• Journal of the Korean Geotechnical Society
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• v.20 no.7
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• pp.141-158
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• 2004

The dependency of criteria used to terminate compatibility tests on the prehydration and quality of bentonite in geosynthetic clay liners (GCLs) is evaluated based on permeation with chemical solutions containing 5, 10, 20, 50, and 100 mM calcium chloride ($CaCl_2$). The hydraulic conductivity tests are not terminated before chemical equilibrium between the effluent and the influent chemistry has been established, resulting in test durations ranging from < 1 day to > 900 days, with longer test durations associated with lower $CaCl_2$ concentrations. The evaluation includes both physical termination criteria (i.e., volumetric flow ratio and steady hydraulic conductivity based on ASTM D 5084, ${\ge}2$ pore volumes of flow, constant thickness of specimen) and chemical termination criteria requiring equilibrium between influent and effluent chemistry (viz., electrical conductivity, pH, and $Ca^{2+}\;and\;Cl^-$ concentrations). For specimens permeated with 5, 10, and 20 mM $CaCl_2$ solutions, only the criterion based on chemical equilibrium in $Ca^{2+}$ concentration correlates well with equilibrium in hydraulic conductivity, regardless of prehydration or quality of bentonite. However, all of the termination criteria, except for the volumetric flow ratio and 2 pore volumes of flow for the prehydrated specimens, correlate well with equilibrium in hydraulic conductivity regardless of prehydration or quality of bentonite when permeated with 50 and 100 mM $CaCl_2$ solutions. The results illustrate the uniqueness of the termination criterion based on solute concentration equilibrium between the effluent and the influent with respect to both prehydration and quality of bentonite in the GCLs.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.4
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• pp.497-505
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• 2012

The nutritional, physicochemical and sensory quality characteristics of chilled loins of Jeju Black Cattle, Hanwoo and imported Australian beef were compared. For nutritional properties, moisture and crude protein contents of Jeju Black Cattle beef were 65.91% and 17.39% respectively, the lowest among the comparison groups. On the other hand, their crude fat and crude ash contents were 15.89% and 0.79%, respectively, the highest among the comparison groups. There was a significant difference in crude ash content, but there was no significant difference in the other properties. The Fe and Zn contents of Jeju Black Cattle beef were 29.85 and 48.13 ppm, respectively, lower than those of Hanwoo beef, although the difference was not significant. These values were higher than those of Australian beef (p<0.05). There was no significant difference among the samples in contents of Ca, P, Na and Cu. The total amino acid and essential amino acid contents of Jeju Black Cattle beef were 16.81% and 9.08%, respectively, the lowest among the samples, although the difference was not significant. The ratio of essential amino acids to total amino acids of Jeju Black Cattle beef was 54.01%, the highest among the samples. The saturated fatty acid (43.25%), stearic acid (13.51%), linoleic acid (2.39%) and essential fatty acid (2.47%) contents of Jeju Black Cattle beef were the lowest. However, their unsaturated fatty acid (56.69%), oleic acid (47.80%) and MUFA/SFA ratios were the highest, and there were significant differences compared with Australian beef. There was no significant difference in the PUFA/SFA ratio. Among physicochemical properties, redness ($a^*$) of Jeju Black Cattle beef was the highest while melting point was the lowest (p<0.05). There were no significant differences in lightness ($L^*$), yellowness ($b^*$), pH, water holding capacity, cooking loss or shear force value. For sensory properties, raw meat aroma, cooked meat aroma and palatability of Jeju Black Cattle beef were superior compared to other comparison groups, with significant differences in comparison with Australian beef (p<0.05). However, there were no significant differences in taste, juiciness, or tenderness of cooked meat.

