Boreal winter Arctic Oscillation as an indicator of summer SST anomalies over the western tropical Indian Ocean

Gong, D. Y.,Guo, D.,Gao, Y.,Yang, J.,Mao, R.,Qu, J.,Gao, M.,Li, S.,Kim, S. J. Springer Science + Business Media 2017 Climate dynamics Vol.48 No.7

<P>The inter-annual relationship between the boreal winter Arctic Oscillation (AO) and summer sea surface temperature (SST) over the western tropical Indian Ocean (TIO) for the period from 1979 to 2015 is investigated. The results show that the January-February-March AO is significantly correlated with the June-July-August SST and SST tendency. When both El Nio/Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) variance are excluded, the winter AO is significantly correlated with the regional mean SST of the western TIO (40-E and S-N), . The multi-month SST tendency, i.e., the SST difference of June-July-August minus April-May, is correlated with the winter AO at . Composite analysis indicates similar warming over the western TIO. Two statistical models are established to predict the subsequent summer's SST and SST tendency. The models use the winter AO, the winter ENSO and the autumn-winter IOD indexes as predictors and explain 65 and 62 % of the variance of the subsequent summer's SST and SST tendency, respectively. Investigation of the regional air-sea fluxes and oceanic dynamics reveals that the net surface heat flux cannot account for the warming, whereas the oceanic Rossby wave plays a predominant role. During positive AO winters, the enhanced Arabian High causes stronger northern winds in the northern Indian Ocean and leads to anomalous cross-equatorial air-flow. The Ekman pumping in association with the anomalous wind stress curl in the central TIO generates a significantly deeper thermocline and above-normal sea surface height at 60-75E and 5-S. The winter AO-forced Rossby wave propagates westward and arrives at the western coast in summer, resulting in the significant SST increase. Forced by the observed winter AO-related wind stress anomalies over the Indian Ocean, the ocean model reasonably reproduces the Rossby wave as well as the resulting surface ocean warming over the western TIO in the subsequent summer. Observational analysis and numerical experiments suggest the importance of the oceanic dynamics in connecting the winter AO and summer SST anomalies.</P>

Biomolecule-entrapped SiO₂ nanoparticles for ultrafast green synthesis of silver nanoparticle–decorated hybrid nanostructures as effective catalysts

Otari, Sachin V.,Shinde, Vijay V.,Hui, Gao,Patel, Sanjay K.S.,Kalia, Vipin C.,Kim, In-Won,Lee, Jung-Kul Elsevier 2019 CERAMICS INTERNATIONAL Vol.45 No.5

<P><B>Abstract</B></P> <P>Noble-metal hybrid nanostructures have gained tremendous attention due to their potential roles in biomedical and catalytic applications. In this study, for the synthesis of silver nanoparticles (Ag NPs)–silica (SiO<SUB>2</SUB>) NPs, a novel green chemistry approach was employed, in which green tea biomolecule–encapsulated SiO<SUB>2</SUB> nanostructures were used for the reduction of silver ions to produce hybrid nanostructures within 300 s. The high-resolution transmission electron microscopy (HrTEM) revealed the formation of uniform ultrafine spherical Ag NPs that were evenly distributed in the nanostructures. The formed nanohybrid structures showed efficient catalytic activity for the formation of derivatives of dihydroquinoline, and retained 91% of their reusability capacity, even after 5 repeated cycles. Hence, this work provides a novel synthesis method not only for the synthesis of biomolecule-entrapped SiO<SUB>2</SUB> nanostructures, but also for the rapid formation of catalytically active hybrid nanostructures.</P>

알루미늄 합금으로 된 경사진 이중외팔보의 충돌에 대한 실험 및 해석

고등 ( Teng Gao ),조재웅 ( J U Cho ),전성식 ( Seong S Cheon ) 한국복합재료학회 2014 Composites research Vol.27 No.2

