• Carbon letters
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• 제1권2호
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• pp.87-90
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• 2000

Porous carbon from charcoal filled polypropylene composites were prepared and their mechanical properties were evaluated. In preparing the composites, crosslinking agent (sodium benzonate) were used in order to improve the bonding force between matrix and fillers. In this study, the effects of charcoal powder and sodium benzonate concentration on the mechanical properties and interface phenomena on the composites were evaluated. The mechanical properties of composites increased progressively with the decrease of filler loading. In the case of addition of the crosslinking agent into the composite, the mechanical properties were increased and showed maximum value at the 3 wt% concentration of sodium benzonate. According to the result of the TGA, the weight loss of composite according to crosslinking agent was not observed and initial thermal degradation temperature of composite reinforced charcoal was located at $390^{\circ}C$.

• 한국산업보건학회지
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• 제6권1호
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• pp.125-137
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• 1996

This study was designed to investigate effects of relative humidity on the breakthrough of charcoal tubes at a fixed vapor concentration and sampling time during mixed organic vapor sampling. A vapor generator was used to generate three different concentrations of mixed organic vapor and a stainless steel chamber was fabricated and utilized to maintain three different percentages of relative humidity while maintaining a constant temperature. The results were as follows; 1. At high relative humidity, breakthrough of mixed organic vapor occurred quickly at low vapor concentration than at high vapor concentration because of the reduced adsorption volume of charcoal tube due to humidity. 2. Breakthrough by competitive adsorption of vapors onto charcoal tube was observed at first from n-hexane having the lowest boiling point and highest vapor pressure among the three organic vapors investigated, followed by TCE. No breakthrough was observed from toluene under all experimental conditions. 3. For n-hexane, breakthrough was observed after 2 hours of sampling and breakthrough rates were increased as relative humidity increased. For TCE, breakthrough was found after 3 hours of sampling and breakthrough rates by sampling time were increased as vapor concentration increased. 4. The adsorbed amount of mixed organic vapor at breakthrough was shown to have statistically significant correlations with sampling time, relative humidity, and vapor concentration in descending order of correlation. Relative humidity and sampling time for n-hexane and sampling time and concentration for TCE were both statistically significantly correlated. 5. Relative humidity was found to affect the amount of breakthrough of mixed organic vapor and n-hexane. Among three percentages of relative humidity investigated, the amount of breakthrough at 85 % relative humidity was significantly larger than those of at lower percentages of relative humidity. No statistically significant difference was found between 25 % and 55 % relative humidity. 6. The results of multiple regression analysis between breakthrough and relative humidity, vapor concentrations showed that the coefficient of determination of mixed organic vapor was 0.263 and those of n-hexane and TCE were 0.275 and 0.189, respectively. 7. Flow rates of sampling pumps used were found to be affected by relative humidity present. At 25 %, 55 %, and 85 % relative humidity, the relative errors of sampling pump were 1.4 %, 13.4 %, and 18.6 %, respectively. In conclusion, the results of this study showed that high relative humidity could reduce the adsorption volume of charcoal tubes and subsequently increase breakthrough rates. Therefore, to prevent breakthrough when sampling mixed organic vapors, it is suggested that either sampling volume be reduced on the flow rate be lowered so as to minimize breakthrough of the most volatile organic vapor in the mixture. In addition, since the flow rates of a sampling pump can be adversely affected by high relative humidity, it is recommended to use a constant flow mode pump when sampling in the highly humid environment.

