• Journal of Soil and Groundwater Environment
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• v.19 no.3
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• pp.111-122
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• 2014

Partitioning interwell tracer test (PITT) is a method to quantify and qualify a site contaminated with NAPLs (Non-Aqueous Phase Liquids). Analytical description of PITT assumes that the injection-pumping well pair is on the line of the ambient groundwater flow direction, but the test-well pair could frequently be off the line in a real field site, which could be an erroneous factor in analyzing PITT data. The purpose of this work is to study the influence of the angle of the test-well pair on the ambient groundwater flow direction based on the result from PITT. From the experiments, it was found that the obliqueness of the test-well pair to the ambient groundwater flow direction could affect the tracer test resulting in a decreased NAPL estimation efficiency. In case of an oblique arrangement of the test-well pair to the ambient flow direction, it was found that the injection of a chase fluid could enhance the estimation efficiency. An increase of the pumping rate could enhance the recovery rate but it cannot be said that a high pumping rate can increase the test efficiency because a high pumping rate cannot give partitioning tracers enough time to partition into NAPLs. The results have a implication that because the arrangement of the test-well pair is a controlling factor in performing and interpreting PITT in the field in addition to the known factors such as heterogeneity and the source zone architecture, flow direction should be seriously considered in arranging test-well pair.

• Nuclear Engineering and Technology
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• v.44 no.7
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• pp.807-816
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• 2012

The Three Mile Island Unit 2 (TMI-2) accident has been studied extensively, as part of both post-accident technical assessment and follow-up computer code calculations. The models used in computer codes for severe accidents have improved significantly over the years due to better understanding. It was decided to reanalyze the severe accident scenario using current state of the art codes and methodologies. This reanalysis was adopted as a part of the joint standard problem exercise for the Atomic Energy Regulatory Board (AERB) - United States Regulatory Commission (USNRC) bilateral safety meet. The accident scenario was divided into four phases for analysis viz., Phase 1 covers from the accident initiation to the shutdown of the last Reactor Coolant Pumps (RCPs) (0 to 100 min), Phase 2 covers initial fuel heat up and core degradation (100 to 174 min), Phase 3 is the period of recovery of the core water level by operating the reactor coolant pump, and the core reheat that followed (174 to 200 min) and Phase 4 covers refilling of the core by high pressure injection (200 to 300 min). The base case analysis was carried out for all four phases. The majority of the predicted parameters are in good agreement with the observed data. However, some parameters have significant deviations compared to the observed data. These discrepancies have arisen from uncertainties in boundary conditions, such as makeup flow, flow during the RCP 2B transient (Phase 3), models used in the code, the adopted nodalisation schemes, etc. In view of this, uncertainty and sensitivity analyses are carried out using simulation based techniques. The paper deals with uncertainty and sensitivity analyses carried out for the first three phases of the accident scenario.

• The Korean Journal of Zoology
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• v.11 no.2
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• pp.48-54
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• 1968

Male rats of the Albino strain received methylene blue in the dose of 40mg/kg by subcutaneous injection and were subjected to total body X-irradiation, 300 roentgen, at 30 minutes after the injection. The protective effect of methylene blue against the single total body X-irradiation was studied for 24 days after X-irradiation with regard to the levels of liver glycogen, blood glucose, and electrolytes in serum. 1. Total body X-irradiation generally casued an increase in the levels of the liver glycogen and blood glucose in both methylene blue treated and control group during the entire experiment. 2. Methylene blue has been shown to delay slightly the increase of the levels of the liver glycogen and blood glucose when comparing with both groups which were given methylene blue and control saline injection before irradiation in the rats. 3. The delay in the increase in the levels of liver glycogen, in experimental group injected with methylene blue, significantly came in two phases. The first phase appeared at there days after the exposure, the second followed at eighth day. It appeared that the recovery phase was at nineteenth day. 4. During the experimental days the levels of the blood glucose increased generally, methylene blue, however, caused delay in two phases; the first at fifth day, the second at eighteenth day after the exposure to X-rays. 5. In electrolytes, there was not a significant difference. The levels of chloride were, however, slightly decreased in both groups, levels of potassium appeared different in two phases at first day and twelfth day, and the levels of sodium appeared to show irregular changes at the same levels, but there was no significant difference. 6. It may be considered that methylene blue greatly reduces the sensitivity of rats to X-rays, provided that methylene blue is given before the exposure.

• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.183-192
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• 2004

Two experiments were conducted to examine the effects of the acute phase response on the performance and superoxide dismutase(SOD) activities in liver and erythrocyte of broiler chicks fed dietary krill meals A and B in experiment 1 and krill meal A in experiment 2. The experimental diets are basal diet based on yellow corn and soybean meal and diets substituted 2.0% of krill meal A or B with soybean meal of the basal diet, respectively. Day-old birds fed on the experimental diets and the acute phase response(immunological stress) was activated in the birds on 8-day of age by alternate day injection i.p. with 3 doses the Salmonella typhymurium lipopolysaccharide(LPS) in saline. The values during the acute phase response were compared with those controls injected with saline. The performance; daily gain, feed intake, and feed efficiency were different between dietary krill meal A and B in birds during the acute phase response and in the control. The acute phase response increased relative liver and spleen weights. Recovery of birds from the immunological stress was different between krill meals. Dietary krill meals increased activities of MnSOD and Cu/ZnSOD in erythrocyte cytosols during the actute phase response. Dietary krill meals did not affect the PHA-p response. The results indicated that the dietary krill meals may accentuate oxidative stress during the acute phase response.

• Bulletin of the Korean Chemical Society
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• v.24 no.5
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• pp.559-565
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• 2003

An analytical method the determination of benzo(a)pyrene (BaP) and its hydroxylated metabolites, 1-hydroxybenzo(a)pyrene (1-OHBaP), 3-hydroxybenzo(a)pyrene (3-OHBaP), benzo(a)pyrene-4,5-dihydrodiol (4,5-diolBaP) and benzo(a)pyrene-7,8-dihydrodiol (7,8-diolBaP), in rat urine and plasma has been developed by HPLC/FLD and GC/MS. The derivatization with alkyl iodide was employed to improve the resolution and the detection of two mono hydroxylated metabolites, 1-OHBaP and 3-OHBaP, in LC and GC. BaP and its four metabolites in spiked urine were successfully separated by gradient elution on reverse phase ODS $C_{18}$ column (4.6 mm I.D., 100 mm length, particle size 5 ㎛) using a binary mixture of MeOH/H₂O (85/15, v/v) as mobile phase after ethylation at 90 ℃ for 10 min. The extraction recoveries of BaP and its metabolites in spiked samples with liquid-liquid extraction, which was better than solid phase extraction, were in the range of 90.3- 101.6% in n-hexane for urine and 95.7-106.3% in acetone for plasma, respectively. The calibration curves has shown good linearity with the correlation coefficients (R²) varying from 0.992 to 1.000 for urine and from 0.996 to 1.000 for plasma, respectively. The detection limits of all analytes were obtained in the range of 0.01-0.1 ng/mL for urine and 0.1-0.4 ng/mL for plasma, respectively. The metabolites of BaP were excreted as mono hydroxy and dihydrodiol forms after intraperitoneal injection of 20 mg/kg of BaP to rats. The total amounts of BaP and four metabolites excreted in dosed rat urine were 3.79 ng over the 0-96 hr period from adminstration and the excretional recovery was less than 0.065% of the injection amounts of BaP. The proposed method was successfully applied to the determination of BaP and its hydroxylated metabolites in rat urine and plasma for the pharmacokinetic studies.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.6
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• pp.621-627
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• 2008

In this study, a technique of speciation and determination of the trace inorganic arsenic(As(III) and As(V)) in water sample using HPLC-DRC-ICP-MS has been developed. Isocratic mobile phase of 10 mM ammonium nitrate and 10 mM ammonium phosphate monobasic was used and methanol(5 v/v%) was used as flushing solvent. Selection of the best flow rate of reaction gas, O$_2$, and optimization of the parameters such as pH and flow rate of mobile phase, and injection volume of sample for the separation and detection of arsenic species were carried out. The oxygen flow rate of 0.5 mL/min, pH of 9.4 and flow rate of 1.5 mL/min of mobile phase, and injection volume of sample of 100 $\mu$L were found to be the best parameters for the speciation and determination of arsenic species. The analytical features of the method were detection limit 0.10 and 0.08 $\mu$g/L, precision(RSD) 4.3% and 3.6%, and recovery 95.2% and 96.4% for As(III) and As(V), respectively. Analysis time was 4 minutes per sample. Linear calibration graphs with r$^2$ = 0.998 were obtained for both As(III) and As(V). Speciation analysis of arsenic species in the raw water samples collected from the tributary streams to Han River and main stream of Paldnag were performed by the proposed method. The concentrations of As(III) ranged from 0.10 to 0.22 $\mu$g/L and As(V) concentrations ranged from 0.44 to 1.19 $\mu$g/L, and 93.5% of total arsenic was found to be As(V).

