• 폴리머
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• 제35권6호
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• pp.580-585
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• 2011

본 연구는 석유유래 생분해성 고분자인 poly(butylene adipate-co-succinate-co-terephthalate)(PBAST)의 생분해도와 친환경성을 높이기 위하여 변형 열가소성 전분(CMPS, chemically modified thermoplastic starch)을 첨가하였다. CMPS는 천연고분자인 전분을 가소제, maleic anhydride(MA) 및 반응개시제로 반응시켜 제조한 일종의 식물유래 생분해성 수지이다. PBAST/CMPS 블렌드의 파단면 사진으로부터 PBAST와 CMPS 상이 분리된 비혼화성 (immiscible blend) 블렌드이지만 상 사이의 계면 형상이 좋은 상용성 블렌드임을 알 수 있었다. 인장강도와 연신율은 CMPS 함량이 증가함에 따라 감소하였지만 탄성률은 증가하였다. 블렌드의 생분해도는 순수 PBAST에 비해 매우 높았고 CMPS의 함량이 증가함에 따라 증가하였다.

• Macromolecular Research
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• 제15권4호
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• pp.291-301
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• 2007

The rheological behaviors and morphologies of polylactide (PLA) and chemically modified plasticized starch (CMPS) blends were investigated. For this study, oscillatory shear flow measurements of the PLA, CMPS and their blends were performed. A scanning electron microscope (SEM) study was also conducted on the extracted extrudates of the blends. The morphology of the blend changed in relation to the composition: sphere-shaped CMPS disperse/continuous PLA, rod-like deformed CMPS phase/continuous PLA, a co-continuous structure with bridged CMPS long rods and PLA dispersed/continuous CMPS. The composition of the phase inversion could be estimated and closely coincided from the observed morphology experimental results. The rheological behavior of the blends, from oscillatory measurements, was found to vary in relation to the composition, and reflected the morphologies of the blends. PLA showed Newtonian flow behavior, while CMPS showed strong shear thinning behavior. The relationships between the morphology and rheological properties were observed in detail.

• 폴리머
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• 제33권2호
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• pp.164-168
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• 2009

본 연구는 화학적으로 개질된 열가소성 전분(chemically modified thermoplastic starch(CMPS))과 poly(lactic acid)(PLA)와 poly(butylene adipate-co-terephthalate)(PBAT) 블렌드의 형태학, 열적 및 기계적 특성에 미치는 영향에 대해서 연구하였다. PLA/PBAT 블렌드에 CMPS를 이 블렌드의 중량기준으로 10, 20, 30 wt%를 첨가하여 이축압출기로 가공하였다. PLA/PBAT/CMPS 블렌드에서 PLA의 유리전이온도($T_g$)는 CMPS 함량이 증가하여도 큰 변화를 나타내지 않았지만, CMPS의 첨가에 의해 PLA상과 PBAT상 사이의 계면상태가 좋아지는 상용성 있는 형태학을 보여주었다.

• 자원환경지질
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• 제41권6호
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• pp.731-746
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• 2008

대부분의 분을 흐름 접근 방식을 따르는 다상흐름모델들은 주로 유체나 매질의 비 압축성을 가정하거나 완전한 삼상 오염물을 다루지 않고 이상 유체 (물 또는 공기, 물 또는 불용융성유체)의 거동만을 다룬다. 그러나 본 연구에서는 유체 및 매질의 압축성과 완전한 삼상 오염물을 가정하는, 분율흐름접근방식을 따르는 수학적 지배방정식을 개발하고, 이를 토대로 압축성 유체 및 매질을 고려한 삼상흐름 수치모의프로그램을 개발하였다 개발된 삼상흐름 수치모의프로그램 (Compressible Multiphase Flow Simulator, CMPS)을 검증하기 위해서 기존에 개발된 비압축성 유체 및 매질을 고려한 삼상흐름수치모의 프로그램인 MPS (Suk and Yeh, 2007; Suk and Yeh, 2008) 및 해석해를 통해서 간접적으로 비교 검증하였다. 비교결과 CMPS와 MPS의 결과와 해석해들은 서로 잘 일치하였다. 따라서 CMPS는 압축성 유체 및 매질을 고려한 삼상흐름 수치모의를 구현 할 수 있는 가능성을 가진다.

• ETRI Journal
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• 제40권6호
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• pp.759-773
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• 2018

Uncore components such as on-chip memory systems and on-chip interconnects consume a large amount of energy in emerging embedded applications. Few studies have focused on next-generation analytical models for future chip-multiprocessors (CMPs) that simultaneously consider the impacts of the power consumption of core and uncore components. In this paper, we propose a convex-optimization approach to design heterogeneous uncore architectures for embedded CMPs. Our convex approach optimizes the number and placement of memory banks with different technologies on the memory layer. In parallel with hybrid memory architecting, optimizing the number and placement of through silicon vias as a viable solution in building three-dimensional (3D) CMPs is another important target of the proposed approach. Experimental results show that the proposed method outperforms 3D CMP designs with hybrid and traditional memory architectures in terms of both energy delay products (EDPs) and performance parameters. The proposed method improves the EDPs by an average of about 43% compared with SRAM design. In addition, it improves the throughput by about 7% compared with dynamic RAM (DRAM) design.

