• Title/Summary/Keyword: 3S

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광화제 첨가가 포틀랜드 시멘트의 Tricalcium Silicate 생성에 미치는 영향 (Effects of Mineralizer Addition on the Formation of Tricalcium Silicate in Portland Cement)

  • 김인태;이창봉;김윤호
    • 한국세라믹학회지
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    • 제31권12호
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    • pp.1417-1422
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    • 1994
  • Effect of MgO, CaSO4, and CaF2 addition on the formation of clinker minerals in portland cement have been investigated by measuring the amounts of free-CaO and C3S in the fired specimens and analyzing the Mg and S concentration in C3S and C2S. It was found that CaSO4 inhibited C3S formation but MgO addition offset this effect of CaSO4. MgO addition also enhanced the mineralizing effect of CaSO4+CaF2, resulting in the acceleration of C3S formation. It was suggested that Mg might inhibit the formation of sulphate compounds rim around C2S and thus C2S+CaOlongrightarrowC3S reaction was facilitated.

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Generalizations of Dixon's and Whipple's Theorems on the Sum of a 3F2

  • Choi, Junesang;Malani, Shaloo;Rathie, Arjun K.
    • Kyungpook Mathematical Journal
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    • 제47권3호
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    • pp.449-454
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    • 2007
  • InIn this paper we consider generalizations of the classical Dixon's theorem and the classical Whipple's theorem on the sum of a $_3F_2$. The results are derived with the help of generalized Watson's theorem obtained earlier by Mitra. A large number of results contiguous to Dixon's and Whipple's theorems obtained earlier by Lavoie, Grondin and Rathie, and Lavoie, Grondin, Rathie and Arora follow special cases of our main findings.

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곤충기생성 성충, Steinernema feltiae와 Heterorhabditis heliothidis를 이용한 고자리파리 및 담배거세미나방의 생물적 방제 (Biological Control of Onion Maggot and Tobacco Cutworm with Insect-parasitic Nematodes, Steinernema feltiae and Heterorhabditis heliothidis)

  • 추호열
    • 한국응용곤충학회지
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    • 제27권4호
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    • pp.185-189
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    • 1988
  • 고자리파리와 담배거세미나방을 방제할 목적으로 곤충기생성 선충, S. feltiae와 H. heliothidis를 이용, 실내 실험한 결과는 다음과 같다. 고자리 파리에서 S. feltiae를 유충 한 마리당 30,60,120,240마리를 접종한 모든 구에서 80-100%의 높은 치사율을 얻었고, H. heliothidis 10,20,40,80마리 접종 구에서도 63.3-100%치사율을 얻었다. 담배거세미나방의 경우 S. feltiae는 유충한마리당 50,100,200,400마리를 접종하여 3령층은 전 선충 접종구에서 100%의 치사율을, 4령충은 76.7-100%, 5령충은 43.3-100%의 치사율을 나타내어 접종량과 령게에 따라 치아율에 차이를 보였다. H. heliothidis는 20,40,80,160마리를 접종하여 3령층에서는 67.7-100%의 높은 치사율을 보였으나 4령충과 5령충에서는 36.7-90%, 3.3-90%의 치사율을 각각 나타내었다. 먹이인 케일에 처리한 경우 S. feltiae는 비교적 효과가 있었으나 H. heliothidis는 효과가 현저히 검소하였다. 그러나 3령충에서는 효과가 있어 3령충이 가장 방제 적기이며 감수적 영기임이 확인되었다.

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Fe-Scale과의 반응에 의한 $Cr_3C_2$계 복합체의 산화손상 (Oxidation of $Cr_3C_2$ Composites with Fe-Scale)

  • 한동빈;홍기곤;박병학
    • 한국세라믹학회지
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    • 제31권7호
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    • pp.767-771
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    • 1994
  • In a salb-preheating furnace of steel-making industry, the oxidation/degradation behavior of Cr3C2 ceramic composited dkid button reaction with scale in Fe-oxide system occurs and was thermodynamically examined. The reaction of scale with Cr3C2 skid button produces Cr3C2(s) and C(s), and Co gas is then evolved from the reaction of C(s) with Fe-scale. Cr3C2(s) from oxidation of Cr3C2(s) reacted with Fe-oxide(s) becomes high-melting chromite. The chromite acts as protection layer against further oxidation and improves resistance of the reaction of Cr3C2 skid button with Fe-scale.

