• 제목/요약/키워드: specific field

검색결과 3,177건 처리시간 0.033초

Analysis of Phase Separation by Thermal Aging in Duplex Stainless Steels by Magnetic Methods

  • Kim, Sunki;Wonmok Jae;Kim, Yongsoo
    • Nuclear Engineering and Technology
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    • 제29권5호
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    • pp.361-367
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    • 1997
  • The phase separation in ferrite phase of duplex stainless steel is the primary cause of thermal aging embrittlement of the LWR primary pressure boundary components. In this study the phase separation of simulated duplex stainless steel was detected by Mossbauer spectroscopy and magnetic property analysis by VSM(Vibrating Specimen Magnetometer). The simulated duplex stainless steels, Fe-Cr binary, Fe-Cr-Ni ternary, and Fe-Cr-Ni-Si quarternary allots, were aged at 370 and 40$0^{\circ}C$ up to 5,340 hours. It was observed from Mossbauer spectra analysis that internal magnetic field increases with aging time and from VSM that the specific saturation magnetization and Curie temperature increase with aging time. These result are indicative that phase separation into Fe-rich region and Cr-rich region is caused by thermal aging in the temperature range of 370~40$0^{\circ}C$ In cases of specimens containing Ni, the increase of specific saturation magnetization is much higher. This implies that Ni seems to promote Fe-Cr interdiffusion, which accelerates the phase separation into Fe-rich $\alpha$ phase and Cr-rich $\alpha$' phase.

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철근 콘크리트 공사의 직종별 가동률 비교·분석 (A Comparative Analysis of Operating Ratio for Reinforced Concrete Construction by Occupation classification)

  • 이강협;김민재;신원상;손창백
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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    • pp.200-201
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    • 2014
  • The construction industry in recent years, due to the multi-species engineering specialty, interest and importance of human resource management is growing. But, not many studies on the operation ratio are being proceeded due to the difficulty of casting people on site and actual survey. Thus, this study proposes the work type-specific quantitative operation ratio through work type-specific operation ratio analysis of reinforced concrete construction which takes up an important part of construction work.

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인공 신경망을 이용한 생물공정의 규명 (Neural network method for bioprocess identification)

  • 박정식;이태용
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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    • pp.1002-1005
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    • 1991
  • It is important to express the specific growth rate of a fermentation reaction as a function of substrate and product concentration in developing bioprocess automation techniques such as modeling of the reactor and controlling it via an advanced control scheme. Typical methods of identification utilize graphical representation of the rate constant data or nonlinear regression with an appropriate noise filter. But the former method fails when the data are erroneous and the latter are mathematically complicated to apply in the field. Neural network is another candidate for the identification from time series data since it is insensitive to the random data error and easy to implement. In this study, we will develop a neural network method of specific growth rate estimation from the time series state variable data and test the performance.

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What we have learned about Gamma-ray bright AGNs using the iMOGABA program

  • Lee, Sang-Sung
    • 천문학회보
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    • 제42권2호
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    • pp.45.1-45.1
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    • 2017
  • A Korean VLBI Network Key Science Program, the Interferometric Monitoring of Gamma-ray Bright AGNs (iMOGABA) program continues to aim at revealing the origins of the gamma-ray flares that are often detected in active galactic nuclei (AGNs). Here in this presentation, we would like to present what we have learned about the Gamma-ray bright AGNs based on the recent results of the Korean VLBI Network Key Science Program: the iMGOABA. The results will include a) the source properties of the whole samples obtained from a single-epoch observation, and b) some of scientific highlights for the iMOGAGBA on specific sources. From those highlighted works, we find that the Gamma-ray bright AGNs become fainter at higher frequencies, yielding optically thin spectra at mm wavelengths. Based on the studies on specific sources, taking into account the synchrotron self-absorption model of the relativistic jet, we estimated the magnetic field strength in the mas emission region during the observing period.

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열간압연한 Fe-17wt%Mn 합금의 기계적 성질과 진동감쇠능에 미치는 티타늄 첨가의 영향 (Effects of Ti on Mechanical Property and Damping Capacity in Hot-rolled Fe-17%Mn Alloy)

  • 김태훈;김정철
    • 한국주조공학회지
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    • 제29권2호
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    • pp.59-63
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    • 2009
  • Effects of Ti on damping capacity and mechanical properties are investigated in hot rolled Fe-17%Mn alloy. The existing damping alloy with Fe-Mn binary system was limited the use by high production cost, however in case of using scrap iron instead of pure iron although the content of carbon is higher it is possible to be applied wider field especially construction items because the production cost is lower. However, the excellent specific damping capacity is dropped due to the high content of carbon, we developed advanced type of damping alloy included Ti. TiC is formed with added Ti and it holds the specific damping capacity similar to existing damping alloy. The effect of Ti on damping capacity is found to be beneficial in carbon-containing alloy, which is attributed to the depletion of carbon solute due to the formation of TiC.

