• Title/Summary/Keyword: charge transport

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A Study on the Railroad Logistics Information Standardization and Information System Improvement (철도 물류 정보 표준화 방안 및 정보시스템 개선에 대한 연구)

  • Ahn, Kyeong-Rim;Kim, Dong-Hee;Park, Chan-Kwon;Park, Jung-Chun
    • The Journal of Society for e-Business Studies
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    • v.13 no.3
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    • pp.121-135
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    • 2008
  • Railroad logistics transporting freight by train takes charge of 10 or 20 percent of domestic cargos. Railroad logistics users such as transport companies including shippers or Inland Container Depot(ICD) use electronic document(EDI or XML) or input data through WEB to process railroad logistics business. However, as business environments evolving into e-business, it is required to upgrade the legacy railroad logistics process. As the increase of using ebXML-based schema format, it is also needed to improve the electronic documents based on DTD format into those of XML schema format. This study deals with information standard for railroad logistics to improve the railroad logistics business. To this purpose railroad business processes were re-defined through the standard business process modeling methodology. Information model was also derived by defining railroad logistics activities from business process model. And Business Information Entities(BIEs) were defined to design new electronic documents according to the extracted information model. An improved system architecture for railroad logistics was proposed as well. The results of this study will provide an effective and flexible business flow to railroad logistics business.

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Corona Discharge Characteristics and Particle Losses in a Unipolar Corona-needle Charger Obtained through Numerical and Experimental Studies

  • Intra, Panich;Yawootti, Artit;Rattanadecho, Phadungsak
    • Journal of Electrical Engineering and Technology
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    • v.12 no.5
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    • pp.2021-2030
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    • 2017
  • In this paper, the unipolar corona-needle charger was developed and its capabilities were both numerically and experimentally investigated. The experimental corona discharges and particle losses in the charger were obtained at different corona voltage, aerosol flow rate and particle diameter for positive and negative coronas. Inside the charger, the electric field and charge distribution and the transport behavior of the charged particle were predicted by a numerical simulation. The experimental results yielded the highest ion number concentrations of about $1.087{\times}10^{15}ions/m^3$ for a positive corona voltage of about 3.2 kV, and $1.247{\times}10^{16}ions/m^3$ for a negative corona voltage of about 2.9 kV, and the highest $N_it$ product for positive and negative coronas was found to about $7.53{\times}10^{13}$ and $8.65{\times}10^{14}ions/m^3$ s was occurred at the positive and negative corona voltages of about 3.2 and 2.9 kV, respectively, and the flow rate of 0.3 L/min. The highest diffusion loss was found to occur at particles with diameter of 30 nm to be about 62.50 and 19.33 % for the aerosol flow rate of 0.3 and 1.5 L/min, respectively, and the highest electrostatic loss was found to occur at particles with diameters of 75 and 50 nm to be about 86.29 and 72.92 % for positive and negative corona voltages of about 2.9 and 2.5 kV, respectively. The numerical results for the electric field distribution and the charged particles migration inside the charger were used to guide the description of the electric field and the behavior of charged particle trajectories to improve the design and refinement of a unipolar corona-needle charger that otherwise could not be seen from the experimental data.

A Study on The Reality of Loran-C System and Its Applications (로란-C 시스템의 현황과 효율적인 활용방안에 관한 연구)

  • Kwon, Hyuk-Dong;Seo, Ki-Yeol;Park, Gyei-Kark
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.10 no.2 s.21
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    • pp.61-67
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    • 2004
  • The development motive and maintenance of navigation system were military strategy purpose since middle of 20th century. During cold war period between the United States and the Soviet since the Second World War, advanced navigation system that two countries are responded individually have done development competitively. These systems are exhibited on general except military purpose gradually and are taking charge of point role in economy transport activity such as transportation of logistics between the country. Navigation system can divide into ground system and satellite system. Representative system of ground system is Loran-C(Long Range Navigation), and representative system of satellite system is GPS(Global Position System). Loran-C system is a system that use much in all the world country sea and ground, but GPS and DGPS that present is a satellite navigation system are used much. According to development of satellite system, examine about actual conditions of Loran-C navigation system and practical use plan in this paper because there is controversy about role of Loran-C navigation device along with Loran-C's operation and user decrease, and discusses for Loran-C's development direction.

