• The Korean Journal of Pesticide Science
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• v.11 no.2
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• pp.87-94
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• 2007

Pyrethroid insecticide have widely been used for agricultural sector and residential environments. To assess the exposure of insecticide which is absorbed through skin the analysis of urinary metabolite is essential. At present, the urinary 3-PBA was analyzed using liquid-phase extraction. But LPE have many limitations, such as long pre-treatment time and low recovery. So, this study was conducted to determine the optimum conditions for analysing 3-PBA in urine using solid phase extraction. Furthermore, this study intend to investigate the relation of concentrations of pyrethroid, deltamethrin in air and 3-PBA in urine. The optimum condition for hydrolysis was found to be done with hydrochloric acid for one hour. The recovery rates of 3-PBA were $84.6%{\pm}1.2%$, $54.8{\pm}0.9%$, $99.8{\pm}1.2%$ with XAD-2, XAD-7, XAD-16 using as the aborbents and acetone as eluents respectively. But acetonitrle and methanol gave low recovery rate and methyl cellosolve could not elute the compound. The amount of acetone for elution were 6mL, 9mL, 3mL for XAD-2, XAD-7, XAD-16 as absorbents respectively. The non-absorbed rates was $0.8{\pm}0.5%$, and $0.7{\pm}0.3%$ under XAD-16, mesh size 140-200, amount of resin 1.4g and the flow rate of eluent was 0.1mL/min. In the concentration process, we obtained 11 times higher concentration of material. The amounts of urinary 3-PBA were. The LODs of 3-PBA and deltamethrin were 0.004 mg/L, 0.038 mg/L, respectively. The further research of minute monitoring which include spray pattern, environmental condition is needed And more research about the relation between total pyrethroid exposure and urinary various metabolite are also necessary.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.5
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• pp.368-372
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• 1984

This paper deals with a rapid method for determination of ATP and its related compounds in fish and shellfish products using high performance liquid chromatography(HPLC). The HPLC used is a HPLC/ALC-224 equiped with UV-spectrophotometer (254 nm) as detector and integrator (Yanagimoto system-1000). The column used is a stainless steel tubing ($30.0\;cm{\times}3.9\;mm\;i.d.$) packed with ${\mu}-Bon-dapak\;C_{18}$. A mixture of $1\%$ triethylamine-phosphoric acid(pH6.5) was used as an eluent and the flow rate of the eluent was controlled at 2 ml/min. For the separation of ATP and its related compounds, a standard mixture of ATP, ADP, AMP, IMP, inosine and hypoxanthine was subjected to HPLC under the above mentioned conditions. Six peaks were obtained with retention times within 20 min, and elution order were hypoxanthine, IMP, inosine, AMP, ADP and ATP. But 5'-IMP and 5'-GMP fractions were not separated by this method. In generally, IMP content in boiled-dried fish and shellfish products purchased from the market was comparatively higher than that of other nucleotides. Especially, boiled-dried big eye herring marked higher value in IMP content than other boiled-dried ones. Hypoxanthine and inosine were major components of ATP-related compounds in dried products and seasoned-dried ones. And IMP content in seasoned-dried products was higher than that of dried ones. This fact is suggested that a part of IMP in seasoned-dried ones was derived from flavoring matter (MSG, 5'-IMP and 5'-GMP) which is added during the seasoning treatment.

• Journal of the Korean GEO-environmental Society
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• v.9 no.3
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• pp.35-43
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• 2008

