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Grouping marian plums harvested at different times by transmittance near-infrared spectroscopy
(2017-11-25)
Teerachaichayut, S.
;
Phonmakham, S.
;
Suktanarak, S.
Marian plum (Bouea burmanica Griff.) ‘Toon Klaow’ is one of Thailand’s favorite fruits. Marian plum’s edible quality depends strongly on its harvest time. This study investigated a non-destructive technique for classifying marian plums according to their harvest time after the day that their blossom set. The non-destructive technique used was transmittance mode, short wavelength near-infrared (SW-NIR) spectroscopy in the wavelength range 660-960 nm. Marian plum samples (n=110) were harvested at 62, 65, 68 and 73 days after flowering. The soluble solids content (SSC) and titratable acid (TA) were determined accurately by standard methods. SW-NIR spectra of these samples were obtained and analyzed by principle component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). The following spectral pretreatments were applied, standard normal variate (SNV), smoothing (Savitsky-Golay), and first derivative, in order to obtain optimal grouping results. The PC1 and PC2 score plot of the PCA could not clearly separate some of the classified groups. For the results of PLS-DA, its cross-validated grouping accuracy was R=0.91 and RMSECV=1.28; hence, it can be concluded that SW-NIR spectroscopy has good potential for determining the harvest time of marian plums.
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Highly-transparent multi-layered spin-coated silk fibroin film
(2017-01-01)
Wasapinyokul, Kamol
;
Kaewpirom, Supranee
;
Chuwongin, Santhad
;
Boonsang, Siridech
In this study, the silk fibroin films with different numbers of layers were fabricated by the spin-coating method and their optical transmittances were observed. The process to synthesise the silk fibroin solution was explained - starting from the silk cocoon until the silk-fibroin solution, approximately 7.5% concentration wt/vol, was obtained. The solution was spin-coated onto clean glass substrates to fabricate samples. Totally 10 samples with different numbers of layers, from 1 to 5 layers, were obtained. All samples can be separated into two groups: those left dried at room temperature after spin-coating and those heated at 60°C. They were then measured for their transmittance over the visible-to-near-infrared region. All samples exhibited the high transmittance where the values were at 95% and 98%, for the samples at room temperature and those at 60°C, respectively. This was believed to be due to the heating effect that caused the silk fibroin to arrange itself after being heated, hence the higher transmittance. These high transmittances were maintained regardless of the number of layers and length of heating time. Results from this study could be used to fabricate a silk fibroin film with high optical transmittance and adjustable other properties.
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Modification of optical properties of spin-coated TiO2 film by heat treatments
(2017-01-01)
Chunarom, Chutinat
;
Yontrarak, Tanapat
;
Wipopcharoenkul, Puttinan
;
Wasapinyokul, Kamol
In this report, effects of heat treatment conditions on the transmittance of titanium dioxide, TiO<inf>2</inf>, films were examined. The colloidal solution of TiO<inf>2</inf> in two different solvents - isopropanol, IPA, and sulfuric acid, H<inf>2</inf>SO<inf>4</inf>, were deposited via a spin-coating method onto clean glass substrates. The films were subsequently annealed and cooled down, either quickly or slowly, before being measured for their optical transmittances in the visible region. Three points were noted: Firstly, when the films were quickly cooled down after annealed, their transmittance depended on their annealing temperature. In IPA and H<inf>2</inf>SO<inf>4</inf>, the transmittance decreased and increased, respectively, when the annealing temperature increased. Secondly, when the films were slowly cooled down after annealed, their transmittance seemed to be independent from the annealing temperature, where the films had roughly equal transmittance regardless of annealing temperature. Lastly, the TiO<inf>2</inf> films with H<inf>2</inf>SO<inf>4</inf> provided higher transmittance than those with IPA. All the three stated characteristics were the same for all wavelengths in the visible region. These results were believed to result from the dispersibility of the TiO<inf>2</inf> in each solvent and the cooling-down processes. Such results could be further developed to select a suitable heat treatment process for a spin-coated TiO<inf>2</inf> film with a desired optical transmittance.
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Non-destructive detection of internal mold infection in sweet tamarind using short wavelength near infrared spectroscopy
(2014-10-20)
Teerachaichayut, S.
;
Suktanarak, S.
;
Kasemsumram, S.