• 한국산업보건학회지
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• 제6권2호
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• pp.209-221
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• 1996

The purpose of this study was to find a suitable cosolvent to $CS_2$ so that desorption efficiency can be improved for both polar and non-polar organic solvent mixtures collected on an activated charcoal tube. Cosolvents added to $CS_2$ include: DMF(N,N-dimethylformamide): $CS_2$ (v/v 1:99), DMF:$CS_2$(v/v 3:97), BC (butyl carbitol, 2-(2-butoxy ethoxy) ethanol):$CS_2$(v/v 1:99), and BC:$CS_2$(v/v 3:97)). The results obtained were as follows : 1. Comparing the desorption efficiency of $CS_2$ with those of $CS_2$ with 1, 3, 5 % DMF and 1, 3 % BC cosolvents for two different groups of charcoal tubes each containing 8 different polar and non-polar organic solvents with 3 different concentration levels, the desorption efficiencies of the cosolvent-added $CS_2$ increased significantly for all polar organic solvents regardless of concentration levels tested. For non-polar organic solvents, no noticeable improvement was detected except xylene and trichloroethylene. The desorption efficiency of xylene increased significantly while that of trichloroethylene increased significantly at the lowest concentration level tested. 2. Either 5 % DMF or 3 % BC was the most suitable cosolvent because the desorption efficiency for non-polar organic solvent mixtures was similar or slightly improved compared with that of $CS_2$, while those of for polar organic solvent mixtures were above 75 % except for cyclohexanone. 3. The smallest variations in desorption efficiency represented by the ratio calculated from the maximum to minimum desorption efficiency for all concentration levels tested were found when 3 % BC was used as a cosolvent. The above results indicate that the desorption efficiency of $CS_2$ particularly for polar organic solvent mixtures collected on a charcoal tube can be significantly improved by the use of cosolvents such as 5 % DMF or 3 % BC. A caution, however, is in order for selecting a cosolvent whenever the cosolvent itself is being used in the workplace or the impurities contained in the cosolvent may interfere with the analytical results. In addition, to improve desorption efficiencies for such organic solvents as cyclohexanone or ketones, it is recommended to use suitable collection and desorption media other than the traditional method of charcoal tube collection/$CS_2$ desorption.

• The Plant Pathology Journal
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• 제22권4호
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• pp.339-347
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• 2006

Riboflavin caused induction of systemic resistance in chickpea against Fusarium wilt and charcoal rot diseases. The dose effect of 0.01 to 20 mM riboflavin showed that 1.0 mM concentration was sufficient for maximum induction of resistance; higher concentration did not increase the effect. At this concentration, riboflavin neither caused cell death of the host plant nor directly affected the pathogen's growth. In time course observation, it was observed that riboflavin treated chickpea plants were inducing resistance 2 days after treatment and reached its maximum level from 5 to 7 days and then decreased. Riboflavin had no effect on salicylic acid(SA) levels in chickpea, however, riboflavin induced plants found accumulation of phenols and a greater activities of phenylalanine ammonia lyase(PAL) and pathogenesis related(PR) protein, peroxidase was observed in induced plant than the control. Riboflavin pre-treated plants challenged with the pathogens exhibited maximum activity of the peroxidases 4 days after treatment. Molecular weight of the purified peroxidase was 42 kDa. From these studies we demonstrated that riboflavin induced resistance is PR-protein mediated but is independent of salicylic acid.

• 식물조직배양학회지
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• 제25권1호
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• pp.21-25
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• 1998

미치광이풀(Socopolia parviflora Nakai) 모상근 배양에서 모상근 생장과 tropane alkaloid 생산에 대한 sucrose농도와 일부 흡착제의 효과를 조사하였다. 모상근 클론 SP 11은 5% sucrose 농도를 함유한 1/2 B5 배지에서 최적인 생장과 tropane alkaloid 생산을 보였다. 모상근에서 tropane alkaloids 생성양상은 모식물에서와 약간의 차이를 보였고 그 중 식물체에서 검출되지 않는 littorine의 생성이 모상근에서 두드러졌다. 조사된 흡착제(0.01% 1%) 중에서, charcoal 0.01%와 XAD-II l%에서 약간의 생장촉진효과를 보인 것을 제외하고는 그 외 농도나 흡착제(amberlita chitosan)에서는 억제효과 또는 유의적인 변화를 보이지 않았다. 반면에 hydroxyapatite는 미치광이풀 모상근의 생장과 tropane alkaloid 생산에 있어 촉진효과가 있음이 확인되었다.

