• 제목/요약/키워드: transport characteristics

검색결과 2,498건 처리시간 0.031초

연직수문의 퇴적토 배출특성에 관한 실험적 연구 (An Experimental Study on the Sediment Transport Characteristics Through Vertical Lift Gate)

  • 이지행;최흥식
    • Ecology and Resilient Infrastructure
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    • 제5권4호
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    • pp.276-284
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    • 2018
  • 하단배출 형태의 연직수문을 대상으로 퇴적토 배출특성에 따른 두부침식 거리비, 퇴적토 이동거리와 이동량을 분석하기 위해 수리 모형실험과 차원해석을 수행하였다. Froude 수와 배출특성의 상관관계를 도식화하고, 퇴적토 배출특성을 지배하는 무차원 매개변수에 의한 다중회귀식을 제안하였다. 두부침식거리, 퇴적토 이동거리와 이동량에 대한 각 다중회귀 분석식의 결정계수는 각각 0.618, 0.632, 0.866으로 높게 나타났다. 개발한 퇴적토 배출특성식의 사용성을 평가하기 위해 실제 측정값과 회귀분석식에 의해 계산된 값의 95%의 예측 신뢰구간 분석을 수행하였고, 두부침식거리, 퇴적토 이동거리와 이동량에 대한 예측의 정확도 분석차원의 NSE (Nash-Sutcliffe Efficiency), RMSE (root mean square)와 MAPE (mean absolute percentage error)는 적절한 것으로 판단되었다.

수송밀도가 넙치(Paralichthys olivaceus) 근육의 물리화학적 변화에 미치는 영향 (Effect of Transport Stocking Density on the Physicochemical Characteristics of Muscle from Olive Flounder Paralichthys olivaceus)

  • 심길보;윤호동
    • 한국수산과학회지
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    • 제47권6호
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    • pp.707-712
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    • 2014
  • The effects of transport stocking density (500, 600 and 700 kg of olive flounder Paralichthys olivaceus/per water tank) on the physicochemical characteristics of muscle were investigated. Transport of the animals took, on average, 10 days from Busan, Korea, to Long Beach, CA, USA. There was no significant difference in the breaking strength of muscle among the three groups. There was also no significant difference in the ATP, lactate, or glycogen content of muscle from the 500 and 600 kg/tank stocking density groups at the beginning and after transport. However, the ATP content decreased sharply while the lactate content increased in muscle from fish transported at a density of 700 kg/tank at the beginning of transport, and the ATP and lactate contents in this group were stable after transport.

Probabilistic and spectral modelling of dynamic wind effects of quayside container cranes

  • Su, Ning;Peng, Shitao;Hong, Ningning;Wu, Xiaotong;Chen, Yunyue
    • Wind and Structures
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    • 제30권4호
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    • pp.405-421
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    • 2020
  • Quayside container cranes are important delivery machineries located in the most frontiers of container terminals, where strong wind attacks happen occasionally. Since the previous researches on quayside container cranes mainly focused on the mean wind load and static response characteristics, the fluctuating wind load and dynamic response characteristics require further investigations. In the present study, the aerodynamic wind loads on quayside container cranes were obtained from wind tunnel tests. The probabilistic and spectral models of the fluctuating aerodynamic loads were established. Then the joint probabilistic distributions of dynamic wind-induced responses were derived theoretically based on a series of Gaussian and independent assumption of resonant components. Finally, the results were validated by time domain analysis using wind tunnel data. It is concluded that the assumptions are acceptable. And the presented approach can estimate peak dynamic sliding force, overturning moments and leg uplifts of quayside container cranes effectively and efficiently.

미생물의 토양 투과성에 영향을 미치는 미생물 표면 및 용액 특성

  • 김용미;류두현;김호영;서성원;정남희;안병구;박준석
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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    • pp.319-322
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    • 2002
  • The bacterial transport in soil media was studied. Nonionic surfactants, enhanced the bacterial transports in soil media. The transport rate in soil column was increased by increasing the number of ethylene oxide in polyoxyethylene oxide surfactants. Ionic strength of solution affected the microbial transport characteristics in soil. The hydrophobicity of cell surface was proved that one of important characteristics on the bacterial transport in soil media.

