• 한국산업보건학회지
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• 제15권3호
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• pp.261-269
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• 2005

To investigate the field applicability of a diffusive sampler (3M OVM #3500, passive sampling method) authors conducted a simultaneous measurement of personal organic solvents exposure in the air of the workplaces by charcoal tube with low volume sampler (active sampling method) and diffusive sampler. Samples were collected and analyzed by NIOSH method ($NMAM^{(R)}$) from thirty-eight workers in 12 factories who work in 6 different processes. Geometric mean (GM) and geometric standard deviation (GSD) were used to describe the result. To compare the results of the two methods, paired t-test was used. According to the manual of the exposure assessment of the mixed organic solvents (Ministry of Labor, Korea), Em was calculated. Simple linear regression was used to evaluate the relationship between the two methods. Results were as follows; 1. Eight different solvents (ethyl acetate, n-hexane, toluene, xylene, acetone, isopropyl alcohol, methyl ethyl ketone (MEK), and methyl isobutyl ketone) were detected simultaneously in the two methods and the concentrations of the personal exposure were lower than 0.5 TLV level. The concentration of the charcoal tube method was higher than that of a diffusive sampler in n-hexane and MEK (p<0.05). 2. Em of the charcoal tube method was higher than that of diffusive sampler method but not significantly different and was lower than the OEL (Occupational Exposure Limit) in all 6 processes. 3. There was a significant correlation between the two methods in low concentrations of the 8 organic solvents (p<0.05). In conclusion, there was no difference in charcoal tube method and diffusive sampler method in low concentrations of some organic solvents, diffusive sampler can be applied to assess the personal monitoring in low level exposure.

• Environmental Engineering Research
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• 제25권3호
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• pp.426-438
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• 2020

In this study, cherry kernel shell pyrolytic charcoal was synthesized (CKSC) and composite beads were obtained by blending this pyrolytic charcoal with chitosan and Fe₂O₃ nanoparticles (Fe-C-CKSC). Cr(VI) adsorption from aqueous solutions by Fe-C-CKSC composite beads and CKSC adsorbents was studied comparatively. The effects of Cr(VI) initial concentration, adsorbent dosage, contact time, pH and temperature parameters on Cr(VI) adsorption were investigated. Adsorption reached an equilibrium point within 120 min for CKSC and Fe-C-CKSC adsorbents. The maximum Cr(VI) removal was obtained at the initial pH value of 1.56 for CKSC and 2.00 for Fe-C-CKSC. The optimum adsorbent dosage was found to be 5 g/L for CKSC and 3 g/L for Fe-C-CKSC. Based on the Langmuir model, the maximum adsorption capacities were calculated as 14.455 mg/g and 47.576 mg/g for CKSC and Fe-C-CKSC, respectively. Thermodynamic and kinetic studies were performed. As a result of adsorption kinetics calculations, adsorption was found to be consistent with the pseudo second order kinetic model. Characterization of the synthesized adsorbents was performed by SEM, BET, FTIR and elemental analysis. This study has shown that low cost adsorbents CKSC and Fe-C-CKSC can be used in Cr(VI) removal from aqueous solutions.

• Plant Resources
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• 제8권3호
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• pp.275-280
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• 2005

Tissue culture systems to optimize regeneration plant species of Ocimum spp were evaluated as a method to micropropagate individual plants and to better study their biology in vitro. Ocimum species were also evaluated for the production of natural plant products during and following the regeneration process. The primary goal of this project was to enhance the regeneration efficiency of basil. Several factors were examined using different Ocimum species and commercial varieties. The effect of cytokinin combination, activated charcoal, gelling agents, and different carbon sources were investigated. Anthocyanin callus spots were produced only in four varieties among six tested. 'Sweet Dani' showed the best results on anthocyanin accumulation, while 'African beauty', 'Tree basil' and 'Methylcinnamate' produced only a few spots. Shoot regeneration was only achieved from 'Sweet Dani' explants. As the activated charcoal concentration increased, callus formation rate decreased respectively compare to the controls for all varieties. There was a decrease in callus growth with increasing concentration of agar and phytagel.

• Korean Chemical Engineering Research
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• 제52권5호
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• pp.620-626
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• 2014

The main focus of this study was the evaluation of arsenic concentration in the ground water of Lahore at different depth and application of different mitigation techniques for arsenic removal. Twenty four hours of solar oxidation gives 90% of arsenic removal as compared to 8 hr. or 16 hr. Among oxides, calcium oxide gives 96% of As removal as compared to 93% by lanthanum oxide. Arsenic removal efficiency was up to 97% by ferric chloride, whereas 95% by alum. Activated alumina showed 99% removal as compared to 97% and 95% removal with bauxite and charcoal, respectively. Elemental analysis of adsorbents showed that the presence of phosphate and silica can cause a reduction of arsenic removal efficiency by activated alumina, bauxite and charcoal. This study has laid a foundation for further research on arsenic in the city of Lahore and has also provided suitable techniques for arsenic removal.

