• Korean Journal of Community Nutrition
• /
• v.5 no.4
• /
• pp.608-614
• /
• 2000

The purpose of this study was to evaluate the relative importance among various biological and environmental factors on refractive errors. Various factors such as diseases, health related behavior such as drinking, smoking and exercise, as well as dietary factors were considered as a possible determinant. Surveys of 492 residents over 20 years of age in Kuri city were conducted during 1998. The survey included a refractive error test adopting a autokerato-refractometer, dietary survey using a 24 hour recall method, disease survey including blood and other diagnosis tests, and a health behavior survey using questionnaires with variables of smoking, drinking, and exercise. A stepwise logistic regression analysis was adopted to analyse the relative importance among independent variables of health behaviors, disease, and dietary factors on ametropias. As a result, in the case of myopia, liver dysfunction appeared to be the most important factors followed by the health related behavior of smoking and exercise as the second most important factors. Nutrient factors such as carotene and protein appeared to be the third most important factors. Similar results had been shown in the case of the hyperopia. In summary, liver dysfunction and the health related behaviors of drinking and smoking appeared to be more influential factors on abnormal eye sight of myopia and hyperopia than dietary factors.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.8 no.4
• /
• pp.463-472
• /
• 1996

Experiments were carried out to study the operation characteristics of a regenerator with a thermo-syphon pump and a surface-flame burner for a lithium bromide (LiBr)-water absorption heat pump. A cylindrical-shape metal-fiber burner and commercial grade propane were used. The emission of carbon monoxide and nitric oxide was measured by a combustion gas analyzer. Ther regeneration rate of water vapor as a refrigerant was measured. It could be as a reference value showing the performance of the regenerator. The circulation rate of the LiBr-water solution was also measured from both the tanks for the weak-and the strong-solution. Using a refractometer, the LiBr concetration in the solution was calculated from the measured refractory index of the solution. Temperature of the solution and the condensed water was recorded at several points in the experimental apparatus with thermocouples, using a personal computer. This data collecting system for measuring temperature was calibrated with a set of standard thermometers. The generating rate of water vapor as refrigerant increased linearly with heat supplied. It was about 4.0g/s with the heat supplied at a rate of 16,500kcal/h. The circulation rate of LiBr solution also increases with the heat supplied. The difference in LiBr concentrations between the weak and the strong solution was in the range of 1 to 5% when the concentration of the strong solution was about 60%. It was dependent upon both the heat supplied and the circulation rate of the solution. The initial concentration and the level of the LiBr solution in the regenerator were measured and recorded before experiments. The effect of them on the generating rate of water vapor and the circulation rate of the solution was also studied. The generating rate of water vapor was not strongly dependent upon both the level of the LiBr solution and the initial LiBr concentration. However, the concentration difference of the solution increases with the initial level of the LiBr solution.

• Korean journal of food and cookery science
• /
• v.14 no.1
• /
• pp.91-96
• /
• 1998

Growth of acrospire length from germinated covered barley with 1.5∼2.0 times length of buds had the highest amylase activity for 9 days at 15$^{\circ}C$. When the extraction of malt was carried out at 50$^{\circ}C$ for 3.5 hr., total sugar, reducing sugar, sweetness determined by refractometer and amylase activity were the highest, and 2.33%, 1.61%, 3.4 brix(%), 28,332 units, respectively. The sikhe saccharificated at 60$^{\circ}C$ for 8 hr. showed total sugar content increased to 3.90∼9.27% in nonwaxy rice, 4.19∼11.91% in waxy rice, and reducing sugar-content increased 3.30∼7.61% in nonwaxy rice, 3.31∼9.11% in waxy rice. Also, brix was increased to 3.6∼10.8 brix (%) in nonwaxy rice, 3.6∼12.8 brix(%) in waxy .ice, as saccharification time increased. The amylase activity was decreased as saccharification time was increased. And pH was gradually decreased according to time increase, however, it changed little after 4 hr. Morphology of cooked rice kernel during saccharification for sikhe gradually enlarged the oval for hydrolyzed starch granule by increasing saccharification time.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
• /
• 2001.06a
• /
• pp.1614-1614
• /
• 2001

