• 제목/요약/키워드: PW

검색결과 341건 처리시간 0.029초

섬유 종류에 따른 고강도 콘크리트의 내화성능에 관한 실험적 연구 (Fire Resistance Performance of High Strength Concrete with Fiber Types)

  • 김정진
    • 한국건축시공학회지
    • /
    • 제14권3호
    • /
    • pp.223-229
    • /
    • 2014
  • 본 연구에서는 고강도 콘크리트의 폭렬특성 분석 및 폭렬방지공법 개발을 위하여 유기 섬유와 PW을 혼입한 고강도 콘크리트로 ${\varphi}100{\times}200mm$ 시험체와 $300{\times}300{\times}600mm$의 모의부재를 제작하여 내화성능 시험을 실시하였다. 실험결과, 섬유 종류 및 PW혼입률 변화에 따른 특성으로, 섬유와 PW의 혼합비가 1:1일 때 유동성이 가장 우수한 것으로 나타났으며, 내화시험을 실시한 결과 PP 0.05%+PW 0.05% 및 PNY 0.05%+PW 0.05% 이상의 경우에서 고강도 콘크리트의 폭렬방지가 가능한 것으로 확인되었다. 또한, $300{\times}300{\times}600mm$의 모의부재는 적정량의 섬유를 혼입한 경우 모든 시험체에서 폭렬이 방지되는 것으로 나타났다. 한편, PW을 혼합한 폴리믹스의 경우도 내화성능면에서 모두 만족하는 것으로 나타났다.

발수제 처리 소나무재의 치수안정성 (Dimensional Stability of Korean Red Pine Treated with Water Repellents)

  • 한규성
    • 한국가구학회지
    • /
    • 제19권3호
    • /
    • pp.172-179
    • /
    • 2008
  • The objective of this study was to investigate the influence of the water repellents' treatment on the water absorptivity and the dimensional stability of Korean red pine wood(Pinus densiflora). The alkylketene dimer(AKD), fluororesin emulsion(Wood-seal, WS), and paraffin wax emulsions(PW25, PW40, and PW1200) were used as water repellents. PW40 and WS were proved as excellent water repellents for pine wood, because the samples treated with these agents showed high contact angles and large reduction in water absorptivities. Also, the dimensional stability(antiswelling efficiency) of pine wood was considerably improved by water repellents treatments, such as PW40 and WS at the pressure of 2MPa. The water repellent treated woods with WS, PW40, and PW1200 at the pressure of 2MPa were relatively stable to the wet-dry cyclic leaching test.

  • PDF

폐흡충 충란항원의 항원성 평가 (Antigenicity of the soluble egg antigen of Paragonimus westermani)

  • 김석일;고응구
    • Parasites, Hosts and Diseases
    • /
    • 제24권1호
    • /
    • pp.49-54
    • /
    • 1986
  • 폐흡충 충란항원의 항원성을 평가하기 위하여 감염 후 10개월된 충체에서 유리된 충란의 수용성 항원을 제작하였다. 실험감염 개 페흠충증에서 특이 IgG, IgM 항체의 생성을 효소면역측정법으로 충체항원과 비교 관찰하였다. 또한 disc-PAGE로 충란항원의 구성 단백질을 관찰하였다. 1. 폐흡충 충란항원에 대한 특이 IgG 항체는 충체가 충란을 형성하는 감염 8주에 상승하기 시작하여 12주에 최대치에 이르고 이후 일정한 항체가를 유지한 반면, 특이 IgM 항체의 생성은 대단히 미약하였다. 2. 폐흡충 충체항원에 대한 특이 IgG 항체는 감염 2주에 상승하여 관찰기간인 13주까지 계속 상승하였다. 항체가도 충란항원보다 높았다. 충체항원에 대한 특이 IgM 항체는 감염 2주부터 나타나 8주까지는 일정량을 유지하나 이후 감소하기 시작하여 12주에는 감염전 상황으로 되돌아왔다. 3. 폐흡충 충란항원은 전기영동상에서 단백질 band 2개로 관찰되었으며 성충의 충체항원에서 관찰되는 10개의 단백질 band중 Band 1과 Band 2에 해당되는 단백질 band임을 확인할 수 있었다. 따라서 2개의 단백질로 구성된 폐흡충의 수용성 충란항원은 특이 IgG 및 특히 IgM 항체 생산을 유도하나 성충충체항원에 비하여 그 항원성이 대단히 미약하다고 판단하였다.

