• 한국환경과학회지
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• 제12권4호
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• pp.469-476
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• 2003

In order to examine the pre-treatment effect of crab shell en Pb$^{2+}$ removal by crab shell in aqueous solution, acid and alkali pre-treated crab shell were used. Electron microscopy techniques such as TEM (transmission electron microscopy) and SEM (scanning electron microscopy), and EDX (energy dispersive X-ray) and FTIR (Fourier transform infrared) spectrometry techniques were used to investigate the process of Pb$^{2+}$ removal by acid and alkali pre-treated crab shell. The Pb$^{2+}$ removal by acid pre-treated crab shell was much lower than that by untreated crab shell because of the decrease of CaCO$_3$ from the crab shell. However, the Pb$^{2+}$removal by alkali pre-treated crab shell increased compared to that by untreated crab shell. The results were confirmed by TEM, SEM, EDX and FTIR.nd FTIR.

• 한국응용과학기술학회지
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• 제31권2호
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• pp.176-182
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• 2014

Using alkali treatment solution, neutrality treatment solution and acid treatment solution, the surface corrosion layer of copper plates and bronze plates that have been artificially corroded using HCl, $H_2SO_4$ and $HNO_3$ solutions were removed. In the case of alkali treatment solution, only air oxidation in the form of black tenorite and white cuproous chloride remained without being removed. In the case of using a neutrality treatment solution, a anhydrous type layer of reddish brown cupric chloride remained without being removed, together with this black and white corrosion substance. In the case of using an acid treatment solution, this red corrosion substance also remained, but all of the oxide was removed on the surface of the specimen that was treated by alternatively using alkali treatment solution and acid treatment solution. In the case of this treatment solution with the order of alkali-acid, oxidation no longer proceeded only through the distilled water cleaning process after treatment, thereby showing that oxidation from the cleaning solution no longer proceeded.

• 농업과학연구
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• 제36권2호
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• pp.225-232
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• 2009

The ratio of saccharification and formation of furans during the acid hydrolysis of agar with oxalic acid and sulfuric acid were examined base on the contents of the agar and acids. The ratio of saccharification in oxalic acid appeared to be 51~59% somewhat higher than 49~61% of sulfuric acid. Formation of the furans during the acid hydrolysis increased proportional to the contents of agar and acid. The relative formation ratio was high 10~47% for furfural (FUR) and 15~29% for hydroxy-methyl furfural (HMF) in 0.5~1.25% sulfuric acid rather than those of oxalic acid. When comparing the removal efficiency of the furans using an alkali treatment, steam stripping and hydrophobic resins, FUR was eliminated 60% by the alkali treatment, 62~90% by steam stripping and 71~75% by Amberlite XAD4 and 7HP, while HMF was removed to low levels of 10.5%, 4~17% and 13~25%, respectively. The loss of reducing sugar was also observed in process of the removal of furans, and the loss rate was the level of 2~4% in alkali treatment, 11~16% in steam stripping and 7~9% in Amberlite resins.

• 한국식품영양과학회지
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• 제12권2호
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• pp.146-149
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• 1983

사골(四骨) 용출액중(溶出液中) 영양성분 특히 칼슘, 인, 질소성분의 용출량을 증가시키기 위한 기초연구로써 우선 산과 알카리 처리효과를 검토하였다. 산 처리로는 acetic acid를 0~0.8%까지, 알카리 처리로는 sodium bicarbonate를 0~0.05%까지 수준별로 처리하였다. 그 결과는 다음과 같다. 산 처리의 경우 칼슘은 acetic acid 농도가 증가될수록 용출량도 유의적으로 증가되었으며 특히 acetic acid 농도가 0.1% 이상일 때 유의적 증가를 보였으며 인은 0.3% 일 때 용출량이 급격히 증가되었다. Ca/P 비(比)는 acetic acid 농도가 0.01%까지는 1~2를 나타냈지만 그 이상의 모든 처리에서는 2 이상을 나타냈다. ${\alpha}$-amino N과 총 질소는 모두 acetic acid농도가 0.5% 이상일 때 유의적 증가를 보였다. 알카리 처리의 경우는 칼슘, 인, 총 질소는 모든 처리에서 유의적 증가를 나타내지 않았지만 ${\alpha}$-amino N은 sodium bicarbonate 농도가 0.05% 일 때 무처리(無處理)에 비해 유의적 증가를 보였다. (P<0.05) 이상의 결과에서 산 처리에 의해 영양성분의 용출은 현저히 증가되었으나 알카리 처리에 의해서는 크게 증가되지 못했다.

• 상하수도학회지
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• 제30권5호
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• pp.571-577
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• 2016

Phosphorus is an essential and irreplaceable element for all living organisms and its resource is limited. Significant amount of used phosphorus is collected in sewage treatment plant as sludge. Sludge ash after incineration contains about 10% of phosphorus in dry mass basis, which is comparable to phosphate rocks, and it is an important source of phosphorus recovery. Acid and alkali were used to leach phosphorus from sludge ash and compared for their leaching kinetics and performance. Phosphorus leaching by NaOH was fast and 0.2 N and 2 N NaOH leached 49% and 56% of the total phosphorus in the sludge ash at the L/S ratio of 100. Phosphorus leaching by sulphuric acid and hydrochloric were very fast and most of the phosphorus was leached in 5 minutes. In case of sulphuric acid 95% of the total phosphorus in the sludge ash was leached by 0.2 N at the L/S ratio of 100 and 93% was leached by 1 N at the L/S ratio of 10. 1 N hydrochloric acid leached 99% of the total phosphorus at the L/S ratio of 10. The results showed acids were more effective than alkali for phosphorus leaching from sludge ash and hydrochloric acid leached more phosphorus than sulphuric acid.