This study was carried out to estimate the performance of modified sequencing batch reactor (SBR) process by the application of SBR process for small advanced wastewater treatment plant. Organic, nitrogen and phosphorus were able to remove in the unit reactor by SBR process and it would be able to select the suitable operation method. The plant was operated to achieve high performance with influent control, optimum anoxic/oxic condition using intermediate aeration method, and solid (sludge) /liquid (effluent) separation by modified decanter. The optimum operating mode was 3Cycles a day and intermediate input and aeration. Under these conditions, the treatment efficiencies were good with 60% of designed flow rate and low influent quality. When the influent concentrations of BOD and CODMn were 120.4 mg/L and 95.7 mg/L, respectively. The effluent concentrations of BOD and CODMn were 6.8 mg/L and 11.0 mg/L, respectively. The average removal efficiencies of BOD and CODMn were 94.4% and 88.5%, respectively. The removal efficiencies of T-N and T-P were 69.6% and 73.6%, respectively when the average T-N and T-P concentrations were 32.2mg/L and 4.65mg/L, respectively. The T-N and T-P removal efficiencies were slightly decreased to 58.8% and 68.5%, respectively in the winter season but its were also stable efficiencies. BOD, T-N and T-P were removed by 90%. 67% and 46% respectively in the first anoxic/oxic condition, in addition to T-P was removed by 70% in the second anoxic/oxic condition. From the results, modified sequencing batch reactor (SBR) process is suitable for small advanced wastewater treatment.

• Journal of the Korea Concrete Institute
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• v.25 no.2
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• pp.201-207
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• 2013

When hot weather concrete is utilized, the cooling methods of cooling pipe, liquid nitrogen, ice, etc., are used to prevent the poor consistency and cold joint due to high temperature. These methods, however, spike the production cost and energy consumption, and make quality control difficult. Among these methods is one that involves the use of a retarder. Although economical, retarder is caused difficulty of retarded hardening and setting time control due to inaccurate weighing and poor working condition. Therefore, how to make a tablet for hot weather concrete, as with the existing pharmacy and foods, is discussed in this study, including the following items: mortar setting time, flow test by elapsed time, physical and mechanical properties of concrete. As a result, gluconic acid is superior to lignosulfonic acid and the possibility of using them for such purpose without quality degradation was confirmed in this study, when retarder is tabletting.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.6
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• pp.732-746
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• 2003

Statement of problem. Soft lining materials, also referred to as tissue conditioning materials, tissue heating materials, relining materials, soft liners or tissue conditioners, were first introduced to dentistry by a plastic manufacturer in 1959. Since the introduction of the materials to the dental field, their material properties have been continually improved through the effort of many researchers. Soft lining materials have become widely accepted, particularly by prosthodontists, because of their numerous clinical advantages and ease of manipulation. Unfortunately, few reports have been issued upon the topic of increasing the bond strength between the base metal alloy used in cast denture bases and PMMA soft liner modified with 4-META, nor upon the pattern of debonding and material change in wet environment like a intra oral situation. Purpose. The purposes of this study were comparing the bond strength between base metal alloy used for the cast denture bases and PMMA soft liner modified with 4-META, and describing the pattern of debonding and material property change in wet environment like the intraoral situation. Material and Methods. This study consisted of four experiments: 1. The in vitro measurement of shear bond strength of the adhesive soft liner. 2. The in vitro measurement of shear bond strength of the adhesive soft liner after 2 weeks of aging. 3. A comparison of debonding patterns. 4. An evaluation the Relation time of modified soft liner. The soft liner used in this study was commercially available as Coe-soft (GC America.IL.,USA), which is provided in forms of powder and liquid. This is a PMMA soft liner commonly used in dental clinics. The metal primer used in this study was 4-META containing primer packed in Meta fast denture base resin (Sun Medical Co., Osaka, Japan). The specimens were formed in a single lap joint desist which is useful for evaluating the apparent shear bond strength of adhesively bonded metal plate by tensile loading. Using the $20{\times}20mm$ transparent grid, percent area of adhesive soft liner remaining on the shear area was calculated to classify the debonding patterns. To evaluate the change of the initial flow of the modified adhesive soft liner, the gelation time was measured with an oscillating rheometer (Haake RS150W/ TC50, Haake Co., Germany). It was a stress control and parallel plate type with the diameter of 35mm. Conclusion. Within the conditions and limitations of this study, the following conclusions were drawn as follows. 1. There was significant increase of bond strength in the 5% 4-META, 10% 4-META containing groups and in the primer coated groups versus the control group(P<0.05). 2. After 2 weeks of aging, no significant increase in bond strength was found except for the group containing 10% 4-META (P<0.05). 3. The gelation times of the modified soft liner were 9.3 minutes for the 5% 4-META containing liner and 11.5 minutes for the 10% 4-META liner. 4. The debonding patterns of the 4-META containing group after 2 weeks of aging were similar to those of immediaely after preparation, but the debonding pattern of the primer group showed more adhesive failure after 2 weeks of aging.

