• Title/Summary/Keyword: Refractometer

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Prediction of Sensory Properties for the Stirred-type Fruit Yogurts by Instrumental Measurements (기계적 측정에 의한 호상요구르트의 관능특성 예측)

  • Oh, Se-Jong;Sim, Jae-Hun;Hur, Jae-Kwan;Shin, Jung-Gul;Kim, Sang-Kyo;Baek, Young-Jin
    • Korean Journal of Food Science and Technology
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    • v.25 no.6
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    • pp.620-625
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    • 1993
  • This experiment was carried out to predict the sensory properties of yogurt by instrumental methodology. Sensory attributes such as viscosity, mouth-feel, taste and quality were investigated. Instrumental parameters were measured with refractometer, viscometer, consistometer and rheometer. Sensory data showed that viscosity of peach yogurt was higher than that of strawberry and tropical-fruit-mixed (TFM) yogurts (p<.05). All instrumental parameters of peach yogurt were higher than those of strawberry and TFM yogurts, except cohesiveness and elasticity (p<.05). Viscosity measured by panelists was significantly correlated with instrumental viscosity, consistency, hardness, adhesiveness and gumminess in the fruit yogurts (p<.05). But mouth-feel and quality of yogurts showed poor relationships with instrumental parameters. The effective instrumental parameters for predicting sensory viscosity ($Y_{1}$) of yogurts were consistency ($X_{1}$), viscosity ($X_{2}$) and cohesiveness ($X_{3}$). And those for predicting mouth-feel ($Y_{2}$) were consistency. The estimated regression equations were as follows; $Y_{1}=4.968-0.0486X_{1}+0.00012X_{2}+0.0348X_{3},\;Y_{2}=5.701+0.0154X_{1}$.

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Synthesis and Characterization of Novel Polythiourethanes (새로운 폴리(티오우레탄)의 합성 및 특성)

  • 김경만;허영태;박인환;이범재
    • Polymer(Korea)
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    • v.27 no.5
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    • pp.470-476
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    • 2003
  • In order to obtain high refractive plastic materials, 1,2 -ethylenedisulfanylbis(2-mercaptomethyl-1-ethanthiol) (ESTT) was newly prepared in good yield by the reaction of 1,2-ethylenedisulfanylbis(2-bromomethyl-1-ethanthiol) (ESTB) with thiourea followed by hydrolysis using an aqueous ammonia solution and characterized by $^1$H-NMR (-SH at 1.7 ppm), $\^$13/C-NMR(-CH$_2$SH at 28.4 ppm) and FT-IR (-SH at 2540 cm$\^$-1/) spectroscopy, etc. Polythiourethanes (PTU) were obtained from the combinations of ESTT with each of 4,4'-methylenebis(phenylisocyanate) (MDI), tolyene 2,4-diisocyanate (TDI), isophorone diisocyanate (IPDI), mxylene diisocyanate (XDI), and 1,6-diisocyanatohexane (HMDI) in the presence of dibutyltin dilaurylate as a catalyst, in a casting mold, and characterized by FT-IR (existence of N=C=O) spectroscopy and elemental analyzer (sulfur content). Accordingly, their thermal, mechanical and optical properties were investigated by using DSC, TGA, hardness tester and refractometer: both the melting point on DSC and crystallinity on X -ray diffraction (XRD) for specimens of PTUs were not observed. PTUs with T$\_$g/s above 110 $^{\circ}C$ showed good hardness (Shore D) in the range of 86 to 89. Thermal stabilities of PTUs obtained by using ESTT and each of diisocyanates containing aromatic rings were especially good. Also, the optical transmittances of amorphous PTUs through UV-visible source in the range of 400 to 600 nm were good. PTUs showed refractive indexes above 1.60, and their refractive indexes gradually increased with increase of sulfur contents.

The Evaluation of Reliability for Exam Distance of Visual Acuity (시력검사거리에 따른 원거리 시력검사 신뢰성 평가)

