• Title/Summary/Keyword: SM 400

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A Study on the Thermal Analysis of the Valve in the Selective Catalytic Reduction(SCR) System (선택적 환원촉매장치(SCR)에서 밸브의 열해석에 관한 연구)

  • Choi, Jae-Wook;Kwag, Dong-Gi
    • Journal of the Korea Convergence Society
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    • v.10 no.8
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    • pp.153-158
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    • 2019
  • The overall environmental regulations of the industry have been strengthened due to environmental pollution that occurred in modern society. Therefore, R&D of selective reduction catalyst (SCR) is needed to meet these environmental regulations. This paper carried out thermal analysis to develop the pneumatic damper valve (PDV), which is a key component of SCR system. For thermal analysis, verification of material properties was performed first. Verification was performed through the thermal properties test and the thermal tensile test of the specimen, and the results were reinforced with the material properties to enhance the reliability of the thermal analysis.The heat analysis was intended to identify thermal characteristics with PDV in total of three materials (SM400B, SS275, SB410) applied under the conditions of use of PDV, and to confirm the structural stability of the PDV.

Fabrication and Characteristics of a White Emission Electroluminicent Device (백색 전계발광소자의 제작과 그 특성)

  • Kim, Woo-Hyun;Choi, Sie-Young
    • Journal of Sensor Science and Technology
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    • v.10 no.6
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    • pp.295-303
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    • 2001
  • White emission thin film electroluminecent device was fabricated with ZnS for phosphor layers and BST ferroelectric thin film for insulating layers. The ZnS:Mn and $ZnS:SmF_3$ layers were used for emission of red color. Also the $ZnS:TbF_3$ and $ZnS:AgF_3$ layers were used to emission of green and blue color, respectively. And the fabrication conditions of the BST insulating layers were followings, that is, the composition ratio of target, substrate temperature, working pressure and operating gas ratio were $Ba_{0.5}Sr_{0.5}Ti_{0.3}$, $400^{\circ}C$, 30 mTorr and 9:1, respectively. The thickness of phosphor were 150 nm for each layers and the insulating layers of upper and bottom were 400 nm and 200 nm, respectively. The luminesence threshold voltage was $75\;V_{rms}$ and the maximum brightness of the thin film electroluminecent device was $3200\;cd/m^2$ at $100\;V_{rms}$.

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Characterization of Streptomyces sp. AMLK-135 Producing Anti- MRSA Antibiotics

  • Lee, Min-Jeong;Lim, Dae-Seog;Lee, Myung-Sub;Yoon, Won-Ho;Kim, Chang-Han
    • Journal of Microbiology and Biotechnology
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    • v.7 no.6
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    • pp.397-401
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    • 1997
  • The present research program was conducted to characterize a strain of actinomycetes producing an anti methicillin-resistant Staphylococcus aureus (MRSA) antibiotic. Soil samples were collected from various sites in Korea and a number of actinomycetes were isolated from the soil samples by applying selective agar for actinomycetes. Among over 400 isolates, a strain (AMLK-135) producing anti-MRSA antibiotic against S. aureus TK 784 was selected. According to the morphological and physiological characteristics, the strain AMLK-135 was confirmed to belong to the genus Streptomyces. From the results of species identification with the TAXON program, the strain AMLK-135 was shown to belong to major cluster 5 (Streptomyces exfoliatus), but it had a low simple matching coefficient ($S_{SM}$ SM/) value to member organisms of major cluster 5. Percentage ($\%$) of strain further away of the strain AMLK-135 was low (1.9400) and it was placed further away than the outer-most members in major cluster 5. Therefore, the strain AMLK-135 was identified as a new species of the genus Streptomyces.

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Distribution of antimicrobial resistances and properties of R-plasmids in E coli isolated from pigs (돼지유래 대장균의 항균제내성 분포와 R-plasmid의 성상)

  • Chung, Myeong-eun;Yeo, Sang-geon
    • Korean Journal of Veterinary Research
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    • v.34 no.4
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    • pp.759-768
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    • 1994
  • E coli strains isolated from pigs were investigated with respect to antimicrobial resistances and prevalence of R-plasmids. Also determined were properties of R-plasmids by plasmid conjugation, curing and southern hybridization using gene probes. All of 400 E coli strains were resistant to CL and SU, and 0.3% to 96.8% of the strains were resistant to most antimicrobials such as TC, PG, AM, SM, CP, GM, EM, NM, etc, while all strains were sensitive to AK. All strains were also multiply resistant to three to twelve antimicrobials. The resistances to PG, SM, TC, AM, CP, SU and ST were transferable and supposed to be mediated by R-plasmids which were opportunistic for transposition into chromosome. Plasmids bigger in size than chromosomal DNA were considered as R-plasmids and most plasmids in small size (<4Kb) proved as cryptic plasmids or nonconjugative R-plasmids. In a strain(No 99), AM resistant property was determined from both chromosomal DNA and R-plasmid DNA which is bigger in size than chromosome.

