• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.556-566
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• 2010

A new kinetic spectrophotometric method is developed for the measurement of Mn(II) in natural water samples. The method is based on the catalytic effect of Mn(II) with the oxidation of Gallocyanin by $KIO_4$ using nitrilotriacetic acid (NTA) as an activation reagent at 620 nm. The optimum conditions obtained are $4.00{\times}1^{-5}\;M$ Gallocyanin, $KIO_4$, $1.00{\times}10^{-4}\;M$ NTA, 0.1 M HAc/NaAc buffer of pH = 3.50, the reaction time of 5 min and the temperature of $30^{\circ}C$. Under the optimum conditions, the proposed method allows the measurement of Mn(II) in a range of $0.1\;-\;4.0\;ng\;mL^{-1}$ and with a detection limit of down to $0.025\;ng\;mL^{-1}$. The recovery efficiency in measuring the standard Mn(II) solution is in a range of 98.5 - 102%, and the RSD is in a range of 0.76 - 1.25%. The newly developed kinetic method has been successfully applied to the measurement of Mn(II) in both some environmental water samples and certified standard reference river water sample, JAC-0031 with satisfying results. Moreover, few cations and anions interfere with the measurement of Mn(II). Compared with the other catalytic-kinetic methods and instrumental methods, the proposed kinetic method shows fairly good selectivity and sensitivity, low cost, cheapness, low detection limit and rapidity. It can easily and successfully be applied to the real water samples with relatively low salt content and complex matrices such as bottled drinking water, cold and hot spring waters, lake water, river water samples.

• Korean Journal of Environmental Agriculture
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• v.32 no.1
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• pp.78-83
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• 2013

BACKGROUND: This study was performed to investigate the change of deltamethrin residue after spraying for control of hygienic insects in bush of levee at Bansuk-dong stream (A) and Juk-dong ditch (B) in Yuseong, Daejeon. The drop concentrations and disappearance of deltamethrin residue in stream water were determined to evaluate the toxic effects of stream ecosystem. METHODS AND RESULTS: Water samples were collected at 7 points including 0, 5, 10, 20, 40, 70 and 100 m downstream from the deltamethrin spraying point. Water sample was partitioned into dichloromethane, and was determined with GC/${\mu}$-ECD. Limit of Quantitation of deltamethrin was 0.04 ${\mu}g/L$. Recoveries of deltamethrin at two fortification levels of 0.4 and 2.0 ${\mu}g/L$ were $91.57{\pm}3.13%$(n=3) and $94.40{\pm}4.59%$(n=3) in A stream, and $88.24{\pm}3.33%$(n=3) and $85.20{\pm}3.73%$(n=3) in B stream, respectively. Residue of A stream were from <0.04 ${\mu}g/L$ to 0.48 ${\mu}g/L$ and B stream were from 0.08 ${\mu}g/L$ to 14.95 ${\mu}g/L$ under practice application condition. And residues were from <0.04 ${\mu}g/L$ to 0.2 ${\mu}g/L$ in A stream treated deltamethrin with 1.0 mg level at the upper region. CONCLUSION(S): Practice application of deltamethrin for the pest control of waterside was not much shown toxic effect to ecosystem of stream.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.550-562
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• 2008

Background: We attempted to reproduce a previously reported method that is known to be effective for decellularization, and we sought to find the optimal condition for decellularization by introducing some modifications to this method. Material and Method: Porcine semilunar valves, arterial walls and pericardium were processed for decellularization with using a variety of combinations and concentrations of decellularizing agents under different conditions of temperature, osmolarity and incubation time. The degree of decellularization and the preservation of the extracellular matrix were evaluated by staining with hematoxylin and eosin and with alpha-Gal and DAPI in some of the decellularized tissues. Result: Decellularization was achieved in the specimens that were treated with sodium deoxycholate, sodium dodesyl sulfate, Triton X-100 and sodium dodesyl sulfate with Triton X-100 as single-step methods, and this was also achieved in the specimens that were treated with hypotonic solution ${\rightarrow}$ Triton X-100 ${\rightarrow}$ sodium dodesyl sulfate, sodium deoxycholate ${\rightarrow}$ hypotonic solution ${\rightarrow}$ sodium dodesyl sulfate, and hypotonic solution sodium dodesyl sulfate as multi-step methods. Conclusion: Considering the number and the amount of the chemicals that were used, the incubation time and the degree of damage to the extracellular matrix, a single-step method with sodium dodesyl sulfate and Triton X-100 and a multi-step method with hypotonic solution followed by sodium dodesyl sulfate were both relatively optimal methods for decellularization in this study.

