• Title/Summary/Keyword: 무게 감소율

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Microwave Sintering of LTCC LC Filter (LTCC LC Filter의 Microwave 소결)

  • 안주환;선용빈;김석범
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2002.05a
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    • pp.121-125
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    • 2002
  • 이동통신기기 등의 고주파용 LTCC(Low Temperature Co-fired Ceramic) LC filter의 소결결에 있어 기존의 소결공정인 전기로 소결공정과 microwave를 이용한 소결공정을 이용하여 소결하였을때 LC filter의 수축율과 무게감소, 그에 따른 밀도의 변화, SEM을 이용한 표면형상 분석을 통해 급속가열을 통한 공정시간의 단축, 낮은 에너지 소비로 인한 제조단가의 절감, 균일한 가열로 인한 소결온도의 저하 등의 장점을 갖는 microwave sintering을 적용할 수 있는 가능성을 제시하였다.

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복합재 연소관 적용에 따른 추진제 구조안정성 연구

  • 최용규;정규동;김중근
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 1995.05a
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    • pp.3-8
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    • 1995
  • 추진기관 적용에 따른 복합재연소관의 일반적 사항들을 논하였다. 추진기관의 효율에 주요인자인 경량화에 있어서 복합재 연소관의 무게가 철금속 연소관에 비해 약 50%의 감소효과가 있으며 단가의 측면에서도 부가가치가 있는 것으로 평가된다. 그러나 추진기관 체계적(추진제 공정 및 구조안정성) 관점에서 추진제 내면변형율(Inner Bore Strain)의 증가, 제작공차, 공정의 재현성, EPDM의 접착기밀성 및 외부습도 유입 문제 등의 앞으로 해결되어야 할 사항들이 제시되었다.

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Effect of Processing Time and Unipolar DC pulse Duty Ratio on Electrode during Gold Nanofluids using Solution Plasma (금 나노유체 제조시 공정시간과 음극파워비율에 따른 전극에 미치는 영향)

  • Kim, Jae-Yong;Kim, Beom-Seok;O, Jong-Ho;Lee, Sang-Yul
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2011.05a
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    • pp.191-191
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    • 2011
  • 유체 플라즈마 공정(SPP)은 최신 나노기술과 열전달 유체 기술이 융합된 나노유체(Nanofluids)를 제조하는 공정이다. 본 연구에서는 이런 유체 플라즈마 공정에서 공정시간과 음극파워비율에 따라 금 나노유체 제조시 사용되는 전극에 미치는 영향을 알아보기 위해 특성분석을 실시하였다. 그 결과 전극의 양극에서는 염화금 이온이 전극에 증착되었고 음극에서는 부식에 의해 무게가 감소하였다.

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The Corrosion Behavior of Cold-Rolled 304 Stainless Steel In Salt Spray Environments (염분분사환경에서 냉연 304 스테인레스강의 부식거동)

  • Chiang, M.F.;Young, M.C.;Huang, J.Y.
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.9 no.2
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    • pp.93-98
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    • 2011
  • Saline corrosion is one of the major degradation mechanisms for stainless steel type 304 (SS304) dry storage cask during the spent fuel interim storage period. Slow strain rate test (SSRT) and neutral salt spray test (NSS) were performed at $85^{\circ}C$ and $200^{\circ}C$ with 0.5 wt% sodium chloride mist sprayed on the cold-rolled SS304 specimens of different degrees of reduction in this study. The weight changes of the NSS specimens tested at $85^{\circ}C$ for 2000 hours differed greatly from those at $200^{\circ}C$. The weight loss of NSS specimens was not significant at $85^{\circ}C$ but the weight gain decreased gradually with increasing the cold-rolled reduction. The yield strength (YS) and ultimate tensile stress (UTS) values obtained from the SSRT tests for lightly cold-rolled specimens in the salt spray environment at $85^{\circ}C$ and $200^{\circ}C$ are slightly lower than in air. But for those with 20% reductions, the specimen strengths were no longer changed by the saline corrosion. The preliminary results demonstrated that the quality and performance of cold-rolled SS304 is acceptable for fabrication of dry storage casks. However, more work on the corrosion behavior of cold-rolled stainless steel in the saline atmosphere is needed to better understand its long-term performance.

STUDIES ON THE SAFETY OF KOREAN GINSENG INGESTED AS FOOD SUBSTANCE (고려인삼의 식품안전성 연구)

