จำนวน Repository ( 30 )

การวิเคราะห์พารามิเตอร์ที่มีผลกระทบต่อความสามารถในการต้านทาน  ของการเจาะทะลุของกระสุนบนผิวเกราะอะลูมิเนียมด้วยระเบียบวิธีไฟไนต์เอลิเมนต์
การวิเคราะห์พารามิเตอร์ที่มีผลกระทบต่อความสามารถในการต้านทาน ของการเจาะทะลุของกระสุนบนผิวเกราะอะลูมิเนียมด้วยระเบียบวิธีไฟไนต์เอลิเมนต์

This research analyzes the parameters affecting the penetrating resistance of shells on the armor surface by the finite element method. In this study the results were compared with real bulletproof armor firing tests and finite element simulations. modeling of bulletproof and bulletproof armor using Solid Works program. Creating and simulating armor firing pattern using ANSYS Explicit Dynamic program. damage test is based on National Institute of Justice (NIJ) level 3 standards with bullets the material of the ammunition is 7.62 mm tungsten carbide (WC). there are two types of bulletproof armor used in this simulation 1) SKD11 2) Aluminum AL7075. The simulations is into 1 category Simulation of stacked armor plates. The sizes of the armor plates are 6 8 and 10 mm and the angles of firing of bulletproof armor are 0 30 and 45 degrees. result of this simulation armor thickness and firing angle are factors of penetration resistance.

2565
การสังเคราะห์อนุภาคนาโนโลหะโดยการระเหยด้วยเลเซอร์ในน้ำ
การสังเคราะห์อนุภาคนาโนโลหะโดยการระเหยด้วยเลเซอร์ในน้ำ

Nanomaterials are widely used in many applications such as medicine cosmetic industry and other. When the size of the particle is reduced the number of atoms on the surface and the ratio between surface area to volume of the material increase result in the enhancement of the material’s physical magnetic and optical properties. There are many methods to synthesize the nanoparticle such as grinding chemical reaction electrochemical method and laser ablation. In this research laser ablation was chosen to synthesize the metal nanoparticles because this method is quick and convenient and does not produce hazardous waste. The results show that the laser with 6V electric potential could synthesize the metal nanoparticles with the smallest size. The metal nanoparticles with larger size were obtained when higher electrical potential of 8V and 10V were used. In conclusion the electric potential of the laser affects the size of the metal nanoparticle obtained from laser ablation.

2564
การดูดซับโลหะหนักโดยใช้เรซินแลกเปลี่ยนไอออนที่ทำจากผงไผ่และการดัดแปรพื้นผิวด้วยแมงกานีสออกไซด์
การดูดซับโลหะหนักโดยใช้เรซินแลกเปลี่ยนไอออนที่ทำจากผงไผ่และการดัดแปรพื้นผิวด้วยแมงกานีสออกไซด์

The objective of this work was to study the adsorption efficiency of bamboo and its surface modified with manganese oxide for removal of Pb(II) ion. The adsorption of Pb(II) from aqueous solution onto bamboo (BB) and manganese oxide-modified bamboo powder (MnO-BB) was evaluated based on batch experiment. The adsorption efficiency of MnO-BB onto Pb(II) was investigated as a function of the initial pH of 6 equilibrium time of 30 min adsorbent concentration of 5 g/L and initial concentration of Pb(II) solution in the range of 50-500 mg/L. The adsorption isotherms of Langmuir Freundlich and Dubinin-Radushkevich were used to describe the equilibrium isotherm. It is observed that the data from MnO-BB adsorbents fitted well to the Langmuir isotherm. The maximum monolayer adsorption capacities of MnO-NC were estimated as 38.76 mg/g. By comparing with BB the amount of Pb(II) adsorbed onto MnO-BB was more than BB by about 40 times under the optimized adsorption condition. According to Dubinin-Radushkevich isotherm the adsorptive mechanism of Pb(II) onto MnO-BB was chemisorption. The kinetic studies of Pb(II) demonstrated that the adsorption of Pb(II) onto MnO-BB adsorbent followed a pseudo second-order model with a good correlation. The adsorption mechanism was processed via chemical ion exchange between H+ and bonded MnO groups and Pb(II) ions in solution

2563
การพัฒนาโครงสร้างเกรนต้านทานการสึกหรอของชิ้นงานความแข็งสูงพิเศษด้วยกระบวนการอบผนึก
การพัฒนาโครงสร้างเกรนต้านทานการสึกหรอของชิ้นงานความแข็งสูงพิเศษด้วยกระบวนการอบผนึก

This study developed the cemented tungsten carbide by steadily sintering at 1430 °C for one hour. The tungsten carbide structure is a long shape. Its grain size has a difference between width and length and there are high distribution of sizes and shapes. In comparison with the work piece which has the similar size of grain structure the milling duration of tungsten carbide is less even though the condition of WC-Co is the same (95% WC – 5% Co). When the sintering of 1400 °C with the identical milling duration is performed. It turned out that both grain structures of the tungsten carbide and the work piece are similar and their grain sizes are slightly different. However when the grain structures are almost the same and sphericity is increased the hardness and wear resistance will also be improved. Therefore the size of grain structure between 1.00 – 3.00 μm with the milling duration of 100 hours will provide a work piece that has a wear resistance according to international standard

2562
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.

2561