• Title/Summary/Keyword: $Cr_{23}C_6$

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Bacterial Quality of Fish Meat Paste Products and Isolation of Thermoduric Bacteria (어육연제품의 세균학적 품질 및 내열성세균의 특성에 관한 연구)

  • 김동판;장동석;김성준
    • Microbiology and Biotechnology Letters
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    • v.13 no.4
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    • pp.409-415
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    • 1985
  • This study has been carried out in order to investigate the bacterial quality of fish meat paste products and the characteristics of isolated thermodurics from the products. Twenty samples of crab-flavored fish stick (Kematsal), 23 samples of plate fish meat paste (Panomuk, Kamaboko), 5 samples of fried fish meat paste (Tigimomuk), 2 samples of roasted fish meat paste (Puduromuk, Chikuwa), 20 samples of fish sausage were collected from processing plants and supermarkets in Pusan, Korea during the period from May to October in 1984. The results obtained are as follows. Amont the samples collected from supermarkets, roasted fish meat paste and fried fish meat paste marked hish counts in coliforms and fungi while very low in the samples of crab-flavored fish stick and plate fish meat paste. Salmonella was not detected in all the samples examined and Staphylococcus aureus was detected only in fried fish meat paste, Thermoduric bacteria were detected less than 10$^2$/g in the samples of crab-flavored fish stick and plate fish meat paste, which might come from subsidiary materials such as starch and seasonings. Among the isolated bacteria, distribution of the proteolytics were more than 87% and the lipolytics were less than 20%. Gram positive bacteria was more than 70% in crab-flavored fish stick and plate fish meat paste, 47.3% in fried fish meat paste. And rod in shape was almost more than 90% in all the samples. The most heat resistant bacterium isolated from the samples was identified as a Bacillus licheniformis(named B. licheniformis CR-11). The strain showed strong proteolytic activity and also grew well at above 2$0^{\circ}C$. The growth rate and generation time of CR-11 strain were 0.31 hr$^{-1}$ , 2.24 hr at 2$0^{\circ}C$, 0.64 hr$^{-1}$ , 1.09 hr at 3$0^{\circ}C$ and 0.78 hr$^{-1}$ , 0.89 hr at 35$^{\circ}C$. Heat resistance value of the spores of CR-11 strain suspended in phosphate buffer solution was D$_{85}$ $^{\circ}C$=41.9 min, D$_{90}$ $^{\circ}C$=27.9 min, D$_{95}$ $^{\circ}C$=10.2 min, D$_{100}$ $^{\circ}C$=4.3 min (Z=13.8$^{\circ}C$)

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Characteristics of microstructure and mechanical strength of ASTM A387-Gr.91 Steel deteriorated under high-temperature (고온 열화된 ASTM A387-Gr. 91 강의 미세 조직 및 기계적 강도 특성)

