• 한국환경과학회지
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• 제2권1호
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• pp.61-72
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• 1993

[에멀존]계에서 거대고리화합물에 의한 효과적인 수송현상을 두가지 관점에서 논의하였다. 하나는 중금속이온($Cd^{2+}$. $Pb^{2+}$ 및 $Hg^{2+}$)을 토루엔막으로 추출하는 경우.만일 금속=거대고리 화합물의 상로작용이 크다면 이 추출효과는 증가한다. 주번째 토루엔-경꼐면에서, 금속이온을 정량적으로 용리시키기 위해서는 금속이온 -Re-cieving Phase와 금속이온-거대고리화합물 사이의 상호작용에 대한 LogK의 사가 충분히 커야한다 첫번째는 거대고리 화합물의 주개원자, 치환제, 그리고 공동반경을 고려함으로써 해결된다. 이 연구의 결과들은 이론과 잘 일치하며, 시료용액의 종류는 에멀존망에 의한 금속이온의 수송현상에 영향을 준다.$SCN^-$,$1^-$ 및 $Br^-$이온과 같은 $A^-$이온을 사용할 경구, 수송순서는 $A^-$ 이온의 용매화순서의 크기에 일치하며, 용해도의 차이때문에 금속이온의 소송능력은 Receiving Phase의 화학종 농도의 크기에 영향을 받는다. 이 연구에서는 적당한 실험조건하에서 조절된 토루엔막을 사용함으로써 $Cd^{2+}$, $Pb^{2+}$, 및 $Hg^{2+}$ 이온의 혼합물로부터 각각의 단일이온들을 효과적으로 분리농축할 수 있었다. 그리고 $Cu^{2+}$,$Ni^{2+}$,$Zn^{2+}$,$Fe^{2+}$, 이온들은 중금속이온들을 분히 농축하는데 부분적으로 방해를 하였다. 그러나 알칼리 및 알칼토금속이온은 방해하지 않았다.

• 자원환경지질
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• 제33권6호
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• pp.519-524
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• 2000

This study has been performed to evaluate the possibility of utilizing stone powder sludges from stone quarry and manufacturing plant as adsorbents for heavy metals in industrial wastewater. The stone powder sludges from stone quarry (IS-01) have the most effective adsorption capacity (above 95％ of initial concentrations) under the given experimental conditions of reaction times (Pb : 15 min, Cu : 2 hr, Zn : 48 hr), initial acidity of solution (pH>3) and dosage (sludge/liquid ratio : 0.02). The stone powder sludges from manufacturing plant (CW-01) show relatively high adsorption capacity (about 95％ of initial concentrations) only for Pb with a reaction times of 12 hours, initial acidity of solution (pH>3) and dosage (sludge/liquid ratio : 0.02). The stone powder sludges (IS-01) from stone quarry having relatively excellent adsorption capacity under the given experimental conditions show their potential utilization as heavy metal adsorbents.

• 한국주조공학회지
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• 제10권6호
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• pp.509-519
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• 1990

A Solidification of the aluminum was studied under the condition of the forced liquid convection. The Al melt was stirred by a highly rotating carbon bar on whose surface the solidified Al was nucleated. The Al was refined by partial solidification and the solute distributions were rationalized through the estimation of the solidification rate which is based on the heat transfer calculation of the process. The microstructure-morphological change of the specimens was also showed.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.97-97
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• 2013

The exterior structures of natural organisms have continuously evolved by controlling wettability, such as the Namib Desert beetle, whose back has hydrophilic/hydrophobic contrast for water harvesting by mist condensation in dry desert environments, and some plant leaves that have hierarchical micro/nanostructures to collect or repel liquid water. In this work, we have provided a method for wettability contrast on metals by both nano-flake or needle patterns and tuning of the surface energy. Metals including steel alloys and aluminum were provided with hierarchical micro/nanostructures of metaloxides induced by fluorination and a subsequent catalytic reaction of fluorine ions on metal surfaces in water with various ranges from room to boiling temperature of water. Then, a hydrophobic material was deposited on the structured surfaces, rendering superhydrophobicity. Plasma oxidization induces the formation of superhydrophilic surfaces on selective regions surrounded by superhydrophobic surfaces. We show that wettability contrast surfaces align liquid water within patterned hydrophilic regions during the condensation process. Furthermore, this method could have a greater potential to align other liquids or living cells.

