• 제목/요약/키워드: formation composition

검색결과 1,460건 처리시간 0.026초

실리사이드 형성 과정에 대한 재 조명 (Reinvestigation on the silicide formation process)

  • 남형진
    • 반도체디스플레이기술학회지
    • /
    • 제7권2호
    • /
    • pp.1-5
    • /
    • 2008
  • Silicide formation process and the formation sequence were investigated in this study. It was postulated that the formation of the second silicide phase involves glass formation between the first silicide phase and Si given that a thin metal film is deposited on a Si substrate. The concentration of glass was assumed to be located where the free energy of the liquid alloy with respect to the first nucleated compound and solid Si (${\Delta}$G') is most negative. It was also mentioned that the glass concentration is close to the composition of the second phase in order to achieve the maximum energy degradation. It was shown that the minimum ${\Delta}$G' concentration can be estimated by interpolating the portion of the liquidus where the liquid alloy is in equilibrium with the two solid constituents, namely the first compound phase and Si, thereby forming a hypothetical eutectic.

  • PDF

줄넘기와 스위스볼 운동이 취학 전 유아의 골형성 지표에 미치는 영향 (The Effects of Rope Jumping and Swiss Ball Exercise on Young Children's Bone Formation Markers)

  • 김태운;이경희;전재영;정성인
    • 생명과학회지
    • /
    • 제19권1호
    • /
    • pp.111-116
    • /
    • 2009
  • 취학 전 유아를 대상으로 12주간 줄넘기운동과 스위스 볼 운동을 병행한 운동 프로그램을 실시한 결과 결론은 다음과 같다. 신체조성의 변화 각 집단 내 운동 효과에 대한 신체조성의 변화에서 운동군과 대조군 모두 산장, 체중, 체지방량 및 체지방률이 모두 유의하게 증가하였다. 시기에 따른 집단 간 상호작용 효과는 나타나지 않았다. 오스테오칼신 각 집단 내 운동 효과에 대한 오스테오칼신의 변화에서 운동군은 남아, 여아 모두 유의성이 나타나지 않았고, 대조군은 여아의 경우만 유의하게 감소하였다. 시기에 따른 집단 간 상호작용효과도 나타나지 않았다. 알카리성 포스파타제 각 집단 내 운동효과에 대한 알카리성 포스파타제의 변화에서 운동군과 대조군 모두 유의한 차이가 나타나지 않았다. 시기에 따른 집단 간 상호작용효과는 있는 것으로 나타났다. 이상의 연구결과에서 줄넘기 및 스위스 볼 운동이 취학전 유아의 시기에 따른 집단간 상호작용효과는 나타내지 못했지만 집단 내 변화에서 대조군 보다 긍정적인 변화를 나타내었으며, 알카리성 포스파타제의 변인에서 상호작용 효과가 나타나 골량의 형성기인 유아들에게 줄넘기 및 스위스 볼 운동의 적용이 발율 향상과 골 건강 증진에 긍정적인 변화를 나타내었다. 하지만 오스테오칼신 농도의 연화에는 영향을 미치지 못하였다. 따라서, 향후 운동강도와 운동기간 등을 고려한 연구가 요구된다.

배암차즈기 열수 추출물 첨가가 고지방-고콜레스테롤 식이를 급여한 흰쥐의 항산화 활성과 지질조성에 미치는 영향 (Effect of Salvia plebeia Water Extract on Antioxidant Activity and Lipid Composition of Rats Fed a High Fat-High Cholesterol Diet)

