• Polymer(Korea)
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• v.27 no.5
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• pp.405-412
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• 2003

Poly(vinyl alcohol) (PVA) and N-(2-hydroxy)propyl-3-trimethylammonium chitosan chloride (HTCC), a water soluble chitosan derivative synthesized by the reaction of quaternary ammonium compound with chitosan, were blended using water as a solvent and the PVA/HTCC blend films with various compositions were prepared by solution casting method. The miscibility between the two polymers and the thermal properties of the blend films were investigated using FT-IR, DSC, DMA, and TGA. Single glass transition temperatures and single melting temperatures of the blend films along with the strong and clear film state for the whole composition of blending ratios suggest the miscibility between PVA and HTCC. The PVA/HTCC blend films with HTCC content of 1% and greater showed excellent antimicrobial activity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.97-97
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• 2009

산업용 온수관련용 자동차용 등의 다양한 용도로 응용이 가능한 고기능성 세라믹 히터 제작을 위해 후막공정 기술을 적용한 적층형 세라믹 히터의 수요가 증가하고 있으며, 고열로 인한 변형의 우려가 있는 내열성 기판 제작에도 적층형 HTCC 세라믹 기판 적용이 확대되고 있다. 이러한 고내열성 세라믹 기판 제작을 위해서는 paste의 균일성, Low TCR 특성 및 세라믹과 paste 매칭성 확보가 중요한 요소이다. 본 연구에서는 W/Mo 함량비를 변화시켜가며 paste를 제조하여 비저항과 TCR 특성을 비교한 후 가장 낮은 값을 나타내는 조성을 선정하였다. 이 조성에 $Al_2O_3$, $Ta_2O_5$ 등의 첨가제를 사용하여 비저항 특성 개선을 위한 실험을 통해 우수한 고내열성 기판용 paste 조성을 확보하고자 하였다. 그리고 이 Paste를 적용하여 HTCC 그린시트와 매칭성 조건을 확인하고자 하였다.

• International Journal of Computer Science & Network Security
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• v.22 no.9
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• pp.414-426
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• 2022

Elliptic Curve Cryptography (ECC) is one of the finest cryptographic technique of recent time due to its lower key length and satisfactory performance with different hardware structures. In this paper, a High Throughput Multiplier architecture is introduced for Elliptic Cryptographic applications based on concurrent computations. With the aid of the concurrent computing approach, the High Throughput Concurrent Computation (HTCC) technology that was just presented improves the processing speed as well as the overall efficiency of the point-multiplier architecture. Here, first and second distinct group operation of point multiplier are combined together and synthesised concurrently. The synthesis of proposed HTCC technique is performed in Xilinx Virtex - 5 and Xilinx Virtex - 7 of Field-programmable gate array (FPGA) family. In terms of slices, flip flops, time delay, maximum frequency, and efficiency, the advantages of the proposed HTCC point multiplier architecture are outlined, and a comparison of these advantages with those of existing state-of-the-art point multiplier approaches is provided over GF(2¹⁶³), GF(2²³³) and GF(2²⁸³). The efficiency using proposed HTCC technique is enhanced by 30.22% and 75.31% for Xilinx Virtex-5 and by 25.13% and 47.75% for Xilinx Virtex-7 in comparison according to the LC design as well as the LL design, in their respective fashions. The experimental results for Virtex - 5 and Virtex - 7 over GF(2²³³) and GF(2²⁸³)are also very satisfactory.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.908-909
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• 2006

The HTCC based multilayer structure plasma head unit have some difficulties in fabrication due to complicated post-processes, such as heat treatment at reduced atmosphere, re-bonding of each layer, and silver metallization. On the other hand, LTCC based technology provides relatively simple process for multilayer plasma unit except weak mechanical properties. To overcome this problem a combined scheme using both LTCC and HTCC technology has been developed in our group, recently. In this work, we report the structural design, materials selection, joining of LTCC with HTCC substrate, and co-firing process for the fabrication of multilayered atmospheric plasma head unit.

