• Journal of the Korean Chemical Society
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• v.50 no.3
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• pp.247-255
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• 2006

The purpose of this study was to investigate the correlation between concepts on chemical reaction rates and concepts on chemical equilibrium in high school students. The subjects of the investigation consisted of 120 third grade students attending high school in K city of Kyunggi province. For this study, questionnaire relevant to the subject of chemical reaction rates and chemical equilibrium was developed and the answers were analyzed. As a result of the study, a large percentage of high school students answered questions on reaction rates correctly, but only a small percentage of the students could give explanations. Many high school students answered questions on the rates of forward reactions correctly, but not the questions on the rates of reverse reactions. For the concepts on chemical equilibrium, many high school students gave correct answers when faced with equilibrium questions that only required the understanding of one side of the reaction. But the students could not answer the questions requiring understanding of both forward and reverse reactions as well. Overall, there was a little high correlation between concepts on chemical reaction rates and concepts on chemical equilibrium in high school students. Especially, high school students with little understanding of reverse reaction rates did not understand that chemical equilibrium is a dynamic equilibrium. Also, high school students with little understanding of the collision mechanism regarding chemical reaction rates did not understand the effect of concentration and catalyst factors on chemical equilibrium. And the correlation between concepts on chemical reaction rates and concepts on chemical equilibrium related to concentration and catalyst factors was low. In conclusion, the formation of scientific concepts on chemical reactions rates can decrease misconceptions on chemical equilibrium. Also the teaching-learning method limited to one side of a reaction can cause difficulty in forming the concepts on chemical dynamic equilibrium. Therefore, the development of a teaching-learning method which covers both the forward and reverse reactions can be effective in helping students form the concepts on chemical equilibrium.

• Korean Journal of Ecology and Environment
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• v.49 no.3
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• pp.197-207
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• 2016

This study aims at providing basic data to objectively evaluate the areas suitable for reintroduction of the species of Asiatic black bear (Ursus thibetanus) in order to effectively preserve the Asiatic black bears in the Korean protection areas including national parks, and for the species restoration success. To this end, this study predicted the potential habitats in East Asia, Southeast Asia and India, where there are the records of Asiatic black bears' appearances using the Maxent model and environmental variables related with climate, topography, road and land use. In addition, this study evaluated the effects of the relevant climate and environmental variables. This study also analyzed inhabitation range area suitable for Asiatic black and geographic change according to future climate change. As for the judgment accuracy of the Maxent model widely utilized for habitat distribution research of wildlife for preservation, AUC value was calculated as 0.893 (sd=0.121). This was useful in predicting Asiatic black bears' potential habitat and evaluate the habitat change characteristics according to future climate change. Compare to the distribution map of Asiatic black bears evaluated by IUCN, Habitat suitability by the Maxent model were regionally diverse in extant areas and low in the extinct areas from IUCN map. This can be the result reflecting the regional difference in the environmental conditions where Asiatic black bears inhabit. As for the environment affecting the potential habitat distribution of Asiatic black bears, inhabitation rate was the highest, according to land coverage type, compared to climate, topography and artificial factors like distance from road. Especially, the area of deciduous broadleaf forest was predicted to be preferred, in comparison with other land coverage types. Annual mean precipitation and the precipitation during the driest period were projected to affect more than temperature's annual range, and the inhabitation possibility was higher, as distance was farther from road. The reason is that Asiatic black bears are conjectured to prefer more stable area without human's intervention, as well as prey resource. The inhabitation range was predicted to be expanded gradually to the southern part of India, China's southeast coast and adjacent inland area, and Vietnam, Laos and Malaysia in the eastern coastal areas of Southeast Asia. The following areas are forecast to be the core areas, where Asiatic black bears can inhabit in the Asian region: Jeonnam, Jeonbuk and Gangwon areas in South Korea, Kyushu, Chugoku, Shikoku, Chubu, Kanto and Tohoku's border area in Japan, and Jiangxi, Zhejiang and Fujian border area in China. This study is expected to be used as basic data for the preservation and efficient management of Asiatic black bear's habitat, artificially introduced individual bear's release area selection, and the management of collision zones with humans.

