• 한국재료학회지
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• 제32권5호
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• pp.237-242
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• 2022

Designing and producing a low-cost, high-current-density electrode with good electrocatalytic activity for the oxygen evolution reaction (OER) is still a major challenge for the industrial hydrogen energy economy. In this study, nanostructured Fe-doped CuCo(OH)₂ was discovered to be a precedent electrocatalyst for OER with low overpotential, low Tafel slope, good durability, and high electrochemically active surface sites at reduced mass loadings. Fe-doped CuCo(OH)₂ nanosheets are made using a hydrothermal synthesis process. These nanosheets are clumped together to form a highly open hierarchical structure. When used as an electrocatalyst, the Fe-doped CuCo(OH)₂ nanosheets required an overpotential of 260 mV to reach a current density of 50 mA cm^-2. Also, it showed a small Tafel slope of 72.9 mV dec^-1, and superior stability while catalyzing the generation of O₂ continuously for 20 hours. The Fe-doped CuCo(OH)₂ was found to have a large number of active sites which provide hierarchical and stable transfer routes for both electrolyte ions and electrons, resulting in exceptional OER performance.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.93-94
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• 2023

Through the industrial revolution that began in the 18th century, the amount of carbon dioxide in the atmosphere increased rapidly as humans used fossil energy such as coal and oil as fuel for steam engines and factory machines. The amount of carbon dioxide emitted while producing cement, the main material of concrete used in construction, is large enough to account for 5-8% of the world's carbon dioxide emissions. In this study, Non cement-based matrix were used to reduce carbon dioxide emissions from cement production. Red mud is an industrial by-product generated in the manufacturing process of aluminum hydroxide using bauxite, and more than 120 million tons are produced worldwide. In addition, red mud is a porous material that can be physically adsorbed, and causes a photocatalytic reaction of TiO₂ to remove harmful substances such as nitrogen oxide formaldehyde in the air and chemically adsorbs ammonia and hydrogen sulfide. Therefore, this study aims to examine the physical properties of the matrix by mixing red mud, an industrial by-product with good adsorption performance, into the Non cement-based matrix.

• Animal Bioscience
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• 제37권2_spc호
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• pp.360-369
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• 2024

Ruminal methane production functions as the main sink for metabolic hydrogen generated through rumen fermentation and is recognized as a considerable source of greenhouse gas emissions. Methane production is a complex trait affected by dry matter intake, feed composition, rumen microbiota and their fermentation, lactation stage, host genetics, and environmental factors. Various mitigation approaches have been proposed. Because individual ruminants exhibit different methane conversion efficiencies, the microbial characteristics of low-methane-emitting animals can be essential for successful rumen manipulation and environment-friendly methane mitigation. Several bacterial species, including Sharpea, uncharacterized Succinivibrionaceae, and certain Prevotella phylotypes have been listed as key players in low-methane-emitting sheep and cows. The functional characteristics of the unclassified bacteria remain unclear, as they are yet to be cultured. Here, we review ruminal methane production and mitigation strategies, focusing on rumen fermentation and the functional role of rumen microbiota, and describe the phylogenetic and physiological characteristics of a novel Prevotella species recently isolated from low methane-emitting and high propionate-producing cows. This review may help to provide a better understanding of the ruminal digestion process and rumen function to identify holistic and environmentally friendly methane mitigation approaches for sustainable ruminant production.

• Nuclear Engineering and Technology
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• 제56권3호
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• pp.966-972
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• 2024

Idaho National Laboratory (INL) announced at COP27 it would reach net zero greenhouse gas (GHG) emissions by 2031. As a Nuclear, Energy and Environment, and National Homeland Security laboratory, the predominant solution to closing the clean energy gap will include nuclear as a safe, clean, reliable and affordable electricity source with the additional benefit of producing heat and hydrogen to fuel INL's large transportation fleet. INL's collaboration first vs. competition is essential to the program's success. The focused actions in INL's Nuclear Roadmap include: Infrastructure, Licensing/Regulatory, Financial, Time to Market, Fuel Cycle and Public Confidence/Communications. The roadmap also includes nuclear technology innovations and creative partnerships with utility providers, regulators, businesses, community members, and Indigenous Peoples to accelerate deployment of advanced reactors. Through development of the Net-Zero Nuclear Roadmap, INL will offer a model to provide safe and secure energy for the nation and the world by: (1) establishing the necessary infrastructure on its 890-square mile site to support demonstration, (2) showing proven pathways through the licensing and regulation process, (3) partnering with utilities to ensure commercial application, and (4) collaborating with industry to site new technologies.