  • 원향례
    • 한국지역사회생활과학회지
    • /
    • 제27권2호
    • /
    • pp.233-243
    • /
    • 2016
  • This study examined the antioxidant activity and lipid composition of rats fed a high fat-high cholesterol diet containing Salvia plebeia water extract. Three levels (50 mg/kg, 200 mg/kg, 500 mg/kg) of Salvia plebeia water extract were administered to seven weeks old male Sprague Dawley rats for four weeks. The activity of glutathione peroxidase in serum was high in all groups that received the Salvia plebeia water extract (p<0.05). The glutathione reductase activity was high (p<0.05) in groups that received 50 mg/kg and 500 mg/kg of Salvia plebeia water extract. When rats received Salvia plebeia water extract, the content of MDA (malondialdehyde) in the serum and liver was low in all groups. In addition, the serum total lipid, triglyceride, total cholesterol and LDL-cholesterol contents decreased significantly (p<0.05). Total cholesterol and triglyceride levels in the liver were significantly lower in the group that received the Salvia plebeia water extract than in the control group (p<0.05). Salvia plebeia water extract improves lipid metabolism and it almost meets with the increase of antioxidant activity and peroxide formation reduction. Based on these results, supplemented of a high fat-hypercholesterol diet with Salvia plebeia can increase antioxidant activity and depress peroxide formation in serum, as well as liver cholesterol and triglycerides.

느타리버섯 자실체의 부위 및 생육시기별 지방산 조성의 변화 (Changes of Fatty Acid Composition by Various Developmental Stage and Fruit Body Section in Pleurotus ostreatus)

  • 류영현;이숙희;조우식;윤재탁
    • 한국균학회지
    • /
    • 제28권2호
    • /
    • pp.109-111
    • /
    • 2000
  • 느타리버섯(원형1호 느타리) 자실체의 부위별로 지방산 조성을 조사한 결과 linoleic acid는 갓부위에서 가장 높았고 대부위로 갈수록 낮아지는 경향이었고 stearic acid와 palmitic acid는 대부위로 갈수록 증가하는 경향이었다. 생육시기별 지방산조성은 oleic acid의 경우 버섯원기형성 후 $11{\sim}12$일 까지는 점차 증가하다가 이후부터는 감소하는 경향을 보였고 linoleic acid와 불포화지방산대비 포화지방산의 비율은 원기형성 후 $3{\sim}4$일까지는 증가하다가 그 후부터는 감소하는 경향을 나타내었다.

  • PDF

고크롬 백주철의 미세조직과 기계적 특성에 미치는 초기응고 조직의 영향 (Effect of Primarily Solidified Structure on the Microstructure and the Mechanical Properties of High Cr White Iron)

  • 조현욱;도정현;조원제;정현득;이재현;조창용
    • 한국주조공학회지
    • /
    • 제35권6호
    • /
    • pp.178-184
    • /
    • 2015
  • Due to excellent abrasion resistance the high-chrome white irons are widely used in mining and mineral industries. Minor variation of carbon content in 28% chrome white iron resulted in difference in primarily solidified microstructure. Sub-eutectic (hypoeutectic) composition led to formation of primarily solidified dendrites. Formation of primarily solidified dendrites which were supersaturated with carbon and chrome also caused precipitation of fine secondary carbides that are different from relatively large plate type $M_7C_3$ carbides in the eutectic structure. Small portion of primarily solidified dendrite expected to contribute significantly to the improvement of abrasion resistance of the white iron because the dendrites provided mechanical support to carbides. The relative fraction of primary dendrite increased with reduction of carbon content from the eutectic composition. The increased fraction of primary dendrite increased hardness value of the white irons.

석탄회의 탄소가 첨가된 질화반응과 AlN, SiC 그리고 Si₃N₄의 생성분포 (Nitrogenation of Coal Ash in the Presence of Carbon and Product Distributions of AlN, SiC and Si₃N₄)

  • 양현수;홍원표;노재성;서동수;손응권
    • 한국세라믹학회지
    • /
    • 제27권8호
    • /
    • pp.956-956
    • /
    • 1990
  • 석탄회의 탄소가 첨가된 질화반응시에 생성된 AIN, SiC 그리고 Si3N4 등의 생성물 분포를 반응온도, 시간 그리고 탄소의 첨가량에 따라 검토하였다. AIN의 조성은 시료입자가 작을수록 증가하였으며 반응온도 14500~1500℃와 약 2시간의 반응시간 그리고 약 30%의 탄소 첨가량 (시료무게 기준) 에서 최대값을 나타내었다. SiC와 Si3N4 조성변화는 서로 상반된 경향을 보였으며 반응온도가 낮고 반응시간이 작으며 그리고 탄소첨가량이 증가할 수록 SiC의 조성은 Si3N4 에 비하여 크게 나타났다.