  • Hong Soon Keun;Lee Song Jae;Kim Young Soo;Jeon Byeong Seon;Lim Chang Hyung
    • Proceedings of the Ginseng society Conference
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    • 1984.09a
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    • pp.199-213
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    • 1984
  • 홍삼 분말을 혼합하여 제조한 사료로 $60{\~}80g$ 의 Sprague Dawley Rat(female) 12마리를 1군으로 하여 $1{\~}6$개월간 사육하였다. 사육기간동안. 체중증가, 혈청의 생화학적 분석, 장기(심장 폐, 신장, 간. 비장, 뇌)의 무게차 이들 장기의 병리조직검사를 하였다. 인삼 사육관과 대조군의 성장율, 장기 무게와 혈구수는 통계적 유의성은 없었으나 혈청중의 triglyce-ride, total cholesterol, free cholesterol 함량은 대조군과 유사하였고 total lipid, free fatty acid는 대조군에 비해 약간씩 감소하였다. 그러나 실험군의 total protein, phospholipid, HDL-cholesterol은 대조군에 비해 증가하였다. 실험군의 병리조직검사에서도 대조군과 차이가 없었으나, 특히 대조군의 비장에서는 조혈기능을 지닌 거핵구세포가 다수 출현하였으며 인삼 투여기간과 용량에는 비례하지 않았다. $F_{1},\;F_{2}$세대의 적혈구, 백혈구, 장기 무게와 병리조직검사는 대조군과 유사하였으며 외형적 기형도 발견되지 않았다. 이상의 결과들로 고려인삼은 건강식품으로도 매우 안전하며 조혈기능도 촉진시킴을 시사해 준다.

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A Study on the Removal of Penalty Elements and the Improvement of Gold Contents from Gold Concentrate Using Microwave-nitric Acid Leaching (마이크로웨이브-질산침출을 이용한 금 정광으로부터 페널티 원소 제거 및 금 품위 향상 연구)

  • Kim, Hyun Soo;Oyunbileg, Purev;Park, Cheon-Young
    • Journal of the Mineralogical Society of Korea
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    • v.32 no.1
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    • pp.1-14
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    • 2019
  • This study used microwave-nitric acid leaching with the aim of removing penalty elements such as As and Bi. Moreover, enhanced gold content from the gold concentrate sample. The leaching conditions were changed: leaching time, nitric acid concentrations and solid-liquid ratio; In order to improve the removal of penalty elements. As a result of the experiment; sample weight loss rate, As and Bi removal rate and gold content in the solid-residues have been increased when the nitric acid concentration and leaching time were increased while the solid-liquid ratio was decreased. The leaching conditions for the maximum As and Bi removal and gold content were: leaching with a 6.0 M nitric acid solution doing 5 min. At these, the solid-residue sample weight loss was 87 %. As removal rate was 98.23 % and Bi was completely removed (100 %). Furthermore, gold content increased from 81.36 g/t to 487.32 g/t. The XRD of the solid residue showed that pyrite disappeared as the nitric acid concentration was increased, whereas sulfur peaks was increased, too.

A Comparative Study on the Characteristics of Accelerated aging at Low and High Temperatures of the Fluorocarbon Rubber Composites (불소 고무복합체의 저온과 고온촉진노화 특성에 대한 비교 연구)

  • Park, JeongBae;Lee, BeomCheol;Jeong, YoonSeok;Park, SungHan
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.915-922
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    • 2017
  • The study on the thermal and oil resistance rubber composite, 2016. [6] predicted the lifetime of Fluorocarbon Rubber by accelerating aging at high temperature ($150^{\circ}C$, $175^{\circ}C$, $200^{\circ}C$). general rubber products are likely to exhibit different properties depending on the degradation factors such as temperature, humidity, ozone, light, emulsion, mechanical and electrical stress. To solve these problems, We compared the rate of change about tensile strength, elongation rate, volume change rate, weight change rate, thickness change rate, thermal conductivity in low temperature promoting aging on the basis of predictive lifetime of high temperature promoting aging. As a result of the review, the required life expectancy was satisfied, but there was a slight difference in the rate of change between the high-temperature promoted aging life result and the low temperature promoted aging life result. The cause was a reduction in "tensile strength / elongation" and an increase in "volume / weight / thickness" caused by the main chain decomposition of fluorine rubber due to aging at high temperature promoting aging. However, the low temperature promoting aging was caused by the curing reaction of fluorine rubber at $80^{\circ}C$. The tensile strength / elongation and volume / weight / thickness changes were small.

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Effect of Induced molting on the Relative Weights and Hormone Levels of Thyroid, Ovary, and Adrenal Glands in Spent Laying Hens (산란노계에서 강제환우가 갑상선, 난소, 부신 및 호르몬 수준에 미치는 영향)

  • M. Akram;rahman, Zia-ur;C.S. Na;Kim, S.H.;K.S. Ryu
    • Korean Journal of Poultry Science
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    • v.29 no.4
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    • pp.243-247
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    • 2002
  • A study was conducted to investigate the effect of induced molting on the relative weight and hormone levels of thyroid, ovary, and adrenal glands in spent laying hens. Three hundred sixty 77-wk-old, Babcock White hens were divided into 36 experimental units of 10 hens each and induced to molt for seven weeks. A diet containing 16% CP and 2,800 kcal ME/kg was fed ad libitum from 84 to 126 weeks of age. Thirty-six birds were randomly selected for blood collection and slaughtered at Pre-molt, 5% egg Production, Peak, and end Phase of the egg Production. Weights of the thyroid, ovary, adrenal glands, and plasma T3, T4, cortisol, and estradiol contents were measured at each stage. Weight of the thyroid reached its highest level at 5% e99 Production stage. The ovary weight was greatly reduced during molting, but started to increase after induced molting until the end of the egg Production Phase (P<0.05). Plasma T3,T4 and cortisol were found to be the highest at the start of the Post-molt Production stage, but reached their minimum at the end Phase of e99 Production. Plasma estradiol was the lowest at the 5% egg Production stage. The Present study demonstrated that molting is a complex Process that require the involvement of endocrine glands to trigger their specific hormones, which play a key role in molt induction.