• 한국토양비료학회지
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• 제4권1호
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• pp.13-19
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• 1971

수도생육초기(水稻生育初期)에 흡수조해물질(吸收阻害物質)의 생성집적(生成集積)이 우려(憂慮)되는 전형적(典型的)인 습답(濕畓)의 개량방법(改良方法)을 확립(確立)시키기 위(爲)해서 적지(適地)를 선정(選定) 석회질물질(石灰質物質), 무류산근비료(無硫酸根肥料), 붕소(硼素) 생고등(生藁等)을 첨가처리(添加處理) 한 포장시험(圃場試驗)을 실시(實施)하고 시기별식물체시료(時期別植物體試料)의 채취분석(採取分析)을 실시(實施)하여 그 결과(結果)들을 평가검토(評價檢討)한 결과(結果) 대략(大約) 다음과 같이 요약(要約)할수 있었다. (1) 습답(濕畓)에서는 소석회(消石灰), 규회석(珪灰石)과 같은 석회질물질(石灰質物質)의 첨가(添加) 붕(硼) 사등(砂等)과 같은 미생물(微生物)의 활동억제물질(活動抑制物質), 무류산근비료(無硫酸根肥料)와 같은 유해물질생성원(有害物質生成源)이 없는 물질(物質)의 시용(施用)으로 현저(顯著)한 정조수양증수(精租收量增收)를 기(期)할수있다. (2) 습답(濕畓)에 있어서 작물학적(作物學的)인 감수원인(減收原因)은 주당수수(株當穗數) 수당입수(穗當粒數), 1000입중등(粒重等)이 감소(減少)되는것이다. (3) 습답(濕畓)에서의 식물영양학적(植物營養學的)인 감수원인(減收原因)은 전생육기간(全生育期間)을 통(通)한 질소흡수조해(窒素吸收阻害)와 유수형성기(幼穗形成) 이후(以後)의 인발흡목조해(燐醱吸牧阻害), 수확기고중(收穫期藁中)의 고토(苦土), 석회(石灰) 규산함량(硅酸含量)의 감소(減少)때문이다. (4) 습답(濕畓)에서의 각종성분(各種成分)의 수도체중함량감소원인(水稻體中含量減少原因)은 다음과 같은 관찰사실(觀察事實)로부터 흡수조해물질(吸收阻害物質)의 생성집적(生成集積)으로 인(因)한 근계(根系)의 피해(被害)때문이라고 추정(推定)된다. (가) 흡수조해물질(吸收阻害物質)의 생성집적(生成集積)이 최고(最高)에 이르는 유수형성기(幼穗形成期)에 있어서 인산(燐酸)의 식물체당함량(植物體當含量)은 인산무처리구(燐酸無處理區)보다 인산시용구(燐酸施用區)에서 적었으며 석회질물질시용(石灰質物質施用)으로 중화(中和)된 구(區)에서는 훨씬 많았다. (나) 생고시용구(生藁施用區)에서 유수형성기(幼穗形成期) 식물체중가리함량(植物體中加里含量)은 필경 생고분해과정(生藁分解過程)에서 생성(生成)된 흡수조해물질(吸收阻害物質)때문에 매우 낮었으나 수확기(收穫期)에는 높았으며 필경 피해근(被害根)에 의(依)한 소극적(消極的) 비대사흡수(非代謝吸收) 때문이다. (다) 유기물(有機物)을 분해(分解)하는 미생물(微生物)의 작용(作用)을 조해(阻害)하는 것으로 알려진 붕소(硼素)의 효과(效果)가 현저(顯著)하였다. (라) 유화수소(硫化水素)와 같은 흡수조해물질생성원(吸收阻害物質生成源)이 없는 무류산근비료처리(無硫酸根肥料處理)의 효과(效果)가 현저(顯著)하였다. (마) 흡수조해물질(吸收阻害物質)의 생성집적량(生成集積量)이 최고(最高)에 이르며 근(根)의 활력(活力)이 최저(最低)에 이르는 유수형성기전후(幼穗形成期前後)에 결정(決定)되는 수량구성요소(收量構成要素)들이 모두 감소(減少)된다.

