• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.985-988
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• 2008

Metal induced crystallization of a-Si with a source of Ni/Si oxide was studied. Its mechanism to induce crystallization was discussed. It was found that new source behaves an effect of self-released nickel and reducing nickel residua, so can provide a wider process tolerance; improve the uniformity and stability of TFTs.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.147-150
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• 2015

When high-pressure gas is suddenly leaked out into the air, unexpected ignition occurs without any external ignition source. Until now, there have been investigations on self-ignition of hydrogen by supplying high-pressure hydrogen gas into a tube. However the mechanism of hydrogen ignition is still unclear. This paper describes the area-ratio effect on hydrogen ignition by inserting a brass plate. The results show that the ignition phenomena differ as the area-ratio changed. Also, the rupture pressure for self-ignition has to be higher.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
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• pp.11-12
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• 2013

To investigate the effect of an inner diameter of the extension tube on the self-ignition when high pressurized hydrogen abruptly released through a tube, both experimental and numerical approach are used. The result show that there is a possibility to have successful ignition when the tube diameter is decreased even at the pressure that could not give sustainable flame with a larger diameter tube. Numerical simulation show the flame development inside the tube and weak and stretch flame spout the tube for 10.9 mm tube, whereas strong complete flame has been generated for 3 mm tube.

• 한국산업융합학회 논문집
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• 제21권6호
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• pp.395-408
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• 2018

Even after the Fukushima nuclear accident in 2011, the rate of production of electric energy using nuclear energy is increasing, but there is a great danger such as the radioactive waste produced when using nuclear power, the catastrophic accident of nuclear power plant, and connection with nuclear weapons. In particular, Cs present in the ionic form of alkaline elements has a long half-life (30.17 years) because it is readily absorbed by the organism and emits intense gamma rays, thus presenting a serious radiation hazard. Therefore, it must be completely removed before it can be released into the natural ecosystem, because it can adversely affect not only humans but also natural ecosystems. Many adsorbents and ion exchangers which have high Cs removal efficiency have been used in recent years to completely separate and remove by self separation in water. Many adsorbents and ion exchangers which have high Cs removal efficiency have been used in recent years to completely separate and remove by self separation in water. In addition, researches have been doing to synthesize magnetic materials with adsorbents such as HCF and PB, and it shows a great effect in the removal rate of Cs present in wastewater or the maximum Cs adsorption amount. In particular, when a magnetic material was applied, excellent results were obtained in which only Cs was selectively removed from other cations. However, new problems such as applicability in the sea where Cs is directly released, applicability in various pH ranges, and failure to preserve the magnetizing force possessed by the magnetic body have been found. However, researches using ferromagnetic field with stronger magnetic properties than those of magnetic bodies is considered to be insufficient. Therefore, it is considered that if the researches combining the ferromagnetic field with the magnetization ability and functional adsorbents more actively, the radioactive material Cs which adversely affects the natural ecosystem can be effectively removed.

• 시큐리티연구
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• 제62호
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• pp.113-134
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• 2020

이 연구는 출소자의 심리건강이 지역사회적응에 미치는 영향을 위험요인과 보호요인으로 구분하여 관계를 검증하고자 수행되었다. 이를 위해 한국법무보호복지공단에서 합동결혼지원을 받은 출소자 216명을 대상으로 수행한 설문자료를 분석하였고, 분석의 결과, 인구사회학적 특성 중 최종학력, 배우자 유무, 월수입 등이 출소자의 지역사회 적응에 긍정적 영향을 미치고 있었으며, 심리건강의 위험요인 중 우울과 대인예민성이 높을수록 지역사회 적응에 부정적인 영향을 미치는 것으로 나타났다. 심리건강 보호요인인 자존감이 높을수록 위험요인인 우울과 대인예민성의 영향력을 감소시켜 지역사회 적응에 긍정적인 영향을 미치는 것으로 나타났다. 종합해보면, 높은 자존감은 출소자들이 출소 후 사회생활 만족도를 높이는 데 기여하고, 위험요인을 긍정적 삶의 변화로 촉진시켜 부정적 상황을 억제하며 성공적인 지역사회 적응의 가능성을 증가시킬 수 있다. 이 연구는 출소자의 성공적인 지역사회 적응을 위해 심리적 요인 중에서 자존감이 가장 중요한 요인이라는 것을 확인하였지만, 출소자의 지역사회 적응과 재범예방을 위해서는 심리적 요인만으로는 해결될 수 없기에 관련된 후속연구 및 다각적 지원이 필요할 것이다.

