• 한국전기전자재료학회논문지
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• 제28권12호
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• pp.792-796
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• 2015

With high integration of electronic components, power inductors are also miniaturized. Recently, thick film processes for small size power inductors were developed and commercialized. However, the thick film process to prepare soft magnetic green sheets was not reported enough. In this study, we used Fe-Si magnetic and CIP (carbonyl iron powders) as starting materials to lead to a bimodal particle size distribution in the sheet. We proposed a newly developed 'Modified slurry preparation process' to get well dispersed condition even at high solid contents. Using the new process, it was possible to prepare a well dispersed slurry over 70 vol% of solid. BYK-103 was better than BYK-111 as dispersant in this slurry and the optimum amount was 0.6 wt%. The optimized slurry was formed into a sheet by tape casting process and then the sheet was laminated. We conformed that small size powder, large size powder, and epoxy resin were well dispersed in the green sheet.

• Journal of Acupuncture Research
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• 제35권4호
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• pp.207-213
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• 2018

Background: The purpose of this study was to examine the effect of Dokhwalgisaeng-tang on immobilization-induced muscle atrophy. Methods: Twenty young male Sprague-Dawley rats were divided into 2 groups. The rats in Dokhwalgisaeng-tang group were orally administered Dokhwalgisaeng-tang water extract, and the rats in the control group were given saline only. Hind limb immobilization was performed with casting tape to keep the left ankle joint in a fully extended position. No intervention was performed on the right leg which was used as an intact region. After 2 weeks of immobilization, all animals were sacrificed, and the gastrocnemius muscle was dissected from both legs and weighed. The morphology of the right and the left gastrocnemius muscle in both the Dokhwalgisaeng-tang and the control group was assessed by hematoxylin and eosin staining. The muscle cross sectional area was examined by image analysis (Axiovision LE software). In addition, immunohistochemical staining was carried out using the free-floating method, and the number of apoptotic related proteins were counted (anti-BAX, anti-Bcl-2). Results: Dokhwalgisaeng-tang showed a significant protective effect against the reduction of the left gastrocnemius muscle (weight and muscle cross sectional area) compared with the control group. Moreover, the treatment with Dokhwalgisaeng-tang significantly reduced protein expression of BAX and increased protein expression of Bcl-2 in the gastrocnemius muscle compared with the control group. Conclusion: Dokhwalgisaeng-tang showed protective effects against disuse muscle atrophy, potentially through altered BAX and Bcl-2 protein expression in the gastrocnemius muscle.

• 전자공학회논문지 IE
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• 제48권2호
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• pp.40-46
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• 2011

본 연구에서는 테입-케스팅 방법을 이용하여 제작한 PZT-5A의 소결온도 변화에 따른 압전특성을 조사한 후 유한요소 해석법을 이용하여 2-2형 압전복합재료를 초음파 트랜스듀서를 설계하고 압전특성을 해석하였다. 2-2형 압전복합재료의 음향임피던스와 압전전하상수($d_{33}$)는 PZT 부피분율이 감소함에 따라 밀도의 감소로 감소하여 0.6~0.2의 범위에서 14~3 MRayl로 초음파 트랜스듀서로 사용가능한 특성을 나타내었다. 공진특성과 전기기계결합계수는 PZT부피분율이 0.6일 때 가장 우수한 특성을 나타내었으며, PZT의 부피분율이 0.2~0.6에서는 $k_t$ 값이 0.64~0.68로 거의 일정한 값을 유지하였지만 그 이상에서는 급격하게 감소하는 것을 확인할 수 있었다. 이상의 실험결과로부터 2-2형 압전복합재료는 초음파 트랜스듀서 재료로 응용 가능성을 확인 할 수 있었다.

• 한국전기전자재료학회논문지
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• 제29권12호
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• pp.786-790
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• 2016

Hole explosion behaviors were observed during drilling fine holes with laser beam on the LTCC green bar of $320{\mu}m$ thick after lamination of green sheets prepared by tape casting of thick film process. The incidence of these hole explosions was inversely proportional to hole sizes. The incidence of hole explosion was 20 % number of hole with the size of $60{\mu}m$ exploded for the UV radiation, while the explosion did not appear for hole sizes over $100{\mu}m$. To prevent hole explosion behavior during laser-drilling of fine holes, carbon black powder was added as an additive in the LTCC composition, which has superior thermal durability. As a consequence, hole explosion rate was suppressed to 0.8 % for the hole size of $50{\mu}m$ green sheet with the carbon black amount of 10 weight % and the laser power of 3 watt. Added carbon is thought to reduce the heat-affected region during laser drilling.