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Evaluation of Structural Stability at High Temperatures for Beams Made of High Strength Structural Steels (SM 570) by Analytical Method (해석적 방법에 의한 고강도 강재(SM 570) 적용 보부재의 고온 시 내력 평가)

  • Kwon, In-Kyu
    • Fire Science and Engineering
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    • v.28 no.3
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    • pp.49-54
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    • 2014
  • Beams play an important role to transfer an applied load on the floor into columns. However, if the beams affected by a fire the length will be changed longer or shorter and the structural stability decreased gradually and resulted in structural failure. Therefore, the fire regulation requires that structural beam has to satisfied with a constant fire resistance. The fire resistance conducted by a constant size and boundary condition in an horizontal furnace. But this is not enough to adopt a beam made of high structural steels having various lengths. In this study, in order to suggest structural behaviors of beams made of high structural steels at high temperature, mechanical properties at high temperature and heat stress analysis were used and the surface temperature, expansion, displacement and variance of maximum load according to lengths of the beam were compared with those of SM 400.

다양한 활성제 이온이 도핑된 La2WO6 형광체의 제조와 발광 특성

  • Ryu, Hyeon-Tae;Hong, Sun-Gi;Im, Myeong-Hwan;Lee, Eun-Gyeong;Sin, Yu-Hui;Jo, Sin-Ho
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.191.1-191.1
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    • 2015
  • 최근에 백색 발광다이오드를 개발하기 위한 고효율의 형광체 개발에 많은 연구가 집중되고 있다. 본 연구에서는 $La_2WO_6$ 모체 결정에 다양한 활성제 이온인 $Eu^{3+}$, $Dy^{3+}$, $Sm^{3+}$, $Tb^{3+}$를 각각 도핑하여 다양한 발광 파장을 갖는 고효율의 형광체를 제조하였다. 합성한 형광체 분말은 초기물질 $La_2O_3$, $WO_3$, 희토류 원소 ($Eu_2O_3$, $Dy_2O_3$, $Sm_2O_3$, $Tb_4O_7$)를 각각 화학양론적으로 준비하여 고상반응법으로 제조하였으며, 이때 하소 공정은 $400^{\circ}C$에서 3시간, 소결 공정은 $1050^{\circ}C$에서 5시간 유지하여 합성하였다. $La_2WO_6:Eu^{3+}$ 형광체 분말의 경우에 320, 395, 465 nm에서 강한 흡광 파장이 발생하였으며, 파장 320 nm로 여기 시켰을 때 최대 발광 세기는 618 nm에서 관측되었다. $Sm^{3+}$을 도핑한 형광체의 흡광 스펙트럼은 310, 375, 406, 475 nm에서 발생하였으며, 310 nm로 여기 시켰을 때 602 nm의 강한 주황색 발광 신호가 나타났다. $Dy^{3+}$가 도핑된 $La_2WO_6$ 형광체는 575 nm에 강한 발광 피크를 갖는 황색을 나타내었으며, 흡광 파장은 313 nm 이었다. $Tb^{3+}$를 도핑한 형광체의 주 흡광 스펙트럼은 316 nm에서 발생하였고, 발광 스펙트럼은 545 nm에 피크를 갖는 녹색 발광 신호가 나타났다. 활성제이온의 종류에 따른 형광체의 흡광과 발광, 결정 구조의 특성을 체계적으로 제시하고자 한다.

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Physicochemical Properties of Dextran Produced by Leuconostoc mesenteroides SM according to Concentration of Yeast Extract and its Modulation of Rheological Properties (효모 추출물 농도에 따른 Leuconostoc mesenteroides SM에 의해 생산된 dextran의 물리화학적 특성 및 물성개량)

  • Kim, Ji-Eun;Whang, Key;Lee, Sam-Pin
    • Korean Journal of Food Science and Technology
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    • v.44 no.2
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    • pp.216-223
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    • 2012
  • Dextran was produced by $Leuconostoc$ $mesenteroides$ SM with various contents of yeast extract and its rheological properties were modulated, via an addition of hydroxypropyl methylcellulose (HPMC) of different viscosities. The conversion yield reached 90% after adding 3% yeast extract, which remained constant, thereafter. The acidity of the cultures was approximately 1.4 and 0.9% after fermentation for 24 h at 25 and $30^{\circ}C$, respectively. The total dextran content (107.3 g/kg) was the highest in the presence of the 3% yeast extract. Under the same conditions, the consistency, viscous modulus (G"), and elastic modulus (G') of the cultures were $37.6\;Pa{\cdot}s^n$, 38 Pa, and 50 Pa, respectively. The rheological properties of the culture were changed drastically by the fortification with HPMC of higher concentration and viscosity. The addition of 10% HPMC (4,000 cp) resulted in a significant increase in G" to 1,950 Pa. Furthermore, adding HPMC to a viscous culture resulted in a remarkable increase in both hardness and firmness.

