• Journal of Korean Clinical Health Science
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• v.2 no.3
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• pp.203-208
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• 2014

Purpose. To analysis the refractive error in 7-9 year-old Korea children. Methods. From July 2013 to June 2014, two hundred eighty two subjects were performed in refraction test using the Auto-Refractometry. Results. The refractive error by spherical equivalent among all subjects was myopia 47.58%, emmetropia 42.35%, astigmatism 32.33%, and hyperopia 8.76%. Myopia was more common in female than males although the difference was not statically significant. The axis of astigmatism was with the rule in 65%, against the rule in 31.5%, and oblique in 3.5% There was a statistical significance between 7 year and 9 year of male in the spherical equivalent power(p=0.010). Also there was a statistical significance between 7 years and 9 years of female in the spherical equivalent power(p=0.036). However, there was not a statistical significance between male and female in spherical equivalent power(p>0.5). Conclusions. In this study, myopia was the most common refractive error. On the other hand, The prevalence of the axis of astigmatism was the with- the- rule. The spherical equivalent of refractive error was similar results between male and female. However The refractive error was different style with aging. these data suggested that the analysis of the refractive error at young children can provide the information of useful diagnosis for the correction of visual acuity.

• Journal of Biosystems Engineering
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• v.29 no.4
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• pp.323-328
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• 2004

A surface plasmon resonance (SPR) sensing system, which belonged to a family of thin film refractometry-based sensors, was fabricated to measure the alcohol contents in alcoholic beverages. In this study, a SPR owe was obtained by a photodiode array with 128 pixels and transformed into a refractive index which was calculated by means of the first moment of values below a baseline of 0.85. When the sensing system was applied to Soju, Cheonju, Igwaduju and Tacju highly linear relationships between the refractive index by SPR and the contents of alcohol were obtained. That is, the coefficients of determination in their linear models were 0.992, 0.933, 0.918 and 0.954, respectively. Meanwhile, the effect of sample preparations on the accuracy of measurement was analyzed. As for Soju and Tacju, the best calibration equations were obtained when no sample preparation was applied. The best calibration models for measurement of Cheonju and Igwaduju were obtained through the samples filtered by $C_{18}$ disks.

• The Journal of Advanced Prosthodontics
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• v.9 no.3
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• pp.200-207
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• 2017

PURPOSE. In this study, three bioceramic materials, [IPS Empress CAD (Ivoclar), IPS e.max CAD (Ivoclar), and Lava Ultimate CAD (3M ESPE)] were treated with three commercial mouthrinses [Listerine, Tantum Verde, and Klorhex]; and changes in colour reflectance and surface roughness values were then quantitatively assessed. MATERIALS AND METHODS. One hundred and twenty ceramic samples, with dimensions of $2{\times}12{\times}14mm$, were prepared and divided into nine sample groups, except three control samples. The samples were immersed in the mouthrinse solutions for 120 hrs, and changes in colour reflectance and surface roughness values were measured by UV light spectrophotometry (Vita Easyshade; VITA Zahnfabrik) and by profilometer device (MitutoyoSurftest SJ-301), respectively. The change of surface roughness was inspected by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). RESULTS. There was a positive correlation between the ${\Delta}E$ and increase in the surface roughness. Two of the ceramic materials, IPS Empress and Lava Ultimate, were affected significantly by the treatment of the mouthrinse solutions (P<.05). The most affecting solution was Tantum Verde and the most affected material was Lava Ultimate. As expected, the most resistant material to ${\Delta}E$ and chemical corrosion was IPS e max CAD among the materials used. CONCLUSION. This work implied that mouthrinse with lower alcohol content had less deteriorating effect on colour and on the surface morphology of the bioceramic materials.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1523-1523
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• 2001