Internal quality of sweet tamarind ('Prakaytong') is an essential commercial attribute. Determination of internal mold cannot be done by visual inspection on the outside of an intact tamarind. Therefore, a non-destructive measurement and data evaluation technique were considered using short wavelength near infrared (SW-NIR) transmittance spectroscopy in order to detect internal mold infection in sweet tamarind. A set of 176 tamarind samples (a calibration set = 124 and a prediction set = 52) were used in this research. Spectra in the region of 665-955 nm were acquired from scanning the center of each seed pod. The averaged spectral reading was used for partial least squares-discriminant analysis (PLS-DA) to establish a classification model for tamarind quality between groups of normal and defected samples. The calibration model obtained optimal result by cross validation using second derivative spectral pretreatment. The classification accuracy on the calibration set was 86.3% (58 out of 62 for the normal samples and 49 out of 62 for the defected samples) and on the prediction set was 84.6% (26 out of 26 for the normal samples and 18 out of 26 for the defected samples). The results showed that SW-NIR transmittance spectroscopy can be used to non-destructively detect internal mold infection in intact sweet tamarind.
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Determination of translucent content in mangosteen by means of near infrared transmittance
(2012-03-01)
Terdwongworakul, Anupun
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Nakawajana, Natrapee
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Teerachaichayut, Sontisuk
;
Janhiran, Athit
Translucent flesh disorder is undesirable in mangosteen meant for export. However, mangosteens are judged as translucent when the translucent flesh is visible on the pulp surface regardless of the quantity of the internal translucent flesh which may result in some mangosteen assessed as normal having the same amount of translucent flesh content as a mangosteen judged as translucent. The critical amount of translucent flesh to be visible on the pulp surface needs to be determined for assessment purposes. A non-destructive technique to measure the translucent content is a practical tool as the first step towards the establishment of the critical value. A non-destructive model was developed to estimate the translucent content in mangosteens using near infrared transmittance. The translucent area of the flesh section on the fruit surface was used to indicate the translucent content. The effects of the orientation of the fruit and also of the light source to the relative position of the detector as well as the effect of the measurement position of the fruit on the predictive performance were examined. The results showed that the best partial least squares model was achieved with spectra acquired from the fruit position which revealed the largest flesh segment (prediction correlation coefficient was 0.86 and root mean square error of prediction was 7.58%). The horizontal stem-calyx fruit axis and a 135° angle from the light source relative to the detector were the optimal fruit orientation and configuration for measurement. © 2011 Elsevier Ltd. All rights reserved.
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Two wavelengths Hematocrit Monitoring by Light Transmittance Method
(2009-12-01)
Phonphruksa, Phimon
;
Tungjitkusolmun, Supan
Methods for measuring the hematocrit level of whole blood includes measuring transmittance light at multiple wavelengths within the visible and infrared spectrum, calculating light transmittance at each of the multiple wavelengths, performing a comparison in a change in light transmittance between the multiple wavelengths, and comparison to total hematocrit value. A system for measuring total hematocrit of whole blood may include discrete LEDs for light source in the range of 430 nm to 950 nm, one photo detector, data processing circuitry, and/or a display unit. We constructed a simplified system and probe, design with LEDs and a photodiode was placed at the other side of the finger, we compare the results of the system with hematocrit levels measured by centrifuge that using blood sample drawn from 120 patients. From our analysis, the wavelengths between 700 nm to 950 nm are insensitivity to hematocrit levels, and between 470 nm to 610 nm are sensitivity to hematocrit levels. The potential optimal wavelengths for light transmittance hematocrit measuring system are in the range of 700 nm-900 nm and 470 nm-610 nm. Then, we used two potential optimal LEDs wavelengths at 585 nm and 875nm for linear algorithm to design of the noninvasive hematocrit measuring system, from the acquired information the system able to predict the hematocrit value to obtained 90% of the 120 data is given an error less than 25%.
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Linear equation method for Hematocrit monitoring by optical transmittance
(2007-01-01)
Phonphruksa, Phimon
;
Chaichanyut, M.
;
Potejanasaja, I.
;
Naktawan, A.
;
Tungjitkusolmun, S.
The objective of the present study is to investigate an optical transmittance system for prediction of hematocrit level by linear equation from the wavelength in the range of 426 nm to 950 nm. We constructed a simplified system with a light detecting finger clip probe to determine the transmittance spectra. We compared the results from our simplified measurement system with the hematocrit levels measured with the centrifuge using blood sample drawn from patients. From the analysis, we discovered that wavelengths between 525 nm to 610 nm, and between 700 to 950 nm are potential optimal choices for use to predict the hematocrit value. Then, four LEDs (525 nm, 585 nm, 875, and 950 nm) were used as the source which shone light through a finger, while the photodiode was placed at the opposite side of the finger for light transmission detection. We calibrated our system with the 117 sample hematocrit levels measured clinically by the centrifuge to obtain the linear equation model. We compared the results of our linear equation model for predicting the hematocrit levels with measured hematocrit levels from the centrifuge. From our analysis, the error obtained from the linear equation was less than 25% in more than 90% of the 117 collected data from patients.

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