The sweetness (。Bix) of fruit is the main quality factor contributing to the fruit taste. The brix of the apple fruit can be measured non-destructively by near infrared (NIR) spectroscopy, allowing the sweetness grading of individual apple fruit. However, the fruit quality is influenced by various factors such as growing location, producing year, variety and harvest time etc., accordingly the robust NIR calibration is required. In this experimental results are presented the influence of two variations such as growing location and producing year of apple fruit in establishing of calibrations for sweetness, and developed a stable and highly accurate calibration. Apple fruit (Fuji) was collected every year from 1995 to 1997 in 3 different growing locations (Andong, Youngchun and Chungsong) of Kyungpook in Korea. NIR reflectance spectra of apple fruit were scanned in wavelength range of 1100∼2500nm using an InfraAlyzer 500C (Bran+Luebbe) with halogen lamp and PbS detector. The multiple linear regression and stepwise was carried out between the NIR raw spectra and the brix measured by refractometer to select the best regression equations. The calibration models by each growing district were well predicted to dependent sample set, but poorly predicted to independent sample set. Combined calibration model using data of three growing districts predicted reasonable well to a population set drawn from all growing districts(SEP = 0.69%, Bias=-0.075). The calibration models by each harvest year were not transferable across harvest year, however a combined calibration model using data of three harvest years was sufficiently robust to predict each sample sets(SEP = 0.53%, Bias = 0.004).

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
• /
• 2001.06a
• /
• pp.1627-1627
• /
• 2001

In this study, a newly constructed optical measurement system, whose main components were a parametric tunable laser and a near infrared photoelectric multiplier, was applied to detection of the information for the inside of Satsuma mandarin using time-of-flight near infrared spectroscopy (TOF-NIRS). The combined effects on the time resolved profile of sample diameter, sugar content, the wavelength of the laser beam, and the detection position of transmitted light were investigated in detail. The samples used were Satsuma mandarin (Citrus unshu $M^{ARC}$.) (location: Wakayama, Japan) having the diameters of 50-84 mm. The sugar content measured by a refractometer varied from 9.9 to 16.3 Brix%. Equator of sample was irradiated vertically with the pulsed laser, and transmitted output power was measured on the restricted position of the equator using the optical fiber cable. The sampling time and the number of averaging the output power were 100 ns and 100 times, respectively. The variation of the attenuance of peak maxima At, the time delay of peak maxima t and the variation of full width at half maximum w were strongly dependent on the detection position and the wavelength of the laser beam. At, t and w increased gradually as the sample diameter increased to be much absorbed and vigorously scattered. On the other hand, each optical parameter had a tendency to increase as the sugar content increased. Such behavior was remarkable when the transmitted light was detected at the side face of a sample. When we apply TOF-NIRS to detection of the information for the inside of fruit with high moisture content like Satsuma mandarin, it is very important to give attention to the difference in the scattered light within tissues and the semi-straightly propagated light. Furthermore, we tried to express the resulting phenomena by using a model samples composed of water, sucrose, and milk. The variation of the time resolved profile is strongly governed by the combination of the light absorption component, scattering medium, and refractive index.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
• /
• 2001.06a
• /
• pp.1626-1626
• /
• 2001

In this study, a newly constructed optical measurement system, whose main components were a parametric tunable laser and a near infrared photoelectric multiplier, was applied to detection of the information for the inside of Satsuma mandarin using time-of-flight near infrared spectroscopy (TOF-NIRS). The combined effects on the time resolved profile of sample diameter, sugar content, the wavelength of the laser beam, and the detection position of transmitted light were investigated in detail. The samples used were Satsuma mandarin (Citrus unshu $M_{ARC}$.) (location: Wakayama, Japan) having the diameters of 50-84 mm. The sugar content measured by a refractometer varied from 9.9 to 16.3 Brix%. Equator of sample was irradiated vertically with the pulsed laser, and transmitted output power was measured on the restricted position of the equator using the optical fiber cable. The sampling time and the number of averaging the output power were 100 ns and 100 times, respectively. The variation of the attenuance of peak maxima At, the time delay of peak maxima $\Delta$t and the variation of full width at half maximum Δw were strongly dependent on the detection position and the wavelength of the laser beam. At, $\Delta$t and $\Delta$w increased gradually as the sample diameter increased to be much absorbed and vigorously scattered. On the other hand, each optical parameter had a tendency to increase as the sugar content increased. Such behavior was remarkable when the transmitted light was detected at the side face of a sample. When we apply TOF-NIRS to detection of the information for the inside of fruit with high moisture content like Satsuma mandarin, it is very important to give attention to the difference in the scattered light within tissues and the semi-straightly propagated light. Furthermore, we tried to express the resulting phenomena by using a model samples composed of water, sucrose, and milk. The variation of the time resolved profile is strongly governed by the combination of the light absorption component, scattering medium, and refractive index.

