• Title/Summary/Keyword: weak limit

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Influences of Grouting Pressure of Microcement to Upper Structures (지반보강용 마이크로시멘트의 주입압이 상부구조물에 미치는 영향)

  • Hwang, Chul-Sung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.4
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    • pp.70-77
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    • 2010
  • Microcement grouting and micro pile are frequently used for ground modification during tunnel construction. The influence of grouting pressure of microcement grouting and micro pile to the existing bridge which is directly over the constructing tunnel is investigated. Three dimensional seepage flow-structure interactive analysis considering firm water pressure with full stages of construction including the construction of upper bridge, microcement grouting, micro pile and tunnel is performed. The settlement and tilting of the pier of existing bridge violate the design code and the reaction of the bridge are highly increased after grouting. The stress of tunnel bracings such as rockbolt and shotcrete also exceed the limit of the code. The pressure of microcement grouting is confined by bedrock and transmit to the surrounded soil and the upper bridge. Microcement grouting needs mid-high pressure to penetrate through weak fault plane and the pressure greatly influence the safety of the upper structure. It is important to decide and care the grouting pressure to improve weak fault plane directly under the existing structures and the pressure of microcement grouting should be considered in underground analysis.

An Analysis of Indonesia Forest Moratorium: With particular reference to Forest Governance (인도네시아 산림 모라토리엄 분석: 산림 거버넌스를 중심으로)

  • JANG, SangKyung;BAE, Jae Soo
    • The Southeast Asian review
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    • v.23 no.3
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    • pp.49-92
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    • 2013
  • In May 2010, Indonesia and Norway signed a Letter of Intent on "Cooperation on Reducing Greenhouse Gas Emissions from Deforestation and Forest Degradation(REDD)." In the LoI, Norway agreed to offer Indonesia a sum of USD 1 billion with a view to encourage Indonesia to significantly contribute to the successful implementation of REDD+. On 20 May 2011, correspondingly, Indonesia announced the 2011 'Forest Moratorium' (the Presidential Instruction No. 10/2011) which was valid for the following consecutive two years. By means of the 2011 'Forest Moratorium', Indonesia aimed at significant reductions in greenhouse gas emissions from deforestation, forest degradation and peatland conversion. In so doing, it also sought to improve forest governance. Meanwhile, concerned stakeholders also raised various questions about the effectiveness of the 'Forest Moratorium'. As an extension of the 2011 'Forest Moratorium', Indonesia announced the 2013 'Forest Moratorium'(the Presidential Instruction No. 6/2013) for another two-year period on 13 May 2013. Indonesia's 'Forest Moratorium' is concerned with stakeholders at various levels, who may play a role of significant 'agent' in the process of implementing the 'Forest Moratorium'. This mechanism of the 'Forest Moratorium' should be understood in the light of forest governance. Employing stakeholder approach, therefore, this article attempts to analyze Indonesia's 'Forest Moratorium' in the light of forest governance. In this regard, it analyzes the detailed contents of the 'Forest Moratorium', the process of making the 'Forest Moratorium', current development of the Indicative Moratorium Map for suspension of new concessions on forest land, and contesting views of various stakeholders. At the same time, it also talks about how 'weak' forest governance had influence upon Indonesia's 'Forest Moratorium'. In so doing, this article consequently attempts to evaluate Indonesia's 'Forest Moratorium' and also put it into perspective in terms of improving forest governance. The 2013 'Forest Moratorium' fundamentally represents a radical policy that is designed to suspend new concessions on forest conversion for another two-year period and its detailed contents attempt to reflect on various stakeholders from related industries and environmental NGOs. However, there are challenging factors in the process of implementing the 'Forest Moratorium', that is, 'weak' forest governance and also a discrepancy between forest planning maps designated by central and regional governments. The announcement of the 2013 'Forest Moratorium', as an extension of the 2011 'Forest Moratorium', may functionally strengthen and improve Indonesia's forest governance. However, at the same time, there is a practical limit due to the fact that it is merely a Presidential Instruction that lacks legal binding.

