• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.2
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• pp.10-19
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• 2009

The working of diesel particulate filters(DPF) needs to periodically burn soot that has been accumulated during loading of the DPF. The prediction of the relation between an uniformity of gas velocity and soot regeneration efficiency with simulations helps to make design decisions and to shorten the development process. This work presents a comprehensive combined 'DOC+CDPF' model approach. All relevant behaviors of flow fluid are studied in a 3D model. The obtained flow fields in the front of DPF is used for 1D simulation for the prediction of the thermal behavior and regeneration efficiency of CDPF. Validation of the present simulation are performed for the axial and radial direction temperature profile and shows goods agreement with experimental data. The coupled simulation of 3D and 1D shows their impact on the overall regeneration efficiency. It is found that the flow non-uniformity may cause severe radial temperature gradient, resulting in degrading regeneration efficiency.

• KIEAE Journal
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• v.16 no.5
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• pp.93-101
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• 2016

Purpose : This research aims to present policy plans for community vitality in the field of the urban regeneration project by analyzing aspects for vitality via domestic and abroad city policies and cases. Methods: The research method works as follows: The first step is 1) to introduce the concept of evaluation matrix to analyze cases of urban generation, 2) to apply to the proposed evaluation matrix, and then 3) to analyze communities' decline diagnosis, counterstrategies, and promotion process. And the second step is to draw features and evaluation of cases and to present the policy plan for communities' vitality with the urban regeneration project in South Korea via a comprehensive analysis. Result : This research confirmed the fact that when different sectors is expanded toward a mutual cooperation, communities are vitalized, having a mutual effect on other related sectors by taking a part in the community positively. Especially in the base of each characteristic and estimation, when various activities and socio-economic programs with residents are promoted in the integrated system, communities are successful. Through this results we present four policy plans for community vitality of the urban regeneration project in South Korea.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.4
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• pp.167-173
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• 2005

Thermal regeneration means burning-off and cleaning-up the particulate matters piled up in DPF(diesel particulate filter), and it requires both high temperature $(550\~600^{\circ}C)$ and appropriate concentration of oxygen at DPF entrance. However, it is not easy to satisfy such conditions because of the low temperature window of the HSDI(high speed direct injection) diesel engine(approximately $200\~350^{\circ}C$ at cycle). Therefore, this study is focused on the method to raise temperature using the trade-off relation between temperature, oxygen concentration, and the influence of many parameters of common rail injection system including post injection. After performing an optimal mapping of the common rail parameters for regeneration mode, the actual cleaning process during regeneration mode is investigated and evaluated the availability of the regeneration mode mapping through regenerating soot trapped in the DPF.

• Current Applied Physics
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• v.18 no.12
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• pp.1600-1604
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• 2018

This paper reports on a systematic and quantitative assessment of light induced degradation (LID) and regeneration in full Al-BSF and passivated emitter rear contact cells (PERC) along with the fundamental understanding of the difference between the two. After LID, PERC cells showed a much greater loss in cell efficiency than full Al-BSF cells (~0.9% vs ~0.6%) because the degradation in bulk lifetime also erodes the benefit of superior BSRV in PERC cells. Three main regeneration conditions involving the combination of heat and light ($75^{\circ}C/1\;Sun/48h$, $130^{\circ}C/2\;Suns/1.5h$ and $200^{\circ}C/3\;Suns/30s$) were implemented to eliminate LID loss due to BO defects. Low temperature/long time ($75^{\circ}C/48h$) and high temperature/short time ($200^{\circ}C/30s$) regeneration process was unable to reach 100% stabilization. The intermediate temperature/time ($130^{\circ}C/1.5h$) generation achieved nearly full recovery and stabilization (over 99%) for both full Al-BSF and PERC cells. We discussed the effect of temperature, time and suns in regeneration mechanism for two cells.

• Journal of Periodontal and Implant Science
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• v.40 no.3
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• pp.125-131
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• 2010

Purpose: Among available biomaterials, bioceramics have drawn special interest due to their bioactivity and the possibility of tailoring their composition. The degradation rate and formulation of bioceramics can be altered to mimic the compositions of the mineral phase of bone. The aim of this study was to investigate the bone formation effect of amorphous calcium phosphate glass cement (CPGC) synthesized by a melting and quenching process. Methods: In five male beagle dogs, $4{\times}4$ mm 1-wall intrabony defects were created bilaterally at the mesial or distal aspect of the mandibular second and fourth premolars. Each of the four defects was divided according to graft materials: CPGC with collagen membrane (CM), biphasic calcium phosphate (BCP) with CM, CM alone, or a surgical flap operation only. The dogs were sacrificed 8 weeks post-surgery, and block sections of the defects were collected for histologic and histometric analysis. Results: There were significant differences in bone formation and cementum regeneration between the experimental and control groups. In particular, the CPGC and BCP groups showed greater bone formation than the CM and control groups. Conclusions: In conclusion, CPGC was replaced rapidly with an abundant volume of new bone; CPGC also contributed slightly to regeneration of the periodontal apparatus.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.7006-7012
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• 2015

Urban regeneration can be an effective tool to promote sustainability and enhance quality of village. Urban regeneration can be considered to be the process of reversing economic, social and physical decay having reached the point where market forces alone will not suffice. For this study, 154 village activist trainees are surveyed. Using the survey results, factor analysis, multi-regression analysis is conducted to identify the factor's significance and to find improvement properties by composing the significance and the satisfaction level. The purpose of this study is to suggest strategy of urban regeneration through the effect of urban regeneration factor on recognition and satisfaction. The findings show that environmental regeneration factor is more influential than economic, social and cultural factors on recognition and satisfaction. This study provide a convenient set of indicators for strategic focus to help urban regeneration policy.