The wine industry requires practical methods for objectively measuring the composition of both red wine grapes on the vine to determine optimal harvest time; and of freshly harvested grapes for efficient allocation to vinery process streams for particular red wine products, and to determine payment of contract grapegrowers. To be practical for industry application these methods must be rapid, inexpensive and accurate. In most cases this restricts the analyses available to measurement of TSS (total soluble solids, predominantly sugars) by refractometry and pH by electropotentiometry. These two parameters, however, do not provide a comprehensive compositional characterization for the purpose of winemaking. The concentration of anthocyanin pigment in red wine grapes is an accepted indicator of potential wine quality and price. However, routine analysis for total anthocyanins is not considered as a practical option by the wider wine industry because of the high cost and slow turnaround time of this multi-step wet chemical laboratory analysis. Recent work by this ${group}^{l,2}$ has established the capability of near infrared (NIR) spectroscopy to provide rapid, accurate and simultaneous measurement of total anthocyanins, TSS and pH in red wine grapes. The analyses may be carried out equally well using either research grade scanning spectrometers or much simpler reduced spectral range portable diode-array based instrumentation. We have recently expanded on this work by collecting thousands of red wine grape samples in Australia. The sample set spans two vintages (1999 and 2000), five distinct geographical winegrowing regions and three main red wine grape varieties used in Australia (Cabernet Sauvignon, Shiraz and Merlot). Homogenized grape samples were scanned in diffuse reflectance mode on a FOSE NIR Systems6500 spectrometer and subject to laboratory analysis by the traditional methods for total anthocyanins, TSS and pH. We report here an analysis of the correlations between the NIR spectra and the laboratory data using standard chemometric algorithms within The Unscrambler software package. In particular, various subsets of the total data set are considered in turn to elucidate the effects of vintage, geographical area and grape variety on the measurement of grape composition by NIR spectroscopy. The relative ability of discrete calibrations to predict within and across these differences is considered. The results are then used to propose an optimal calibration strategy for red wine grape analysis.

• Food Engineering Progress
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• v.14 no.1
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• pp.49-53
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• 2010

Surface plasmon resonance (SPR) which is utilized in thin film refractometry-based sensors has been concerned on measurement of physical, chemical and biological quantities because of its high sensitivity and label-free feature. In this paper, an application of SPR to detection of alcohol content in wine and liquor was investigated. The result showed that SPR sensor had high potential to evaluate alcohol content. Nevertheless, food industry may need SPR sensor with higher sensitivity. Herein, we introduced a nano-technique into fabrication of SPR chip to enhance SPR sensitivity. Using Langmuir-Blodgett (LB) method, gold film with nano-structured surface was devised. In order to make a new SPR chip, firstly, a single layer of nano-scaled silica particles adhered to plain surface of gold film. Thereafter, gold was deposited on the template by an e-beam evaporator. Finally, the nano-structured surface with basin-like shape was obtained after removing the silica particles by sonication. In this study, two types of silica particles, or 130 nm and 300 nm, were used as template beads and sensitivity of the new SPR chip was tested with ethanol solution, respectively. Applying the new developed SPR sensor to a model food of alcoholic beverage, the sensitivity showed improvement of 95% over the conventional one.

• Journal of Korean Clinical Health Science
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• v.9 no.1
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• pp.1478-1485
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• 2021

Purpose. To analysis of astigmatism in Korean adults from 20 to 29 years old. Methods. From January 2019 to February 2020, one hundred two subjects were performed in refraction test using the Auto-Refractometry. Results. In the type of astigmatism based on refractive error, the male's right eye was 4.26% simple myopic astigmatism and 95.74% complex myopic astigmatism, and the left eye was 2.22% simple myopic astigmatism and 97.78% complex myopic astigmatism. However, in the female's right eye, simple myopic astigmatism was 2.27%, complex myopic astigmatism was 97.73%, and left eye was simple myopic astigmatism was 2.17%, complex myopic astigmatism was 97.83%. The types of astigmatism in men and women similar to other. The mean refractive astigmatism values were -0.922±-0.798 diopter and -0.877±-0.707 diopter for male right and left eye, and -0.765±-0.599 diopter and -0.853±-0.586 diopter for female. On the other hand, the refraction values of the right and left eyes of men and women have statistical significance(p=0.000). The mean power comparative between refractive astigmatism and corneal astigmatism power were -0.186±-0.745 diopter, -1.091±-0.589 diopter in male and -1.140±-0.593 diopter, -1.140±-0.534 diopter in female. Therefore, the mean power values of the refractive astigmatism and corneal astigmatism of men and women were statistical significance(p=0.000). At the 0.75 diopter or more, which can have clinical symptoms of astigmatism power, males have 60.86% and 72.09% of the right and left eyes, and females have 47,64% and 60.10% of the right and left eyes. At 0.75 diopter or more, which can have clinical symptoms of corneal astigmatism power, males have 68.75% and 74% of the right and left eyes, and females have 86.50% and 82.35% of the right and left eyes. In the type of astigmatism axis, both men and women had a high frequency of the rule astigmatism. However, men had a high frequency of against-the-rule astigmatism and women showed a high frequency of oblique astigmatism. Conclusions. In this study, the complex myopic astigmatism and with-the rule astigmatism was the most common of all subjects. However, there was a statistical significance between right and left eyes of all subjects. The corneal astigmatism was higher refractive values in both males and females than refractive astigmatism. This study suggests that the analysis of the astigmatism can provide the useful diagnosis information for the correction of visual acuity.