• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.223-224
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• 2016

Recent local advantages to improve the aesthetics of building materials connected with one of the trend of Exposed Concrete and Construction Method in various facilities and to diversify Showing a tendency to both application and development. This exposed concrete form of the features and materials is, the impact of large commercial viability and can consider I can apply to the surface of construction on a surface The diversification of the material was soon exposed directly linked to the varying aesthetics of concrete, and currently take advantage of the form of material is based on such important factor in our country Based on the concept of Exposed Concrete utilized by some construction site, design and be considered is very important elements of the put to practical use.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1154-1157
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• 2005

This report is to do design management for constructability review of high quality exposed concrete, which is used increasingly in recent. To secure systematic management at design phase, we reviewed each definition and work at each design phase, we define high quality exposed concrete, a part of architectural concrete, as "an exposed concrete which has well ordered joint & is in pursuit of smooth surface." We reviewed requirements and influential factor to obtain High quality finishing surface and compared construction process of high quality exposed concrete with that of other finishing method. Management method at each design phase for constructability review to meet additional works and requirements is presented.

• The Korean Journal of Ecology
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• v.17 no.2
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• pp.131-141
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• 1994

One-year-old yellow-poplar (Liriodendron tulipifera L.) and sweetgum (Liquidambar styraciflua L.) seedlings were exposed to 0.10 ${\mu}l/l\;O_3$and simulated acid rain at pH 3.0 for ten consecutive weeks. Shoot height growth (SHG), fresh weight (FWT), dry weight (DWT), apparent plastochron duration (APD) and foliar nutrient concentrations were measured. None of growth measurements, except the apparent plastochron duration (APD), were significantly affected by any treatment in yellow-poplar seedlings. APD was approximately 30% higher in seedlings exposed to $0.1{\mu}l/l\;O_3$ ＋ pH 5.6 solution than any other treatment. Ozone significantly reduced SHG of sweetgum seedlings by 24% at the end of the ten-week fumigation. There were also significant effects of single and combined effects of ozone and simulated acid rain on APD in sweetgum. APD was significantly increased by 19.8% and 25.7% in seedlings exposed to $0.1{\mu}l/l\;O_3$ and pH 5.6 solution, respectively, and resulted in 46.1% higher APD in seedlings exposed to $0.1{\mu}l/l\;O_3$ + pH 5.6 solution compared with seedlings exposed to $0.0{\mu}l/l\;O_3$ ＋ pH 3.0 solution. Phosphorus and sulphur were significantly greater in seedlings exposed to simulated rain at pH 3.0 compared with pH 5.6 for both species. Foliar S concentration was higher in seedlings exposed to $0.0{\mu}l/l\;O_3$ ＋ pH 3.0 than in seedlings exposed to any other treatment in sweetgum. Ozone significantly increased Ca in sweetgum seedlings, however, ozone reduced Ca in yellow-poplar. Ozone also reduced S and Mg in sweetgum seedlings.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.4
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• pp.447-454
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• 2014

The marine microalgae Chaetoceros calcitrans was cultured under a fluorescent lamp (CON) and light-emitting diodes (LEDs) of various wavelengths (blue, LB; red, LR; green, LG; white, LW); changes in growth, fucoxanthin, chlorophyll-a, amino acid and fatty acid profiles were investigated. LR-exposed cultures exhibited the highest specific growth rate (SGR) (0.34), whereas LG-exposed cultures showed the lowest SGR (0.26). After cultivation for 10 days, the maximum dry cell weight (g/L) of LR-exposed cultures was significantly higher than that of those exposed to other light conditions (LR${\geq_-}$CON>LB${\geq_-}$LW${\geq_-}$LG). Eicosapentaenoic acid (EPA) levels were significantly higher in CON-exposed cultures compared to those exposed to LW (P<0.05), with no marked difference compared to those exposed to LB, LR and LG (P>0.05). The fucoxanthin content was highest in LB-exposed cultures ($6.3{\mu}g/mL$), whereas LW showed the lowest ($3.6{\mu}g/mL$; P<0.05). Chlorophyll-a content was highest in cultures exposed to LB compared to other light sources. These results suggest consistent differences in growth and biochemical composition after exposure to light of different wavelengths.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.1
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• pp.49-54
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• 2011

