จำนวน Repository ( 2131 )

การวิเคราะห์หาปริมาณคลอร์ไพรีฟอสและโลหะหนักที่เป็นพิษบางชนิดในตัวอย่างผักจากแม่น้ำเลย
การวิเคราะห์หาปริมาณคลอร์ไพรีฟอสและโลหะหนักที่เป็นพิษบางชนิดในตัวอย่างผักจากแม่น้ำเลย

The research aimed to analyze and compare contents of accumulated residue of chlorpyrifos chromium lead and cadmium in five varieties of vegetables in Loei River Loei Province. Five varieties of vegetables such as Vegetable fern (Diplazium esculentum Limnocharis flava (L.)) Limnocharis flava (L.) Buch Lasia spinosa (L.) Thwaites swamp cabbge (Ipomoea aquatica Forsk) and water mimosa (Neptunia oleracea Lour.) were collected during winter summer and rainy seasons from Phu Luang Mueang Loei and Chiang Khan District. Chlorpyrifos was analyzed by high performance liquid chromatography (HPLC). The results showed that the highest chlorpyrifos contents were found in vegetables in winter and summer season in the amount of 0.04±0.00 mg/kg. Analysis of all three heavy metals were carried out dry ashing at 500C and acid digestion with nitric acid prior to analyzing by flame atomic absorption spectrophotometry (FAAS). The results showed that cadmium accumulation in the highest content among all metals in water mimosa (Neptunia oleracea Lour.) in summer season from Phu Luang District (1.83±0.01 mg/kg). The second highest metal content was lead which has found in swamp cabbge (Ipomoea aquatica Forsk) in summer from Mueang Loei District (1.40±0.08 mg/kg). chromium showed the lowest content in Limnocharis flava (L.) Buch in winter from Mueang Loei District (0.47±0.04 mg/kg). The contents of chlorpyrifos and heavy metals were not exceed the legal limits set by International Standard Food and Ministry of Republic Health No.98 of Thailand except Ipomoea aquatica Forsk which collected in summer that showed the lead content higher than the legal limits.

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เทคนิคการจัดเรียงสายป้อนและการกำหนดตำแหน่งตัวเก็บประจุในระบบจำหน่ายไฟฟ้าเพื่อทำให้ค่าดัชนีโหลดสมดุลต่ำสุด
เทคนิคการจัดเรียงสายป้อนและการกำหนดตำแหน่งตัวเก็บประจุในระบบจำหน่ายไฟฟ้าเพื่อทำให้ค่าดัชนีโหลดสมดุลต่ำสุด

This paper presents an efficient algorithm for optimization of radial distribution systems by a feeder reconfiguration to balance feeder loads and eliminate overload conditions. The system load-balancing index is used to determine the loading conditions of the system and maximum system loading capacity. The index value has to be minimum in the optimal feeder reconfiguration of load balancing. A method based on Tabu search algorithm The Tabu search algorithm is employed to search for the optimal feeder reconfiguration. Simulation results for a radial 69-bus system with reconfiguration and capacitors placement. The study results show that the distribution system with capacitor placement and optimal on/off patterns of the switches feeders reconfiguration can be load balancing in distribution systems.

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การเปรียบเทียบประสิทธิภาพของตัวสถิติทดสอบสำหรับการทดสอบ ความแตกต่างของค่าเฉลี่ยระหว่างประชากร 2 กลุ่มที่อิสระกัน
การเปรียบเทียบประสิทธิภาพของตัวสถิติทดสอบสำหรับการทดสอบ ความแตกต่างของค่าเฉลี่ยระหว่างประชากร 2 กลุ่มที่อิสระกัน

The objectives of this study were to calculate the probability of type I error power of a test and to compare the performance of three test statistics: Z Student’s t and Welch’s t. Including the recommending the appropriate test statistic. Classification of the population according to five distribution. The ratios of mean group 1 per group 2 were three levels. The ratios of variance group 1 per group 2 were three levels. The sample sizes of two populations were nine sizes. The significance levels that to study were 0.01 and 0.05. The data were simulated by using SAS programming with 1000 replicates. Results of the research were Z test statistic could control the probability of type I error and had higher power of a test than other test statistics but this test is necessary to know the variances of the two groups. Therefore it was appropriate to apply the other test statistics i.e. Student’s t or Welch’s t. If the variances of the two groups were equal Student’s t was a more appropriate test statistic than Welch’s t. But if the variances of the two groups were not equal Welch’s t was a more appropriate. When both sample sizes were large and the population variances were equal we could use any tests since there is no difference in the performance.

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การเตรียม การตรวจสอบคุณลักษณะ และศึกษาการปลดปล่อยยาปฏิชีวนะด้วยจีโอโพลิเมอร์
การเตรียม การตรวจสอบคุณลักษณะ และศึกษาการปลดปล่อยยาปฏิชีวนะด้วยจีโอโพลิเมอร์

The aims of this study were developed geopolymer matrix for controlled release amoxicillin antibiotic drug in the in vitro gastric and intestines (pH 1 and pH 6.8 temperature 37 ºC conditions). Three formulations of geopolymer tablets (GeAmSF5 GeAmSF7.5 and GeAmSF10) which different silica fume content were used in this study. Geopolymer tablets were measured compressive strength and characterized by using 3D laser microscope Scanning electron microscope (SEM) X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The amoxicillin release was analyzed by UV-VIS spectrophotometer. It was found that amoxicillin in geopolymer tablet was more resistance with various extraction solvents (ethanol water 50 oC pH 1 and 12 solutions) than amoxicillin commercial tablet in 2 hours. Moreover the amoxicillin constantly release from geopolymer matrix after 3 hours in both in vitro gastric and intestines. However amoxicillin was more release in gastric than intestines condition due to the strong acid leached aluminum ion causing damages geopolymer structure. Mathematical modeling of amoxicillin release from geopolymer matrix was fitted best with Higuchi model indicating diffusion of the drug out of matrix.

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การดูดซับทางชีวภาพสีย้อมโรดามีน บีด้วยรากผักตบชวาดัดแปร
การดูดซับทางชีวภาพสีย้อมโรดามีน บีด้วยรากผักตบชวาดัดแปร

The biosorption of Rhodamine B using modified water hyacinth roots was studied. The adsorption experiments were conducted in a batch setup. Parameters affecting the adsorption of Rhodamine B including pH of a solution adsorption time adsorbent dose and dyes concentration were investigated. With the 80 mg/L Rhodamine B solution of pH 6.0 adsorption time of 60 min and 0.10 g of modified water hyacinth roots the kinetic models pseudo-first order and pseudo-second order kinetic model were applied to examine the kinetic adsorption. The adsorption kinetic data correlates with pseudo-second order kinetic model. The Langmuir and Freundlich adsorption models were applied to describe the isotherms and isotherm constants. Adsorption isotherm data correlates with Langmuir adsorption model. The maximum adsorption capacity of modified water hyacinth roots for Rhodamine B was found to be 63 mg/g

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