จำนวน Repository ( 88 )

กรรมวิธีการปรับกรดของผักและสลักด้วยเครื่องปรับสภาพความเป็นกรดภายใต้การควบคุมอุณหภูมิและความดันบรรยากาศ
กรรมวิธีการปรับกรดของผักและสลักด้วยเครื่องปรับสภาพความเป็นกรดภายใต้การควบคุมอุณหภูมิและความดันบรรยากาศ

. This research aimed to study the acidification processes of carving vegetable using acid conditioning machine under emperature and pressure control which was developed in this study. Four acidification procedures were done at normal atmospheric pressure (method 1) under vacuum pressure for 10 (method 2) and 20 min (method 3) and vacuum pressure alternating with normal atmospheric pressure for each of 1 hour. There were two main parts of acid conditioning machine including the temperature controller inside the pickle tank and heat conductor tank and the pressure controller inside the pickle tank. The pickling temperature was stabled at 40oC under the pressure of 0.5 Bar. PLC (Programmable Logic Controller) program was used to write the ladder for controlling all processes and display through SCADA system. The results showed that the acidification method by soaking the carved-rose carrot under vacuum pressure alternating with normal atmospheric pressure showed the shortest time to equilibrium by 7 hours. Then the carved-rose carrot was packed in the glass jar followed by sterilized in boiling water for 15 minutes and stored at room temperature for 7 days. Total bacteria count Escherichia coli and Yeast-mold were not exceeded than the standard limit. Staphylococcus aureus was not detected throughout the storage periods

2564
ระบบควบคุมการปลูกผักไฮโดรโพนิกส์อัจฉริยะสำหรับเกษตรกร
ระบบควบคุมการปลูกผักไฮโดรโพนิกส์อัจฉริยะสำหรับเกษตรกร

Objective of this research is to research intelligent hydroponic vegetable cultivation control system for farmers. This is a group of lettuce that needs acid-base (pH) and conductivity (EC) in the same system on the planting table with Dynamic Root Floating Technique System (DRFT). By using Internet of Things (IoTs) devices as sensors For controlling the on-off system of the water filling system the on-off of nutrient solution A and B as well as the water spray system to reduce the temperature at the vegetable growing table. The developed hydroponic vegetable control system can effectively replace the workers labor. Vegetables grown are of the same quality used by farmers. Therefore the developed salad cultivation system could be used as a substitute for farmers. It has an easy to use control system.

2564
Bidirectional resonant converter using duty cycle voltage control for CCTV solar energy
Bidirectional resonant converter using duty cycle voltage control for CCTV solar energy

This paper proposes the bidirectional resonant converter with duty cycle voltage control using for CCTV with solar energy. The converter designed at 20 KHz for 20 W with 92.85 % of efficiency is operated at zero voltage switch mode for reducing the losses of converter. The modes of operation divide in two modes for operating bidirectional current. The first part is buck mode which has 5 volt at the output voltage and second is boost mode which has 8 volt at the output voltage. The two operation modes of converter will be discussed in this paper.

2563
การควบคุมความถี่ -โหลด ของการเชื่อมต่อระบบการผลิตไฟฟ้าจากโซล่าร์ฟาร์มและกังหันลม
การควบคุมความถี่ -โหลด ของการเชื่อมต่อระบบการผลิตไฟฟ้าจากโซล่าร์ฟาร์มและกังหันลม

The effects of load frequency control (LFC) of interconnected distribution power system in tie-line substation area load –frequency stability and the frequency respond at distribution generator (DG) are very important for interconnected control power system of tie-line area. The generating power system of solar farm and wind turbine which have interconnected distribution power system in tie-line substation area were tested using 3 simulation parameters: non-controller Automatic Voltage Regulator (AVR) and with Pl Controller. The results showed that there were 3 types of load and frequency changing in the interconnected area: load changed 0.02 p.u. had frequency of load changed 0.025 Hz and large disturbance. Comparisons of load-frequency to respond for steady state the time respond was 7.9 seconds for non-controller 5.4 seconds for AVR and 1.7 seconds for under controlled system at 0.1 p.u using Pl controller. Therefore the Pl controller has better efficiency than non-controller about 31 % and AVR about 16%. It can be concluded that the interconnected distribution power system in tie-line substation area controlling for storage for connected grid had better efficiency and optimization of generating power from renewable solar farm and wind turbine which have interconnected distribution power system in the nearby are balance of controlling of the original system.

2563
Fuel consumption monitoring system using control signal and characteristic correlations of fuel injector
Fuel consumption monitoring system using control signal and characteristic correlations of fuel injector

Objectives of this study are (i) to investigate characteristics of a fuel injector and to establish the characteristic correlation for correcting the fuel injection rate calculated from the control signal of a fuel injector and (ii) to design and fabricate the fuel consumption monitoring system by measuring the control signal of fuel injector in conjunction with considering the obtained characteristic correlation to enhance accuracy of the measured fuel consumption rate. The characteristics of a fuel injector (maximum fuel injection rate of 270 cm3/min) e.g. engine speeds percentages of injector’s duty cycle and pressure differences between fuel rail and intake manifold were experimentally investigated on a test set in the laboratory. The study found that when the engine speed increased the fuel injection rate increased. When the percentages of infector’s duty cycle increased the increasing ratio was less than the one-to-one increasing ratio as a case of the ideal. Moreover when the pressure difference increased the fuel injection rate increased. After that the fuel consumption monitoring system was designed and fabricated based on the Arduino Mega 2560 microcontroller. Trip distance was measured by a GPS module. The real-time fuel consumption rate could be shown on a LCD display. All recorded data were stored onto a SD card for further data analysis. Finally the on-road-test validation was conducted by on the 2011 Mitsubishi Triton installed with the 4-cylinder gasoline engine with total displacement of 2351 cm3. It was found from that the average discrepancy of the measured fuel volume was ± 1.88% compared to the actual fuel volume obtained by measuring a decreasing volume of consumed fuel.

2563