• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.107-110
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• 2001

제철소에서 매년 대량 발생되어 주로 매립처분되고 있는 제강분진의 재활용 방안으로서, 폐수처리분야에 널리 사용되고 있는 펜톤산화공정의 반응촉매원인 Fe 공급원으로서 제강분 진의 활용 가능성에 대한 연구를 수행하였다. 본 연구에서는 포항제철소에서 제철부산물로 발생되는 제강분진을 전처리 없이 산화촉매로 사용하여 김포 수도권 매립지의 침출수 처리 공정에서 펜톤산화조에 유입되는 원수를 대상으로 과산화수소에 의한 산화처리 실험을 수행하였다. 반응은 회분식으로 수행하였으며, 일반적으로 알려진 펜톤산화반응의 주요 반응조 건인 운전 pH, 과산화수소 주입량 및 분할주입, 제강분진의 주입량 등의 변화에 따른 각 조 건별 시간에 따른 반응결과를 알아보았다. 또한 기존의 Fe 공급원으로 사용되고 있는 FeSO$_4$와 처리성능 및 적용조건에 대한 비교 실험도 수행하였다. 침출수 수질변화는 TOC (Total Organic Carbon) analyzer를 사용하여 측정한 TOC값으로 나타냈으며, pH controller 와 정량펌프를 사용하여 HCl과 NaOH주입을 통해 반응기간동안 일정 pH를 유지하였다. 본 연구결과, 최적 pH 조건인 4에서 최대 75% TOC 제거율을 나타내었으며, 대부분의 반응은 30분 이내에 이루어졌다. 주어진 실험조건에서 FeSO$_4$와 비교하여 반응속도와 처리효율에서 향상된 결과를 나타내었으며 반응 후 응집침전실험에서도 보다 높은 처리효과를 얻을 수 있었다. 결론적으로, 과산화수소/제강분진 시스템을 이용한 화학적 산화처리방법은 경제성과 처리성능에서 기존의 펜톤산화공정의 대체방안으로서 향 후 적용가능성이 높을 것으로 기대된다.g, 200 mg/kg, 300 mg/kg의 순서로 함량이 점차 감소하는 결과를 얻을 수 있었다. 이상의 결과를 종합하여 볼 때 가자 메탄올추출물은 PQ 유도독성을 신장 및 폐조직에서 효과적으로 경감시키는 것으로 나타났다.ted retailers ("sellers") must accept end-of-life items returned to them by the consumers. At the local level, Taipei City implements a pay-as-you-throw program, whereby citizens pay waste collection and treatment fees through the purchase of special trash bags approved by the Taipei City Government. However. recyclables that are separated by citizens are collected free-of-charge by the City. Taichung City and Kaohsiung City, on the other hand, enforce mandatory sorting schemes, whereby citizens face penalties if they don't separate recyclables from the trash before pick-up. These programs have resulted in a significant reduction in municipal waste. Per capita waste collected per day has dropped from 1.143

• Journal of Radiation Protection and Research
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• v.27 no.2
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• pp.95-100
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• 2002

Conventional and modified electrolytic decontamination experiment were performed in the 1.7 M solution of sodium sulfate and sodium nitrate tot decontamination of carbon steel as the simulated metal wastes which have been produced in large amounts from nuclear power plants. Anode ant cathode were used as inconel and titanium respective. The reaction time and temperature were 1 hr and $25^{\circ}C$ The analyses were performed of the characteristics such as weight loss arid thickness change of metal waste. suspended solid in electrolyte and SEM observation. In modified electrolyte decontamination system with increased current density ranged from 0.1 to $0.6A/cm^2$, the metal waste showed thickness changes of $0.48{\pm}0.005$ to $67.7{\pm}0.02{\mu}m$ in 1.7 M sodium sulfate and those of $0.06{\pm}0.005$ to $17.7{\pm}0.05{\mu}m$ in sodium nitrate. Metal waste in modified electrolyte decontamination system showed the thickness change of $9.8{\pm}0.01{\mu}m$ while it reacted up to $3.7{\pm}0.03{\mu}m$ in conventional system with $0.3 A/cm^2$ of current density and 1.7 M sodium sulfate. Decontamination efficiencies of modified electrolytic process ate much hither than that of conventional electrolytic process when both are applied to metal waste.