• Journal of agricultural medicine and community health
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• v.28 no.2
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• pp.61-70
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• 2003

Objectives: Traffic accidents often occur to power tillers without reflective light in the dawn, evening and night. Because of this reason, there has been a 'campaign to attach reflective lights' to power-tillers in recent years. Therefore, the authors investigated the relationship between reflective light and traffic accidents involving power-tillers. Methods: We defined traffic accidents of power tillers as those cases of rear-end collision by a car in the dawn, evening or night. According to our definition, four cases were confirmed in Hyungok-myeon, Gyeongju and five cases in Gigye-myeon, Pohang. We selected a control group from people in the same village with similar age, sex, driving history and education. Results: The study group contained 9 accidents and 36 non-accidents. Power tillers with reflective light were 32 cases (72.7%) of 44 cases (excluded one case due to death). Of those, the status of reflective light was 'clean' in 18 cases (56.3%). The recognition that reflective light can prevent accidents was 'Yes' in 26 cases of 44 cases (59.1%). The recognition of the 'campaign to attach reflective lights' to power tillers was 'Yes' in 38 cases of 44 cases (86.4%). The recognition about the safety regulation of driving power-tillers was 'Yes' in 32 cases of 44 cases (72.7%). Odds ratio of traffic accidents for no reflective light was 7.00 (95% CI: 1.06-58.37). Conclusions: Although the 'campaign to attach reflective lights' to power tillers are going on, its effectiveness may unknown. Therefore, more extensive epidemiologic study is needed into the relationship between reflective light and power tiller traffic accidents, with effective administration of the government and the attention of medical persons.

• Journal of Yeungnam Medical Science
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• v.8 no.2
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• pp.174-184
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• 1991

To determine the incidence rate of accidents and its associated factors, a prospective survey was carried out in a rural area of a total of 1,360 residents for 1 year from January 1 to December 31, 1988 in Shin-am Ri, Jungdong Myun, Sangju Kun, Kyungpook Province. Data for accidents were collected by the community health practitioner who is working at Primary Health Post in Shin-am Ri. A total number of accident cases was 85 among 1,360 persons during one year study period, and annual incidence rate was 62.5 per 1,000 persons. The highest incidence rate of accident was observed in the age group of 30-39 was 179.8. The incidence rate of accident in male was 86.5 which was about 2 times that in female. In male, the highest incidence rate was seen in 30-39 age group and in female, 60-69 age group. The highest incidence rate of accident was observed in spring(29.4%) and summer(29.4%), and the lowest in fall(17.7%). The highest incidence rate of accident was observed in Friday(24.5%) by day of week, and between 9 a.m. to 12 a.m. by time zone. The most frequent use of medical facilities was Primary Health Post(51.8%) and the next was clinic(38.8%). Mean duration of treatment was 9.8 days. The accident occured in the room and kitchen(23.5%), in the yard and barn(23.5%), on the road(22.4%). and in the rice field and dry field(20.0%). The causes of accident were motor vehicle accident(20.0%), piercing or cutting(20.0%), collision or fighting(12.9%), and poisoning(11.8%) in order of frequency. The most common type of injury was open wound which was 43.5%. The most common tool of accident was farm machine which was 23.5%. The most common injuried part of body was extremity(55.3%).

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.2
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• pp.95-104
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• 2000

Depths to four seismic sequence boundaries and the thickness of each sequence were estimated and mapped based on multi-channel seismic data in the Ulleung Basin. These depth-structure and isopach maps were incorporated into the interpretation of gravity and magnetic anomaly maps. The sediment thickness ranges from 3,000 m to 4,000 m in the central basin, while it reaches 6,000 m locally along the southwestern, western, and southeastern margins. The acoustic basement forms a northeast-southwest elongated depression deeper than 5000 m, and locally deepens up to 7,500 m in the southwestern and western margins. Low gravity anomalies along the western and southern margins are associated with basement depressions with thick sediment as well as the transitional crust between the continental and oceanic crusts. Higher gravity anomalies, dominant in the central Ulleung basin, broaden from southwest toward northeast, are likely due to the shallow mantle and a dense crust. A pair of magnetic elongations in the southeastern and northwestern margins appear to separate the central Ulleung basin from its margin. These magnetic elongations are largely dominated by intrusive or extrusive volcanics which occurred along the rifted margin of the Ulleung basin formed during the basin opening. The crust in the central Ulleung Basin, surrounded by the magnetic elongations, is possibly oceanic as inferred from the seismic velocity. The oceanic crust can be mapped in the central zone where it widens to 120 km from the southwest toward northeast. Bending of the crustal boundary in the southern part of the Ulleung Basin suggests that the Ulleung Basin has been deformed by a collision of the Phillipine plate into the Japan arc.