In order to develop the methods for exposure assessment and find susceptibility markers for the workers who are exposed to low doses of toluene, xylene and other chemical in petroleum industries, we investigated the application of P-450 expression in human lymphocytes utilizing mouse monoclonal anti-rat CYP2B1/2, the levels of toluene and xylene in air and their metabolite levels in urine with the levels of expressed CYP2B1/2 proteins. The general characteristics such as age, smoking and drinking habit were no significant difference between the control and exposed workers, but the working durations and working hours were significantly different. Workers in exposed group were exposed to the mean of 2.1 ppm (range, 0.00-4.54) of toluene and 0.3 ppm (rang, 0.00-1.23) of xylene. The mean concentration of urinary hippuric acid was low and less than 1/5 of the biological exposure index recommended by the Ministry of Employment and Labor Korea. Methyl hippuric acid in urine was not detected in control and exposed workers. Also, there were no significant differences in the levels of the urinary metabolites between the control and exposed group. When chemiluminescence dot blottings were carried out utilizing mouse monoclonal antibody against CYP2B1/2, the strong density dots corresponding to a mouse monoclonal antibody was observed in the human lymphocytes from the exposed workers. These results suggested that the chemiluminescence dot blot assay for CYP of lymphocytes should be valuable for identifying CYP expression as biomarkers in the workers exposed to toluene and xylene.

• Korean Journal of Veterinary Research
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• v.29 no.3
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• pp.343-359
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• 1989

To study the effects of ibaraki virus on preimplantation mouse embryos collected from prepubertal ICR and BALB/cByJ mice (30~40days old) by superovulation, zona pellucidaintact(ZPI) or free(ZPF) embryos(n=774) of 4- to 8-cell and morulae were exposed to $10^{5.8}$ $TCID_{50}$ of the virus up to 96 hours. The embryos were examined morphologically by observing the degeneration and hatching rates, and virologically and immunologically by determining the presence of infection with the virus, in addition, the effect of washing the embryos to remove virus possibly attached to was also investigated. The ZPI 4- to 8-cell embryos and morulae exposed to the virus showed considerably higher degeneration rate than those not exposed, for 96, and for 72 to 96 hours, respectively(p<0.01). The ZPF 4- to 8-cell embryos and morulae exposed to the virus showed considerably higher degeneration rates than those not exposed, throughout the whole culture hours in vitro (p<0.01). The ZPI 4- to 8-cell embryos and morulae not exposed to the virus showed considerably higher rates of hatched blastocyst than those exposed (p<0.01). The virus infection rates of the ZPF 4- to 8-cell embryos and morulae were significantly higher than those of the ZPI embryos according to cell culture system. The viral antigen was detected exclusively on the zona pellucida of ZPI embryos, while the antigen was evenly distributed in the blastomeres of ZPF embryos by the immunofluorescent assay. In the ZPI embryos exposed to ibaraki virus, the virus was detected in the two times-washing groups, but not in the ten times-washing groups. The results indicated that zona pellucida of murine embryos would provide an effective protection and that ten times-washing of the ZPI embryos previously exposed to the virus was effective to remove virus from the embryos.

• Korean Journal of Veterinary Research
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• v.34 no.3
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• pp.549-557
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• 1994

This study was done to find the method of the extermination of Fasciola hepatica matacercariae. And the artificial infection was carried out with 30 metacercarae exposed to 5% ammonia water and not-exposed to 5% ammonia water. Serial determinations of live weight, red blood cell, hemoglobin, packed cell volume, and eosinophils were performed in rats at 7 days interval for 16 weeks after infection (WAI). Recovery of worm burden and microscopic findings of livr was performed in rats at 10 WAI. The results in this work were summarized as follows; 1. Fasciola spp metacercariae exposed to 5% ammonia water have lost their ability of infection. 2. In teh exposed group, the mean of worm recovered was 2.25 and the common bile duct was swelling up to 0.71cm in diameter. 3. The value of live weight was different in two groups as the not-exposed group and the exposed group were 321.28, 384.38 at 10 WAI, respectively. 4. In the not-exposed group, at 7 WAI, hemoglobin at 5 WAI and packed cell volume at 7 WAI wre minimally decreased to $5.84{\times}10^{-6}/mm^3$, 11.53g/dl and 43.2%, respectively. But those three values were slowly increased at 10 WAI. Rercent cosinophil was increased to 12.2% at 4 WAI and slightly decreased to 7.9% at 10 WAI. But there are no stastistical singnificance between the exposed group and the normal control group. 5. In histolgical findings in the not-exposed group, the dilated common bile ducts and intrahepatic bile ducts showed distinct hyperplasia of the epithelium. Lymphocytes and eosinophils were infilterated around the bile ducts. The hepatic cells and Kupffer cells showed swollen appearance.