생체재료용 Ti-10Ta-10Nb 합금의 열적 특성 고찰 (Study on the thermal-property of Ti-10Ta-10Nb)

  • 반재삼;이경원;정상원;유영선;조규종
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.1370-1373
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    • 2003
  • Specimens of Ti-10Ta-10Nb have been tested for Rockwall hardness after heating to either the $\alpha$+$\beta$ and $\beta$-phase field. And the specific heat and the dilatometer of Ti-10Ta-103Nb swaged have been measured. From the result, the $\beta$ transus of the alloy was determined to be 82$0^{\circ}C$. The hot deformation behavior of Ti-10Ta-10Nb with an $\alpha$+$\beta$ microstructure is modeled in the temperature 75$0^{\circ}C$ and strain rate range 0.001-10$^{-1}$

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New Fungicides: Opportunities and Challenges - A Case Study with Dimethomorph

  • Spadafora, V. J.;Sieverding, E.
    • 한국식물병리학회:학술대회논문집
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    • 한국식물병리학회 1998년도 Proceedings of International symposium on Recent Technology of Chemical Control of Plant Diseases
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    • pp.50-69
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    • 1998
  • Dimethomorph is a novel fungicide with a high level of activity against diseases induced by certain Oomycetes, including fungal populations that are resistant to other products. In several ways, this fungicide illustrates the opportunities and challenges presented by many modern pesticides. The specific mode of action, which affects cell wall formation, is associated with a very high level of performance and low dose rates under field conditions. These low dose rates, combined with a low level of toxicity to non-target organisms present an outstanding safety profile. This same highly-specific mode of action, however, limits the spectrum of activity and suggests the need for a resistance management plan, both of which must be addressed in new product development. In addition, the biological and physiochemical properties of this, and other new products are not adequately described by the traditional classification of fungicides into“protectant”and“systemic”types. These unique profiles provide novel and useful products for disease control.

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Prevalence of Haplorchis taichui in Field-Collected Snails: A Molecular Approach

  • Chontananarth, Thapana;Wongsawad, Chalobol
    • Parasites, Hosts and Diseases
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    • 제48권4호
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    • pp.343-346
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    • 2010
  • The prevalence of the cercarial stage of an intestinal trematode, Haplorchis taichui, in thiarid snails (Gastropoda: Thiaridae) was investigated using light microscope and species-specific PCR procedures. A total of 988 snails were collected from Mae Taeng district, Chiang Mai province, northern Thailand, which comprised of 3 species; Melanoides tuberculata, Tarebia granifera, and Thiara scabra. The overall prevalence of pleurolophocercous cercariae was 21.7% as determined by the morphology. For genetic detection of H. taichui infection in snails, 2 primers Hapt_F (5'-GGCCAACGCAATCGTCATCC-3') and Hapt_R (5'-GCGTCGGGTTTCAGACATGG-3'), were used. The genomic DNA of H. taichui, which was used as a positive control, gave an amplification of the 256 bp fragment. The overall prevalence of H. taichui from specific PCR was 9.7%. The proportion of H. taichui among the pleurolophocercous cercariae in this study was 44.9%.

Nucleic Acid Aptamers: New Methods for Selection, Stabilization, and Application in Biomedical Science

  • Kong, Hoon Young;Byun, Jonghoe
    • Biomolecules & Therapeutics
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    • 제21권6호
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    • pp.423-434
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    • 2013
  • The adoption of oligonucleotide aptamer is well on the rise, serving an ever increasing demand for versatility in biomedical field. Through the SELEX (Systematic Evolution of Ligands by EXponential enrichment), aptamer that can bind to specific target with high affinity and specificity can be obtained. Aptamers are single-stranded nucleic acid molecules that can fold into complex three-dimensional structures, forming binding pockets and clefts for the specific recognition and tight binding of any given molecular target. Recently, aptamers have attracted much attention because they not only have all of the advantages of antibodies, but also have unique merits such as thermal stability, ease of synthesis, reversibility, and little immunogenicity. The advent of novel technologies is revolutionizing aptamer applications. Aptamers can be easily modified by various chemical reactions to introduce functional groups and/or nucleotide extensions. They can also be conjugated to therapeutic molecules such as drugs, drug containing carriers, toxins, or photosensitizers. Here, we discuss new SELEX strategies and stabilization methods as well as applications in drug delivery and molecular imaging.

RF 전자기장 생체 영향 실험에서 통계적 방법을 통한 전자기장 노출 불확실성 분석 (The analysis of RF dosimetric uncertainties by using statistical method at in-vivo and in-vitro experiments)

  • 최성호;김남
    • 한국전자파학회:학술대회논문집
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    • 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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    • pp.74-78
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    • 2003
  • This paper shows the dosimetric uncertainties of electromagnetic field at in-vivo and in-vitro experiments. For more accurate consequences of these researches, we have tried to find out any correlations among output power, power density and specific absorption rate(SAR) with the results of in-vivo, in-vitro tests and SAR reports of cellular phone and PDA. In the case of in-vivo tests, the power density has close statistical correlations with SAR value and in the event of in-vitro tests, the output power has considerable statistical correlations with SAR containing duty factor. On the other hand, we found that both power density and output power don't have any close correlations with SAR. And, we obtained fitted regression form among frequency, power density and SAR containing duty factor through multiple linear regression analysis.

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