• 한국세라믹학회지
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• 제28권4호
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• pp.269-278
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• 1991

Fine AlN powder was synthesized by carbothermal reduction and nitridation of alumimun hydroxide prepared from Al-isopropoxide. AlN ceramics with Y2O3 and CaO were prepared by hot-pressing under the pressure of 30 MPa at 180$0^{\circ}C$ for 1 h in N2 atmosphere. Grain boundary behavior and purification mechanism of AlN lattice were examined by heat treatment of AlN ceramics at 185$0^{\circ}C$ for 1-6 h in N2 atmosphere. AlN ceramics without sintering additives showed poor sinterability. However, Y2O3-doped and CaO-doped AlN ceramics were fully densified nearly to theoretical density. As the heat treatment time increased, c-axis lattice parameter increased. This is attributed to the removal of Al2O3 in AlN lattice. This purification effect of AlN attice depended upon the quantity of secondary oxide phase in the inintial stage of heat treatment and the heat treatment time.

• 한국세라믹학회지
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• 제28권1호
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• pp.53-59
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• 1991

The reaction product between Si3N4 and ZrO2 has been studied by heat treatment of Si3N4-Zr(Y)O2 composite in high vacuum(<10-5 torr) and in air at $700^{\circ}C$. ZrN was formed after heat treatment in vacuum and easily oxidized after heat treatment in air. The amount of ZrN is related to the Y2O3 content dissolved in ZrO2. After the heat treatment in air the toughness increased and the spalling due to the oxidation of ZrN in specimen surface was observed. As a result, it is suggested that the formation of ZrN phase in Si3N4-ZrO2 composite enhance the toughness of the composite in an oxidation conditon.

• 원예과학기술지
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• 제30권1호
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• pp.42-49
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• 2012

아산화질소($N_2O$)가 원예 작물의 저장 중 품질에 미치는 영향을 알아보기 위하여 9월 하순에 수확된 '장호원 황도' 복숭아를 대상으로 연구를 수행하였다. $N_2O$ 처리는 70% $N_2O$ + 20% $O_2$ + 10% air, 80% $N_2O$ + 20% $O_2$, 그리고 90% $N_2O$ + 10% $O_2$의 3가지 농도로 48시간 동안 처리하였으며 처리 후 $15^{\circ}C$에서 저장하였다. 경도와 당도의 변화는 air(대조구) 및 $N_2O$ 처리간 뚜렷한 차이가 없었으나, 외관 변화 및 식미에 있어서는 80% $N_2O$를 48시간 동안 처리한 것이 처리하지 않았을 때보다 뚜렷한 품질 유지 효과를 보였다. 90% $N_2O$를 처리하였을 때에는 산소 부족으로 인한 발효로 중량 감소와 식미가 오히려 악화되는 양상을 나타내었다. 복숭아의 주된 부패 원인이 되는 잿빛곰팡이(Botrytis cinerea)를 분리하여 80% $N_2O$를 처리하였을 때 air에 비해 곰팡이 성장이 12일까지 약 80% 억제되었다. 복숭아의 타박상이 생긴 부분의 갈변 방지 억제 효과를 알아보기 위해 80% $N_2O$를 처리하고 타박상을 입혔을 때에, 타박상 부분의 갈변이 air에 비해 억제되었으며, 과실로부터 추출한 polyphenol oxidase(PPO)에 80% $N_2O$를 처리한 결과 PPO의 활성이 80% 이상 억제되었다. 80% $N_2O$ 처리는 복숭아 저장 중 식미를 유지시키고, 부패와 타박상에 의한 연화 및 갈변을 억제하는 것으로 품질을 유지시켜 저장 기간을 연장시킬 수 있었다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.563-566
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• 2002

We investigated to decrease the leakage current of SiNx film by employing $N_2$ plasma treatment. The insulator layers were prepared by two step process; the $N_2$ plasma treatment and then PECVD SiNx deposition with $SiH_4$, $N_2$ gases. To prove the influence of the $N_2$ plasma treatment, the Si substrate was exposed to the plasma, which was generated in Ne gas ambient. Without plasma treatment SiNx film grow at the rate of 7. 03 nm/min, has a refractive index n = 1.77 and hydrogen content of $2.16{\times}10^{22}cm^{-3}$ for $N_2/SiH_4$ gas flow ratio of 20. The obtained films were analyzed in terms of deposition rates, refractive index, hydrogen concentration, and electrical properties. By employing $N_2$ plasma treatment, interface traps such as mobile charges and injected charges were removed, hysteresis of capacitance-voltage (C-V) disappeared. We observed plasma treated sample were decreased the leakage current density reduces by 2 orders with respect to the sample having no plasma treatment.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.360-363
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• 2003

