• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.351-359
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• 1989

This study was conducted to observe the physico-chemical exchange and effect of amino-carbonyl reaction between fructose and glycine . When various buffer solutions were added to equimolar mixture of fructose and glycine at pH 6.0 and $100^{\circ}C$, the browning effect was markedly observed by Mcllvaine buffer. Among the combinations of temperature and reaction time, the deep browning effect was obtained above $100^{\circ}C$, 3hr A marked browning effect obtained above pH 7.0 but little observed below pH 7.0. The browning effect was markedly increased at high fructose concentration. It required 4.0hrs and 32.9hrs to decrease 50% of initial concentration of fructose and glycine at $100^{\circ}C$ and pH 7 but 0.9hrs and 3.8hrs at $120^{\circ}C$, pH 7.0, respectively. The rate constant of fructose and glycine at $100^{\circ}C\;and\;120^{\circ}C$ were $1.78{\times}10^{-1},\;2.11{\times}10^{-2}\;and\;7.74{\times}10^{-1},\;1.83{\times}10^{-1}$, respectively. The formation of HMF was likely to follow the first order kinetics. The addition of 0.1M sodium sulfite, 0.1M sodium bisulfite and 0.1M calcium chloride to equimolar mixture (0.05M) surpressed the reaction up to 76.8%, 76.8% and 96.4%, respectively.

• Korean Journal of Heritage: History & Science
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• v.43 no.3
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• pp.306-333
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• 2010

Previous studies on Wolseong fortress have focused on capital system of Silla Dynasty and on the recreation of Wolseong fortress due to the excavations in and around Wolseong moat. Since the report on the Geographical Survey of Wolseong fortress was published and GPR survey in Wolseong fortress was executed as a trial test in 2004, the academic interest in the site has now expanded to the inside of the fortress. From such context, the preliminary research on the fortress including geophysical survey had been commenced. GPR survey had been conducted for a year from March, 2007. The principal purpose of the recent 3D GPR survey was to provide visualization of subsurface images of the entire Wolseong fortress area. In order to obtain 3D GPR data, dense profile lines were laid in grid-form. The total area surveyed was $112,535m^2$. Depth slice was applied to analyse each level to examine how the layers of the remains had changed and overlapped over time. In addition, slice overlay analysis methodology was used to gather reflects of each depth on a single map. Isolated surface visualization, which is one of 3D analysis methods, was also employed to gain more in-depth understanding and more accurate interpretations of the remain The GPR survey has confirmed that there are building sites whose archaeological features can be classified into 14 different groups. Three interesting areas with huge public building arrangement have been found in Zone 2 in the far west, Zone 9 in the middle, and Zone 14 in the far east. It is recognized that such areas must had been used for important public functions. This research has displayed that 3D GPR survey can be effective for a vast area of archaeological remains and that slice overlay images can provide clearer image with high contrast for objects and remains buried the site.

• Journal of Food Hygiene and Safety
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• v.36 no.3
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• pp.228-238
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• 2021

The aim of this research was to develop a rapid and easy multi-residue method for determining dimethipin, omethoate, dimethipin, chlorfenvinphos and azinphos-methyl in agricultural products (hulled rice, potato, soybean, mandarin and green pepper). Samples were prepared using QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) and analyzed using gas chromatography-tandem mass spectrometry (GC-MS/MS). Residual pesticides were extracted with 1% acetic acid in acetonitrile followed by addition of anhydrous magnesium sulfate (MgSO₄) and anhydrous sodium acetate. The extracts were cleaned up using MgSO₄, primary secondary amine (PSA) and octadecyl (C₁₈). The linearity of the calibration curves, which waas excellent by matrix-matched standards, ranged from 0.005 mg/kg to 0.3 mg/kg and yielded the coefficients of determination (R²) ≥ 0.9934 for all analytes. Average recoveries spiked at three levels (0.01, 0.1, 0.5 mg/kg) and were in the range of 74.2-119.3%, while standard deviation values were less than 14.6%, which is below the Codex guideline (CODEX CAC/GL 40).