• 농업과학연구
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• 제43권3호
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• pp.424-431
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• 2016

The nutrients in livestock manure produced during fermentation processes in public livestock recycling centers are used as fertilizers. However, the large amounts of swine manure produced in intensive livestock farms can be a nonpoint source of pollution. In this experiment, we investigated the chemical properties, inorganic components, and heavy metal contents in 101 samples of liquid swine manure collected from 28 public livestock recycling centers throughout the nation. Results showed that the average pH of the samples was alkaline (pH range 5.18 to 9.54), and their maximum EC was $53.2dS\;m^{-1}$. The amounts of total nitrogen and total phosphorus were in the range of 1000 - 2000 and $200-800mg\;L^{-1}$ while potassium, which constituted 47% of the total inorganic ions recovered from the liquid swine manure, amounted to $1500mg\;L^{-1}$. The most distinctive heavy metals recovered from the liquid swine manure were copper and zinc although the amounts of both heavy metals were much lesser than those of the standards as livestock liquid fertilizer set by the Rural Development Administration. On the other hand, the amount of nitrogen decreased rapidly with an increasing fermentation period from immature to mature, assumed to be lost as volatile compounds, such as ammonia, which are the major odor components during the fermentation process.

• Journal of Welding and Joining
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• 제19권5호
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• pp.534-539
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• 2001

The formation mechanism of microconstituents in brazed joints of duplex stainless steel and Cr-Cu alloy which is an essential process of rocket engine manufacturing was investigated using Cu base insert metal. $SUS329J_3L$ and C18200 were used for base metal and AMS 4764 was used for insert metal. The brazing was carried out under various conditions. There were various phases in the joints, because of reaction between liquid insert metal and base metals. Since liquid insert metal reacts with duplex stainless steel, liquid Cu from insert metal infiltrated into the $\alpha/\beta$ interface of duplex stainless steel. Through the process of Cu infiltration, isolated stainless steel pieces come into the liquid insert metal. Since liquid insert metal reacts with Cr-Cu alloy. Cr precipitates from C18200 come into the liquid insert metal. With increment of bonding temperature and holding time, amounts and sizes of phases increased. but Cr-Mn compounds decreased at 1303k for 1.2ks and Mn-rich phases disappeared Fe-Cr compounds formed.

• 한국환경과학회지
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• 제14권7호
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• pp.691-697
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• 2005

Waste sludge may be used to recovery wastewater contaminated with heavy metals. The waste sludge is an inexpensive readily available source of biomass for biosorption with metal-bearing wastewater. The biosorption of heavy metals such as Pb(II), Cu(II), Cr(II), and Cd(II) onto waste sludge was investigated in batch ex­periments and waste sludge loaded heavy metals was separated by dissolved air flotation. The biosorption equi­bria of heavy metals could be described by Langmuir and Freundich isotherms. The adsorption capacity for waste sludge was in the sequence of Pb(II)>Cr(II)>Cu(II)>Cd(II). The system attained equilibrium about 20 min. The Langmuir and Freundlich adsorption model effectively described the biosorption equilibrium of Cu(II) and Cr(II) ions on waste sludge. Maximum adsorption capacity of Cu(II) and Cr(II) were 196.08 and 158.73 mg/g, respectively. Solid-liquid separation efficiencies were kept above $95\%$ on waste sludge loaded heavy metals, and were decreased with pH increasing.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1991년도 특별강연 및 추계학술발표 개요집
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• pp.64-65
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• 1991

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 1999년도 추계학술강연 및 발표대회 강연 및 발표논문 초록집
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• pp.18-18
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• 1999

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1200-1201
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• 2006

Attempts have been made to describe the influence of production process parameters on the microstructure and properties of W-Ag and Mo-Ag composites. The compositions of powder mixtures are W+30% Ag and Mo+30%Ag. Silver additions assists densification during sintering by a liquid phase sintering process. The main goal of this work is to compare properties and microstructure of as-sintered and as-infiltrated composites.