  • PDF

mPW1PW91 Calculated Structures and IR Spectra of Thiacalix[4]biscrown-5 Complexed with Alkali Metal Ions

  • Choe, Jong-In
    • Bulletin of the Korean Chemical Society
    • /
    • 제32권5호
    • /
    • pp.1685-1691
    • /
    • 2011
  • The molecular structures of thiacalix[4]biscrown-5 (1) and p-tert-butylthiacalix[4]biscrown-5 (2) and their alkali-metal-ion complexes were optimized using the DFT BLYP/6-31G(d) and mPW1PW91/6-31G(d,p) (hybrid HF-DF) calculations. The total electronic energies, the normal vibrational modes, and the Gibbs free energies of the mono- and di-topic complexes of each host with the sodium and potassium ions were analyzed. The $K^+$-complexes exhibited relatively stronger binding efficiencies than $Na^+$-complexes for both the monoand di-topic complexes of 1 and 2 comparing the efficiencies of the sodium and potassium complexes with an anisole and phenol. The mPW1PW91/6-31G(d,p) calculated distances between the oxygen atoms and the alkali metal ions were reported in the alkali-metal-ion complexes ($1{\cdot}Na^+$, $1{\cdot}2Na^+$, $1{\cdot}K^+$, $1{\cdot}2K^+$, $2{\cdot}Na^+$, $2{\cdot}Na^+$, $2{\cdot}K^+$, $2{\cdot}2K^+$). The BLYP/6-31G(d) calculated IR spectra of the host 1 and its mono-topic alkali-metal-ion complexes are compared.

mPW1PW91 Calculated Structures and IR Spectra of the Conformational Stereoisomers of C-Cyanophenyl Pyrogallol[4]arene

  • Ahn, Sangdoo;Park, Tae Jung;Choe, Jong-In
    • Bulletin of the Korean Chemical Society
    • /
    • 제35권5호
    • /
    • pp.1323-1328
    • /
    • 2014
  • Molecular structures of the various conformational stereoisomers of 2,8,14,20-cyanophenyl pyrogallol[4]arenes 1 were optimized using the mPW1PW91 (hybrid Hartree-Fock density functional) calculation method. The total electronic and Gibbs free energies and the normal vibrational frequencies of the different structures from three major conformations (CHAIR, TABLE, and 1,2-Alternate) of the four stereoisomers [1(rccc), 1(rcct), 1(rctt), and 1(rtct)] were analyzed. The mPW1PW91/6-31G(d,p) calculations suggested that $1(rcct)_{1,2-A}$, 1(rctt)CHAIR, and $1(rtct)_{CHAIR}$ were the more stable conformations of the respective stereoisomers. Hydrogen bonding is the primary factor for the relative stabilities of the various conformational isomers, and maximizing the ${\pi}-{\pi}$ interaction between the cyanophenyl rings is the secondary factor. The calculated IR spectra of the more stable conformers [$1(rctt)_{CHAIR}$, $1(rcct)_{1,2-A}$, $1(rtct)_{CHAIR}$] were compared with the experimental IR spectrum of $1(rtct)_{CHAIR}$.