• YAKHAK HOEJI
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• v.51 no.2
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• pp.133-139
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• 2007

A simple and sensitive HPLC-MS method for quantitation of 10${\alpha}$-methoxy-9,10-dihydrolysergol (MDL), the main metabolite of nicergoline, in human plasma was developed and the bioavailability parameters of MDL was assessed in Korean healthy male volunteers. Clomipramine was used as an internal standard. MDL and internal standard in plasma sample were extracted using ethyl acetate. A centrifuged upper layer was then evaporated and reconstituted with mobile phase of 10 mM ammonium acetate-acetonitrile (10 : 90, v/v). The reconstituted samples were injected into a Zorbax SB-C8 column (2.1${\times}$150 mm,5 ${\mu}$m) at a flow-rate of 0.3 ml/min. Using MS with selected ion monitoring (SIM) mode, MDL and clomipramine were detected without severe interference from human plasma matrix. MDL produced a protonated molecular ion ([M+H]$^+$) at m/z 287. Internal standard produced a protonated molecular ion ([M+H]$^+$) at m/z 315. A linear relationship for MDL was found in the range of 2.5${\sim}$100 ng/ml. The lower limit of quantitation (LLOQ) was 2.5 ng/ml with acceptable precision and accuracy. The intra- and inter-day validation for all coefficients of variation (R.S.D.%) were found less than 15%. Main pharmacokinetic parameters of 30 mg of nicergoline were revealed as follows: AUC$_t$ 321.1${\pm}$64.5 ng${\cdot}$hr/ml, C$_{max}$, 51.2${\pm}$25.3 ng/ml, T$_{max}$ 3.6${\pm}$1.5 hr, K$_{el}$ 0.12${\pm}$0.07 hr$^{-1}$ and t$_{1/2}$ 7.6${\pm}$3.4 hr. Inter subject variations and race differences were shown in comparison with the published data in the literature.

• Journal of Embryo Transfer
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• v.29 no.4
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• pp.385-391
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• 2014

Objective of this study was to investigate the effect of nicotinic acid (NA) on the characteristics in fresh semen of miniature pig. We evaluated viability, acrosome reaction and mitochondrial integrity of sperm on 0, 3, 7 and 10 days during storage period with nicotinic acid. As results, the survival rate of sperm in 15 mM NA (day 3, $87.8{\pm}1.2%$; day 5, $84.0{\pm}2.7%$; day 7, $82.2{\pm}0.9%$) and 30 mM NA (day 3, $87.7{\pm}0.3%$; day 5, $84.4{\pm}2.5%$; day 7, $82.3{\pm}0.7%$) groups were higher than control and 5 mM NA groups in 3, 7 and 10 days of semen storage. The NA-treated sperm on 10 day was used day for observing acrosome integrity. The survival sperm with acrosome reaction was higher in 30 mM NA group (day 3, $2.7{\pm}0.2%$; day 5, $3.3{\pm}0.6%$; day 7, $11.4{\pm}0.3%$) than in the control, significantly (P<0.05). Moreover, the live sperm with mitochondrial integrity was higher in whole treatment groups of NA than control group, significantly (P<0.05). Specially, most mitochondrial integrity on 10 day of semen storage was significantly higher in 30 mM NA group ($90.2{\pm}1.6%$) than other treatment groups (control, $81.8{\pm}3.1%$; 5 mM NA, $83.4{\pm}3.0%$; 15 mM NA, $89.1{\pm}0.7%$, P<0.05). In conclusion, supplement of NA in liquid semen of miniature pig can improve and maintain semen quality, such as viability, acrosome reaction, and mitochondria integrity.

