• Title, Summary, Keyword: NMA

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Synthesis of Modified Polyetherimide and Toughening of Epoxy Resin (변성 폴리에테르이미드의 합성과 이를 이용한 에폭시 수지의 강인화)

  • Lee Sin Duk;Ahn Byung Hyun;Lee Kwang Gi;Kim Won Ho
    • Polymer Korea
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    • v.29 no.3
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    • pp.231-236
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    • 2005
  • Amino terminated polyetherimide (AP-PEI) has been synthesized using 2,2'-bis [4-(3,4-dicarboxyphenoxy)-phenyl]propane dianhydride (BPADA) and m-phenylenediamine. Polyetherimide containing pendant carboxy group (CP-PEI) has also been synthesized by the reaction of BPADA, m-phenylenediamine and 3,5-diaminobenzoic acid. The modified PEIs were used as toughening agent for diglycidyl ether of bisphenol-A epoxy resin which was cured with nadic methyl anhydride (NMA). Thermal properties, fracture toughness ($K_{IC}$) and solvent resistance of toughened epoxy resin were measured. The $K_{IC}$ of epoxy resin containing 20 phr of AT-PEI was 2.88$MPa{\cdot}m^{0.5}$ without sacrificing thermal properties. The $K_{IC}$ of epoxy resin which contained 20 phr of CP-PEI was 2.82$MPa{\cdot}m^{0.5}$.

Ascitic Fluid Analysis for the Differentiation of Malignancy-Related and Nonmalignant Ascites (악성 복수와 비악성 복수의 감별을 위한 복수액 분석)

  • Lee, Eun-Young;Kim, Byeoung-Deok;Choi, Jae-Hyuk;Lee, Sang-Yeop;Ryu, Hun-Mo;Lee, Kyung-Hee;Hyun, Myung-Soo
    • Yeungnam University Journal of Medicine
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    • v.16 no.1
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    • pp.76-84
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    • 1999
  • The differentiation between malignancy-related ascites(MRA) and non-malignant ascites (NMA) is important for further diagnostic and therapeutic purposes. Although many parameters were investigated, none has provided a complete distinction between MRA and NMA. We investigated several ascitic fluid parameters to determine the differential power, and to differentiate malignant-related from nonmalignant-related ascites with a sequence of sensitive parameters followed by specific parameters. For the present study, 80 patients with ascites were divided into two groups: MRA and NMA, The MRA group was consisted of 27 patients with proven malignancy by image study, biopsy, and follow up: 21 of these patients had peritoneal carcinomatosis, but the remaining 6 showed no evidence of peritoneal carcinomatosis. The NMA group was consisted of 53 patients with no evidence of malignancy: among these patients, one had SLE, and others had liver cirrhosis, The samples of blood and ascites were obtained simultaneously, and then the levels of ascites cholesterol, CEA. protein and LDH, cytology, albumin gradient, ascites/serum concen-tration ratios of LDH(LDH A/S), and ascites/serum concentration ratios of protein(protein A/S) were measured. Applying cut-off limits for determined parameters, we estimated the diagnostic efficacy of each parameter, Among the eight parameters investigated, ascites fluid cholesterol yielded the best sensitive value of 93%(cut-off value 30mg/dl), and cytologic examination and the protein A/S(cut-off value 0.5) showed the most specific value of 100% and 96%, respectively. Based on the above results, the diagnostic sequence with cholesterol as a sensitive parameter followed by the combination of cytologic examination and protein A/S as specific parameters, was tested in 80 patients. This diagnostic sequence identified 81.5% of patients with malignancy, and all patients with peritoneal carcinomatosis were classified as malignancy-related ascites. In spite of many limitations, this proposed diagnostic sequence may permit a cost-effective and simple differentiation of malignancy-related ascites from nonmalignant ascites.