  • Jeong, Gwang-Hu;Han, Min-Su;Kim, Seong-Jong
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2018.06a
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    • pp.111-111
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    • 2018
  • ASTM A387-Gr.91 강은 우수한 고온 강도, 크리이프 저항성 그리고 내산화성 등으로 인해 화력 및 바이오매스 발전 시설과 같은 고온 설비의 구조재료로 널리 사용되고 있다. 고온 환경에서 높은 강도는 탄화물과 탄질화물에 의한 석출강화가 주 요인으로 작용한다. 열처리 과정에서 Mo, Cr, Mn, 그리고 Fe는 구-오스테나이트 및 마르텐사이트 라스 입계에 $M_{23}C_6$ 탄화물로 석출되며, V, Nb, 및 N은 조직 내부에 미세한 MX 탄질화물로 석출된다. 따라서 합금의 고온 강도는 조직 내 석출물의 개수밀도와 크기에 크게 의존한다. 그러나 적용 환경의 특성 상 고온 노출에 따른 2차상 석출 및 조대화의 조직열화 현상이 발생하며, 이는 재료의 강도를 저하시킨다. 본 연구에서는 ASTM A387-Gr.91 강의 미세조직 열화에 따른 강도저하 및 파괴 양상을 고찰하는데 그 목적을 두었다. 본 연구에서 사용된 ASTM A387-Gr.91 강의 화학성분(wt, %)은 0.1 C, 0.38 Si, 0.46 Mn, 0.25 Ni, 8.38 Cr, 0.93 Mo, 0.18 V, 0.09 Nb, 그리고 나머지는 Fe 이다. 조직열화 및 기계적 강도저하 특성을 평가하기 위한 등온열화는 $650^{\circ}C$의 대기 환경에서 최대 1000시간동안 실시하였다. 열화된 시험편의 미세조직 및 탄화물에 대한 분석은 SEM과 EDS를 이용하여 실시하였다. 그리고 기계적 강도 평가는 인장실험과 비커스 경도시험을 통해 실시하였다. 또한 열화 시간에 따른 파단양상의 변화를 관찰하기 위해 인장시험편의 파단면을 SEM과 EDS를 이용하여 분석하였다. 그 결과, 열화에 따른 마르텐사이트 라스의 소실, 탄화물의 조대화, 그리고 2차상 석출의 조직 열화현상이 나타났다. 또한 기계적 강도는 조직 열화에 따라 저하되는 경향을 나타냈다.

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Improvement of Corrosion Resistance and Nano-hardness of Ti-Al-N Deposit Formed by Arc Ion Plating (아크 이온 증착된 TiAlN 도포층의 내식성과 나노 경도 개선)

  • Gang, Bo-Gyeong;Choe, Yong;Gwon, Sik-Cheol;Zang, Shi-Hong
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2014.11a
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    • pp.213-213
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    • 2014
  • $300^{\circ}C$$500^{\circ}C$에서 아크 이온 증착된 도포층의 조성은 각각 Fe : Al : Ti : Si : N = 1.31 : 36.52 : 31.31 : 0.48 : 30.38 [wt.%]와 Fe : Cr : Al : Ti : Si : N = 1.24 : 0.56 : 36.82 : 32.72 : 0.59 : 28.07 [wt.%] 이었다. 0.1N $H_2SO_4$ 수용액과 인공해수 (ASTM D1141-98) 분위기에서 $300^{\circ}C$, $500^{\circ}C$에서 증착된 도포층의 부식전압과 부식속도는 각각 $-0.2787V_{SHE}$, $0.002A/cm^2$, $-2.764V_{SHE}$, $0.002A/cm^2$$-0.2799V_{SHE}$, $0.002A/cm^2$, $-0.0394V_{SHE}$, $0.002A/cm^2$이었다. 나노 경도값은 각각 23.6, 25.8 GPa 이었다. 이는 각각 2208.2, $2434.2H_V$에 해당되었다.

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The Evaluation of STS304 Coating Layer on S45C Substrate by Friction Surfacing Process (마찰 육성법을 이용한 S45C 탄소강에 대한 STS304의 코팅층 특성 평가)

  • Noh Joong-Suk;Cho Houn-Jin;Kim Heung-Ju;Chun Chang-Gun;Chang Woong-Seong
    • Journal of Welding and Joining
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    • v.23 no.6
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    • pp.72-76
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    • 2005
  • Friction surfacing of STS304 consumable rod on S45C substrate was investigated by microstructural observation and mechanical tests. STS304 layer formed a strongly-bonded thick layer under a wide range of surfacing conditions. The highest coating eefficiency was obtained in the condition of 1000rpm-2.5mm/sec-2.5mm/sec. The hardness distribution showed the peak value in the boundary layer and as the consumable rotation speed increased, the boundary layer also hardness increasing. As the consumable rotation speed and the traveling speed increased, the coating efficiency tended to decrease. On the other hand, as the feeding speed increased, the coating efficiency appeared to be increased. The new Fe-Cr-Ni alloy layer is showed in the interface layer on $5\~15{\mu}m$ width. After friction surfacing, corrosion resistance of STS 304 surfacing layers were equaled to that of STS304 consumable rod.

