• Journal of Food Hygiene and Safety
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• v.5 no.4
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• pp.213-217
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• 1990

A simple and practical method for the determination of caffeine in coffee, black tea and green tea was studied. The analysis of caffeine was performed by reverse phase high perfomance liquid chromatography using a ${\mu}-Bondapak$ C18 column at isocratic condition with methanol-acetic acid-water (20: 1: 79) on UV detector at 280 nm. The extraction and clean-up of caffeine in sample is based on combing a simple pretreatment with the use of a Sep-Pak Alumina A cartridge. The average recoveries of caffeine from several samples were 95.2 -101.3%, the relative standard deviation for the whole procedure was 0.10 ~ 0.62%, and the detection limit of caffeine in sample solution was about $0.1\;\mu\textrm{g}\;per\;ml$.

• Analytical Science and Technology
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• v.30 no.2
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• pp.82-88
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• 2017

Adenophorae Radix (AR) is a frequently used medicinal herb; because of its popularity, products containing similar herbal products are often sold as substitutes, especially if their morphology is similar. However, any analytical method to identify AR based on quantitative analysis is not registered in Korea, Japan and China Pharmacopoeias. This study developed a simple HPLC method to discriminate between authentic AR and substitutes. Linoleic acid was used as a marker compound of AR. Our optimized HPLC-UV conditions included a mobile phase of 90 % acetonitrile under isocratic condition, and a flow rate of 1.0 mL/min at room temperature. Detection wavelength was set at 205 nm. Linoleic acid was detected at 13.5 minutes for a total analysis time of 20 minutes. The standard herb of AR contained 0.025 % of linoleic acid, while four authentic AR samples and eight substitutes contained 0.040~0.071 % and 0.004~0.014 %, respectively. Comparison of the linoleic acid concentrations of the sample types to reference AR showed that among 12 samples, only the four samples were authentic. Thus, our HPLC-UV method, along with our suggested content criterion for linoleic acid concentration, can be used for the quick and accurate determination whether the herbal products are authentic AR or substitute.

• Journal of Nutrition and Health
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• v.31 no.3
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• pp.354-362
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• 1998

The purposes of this study were to develop standardized indices of staffing needs in each school, foodservice system through work sampling methodology . Conventional school foodservices were classified into 5 groups depending on size of meals served. Commissary school foodservices were also classified into 5 groups by cluster analysis using number of meals served, number of satellite schools, and time for transportation of food. Work measurement through work sampling methodology was conducted in 15 conventional and 21 commissary foodservices during 3 consecutive days from September to October in 1995. Statistical data analysis was completed using the SAS programs for descriptive analysis, cluster analysis, and simple linear regression. The results were as follows : Average points of leveling factors of conventional and commissary foodservices were 1.066 and 1.061 , respectively. Mean labor hours per work force was 328 minutes and 366 minutes in conventional and commissary foodservice , respectively. Standardized work time was calculated using leveling factor, ILO allowance rate (175) , and observational work time. The model for standardized indices of staffing needs was developed based on simple linear regression in each school foodservice system. In conventional school foodservice systems(for 100-1,900 meals per day) standardized staffing needs=3.2497 +0.005267$\times$number of meals served (F=273.1, R-square 0.9750, p<0.001). In commissary school foodservice systems (for 200-1,600 meals per day ) Standardized staffing needs=3.393384 +0.0063$\times$number of meals served (F=30.78, R-square 0.6580, p<0.001).

• Bulletin of the Korean Chemical Society
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• v.25 no.12
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• pp.1877-1880
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• 2004

The simple and convenient determination of trace Hg(II) with its 2-mercaptobenzothiazole (MBT) complex in cetyltrimethylammonium bromide (CTAB) media has been studied. The UV-visible spectrum of Hg(II)-MBT complex in CTAB media had a good sensitivity and reproducibility. The Hg(II)-MBT complex in CTAB solution was very stable at pH 10.0 and could be quantitatively complexed if MBT were added to the sample solution more than 10 equivalent of Hg(II). The optimum concentration of CTAB was 0.001%. The calibration curve of Hg(II)-MBT complex with good linearity ($R^2$ = 0.9985) was obtained at the concentration range between $1.0{\times}10^-7$ and $1.0{\times}10^-5$ M in 0.001% CTAB media. The detection limit was $3.1{\times}10^-8$ M (6.2 ng m$L^{-1}$). Hg(II) in the synthetic samples and in the wastewater of the university's wastewater tank and the industrial wastewater tank could also be determined. Based on the experimental results, this proposed technique could be applied to the simple and convenient determination of trace Hg(II) in real samples.

