimens size was cast in 555 cm and curing in ambient temperature for 7 and 28 days. Testing series of physico-mechanical properties performed on bulk density water absorption electrical resistivity Shore hardness and compressive strength were determined. Moreover microstructure via scanning electron microscope was analyzed. Effect of curing ages enhanced properties of samples such as electrical resistivity Shore hardness and compressive strength. Particularly the 28-day specimen that contained 20wt.% PRWFA and 0.2wt.% UEO provided bulk density of 1.61 g/cm3 and highest compressive strength of 22.09 MPa.
การพัฒนาผลิตภัณฑ์ของที่ระลึกจากหินเพอร์ไลต์ด้วยการตกแต่งกลิ่น
Research on the development of souvenir products from research and development of scientific research applications using scientific research methods Create a blog as a tool. Ask experts in the development of souvenir products that are suitable for weddings. 3 types. Most experts choose the format. Contemporary styles and modern forms of invention with a pattern that is not ancient and not too advanced. The colors of contemporary styles are adjusted with modern styles. Cost reduction in the production of souvenirs Then comparing the efficiency of the odor release between perlite stone scent decoration and postmodern. Based on gas chromatography-mass spectometry (GC-MS) technique it was found that the release of the aroma of perlite coated with non-coated peril stone film And postmodern in various time periods that are measured by% peak area Compared by setting it in the open system Saw that the amount of substance decreased with time The coated perlite stone keeps the smell well after 23 days more than the coated perlite stone. And the bushes that have released the fragrance for a minimum of 11 days Then study the satisfaction of the target group on the development of the perlite stone by the scent decoration. By dividing the 4 aspects of the study namely the product side it was found that most respondents had the highest level of satisfaction (4.60) in terms of materials. Most respondents were satisfied at the highest level (4.70). The respondents were satisfied at a high level (4.39) and the value of the respondents were mostly satisfied at a high level (4.15).