• 한국세라믹학회지
• /
• 제40권12호
• /
• pp.1141-1149
• /
• 2003

Refractory industry in technologically advanced countries has long been on gradual decline due to leveled-off steel production and decreasing unit consumption of refractories for steel. Notable technological achievements by refractory industry that contributed significantly to steel production are briefly reviewed covering from blast furnace, basic oxygen furnace to continuous casting. Future possibility to revitalize the refractory industry is discussed on the basis of the review, taking into account opportunities available in environment and energy related sector of industries.

• 한국주조공학회지
• /
• 제25권1호
• /
• pp.3-9
• /
• 2005

• 한국동물학회:학술대회논문집
• /
• 한국동물학회 2003년도 한국생물과학협회 학술발표대회
• /
• pp.174.1-174
• /
• 2003

No Abstract, See Full Text

• 보존과학회지
• /
• 제36권2호
• /
• pp.143-151
• /
• 2020

본 연구에서는 인제 부평리유적 4-2지구 통일신라시대 제철유적에서 출토된 슬래그 5점에 대해 분석을 수행하였으며 그 결과를 통하여 당시의 제철공정을 밝히고자 하였다. 인제 부평리유적출토 슬래그의 전철량은 3.65~23.78%로 고대 제철에서 일반적으로 나타나는 전철량보다 상당히 낮았다. 조재량 또한 65.92~88.96%로 매우 높아 철과 슬래그의 분리가 원활하게 이루어졌을 것으로 보이며 그로 인해 철의 회수율이 상당히 좋았을 것으로 추정된다. 화합물 분석결과 대부분의 시료에서는 크리스토발라이트가 검출되었으며 FAS 상태도와 FCS 상태도에 분석된 데이터를 대입하여 추정한 노 내 온도 또한 1600℃ 이상으로 나타나 탄소를 포함한 철이 완전히 용융되어 주철을 생산하기에 충분한 온도로 조업이 이루어졌음을 확인하였다. 미세조직 관찰 결과 철편에서는 백주철 조직이 관찰되고 백주철 조직에서 철-탄소-인의 3원계 공정인 스테다이트가 함께 관찰되었다. 이는 제철부산물이 생성될 당시 주조 공정을 위한 간접제련이 이루어졌다는 증거가 된다. 분석결과를 토대로 인제 부평리유적은 철광석을 용해하여 선철을 생산한 간접제련유적인 것을 추정하였다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제16권1호
• /
• pp.57-62
• /
• 2003

An effort was made to assess comparative production performance in broiler chickens fed diets containing solvent extracted cottonseed meal (CSM) processed from BT and Parental Non-BT lines. Processed meal of national check and commercial produce cottonseeds were also used for comparison. The free gossypol contents were 0.02, 0.02, 0.44 and 0.03% in meals of BT, Parental Non-BT, national check and commercial produce cottonseeds, respectively. Day-old broiler chicks (n=243) were divided to 27 groups of 9 each. Nine dietary treatments (iso-nitrogenous, 23% CP and iso-caloric, 2,800 kcal ME/kg) were formulated viz., D1 (control, soybean meal-SBM based), D2 and D3 (BT CSM at 10% of diet with and without additional iron), D4 and D5 (non-BT CSM with and without additional iron), D6 and D7 (national check CSM with or without additional iron), and D8 and D9 (commercial produce CSM with or without additional iron at 2 ppm for every 1 ppm of free gossypol, respectively). Each dietary treatment was offered to three replicated groups up to 6 weeks of age. At the end of 6 weeks of age, 10 birds were taken out randomly from each treatment and were sacrificed to study carcass traits, organs' yield and histo-pathological changes in vital organs. The broiler chickens received CSM processed from BT (D2, 1,753 g and D3, 1,638 g) and Parental Non-BT (D4, 1,653 g and D5, 1,687 g) with or without additional Fe grew at same rate as observed in soybean meal (solvent ext.) based diet (D1, 1,676 g). The feed intake and feed conversion efficiency (feed: gain) in these dietary treatments (BT, non-BT line based diets) also did not differ significantly (p>0.05) from control diet. Similar observation was also observed in dietary treatments (D8 and D9) containing solvent extracted cottonseed meal of commercial produce origin. However, a decrease (p<0.05) in body weight gain and feed intake was observed in D6 containing national check CSM with high gossypol content. Addition of Fe in the diet (D7) improved (p<0.05) feed intake and weight gain but not to the extent as observed in diets containing BT, parental non-BT, and commercial produce CSM or control. However, any type of CSM did not affect feed conversion efficiency when fed with or without additional iron. The carcass characteristics in terms of dressing percentage, liver weight and heart weight was not significantly (p>0.05) different between the treatments. The eviscerated yields emanated from diets containing either BT, non-BT or commercial produce were statistically similar to control. However, eviscerated yield of broilers fed national check CSM with or without iron supplementation was lower (p<0.05) than BT cotton with Fe supplementation and commercial produce CSM. The study envisaged that BT, parental non-BT and commercial produce solvent extracted cottonseed meal can be included at 10% in soybean meal based broiler diet replacing soybean meal and rice bran without additional iron.