• 한국의류학회지
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• 제20권5호
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• pp.728-737
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• 1996

The purpose of this study is to investigate the change of the chemical properties of wool treated with six kinds of alkali (NaOH, Naac03, NH40H, NH2CH3CH30H, TMAH and BTMAH) with or without CTAB. Content of bound fatty acid liberated from wool surface, elemental composition and allw6rden time were measured to compare the surface modification of untreated and alkali treated wool. Also, the chemical degradation of the fiber was investigated by measuring cystine contents and urea-hydrogensulfite solubility. The result were as follows: 1. By the alkali treatment of wool, the covalently bound fatty acid of the epicuticle was removed and the allworden time was shortened, and in the case of wool treated with TMAH, BTMAH, the allw6rden sacs were formed unevenly and rarely. Also, cystine contents and urea-hydrogensulfite solubility were decreased by alkali treatment on wool. 2. The modification of epicuticle and the chemical degradation of wool were occurred due to alkaline hydrolysis in the order of TMAH, BTMAH > NaOH, Na3c03> NH2CH3CHaOH, NH40H. 3. As a treating time increased, the modification of epicuticle and chemical degradation of wool were accelerated. By the addition of CTAB to the alkali solution, the modification of epicuticle was increase, and the cystine contents and urea-hydrogensulfite solubility were reduced than that of wool teated with alkli without CTAB due to reduction of negative charge on the wool surface by the adhesion of CTAB.

• 한국식품과학회지
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• 제31권6호
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• pp.1453-1457
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• 1999

항산화 및 항암 작용이 있는 것으로 알려진 conjugated linoleic acid(CLA)를 식물성 유지로부터 알칼리 이성질화에 의해 고 농도의 CLA 농축물을 얻기 위한 최적 조건을 연구하였다. 지방산 조성이 상이한 식물성 유지를 알칼리 이성질화 하였을 때 CLA 생성량은 유지중 linoleic acid 함량이 많은 것이 가장 높았다. 홍화유를 알칼리 이성질화할 때 KOH 농도는 $8{\sim}11%$, 가열온도는 $180{\sim]185^{\circ}C$에서 cis-9, trans-11 CLA와 총 CLA 생성량이 가장 높았고, 가열시간은 CLA 생성량에 큰 영향을 미치지는 않았으나 $20{\sim}40$분이 가장 적당하였다. 홍화유를 silicic acid column chromatograph)에 의해 중성, 당 및 인지방질의 lipid class를 분획하여 알칼리 이성질화를 시켰을 때 중성지방질의 획분에 CLA가 가장 많이 함유되었다. 알칼리 이성질화시킨 홍화유를 요소처리와 HPLC 분획에 의해 95.4%의 CLA 농축물을 얻을 수 있었다.

• 한국식품저장유통학회지
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• 제6권3호
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• pp.308-312
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• 1999

밤의 효율적 박피 방법을 개발하기 위하여 산 및 알카리 처리에 의한 내피 및 외피의 박피효과를 조사하고, 밤의 형태학적, 물리적 특성을 조사하였다. 알카리 처리에 의한 밤 내피의 박피 정도는 4%, NaOH 15분 처리시 박피가 가장 잘 되었으며, 산처리에 의한 박피는 3% HCIO$_4$ 농도로 5$0^{\circ}C$에서 30분 처리시 박피가 가장 잘 되었다. 그러나 이러한 화학적 처리시 온도가 높아지고 처리시간이 길어질수록 색상, 경도 등의 품질저하가 나타나 낮은 온도에서 단시간 처리가 요구된다. 축파와 은기 품종의 중량, 장경, 단경, 체적 및 내 외피 중량을 측정하고, 이들 두 품종의 물리적 특성치간의 상관성을 조사한 바 중량과 내ㆍ외피 중량간의 상관성이 다른 특성치들보다 높게 나타났으며 이러한 물리적 특성치로부터 내피 및 외피의 중량을 구할 수 있는 다중 회귀식을 구하였다.

• 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.

• 한국표면공학회지
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• 제25권3호
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• pp.144-149
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• 1992

The adsorption and molecular sieve characteristics of water, methanol, ethanol, butanol and benzene on acid-alkali treated natural zeolite from Kampo area were investigated by the Diamond·Kinter method, and it was compared with synthetic zeolite A. Adsorption amount of water increased with the treatment of acid rather than the treatment of alkali. Similar tendency was observedd in adsorption of alcohols such as methanol, ethanol and butanol, but the amount of adsorption decreased. From the views of the molecular size, adsorption amount of benzene decreased because of surface activity according to the cations species rather than chemical treatment. And it was almost same value that the amount of adsorption was compared acid treated natural zeolite with synthetic zeolite A.