• 대한치과보철학회지
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• 제33권3호
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• pp.584-609
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• 1995

The purpose of this study was to evaluate the difference of the galvanic corrosion behaviour of the titanium in contact with gold alloy, silva-palladium alloy, and nickel-chromium alloy using the immersion and electrochemical method. And the effects of galvallit couples between titanium and the dental alloys were assessed for their usefulness as materials for superstructure. The immersion method was performed by measuring the amount of metal elementsreleased by Inductivey coupled plasma emission spectroscopy(ICPES) The specimen of fifteen titanium plates, the five gold alloy, five silver-palladium, five nickel-chromium plates, and twenty acrylic resin plates ware fabricated, and also the specimen of sixty titanium plugs, the thirty gold alloy, thirty silver-palladium, and nickelc-hromium plugs were made. Thereafter, each plug of gold alloy, silver-palladium, and nickel-chromium inserted into the the titanium and acrylic resin plate, and also titanium plug inserted into the acrylic resin plate. The combination specimens uf galvanic couples immersed in 70m1 artificial saliva solution, and also specimens of four type alloy(that is, titanium, gold, silver-palladium and nickel-chromium alloy) plugs were immersed solely in 70m1 artificial sativa solution. The amount of metal elements released was observed during 21 weeks in the interval of each seven week. The electrochemical method was performed using computer-controlled potentiosta(Autostat 251. Sycopel Sicentific Ltd., U.K). The wax patterns(diameter 11.0mm, thickness,in 1.5mm) of four dental casting alloys were casted by centrifugal method and embedded in self-curing acrylic resin to be about $1.0cm^2$ of exposed surface area. Embedded specimens were polished with silicone carbide paper to #2,000, and ultrasonically cleaned. The working electrode is the specimen of four dental casting alloys, the reference electrode is a saturated calmel electrode(SCE) and the ounter electrode is made of platinum plate. In the artificial saliva solution, the potential scanning was carried out starting from-700mV(SCE) TO +1,000mV(SCE) and the scan rate was 75mV/min. Each polarization curve of alloy was recorded automatically on a logrithmic graphic paper by XY recorder. From the polarization curves of each galvanic couple, corrosion potential and corrosion rates, that is, corrosion density were compared and order of corrosion tendency was determined. From the experiments, the following results were obtained : 1. In the case of immersing titanium, gold alloy, silver-palladium alloy, and nickel-chromium alloysolely in the artificial saliva solution(group 1, 2, 3, and 4), the total amount of metal elements released was that group 4 was greater about 2, 3 times than group 3, and about 7.8 times than group 2. In the case of group 1, the amount of titanium released was not found after 8 week(p<0.001). 2. In the case of galvanic couples of titanium in contact with alloy(group 5, 6), the total amount of metal elements released of group 5 and 6 was less than that of group 7, 8, 9, and 10(p<0.05). 3. In the case of galvanic couples of titanium in contact with silver-palladium alloy(group 7, 8), the total amount of metal elements released of group 7 was greater about twice than that of group 5, and that of group 8 was about 14 times than that of group 6(p<0.05). 4. In the case of galvanic couples of titanium in contact with nickel-chromium alloy(group 9, 10), the total amount of metal elements released of group 9 and 10 was greater about 1.8-3.2 times than that of group 7 and 8, and was greater about 4.3~25 times than that of group 5 and 6(p<0.05). 5. In the effect of galvanic corrosion according to the difference of the area ratio of cathode and anode, the total amount of metal elements released was that group 5 was greater about 4 times than group 6, group 8 was greater about twice than group 7, and group 10 was greater about 1.5 times than group 9(p<0.05). 6. In the effect of galvanic corrosion according to the elasped time during 21 week in the interval of each 7 week, the amount of metal elements released was decreased markedly in the case of galvanic couples of the titanium in contact with gold alloy and silver-palladium alloy but the total amount of nickel and beryllium released was not decreased markedly in the case of galvanic couples of the titanium in contact with nickel-chromium alloy(p<0.05). 7. In the case of galvanic couples of titanium in contact with gold alloy, galvanic current was lower than any other galvanic couple. 8. In the case of galvanic couples of titanium in contact with nickel-chromium alloy, galvanic current was highest among other galvanic couples.