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EXAMPLES OF KNOTS IN S3 ADMITTING SEIFERT-FIBERED SURGERIES OVER S2 WITH FOUR EXCEPTIONAL FIBERS

  • Kang, Sungmo
    • 호남수학학술지
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    • 제40권3호
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    • pp.591-600
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    • 2018
  • In [4] Miyazaki and Motegi constructed one family of knots in $S^3$ which admits Dehn surgery producing a Seifert-fibered space over $S^2$ with four exceptional fibers. On the other hand, in [3] using doubly hyper Seifert twisted torus knots, the author constructed six families of knots in $S^3$ which admit Dehn surgery yielding a Seifert-fibered space over $S^2$ with four exceptional fibers. It is questioned in [3] whether or not the family of the knots constructed in [4] belongs to one of the six families of the knots in [3]. In this paper, we give the positive answer for this question.

게 껍질을 이용한 수중의 납 이온 제거공정의 메커니즘 규명에 관한 연구

  • 신주남
    • 한국환경과학회:학술대회논문집
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    • 한국환경과학회 2001년도 정기총회 및 봄 학술발표회 초록집
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    • pp.211-216
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    • 2001
  • 수용액상에서 게 껍질에 의한 납 이온 제거시 납 이온 메카니즘을 규명하기 위하여 납이온 제거에 미치는 pH의 영향에 대해 조사하였다. 게 껍질에 의한 납 이온의 제거는 게껍질 내에 함유되어 있는 CaC $O_{3(S)}$의 용해에 따른 미세침전에 의한 제거가 대부분인 것으로 나타났다. pH가 증가하면 납 이온 제거량도 증가하였고 이온교환에 의해 발생되는 칼슘 이온의 유출은 납 이온 제거를 더욱 증가시키고 게 껍질 내의 $CO_{3}^{2-}$는 납 이온의 침투로 게 껍질 내부에 $PbCO_{3(S)}$ 형태의 복합체를 형성하는 것으로 판단되었다. 납 이온의 제거는 대부분 게 껍질 내 $PbCO_{3(S)}$의 용해로 인해 발생되는 $Pb_{3}(CO_{3}){2}(OH)_{2(S)}$$PbCO_{3(S)}$의 침전으로 이루어졌다. 수용액 중의 납 이온은 게 껍질 내 CaC $O_{3(S)}$의 용해를 가속화시키며 게 껍질 내부에서도 납 이온의 침전물이 발생하는 것으로 관찰되었다.

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Synthesis and Characterization of New Group 13 Complexes of 2-Acetylpyridine-S-methyldithiocarbazate. Single-Crystal Structure of Me₂Ga[$NC_5H_4C$(CH₃)NNC(S)SMe] and Me₂In[$NC_5H_5C$(CH₃)NNC(S)SMe]

  • 백철기;강상욱;이채호;이영행;고재정
    • Bulletin of the Korean Chemical Society
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    • 제18권3호
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    • pp.311-316
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    • 1997
  • The synthesis and characterization of the mononuclear group 13 heterocyclic carboxaldehyde methyldithiocarbazate complexes Me2M[NC5H4CRNNC(S)SCH3] (M=Al, R=H(1); M=Ga, R=H(2); M=Al, R=CH3(3); M-Ga, R=CH3(4); M=In, R=CH3(5)) are described. Compounds 1-5 were prepared by the reaction of MMe3 (M=Al, Ga, In) with 2-formy or 2-acetylpyridine-S-methyldithiocarbazate in toluene. These compounds 1-5 have been characterized by microanalysis, NMR (1H, 13C) spectroscopy, mass spectra, and single-crystal X-ray diffraction. X-ray single-crystal diffraction analyses reveal that 4-5 are mononuclear metal compounds with coordination number of 5 and N,N,S coordination mode.

희토류 첨가 광소재의 나노구조 : Dy 첨가 Ge-As-S 유리의 X-선 흡수 스펙트럼 분석 (Nanostructure of Optical Materials Doped with Rare-Earths: X-Ray Absorption Spectroscopy of Dy-Doped Ge-As-S Glass)

