• 제목/요약/키워드: Transport loss

검색결과 601건 처리시간 0.023초

친환경 교통수단으로서 KTX의 역할과 기대

  • 방연근
    • 한국철도학회지
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    • 제9권2호
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    • pp.19-24
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    • 2006
  • Green gas emissions Trading System(ETS) came into effect in the Europe last year 2005. All transport modes have tried to reduce green gas emission and EU member countries are promoting the use of environmental friendly transport mode to avoid economic loss due to green gas emission. Besides ETS, rapidly rising of oil price and peak oil urge to invest more in the environmental friendly public transport mode and to discourage the use of private cars. The operation of KTX is estimated to bring external cost reduction up to 570 bil. won in 2004 based on European external unit costs of transport modes. This result implies that the expansion of high speed rail network and reconsideration of East-West high speed rail network which is not considered because of weak economic validity is required.

볼트체결방식의 IP-2형 운반용기의 낙하예비시험 (A Preliminary Drop Test of a Type IP-2 Transport Package with a Bolted Lid Type)

  • 김동학;서기석;박홍윤;이경호;윤정현;이흥영
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2005년도 추계 학술대회 논문집
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    • pp.339-347
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    • 2005
  • IP-2형 운반용기는 정상운반조건의 낙하시험을 거친 후에 방사성내용물의 유실 또는 분산이 없고 외부표면에서의 방사선량률이 $20\%$ 이상 증가할 수 있는 차폐능력의 상실이 없어야 한다. 차폐체의 두께가 큰 경우에는, 볼트체결방식을 사용하면 IP형 운반용기로 많이 사용되고 있는 ISO 컨테이너에서의 문을 사용하는 경우보다 방사성내용물의 유실 또는 분산이 일어나지 않을 것이다. 본 연구에서는 볼트체결방식의 IP-2형 운반용기에 대한 낙하시험을 실시하기 전에, 낙하방향에 따른 볼트인장력과 볼트체결력을 시험으로 평가하는 방법을 알아보기 위하여 예비시험모델을 제작하여 시험 및 평가하였다. 바닥과 뚜껑방향의 수직낙하, 수평낙하, 4방향의 경사낙하 등 총 7가지 낙하방향으로 자유낙하를 실시하였다. 낙하충격에 의한 볼트인장력은 힘센서를 이용하여 측정하였고, 볼트체결력은 낙하시험 전의 체결토르크에서 낙하충격 이후의 풀림토르크의 변화를 이용하여 알아보았다.

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신용장거래에서 운송서류의 위험요인에 관한 연구 (The Risks of Transport Documents under L/C Transaction)

  • 박세운
    • 무역상무연구
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    • 제45권
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    • pp.85-109
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    • 2010
  • L/C provides the exporter and the importer with safe assurance in the exchange of goods for payment in international trade. It involves a number of parties. Although the parties may have confidence in their client, bad faith or ignorance of international banking practice by any of these parties could cause the failure of transaction, which makes international trade a risky business. Most of the risks are found in transport document, which can cause disputes. There are many factors in the risk of transport documents under L/C transaction. One most common risk factor for the beneficiary in all transport documents is even if there is no discrepancy in document, the issuing bank or the applicant refuses to pay or delay payment insisting there is a discrepancy. In some very rare cases, the beneficiary may not get paid due to unfair injunction of the local court of the applicant. For the applicant, most common risk factors are fake bill and fraud. Risks classified according to the sorts of transport documents are as follows. 1. In B/L, payment can be refused because it is regarded as charter party B/L, although there is no real charter party contract. And the applicant can bear the potential risk of the loss or deterioration of cargo through transhipment of the cargo loaded on board in container if transhipment is prohibited without excluding of UCP 600 article 20 (c). 2. In charter party B/L, the applicant may take delivery without paying when charter party B/L is signed by charterer, which can result in a big loss for the beneficiary and the negotiating bank. And risks may arise when cargo is seized because the charterer does not pay the hire. The applicant and the issuing bank are also vulnerable to a risk - Against whom should they file a suit when cargo gets damaged during transportation? 3. In multimodal transport document, which is subject to a conflict because there is a big difference in viewpoints between transport industry and banks, conflicts may also arise when L/C requires ocean B/L and accepts multimodal transport document at the same time, but does not specify the details. 4. In air waybill, where the consignee is not the issuing bank but the applicant, risks may take place to the beneficiary when the applicant takes delivery but refuses to pay asserting minor discrepancies in document. The applicant may also bear the risk when cargo may not be loaded because air waybill is a received bill. Another risk may arise when although the applicant prohibits transhipment without excluding UCP 600 article 23 (c), the cargo may be transhipped, provided that the entire carriage is covered by one and the same air waybill.

