06642nas a2200433 a 4500 20260818175229.0 150615s2012 th uu|m rtt 0| a1eng d .b12153436 AIT Diss. no.FB-12-01 Preedawan Chaisrichonlathan Quality grading of mangosteens using ultrasonic specific based control system Pathum Thani, Thailand : Asian Institute of Technology, 2012 120 p. : ill. (some col.) Dissertation ; no. FB-12-01 A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering in Food Engine ering and Bioprocess Technology, School of Environment, Resources and Development The specific gravity controlling sy stem using ultrasonic for quality determination of mangosteens has been studied in term of non - destructive quality sorting of fruits. Appropriate specific gravity value for translucent flesh mangosteens grading was investigated. Ultrasonic specific gravity sensors were designed and developed for measuring different specific gravity. Effects of the direct and reflective sensing systems with dual ultrasonic transducer were studied for level measurement of ultrasonic specific gravity sensor. Mangosteen specifi c gravity grading system prototype was designed and performance was evaluated. Specific gravity value of normal flesh was observed lower than that of translucent flesh fruits, but both distributions were found overlapping. Average specific gravity of norm al flesh, mild translucent flesh and moderate to severe translucent flesh fruits were observed as 0.97, 1.00 and 1.01, respectively. The designed equipment using ultrasonic distance measurement technique was proved feasibility of the principle and instrum entation. The specific sensor was designed in such way that, constant specific gravity object is floated up or down when specific gravity of the solution is increased or decreased, respectively. Ultrasonic distance measurement technique was used to measure the change in distance of floating object. Suitable specific gravity sensor components, namely, ultrasonic waveguide , transmitting and receiving circuits were identified. Specific gravity sensor was required to have possible less diameter of waveguide for reducing effect of reflected signal from waveguide surface whereas, a stable circuit was used for transmitting circuit. Receiving circuit consisted of amplifying, conditioning and filtering circuit for converting received signal in two terms of phase diff erence between transmitting and receiving signals, and amplitude of received signal.Ultrasonic specific gravity sensor design was considered in direct and reflective distance measurement forms. In direct sensing system, ultrasonic signal from transmittin g transducer is sent to receiving transducers on the same center line. While in reflective sensing system, ultrasonic signal is sent to reflective material and is echoed to receiving transducer. Effect of direct and reflective sensing systems was observed from trend line or regression line of relationship between electrical properties such as phase difference between transmitting and receiving signals and amplitude of receiving signal and measuring distance of sensor . Reflective sensing system was revealed as the suitable specific gravity design in term of phase difference measurement. Linear trend of transmitting and receiving unit in direct sensing system was in fact twice of the distance value between transducing and reflecting units in reflective sensing system. Linear relationship between electrical properties and distance of ultrasonic specific gravity sensor was obtained with R 2 = 0.98. For controlling specific gravity of grading solution, mangosteen specific gravity grading system prototype was desig ned using specific gravity sensor, conditioning circuit, microcontroller, separating tank, pump, solenoid valve, separating tank and sensor stabilizer. Feedback control mechanism was designed to control flow of prepared solution from supply tank to separat ing tank by pump through solenoid valve. Sensor stabilizer was used for preventing specific gravity sensor from solution surface ripple. Results indicated that the continuous on - off mechanism can maintain specific gravity value of the solution in separatin g tank at setting point value. Grading specific gravity value or the prepared solution can be set in the range from 1.00 to 1.04. Efficiency of grading system during summer season was 84 percentages which was higher than 82 percentage of rainy season due t o the increase in sucked water and overlapping of specific gravity value during April to May. Average sorting efficiency of normal fruit by sample dribbling method was 87 percentage, with break even point of 136,000 kg of grading at the rate of 94 kg/hr. Thesis (Ph.D.) - Asian Institute of Technology, 2010 Mangosteen Ultrasonic Specific gravity Athapol Noomhorm, Chairperson Sudip K. Rakshit, Examination committee Anil K. Anal, Examination committee Peeyush, Soni, Examination committee Ministry o f Agriculture and Cooperatives (M O AC) , Thailand, Scholarship Donor AIT Fellowship, Scholarship donor Asian Institute of Technology. Dissertation ; no. FB-12-01 Full-Text http://203.159.5.9/ait-thesis/detail.php?q=B00601 .b12153436 mnait z 240404 0 150615 m a z 0 000:001:PDF:b1215343:002190:0:0:0:0:0:0 Abstract--ultrasonic n mnait mnait 20 Barcode : 30050120725428 CREATED : 2015-06-15 RECORD # : i12852156 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 Barcode : 30050120725436 CREATED : 2015-06-15 RECORD # : i12852168 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 96530 96530 0 0 0 0 MAIN MAIN mnait 2026-08-18 50.00 0 AIT Diss. no.FB-12-01 30050120725428 2026-08-18 17:52:29 1 2026-08-18 20 0 0 0 0 MAIN MAIN mnait 2026-08-18 50.00 0 AIT Diss. no.FB-12-01 30050120725436 2026-08-18 17:52:29 2 2026-08-18 20