• Title/Summary/Keyword: Transport

Search Result 15,359, Processing Time 0.041 seconds

Transport of a capsule immersed in a vertical pipe (수직한 수송관 내부의 캡슐 이송)

  • Kim, Taehong;Park, Ryeol;Jeong, Joonho;Kim, Wonjung
    • Journal of the Korean Society of Visualization
    • /
    • v.17 no.1
    • /
    • pp.19-25
    • /
    • 2019
  • We report a study on the dynamics of the transport of a capsule immersed in a vertical pipe. Techniques to convey objects through liquid flow pipes using a hydraulic mean are used to transport sludge and hazardous materials. For the better understanding of the techniques, we developed a theoretical model to predict the transport speed of a cylindrical capsule in a vertical pipe. The comparison of the model prediction with the experiments shows that our model using the lubrication approximation precisely describes the experimental observations in cases where the gap between the capsule and pipe wall is sufficiently small. Our study suggests parameters to control the falling speed and thus enable an accurate control of the capsule speed in hydraulic transport systems.

Interscale transport of the Reynolds stress in a turbulent boundary layer subjected to adverse pressure gradient (역압력 구배 난류 경계층에서 레이놀즈 응력의 스케일 간 수송)

  • Yoon, Min
    • Journal of the Korean Society of Visualization
    • /
    • v.20 no.1
    • /
    • pp.38-44
    • /
    • 2022
  • An interscale transport of the turbulent kinetic energy (TKE) and Reynolds shear stress (RSS) is examined in an adverse pressure gradient (APG) turbulent boundary layer (TBL). The direct numerical simulation data of an APG TBL at Reτ = 834 and β = 1.45 is employed. The TKE and RSS transport equations are divided into large and small scales, leading to the introduction of interscale transport. The TKE mainly transfers from large scales to small ones in the outer region, and vice versa for the RSS. An interscale transport of TKE and inverse interscale transport of RSS are amplified by APG, and the latter results in the increase in large scales of TKE production. Some of outer large scales of enhanced TKE transfer to small scales and then dissipate by viscosity, and the remains dissipate turbulent-non-turbulent interfaces by turbulent transport.

Impact of Blockchain Technology on Maritime Transport in the Shipping Industry

  • Byun, Sang-phil;Oh, Jeong-Hun
    • Asia-Pacific Journal of Business
    • /
    • v.12 no.4
    • /
    • pp.53-61
    • /
    • 2021
  • Purpose - The purpose of this paper is to assess the empirical evidence that shows blockchain technology has been a significant contributor to the growth of maritime transport in the shipping industry. Design/methodology/approach - Employing a generalized linear model using data from 2010 to 2019, this paper presents empirical evidence to demonstrate the positive impact of the adoption of blockchain technology on the maritime transport industry. Findings - Results from Granger causality tests confirm that there is a positive unidirectional causality from blockchain technology to maritime transport. This paper also demonstrates the positive effects of information technology (IT) and GDP growth on maritime transport. On the other hand, maritime transport is negatively influenced by the tax burden. Research implications or Originality - The results of this paper suggest a potential sustainable development strategy for the maritime transport industry involving the redirection of economic resources toward blockchain technology. Adopting other forms of IT and reducing the tax burden are also useful strategies for the development of the industry.

Measuring stress responses using active biotelemetry in cattle II. Fluid administration for reducing transport stress (Active biotelemetry를 이용한 젖소의 스트레스 반응 측정: II. 수송 스트레스 감소를 위한 수액투여 효과)

  • Lee, Su-han;Lee, Byeong-han;Lim, Joa-jin;Kim, Jin-young;Lee, Dong-hee;Kim, Jae-kyung;Choe, Nong-hoon;Jeong, Soon-wuk;Chung, Byung-hyun
    • Korean Journal of Veterinary Research
    • /
    • v.41 no.4
    • /
    • pp.603-609
    • /
    • 2001
  • A transport stress is one of the main causes of economic losses and physiological dysfunction. The present study has been performed to suggest a method to decrease the adverse effects above mentioned from transport. The groups were prepared as follows; (1) Control group : 4 cattle transported for 5 hrs (274 km) without any treatment, (2) Treatment group : 4 cattle treated with electrolyte-mineral solution (I.V.) at 1 hr before the enrollment of transport under same experimental condition with Control group. The blood specimens were collected at 1 hr before transport, 2.3 hrs (135 km) and 5 hrs (274 km) after the enrollment of transport, and 1, 6 and 18 hrs after fulfillment of transport. The collected blood specimens were analyzed for cortisol and epinephrine. Core temperature and heart rate were measured with active biotelemetry in every 30 minutes from 0.5 hr before the start of transport to 18 hrs after the end of transport. In results, the level of cortisol considerably increased to the peak either in Control group ($5.3{\pm}1.3{\mu}g/d{\ell}$) and in Treatment group ($4.0{\pm}2.6{\mu}g/d{\ell}$) at 2.3 hrs in transport. The concentration of epinephrine of Treatment group had been higher than that of Control group from the start of transport to 18 hrs after the fulfillment of transport. Particularly there was the biggest gap between Control and Treatment groups, $424.0{\pm}194.1pg/m{\ell}$ and $209.1{\pm}65.1pg/m{\ell}$ respectively, at 6 hrs after the end of transport. The heart rates were considerably increased either in Control group ($81.5{\pm}18.5$ to $126.3{\pm}7.8beats/min$) and in Treatment group ($114.3{\pm}14.4$ to $140.8{\pm}22.4beats/min$) with the enrollment of transport. These results indicate that the concentration of cortisol and the heart rate were pertinent to cognitive parameters to evaluate physiological responses against stress such as transport. In addition, the intravenous administration of electrolyte-mineral solution could be suggested as the method to decrease the adverse effects from a transport stress.

