• Korean Journal of Environmental Agriculture
• /
• v.31 no.2
• /
• pp.157-163
• /
• 2012

BACKGROUND: For the safety of imported agricultural products, the study was conducted to develop the analytical method of unregistered pesticides in domestic. The analytical method of 6 pesticides, chlorthal-dimethyl, clomeprop, diflufenican, hexachlorobenzene, picolinafen, and propyzamide, for a fast multi-residue analysis were established for two different type crops, orange and brown rice by GC-ECD and confirmed by mass spectrometry. METHODS AND RESULTS: The analytical method was evaluated to limit of quantification, linearity and recoveries. The crop samples were extracted with acetonitrile and performed cleanup by liquid-liquid partition and Florisil SPE to remove co-extracted matrix. The extracted samples were analyzed by GC-ECD with good sensitivity and selectivity of the method. The limits of quantification (LOQ) range of the method with S/N ratio of 10 was 0.02~0.05 mg/kg for orange and brown rice. The linearity for targeted pesticides were $R^2$ >0.999 at the levels ranged from 0.05 to 10.0 mg/kg. The average recoveries ranged from 74.4% to 110.3% with the percentage of coefficient variation in the range 0.2~8.8% at two different spiking levels (0.02 mg/kg and 0.2 mg/kg, 0.05 mg/kg and 0.5 mg/kg) in brown rice. And the average recoveries ranged from 77.8% to 118.4% with the percentage of coefficient variation in the range 0.2~6.6% at two different spiking levels (0.02 mg/kg and 0.2 mg/kg, 0.05 mg/kg and 0.5 mg/kg) in orange. Final determination was by gas chromatography/mass spectrometry/selected ion monitoring (GC/MS/SIM) to identify the targeted pesticides. CONCLUSION: As a result, this developed analytical method can be used as an official method for imported agricultural products.

• Korean Journal of Food Science and Technology
• /
• v.42 no.1
• /
• pp.27-32
• /
• 2010

This study was conducted to monitor aflatoxins in various medicinal herbs, providing available data for the safety of those products. To monitor aflatoxins in medicinal herbs, a total of 400 samples of 40 different herbs were collected in commercial retailers in Seoul, Daejeon, Gwangju, Daegu, and Busan from March to August, 2008. The samples that passed the sensory evaluation were tested for aflatoxins. Aflatoxins in samples were analyzed by HPLC-florescence coupled with photochemical enhancement. Samples were extracted with 70% methanol and then diluted to the appropriate concentration. A refining process was performed using an immunoaffinity column. The analytical method used in this study was validated. The $R^2$ value for aflatoxin $B_1$ was 0.99946, and the detection range was from 0.25 to 10.0 ng/mL. The accuracy of the analysis was ranged from 83.2% to 101.8%. The relative standard deviation (RSD) in the aflatoxin $B_1$ analysis was 3.4%, demonstrating the precision of this method. In addition, the detection limit and quantitative analysis limit of aflatoxin $B_1$ was $0.53\;{\mu}g/kg$ and $1.76\;{\mu}g/kg$, respectively. These results indicated that the analytical method used in this study was appropriate. The results of HPLC showed that 1% (4 samples) of the samples may contain aflatoxins. The concentration of quantified aflatoxin was $2.3\;{\mu}g/kg$ for both Quisqualis fructus and Remotiflori radix samples. The other samples were below the limit of quantification. Moreover, the concentration of aflatoxin $B_1$ which is made by specific fungi were below the level of regulation. Only 20% of aflatoxin $B_1$ were transferred to hot water. Therefore, the levels of aflatoxins in medicinal herbs were considered to be safe especially considering the aflatoxin transfer ratio.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.5
• /
• pp.579-596
• /
• 1997