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A Study on Trucker Recognition in Korean Cargo Distribution O2O Business Model (화물유통 O2O 비즈니스모델에 대한 차주의 인식 연구)

  • Coo, Byung-Mo
    • Journal of Distribution Science
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    • v.15 no.2
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    • pp.79-90
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    • 2017
  • Purpose - Cargo Distribution O2O Business Model is the form of business that connects the cargo and empty cargo-truck based on mobile online platform. In Korean cargo distribution market, FIN(Freight Information Network) is the only model that represents O2O Business Model. The purpose of this paper is investigating the recognition of driver who is the only source of income toward cargo distribution O2O Business Model, and based on the investigated recognition of trucker, suggesting strategic implication. Research design, data, and methodology - PESTLE methodology which is massive environment analysis, and 5 Forces Model when analyze the present and future of cargo distribution O2O business market of industrial structure analysis were used as investigation methodology. Also structured questionnaire was used for trucker's recognition investigation. Based on collected 196 structured effective questionnaires organized with 26 questions were analyzed using statistics package. Results - 51.3% of responded driver is non-differentiated, deprofessionalize form that transport all types of cargo. 95.4% recognize cargo distribution O2O Business Model, FIN is needed, especially during back-hall(94.7%). As a payment method, monthly due is preferred(73%), but it is also needed to pay annual due and pay whenever cargo and cargo-truck are connected(24.5%). Trucker prefer FIN operation corporation which has rich supply(85.2%), and is liberal in supply in any domestic area(75.5%). Conclusions - First, 91% was the member of FIN, and 95% of non-member recognized FIN is needed. 83% of them has the intent to be the member of FIN. Second, besides of monthly due as payment method of FIN, 25% has positive recognition toward new payment method. The new payment method means paying annual due and pay whenever cargo and cargo-truck are connected. Third, because of information imbalance about the cargo and cargo-truck among, operators whose business goal is FIN, it was investigated that transportation fee is low and commission charge of broker is high. The core of Korean Cargo Distribution O2O Business Model, FIN, is online platform that matches cargo and cargo-truck. Therefore, FIN operator should minimize the amount of single transportation of trucker. This study suggests the development of shipper using FIN, diversify distribution channel, suggesting backhaul toward trucker as solution to FIN operator.

An Exploration on Food Waste Management of Local Governments (전국 지방자치단체의 음식물쓰레기 관리 분석)

  • Oh, Jeongik;Lee, Hyunjeong
    • Journal of Korean Society of Environmental Engineers
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    • v.38 no.3
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    • pp.101-109
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    • 2016
  • This research is to explore food waste management across local governments. In particular, pubic administration on food waste, food waste management (from generation to disposal) and civil complaints in jurisdiction are examined. In doing so, a self-administered questionnaire survey was conducted among civil officers in charge of food waste management, and all the collected responses were statistically analyzed. The main results were as follows: public spending on food waste management was a little larger in metropolises than in provincial cities, and the largest food waste source was identified as households (in housing). While regular collection of food waste by trucks was the most common transport method adopted by local governments, resource recovery for compost/fertilizer production was widely used. Also, most of the respondents agreed that the current approach to food waste handling practices are necessarily replaced with more advanced technology converting waste into energy or fuel. Further, it's found that the civil complaints on food waste management were largely categorized into 3 groups - food waste handling, civil service and food waste retrieval. Therefore, the findings indicate that the development and application of no-food waste or waste-to-resource systems are effective in housing estates where large amount of food waste is generated and eliminated.

Anode Properties of TiO2 Nanotube for Lithium-Ion Batteries (리튬이온전지용 TiO2 나노튜브 음전극 특성)

  • Choi, Min Gyu;Lee, Young-Gi;Kim, Kwang Man
    • Korean Chemical Engineering Research
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    • v.48 no.3
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    • pp.283-291
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    • 2010
  • In this review, the studies on the electrochemical properties of $TiO_2$ nanotube as an anode material of lithium-ion battery, which was prepared by an alkaline hydrothermal reaction and anneling process, were investigated andanalyzed in terms of charge-dischage characteristics. Up to date, a maximum discharge capacity of $338mAh\;g^{-1}$(x=1.01) was achieved by the nanotube with $TiO_2(B)$ phase, whereas the theoretical capacity of $TiO_2$ anode was $335mAh\;g^{-1}$(x=1) in the basis of $Li_xTiO_2$ as a product of electrochemical reaction between $TiO_2$ and lithium. This was due to fast lithium transport by a shortened diffusion path provided by controlling the nanostructure of $TiO_2$, because the self-diffusion of lithium was slow in a basis of its activation energy as 0.48 eV. Due to an excellent ion storage capabilities in both the surface and the bulk phase, the $TiO_2$ nanotube could be a promising active material as both an anode of lithium-ion battery and an electrode of capacitor with high-rate performances.

Effect of Force-field Types on the Proton Diffusivity Calculation in Molecular Dynamics (MD) Simulation (분자동역학 전산모사에서 force-field의 종류가 수소이온 확산도 계산에 미치는 영향)

  • Lee, Ji Hyun;Park, Chi Hoon
    • Membrane Journal
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    • v.27 no.4
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    • pp.358-366
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    • 2017
  • The most important factor in the performances of polymer electrolyte membranes for fuel cells is how fast hydrogen ions can be transported along the water channel formed inside the electrolyte membrane. Since the morphology of the water channel and the diffusivity of the protons are very important factors for the proton transport behavior, various molecular dynamics simulation studies are being carried out to clarify this. The force-field is an important variable parameterizing the movement and interaction of each atom in molecular dynamics simulation. In this study, proton diffusivities of the 3D models of polymer electrolyte membranes were calculated in order to analyze the effects of various types of force-fields on the molecular simulation. It has been found that the charge value determining the non-bonding interaction plays a very important role in the formation of the water channel morphology, and the COMPASS force-field can calculate the accurate proton diffusion behavior. Accordingly, for molecular dynamics simulation of polymer electrolyte membranes, the proper selection of the force-field is very important due to its great effect on the proton diffusion as well as the final molecular structure.