• Economic and Environmental Geology
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• v.49 no.4
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• pp.249-267
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• 2016

The Hongseong area of the central-western Korean Peninsula is considered to be a part of collision zone that is tectonically correlated to the Qinling-Dabie-Sulu belt of China. The area includes the elliptical-shaped serpentinized ultramafic bodies, together with mafic rocks. The studied bodies are in contact with the surrounded Neoproterozoic alkali granites at the Baekdong and Wonnojeon bodies and the Paleoproterozoic Yugu gneiss at the Bibong body. The Baekdong body contains the blocks of the Neoproterozoic alkali granites and the Late Paleozoic metabasites. The Bibong body also includes the Neoproterozoic alkali granite blocks. The Mesozoic intrusive rocks are also recognized at the Baekdong, Wonnojeon and Bibong bodies. On the other hand, the Early Cretaceous volcanic rocks are occurred at the Bibong body. The detrital zircon SHRIMP U-Pb ages of the serpentinites at three bodies range variously from Neoarchean to Middle Paleozoic at the Baekdong body, and from Neoarchean to Early Cretaceous at the Wonnojeon and Bibong bodies. Although serpentinization does not generally produce minerals suitable for direct isotopic dating, the youngest Middle Paleozoic age at the Baekdong body and the Early Cretaceous age at the Wonnojeon and Bibong bodies indicate the possible upper age limit for the (re)serpentinization. Especially, the Early Cretaceous serpentinization ages may be related to the widespread Early Cretaceous igneous activity in the central-southern Korean Peninsula. Age results for the serpentinite bodies and the included blocks of the studied serpentinized ultramafic bodies in the Hongseong area, therefore, provide several possible interpretations for the serpentinization ages of the ultramafic rocks as well as the geotectonic implications of serpentinization, requiring more detailed study including other serpentinized ultramafic bodies in the Hongseong area.

• Economic and Environmental Geology
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• v.35 no.1
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• pp.1-12
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• 2002

Manus Basin, located in the equatorial western Pacific, is a back arc basin formed by collision between the IndoAustralian and the Pacific Plates. The basin is host to numerous hydrothermal vent fields and ore deposits. The basement rocks of the Manus Basin consist primarily of dacite and basaltic andesite. Some of the minerals that form the hydrothermal chimneys that were dredged on the Manus basin include pyrite, chalcopyrite, marcasite, sphalerite and galena. The chimneys can be classified into chalcopyrite dominant Cu-rich type and sphalerite dominant Zn-rich type. The concentration of Zn shows good positive correlation with that of Sb, Cd and Ag. The content of Cu, on the other hand, positively correlates with that of Mo, Mn and Co. For samples that were taken from Zn-rich chimney, a strong positive correlation is found between Au and Zn contents. The chimney also shows enrichments of Cd, Mn and Sb. On the other hand, the samples from Cu-rich chimney exhibit strong correlation among Au, Zn and Pb, and are enriched in Mo and Co concentration. Average contents of Au in Cu-rich and Znrich chimneys were 15.9 ppm and 29.0 ppm, respectively. Because of high concentration of Au with Ag and Cu, the ore deposit have high economic potential. Homogenization temperatures and salinities of fluid inclusions in anhydrite and amorphous silica from Zn-rich chimney are estimated to be l74-220$^{\circ}$C and 2.7-3.6 equiv. wt. % NaCI, respectively. These value suggest that ore forming processes were occurred at around 200$^{\circ}$C and that the oxygen fugacity changed from 2: 10$^{-39.5}$bar to -s: 10$^{-40.8}$bar and the sulfur fugacity from -s: 10$^{-14.7}$bar to 10$^{-13.4}$bar during the process. It appears that the temperature at which the ores formed on Cu-rich chimney was higher than that on Zn-rich chimney.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.388-394
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• 2010

Metabolomics aims at the comprehensive, qualitative and quantitative analysis of wide arrays of endogenous metabolites in biological samples. It has shown particular promise in the area of toxicology and drug development, functional genomics, system biology and clinical diagnosis. In this study, analytical technique of MS instrument with high resolution mass measurement, such as time-of-flight (TOF) was validated for the purpose of investigation of amino acids, sugars and fatty acids. Rat urine and serum samples were extracted by selected each solvent (50% acetonitrile, 100% acetonitrile, acetone, methanol, water, ether) extraction method. We determined the optimized liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) system and selected appropriated columns, mobile phases, fragment energy and collision energy, which could search 17 metabolites. The spectral data collected from LC/TOFMS were tested by ANOVA. Obtained with the use of LC/TOFMS technique, our results indicated that (1) MS and MS/MS parameters were optimized and most abundant product ion of each metabolite were selected to be monitorized; (2) with design of experiment analysis, methanol yielded the optimal extraction efficiency. Therefore, the results of this study are expected to be useful in the endogenous metabolite fields according to validated SOP for endogenous amino acids, sugars and fatty acids.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.628-636
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• 2018

