• Journal of the Korean Wood Science and Technology
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• 제49권6호
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• pp.667-678
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• 2021

The flame retardancy of plywood should be improved as much as possible while minimizing the impact on the bonding strength of plywood. Six commercial flame retardants and three laboratory synthesized phosphorous nitrogen flame retardants were selected. E₀, E₁ and E₂ grade commercial formaldehyde resins (UF) were applied in this study to evaluate the effect of different flame retardants on the curing time of resin, bonding strength, flame retardant performance, and formaldehyde emission of plywood. The results show that the effect of the addition of different flame retardants on the bonding strength of plywood gradually decreased with the increase of the formaldehyde molar ratio of the resin. The effect of flame retardants on the curing time of UF gradually decreased as the mole ratio of formaldehyde increasing, while the amount of formaldehyde emission varied according to the content of formaldehyde in the flame retardant. Compared with plywood without flame retardant, flame retardant of plywood added with phosphorous nitrogen flame retardant was improved.

• 한국환경과학회지
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• 제27권10호
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• pp.809-820
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• 2018

DeNOx experiments for the effects of hydrocarbon additives on diesel SNCR process were conducted under oxidizing diesel exhaust conditions. A diesel-fueled combustion system was set up to simulate the actual cylinder and head, exhaust pipe and combustion products, where the reducing agent $NH_3$ and $C_2H_6/diesel$ fuel additives were separately or simultaneously injected into the exhaust pipe, used as the SNCR flow reactor. A wide range of air/fuel ratios (A/F=20~40) were maintained, based on engine speeds where an initial NOx level was 530 ppm and the molar ratios (${\beta}=NH_3/NOx$) ranged between 1.0~2.0, together with adjusting the amounts of hydrocarbon additives. Temperature windows were normally formed in the range of 1200~1350K, which were shifted downwards by 50~100K with injecting $C_2H_6/diesel$ fuel additives. About 50~68% NOx reduction was possible with the above molar ratios (${\beta}$) at the optimum flow #1 ($T_{in}=1260K$). Injecting a small amount of $C_2H_6$ or diesel fuel (${\gamma}=hydrocarbon/NOx$) gave the promising results, particularly in the lower exhaust temperatures, by contributing to the sufficient production of active radicals ($OH/O/HO_2/H$) for NOx reduction. Unfortunately, the addition of hydrocarbons increased the concentrations of byproducts such as CO, UHC, $N_2O$ and $NO_2$, and their emission levels are discussed. Among them, Injecting diesel fuel together with the primary reductant seems to be more encouraging for practical reason and could be suggested as an alternative SNCR DeNOx strategy under diesel exhaust systems, following further optimization of chemicals used for lower emission levels of byproducts.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.189.1-189.1
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• 2011

Global warming effect was intensified due to rapid growth of fossil fuel consumption caused by urbanization and industrialization. Various efforts was being done to solve the problems leading to anomaly climate such as flood, downpour, heavy snow. As a results of international efforts for management of global warming, Kyoto Protocol, which was passed in Kyoto, Japan in 1997, designated $CO_2$, $CH_4$, $N_2O$, HFCs, PFCs, $SF_6$ as a global warming gases. And IPCC(Intergovernmental Panel on Climate Change) suggested IPCC guideline for systematic establishment of national greenhouse gas inventory. Among five categories in IPCC guideline, the representative emission source of waste category is SWDS(solid waste disposal site). The concentrative research should progress for effective management of greenhouse gas related with waste. In this study, Tier1 and Tier2 methods which was suggested by 2006 IPCC(Intergovernmental Panel on Climate Change) guideline, was used to predict methane generation from C sanitary landfill located in Chungju area. To predict methane generation from C sanitary landfill, all factors were defaults values that were provided by 2006 IPCC guideline and Korea emission factors for Tier1 and Tier2 method. And economics of generated methane was estimated. From the predicted result using IPCC guideline, the methane generation was persistingly increased over a 9-year period(2000 ~ 2008). Aggregated amount of methane generation was about 3,017ton and 3,170ton predicted by Tier1 and Tier2, respectively. From the results of estimated economic value gained by generated methane from the C sanitary landfill for ten years from now(2010 ~ 2020), the profit was about 2.39 ~ 2.76 hundred million won.

• 한국유기농업학회지
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• 제20권4호
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• pp.503-518
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• 2012