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싸이오펜 기반 청색 인광용 정공수송층 개발 (Development of Blue Fluorescent Light Hole Transport Layer of Thiophene Base)

  • 기현철;신현오;황은혜;권태혁
    • 한국전기전자재료학회논문지
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    • 제30권2호
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    • pp.91-95
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    • 2017
  • We were designed the hole transport layer of the new composite skeleton structure having a high charge mobility and thermal stability. In this paper, a hole transport layer material based on thiophene molecular structure capable of hole mobility characteristics and high triplet energy was designed and synthesized. The structures and properties of the synthesized compounds were characterized by NMR, fluorescence spectroscopy and energy band gap. As a result of NMR measurement, it was confirmed that when analyzing the integrated type with the position where the measured peak is displayed, it agrees with the structure of hole transport materials. The emission characteristics of the hole transport layer material showed absorption characteristics at 412 nm and 426 nm, respectively, and exhibited emission characteristics in the range of 469 nm and 516 nm.

Transport Risk Assessment for On-Road/Sea Transport of Decommissioning Waste of Kori Unit 1

  • Woo Yong Kim;Hyun Woo Song;Jisoo Yoon;Moon Oh Kim
    • 방사성폐기물학회지
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    • 제21권2호
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    • pp.255-269
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    • 2023
  • Compared to operational wastes, nuclear power plant (NPP) decommissioning wastes are generated in larger quantities within a short time and include diverse types with a wider range of radiation characteristics. Currently used 200 L drums and IP-2 type transport containers are inefficient and restrictive in packaging and transporting decommissioning wastes. Therefore, new packaging and transport containers with greater size, loading weight, and shielding performance have been developed. When transporting radioactive materials, radiological safety should be assessed by reflecting parameters such as the type and quantity of the package, transport route, and transport environment. Thus far, safety evaluations of radioactive waste transport have mainly targeted operational wastes, that have less radioactivity and a smaller amount per transport than decommissioning wastes. Therefore, in this study, the possible radiation effects during the transport from NPP to disposal facilities were evaluated to reflect the characteristics of the newly developed containers and decommissioning wastes. According to the evaluation results, the exposure dose to transport workers, handling workers, and the public was lower than the domestic regulatory limit. In addition, all exposure dose results were confirmed, through sensitivity analysis, to satisfy the evaluation criteria even under circumstances when radioactive materials were released 100% from the container.

Factors Affecting Tax Compliance among Small- and Medium-sized Enterprises: Evidence from Vietnam

  • LE, Hoang Thi Hong;TUYET, Vuong Thi Bach;HANH, Chu Thi Bich;DO, Quang Hung
    • The Journal of Asian Finance, Economics and Business
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    • 제7권7호
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    • pp.209-217
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    • 2020
  • Taxes are levied in almost every country, primarily to raise revenue for government expenditures. This study explores factors influencing tax compliance of small- and medium-sized enterprises (SMEs) in Vietnam. Data from 376 SMEs, who are business taxpayers, were collected through a researcher-administered questionnaire survey method. The results indicate that six groups of factors have significant impacts on tax compliance among Vietnamese SMEs. These groups include: Business characteristics (BC), Characteristics of accounting practices within organization (AP), Awareness of tax obligations (TO), Tax policy (TP), View on tax compliance (TC), and Probability of tax examination on taxpayer compliance (TE). Multivariate analysis was adopted; Cronbach's alpha coefficients were calculated, then, Exploratory Factor Analysis (EFA) was used. The findings show that, among these six factors, the most influential is Characteristics of accounting practices (AP). Thus, it is recommended that tax agencies should help SMEs improve their accounting skills and increase their knowledge by organizing training workshops and short courses on taxation. SMEs also need to have an adequate accounting system in accordance with principles and standards prescribed by the Tax Law. It is expected that this study can provide important insights and understandings to policy-makers, practitioners, academicians and other regulatory authorities in tax policy formulations.