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LMA 및 VLBI 계획에 대하여

  • 정현수
    • Bulletin of the Korean Space Science Society
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    • pp.23-25
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    • 1993
  • 밀리미터파 영역에서의 관측장치를 살펴보면, 단일망원경을 제외하고도 세계의 밀리미터파 간섭계의 그 어느 것이나 현재 확장작업을 진행중이며, 또 밀리미터파서브밀리미터파영역에서의 고분해능 관측의 천문학적 성과를 올리기 위해 서브밀리미터파 간섭계의 건설계획을 추진하고 있고, NARO에서도 NMA계획을 발표하여 그 준비가 착착 진행되고 있다. 이들에 대해, 일본의 NRO에서도 HMA확충계획을 진행시키는 한편, 대형밀리미더파 간섭계(LMA) 계획을 발표하고 있다. 따라서 일본 내부에서는 SUBARU 망원경건설 이후의 천문학 분야에서의 차기 대형 장래계획으로서 LMA가 자리잡고 있다. 따라서 본 발표에서는, 세계의 이러한 추세 속에서 향후 5년 내지는 10년 이후를 내다보고 우리나라 전파천문학은 앞으로 무엇을 해 나가야 할 것인가, 그리고 무엇이 우리의 실정에 가장 적합한 천문학인지를 생각해 보기 위한 한 방편으로, 측지적인 목적과 전파천문학적인 견지에서의 국내 및 국외 VLBI Network 형성과 LMA 계획을 분석해보고자 한다.

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Development of epoxy resin with modified thermoplastic polymer and application to the carbon fiber composites (개질된 열가소성 고분자를 이용한 에폭시 수지 개발과 탄소섬유 복합재료에의 응용)

  • 이광기;김민영;김원호;안병현;황병선
    • Proceedings of the Korean Society For Composite Materials Conference
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    • pp.237-240
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    • 2002
  • Amino terminated polyetherimide(ATPEI) has been synthesized by bisphthalic anhydride arid m-phenylenediamine, after that characterized by differential scanning calorimetry(DSC), thermogravimetric analyzer(TGA). Fourier transform (FT-IR) spectroscopy and gel permeation chromatography(GPC). ATPEI was blend to improve the toughness of bisphenol-A type epoxy resin which was cured by nadic methyl anhydride(NMA). The fracture toughness and the molphology of the toughened epoxy resin was evaluated. The toughness of ATPEI modified epoxy resin was higher than that of the PEI modified epoxy resin. In addtion, carbon fiber/ATPEI modified epoxy resin composites were fabricated and the mechanical properties of the resulted composites were investigated.

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A Study on the Curing Behavior and Toughness of Amine Terminated Polyetherimide/Epoxy Resin System (Amine Terminated Polyetherimide/에폭시 수지 시스템의 경화공정연구와 파괴인성에 관한 연구)

  • 김민영;이광기;김원호;황병선;김대식;박종만
    • Proceedings of the Korean Society For Composite Materials Conference
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    • pp.147-150
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    • 2002
  • The cure kinetics of blends of epoxy (DGEBA:diglycidyl ether of bisphenol A)/anhydride (NMA:nadic methyl anhydride) resin with synthesized amino terminated polyetherimide (AT-PEI) were studied using differential scanning calorimetry (DSC) and Dynamic Mechanical Analysizer(DMA) under isothermal condition to determine the reaction parameters and gel-vitrification behavior. The fracture toughness of AT-PEI 20phr/epoxy resin system was improved over 224% and 42.5% more than neat epoxy resin and commercial PEI/Epoxy Resin System.

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A Study on the Aging Characteristics of NEPE Propellants (NEPE 추진제의 노화 특성에 관한 연구)

  • 류백능;박명규;박영철
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.141-146
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    • 1996
  • ABSTRACT : The aging characteristics of NEPE propellant is studied by HPLC analysis, cube crack test, swelling, and mechanical property test. The depletion of mixed stabilizer NMAI2-NDPA is analysed by Berthelot's law. The stabilizer NMA was completely comsumed after 16 weeks at $70{\circ}$ and after 6 weeks at $80{\circ}$ and the cracks developed in the sample. The aging trend of the propellant was shown hardening phenomena in the range of 20-$60{\circ}$ due to evaporation of energetic plasticizers.

