• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.2
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• pp.115-122
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• 2012

Frequency distribution of carapace width, relative growth, sex ratio and fecundity of blue crab Portunus trituberculatus in Younggwang adjacent water were investigated. A total number of individuals collected for this study were 658(Males : 305 and females : 353). Water temperature and salinity of the study areas varied from 5.9 to $27.3^{\circ}C$ and 28.1 to 31.6 psu, respectively. The carapace length-width and carapace width-weight relationship was calculated and the equations obtained are; For males; CL = 1.3652CW + 22.495($R^2$=0.741), $TW=0.0068CW^{2.4001}$($R^2$=0.749), For females; CL = 1.3073 CW + 25.684($R^2$=0.791), $TW=0.0061CW^{2.4231}$($R^2$=0.801). The sex ratios(Males : females) for blue crab were 0.86 : 1. The value of correlations coefficient between total weight and fecundity of the blue crabs was higher that of between carapace width and fecundity.

• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.54-58
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• 2006

The genetic analyses of Acanthopanax senticosus Harms from Korea, China and Russia, were made by comparing the internal transcribed spacer (ITS) sequences of the nuclear ribosomal DNA. The ITS region of A. senticosus was amplified by polymerase chain reaction (PCR) using the universal primers and then directly sequenced. The length of the ITS region including 162 bp 5.85 rRNA gene ranged from 608 bp (for Korean and Chinese) to 611 bp (for Russian). The G+C content of ITS region were 60.20% for Korean and Chinese plants and 60.06% for Russian plants. Sequence comparisons indicated that ITS regions of A. senticosus from Korea and China were identical, whereas the ITS sequence of A. senticosus from Russia showed 99.2% homology with the plants from Korea. Variation in sequences were attributable to 5 bp substitution such as transversion or insertion events. These results suggested that A. senticosus Harms from Korea and China were closely related in phylogenetic relationship compared to Russian. In addition, A. senticosus Harms were more similar to Kalopanax pictus than A. sessiliflorus in their ITS sequences.

• Korean Journal of Environment and Ecology
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• v.25 no.3
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• pp.421-431
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• 2011

This study examined visitors' perceptions and attitudes about establishing cable car in Mudeungsan Provincial Park (MPP). Data were collected from 401 respondents by a field questionnaire survey in MPP during the September of 2010. 61.7% of respondents opposed to establishing cable car in MPP while 20.6 percent supported it. Respondents showed high level of belief to possible consequences that establishing cable car will result in 'deterioration of ecosystem and natural landscape', 'crowding problem by increased number of visitors', 'disappearance of naturalness or previous nature experiences in MPP'. Respondents, however, presented low belief to 'positive effects on increasing economic income and local economic growth by attracting tourists'. 32.4 percent of the survey respondents evaluated the present MPP as a place of 'Nature Preservation Area (NPA)' and 10.5% as 'Developed Park Area (DPA)'. 48.8% of respondents answered that MPP should be managed as 'NPA' with only 2.5% as DPA. Respondents' socio-demographic characteristics (i.e., gender, age, education level, length of residence in Gwang-ju city), use patterns (number of visits to MPP or to Jungbong and surrounding areas), and normative place condition of MPP showed relationship with the overall support rates about establishing cable car. The results and their implications were discussed.

• Journal of Veterinary Clinics
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• v.37 no.5
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• pp.242-248
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• 2020

An intestinal strigeiid trematode, Apharyngostrigea pipientis, was detected from Ardea cinerea jouyi, Egretta intermedia and Nycticorax nycticorax between July, 2006 and June, 2020 in Daejeon metropolitan city and Kangwon-do, Republic of Korea. It was observed with a light and scanning electron microscope (SEM), and molecularly analyzed with 18S rRNA genes. The infection rate of the strigeiid trematode was 25.9% (7/27). The body is cylindrical in whole mount, greatly elongated in outline and shows a strong dorsal curvature. The overall measurements are: length 4.1-4.8 mm; fore-body 1.00-1.20 mm by 0.8-0.9 mm; hind-body 3.2-3.6 mm by 0.43-0.46 mm. The body is covered by a relatively thick cuticle, devoid of spines. The oral sucker leads into a short esophagus that is devoid of a muscular pharynx. The holdfast organ is enormously developed. The vitelline follicles distributed dorsal wall of fore-body and hind-body. This strigeiid trematode especially differs from other species of genus Apharyngostrigea in morphology. Although these A. pipientis are several morphological distinctions from Apharyngostrigea cornu, the partial sequence of 18S rRNA showed the sequence homology of A. pipientis (99.9%) and A. cornu (99.8%), and this result revealed their conspecific relationship between A. cornu and A. pipientis. This is the first report of A. pipientis in the Republic of Korea.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.169-176
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• 2010