가역 루프 히트파이프의 작동특성에 관한 실험적 연구 (An Experimental Investigation on the Operating Characteristics of a Reversible Loop Heat Pipe)

  • 김봉훈;최준민
    • 설비공학논문집
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    • 제18권3호
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    • pp.231-239
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    • 2006
  • An experimental investigation of a Reversible Loop Heat Pipe (RLHP) was conducted to determine the operating limits and performance characteristics as functions of the thermophysical parameters, the heat input, and the cooling intensity. Variations in both temperature and heat transport capacity were measured and analyzed in order to accurately evaluate the transient operating characteristics. In addition, the maximum heat transport as a function of the mean evaporator temperature, the ratio of heat transport to heater input power as a function of the mean evaporator temperature, and the overall thermal resistance as a function of the overall heat transport capacity were examined as well. Results indicated that the cooling intensity played an important role on the operating characteristics and performance limitation. The maximum heat transports corresponding to cooling intensity $72W/^{\circ}C$ and $290W/^{\circ}C$ were 446 W and 924 W, respectively. Also, observation of the startup characteristics indicated that the mean evaporator temperature should be maintained between $40^{\circ}C$ and $60^{\circ}C$, and overall thermal resistance were measured as $0.02^{\circ}C/W$.

Effects of Pentoses on 2-deoxy-D-Glucose Transport of the Endogenous Sugar Transport Systems in Spodoptera frugiperda Clone 9 Cells

  • 이종기
    • 대한의생명과학회지
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    • 제15권1호
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    • pp.55-60
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    • 2009
  • Insect cells such as Spodoptera frugiperda Clone 9 (Sf9) cells are widely chosen as the host for heterologous expression of a mammalian sugar transport protein using the baculovirus expression system. Characterization of the expressed protein is expected to include assay of its function, including its ability to transport sugars and to bind inhibitory ligands such as cytochalasin B. It is therefore very important first to establish the transport characteristics and other properties of the endogenous sugar transport proteins of the host insect cells. However, very little is known of the transport characteristics of Sf9 cells, although their ability to grow on TC-100 medium strongly suggested the presence of endogenous glucose transport system. In order to investigate the substrate and inhibitor recognition properties of the Sf9 cell transporter, the ability of pentoses to inhibit 2-deoxy-D-glucose (2dGlc) transport was investigated by measuring inhibition constants $(K_i)$. To determine the time period over which of sugar into the Sf cells was linear, the uptake of 2dGlc 0.1mM extracellular concentration was measured over periods ranging from 30 seconds to 30 minutes. The uptake was linear for at least 2 minutes at the concentration, implying that uptake made over a 1 minute time course would reflect initial rates of the sugar uptake. The data have also revealed the existence of a saturable transport system for pentose uptake by the insect cells. The transport was inhibited by D-xylose and D-ribose, although not as effective as hexoses. However, L-xylose had a little effect on 2dGlc transport in the Sf9 cells, indicating that the transport is stereoselective. Unlike the human erythrocyte-type glucose transport system, D-ribose had a somewhat greater apparent affinity for the Sf9 cell transporter than D-xylose. It is therefore concluded that Sf9 cells contain an endogenous sugar transport activity that in some aspects resembled the human erythrocyte-type counterpart, although the Sf9 and human transport systems do differ in their affinity for cytochalasin B.

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초음파를 이용한 광소자 이송시스템의 빔형상에 따른 이송특성에 관한 연구 (A Study on the Transportation Characteristics according to Beam Shape of Optical Lens Transport System using Ultrasonic Wave)

  • 정상화;최석봉;차경래;송석;김광호
    • 한국공작기계학회논문집
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    • 제15권6호
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    • pp.8-14
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    • 2006
  • The object transport system is used in many industry field such as the conveyor belt, which transports huge goods in container harbor, the magnetic levitation system, and the indexing system which transports precision components such as semiconductor and optical components. In conventional transport system, the magnetic field may damage semiconductor and the contact force may scratch on the optical lens. So ultrasonic wave transport system has been proposed to replace the previous transport system. In this paper, the good transport condition of optical lens is obtained according to the flexural beam shapes. The working frequency and transport speed are measured and the vibration characteristics of the flexural beams are investigated by Laser Scanning Vibrometer.