Effect of renin inhibition on an experimental glomerulonephritis - a preliminary report (레닌 억제제가 실험적 사구체 콩팥염에 미치는 효과 - 예비 보고)

  • Kang, Ju-Hyung;Heo, Jae-Kyung;Lee, Young-Sook;Han, Ji-Young;Ha, Il-Soo
    • Clinical and Experimental Pediatrics
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    • v.52 no.8
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    • pp.938-943
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    • 2009
  • Purpose : We performed this study in order to investigate the effect of direct renin inhibition on an experimental animal model with nephrotoxic serum nephritis and tried to give useful information for clinical research and renin inhibitor treatment. Methods : Thirty BALB/c 6-week-old male mice were divided into 4 groups: control group (CO, n=5), control-treatment group with aliskiren (CT, n=5), disease group (DO, n=10), and disease treatment group with aliskiren (DT, n=10). Nephritis was induced by an intravenous injection of 0.25 mg/g weight of rabbit anti-GBM immunoglobulin G. Model 2002 Alzet mini-osmotic pumps (Durect Corp.) for aliskiren infusion were implanted into CT and DT. Each group strain was sacrificed serially one at a time on day 14. We estimated the protein-creatinine ratio in 12-hour-collected urine (UP/Cr) and measured the mesangial matrix score in the PAS-stained kidney of each strain. Results : One strain at CT and DT died on day 6 and 7, respectively. Each group strain was sacrificed serially at a time on day 10 because DO were seriously ill. The UP/Cr of each group is as follows: CO, $31.24{\pm}6.54mg/mg$, CT, $23.38{\pm}13.60mg/mg$, DO, $112.72{\pm}10.97mg/mg$, DT $114.07{\pm}32.30mg/mg$. There was no significant difference between DO and DT. The mesangial matrix score of each group was CO, $0.23{\pm}0.10$; CT, $0.13{\pm}0.03$; DO, $1.90{\pm}0.48$; and DT, $1.28{\pm}0.41$, respectively, and there was a significant difference between DO and DT in the extent of mesangial matrix expansion (P=0.008). Conclusion : We found that renin inhibition was able to suppress the mesangial matrix expansion in experimental mice with acute nephritis, although there were no significant differences in UP/Cr.

The Bioequivalence of Two Carbamazepine Controlled Release Formulations (카르바마제핀 서방형 제제간의 생물학적 동등성 비교)

  • Kim, Min J.;Lee, Hyun J.;Rheu, Yoon M.;Shin, Wan G.;Park, Sung H.
    • Korean Journal of Clinical Pharmacy
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    • v.6 no.2
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    • pp.19-23
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    • 1996
  • Carbamazepine is an anticonvulsant drug that has been shown to be as effective as phenytoin or phenobarbital in treatment of grand mal and complex partial seizures and is also approved as the drug of choice for treatment of the pain associated with trigerminal neuralgia. And the therapeutic or toxic effects of carbamazepine are better related to plasma concentration than to dosage, which can be attributed to interindividual variability in the pharmacokinetics. A slow rate of carbamazepine dissolution in the gastrointestinal tract is believed to be the cause of its relatively slow and erratic rate of absorption. For these reasons pharmacokinetic evaluation of newly formulated carbamazepine is neccessary. In this study, the bioequivalence in carbamazepine between the $TegretoI^{TM}$ CR tablet (Geigy Co.) and $Carmazepine^{TM}$ CR tablet (Myung In Co.) was evaluated. 12 normal volunteers (age $21\~27$ years old) was divided into two groups, and a randomized cross-over study was employed. The pharmacokinetic parameters ($C_{max},\;T_{max}$ and AUC) obtained of oral administration of each formulatim of carbamazepine 400 mg were evaluated and ANOVA was utilized for the statistical analysis of parameters. $C_{max}\;is\;8.26{\pm}3.1{\mu}g/ml\;(C.V.\;37.3\%)\;in\;TegretoI^{TM}\;and\;9.39\{pm}2.9{\mu}g/ml\;(C.V.\;30.5\%)$ in $Carmazepine^{TM},\;T_{max}\;is\;28.0{\pm}5.9\;hrs(C.V.\;21.1\%)$ in $Tegretol^{TM}\;and\;24.0{\pm}7.2\;hrs(C.V.\;30.2\%)$ in $Carmazepine^{TM}$ and AUC is $786.4{\pm}360.5{\mu}g{\cdot}hr/ml\;(C.V.\;45.8\%)$ in $TegretoI^{TM}\;and\;792.8{\pm}228.6{\mu}g{\cdot}hr/ml\;(C.V.\;28.8\%)$ in $Carmazepine^{TM}$, respectively. As the result of the data, two formulations are bioequvalent, and the lower C.V. of $Carmazepine^{TM}$ in every individual can be merit.