• Korean Journal of Poultry Science
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• v.37 no.4
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• pp.389-398
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• 2010

The present experiment was carried out to compare performance, carcass characteristics and meat quality among three major meat-type duck strains in Korea. Two commercial duck (CD) strains, produced from parent stocks (PS) (Cherry Valley and Grimaud), and $F_1$ strains, self-produced by farmers, were used in an 8-week feeding experiment. Both feed conversion ratio and production index were significantly higher in Cherry Valley strain compared with the other two at the ends of 6 and 8 weeks (p<0.05). However, no differences were found in carcass characteristics and meat quality, with the exception of abdominal fat weight where Grimaud were higher than the others. Overall, the results of the current study show that Cherry Valley CD strain had higher performance among three strains tested.

• Journal of Yeungnam Medical Science
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• v.16 no.2
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• pp.228-236
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• 1999

Background: Thyrotoxic periodic paralysis is an uncommon illness characterized by intermittent flaccid paralysis of skeletal muscle, usually accompanied by hypokalemia, in patient with hyperthyroidism. However, the pathophysiology of thyrotoxic periodic paralysis remains largely unexplained and controversial. This report describes the clinical and biochemical findings in 19 patients with thyrotoxic periodic paralysis who were examined at the Yeungnam University Medical Center(YUMC) during the past decade. Methods: The medical records of 997 YUMC patients, seen between 1986 and 1996, with diagnosis of hyperthyroidism were reviewed. Nineteen patients out of 997 hyperthyroidism patients were diagnosed, and examined by history, physical examination, serum electrolyte value, and thyroid function test during paralysis. On the basis of these results, comparisons were made on age, sex, precipitating factors, timing, affected limbs, prognosis, serum potassium and serum phosphate and thyroid hormone levels. Results: The prevalence of periodic paralysis in hyperthyroidism was 1.9 percent and the male to female prevalence ratio was 30:1 and in all patients, the development of perodic paralysis was correlated with hyperfunctional state of the thyroid gland. Eleven cases of periodic paralysis were associated with hypokalemia and their thyroid hormone levels were significantly more increased than those of the patients without hypokalemia. Interestingly, our study shows the recurrence of paralysis after treatment. Conclusion: Although the precise pathophysiology of the disease is as yet undefined and controversial, it occurs primarily in Asians with an overwhelming male preponderance and prevalence of 2 percent in hyperthyroidism. The interactive roles of thyroid hormone, Na-K pump, and genetically inherited defect in the cellular membrane potential of the skeletal muscle can be speculated. Further investigation will be needed to firmly establish the mechanism of thyrotoxic periodic paralysis.

• Korean Journal of Environmental Agriculture
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• v.35 no.4
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• pp.286-293
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• 2016

BACKGROUND: 18% of difenoconazole+iminoctadin triacetate microemulsion (3%+15%) formulation were mixed and sprayed as closely as possible to normal practice on the ten of farms located in the Youngju of South Korea. Patches, cotton gloves, socks, masks and XAD-2 resin were used to measure the potential exposure for applicators wearing standardized whole-body outer and inner dosimeter (WBD). This study has been carried out to determine the dermal and inhalation exposure to difenoconazole during preparation of spray suspension and application with a power sprayer on a grape orchard. METHODS AND RESULTS: A personal air monitor equipped with an air pump IOM sampler and cassette and glass fiber filter were used for inhalation exposure. The field studies were carried out in a grape orchard. The temperature and relative humidity were monitored with a thermometer and a hygrometer. Wind speed was measured using a pocket weather meter. All mean field fortification recoveries were between 97.3% and 119.6% in the level of 100 LOQ (limit of quantification) while the LOQ for difenoconazole was $0.025{\mu}g/mL$ using HPLC-UVD. The arms exposure to difenoconazole for the mixer/loader (0.0794 mg) was higher than other body parts (head, hands, upper body, legs). The exposure to difenoconazole in the legs for applicator (3.78 mg) was highest in the parts of body. The dermal exposure for mixer/loader and applicator were 0.02 and 2.28 mg on a grape orchard, respectively. The inhalation exposure during application was estimated as 0.02 mg. The ratio of inhalation exposure to dermal exposure was equivalent to 0.9% of the dermal exposure. CONCLUSION: The inhalation exposure for applicator indicated $18.8{\times}10^{-3}mg$, which was level of 0.9% of the dermal exposure (2.28 mg). Operator exposure (0.004 mg/kg bw/day) to difenoconazole during treatment for grape is calculated as 2.5% of the established AOEL (0.16 mg/kg bw/day).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.333-338
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• 2008

