• Title/Summary/Keyword: SS41

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Overlap myositis associated with Sjögren's syndrome

  • Eun Ji Lee;Rae On Kim;Yon Hee Kim;Hakjae Roh
    • Annals of Clinical Neurophysiology
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    • v.25 no.1
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    • pp.41-44
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    • 2023
  • Overlap myositis (OM) associated with Sjögrens syndrome (SS) is a relatively uncommon disorder. It is more difficult to detect OM when a patient had not been previously diagnosed with SS. We report a case of OM associated SS that initially presented with dysphagia followed by proximal weakness. If proximal muscle weakness is preceded by dysphagia, the possibility of OM associated with connective-tissue disease should be considered.

The study on dynamic fracture toughness of friction-welded M.E.F. dual phase steel (복합조직강의 마찰용접부에 대한 동적파괴특성)

  • 오세욱;유재환;이경봉
    • Journal of Welding and Joining
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    • v.7 no.3
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    • pp.19-27
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    • 1989
  • Both the SS41 steel and the M.E.F(martensite encapsulated islands of frrite) dual phase steel made of SS41 steel by heat treatment were welded by friction welding, and then manufactured machinemade Vnotch standard Charpy impact specimens and precracked with a fatigue system at BM(base metal), HAZ(heat affected zone) and WZ(weld interface Zone). The impact test of them was performed with an instrumented impact test machine at a number of temperatures in constant loading velocity and the dynamic fracture characteristics were studied on bases of the absorbed energy, dynamic fracture toughness and fractography from the test. The results obtained are as follows; At the room temperature, the absorbed energy is HAZ.geq.WZ.geq.BM in case of the M.E.F. dual phase steel: BM.geq.HAZ.geq.WZ in case of the SS41 steel, HAZ.geq.BM.geq.WZ at the low temperature. The absorbed energy is decreased markedly with the temperature lowering; it is highly dependent on the temperature. The dynamic fracture toughness of the M.E.F. dual phase steel is HAZ.geq.WZ.geq.BM at the room temperature; BM.geq.WZ.geq.HAZ below-60.deg. C. Therefore the reliability of friction welding is uncertain at the low temperature(below-60.deg. C). The dynamic fracture toughness of the SS41 steel; HZA.geq.WZ.geq.BM at overall temperature region. The flaw formed by rotational upsetting pressure was shown y SEM; in this region. The absorbed energy per unit area and dynamic fracture toughness were low relative to other region.

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Feasibility Study of UV-Disinfection for Water Reuse of Effluent from Wastewater Treatment Plant (용수재이용을 위한 하수처리 유출수의 UV 소독 효율 연구)

  • 윤춘경;정광욱;함종화;전지홍
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.45 no.2
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    • pp.126-137
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    • 2003
  • The feasibility study of UV-disinfection system was performed for disinfection of effluent from wastewater treatment plant. Three low-pressure UV lamps of 17, 25, and 41 W were examined with various flow rates. Low-pressure UV lamps of 17W were examined with various turbidity, DOM (dissolved organic matter), and SS (suspended solid). The pilot plant was a flow-through type UV-disinfection system, and the range of exposure time varied from 5 to 40 seconds, turbidity from 0 to 40 NTU, DOM from 0 to 30 mg/L, and SS from 10 to 40 mg/L. The 41W lamp demonstrated complete disinfection showing no survival ratio in all the experimental conditions, and generally 17W and 25W lamps also showed high removal ratio over 97%. For the same UV dose (UV intensity times exposure time), high intensity-short exposure conditions showed better disinfection efficiency than low intensity-long exposure conditions. While the effects of turbidity and DOM were not apparent, the effects of SS was significant on the disinfection efficiency which indicates that SS control before UV-disinfection appears to be necessary to increase removal efficiency. Considering characteristics of effluent from existing wastewater treatment plants, cost-effectiveness, stable performance, and minimum maintenance, the flow-through type UV-disinfection system with high intensity and low-pressure lamps was thought to be a competitive disinfection system for wastewater reclamation.