• KSBB Journal
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• v.21 no.6 s.101
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• pp.479-483
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• 2006

[ ${\beta}-Glucan$ ], one of the cell wall components, is most plentiful polysaccharides in cell wall and has several advantages in immune system. In yeast ${\beta}-glucan$ is mainly contained in the yeast cell wall, and thus it is important to produce high levels of cell mass for the mass production of yeast ${\beta}-glucan$. The best carbon and nitrogen sources on cell mass production were high fructose syrup and yeast extract. Response surface methodology (RSM) was very potential tool for the optimization of process factor and medium component. It was applied to estimate the effects of medium components on the production of cell mass. Optimal concentrations of high fructose syrup and yeast extract by response surface methodology were 8.0% (v/v) and 5.2% (w/v), respectively and the cell mass predicted was $17.0\;g/{\ell}$ at 20 h of cultivation.

• Korean Chemical Engineering Research
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• v.43 no.4
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• pp.537-541
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• 2005

A bubbling fluidized bed reactor was used to study $CO_2$ capture from flue gas using a sodium-based dry regenerable sorbent, sorbA which was manufactured by Korea Electric Power Research Institute. A dry sorbent, sorbA, consists of $Na_2CO_3$ for absorption and supporters for mechanical strength. $CO_2$ capture was effective in the lower temperature range of $50-70^{\circ}C$, while regeneration occurred in the range of $120-300^{\circ}C$. To increase initial $CO_2$ removal, some amount of steam was absorbed in the sorbents before injecting simulated flue gas. It was possible to remove most $CO_2$ for 1-2 minutes at $50^{\circ}C$ and residence time of 2 seconds with steam pretreatment. Little or no reduction in initial reaction rate and capture capacity was observed in multicycle tests. The carbonated and regenerated sorbent samples were analyzed by NMR to confirm the extent of reaction. The results obtained in this study can be used as basic data for the scale-up design and operation of the $CO_2$ capture process with two fluidized bed reactors.

• Journal of Korean Society of Forest Science
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• v.94 no.3 s.160
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• pp.161-167
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• 2005

Above and belowground biomass for Phyllostachys pubescens was determined in Jinju, Gyeongsangnam-do. Regression analyses of dry weights of culms, foliages, and twigs versus diameter at breast height were used to calculate regression equations of the form of log Y = a + blogX. Total aboveground biomass for Phyllostachys pubescens was 69.7 ton/ha and rhizomes and roots biomass were 13.7 ton/ha and 7.5 ton/ha, respectively. Culms account for about 60% of total aboveground biomass. The aboveground biomass of each component was decreased in the order of culms>foliages>twigs. As diameter at breast height grew thicker, the proportion of culms to total aboveground biomass increased. The proportion of dry weight of culms to green weight gradually increased with height in a bamboo tree and ages. Nutrients (kg/ha) of litter layer were distributed as follows: N(45.1), Ca(17.3), K(6.1), Mg(3.6), P(3.5) and Na(0.7). Nitrogen and K were given much weight in total nutrients of rhizomes and roots. These results will be useful in measuring carbon stock and drawing up management plan to increase it for Phyllostachys pubescens stand.

• Korean Chemical Engineering Research
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• v.49 no.2
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• pp.250-255
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• 2011

In this study, by using the polymeric membrane separation process, the $CO_{2}/CH_{4}$ separation and $H_{2}S$ removal from biogas were performed in order to $CH_{4}$ purification and enrichment for the fuel cell energy source application. Fibers were spun by dry/wet phase inversion method. The module was manufactured by fabricating fibers after surface coating with silicone elastomer. The scanning electron microscopy(SEM) studies showed that the produced fibers typically had an asymmetric structure; a dense top layer supported by a porous, sponge substructure. The permeance of $CO_{2}$ and $CO_{2}/CH_{4}$ selectivity increased with pressure and temperature. Mixture gas with increasing pressure and temperature, removal efficiency of the $CO_{2}$ and $H_{2}S$ were decreased while concentration of $CH_{4}$ was increased up to 100%. When retentate flow rate was increased with the decreasing of pressure and temperature the $CH_{4}$ recovery ratio in retentate side was increased while the $CH_{4}$ purity in retentate side was decreased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.442-442
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• 2008