• Analytical Science and Technology
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• v.15 no.6
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• pp.514-520
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• 2002

The electrothermal vaporization (ETV) hollow cathode glow discharge atomic emission spectrometer for analysis of liquid sample has been developed and characterized. This system has improved the sample introduction method of electrothermal vaporization and the hollow cathode glow discharge. The sample introduction method was possible to provide high analyte transport efficiency to the plasma by helix coil made of tungsten material. In addition, small volume samples (<$30{\mu}{\ell}$) could be used. The system has glow discharge cell with special design for improvement of precision. The effect of discharge parameters such as discharge power, gas flow rate has been studied to find optimum condition. The emitted light was effectively carried into detector by fiber optic cable in UV region. The calibration curve of Pb, Cd were obtained with 3 samples.

• Journal of the Korean Society of Safety
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• v.11 no.4
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• pp.143-150
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• 1996

This is an explicit-Implicit, finite element analysis for linear as well as nonlinear hygrothermal stress problems. Additional features, such as moisture diffusion equation, crack element and virtual crack extension(VCE ) method for evaluating J-integral are implemented in this program. The Linear Elastic Fracture Mechanics(LEFM) Theory is employed to estimate the crack driving force under the transient condition for and existing crack. Pores in materials are assumed to be saturated with moisture in the liquid form at the room temperature, which may vaporize as the temperature increases. The vaporization effects on the crack driving force are also studied. The Ideal gas equation is employed to estimate the thermodynamic pressure due to vaporization at each time step after solving basic nodal values. A set of field equations governing the time dependent response of porous media are derived from balance laws based on the mixture theory Darcy's law Is assumed for the fluid flow through the porous media. Perzyna's viscoplastic model incorporating the Von-Mises yield criterion are implemented. The Green-Naghdi stress rate is used for the invariant of stress tensor under superposed rigid body motion. Isotropic elements are used for the spatial discretization and an iterative scheme based on the full newton-Raphson method is used for solving the nonlinear governing equations.

• Korean journal of food and cookery science
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• v.19 no.3
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• pp.339-353
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• 2003

The rapid increase in food borne illness outbreaks in Korea has been one of the major threats to the Nation's Health. Foodservice establishments have been identified as the major place for these outbreaks, mainly due to the lack of sanitary management and sanitary facility management practices. The purposes of the study were to develop hospital foodservice facility evaluation tools, based on the general HACCP-based standards and guidelines, for hospital food service establishments, to ensure the safety of these foodservices and to reduce the risk of food home illness. The scope of this study included: 1) an assessment of the current foodservice sanitation practices and managements for 6 general hospitals, with more than 400 beds, and 3 general hospitals, with less than 400 beds; 2) the development of foodservice establishments sanitation evaluation tools and sanitation standards, based on the HACCP system. The survey data showed varied results between the hospitals surveyed. Most of the hospital foodservice operations had many problems with ventilation and the plumbing. The total dimensional mean scores for the hospitals with more than 400 beds and less than 400 beds were 31.5 and 27.0, respectively. The highest dimension scores were for the water supply facility and lighting, with the lowest for insect and rodent control and toxic materials management. The levels of the mean scores were very low, especially for the general hospitals with less than 400 beds. These low mean scores may have arisen from critical problems within the hospital foodservice operations. The most needed facility management items for improvement were: storage shelf should be spaced 6 inches from the floor and walls, the use of three compartment sinks, utility sinks and cleaning facilities, with a floor drain for cleaning mops or liquid wastes, a ventilation hood designed to prevent dripping onto food, cooking facilities should be disassembled for washing and sanitizing, a separated hand washing sink and a sanitized food board for each area should be provided, all toxic material must have warning labels attached, and be stored in an area away from food preparation under padlock. The evaluation tool consisted of 14 dimensions, with 65 check-off items. The results of this study will provide basic facilities' guidelines to regulators, or foodservice industry personnel, wishing to build, or expend, and establish an efficient flow of food. As a result, food borne illnesses will be effectively prevented, and the Nation's health will be promoted for the development of their own sanitation standards, with a checklist for the safe production of foods.