Slope Stability Analysis by Slice Method and Finite Difference Method- A Comparative Study - (절편법과 유한차분법에 의한 사면안정해석 비교연구)

  • 박연준;채영수;유광호;백영식
    • Journal of the Korean Geotechnical Society
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    • v.15 no.6
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    • pp.263-272
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    • 1999
  • Slice method is commonly used in solving slope stability problems since it is easy to use and its computation time is rather short. But depending upon the assumptions on the inter-slice forces, different methods are available. Quite often the difference between methods are so big that it is very difficult to make engineering decisions. This paper describes a method to calculate the factor of safety of a slope using FLAC, a finite difference based program. A FISH routine is developed to calculate the factor of safety, and verified by comparing with Chen's limit equilibrium solution. An example problem was selected from Fredlund and Krhan's paper, and results were compared for different soil and water conditions. The difference was less than 0.01 when the soil is homogeneous, and less than 5 % when a weak layer is embedded. Since most geotechnical application programs are capable of considering complicated ground conditions as well as the effect of ground supports, numerical methods are believed to be very useful in making engineering decisions. The developed routine can be applied to the calculation of the factor of safety of jointed rock slopes or weathered rock slopes where the use of slice method is limited.

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A Study on the Development Lightweight Aggregate using Recycled-Paint for Reduction in Freezing Ground (단열골재 개발을 통한 동토방지 기술개발에 관한 연구)

  • Moon, Jong-Wook;Back, Min-Ho
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.4
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    • pp.47-54
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    • 2010
  • This study is progressed function ratio, it's trued taste by an experiment to present data for human work light weight aggregate development that use clink ash progressed liquid limit, small success limit, wear loss in quantity, sand equivalent, sieve cutting examination. 80:20's match of function rain examination is 1.4, and that use rubble aggregate as recyeled-panit lightweight aggregate's capacity ratio increases by 1.0 increase of function rain many. Also, examination multiplied delicate flavor gradually according to increase of the mixing rate, and absorption coefficient increased. This is judged by phenomenon that appear by special quality upper recycled-panit of polystyrene bid and porosity's increase between lightweight aggregate. It is case that use aggregate of wear loss in quantity is 13.5 in sand equivalent and a wear loss in quantity experiment and although case that mix 20% increases by 14.4, this phenomenon by weak tissue of lightweight aggergate be judged. When it's as a these experiment, the statue prevention floor of a street improvement specifications is prescribing so that satisfy by sand equivalent 20, CBR 10. This is showed result that this satisfies in quality standard all in match experiment ago that see.

The Application of Octa-Substituted Metallophthalocyanine Langmuir-Blodgett films for $NO_2$ Measurement (수정진동자를 이용한 프탈로시아닌 LB박막의 $NO_2$ 감지 특성)

  • Kwon, H.J.;Lee, Y.J.;Chang, Y.K.;Kim, J.D.
    • Journal of Sensor Science and Technology
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    • v.7 no.4
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    • pp.254-262
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    • 1998
  • Multilayer Langmuir-Blodgett (LB) films coated on quartz crystal microbalance (QCM) of octa-substituted metallophhtalocyanines ($MPc(OEH)_8$, M = Cu, Co, and Sn) and dihydrogen phthalocyanines ($H_2Pc(OEH)_8$) were used to quantify $NO_2$ concentrations. They were exposed to various concentrations of $NO_2$ in dry $N_2$. Among the four phthalocyanines we tested, the metal-free $H_2Pc(OEH)_8$ was observed to be most sensitive to $NO_2$. However, its LB film showed a partially irreversible behavior, that is part of the frequency change due to $NO_2$ adsorption could not be recovered even after purging with pure $N_2$ gas for an extended period. Examining the spectra of NMR and FTIR revealed fact that the irreversible portion of frequency change was due to ether groups in the linkage between side chains and the Pc unit. In order to remove the effect of such initial deactivation, on $NO_2$ quantification experiment, a freshly fabricated LB film was treated at a high concentration of $NO_2$ so that the ether sites were saturated. A pretreated LB film showed a reproducible performance for repeated uses. The $CuPc(OEH)_8$ LB film showed a satisfactory sensing performance down to as low as 4 ppm. For the $H_2Pc(OEH)_8$ LB film, the lower detection limit was found to be 35ppb of $NO_2$. In order to make the experimental condition more realistic, the carrier gas, dry nitrogen, was replaced by air. It was observed that the presence of oxygen, a weak electron acceptor, reduced the sensitivity and thus increased the sensing limit to hundreds of ppb. Results of experiments with moisture added showed that the interference of moisture was quite severe.