• Korean Journal of Construction Engineering and Management
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• v.11 no.3
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• pp.43-54
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• 2010

As Urban Regeneration is being carried out, stakeholders are most likely to have disagreements on their interests. Besides, dispersion of numerous communication routes and obscure decision processes aggravate the situation. Eventually, fragmented decision-making processes and complex structure lead to inefficient outcome and delay of projects. This paper is a study on decision-making support not only helps the program manager have more efficient and optimum decision, but also provides alternatives for Urban Regeneration. This study is conducted as follows. Firstly, the project process and the decision-making structure among stakeholders in Urban Regeneration are analyzed, and then the current status of decision-making in Urban Regeneration project is classified. Secondly, with literature study on "Gateway Review", the decision-making gateway review process in Urban Regeneration is defined, and then the "Gateway Review Elements" are listed. Thirdly, to establish gateway review process, this paper presents a check points, namely gate which supports a program manager to monitor and to control the program management in Urban Regeneration. Each gate has several supporting tools such as diagram of critical decision points relation, scheme of stakeholder, checklist. Fourthly, the proposed concept is verified by experts who have been carefully selected to provide their respective reviews. Finally, decision-making support gateway review system is modified based on their critiques and suggestions.

• Korean Chemical Engineering Research
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• v.43 no.3
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• pp.432-437
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• 2005

An electric swing adsorption (ESA) process for recovering highly pure $CO_2$ from the mixed gases was tested. In this study, activated carbon fibers were used as an adsorbent. The activated carbon fibers showed fast adsorption rate and the high adsorption capacity for $CO_2$ adsorption under the condition of the ambient pressure. Activated carbon fiber with higher specific surface area was suitable to repeated adsorption-desorption cycle process, showing consistent breakthrough curve. Especially, the regeneration method by vacuum combined with ESA improved the performance of desorption process by an additional 17％ regeneration efficiency compared to a vacuum only method, and showed the high regeneration efficiency at comparatively low 7-8 Wh energy.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.2
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• pp.161-173
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• 2002

Recently, absorbent biofilters, which are inexpensive and easy to manacle, have been supplied to the rural areas, but have limitations in removing the nutrients effectively. Accordingly, as an alternative plan. natural zeolites were arranged in front or at the rear of the absorbent biofilters, and their removal efficiency for nitrogen and, ultimately, their applicability to the on-site wastewater treatment system were studied. Furthermore, the same experiments were carried out on artificial zeolites, made from coal ashes at National Honam Agricultural Experiment Station, to compare natural zeolites with artificial ones. Treated wastewater through the Absorbent Biofilter showed 22.6% nitrogen removal efficiency, while 64.6% was attained when natural Zeolites were placed in front of the absorbent biofilters (Zeolite-Aerobic process). As an addition, phosphorus was also efficiently removed. On the other hand, Aerobic-Zeolite process, which arranged natural zeolites at the rear of the biofilters, did not have significantly higher nitrogen removal as compared to the treatment using only the absorbent biofilters. Furthermore, upon regeneration of the natural zeolite, the ion exchange rate was fecund to increase over 10% as compared to before regeneration. Our results show that natural zeolites, applied to the on-site wastewater treatment system through the Zeolite-Aerobic process, not only increase the removal efficiency of nutrients, but, by choosing the appropriate regeneration time, can also be cast-effective. Artificial zeolites, on the other hand, though more efficient in removing nutrients, cannot be regenerated and, therefore, are not cost-effective.

• Molecules and Cells
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• v.27 no.4
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• pp.403-408
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• 2009

Skeletal muscle regeneration is a highly orchestrated process initiated by activation of adult muscle satellite cells. Upon muscle injury, the inflammatory process is always accompanied by muscle regeneration. Leukotriene $B_4$ is one of the essential inflammatory mediators. We isolated and cultured primary satellite cells. RT-PCR showed that myoblasts expressed mRNA for $LTB_4$ receptors BLT1 and BLT2, and $LTB_4$ promoted myoblast proliferation and fusion. Quantitative real-time PCR and immunoblotting showed that $LTB_4$ treatment expedited the expression process of differentiation markers MyoD and M-cadherin. U-75302, a specific BLT1 inhibitor, but not LY2552833, a specific BLT2 inhibitor, blocked proliferation and differentiation of myoblasts induced by $LTB_4$, which implies the involvement of the BLT1 pathway. Overall, the data suggest that $LTB_4$ contributes to muscle regeneration by accelerating proliferation and differentiation of satellite cells.