• Korean Journal of Food Science and Technology
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• v.16 no.2
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• pp.251-253
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• 1984

A simple and modified method is developed to determine a lipase activity. A linear relationship exists between the color intensity and the free fatty acid liberated by enzyme action. The range of determination is from 0.05 to $1.5\;{\mu}moles$ of long chain fatty acid (oleic acid) and 0.2 to $2.0\;{\mu}moles$ of short chain fatty acid (caproic acid). The cumbersome procedure of the removal of the upper aqueous phase which was required in the previous copper soap extraction method was eliminated by the movement of solvent phase to upper phase in the respective biphasic system with a mixture solvent (chloroform: n-hexane:ethanol = 49:49:2) and copper reagent saturated with sodium chloride.

• Journal of Sensor Science and Technology
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• v.32 no.1
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• pp.16-21
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• 2023

This study reports the potential of using commercial copy papers as substrates for simple sensitive glucose detection. Typical paper-based devices use filter papers as porous substrates that can contain reagents; however, this is the first study to report the use of copy papers for the purpose of enhancing enzymatic colorimetric detection. Glucose detection using glucose oxidase, horseradish peroxidase and potassium iodide was performed on a copy paper, cellulose-based filter paper, and polyethylene film. The results indicated that the copy paper exhibited a stronger coloration than the other substrates. Reagents required for detection were dried on the copy paper, and a 3D-printed holder was designed to provide an environment for consistent imaging, making it a convenient cost-effective option for point-of-care testing using a mobile phone camera. The simple paper-based glucose sensor exhibited a linear range of 0.1-20 mM, limit of quantification of 0.477 mM, and limit of detection of 0.143 mM.

• The Journal of the Acoustical Society of Korea
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• v.19 no.5
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• pp.60-64
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• 2000

This paper studies the relation between the Fundamental Frequency (F0) and the formants of simple vowels in the Korean language sung by sopranos. It is hewn that, in soprano singing, the F0 of a vowel affects its formants. For this reason the formants of simple vowels sung by sopranos must be considered in all over the soprano singing range. We recorded the five simple vowel sounds /a/, /e/, /i/, /o/, and /u/ sung by five professional sopranos from A3 (220.0Hz) to A5 (880.0Hz) in the major scale and compared the formants of the sung vowels with those of spoken vowels. We observed that F1 and F2 of sung vowels were stable in low F0 (lower than B4) but in high F0 (higher than B4), F1 and F2 lost their stabilities. In the case of /a/, /o/, and /u/, the slope of the F1-F2 graph was about 2.6, and those of the F0-F2 and F0-Fl graphs were 2.2-2.5 and 0.7-1.0, respectively. And as the F0 increases, the F1 and F2 of sung vowels /a/, /e/, /i/, /o/, and /u/ were almost the same. At A5, the Fl and F2 of five sung vowels had the same values. This results suggest that the relation between the F0 and the formants be used to synthesize soprano's singing vowels.

• Journal of radiological science and technology
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• v.27 no.4
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• pp.43-48
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• 2004

The purpose of this study is to measure cardiothoracic ratio and to report the opinions on it, targeting 500 persons who were conducted simple chest radiography, in terms of clinical symptom, by visiting a medical examination center for S university hospital. As to the general characteristic of 500 research targets, it comprised 263 persons (52%) for males and 237 persons (48%), and the average age is 49.4. Out of 500 persons, it showed 125 persons (25%) in their thirties, 125 persons (25%) in their forties, 125 persons (25%) in their fifties, and 125 persons (25%) in their sixties. 1. In terms of the wholly 500 targets, the average value of cardiothoracic ratio was 0.48, and the average cardiothoracic ratio showed 0.45 in their thirties, 0.46 in their forties, 0.50 in their fifties, and 0.53 in their sixties. 2. The minimum value of cardiothoracic ratio was 0.33, and its maximum value was 0.70, and it showed 319 persons (63.8%) as to a case lower than 0.5, which is a normal value, and 181 persons (36.2%) as to a case more than 0.5, which is a normal value. 3. Among 181 persons who showed cardiothoracic ratio higher than normality, it showed 17 persons (9.4%) in their thirties, 22 persons (12%) in their forties, 54 persons (30%) in their fifties, and 88 persons (49%) in their sixties. 4. The average for the internal diameter (ID) of thorax was 141.8 mm, 229.6 mm at the minimum, and 353.5 mm at the maximum. 5. The average for the maximum transverse diameter of right side of the heart (MRD) was 48.0 mm, 4.95 mm at the minimum, and 84.5 mm at the maximum. The average for the maximum transverse diameter of left side of the heart (MLD) was 93.5 mm, 56.7 mm at the minimum, and 138.5 mm at the maximum. 6. The average for TD (MRD+MLD) of the heart was 292.6 mm, 96.6 mm at the minimum, and 199.2 mm at the maximum. 7. The average of cardiothoracic ratio (MRD+MLD/ID) was 0.48, 0.33 at the minimum, and 0.70 at the maximum.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.1
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• pp.220-225
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• 2004

