Vibration effects on the quality of tomatoes

In Conferences - Abstracts
Ranatunga, C. L., Jayaweera, H. H. E. & Ariyaratne, T. R.
Research Symposium - University of Colombo
Publication year: 2010

Ranatunga, C. L., Jayaweera, H. H. E. & Ariyaratne, T. R., (2010) Vibration effects on the quality of tomatoes. Research Symposium – University of Colombo. Colombo, Sri Lanka.

Vibration effects in vehicular road transportation

In Conferences - Full Text
Ranatunga, C. L., Jayaweera, H. H. E., Suraweera, S. K. K., Ruvinda, K. K. D. L., Wattage, S. C. & Ariyaratne, T. R.
26th technical sessions. Institute of Physics
Publication year: 2010

ABSTRACT:

This study focuses to certain elements of th e Road-Vehicle-Load system which are responsible for the inflicted damage to consignment during road transportation. Bruising injury depends on the energy absorbed by the cargo. Distribution of the power spectral density (PSD) was used as a measure of the vibration energy generated during transportation. “Poor” quality (IRI range 10 to 5) roads induce nearly four times severe damage than that induced by “fair” or “good” quality roads (IRI range 3.5 to 2 or, 2 to 0.9). PSD of the generated vibration is relatively higher in the critical frequency range below 10 Hz. In this frequency range, the rear side of the truck bed indicates nearly a 10 times higher PSD compared to that of the front side of the truck. A higher PSD distribution was also observed at tomatoes occupying higher layer levels in multi-layered tomato columns. Higher PSD levels were observed at very poor quality roads even at lower vehicle speeds. Fair quality roads also produced higher PSD levels, but when travelling at higher speeds. In case of stacked cargo boxes, an increase in PSD level was observed with stack height from the truck bed. Studies performed using the instrumented sphere reveals that, among the positions of multilayered items within the cargo box, the position of the topmost item registered highest PSD level. In addition, the top most item in multilayered cargo packages, has freedom to move and resulting damage can be even higher. The PSD generated by the truck has a good relationship to the quality of the road (judged by a panel in terms of PSR or IRI) and the speed of the truck.

Development of an online chess game emulator

In Conferences - Full Text
Kumara, D. M. D. D. P., Thiruparan, B., Jayaweera, H. H. E. & Lelwala, R.
26th technical sessions.Institute of Physics
Publication year: 2010

Kumara, D. M. D. D. P., Thiruparan, B., Jayaweera, H. H. E. & Lelwala, R., (2010) Development of an online chess game emulator. 26th technical sessions.Institute of Physics – Sri Lanka.

Classification of Sri Lankan tomato varieties based on image analysis

In Conferences - Abstracts
Jayaweera, H. H. E., Ranatunga, C. L., Suraweera, S.K.K., Ruvinda, & Ariyaratne, T. R.,
Research Symposium - University of Colombo
Publication year: 2010

ABSTRACT:

A non-destructive image analysis method for classification of tomato (Lycopersicon esculentum) varieties (Sri Lankan hybrids) has been developed. Maheshi, Rajitha, T245 and Thilina varieties grown in Atipola, Sri Lanka during Yala season, 2009 were used in the study. Multispectral imaging system with white LEDs as light source was used for data acquisition. Two plane polarizers have been employed in order to acquire multiple scattered light coming from the interior of the sample. The acquired data were corrected for intensity variations occurred due to the 3-dimensional nature of objects by transferring them to 2-dimensional images. The 2-dimensional data were subsequently transformed into a 1-dimentional array in order for efficient computer processing. The acquired data were compressed using singular value decomposition and trained them with a linear model with an offset. After successful training of …

Thin-Layer Drying of Some Sri Lankan Paddy Varieties Under Low Humid Environment

In Conferences - Full Text
Shyamali, A. K., Jayaweera, H. H. E. & Ariyaratne, T. R.
25th technical sessions.Institute of Physics
Publication year: 2009