A simulation study was carried out to delineate potential effects of the lake-induced climate change on crop productivity around Lake Imha which was formed after a multi-purpose dam construction in Andong, Korea. Twenty seven cropping zones were identified within the 30 km by 25 km study area. Five automated weather stations were installed within the study area and operated for five years after the lake formation. A geostatistical method was used to calculate the monthly climatological normals of daily maximum and minimum temperature, solar radiation and precipitation for each cropping zone before and after the dam construction. Daily weather data sets for 30 years were generated for each cropping zone from the monthly normals data representing "No lake" and "After lake" climatic scenarios, respectively. They were fed into crop models (ORYZA1 for rice, SOYGRO for soybean, CERES-maize for corn) to simulate the yield potential of each cropping zone. Calculated daily maximum temperature was higher after the dam construction for the period of October through March and lower for the remaining months except June and July. Decrease in daily minimum temperature was predicted for the period of April through August. Monthly total radiation was predicted to decrease after the lake formation in all the months except February, June, and September and the largest drop was found in winter. But there was no consistent pattern in precipitation change. According to the model calculation, the number of cropping zones which showed a decreased yield potential was 2 for soybean and 6 for corn out of 27 zones with a 10 to 17% yield drop. Little change in yield potential was found at most cropping zones in the case of paddy rice, but interannual variation was predicted to increase after the lake formation. the lake formation.

• Analytical Science and Technology
• /
• v.27 no.5
• /
• pp.234-242
• /
• 2014

Imicyafos which is a nematicide for controlling root-knot nematodes has been registered in the Republic of Korea in 2012, and the maximum residue limits of imicyafos are set to watermelon and korean melon as each 0.05 mg/kg. Extremely reliable and sensitive analytical method is required for ensuring food safety on imicyafos residues in agricultural commodities. Imicyafos residues in samples were extracted with acetone, partitioned with hexane and dichloromethane, and then purified with florisil. The purified samples were analyzed by HPLC-UVD and confirmed with LC-MS. Linear range was between 0.1~5 mg/kg with the correlation coefficient ($r^2$) 0.99997. Average recoveries of imicyafos ranged from 77.0 to 115.4% at the spiked levels of 0.02 and 0.05 mg/kg with the relative standard deviations of 2.2~9.6%. Limit of detection and quantification were 0.005 and 0.02 mg/kg, respectively. An inter-laboratory study was conducted to validate the determination method in depth, and the results were satisfactory. All of the validation results revealed that the developed analytical method in this study is relevant for imicyafos determination in agricultural commodities and will be used as an official analytical method.

• Korean Journal of Ecology and Environment
• /
• v.43 no.2
• /
• pp.279-287
• /
• 2010

This study was to evaluate ecological conditions of Hyeongsan River watershed from April to September 2009. The ecological health assessments was based on Qualitative Habitat Evaluation Index (QHEI), water chemistry during 2000~2009, and the fish multi-metric model, Index of Biological Integrity (IBI). For the study, the models of IBI and QHEI were modified as 8 and 11 metric attributes, respectively. Values of IBI averaged 25.4 (n=6), which is judged as a "fair" condition (C) after the criteria of Barbour et al. (1999). The distinct spatial variation was found in the IBI. Physical habitat health, based on the values of QHEI, varied from 76 in the downriver (H6) to 150.5 in the headwater (H1) and was evidently more disturbed in the downriver reach. Values of BOD and COD averaged 2.4 $mgL^{-1}$ (range: 0.3~13.8 $mgL^{-1}$) and 4.3 $mgL^{-1}$ (scope: 0.6~12.8 $mgL^{-1}$), respectively during the study period. Total nitrogen (TN) and total phosphorus (TP) averaged 3.0 $mgL^{-1}$ and 103.5 ${\mu}gL^{-1}$, respectively, indicating a severe eutrophication, and the nutrients increased more in the downriver than the headwater. Overall, physical, chemical and IBI parameters showed a typical downriver degradation along main axis of the river from the headwater-to-the downriver. This was mainly attributed to livestock waste and residential influences along with industrial discharge from the urban region.

• Journal of The Korean Association For Science Education
• /
• v.21 no.1
• /
• pp.102-113
• /
• 2001

