• Journal of the Korean GEO-environmental Society
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• v.2 no.1
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• pp.103-114
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• 2001

Sorption studies were conducted to determine if slow sorption fraction is observed in recent1y deposited organic matter by studying wetland soils explicitly. Sorption characteristics of hydrophobic organic compounds (chlorobenzene and phenanthrene) in recently deposited freshwater marsh soils were determined using a batch sorption procedure. Relative indicators of organic matter age were assessed using several techniques including the ratio of elemental oxygen to carbon in the organic matter. Slow sorption characteristics for both surface marsh soil (top 0-2 cm, <5 years old) and deeper marsh soil (below 10-cm, >20 years old) were compared against relatively older PPI (Petro Processors, Inc. Superfund site) and BM (Bayou Manchac) soils to investigate whether soil age can cause differences in sorption of organic compounds in wetland soils. Increases in sorption non-linearity of slow sorption model parameters (increase in KF and decrease in N) explain the existence of slow sorption fraction. The results of slow sorption model indicates the presence of a sizable slow sorption fraction; 25.4 - 26.3% (chlorobenzene) and 1.4 - 1.9% (phenanthrene) of the sorbed mass in wetland soils and 40.0 - 55.93% (chlorobenzene) and 2.9 - 3.19% (phenanthrene) of the sorbed mass in PPI and BM soils, respectively. The slow sorption fraction increased in the order of surface < deeper < PPI < BM soil indicating that size of the slow sorption fraction increases with soil organic matter age.

• Korean Journal of Environmental Biology
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• v.27 no.1
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• pp.31-39
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• 2009

To recognize the species composition and community of chironomid midge in agroecosystem and evaluate removal capacity of organic matter using the dominant species among them. Chironomid midge and invertebrate cohabitants were quantitatively collected at 78 representative stations of five habitat types (in arable land during 2004$\sim$2006) A, paddy fields of the large scale arable land; B, paddy fields of the environmental friendly arable land; C, influent of domestic waste water; D, influent of waste water by livestock; E, the irrigation ditch of paddy area. The total sixteen species of chironomid midges at arable land were presented. And also chironomid midges were recognized by five habitat types: eleven species in D, eight in A, seven in E, six in B, and two in C. We confirmed dominant species in each habitat types as followings: Chironomus nipponensis in A, C, and D; Cricotopus sylvestris in E; Tanytarsus seosanensis in B. Water quality and community index were high in E, but low in A, B, C, and D. Comparing with non-treatment, removal activities of organic matter in bottom by C. nipponensis were increased 18% in 90 individuals treatment.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.3 s.26
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• pp.165-170
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• 2006

In this study, organic matters production was calculated with long term data in Wando costal area where was selected for non influent of fresh water. The objective of this study was to evaluate relationship between nutrients and phytoplankton and, between phytoplankton and organic matter. The result of DIN was the highest with 0.138 mg/L in winter season and the lowest with 0.052 mg/L in summer season. Similarly, DIP was shown to be 0. 017 mg/L in winter and 0.011 mg/L in summer. Limiting nutrient was revealed with nitrogen in Wando costal area. Specially in summer season, nitrogen limitation was the greatest with 10.5 of N/P ratio. Chl. -a was increased 80%, 108% in spring and summer compare with winter. COD was the lowest with 0.84 mg/L in winter and the highest with 1.10 mg/L in summer. The interrelation between nutrients and Chl. -a was high. Relationship $coefficient(r^2)$ were 0.93(P<0.05), 0.89(P <0.05) between DIN and Chi. -a, DIP and Chl. -a. This results suggest dissolved nutrients might be utilized at the production of phytoplankton. Also Relationship $coefficient(r^2)$ was 0.77(P<0.05) between Chl. -a and COD. COD production rate was calculated with regression equation. The COD production rate was 17% in winter and 36% in summer. It was revealed nutrients were decreased according to temperature increasing and then Phytoplankton and organic matter were increased. The Relationship of Nutrients, Chl. -a and COD was very high.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.9
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• pp.1373-1380
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• 2019

Objective: This study ascertained effects of cactus pear in association with different roughage in the diet of F1 Holstein/Zebu cows on intake, nutrient digestibility, nitrogen balance, ingestive behavior and performance. Methods: Eight cows with $72{\pm}11$ days of lactation were used. The experimental design was simultaneous in two $4{\times}4$ Latin squares. Four experimental diets were used: Diet 1, sorghum silage as exclusive roughage; Diet 2, sorghum silage associated with cactus pear in a proportion of 50% of the roughage (dry matter basis); Diet 3, elephant grass (Pennisetum purpureum cv. Roxo) as exclusive roughage; Diet 4, elephant grass associated with cactus pear in a proportion of 50% of the roughage. The roughage:concentrate ratio was 75:25. Results: Dry matter intake (p = 0.01) was higher with sorghum silage. There were differences in dry matter intake (p = 0.01), crude protein (p<0.01), ether extract (p = 0.01), non-fibrous carbohydrates (p<0.01) and total digestible nutrients (p = 0.01) among the diets. Cactus pear in the diet reduced water intake by 44.52% (p<0.01). The nitrogen balance was 59.71% and 27.49% lower in animals treated with exclusive sorghum silage and sorghum silage associated with cactus pear in relation to diets with elephant grass and elephant grass associated with cactus pear, respectively (p<0.01). The diets did not influence the milk production (p = 0.70), 3.5% fat corrected milk production (p = 0.72) or feed efficiency (p = 0.61). Conclusion: The association of cactus pear with sorghum or elephant grass silage does not alter milk production, reduces the intake of dry matter and water and improves the digestibility of nutrients.