Hydrogen was produced by water plasma excited in very high frequency inductively coupled tube reactor. Mass spectrometry was used to monitor gas phase species at various process conditions. Water dissociation rate depend on the process parameters such as ICP power, flow-rate and pressure. Water dissociation percent in ICP reactor decrease with increase of chamber pressure and $H_2O$ flow rate, while increase with increase of ICP power. In our experimental range, maximum water dissociation rate was 65.5% at the process conditions of 265 mTorr, 68 sccm, and 400 Watt. The effect of $CH_4$ addition to a water plasma on the hydrogen production has been studied in a VHF ICP reactor. With the addition of $CH_4$ gas, $H_2$ production increases to 12% until the $CH_4$ flow rate increases up to 15 sccm. But, with the flow rate of $CH_4$ more than 20 sccm, chamber wall was deposited with carbon film because of deficiency of oxygen in gas phase, hydrogen production rate decreased. The main roles of $CH_4$ gas are to reacts with O forming CO, CHO and $CO_2$ and releasing additional $H_2$ and furthermore to prevent reverse reaction for forming $H_2O$ from $H_2$ and $O_2$. But, $CH_4$ addition has negative effects such as cost increase and $CO_x$ emission, therefore process optimization is required.

• Journal of Forest and Environmental Science
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• v.22 no.1
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• pp.1-12
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• 2006

This study was carried out to compile year 2001 forest resource statistics for the State of Virginia. USA. Virginia has 15.8 million acres (6.4 million ha) of forested 1and, accounting for 62% of the landcover with non-industrial private forest landowners owning 77% of the forested area. Deciduous forests make up 78% of Virginia's forests. Total tree volume is 26.5 billion cubic ft, of which average volume per acre is $1.677ft^3/ac(117m^3/ha)$. The overall annual volume of roundwood output is $543\;million\;ft^3$. Tree growth exceeds removals by $271\;million\;ft^3$ each year for all species statewide. Average net forest land loss in Virginia is 20,000 acre (8,094 ha) per year. In 1999, the forest products industry contributed over $25.4 billion to Virginia's economy while providing over 248,000 jobs. Among forest industries logging contributes to the economy at over $863 million/yr; timber accounts for the greatest amount (28%) of the total market value of Virginia's agricultural crops. Revenue received from stumpage by landowners exceeded $345 million/yr. In their entirety. Virginia's forests provide over $30.5 billion in annual return. including $3 billion for recreation and $1.9 billion for carbon sequestation and pollution control.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.1
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• pp.7-14
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• 2015

The aim of this research is suggesting dry processed bottom ash as a new and economical source of lightweight aggregate for mortar and concrete. The dry process of bottom ash is an advance method of water-free and no chloride because only cooled down by double dry conveyer belt systems. Furthermore, because of relatively slow cooling down process helps burning up the remaining carbon in bottom ash. Using this dry process bottom ash, to evaluate the feasibility of using as a lightweight aggregate for mortar and concrete, two-phase of experiments were conducted: 1) improving shape of the bottom ash, and 2) controlling grade of the bottom ash. From the first phase of experiment, additional abrasing process was conducted for round shape bottom ash, hence improved workability and compressive strength was achieved while unit weight was increased comparatively. Based on the better shape of bottom ash, from the second phase, various grades were adopted on cement mortar, standard grade showed the most favorable results on fresh and hardened properties. It is considered that the results of this research contribute on widening sustainable method of using bottom ash based on the dry process and increasing value of bottom ash as a lightweight aggregate for concrete.

• Journal of the Korean Electrochemical Society
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• v.11 no.4
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• pp.268-272
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• 2008

$LiFePO_4$ material was synthesized by electrospinning method to obtain optimal particle size($50{\sim}100\;nm$) without carbon coating or ball milling. This material showed an orthorthombic structure with Pnma space group without any impurities, such as FeP or $Fe_2P$, in the XRD pattern. The particle morphology and particle shape were observed by SEM analysis. Li/$LiFePO_4$ cell showed a high initial discharge capacity of 135 mAh/g, at current density of $0.1\;mA/cm^2$ with a cut-off voltage of 2.8 to 4.0V. This cell exhibited a perfect cycle performance over 99.9% cycle retention rate up to 50 cycles.