In order to compare with the 6th and 7th science curricular for the inquiry skill elements in the elementary and secondary school, we divided skill domains into five classes which were process skill, step skill for inquiry instruction, inquiry activity skill, manipulative skill and breeding-farming skill. And then we investigated the kinds and frequencies for the inquiry skill elements of the 6th and 7th curricular in the elementary and secondary school. The results were as follows: 1. The total kinds of inquiry skill element showed 17 kinds in the 6th curriculum and 23 kinds in the 7th. Therefore, the 7th curriculum was higher 1.4 times than the 6th curriculum in the kinds of skill elements. 2. The total frequencies for the inquiry skill elements of the 6th curriculum were 408 and those of the 7th were 729. Therefore, the 7th curriculum was about 1.8 times as many as the 6th. 3. In the kinds of inquiry skill elements according to the school levels, the course of the elementary school showed 14 kinds in the 6th curriculum and 18 kinds in the 7th. The course of middle school showed 7 kinds in 6th and 16 kinds in 7th. The integrated science course of high school was 10 kinds in the 6th and 10 kinds in the 7th. The skill elements in four science curricular of the high school course showed total 11 kinds in the 6th and 21 kinds in the 7th. And then the kinds of inquiry skill elements of the 7th curriculum in the middle and high school course showed about 2 times as many as the 6th curriculum. In the school level, the increase of skill elements showed the highest in the middle school course, and then in the high school course. 4. The total skill elements from the elementary school to the high school in the 6th science curriculum showed 17 kinds and in the order from the highest to the lowest rates, such as experimenting 20%, observing 15%, interpreting and analyzing data 13%, investigating 9%, measuring 7%, drawing a conclusion and assessment 7%, discussion 6%, communicating 5%, classifying 4%, recognizing problems and formulating hypothesis 4%, predicting 3%, designing and carrying out an experiment 3%, collecting and treating data 2%, manipulating skill 1%, modeling 0.5%, breeding and farming 0.3% and inferring 0.2%. 5. The total skill elements from the elementary school to the high school in the 7th curriculum appeared 23 kinds and in the order from the highest to the lowest rates, such as drawing a conclusion and assessment 31%, investigating 14%, collecting and treating data 8%, observing 7%, experimenting 7%, recognizing problems and formulating hypothesis 6%, interpreting and analyzing data 4%, measuring 3%, discussion 3%, manipulating skill 3%, modeling 3%, classifying 2%, project 2%, educational visits 1%, controlling variables 1%, predicting 1%, inferring 1%, operational definition 1%, communicating 1%, designing and carrying out an experiment 0.3%, breeding and farming 0.3%, applicating a number 0.2% and relating with time and space 0.2%. In the conclusion, the 7th curriculum was added 6 kinds of skill elements to the 6th curriculum, such as operational definition, applicating a number, relating with time and space, controlling variables, educational visits and project.

• Journal of dental hygiene science
• /
• v.13 no.4
• /
• pp.510-517
• /
• 2013

This study was carried out in order to be utilized as basic data necessary for developing dental hygiene curriculum by confirming the difference in propensity level and the variables of having influence upon problem-solving ability of dental hygiene students and by grasping influence of relevant variables at the point of time that requires arrangement of a learning system for promoting problem solving ability aiming to train talents who have ability available for performing successful practical affairs. The influence of factors upon the problem solving ability had statistically significant relationship with academic year, interpersonal relations, school record, and major satisfaction. According to academic year, the problem solving ability of sophomore (B=-0.182, p=0.010) was shown the lower tendency than junior. The problem solving ability was lower in when being bad (B=-0.349, p=0.020) compared to when being good as for interpersonal relations, in when the mark is under 3.0 (B=-0.328, p=0.004) than over 4.0 as for academic achievement, and in when being dissatisfied (B=-0.483, p=0.005) than when being satisfied as for the major satisfaction. Hence, to train competent people who have ability available for performing successful practical affairs, the education is considered to be likely needed that has substantial problem solving ability for reinforcing problem solving ability by grasping a learning problem oneself without the differentiated curriculum, by establishing an alternative plan for solving problem, and by searching for and acquiring necessary data according to factors of having influence upon problem solving ability of dental hygiene students.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.39 no.3
• /
• pp.241-249
• /
• 2013

