จำนวน Repository ( 1087 )

การเสริมกำลังคานลึกคอนกรีตเสริมเหล็กที่เสื่อมสภาพเนื่องจากคลอไรด์ด้วยแผ่นคาร์บอนไฟเบอร์
การเสริมกำลังคานลึกคอนกรีตเสริมเหล็กที่เสื่อมสภาพเนื่องจากคลอไรด์ด้วยแผ่นคาร์บอนไฟเบอร์

Deterioration of reinforced concrete deep beam structure caused by chloride is severe andtakes up wide area even though the structure is not exposed to sea water or brackish water. Even the structure which is far from sea water or brackish water is affected by this problem.When the reinforced concreate deep beam structure is affected by chloride steel reinforced inside the structure is corroded resulting in reducing the cross-sectional area of the reinforced steel affecting load capacity deflection and beam failure. If there is no repair or strengthening such capabilities are continuously reduced until it is no longer safe to use the beam. Therefore it is necessary to repair or strengthening the deteriorated structure to be safely used. This research investigated strengthening of deteriorated reinforced concrete deep beam caused by chloride with 4 formats of carbon Fiber sheets to seek guidelines for the most efficient strengthening. The resultshowed that the strengthening by the 4 format of carbon fiber sheet could increase ultimate loadcapability yet could not improve ductility of the deteriorated beam to become close to the beamthat is not deteriorated. The strengthening that could increase the maximum ultimate load capability was the table format strengthening. In addition the strengthening that the carbon fiber making 45 degrees with the length of the beam could best prevent diagonal cracks.

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การกำจัดสีย้อมผ้าด้วยถ่านกัมมันต์จากเมล็ดสละพันธุ์สุมาลีที่กระตุ้น ด้วยสารละลายโพแทสเซียมไฮดรอกไซด์
การกำจัดสีย้อมผ้าด้วยถ่านกัมมันต์จากเมล็ดสละพันธุ์สุมาลีที่กระตุ้น ด้วยสารละลายโพแทสเซียมไฮดรอกไซด์

Dyes contaminated in wastewater that negatively affecting the environment and human health. The objectives of this study to prepare activated carbon from Salacca zalacca (Sumalee) seeds activated by 36 mmol/g KOH dye solution and activated carbon ratio 20:32 ml/g for dye removal. The influents of dye removal from wastewater by Salacca zalacca (Sumalee) seeds activated carbon were investigated as initial dye concentration activated carbon and dye solution ratio and contraction time. The moisture content the iodine number the methylene blue index and the functional groups by FTIR technique of the Salacca zalacca (Sumalee) activated carbon were characterized and the kinetics adsorption were also analyzed. The results showed that the activated carbon was the microporous material the highest dye removal from wastewater was 7.50 ± 0.25 mg/g the equilibrium time was 150 min with the activated carbon to dye solution ratio of 1:500 g/ml for 200 mg/l initial concentration. The kinetics of the adsorption process can be described by a pseudo-second order model (R2 = 0.9999). When increasing the initial concentration of dyes the adsorption efficiency was increased. The amount of activated carbon increased resulting in lower adsorption efficiency and the equilibrium time was longer

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การพัฒนาผลิตภัณฑ์ผงปรุงรสและผงโรยข้าวจากถั่วเหลืองหมักพื้นบ้าน
การพัฒนาผลิตภัณฑ์ผงปรุงรสและผงโรยข้าวจากถั่วเหลืองหมักพื้นบ้าน

This research aims to develop the new product from a northern local fermented soy bean which were seasoning powder and furikake-rice seasoning and analyze to observe the nutritional chemical component and antioxidant of the products. The fermented soy bean was dried using hot air oven to achieve a required moisture content prior to apply to the new product. The best ratio of the dried fermented soybean powder was of 35%. The sensory test was used to evaluate the customer acceptance in these developed products. The results showed that the panelist moderately like the products with the overall acceptable score of 7 . 8 5±0 . 3 6 for the seasoning powder and 7 . 4 6±0 . 6 7 and 7 . 4 4±1 . 0 1 for furikake-rice seasoning in sesame-seaweed and garlic flavors respectively. The analysis of the nutritional values (protein fat and antioxidant) of the product were analyzed. The result showed that the seasoning powder has the highest values of nutritional values which were 43.80% 19.24% and 3.72 μmol TE/g for protein fat and antioxidant respectively. The furikake-rice seasoning sesame-seaweed have the values of protein fat and antioxidant of 2 9 . 9 0 %9.72% and 1.79 μmol TE/g respectively. The garlic flavor has the values of protein fat and antioxidant of 31.70% 20.51% 1.96 μmol TE/g respectively. The developed product would be continuously produced in a commercial product for the local community since the fermented soybean products have high amount of nutrition especially the protein content.

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ฤทธิ์ต้านอนุมูลอิสระของกุ่มบก
ฤทธิ์ต้านอนุมูลอิสระของกุ่มบก

The aim of this research was determine total phenolic content total flavonoid content and antioxidant activity by DPPH and ABTS assay from leaves flower and stem of Crateva adansonii DC. subsp. trifoliate (Roxb) Jacobs that was extracted by Soxhlet method using ethanol dichloromethane and ethyl acetate as solvent. Leaves extract showed the highest total phenolic content and antioxidant activity. Ethanolic leaf extract showed the highest total phenolic content (157.13±0.32 mg GAE/g extract) and antioxidant activity by DPPH assay (53.64±3.78% (IC50 = 1.49±0.02 mg/ml)) and ABTS assay (76.51±0.97% (IC50 = 0.84±0.01 mg/ml)).When we considering solvent effect found that ethanolic extract showed the highest total phenolic content and antioxidant activity. Total flavonoid content ethyl acetate extract showed the highest total flavonoid content. Total phenolic content significantly correlated with antioxidant activity.

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กาวหลอมร้อนจากยางธรรมชาติ
กาวหลอมร้อนจากยางธรรมชาติ

The purpose of this research was to study hot-melt adhesives from natural rubber (Standard Thai Rubber 20 STR 20). In order to improve the adhesion and melting properties of hot-melt adhesive to get the best glue formula from STR 20 the ethylene vinyl acetate content (EVA) paraffin wax (Wax) and petroleum resin (Resin) were varied from 25 50 100 125 and 150 phr (Part Per Hundred Rubber). It was found that the best adhesive formulas consisted of 100 phr of STR 20 25 phr of wax 150 phr of EVA and 150 phr of resin. For preparing hot-melt adhesive first the wax was heated and maintained at 160-170 ºC then cut the STR 20 into small pieces and slowly added the rubber into the melted wax until the rubber was completely melted. And then added resin and EVA and cooled to room temperature finally the results show that hot-melt adhesive was dark brown hard and odorless smooth texture and easy to melt with 514±14 centipoises of Viscosity at 150 ºC 82.49±1.4 lbf/in2 of shear strength and 2.06±0.02 kN/m of cleavage peel strength.

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