Amoranto Trisnobudi

Ultrasonic system for automation of internal quality evaluation of durian

Abstract An investigation has been carried out to determine the relationship of the physico-chemical properties of durian meat ( Durio zibethinus Murr): the firmness and the sugar content with its ultrasonic properties. For this purpose, a measurement system based on the ultrasonic method was developed and controlled by a PC computer. The objective of the research is to develop a nondestructive method for the quality evaluation of whole intact durian by the ultrasonic method. Three kinds of ultrasonic transducer (1 MHz, 500 kHz, and 50 kHz) were tested for measuring the transmission characteristics of the durian meat. The test results revealed that the ultrasonic wave capable to be transmitted into the durian meat was the one with 50 kHz. There was a significant relationship between the ultrasonic wave transmission at 50 kHz with the meat firmness, as well as with the meat sugar content.

Summation convolution filtered back projection and algebraic reconstruction technique for ring array ultrasound tomography based on time of flight

Purpose of the study is to apply SCFBP and ART methods on a ring array ultrasound tomography system based on time of flight. The study was conducted with numerical and experimental object by 16 positions in circular phantom. The data set of ring array was rearranged and interpolated into parallel scheme to reconstructed by SCFBP and ART methods. The result indicated that rearrangement and interpolation is feasible to use SCFBP methods, improve speed and reconstructed image quality on ART methods.

Determination of Acoustic Properties of Durian Fruit

Abstract The objective of the research is to determine acoustic properties of durian ( Durio zibethinus Murr.) cv Sunan by ultrasonic method. Twelve mature durians of (95±3) days after fullbloom and 12 immature durians of (70±3) days after fullbloom were used to determine the velocity and the attenuation. For this proposes, a measurement system based on ultrasonic method was developed and controlled by a PC computer. The experimental apparatus for measuring the transmission of the ultrasonic wave was developed consist of 1) an ultrasonic tester, 2) a transmitter and receiver transducer (50 kHz), 3) an analog oscilloscope, 4) a digital oscilloscope, 5) an A/D converter and 6) a personal computer. A low frequency (50 kHz) ultrasonic was used and placed underwater to transmit and receive ultrasound signal. The ultrasonic signal transmitted through the durian fruit sampled and displayed on the digital oscilloscope. An interface PC Lab Card was used to transfer the signal stored in the digital oscilloscope to the PC computer. The power spectra were obtained by means of Fast Fourier Transfonn (FFT) techniques. The attenuation calculated with formula A x = A 0 e -αx and the velocity calculated by formula V = (Δt - L/V water )/L . The result shows that mature durian had attenuation of 0.521 dB/cm and the immature one was 0.311 dB/cm. The velocity of mature durian was 423.49 m/sec and the immature one was 538.64 m/sec. The relationship between velocity and quality indices were linear (r 2 = 0.82 for firmness and r 2 = 0.73 for sugar content). The relationship between attenuation, and quality indices seems to be exponential with r 2 = 0.83 for firmness and r 2 = 0.73 for sugar content.