• 동의생리병리학회지
• /
• 제29권1호
• /
• pp.18-26
• /
• 2015

Akebiae Caulis is a galenical originated from Akebia quinata Decaisne species. It is commonly used in the treatment of oposiuria, inflammation, nociceptive and fever. Here, we investigated the effect of Akebiae Caulis extract (ACE) to protect hepatocyte against the malfunction of mitochondria and apoptosis. Arachidonic acid (AA)+iron promoted excessive reactive oxygen species (ROS) production and exerted a deleterious effect on mitochondria. Treatment with ACE protected hepatocytes from AA+iron-induced cytotoxicity, as shown by alterations in the protein levels related with apoptosis such as poly(ADP-ribose) polymerase, pro-caspase 3, Bcl-XL and Bcl-2. Moreover, AA+iron-induced $H_2O_2$ production, GSH depletion and mitochondrial dysfunction were alleviated by ACE pretreatment. As a potential molecular mechanism for the ACE-mediated cytoprotection, phosphorylation of AMP-activated protein kinase (AMPK), a key regulator in determining cell survival or death, was increased by ACE. Moreover, ACE treatment enhanced inactive phosphorylation of glycogen synthase kinase-$3{\beta}$ ($GSK3{\beta}$), downstream substrate kinase of AMPK. More importantly, ACE prevented a decrease in the $GSK3{\beta}$ phosphorylation derived by AA+iron, which might contribute to mitohondiral protection and cell survival. To further identify essential compounds in Akebiae Caulis for the protection of AA+iron-mediated cytotoxicity, we found that betulin in combination with hederagenin protected from AA+iron-induced mitochondrial dysfunction. Betulin+hederagenin treatment also increased inactive phosphorylation of $GSK3{\beta}$ in common with ACE. These results suggest that ACE protected hepatocytes against oxidative stress and mitochondrial dysfunction, which is mediated with inactive $GSK3{\beta}$ phosphorylation downstream of AMPK.

• 보존과학회지
• /
• 제34권6호
• /
• pp.581-593
• /
• 2018

최근 고대 제철기술 연구를 위한 복원실험이 활발하게 이루어짐에 따라 세부 기술체계나 조업방식 등에 대한 해석이 가능해지는 등 성과를 이루었다. 이에 본 연구에서는 고대 제련-단야기술 복원실험을 위한 적정 온도조건을 확인하여 고대 기술의 복원에 근접하기 위한 적정한 실험 방향을 제시하고자 하였다. 복원대상은 고대 중원지역의 출토 사례를 기본으로 하였으며 기존의 연구 자료를 참고하여 최대한 변수를 통제한 실험을 설계하였다. 저온으로 조업한 실험A와 고온으로 조업한 실험B를 실시한 결과 실험A에서 생성된 철은 탄소함량이 적고 단야조업에도 적합한 것으로 확인되었다. 또한 슬래그의 미세조직 및 성분조성과 노벽의 침식 등 전반적인 양상도 실험A가 고대 제련기술에 근접한 결과를 보였다. 실험을 통한 고대 제철기술의 복원은 유적에서 나타나는 현상의 복원될 때 이루어질 수 있으므로 고대제련-단야 기술체계의 복원을 위한 실험은 실험A와 같은 저온조업을 중심으로 진행되는 것이 적절할 것으로 판단된다.