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Effect of High Frequency Heat Treatment on the Microstructure and Wear Properties of Ni based Self Fluxing Composite Coating Layer Manufactured by HVOF Spray Process (High Velocity Oxygen Fuel 공정으로 제조된 Ni 계 자용성 복합 코팅 소재의 미세조직과 마모 특성에 미치는 고주파 열처리의 영향)

  • Wi, Dong-Yeol;Ham, Gi-Su;Park, Sun-Hong;Lee, Kee-Ahn
    • Journal of Powder Materials
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    • v.26 no.5
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    • pp.421-431
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    • 2019
  • In this study, the formation, microstructure, and wear properties of Colmonoy 88 (Ni-17W-15Cr-3B-4Si wt.%) + Stellite 1 (Co-32Cr-17W wt.%) coating layers fabricated by high-velocity oxygen fuel (HVOF) spraying are investigated. Colmonoy 88 and Stellite 1 powders were mixed at a ratio of 1:0 and 5:5 vol.%. HVOF sprayed self-fluxing composite coating layers were fabricated using the mixed powder feedstocks. The microstructures and wear properties of the composite coating layers are controlled via a high-frequency heat treatment. The two coating layers are composed of ${\gamma}-Ni$, $Ni_3B$, $W_2B$, and $Cr_{23}C_6$ phases. Co peaks are detected after the addition of Stellite 1 powder. Moreover, the WCrB2 hard phase is detected in all coating layers after the high-frequency heat treatment. Porosities were changed from 0.44% (Colmonoy 88) to 3.89% (Colmonoy 88 + ST#1) as the content of Stellite 1 powder increased. And porosity is denoted as 0.3% or less by inducing high-frequency heat treatment. The wear results confirm that the wear property significantly improves after the high-frequency heat treatment, because of the presence of well-controlled defects in the coating layers. The wear surfaces of the coated layers are observed and a wear mechanism for the Ni-based self-fluxing composite coating layers is proposed.

A Study on Hot Ductility Behavior of Ni-based Superalloys (니켈기 초내열합금의 고온연성거동에 관한 연구)

  • Lee, Choung-Rae;Um, Sang-Ho;Kim, Sung-Wook;Choi, Cheol;Lee, Chang-Hee
    • Journal of Welding and Joining
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    • v.22 no.2
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    • pp.59-68
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    • 2004
  • Plasma transferred arc welding (PTAW) has been taken into consideration for repairing Ni-based superalloy components used gas turbine blades. Various cracks has been generally reported to be found in the base metal heat affected zone(HAZ) along grain boundary. Thus, hot cracking susceptibility of Ni-based superalloys was evaluated according to heat treatments. Hot ductility test was conducted on specimens with solution treated at 112$0^{\circ}C$ for 2 hours and aging treated at 845$^{\circ}C$ for 24hours after solution treatment. The results of the hot ductility test appeared that solution treated specimens were the highest ductility recovery rate among three conditions. The loss of ductility at high temperature in Ni-based superalloy was mainly controlled by the degree of pain boundary wetting due to constitutional liquation of MC carbide precipitates. Meanwhile, the highest ductility recovery rate in solution-treated alloys seems to be lack of M23C6, which can be dissolved during heating and then result in the local enrichment of Cr in the vicinity of the grain boundary.