• 한국세라믹학회지
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• 제44권5호
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• pp.179-183
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• 2007

BCB $Resin-BaNd_2Ti_4O_{12}$(BNT) composites with BNT contents were prepared by tape casting method and epoxy resin-BNT composites were prepared by using heating press. Their dielectric properties and microstructures were investigated. The dielectric properties such as dielectric constant and dielectric loss at 1 MHz for epoxy resin-BNT composites and BCB resin-BNT composites are improved with an increase of BNT volume fraction. The dielectric constant of the Epoxy-BNT composite increased from 5.9 to 7.8 as the volume fraction of BNT increased from 15 to 25. The dielectric constant of the BCB-BNT composite increased from 9.1 to 15.5 as the volume fraction of BNT increased from 30 to 50. The dielectric behavior of BCB-BNT system can be explained by Lichtenecker's equation. The dielectric constant of epoxy resin-BNT composite is smaller than that of BCB resin-BNT composite. These results are considered to be related with the dispersion of BNT filler in polymer matrix from the result of SEM photograph.

• 한방재활의학과학회지
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• 제28권4호
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• pp.1-9
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• 2018

Objectives Disuse muscle atrophy occurs in response to pathologies such as joint immobilization, inactivity or bed rest. Muscle disuse is accompanied by an increase in apoptotic signaling, which mediates some of the responses to unloading in the muscle. GB34 (Yanglingquan) is a acupuncture point on the lower leg and one of the most frequently used points in various skeletomuscular diseases. In this study, the hypothesis that the acupuncture at GB34 could attenuate immobilization-induced skeletal muscle atrophy was tested. Methods The left hindlimb immobilization was performed with casting tape in both GB34 group (n=10) and Control group (n=10). The rats in GB34 group were daily treated with acupuncture at GB34. After 2 weeks of immobilization, the morphology of right and left gastrocnemius muscles in both GB34 and Control groups were assessed by hematoxylin and eosin staining. To investigate the immobilization-induced muscular apoptosis, the immunohistochemical analysis of Bax and Bcl-2 was carried out. Results GB34 group represented the significant protective effects against the reductions of the left gastrocnemius muscles weight and average cross section area to compared with Control group. The acupuncture at GB34 significantly reduced the immunoreactivity of BAX and increased the immunoreactivity of Bcl-2 in gastrocnemius muscle compared with Control group. Conclusions These results suggest that the acupuncture at GB34 has protective effects against immobilization-induced muscle atrophy by regulating the activities of apoptosis-associated BAX/Bcl-2 proteins in gastrocnemius muscle.

• 자원리싸이클링
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• 제7권4호
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• pp.35-42
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• 1998

오늘날 전자부품 산업에 실장기술은 크게 각광을 받고 있다. 페라이트 칩인덕터와 같이 전자부품의 소형화를 위해서는, 쉬트 적층법이나 스크린 인쇄법 등을 위하여 유기용매를 사용하는 세라믹 습식공정이 널리 사용되고 있다. 본연구에서는 물이 혼합된 용매계를 이용한 NiCuZn Ferrite(NCZF) 슬러리와 그린쉬트의 제조 및 평가에 관한 연구를 하였다. 볼밀링에 의하여 21 vol%의 NCZF 슬러리를 제조하였으며, polacrylic vinyl copolymer를 바인더로서 사용하였다. 용매로서는 isopropyl alcohol과 2-butoxy ethanol에 40∼80% 물을 혼합하여 사용하였다. 그 결과, NCZF 슬러리의 분산안정성은 입자의 정전기적 힘보다는 free polymer에 의해 나타났으며, 슬러리의 점성은 용매중의 물함량에 크게 의존하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.181-181
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• 2007