We undertook this study to investigate the effects of acupuncture and electroacupuncture on colonic transit time in old age constipation persons. Twenty three volunteers were old age constipation persons(mean age 69.72±2.43 years, mean defecation rate 1.83±0.41/week). Before acupuncture was only to check the radio-opaque markers transit time all the way through gastrointestinal tract. Simple acupuncture was to apply acupuncture therapy for three days. The fourth acupoints(both ST.25, TE.6) were selected and the needle was kept for 15 minutes. Electroacupuncture was same as the simple acupuncture except for applying 2Hz electrical stimulation. After Then we compare with three method Each transit time in the whole colon, right colon, left colon and rectosigmoid colon were checked in the order of before acupuncture, simple acupuncture, and electroacupuncture stimulation. In the before acupuncture stimulation, the transit time in each part of colon was as follows 19.48±1.76 32.74±2.69 25.61±2.13 76.62±7.95 hours. Simple acupuncture stimulation, the transit time was 17.47±1.10 33.10±1.87 24.12±1.65 74.87±3.91 hours. Compared with before acupuncture stimulation, the transit time was significantly shortened(P<0.05), especially in right colon transit time of simple acupuncture stimulation was significantly shortened(P<0.05). Electroacupuncture stimulation, was 16.32±1.97 32.91±2.48 21.53±1.94 71.59±2.82. Compared with the previous two trial, transit time in right colon and rectosigmoid colon were significantly shortened(P<0.05). Acupuncture and electroacupuncture stimulation change on the right colonic transit time in old age constipation persons and rectosigmoid colonic transit time was changed as electroacupuncture stimulation. In other words, old age constipation persons who suffer chronic constipation, acupuncture and electroacupuncture stimulation reduces the total colonic transit time.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.7
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• pp.1059-1064
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• 2006

Six muscles were seamed out randomly from Hanwoo carcasses (n = 12) of each quality grade (quality grades 1, 2 and 3). Samples were analysed for their total and soluble collagen contents, IMCT (intramuscular connective tissue) and Warner-Bratzler shear force (WBSF). Simple correlation (n = 21) was determined for WBSF among major muscles. For LT (longissimus thoracis), total collagen content was significantly higher (p<0.05) for quality grade 3 than those for quality grades 1 and 2. For semitendinosus (ST), semimembranosus (SM), psoas major (PM) and serratus ventralis (SV), total collagen content of quality grade 1 was lowest (p<0.05) of all quality grades. IMCT shear force for gluteus medius (GM) decreased (p<0.05) with better quality grade, and those for other muscles, with the exception of GM, were higher (p<0.05) for quality grade 3 than for quality grades 1 and 2. WBSF values showed GM and LT to be decreased (p<0.05) with better quality grade, and PM to be higher (p<0.05) for quality grade 3 than those for quality grades 1 and 2. SM, ST and SV from quality grade 1 had lower (p<0.05) WBSF value than those from quality grades 2 and 3. Total collagen content of ST was highest (p<0.05) of all muscles, whereas that of PM was lowest (p<0.05). Soluble collagen contents of LT and SV from quality grades 1 and 2 were, in general, higher (p<0.05) than other muscles, but that of SM was lowest (p<0.05). ST and SM had higher (p<0.05) WBSF values for three quality grades when compared to other muscles, whereas PM was lowest (p<0.05). LT had the strongest simple correlation with SV (r = 0.78) and GM (r = 0.77), and SM had the strongest correlation with ST (r = 0.73) and LT (r = 0.73). Also, PM had the strongest correlation with SV (r = 0.62).