  • Chun, Young-Yun;Choi, Hyun-Soo;Park, Seong-Jong;Lee, Seok-Ju
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.1
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    • pp.17-22
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    • 2014
  • Purpose: We aimed to evaluate reliability of eye exam for visual acuity as a function of distance. Methods: There were 39 patients (78 eyes) who had visual acuity 1.0 or more at 5 meters. We measured refractive power of patients at each distances, 5 meters, 4 meters and 3 meters. Automatic chart (LCD-700, Hyeseong Optic. Co., Korea) used for visual acuity, skiascope (Beta 200, Heine, Germany) and auto refractometer (RK-5, Canon, Japan) used as for objective refraction. Accommodation was examined by minus lens addition methods, and Accommodative lag was examined by grid chart for reading distance. Results: Being compared to 3 meter test, Amount of corrected spherical refractive power decreased by $0.10{\pm}0.38$ D, astigmatism decreased by $0.05{\pm}0.10$ D, and axis of astigmatism rotated toward to temporal by $2.64{\pm}18.75$ degrees for right eyes, by $11.43{\pm}48.55$ degrees for left eyes in case of 5 meter test. Changes of corrected refraction and astigmatism were slightly correlated (r=-0.31, r=-0.29). Conclusions: Because corrected refraction power and amount of astigmatism decreased and axis of astigmatism tends to turn the temporal direction according to exam distance, examination distance of visual acuity should improved as to 5 meters.

The Change of Corneal Refractive Power by Everted Silicone Hydrogel Contact Lens Wear (역방향 실리콘 하이드로겔 렌즈 착용에 따른 각막 굴절력 변화)

  • Kim, Soo-Hyun;Shin, Dong-Min;Jeong, Ju-Hyun
    • Journal of Korean Ophthalmic Optics Society
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    • v.18 no.3
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    • pp.271-277
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    • 2013
  • Purpose: The purpose was to study the corneal refractive power changes associated with the wearing of everted silicone hydrogel soft lenses. Methods: The corneal refractive power and corneal astigmatism were measured using corneal topographer (CT-1000, Shin-nippon Co., Japan) for checking change of corneal refractive power and objective refractive error was measured by auto-refractometer (Natural vision-K 5001, Shin-nippon Co., Japan). We measured at baseline and 1 week after lens wearing. Results: The correcting of corneal refractive power could be effective in low myopia. It's more effective to the higher power of greatest meridian of cornea and the more corneal astigmatism. 73% of subjects' refractive error was decrease less than 1 D and 17% of the subjects had an reverse effect (increase) occurs. The reduction of objective refractive error was more effective when cornea refractive power was great or corneal astigmatism was much. Conclusions: Pressure which the everted silicone hydrogel lens to the cornea could be caused. It occurred as the degrees of corneal power, corneal astigmatism and objective refractive error differences. Selection of an appropriate subject is important considering difficulty of changing the parameters of the lens.

Cellulose Acetate Membrane Electrophoresis of Bull Serum Protein (Cellulose Acetate막(膜) 전기영동법(電氣泳動法)에 의한 종모우(種牡牛)의 혈청단백분획(血淸蛋白分劃)에 관한 조사(調査))

  • Lee, Chang-Woo
    • Korean Journal of Veterinary Research
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    • v.22 no.2
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    • pp.115-119
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    • 1982
  • Total protein levels of 60 bovine bull sera were treasured with refractometer and the strum proteins were fractionated by cellulose acetate membrane electorphoresis and the relative amount of each fraction was measured with automatic scanning densitometer. The sixty bovine bulls consisted of 17 Charolais bulls, 28 Holstein bulls and 15 Korean bulls. Mean total serum protein level of the total bulls was $7.50{\pm}0.50(Mean{\pm}SD)$, with the mean of Charolais $7.04{\pm}0.37g/dl$, the mean of Holstein $7.62{\pm}0.40g/dl$ and the mean of Korean $7.81{\pm}0.43g/dl$. As barbital-calcium buffer was used in fractionating the bovine serum protein with cellulose acetate membrane, electric current of 0.4 mA per centimeter width of the membrane for an hour resulted in more clear separation between ${\alpha}_1$-globulin and ${\alpha}_2$-globulin than electric current of 0.6 or 1.0 mA for an hour. However ${\alpha}_1$-globulin and ${\alpha}_2$-globulin could not be measured separately with automatic scanning densitometer. Mean serum albumin level of total bulls was $3.54{\pm}0.42g/dl$, with the mean of Charolais $3.42{\pm}0.26g/dl$, the mean of Holstein $3.69{\pm}0.38g/dl$ and the mean of Korean $3.39{\pm}0.55g/dl$. Mean serum ${\alpha}$-globulin level of the total bulls was $0.62{\pm}0.14g/dl$, with the mean of Charolais $0.61{\pm}0.07g/dl$, the mean of Holstein $0.60{\pm}0.11g/dl$ and the mean of Korean $0.67{\pm}0.23g/dl$. Mean ${\beta}$-globulin level of the total bulls was $0.85{\pm}0.21g/dl$, with the mean of Charolais $0.74{\pm}0.11g/dl$, the mean of Holstein $0.83{\pm}0.14g/dl$ and the mean of Korean $1.02{\pm}0.30g/dl$. Mean serum ${\gamma}$-globulin level of the total bulls was $2.48{\pm}0.45g/dl$ with the mean of Charolais $2.27{\pm}0.37g/dl$, the mean of Holstein $2.48{\pm}0.44g/dl$ and the mean of Korean $2.72{\pm}0.47g/dl$.

