จำนวน Repository ( 36 )

การศึกษาอุณหภูมิการหล่อต้นแบบแว็กซ์ชนิด EC 500 เพื่อลดของเสียจากกระบวนการผลิตเครื่องประดับเงิน
การศึกษาอุณหภูมิการหล่อต้นแบบแว็กซ์ชนิด EC 500 เพื่อลดของเสียจากกระบวนการผลิตเครื่องประดับเงิน

This research is a study of the optimum heat temperature for baking sintered castings for burnout removal of EC 500 type ash wax from cast mortar. Improving jewelry casting process to reduce waste from silver jewelry production process. By studying the temperature of the mortar. To burn remove wax from the mortar and clean the gaps. Then try to bring silver water instead of metal casting. The results of a baked casing study using the EC500 housing prototype from the study showed that the EC500 wax material is melted from all solids to ash wax by heating at 850 ° C to burn. Remove ash wax which makes the cavity clean. When the casting was casted with 925 sterling silver the most complete workpiece after the improvement of the waste jewelry casting process was found to be 1 piece 1 percent 99 pieces or 99 percent.

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การศึกษาอุณหภูมิการหล่อต้นแบบแว็กซ์ชนิด EC 500 เพื่อลดของเสียจากกระบวนการผลิตเครื่องประดับเงิน
การศึกษาอุณหภูมิการหล่อต้นแบบแว็กซ์ชนิด EC 500 เพื่อลดของเสียจากกระบวนการผลิตเครื่องประดับเงิน

The purpose of this research was to investigate the optimum heat temperature for the EC500 wax cured basecoat extrusion from all castings without waxing in the mortar. To reduce waste when the casting mortar through the casting process Silver Sterling 925 silver jewelry company Muang District Chiang Mai where the waste is caused by waxing outflow. The imperfections and leave waxing inside. Experiment with high temperature heat in mortar. And analyze the quality of work surface after casting with microscope. To find defects such as droplets and porosities caused by a range of temperatures. Temperature of baking mortar There is a difference from the conventional waxing mortar temperature. That is outflow of EC500 type wax. In the mortar to live. High heat The results of the 100 sample EC500 wax samples were tested at a temperature of 25 ° C. The mortar temperature was 700 ° C. 60 percent of waste was found the mortar was laid at 750 ° C 54 percent of waste was found. The mortar temperature was 800 ° C 32 percent waste was found the mortar temperature was 850° C Detecting 1 percent waste. The results of the study show that heat temperatures of up to 850 ° C can solve the problem of casting sterling silver alloys from the EC500 wax model. Finds the least waste.

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การพยากรณ์ราคาพริกไทยดำ
การพยากรณ์ราคาพริกไทยดำ

The objective of this study was to construct the black pepper prices forecasting model by 4 statistical methods: Box-Jenkins method Holt’s exponential smoothing method Brown’s exponential smoothing method and damped trend exponential smoothing method. Time series of monthly black pepper prices which were gathered from the website of the Office of Agricultural Economics during January 2005 to December 2018 of 168 observations were divided into 2 datasets. The first dataset had 156 observations from January 2005 to December 2017 for constructing the forecasting models. The second dataset had 12 observations from January to December 2018 for comparing the accuracy of the forecasts via the criteria of the lowest mean absolute percentage error (MAPE) and root mean squared error (RMSE). Research findings indicated that for all forecasting methods that had been studied the most accurate method was damped trend exponential smoothing method (MAPE = 6.5773 RMSE = 10.3775)

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การพยากรณ์ราคาข้าวโพดเลี้ยงสัตว์ของประเทศไทย
การพยากรณ์ราคาข้าวโพดเลี้ยงสัตว์ของประเทศไทย

The purpose of this research was to construct the appropriate forecasting model for the prices of field corn in Thailand using four time series analysis methods including Box-Jenkins method Holt’s exponential smoothing method damped trend exponential smoothing method and combined forecasting method. Time series data from the website of the Office of Agricultural Economics with total 227 months during January 1997 to November 2015 are used and divided into two series. The first 216 months from January 1997 until December 2014 used to build the forecasting models and the last 11 months from January until November 2015 used to compare the forecasting methods accuracies via the criteria of the lowest mean absolute percentage error and root mean squared error. Research finding indicated that combined forecasting model was the most accurate.

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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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