• Journal of Food Hygiene and Safety
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• v.37 no.3
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• pp.136-142
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• 2022

The research aims to develop a rapid and easy analytical method for methoprene using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A simple, highly sensitive, and specific analytical method for the determination of methoprene in livestock products (beef, pork, chicken, milk, eggs, and fat) was developed. Methoprene was effectively extracted with 1% acetic acid in acetonitrile and acetone (1:1), followed by the addition of anhydrous magnesium sulfate (MgSO₄) and anhydrous sodium acetate. Subsequently, the lipids in the livestock sample were extracted by freezing them at -20℃. The extracts were cleaned using MgSO₄, primary secondary amine (PSA), and octadecyl (C₁₈), which were then centrifuged to separate the supernatant. Nitrogen gas was used to evaporate the supernatant, which was then dissolved in methanol. The matrix-matched calibration curves were constructed using 8 levels (1, 2.5, 5, 10, 25, 50, 100, 150 ng/mL) and the coefficient of determination (R²) was above 0.9964. Average recoveries spiked at three levels (0.01, 0.1, and 0.5 mg/kg), and ranged from 79.5-105.1%, with relative standard deviations (RSDs) smaller than 14.2%, as required by the Codex guideline (CODEX CAC/GL 40). This study could be useful for residue safety management in livestock products.

• The Korean Journal of Mycology
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• v.7 no.1
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• pp.13-73
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• 1979

These studies were conducted to investigate nutrient sources and supplementary materials of synthetic compost media for Agaricus bisporus culture. Investigation were carried out to establish the optimum composition for compost of Agaricus bisporus methods of out-door fermentation and peakheating with rice straw as the main substrate of the media. The incidence and flora of harmful organisms in rice straw compost and their control were also studied. 1. When rice straw was used as the main substrate in synthetic compost as a carbon source. yields were remarkably high. Fermentation was more rapid than that of barley straw or wheat straw, and the total nitrogen content was high in rice straw compost. 2. Since the morphological and physico-chemical nature of Japonica and Indica types of rice straw are greatly dissimilar. there were apparent differences in the process of compost fermentation. Fermentation of Indica type straw proceeded more rapidly with a shortening the compost period, reducing the water supply, and required adding of supplementary materials for producing stable physical conditions. 3. Use of barley straw compost resulted in a smaller crop compared with rice straw. but when a 50%, barley straw and 50% rice straw mixture was used, the yield was almost the same as that using only rice straw. 4. There were extremely high positive correlations between yield of Agaricus bisporus and the total nitrogen, organic nitrogen, amino acids, amides and amino sugar nitrogen content of compost. The mycerial growth and fruit body formation were severely inhibited by ammonium nitrogen. 5. When rice straw was used as the main substrate for compost media, urea was the most suitable source of nitrogen. Poor results were obtained with calcium cyanamide and ammonium sulfate. When urea was applied three separate times, nitrogen loss during composting was decreased and the total nitrogen content of compost was increased. 6. The supplementation of organic nutrient activated compost fermentation and increased yield of Agaricus bisporus. The best sources of organic nutrients were: perilla meal, sesame meal, wheat bran and poultry manure, etc. 7. Soybean meal, tobacco powder and glutamic acid fermentation by-products which were industrial wastes, could be substituted for perilla meal, sesame meal and wheat bran as organic nutrient sources for compost media. B. When gypsum and zeolite were added to rice straw. physical deterioration of compost due to excess moisture and caramelization was observed. The Indica type of straw was more remarkable in increase of yield of Agricus bisporus by addition of supplementing materials than Japonica straw. 9. For preparing rice straw compost, the best mixture was prepared by 10% poultry manure, 5% perilla meal, 1. 2 to 1. 5% urea and 1% gypsum. At spring cropping, it was good to add rice bran to accelerate heat generation of the compost heap. 10. There was significantly high positive correlation (r=0.97) between accumulated temperature and the decomposition degree of compost during outdoor composting. The yield was highest at accumulated temperatures between 900 and $1,000^{\circ}C$. 11. Prolonging the composting period brought about an increase in decomposition degree and total nitrogen content, but a decrease in ammonium nitrogen. In the spring the suitable period of composting was 20 to 25 days. and about 15 days in autumn. For those periods, the degree of decomposition was 19 to 24%. 12. Compactness of wet compost at filling caused an increase in the residual ammonium nitrogen. methane and organic acid during peak heating. There was negative correlation between methane content and yield (r=0.76)and the same was true between volatile organic acid and yield (r=0.73). 13. In compost with a moisture content range between 69 to 80% at filling. the higher the moisture content, the lower the yield (r=0.78). This result was attributed to a reduction in the porosity of compost at filling the beds. The optimum porosity for good fermentation was between 41 and 53%. 14. Peak heating of the compost was essential for the prevention of harmful microorganisms and insect pests. and for the removal of excess ammonia. It was necessary to continue fer mentatiion for four days after peak heating. 15. Ten species of fungi which are harmful or competitive to Agaricus bisporus were identified from the rice compost, including Diehliomyces microsporus, Trichoderma sp. and Stysanus stemoites. The frequency of occurrance was notably high with serious damage to Agaricus bisporus. 16. Diehliomyces microsporus could be controlled by temperature adjustment of the growing room and by fumigating the compost and the house with Basamid and Vapam. Trichoderma was prevented by the use of Bavistin and Benomyl. 17. Four species of nematodes and five species of mites occured in compost during out-door composting. These orgnanisms could be controlled through peakheating compost for 6 hours at $60^{\circ}C$.

