• 제목/요약/키워드: over-potential

검색결과 3,581건 처리시간 0.023초

참치 선망어선의 선형개발을 위한 조파저항의 수치해석 (Numerical Analysis on the Wave Resistance for Development of Ship`s From of Tuna Purse Seiner)

  • 김인철
    • 수산해양기술연구
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    • 제28권2호
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    • pp.228-239
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    • 1992
  • The purpose of the present research is to develop an efficient numerical method for the calculation of potential flow and predict the wave-making resistance for the application to ship design of tuna purse seiner. The paper deals with the numerical calculation of potential flow around the series 60 with forward velocity by the new slender ship theory. This new slender ship theory is based on the asymptotic expression of the Kelvin-source, distributed over the small matrix at each transverse section so as to satisfy the approximate hull boundary condition due to the assumption of slender body. Some numerical results for series 60, C sub(b) =0.6, hull are presented in this paper. The wave pattern and wave resistance are computed at two Froude numbers, 0.267 and 0.304. These results are better than those of Michell's thin ship theory in comparison with measured results. However, it costs much time to compute not only wave resistance but also wave pattern over some range of Froude numbers. More improvements are strongly desired in the numerical procedure.

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Simulation on Surface Tracking Pattern using the Dielectric Breakdown Model

  • Kim, Jun-Won;Roh, Young-Su
    • Journal of Electrical Engineering and Technology
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    • 제6권3호
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    • pp.391-396
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    • 2011
  • The tracking pattern formed on the dielectric surface due to a surface electrical discharge exhibits fractal structure. In order to quantitatively investigate the fractal characteristics of the surface tracking pattern, the dielectric breakdown model has been employed to numerically generate the surface tracking pattern. In dielectric breakdown model, the pattern growth is determined stochastically by a probability function depending on the local electric potential difference. For the computation of the electric potential for all points of the lattice, a two-dimensional discrete Laplace equation is solved by mean of the successive over-relaxation method combined to the Gauss-Seidel method. The box counting method has been used to calculate the fractal dimensions of the simulated patterns with various exponent $\eta$ and breakdown voltage $\phi_b$. As a result of the simulation, it is found that the fractal nature of the surface tracking pattern depends strongly on $\eta$ and $\phi_b$.

Osmotic Cross Second Virial Coefficient ($B_{23}$) of Unfavorable Proteins: Modified Lennard-Jones Potential

  • Choi, Sang-Ha;Bae, Young-Chan
    • Macromolecular Research
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    • 제17권10호
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    • pp.763-769
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    • 2009
  • A chromatographic method is used to measure interactions between dissimilar proteins in aqueous electrolyte solutions as a function of ionic strength, salt type, and pH. One protein is immobilized on the surface of the stationary phase, and the other is dissolved in electrolyte solution conditions flowing over that surface. The relative retention of proteins reflects the mean interactions between immobile and mobile proteins. The osmotic cross second virial coefficient calculated by assuming a proposed potential function shows that the interactions of unfavorable proteins depend on solution conditions, and the proposed model shows good agreement with the experimental data of the given systems.

한국에 있어서 식품조사 기술의 진보와 식품산업에서의 역할 (Advances in Food Irradiation and It's Potential Roles in Korea)

  • 권중호
    • 한국식품위생안전성학회:학술대회논문집
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    • 한국식품위생안전성학회 1994년도 방사선 조사 식품의 안전성 및 실용화에관한 국제심포지움
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    • pp.35-49
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    • 1994
  • Based on the safety of irradiated foods which was demonstrated from the toxicological, microbiological and nutritional points of view, irradiation has been identified as a viable technology for food preservation and processing, having a potential both of reducing storage losses by controlling spoilage organisms, sprouting and ripening, and of improving hygienic quality of raw and processed products. Research and development over decades in the field of food irradiation have led to the regulatory approval in 37 countries and of them 25 countries including Korea are commercially utilizing food irradiation process. Although progress towards acceptance of food irradiation by the industry is slow, actual market trials have shown that once consumers have understood this technology, they are willing to buy irradiated foods. Considering recent advances in food irradiation and restrictions in the use of chemical fumigants, it is expected that food irradiation is in the process of "taking off". This paper deals with up-to-date progress in food irradiation with particular reference to domestic activities in legislation, consumer perception, commercialization, and potential applications in the food industry.