본 연구에 적용된 한국형 무경운(no-tillage)농법은 한국의 기상특성 및 농업현실에 맞도록 초기 두둑을 형성한 후 이를 지속적으로 재활용하는 방식을 적용하였다. 한국형 무경운 농법은 생산량 저하 등 부정적인 영향이 거의 없는 것으로 보고되었으며 경운작업 등 농자재사용은 크게 절감되는 효과로 인하여 에너지 및 농자재 비용의 절감과 노동시간 단축 등 긍정적인 효과가 높은 것으로 보고되었다(Yang et al., 2012). 무경운농법에 의한 고추재배는 일반적인 고추재배 방식과(국가평균) 비교하여 10a ($1,000m^2$)당 $344.7kgCO_2$(58%)의 온실가스저감 효과를 갖는 것으로 분석되었다. 이 중 비료절감에 의한 직-간접효과가 92%, 에너지사용 절감에 의한 효과는 44%로 높은 탄소저감효과를 나타내었다. 또한, 무경운농법의 직접적인 효과에 부가하여 무경운방식의 토양관리는 일반적으로 시간이 흐를수록 토양의 탄소격리 효과가(carbon sequestration effect) 높아지는 특징을 갖고 있기 때문에 연속적인 무경운농법을 수행할 경우 연구대상지의 지속적인 탄소저감 효과가 기대된다. 본 연구의 결과를 바탕으로 한국형 무경운농법은 농업부문 국가온실가스 저감목표 달성을 위한 주요한 녹색농업기술(agro-green technologies)로서 역할을 수행할 것으로 기대되며, 관련기술의 보급 및 확대를 위한 국가적 차원의 노력이 절실히 요구된다.

• 대한환경공학회지
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• 제30권9호
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• pp.961-972
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• 2008

2004년 기준, 온실가스(GHG; Greenhouse Gas) 총 배출량 약 5억9,060만톤(t)$CO_2$로 배출량 세계 10위권인 우리나라는 국제 환경의 변화를 볼 때 향후 반드시 GHG를 감축해야한다. 2004년 국내 에너지 부문 중, 전력 발전 및 산업 부분에서 배출된 이산화탄소(CO$_2$)량은 총 2억9,685만t으로 우리나라 GHG 전체 발생량의 53.3%를 차지하여 이 두 분야에서 CO$_2$ 배출을 감축시키는 것이 가장 시급하고 중요한 문제이다. 또한 이 두 분야는 산업의 특성상 CCS(Carbon Capture and Storage) 기술을 적용하여 효율적으로 CO$_2$를 저감할 수 있는 가장 잠재력이 높은 분야이다. 두 분야에서 효율적으로 적용될 수 있는 CCS 기술로 단기적으로는 amine을 이용한 화합흡수법이, 중, 장기적으로는 ATR(Autothermal reforming), 또는 MSR-H2(Methane steam reformer with hydrogen separation membrane reactor)가 장착된 연소 전 기술과, SOFC+GT(Solid oxide fuel cell-Gas turbine) 같은 순산소 연소 기술이 가장 유리 할 것으로 예상된다. 이와 같은 최신 연소 전 및 순산소 연소 기술을 이용하면 향후 CO$_2$ 포집 비용을 $US 8.5-43.5/tCO$_2$로 줄일 수 있으며 이를 이용하여 전력 발전 및 산업 부분에서 발생하는 CO$_2$의 10%만을 감축하더라도 약 3,000만t의 CO$_2$를 저감할 수 있겠다.

• 한국환경농학회지
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• 제28권1호
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• pp.20-24
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• 2009

퇴비화 과정 중 암모니아 휘산과 관련된 난분해성 및 이분해성 유기물의 역할을 재조명하기 위해 분뇨와 톱밥(난분해성) 또는 쌀겨(이분해성)를 혼합한 후 4주간 $CO_2$ 발생량과 $NH_3$ 휘산량을 조사하였다. 이산화탄소 발생량은 톱밥처리구에 비해 쌀겨처리구에서 43$\sim$122% 정도 높았으며, 이에 상응하게 최종 건물중 손실률도 쌀겨처리구가 35.1$\sim$41.5%로 톱밥처리구의 18.7$\sim$22.6%에 비해 유의하게(P$\sim$0.05) 높았다. 톱밥처리구에서는 시험기간인 4주간 암모니아 휘산이 발생하지 않았는데, 이는 톱밥의 C/N 비가 높아 질소무기화가 지체되었고 톱밥 자체가 $NH_4^+$를 흡착할 수 있는 능력이 있기 때문으로 판단되었다. 반면, 이분해성인 쌀겨 처리구에서는 퇴비화 초기에는 질소부동화에 의해 암모니아 휘산이 나타나지 않았지만, 8일 이후부터는 쌀겨처리량이 낮은 순서대로 이분해성 유기물의 고갈에 의한 질소재무기화에 의해 암모니아 휘산이 관측되었다. 따라서, 이분해성 유기물은 초기 암모니아 부동화를 통해 암모니아 휘산을 감소시킬 수 있지만, 부동화된 질소의 재무기화에 의해 퇴비화 중반기에 오히려 암모니아 휘산이 증가할 수 있는 것으로 나타났다. 반면, 난분해성 유기물인 톱밥은 암모니아 고정능이 있어 물리화학적 흡착에 의해 암모니아 휘산을 저감시킬 수 있는 것으로 판단되었다.