ABSTRACT:

Thin-layer drying characteristics of paddy were examined within the relative humidity range from 30% to 60%. A test chamber has been constructed with Perspex and continuously flushed with low humid air to control the inside relative humidly at required levels and several homogeneous thin layer paddy samples were dried inside the chamber. BG 300, BG 352 and BG 357 paddy varieties developed by Rice Research and Development Institute, Bathalegoda, Sri Lanka have been used in this study. Normalized drying data was transformed into dimensionless parameter called Moisture Ratio, and fitted with four semi-theore tical models. Correlation coefficients, standard errors and residual plots were used as criteria for evaluating the goodnes s-of-fit. Of the models used the two-term exponential model was found to fit well with the experimental data and is recommended as the thin-layer drying model for paddy.

Effect of measurement of non-destructive firmness on tomato quality and a comparison between non-destructive and destructive methods

In Conferences - Full Text
Ranatunga, C. L., Jayaweera, H. H. E., Suraweera, S. K. K. & Ariyaratne, T. R.
25th technical sessions. Institute of Physics
Publication year: 2009

ABSTRACT:

Almost all instrumental non-destructive (ND) type firmness test methods which involve a physical contact with the tomato when used for testing, deliver at least a minute damage to the fruit. The damage induced on a fruit was estimated when a so-called non-destructive firmness test was performed repeatedly on tomato fruit. The common method of firmness testing uses Magness-Taylor (MT) type firmness tester and in this destructive type test method, after having peeled, the tomato pulp is pierced with a probe. Qualitest (HPE-ll-FFF model) tester and the Bishop (FT 327 model) tester were used as ND and MT type firmness testers, respectively. Tomato variety “Rajitha” grown in Rathkinda area in Matale, during Maha season (Sept 2008) was subjected to this investigation. In a series of repeated ND type firmness test , a loss of firmness of 9.5 % was observed between the fi rst and the second measurement, regardless the ripeness level of tomato. At lower ripeness leve ls, tomato exhibited an exponential decay in percentage loss of firmness when subjected to repeated ND test, while red-ripe tomatoes demonstrated a slightly deviated behaviour. A study on the behaviour of MT vs. ND type firmness suggests a good linear relationship with a non-zero intercept. The relationship proposes a ND type firmness of 0.405 kg for a tomato which registers zero MT type firmness. Hence the contribution of the peel to th e ND type firmness would be 0.405 kg.

Development of server room monitoring and alarming system based on Global System for Mobile communication (GSM)

In Conferences - Abstracts
Wattage, S. C., Ariyadewa, P. D. & Jayaweera, H. H. E.,
65th Annual Technical Sessions
Publication year: 2009

Wattage, S. C., Ariyadewa, P. D. & Jayaweera, H. H. E., (2009) Development of server room monitoring and alarming system based on Global System for Mobile communication (GSM). 65th Annual Technical Sessions.University of Kelaniya, Kelaniya, Sri Lanka – Association for Advancement of Science.

Development and evaluation of a calibration procedure for a 2D accelerometer as a tilt and vibration sensor

In Conferences - Full Text
Hewawasam, K., Jayaweera, H. H. E., Ranatunga, C. L. & Ariyaratne, T. R.,
25th technical sessions.Institute of Physics
Publication year: 2009

ABSTRACT:

Measuring tilt and vibration are two of the major applications of accelerometers. An experimental method to calibrate a commercially available 2D accelerometer (ADXL202JQC) as a tilt and a vibration measuring device is discus sed in this publication. Calibration of tilt measurements (measuring acceleration due to th e gravity – the static case) was done by rotating the accelerometer in a vertical plane. Also the effect of minor inclinations of the plane rotation of this experiment was investigated and observed to be minute. Based on the calibration for the static case, the accelerometer was tested in a dynamic case. A known type of motion; the motion of a tip of a cantilever, was us ed to test the calibration of the accelerometer for the dynamic case. Motion of the tip of a cant ilever was considered as a damping oscillation thus the variation of acceleration of the tip of the cantilever was considered a decaying sinusoidal. The measurements obtained through accelerometer agreed to this proposed model with R 2 values in the range of 0.93 to 0.98. The frequency of osc illation of the cantilever was varied by changing the length of the cantilever. The periods of oscillation obtained by the accelerometer agreed with the same values obtained from a stroboscope to maximum percentage deviation of approximately 3%.