• Journal of Animal Science and Technology
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• 제59권11호
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• pp.27.1-27.7
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• 2017

Background: Cashew nut shell liquid (CNSL) is an agricultural byproduct containing alkylphenols that has been shown to favorably change the rumen fermentation pattern only under experimentally fixed feeding conditions. Investigation of CNSL potency in rumen modulation under a variety of feeding regimens, and evidence leading to the understanding of CNSL action are obviously necessary for further CNSL applications. The objective of this study was to evaluate the potency of CNSL for rumen modulation under different dietary conditions, and to visually demonstrate its surfactant action against selected rumen bacteria. Methods: Batch culture studies were carried out using various diets with 5 different forage to concentrate (F:C) ratios (9:1, 7:3, 5:5. 3:7 and 1:9). Strained rumen fluid was diluted with a buffer and incubated with each diet. Gas and short chain fatty acid (SCFA) profiles were characterized after 18 h incubation at $39^{\circ}C$. Monensin was also evaluated as a reference additive under the same conditions. Four species of rumen bacteria were grown in pure culture and exposed to CNSL to determine their morphological sensitivity to the surfactant action of CNSL. Results: CNSL supplementation decreased total gas production in diets with 5:5 and 3:7 F:C ratios, whereas the F:C ratio alone did not affect any gas production. Methane decrease by CNSL addition was more apparent in diets with 5:5, 3:7, and 1:9 F:C ratios. An interactive effect of CNSL and the F:C ratio was also observed for methane production. CNSL supplementation enhanced propionate production, while total SCFA production was not affected. Monensin decreased methane production but only in a diet with a 1:9 F:C ratio with increased propionate. Studies of pure cultures indicated that CNSL damaged the cell surface of hydrogen- and formate-producing bacteria, but did not change that of propionate-producing bacteria. Conclusion: CNSL can selectively inhibit rumen bacteria through its surfactant action to lead fermentation toward less methane and more propionate production. As CNSL is effective over a wider range of dietary conditions for such modulation of rumen fermentation in comparison with monensin, this new additive candidate might be applied to ruminant animals for various production purposes and at various stages.

• 대한토목학회논문집
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• 제35권2호
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• pp.353-359
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• 2015

본 연구는 실제 아파트 단지의 재생이 필요한 환경 인프라를 경제적이고 효율적인 녹색 인프라 기술로 재생하기 위한 계획을 수립하였으며, 단지내 물과 폐기물의 자원 순환 및 재이용을 위해 단지형 도시 중수 생산 기술과 단지형 유기성 폐기물 에너지화 기술, 무막힘 탄성포장 우수 재이용 기술, 도시농장 기술을 현장에 적용한 결과를 보여주고 있다. 도심 중수 생산 기술은 하수, 우수, 지하수를 대상으로 중수를 생산하여 단지내 공공용수로 이용하기 위한 기반 기술이며, 무막힘 탄성포장 우수배수구 기술은 단지 내에서 우수의 재이용율 극대화시키기 위한 기반 기술이다. 유기성 폐기물 에너지화 기술은 단지에서 발생하는 음식폐기물 및 분뇨 등의 유기성 폐기물을 처리하는 과정에서 바이오가스와 비료를 만들어 에너지원으로 활용할 수 있으며, 도시농장은 재생용수, 재생에너지, 재생비료를 활용하여 주거민들의 건강 및 여가공간으로 활용할 수 있는 기반기술이다. 이를 통해 단지 내에서 자원 순환 및 재이용이 가능한 하나의 에코시스템을 구축하였으며, 재생 후 녹색지표결과에서 에너지 부문은 4.23, 물부문은 0.32, 폐기물 부문은 0, 토지이용 부문은 0, 환경부문은 2.12가 상승하는 결과를 가져올 수 있었다.

• KSBB Journal
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• 제23권5호
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• pp.425-430
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• 2008

생체에서의 황화수소는 의약 분야와 발효 산업에 있어서 중요한 역할을 하고 있다. 본 연구에서는 Saccharomyces cerevisiae을 이용하여 기질인 L-cysteine과 $\beta$-mercaptoethanol로부터 $\beta$-replacement 반응에 인한 황화수소를 발생시킬 수 있는 효소를 간편하고 신속하게 동정하는 방법의 확립을 목적으로 하였다. 효소에 의해 발생된 황화수소와 Pb-acetate의 반응으로 생성된 Pb-S를 gel상에서 간편하게 확인한 후, 확인된 단백질들을 이온교환컬럼를 수행한 후 gel에서 추출하는 방법으로 MALDI-TOFMS의 시료를 간단히 얻을 수 있었다. PMF 방법과 MS/MS ion search 분석을 통해 간편하게 효모에서 황화수소를 형성할 가능성이 있는 세가지 단백질의 동정에 성공하였다. 이 세 가지 단백질은 CYS3, CYS4, MET17 유전자의 단백질로서 cystathionine $\gamma$-lyase, CBS, OASS 임이 밝혀졌다. 그리고 이 세 단백질들은 L-cysteine과 $\beta$-mercaptoethanol의 존재하에서 황화수소를 실제로 생성함을 확인하였다. 본 연구에서 표적의 물질을 생산하는 단백질들을 젤상에서의 활성측정과 MALDI-TOF MS를 이용하여 간단히 그리고 정확하게 동정하는 방법을 확립하였다.