• Journal of the Korean Wood Science and Technology
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• 제48권6호
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• pp.847-860
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• 2020

본 연구는 국내 숯불구이 음식점의 화구당 평균 공간을 바탕으로 제작된 모형 연소방을 이용하여 국내에서 유통되고 있는 숯과 성형숯의 연소 조건에 따라 발생하는 연소 가스와 연소 특성에 관한 연구를 수행하였다. 각각 3종의 숯과 성형숯의 연료 특성과 연소 특성을 분석하였다. 또한, 밀폐 조건과 환기 조건으로 구분하고 총 20분의 연소과정 동안 발생하는 CO, CO₂, NO_x의 농도와 O₂ 농도의 변화량을 분석하였다. 분석 결과, CO의 발생량은 밀폐 조건에서 1390~4703 ppm의 범위로 측정되었으며, 환기 시 약 29.8%~57.4%의 환기율을 보였다. CO₂는 밀폐 조건에서 1.34%~2.42%의 범위로 나타났으며, 환기시 특정 시점(10분)에 1.5% 이상 발생한 시료에서 44.1%~53.6%의 환기율을 보였다. NO_x의 발생량은 밀폐 조건의 경우 불완전 연소로 인해 지속적으로 발생량이 증가하여 29 ppm~47 ppm의 범위로 발생하는 경우와 특정 시점(1분) 이후 9 ppm~18 ppm의 범위로 비교적 일정한 발생량을 보이는 경우로 나뉘었다. 환기 조건의 NO_x 배출량은 밀폐 조건과 유사한 경향을 보였으며, 최대 62.5%의 환기율을 보였다. 따라서, 본 연구 결과를 바탕으로 숯과 성형숯의 사용환경을 모사하여 인체 유해성 평가에 활용 가능할 것으로 판단된다.

• 한국환경과학회지
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• 제24권12호
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• pp.1601-1608
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• 2015

This study evaluates heavy metal(Cu and Cr) adsorption characteristics produced from food waste charcoal extracted in an optimal operation condition after analyzing activated charcoal of iodine adsorption and heavy metals that derived from an activation process of carbide by the developed by-products of food waste treatment facility using the methods from previous studies. As experiment apparatus, this study used a tube-shaped high temp furnace. The mixing ratio of by-products of food waste treatment facility, carbide, and activation component($ZnCl_2$) was 1:1. The experiment was proceeded as adjusting the activation temperature from 400 to $800^{\circ}C$ and activation time from 30 to 120 minutes. The optimal activation condition for iodine absorption was 90 minutes at $700^{\circ}C$ and by using the produced food waste charcoal, this study conducted an experiment on absorption of heavy metals (Cu and Cr) as changing pH of artificial wastewater and stirring time. As a result, pH 7 showed the highest heavy metal decontamination ratio and in terms of stirring time, it revealed balance adsorption after 10 minutes. This result can be particularly applied as basic data for recyclability of high concentration organic waste, by-products of food waste treatment facility, as an food waste charcoal.

• 한국환경농학회지
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• 제24권2호
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• pp.185-190
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• 2005

일부 농가에서 이용하고 있는 기능성 쌀 생산 농자재인 게 껍질, 견운모 및 숯 분말의 시용이 벼의 생육, 수량 및 쌀의 품질에 미치는 영향을 구명하고자 본 실험을 실시하였다. 게 껍질 분말 시용구는 다른 처리에 비하여 분얼수, 이삭수, 엽면적지수, 식물체의 질소함량을 증가시켰으나 등숙율은 낮았고, 백미수량은 차이가 없었다. 미질은 게 껍질 분말 시용구에서 완전미 비율과 Toyo 식미치는 낮았고, 분상질미 비율, 단백질 함량은 높았다. 견운모와 숯 분말 처리는 벼의 생육, 수량 및 수량구성요소, 쌀의 품질은 무처리와 차이가 없었고, 단백질 함량는 무처리보다 높았으나 Toyo 식미치는 낮았다.

• 한국산업보건학회지
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• 제7권1호
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• pp.3-18
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• 1997

