• Economic and Environmental Geology
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• v.44 no.5
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• pp.399-412
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• 2011

A DEM (digital elevation model) is produced using a digital topographic map and is now a commonly used tool in geologic surveys. This study aimed to clarify the relationship between knickpoints and faults in the Namdae stream by analyzing a DEM of the area. The Namdae drainage basin was divided into three subbasins (S1, S2 and S3) and their knickpoints developed for the middle to mid-upper regions were extracted from the DEM. The relative steepness Ks and concavity depending on the incision rate was higher in S1 than in S2 and S3 regions. We assumed that the incision rate caused by active erosion resulted from several faults crossing the basins rather than differences in rock types. There are 77 knickpoints in the Namdae drainage area, including the low-ranking branch, and 24 of thses are on the main river system (S1, S2, S3). Of these 77 knickpoints, 27 (38%) are matched by faults, and from the three basins, 13 (54%) correspond with faults, indicating that the knickpoints are connected closely with the faults. For example the average Ks (relative steepness), was 38.8, but in the overlapping area of the Samdang and Doocheon faults the Ks value was 42.99~43.39. We suggest that the faults resulted in geomorphic deformation such as the high-Ksn knickpoints. There was little evdence of relationship between the knickpoints and rock boundaries, with 54% of the knickpoints distributed on the S1, S2, and S3 subbasins. We concluded that the drainage basin knickpoints are the result of fault movement and are a type of geomorphologic deformation that could be useful for surveying Quaternary faults or fault extension.

• Economic and Environmental Geology
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• v.53 no.4
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• pp.383-395
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• 2020

The stratigraphical position of the Haengmae Formation can provide clues towards solving the hot issue on the Silurian formation, also known as Hoedongri Formation. Since the 2010s, there have been several reports denying the Haengmae Formation as a lithostratigraphic unit. This study aimed to clarify the lithostratigraphic and chronostratigraphic significance of the Haengmae Formation. The distribution and structural geometry of the Haengmae Formation were studied through geologic mapping, and the correlation of relative geologic age and the absolute age was performed through conodont biostratigraphy and zircon U-Pb dating respectively. The representative rock of the Haengmae Formation is massive and yellow-yellowish brown pebble-bearing carbonate rocks with a granular texture similar to sandstone. Its surface is rough with a considerable amount of pores. By studying the mineral composition, contents, and microstructure of the rocks, they have been classified as pebble-bearing clastic rocks composed of dolomite pebbles and matrix. They chiefly comprise of euhedral or subhedral dolomite, and rounded, well-sorted fine-grained quartz, which are continuously distributed in the study area from Biryong-dong to Pyeongan-ri. Bedding attitude and the thickness of the Haengmae Formation are similar to that of the Hoedongri Formation in the north-eastern area (Biryong-dong to Haengmae-dong). The dip-direction attitudes were maintained 340°/15° from Biryong-dong to Haengmae-dong with a thickness of ca. 200 m. However, around the southwest of the studied area, the attitude is suddenly changed and the stratigraphic sequence is in disorder because of fold and thrust. Consequently, the formation is exposed to a wide low-relief area of 1.5 km × 2.5 km. Zircon U-Pb age dating results ranged from 470 to 449 Ma, which indicates that the Haengmae Formation formed during the Upper Ordovician or later. The pebble-bearing carbonate rock consisted of clastic sediments, suggesting that the Middle Ordovician conodonts from the Haengmae Formation must be reworked. Therefore, the above-stated evidence supports that the geologic age of the Haengmae Formation should be Upper Ordovician or later. This study revealed that the Haengmae Formation is neither shear zone, nor an upper part of the Jeongseon Limestone, and is also not the same age as the Jeongseon Limestone. Furthermore, it was confirmed that the Haengmae Formation should be considered a unit of lithostratigraphy in accordance with the stratigraphic guide of the International Commission on Stratigraphy (ICS).

