• 한국진공학회지
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• 제9권3호
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• pp.197-206
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• 2000

(hfc)Cu(1,5-COD)(1,1,1,5,5,5-hexafluoro-2,4-pentadionato Cu(I) 1,5-cyclooctadine) 증착원을 이용하여 MOCVD(Metal Organic Chemical Vapor Deposition) Cu박막을 형성하였고, 운반기체가 MOCVD Cu 증착 특성에 미치는 영향에 관하여 조사하였다. 증착된 Cu 박막은 $H_2$ 운반 기체를 사용한 경우 Ar을 운반기체로 사용한 경우에 비하여 증착률의 증가와 더불어 낮은 비저항을 갖는 박막을 얻을 수 있었다. 또한 표면 거칠기의 개선과 강한 (111) 우선 배향성을 나타내는 박막을 얻을 수 있었으나 접착성의 경우에 있어서는 H$_2$운반 기체를 사용한 경우 감소하는 결과를 나타내었다. 이러한 접착성 감소의 원인은 AES분석에서 확인된 바와 같이 박막내부에 존재하는 F의 영향인 것으로 사료된다. H(hfac) ligand의 첨가 효과에 대하여 조사한 결과에서는 Ar 운반 기체를 사용한 경우 H(hfac)첨가시 증착률의 향상이 이루어졌으나 $H_2$운반 기체의 경우 큰 변화를 나타내지 않았고, 비저항의 경우에는 운반 기체와 관계없이 감소하는 결과를 보여 H(hfac) 사용이 증착 특성 개선에 효과적으로 나타났다. 따라서 본 연구에서는 운반기체 변화 및 H(hfac) ligand의 첨가 실험을 통해 MOCVD Cu의 증착기구를 조사하였으며, 이러한 공정조건의 변화가 Cu 박막의 표면거칠기 개선과 동시에 비저항을 낮추는 역할을 하는 것으로 나타났다.

• Journal of Welding and Joining
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• 제5권2호
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• pp.17-26
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• 1987

In this study, the experiments were carried out for the purpose of establishment of the arc sparing method which reducing oxides or oxide film by using the inert gas as the carrier gas of atomizing particles. Main results obtained are as follows; 1. Oxides and oxide film which lower the adhesion strength are largely reduced by using the inert gas as the carrier gas of atomizing particles, and adhesion strength of coating film are improved. 2. The coating film characteristics appear to be no difference between the inert gas arc spraying in air environment and that in argon gas environment. 3. Inert gas arc spraying using argon as the carrie gas has higher reduction rate of composition element in coating film than compressed air spraying does.

• 한국분말재료학회지
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• 제20권1호
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• pp.24-32
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• 2013

The effect of carrier gases (He, $N_2$) on the properties of Ti coating layers were investigated to manufacture high-density Ti coating layers. Cold spray coating layers manufactured using He gas had denser and more homogenous structures than those using $N_2$ gas. The He gas coating layers showed porosity value of 0.02% and hardness value of Hv 229.1, indicating more excellent properties than the porosity and hardness of $N_2$ gas coating layers. Bond strengths were examined, and coating layers manufactured using He recorded a value of 74.3 MPa; those manufactured using $N_2$ gas had a value of 64.6 MPa. The aforementioned results were associated with the fact that, when coating layers were manufactured using He gas, the powder could be easily deposited because of its high particle impact velocity. When Ti coating layers were manufactured by the cold spray process, He carrier gas was more suitable than $N_2$ gas for manufacturing excellent coating layers.

• 대한화학회지
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• 제30권3호
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• pp.327-332
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• 1986

유도결합 플라스마 공간내의 전자밀도를 측정하였다. 전자밀도의 측정시 유도결합 플라스마의 작동조건은, (1) 냉각기체만 사용할 때, (2) 냉각기체와 운반기체만을 사용할 때, (3) 보통의 작동조건은, 즉 에아로졸을 포함한 운반기체를 사용할 때, (4) 약 88%의 에아로졸을 제거시켰을 때, 그리고 (5) 과량의 리튬을 주입시켰을 때로서 분류하였다. 보통의 작동조건에서 플라스마의 낮은 부분에서는 전자밀도가 상당히 감소하여 플라스마내의 가장 전자밀도가 큰 곳보다 약 80배 감소하였다. 이온화 방해영향을 일으키는 알칼리금속을 과량으로 넣었을 때 전자밀도의 변화는 관찰되지 않았고 유도코일의 power를 증가시키면 전자밀도도 증가하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.89-90
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• 2007

This paper presents the mechanical properties of 3C-SiC thin film according to 0, 7, and 10% carrier gas $(H_2)$ concentrations using Nano Indentation. When carrier gas $(H_2)$ concentration was 10%, it has been proved that the mechanical properties, elastic modulus and hardness, of 3C-SiC are the best of them. In the case of 10% carrier gas concentration, Young's modulus and Hardness were obtained as 367 GPa and 36 GPa, respectively. When the surface roughness according to $H_2$ concentrations was investigated by AFM (atomic force microscope), when $H_2$ concentration was 10%, the roughness of 3C-SiC thin was 9.92 nm, which is also the best of them. Therefore, in order to apply poly 3C-SiC thin film to MEMS applications, $H_2$ concentration's rate should increase to obtain better mechanical properties and surface roughness.