• Journal of the Korean Geosynthetics Society
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• v.23 no.2
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• pp.53-62
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• 2024

Recently, development of non-traditional energy such as oil sands has been actively conducted in the cold region such as Canada. Frozen soil has different thermal and mechanical characteristics from general soil due to its high organic contents. This study evaluated the impact of organic matter content on the thermal and mechanical behavior of frozen soil samples collected from Alberta, Canada, and Gangwon Province, South Korea. As the organic content increases, the maximum dry unit weight decreases and the optimum moisture content increases in compaction tests. In uniaxial compression tests under frozen conditions, the strength of the frozen specimens increased as the temperature decreased. The strength of Canada soil sample increased with higher organic matter content at low temperatures. However, the strength of frozen soil was not significantly affected by organic matter content due to the complex behavior and unfrozen water content. Thermal conductivity tests showed higher thermal conductivity in frozen conditions compared to unfrozen conditions, due to the higher thermal conductivity of ice compared to water. These findings provide essential data for geotechnical design and construction in large-scale projects such as oil sands development in cold regions. Further research is needed to explore the impact of organic matter content on different types of frozen soils.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.11
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• pp.1634-1641
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• 2005

Generally, dietary fibre (DF) includes lignin, non-starch polysaccharides (NSP) and resistant starch (RS). In monogastric species, low levels of dietary fibre in the diet are associated with various diseases and high levels reduce nutrient digestibilities. In this study, the effects of different types and levels of NSP (soluble: $\beta$-glucan, insoluble cellulose) and resistant starch on mucin secretion and endogenous nitrogen and amino acid losses in pigs were investigated. A total of 25 five-week-old weaner pigs (9.5 kg${\pm}$1.5 kg), were randomly allocated to each of five experimental diets. Different levels of purified barley $\beta$-glucan (BG) extract (5 or 10% of $Glucagel^{(R)}$ $\beta$-glucan, providing 4 or 8% of BG in the diet), and resistant starch (RS) (8.3 or 16.6% of Hi-$Maize^{TM}$, providing 5 or 10% RS in the diet) were substituted for wheat starch in a purified diet in which enzymatically-hydrolysed casein was the sole source of protein. The diets were fed for 21 days. No statistically significant difference between treatments (p>0.05) was observed for growth performance and organs weights. No difference in ileal starch digestibility was observed between pigs on the cellulose or $\beta$-glucan diets. However, as the level of resistant starch in the diet increased the ileal starch digestibility decreased (p<0.05). The inclusion of resistant starch in the diet (5 or 10%) did not increase mucin production when compared with the cellulose-only diet. However, as the level of beta-glucan in the diet increased, both crude mucin in the digesta dry matter and per kg dry matter intake increased (p<0.05). Pigs fed the diet containing 8% of beta-glucan had higher endogenous loss flow than those fed the diets including 5 or 10% of resistant starch or 4% of $\beta$-glucan. In conclusion, dietary inclusion of resistant starch increased the level of starch reaching the large intestine without any effect on mucin secretion, or endogenous nitrogen or amino acid losses content in the small intestine. The addition of $\beta$-glucan to a diet containing cellulose increases both mucin secretion and endogenous amino acid and nitrogen losses in the small intestine.

• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.300-308
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• 2000

The degradation of herbicide $^{14}C-bifenox$ was studied in soils under anaerobic conditions. $^{14}C-bifenox$ was treated in silty loam and sandy loam soils, respectively at a rate of 2.1 mg/kg, and the soil was incubated under anaerobic conditions at $25^{\circ}C$ for 180 days. The mineralization, solvent extractable and non-extractable residues, degradation products of bifenox were investigated during the experiments. The relative amounts of $^{14}CO_2$ were 1.97 and 0.9% of applied $^{14}C$ in silty loam and sandy loam soils, respectively. The non-extractable residues of sandy loam soil increased dramatically up to 79.12% of applied $^{14}C$, and were higher than those of silt loam soil, suggesting physico-chemical properties and especially organic matter contributed to the difference of $^{14}C$ between two soils. The non-extractable residues were formed mainly humin fraction and increased with time. The major metabolites were nitrofen, 5-(2,4-dichlorophenoxy)-2-Nitrobenzoate, 2,4-dichlorophenoxy aniline and methyl 5-(2,4-dichlorophenoxy) anthranilate by GC/MS analysis. From the results of volatilization, mineralization and degradation of bifenox, bifenox was stable chemically and biologically in soil.