• Journal of Food Hygiene and Safety
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• v.22 no.2
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• pp.127-131
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• 2007

This study evaluated the bactericidal effect of 10 sanitizers and disinfectants such as ethanol (75 and 95%), iodine (15 and 25 ppm), chlorine (100 and 200 ppm), quaternary ammonium, acid, hydrogen peroxide, and peroxide acetic acid against V. parahaemolyticus. Ten strains of V. parahaemolyticus isolated from Korean foods and 4 strains of standard V. parahaemolyticus were compared for efficacies of various sanitizers and disinfectants by EN 1276 method based on quantitative suspension test. Ethanol (75 and 95%), 25 ppm of iodine, 100 ppm of quaternary ammonium, 145 ppm of hydrogen peroxide and acid showed more than $5log_{10}CFU/mL$ reduction in both clean and dirty conditions. Tests result of chlorine (100 ppm) showed more than $5log_{10}CFU/mL$ reduction in clean condition. Iodine (15 ppm) showed more than $5log_{10}CFU/mL$ reduction except 4 isolated and 1 standard V. parahaemolyticus in clean condition. iodine (15 ppm) also showed under $5log_{10}CFU/mL$ reduction $(0.93{\sim}3.73log_{10}CFU/mL)$ in dirty condition. Eleven hundred ppm of hydrogen peroxide was evaluated as weak sanitizer and disinfectant due to their $0.99{\sim}4.79log_{10}CFU/mL$ reduction on both clean and dirty conditions. Consequently, ethanol, iodine (25 ppm), chlorine (200 ppm), quaternary ammonium, acid and peroxide acetic acid were thought to be effective sanitizer and disinfectant against V. parahaemolyticus.

• Journal of Food Hygiene and Safety
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• v.25 no.1
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• pp.36-42
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• 2010

The method for the determination of ethylenediamine (EDA) and hexamethylenediamine (HMDA) in food simulants was developed, and migration amounts of these compounds was monitored for 124 polyamide (PA) utensils. The diurethane derivatives of EDA and HMDA, which produced by reaction with ethyl chloroformate, were analyzed by using gas chromatograph (GC)/flame ionization detector (FID) and GC/mass spectrometer (MS). The developed method was validated with $0.3\;{\mu}g/mL$ of limit of detection (LOD) for EDA and $0.1\;{\mu}g/mL$ of LOD for HMDA, > 0.999 of linearity($r^2$) and > 88% of recovery. The EDA was detected 1.31 and $02.06\;{\mu}g/mL$ for 2 samples in water. The HMDA was detected $0.29\;-\;0.93\;{\mu}g/mL$ for 3 samples in 20% ethanol and $0.26\;-\;0.44\;{\mu}g/mL$ for 10 samples in n-heptane. These migration levels were below the specific migration limits (SML) of $12\;{\mu}g/mL$ and $2.4\;{\mu}g/mL$ for EDA and HMDA established in EU.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.2
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• pp.125-131
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• 2017

'Saeyoung', a winter triticale (X Triticosecale Wittmack) for forage, was developed at the Department of Rice and Winter Cereal Crop, NICS, RDA in 2012. The cultivar 'Saeyoung' has narrow and long leaves of light green color, middle size and thin culm, and a medium grain of brown color. The heading date and yellow ripe stage of 'Saeyoung' was May 3 and May 27, which were similar to check cultivar 'Shinyoung', respectively. 'Saeyoung' showed a little stronger in cold tolerance and a little weaker in resistance to lodging than the check, and wet injury, powdery mildew, and leaf rust were similar to those of the check cultivar. The forage fresh and dry matter yields of 'Saeyoung' at milk-ripe stages were 47.2 and $15.6MT\;ha^{-1}$, respectively, which was 9% and 4% higher than those of the check. The crude protein content of 'Saeyoung' was 0.4% lower than 6.8% of the check, while was higher than the check cultivar 'Shinyoung' in neutral detergent fiber, acid detergent fiber. Total digestible nutrients of 'Saeyoung' was also 3% lower than 62.8% of the check cultivar. It showed grain yield of $4.1MT\;ha^{-1}$, which was 11% higher than that of the check. 'Saeyoung' is recommended for fall sowing forage crops in areas in which average daily minimum mean temperatures in January are higher than $-10^{\circ}C$.