In this paper, we investigated SiNx film as a buffer layer of TFT-FRAM. Buffer layers were prepared by two step process of a $N_2$ plasma treatment and subsequent $SiN_x$ deposition. By employing $N_2$ plasma treatment, interface traps such as mobile charges and injected charges were removed, hysteresis of current-voltage curve disappeared. After $N_2$ plasma treatment, a leakage current was decreased about 2 orders. From these results, it is possible to perform the plasma treating process to make a good quality buffer layer of MFIS-FET or capacitor as an application of non-volatile memory.

• 한국환경과학회지
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• 제27권2호
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• pp.99-107
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• 2018

In order to design the improvement process for T-N removal, the treatment process of Suyoung, Gangbyeon, and Noxan sewage treatment plants (STP) in Busan was anlayzed. Suyoung STP shows a T-N removal efficiency of about 69.8% with MLE(Modified Ludzack ettinger) and A2O+MBR. However, it is necessary to improve the process to maintain over DO of 1 mg/L and is required to install a flow control tank to minimize the rainfall effect. Gangbyun STP shows a about 70.2% T-N removal efficiency with A2O+GFF(gravity fiber filtration). However, in order to improve T-N removal efficiency, it is needed to install MLE process to treat recycle water. Noksan STP shows a T-N removal efficiency of about 71.0% with MLE+Chemical treatment and shows stable T-N concentration in effluent. However, it is required a toxic chemical management process because bad wastewater flows into the STP, also is necessary a process improvement in order to increase internal recycling ratio. Especially, it is required a process improvement to increase HRT of nitrification tank because Suyoung and Gangbyeon STPs shows low nitrification efficiency during winter season.

• 생물환경조절학회지
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• 제5권2호
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• pp.120-130
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• 1996

본 실험은 NFT재배에서 배양액내 NO$_3$-N과 NH$_4$-N의 비율과 $CO_2$ 시용이 결구상추의 생육, 수량 및 품질에 미치는 영향을 구명하고자 실시하였는데, 그 결과는 다음과 같다. 1. 배양액의 pH와 EC를 보정하지 않았을 경우, NO$_3$-N:NH$_4$-N이 100:0인 구에서의 pH는 점차적으로 증가하였고, NH$_4$-N의 비율이 높을수록 급격히 저하하여 pH4.0까지 낮아졌다. 2. 배양액을 보정하지 않은 상태에서 NO$_3$-N 및 NH$_4$-N의 일 변화를 측정하여 본 결과, NO$_3$-N의 흡수율은 NO$_3$-N:NH$_4$-N이 75:25, 50:50 처리구에서 각각 27.7%, 26.1% 였으나 NH$_4$-N의 흡수율은 87.9%, 71.2%로 결구상추는 NH$_4$-N을 우선적으로 흡수하였다. 3. 엽내 무기성분 함량에서 T-N는 NO$_3$-N과 NH$_4$-N 비율에 따른 큰 차이를 보이지 않았으나, P$_2$O$_{5}$, $K_2$O, CaO, MgO는 생육이 가장 좋았던 $CO_2$ 1500ppm 시용과 NO$_3$-N:NH$_4$-N이 100:0에서 높게 나타났다. 4. $CO_2$ 시용에 의한 각 처리별 $CO_2$ 동화율도 수량과 같은 경향을 나타내어 $CO_2$ 1500ppm 시용과 NO$_3$-N:NH$_4$-N이 100:0 처리에서 가장 높았고, 배양액의 NH$_4$-N비율이 높아질수록 현저히 떨어졌다. 5. 결구상추의 생육은 $CO_2$ 1500ppm 시용과 NO$_3$-N:NH$_4$-N이 100:0 처리에서 가장 좋았고, $CO_2$ 무처리구에 비하여 $CO_2$ 1500ppm 처리구에서 대체로 양호하였으나, NO$_3$-N:NH$_4$-N이 75:25, 50:50인 처리에서는 $CO_2$ 시용에 의한 수량의 증가가 경미하여 처리간 차이가 인정되지 않았다. 6. 엽중 nitrate함량은 배양액의 NO$_3$-N함량과 비례하여 NO$_3$-N:NH$_4$-N 이 100:0에서 가장 높았고, vitamin C 함량은 NO$_3$-N:NH$_4$-N이 100:0인 처리에서 가장 낮고, NH$_4$-N의 비율이 많을수록 높아졌다. $CO_2$ 시용에 의하여 엽중 질산염함량은 경감할 수는 있었으나 그 효과는 경미하였다.다.

