• 한국주조공학회지
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• 제32권6호
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• pp.261-268
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• 2012

The effects of thickness, base element and additive to inoculant on the number of eutectic cells and chill depth of thin-section gray cast iron were investigated. Meanwhile the number of eutectic cells increased by inoculation, chill depth decreased. The former decreased and the latter increased by holding the melt at the temperature range between 1,450 and $1,500^{\circ}C$. The former was more for the thinner casting with the thickness of 5 mm than the other. The result of thermal analysis coincided well with the change of macrostructure. The former increased and the latter decreased with the increased contents of carbon, silicon and the silicon content by inoculation. The former decreased and the latter increased with increased manganese content. The number of eutectic cells decreased as the amounts of rare earth and the bismuth added to this inoculant increased. With the addition of sulfur of 0.10 wt% of the weight of this inoculant, the maximum number of eutectic cells was obtained.

• 한국주조공학회지
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• 제13권2호
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• pp.175-186
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• 1993

In this study, the effect of Mo addition on the microstructure and mechanical properties of ductile cast iron have been investigated. The amounts of Mo and the thickness of specimen have been varied from 0 to 4.79wt% and 13mm, 10mm and 6mm, respectively. As the casting thickness decreases, the average size of spheroidal graphite is decreased and the hardness increases. By increasing the Mo content, the tensile strength of ferrite and pearlite matrix increases and shows maximum which is about $30{\sim}40%$ higher than ordinary ductile cast iron. After the maximum, adding more Mo results in gradual transformation of ferrite and pearlite to bainite and thus tensile strength decreases again. The elongation decreases continueously with Mo content. The addition of Mo about $0.5{\sim}1.0wt%$ improves the wear resistance and tensile strength of thin ductile cast iron.

• Animal cells and systems
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• 제13권2호
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• pp.105-112
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• 2009

In this study, the effects of iron on cytochrome c oxidase (CcO) in rat lung mitochondria were examined. Similar to liver mitochondria, iron accumulated considerably in lung mitochondria (more than 2-fold). Likewise, the reactive oxygen species and nitric oxide (NO) content of mitochondria were increased by more than 50% and 100%, respectively. NO might be produced by nitric oxide synthase (NOS), eNOS and iNOS type, with particular contribution by NOS in mitochondria. The respiratory control ratio of iron overloaded lung mitochondria dropped to nearly 50% due to increased state 4. Likewise, cytochrome c oxidase activity was lowered significantly to approximately 50% due to excess iron. Real-time PCR revealed that the expression of isoforms 1 and 2 of subunit IV of CeO was enhanced greatly under excess iron conditions. Taken together, these results show that oxidative phosphorylation within lung mitochondria may be influenced by iron overload through changes in cytochrome c oxidase and NO.

• 대한한의학방제학회지
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• 제28권3호
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• pp.281-287
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• 2020

Objectives : In case of herbs decoction, the ceramic or earthware pots was recommended, but not the metals, particularly iron or aluminum, which could cause unknown chemical reactions. In Korean Medical classics, it has been known that some herbs including Caulis Lonicerae Japonicae (CL) were not recommended to boil with iron pot. This study investigates the physical changes of extracts of CL with or without iron. Methods : CL was decocted with reflux cooling extraction system to prevent evaporation and volatilization. Content of polyphenol was detected by Folin-Denis method and the levels of loganin and chlorogenic acid were evaluated by UPLC. Results : The color of extract with glass beads (GB) is yellowish brown, and the iron beads (IB) is blackish brown. Polyphenol and chlorogenic acid levels were reduced in IB extracts. Conclusions : The color of extract was change to blackish brown, and polyphenol and chlorogenic acid levels were reduced in CL extract with iron. Therefore, iron pots is not suitable for CL extraction.

