• Title/Summary/Keyword: effective diffusion

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Ion Nitriding Using Pulsed D.C Glow Discharge Combined with Inductively Coupled Plasma (펄스직류방전과 유도결합방전의 복합에 의한 SCM440강의 이온질화)

  • Kim, Yoon-Kee
    • Journal of the Korean institute of surface engineering
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    • v.43 no.2
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    • pp.91-96
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    • 2010
  • SCM440 steels were nitrided using pulsed dc plasma combined with inductively coupled plasma (ICP) generated by 13.56 MHz rf power in order to enhance case hardening depth. The case hardening depth was increased with rf power. The effective case-depth with ICP at 900 watt was as 1.6 times as that nitrided without ICP. The hardening depth was also increased up to 1.45 times. The compound layers formed on top surface were dense and thin when pulsed dc plasma was combined with ICP.

Strategic Management of Royalty System in the National R&D Programs for Industrial Technology (국가연구개발사업의 기술료 제도 개선: 산업 기술개발사업을 중심으로)

  • 박정희;문태희;손소영
    • Journal of Technology Innovation
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    • v.13 no.3
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    • pp.131-151
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    • 2005
  • Industrial Technology Development Program enables the recipient to set up technology infrastructure and to facilitate technology diffusion. In return, government charges royalty from the program recipient. However, the current royalty system is not in the effective form. This study analyzes the various aspects of royalty collection methods applied to the Industrial Technology Development Program and recommend the following: (1) employ the combination of fixed amount royalty and running royalty with predetermined portion of revenue generated, (2) adjust the royalty collection duration by applying product life cycle, and (3) devise new program to link extra-gain from royalty collection with commercialization and other means to increase the effectiveness of research and development activities.

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Bulky carbon layer inlaid with nanoscale Fe2O3 as an excellent lithium-storage anode material

  • Nguyen, Thuy-An;Lee, Sang-Wha
    • Journal of Industrial and Engineering Chemistry
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    • v.68
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    • pp.140-145
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    • 2018
  • Bulky carbon layer uniformly distributed with nanoscale $Fe_2O_3$ was prepared via a direct carbonation of $Fe^{3+}$-polyacrylonitrile complexes at $700^{\circ}C$ under $N_2$ flow. The iron oxide carbon composites exhibited an excellent cycling performance for lithium storage with a reversible capacity of ${\sim}810mAh\;g^{-1}$ after 250 cycles at a current rate of $100mA\;g^{-1}$. The enhancement was mainly attributed to dual functions of bulky carbon layer which facilitated the lithium-ion diffusion and accommodated the volume changes of active $Fe_2O_3$ during charge/discharge process. Our novel chemical strategy is quite effective for scalable fabrication of high capacity lithium-storage materials.

Memristive Devices Based on RGO Nano-sheet Nanocomposites with an Embedded GQD Layer (저결함 그래핀 양자점 구조를 갖는 RGO 나노 복합체 기반의 저항성 메모리 특성)

  • Kim, Yongwoo;Hwang, Sung Won
    • Journal of the Semiconductor & Display Technology
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    • v.20 no.1
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    • pp.54-58
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    • 2021
  • The RGO with controllable oxygen functional groups is a novel material as the active layer of resistive switching memory through a reduction process. We designed a nanoscale conductive channel induced by local oxygen ion diffusion in an Au / RGO+GQD / Al resistive switching memory structure. A strong electric field was locally generated around the Al metal channel generated in BIL, and the local formation of a direct conductive low-dimensional channel in the complex RGO graphene quantum dot region was confirmed. The resistive memory design of the complex RGO graphene quantum dot structure can be applied as an effective structure for charge transport, and it has been shown that the resistive switching mechanism based on the movement of oxygen and metal ions is a fundamental alternative to understanding and application of next-generation intelligent semiconductor systems.

The Development of Subject Gateway and Library Operating Model for the Diffusion of Entrepreneurship ― Focus on Job and Employment Services

  • Park, Ok Nam
    • International Journal of Knowledge Content Development & Technology
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    • v.11 no.1
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    • pp.7-27
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    • 2021
  • High unemployment rates repeatedly cause recurring social problems such as fewer employment opportunities and employment insecurity. Following this trend, various programs related to employment have been provided through various government and institutions. However, they have established overlapping policies and programs and there is no one stop gateway to find effective and efficient way to find relevant information. For this purpose, this study aims to provide employment and job search subject gateway development. The study has carried out case studies, literature reviews, and user survey. Based on this study, it suggested a linked metadata model to organize and link scattered information together, and a digital gateway operating diverse information services. It is expected to provide a basis to develop comprehensive information service model for employment.