• Korean Chemical Engineering Research
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• 제53권3호
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• pp.397-400
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• 2015

N-[3-(Trimethoxysilyl)propyl]ethylenediamine (2NS)와 $N^1$-(3-trimethoxysilylpropyl)diethylenetriamine (3NS), 3-cyanopropyltriethoxysilane(1NCy)를 실리카 표면에 grafting한 후 미반응된 화합물을 제거하기 위한 세척방법과 표면처리 온도가 촉매특성에 미치는 영향을 조사하였다. Filtering법을 이용하여 합성된 담지 촉매의 Zr 담지량이 washing법 보다 높게 측정되었으나 중합 활성은 washing법으로 합성된 담지 촉매가 filtering법으로 합성된 담지 촉매보다 높았다. 표면처리 방법과 관계없이 $SiO_2/2NS/(n-BuCp)_2ZrCl_2>SiO_2/1NCy/(n-BuCp)_2ZrCl_2>SiO_2/3NS/(n-BuCp)_2ZrCl_2$ 순의 중합활성을 보였다. 아미노실란의 실리카 표면처리 온도가 증가하면 에틸렌 중합활성도 증가하였다.

• 한국토양비료학회지
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• 제48권6호
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• pp.610-617
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• 2015

The impact of 1 pound of nitrous oxide ($N_2O$) on warming the atmosphere is almost 310 times that of 1 pound of carbon dioxide. Agricultural soil management is the largest source of $N_2O$ emissions, accounting for about 73% of total $N_2O$ emissions. This study was conducted to evaluate the nitrous oxide emission in the cultivation of soybean during the first year of No-tillage (NT) and Conventional-tillage (CT) practices, under the various conditions such as different kinds of fertilizers, soil temperature, and moisture level. In the experiment, we set CT and NT treatments into 4 different groups - control treatments (no fertilization), green manure treatments, chemical fertilizer treatments and organic manure treatments. In the case of chemical fertilizer treatments, $N_2O$ emission of NT treatment was 7.78 to 22.59% lower than CT treatment. In organic manure treatment, $N_2O$ emission of NT treatment was 6.62% higher than CT treatment in August. But In July and September, $N_2O$ emission of NT treatment was 9.50% 28.38% lower than CT treatment, respectively. Soil temperature was correlated with $N_2O$ emission positively. In the future, continued long-term research on influence of various environmental factors on the generation of $N_2O$ and the economic value of no-till farming is required.

• 대한금속재료학회지
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• 제47권11호
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• pp.716-721
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• 2009

The major drive for the application of low-temperature plasma treatment in nitrocarburizing of austenitic stainless steels lies in improved surface hardness without degraded corrosion resistance. The low-temperature plasma nitrocarburizing was performed in a gas mixture of $N_{2}$, $H_{2}$, and carbon-containing gas such as $CH_{4}$ at $450^{\circ}C$. The influence of the processing time (5~30 h) and $N_{2}$ gas composition (15~35%) on the surface properties of the nitrocarburized layer was investigated. The resultant nitrocarburized layer was a dual-layer structure, which was comprised of a N-enriched layer (${\gamma}_N$) with a high nitrogen content on top of a C-enriched layer (${\gamma}_C$) with a high carbon content, leading to a significant increase in surface hardness. The surface hardness reached up to about $1050HV_{0.01}$, which is about 4 times higher than that of the untreated sample ($250HV_{0.01}$). The thickness of the hardened layer increased with increasing treatment time and $N_{2}$ gas level in the atmosphere and reached up to about $25{\mu}m$. In addition, the corrosion resistance of the treated samples without containing $Cr_{2}N$ precipitates was enhanced than that of the untreated samples due to a high concentration of N on the surface. However, longer treatment time (25% $N_{2}$, 30 h) and higher $N_{2}$ gas composition (35% $N_{2}$, 20 h) resulted in the formation of $Cr_{2}N$ precipitates in the N-enriched layer, which caused the degradation of corrosion resistance.