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원위치 시험 성과에 의한 액상화 발생가능성 평가에 관한 연구 (A Study on Evaluation of Liquefaction Potential Using in Situ Test Data)

  • 허정우;김찬홍;박성재;정경환
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2001년도 봄 학술발표회 논문집
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    • pp.477-484
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    • 2001
  • In this paper shows the evaluation of the liquefaction potential of soils using in situ test. There are different types of in situ test used in the evaluation the liquefaction potential. In the particular study the Standard penetration test(SPT), Cone penetration test(CPT), ad Seismic cone penetration test (SCPT) were used. The SPT N value has been used all over for a very long time. The evaluation of the liquefaction of soil was preformed using the worldwide renowned CPT and SCPT. Shake 91 program was used to evaluate the results obtained by different in situ test and were later analyzed.

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Evaluation of wind power potential for selecting suitable wind turbine

  • Sukkiramathi, K.;Rajkumar, R.;Seshaiah, C.V.
    • Wind and Structures
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    • 제31권4호
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    • pp.311-319
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    • 2020
  • India is a developing nation and heavily spends on the development of wind power plants to meet the national energy demand. The objective of this paper is to investigate wind power potential of Ennore site using wind data collected over a period of two years by three parameter Weibull distribution. The Weibull parameters are estimated using maximum likelihood, least square method and moment method and the accuracy is determined using R2 and root mean square error values. The site specific capacity factor is calculated by the mathematical model developed by three parameter Weibull distribution at different hub heights above the ground level. At last, the wind energy economic analysis is carried out using capacity factor at 30 m, 40 m and 50 m height for different wind turbine models. The analysis showed that the site has potential to install utility wind turbines to generate energy at the lowest cost per kilowatt-hour at height of 50 m. This research provides information of wind characteristics of potential sites and helps in selecting suitable wind turbine.

지하수 부존 가능지역 추출을 위한 LANDSAT TM 자료와 GIS의 통합(II) - 지하정보시스템에 의한 지하수 부존 가능성의 suitability map 작성 - (The Integration of GIS with LANDSAT TM Data for Groundwater Potential Area Mapping(II) - Suitablility Mapping for Groundwater Exploration Using the Geographic Infornation System -)

  • 지광훈
    • 대한원격탐사학회지
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    • 제8권1호
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    • pp.45-58
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    • 1992
  • The study is aimed at extraction of the groundwater potential area using the Geographic Information System. The study was to develop techniques of the thematic mapping such as slope map, geologic map, soil map and suitability mapping for grotential area. There thematic maps were combined and weightages were given to produce suitability map for groundwater potential area. The results of this study are as follows. 1) The 78% of cased wells have releation to lineament coincided with the appraisement point of the suitability map. 2) The 9 sites of 18 test sites produced over than 200 m$^3$/day. The with the highest appraisement point of the suitability map. 3) Suitability map is effective to extract groundwater potential area which can not be extracted from the remotely sensed data. The developed suitability mapping techniques are expected to do as an important tool for exploration and development of the newable and unnewable resources such as groundwater, petroleum etc.

