• Journal of the Korean Wood Science and Technology
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• 제43권1호
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• pp.76-85
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• 2015

본 연구에서는 2단계 산 처리 방법을 이용하여 목질계 바이오매스로부터 푸르푸랄(furfural) 생산 조건을 탐색하고 생성된 푸르푸랄은 XAD-4 resin을 이용하여 회수하였다. 1차 산 처리 촉매로는 옥살산(oxalic acid)과 황산(sulfuric acid)을 사용하였다. 1차 산 처리로부터 얻어진 액상가수분해산물에 포함된 자일로스 농도는 옥살산과 황산 촉매에서 각각 $18.86g/{\ell}$, $19.35g/{\ell}$로 유사한 값을 나타냈다. 반면 올리고머 함량은 황산 촉매에서 높은 값을 나타냈다. 옥살산 전처리와 2차 황산 처리(황산 $0.1m{\ell}$, 90분)의 연속과정에서 최대 55.10%의 푸르푸랄 생산 수율을 나타냈다. 2차 산처리 과정에서 반응시간이 증가할수록 푸르푸랄 생산 수율은 증가하였다. 생성된 푸르푸랄은 XAD-4 resin을 이용하여 대부분 회수하였다.

• 한국환경과학회지
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• 제27권1호
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• pp.1-10
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• 2018

A continuous process of persulfate oxidation and citric acid washing was investigated for ex-situ remediation of complex contaminated soil containing total recoverable petroleum hydrocarbons (TRPHs) and heavy metals (Cu, Pb, and Zn). The batch experiment results showed that TRPHs could be degraded by $Fe^{2+}$ activated persulfate oxidation and that heavy metals could be removed by washing with citric acid. For efficient remediation of the complex contaminated soil, two-stage and three-stage processes were evaluated. Removal efficiency of the two-stage process (persulfate oxidation - citric acid washing) was 83% for TRPHs and 49%, 53%, 24% for Cu, Zn, and Pb, respectively. To improve the removal efficiency, a three-stage process was also tested; case A) water washing - persulfate oxidation - citirc acid washing and case B) persulfate oxidation - citric acid washing (1) - citric acid washing (2). In case A, 63% of TRPHs, 73% of Cu, 60% of Zn, and 55% of Pb were removed, while the removal efficiencies of TRPHs, Cu, Pb, and Zn were 24%, 68%, 62%, and 59% in case B, respectively. The results indicated that case A was better than case B. The three-stage process was more effective than the two-stage process for the remediation of complex-contaminated soil in therms of overall removal efficiency.

• Environmental Engineering Research
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• 제19권4호
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• pp.355-361
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• 2014

The wastewater treatment with a two-phase expanded granular sludge bed (EGSB) system for anaerobic degradation of acetate, benzoate, terephtalate and p-toluate from purified terephtalic acid (PTA) production was studied. The feasibility and effectiveness of the system was evaluated in terms of organic oxidation by chemical oxygen demand (COD), gas production, bacterial adaptability and stability in the granular sludge. Average removal efficiencies 93.5% and 72.7% were achieved in the EGSB reactors under volumetric loading rates of $1.0-15kg-COD/m^3/day$ and terephtalate and p-toluate of 351-526 mg/L, respectively. Gas production reached total methane production rate of 0.30 L/g-COD under these conditions in the sequential EGSB reactor system. Higher strength influent COD concentration above 4.8 g-COD/L related to field conditions was fed to observe the disturbance of the EGSB reactors.

• Animal cells and systems
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• 제4권2호
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• pp.145-150
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• 2000

Retinoic acid (RA) evokes pattern duplication in the regenerating salamander limb. Interestingly, it also enhances dedifferentiation in the regenerate by the morphological, histological and biochemical criteria. To examine whether there is any correlation between the RA-evoked pattern duplication and de novo protein synthetic profile in the regenerating salamander limb, especially during dedifferentiation, we analyzed stage-specific protein synthesis pattern in the normal and RA-treated regenerating limbs by metabolic labeling followed by two-dimensional gel electrophoresis. In the regenerating limbs without RA treatment, a few hundred kinds of proteins were found to be synthesized at the stage of wound healing and the total number of protein synthesized increased greatly as regeneration proceeded. The same trend was also observed in the RA-treated regenerating limbs. Interestingly, some protein spots were noted to be either newly synthesized or highly expressed by the RA treatment especially at the stage of dedifferentiation. The results shows that the enhancement of dedifferentiation state after the RA treatment correlates well with the protein synthesis profile, and suggest that those proteins are important for the RA-evoked pattern duplication in the regenerating limbs of salamander.

• 한국표면공학회지
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• 제49권3호
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• pp.265-273
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• 2016

The effects of surface modification by nitric acid on the pre-treatment of electroless copper plating were investigated. Copper was electroless-plated on the nitric acid treated graphite activated by a two-step pre-treatment process (sensitization + activation). The chemical state and relative quantities of the various surface species were determined by X-ray photoelectron spectroscopy (XPS) after nitric acid modification or pre-treatment. The acid treatment increased the surface roughness of the graphite due to deep and fine pores and introduced the oxygen-containing functional groups (-COOH and O-C=O) on the surface of graphite. In the pre-treatment step, the high roughness and many functional groups on the nitric acid treated graphite promoted the adsorption of Sn and Pd ions, leading to the uniform adsorption of catalyst ($Pd^0$) for Cu deposition. In the early stage of electroless plating, a lot of tiny copper particles were formed on the whole surface of acid treated graphite and then homogeneous copper film with low variation in thickness was formed after 30 min.

