จำนวน Repository ( 27 )

Surface modification of perlite by using silane for the enhancement of heat aging resistance of natural rubber vulcanisates
Surface modification of perlite by using silane for the enhancement of heat aging resistance of natural rubber vulcanisates

The enhancement of mechanical properties of natural rubber vulcanisates was expected by surface modification of perlite particles. Thus the objective of the present study was to investigate the cure properties and the heat aging resistance properties in terms of stress at 100% elongation tensile strength and percentage elongation at break after surface modification. Furthermore the rebound resilience and abrasion resistance of perlite treated with silane filled in NR vulcanisates were investigated. In a comparison the properties of clay-filled NR vulcanisates were determined. The results reveal that surface modification by using silane caused a reduction of scorch time and cure time but an increase in torque difference and swelling resistance. Also surface modification gives better perlite-NR interactions before and after aging. The better heat resistance properties of perlite-filled NR vulcanisates than those of clay-filled vulcanisates is detected from relative property data. Nevertheless a lower percentage of rebound resilience and abrasion resistance of perlite-filled vulcanisates before and after surface modification than those of clay-filled vulcanisates are observed. This is owing to the large particle size low specific surface area poor dispersion and agglomeration of perlite in NR vulcanisates.

2563
อิทธิพลของของวัสดุปอซโซลานโดยระบบสามประสานต่อกำลังและความต้านทานคลอไรด์ของคอนกรีต
อิทธิพลของของวัสดุปอซโซลานโดยระบบสามประสานต่อกำลังและความต้านทานคลอไรด์ของคอนกรีต

This objective research to study the possibility of used pozzolan material in the ternary blend by fly ash metakaolin and silica powder by replacement cement partially on the strength and resistance to chloride migration. Consideration of concrete with compressive strength in the range of 240-350 kg per sq. cm by varying the ratio of water/binder (w/b) there are three values are 0.4 0.45 and 0.50 and variable amounts of replacement cement some. The ternary blend of the fly ash metakaolin and silica powder of percentage of 0 2.5 5 10 15 20 and 25 by weight of cement. and the control specimens (w/b) without contain fly ash kaolin and silica powder the slump test in the range of 3-5 cm and the use superplasticizer to control the slump test of concrete. By casting specimens of cylindrical diameter 10x20 cm cube 10x10x10 cm and the beam size 10x10x35 cm after curing 28 days and test compressive tensile and flexural strength of concrete all specimens each ingredient by Chloride Migration Test method and the results showed that concrete is a mixture with pozzolan such as silica powder metakaolin and fly ash with amount increase replacement. The increase will help improve the quality of the concrete physical properties. The increased of compressive and Tension strength as the percentage increase especially to replacement cement increased by fly ash metakaolin and silica powder reduces the penetration of chloride in concrete respectively As a result of the porosity of the concrete with lower amounts of tightness concrete has increased

2562
การพัฒนาโครงสร้างเกรนต้านทานการสึกหรอของชิ้นงานความแข็งสูงพิเศษด้วยกระบวนการอบผนึก
การพัฒนาโครงสร้างเกรนต้านทานการสึกหรอของชิ้นงานความแข็งสูงพิเศษด้วยกระบวนการอบผนึก

This study developed the cemented tungsten carbide by steadily sintering at 1430 °C for one hour. The tungsten carbide structure is a long shape. Its grain size has a difference between width and length and there are high distribution of sizes and shapes. In comparison with the work piece which has the similar size of grain structure the milling duration of tungsten carbide is less even though the condition of WC-Co is the same (95% WC – 5% Co). When the sintering of 1400 °C with the identical milling duration is performed. It turned out that both grain structures of the tungsten carbide and the work piece are similar and their grain sizes are slightly different. However when the grain structures are almost the same and sphericity is increased the hardness and wear resistance will also be improved. Therefore the size of grain structure between 1.00 – 3.00 μm with the milling duration of 100 hours will provide a work piece that has a wear resistance according to international standard

2562
ผลิตภัณฑ์แผ่นฝ้าเพดานผสมขุยมะพร้าวที่มีสมบัติต้านทานการดูดซึมน้า และเป็นฉนวนป้องกันความร้อน สำหรับชุมชนท้องถิ่น
ผลิตภัณฑ์แผ่นฝ้าเพดานผสมขุยมะพร้าวที่มีสมบัติต้านทานการดูดซึมน้า และเป็นฉนวนป้องกันความร้อน สำหรับชุมชนท้องถิ่น

This research aims to develop the ceiling board mixed with coconut coir. The 5 ratios of gypsum plaster: coconut coir: sodium silicate: tap water are equal to 1 : 0 : 1: 0.03 1: 100: 1: 0.03 1: 150: 1: 0.03 1: 200: 1: 0.03 1: 250: 1: 0.03 และ 1: 300: 1: 0.03 by weight. The ceiling boards were produced by casting in normal temperature (30 – 35 degree of Celsius). The properties testing of ceiling board mixed with coconut coir followed the TIS 219-2009 standard (gypsum plasterboard) including: breaking load nail pull resistance deflection water absorption density and thermal conductivity coefficient. From the results 1 : 1 5 0 : 1: 0.03 is the most suitable ratio of ceiling board mixed with coconut coir. This developed ceiling boards can reduce the quantity of coconut coir waste and get the good thermal insulation ceiling board products

2561
ผลของไคโตซานต่อปริมาณสารต้านอนุมูลอิสระและการต้านทานโรคใบไหม้ในข้าวสังข์หยดพัทลุง
ผลของไคโตซานต่อปริมาณสารต้านอนุมูลอิสระและการต้านทานโรคใบไหม้ในข้าวสังข์หยดพัทลุง

This research was aimed to study the effect of chitosan on total polyphenol contents anthocyanin contents antiradical properties and resistance of rice blast disease in Sung Yod Phatthalung rice (Oryza sativar L.) cultivars. The chitosan was applied on rice leaves at concentrations of 50 100 and 500 ppm compared with the control (without the chitosan and only adding a 0.025% acetic acid respectively). The result showed that 500 ppm of chitosan could significantly increase the total polyphenol contents (220.75 mg GAE/100 g dry weight sample) anthocyanin contents (2.98 mg/100 g dry weight sample) and antiradical properties (83.15%) in the grain extracts of Sung Yod Phatthalung rice. In addition Necrosis test on rice leaves treated with 500 ppm of chitosans clearly indicated the plant resistance againt Pyricularia grisea. Therefore the future studies of chitosan activation mechanism will give more valuable information that possible to be applied in the healthy rice product development and fungal disease control.

2560