จำนวน Repository ( 62 )
การคัดเลือกแบคทีเรียจากลำไส้กุ้งกุลาดำเพื่อใช้เป็นโพรไบโอติกสำหรับการเพาะเลี้ยงสัตว์น้ำ
In this study 14 bacterial strains isolated from gastrointestinal tract of black tiger shrimp (Penaeus monodon) was investigated for their probiotic potential. The results showed that 6 strains namely S1 S3 S6 S7 T4 and T5 were able to degrade 3 nutrient substances including protein starch and lipid among which S3 S7 and S2 were the best tested nutrient-degrading bacteria respectively. Six bacterial strains were unable to lyse red blood cells including S2 S3 T0 T1 T2 and T3. S2 strain showed the strongest antibacterial activity against shrimp pathogenic Vibrio harveyi following an agar overlay technique. Based on environmental tolerance tests S2 and T0 strains grew well under wide ranges of environmental conditions e.g. sodium chloride concentration (0-8%) pH (6-10) and temperature (25-37C). As a consequence S2 strain had the most probiotic potential for shrimp culture owing to no hemolysis of red blood cells inhibition of V. harveyi growth protein and lipid degrading ability and high environmental tolerance for shrimp cultivation. The strain was identified as Micrococcus sp. S2. However additional study focused on immune response nutrient digestibility and growth promotion of the strain should be further performed in marine shrimp.
การทดสอบความล้าของเหล็กกล้า S45C แบบหมุนดัดปลาย
This research is to test the fatigue endurance of the material by using end bending of specimen. The testing material is S45C steel and forming to the standard size for testing. The specimens with a diameter of 8 mm required a different bending moment. It was found that the large bending moment affects the fatigue of the specimen. The specimen quickly damaged due to the high bending stress and there were a small number of load cycles. If the bending moment acting on the specimen was reduced to the bending stress decreased and the number of load cycles increasing. It was shown that the bending stress and the magnitude of the bending moment affected the fatigue of the material. Also the appearance of damage marks of the specimen will have a flaw around the fracture surface. Then the flaw will be enlarged until the specimen will be damaged by fracture.
การเปรียบเทียบเครื่องทดสอบความต้านทานการหมุนของยางล้อรถยนต์ที่ใช้การคำนวณระบบแรงและระบบแรงบิด
This research aims to study and compare the test results obtained from the rolling resistance tester of automobile tires based on force method and torque method system. The four newly manufactured tires were sampled from two tire classes namely passenger car tires (Class C1) and light truck tires (Class C2). The tire rolling resistance test according to the international standard UN ECE Regulation No.117 was used as an important research process. The experimental work discovers that the rolling resistance of the same tire obtained from the test between the two different methods of testing machines was not more than 6 percent different. The testing results that used the torque method system calculation are high reliability because of the principle of calculation from the measurement value directly results in. and suitable for research testing. However the force method tester can perform more than a tire simultaneous test which is suitable for working in industrial applications where time is limited.
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.
การประเมินชั้นดินและค่ากำลังแรงแบกทานที่ยอมให้ด้วยการทดสอบการเจาะสำรวจแบบหยั่งเบา
This study applied the kunzelstab penetration Test (KPT) or Light Penetrometer to examined penetration resistance values geological profiles and estimate shear strength properties of soils. KPT tests were carried out on steep slopes that exhibit potential slope movement in Chiang Rai province. The principal uses of the KPT are examined; i.e. correction method for N’KPT’ soil profile and allowable bearing capacity of soil foundation. KPT tests were conducted at 13 boreholes each measuring 4.00 m long along the crown of the slope. The results indicated the compacted layer and located the firm layer of soil foundation. The average allowable bearing capacities were 1.53 t/m2 at depth of 1.00-5.00 m and 17.06 t/m2 for 5.00-6.00 m depth respectively. Furthermore this paper presents an analysis of the stability of a slope with the shear strength parameters of the soil and the geological profile were defined based on the results of KPT. The results of factor of safety were below the stable value for analysis cases with groundwater table. Test results demonstrate the usefulness of the KPT method in geotechnical investigations to estimate soil profile and bearing capacity efficiently and economically. This approach is also less time consuming compared to other geotechnical site investigation methods.