• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.969-970
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• 2011

• 한국건설순환자원학회논문집
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• 제4권3호
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• pp.62-68
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• 2009

본 연구는 BFS치환율 증가에 따른 고강도 콘크리트의 제반 공학적 특성을 검토하였는데, 그 결과를 요약하면 다음과 같다. 굳지않은 콘크리트의 유동성은 BFS 치환율이 증가할수록 증가하는 경향을 나타내었고, 공기량은 다소 감소하는 경향을 나타내었으나 AE제 사용량 증가로 적정량의 공기량 확보는 가능할 것으로 판단된다. 응결시간은 BFS 치환율이 증가할수록 비례적으로 크게 지연되는 것으로 나타났다. 경화 콘크리트의 압축강도는 BFS의 잠재수경성 반응에 기인하여 BFS 치환율이 증가할수록 재령 28일 미만에서는 OPC에 비하여 저하하였으나, 그 이후 재령에서는 동등 이상의 수준을 발휘 하는 것으로 나타나 특히, 고강도 콘크리트의 활용에 탁월한 효과가 있는 것으로 분석되었다. 건조수축길이 변화율은 W/B가 클수록 수화반응시 콘크리트 내부에 존재하는 자유수의 양이 증가함에 기인하여 다소 크게 나타났고, BFS 치환율이 증가할수록 건조수축량은 증가하는 경향이 나타났으나, 모든 배합에서 $-500{\times}10^{-6}$이하로 비교적 양호하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표회 논문집(I)
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• pp.60-65
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• 1998

This experimental Study presents the strength properties of mortar Using the Blast-furnace Slag Sand. It gives following result. The 3-days and 7-days compression strength is increase as substitution rate is higher. As W/C ratio increase, the strength is decrease. The flexural strength is increase as substitution rate is higher specially. As flexural strength ratio for compression strength is each 16.7%, 21.1%, 25.4% on 3-days, 7-days, 28-days, long age flexural strength is higher than short age.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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• pp.215-222
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• 1997

Flow experimental on not to be solid mortar which use Quenched Blast-furnace Slag as a fine aggregate was carried out for basic research data about fundamental study of application possibility of Quenched Blast-furnace Slag as a fine aggregate. It gives following result. The substitution rate is inversely proportional to Flow and C/S-rate same that. The relation with W/C-rate augment appear proportional : in case of C/S-rate, 1:3 increasing degree is a half of sand mortar that. Consequencely, Quenched Blast-furnace Slag motar is a counteraction to Flow in as same water content per unit. But suitable substitution rate and C/S-rate influence a little to the mortar consistency. And that reason, if C/S-rate and substitution rate will be regulated when we mix the mortar with quenched Blast-furnace Slag. that will be economic mixture.

• Asian-Australasian Journal of Animal Sciences
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• 제29권10호
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• pp.1424-1431
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• 2016

The objective of this study was to evaluate the effect of diets containing different amounts of wheat, as a partial or whole substitute for corn, on digestibility, digestive enzyme activities, serum metabolite contents and ruminal fermentation in beef cattle. Four Limousin${\times}$LuXi crossbred cattle with a body weight ($400{\pm}10kg$), fitted with permanent ruminal, proximal duodenal and terminal ileal cannulas, were used in a $4{\times}4$ Latin square design with four treatments: Control (100% corn), 33% wheat (33% substitution for corn), 67% wheat (67% substitution for corn), and 100% wheat (100% substitution for corn) on a dry matter basis. The results showed that replacing corn with increasing amounts of wheat increased the apparent digestibility values of dry matter, organic matter, and crude protein (p<0.05). While the apparent digestibility of acid detergent fiber and neutral detergent fiber were lower with increasing amounts of wheat. Digestive enzyme activities of lipase, protease and amylase in the duodenum were higher with increasing wheat amounts (p<0.05), and showed similar results to those for the enzymes in the ileum except for amylase. Increased substitution of wheat for corn increased the serum alanine aminotransferase concentration (p<0.05). Ruminal pH was not different between those given only corn and those given 33% wheat. Increasing the substitution of wheat for corn increased the molar proportion of acetate and tended to increase the acetate-to-propionate ratio. Cattle fed 100% wheat tended to have the lowest ruminal $NH_3-N$ concentration compared with control (p<0.05), whereas no differences were observed among the cattle fed 33% and 67% wheat. These findings indicate that wheat can be effectively used to replace corn in moderate amounts to meet the energy and fiber requirements of beef cattle.