• 멤브레인
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• 제6권2호
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• pp.72-78
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• 1996

양이온성의 quaternary ammonium polysulfone인 AMPS는 2단계 과정을 통하여 제조하였다. 먼저, 폴리술폰을 chloromethyl methyl ether와 촉매로 ZnO를 사용하여 chloromethylation반응으로 CMPS를 제조하는 단계와 준비된 CMPS에 triethylamine을 반응시켜 quaternary ammonium기를 도입시키는 amination 단계로 이루어 진다.

• Journal of Magnetics
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• 제16권2호
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• pp.88-91
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• 2011

Steam generator tubes (SGTs) in nuclear power plants (NPPs) are a boundary between the primary side generating heat by nuclear fission and the secondary side generating electric power by a turbine. The water inside the SGT is high temperature and high pressure. Therefore, defects and magnetic phases (MPs) are partly produced in non-magnetic SGT by high stresses and temperatures. This causes trouble regarding the safety of SGTs but it is difficult to detect the MP using the conventional eddy current technique (ECT). In particular, a circumferential defect (CD) and circumferential magnetic phase (CMP) cannot detected by ECT. Consequently, a new method is needed to detect CDs and CMPs in SGT. A new U-type yoke with two types of coils was designed and the reactance signal by the CMPs and CDs in the SGT material was simulated.

• JSTS:Journal of Semiconductor Technology and Science
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• 제11권4호
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• pp.318-328
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• 2011

Stage-level reconfigurable chip multiprocessor (CMP) aims to achieve highly reliable and fault tolerant computing by using interwoven pipeline stages and on-chip interconnect for communicating with each other. The existing crossbar-switch based stage-level reconfigurable CMPs offer high reliability at the cost of significant area/power overheads. These overheads make realizing large CMPs prohibitive due to the area and power consumed by heavy interconnection networks. On other hand, area/power-efficient architectures offer less reliability and inefficient stage-level resource utilization. In this paper, I propose a hierarchical multiplexing interconnection structure in lieu of crossbar interconnect to design area/power-efficient stage-level reconfigurable CMP. The proposed approach is able to keep the reliability offered by the crossbar-switch while reducing the area and power overheads. Experimental results show that the proposed approach reduces area by up to 21% and power by up to 32% when compared with the crossbar-switch based interconnection network.

• Restorative Dentistry and Endodontics
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• 제45권4호
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• pp.49.1-49.11
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• 2020

Objectives: The aim of this study was to perform a clinical and radiographic analysis of endodontically treated teeth (ETT) restored with cast metal posts (CMPs) or prefabricated glass fiber posts (GFPs) and crowns. Materials and Methods: Fifty ETT were restored with 25 CMPs and 25 GFPs at a private dental clinic between 2001 and 2016. The restorations consisted of 12 all-ceramic crowns, 31 metal-ceramic crowns, and 7 composite resin crowns. Demographic data, type of teeth, type of post-and-core system, time of placement, crown restorations, the number of proximal contacts, the type of antagonist, and reports of any complications after post-and-core placement were recorded for each patient. Assessments were performed at baseline (radiographic) and follow-up (radiographic and clinical). Data were analyzed by the McNemar test, the Pearson χ² test, and Kaplan-Meier survival curves (α = 0.05). The mean follow-up was 67.6 months. Results: No significant difference was observed for any of the radiographic parameters when the baseline and final radiographs were compared. In the clinical evaluation, anatomical form (p = 0.009) and occlusion (p = 0.001) showed significant differences according to the type of crown restoration; specifically, metal-ceramic and all-ceramic crowns outperformed composite resin crowns. Conclusions: CMPs and GFPs showed favorable results for restoring ETT after 6 years of follow-up. All-ceramic and metal-ceramic crowns showed higher survival rates and better clinical outcomes.

• Natural Product Sciences
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• 제27권4호
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• pp.264-273
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• 2021

Simultaneous quantification of multiple marker compounds in herbal medicine by high performance liquid chromatography (HPLC) analysis is still a challenge due to the complexity in various parameters to be considered and co-existing multi-components. As a case study, a reliable HPLC method for simultaneous quantification of paeoniflorin from Paeoniae Radix and decursin from Angelicae Gigantis Radix in various commercial herbal medicine was developed based on analytical quality by design (AQbD) strategy. As a first step, risk assessment was performed to select the critical method parameters (CMPs) which were decided as organic mobile phase ratio and column oven temperature. In order to evaluate the effect of the CMPs on critical method attributes (CMAs) of peak resolution and tailing, central composite design (CCD) was employed. The final chromatographic conditions were optimized as follows: column- C₁₈, 4.6 × 250 mm, 5 ㎛ particle size; mobile phase- A: acetonitrile, B: 0.1% acetic acid water; detection wavelength- 235 nm for paeoniflorin, 325 nm for decursin; column oven temperature- 25℃; flow rate- 1.0 mL/min; gradient mobile phase system as Time (min) : % A, 0:14, 25:14, 30:50, 60:50, 61:100, 65:100, 66:14, 75:14. The method was successfully validated according to the International Conference on Harmonization (ICH) guidelines and piloted for ten commercial herbal medicines.