  • PDF

Freight Demand Analysis for Multimodal Shipments (복합수단운송을 고려한 화물통행수요분석 방안)

  • Hong, Da-Hee;Park, Min-Choul;Lee, Jung-Yub;Hahn, Jin-Seok;Kang, Jae-Won
    • Journal of Korean Society of Transportation
    • /
    • v.30 no.4
    • /
    • pp.85-94
    • /
    • 2012
  • Modern freight transport pursues not only the reduction of logistic costs but also aims at green logistics and efficient shipments. In order to accomplish these goals, various policies regarding the multimodal shipment and stopover to logistic facilities have widely been made. Such situation requires changes in existing methods for analyzing freight demand. However, the reality is that a reliable freight demand forecast is limited, since in the transport research field there is no robust freight demand model that can accommodate transshipments at logistic facilities. This study suggested a novel method to analyze freight demand, which can consider transshipments in multi-modal networks. Also, the applicability of this method was discussed through an example test.

Transport losses in finisher pigs: impact of transport distance and season of the year

  • Voslarova, Eva;Vecerek, Vladimir;Passantino, Annamaria;Chloupek, Petr;Bedanova, Iveta
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.30 no.1
    • /
    • pp.119-124
    • /
    • 2017
  • Objective: The death of animals during transport for slaughter is a major factor indicating the level of welfare in transported animals. The aim of this study was to assess mortality related to the commercial transport of finisher pigs for slaughter in the Czech Republic. Methods: The inspectors of the State Veterinary Administration of the Czech Republic recorded the numbers of finisher pigs transported to processing plants in the Czech Republic for slaughter and the mortality in these pigs in relation to transport in the period from 2009 to 2014. Results: Our results show that the likelihood of death losses in transported pigs increases with increasing transport distance. The transport-related mortality ranged from 0.049% in pigs transported for distances below 50 km to 0.145% in pigs transported for distances exceeding 300 km. The impact of external air temperature on the transport-related mortality found in our study clearly shows that current transport practices fail to ensure the welfare of pigs transported under other than moderate weather. Particularly cold temperatures below $-2^{\circ}C$ were associated with increased death losses in winter transport. Conclusion: Despite a decreasing trend in the mortality of finisher pigs transported for slaughter in Europe, our study suggests that current transport conditions are not efficient at ensuring the welfare of pigs during transport for longer distances and the protection of pigs against the negative impact of extreme ambient temperatures. Further research should focus on developing practical guidelines to improve the welfare of pigs in transit accordingly.

Volume Transport on the Texas-Louisiana Continental Shelf

  • Cho Kwang-Woo
    • Fisheries and Aquatic Sciences
    • /
    • v.1 no.1
    • /
    • pp.48-62
    • /
    • 1998
  • Seasonal volume transport on the Texas-Louisiana continental shelf is investigated in terms of objectively fitted transport streamfunction fields based on the current meter data of the Texas­Louisiana Shelf Circulation and Transport Processes Study. Adopted here for the objective mapping is a method employing a two-dimensional truncated Fourier representation of the streamfunction over a domain, with the amplitudes determined by least square fit of the observation. The fitting was done with depth-averaged flow rather than depth-integrated flow to reduce the root-mean-square error. The fitting process filters out $11\%$ of the kinetic energy in the monthly mean transport fields. The shelf-wide pattern of streamfunction fields is similar to that of near-surface velocity fields over the region. The nearshore transport, about 0.1 to 0.3 Sv $(1 Sv= 10^6\;m^3/sec)$, is well correlated with the seasonal signal of along-shelf wind stress. The spring transport is weak compared to other seasons in the inner shelf region. The transport along the shelf break is large and variable. In the southwestern shelf break, transport amounts up to 4.7 Sv, which is associated with the activities of the encroaching of energetic anticyclonic eddies originated in Loop Current of the eastern Gulf of Mexico. The first empirical orthogonal function (EOF) of streamfunction variability contains $67.3\%$ of the variance and shows a simple, shelf-wide, along-shelf pattern of transport. The amplitude evolution of the first EOF is highly correlated (correlation coefficient: 0.88) with the evolution of the along-shelf wind stress. This provides strong evidence that the large portion of seasonal variation of the shelf transport is wind-forced. The second EOF contains $23.7\%$ of the variance and shows eddy activities at the southwestern shelf break. The correlation coefficient between the amplitudes of the second EOF and wind stress is 0.42. We assume that this mode is coupled a periodic inner shelf process with a non-periodic eddy process on the shelf break. The third EOF (accounting for $7.2\% of the variance) shows several cell structures near the shelf break associated with the variability of the Loop Current Eddies. The amplitude time series of the third EOF show little correlation with the along-shelf wind.