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Research about the Distribution of Refractive Errors in Distinction of Gender and at Age of Kyonggi Province's Part Area (경기도 일부지역의 성별, 연령별 굴절이상 분포에 관한 연구)

  • Lee, Eun-Hee;Lee, Hee-Jung;Cho, Sung-Il;Paek, Do-Myung
    • Journal of Korean Ophthalmic Optics Society
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    • v.11 no.2
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    • pp.121-129
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    • 2006
  • Prevalence of refractive error have revealed variation in relation to ethnicity, educational level, age, gender, and social economic status. Especially prevalence of refractive error varies by country, estimation of prevalence of refractive error have shown increase in Asia than in Western world. The present report aimed to investigate the prevalence of refractive errors by the age and gender in Korean population without eye disease. A total of 960 subjects were sampled and their refractive error was determined using Auto refractometer. Prevalence of emmetropia was 29% and that for myopia and hyperopia was 67%, 4%, respectively. Astigmatism was 22%, and the simple astigmatism was 1%. However the compound astigmatism was 99%. Prevalence of refractive errors differed significantly among age and gender group in our results. The percentages of with-the-rule, against-the-rule and oblique astigmatism among people with astigmatism were 36.6%, 20.7% and 42.7% for right eye and 31.8%, 10% and 58.1% for left eye.

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The Study of Kinetic Visual Acuity in College Students (대학생의 동적시력에 관한 연구)

  • Shim, Moon-Sik;Kim, Sang-Hyun;Kang, Hye-Sook;Shim, Hyun-Suk
    • Journal of Korean Ophthalmic Optics Society
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    • v.17 no.4
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    • pp.419-424
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    • 2012
  • Purpose: We were to obtain the basic data for studying kinetic visual acuity through the comparative analysis in kinetic visual acuity, visual acuity, refractive error, pupil size, and hand reaction time for college students. Methods: We had tested the kinetic visual acuity, visual acuity, refractive error and hand reaction time using the kinetic visual acuity tester (KOWA AS-4A), the hand reaction time program and auto-refractometer for thirty-nine male and same female optometry students with more than +0.1 LogMAR visual acuity in both eyes. And the results were examined gender differences of kinetic visual acuity and the factors correlation. Results: In the measured values of male, pupil size were 6.00 mm, hand reaction time 0.23 msec, refractive error -1.66 D, visual acuity -0.07, kinetic visual acuity 0.59 and pupil size 5.86 mm, hand reaction time 0.24 msec, refractive error -2.08 D, visual acuity -0.02, kinetic visual acuity 0.46 in female. It was significant difference for kinetic visual acuity values but other factors were not. The kinetic visual acuity and left visual acuity had the highest correlation, r=-0.406. The kinetic visual acuity indicated more excellent values in the case of increasing visual acuity and decreasing myopia amount. Conclusions: It was able to see that male college students were better than female for kinetic visual acuity and the visual acuity were related to kinetic visual acuity.

A Study on Improvement of Wettability and Comfort in Contact lens with Hyaluronic acid (Hyaluronic acid 함유 콘택트렌즈의 습윤성과 착용감 향상 효과 연구)

  • Kim, Hyun Jung;Kim, Soo-Hyun;Kim, Jai-Min
    • Journal of Korean Ophthalmic Optics Society
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    • v.16 no.3
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    • pp.255-264
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    • 2011
  • Purpose: To study the effect of hyaluronic acid(HA), which was widely used in artificial tears, multi-purpose solution(MPS), cosmetics, and drug acting on the musculo-skeletal system, in wettability and comfort of contact lens, we compared HA including lens(+HA) with HA excluding lens(-HA) by clinical evaluation. Methods: During four weeks, the selected 28 university student volunteers who did not have any eye disease wore +HA contact lens on their right eyes, and -HA contact lens on their left eyes, and then compared right eyes to left eyes as control. After prescribing by spherical equivalent calculation, over-refraction by auto-refractometer, and contact lens wearing for two weeks and four weeks, tear evaluation, the anterior of eyes examination, fitting convenience evaluation, surface wetting test, surveys were checked up. Results: Compared with the control group (-HA contact lens), +HA contact lens provided better wetting properties. The amount of released tear in -HA contact lens group became less in four weeks than before, but that in +HA contact lens group showed no significant difference from the initial one. In terms of the redness in eye, there was no significant difference between +HA and -HA contact lens groups. Fitting of +HA contact lens on eye was much easier than the control, -HA contact lens. From the results of survey, comfort, wettability, ease of cleaning, and dryness of eye in +HA contact lens group were generally better than those of -HA group, but redness and contact lens handling showed little difference. Conclusions: The addition of HA in soft contact lens(+HA) may enhance the wettability of lens during lens wearing, resulted in the better comfortable wearing of lens eventually.