• 대한조선학회 특별논문집
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• 대한조선학회 2007년도 특별논문집
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• pp.89-93
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• 2007

The Boil-off gas (BOG) generation during the voyage is inevitable since Natural Gas (NG) in normally liquefied below -160 degree C in atmosphere condition and small heat ingress due to relatively hot outside keeps evaporating continuously. The one of major issue in LNG carriers is to handle generated BOG from cargo tank. The generated BOG affects to increase the cargo tank pressure and Gas Management System (GMS) for LNG carriers is closely related to cargo tank pressure maintenance. Economically, BOG is generally used as fuel in LNG carrier. Newly developed GMS for LNG carrier in boiler propulsion system, VaCo System, not only accomplish automatic control in GMS but also ensure safer operation.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.154-157
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• 2011

Hydrogenated silicon nitride deposited by LF-PECVD is commonly used for anti-reflection coating and passivation in silicon solar cell fabrication. The deposition of the optimized silicon nitride on the surface is elemental in crystalline silicon solar cell. In this work, the carrier lifetimes were measured while the thicknesses of $SiN_x$ were changed from 700 ${\AA}$ to 1150 ${\AA}$ with the gas flow of $SiH_4$ as 40 sccm and $NH_3$ as 120 sccm,. The carrier lifetime enhanced as the thickness of $SiN_x$ increased due to improved passivation effect. To study the characteristics of $SiN_x$ with various gas ratios, the gas flow of $NH_3$ was changed from 40 sccm to 200 sccm with intervals of 40 sccm. The thickness of $SiN_x$ was fixed as 1000 ${\AA}$ and the gas flow of $SiH_4$ as 40 sccm. The refractive index of SiNx and the carrier lifetime were measured before and after heat treating at $650^{\circ}C$ to investigate their change by the firing process in solar cell fabrication. The index of refraction of SiNx decreased as the gas ratios increased and the longest carrier lifetime was measured with the gas ratio $NH_3/SiH_4$ of 3.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1477-1479
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• 2005

In this work, the ITO thin films were prepared by FTS (Facing Targets Sputtering) system under different sputtering conditions which were varying $O_2$ gas flow, input current at room temperature. As a function of sputtering conditions, electrical and optical properties of prepared ITO thin films were measured. The electrical, optical characteristics and surface roughness of prepared ITO thin films were measured. In the results, as increasing $O_2$ gas 0.1[sccm] to 0.7[sccm], resistivity of ITO thin film was increased with a decreasing carrier concentration, $O_2$ gas over 0.3[sccm] the carrier mobility have a similarly value. Transmittance of prepared ITO thin films were improved at increasing $O_2$ gas 0.1[sccm] to 0.7[sccm]. And transmittance of all of the prepared ITO thin films was over 80%. We could obtain resistivity $6.19{\times}10^{-4}[{\omega}{\cdot}cm]$, carrier mobility $22.9[cm^2/V{\cdot}sec]$, carrier concentration $4.41{\times}10^{20}[cm^{-3}]$ and transmittance over 80% of ITO thin film prepared at working pressure 1mTorr, input current 0.4A without any substrate heating.

• 한국수소및신에너지학회논문집
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• 제20권2호
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• pp.151-160
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• 2009

Natural gas combustion characteristics of mass produced oxygen carrier particles were investigated in a batch type bubbling fluidized bed reactor. Five particles, NiO/bentonite, OCN601-650, OCN702-1100, OCN703-950, OCN703-1100 were used as oxygen carrier particles. Natural gas and air were used as reactants for reduction and oxidation, respectively. During reduction reaction, high fuel conversion and high $CO_2$ selectivity were achieved for most of oxygen carriers. During oxidation, NO emission was very low. These results indicate that inherent $CO_2$ separation and low NOx combustion are feasible for the natural gas fueled chemical-looping combustion system. Among the five oxygen carriers, OCN703-1100 particle was selected as the best candidate for demonstration of long-term operation in large-scale chemical-looping combustor from the viewpoints of fuel conversion, $CO_2$ selectivity, $CH_4$ concentration, and CO concentration.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권5호
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• pp.609-616
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• 2018

The cargo handling system, which is composed of a fuel gas supply unit and cargo tank pressure control unit, is the second largest power consumer in a Liquefied Natural Gas (LNG) carrier. Because of recent enhancements in ship efficiency, the surplus boil-off gas that remains after supplying fuel gas for ship propulsion must be reliquefied or burned to regulate the cargo tank pressure. A full or partial liquefaction process can be applied to return the surplus gas to the cargo tank. The purpose of this study is to review the current partial liquefaction process for LNG carriers and develop new processes for reducing power consumption using exergy analysis. The developed partial liquefaction process was also compared with the full liquefaction process applicable to a LNG carrier with a varying boil-off gas composition and varying liquefaction amounts. An exergy analysis showed that the Joule-Thomson valve is the key component needed for improvements to the system, and that the proposed system showed an 8% enhancement relative to the current prevailing system. A comparison of the study results with a partial/full liquefaction process showed that power consumption is strongly affected by the returned liquefied amount.