จำนวน Repository ( 27 )
Effect of glass cullet on compressive strength and abrasion resistance of terrazzo floor tile
This research was aimed to study the compressive strength and the abrasion resistance of Terrazzo floor which used glass cullet as aggregate. The mix proportion of Terrazzo was 1 : 2.5 (white cement : chipped stone) by weight. The weight percentages of replacement of chipped stone by glass cullet were 0 10 25 50 75 and 100% by weight of aggregate. The compressive strength and abrasion resistance of Terrazzo specimens were measured at 7 14 and 28 days. The results indicated that the compressive strength of mixtures with glass cullet of 0 10 25 50 75 and 100% were 581.11 540.81 534.83 480.94 435.42 and 343.71 kg/cm2 respectively. It showed that the compressive strength decreased with the increase of glass cullet content. The abrasion test of Terrazzo specimens showed that at low glass cullet content (10-50%) the abrasion resistance increased with the increase of glass cullet content. The mixtures with glass cullet of 75 and 100% have abrasion resistance nearly the same as the mixture without glass cullet
Evaluation technique for northern corn leaf blight resistance and identification of resistance genes position in maize with dna markers
This study aims to develop a new evaluation technique for Northern Corn Leaf Blight (NCLB) resistance in maize under greenhouse condition. Ki48/Ki47 F2 (160 lines) and 2 commercial verities (Hi-Brix3 and Insee2) were evaluated. For this technique 10-14 day old seedlings (4-5 leaves) were sprayed with ACIL1 spore suspension (104spores/ml.) for infection. The results of this technique correlated with the results from the common technique under field condition which used 21-25 days old seedlings (6-7 leaves) (correlation value = 0.658). This evaluation technique was used to assist in QTL mapping of NCLB resistance. Population of Ki48/Ki47 F2 (160 lines) were analyzed for QTL mapping by using Simple Sequence Repeats (SSR) markers. It was found that major parental polymorphism located on chromosome 5 and chromosome 8. When Single QTL analysis was performed SSR marker UMC1365 could clearly indentified qualitative trait loci on chromosome 5 and SSR markers UMC1095 UMC1268 and UMC2356 could clearly indentified qualitative trait loci on chromosome 8.
การพัฒนาเครื่องมือวัดอัตราการเกิดสนิมของเหล็กเสริมในคอนกรีตโดยใช้หลักการความต้านทานโพลาไลน์เซชั่นเชิงเส้น
งานวิจัยนี้มีวัตถุประสงค์เพื่อใช้ในงานวัดอัตราการเป็นสนิมของโครงสร้างคอนกรีตเสริมเหล็กโดยทั่วไป มักจะได้รับผลกระทบจากการเกิดสนิมของเหล็กเป็นส่วนมากเป็นผลให้กำลังของโครงสร้างคอนกรีตลดน้อยมีการพบการเสื่อมสภาพของโครงสร้างจากเหล็กเสริมเป็นสนิมอย่างแพร่หลายโดยเฉพาะโครงสร้างที่อยู่บริเวณชายฝั่งทะเล โดยสาเหตุสำคัญส่วนใหญ่ที่ทำให้เกิดสนิมมักเกิดจากคลอไรด์ซึมผ่านคอนกรีตเข้าไปถึงเหล็กเสริมและเมื่อคลอไรด์ซึมผ่านเข้าไปในคอนกรีตจนถึงระดับของเหล็กเสริม มีปริมาณมากเพียงพอก็จะทำลายฟิล์มที่ป้องกันที่ผิวเหล็กเสริม และทำให้โครงสร้างคอนกรีตเสริมเหล็กนั้นเกิดสนิมสะสมเพิ่มขึ้นเพียงพอที่จะทำให้เกิดหน่วยแรงและดันให้คอนกรีตเกิดความเสียหายเป็นผลทำให้กำลังของโครงสร้างลดน้อยลงจนไม่สามารถรับกำลังได้อีกและโครงสร้างจะเกิดการวิบัติในภายหลัง
Influence of Electrode Force Affecting the Complete of the Resistance Spot Welding
This research was to influence of electrode force affecting the complete of the resistance spot welding. The specimen was mild steel sheet metal has 1 mm. thickness. Then applied the force to the specimen are 1.0 2.0 3.0 4.0 and 5.0 kN. The welded specimens were tested by tensile shear testing according to JIS Z 3136: 1999 and Macro structure testing according to JIS Z 3139: 1978.The results showed that electrode force had affected on tensile shear and nugget size at 95% confidential (P value > 0.05). The low electrode force had increase the nugget heating because it had a high resistance (Q=I2Rt) and increase the gab between specimen. When the resistance increasing so the current flow will difficult to passed that fusion zone will had a high heating. It will affected to nugget seize heat affected zone and mechanical properties decreasing. The electrode forces are complete 2.0 kN. Tensile shear 6.39 kN and Nugget Size 5.83 mm. This data can be applied to be used as process monitoring of resistance spot weld quality.
Strength and chloride resistance of blended Portland cement mortar containing palm oil fuel ash and fly ash
This paper presented a study on the strength and chloride resistance of mortars made with ternary blends of ordinary Portland cement (OPC) ground palm oil fuel ash (POA) and classified fly ash (FA). The mortar mixtures were made with Portland cement type I containing 0-40wt% FA and POA. FA and POA with 1wt%-3wt% retained on a sieve No.325 were used. The compressive strength and rapid chloride penetration depth of mortars were determined. The results reveal that the use of ternary blended cements produces good strength mortars. The use of the blend of FA and POA also produces high strength mortars and excellent resistance to chloride penetration owing to the synergic effect of FA and POA. A mathematical analysis and two-parameter polynomial model were presented to predict the compressive strength. The mathematical model correlated well with the experimental results. The computer 3-D graphics of strength of the ternary blended mortars were also constructed and could be used to aid the understanding and the proportioning of the blended system.