PTCR 세라믹스를 적층형 부품으로 제조할 경우 소형화, 저 저항화 및 과전류 유입 시 빠른 응답특성을 갖는다는 장점을 가지고 있으며, 이러한 적층형 부품제조시에는 내부전극재가 부품소자의 물성에 중요한 영향을 미친다. 특히 우수한 옴성 접촉(Ohmic Contact)을 갖는 Zn, Fe, Sn, Ni 등의 적층 PTC용 전극재는 높은 산화특성으로 인해 재산화 과정에서의 비옴성 접촉(Non-ohmic contact)을 갖게 되어 PTC 특성을 저하시킬 우려가 있다. 따라서 본 연구에서는 적층형 PTCR 세라믹스의 내부전극재와 반도체 세라믹층의 동시소성거동 및 적층 PTCR 세라믹스의 전기적 특성을 평가하였다. 본 연구에 적용된 내부전극재로는 Ni 전극을 사용하였고, Ni 전극용 paste로는 무공제 paste, 반도체 세라믹공제 paste, $BaTiO_3$ 공제 paste의 3종 전극재가 이용되었다. 적층형 PTCR 세라믹스의 제조공정은 테이프 캐스팅(Tape casting), 내부전극인쇄, 적층 및 동시소성을 포함하는 적층화공정을 적용하였다. 각각의 전극 paste를 적용하여 제조된 chip은 미세구조관찰, I-V특성, R-T특성 등을 평가하여 내부전극내 세라믹공제의 영향을 고찰하였다.

• Journal of Acupuncture Research
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• 제36권4호
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• pp.238-244
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• 2019

Background: This study aimed to investigate the protective effects of Zanthoxylum bungeanum Maxim pharmacopuncture on disuse muscle atrophy in the gastrocnemius muscle of rats. Methods: Thirty male 250 g Sprague-Dawley rats were distributed randomly into 3 groups. The left hindlimb immobilization was performed with casting tape for 2 weeks, and no treatment was given to the right hindlimb. Rats received pharmacopuncture and were injected daily on the BL57 with either 2 mL of Zanthoxylum bungeanum Maxim aqueous extract (ZM-W group), 1 mL pharmacopuncture of Zanthoxylum bungeanum Maxim ethanol extract (ZM-E group), or 2 mL normal saline (control group). After 2 weeks of immobilization, the weight of the whole gastrocnemius muscle was measured, and the morphology of both the left and the right gastrocnemius muscles were assessed by Hematoxylin and Eosin staining. To investigate the immobilization-induced muscular apoptosis, the immunohistochemical analysis of BAX and Bcl-2 was carried out. Results: ZM-W and ZM-E significantly inhibited the reduction in weight of the left gastrocnemius muscle, the reduction in the left myofibrils, and the cross-sectional area of gastrocnemius, as compared with the control. Moreover, the ZM-W and ZM-E groups showed significantly reduced immunoreactivity for BAX, and increased immunoreactivity of Bcl-2 in left gastrocnemius muscle compared with the control group. Conclusion: These results suggest that Zanthoxylum bungeanum Maxim pharmacopuncture has protective effects against immobilization-induced muscle atrophy by regulating the activity of apoptosis-associated BAX / Bcl-2 proteins in the gastrocnemius muscle.

• 한국결정성장학회지
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• 제29권2호
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• pp.77-81
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• 2019

최근 환경오염에 관한 문제가 대두됨에 따라서 친환경 수처리 공법에 관한 다양한 방법들이 논의되고 있다. 현재 시장을 주도하고 있는 고분자 멤브레인은 저가이나, 내화학성 및 내구성 측면에서 많은 문제점을 안고 있다. 이에 따라 친환경적이며 내구성, 내화학성이 뛰어난 세라믹 멤브레인의 기공 구조, 크기 및 표면 처리를 통하여 고효율의 수처리용 세라믹 멤브레인을 제작하였다. $ZrO_2$ 및 $TiO_2$의 균일한 코팅막 형성을 통하여 멤브레인의 기공 크기를 조절 하였다. 테입케스팅, 졸겔 공정법을 활용하여 멤브레인 표면에 성공적으로 나노기공을 가지는 세라믹 코팅막을 형성하였다. 세라믹 멤브레인의 미세조직 분석, 코팅막의 기공의 크기 분석을 진행하였으며 이에 대한 수처리 특성 변화를 관측하였다.