• Ceramist
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• v.15 no.1
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• pp.32-37
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• 2012

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.11 s.353
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• pp.8-13
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• 2006

Recent RF SAW filters are made using a HTCC package with a CSP(chip scale Package) technology. This paper describes a development of a new $1.4{\times}1.1\;and\;2.0{\times}1.4mm$ RF SAW liters made by PCB substrate instead of HTCC package, and this technology can reduce the cost of materials down to 40%. We have investigated the multi-layered PCB substrate structures and raw materials to find out the optimal flip-bonding condition between the $LiTaO_3$ wafer and PCB substrates. Also the optimal materials and processing conditions of epoxy laminating film were found out through the experiments which can reduce the bending moment caused by the difference of the thermal expansion between the PCB substrate and laminating film. The new PCB SAW filter shows good electrical and reliability performances with respect to the present SAW filters.

• Proceedings of the Korean Fiber Society Conference
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• 1998.04a
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• pp.40-44
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• 1998

키토산은 키틴을 탈아세틸화시켜 제조한 물질로서, 우수한 항미생물성, 생분해성, 비독성 및 강한 이온흡착능을 지니고 있어 이러한 우수한 성질을 섬유에 응용하기 위하여 저분자화하여 가교제로서 섬유에 부착시키는 방법[1], 섬유고분자와의 블렌딩[2,3] 등 여러 방법이 연구되어 왔으나 제조비용과 공정상의 단점 둥으로 사용에 제한이 따르고 있다.(중략)

• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.17-20
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• 1998

키토산은 키틴을 탈아세틸화시켜 제조한 물질로서, 우수한 항미생물성, 생분해성, 비독성 및 강한 이온흡착능 등 여러 가지 우수한 성질을 지니고 있어 이러한 특성을 섬유에 응용하기 위하여 저분자화하여 가교제로서 섬유에 부착시키는 방법[1], 섬유고분자와의 블렌딩[2,3] 등 여러 방법이 연구되어 왔으나 제조비용 및 공정상의 단점 등으로 사용에 제한이 따르고 있다. (중략)

• Corrosion Science and Technology
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• v.15 no.2
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• pp.84-91
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• 2016

The transport and deposition of corrosion products in pressurized water nuclear reactor (PWR) steam generators have led to corrosion (SCC, denting etc.) problems. Lancing, mechanical cleaning and chemical cleaning have been used to reduce these problems. The methods of lancing and mechanical cleaning have limitations in removing corrosion products due to the structure of steam generator tubes. But high temperature chemical cleaning (HTCC) with EDTA is the most effective method to remove corrosion products regardless of the structure. However, EDTA in chemical cleaning aqueous solution and chemical cleaning environments affects the integrity of materials used in steam generators. The nuclear power plants have to perform the pre-test (also called as qualification test (QT)) that confirms the effect on the integrity of materials after HTCC. This is one of the series studies that assess the effect, and this study determines the effects of 20 % EDTA aqueous solution on defective tubes in high temperature chemical cleaning environments. The depth and magnitude of defects in steam generator (SG) tubes were measured by eddy current test (ECT) signals. Surface analysis and magnitude of defects were performed by using SEM/EDS. Corrosion rate was assessed by weight loss of specimens. The ECT signals (potential and depth %) of defective tubes increased marginally. But the lengths of defects, oxides on the surface and weights of specimens did not change. The average corrosion rate of standard corrosion specimens was negligible. But the surfaces on specimens showed traces of etching. The depth of etching showed a range on the nanometer. After comprehensive evaluation of all the results, it is concluded that 20 % EDTA aqueous solution in high temperature chemical cleaning environments does not have a negative effect on defective tubes.

• Journal of the Korean Ceramic Society
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• v.47 no.4
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• pp.319-324
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• 2010

Screen printable $MoSi_2$ paste and its ceramic sheet heater were investigated. $MoSi_2$ powder without $Mo_5Si_3$ second phase, which causes so-called pest phenomena, was synthesized by SHS technique. Over glaze was also developed for preventing pest phenomenon. The maximum temperature of $MoSi_2$ ceramic heater was over $500^{\circ}C$. After several heat up and cooling cycle, the $MoSi_2$ heater reveals pest phenomenon. Conductive $MoSi_2$ paste could be used in electronic ceramics, i.e., MLCC, LTCC, HTCC, and etc.