• Journal of Applied Biological Chemistry
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• 제58권4호
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• pp.311-316
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• 2015

요구르트 제조시 사용하는 탈지분유의 일부를 자색고구마 효소 분해물로 대체(고형분 기준 10, 30, 50%)하여 요구르트를 제조한 후 탈지분유만을 사용한 대조구와 발효특성(pH, 적정산도, 환원당 함량, 젖산균의 생육), 생리활성(총 폴리페놀 함량, 항산화 활성) 및 관능특성을 비교하였다. pH는 모든 실험구에서 발효 9시간까지 급격하게 감소하였으며, 그 이후 발효 15시간에 pH 3.9 부근까지 다소 완만하게 감소하였다. 적정산도는 pH와 유사하게 모든 실험구에서 발효 9시간까지 급격하게 증가하였으며 발효 15시간 후 대조구는 0.93%, 자색고구마 분해물 첨가 요구르트는 0.80-0.89%로 자색고구마 분해물의 사용량이 증가할수록 산의 생성은 감소하였다. 발효과정에서 자색고구마 분해물의 사용량이 증가할수록 환원당 함량이 높게 유지되었다. 발효 12시간에 대조군의 젖산균 생균수는 8.89 log CFU/g, 자색고구마 효소분해물 첨가 요구르트는 8.02-8.65 log CFU/g로 탈지분유 대체 정도가 높아질수록 젖산균 생균수도 감소하였다. 관능검사 결과, 전체적인 기호도는 탈지분유의 30%를 대체하여 제조한 요구르트가 가장 우수하였다. 발효 12시간에 탈지분유 30%를 자색고구마 효소분해물로 대체한 요구르트의 총 폴리페놀 함량은 대조구보다 40% 높았으며, DPPH radical 소거활성도 동일하게 증가하였다.

• Corrosion Science and Technology
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• 제5권6호
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• pp.189-195
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• 2006

Effects of tungsten (W) on the precipitation kinetics of secondary phases and the associated resistance to pitting corrosion of 25%Cr duplex stainless steels were investigated through microstructural and electrochemical noise analyses. With the partial substitution of W for Mo in duplex stainless steel, the potential and current noises of the alloy were significantly decreased in chloride solution due to retardation of the ${\sigma}$ phase precipitation. The preferential precipitation of the $\chi$ phase in the W-containing alloy during the early period of aging contributed to retarding the precipitation of the $\sigma$ phase by depleting W and Mo along grain boundaries. In addition, the retardation of the nucleation and growth of the $\sigma$ phase in the W-containing alloy appears to be attributed to the inherently low diffusivity of W compared with that of Mo.

• Corrosion Science and Technology
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• 제5권5호
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• pp.153-159
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• 2006

Austenitic stainless steels with addition of various amounts of Mo and W were evaluated in terms of corrosion and contact resistance to determine optimum alloy composition of metallic bipolar plate for PEMFC. The corrosion property was evaluated by both acid fume exposure test at $130^{\circ}C$ and by electrochemical polarization tests in $H_3PO_4$ solution at $80^{\circ}C$. Austenitic stainless steel with proper amount of Mo and W demonstrated not only good corrosion resistance but also low contact resistance. Analyses on the passive film show that partial substitution of Mo by W enhances passive film stability and repassivation property. Test results suggest that austenitic stainless steel with 2 wt%Mo and 4 wt%W has optimum composition for metallic bipolar plate used in PEMFC.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 춘계총회 및 연구발표회 초록집
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• pp.186.2-186
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• 2003

• 대한화학회지
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• 제57권6호
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• pp.677-683
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• 2013

A theoretical study of the electronic structures of $TiC_{1-x}$ and $Ti_{1-x}W_xC$ (x = 0, 0.25) is presented. The density of states and crystal orbital overlap population calculations were used to interpret variations of elastic properties induced by carbon vacancies and alloying substitutions. Our results show why the introduction of vacancies into TiC reduces bulk moduli, while W substitution at a Ti site increases the elastic modulus. The effect of the point defects on the bonding in TiC is investigated by means of extended Huckel tight-binding band calculations.