• 자원환경지질
• /
• 제41권5호
• /
• pp.497-507
• /
• 2008

본 연구는 국내 5대 수출 품목 중 하나이며, 국내 주요 수출품의 원자재로서 지속가능한 자원관리의 파급효과가 큰 철강을 대상으로 히든플로우와 물질집중도를 MIPS방법론을 이용하여 정량화하였다. 2005년에 4.8천톤의 철강재와 17.6백만달러(2000년 기준)의 부가가치를 생산하기 위해 71백만톤의 윈재료와 18백만Toe의 에너지를 사용하였다. 이러한 원재료와 에너지사용으로 인한 천연자원사용량은 TMR(total Material Requirement, 총물질요구량) 245백만톤, water 1524백만톤, air 34백만톤이었다. 그리고 material intensity, 즉 철강재 1톤을 생산하기 위해서 TMR 4.3톤, water 28톤, air 0.5톤의 자연자원이 사용되었다.

• 박물관보존과학
• /
• 제12권
• /
• pp.35-45
• /
• 2011

국립중앙박물관에서는 일제 강점기에 발굴된 미정리유물 정리사업의 일환으로 서봉총(瑞鳳塚), 식리총(飾履塚), 금령총(金鈴塚) 출토 행엽(杏葉) 중 일부를 선별하여 보존처리 및 제작기법을 연구하였다. 선별된 행엽은 편원어미형(扁圓魚尾形), 심엽형(心葉形), 이형(異形)으로 구분할 수 있으며 실체현미경관찰 및 XRF, SEM-EDS 분석결과 지판(地板)의 재질은 철(Fe)이며, 상판(上板) 및 문양판의 재질은 철(Fe), 구리(Cu), 은(Ag)이 각각 확인되었다. 편원어미형과 십자문심엽형행엽의 경우 세 분묘 모두 제작기법과 크기가 동일한 행엽이 각각 철(Fe)과 구리(Cu)로 제작된 것이 특징이다. 도금층이 존재하지 않는 이형행엽을 제외한 나머지 행엽의 도금층은 수은아말감도금이었다.

• The Korean Journal of Physiology and Pharmacology
• /
• 제3권2호
• /
• pp.183-189
• /
• 1999

This investigation is to determine whether the surface complexation of iron influence acute pulmonary responses induced by silica. For this study, three varieties of cation complexed silica were used: $silica-H^+,\;-Zn^{2+},\;and\;-Fe^{3+},$ since the first two are not active in the transport of electrons and generate little free radicals relative to the dust with the surface iron. Rats (270 to 280 g) were intratracheally (IT) instilled with saline, $silica-H^+,\;-Zn^{2+},\;or\;-Fe^{3+}$(5 mg in 0.5 ml saline). After 4 h, cell number, type, and differentiation were analysed in the bronchoalveolar lavage cells, and the levels of lactate dehydrogenase (LDH) and total protein were determined in the lavage fluid. In addition, bronchoalveolar lavage cells were cultured, and nitric oxide production was measured using nitrate assay. Inducible nitric oxide synthase (iNOS) mRNA in the bronchoalveolar lavage cells was also determined by northern blot analysis. Differential counts of the lavage cells showed that red blood cells were increased by 9-, 8-, and 13-fold and total leukocytes (lymphocytes plus polymorphonuclear neutrophils) by 48-, 36-, and 33-fold, following IT $silica-H^+,\;-Zn^{2+},\;and\;-Fe^{3+},$ respectively compared with the saline group. Meanwhile, there were no significant differences in red blood cells and total leukocytes among any of the cation complexed silica groups. The levels of LDH and total protein in the lavage fluid were significantly increased by 3- to 4-fold. However, compared among these silica groups, $Fe^{3+}$? complexation did not significantly change the LDH activity and total protein. NO production in cultured bronchoalveolar lavage cells was elevated by 2-fold, following IT any of the silica treatments compared with the saline group. Furthermore, the steady-state levels of iNOS mRNA in the lavage cells were greatly increased. There were any differences in iNOS mRNA expression among the silica-treated groups as with NO production. These findings suggest that surface complexed iron may not influence the acute pulmonary responses resulted from 4h exposure to silica.