• Journal of Animal Science and Technology
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• 제66권2호
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• pp.237-250
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• 2024

The emission of noxious gases is a significant problem in pig production, as it can lead to poor production, welfare concerns, and environmental pollution. The noxious gases are the gasses emitted from the pig manure that contribute to air pollution. The increased concentration of various harmful gasses can pose health risks to both animals and humans. The major gases produced in the pig farm include methane, hydrogen sulfide, carbon dioxide, ammonia, sulfur dioxide and volatile fatty acids, which are mainly derived from the fermentation of undigested or poorly digested nutrients. Nowadays research has focused on more holistic approaches to obtain a healthy farm environment that helps animal production. The use of probiotics, prebiotics, dietary enzymes, and medicinal plants in animal diets has been explored as a means of reducing harmful gas emissions. This review paper focuses on the harmful gas emissions from pig farm, the mechanisms of gas production, and strategies for reducing these emissions. Additionally, various methods for reducing gas in pigs, including probiotic interventions; prebiotic interventions, dietary enzymes supplementation, and use of medicinal plants and organic acids are discussed. Overall, this paper provides a comprehensive review of the current state of knowledge on reducing noxious gas in pigs and offers valuable insights for pig producers, nutritionists, and researchers working in this area.

• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.213-218
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• 2013

To respond to global warming and climate change, Korean Government has implemented the GHG Target Management, which leads to a voluntary reduction in greenhouse gases from large businesses. Korean universities have put efforts on reducing GHG emissions and energy consumptions in the campuses, however, because of various activities and its characteristic of non-profit organization, establishing a long-term plan for reducing greenhouse gases is necessary. In this research, the Seoul National University's energy usage is analyzed and applicable technologies for reducing GHG emissions are extracted. Hence, three scenarios for performing the GHG Target Management are established. Proposed scenario is available for GHG Target Management and it would be expected to support decision- makings for reducing GHG emissions.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.748-751
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• 2010

로켓을 발사하기 위해서는 발사대에 로켓을 세워놓고 추진제와 고압가스 등을 충전한 다음 원격제어로 로켓을 발사하게 된다. 로켓 발사대로는 지상저장탱크에 고압으로 저장되어 있는 고압가스가 여러 종류의 압력조정기를 통과하여 운용압력으로 감압되어 공급된다. 로켓 발사시에는 발사통제실에서 원격으로 모든 운용이 이루어지기 때문에 압력조정기 전단에는 급격한 가스 공급이나 압력변동 등으로 인하여 운용압력을 벗어나거나 압력조정기가 파손되는 경우가 발생할 수 있다. 본 논문에서는 고압가스가 안정적으로 감압되어 발사대로 공급되기 위한 고압가스감압시스템 최적화 설계기법을 고찰하였다.

• 제어로봇시스템학회논문지
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• 제13권7호
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• pp.616-623
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• 2007

A dual micro gas sensor array was fabricated using nano sized $SnO_2$ thin films which had good sensitivities to CO and combustible gases, or $H_2S$ gas for air quality sensors in automobile. The already existed air quality sensor detects oxidizing gases and reducing gases, the air quality sensor(AQS), located near the fresh air inlet detected the harmful gases, the fresh air inlet door/ventilation flap was closed to reduce the amount of pollution entering the vehicle cabin through HVAC(heating, ventilating, and air conditioning) system. In this study, to make $SnO_2$ thin film AQS sensor, thin tin metal layer between 1000 and $2000{\AA}$ thick was oxidized between 600 and $800^{\circ}C$ by thermal oxidation. The gas sensing layers such as $SnO_2$, $SnO_2$(pt) and $SnO_2$(+CuO) were patterned by metal shadow mask for simple fabrication process on the silicon substrate. The micro gas sensors with $SnO_2$(+Pt) and $SnO_2$(CuO) showed good selectivity to CO gas among reducing gases and good sensitivity to $H_2S$ that is main component of bad odor, separately.

• 한국세라믹학회지
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• 제40권10호
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• pp.973-980
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• 2003

n-type 반도체인 SnO$_2$ 가스센서에서 첨가제가 산화성 가스에 대한 감지특성에 미치는 영향을 살펴보았다 SnO$_2$ 센서는 환원성 가스에 노출될 경우 전자 주게로 작용하여 저항이 감소하지만, 반대로 산화성 가스에 노출될 경우 전자 받게로 작용하여 저항이 증가하는 특성을 보인다 산화성 가스와 SnO$_2$ 분말 사이의 반응생성물을 가스 크로마토그래피 분석을 통하여 환원성 가스인 알콜의 반응 생성물과 비교하였다. PdC1$_2$혹은 A1$_2$O$_3$가 첨가된 센서는 산화성의 $CH_3$CN와 $CH_3$NO$_2$에 대해 동작온도에 따라 독특한 이중반응특성을 보였다. 이들 센서들의 조합과 패턴인식 기법을 이용하면 전자수용기를 가진 가스들에 대한 선택성을 높일 수 있을 것이다.