Distributions of Organic Matter and Heavy Metals in the Surface Sediment of Jaran Bay, Korea (자란만 표층 퇴적물 중 유기물과 중금속 농도분포)

  • Hwang, Hyunjin;Hwang, Dong-Woon;Lee, Garam;Kim, Hyung-Chul;Kwon, Jung-No
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.1
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    • pp.78-91
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    • 2018
  • In order to understand the distributions of organic matter and heavy metal concentrations in the surface sediment of Jaran Bay, we measured the grain size, total organic carbon (TOC), total nitrogen (TN), and heavy metals (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, and Zn) in surface sediments collected at 15 stations in this bay in November 2014. The sediment consisted of finer sediment such as mud and clay, with 8.6-9.8Ø($9.3{\pm}0.3$Ø) of mean grain size. The concentrations of TOC and TN in the sediment ranged from 1.51-2.39 % ($1.74{\pm}0.22%$) and 0.20-0.33 % ($0.23{\pm}0.03%$), respectively, and did not show spatial difference. The carbon to nitrogen ratio (C/N ratio) ranged from 5-10, indicating that organic matter in the sediment originated from oceanic sources such as animal by-products from fish and shellfish farms. The concentrations of Cr, Fe, and Mn were much higher in the mouth of the bay than in the inner bay, and the concentrations of As, Cd, Cu, Hg, Pb, and Zn showed an opposite distribution pattern. Based on the results of the sediment quality guidelines (SQGs), enrichment factor (EF), geoaccumulation index ($I_{geo}$), pollutant load index (PLI), and ecological risk index (ERI), the surface sediment in Jaran Bay is not polluted or only slightly polluted with Cd, Cr, Cu, Hg, Pb, and Zn, whereas it is moderately to strongly polluted with As. In particular, some regions in the bay were identified as having a considerable risk status, indicating that metal concentration in the sediment could impact benthic organisms. Thus, the systematic management for marine and land sources of organic matter and heavy metals around Jaran Bay is necessary in order to ensure seafood safety and maintain sustainable production on shellfish farms.

The Horse Manure Fertilizers and Pollutants Characteristics Analysis Research (말 분뇨의 비료성분 및 오염물질 특성 조사 연구)

  • Kwag, J.H.;Jeong, M.W.;Choi, D.Y.;Kim, J.H.;Kim, Y.H.;Park, J.C.;Kim, I.C.;Yang, C.B.;La, C.C.
    • Journal of Animal Environmental Science
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    • v.18 no.3
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    • pp.201-206
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    • 2012
  • Horse manure general composition and contaminants, heavy metals content analysis was investigated as follows. The moisture content of horse feces was 76.1% and 96% for horse urine. The average T-N, T-P, T-K concentrations of the racing horse were 0.18%, 0.10%, 0.22% respectively and 2.88%, 0.0015%, 0.84% for urine. And the average BODs, COD, SS concentrations were 26,906 $mg/{\ell}$, 36,642 $mg/{\ell}$, 89,375 $mg/{\ell}$ respectively and 14,298 $mg/{\ell}$, 7,484 $mg/{\ell}$, 6,987 $mg/{\ell}$ for urine. In addition, the Cr, Cu, Ni, Cd, Pb, Zn concentrations of feces were 2.65 mg/kg, 7.05 mg/kg, 1.24 mg/kg, 0.07 mg/kg, 0.01 mg/kg, 45.11 mg/kg respectively and 1.52 mg/kg, 1.62 mg/kg, 0.00 mg/kg, 0.03 mg/kg, 0.03 mg/kg, 4.49 mg/kg for urine on the fresh matter basis. The end of the survey was that the quality of the compost can be used as a raw material, and manure is necessary to constantly driven forward horse manure composting research.