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A Study on the Development Lightweight Aggregate using Clink Ash for Reduction in Freezing Ground (지반의 동결저감 대책기술을 수립하기 위한 클링커애쉬 인공경량골재 개발에 관한 연구)

  • Moon, Jong-Wook
    • Fire Science and Engineering
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    • v.23 no.6
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    • pp.116-125
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    • 2009
  • This study is progressed function ratio, it's trued taste by an experiment to present data for human work light weight aggregate development that use clink ash progressed liquid limit, small success limit, wear loss in quantity, sand equivalent, sieve cutting examination. 80 : 20's match of function rain examination is 1.4, and that use rubble Goljae as ckink ash lightweight aggregate's capacity ratio increases by 1.0 increase of function rain many. Also, examination multiplied delicate flavor gradually according to increase of the mixing rate, and absorption coefficient increased. This is judged by phenomenon that appear by special quality upper clink ash of polystyrene bid and porosity's increase between lightweight aggregate. It is case that use aggregate of wear loss in quantity is 13.5 in sand equivalent and a wear loss in quantity experiment and although case that mix 20% increases by 14.4, this phenomenon by weak tissue of lightweight aggergate be judge. When it's as a these experiment, the statue prevention floor of a street improvement specifications is prescribing so that satisfy by sand equivalent 20, CBR 10. This is showed result that this satisfies in quality standard all in match experiment ago that see.

Three-Dimensional Limit Equilibrium Stability Analysis of Spile-Reinforced Shallow Tunnel

    • Geotechnical Engineering
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    • v.13 no.3
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    • pp.101-122
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    • 1997
  • A spiting reinforcement system is composed of a series of radially installed reinforcing spites along the perimeter of the tunnel opening ahead of excavation. The reinforcing spill network is extended into the in-situ soil mass both radially and longitudinally The sailing reinforcement system has been successfully used for the construction of underground openings to reinforce weak rock formations on several occasions. The application of this spiting reinforcement system is currently extended to soft ground tunneling in limited occasions because of lack of reliable analysis and design methods. A method of threetimensional limit equilibrium stability analysis of the smile-reinforced shallow tunnel in soft ground is presented. The shape of the potential failure wedge for the case of smile-reinforced shallow tunnel is assumed on the basis of the results of three dimensional finite element analyses. A criterion to differentiate the spill-reinforced shallow tunnel from the smile-reinforced deep tunnel is also formulated, where the tunnel depth, soil type, geometry of the tunnel and reinforcing spites, together with soil arching effects, are considered. To examine the suitability of the proposed method of threedimensional stability analysis in practice, overall stability of the spill-reinforced shallow tunnel at facing is evaluated, and the predicted safety factors are compared with results from twotimensional analyses. Using the proposed method of threetimensional limit equilibrium stability analysis of the smile-reinforced shallow tunnel in soft ground, a parametric study is also made to investigate the effects of various design parameters such as tunnel depth, smile length and wadial spill spacing. With slight modifications the analytical method of threeiimensional stability analysis proposed may also be extended for the analysis and design of steel pipe reinforced multi -step grouting technique frequently used as a supplementary reinforcing method in soft ground tunnel construction.