• The Korean Journal of Ecology
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• 제13권2호
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• pp.75-82
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• 1990

Toxic effert of water extract from leaves of Pinus rigida and some phenolic compounds on the seeds germination of Raphanus sativus var. hortensis for. acanthiformis Makino has been studied. There was little difference of germination percentage among the pH value of leaf extract (pH3~9). The germination percentage drastically with increased concentration level of leaf extract at about 60 percent. Seeds gemination of Raphanus sativus var. hortensis for. acanthiformis Makino inhibited severely by caffeic acid, ferulic acid and p-coumaric acid at M, but the germination percentage was higher than that of the control group in vanillic acid. In electrophoresis, there was no differences at earlier seedling stage of protein band between allelochemical treated and non-treated group, but in late stage, two protein band near 58kd and 27kd did not appeared in the toxic affected group. In case of caffeic acid treatment, two protein band near 58kd and 27kd did not found at late stage too.

• 자원리싸이클링
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• 제2권2호
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• pp.22-26
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• 1993

아연 제련잔사로부터 갈륨과 인디움을 동시에 회수하기 위한 연속공정도를 확립하고자 하였다. 갈륨만을 회수하는 알칼리처리법과는 달리 황산침출에 의할 경우 갈륨과 인디움의 동시회수가 가능하며, 2단계 중화를 통하여 용액중의 다량의 철분을 분리제거할 수 있었다. 1차처리하여 얻은 갈륨과 인디움의 침천물은 알칼리 및 산처리에 의해 갈륨과 인디움을 각각 분리회수할 수있었으며, 약산성 용액에서 저농도의 인디움을 회수하고자 할 경우 아연금속분말에 의한 cementation법을 사용하는 것이 효고적이었다.

• The Plant Pathology Journal
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• 제34권1호
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• pp.78-84
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• 2018

Peroxyacetic acid mixture Perosan, composed of peroxyacetic acid, hydrogen peroxide and acetic acid, was evaluated for eco-friendly management of tomato bacterial wilt by Ralstonia pseudosolanacearum. Perosan drastically suppressed in vitro growth of R. pseudosolanacearum in liquid cultures in dose- and incubation time-dependent manners. Higher perosan doses (0.1 and 1%) caused lowered pH and phytotoxicity to detached leaves of two tomato cultivars Cupirang and Benekia 220 in aqueous solution. Treatment with 0.01% of Perosan delayed wilting symptom significantly in the detached leaves of two cultivars inoculated with R. pseudosolanacearum ($10^7cfu/ml$). Soil drenching of 5% Perosan solution in pots caused severe tissue collapse of tomato seedlings at the four-week-old stage of two tomato cultivars. Treatment with 1% Perosan by soil-drenching significantly reduced bacterial wilt in the tomato seedlings of two cultivars. These findings suggest that Perosan treatment can be applied to suppress bacterial wilt during tomato production.

• 한국식품영양과학회지
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• 제23권1호
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• pp.73-77
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• 1994

This study was conducted to investigate and make comparison between treatment which was reduced the reducing sugar content from Chinese cabbage using salting and desalting processes prior to Kimchi fermentation , and control for the effect of reducing sugar content on Kimchi fermentation at $25^{\circ}C$. In the early stage of Kimchi fermentation , the amount of reducing sugar (5.7mg/ml) in treatment was much smaller than that (15.1mg/ml) in control. Reducing sugar content of treatment decreased drastically during the first two days and then levelled off . Whereas, that of control dropped significantly up to the first four days of fermentation. pHs of treatment and control decreased significantly during the first two days and then showed gentle slopes. Acidities of treatment and control were increased continuously during the entire range of fermentation . The acidity of control reached to 0.75% in 3 days of fermentation, while that of treatment was shown after 6 days. Hardnesses of treatment and control using a puncture test were almost constant and the hardness value of treatment was higher than that of control during whole fermentation period. The total bacteria and lactic acid bacteria counts increased drastically during the first day of fermentation and the increase of total bacteria counts was mainly caused by that of lactic acid bacteria counts.

• International Journal of Industrial Entomology and Biomaterials
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• 제17권2호
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• pp.165-168
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• 2008

The hybrid ($CSR2{\times}CSR4$) eggs treated with acid were taken up for the study with an objective to develop long-term preservation schedule. The hybrid eggs obtained with two mating duration (3 h and 6 h) and oviposition period (6 h and 24 h) with two age groups of eggs (24 h and 36 h) were treated with Hydrochloric acid. These eggs were subjected to preservation at $5^{\circ}C$ in single step refrigeration and at $5^{\circ}C$ and $2.5^{\circ}C$ under double step refrigeration from $10{\sim}120$ days. These eggs were released from the cold storage as per the specified durations and incubated at standard conditions and allowed 2 h for hatching at 450 lux light. Hatchability was found to be significantly higher or on par with the control in three treatments (T1, T2 and T4) where the eggs are preserved continuously at $5^{\circ}C$ up to 30 days. However under double step refrigeration, hatching was not significantly affected in 20+60 day's combination of T1 treatment up to 80 days. Bioassay studies of the promising treatment i.e.. T1 with (20+60) days indicated that early stage loss and cocoon yield was found to be on par with the control. Hence this treatment was recommended for preservation of acid treated new bivoltine hybrid layings. Details of the hatchability and rearing performance of long term preservation of acid treated eggs are discussed.