This study was conducted to evaluate desorption efficiencies by types of desorption solvent for polar and non-polar organic compounds collected on activated charcoal tubes. Analytes tested were toluene, m-xylene, isobutyl alcohol, n-butyl alcohol, cellosolve acetate, and butyl cellosolve. Three different concentration levels of spiked sample were made. Types of cosolvent mixed with the main solvent, $CS_2$, were methanol, pentanol, and dimethylformamide (DMF) and the cosolvent for methylenechloride was methanol. The amounts of cosolvent added to the main solvent were 1, 5, and 10% by volume (v/v%), respectively. The results were as follows: 1. For all mixed solvents except 1% methanol and 1% pentanol with $CS_2$, desorption efficiency significantly increased, compared with that of $CS_2$ alone. 2. Desorption efficiency increased by increasing analyte loading on charcoal tube regardless of mixed solvents used and the material polarity. 3. For all cosolvents mixed with $CS_2$ by 1% and 5% volume, desorption efficiency for non-polar compound was significantly higher than that of polar compound. For the 10% mixed solvents and the methylenechloride mixed with methanol, the results were opposite. 4. The lowest mean percent bias of 4.79% was obtained from the 5% DMF-$CS_2$ mixed solvent, followed by 4.82% from the 10% DMF-$CS_2$ solvent while the highest bias of 23.26% was from the solvent of $CS_2$ alone. Based on the results of this study, in order to increase desorption efficiency, it is recommended to add such cosolvents as methanol, pentanol, and DMF to $CS_2$, preferably 5% by volume for analyzing polar compounds collected in charcoal tubes.

• Journal of Plant Biotechnology
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• 제29권4호
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• pp.253-257
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• 2002

To establish the optimum condition for plant regeneration from somatic embryos of Acanthopanax sessiliflorus Rupr. et Maxim, a medicinal plant, somatic embryos were induced from zygotic embryo-derived embryogenic callus in hormoen-free MS medium. To induce plantlet conversion, cotyledonary somatic embryos were cultured on MS solid medium with GA$_3$at various concentrations (0~10 mg/L) for three weeks. Plantlets were transferred to 1/3 MS solid medium with 0.5% charcoal for 7 weeks. Stem length was increased proportionally to the concentration and treatment period of GA$_3$. Also, the highest leaf width (8.9 mm) and leaf number (2.84) of plantlet were obtained when plantlets were converted on 5,10 mg/L GA$_3$pretreatments, respectively. The highest plant conversion frequency (66.7%) was obtained when the somatic embryos were cultured on medium containing 5 mg/L GA$_3$ for 3 weeks and then were transferred to 1/3 MS medium with 0.5% charcoal. The highest survival rate of soil transfer was 90% when plantlets were regenerated on medium with 5 mg/L GA$_3$ for 3 weeks and then transferred to plastic pots containing vermiculite and sand mixture for 4 weeks.

• 한국유기농업학회지
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• 제22권3호
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• pp.503-519
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• 2014

녹비작물로서 녹비보리와 헤어리베치를 환원하고, 토양개량제로서 charcoal을 시용하여 생강연작 재배지에서 생강을 재배한 결과, 토양 pH가 시험 전 6.9~8.1에서 수확 후 6.8~7.6로 감소하였으며, 전기전도도(electrical conductivity, EC)는 한 시험 전 $0.45{\sim}1.25dSm^{-1}$에서 수확 후 $0.30{\sim}0.61dSm^{-1}$로 감소하였다. 토양유기물(soil organic matter, SOM) 함량과 토양 중 총질소(total-nitrogen, T-N) 함량은 증가하였다. 유효인산 함량과 치환성 K, Ca, Mg 함량은 유의성 있는 차이가 나타나지 않았다. 그러나, 토양 pH를 중성화시키고, EC 경감, SOM과 T-N 함량의 증가는 토양 화학성 변화에 있어 긍정적으로 평가할 수 있다. 생강양분의 함량적 차이를 정상근과 이병근의 함량 차이, 토양의 점토함량 별 양분 함량 차이로 조사한 결과, 유의성이 있는 결과를 얻었으며, 처리구별로 차이가 있는 것으로 나타났다. 특히, 망간(manganese, Mn)의 경우, 이병근의 지하부에서 3~4배 정도 높은 것으로 나타났는데, 망간(Mn)은 식물 뿌리에 대한 독성 작용으로 뿌리를 갈변시키고 균열을 일으키는 것으로 보고된바, 뿌리썩음병의 발생으로 Mn이 작용하여 이병근의 Mn 함량이 높은 것으로 보인다. 따라서, 뿌리썩음병과 Mn의 상관관계를 밝히는 추가 연구가 필요할 것으로 판단된다. 또한, 생강 수확 후 생강 생육 상태와 생산량을 조사한 결과, 녹비보리, 헤어리베치, 녹비보리+charcoal, 헤어리베치+charcoal을 처리한 시험구(Plot 2, Plot 3, Plot 4, Plot 5)에서 생강의 생육상태가 양호하고 생산량이 높아 병발생률이 상대적으로 낮게 나타났다. 특히, Plot 4(헤어리베치+charcoal)-LCC에서는 100%의 생산량을 보였다. 녹비작물과 charcoal의 처리가 생강생육과 생산에 있어 긍정적인 영향을 미친 것으로 판단된다. 그리고, 상대적으로 점토함량이 낮은 처리구가 점토함량이 높은 처리구보다 생육 상태와 생산량에서 우세하였는데, 모래와 점토 함량 차이에 따른 배수와 토양의 수분보유력이 생강생육에 큰 영향을 준 것으로 판단된다.