The effects of 3.5% NaCl solution on the corrosion fatigue crack propagation characteristics of SS41 steel (SS41강의 부식피로 균열 전파특성에 미치는 3.5% NaCl수용액의 영향)

  • 오세욱;김재철;최영수
    • Journal of Ocean Engineering and Technology
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    • v.1 no.1
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    • pp.111-119
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    • 1987
  • The corrosion fatigue crack propagation characteristics of SS41 steel in 3.5% NaCl solution have been evaluated for loading frequencies of 1Hz and 0.2Hz. A sine wave loading profile was used for fatigue testing. Each test was carried out at a constant stress ratio, R(0.1). The main results are summarized as follows; 1. Fatigue crack propagation rate was higher in 3.5% NaCl solution than in air, higher in the base metal than in the weld metal, and higher at f =0.2Hz than at f =1Hz. 2. The crack closure level of the base metal was not influenced by cyclic frequencies, but that of the weld metal was much influenced. 3. When the crack closure effect was eliminated in the evaluation of crack propagation characteristics by using $\Delta K_{eff}$, the envirommental influence was distinctly observed. At the base metal, crack propagation rate was enhanced by the hydrogen embrittlement, and the weld metal was reduced by the crac closure. 4. There was clearly observed hydrogen embrittlement and severely corroded aspect at fracture surface of lower frequency than that of higher frequency, and at that of base metal than that of the weld metal.

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A Study on the Fatigue Crack Growth Behavior in Residual Stress Field of the SS41 Welding Material (SS41 용접재의 잔류응력장내에서의 피로균열 성장거동에 관한 연구)

  • Choi, Byung-Ki
    • Journal of the Korean Society of Safety
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    • v.17 no.1
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    • pp.33-38
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    • 2002
  • SS41 material is welded automatically and is investigated some effects of the welding residual stress on the growth and propagation of fatigue crack, so as to study the fatigue behaviour in the welding residual stress field. The summarized results are as follows; 1) In case of the load amplitude is constant, as the stress ration is changing to 0.1, 0.33 and 0.5 the propagation life is constant but the initiation life decreases. And than, when maximum load or minimum load is constant, s the stress ration increases the initiation life and propagation life. 2) It was shown that the fatigue crack propagation ratio da/dn was almost constant regardless of the stress ratio change at constant load amplitude and that the larger stress ratio, the slower was the fatigue crack propagation ratio. 3) The opening ratio U is influenced by $K_{max}$ but it isn't only the function of $K_{max}$ because data range is very large. 4) The fatigue life of the specimens on tensile compressive residual stress field was decreased and increased respectably more than that of the base metal.

The Influence of Marine Environmental Factor on the Corrosion Fatigue Fracture of SS41 Steel (SS41강의 부식피로파양에 미치는 해양환경인자의 영향)

  • 김원영;임종문
    • Journal of Advanced Marine Engineering and Technology
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    • v.15 no.1
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    • pp.51-58
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    • 1991
  • Corrosion fatigue test was performed by the use of plane bending fatigue tester in marine environment having various specific resistance from 25(natural sea water) to 5000.ohm.cm. It is in order to investigate the effects of marine environmental factor on the corrosion fatigue fracture of SS41 steel. The main results obtained are as follows; 1. The aspect ratio(b/a) of corner crack growing in natural sea water is lower than that in air. 2. The surface crack growth rate(da/dN) in marine environment is faster than that in air and da/dN delaies with the specific resistance increased. 3. The experimental constant m of paris rule [da/dN=C(${\delta}$K)$^m$] decrease with the specific resistance decreased and the effect of corrosion in proportion to the specific resistance is more sensitive than that of stress intensity factor range(${\delta}$K) under region II. 4. The accelerative factor(${\alpha}$) in marine environment is about 1.1-2.7 and .alpha. is increase under the low region of stress intensity factor range(${\delta}$K). 5. The electrode potential($E_0$) gets less noble potential with the specific resistance decreased.

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Influence of Notch Change on Corrosion Fatigue Fracture in F.E.M. Dual phase Steel of SS41 Steel (SS41강의 F.E.M.복합조직강에서 노치변화가 부식피로파괴에 미치는 영향)

  • 도영민;이규천
    • Journal of the Korean Society of Safety
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    • v.16 no.2
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    • pp.44-50
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    • 2001
  • The rotated bending fatigue test was conducted in air md in 3.5% NaCl salt solution to investigate the fatigue fracture behaviour of raw material and F.E.M dual phase steel made from raw material(SS41) by a suitable heat treatment. This study has compared the initial microcrack creation of material by tensile test with that by fatigue test. And the rotated bending test of cantilever type under the condition of 3.5% NaCl salt solution and air has investigated the corrosion fatigue fracture behaviour with the variation of stress concentration factor determined by each of notch shapes. The initial microcrack have been developed in fragile grainboundary with general corrosion occurring in raw material : in the pits built up by corrosion in F.E.M. dual phase steel because pits bring out stress concentration. It is small that the degree of decrease in corrosion fatigue life for F.E.M. dual phase steel compared with raw material because the notch sensitivity of F.E.M. dual phase steel is lower than raw material in reason of characteristics with two-phase construction.