• Restorative Dentistry and Endodontics
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• v.32 no.2
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• pp.95-101
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• 2007

This study was performed to verify the possibility of MTA and calcium sulfate as a pulp capping agent through comparing the dental pulp response in dogs after capping with MTA, calcium sulfate, and calcium hydroxide. 24 teeth of 2 dogs, 8 month old, were used in this study. Under general anesthesia, cervical cavities were prepared and pulp was exposed with sterilized #2 round bur in a high speed handpiece. MTA calcium hydroxide, and calcium sulfate were applied on the exposed pulp. Then the coronal openin,fs were sealed with IRM and light-cured composite. Two months after treatment, the animals were sacrificed. The extracted teeth were fixed in 10% neutral-buffered formalin solution and were decalcified in formic acid-sodium citrate. They were prepared for histological examination in the usual manner. The sections were stained with haematoxylin and eosin. In MTA group, a hard tissue bridges formation and newly formed odontoblasts layer was observed. There was no sign of pulp inflammatory reaction in pulp tissue. In calcium hydroxide group, there was no odontoblast layer below the dentin bridge. In pulpal tissue, chronic inflammatory reaction with variable intensity and extension occurred in all samples. In calcium sulfate group, newly formed odontoblast layer was observed below the bridge. Mild chronic inflammation with a few neutrophil infiltrations was observed on pulp tissue. These results suggest that MTA is more biocompatible on pulp tissue than calcium hydroxide or calcium sulfate.

• Journal of Animal Science and Technology
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• v.53 no.2
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• pp.119-126
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• 2011

The study was conducted to investigate the effects of dietary energy and protein levels on productivity and feed cost in crossbred chicks. Experiment was divided into starting (0~5 weeks), growing (6~10 weeks), and finishing (11~14 weeks) periods. Design of feeding trials was 3 ${\times}$ 3 factorial to feed different energy and protein levels for starting (ME 2,950, 3,000, and 3,050 kcal/kg CP 18, 19, and 20%), growing (ME 3,000, 3,050, and 3,100 kcal/kg CP 17, 18, and 19%) and finishing (ME 3,050, 3,100, and 3,150 kcal/kg CP 16, 17, and 18%) periods, respectively. In the starting period, weight gain and FCR was improved by dietary protein level (P<0.05). Interaction effect existed in feed intake and FCR (P<0.05). Weight gain was higher in 3,000 kcal/kg ME treatment than 3,100 kcal/kg ME treatment for growing period (P<0.05). In finishing period, feed intake was significantly decreased in ME 3,150 kcal/kg treatment than the other ME treatments (P<0.05). Feed cost/weight gain (FC/WG) was significantly decreased in chicks fed with 2,950 kcal/kg ME and 19% CP in starting period (P<0.05). For the growing period, FC/WG was notably increased in ME 3,000, 3,050 kcal/kg treatment than ME 3,100 kcal/kg treatment, and the FC/WG of CP 17, 18% treatment was significantly higher than CP 16% treatment (P<0.05). Thus, the optimum levels of ME and CP to improve the productivity and feed cost for starting, growing and finishing periods were 2,950 kcal/kg ME, 19% CP 3,000 kcal/kg ME, 18% CP and 3,100 kcal/kg ME, 17 or 16% CP, respectively.

• Journal of Food Hygiene and Safety
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• v.31 no.4
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• pp.227-249
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• 2016

Arsenic and its compounds vary in their toxicity according to the chemical forms. Inorganic arsenic is more toxic and known as carcinogen. The provisional tolerable weekly intake (PTWI) of $15{\mu}g/kg$ b.w./week established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) has been withdrawn, while the EFSA panel suggested $BMDL_{0.1}$ $0.3{\sim}8{\mu}g/kg\;b.w./day$ for cancers of the lung, skin and bladder, as well as skin lesions. Rice, seaweed and beverages are known as food being rich in inorganic arsenic. As(III) is the major form of inorganic arsenic in rice and anaerobic paddy soils, while most of inorganic arsenic in seaweed is present as As(V). The inorganic arsenic in food was extracted with solvent such as distilled water, methanol, nitric acid and so on in heat-assisted condition or at room temperature. Arsenic speciation analysis was based on ion-exchange chromatography and high-performance liquid chromatography equipped with atomic absorption spectrometry and inductively coupled plasma mass spectrometry. However, there has been no harmonized and standardized method for inorganic arsenic analysis internationally. The inorganic arsenic exposure from food has been estimated to range of $0.13{\sim}0.7{\mu}g/kg$ bw/day for European, American and Australian, and $0.22{\sim}5{\mu}g/kg$ bw/day for Asian. The maximum level (ML) for inorganic arsenic in food has established by EU, China, Australia and New Zealand, but are under review in Korea. Until now, several studies have conducted for reduction of inorganic arsenic in food. Inorganic arsenic levels in rice and seaweed were reduced by more polishing and washing, boiling and washing, respectively. Further research for international harmonization of analytical method, monitoring and risk assessment will be needed to strengthen safety management of inorganic arsenic of foods in Korea.