A Clinical Study on Relation among Accommodative Amplitude, Response, and Facility in young adults (근시성 굴절부등에 대한 임상적 고찰)

  • Joo, Seok-Hee;Shim, Moon-Sik;Shim, Hyun-Seog
    • Journal of Korean Ophthalmic Optics Society
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    • v.14 no.1
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    • pp.121-125
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    • 2009
  • Purpose: This study has been conducted to know the prevalence of anisometropia and corneal refraction, accommodative response of myopic anisometropia. Methods: The study subject were 67 persons who myopic anisometropia of at least 1.00D, from among 808 total subject without ophthalmic diseases history from age 5 to 89 and the test were used to examine with both eyes open-view autorefractometer (NvisionK-5001). Results: The case which anisometropia were 85(10.5%) persons and myopic anisometropia were 67(78.8%) persons among the anisometropia. Difference between higher myopic eye and lower myopic eye were -1.22D${\pm}$0.94 in spherical equivalent, -0.25D${\pm}$0.72 in accommodative response, 0.04D${\pm}$0.68 in corneal refraction. In addition, the same case of both eyes accommodative response were 33(49.3%) persons, the great case of lower myopic eye accommodative response were 25(37.3%) persons and the great case of higher myopic eye accommodative response were 9(13.4%) persons. Conclusions: Myopic anisometropia was not affected by corneal refraction and both eyes difference of spherical equivalent was less as compared with both eyes difference of accommodative response.

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Evaluation of Albumin Creatinine Ratio as an Early Urinary Biomarker for Chronic Kidney Disease in Dogs

  • Hyun-Min Kang;Heyong-Seok Kim;Min-Hee Kang;Jong-Won Kim;Dong-Jae Kang;Woong-Bin Ro;Doo-Won Song;Ga-Won Lee;Hee-Myung Park;Hwi-Yool Kim
    • Journal of Veterinary Clinics
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    • v.40 no.6
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    • pp.399-407
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    • 2023
  • Chronic kidney disease (CKD) occurs in more than 15% of the dogs over 10 years of age and causes irreversible renal function deterioration. Therefore, it is important to diagnose CKD early and treat the disease properly. The purpose of this study aimed to to evaluate the clinical utility of urine albumin/creatinine ratio (ACR) using POC (point-of-care) device as an early detection urinary biomarker in CKD dogs and to confirm the correlation between ACR and other known CKD biomarkers. Urine and serum samples were obtained from 50 healthy dogs and 50 dogs with CKD. Serum blood urea nitrogen (BUN), creatinine, and symmetric dimethylarginine (SDMA) concentrations, and urine protein creatinine ratio (UPC) were measured. Urine specific gravity (USG) was evaluated using refractometer, and ACR was measured using an i-SENS A1Care analyzer. The ACR values of dogs with CKD were significantly different from those of healthy dogs (p < 0.001), as with other renal biomarkers. ACR showed significant differences between healthy dogs and dogs with CKD at every IRIS stage (p < 0.005), whereas no significant differences were observed between dogs with CKD IRIS stage I and healthy dogs with UPC. There are significant positive correlation between ACR and BUN (r = 0.611, p < 0.001), creatinine (r = 0.788, p < 0.001), SDMA (r = 0.747, p < 0.001), and UPC (r = 0.784, p < 0.001), and significant negative correlation between ACR and USG (r = -0.700, p < 0.001). In receiver operator characteristic curve analysis, the area under the curve (AUC) was 0.982 (95% CI 0.963-1.000, p < 0.001), with an optimal cut-off value of 64.20 mg/g (94% sensitivity and 94% specificity). Thus, ACR is a useful urinary biomarker for the early diagnosis of proteinuria in CKD and combined use of ACR and other renal biomarkers may be helpful for early diagnosis and prevention of CKD in dogs.