Because large buoys are mainly made of steel, they are heavy and vulnerable to corrosion by sea water. This makes buoy installation and maintenance difficult. Moreover, vessel collision accidents with buoys and damage to vessels due to the material of buoys (e.g., steel) are reported every year. Recently, light buoys adopting eco-friendly and lightweight materials have come into the spotlight in order to solve the previously-mentioned problems. In Korea, a new lightweight buoy with a 7-Nautical Mile lantern adopting expanded polypropylene (EPP) and aluminum to create a buoyant body and tower structure, respectively, was developed in 2017. When these light buoys are operated in the ocean, the visibility and angle of light from the lantern installed on the light buoys changes, which may cause them to function improperly. Therefore, research on the performance of light buoys is needed since the weight distribution and motion characteristics of these new buoys differ from conventional models. In this study, stability estimation and motion analyses for newly-developed buoys under various environmental conditions considering a mooring line were carried out using ANSYS AQWA. Numerical simulations for the estimation of wind and current loads were performed using commercial CFD software, Siemens STAR-CCM+, to increase the accuracy of motion analysis. By comparing the estimated maximum significant motions of the light buoys, it was found that waves and currents were more influential in the motion of the buoys. And, the estimated motions of the buoys became larger as the sea state became worser, which might be the reason that the peak frequencies of the wave spectra got closer to those of the buoys.

• The Journal of the Petrological Society of Korea
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• v.26 no.3
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• pp.235-254
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• 2017

We investigate the geological history that formed geology and landscapes of the Juwangsan National Park and its surrounding areas. The Juwangsan area is composed of Precambrian gneisses, Paleozoic metasedimentary rocks, Permian to Triassic plutonic rocks, Early Mesozoic sedimentary rocks, Late Mesozoic plutonic and volcanic rocks, Cenozoic Tertiary rhyolites and Quaternary taluses. The Precambrian gneisses and Paleozoic metasedimentary rocks of the Ryeongnam massif occurs as xenolithes and roof-pendents in the Permian to Triassic Yeongdeok and Cheongsong plutonic rocks, which were formed as the Songrim orogeny by magmatic intrusions occurring in a subduction environment under the northeastern and western parts of the area before a continental collision between Sino-Korean and South China lands. The Cheongsong plutonic rocks were intruded by the Late Triassic granodiorite, which include to be metamorphosed as an orthogneiss. The granodiorite includes geosites of orbicular structure and mineral spring. During the Cretaceous, the Gyeongsang Basin and Gyeongsang arc were formed by a subduction of the Izanagi plate below East Asia continent in the southeastern Korean Peninsula. The Gyeongsang Basin was developed to separate into Yeongyang and Cheongsong subbasins, in which deposited Dongwach/Hupyeongdong Formation, Gasongdong/Jeomgok Formation, and Dogyedong/Sagok Formation in turn. There was intercalated by the Daejeonsa Basalt in the upper part of Dogyedong Formation in Juwangsan entrance. During the Late Cretaceous 75~77 Ma, the Bunam granitoid stock, which consists of various lithofacies in southwestern part, was made by a plutonism that was mixing to have an injection of mafic magma into felsic magma. During the latest Cretaceous, the volcanic rocks were made by several volcanisms from ubiquitous andesitic and rhyolitic magmas, and stratigraphically consist of Ipbong Andesite derived from Dalsan, Jipum Volcanics from Jipum, Naeyeonsan Tuff from Cheongha, Juwangsan Tuff from Dalsan, Neogudong Formation and Muposan Tuff. Especially the Juwangsan Tuff includes many beautiful cliffs, cayon, caves and falls because of vertical columnar joints by cooling in the dense welding zone. During the Cenozoic Tertiary, rhyolite intrusions formed lacolith, stocks and dykes in many sites. Especially many rhyolite dykes make a radial Cheongsong dyke swarm, of which spherulitic rhyolite dykes have various floral patterns. During the Quaternary, some taluses have been developed down the cliffs of Jungtaesan lacolith and Muposan Tuff.