จำนวน Repository ( 96 )
Preparation of Ceria Fibers Via Electrospinning Process
Electrospinning is an interesting technique with various potential applications. CeO2 fibers production was achieved via this technique. In this work the prepared condition and the fiber morphology were investigated and described. The optimum condition was 15 kV 7 cm in distance between needle tip and ground collector 50 wt% of i-propanol in the co-solvent. The obtained fibers were continuous with a diameter of 900 nm. The smooth electrospun fibers produced were dried for one hour and then calcined at 450 OC for 3 hours. The calcined fibers were reduced to 600 nm and cracked on the fibers. They were ceria fibers what verified by EDX and XRD pattern. They had high specific surface area to volume ratio and monolith fibers which is applied for catalytic applications.
Flexural performance of corroded reinforced concrete beams repaired with CFRP sheets
Corrosion of steel reinforcements in concrete is one of the main causes of early deterioration and reduction of service loads of reinforced concrete (RC) structures. This paper reports the results of an experimental program that was carried out to evaluate the effect of reinforcement corrosion on the flexural performance of RC beams and to investigate the efficiency of externally bonded carbon fiber reinforced polymer (CFRP) sheets to repair the corrosion-damaged RC beams. Seven RC beams with the same cross section and reinforcement details were prepared including the control beam (B0). First tension reinforcements of six RC beams were corroded by using an accelerated impress-current process to obtain corrosion levels of 15% 30% and 50% of weight loss according to Faraday’s law. Then three beams were repaired using CFRP sheets attached to the bottom surface leaving the other three unrepaired. All beams were subjected to the four-point bending load test. The experimental results show that the corrosion specimens demonstrated a significant deterioration on the structural performance and the integrity by decreasing in their ultimate load capacity stiffness and ductility. The deterioration by corrosion of tension reinforcements can be successfully overcome using CFRP sheets as the repair material. The technique can restore the beam strength to its original design strength except specimen B50F2 having severe steel-corrosion damage of 50%. A conservative value of the ultimate bending capacity of the beams with low corrosions (15%-30%) can be predicted by using RC conventional models as suggested in ACI 318. However the opposite trend is obtained for the high corrosion beam (50%). Appling ACI 440.2R provision to predict the ultimate flexural capacity of corroded beams repaired with CFRP sheets shows rather fair values for low corrosions (15%-30%) but significantly overestimates the strength of the high corrosion beam (50%).
การออกแบบอุปกรณ์เสริมช่วยในการทดสอบเฟสอาร์เรย์อัลตร้าโซนิค
The objective of this research is to construct a phased array device to be able to inspect all sizes of welded pipes and to study materials suitable for creating a phased array. The results obtained from testing both materials are PLA plastics carbon fiber. In order to obtain the force exerted on the material and the intensity of the force exerted on the same material it is found that the strength of the comparison between the two materials is different from the PLA plastic test. Of carbon fibers will be strong and lighter than plastic. Result from the test for Elastic In the impact and strength tests of both materials it can be used to examine pipes with a circumference of 50 centimeters to 100 centimeters and to use a 34 mm. length phased array probe with a width of 24.6 mm. 36 degrees angle and then adjust the strap as needed to reduce the steps during the use of inspection equipment.
ผลของการใช้เปลือกทุเรียนผงทดแทนแป้งข้าวสาลีต่อคุณภาพของเค้กบราวนี
This research aims to study the physical and chemical properties of Cha-nee durian rind powder and using durian rind powder to replace wheat flour in brownie cakes at 1020 and 30% (w/w). Texture profile chemical composition and sensory evaluation of brownie cakes were analyzed. The results showed that durian rind powder contained 50% of dietary fiber. Brownie cake with durian rind powder showed significant decreasing of lightness (L*) and hardness while green-red component (a*) blue-yellow component (b*) toughness and cohesiveness values were significantly higher than the control sample (p<0.05). Proximate analysis of the products showed that brownie cake with durian rind powder had dietary fiber higher than control brownie cake sample significantly. At 30% replacing of durian rind powder brownie cake showed 18.2% increasing of dietary fiber as compared with the control sample. The acceptance score including appearance color odor flavor texture and overall scores of all samples in this study were not significant different. Results indicate that 30% of durian rind powder replacing wheat flour is appropriate for making brownie cake. Brownie cake with durian rind powder could be an alternative for food choice of healthy bakery product which are lower calorie (123.73 kcal per serving) and high amount of dietary fiber (6.37 g per serving). Moreover durian rind powder can be used as a food ingredient and source of dietary fiber in other food recipes for further study.
การใช้ยางธรรมชาติผสมขุยมะพร้าวสำหรับขึ้นรูปแผ่นผนังป้องกันเสียงและความร้อนภายในอาคาร
This research aims to develop the coconut coir and fiber indoor acoustic and thermal insulation boards mixed with natural latex. The 5 ratios of coconut coir: coconut fiber: natural rubber were equal to 0.1: 0.9: 0.1 0.1: 0.9: 0.15 0.1: 0.9: 0.2 0.1: 0.9: 0.25 and 0.1: 0.9: 0.3 by weight. The indoor acoustic and thermal insulation boards were produced by knitting the coconut coir and fiber spraying the natural latex and heat compressing. The properties testing of indoor acoustic and thermal insulation boards included the density test water absorption test tensile strength test thermal conductivity test sound protection efficiency test and real usage test. From the results 0.1: 0.9: 0.15 ratio is the most suitable ratio of coconut coir and fiber indoor acoustic and thermal insulation board mixed with natural latex. The natural latex which putted in these indoor acoustic and thermal insulation boards can reduce the water absorption and increase tensile strength and sound protection efficiency.