• 한국재료학회지
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• 제21권1호
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• pp.1-7
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• 2011

Methods of producing hydrogen include steam reforming, electrochemical decomposition of water, and the SI process. Among these methods, the Sulfur iodine process is one of the most promising processes for hydrogen production. The thermochemical sulfur-iodine (SI) process uses heat from a high-temperature-gas nuclear reactor to produce $H_2$ gas; this process is known for its production of clean energy as it does not emit $CO_2$ from water. But the SI-process takes place in an extremely corrosive environment for the materials. To endure SI environments, the materials for the SI environment will have to have strong corrosion resistance. This work studies the corrosion resistances of the Fe-Si, Ni-Ti and Ni Alloys, which are tested in SI-process environments. Among the SI-process environments, the conditions of boiling sulfuric acid and decomposed sulfuric acid are selected in this study. Before testing in boiling sulfuric acid environments, the specimens of Fe-4.5Si, Fe-6Si, Ni-4.5Si, Ni-Ti-Si-Nb and Ni-Ti-Si-Nb-B are previously given heat treatment at $1000^{\circ}C$ for 48 hrs. The reason for this heat treatment is that those specimens have a passive film on the surface. The specimens are immersed for 3~14 days in 98wt% boiling sulfuric acid. Corrosion rates are measured by using the weight change after immersion. The corrosion rates of the Fe-6Si and Ni-Ti-Si-Nb-B are found to decrease as the time passes. The corrosion rates of Fe-6si and Ni-Ti-Si-Nb-B are measured at 0.056 mm/yr and 0.16 mm/yr, respectively. Hastelloy-X, Alloy 617, Alloy 800H and Haynes 230 are tested in the decomposed sulfuric acid for one day. Alloy 800H was found to show the best corrosion resistance among the materials. The corrosion rate of Alloy 800H is measured at -0.35 mm/yr. In these results, the corrosion resistance of materials depends on the stability of the oxide film formed on the surface. After testing in boiling sulfuric acid and in decomposed sulfuric acid environments, the surfaces and compositions of specimens are analyzed by SEM and EDX.

• 한국식품과학회지
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• 제39권4호
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• pp.419-424
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• 2007

생 홍고추를 열수, 오존수, 과산화수소와 차아염소산나트륨으로 살균 처리하여 적정 살균조건을 선정하고 선정된 조건에서 살균한 홍고추를 $-70^{\circ}C$로 냉동하여 $-30^{\circ}C$에서 30일 동안 저장한 후 품질변화를 측정하였다. $95^{\circ}C$에서 4분간 열수 처리하였을 때 E. coli와 coliform이 음성을 나타내었으며, 오존수 처리는 0.5 ppm에서 6분간 살균 처리하였을 때, 과산화수소는 2% 용액으로 12분간 살균처리로 음성을 나타냈다. 차아염소산나트륨 처리는 3% 용액으로 4분간 처리하였을 때 음성을 나타내었다. 선정된 각 최적조건에서 살균 처리하여 냉동저장 후 품질변화를 측정한 결과, 드립발생은 열수처리 시료가 15%로 가장 높았다. Ascorbic acid 함량은 오존수 처리 시료를 제외한 다른 처리구들은 대조구의 40%에도 미치지 못하는 함량을 나타내었으며, carotenoids 함량은 오존수 처리 시료가 124.16-182.87 mg%로 가장 적은 손실을 보였다. 관능검사 결과 오존수 처리 시료를 제외한 다른 처리구들은 내피의 탈색이 심하게 일어나고, 특히 열수처리의 경우 살균 처리에 의해 과육이 물러져서 외관이 심하게 손상되어 대조구와 유의적 차이를 나타내었다(p < 0.05). 따라서 시험한 살균방법 중에서 오존수처리가 가장 우수한 품질의 살균 생 홍고추를 생산하는데 적합한 방법으로 평가되었다.