IMPLEMENTING WEB-BASED COLLABORATION PLATFORMS IN CONSTRUCTION: EVALUATING THE LANE COVE TUNNEL (LCT) EXPERIENCE

  • Rodney A. Stewart ;Debbie Smit ;Martin Betts
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.544-549
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    • 2005
  • Web-based collaboration platforms present construction project teams with an opportunity to improve the efficiency of document exchange, better control project communications and enhance team collaboration. However, many construction professionals are still not convinced that these platforms, in their current form, are fit-for-purpose and yield sufficient efficiencies for the construction procurement process. In an attempt to improve the current ICT diffusion process, this paper evaluates the implementation of a web-based collaboration tool on the Lane Cove Tunnel (LCT) project in Sydney, Australia. Moreover, the paper provides strategies for achieving more effective implementation of web-based collaboration platforms in the construction sector.

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Effect of Nickel Addition in Hot Dip Galvanizing of Mini-mill Steels Containing Silicon (실리콘을 함유한 미니밀 소재의 용융아연도금성에 미치는 니켈첨가의 영향)

  • Lee, H.J.;Kim, J.S.;Chung, J.H.
    • Journal of the Korean institute of surface engineering
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    • v.32 no.2
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    • pp.157-164
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    • 1999
  • In this study the effect of nickel addition on the coating weight of mini-mill steels containing silicon has been studied. It is shown that the pure zinc accelerated growth of the alloy layers occurred by a rapid growth of the zeta phase at 0.06%Si. The addition of 0.06%Ni to a pure zinc bath was found to be very effective in reducing the coating weight and promoting preferential development of the delta phase. The coating obtained by immersion in the Zn-Ni bath shows the presence of a nickel-rich region between the zeta phase and the eta phase. It is suggested that nickel prevents the rapid growth of the zeta phase due to the formation of the Zn-Ni-Fe ternary compound, which may act as a barrier to inward diffusion of zinc or iron at the zeta-eta boundary.

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Predicting drying shrinkage of steel reinforced concrete columns with enclosed section steels

  • Jie Wu;Xiao Wei;Xiaoqun Luo
    • Steel and Composite Structures
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    • v.47 no.4
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    • pp.539-550
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    • 2023
  • Owing to the obstruction of section steel on the moisture diffusion in concrete, the existing shrinkage prediction models overestimate the time-dependent deformation of steel reinforced concrete (SRC) columns, particularly for the SRC columns with enclosed section steels. To solve this issue, this study deals with analytical and experimental studies on the drying shrinkage for this type of column. First, an effective method for predicting the drying shrinkage of concrete based on finite element model is introduced and two crucial parameters for simulation of humidity field are determined. Then, the drying shrinkage of SRC columns with enclosed section steels is investigated and two modified parameters, which depend on the ambient relative humidity and the ratio of section steel size to column size, are introduced to the B3 model. Finally, an experiment on the shrinkage deformation of SRC columns with enclosed section steels is conducted. Comparing the predicted results with the experimental ones, it demonstrates that the modified B3 model is quite reasonable.

Findings from the Survey Responses by Cambodian Doctors and Patients for Telemedicine (캄보디아 환자와 의사의 원격 의료에 대한 반응 조사)

  • Yoo, Sun-gil;Oh, Dongik;Min, Sedong;Shin, Wonhan
    • Journal of Internet Computing and Services
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    • v.16 no.4
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    • pp.13-23
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    • 2015
  • In order to reduce public medical expenses as well as to provide effective medical services, telemedicine between doctors and patients is considered as an alternative to the conventional hospital visit. But the medical community has been protesting the introduction of telemedicine for the efficacy and safety reasons. Korean government has been conducting a number of pilot projects to demonstrate the efficacy and safety of telemedicine for more than 10 years. However, still the system is not yet legalized. In this study, we have conducted a telemedicine pilot project in Cambodia for one year, where telemedicine can be more freely exercised. After the project, we conducted a survey based on the 'Rogers diffusion' theory. Survey results show that both physicians and patients are positive about the relative advantage of the telemedicine. However, the complexity and high cost of the equipment used in telemedicine has been found to be a possible obstacle. In addition, we found that there is no problem for providing telemedicine services under challenged environment, such as in Cambodia.

Probabilistic Service Life Evaluation for OPC Concrete under Carbonation Considering Cold Joint and Induced Stress Level (콜드조인트 및 재하 응력을 고려한 탄산화에 노출된 OPC 콘크리트의 확률론적 내구수명평가)

  • Kwon, Seung-Jun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.6
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    • pp.45-52
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    • 2019
  • Steel corrosion due to carbonation in RC (Reinforced Concrete) structures easily occurs in urban cities with high CO2 concentration. RC structures are always subjected to external loading with various boundary conditions. The induced stress level causes changes in diffusion of harmful ion like CO2. In this work, a quantification of carbonation progress with stress level is carried out and carbonation prediction is derived through the relations. Determining the design parameters like cover depth, CO2 diffusion coefficient, carbonatable materials, and exterior CO2 concentration as random variables, service lifes under carbonation with design parameter's variation are obtained through MCS(Monte Carlo Simulation). Additionally the service life with different stress level is derived and the results are compared with those from deterministic method. Cover depth and cement hydrates are evaluated to be very effective to resist carbonation, and the proposed method which can consider the effect of stress on service life can be applied to maintenance priority determination.