A pilot-scale wastewater treatment plant combined with rotating biological contactor and tapered aeration reactors was operated with the wastewater discharged from a food factory for 5 months. The bacterial communities of this plant were investigated by terminal restriction fragment length polymorphism (T-RFLP) and phylogenetic analysis of 16S rRNA genes. In spite of high concentration of nitrogen and phosphorus as well as organic carbon, removal efficiency of chemical oxygen demand, total nitrogen, and total phosphorus was 98%, 93%, and 95%, respectively. Bacterial community at the initial operation stage was clearly distinguished from that of the stable operation stage. The most predominant phylum in the sample of stable stage was Bacteroidetes. Major population of operation period was Haliscomenobacter, Sphaerotilus, and candidate division TM7, which were classified as filamentous bacteria. However, sludge bulking caused by these bacteria was not observed. The population that has a close relationship with Haliscomenobacter increased during the stable operation stage, emerging as the most predominant group. These results suggest that the filamentous bacteria participated in nutrient removal when using rotating biological contactor and tapered aeration reactor.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.1
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• pp.59-68
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• 1994

The effects of silt and clay, water temperature and salinity on the metabolic activities: rates of respiration, filtration and nitrogen excretion in the clam, Mactra veneriformis, were investigated in ranges of $0{\sim}250ppm,\;15{\sim}25^{\circ}C\;and\;10{\sim}30\%0$ respectively. The weight specific respiration rate decreased with shell length and significantly declined at lower temperatures and lower salinity levels. Average respiration rates, filtration rates and ammonia excretion rates of the clam groups declined as water temperature was lowered. The respiration rate(R) and the filtration rate(F) decreased as the concentration of silt and clay(C) increased, the relationships between the two parameters were expressed as a regression line, R=a+b LogC and LogF=a+b LogC, respectively. On the rearing experiment treated with 50ppm of silt and clay, the relationship between the accumulative mortality(M) and the elapsed day(T) was $M=0.0186T^{2.7965}$, and the median lethal time was calculated at 16.8 days. From the rearing experiment, both rate of respiration and ammonia nitrogen excretion of experimental groups and control groups decreased with elapsed days, the rates of experimental groups, especially declined more compared with those of the control groups.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.4
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• pp.234-241
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• 1975

Reproductive cycle of Haliotis discus hannai Ino was studied based on the samples which were collected in Yeosu area from January, 1973 to December, 1974. Particular emphasis was paid on the seasonal variation of gonad maturity factor, coefficieot of gonad maturity, fatnesss, and relationship of gonad weight to growth of the abalone. seasonal fluctuation of water temperature and induction of artificial spawnings were also checked. The abalone of this area spawns twice a year: spring spawning(early May-late July) and Autumn spawning(early September-late November). peak spawning occurs from late May to middle of June for spring spawning: it occurs from late September to early November for Autumn spawning. Gonad maturity factor was closely related to the spawning seasons. For the spring spawning Gonad maturity factor reached to its maximum value as 18.84 in April; for the Autumn spawning it reached to its maximum value as 22.65 in September. Annual minimum value was 12.65 in January. Annual maximum values of coefficient of gonad maturity were 44.10 in May and 49.05 in September and the annual minimum was 10.09 in January. Fatnesswas highest in July as 0.221 and it was lowest in October as 0.1058. Ratios of shell length to gonad weight were formulated as follows : $$In\;September\;GW=0.000003710SL^{3.7860}$$ $$In\;January\;GW=0.000021198SL^{2.8564}$$ $$Annual\;mean\;GW=0.00000005013SL^{4.2273}$$ Relations of total weight to gonad weight were formulated as follows : In September GW=0.1918TW-4.9231 In January GW=0.0992TW-0.1759 Annual maan GW=0.1568UW-3.5256.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.1
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• pp.18-24
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• 2016