• 복합신소재구조학회 논문집
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• 제7권1호
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• pp.45-52
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• 2016

There are only 10 projects of the domestic greenhouse gas(GHG) emissions trading scheme in building sector (i.e., 1.5% of 652 registered projects) because the certified methodologies to reduce GHG emissions can not be applied to building sector. This study presents remodeling techniques to reduce GHG emissions in existing buildings. First of all, preconditions and related regulations were reviewed. And then, a pool of factors for GHG reduction are selected and evaluated with respect to factors for reducing energy consumption. This study also investigates the criteria and the decision making process for remodeling techniques to reduce GHG emissions. Finally, the remodeling techniques using the decision making process were grouped based on redundancy of each effect. If reducing methodologies for GHG offset program can be developed using the analyzed remodeling techniques in this study, registered projects in building sector would be increase.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.826-829
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• 2002

$MoO_3$ thin films were deposited on electrode and heater screen-printed alumina substrates in en atmosphere by RF reactive sputtering. The deposition was performed at $300^{\circ}C$ with 350W of a forward power in an $Ar-O_2$ atmosphere. The working pressure was maintained at $3{\times}10^{-2}$mtorr and all deposited films were annealed at $500^{\circ}C$ for 5hours. The surface morphology of films was observed by using a SEM and crystalline phases were analyzed by XRD. The sensing properties were investigated in term of gas concentration under exposure of reducing gases such as $H_2$, $NH_3$ and CO.

• 한국세라믹학회지
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• 제36권5호
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• pp.465-470
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• 1999

Sensing properties of $\alpha$-Fe2O3 thin film to reducing gases such as CHx and CO were systematically examined after deposition on Al2O3 substrate by PECVD(Plasma Enhanced Chemical Vapor Deposition)technique. Microstructure of deposited $\alpha$-Fe2O3 thin film showed the porous island structure. This specimen was annealed at 450, 550, $650^{\circ}C$ to enhance the gas sensing properties and investigated in terms of CO and C4H10 concentration from 500ppm to 3,000 ppm at operating temperature of 35$0^{\circ}C$ The gas sensitivity(%) to C4H10 measured at the operating temperature of 35$0^{\circ}C$ was 98.24 (highest sensitivity) 69.51 to CO and 2% to CH4 respectviely.

• 한국도로학회논문집
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• 제18권1호
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• pp.23-31
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• 2016

PURPOSES : This study aimed to offer a greenhouse gases table to assist a road designer in calculating the greenhouse gases for a road environment when making a decision about an alternative road. METHODS : This study developed an operation mode table of greenhouse gases using the MOVES program. Similar factors for Korean vehicles and fuels are reflected in the MOVES program, which was made in the USA. Finally, a paired t-test was conducted to calculate the site data and MOVES data. Through these studies, a methodology was suggested for calculating carbon emissions based on various types of roads alignments. RESULTS : The site results for a passenger truck on the road were statistically significant when the vehicle speed was above 65 km/h. However, a future study will consider factors for various road alignments and vehicles. CONCLUSIONS : This study will contribute to the theoretical basis for reducing carbon emissions from roads by helping road designers make decisions about road alternatives in terms of the road environment.

• 한국재료학회지
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• 제34권5호
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• pp.235-241
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• 2024

Gas identification techniques using pattern recognition methods were developed from four micro-electronic gas sensors for noxious gas mixture analysis. The target gases for the air quality monitoring inside vehicles were two exhaust gases, carbon monoxide (CO) and nitrogen oxides (NO_x), and two odor gases, ammonia (NH₃) and formaldehyde (HCHO). Four MEMS gas sensors with sensing materials of Pd-SnO₂ for CO, In₂O₃ for NO_X, Ru-WO₃ for NH₃, and hybridized SnO₂-ZnO material for HCHO were fabricated. In six binary mixed gas systems with oxidizing and reducing gases, the gas sensing behaviors and the sensor responses of these methods were examined for the discrimination of gas species. The gas sensitivity data was extracted and their patterns were determined using principal component analysis (PCA) techniques. The PCA plot results showed good separation among the mixed gas systems, suggesting that the gas mixture tests for noxious gases and their mixtures could be well classified and discriminated changes.