• 한국대기환경학회지
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• 제30권3호
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• pp.211-222
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• 2014

Pork belly meat is one of the most preferred food items for many Korean people. The odorants released from cooking of pork belly meat were measured by three kinds of cooking methods (Charcoal-grill (C), Electric Pan (E), and Gas burner-pan (G)). A total of 16 target compounds including carbonyl compounds, volatile organic compounds, and poly aromatic hydrocarbon were selected and analyzed for comparative purposes. Their emission concentrations were quantified using HPLC-UV, GC-MS, GC-TOF-MS, etc. The gas samples collected by Charcoal-grill cooking showed generally enhanced concentrations of most target compounds among all three kinds of cooking methods. In Charcoal-grill, concentration of benzene, formaldehyde and pyrene went up to 543, 516, and 402 ppb, respectively. It the results are compared in terms of the sum of odor intensity, the highest value (4.25) was also seen from Charcoal-grill. The results of this study confirm that the significantly reduced emission of harmful pollutants can be attained, it pork belly meat is cooked by the Gas or electric pan instead of Charcoal-grill.

• 한국어병학회지
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• 제15권1호
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• pp.17-24
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• 2002

The charcoal effects on the immune responses of flounder, Paralichthys olivaceus were studied. Fish were fed an experimental diet supplemented with 1%, 3% or 5% of charcoal to a commercial diet. Several factors such as weight gain, hematological parameters, nonspecific immune responses and resistance against Edwardsiella tarda were evaluated 4 and 8 weeks after the administraion. The changes of body weight and lysozyme activities were not signigicant among tested groups. But cholesterol and total protein concentration in the blood were significantly lower in the 5% supplemented group than in the control. The production of superoxide by macrophage from the head kidney, examined by NBT reduction, was significantly higher in the 3% charcoal supplemented groups than in the control. The survival rate after an artificial challenge with 1×10^exp(7) cells of E. tarda per fish was significantly the highest in the 3% charcoal supplemented group.

• 한국산업보건학회지
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• 제4권2호
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• pp.127-136
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• 1994

활성탄관을 이용한 작업환경 공기중 유기용제의 시료채취는 여러 가지 어려운 점이 있으나 확산형 시료포집기는 이러한 점을 보완하는 새로운 포집기이다. 따라서 본 연구는 확산형 시료포집기가 혼합 유기용제를 사용하는 사업장을 대상으로 확산형 포집기와 활성탄관을 이용, 한 근로자에 대하여 동시에 각 1개씩, 총 181개의 시료를 포집하여 활성탄과 어떠한 차이가 있는 가를 확인하며, 고전적인 활성탄관 시료채취법을 대신할 수 있는 가를 확인하기 위하여 시도한 바 몇가지의 결과를 얻어 보고하는 바이다. 1. 활성탄관 시료포집기에 비하여 확산형의 시료포집기는 톨루엔(toluene), 키시렌(xylene) 등의 방향족 화합물은 다소 높은 농도를 나타내나 전반적으로 통계적인 유의성은 없었다. 2. 엠이케이(methyl ethyl ketone)와 시크로헥사논(c-hexanone)에 대하여 확산형 포집기는 적어도 저농도(허용농도의 1/8 및 1/10 이하농도)에서 활성탄관에 비하여 약 2배 정도 높게 측정되었다(p<0.01). 그러나 공기중 엠이케이와 시크로헥사논의 농도가 증가함에 따라서 확산형의 포집효율은 활성탄관 보다 적은 것으로 나타났다. 3. 활성탄관의 측정치(B)를 1.00으로 하였을 때 확산형 포집기(A)의 측정치 비(A/B)는 톨루엔의 경우 1.11, 키시렌은 1.07, 엠이케이는 1.63, 시크로헥사논은 3.65배 였다. 4. 활성탄관과 확산형 포집기에서의 측정치 비가 0.75-1.25 범위(${\pm}25%$)에 드는 것은 톨루엔 57%, 키시렌 74%였으며, 엠이케이 34%, 시크로헥사논은 약 32%에 불과하였다. 5. 활성탄관과 확산형 포집기에서의 측정치 간의 각 유기용제 별 상관은 톨루엔 0.963, 키시렌 0.957, 엠이케이 0.943, 시크로헥사논은 0.562로서 모두 통계적으로 유의하였다.