BLYP and mPW1PW91 Calculated Structures and IR Spectra of the Stereoisomers of Tetra-O-methylsulfinylcalix[4]arene

  • Choe, Jong-In
    • Bulletin of the Korean Chemical Society
    • /
    • 제31권11호
    • /
    • pp.3247-3251
    • /
    • 2010
  • Molecular structures of the various conformers for the four stereoisomers of tetra-t-butyl-tetra-O-methylsulfinylcalix[4]arene (1) were optimized using DFT BLYP and mPW1PW91/6-31G(d,p) (hybrid HF-DF) calculation methods. We have analyzed the total electronic and Gibbs free energies and normal vibrational frequencies of 16 different structures from four major conformations (cone (CONE), partial cone (PC), 1,2-alternate (1,2-A), 1,3-alternate (1,3-A)) of the four stereoisomers [1(rccc), 1(rcct), 1(rctt), 1(rtct)]. The mPW1PW91/6-31G(d,p) calculations suggested that the $1(rccc)_{CONE}$, $1(rcct)_{PC}$, $1(rctt)_{PC}$, and $1(rtct)_{1,3-A}$ were the most stable conformations of the respective stereoisomers. These outcomes are in accordance with the experimental structures obtained from X-ray crystallography. The electrostatic repulsion between the sulfinyl and methoxy groups is a primary factor for the relative stabilities of the four different conformations. The IR spectra of the most stable conformers [$1(rccc)_{CONE}$, $1(rcct)_{PC}$, $1(rctt)_{PC}$, $1(rtct)_{1,3-A}$] of each stereoisomer were compared to each other.

mPW1PW91 Conformational Study of Di-t-butyl-dinitro-tetramethoxysulfonylcalix[4]arene

  • Choe, Jong-In
    • Bulletin of the Korean Chemical Society
    • /
    • 제32권1호
    • /
    • pp.100-104
    • /
    • 2011
  • The structures of the conformers for 1,3-di-t-butyl-2,4-dinitro-tetramethoxysulfonylcalix[4]arene (1) and 1,2-di-t-butyl-3,4-dinitro-tetramethoxysulfonylcalix[4]arene (2) were optimized using DFT BLYP and mPW1PW91/6-31G(d,p) (hybrid HF-DF) calculation methods. We have analyzed the total electronic and Gibbs free energies and the differences between the various conformations (cone, partial-cone (PC), 1,2-alternate, and 1,3-alternate) of 1 and 2. For both compounds, the 1,3-alternate (1,3-A) conformers were calculated to be the most stable, which correlate very well with the experimental results. The orderings of the relative stability of 1 and 2 that resulted from the mPW1PW91/6-31G(d,p) calculations are the following: 1: 1,3-A (syn) > PC (syn) > PC (anti) > 1,2-A (anti) > CONE (syn); 2: 1,3-A (anti) > PC (anti) > PC (syn) > 1,2-A (anti) > 1,2-A (syn) > CONE (syn). The BLYP/6-31G(d) calculated IR spectra of the most stable 1,3-A conformers of 1 and 2 are compared.

일회용 세션을 활용한 인증정보 기반의 사용자 인증 방안 (User Authentication Mechanism based on Authentication Information using One-time Sessions)

  • 박영수;이병엽
    • 한국콘텐츠학회논문지
    • /
    • 제19권7호
    • /
    • pp.421-426
    • /
    • 2019
  • 현재 사용자 인증에는 지식기반(ID/PW 등)인증과 생체기반(홍채/지문/정맥 인식 등)인증, 소유기반(OTP, 보안카드 등)인증 등 다양한 종류의 기술을 사용하고 있다. 지식기반 인증인 ID/PW인증 기술은 구현 및 유지 보수 비용이 적게 들며, 사용자에게 익숙한 방식이라는 장점에도 불구하고 해킹 공격에 취약하다는 단점을 가지고 있다. 다른 인증 방식들은 ID/PW인증기술에서의 취약점을 해결하였지만, 초기 구축비용과 유지보수시 비용이 많이 발생한다는 점과 재발급 시 번거로운 문제점을 가지고 있다. 본 논문에서는 기존의 ID/PW기반 인증 기술보다 보안성과 편리성을 증진시키고, 인증에 사용되는 기기에 제약이 없는 사용자 인증을 안전하게 할 수 있는 방안을 제안한다.