  • PDF

Choice Factors of Freight Transport Mode in Korea: Literature Review and Directions for Future Research (국내 화물운송수단 선택요인의 문헌 연구와 향후 연구 방향)

  • Choi, Chang-Ho
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.17 no.4
    • /
    • pp.1-13
    • /
    • 2018
  • The present study was conducted to analyze transport mode choice factors of shippers in Korea and to suggest policy implications and directions for future research. The findings showed that the research on freight mode choice factors in Korea is somewhat insufficient compared to that of other countries. In order to enhance the research, it is necessary to expand the number of studies and to strengthen the research to reflect characteristics of each transport mode. In particular, it is necessary to focus on identifying the characteristics of multimodal transport, including railway and shipping linked to truck. On the other hand, it was confirmed that the major factors influencing the choice of transport mode of shippers in Korea overlapped with foreign research cases. In addition, the implications for policy were derived when the analysis was separately conducted for Korea and other countries regarding individual transport mode and transport range. These results could be applied to various fields such as policy making to improve the efficiency of shippers' selection of transport mode and the estimation of transport mode choice model.

Water Vapor Transport Properties of Nonwoven Batting Materials (부직포 충전재의 수분투파성)

  • Kim, Hui-Suk;Na, Mi-Hui;Kim, Eun-Ae
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.22 no.1
    • /
    • pp.72-79
    • /
    • 1998
  • Journal of the Korean Society of Clothing and Textiles Vol. 22, No. 1 (1998) p. 72∼79 The purpose of this study was to investigate the effects of geometrical structure and fiber type on the water vapor transport properties of nonwoven batting materials. Two types of fiber were used such as polyester and wool. Correlation between physical properties of nonwovens and water vapor transport rate was analyzed by Pearson Correlation. Steady and dynamic state water vapor transport properties were measured by absorption, evaporation and cobaltots chloride method respectively. The results were as follows: 1) In geometrical structure, thickness of nonwovens was effected on absorption and evaporation rate and air permeability was more influencing factor on water vapor transport rate than porosity. There were no decreasing of water vapor transport rate in hydrophilic fiber at high relative humudity. 2) The hydrophilicity of fiber affected steady and dynamic state water vapor permeabilities and wool nonwoven showed higher water vapor transport rate than polyester at high relative humidity. 3) Thickness showed higher correlation coefficient with water vapor transport rate than other physical properties of nonwovens.

  • PDF

Reaarding Effect of Dietary Fibers Isolated from Tangerine Peels on Glucose, Bile Acid, Cadmium transport In Vitro (감귤과피로부터 분리한 식이섬유의 포도당, 담즙산, 카드뮴 투과억제에 관한 In Vitro 연구)

  • 김미경
    • Journal of Nutrition and Health
    • /
    • v.30 no.2
    • /
    • pp.210-219
    • /
    • 1997
  • Retarding effects of the dietary fibers from tangerine peels on glucose, bile acid and cadmium transport were evaluated by dialysis method, and were compared with those of commercial dietary fibers(citrus pection, CM-cellulose, guar gum, $\alpha$-cellulose). Yields of total (TDF), insoluble(IDF) and soluble dietary fibers(SDF) from tangerine peels on the fresh matter basis were 2.84%, 1.95% and 0.39% respectively. The amount of insoluble fibers was 5.2 times higher than that of soluble fibers. Soluble fibers(guar gum, CM-cellulose, SDF, pectin) had the retarding effect on glucose transport, while IDF, TDF and $\alpha$-cellulose did not have. Guar gum showed the greatest effect, followed by CM-cellulose, SDF and pectin. Among the extracted fibers, only SDF had the effect on glucose transport retardation. Regarding bile acid dialysis, guar gum had the greatest retarding effect, and all dietary fibers from tangerine peels, especially SDF, showed the effect of bile acid retardation. On cadmium transport retardation, CM-cellulose had the greatest effect, followed by SDF, TDF, IDF, guar gum and pectin. Among the extracted fibers, SDF had the greatest effect on Cd trasport transport retardation. The extracted dietary fibers showed higher retarding effect on Cd transport than glucose and bile acid transport, and the effect of SDF was higher than IDF.

  • PDF