본 연구에서는 알루미늄 합금으로 된 경사진 이중외팔보의 충돌에 대해서 각각의 충격속도 2.5m/s, 7.5m/s, 12.5 m/s 별로 실험과 시뮬레이션 해석을 하였다. 접착부분에 발생하는 에너지 해방율과 응력을 평가하여 알루미늄 합금의 기계적 특성을 고찰하였다. 실험상에서는 접착 부분에서 에너지 해방율의 값이 높은 것으로 나타났다. 이는 실험에서 시험편이 분리된 후에도 접착력이 유지되는 특성 때문인 것으로 사료된다. 충격속도와 상관없이 균열이 진전하다가 접착된 부분의 끝에서 높은 응력을 발생하기 때문에 최대 등가응력은 마지막 단계에서는 올라간다. 본 연구에서의 실험 및 해석결과들은 충돌에 의한 균열 진전을 방지할 수 있는 복합재료에 대한 안전설계의 개발에 필요한 자료로 사료된다. This study is investigated by experiments and analyses at rates of 2.5m/s, 7.5m/s and 12.5m/s on the impact of tapered double cantilever beam specimens with aluminium alloy. It aims to examine the mechanical property of aluminum alloy by evaluating energy release rate and equivalent stress happened at the bonded part of specimen. Because bonding force remains after the separation of specimen, the energy release rate at the bonded part becomes highest. As crack propagates and the high stress happens at the end of the bonded part, the maximum equivalent stress becomes higher at the last stage, regardless of impact rate. These results of experiments and analyses are the data necessary to develop the safe design of composite material to prevent crack propagation due to impact.

Malic Acid 혹은 Citric acid 의 첨가가 반추위 혼합미생물의 성장 및 대사에 미치는 영향

고주,이성실,노영애,김홍대,하종규,감동근,전현식 한국영양사료학회 1999 韓國營養飼料學會誌 Vol.23 No.3

본 연구는 malic acid와 citric acid의 첨가가 반추위 혼합미생물의 성장 및 대사에 미치는 영향을 구명하기 위해서 실시되었는데, 시험결과를 요약하면 다음과 같다. Malic acid와 citric acid를 각각 혼합미생물의 배지에 첨가했을 때 배양 12∼24시간에서 두 처리구에서 모두 박테리아의 성장이 크게 촉진되었어며 citric aicd의 첨가효과가 malic acid보다 더 좋았고 박테리아중 amylase를 분비하는 박테리아가 주로 많이 성장하였다. 그리고 곰팡이는 12∼24시간까지는 malic acid와 citric acid 첨가구에서 모두 대조구에 비하여 유의성있게 증가하다 48시간 후에는 급격히 감소하였다. 따라서 섬유소 분해효소의 활력도 48시간부터 급격히 감소하는 것으로 나타났다. This study was conducted to evaluate the effects of malic or citric acid on the growth and cellulolytic activity of mixed rumen microbes. The mixed rumen microbes were inoculated into Lowe's medium containing 0.01% malic or citric acid, and incubated for 12, 24, 48, 72, 120 and 168 hours. After incubation, enzyme (CMCase, xylanase, amylase and protease) activity, microbial growth and gas production were estimated. Results were obtained as below Bacterial growth rate and amylase activity were increased by addition of 0.01% malic acid or citric acid at 12 and 24 hour after incubation, and this stimulatory effect was more obvious with citric acid than with malic acid. Malic or citric acid addition increased fungal growth and cellulolytic enzyme activity upto 24 hour incubation.

A Statistical Approach for Deriving Key NFC Evaluation Criteria

S. K. Kim,G.B. Kang,W. I. Ko,S. R. YOUN,R.X. GAO 한국원자력학회 2014 Nuclear Engineering and Technology Vol.46 No.1

This study suggests 5 evaluation criteria (safety and technology, environmental impact, economic feasibility, socialfactors, and institutional factors) and 24 evaluation indicators for a NFC (nuclear fuel cycle) derived using factor analysis. To do so, a survey using 1 on 1 interview was given to nuclear energy experts and local residents who live near nuclearpower plants. In addition, by conducting a factor analysis, homogeneous evaluation indicators were grouped with the sameevaluation criteria, and unnecessary evaluation criteria and evaluation indicators were dropped out. As a result of analyzing the weight of evaluation criteria with the sample of nuclear power experts and the general public,both sides recognized safety as the most important evaluation criterion, and the social factors such as public acceptanceappeared to be ranked as more important evaluation criteria by the nuclear energy experts than the general public.