• 생명과학회지
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• 제20권11호
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• pp.1611-1616
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• 2010

W/O/W multiple emulsion의 산화에 미치는 surfactant micelle의 영향을 규명하기 위하여 W/O/W multiple emulsion에서 continuous phase로 전이되는 ferric iron의 양과 hydroperoxide의 양을 측정한 결과, continuous phase로 전이된 ferric iron과 hydroperoxide의 양은 첨가한 과량의 surfactant micelle에 의해, 저장기간이 길어질수록 증가하였다. Ferric iron을 함유한 W/O/W multiple emulsion의 지방산화 정도는 hydroperoxide와 TBA값 및 headspace hexanal을 측정하여 살펴본 결과 과량의 surfactant에 의해 산화는 감소하였다. 이상의 결과로 첨가된 과량의 surfactant에 의해 W/O/W multiple emulsion에서 prooxidant로 작용하는 ferric iron의 위치가 변화되어 산화를 줄일 수 있을 것으로 판단하였다.

• Advances in materials Research
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• 제6권3호
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• pp.245-255
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• 2017

High energy ball milling is employed to produce iron matrix- multiwall carbon nanotube (MWCNT) reinforced composite. The damage caused to MWCNT due to harsh ball milling condition and its influence on interfacial bonding is studied. Different amount of MWCNT is used to find the optimal percentage of MWCNT for avoidance of the formation of chemical reaction product at the matrix - reinforcement interface. Effect of process control agent is assessed by the use of different materials for the purpose. It is observed that ethanol as a process control agent (PCA) causes degradation of MWCNT reinforcements after milling for two hours whereas solid stearic acid used as process control agent, allows satisfactory conservation of MWCNT structure. It is further noted that at a high MWCNT content (~ 2wt.%), high energy ball milling leads to reaction of iron and carbon and forms iron carbide (cementite) at the iron-MWCNT interface. At low percentage of MWCNT, dissolution of carbon in iron takes place and the amount of reinforcement in iron matrix composite becomes negligibly small. However, under the present ball milling condition (ball to metal ratio~ 6:1 and 200 rpm vial speed) iron-1wt.% MWCNT composite of good interfacial bonding can retain the tubular structure of reinforcing MWCNT.

• Applied Biological Chemistry
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• 제22권3호
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• pp.160-165
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• 1979

본(本) 실험(實驗)은 장류제조(醬類製造) 과정중(過程中)의 철분(鐵分)의 혼입경로(混入經路) 함량변화(含量變化) 및 제품(製品)의 질(質)에 미치는 영향(影響)을 규명(糾明)할 목적(目的)으로 시도(試圖)되었으며 그 일단계로서 간장 양조(釀造) 과정중(過程中)의 철분함량(鐵分含量)과 시판(市販) 간장중(中)의 철분함량등(鐵分含量等)에 대(對)하며 실험(實驗)한 결과(結果)는 아래와 같다. 1. 간장 양조원료중(釀造原料中)의 철분함량(鐵分含量)은 대두(大豆)에는 108 ppm, 탈지대두(脫脂大豆)에서 133ppm, 소맥에서 79ppm, 식염(食鹽)에서 5ppm, 종국(種麴)에서 58ppm, 황국균(黃麴菌) 포자(胞子)에서 $300{\sim}2000ppm$, gluten에서 240ppm, $Na_2CO_3$에서 20ppm(이상(以上) 건물당(乾物當))이며 HCl에서 6ppm, Caramel에서 18ppm, 양조용수(讓造用水)에서 0.3ppm으로 각각(各各) 나타났다. 2. 제국과정중(製麴過程中)의 철분합량(鐵分合量)은 $200{\sim}240ppm$(건물당(乾物當))으로 제국기간(製麴期間)의 경과(經過)에 따라 다소(多少) 증가(增加)하는 경향(傾向)을 보였다. 3. 간장 발효과정중(醱酵過程中)의 철분함량(鐵分含量)은 담금후 1개월(個月) 경과후(經過後)에 40ppm, 3개월(個月) 경과후(經過後)에 $43{\sim}47ppm$, 6개월(個月) 경과후(經過後)에 $49{\sim}62ppm$으로 각각(各各) 나타났다. 4. 양조(讓造)간장의 압착과정(壓搾過程)에서 즙액중(中)의 철분(鐵分)은 감소(減少)하나 살균과정(殺菌過程)에서는 별다른 변화(變化)가 없었다. 5. 화학(化學)간강 제조과정중(製造過程中)의 철분함량(鐵分含量)은 소맥 gluten의 염산(鹽酸) 분해액중(分解液中)에 159ppm, 중화액중(中和液中)에 184ppm으로 중화(中和)에 의(依)하여 다소(多少) 증가(增加)하였다. 6. 제품(製品) 양조(釀造)간장과 화학(化學)간장의 총질소농도(總窒素濃度)를 달리하여 철분함량(鐵分含量)을 측정(測定)한 결과(結果) 총질소(總窒素) 농도(濃度)가 증가(增加)함에 따라 철분함량(鐵分含量)은 증가(增加)하였으며 동일(同一)한 총질소농도(總窒素濃度)에 있어서 화학(化學)간장은 양조(釀造)간장은 비(比)해 철분함량(鐵分含量)이 높았다. 7. 시판(市販)간장중(中)의 철분함량(鐵分含量)은 제조원(製造元)에 따라 다양하나 총질소(總窒素) 1.0으로 환산(換算)하여 평균(平均) 62.7ppm이었으며 재래식(在來式) 간장의 철분함량(鐵分含量)은 평균(平均) 37.68ppm이었다.