• Journal of dental hygiene science
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• v.16 no.3
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• pp.235-241
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• 2016

This study was conducted to provide basic understanding regarding possible enamel erosion by three kinds of fist-aid antipyretic and analgesic medicines over a period of time, with comparison and analysis of the resulting deciduous teeth surface and microhardness changes. The analysis was performed using energy dispersive X-ray spectroscopy (EDX) and scanning electron microscope (SEM) to examine the surface erosion and changes. The Kruskal-Wallis test show differences in surface erosion and changes after 3, 5 and 8 days of treatment as well as before and after the treatment in each group. According to the results, there was no significant difference in the early deciduous teeth enamel surface microhardness (p>0.01). However there were signigicant changes after 3, 5, and 8 days (p<0.01). Calcim (Ca) and phosphorous (P) analysis using EDX showed significant differences in the enamel characteristics according to each tissue area after 8 days (p<0.05), but there was no significant difference in any of the areas for P content (p>0.05). In the surface observation with the SEM treatment with Children's Tylenol$^{(R)}$ tablet, which has the lowest pH, looked the roughest, followed by Brufen syrup for children and Children's Tylenol$^{(R)}$ suspension. Based on these results, it should be considered that antipyretic and analgesic medicines for children, which have lower pH values, may cause tooth erosion. Hence, it is necessary to give special attention to oral hygiene in young children or infants by brushing their teeth after such drugs are administered.

• Korean journal of applied entomology
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• v.43 no.3 s.136
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• pp.195-200
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• 2004

The occurrence pattern and bionomics of Selatosomus puncticollis (Motschulsky) were surveyed in three net house (6$\times$70m) in the field and in a laboratory ($20^{\circ}C$, RH$75\%$, L16/DB). Emergence of hibernated adults of S. puncricollis started from early May, reached peak at early June and diminished in late June. Occurrence rate to total number was $42.1\%$ in early June and $31.7\%$ in late May, when most of hibernated adults emerged at these periods. Adults started to oviposit from mid June, and eggs hatched from early July Larvae turned into pupae from mid July and emerged to adults from mid August. Egg-period was 23 days and pupal period was 21 days. It is estimated that preovipositional period and larval period were approximately 10 months and 30 months, respectively. Wireworms were distributed at the soil depth of 10-5 cm, $56.8\%$ in 1997 and $45.8\%$ in 1998. To establish bait techniques to attract wireworms in the soil, six baits: pieces of potato, carrot, and sweet potato, wheat grains, corns, and flour dough wrapped with gauze, were buried at 15 cm of soil depth, and collected after 5 and 10 days. The numbers of wireworms attracted by potato pieces, wheat grains and sweet potato pieces after 10 days were 1.8, 1.6, and 1.4/bait, respectively. Therefore, burying potato pieces at 15 cm of soil depth and collected after 10 days could be recommended as a wireworm baiting technique.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.2
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• pp.85-94
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• 1997