백시멘트의 백색도에 미치는 염화물의 영향 (Influences of Chlorides on the Whiteness in White Portland Cement)

  • 한기성;최상흘;서일영
    • 한국세라믹학회지
    • /
    • 제13권2호
    • /
    • pp.3-7
    • /
    • 1976
  • Influences of chlorides(CaCl2, MgCl2, NaCl) on the colouring effect of Fe component in white portland cement was investigated. Chlorides enhance the whiteness of the white portland cement owing to volatilization of Fe2O3 and translation of ferrite composition toward C2F. This translation is caused by consumption of alumina at the formation of C12A7, the formation of which is promoted in the presence of chloride. With decrease of p in ferrite composition C6F1-pAp, transfer of Fe3+ from 4 to 6 coordinated cite is occurred, and as a result, whiteness is raised. Hydration process of the cement containing a small amount of chloride differs little from the one without chloride.

  • PDF

Dielectric Characteristics of $Pb(Sc_{1/2-x} Ta1_{/2+x}) O_{3+x}$ Ceramic System

  • Nam-Kyung Kim;Dwight D. Viehland;David A. Payne
    • The Korean Journal of Ceramics
    • /
    • 제1권2호
    • /
    • pp.81-85
    • /
    • 1995
  • PST-series spcimens with stoichimetric and nonstoichimtric compositins were prepared and the effects of compositionl modification on phase formation and dielectric presponse were investigated. The phases formed on calcination were mainly perovskite and trace amount of phyrochlore(s), with an increase of the latter phase(s) as the composition became more ononstoichiometric. The sintered samples showed thermal hysteresis and diffuseness in phase transition with a small degree of frequency relaxation. Temperatures corresponding to maximum values of dielectric constant and loss were relatively insensitive to the composition change while the maximum values were very sensitive to that.

  • PDF

전해법에 의한 Mn-ferrite 생성 (The formation of Mn-ferrite by electrolysis)

  • 김유상;황용길
    • 한국표면공학회지
    • /
    • 제24권1호
    • /
    • pp.1.2-1.2
    • /
    • 1991
  • The formation of managanese ferrite has been performed to investigate some properties according to the variation of compositions, pH, current density by electrolysis. It has been found that the amount of oxidized weight of anode were increased with increasing current density. The amount of oxidized weight of anode were most in pH10. As the result of X-ray diffraction Mn Fe2O4 crystal composition in pH13. When the particles of Mnx Fe3-x O4 were heated at 30$0^{\circ}C$, it has been shown typical MnFe2O4(JCPDS Card No. 10-319) in X-1 composition. As the result of SEM observation, the size of MnFe2O4 particles were about 0.1$\mu\textrm{m}$, the shape of particles were spherical type. According to the above mentioned experimental condition, 0.1-0.5$\mu\textrm{m}$ sub-micron particles of manganese ferrite were formed from the wasted manganese dry cell, through washing longrightarrow reduction longrightarrow electrloysis.

전해법에 의한 Mn-ferrite 생성 (The formation of Mn-ferrite by electrolysis)

  • 김유상;황용길
    • 한국표면공학회지
    • /
    • 제25권1호
    • /
    • pp.1-7
    • /
    • 1992
  • The formation of manganese ferrite has been performed to investigate some properties according to the variation of compositions, pH, current density by electrolysis. It has been found that the amount of oxidized weight of anode were increased with increasing current density. The amount of oxidized weight of anode were most in pH 10. As the result of X-ray diffraction Mn Fe₂O₄ crystal composition in pH13. When the particles of Mn/sub x/ Fe/sub 3-x/O₄ were heated at 300℃, it has been shown typical Mn Fe₂O₄(JCPDS Card No. 10-319) in X=1 composition. As the result of SEM observation, the size of MnFe₂O₄ particles were about 0.1㎛, the shape of particles were spherical type. According to the above mentioned experimental condition, 0.1-0.5㎛ sub-micron particles of manganese ferrite were formed from the wasted manganese dry cell, through washing → reduction → electrloysis.

  • PDF