• Journal of Soil and Groundwater Environment
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• v.11 no.1
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• pp.54-64
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• 2006

Chromated copper arsenate (CCA), a wood preservative, has been widely used to protect wood products from attacks by bacteria, fungi and insects. However, the use of CCA is currently forbidden or limited to some applications in many countries because the toxic elements (Cr, Cu, and As) of CCA are released into the environments during outdoor uses, which may cause adverse health effects on humans and ecological systems. This study was conducted to investigate the distributions of chromium, copper and arsenic in soils adjacent to two CCA-treated wood structures. In a 7 month old pond entry structure, ten surface soil samples (0-2.5 cm) were collected at lateral distances of 0, 0.5, and 1 m from the stairway, and nine surface soil samples were collected beneath the deck. Nine top soil samples were taken from a 2 year old sound barrier structure at lateral distances of 0, 1, and 2 m. Background surface soil samples were also collected from each structure. Samples were analyzed for some physicochemical properties such as pH, electrical conductivity, organic matter content, and soil texture. Following the extraction of the elements with a microwave digestion system, samples were analyzed for Cr, Cu, and As. The concentrations of the three elements in soils adjacent to the structures were significantly elevated compared to the background levels, indicating that the elements have been leached out of the structures. Released e1ements showed lateral concentration gradients within 1 m. The elevations of the three elements in soils underneath the deck did not seem different (background-corrected concentrations: Cr, 5.01 mg/kg; Cu, 5.50 mg/kg; As, 4.91 mg/kg), while the elements in soils near the sound barrier were elevated in the order of As>Cu>Cr with measured concentrations of 49.7, 44.7 and 52.5 mg/kg, respectively. Background As, Cu, and Cr concentrations near the sound barrier were 9.88, 30.8, and 46.5 mg/kg, respectively. These results showed that CCA constituents are released into the environment and it is suggested that risk assessment need to be conducted to investigate harmful effects of the released elements on humans and ecological systems.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.3
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• pp.189-203
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• 2008

The physical and chemical properties of radioactive waste drums, which have been temporarily stored on site, should be characterized before their shipment to a disposal facility in order to prove that the properties meet the acceptance guideline. The investigation of NDT(Nondestructive Test) method was figured out that the contents in drum, the quantitative analysis of free standing water and void fraction can be examined with X-ray NDT techniques. This paper describes the characteristics of X-ray NDT such as its principles, the considerations for selection of X-ray system, etc. And then, the waste drum characteristics such as drum type and dimension, contents in drum, etc. were examined, which are necessary to estimate the optimal X-ray energy for NDT of a drum. The estimation results were that: $(R)\acute{A}$ the proper X-ray energy is under 3 MeV to test the drums of 320 ${\beta}\S$ and less; $(R)\ddot{E}$ both X-ray systems of 450 keV and/or 3 MeV might be needed considering the economical efficiency and the realization. The number of drums that can be tested with 450 keV and 3 MeV X-ray system was figured out as 42,327 and 18,105 drums (based on storage of 2006. 12), respectively. Four testing scenarios were derived considering equipment procurement method, outsourcing or not, etc. The economical and feasibility assessment for the scenarios was resulted in that an optimal scenario is dependent on the acceptance guide line, the waste generator's policy on the waste treatment and the delivery to a disposal facility, etc. For example, it might be desirable that a waste generator purchases two 450 keV mobile system to examine the drums containing low density waste, and that outsourcing examination for the high density drums, if all NDT items such as quantitative analysis for 'free standing water' and 'void fraction', and confirmation of contents in drum have to be characterized. However, one 450 keV mobile system seems to be required to test only the contents in 13,000 drums per year.