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Modeling of pentacene MIS capacitors with admittance measurements and the effects of dispersive charge transport

  • Jung, Keum-Dong;Lee, Cheon-An;Park, Dong-Wook;Park, Byung-Gook;Shin, Hyung-Cheol;Lee, Jong-Duk
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.67-69
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    • 2006
  • Capacitance and loss values of pentacene MIS capacitors with different thicknesses are measured as a function of frequency for the modeling of the devices. The equivalent circuit for the ideal MIS capacitor is adopted to model the obtained admittance, so the values of $C_i,\;C_d,\;C_b$, and $R_b$ are determined for each pentacene thickness. In the loss curve, broader loss peaks are observed in measurement than the modeling results regardless of the pentacene thickness. By considering the effects of dispersive charge transport in bulk semiconductor, more accurate modeling results are obtained.

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Analytical polarization curve of DMFC anode

  • Kulikovsky, A.A.
    • Advances in Energy Research
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    • 제1권1호
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    • pp.35-52
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    • 2013
  • A model for DMFC anode performance is developed. The model takes into account potential--independent methanol adsorption on the catalyst surface, finite rate of proton transport through the anode catalyst layer (ACL), and a potential loss due to methanol transport in the anode backing layer. An approximate analytical half--cell polarization curve is derived and equations for the anode limiting current density are obtained. The polarization curve is fitted to the curves measured by Nordlund and Lindbergh and parameters resulted from the fitting are discussed.

Analysis of Flow Rate Inducing Voltage Loss in a 100 cm2 Class Molten Carbonate Fuel Cell

  • Lee, Choong-Gon
    • Journal of Electrochemical Science and Technology
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    • 제2권1호
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    • pp.20-25
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    • 2011
  • This work focuses on the behavior of the overpotential increase due to a utilization rise in a molten carbonate fuel cell. The behavior is generally explained by Nernst loss, which is a kind of voltage loss due to the thermodynamic potential gradients in a polarization state due to the concentration distribution of reactant species through the gas flow direction. The evaluation of Nernst loss is carried out with a traditional experimental method of constant gas utilization (CU). On the other hand, overpotential due to the gas-phase mass-transport resistance at the anode and cathode shows dependence on the utilization, which can be measured using the inert gas step addition (ISA) method. Since the Nernst loss is assumed to be due to the thermodynamic reasons, the voltage loss can be calculated by the Nernst equation, referred to as a simple calculation (SC) in this work. The three values of voltage loss due to CU, ISA, and SC are compared, showing that these values rise with increases in the utilization within acceptable deviations. When we consider that the anode and cathode reactions are significantly affected by the gas-phase mass transfer, the behavior strongly implies that the voltage loss is attributable not to thermodynamic reasons, namely Nernst loss, but to the kinetic reason of mass-transfer resistance in the gas phase.

Evaluation of Bacterial Transport Models for Saturated Column Experiments

  • Ham, Young-Ju;Kim, Song-Bae;Kim, Min-Kyu;Park, Seong-Jik
    • 한국농공학회논문집
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    • 제48권7호
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    • pp.55-63
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    • 2006
  • Bacterial transport models were evaluated in this study to determine the suitable model at describing bacterial transport in saturated column experiments. Four models used in the evaluation were: advective-dispersive equation (ADE) + equilibrium sorption/retardation (ER) + kinetic reversible sorption (KR) (Model I), ADE + two-site sorption (Model 2), ADE + ER + kinetic irreversible sorption (KI) (Model 3), ADE + KR + KI (Model 4). Firstly, analyses were performed with the first experimental data, showing that Model 4 is appropriate for describing bacterial transport. Even if Model 1 and 2 fit well to the observed data, they have a defect of not including the irreversible sorption, which is directly related to mass loss of bacteria. Model 3 can not properly describe the tailing observed in the data. However, further analysis with the second data indicates that Model 4 can not describe retardation of bacteria, even if the sorption-related parameters are varied. Therefore, Model 4 is modified by incorporating retardation factor into the model, resulting in the improved fitting to the data. It indicates that the transport model, into which retardation, kinetic reversible sorption, and kinetic irreversible sorption are incorporated, is suitable at describing bacterial transport in saturated column experiments. It is expected that the selected transport model could be applied to properly analyze the bacterial transport in saturated porous media.

테이프 배열이 3본-도체의 교류손실 특성에 미치는 영향 (Influence of tape′s arrangements on AC Loss Characteristics in a 3-conductor)

  • 조영호;허대행;류경우;최병주;황시돌
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 2003년도 추계학술대회 논문집
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    • pp.260-262
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    • 2003
  • AC loss is an important issue in the design of high-T$_{c}$, superconducting power cables which consist of a number of Bi-2223 tapes wound on a cylindrical former. In this paper, the ac loss characteristics in the 3-conductor have investigated experimentally. The loss test results indicate that the ac loss is not related to the arrangement of Bi-2223 tapes, contact position and applied frequency. The measured losses in face-to-face arrangement are larger than those in edge-to-edge arrangement. The measured losses in the 3-conductor also agree well with the sum of the transport losses measured in each Bi-2223 tape.e.

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