• The Journal of Korean Physical Therapy
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• v.19 no.2
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• pp.41-55
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• 2007

Purpose: This study aimed to compare the effect on nerve regeneration of ultrasound irradiation in rats with peripheral nerve injury. Methods: To investigate alterations of the NCAM immunoreactivity in non-crushed part and crushed part of the spinal cord, the unilateral sciatic nerve of the rats were crushed. The expression of NCAM was used as the marked of peripheral nerve regeneration, and also plays an important role in developing nerve system. Experimental animals were sacrificed by perfusion fixation at post-injury 1, 3, 7, 14 days after ultrasound irradiation. The pulsed US was applied at a frequency of 1MHz and a spatial average-temporal average Intensity of 0.5W/of (20% pulse ratio) for 1 mins. The Luxol fast blue-cresyl violet stain were also done to observe the morphological changes. Results: Alteration of NCAM immunoreactivity in the crushed part and the non-crushed part of lower lumbar spinal cord were observed. NCAM-immunoreactivity cells were some increased in the dorsal horn lamina I, III and cell ventral horn at 1 day after unilateral sciatic nerve injury. However, there was not significant difference in the relationship between crushed part and non-crushed part. NCAM-inmmunoreactivity was remarkably increased at 3 days after unilateral sciatic nerve injuryin the gray matter and white matter. NCAM-immunoreactivity was increased in the ventral horn and post horn of experimental crushed part. Also, NCAM-immunoreactivity in large motor neurons in ventral horns lamina VIII, IX were increased at 7 days after unilateral sciatic nerve injury. At 14 days after sciatic nerve crushed injury, there was no significant difference. All group were decreased for 14 days. In the time course of NCAM expression, all groups showed a significant difference at 3day groups(p<0.05). Whereas, CC group was noted a significant difference between 3day and 7 day group respectively. In NCAM expression, there were significantly increased in all group. In the relationship between CNC group and ENC group, significant difference was detected among 3, 7, 14 day group(p<0.05). The difference between CC group and ENC group were noted in all groups(p<0.05). Conclusion: It is consequently suggested that the effects of the ultrasound irradiation may increase the NCAM immunoreactive neurons and glial cell in the spinal cord after unilateral sciatic nerve crushed injury. Therefore, the increased NCAM immunoreactivity in the spinal cord may reflect the neuronal damage and healing process induced by a ultrasound irradiation after peripheral nerve injury in rat.

• Journal of Korean Elementary Science Education
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• v.25 no.2
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• pp.118-125
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• 2006

The purpose of the study was to research science gifted students' learning styles and perceptions on subject matter content. The data was collected from primary science and mathematics classes of a University Center for Science Gifted Education, science classes of a Metrocity Primary Gifted Education Institute, and classes of a normal school. The results of the study were that gifted students perceived the school curriculum much easier than non-gifted students did, ($X^2(4)=33.180$, p<.001), and that levels of interest in the content did not differ between the groups, but 34.6 percent of the total students responded that they found the content uninteresting. Gifted students did not see the content as being important compared to the non-gifted students, ($X^2(4)=12.443$, p<.05), and gifted students valued the methods used higher than the actual content of the textbook. The most helpful activities for their teaming that gifted students chose were projects, listening to teachers, and conducting experiments, amongst others. They also preformed 'teaming at their own speed in a mixed group'" for the study of social studies, science, and mathematics, whereas non-gifted students preformed teaming at the same speed. The two groups of science gifted students varied especially in their perceptions of most helpful activities. It is suggested that special programs for fulfilling gifted students' needs and abilities need to be developed and implemented.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.6
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• pp.803-810
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• 2013

The purpose of this research is to analyze the effect of shape of the inductive textile electrode on the non-contact heart activity sensing, based on the magnetic-induced conductivity principle. Four types of the inductive textile electrodes were determined according to the combinations of the two shape features. A fiber-metal hybrid-typed conductive thread was developed and applied to materialization of the textile electrodes by embroidery method. The heart activity was extracted through the textile electrode sewn on a T-shirt. The experiments were implemented to constantly measure the heart activity for 20 seconds, in each case of 5 healthy male subjects. The heart activity signals acquired in each type of the inductive textile electrode were analyzed, 1)by drawing a comparison of morphology with those of ECG signal (LeadII), and 2)by calculation of the normalized mean and standard deviation of magnitude of the heart activity signals. The analysis resulted that the relatively better quality of signals were acquired in the 'square' types in the matter of whole shape, while the better results were obtained in 'donut' types in the matter of center hole. Accordingly, the relatively best quality of signals was obtained in the case of 'Square-Donut' type of the inductive textile electrode.