• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.201-202
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• 2000

순환여과식 양식은 어류를 효과적으로 대량 생산할 수 있는 반면 어류의 배설물과 미섭취 사료 등에 의해서 암모니아, 아질산 및 유기질 고형 성분 등이 발생하여 사육중인 어류에 나쁜 영향을 야기하게 된다. 배설물과 미섭취 사료는 대부분 유기성 고형물로 어류의 아가미에 끼여 질병을 유발시키며 미생물에 의해 분해되면서 어류에 유해한 암모니아나 아질산으로 전환되어 어류에 유해하다. 그러므로 미생물에 의해 분해되기 전에 신속하고 효과적으로 제거하여야 한다. (중략)

• Clean Technology
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• v.21 no.2
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• pp.108-116
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• 2015

Hydrogen sulfide and ammonia are one of the common malodorous compounds that can be found in emissions from many sewages treatment plants and industrial plants. Therefore, removing these harmful gases from emissions is of significance in both life and industry because they can cause health problems to human and detrimental effects on the catalysts. In this work, pyrolytic carbon blacks from waste tires were used to develop adsorbent with good adsorption capacity for removal of hydrogen and ammonia. Pellet-type adsorbents were prepared by a mixture of carbon black, metal oxide and sodium hydroxide or hydrochloric acid, and their adsorption capacities were estimated by using breakthrough curve of a continuous fixed bed adsorption column at ambient condition. The adsorbent manufactured with a mixture of carbon black, iron oxide(III) and sodium hydroxide showed the maximum working capacity of hydrogen sulfide. For ammonia, maximum working capacity was obtained by the adsorbent manufactured with a mixture of carbon black, copper oxide(II) and hydrochloric acid.

• Journal of Navigation and Port Research
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• v.30 no.8 s.114
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• pp.721-727
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• 2006

Ammoniac nitrogen excretion is not able to be removed in ocean fish farm. It is the reason for fish being dead in large quantities or declining feeding activity that ammoniac nitrogen is not removed efficiently in ocean fish farm. Because of declining with feeding activity, it is true that feed is wasted for the present. To solve this problem, NH3, one of environment factors in ocean fish farm, monitoring system is suggested to be formed in this paper.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.2 no.2
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• pp.69-77
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• 1997

A 12-cm long sediment core was collected from a station in Lake Shihwa where high salinity-anoxic deep water is isolated from low salinity-oxic surface water by a strong halocline barrier. Unprecedented concentrations of porewater ammonia and lead are encountered: at 9 cm sediment depth ammonia builds up to 1420 ${\mu}M$ and at 3 cm lead to 1348 nM. As they are stable in anoxic condition, high concentrations of ammonia and lead suggest a development of notorious anoxic condition in the benthic environment of the lake. The degree of pollution of the deep water is likely to be directly proportional to the magnitude of benthic flux, because the deep water is isolated from the surface water by the halocline. Apparent coincidence of the ammonia residence time in the deep water with the elapsing time after the completion of the artificial lake construction, as about three years, suggests that the deep water pollution is being progressed entirely by benthic flux at least with respect to ammonia. The residence time for lead is such a short 20 days that it suggests a rapid return of the bottom water lead, which is originated from porewater by benthic flux, back to sediments probably as metal sulfide phases. The speculation on the return of lead as sulfide phases is likely to be supported by high concentration of hydrogen sulfide in the deep water and by high sinking rate of non-organic particles in Lake Shihwa.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.646-646
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• 2013