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Fusion Peptide Improves Stability and Bioactivity of Single Chain Antibody against Rabies Virus

  • Xi, Hualong;Zhang, Kaixin;Yin, Yanchun;Gu, Tiejun;Sun, Qing;Shi, Linqing;Zhang, Renxia;Jiang, Chunlai;Kong, Wei;Wu, Yongge
    • Journal of Microbiology and Biotechnology
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    • v.27 no.4
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    • pp.718-724
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    • 2017
  • The combination of rabies immunoglobulin (RIG) with a vaccine is currently effective against rabies infections, but improvements are needed. Genetic engineering antibody technology is an attractive approach for developing novel antibodies to replace RIG. In our previous study, a single-chain variable fragment, scFv57R, against rabies virus glycoprotein was constructed. However, its inherent weak stability and short half-life compared with the parent RIG may limit its diagnostic and therapeutic application. Therefore, an acidic tail of synuclein (ATS) derived from the C-terminal acidic tail of human alpha-synuclein protein was fused to the C-terminus of scFv57R in order to help it resist adverse stress and improve the stability and half-life. The tail showed no apparent effect on the preparation procedure and affinity of the protein, nor did it change the neutralizing potency in vitro. In the ELISA test of molecular stability, the ATS fusion form of the protein, scFv57R-ATS, showed an increase in thermal stability and longer half-life in serum than scFv57R. The protection against fatal rabies virus challenge improved after fusing the tail to the scFv, which may be attributed to the improved stability. Thus, the ATS fusion approach presented here is easily implemented and can be used as a new strategy to improve the stability and half-life of engineered antibody proteins for practical applications.

Sensitivity Enhancement of RF Plasma Etch Endpoint Detection With K-means Cluster Analysis

  • Lee, Honyoung;Jang, Haegyu;Lee, Hak-Seung;Chae, Heeyeop
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.142.2-142.2
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    • 2015
  • Plasma etch endpoint detection (EPD) of SiO2 and PR layer is demonstrated by plasma impedance monitoring in this work. Plasma etching process is the core process for making fine pattern devices in semiconductor fabrication, and the etching endpoint detection is one of the essential FDC (Fault Detection and Classification) for yield management and mass production. In general, Optical emission spectrocopy (OES) has been used to detect endpoint because OES can be a simple, non-invasive and real-time plasma monitoring tool. In OES, the trend of a few sensitive wavelengths is traced. However, in case of small-open area etch endpoint detection (ex. contact etch), it is at the boundary of the detection limit because of weak signal intensities of reaction reactants and products. Furthemore, the various materials covering the wafer such as photoresist (PR), dielectric materials, and metals make the analysis of OES signals complicated. In this study, full spectra of optical emission signals were collected and the data were analyzed by a data-mining approach, modified K-means cluster analysis. The K-means cluster analysis is modified suitably to analyze a thousand of wavelength variables from OES. This technique can improve the sensitivity of EPD for small area oxide layer etching processes: about 1.0 % oxide area. This technique is expected to be applied to various plasma monitoring applications including fault detections as well as EPD.

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Luminescence properties of a new $Tb^{3+}$ ion activated long persistent phosphor (새로운 $Tb^{3+}$ 이온 활성 축광성 형광체의 발광 특성)

  • Park, Byeong-Seok;Choi, Jong-Geon
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.19 no.3
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    • pp.130-134
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    • 2009
  • A new long persistent phosphors of $CaZrO_3$ was synthesized at high temperature with weak reduction atmosphere by a traditional solid state reaction method. Photoluminescence spectra analysis showed that the $CaZrO_3$ doped with $Tb^{3+}$ emitted green-yellow emission caused by the energy level transition from the $^5D_3$ and $^5D_4$ to $^7F_1{\sim}^7F_6$. The main emission spectra of 542 nm peak by the $^5D_4{\rightarrow}^7F_5$ transition was revealed through synthesizing at high temperature in $N_2$ gas atmosphere. The afterglow emission spectra of $CaZrO_3:Tb^{3+}$ long persistent phosphores arise at 546 nm peak of narrow range. After the 254 nm ultraviolet light excitation source was switched off, the green-yellow long persistent phosphor can be observed which could last for 8 h in the limit of light perception of dark-adapted human eyes ($0.32\;mcd/m^2$).