• Journal of the Korean Ceramic Society
• /
• v.30 no.4
• /
• pp.289-298
• /
• 1993

Properties in terms of the variation of the glass compositions, which were density (p), molar volume(Vm), atom/ion packing density (Dp), refractive index (nD), transformation temperature (Tg), dilatometric softening point (Td), thermal expansion coefficient (α), Young's modulus (E), and knoop hardness (KHN) were investigated in CaO-SiO2 glasses and CaO-P2O5-SiO2 glasses containing less than 10mole% of P2O5. Those properties were measured by density measurement kit, Abbe refractometer, dilatometer, ultrasonic pulse echo equipment, and micro hardness tester. When CaO content was increased in CaO-SiO2 glasses, p, Dp, nD, Tg, Td, α, E and KHN were increased, while Vm was decreased. When P2O5 was added to the CaO-SiO2 glasses with constant CaO/SiO2 ratio as 1.07, p, Dp, nD, Tg, Td, α, E and KHN were decreased, while Vm was increased. When the amount of P2O5 in glasses was kept constant, the changes of the properties with variation of CaO content in the CaO-P2O5-SiO2 glasses were very similar to those of CaO-SiO2 glasses. These phenomena could be explained by the structural role of P2O5 in the CaO-P2O5-SiO2 glasses, which was polymerization of siicate structures and resulted in [PO4] monomer structure in glasses. Due to this structural characteristics, the bond strength and packing density were changed with compositions. Proportional relationships between 1) np and Dp, 2) Tg, Td, α and CaO content, 3) E and Vm-1, and 4) KHN and P2O5 content were evaluated in this investigation.

• Journal of Korean Ophthalmic Optics Society
• /
• v.18 no.2
• /
• pp.173-178
• /
• 2013

Purpose: This study is to predict refractive errors according to uncorrected visual acuity using uncorrected visual acuity of the first glasses wearers. Methods: For 886 children who visited an ophthalmic clinic, subjective refraction was carried out with maintain refraction (MR) and cycloplegic refraction (CR), and objective refraction was carried out using auto-refractometer. Uncorrected visual acuity and corrected visual acuity were tested using on a trial lens and a Han's visual acuity chart. Results: In correlation between with the uncorrected visual acuity and refractive the myopia was the highest (r=0.774) and followed by hyperopia (r=0.670), simple astigmatism (r=0.623), simple with-the-rule astigmatism (r=0.604)and simple against-the-rule astigmatism (r=0.508). Conclusions: There were differences in the predictions between uncorrected visual acuity and refractive error according to the types of refractive error and astigmatism.

• Journal of the Mineralogical Society of Korea
• /
• v.9 no.2
• /
• pp.102-112
• /
• 1996

The precious serpentine, referring to a rare and highly valuable gem variety of serpentine group minerals, is found to occur in serpentinite from Booyo Gren Jade Mine which is located in Oesan-myun, Booyo-gun of Chungchungnam-do. Geommological properties of the precious serpentine have been investigated by use of polarizing microscope, specific gravity balance, refractometer, hardness pencils, X-ray diffractometer, XRF, ICP-MS analyser, and infrared absorption spectroscope.The precious serpentine from Booyo is colored deep green with oily luster and semi-transparent. It is highly tough and Mohs's scale of hardness is measured to be 5-6. Specific gravity is determined to be 2.67, and a single refractive index ND=1.56 is observed by a spot method, using sodium light source. X-ray powder diffraction data is represented by the reflection lines at 7.40(100), 4.64(25), 3.68(68), 2.757(69), 2.530(49), 2.549(32), and 1.710(21${\AA}$), which compares very well with that of antigorite of serpentine group minerals. The major chemical compositions of the precious serpentine group minerals. The major chemical compositions of the precious serpentine are SiO2 42.49%, MgO 39.08%, Fe2O3 3.85%, and H2O 11.87%. Besides, trace elements such as Cr(2188), Ni(1110ppm), Co(58ppm), and Ta (108ppm) are relatively spectrum shows peaks at 3670, 1190, 1070, 980 and 610cm-1. Strong absorption at 3670cm-1 is due to OH stretching, and 1190, 1070 and 980cm-1 due to SiO stretching. The absorption 610cm-1 is formed by alteration of pre-existing ultramafic rock, namely peridotite, with an introduction of fluid with very little content of CO2, under 400$^{\circ}C$ environment. Magnetite inclusions, finely disseminated in the precious serpentine, may be a result of Fe precipitation, during serpentinization of olivine-bearing country rock.

• Applied Biological Chemistry
• /
• v.41 no.2
• /
• pp.153-159
• /
• 1998

A possibility of evaluation of the major internal quality factors-Brix, moisture contents, firmness and acid content in the Korean domestic 'Fuji'apple fruits by near-infrared reflectance spectroscopic (NIRS) methods were investigated. A multiple linear regression(MLR) analysis between the data obtained by physico- chemical analysis method using refractometer, freeze drier, texture analyzer and titrater and NIR spectral data was carried out to make a calibration. The standard error of prediction(SEP) of Brix, moisture, firmness and acid content were $0.50^{\circ}Brix,\;0.64%,\;0.14kg/cm^2$ and 0.07%. It is concluded that NIRS methods can be used to evaluate Brix and moisture contents of in a apple non-destructive and rapid way but the accuracy for determination of firmness and acid content was slightly low.