The tea has traditionally been used as a foodstuff by unique flavor, however recently not only the diversity of consumer demands but also the public interest in unique favorite and functional aspects have increased. It has been also reported that the main components contained in the leaves of tea (Camellia sinensis) include total nitrogen, free amino acids, polyphenols, and fiber, of which catechin has powerful bioactive effect such as anti-cancer, anti-aging, and anti-diabetic. (-)-Epigallocatechin gallate (EGCG) which is a major phenolic constituent of green tea extract has received considerable attention for a variety of important bioactivities. This study was carried out to obtain useful information for tea breeding programs, and to investigate the concentration of quality and functional related components in Korean indigenous tea germplasms. Korean indigenous tea lines were classified into three groups of sprout time, i.e, early, medium and late sprout time, and the ratio were 20%, 43% and 37%, respectively. There was a difference in characteristics among these Korean indigenous tea lines, leaf width of those ranged from 19.8 to 75 mm, leaf length was 35.5-160.0 mm, and leaf area was $660-8,400\;mm^2$. Experimental data on chlorophyll content (SPAD value) of Korean indigenous tea genetic resources ranged from 51.3 to 82.3. The concentrations of the total nitrogen, total free amino acids, and theanine were ranged 4.18-6.07%, 2.87-4.58%, and 1.64-2.66%, respectively. Also, catechin concentration showed from 11.54 to 15.07%, and concentration of caffeine was 2.82-4.23%. These results indicated indicated that it is possible to select elite lines with high concentration of quality related components and low concentration of caffeine from Korean domestic tea germplasms.

• Journal of Life Science
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• v.20 no.4
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• pp.535-542
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• 2010

This study was carried out to examine anthropometric parameters and related habits in female college students. Mean age, height, and body weight of the subjects in total (n=212) were 20.7 yrs, 161.8 cm, and 53.5 kg, respectively. Anthropometric parameters were measured by bioelectrical impedance analysis. Mean degree of obesity, body mass index (BMI), and waist-hip ratio (WHR) were 98.4%, $20.6\;kg/m^2$, and 0.80 respectively. Surprisingly, 63.7% of the subjects showed unbalanced weak upper bodies compared to their lower bodies. Therefore, they were divided into two groups: unbalanced weak upper body group (UU, n=135) and balanced upper body groups (BU, n=77). Bodyweight, degree of obesity, BMI, and WHR in the UU group were significantly lower than those in the BU group. Amounts of body protein, body fat, and body mineral in the UU group were also significantly lower than those of the BU group. Mid-arm muscle circumference of the UU group ($18.5{\pm}0.8\;cm$) was significantly lower than those of BU group ($20.4{\pm}1.2\;cm$), although mid-arm circumference of the UU group was not significantly different compared to those of the BU group. On a questionnaire on exercise habits, 1.5% of the UU group and 7.8% of the BU group answered that they exercised regularly, and 55.5% of the UU group and 31.2% of the BU group reported that they never exercised (p<0.01). Even in the subjects who exercised, the duration of the exercise was not sufficient because 38.4% of the UU group and 35.8% of the BU group answered that they exercised for less than 30 min. In conclusion, interventions in exercise habits may be needed for female college students who have unbalanced weak upper bodies.

