จำนวน Repository ( 23 )

พฤกษเคมีและกิจกรรมยับยั้งเอนไซม์แซนทีนออกซิเดสของสารสกัดจากผลมะม่วงหาวมะนาวโห่
พฤกษเคมีและกิจกรรมยับยั้งเอนไซม์แซนทีนออกซิเดสของสารสกัดจากผลมะม่วงหาวมะนาวโห่

The Thai wisdom knows the benefits of Carissa carandas L. to be used as a traditional herbal medicine. However there was no scientific evidence to show that Carissa carandas L. of Thailand can treat gout or not. In this research the Carissa carandas L. fruit extract in semi-ripening and ripe stage were studied for the phytochemical and inhibitory activity of xanthine oxidase one of the causes of gout. The result of hytochemical indicated that the crude extract from semi-ripening stage fruit contained many substances; phenolic compounds alkaloids flavonoids terpenoids saponins and deoxy sugars. While the ripe stage fruit contained the similar substances excepted saponins. The extract solution of Carissa carandas L. showed the xanthine oxidase inhibitory activity as the ethanolic extract solution gave the higher activity than water extract solution. The crude extracts of semi-ripening stage fruit presented the higher activity than the ripe stage one with the IC 50 values of 2.40 ± 0.05 and 2.87 ± 0.37 mg/mL respectively. The result of ripening stage with different phytochemical may be related to inhibition of xanthine oxidase activity. Therefore the selecting of sampling period and purification of extract may be a choice for using as medicine for gout

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อิทธิพลของความเร็วรอบที่ส่งผลต่อสมบัติทางกลของการเชื่อมอะลูมิเนียมต่างชนิด ระหว่าง SSM7075 กับ SSM356 ด้วยการเชื่อมเสียดทาน
อิทธิพลของความเร็วรอบที่ส่งผลต่อสมบัติทางกลของการเชื่อมอะลูมิเนียมต่างชนิด ระหว่าง SSM7075 กับ SSM356 ด้วยการเชื่อมเสียดทาน

The objective of this research is to study how rotation speeds affect mechanical properties with friction welding between semi-solid metal 7075 aluminum alloys and semi-solid metal 356 aluminum alloys. The factor of interest is rotation speeds with different conditions at 800 1000 1200 1400 and 1600 rpm respectively. 1.8 millimeter for burn of length 30 seconds for welding time and clockwise rotation are set as a control constant condition for the entire experiment. After friction welding we found that different rotation speeds significantly affected mechanical properties of these alloys. At rotation speed 1400 rpm the maximum tensile strength is 122.24 MPa and the maximum hardness in welded zone is 140.5 HV. The microstructure size is 2.250 µm long and 2.144 µm wide. Its size in welded zone is practically small because of friction force. Moreover this friction force causes the mixture of MgZn2 and Mg2Si in welded zone.

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The Efficacy of Peroxyacetic Acid and Sodium Hypochlorite Solutions in Reducing Microorganisms on the Surface of Carved Fruits and Vegetables
The Efficacy of Peroxyacetic Acid and Sodium Hypochlorite Solutions in Reducing Microorganisms on the Surface of Carved Fruits and Vegetables

This study examined the efficacy of two sanitizers; peroxyacetic acid (PAA) and sodium hypochlorite (NaOCl) in reducing total microbial counts on the carved leaf-shape surface of five types of fruits and vegetables: pumpkin carrot radish cantaloupe and Japanese cucumber. The samples were dipped for 3 or 5 min in various concentrations of PAA (40 60 or 80 mg/L) and NaOCl (50 or 75 mg/L) with distilled water as the control. After dipping the samples were drained for 5 min and the total plate counts were determined in triplicate. Dipping in 60 mg/L of PAA for 3 min was the best treatment for reducing microorganisms on the surface of carved carrot and radish; and 80 mg/L of PAA for 5 min was the best treatment for reducing microorganisms on the surface of carved pumpkin cantaloupe and Japanese cucumber. PAA at concentration 60 -80 mg/L showed potential as an effective sanitizer for carved fruits and vegetables more so than both concentrations of NaOCl.

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