• Asian Journal of Atmospheric Environment
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• 제5권1호
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• pp.41-46
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• 2011

The port of Busan is the fifth busiest container port in the world in terms of total mass of 20-foot equivalent units transported. Yet no attempts have been made to estimate the greenhouse gas (GHG) emissions from the port of Busan by accounting for all port-related activities of the various transportation modes. With these challenges in mind, this study estimates the first activity-based GHG emissions inventory in the port of Busan, which consists of four transportation modes: marine vessels, cargo-handling equipment, heavy-duty trucks, and railroad locomotives. The estimation results based on the most recent and complete port-related activity data are as follows. First, the average annual transportation GHG emission in the port of Busan during the analysis period from 2000 to 2007 was 802 Gg $CO_2$-eq, with a lower value of 773 Gg $CO_2$-eq and an upper value of 813 Gg $CO_2$-eq. Second, the increase in the transportation-related GHG emissions in the port of Busan during the analysis period can be systematically explained by the amount of cargo handled ($R^2$=0.98). Third, about 64% of total GHG emissions in the port of Busan were from marine vessels because more than 40% of all maritime containerized trade flows in the port were transshipment traffic. Fourth, approximately 22% of the total GHG emissions in the port of Busan were from on-road or railroad vehicles, which transport cargo to and from the port of Busan. Finally, the remaining 14% of total GHG emissions were from the cargo handling equipment, such as cranes, yard tractors, and reach stackers.

• 한국식품영양학회지
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• 제31권2호
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• pp.308-312
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• 2018

Even though chlorine dioxide ($ClO_2$) is utilized in a pre-treatment due to its effective sterilizing activity for microorganisms and its safety for food, it has a limitation in maintaining freshness of the food product. In this study, a low-concentration $ClO_2$ gas was produced in a packaging form of air-permeable gel pack so that it could be released continuously over several days. The amount of $ClO_2$ gas emission and microbial inactivation effect against foodborne pathogens were measured during the release of $ClO_2$ gas. As a result of measuring the change of color in order to confirm whether the chlorine dioxide gas was eluted in the form of a sustained release, the yellowness was significantly higher at higher gel pack concentration and higher value during storage periods. The slow-released $ClO_2$ gel-pack showed clear inactivation effect against Escherichia coli and Staphylococcus aureus with 99.9% inactivation efficiency. As a result of measuring the sterilization effect of Listeria monocytogenes by the concentration of chlorine dioxide gas, the sterilization effect was increased as the concentration was increased. Therefore, the slow-released $ClO_2$ gel-pack is feasible to apply for industry usages.

• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.389-393
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• 2013

A rhodamine B-based fluorescent probe for nitrite ion ($NO{_2}^-$) has been designed, synthesized, characterized and its properties for recognition of $NO{_2}^-$ were studied. Nearly non fluorescent probe upon reaction with nitrite ion significantly triggered the fluorescence. Fluorescence response is based on ring opening of the spirolactam of rhodamine B phenyl hydrazide showing maximum absorbance at 552 nm and maximum emission at 584 nm. Probe 3 exhibited high sensitivity and extreme selectivity for nitrite ion over other common ions and oxidants ($Cl^-$, $ClO^-$, $ClO{_2}^-$, $ClO{_3}^-$, $ClO{_4}^-$, $SO{_4}^{2-}$, $SiO{_3}^{2-}$, $NO{_3}^{2-}$, $CO{_3}^{2-}$) examined in methanol water (1:1, v/v) at pH 7.0. The probe might be a new efficient tool for detection of nitrite ion in natural water and biological system.

• 한국자기학회지
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• 제19권6호
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• pp.209-215
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• 2009

M-type 바륨 페라이트(BaFe12O19)분말을 공침법을 이용하여 합성하였다. 출발물질의 조성은 $Fe^{3+}:\;Ba^{2+}$ 몰 비를 8로 고정하고 $Fe^{3+}$와 $Ba^{2+}$의 상대적인 양을 조절하였다. 열처리 방법과 pH의 차이에 의한 자기적 성질과 결정구조, 입자형상의 변화를 XRD(XRay Diffractometer), FESEM(Field Emission Scanning Electron Microscope), VSM(Vibrating Sample Magnetometer)을 이용하여 조사하였다. pH가 8이고 $Fe^{3+}:\;Ba^{2+}$의 비가 12 : 1.5 일 때 가장 큰 보자력 값을 얻었다. pH가 8일 때는 $Fe^{3+}$와 $Ba^{2+}$의 상대적인 양과 열처리 조건에 따라 보자력과 포화 자화 값의 변화가 크게 나타났다. 이것은 바륨 페라이트로 전이가 안 된 $\alpha$-$Fe_2O_3$ 상 때문이다. pH가 10일 때는 열처리 조건과 $Fe^{3+}$와 $Ba^{2+}$의 양과 상관없이 단일 상 M-type 바륨 페라이트를 얻을 수 있었으며 우수한 자화 값과 보자력을 나타내는 분말을 얻을 수 있었다. $Fe^{3+}$와 $Ba^{2+}$의 비가 13.6 : 1.7일 때 가장 큰 자화 값(55.7 emu/g)을 얻을 수 있었으며, 산소분위기에서 열처리 후 노냉한 분말이 높은 보자력과 자화 값을 나타내었다. FESEM으로 관찰된 입자의 크기는 50~200 nm이었다.