จำนวน Repository ( 3447 )

การวิเคราะห์ปริมาณสารสำคัญและฤทธิ์ต้านอนุมูลอิสระของสารสกัดใบกะเปียดเครือ
การวิเคราะห์ปริมาณสารสำคัญและฤทธิ์ต้านอนุมูลอิสระของสารสกัดใบกะเปียดเครือ

Premna trichostoma Miq. (Lamiaceae) mainly distribute in Asia including Thailand. Folk healers use this plant to treat fever as a juice splash and bathe. The aims of this study are to evaluate the quantity of active constituents and antioxidant activity of P. trichostoma leaf extract. Total phenolic compounds were determined using Folin-Ciocalteu method. Total flavonoid contents were determined by Aluminum chloride method. The amount of apigenin and kaempferol contents were analyzed by high performance liquid chromatography (HPLC). In addition the antioxidant activity was evaluated by DPPH and ABTS assay. The results showed that total phenolic contents total flavonoid contents and the amount of apigenin and kaempferol of P. trichostoma leaf extract was 46.45±15.30 mg GAE/g extract 25.48±2.02 mg CE/g extract 11.16±0.04 and 4.54±0.08 µg/g extract respectively. The IC50 values from the DPPH and ABTS assay was 117.50±1.22 and 36.14±1.53 µg/ml respectively. This study shows the antioxidant properties and active constituents of P. trichostoma leaf extract which indicates the potentials for further development of this plant

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การควบคุมคุณภาพและลดการสูญเสียในกระบวนการประกอบชิ้นส่วนบังโคลนหน้าแก้มข้างรถยนต์ด้วยวิธีโพคา-โยเกะ
การควบคุมคุณภาพและลดการสูญเสียในกระบวนการประกอบชิ้นส่วนบังโคลนหน้าแก้มข้างรถยนต์ด้วยวิธีโพคา-โยเกะ

This study aimed to use Poka-Yoke techniques to help prevent errors and reduce loss in Front Side Fender Model assembly process. The researchers used four tools in the 7QC tools which were Check Sheet Cause-and-Effect Diagram and Graphs to search for causes and ways to solve problems and Cause and Effect Matrix and ECRS Techniques. The study revealed that the main cause of the problems was that the incorrect assembled side fenders were submitted to another department. This mistake had bad effects on time and workforce spent for correcting work including more expenses. The mistakes occurred because there was no tool for detecting errors in the work piece. Therefore the researchers use Poka-Yoke techniques in order to decrease errors by designing a control system for target detection while it was moving through the process. After collecting data the study showed that before the improvement during January to August 2019 the number of problems caused by the process were 0.093. However the number of problems after the improvement during September to December 2019 reduced to 0. It was obvious that this improvement reduced the loss from the front side fender assembly process up to 100.

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Real-time travel time prediction algorithm using spatiotemporal speed interval patterns matching
Real-time travel time prediction algorithm using spatiotemporal speed interval patterns matching

Accurate efficient and robust travel time prediction is crucial to the development of advanced traveler information systems for providing route guidance information. To achieve this goal this paper proposed a travel time prediction through the matching of the current speed interval pattern to that in a historical database. Speed intervals instead of speeds are considered in this study to simplify the structure of matching patterns for improving matching efficiency. In this study speed interval patterns are defined by sets of link speed intervals that are either spatially or temporarily correlated with the link considered. With the speed interval patterns the algorithm is developed for searching the historical pattern(s) that is/are the closest match with the current one. Then link speeds from these matched patterns are combined for travel time prediction. By using the GPS probe taxi data which the collected speeds are aggregated in every 5 minutes the proposed travel time prediction system is implemented in Bangkok. With the speed data from probe taxi this paper has chosen four links/paths with different geometric and flow characteristics for testing the performance of the proposed travel time prediction system. From these tests it is found that the optimal speed interval pattern should include: 1) speeds of the studied link within three preceding time intervals and; 2) speeds of links in the first connection level of the studied link. Also while the computational time is capable of real-time application the proposed prediction algorithm is more accurate under uninterrupted flow conditions.

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Properties of polypropylene conductive fiber from sheath-core  bicomponent fiber
Properties of polypropylene conductive fiber from sheath-core bicomponent fiber

This is the study of a conductive sheath-core bicomponent fibers. The intentions of the experiments were to investigate feasibility of conductive sheath-core bicomponent fiber forming using selected materials and the fibers’ properties. The trails were to extrude the bicomponent fibers with conductive materials in sheath section and supporting materials in core section. The conductive carbon black was selected as conductive material to compound with polypropylene. The virgin polypropylene was chosen as core material in the fibers. It was problematic to form fibers using the conductive carbon black polypropylene compound alone therefore the virgin polypropylene was used as the core section in the fibers to promote production stability. The sheath-core carbon black compound bicomponent fibers were steadily produced with designated machine settings. The produced fibers were tested for their physical and mechanical properties and electrical conductivity. The results shows that the fibers with the carbon black polypropylene compound as the fibers’ sheath section and the virgin polypropylene as the fibers’ core section have conductive property. The conductivity of the fibers increased when their sheath sections were thicker as the ratio of the carbon black compound become higher. Even though thicker sheath section of the fibers (40% and over) have higher conductivity the physical properties of the fibers become weaken and less applicable as textile fibers.

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การใช้สารฮิวเมกเตนท์ในผลิตภัณฑ์มัลเบอร์รีกวน
การใช้สารฮิวเมกเตนท์ในผลิตภัณฑ์มัลเบอร์รีกวน

The shelf-life extension of mulberry paste by using humectants to place sugar content could maintain the moisture while reducing the water activity (aw) of the product. The objectives of this research were to study on humectants replacement and the changes of the mulberry paste product quality during storage. The sugar content in the standard formula was replaced by 10% w/w glycerol and 90% w/w of maltitol and maltodextrin mixture (20:80 w/w). The final mulberry paste product consisted of mulberry maltodextrin maltitol glycerol salt and citric acid by 69.80% 21.62% 5.40% 3.01% 0.17% and 0.07% respectively. The chemical compositions: carbohydrates proteins fat ash fiber and moisture of the product were 76.92% 2.39% 0.14% 4.19% 4.30% 12.06% respectively. The total energy by calculation was 318.50 kcal/100 g. The anthocyanin content was 68.32 mg cyanidin- 3-glucoside/g. Total titratable acidity (citric acid equivalent) was 0.60%. The reducing sugar and total sugar values were 1.74% and 3.90% respectively. The consumer acceptance as evaluated by untrained panelists was in the level of moderately like (7 score). The product packed in glass bottle containers was stored at 27±2 ºC for 4 weeks. The aw was increased while the textural properties: hardness adhesiveness and chewiness were decreased. The chemical quality analysis showed significant decreases (p≤0.05) in the moisture and the anthocyanin contents. The microbial quality; total plate count and yeast and mold measurements were significantly increased (p≤0.05) however the values were within the acceptable range according to the Thai community product standard (35/2558).

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