• Resources Recycling
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• v.28 no.4
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• pp.30-36
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• 2019

In this study, Li powder was recovered from the by-product of LNO ($Li_2NiO_2$) process, which is the positive electrode active material of waste lithium ion battery, through the $CO_2$ thermal reaction process. In the process of recovering Li powder, the $CO_2$ injection amount is 300 cc/min. The $Li_2NiO_2$ award was phase-separated into the $Li_2CO_3$ phase and the NiO phase by holding at $600^{\circ}C$ for 1 min. After this, the collected sample:distilled water = 1:50 weight ratio, and after leaching, the solution was subjected to vacuum filtration to recover $Li_2CO_3$ from the solution, and the NiO powder was recovered. In order to increase the purity of Ni, it was maintained in $H_2$ atmosphere for 3 hours to reduce NiO to Ni. Through the above-mentioned steps, the purity of Li was 2290 ppm and the recovery was 92.74% from the solution, and Ni was finally produced 90.1% purity, 92.6% recovery.

• Korean Journal of Materials Research
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• v.11 no.2
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• pp.151-154
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• 2001

The leakage current behaviors of PLZT capacitors with top electrodes of Pt, Ir, and $IrO_2$ are investigated before and after hydrogen forming gas anneal. The P-E hysteresis and fatigue properties of Pt/PLZT/Pt capacitors are almost recovered after recovery anneal in $O_2$ ambient. The leakage current mechanisms of PLZT capacitors with Pt and $IrO_2$ top electrodes are consistent with space-charge influenced injection model showing the strong time dependence irrespective of annealing conditions. On the other hand, the leakage current behavior of Ir/PLZT/Pt capacitor shows steady state independent of time because IrPb, conducting phase, formed at interface between Ir top and PLZT is a high conduction path. Teh leakage current mechanism of Ir/PLZT/Pt capacitor is consistent with Schottky barrier model.

• Analytical Science and Technology
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• v.28 no.3
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• pp.228-235
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• 2015

The efficiency and applicability of the solid phase extraction disk method in a ²²⁶Ra analysis were examined by the gamma ray spectrometer (GRS) method using a Marinelli beaker and the liquid scintillation counter (LSC) method for groundwater. The recovered ²²⁶Ra, which was filtered by the solid phase extraction disk, was analyzed using gamma ray spectrometer The disks, which were pretreated for caulking the daughter nuclide, were sealed with polyethylene film. Distilled water was used for the blank value of the ²²⁶Ra activity. The recovery values of ²¹⁴Bi and ²¹⁴Pb in the solid phase extraction disk, which used ²²⁶Ra standard material, were 80% (295.21 Kev) and 104% (351.92 Kev), respectively, which were higher than 75% determined by the LSC. The injection of nitrogen gas into the measuring chamber reduced the interference values by about 10%. The detection limits of the ²²⁶Ra activity in a blank sample of 5 L were 0.17~0.40 pCi/L after 80,000 seconds of measuring time. The relationship of the ²²⁶Ra activity in the solid phase extraction disk method and in the LSC method in seven groundwater samples showed a correlation coefficient value 0.987, which implies the applicability of the solid phase extraction disk method. The results showed that ²²⁶Ra activity in groundwater using the solid phase extraction disk method has the following benefits: simple pretreatment, time saving, high recovery values, a low detection limit, and so on. Compared with the LSC method and the GRS method using the Marinelli beaker for the ²²⁶Ra analysis, the solid phase extraction disk method could be useful in groundwater samples with low levels of activities of radionuclides because the method is not restricted by the volume of the sample.

• Korean Journal of Clinical Pharmacy
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• v.22 no.2
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• pp.160-166
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• 2012

Purpose: The purpose of the present study was to investigate the pharmacokinetics of urea, a new potential diagnosis reagent of Helicobacter pylori infection. Methods: Considering the mechanism of urea breath test, we determined the excretion of urea in expired air after its oral administration in rats and beagle dogs at the dose of 2 mg/kg (including 50 mCi/mmol $^{14}C$-urea 50 ${\mu}Ci/kg$ for rats and 13.5 ${\mu}Ci/kg$ for dogs). Results: Urea was rapidly disappeared from the blood circulation by 1 hr after its i.v. bolus injection, followed by a slow disappearance by 24 hr. The half-lives at the distributive phase ($t_{1/2{\alpha}}$) and post-distributive phase ($t_{1/2{\beta}}$) were 2 min and 6 hr, respectively. The bioavailability of urea was 64.3% after its oral administration. The values of the volume of distribution ($V_{dss}$) and the total body clearance ($CL_t$) after the oral administration were compatible with those after i.v. administration. The recovery of urea in the bile was about 0.1% of the dose by 24 hr after its oral administration. Urea was extensively eliminated in the urine by 48 hr. The recovery ratios of urea in the urine and expired air were about 86.8% and 2.99% of the dose by 48 hr, respectively. Moreover, urea was mostly distributed from the blood circulation to the kidney, followed by being eliminated in the urine without metabolism. The concentration of urea in the kidney was 4.0 times higher than that of plasma at 40 min after its oral administration. Conclusions: These findings indicated that oral route appears to be available for the administration of urea. Orally administered urea, thus, was considered to be useful for the diagnosis of Helicobacter pylori infection.