• 한국산업보건학회지
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• 제5권2호
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• pp.200-211
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• 1995

This study was designed to evaluate the effects of temperature and humidity on the sampling efficiency of mixed organic vapors of l,2-DCE, benzene, and MIBK by 3 different types of diffusion monitors. Independent variables used for the study were temperatures ($25^{\circ}C$, $35^{\circ}C$), humidities (30%, 80%), and vapor concentrations (low, medium, and high). In addition, vapor concentrations measured by the traditional charcoal tube method were used as reference values and were compared with those of by diffusion monitors. The results were as follows: 1. The desorption efficiencies(DE) of 1,2-DCE and benzene from charcoal tubes and from diffusion monitors ranged from 98% to 105%. In contrast, the DEs of MIBK from charcoal tubes and diffusion monitors except DM1 ranged from 71% to 85%. The DE of MIBK from DM1 was 98%. 2. No statistically significant differences of 1,2-DCE concentrations and the sampling efficiencies regardless of temperatures and humidities studied between charcoal tube and 3 diffusion monitors were found. 3. At 80% humidity, increasing frequencies of 1,2-DCE breakthrough at higher temperature and higher vapor concentration measured by charcoal tubes were observed. 4. No statistically significant difference of benzene concentrations were found between charcoal tube and diffusion monitors except DM3. The sampling efficiencies of DM3 were statistically significantly lower at all experimental conditions except the $35^{\circ}C$ and 30% humidity condition. 5. No statistically significant difference of MIBK concentrations were found between charcoal tube and diffusion monitors except DM3. The sampling efficiencies of DM3 were statistically significantly higher at higher humidity conditions regardless of temperature. Although statistically not significant, sampling efficiency of MIBK showed positive correlation with humidity while negative correlation with concentration was observed. 6. For sampling 1,2-DCE and benzene, no significant variations of concentrations among three diffusion monitors regardless of temperature and humidity conditions were found. For MIBK sampling, however, wide variations with increasing humidity among diffusion monitors were obtained. In conclusion, this study suggests that diffusion monitors will be a reasonables substitute for the traditional charcoal tubes for sampling non-polar organic vapors at temperature and humidity conditions studied. For polar organic vapors, use of an alternative desorption solution other than CS2 is recommended because of its low desorption efficiency. In addition, since variable among diffusion monitors for polar organic vapors particularly at higher humidity conditions were observed, further study is recommended of the effects of humidity on the performance of diffusion monitors.

• 한국토양비료학회지
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• 제14권3호
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• pp.130-136
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• 1981

Rice hull was reduced to ash by carbonization grades to illcuidate alkalinity increase and extract of inorganic nutrients in the rice hull charcoal. Alkaline reaction of water extraction was neutral at less carbonized charcoal, but much carbonized ash from 65% weight loss reached over 10 of pH value, also origin shape of rice hull was maintained until near 65% carbonized grade. Therefore, physical properties sustained good condition for seedling bed. The more charcoal carbonized to ash, the pH value and concentration of inorganic nutrient in their extracts were increased gradually. Nitric acid concentrations for neutralizing extract from charcoal were stronger in proportion to the carbonized grade but 0.1 N nitric acid solution was very reasonable to neutralize the 65% carbonized charcoal for mixing with heavy texture acidy soil(pH 5.3) of uncultivated deep horizon to transplant the tobacco seedlings. Volume ratio mixing for seedling bed is adequate at five of ash to one of acid solution. Neutralization with nitric acid solution also accelerated extraction of the inorganic nutrient in rice hull ash. Tobacco seedlings grown on bed mixed with neutralized rice hull charcoal and soil had shown better results on the agronomic measurement than alkaline ash bed, and phosphorus and cations were uptaken more amounts.