• 한국주조공학회지
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• 제3권3호
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• pp.159-166
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• 1983

In order to develope domestic carburizers, the experiment was carried out by applying crystallization heat treatment to domestic anthracites and also to foreign products to compare with domestic anthracites.The present work was mainly concerned with the effect of their degree of crystallization of carbon-bearing materials on carbon pick-up in molten iron.Those effects were evaluated by the measurement of density, chemical composition, specific electric resistivity, and X-ray intensity of carbon-bearing materials. Experimental results thus obtained were summurized as follows. 1. The degree of crystallization of domestic anthracites and foreign products was increased with increasing heat treatment temperature. 2. The more degree of crystallization, the shorter the dissolving time of domestic anthracites in molten iron was obtained, while that of foreign products was remained constant. 3. As the degree of crystallization of domestic anthracites and foreign products was increased, the carbon content as well as carbon recovery in molten iron was increased.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.62-65
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• 2002

Permeable reactive barriers (PRBs) are in-situ barriers constructed in a subsurface to treat contaminated groundwater using various reactive media. The common reactive medium used in PRB is zero-valent iron, which has been widely used to treat chlorinated solvents (i.e., PCE, TCE). A disadvantage of iron media is high cost. In this study, waste foundry sands were tested to determine the feasibility of their use as a low cost reactive medium. Batch and column tests were conducted with TCE to determine transport parameters and reactivity of the foundry sands. The reactivities of foundry sands for common groundwater contaminants are comparable to or slightly higher than those for Peerless iron, a common medium used in PRBs. In addition, the TOC and clay in foundry sands can significantly retard the movement of target contaminant, which may result in lower effluent concentration of contaminant due to biodegradation. In general, PRBs 1-m thick can be constructed with many foundry sands to treat TCE provided the zero-valent iron content in the foundry sand is higher than 1%.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.790-791
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• 2006

The fracture behavior and mechanical characteristics of sintered rare-earth magnets were investigated. It shows that the fracture behavior and bending strength of the magnets obviously exhibit anisotropy. Sm-Co magnets tend to cleavage fracture in the close-packed (0001) plane or in the ($10\bar{1}1$) plane. The fracture mechanism of $Nd_2Fe_{14}B$ magnet mainly appears to be intergranular fracture. The anisotropy of fracture behavior and mechanical strength of sintered rare-earth magnets is caused mainly by the strong crystal-structure anisotropy and the grain alignment texture. The effects of Nd content, and Pr, Dy substitution on the impact stability of $Nd_2Fe_{14}B$ magnets were also reported.