• 한국학교수학회논문집
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• 제18권1호
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• pp.123-148
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• 2015

정부의 사교육 경감 대책 및 수학교육 선진화 방안이 발표되고, 교육부에서는 '농산어촌 ICT 지원 사업'으로 농산어촌의 교육정보화 격차를 줄이는 사업을 진행하고 있다. 또한 한국교육방송(EBS)에서는 EBSmath 라는 수학 자기 주도 학습 사이트를 개설하고, 다양한 맞춤형 서비스를 제공하고 있다. '농산어촌 ICT 지원 사업'에서 지원된 스마트기기를 활용하여 EBSmath 사이트를 활용한 학습이 여러 가지의 교육정보화가 열악한 농촌학생들에게 스스로의 힘으로 지식을 습득하고 체계적으로 정리하여 새로운 지식을 산출하는 능력, 즉 수학 자기주도 학습에 어떠한 영향을 미치는지에 대하여 본고에서 연구하였다.

• 한국포장학회지
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• 제29권1호
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• pp.1-7
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• 2023

본 연구에서는 PEBAX/PEG-CA 복합필름을 제조하여 내부에 아염소산나트륨 분말을 포함한 스마트 샤쉐를 제작하였다. 또한, TGA, DSC, FT-IR, UV-vis를 통해 샤쉐의 화학적 구조 및 열적 특성과 더불어 샤쉐 적용성 평가를 위해 이산화염소 가스 방출량을 측정하였다. PEBAX/PEG-CA 복합필름은 친수성 및 혼화성을 바탕으로 매트릭스 내에서 강한 화학적 상호작용을 하는 것을 확인하였다. 특히, 구연산의 함량이 높아질수록 복합필름의 열 안정성이 저하되었지만, 저온 및 상온의 유통환경과 필름 제작 온도 범위(<℃)에서 열분해가 발생하지 않았으므로 샤쉐의 제작 및 적용이 가능할 것으로 사료된다. 본 연구의 핵심인 이산화염소 가스 방출량 측정에서는 스마트 샤쉐가 측정 기간인 14일 동안 내부 아염소산나트륨의 이산화염소 가스 방출을 지속적으로 활성화했으며, 산층의 구연산 함량이 높아짐에 따라 방출량이 증가하는 것을 확인하였다. 따라서, 스마트 샤쉐 내부의 아염소산나트륨 함량 및 산층의 구연산 함량 조절 또는 포장크기의 변경 등을 통해 이산화염소 방출량을 효과적으로 조절할 수 있으며, 이는 별도의 설비 및 고가의 장비 없이도 살균 효과를 연장시키는 이점이 있다. 위 실험 결과에 따라 제품 특성 및 포장 용적에 따라 스마트 샤쉐의 응용 적용이 가능할 것으로 판단된다. 하지만, 확실한 소비자 안정성 확보와 스마트 샤쉐의 적용 확장성을 확인하기 위해 항균성 및 저장성 측면에서 향후 연구가 필요하다.