Flexural Behavior and Design of Concrete-filled U-shape Hybrid Composite Beams Fabricated from 570MPa High-strength Steel (570MPa급 고강도강을 적용한 콘크리트 채움 U형 하이브리드 합성보의 휨거동 및 설계)

  • Lee, Cheol Ho;So, Hyun Joon;Park, Chang Hee;Lee, Chang Nam;Lee, Seung Hwan;Oh, Ha Nool
    • Journal of Korean Society of Steel Construction
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    • v.28 no.2
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    • pp.109-120
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    • 2016
  • Flexural tests of full-scale concrete-filled U-shape hybrid composite beams were conducted. Ordinary (SS400) and high-strength (SM570) steel plates were used in the web and in the bottom flange of U-shape steel section respectively. The primary objectives were to develop the hybrid section configuration with maximized flexural capacity and to investigate its flexural strength and deformation capacity. All the hybrid test specimens in this study exhibited the plastic moment capacity and resonable deformability. It is shown that the plastic stress distribution can be assumed in calculating the flexural strength of the proposed hybrid composite beams if the plastic neural axis is located within 15% of the total beam depth from the top of the composite slab. The procedure for computing the effective flexural stiffness of hybrid composite beams is also recommended based on test results.

Reliability Evaluation of Hardness and Impact Absorption Energy of Tempered Structure Steel SCM435 (뜨임한 구조용강 SCM435의 경도 및 충격 흡수에너지에 대한 신뢰성 평가)

  • Yun, Seo-Hyun;Gu, Se-Hun;Nam, Ki-Woo
    • Journal of the Korean Society of Industry Convergence
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    • v.22 no.6
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    • pp.681-688
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    • 2019
  • SM45C steel, which is widely used for mechanical structure, was carburized at 870℃ for 4 hours and tempered at 300℃ and 400℃ for 1, 3 and 6 hours. The tempered materials were evaluated for tensile test, hardness test and impact test. In particular, the hardness and the absorption energy were evaluate the reliability by the Weibull statistical analysis. 300℃-1h specimen is considered to be the best heat treatment condition in the tensile stress and the observation of fracture surface. 300℃-1h specimen showed larger shape and scale parameter than the other specimens, and Rockwell hardness variance was small and showed the best characteristics. 400℃-3h specimen showed larger shape and scale parameter than the other specimens, the dispersion of impact absorption energy is small, and showed excellent characteristics.

Evaluation on the Effects of Deicing Salts on Crop using Seedling Emergence Assay of Oilseed Rape (Brassica napus) (유채의 출아 검정을 통한 제설제의 작물 영향 평가)

  • Lim, Soo-Hyun;Yu, Hyejin;Lee, Chan-Young;Gong, Yu-Seok;Lee, Byung-Duk;Kim, Do-Soon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.66 no.1
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    • pp.72-79
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    • 2021
  • The increasing use of deicing salts has caused various environmental problems, including crop damage along the motorway where deicing salts are sprayed during winter. Deicing salts used on roads have been reported to negatively affect crops, but little information is known about their impact on crops. A seedling emergence assay was conducted to evaluate the effects of deicing salts on crops using oilseed rape (Brassica napus) as a model plant. We tested five chloride deicing salts consisting of NaCl, CaCl2, or MgCl2 and 1 non-chloride deicing salt (SM-3) at a range of concentrations (25, 50, 100, 200, and 400 mM), and untreated control. Regardless of deicing salts, they significantly delayed and reduced seedling emergence of oilseed rape with increasing salt concentration. Non-linear regression analysis of seedling emergence with a range of salt concentrations by fitting to the log-logistic model revealed that the chloride deicing salts reduced seedling emergence more than the non-chloride deicing salt SM-3. The GR50 value, the concentration causing 50% seedling emergence, of SM-3 was 47.1 mM, while those of the chloride deicing salts ranged from 30.7 mM (PC-10) to 37.5 mM (ES-1), showing approximately 10 mM difference between non-chloride and chloride deicing salts. Our findings suggest that seedling emergence assay is a useful tool to estimate the potential damage caused by deicing salts on crops.