폐흡충증 진단에 있어서 각종 항원의 적용성 (Studies on the Applicability of Various Antigen Preparations in Immunoblot Diagnosis of Paragonimiasis)

  • 이동수;정명숙;주경환;임한종
    • 농촌의학ㆍ지역보건
    • /
    • 제17권1호
    • /
    • pp.46-55
    • /
    • 1992
  • A systematic study was conducted to identify and isolate a serologically pertinent antigen with high specific activity and low cross reactivity from P.westermani antigen. Differential centrifugation of the homogenate yield three particulate and one soluble fractions ; the $480{\times}G$ pellet(Pw1), the $7650{\times}G$ pellet(Pw2) treated with n-butanol(Pw3), and $100000{\times}G$ supernatnat(Pw4). Comparison of antigenicity of these antigens, based upon differential centrifugation, to that of saline extract of P. westermani worm(SEP) was performed by SDS-PAGE and immunoblot techniques. The results obtained were as follows : 1) The ratio of absorbance value of ELISA against paragonimiasis positive pool sera to that of negative sera was highest when using Pw3 as antigen and that was lowest using Pwl. 2) Silver stained and SDS-PAGE of each antigen showed 34 and 13Kd band as common antigen band, but Pw2 didn't show clear band. 3) By immunoblot 55 and 34Kd bands using SEP and Pw4 showed strong positive reaction without cross reaction with sera from other helmenthic infections. Using Pw3, 10Kd band was observed as specific band. In conclusion, Pw3($100000{\times}G$ pellet urea soluble, treated with n-butanol) and Pw4($100000{\times}G$ supernatant) were usable for ELISA and immunoblot technique.

  • PDF

평위산가미방(平胃散加味方)이 아토피피부염을 유발한 NC/Nga mouse에 미치는 영향 (The Effects of Pyeongwi-san-gamibang on NC/Nga mice with atopic dermatitis)

  • 정의령;김윤범
    • 한방안이비인후피부과학회지
    • /
    • 제24권2호
    • /
    • pp.16-27
    • /
    • 2011
  • Objective : To investigate the effects of Pyeongwi-san-gamibang on atopic dermatitis, this study measured TEWL(transepidermal water loss), observed scratching behaviors and checked levels of Total IgE, IL-4, IFN-${\gamma}$ and conducted skin biopsy on NC/Nga mice with atopic dermatitis. Methods : NC/Nga mice were challenged with DNCB during 5 weeks to develop atopic dermatitis-like skin lesions. The NC/Nga mice with atopic dermatitis were divided into three groups of control group, PW-d, PW-e group. Once a day for 22 days, Pyeongwi-san-GamiBang extract with water was administered for the PW-d group and the extract with 80% ethanol was administered for PW-e group compared with saline solution for control group. During drug administration, sensitization by DNCB had lasted for three times per week. Results : 1. TEWL had no statistical difference among 3 groups. 2. The scratching behaviors had no statistical difference among 3 groups. 3. The levels of Total IgE in PW-d, PW-e group had a statistically significantly higher than that of the control group although difference between the control group and the PW-d, PW-e group were similar. 4. The level of IL-4 had no statistical difference among 3 groups. 5. The level of IFN-${\gamma}$ had no statistical difference among 3 groups. 6. As the observation of toluidine blue stained lesion, both PW-d and PW-e group had lower level of histamine releasement compared with the control group. Conclusion : Result based on these experiments, Pyeongwi-san-GamiBang on atopic dermatitis-like skin inflammation in NC/Nga mice is not effective. But, as the study showed significantly individual differece, we need to repeat these study after supplementing the object number and modified indicator of clinical severity.