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Polymerization-Crosslinking of Cotton Fabrics for Superior Textile Performance(I) -New Improved Treatment Procedures- (면직물의 성능개선을 위한 중합 및 가교화반응(I) -개선된 가공처리공정-)

  • ;Kwa
    • Textile Science and Engineering
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    • v.26 no.2
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    • pp.31-37
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    • 1989
  • The new and improved procedures were investigated to achieve superior balance of strength and durable press(DP) performance. The resin mixture of a polymer builder(NMA) and a crosslinker(DMDHEU) was used with the WF and SF processes, and the treated fabrics were compared with those from the conventional PDC(DMDHEU) process. With the WF process, a 2.7:1 resin mixture ratio gave improved tear strength retention by 80%, abrasion resistance retention by 200%, as compared to the conventional PDC(DMDHEU) process. With the SF process, 1:1.3 mixture ratio produced fabrics with softer hand and higher strengths and abrasion resistance retentions than those of treated with the WF process.

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Dyeing Properties of Cationized Cotton Fiber with Acid Dye (캐티온화한 면섬유에 대한 산성염료의 염색성)

  • 정영진;이영희;박수민;겸경환
    • Textile Coloration and Finishing
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    • v.6 no.1
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    • pp.54-61
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    • 1994
  • Acrylamidomethylated cellulose(AMC) was prepared by a reaction of N-methy-lolacrylamide(NMA) in the presence of acid catalyst, and pendent C=C double bonds are created on cellulose. Using the pendant double bonds as a site for Michael addition, a number of modified cellulose could be readily prepared. When AMC is treated in an aqueous solution containing sodium dihydrogen phospate and methylamine, the chemical structure of cellulose is represented as follow ; Cell-O-$CH_{2}$-NHCO-$CH_{2}$-$CH_{2}$-NHMe. Therefore in this paper, dyeing properties of modified cellulose for the acid dye were investigated.

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Chemistry of Ruthenium Hydridonitrosyl Complexes Containing Chelating Triphosphines I-Structures of RuH(NO)$P_3$ ($P_3$ : Chelating Triphosphines)

  • Ik Mo Lee;Devon W. Mee;Judith Gallucci
    • Bulletin of the Korean Chemical Society
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    • v.13 no.5
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    • pp.491-498
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    • 1992
  • Chelating triphosphines were applied to freeze the fluxionality and to minimize the number of isomers found in the monophosphine analogues and this technique was proved to be useful. RuH(NO)$P_3$($P_3$; Cyttp, ttp and etp) complexes were characterized to have similar trigonal bipyramidal structures with linear NO groups. Cyttp prefers to have a meridional geometry while etp prefers a facial one and ttp complexes are mixture of these two isomers. The crystal structure of RuH(NO)(Cyttp) has been determined to have a distorted trigonal bipyramidal structure with a linear NO in the equatorial plane. The crystals are orthorhombic, space group $P_{nma}$, with unit cell dimensions a = 16.356(2), b = 20.474(2), c = 10.915(l) ${\AA}$, V = 3655 ${\AA}^3$, Z = 4, R = 0.035 and $R_w$ = 0.034 for the 2900 intensities with $F_o^2 >3{\sigma}(F_o^2)$ and the 208 variables.

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Water Resistance and Thermal Properties of Resin Based on Silane-modified Vinyl Acetate-Acrylic Emulsion Copolymers (실리콘 수식 비닐아세테이트-아크릴 공중합체 수지의 방수성 및 열적 성질)

  • Naghash, Hamid Javaherian
    • Polymer Korea
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    • v.34 no.4
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    • pp.306-312
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    • 2010
  • Triphenylvinylsilane (TPVS) containing vinyl acetate (VAc), butyl acrylate (BA), and Nmethylolacrylamide (NMA) copolymers were prepared by emulsion polymerization. The polymerization was performed at $80^{\circ}C$ in the presence of auxiliary agents and ammonium peroxodisulfate (APS) as the initiator. Sodium dodecyl sulphate (SDS) and Arkupal N-300 were used as anionic and nonionic emulsifiers, respectively. The resulting copolymers were characterized by using Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), and dynamic light scattering (DLS). Thermal properties of the copolymers were studied by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The morphology of copolymers was also investigated by scanning electron microscopy (SEM) and then the effects of silicone concentrations on the properties of the TPVS-containing VAc-acrylic emulsion copolymers were discussed. The obtained copolymers have high solid content (50%) and can be used in weather resistant emulsion paints as a binder.