• Journal of Environmental Science International
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• v.13 no.10
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• pp.939-946
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• 2004

The relationships between subjective symptoms of toluene exposed workers and concentration of their urinary excretion of hippuric acid were investigated. The exposed groups of 146 workers exposed to toluene and the control groups of 47 workers have never been exposed to toluene in Ulsan area were selected and studied. Hippuric acid was measured by HPLC, and counts of blood cells and liver function test were also performed. The mean value of urinary hippuric acid concentration of the control group was 0.322($\pm$0.267) g/L, while that of the exposed group was 1.260($\pm$0.395) g/L. As the concentration of hippuric acid had statistical proximity in $0.1\%$ level, WBC, GOT, and GPT didn't have any proximity(P>0.05). The exposed group showed lower level of leucocyte counts 6522.40(1710.3) than the control group 6891.50(1483.7). The exposed group showed higher level of GOT(25.75), GPT(27.09) than GOT(23.75), GPT(25.21) of the control group. Dried skin was the highest complained symptom of toluene exposed workers, the second strained eye, the third poor auditory function, and the fourth was headache.

• Toxicological Research
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• v.12 no.1
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• pp.1-8
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• 1996

The variation in the enzyme activities of human liver usually represents the particular physiological conditions of each individuals. Thus, we investigated the variation in the activities of SOD, HR and LPO of (1) non-exposed workers (56 subjects), and (2) exposed workers to DMF (43 subjects) in synthetic leather process. Serum levels of enzyme activities of exposed workers (AST:$30.26{\pm}20.041$U/L, ALT:$32.72{\pm}23.393$U/L, GGT:$28.47{\pm}18.635$ U/L, ALP:$81.77{\pm}34.879$ U/L)were slightly higher than those in nonexposed workers (AST:$24.00{\pm}9.441$ U/L, ALT:$23.89{\pm}18.305$U/L, GGT:$21.95{\pm}17.970$U/L, ALP:$70.84{\pm}24.678$U/L), but only the level of ALT was statistically significant (p< 0.05). Serum levels of LDH, TRF and CHOL in non-exposed workers were slightly higher than those of exposed workers. However, they were not statistically significant (p > 0.05). Serum levels of HR and LPO of the exposed workers appeared to be reduced, but not those of the non-exposed workers. The SOD activities of exposed workers were also slightly higher than those of non-exposed workers, but the results were not statistically significant (p > 0.05). The level of HR was increased with age, but the SOD level was not. These results suggest that the intermittent exposure to DMF at time-weighted average (TWA) level (10 ppm/$m^3$) has affected on the activities of enzymes such as AST, ALT, TRF, but not on the generation of HR, activity of SOD. However, if high dose of DMF was used, there would be severe effects for the generation of HR and LPO.

• Korean Journal of Construction Engineering and Management
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• v.20 no.4
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• pp.46-55
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• 2019

The exposed concrete has been widely used in building construction. Therefore, many researches are presented to secure a proper construction quality of exposed concrete. Low quality and management absence, however, still remained in construction fields. Thus, many studies have been conducted to improve the quality, but defects still occur in the exposed concrete finishing work. In this study, the causes of defects were analyzed by process in order to prevent the generation of defects and to enhance the need for integrated management to secure quality. In addition, a case study and AHP analysis have derived the importance of defects occurring in the exposed concrete finishing work. The study concluded that the occurrence of the exposed concrete finishing work needs to be managed throughout the process, not the management limited by one process, according to the causes of the existing defects, and integrated management is required to prevent defects and improve quality of exposed concrete finishing work.