• 한국건설순환자원학회논문집
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• 제8권1호
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• pp.88-96
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• 2020

이 연구에서는 고흡수율 폴리머(SAPs)를 포함하는 시멘트계 재료의 자기치유에 대한 습윤/건조 반복 작용의 영향을 실험적으로 평가하였다. 매 주기마다 SAP 함량을 변수로 하는 시멘트 페이스트 시편을 균열 이후 1시간 동안 습윤 조건에 노출시키고(흡수율시험 및 투수시험 진행), 47시간 동안 건조 조건에 노출시켰다. 흡수율시험 결과 SAP 미혼입 시편, SAP 0.5%, SAP 1.0%, SAP 1.5% 혼입 시편의 균열을 통한 흡수율이 각각 1주기 대비 8주기 이후 22.9%, 36.8%, 42.8%, 46.3% 감소한 것으로 나타났다. 또한, 투수시험 결과 모든 시편의 균열을 통한 물 유출량은 습윤/건조 주기에 따라 점차 감소하였으며, 특히 SAP 함량이 증가할수록 유량 감소율은 증가하였다. 또한, X-ray CT 분석을 통해 균열 내 SAPs의 유입수에 의한 팽윤 거동이 확인되었다. 실험 결과는 SAPs가 유입수를 흡수하여 팽윤함에 따라 유효 균열폭이 감소될 수 있고, SAPs는 흡수한 물을 건조 조건에서 주변 균열부에 공급함에 따라 치유 생성물의 형성을 촉진시킬 수 있음을 나타낸다. 이 연구의 결과는 SAPs의 혼입이 균열의 수밀성을 증가시킴에 따라 시멘트계 재료의 자기치유 성능을 향상시킬 수 있음을 나타낸다.

• Natural Product Sciences
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• 제19권1호
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• pp.36-48
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• 2013

The aim of the present study was to investigate the effects of several fractions obtained from methylene chloride ($CH_2Cl_2$) extract of self-fermented pine needle (SFPNE) on the acetylcholine (ACh)-evoked CA release from the isolated perfused model of the rat adrenal medulla and to establish the mechanism of the most active fraction (Fr.)-induced inhibitory action on the CA release. We obtained 6 fractions from $CH_2Cl_2$ extract of self-fermented pine needle. For the ACh (5.32 mM)-evoked CA release, the following rank order of inhibitory potency was obtained: Fr.4-5 > Fr.8-11 ${\gg}$ Fr.3 > Fr.6 = Fr.7 > Fr.1-2. Fr. 4 - 5 (60 ${\mu}g/mL$) perfused into an adrenal vein for 90 min produced relatively time-dependent inhibition of the CA secretory responses to ACh (5.32 mM), DMPP (100 ${\mu}M$), McN-A-343 (100 ${\mu}M$) and high $K^+$ (56 mM). Fr. 4 - 5 itself did not affect basal CA secretion. Also, in the presence of Fr. 4 - 5 (60 ${\mu}g/mL$), the CA secretory responses to angiotensin II (AngII, 0.1 ${\mu}M$), veratridine (50 ${\mu}M$), Bay-K-8644 (10 ${\mu}M$), and cyclopiazonic acid (10 ${\mu}M$) were significantly reduced, respectively. In the simultaneous presence of Fr. 4 - 5 (60 ${\mu}g/mL$) and L-NAME (30 ${\mu}M$), the inhibitory responses of Fr. 4 - 5 on the CA secretion evoked by ACh, DMPP, high $K^+$, AngII, Bay-K-8644 and veratridine were considerably recovered to the extent of the corresponding control secretion compared with that of Fr. 4 - 5-treatment alone. The level of NO released from adrenal medulla after the treatment of Fr. 4 - 5 (60 ${\mu}g/mL$) was greatly elevated compared with the basal level. Taken together, these results demonstrate that Fr. 4 - 5 inhibits the CA secretion from the isolated perfused rat adrenal medulla evoked by stimulation of cholinergic receptors as well as by direct membrane-depolarization. It seems that this inhibitory effect of Fr. 4 - 5 is mediated by blocking the influx of $Ca^{2+}$ and $Na^+$ into the adrenomedullary chromaffin cells as well as by inhibition of $Ca^{2+}$ release from the cytoplasmic calcium store, which is evoked at least partly through the increased NO production due to the activation of NO synthase. Based on these results, it is also thought that Fr. 4 - 5 isolated from $CH_2Cl_2$ extract of pine needle may contain beneficial antihypertensive components to prevent or treat hypertension.