• Korean Journal of Environment and Ecology
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• v.30 no.1
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• pp.110-117
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• 2016

Litter fall is a source of nutrients and carbon transfer in terrestrial ecosystems. Litter decomposition provides nutrients needed for plant growth, sustains soil fertility, and supplies $CO_2$ to the atmosphere. We collected the leaf litter of evergreen broadleaf tree, Camellia japonica L., and carried out a decomposition experiment using the litterbag method in Ju-do, Wando-gun, Korea for 731 days from Dec 25, 2011 to Dec 25, 2013. The leaf litter of C. japonica remained 42.6% of the initial litter mass after experiment. The decay constant (k) of C. japonica leaf litter was $0.427yr^{-1}$. The carbon content of C. japonica leaf litter was 44.6%, and the remaining carbon content during the decomposition tended to coincide with the changes in litter mass. The initial nitrogen and phosphorus content was 0.47% and 324.7 mg/g, respectively. The remaining N in decaying litter increased 1.66-fold in the early decomposition stage, then gradually decreased to 1.18-fold after 731 days. The content of P showed the highest value (1.64-fold of initial content) after 456 days, which then fell to a 1.15-fold after 731 days. The remaining Ca, K, Mg and Na content in C. japonica leaf litter tended to decrease during decomposition. The remaining K showed a remaining mass of 8.9% as a result of rapid reduction. The initial C/N and C/P ratio of C. japonica leaf litter was 94.87 and 1368.5, respectively. However, it tended to decrease as decomposition progressed because of the immobilization of N and P (2.78 and 2.68-fold of initial content, respectively) during the leaf litter decaying. The study results showed that N and P was immobilized and other nutrients was mineralized in C. japonica leaf litter during experimental period.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.6
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• pp.721-729
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• 2017

This study aimed to improve customer perception of Prunus mume through analysis of amygdalin contents according to changes in variety, harvest time, and fermentation conditions. Five Prunus mume domestic cultivars were harvested at five harvest times. We compared cyanogenic glucosides in four types of fruits on the market. For amygdalin contents in seeds and flesh of Prunus mume by variety and harvest time, seeds contained higher amygdalin contents than flesh with time. As Prunus mume ripened, both amygdalin contents in seed and flesh increased. However, the rate of increase gradually decreased. For prunasin contents in Prunus mume, we determined that the dramatic increase in amygdalin from May 3 to 19 was due to amygdalin synthesis from prunasin. Moreover, in the case of fermented Prunus mume, we observed lower amygdalin content as the sugar ratio and fermentation time increased until around 90 days, followed by a decrease. Furthermore, we analyzed alteration of organic acids in Prunus mume and fermented solution based on analysis of amygdalin content in four other market fruits. Amygdalin was detected at $252.37{\pm}2.3$, $22.01{\pm}0.31$, and $8.75{\pm}0.14mg$ per 100 g in plums, peaches, and grape seeds, respectively. In flesh of plums and peaches, amygdalin contents were detected at $84.14{\pm}0.26$ and $7.54{\pm}0.06mg$ per 100 g, respectively. These results suggest scientific improvements for consumption and breeding lines.

• Korean Journal of Environmental Biology
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• v.28 no.2
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• pp.86-94
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• 2010

This study compares and contrasts the dynamics of plankton in 31 temperate lakes and reservoirs, and considers particularly the biomass ratio of zooplankton to phytoplankton and ecological model application. A total of 89 species of zooplankton were identified (70 rotifers, 14 cladocerans and 5 copepods) and a total of 554 species of phytoplankton were identified (176 Bacillariophyceae, 237 Chlorophyceae, 68 Cyanophyceae, and 73 other algal taxa). The total plankton abundance and species diversity were showed distinctive spatial and seasonal variation. Annual average phytoplankton density was $7,350{\pm}15,592$ cells $mL^{-1}$ (n=124), and the lowest was $855{\pm}448$ cells $mL^{-1}$ (n=4), while the highest was $72,048{\pm}13,4631$ cells $mL^{-1}$ (n=4). For zooplankton, small rotifer groups dominated the study sites, and approximately 3~10 species appeared in the study sites. Statistical analysis and an ecological model application revealed that the size of reservoirs affected the structure size of plankton community, i.e. relatively large number of species were found in smaller reservoirs. From this result, we can conclude that management strategy for the reservoir environment has to be focused more on small-size reservoirs, in terms of plankton community ecology.