Study of density of local paddy varieties

In Conferences - Abstracts
Shyamali, A. K., Jayaweera, H. H. E. & Ariyaratne, T. R.,
64th Annual Technical Sessions
Publication year: 2008

Shyamali, A. K., Jayaweera, H. H. E. & Ariyaratne, T. R., (2008) Study of density of local paddy varieties. 64th Annual Technical Sessions.University of Colombo, Colombo, Sri Lanka – Association for Advancement of Science.

Realization of deep-frying condition with a lesser quantity of oil

In Conferences - Abstracts
Ariyaratne, T. R., Jayaweera, H. H. E. & Randunu, R. P. N.
Research Symposium
Publication year: 2008

Ariyaratne, T. R., Jayaweera, H. H. E. & Randunu, R. P. N., (2008) Realization of deep-frying condition with a lesser quantity of oil. Research Symposium – University of Colombo. Colombo, Sri Lanka.

Quality of Tomatoes - degradation and estimation at retail market

In Conferences - Abstracts
Ranatunga, C. L., Jayaweera, H. H. E. & Ariyaratne, T. R.,
Research Symposium
Publication year: 2008

ABSTRACT:

Tomato (Lycopersicum esculentum) is a delicate horticultural crop grown in many areas in Sri Lanka. Most of the tomato farms are situated away from main roads. Often tomato collecting trucks have to cross potholes, kerbs, bumps and even causeways. Vertical vibration acceleration experienced by tomatoes during transportation contributes towards increased post-harvest losses. It causes shortening of their shelf life. Objective of this study is to identify and estimate the key parameters leading to losses due to vibration at vehicular road transportation. A tri-axial accelerometer (Steval LIS 302 DL) has been used in this study to detect and record the vibration acceleration. Energy associated with the vibration was estimated in terms of the power spectral density (PSD). At poor road conditions (having higher IRI values) and at higher truck speeds the generated vertical vibration levels are higher and the resulting …

Method of operation of the ‘voting panel’ of the electronic voting machine for presidential elections in Sri Lanka

In Conferences - Abstracts
Lelwala, R., Abeysekara, A. U., Indunil, B. A., Ariyaratne, T. R. & Jayaweera, H. H. E.
Research Symposium
Publication year: 2008

Lelwala, R., Abeysekara, A. U., Indunil, B. A., Ariyaratne, T. R. & Jayaweera, H. H. E., (2008) Method of operation of the ‘voting panel’ of the electronic voting machine for presidential elections in Sri Lanka. Research Symposium – University of Colombo. Colombo, Sri Lanka.

Evaluation of finger-feel firmness as a subjective measurement of Tomato quality degradation at retail market

In Refereed Journals
Ranatunga, C. L., Jayaweera, H. H. E. & Ariyaratne, T. R.
Tropical Agricultural Research, 20(1),
Publication year: 2008

ABSTRACT:

The versatility of the Finger-Feel-Firmness (FFF) test method has been proved with a series of panel evaluations. Judgment of the panel on the pattern of the variation of FFF, agrees with that of the author. An individual can be trained to monitor the pattern of variation of FFF. Absolute values of FFF however, depend on the personal force- sensitivity of the individual. Degradation of the firmness due to squeezes made in FFF test itself has also been investigated. Retail market tomatoes registered a rate of loss of average FFF from 60 to 65 g/d and the level of ripeness of the sample had no significant effect on this rate. On repeated squeezing in the FFF test itself, the rate of loss of FFF was only about 4 g/squeeze. Development in red colour with shelf-life in less-ripe tomatoes was nearly 3 times faster compared to 0.5 rank/d in red-ripe tomatoes. However, the loss of FFF with the development in red colour in less-ripe tomatoes was 40 g/rank and it was more or less 3 times slower compared to 121 g/rank in red-ripe tomatoes. It was clear that the natural deterioration does about 15 times severe damage to the whole fruit, compared to the induced local damage by squeezing in the FFF test. With knowledge of colour and FFF value, it is possible to estimate the expected shelf life of tomatoes. Tomatoes ripened up to colour rank 10 would spend a shelf-life till they reach a range of FFF as low as 100 to 200 g (subject to personal force-sensitivity, tomato variety and post-harvest management methods.)

Comparison of firmness of tomato varieties grown in Sri Lanka

In Conferences - Full Text
Ranatunga, C. L., Jayaweera, H. H. E. & Ariyaratne, T. R.
24th technical sessions.Institute of Physics
Publication year: 2008

ABSTRACT:

Firmnesses of farm fresh samples of three tomato (Lycopersicon esculentum) varieties grown in Sri Lanka, named, Maheshi, HF-2 and T-146 were studied. The firmness of the tomatoes was measured using Effegi type Bishop FT 327 firmness tester. Measurements were carried out for three consecutive days after plucking them from plants. Ever since tomatoes were harvested, the firmness was found to decrease daily. Throughout the three-day period of shelf life, all three varieties registered a higher firmness value for sun-shaded side than the corresponding firmness value for the sun-exposed side. Among the three tomato varieties, Maheshi at all times registered the highest firmness value while T-146 variety registered the lowest. Also the Maheshi variety indicated the lowest rate of loss-of-firmness with time. As a result, the first officially released hybrid tomato variety Maheshi stands out with its superior and promising quality over the other two varieties, throughout the handling process, storage and shelf life in marketing chain.(The firmness measurements were made on peeled-off tomatoes, with a plunger of diameter 11.3 mm).

Thin layer drying kinetics of Sri Lankan paddy varieties under low humid conditions

In Conferences - Abstracts
Randunu, R. P. N., Jayaweera, H. H. E. & Ariyaratne, T. R.,
63th Annual Technical Sessions
Publication year: 2007

ABSTRACT:

Thin-layer drying characteristics of paddy were examined within the relative humidity range from 30% to 60%. A test chamber has been constructed with Perspex and continuously flushed with low humid air to control the inside relative humidly at required levels and several homogeneous thin layer paddy samples were dried inside the chamber. BG 300, BG 352 and BG 357 paddy varieties developed by Rice Research and Development Institute, Bathalegoda, Sri Lanka have been used in this study. Normalized drying data was transformed into dimensionless parameter called Moisture Ratio, and fitted with four semi-theore tical models. Correlation coefficients, standard errors and residual plots were used as criteria for evaluating the goodnes s-of-fit. Of the models used the two-term exponential model was found to fit well with the experimental data and is recommended as the thin-layer drying model for paddy.

Construction of telephone operable messaging system. 23rd technical sessions

In Conferences - Full Text
Jayaweera, H. H. E. & Lelwala, R.
23rd technical sessions.Institute of Physics
Publication year: 2007

ABSTRACT:

A password protected, dynam i c LCD (Liquid Crystal Display) m e ssaging board is developed to use with ordinary telephone is discussed in this publication. The device should be connected in parallel to a fixed- line telephone (called host telephone) and can be operated via host telephone itself or any other fixed-line or m obile telephone. After authentication, user can feed a m e ssage by using the built in standard m e ssage list or by typing each character via telephone keypa d. There are 9 standard m e ssages and a standard m e ssage can be extended up to 250 ch aracters and any of the ASCII characters can be used but only capital English letters, 0 to 9 and space are allowed when user feeding his own m e ssage through a telephone keypad.