This study was aimed to provide the fundamental data about oxidized hair color products. For this reason, we collected 125 oxidized hair color products, which were distributed in domestic market from January to October, 2012, and measured the heavy metal concentrations of lead, arsenic, cadmium, chromium, manganese, nickel, copper in the samples. Results were compared by domestic, foreign, henna, type and color. The average metal concentrations were as follows; 0.211 ${\mu}g/g$ for lead, 0.008 ${\mu}g/g$ for cadmium, 0.051 ${\mu}g/g$ for arsenic, 0.954 ${\mu}g/g$ for chromium, 6.250 ${\mu}g/g$ for manganese, 0.591 ${\mu}g/g$ for nickel and 0.544 ${\mu}g/g$ for copper. In case of lead and arsenic, the concentrations were much less than the regulated amount (20 ${\mu}g/g$ and 10 ${\mu}g/g$, respectively) suggested by MFDS (Ministry of Food and Drug Safety). In henna (p < 0.05), the concentrations were significantly higher than those of other domestic and foreign oxidized hair color products as follows; 1.264 ${\mu}g/g$ for lead, 0.267 ${\mu}g/g$ for arsenic, 0.025 ${\mu}g/g$ for cadmium, 4.055 ${\mu}g/g$ for chromium, 72.044 ${\mu}g/g$ for manganese, 3.076 ${\mu}g/g$ for nickel and 4.640 ${\mu}g/g$ for copper. Statistically, it showed that the heavy metal concentrations were quite different for the different types of hair color products. The cream and liquid type products had the highest average concentration in chromium (0.708 ${\mu}g/g$, 0.478 ${\mu}g/g$, respectively). On the other hand, powder type products showed the highest concentration in manganese (60.041 ${\mu}g/g$). In addition, the concentrations of heavy metals and the color of products are not quite correlated. It was shown that average concentrations of lead and chromium were higher for yellow, chromium for red and pink, manganese for brown and black, and nickel for green.

• Korean journal of applied entomology
• /
• v.37 no.2
• /
• pp.171-178
• /
• 1998

This study was conducted to investigate the effect of temperature on the development of amushroom-infesting sciarid fly, Bradysia sp. (Diptera: Sciaridae). Egg period was 12.1, 7.0, 4.4, 3.4, and3.2 days, larval period was 38.3, 26.5, 13.4, 13.2, 12.7 days and pupal period was 10.4, 7.1, 4.4, 3.3, 3.2days, and total development period from egg to adult emergence was 60.8,40.6, 22.2, 19.9, and 19.1 daysat 10, 15, 20,25, 28"C, respectively. Development threshold temperature (DT) and effective accumulativetemperatures (ET) were 3.8"C, 74.8DD in eggs, 1.2"C, 321.8DD in larva, and 3.1$^{\circ}$C, 76.5DD in pupa,respectively. The number of eggs laid per female was 107.9, 129.7, 131.8, 86.9, and 82.7 at respectivetemperatures. Preoviposition period was 6.6, 4.4, 2.2, 1.3, 1.8 days, oviposition period 1.5, 1.5, 1.1, 1.1,1.1 days, postoviposition period 2.0, 1.1, 0.9, 0.6, and 0.3 days at th'e temperature of 10, 15, 20, 25 and 28"C, respectively. The longevity of male and female at the temperature was 13.3, 7.8, 5.9,4.1, 3.4 days and10.4, 7.0, 4.2, 3.0, 3.3days, respectively. The optimum temperature for hatchability was estimated to the20$^{\circ}$C and adult emergence was highest at 20$^{\circ}$C. Pupation rate was 50.7, 68.4, 84.3, 86.5, 45.4% at 10, 15,20, 25, and 28"C, respectively. at 10, 15,20, 25, and 28"C, respectively.tively.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.34 no.3
• /
• pp.98-114
• /
• 2016

The this study aimed to expand urban heritage using Public Goods and to suggest the assemblage of urban heritage and urban spaces in order to improve landscape conservation and management scheme of urban heritage exposed to a rapidly changing urban environment. The results obtained in this study were summarized as follows: First, in order to improve understanding of the heritage in urban spaces, urban heritage were illustrated on a 1:1000 map with all the public facilities surrounding it using a cultural heritage conservation map listed on the Cultural Heritage Administration's web site, standards for changing present condition, and a topographic map. Second, the status and changes of urban heritage and surroundings were analyzed using the minutes of Historical Cultural Heritage Division Committee for 10 years from 2005 to 2014 to create a status map of urban heritage. Land uses surrounding the urban heritage were investigated the areas of conservation potential and the places that can enhance the to find out values of urban heritage. Also, a profile was created to examine the site characteristics surrounding urban heritage, and photos were taken at important heritage areas and public facilities in order to record the field. Third, analyzed were the relationship of the distance, location, function, and distribution between urban heritage and public facilities surrounding the heritage. using visual features and moving routes in order to identify their impacts on urban heritage and their functions as potential resources. In addition, the role of Public Goods in urban spaces and the plan for revitalizing surrounding areas asset were examined. Fourth, selections were made on Public Goods that have direct or indirect effects on urban heritage. The role of public asset was investigated through visual, areal, and linear elements. The results were summarized to suggest improvement landscape and management mauser on of urban heritage.