Market Oriented Revenue Assistance for Farmers: A Case Study of the United State's ACRE Program

  • Zulauf, Carl;Rhew, Chan-Hee;Kim, Sang-Hyo
    • 유통과학연구
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    • 제14권11호
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    • pp.29-36
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    • 2016
  • Purpose - Intense debate is occurring over support for farmers in Korea, specifically on the justification, policy design, and equality issues of the farm support programs. Given this debate, a new type of farm program in the US, a market flexible revenue program(the Average Crop Revenue Election, ACRE), is examined. ACRE stands in contrast to traditional programs that tie payments to price and have parameters that are fixed or change only infrequently. Research design, data, and methodology - Based on the ACRE program formulas, the potential payments are estimated by crop year, program crop and geographical area using the FSA acreage and payment rate data. Results - If all US farm program acres were in ACRE over the 2009-2013 crop years, payments would have totaled $7.95 billion or 1.2 percent of average market receipts for US crops. Enacting ACRE as a revenue program instead of a similarly-structured price-only program increased payments by $1.75 billion or 28 percent. Conclusions - Potential payments by ACRE largely reflected the distribution of the value of production across the program crops eligible for ACRE as well as across state geographical areas. If program parameters can be made acceptable and if data availability issues can be addressed, market flexible revenue programs offer a farm policy option that can address many of the concerns that have arisen over farm policy in Korea.

Childbearing women of twenty and under are at greater risk than those of twenty-five and over for compromised folate status

  • Kim, Hee-Ah;Choi, Jeong-Hwa;Lim, Hyeon-Sook
    • Nutrition Research and Practice
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    • 제1권4호
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    • pp.254-259
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    • 2007
  • This study assessed folate intakes, folate concentrations in plasma and erythrocytes, plasma total homocysteine (tHcy) concentration, and urinary excretion of folate metabolites in Korean women with childbearing potential. A total of 23 women voluntarily participated in this study. Precise dietary intakes for 3 consecutive days were determined by weighing all foods consumed and folate intake was calculated using a computer-aided dietary analysis system. Folate concentration of plasma and erythrocytes was determined by a microbiological method. Plasma tHcy concentration was assayed using an HPLC analysis method. Urine excreted over the same period of time was collected and folate catabolites, para-aminobenzoylglutamate (pABG) and para-acetamidobenzoylglutamate (ApABG), were evaluated using a reverse-phase HPLC method after affinity chromatography. Young women of 20 and under were likely to consume less folate with low energy intake, had lower folate concentration in plasma and erythrocytes, and excreted a lesser amount of ApABG and total folate catabolites than women of 25 years and over. The results of this study confirmed that young Korean women with childbearing potential, especially those under 21 years of age, might be at risk for compromised folate status due to insufficient folate intakes from inadequate energy consumption.

Ketorolac Ester Enhancer-prodrugs: Preparation and Evaluation of Their Physicochemical Properties

  • Yun, Sung-Il;Kim, Jung-Sun;Yong, Chul-Soon
    • Journal of Pharmaceutical Investigation
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    • 제38권6호
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    • pp.405-412
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    • 2008
  • Six ester analogues of Ketorolac were synthesized as potential enhancer prodrugs for transdermal delivery. Solubility of these esters was determined in 10% propylene glycol (PG)/isotonic phosphate buffer (IPB) at room temperature while lipophilicity was obtained as partition coefficients (log P) and capacity factors (k') using HPLC. Stability of the prodrugs in skin extract and in plasma was investigated at $37^{\circ}C$. The lipophilicity of the potential prodrugs increased in proportion to their alkyl chain length. Good linear relationship between partition coefficients (log P) and capacity factors (log k') was observed ($R^2=0.9961$). All of the analogues were fairly stable but slowly degraded in IPB over a 12 hour period. However, their stability in skin extract and in plasma varied with most compounds gradually decomposing over a 12 hour period. Although unsaturation of the alkyl ester chain did not alter the over all lipophilicity of the compound, the half-life was significantly affected. In plasma, degradation of the esters was slower than in the skin extract, which is a desirable trait for enhancer-prodrugs. However, the overall hydrolysis in the skin extract needs to be facilitated for the development of an effective enhancer prodrug. The analogue with the shortest half life in the skin extract was the unsaturated C-12 analogue of 0.96 hr.