Malic acid 와 Citric acid 의 첨가가 반추위 곰팡이의 성장 및 섬유소 분해율에 미치는 영향

고주,이성실,노영애,김홍대,하종규,양승학 한국영양사료학회 1999 韓國營養飼料學會誌 Vol.23 No.3

본 실험은 처음으로 malic acid와 citric acid의 첨가가 곰팡이의 성장 및 섬유소 분해력에 미치는 영향을 관찰하였고 혼합 미생물의 성장 및 대사에 미치는 영향을 구명하고자 실험 1, 2, 3으로 나누어 수행하였는데, malic acid의 농도가 배지의 0.001%∼0.01%까지는 곰팡이의 성장 및 섬유소 분해효소의 활력과 섬유소 분해율을 증가시켰다. 그러나 0.1% 이상의 malic acid를 첨가하면 오히려 곰팡이의 성장이나 섬유소 분해효소 및 섬유소 분해력이 떨어지는 것으로 나타났다. 그리고 citic acid를 배지의 0.005% 첨가했을 때 곰팡이의 성장량과 섬유소 분해효소의 활력 및 섬유소 분해율이 대조구에 비하여 유의적으로 증가하였으며 0.1%에서는 크게 억제되는 것으로 나타났다 This study was conducted to evaluate the effects of malic or citric acid supplementation on the growth and cellulolytic activity of rumen fungi. Malic acid or citric acid were supplemented into Lowe's medium at the level of 0.001, 0.005, 0.01, 0.05 and 0.1%, respectively. N. frontalis was used as inoculant. Incubation was lasted for 1, 2, 3, 5 and 7 days and pH, CMCase and xylanase activity, filter paper degradability and fungal protein were estimated after incubation. When supplementation level was from 0.001 to 0.01%, malic acid stimulated the fungal growth, cellulolytic enzymes activity and cellulose degradability, but results were reversed when malic acid concentration was above 0.1%. Citric acid affected rumen fungal growth and cellulolytic enzyme activity in the similar trend. .

Characterization of FSW Butt Joints of Aluminum-clad Aluminum Thin Sheets

S. Basak(바삭 소우미야브라타),M. Mondal(몬달 무나리크),K. Gao(가오 쿤),S. Y. Anaman(아나만 샘 요),H.-H. Cho(훈휴 조),S.-T. Hong(홍성태) Korean Society for Precision Engineering 2021 한국정밀공학회 학술발표대회 논문집 Vol.2021 No.5월

Stromal fibroblasts from the interface zone of human breast carcinomas induce an epithelial-mesenchymal transition-like state in breast cancer cells in vitro

Gao, M.-Q.,Kim, B.G.,Kang, S.,Choi, Y.P.,Park, H.,Kang, K.S.,Cho, N.H. COMPANY OF BIOLOGIST LTD 2010 Journal of cell science Vol.123 No.20

Design of a Microcontroller Based Electronic Load Controller for a Self Excited Induction Generator Supplying Single-Phase Loads

Gao, Sarsing,Murthy, S. S.,Bhuvaneswari, G.,Gayathri, M. Sree Lalitha The Korean Institute of Power Electronics 2010 JOURNAL OF POWER ELECTRONICS Vol.10 No.4

The generation of electric power using self excited induction generation (SEIG) is a viable option in remote and rural areas where grid electricity is not available. The generated voltage and frequency of these machines, however, varies with varying loads. This characteristic can be resolved either by adjusting the values of the excitation capacitance or by controlling the prime mover speed. Further, in a single-point constant power application, where the machines deliver a fixed amount of power, the electronic load controller (ELC) can be used to switch-in or switch-out a dump load whenever the consumer load decreases or increases respectively. This paper presents a detailed analysis and the design of a microcontroller based SEIG -ELC system intended for stand-alone pico hydro power generation. The simulated performance of the controller is supplemented by experimental results.

NUCLEAR FUEL CYCLE COST ESTIMATION AND SENSITIVITY ANALYSIS OF UNIT COSTS ON THE BASIS OF AN EQUILIBRIUM MODEL

S.K. KIM,W. I. KO,S. R. YOUN,R.X. GAO 한국원자력학회 2015 Nuclear Engineering and Technology Vol.47 No.3

This paper examines the difference in the value of the nuclear fuel cycle cost calculated by the deterministic and probabilistic methods on the basis of an equilibrium model. Calculating using the deterministic method, the direct disposal cost and Pyro-SFR (sodium-cooled fast reactor) nuclear fuel cycle cost, including the reactor cost, were found to be 66.41 mills/kWh and 77.82 mills/kWh, respectively (1 mill = one thousand of a dollar, i.e., 10−3 $). This is because the cost of SFR is considerably expensive. Calculating again using the probabilistic method, however, the direct disposal cost and Pyro-SFR nuclear fuel cycle cost, excluding the reactor cost, were found be 7.47 mills/kWh and 6.40 mills/kWh, respectively, on the basis of the most likely value. This is because the nuclear fuel cycle cost is significantly affected by the standard deviation and the mean of the unit cost that includes uncertainty. Thus, it is judged that not only the deterministic method, but also the probabilistic method, would also be necessary to evaluate the nuclear fuel cycle cost. By analyzing the sensitivity of the unit cost in each phase of the nuclear fuel cycle, it was found that the uranium unit price is the most influential factor in determining nuclear fuel cycle costs.