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Optimization of Mixture Composition to Improve Emulsifying Power and Solubilization of Sucrose Stearate (수크로스 스테아레이트의 유화력 및 가용화력 향상을 위한 혼합물 조성 최적화)

  • Jong Hwan Bae;Maria Song;Byung Suk Jin
    • Journal of the Korean Applied Science and Technology
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    • v.41 no.2
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    • pp.318-328
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    • 2024
  • In this study, we enhanced the emulsifying power and solubilization of sucrose stearate (SS) by creating mixtures with sodium deoxycholate (SDOC) and PEG-40 hydrogenated castor oil (HCO). We employed the design of mixture experiments (DOME) methodology to identify the optimal composition of the mixture, and the impact of varying the mixture composition on its characteristics was examined through regression analysis of the experimental data. It was revealed that the emulsifying power for coconut oil was most improved when only SDOC was added to SS, and solubilization was most improved when only HCO was added, while the emulsifying power for cetyl ethylhexanoate (CEH) was most significantly improved when SDOC and HCO were added together. As a result of simultaneous optimization of three characteristics, emulsifying power for each of coconut oil and CEH, and solubilization, the optimal surfactant mixture composition was determined as SS 0.7939, SDOC 0.0586, and HCO 0.1475.

Properties of Solar Radiation Components Reflected by the Sea Surface: - A Case of Jeju Island, South Korea - (해수면에 의해 반사된 태양복사 성분의 특성: 남한의 제주도 사례)

  • Fumichika, Uno;Hayashi, Yousay;Hwang, Soo-Jin;Kim, Hae-Dong
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.13 no.2
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    • pp.48-55
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    • 2011
  • Solar radiation components reflected by the sea surface ($R_{ss}\uparrow$) are additional energy sources comprising the solar radiation regime. Previous studies, based on observational approaches, indicated that $R_{ss}\uparrow$ is an available climatological resource. However, an estimation process for $R_{ss}\uparrow$ has not been established. In this case study over Jeju Island in South Korea, we applied a new estimation process to solar radiation modeling and discussed the spatial distribution of $R_{ss}\uparrow$ and its seasonal variation. Our results showed that the illuminated area and the intensity of $R_{ss}\uparrow$ became greatest at the winter solstice and least at the summer solstice. We estimated the illuminated area of $R_{ss}\uparrow$ as it expanded over the southern slope of Jeju Island. At the winter solstice, on a daily basis, the area and intensity of illumination by $R_{ss}\uparrow$ were $182.3km^2$ and $0.41\;MJ\;m^{-2}\;day\;{-1}$, respectively. Comparing the daily accumulative and instantaneous values of $R_{ss}\uparrow$ intensity, the difference was about 20 times greater in daily cases than in instantaneous cases. On the other hand, for instantaneous values, the $R_{ss}\uparrow$ intensity accounted for up to 33% of the three components, i.e., direct, diffuse and reflected radiation in winter solstice. In addition, it was estimated that the sea surface reflectance depended on the wind speed. Therefore, in a practical use of this revised model, wind conditions should be considered as a critical factor in estimating $R_{ss}\uparrow$.

Chemical Properties of the Insecticidal Compound Produced by an Actinomycetes, SS-4993 (방선균 SS-4993이 분비하는 살충물질의 화학적 성상 및 작용기작)

  • 이은정;강경돈;황교열;김두호;이상몽;김신덕;성수일
    • Journal of Sericultural and Entomological Science
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    • v.41 no.3
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    • pp.180-184
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    • 1999
  • The insecticidal compound priduced by Streptomyces SS-4993 strain was indicated to be a relatively stable small compound by pancreatin treatment. The active compound was adsorbed on HP20 and eluted with 70% acetone. Then, the eluate was extracted with ethyl acetate. The content of the extract was determined by thin layer chromatography (Silica gel 60 F254, hexane-ethyl ether-acetic acid,80 : 20 :1). Three active bands (Rf 0.08, 0.07, 0.88) were identified by dermal application using Bombyx mori larvae. Electrophoretic analysis revealed that the injection of strain SS-4993 culture broth into B. mori larvae induce the reduction of the hemolymph proteins level. Especially, the level of apolipophorin-I was decreased drastically.

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