Organo-Compatible Gate Dielectrics for High-performance Organic Field-effect Transistors (고성능 유기 전계효과 트랜지스터를 위한 유기친화 게이트 절연층)

  • Lee, Minjung;Lee, Seulyi;Yoo, Jaeseok;Jang, Mi;Yang, Hoichang
    • Applied Chemistry for Engineering
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    • v.24 no.3
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    • pp.219-226
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    • 2013
  • Organic semiconductor-based soft electronics has potential advantages for next-generation electronics and displays, which request mobile convenience, flexibility, light-weight, large area, etc. Organic field-effect transistors (OFET) are core elements for soft electronic applications, such as e-paper, e-book, smart card, RFID tag, photovoltaics, portable computer, sensor, memory, etc. An optimal multi-layered structure of organic semiconductor, insulator, and electrodes is required to achieve high-performance OFET. Since most organic semiconductors are self-assembled structures with weak van der Waals forces during film formation, their crystalline structures and orientation are significantly affected by environmental conditions, specifically, substrate properties of surface energy and roughness, changing the corresponding OFET. Organo-compatible insulators and surface treatments can induce the crystal structure and orientation of solution- or vacuum-processable organic semiconductors preferential to the charge-carrier transport in OFET.

Electrical Transport Properties of La2/3TiO2.84 Ceramic (La2/3TiO2.84 세라믹스의 전기전도특성)

  • Jung, Woo-Hwan
    • Journal of the Korean Ceramic Society
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    • v.41 no.11
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    • pp.858-863
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    • 2004
  • The thermoelectric power, dc conductivity and magnetic properties of the cubic L $a_{2}$ 3/Ti $O_{2.84}$ were investigated. The thermoelectric power was negative below 350 K. The measured thermoelectric power of L $a_{2}$ 3/Ti $O_{2.84}$ increased linearly with temperature, in agreement with model proposed by Emin and Wood, and was represented by A+BT. Temperature dependence indicates that the charge carrier in this material is a small polaron. L $a_{2}$ 3/Ti $O_{2.84}$ exhibited a cross over from variable range hopping to small polaron hopping conduction at a characteristic temperature well below room temperature. The low temperature do conduction mechanism in L $a_{2}$ 3/Ti $O_{2.84}$ was analyzed using Mott's approach. Mott parameter analysis gave values for the density of state at Fermi level [N( $E_{F}$)] = 3.18${\times}$10$^{20}$ c $m^{-3}$ e $V^{-1}$ . The disorder energy ( $W_{d}$) was found to be 0.93 eV, However, it was noted that the value of the disorder energy was much higher than the high temperature activation energy. The exist linear relation between log($\sigma$T)와 1/T in the range of 200 to 300 K, the activation energy for small polaron hopping was 0.15 eV.

The Effect of Surfactant on Controlled Release of Amino acids Through Poly(2-Hydroxyethyl Methacrylate) Membrane (Poly(2-Hydroxyethyl Methacrylate)막을 통한 아미노산의 방출 조절에 대한 계면활성제의 효과)

  • Kim Ui-Rak;Jeong Bong-Jin;Lee Myung-Jae;Min Kyung-Sub
    • Journal of the Korean Chemical Society
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    • v.37 no.1
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    • pp.22-35
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    • 1993
  • The transport phenomena of the free amino acids through poly(hydroxyethyl methacrylate)[P(HEMA)] have been investigated with and without various kinds of surfactants solution and in the mixed surfactants solution. Glutamine has the highest diffusivity among 4 amino acids at 1CMC of cetyldimethylethylammonium bromide(CTABr) surfactant. Glutamic acid is not affected by the concentration of CTABr. Methionine and Lysine shows slight decreased diffusivity at 0.5 CMC, but increase its diffusivity at 1CMC and 2CMC due to the structure change of membrane and the viscosity change of surfactant solution. Glutamic acid has the highest diffusivity among four amino acids at sodium dodecyl sulfate(SDS) and Triton X-100 surfactant. In mixed surfactant solution, each amino acids shows high diffusivity through 45% water content membrane at the 0.5 mole fraction of SDS in the SDS/TX-100 surfactant mixtures. It has been found that not only the property of membrane but also the effects of solute-solvent interactions and solvent effect are very important as the permeation of amino acids occurs through P(HEMA) membrane. The diffusivities of free amino acids through membrane depend upon their molecular shape, size and charge.

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