• Korean journal of food and cookery science
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• v.16 no.3
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• pp.267-271
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• 2000

The present study was designed to develop the standardized formula for the preparation Jeung-Pyun with added raw soy flour and to investigate the applicability of Jeung-Pyun as the substitute of regular pizza crust made with wheat flour. The effect of adding raw soy flour at 3%, 5% level on fermentation time and viscosity of batters and texture and general desirability of Jeung-Pyun pizza were also studied. As the level of raw soy flour was increased the time required for 1 st and 2nd fermentation decreased and viscosity of batters increased significantly. Jeung-Pyun crust after steaming found to have appropriate texture and form for a substitute of wheat flour pizza crust. Texture parameters determined by QST showed that Jeung-Pyun crust with added raw soy flour had lower values in hardness, cohesiveness and gumminess without any significant difference. However, chewiness of 5% raw soy flour group was significantly lower than control group. Texture of Jeung-Pyun crust and general desirability of Jeung-Pyun pizza were determined by sensory evaluation. Textural parameters of Jeung-Pyun crust were evaluated on the basis of hardness, cohesiveness, adhesiveness, tenderness and wetness. As a result of sensory evaluation Jeung-Pyun crust made with 5% raw soy flour had significant lower values in hardness, cohesiveness, tenderness and wetness than the control. However, the textural parameters between control and 3 % raw soy flour group were not significantly different. Jeung-Pyun pizza with topping were evaluated by sensory panel. Jeung-Pyun pizza made with 3% raw soy flour received the highest score in apperance and general desirability without any significant difference. 5% raw soy flour group had significantly lower score in general desirability among 3 treatment groups. In conclusion, Jeung-Pyun crust made by traditional Jeung-Pyun preparation method will be a good alternative to replace wheat flour pizza crust. Adding raw soy flour at 3% level did not affect the quality of Jeung-Pyun crust and had an effect of promoting fermentation. Jeung-Pyun Pizza crust was expected to have tender texture and slower retrogradation rate than regular pizza crust with wheat flour.

• Journal of Life Science
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• v.27 no.2
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• pp.202-210
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• 2017

As an effort to find a potential biopreservative, we isolated bacterial strains producing bacteriocin from fermented foods. A strain was finally selected and characteristics of the bacteriocin were investigated. The selected strain was identified as Bacillus subtilis E9-1 based on the 16S rRNA gene analysis. The culture supernatant of B. subtilis E9-1 showed antimicrobial activity against Gram-positive bacteria. Subtilisin A, ${\alpha}$-chymotrypsin, trypsin and proteinase K inactivated the antimicrobial activity, which means its proteinaceous nature, a bacteriocin. The bacteriocin activity was fully retained at the pH range from 2.0 to 8.0 and stable at up to $100^{\circ}C$ for 60 min. Solvents such as ethanol, isopropanol and methanol had no effect on the antimicrobial activity at the concentration of 100% but acetone and acetonitrile reduced the activity at up to 100% concentration. Cell growth of four indicator strains was dramatically decreased in dose-dependent manner. Listeria monocytogenes was the most sensitive, but Enterococcus faecium was the most resistant. Bacillus cereus and Staphylococcus aureus showed the medium sensitivity. The bacteriocin showed its antimicrobial activity against B. cereus and L. monocytogenes via bactericidal action. The number of viable cells of L. monocytogenes started to reduce after addition of bacteriocin to the minced beef. The bacteriocin was purified through acetone concentration, gel filtration chromatography and RP-HPLC. The whole purification step led to a 6.82 fold increase in the specific activity and 6% yield of bacteriocin activity. The molecular weight of the purified bacteriocin was determined to be 3.3 kDa by MALDI-TOF/TOF mass spectrometry.