Bee Venom Inhibits Prostate Cancer Growth in LNCaP Xenografts via Apoptosis (Bee venom의 세포자멸사를 통한 전립선 암세포의 성장 및 LNCaP의 이종이식에 미치는 영향)

  • Yang, Chang-Yeol;Song, Ho-Sueb
    • Journal of Pharmacopuncture
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    • v.13 no.1
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    • pp.15-35
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    • 2010
  • 연구목적 : 이 연구는 봉약침의 봉독이 NF-${\kappa}B$ 활성억제와 안드로겐 수용체 조절 단백질 및 세포자멸사 조절 단백질의 발현을 통하여 세포자멸사를 유도하고, 전립선 암세포를 이식한 쥐에서의 세포자멸사 유도 효과를 확인함으로써, 봉약침의 봉독이 생체 내에서도 세포자멸사를 유도하여 전립선암에 효과를 나타냄을 확인하고자 하였다. 실험방법 : 세포자멸사의 관찰에는 DAPI, TUNEL staining assay를 시행하였으며, 세포자멸사 조절 단백질의 변동 관찰에는 western blot analysis를 시행하였고, 세포자멸사와 연관된 NF-${\kappa}B$의 활성 변화를 관찰하기 위해 EMSA를 시행하였다. 결과 : 1. DAPI, TUNEL staining assay 결과 봉독 및 melittin을 처리한 LNCaP 세포 모두에서 세포자멸사 유도율이 유의한 증가를 나타내었다. 2. LNCaP 세포에 봉독이나 melittin을 처리한 결과, 안드로겐 수용체 조절 단백질 중 p-Akt, COX-2, calpain은 봉독과 melittin 모두에서 유의한 감소를 나타내었고, Akt는 melittin에서 유의한 감소를 나타냈으며, 봉독에서 증가하는 경향을 보였고, MMP-9은 증가하였다. 3. 생체 내에서의 봉독의 항암효과를 확인하기 위해 전립선암세포가 이식된 쥐에 봉독을 처리한 후 암세포의 부피와 무게, 쥐의 체중을 측정한 결과, 봉독을 처리한 군에서 암 세포 부피비율 및 무게는 감소하였고, 쥐의 체중은 증가하였다. 4. 전립선암세포가 이식된 쥐에 봉독을 처리한 결과, NF-${\kappa}B$ 활성에서 유의한 감소를 나타내었다. 5. 전립선암세포가 이식된 쥐에 봉독을 처리한 결과, 세포자멸사 조절 단백질 중 Bax/Bcl-2, p53, caspase-3, caspase-9, calpain은 유의한 증가를, COX-2는 유의한 감소를 나타냈으며, MMP-9는 증가를 나타내었다. 결론 : 이상의 결과는 봉독이 시험관 내에서 뿐만 아니라 생체 내에서도 NF-${\kappa}B$의 활성을 억제하고 안드로겐 수용체 조절 단백질 및 세포자멸사 조절 단백질의 조절을 통하여 인간 전립선암 세포주인 LNCaP의 세포자멸사를 유도함으로써 전립선암 세포 증식억제 효과 및 호르몬 비의존적인 전립선암으로의 전이를 지연시키는 경향이 있을 것으로 사료되고, 봉독이 전립선암의 예방과 치료에 효과적으로 활용될 수 있을 것으로 기대된다.

A Study on Deterioration of Stone Monuments by Acid Fog (산성안개에 의한 석조문화재 구성암석의 손상 연구)

  • Do, Jin Young;Kim, Sang Woo;Cho, Hyen Goo
    • Journal of the Mineralogical Society of Korea
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    • v.28 no.2
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    • pp.135-145
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    • 2015
  • In order to predict the deterioration of stone monument due to acid fog, an artificial fog test using pH4.0 and pH5.6 was applied to the Gyeongju Namsan granite, decite and marble. After the test had weathered Gyeongju Namsan granite a larger weight reduction due to acid fog than fresh one. Decite has shown the most significant changes among the tested rocks with about 0.005 % of weight reduction. Decite and weathered granite will have considerable weight reduction due to acid rain than the acid fog, whereas the marble was expected to show a weight reduction regardless of the phase of water. The porosity and water absorption rate of weathered granite had significantly increased. This result means that the weathered rock is predicted to be more susceptible to acid fog than the fresh rock. The absorption rate of the marble after the test had shown approximately 50 % increase. The color of the samples had slightly changed towards yellow, such tendency was greater shown in weathered rocks. The marble reacted with acid fog had an increased whiteness. A large amount of cation in the samples is caused mainly by the dissociation of minerals through the reaction with acid fog.