  • 최용규;송재혁;신용범;;허종
    • 한국세라믹학회지
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    • 제43권3호
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    • pp.177-184
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    • 2006
  • Dy $L_3$-edge XANES and EXAFS spectra of chalcogenide Ge-As-S glass doped with ca. 0.2 wt% dysprosium have been investigated along with some reference Dy-containing crystals. Amplitude of the white-line peak in XANES spectrum of the glass sample turns out to be stronger than that of other reference crystals, i.e., $DY_2S_3,\;Dy_2O_3\;and\;DyBr_3$. It has been verified from the Dy $L_3$-edge EXAFS spectra that a central Dy atom is surrounded by $6.7{\pm}0.5$ sulfur atoms in its first coordination shell in the Ge-As-S glass, which is relatively smaller than 7.5 of the $Dy_2S_3$ crystal. Averaged Dy-S inter-atomic-distance of the glass ($2.78{\pm}0.01{\AA}$) also turns out to be somewhat shorter than that of the $Dy_2S_3$ crystal ($2.82{\pm}0.01{\AA}$). Such nanostructural changes occurring at Dy atoms imply there being stronger covalency of Dy-S chemical bonds in the Ge-As-S glass than in the crystal counterpart. The enhanced covalency in the nanostructural environment of $Dy^{3+}$ ions inside the glass would then be responsible for optical characteristics of the $4f{\leftrightarrow}4f$ transitions of the dopants, i.e., increase of oscillator strengths and spontaneous radiative transition probabilities.

B3G 네트워크에서 SLA 기반 QoS 매핑을 위한 연구 (A Study of QoS Mapping based on SLA in B3G Networks)

  • 문현주;이진관;정규철;이종찬;박상준;신성윤
    • 한국컴퓨터정보학회논문지
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    • 제16권3호
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    • pp.157-165
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    • 2011
  • B3G 네트워크에서 SLA 기반 QoS 관리방안은 서비스 이용자와 서비스 제공자 사이에서 이루어지는 협약으로 서비스 제공자는 협약된 사항을 근거로 사용자에게 통신 서비스를 제공하게 된다. 서비스 제공자는 협의된 서비스 레벨을 유지하기 위한 QoS 방안을 제공하며 이는 정책레벨에서 시스템 레벨까지의 세부방안을 포괄하여 다룬다. 협약된 서비스 정책에 의하여 서비스 제공자는 서비스 사용자와의 협약에 맞추어 정해진 QoS를 제공하며, 따라서 서비스 사용자는 신뢰적으로 서비스를 제공받을 수 있다. 따라서 본 논문에서는 B3G 네트워크에서 SLA 기반에서 이루어질 수 있는 서비스 협약을 통하여 사용자 서비스 제공을 위한 융합 망의 QoS 매핑에 대한 방안을 제안한다.

Microbiological Composition and Sensory Characterization Analysis of Fermented Sausage Using Strains Isolated from Korean Fermented Foods

  • Jeong, Chang-Hwan;Lee, Sol-Hee;Kim, Hack-Youn
    • 한국축산식품학회지
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    • 제42권6호
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    • pp.928-941
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    • 2022
  • This study aimed to analyze the microbiological composition and sensory characterization of fermented sausage using strains isolated from Kimchi (GK1, Pediococcus pentosaceus SMFM2016-GK1; NK3, P. pentosaceus SMFM2016-NK3), Doenjang (D1, Debaryomyces hansenii SMFM2021-D1), and spontaneously fermented sausage (S8, D. hansenii SMFM2021-S8; S6, Penicillium nalgiovense SMFM2021-S6). The control was commercial starter culture. Nine treatments were applied [GD (GK1+D1), GS (GK1+S8), GDS (GK1+D1+S8), ND (NK3+D1), NS (NK3+S8), NDS (NK3+D1+S8), GND (GK1+NK3+D1), GNS (GK1+NK3+S8), and GNDS (GK1+NK3+D1+S8)] by mixing lactic acid bacteria and yeast, and S6 was sprayed. The microbial composition of fermented sausage was analyzed [aerobic bacteria (AC), Lactobacillus spp. (LABC), Staphylococcus spp. (STPC), and yeast and mold (YMC)], and pH and electronic nose and tongue measurements were taken. The AC, LABC, STPC, and YMC values of the control and treatment groups tended to increase during fermentation (p>0.05). The STPC values of the GD, GS, ND, and GDS groups were similar to that of the control on day 3. The pH of the control on day 3 was significantly lower than that of the GD, ND, and GND groups (p<0.05). Higher levels of 4-methylpentanol, 2-furanmethanol, and propyl nonanoate, which provide a "fermented" flavor, were detected in the GD group compared to in the control and other treatment groups. GD and ND groups showed higher umami values than the control and other treatment groups. Therefore, it is expected that GD can be valuable as a starter culture unique to Korea when manufacturing fermented sausage.