• Title/Summary/Keyword: refractometer

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건강 및 식이요인과 굴절이상 시력장애와의 관련성 (The Relationship between Ophthalmic Refractive Errors and Factors of Nutrition and Health)

  • 김영옥;최혜정;이순영
    • 대한지역사회영양학회지
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    • 제5권4호
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    • pp.608-614
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    • 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.

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기포 펌프를 적용한 흡수식 열펌프용 고온 재생기의 작동 특성 실험 (Experiments on a Regenerator with Thermosyphon for Absorption Heat Pumps)

  • 박찬우;정종수;남평우
    • 설비공학논문집
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    • 제8권4호
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    • pp.463-472
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    • 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.

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식혜제조과정 중 밥알의 형태 변화 (Morphological Changes of Cooked Rice Kernel During Saccharification for Sikhe)

  • 전은례;김경애;정난희
    • 한국식품조리과학회지
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    • 제14권1호
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    • pp.91-96
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    • 1998
  • 맥아제조(15$^{\circ}C$)시 amylase 활성이 가장 높은 1.5배~2.0배(1.20 cm-1.95 cm)의 잎눈 길이는 9일 째에 관찰되었고, 엿기름의 추출시간에 따른 총당과 환원당은 3시간 30분에 2.33%, 1.61%로 가장 높았고 4시간에는 다소 감소하였으며, 굴절당도계로 측정한 당도와 amy- lase 활성도 3시간 30분에 3.4 brix(%), 28,332 units로 같은 양상을 보였다. 당화과정 중 당화초기에서 8시간까지 변화를 보면 총당은 멥쌀의 경우 3.90%에서 9.27%로, 찹쌀의 경우 4.19%에서 11.91%로 증가하였고 환원당도 멥쌀의 경우 3.30%에서 7.61%로, 찹쌀의 경우 3.31%에서 9.11%로 각각 증가하였다 Brix도 멥쌀의 경우 3.6 brix(%)에서 10.8 brix(%)로, 찹쌀의 경우 3.6 brix(%)에서 12.8 brix(%)로 당화시간이 증가할수록 증가하였다. amylase 활성은 당화시간이 증가할수록 감소하는 경향을 보였고 pH는 서서히 감소하다가 4시간 이후에는 거의 변화가 없었다. 식혜밥알의 형태는 당화시간이 증가할수록 가수분해되어 전분립이 빠져 나와 구멍이 점점 크게 나타남을 볼 수 있었다.

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Development of robust Calibration for Determination Apple Sweetness using Near Infrared Spectroscopy

  • Sohn, Mi-Ryeong;Kwon, Young-Kil;Cho, Rae-Kwang
    • 한국근적외분광분석학회:학술대회논문집
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    • 한국근적외분광분석학회 2001년도 NIR-2001
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    • pp.1614-1614
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    • 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).

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Application of time-of-flight near infrared spectroscopy to Satsuma mandarin

  • Tsuchikawa, Satoru;Ito, Satomi;Inoue, Kinuyo;Miyamoto, Kumi
    • 한국근적외분광분석학회:학술대회논문집
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    • 한국근적외분광분석학회 2001년도 NIR-2001
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    • pp.1627-1627
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    • 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.

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Application of time-of-flight near infrared spectroscopy to Satsuma mandarin

  • Tsuchikawa, Satoru;Ito, Satomi;Inoue, Kinuyo;Miyamoto, Kumi
    • 한국근적외분광분석학회:학술대회논문집
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    • 한국근적외분광분석학회 2001년도 NIR-2001
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    • pp.1626-1626
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    • 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.

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$CaO-P_2O_5-SiO_2$계 유리의 물성 (Properties of $CaO-P_2O_5-SiO_2$ Glasses)

  • 조정식;김철영
    • 한국세라믹학회지
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    • 제30권4호
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    • pp.289-298
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    • 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.

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소아, 청소년의 나안시력과 굴절이상의 상관성 분석 (Relationship between Uncorrected Visual Acuity and Refraction of the Children and Teenagers)

  • 김상문;심현석;심준범
    • 한국안광학회지
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    • 제18권2호
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    • pp.173-178
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    • 2013
  • 목적: 본 연구에서는 최초 안경착용자의 나안시력을 이용하여 그에 따른 굴절이상량을 예측하고자 하였다. 방법: 안과병원을 내원한 886명을 대상으로 자각굴절검사는 현성굴절검사(M.R)와 조절마비굴절검사(C.R)를 같이 실시하였으며, 타각적굴절검사는 자동굴절계를 이용하였다. 나안시력 검사와 교정시력은 시험렌즈와 한천석시력표를 이용하여 실시하였다. 결과: 나안시력과 굴절이상의 상관성은 근시안이 r=0.774로 가장 높게 나타났으며 원시안 r=0.670, 단성직난시 r=0.623, 단성난시 r=0.604, 단성도난시 r=0.508 순서로 나타났다. 결론: 굴절이상과 난시 종류에 따라 나안시력과 굴절이상의 예측에 차이가 있었다.

부여산 귀사문석의 보석학적 특성 연구 (Gemmological Characterization of Precious Serpentine from Booyo, Korea)

  • 김원사;우영균;이재열;김경수
    • 한국광물학회지
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    • 제9권2호
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    • pp.102-112
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    • 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.

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근적외 분광분석법을 응용한 사과의 비파괴 품질 측정 가능성 조사 (Possibility of the Nondestructive Quality Evaluation of Apples using Near-infrared Spectroscopy)

  • 손미령;권영길;이경희;박우철;조래광
    • Applied Biological Chemistry
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    • 제41권2호
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    • pp.153-159
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    • 1998
  • 국내산 후지 사과의 주요 내부 품질 요인인 당도, 수분 함량, 경도 및 산 함량을 근적외 분광분석법에 의해 동시에 신속, 정확하게 비파괴 측정할 수 있는지의 가능성을 조사하였다. 굴절당도계에 의한 당도, 동결 건조법에 의한 수분 함량, texture analyzer에 의한 경도 및 알칼리 적정법에 의해 얻어진 산 함량 데이터와 근적외 영역의 흡광도 데이터 사이에 각각 중회귀분석을 행한 결과, 당도, 수분 함량, 경도 및 산 함량의 측정 오차(SEP)는 각각 $0.50^{\circ}Brix,\;0.64%,\;0.14kg/cm^2$ 및 0.07%이었다. 이로서 근적외 분광 분석법을 응용하여 사과의 당도와 수분 함량은 비파괴적으로 신속, 정확하게 측정 가능함을 알 수 있었으나, 경도와 산 함량의 측정 정확도는 다소 낮은 편이었다.

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