จำนวน Repository ( 3447 )

การลดผลกระทบจากฟ้าผ่าในระบบจำหน่ายไฟฟ้า
การลดผลกระทบจากฟ้าผ่าในระบบจำหน่ายไฟฟ้า

Most of Metropolitan Electricity Authority (MEA) electric power system is using overhead line. It is 94% in the system including subtransmission distribution and low voltage system. All of them were installed on concrete pole. At present many public facilities have been built such as Sky-Train. It causes more constrains for construction with concrete pole due to lack of right of way. MEA needs to using electrical monopole plays an important role. It’s easier than concrete pole for construction and it requires less construction area than concrete pole. This research evaluation of The Reduce Effect of Lightning on Transmission Line. Case lightning strike on overhead ground wire (OHGW) at pole top of electrical monopole with suspension insulator Focusing on three factors is pole top voltage critical current and back flashover rate (BFOR). ATP-EMTP software is used for simulation. The results show that BFOR is reduced by 79% on electrical monopole structure with suspension insulator compared with existing concrete pole. BFOR is also reduced by 33.17% on concrete pole with external ground wire. The results could be served as a guideline in subtransmission line design and improvement in MEA power system.

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เครื่องทดสอบความล้าตัวของวัสดุ แบบหมุนดัดปลายอิสระ
เครื่องทดสอบความล้าตัวของวัสดุ แบบหมุนดัดปลายอิสระ

The purpose of this research was to construct the rotating bending fatigue testing machine for metal material to find out the built-in machine performance and compare it with machines that meet international standards. The machine built into a compact machine using weight knob for a heavy load in testing. It can test the force range 50-300 Newton (N) the motor is a 1 HP transmitter with a speed of 2800 rpm. Start by pressing the Start button to release the weight that sends power to the workpiece and attend a sensor counting is available to detect the lack of testing material. For the efficiency performance of the machine uses 10 piece steel shafts diameter of 8 mm according to the standard of the material fatigue tester by independent end bend rotation. For testing to compare with the test international standard machine also uses 10 piece steel shafts using force 150 N. For the analysis to test statistical hypotheses with the Minitab computer program at the significance level of 0.05 it was found that the values obtained from be made the rotating bending fatigue testing machine for metal material there is no difference with standard machines from statistically significant. All values are within the set limits. In conclusion the machine was created to be as effective as the international standard machine.

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การศึกษาประสิทธิภาพทิศทางการกัดงานที่มีผลต่อความหยาบผิวโดยวิธีการทากุชิ
การศึกษาประสิทธิภาพทิศทางการกัดงานที่มีผลต่อความหยาบผิวโดยวิธีการทากุชิ

A Study direction milling affecting surface roughness by the Taguchi method with a 10 mm. bite milling cutter the direction of milling is clockwise G41 and counter clockwise milling. G42 is intended to measure the milling direction of the workpiece by testing with brass and aluminum materials. By measuring the milling direction the feed rate is 100 mm / min the speed is 1500 rpm and the depth of milling is 3 mm. The clockwise and counterclockwise hands provide better surface roughness and from the test the factors that affect the roughness of the surface are brass and aluminum. The coefficient of variation in surface roughness of the test specimens was 4 factors namely feed rate of 80 100 and 120 mm/min speed of 1200 1500 and 1800 rpm. The 3 4 and 5 mm workpieces are machined and the milling direction is divided into two parts: G41 clockwise bite counterclockwise G42 brass and brass material testing. It is found that the correct direction for brass milling is the direction of machining G41 with a cutting speed of 1200 rpm. The feed rate is 120 mm/min. And the depth of bite is 4 mm. The surface roughness of the workpiece is minimal. The surface roughness is 0.84 ?m. The optimum direction for aluminum milling is G42 cutting direction. The cutting speed is 1200 m/min. The feed rate is 120 mm/min. And the depth of biting is 5 mm. The surface roughness of the workpiece is minimal. The surface roughness was 0.75 ?m.

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การศึกษาอิทธิพลส่วนผสมโลหะทองขาว 6k ที่มีผลต่อสมบัติทางกายภาพสำหรับกระบวนการผลิตตัวเรือนเครื่องประดับ
การศึกษาอิทธิพลส่วนผสมโลหะทองขาว 6k ที่มีผลต่อสมบัติทางกายภาพสำหรับกระบวนการผลิตตัวเรือนเครื่องประดับ

This Research is to Study the Development of 6k White Gold Alloys for Jewelry Production. By Studying the Influence of 6k White Gold Alloys on Physical Properties for Jewelry Molding Process. Of 6k Gold Alloys at Various Compound Rates. The Results of the Experiments Show that the Chemical Composition of 6k White Gold Alloys is Slightly Different when Compared with the XRF (X-ray Fluorescence Spectrometers). Compare the pre and Post-Melting Quantities. The Result of the Compounding Test with the Color Level of 6k White Gold at the Compound Rate 25%Au+54%Ag+0%Cu+3%Zn+18%Pd The Lowest Color Level was L * = 82.14 a * = -0.16 b * = 7.71 and the Lowest Color Difference was 21.07. With other Ingredients It Shows that the Test Specimen of 6k White Gold has a Rather Greenish Color and is Slightly Yellowish Compared to the Blue Line that Approaches the Standard line. These Properties are the Physical Properties Required to Produce a 6k White Gold Jewelry Body.

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การศึกษาสภาวะที่เหมาะสมสำหรับการหล่อขึ้นรูปตัวเรือนเครื่องประดับโลหะทองขาว 6k
การศึกษาสภาวะที่เหมาะสมสำหรับการหล่อขึ้นรูปตัวเรือนเครื่องประดับโลหะทองขาว 6k

This Research is to Study the Development of 6k White Gold Alloys for Jewelry Production.The Optimum Conditions for Casting Jewelry and Jewelry were Investigated. The Results of the Experiments Show that the Chemical Composition of the 6k White Gold Alloys is Slightly Different when Compared with XRF (X-ray Fluorescence Spectrometers) Pre-and Post-Melting Quantities The Heat of the Test Specimen was found to be 5%Au+42%Ag+12%Cu+3%Zn+18%Pd 25%Au+46%Ag+8%Cu+3%Zn+ 18%Pd 25%Au+50%Ag+4% Cu+3% Zn+18% Pd and 25%Au+54%Ag+0%Cu+3%Zn+ 18%Pd It is Found that the Heat from the Beginning to the Level of Change before the Liquid is used the Average Temperature of 702.3 - 636.7 Degrees Celsius Respectively 25%Au+54%Ag+0%Cu+3%Zn+18%Pd It is the Formula that Gives the Lowest Value of Liquid State Change from 636.7 Degrees Celsius to the Best Value of this Experiment. Suitable for use in the Manufacture of Jewelry due to its Melting Ability for Molding. Melting for Molding and Formed by Hand. The Amount of Zinc(Zn) may be an Important Factor in the Variation which is Directly Proportional to the Maximum Increase in the Final order of 3.58 Percent.

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