그래핀은 이차원의 탄소 원자들이 벌집구조를 이루는 탄소 원자 한 층의 물질이다. 우수한 기계적, 전기적, 광학적 특성으로 인해 투명전극, 가스 센서, 트랜지스터 등과 같이 다양한 응용이 가능하고 연구가 행해지고 있다. 최근 몇 년 동안, 그래핀의 우수한 특성을 이용해서 마이크로센서나 신축성 있는 전자소자를 위한 전도막과 같은 응용이 시도되고 있다. 본 연구에서는 화학기상증착법 (CVD)으로 합성한 그래핀을 이용해서 암모니아 가스 센서 소자를 제작, 센서 특성을 관찰하였다. 구리 기판을 이용하여 화학기상증착법으로 그래핀을 합성하였으며 진공로에서 수소(H2)와 메탄(CH4) 가스를 사용하였다. 그래핀 합성 온도, 가스 유량 등을 변화시키며 그래핀을 합성하고, 합성된 그래핀을 구리기판을 식각용액을 이용해 제거하는 방법으로 그래핀을 전사시키는 공정거쳐 Au/Ni 전극패턴 위에 전사시킴으로 가스 센서 소자를 제작하였다. 제작된 센서 소자를 이용해 상온에서 암모니아(NH3) 가스의 유량을 변화시키며 실험하였다. 암모니아 가스가 흐를 때 그래핀에 암모니아 분자가 흡착되어 그래핀의 전기저항을 증가시켜 이를 이용해서 암모니아 가스를 감지할 수 있었다. 본 연구에서 제작한 소자는 상온에서 암모니아 가스에 민감하게 반응했으며 이는 기존의 금속산화물을 이용한 암모니아 센서는 대부분 고온에서 작동하는 점과 비교 하였을 때 가스 센서 소자로써 큰 장점이라고 할 수 있다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.6
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• pp.483-491
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• 2014

In this study, a thermodynamic analysis was carried out for a combined power generation system using a low-temperature heat source in the form of sensitive energy and liquefied natural gas cold energy. An ammonia-water mixture, which is a zeotropic mixture, was used as the working fluid, and systems with and without a regenerator were comparatively analyzed. The effects of the mass fraction of ammonia and the condensation temperature of the working fluid on the system variables, including the net work production, exergy destruction, and thermal and exergy efficiencies, are analyzed and discussed. The results show that the performance characteristics of the system varied sensitively with the ammonia concentration or condensation temperature of the working fluid. The system without regeneration was found to be better in relation to the net work per unit mass of the source fluid, whereas the system with regeneration was better in relation to the thermal or exergy efficiency.

• Journal of the Korean Chemical Society
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• v.65 no.4
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• pp.260-267
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• 2021

Increasing the needs for eco-friendly natural materials, much attention on natural dyes has been attracted. Curcumin, one of abundant natural dyes available in nature, is an eco-friendly molecule found in turmeric. In this study, the colorimetric sensing behavior characteristics of ammonia and hydrogen chloride gases was analyzed using curcumin ink-printed paper and cotton fabric by inkjet printing method. The fabricated paper and fabric were utilized as a colorimetric sensor that can track food spoilage. The color changes of the samples printed on the paper and cotton upon exposure to the toxic gases, the reversibility of the color changes, and the water resistance were investigated. Both samples showed reversible reactions with NH3 and HCl, and small amount of ammonia produced by food spoilage was successfully sensed with naked eyes, confirming its capability to warn food spoilage in our daily life.

• Journal of the Korean Chemical Society
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• v.41 no.5
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• pp.234-238
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• 1997

The photochemical reaction of ammonia in deoxygenated aqueous methanol has been investigated at 25$^{\circ}C$ using 184.9 nm UV light. Amination was carried out by irradiating the solution of reaction mixture, and the formation of methoxyamine, hexamine, 1,1-dimethylhydrazine, dimethylamine, formamide, and a small amount of ethylenediamine was observed. In addition to these, carbonyl compounds such as formaldehyde, ethyleneglycol, glyoxal, and hydrazine were also produced. The initial quantum yields of the products were determined and probable mechanisms for the photochemical reaction were presented on the basis of product analysis.

• Ceramist
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• v.16 no.4
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• pp.67-75
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• 2013

• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.325-327
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• 2003

원자력 발전소 2차계통수에는 pH를 조절하여 부식을 억제하기 위해 pH제어제로 암모니아를 사용하였으나 상변화 지역에서 액상의 pH가 낮아 부식생성물이 생성, 증기발생기로 유입되어 진열관의 부식을 촉진 시킨다. pH 제어제로 암모니아 대신 ETA를 도입하여 pH를 증가시키고 증기발생기로 유입되는 부식생성물의 양을 감소하여 진열관의 부식을 억제시키고 있다. 그러나 암모니아에서 ETA로 변경함에 따라 증기 발생기취출수계통의 탈염의 운진기간이 단축되었다. 따라서 본 연구의 목적은 탈염기의 수지 교체주기도 연장시키고 안전성도 확보할 수 있는 탈염기내 양ㆍ음이온 이온교환수지 조성 비율을 최적화하는데 있다. 연속화학평형모델을 이용한 결과 양ㆍ음이온 이온교환수지 비율이 10:1일 경우 최적인 것으로 조사되었다.