The study is aimed to find out the causes of rapidly increasing chloride (Cl$^{－}$) concentration of the Samyang 3rd pumping station originated from coastal springs of Cheju since January 1996. The study results show that it was caused by following complicated natural and anthropogenic effects. Due to severe draught in 1996 with total rainfall of only 41.7% of annual mean of the last 36 years (1991 to 1995), it creates firstly), significant decrease of the spring discharges as well decline of the groundwater level at the site . Sea water level was in general 4.4 cm to 12.4 cm higher than the groundwater level of the site during 2 to 3.8 hours at each high tide. Those higher potential head of sea water motivates the sea water intrusion into the fresh water lens through the permeable clinkers and fracture zones situated beneath the existing grouted zone which was installed to a maximum 10 m below the ground water surface, The repeated expansion and contraction of the fresh water lens occurred by periodic changes of the sea water level at high and low tide accelerates secondly the enlargement of the transition zone between the fresh and sea water at the site. The decrease of recharge amount by rainfall shortage creates thirdly the reverse flow at the interface of sea water and groundwater. The repeated groundwater extraction of 2790${\pm}$450 $m^3$d$^{－1}$ at the time of low tide, when the fresh water lens of the sire is under the contraction stare, makes additional drawdown of the ground water level and induces the upconing of salt water into the fresh water lens. The duration of spring discharge whose Cl concentration is less than 150 mg/1 at the low tide measured at the nearby springs was about two hours with discharge rate of 532 $m^3$d$^{－1}$ and after that Cl$^{－}$ concentration is increased up to more than 1900 mg/ι.eased up to more than 1900 mg/L.

• Journal of Animal Environmental Science
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• v.17 no.2
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• pp.81-92
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• 2011

When we bury the infected poultry into the ground, we have many problems such as the difficulty of making sufficient area for burying, environmental contamination by the leachate, unpleasant ordor. Also, in case of burning the carcass of the infected poultry, there are some problems such as high cost, dust, unpleasant odor, etc. It could cause environmental contamination which many peoples and environmental organization complains about. In this study, we develop a treating system which treats the infected poultry carcass in a environmental method preventing the environment contamination. This system is composed of many processes. The euthanasia system uses rigid vinyl to trap and to do a euthanasia the infected poultry with lethal gas, carbon dioxide. And then, with the tractor attached grappler infected poultry carcass could be put into the carcass treating system. The euthanasia system uses rigid vinyl to trap the infected birds and to confine lethal gas, carbon dioxide. Infected poultry carcass are moved to carcass disposal system by collecting device which is attached at tractor. The carcass treatment system (capacity of disposal : 6.3 $m^3$) is installed on a truck and do one pass work, which is input, crush, stir, sterilize, and discharge treated carcass. 1,000 chickens was killed within 9.7min by $CO_2$ (300L/min) in the tent (10 $m^3$). The collecting device could carry 142 chickens at a time, and the movable carcass treatment system could sterilize 2 tons carcass per hour (at one time). This treatment systems was eco-friendly because it reduced the volume of carcass by 31.9% with no wastewater generation.

• Economic and Environmental Geology
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• v.26 no.4
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• pp.433-444
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• 1993

Electrum (32~73 atom. % Ag)-sulfide mineralization of the Bodeok mine in the Boseong area was deposited in two stages of mineralogically simple, massive quartz veins that fill the fractures along fault shear zones in Precambrian gneiss. Radiometric dating indicates that mineralization is Late Jurassic age ($155.9{\pm}2.3$ Ma). Fluid inclusion data show that ore mineralization was formed from $H_2O-CO_2$ fluids with variable $CO_2$ contents ($X_{CO_2}=0.0$ to 0.7) and low salinities (0.0 to 7.4 wt. % eq. NaCl) at temperatures between $200^{\circ}$ and $370^{\circ}C$. Evidence of fluid unmixing ($CO_2$ effervescence) indicates pressures up to 1 kbar. Gold-silver deposition occurred later than base-metal sulfide deposition, at temperatures near $250^{\circ}C$ and was probably a result of cooling and decreasing sulfur activity caused by sulfide precipitation and/or $H_2S$ loss (through fluid unmixing). Calculated sulfur isotope compositions of ore fluids (${\delta}^{34}S_{{\Sigma}S}=1.7$ to 3.3‰) indicate an igneous source of sulfur in hydrothermal fluids. Measured and calculated O and H isotope compositions of ore fluids (${\delta}^{18}O_{water}=4.8$ to 7.2‰, ${\delta}D_{water}=-73$ to -76‰) indicate that mesothermal auriferous fluids at Bodeok were likely mixtures of $H_2O-rich$, isotopically evolved meteoric waters and magmatic $H_2O-CO_2$ fluids.