The purpose of this study is to induce the ductile behavior of the Ultra High Perfomance Concrete Reinforced I beam by substituting the part of steel fiber for bundle of reinforcing bars. Experiment of flexural behavior of the Ultra High Performance Concrete I shaped beam with the combination of the steel fiber and bundle of reinforcement bars was carried out. The volume fractions of steel fiber are 0%, 0.7%, 1%, 2%. The bundle of reinforcing bars and prestressing wire are used to restrain the concrete in compression zone. Length of bundle of reinforcing bar and prestressing wire is the one of test factors. The 9 Reinforced UHPC I shaped beam were made with these test factors. Not only steel fiber but also bundle of longitudinal reinforcing bar has effect to induce the ductile behavior of Reinforced UHPC I beam. The combination of 0.7% or 1.0% steel fiber and bundle of reinforcing bar showed the effective ductile behavior of I beam. The relationship of load-deflection and the crack pattern indicate the usefulness of the bundle of the longitudinal bar which has small diameter with close arrangement each other.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.4
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• pp.10-17
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• 2020

The recent earthquake in Korea caused large and small damages to many school building. School building is an important building that is used as a shelter in the event of disaster. Among the seismic retrofit methods, the internal steel braced frame type method is used for its relatively easy construction and excellent performance. In this study, the maximum shear force and displacement were compared and examined by applying the brace frame to existing concrete school buildings. As a result, we verified the adequacy of the analytical model and compared and examined the effect of brace-height ratio on the span of the existing school buildings. The adequacy of the maximum shear force and displacement relationship can be confirmed in the model with a length of 0.3. In addition, seismic frame was applied to the actual non-seismic reinforced concrete school building, and the seismic performance was evaluated by nonlinear static analysis(Push-over analysis) according to the ratio of brace-height. As a result, the increase of the brace-height according to the brace-height ratio has the effect of increasing the maximum shear force and maximum load at the performance point. But the collapse of the braced frame due to the increase in the lateral stiffness occurred, indicating that seismic retrofit according to the proper brace-height is necessary. Therefore, in the seismic retrofit design of brace frame of existing school building, it is necessary to select the proper brace-height after retrofit analysis according to the brace-height ratio.

• Archives of Pharmacal Research
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• v.27 no.6
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• pp.646-652
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• 2004

The objective of this study was to determine the acute effect of trimetazidine (TMZ) on the pre-fatigue, fatigue and post-fatigue contractile characteristics and tension-frequency relationships of isolated rat diaphragm muscle. Muscle strips were taken from the ventral-costal aspects of the diaphragm muscle of rats killed by decapitation. The muscle strips were suspended in organ baths containing Krebs solution, with a gas mixture of 95% $O_2$ and 5% $CO_2$ at $37^{\circ}C$ and pH 7.35-7.45. After determining the thermoregulation and optimum muscle length the muscles were subjected to direct supramaximal stimulation with 0.05 Hz frequency square pulses for periods of 0.5 msec to obtain control values. After adding $5{\times}10^{-6}{\;}and{\;}5{\times}10^{-5}$ M trimetazidine solution to the respective bath media, the contractile parameters of the muscles were recorded. The contractile parameters were also recorded for both the trimetazidine and tri-metazidine-free media after application of the high frequency fatigue protocols. Later, the tension-frequency relationship was determined by applying stimulating pulses of 10, 20, 50 and 100 Hz to the muscle strips. Whilst the twitch tension obtained from the $5{\times}10^{-6}{\;}and{\;}5{\times}10^{-5}$ M trimetazidine media showed numerical increases compared to that of the controls, these were not statistically significant (p>0.05). The contraction time exhibited a dose dependent increase (p<0.001), whilst the contraction and relaxation rates did not differ significantly. The isometric contraction forces obtained with the different stimulating frequencies showed a significant increase in the tetanic contraction only at 100 Hz (p<0.05). A comparison of the pre- and post-fatigue twitch tensions in the trimetazidine media showed the post- fatigue twitch tensions to be significantly higher than those of the pre-fatigue contraction forces (p<0.05). In the $5{\times}10^{-6}{\;}and{\;}5{\times}10^{-5}$ M trimetazidine media the increases in the post-fatigue contraction force were 22 and 30%, respectively. These results demonstrated that in isolated rat diaphragm muscle, TMZ significantly limited the mechanical performance decrease during fatigue. It is our opinion that trimetazidine contributed to the observed fatigue tolerance by eliminating the factors of fatigue, due to preservation of intracellular calcium homeostasis, provision of the ATP energy levels needed by ATPase dependent pumps and especially by keeping the intracellular pH within cer-tain limits.