• Journal of Aquaculture
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• v.8 no.3
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• pp.149-157
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• 1995

In order to obtain the basic knowledges concerned to the semen preservation of aquacultural fishes, studies on the physical and chemical properties of semen, and sperm motility with the different osmotic pressures making by adding $Na^+,\;K^+,\; Mg^{++},\;and\;Ca^{++}$ to artificial seawater (ASW) were conducted in black seabream, Acanthopagrus schlegeli. Average semen volume per fish in one strip was 1.97ml and sperm concentration was $2.33\pm1.30\times10^{10}$ sperm/ml. Spermatocrit and pH of semen were $90.6\pm5.0\;and\;8.3\pm0.1$, respectively, Osmotic pressures of rearing seawater, seminal fluid and plasma were $939\pm24,382\pm70\;and\;342\pm77$ mOsm/l, and $Na^+,\;K^+$ and $Cl^-$ concentrations of seminal fluid were $169.5\pm4.5,\;4.9\pm2.2,\;156.0\pm2.0\;mM/l$, respectively. When semen were diluted by using $Na^+,\;K^+,\;Mg^{++}\;and\;Ca^{++}$ free ASW, only $Na^+$ free ASW had no sperm motility. As raising osmotic pressure graduary by addition of 1M NaCl to the $Na^+$ free ASW, spermatozoa showed the high motilities in 457-1128 mOsm/l, but the low motilities in 1398-1736 mOsm/l. In the case of same treatments with 1M of KCl, $MgC1_2\;and\;CaC1_2$ to the $K^+,\;Mg^{++}\;and\;Ca^{++}$ free ASW, spermatozoa revealed the high motilities in $904\~1434,\;818\~1175\;and\;956\~1343$ mOsm/l, respectively.

• Korean journal of food and cookery science
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• v.11 no.1
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• pp.69-76
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• 1995

This study was concentrated on the subject of chou formation and physicochemical characteristics on medium flour mixed with 0, 25, 50, 75, 100% of rice flour in order to clarify the possibility to substitute rice flour for wheat flour on chou preparation. The water holding capacity, swelling power, and maximum viscosity were higher in rice flour than those in medium flour but the initial pasting temperature was equal to 65$^{\circ}C$ in the two flour groups. The ratio of setback during cooling became 0.94 in the rice flour and 1.14 in the medium flour. So, the rice flour showed a slow tendency during gel formation as compared with the medium flour. The volumes of the rice choux were ranged from 80.0% to 89.0% according to the mixing ratio of medium flour as compared with that of the chou of wheat flour. But, the choux formation were increased as much as 108.8% out the paste added gelation of glutinous substance and 124.4% at the paste added Span20 of emulsifier compared to the non-addition treatment. The paste of rice flour added gelatin and Span20 showed better dispersion of components, especially, the small granules of lipid were fairly or plentifully dispersed in the paste added Span20 due to emulsifying activity. In sensory evaluation, the chou of l00% rice flour was inferior to that of medium flour on cavity-forming but the choux of wheat flour mixed with 25%, 50%, and 75% of rice flour were equal or superior to that of medium flour on all characteristics tested such as appearance, surface color, cavity-forming, chewiness, and taste. There were no significant differences on the cavity-forming expansion and taste between choux of rice flour and wheat flour Therefore, the results of this study made conclusion that rice flour would be substituted for wheat flour on the chou preparation.

• Journal of Animal Science and Technology
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• v.51 no.4
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• pp.337-342
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• 2009

The feasibility of reutilization of magnesium ammonium phosphate (MAP) or struvite slurry recovered from the process through microwave irradiation was studied in this experiment. For this purpose, 4 different operations were performed with or without Mg source addition and different levels of MAP recycled in a batch reactor. Dissolution rate of MAP, ${NH_4}^+$ elimination pattern and physicochemical changes of MAP during microwave irradiation were also studied. The result showed that only 33% orthophosphate ($PO_4-P$) and 27% $NH_4-N$ removal occurred without adding any external Mg source (run A), whereas 87% $PO_4-P$ and 40% $NH_4-N$ removed when 1.0 M ratio of $MgCl_2$ (run B) was added based on $PO_4-P$ in influent. Although the addition of 1.0 molar ratio of microwave irradiated MAP (Run C) removed lower $PO_4-P$ and $NH_4-N$ than 1.0 M $MgCl_2$ (run B), $PO_4-P$ removal was double when compared with no Mg addition (run A). Addition of half MAP and half $MgCl_2$ (run D) showed the similar removal efficiency (88% $PO_4-P$ and 35% $NH_4-N$) with sole $MgCl_2$ addition (run B). Based on these results, the reutilization of MAP irradiated by microwave would be a feasible way to enhance the removal efficiencies of N and P, as well as curtail the Mg chemical usage. Track study showed that $NH_4-N$ gradually increased at initial stage of microwave irradiation of MAP, and then started eliminating from liquor as temperature increased over $45^{\circ}C$. Dissolution rate of ${PO_4}^{-3}$ during microwave irradiation was proportional to the initial MAP concentration, having $0.0091x^{0.6373}$ mg/sec. It was found from the scanning electron microscope (SEM) study that physical structure of MAP crystal started breaking down into small cube granules within very short time by electromagnetic vibration force during microwave irradiation and then gradually melted down into solution.