• 제목/요약/키워드: sulfur-containing material

검색결과 36건 처리시간 0.03초

다구찌 방법을 이용한 Inconel 718 소재의 선삭가공에서 표면거칠기 최적화 (Searching Optimal Cutting Condition for Surface Roughness In Turning Operation on Inconel 718 using Taguchi Method)

  • 차진훈;한상보
    • 한국생산제조학회지
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    • 제19권2호
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    • pp.295-300
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    • 2010
  • Inconel 718 alloy, widely used as material of aircraft engine, has a good mechanical property in high temperature, strong anti-oxidation characteristics in oxidated current over $900^{\circ}C$, and also is not easily digested in the air containing sulfur, therefore, its usage as mechanical component is expanding rapidly. Even though Inconel alloy 718 is difficult to machine, it requires highly precise processing/machining to sustain its component quality of high accuracy. In this paper, general turning operation conditions arc tested to select the best cutting process condition by measuring surface roughness through implementing experiments with orthogonal array of cutting speed, feeding speed and cutting depth as processing parameters based on the Taguchi method. Optimal turning operation conditions are extracted from the proposed experimental models.

선삭가공시의 인코넬 718합금의 표면거칠기 최적 절삭조건 (Optimal Cutting Conditions of Surface Roughness for Inconel 718 Alloy in Turning Operation)

  • 박종민;최원식;권순홍;차진훈
    • 한국기계가공학회지
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    • 제8권4호
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    • pp.48-53
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    • 2009
  • Inconel 718 alloy, widely used as material of aircraft engine, has a good mechanical property in high temperature, strong anti-oxidation characteristics in oxidated current over $900^{\circ}C$, and also is not easily digested in the air containing sulfur, therefore, its usage as mechanical component is expanding rapidly. Even though Inconel alloy 718 is difficult to machine, it requires highly precise processing/machining to sustain its component quality of high accuracy. In this paper, general turning operation conditions are tested to select the best cutting process condition by measuring surface roughness through implementing experiments with orthogonal array of cutting speed, feeding speed and cutting depth as processing parameters based on the Taguchi method. Optimal turning operation conditions are extracted from the proposed experimental models.

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전해질 변화에 따른 Viologen 자기조립박막의 전하이동 특성 연구 (Electron-transfer Properties of Viologen Self-assembled MonoLayers in Different Electrolyte Solutions)

  • 이동윤;박상현;신훈규;박재철;장정수;권영수
    • 한국전기전자재료학회논문지
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    • 제17권12호
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    • pp.1337-1340
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    • 2004
  • The self-assembled monolayers of alkane derivatives with sulfur containing head groups on gold substrates have been widely examined recently, since the binding between S atoms and Au surface is strong. The viologen has been widely investigated their well-behaved electrochemistry including electron transfer mediation, the surface-enhanced of the adsorption and the behavior of supramolecular assemblies at electrode surfaces in theses and various studies. Yiologen monolayers are formed onto QCM by self-assembly method. We studied the relationship of electron transfer from changing the anions in 0.1 M NaCl and NaClO$_4$ electrolyte solution. The EQCM measurements revealed the anions transfer during reduction and oxidation, respectively From the EQCM data, the well-defined shape peaks were nearly equal charges by cyclic voltammetry.

Head-space GC-MS를 활용한 마늘추출물 함유 유기농자재 중 Allylmethyl Sulfide, Dimethyl Disulfide 및 Dipropyl Sulfide 분석 (Quantitative Analysis of Allylmethyl Sulfide, Dimethyl Disulfide, and Dipropyl Sulfide in Biopesticides Containing Allium sativum Extract Using Gas Chromatography Mass Spectrometry-Head Space Sampler)

  • 임성진;오영탁;김진효;최근형;박병준
    • 한국환경농학회지
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    • 제34권3호
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    • pp.217-222
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    • 2015
  • BACKGROUND: Garlic (Allium sativum) contains polyphenols and sulfur compounds that are recognized as antioxidant, antithrombotic, anticancer, antibacterial, antimicrobial, nematicidal, and insecticidal activity. For this reason, the Environmentally-friendly Agriculture Promotion Act allowed the garlic extract as commercial biopesticide material for crop protection, nine commercial biopesticides containing A. sativum extract have been marketed in Korea. METHODS AND RESULTS: The determination of allylmethyl sulfide (AMS), dimethyl disulfide (DMDS), and dipropyl sulfide (DPS) in biopesticides containing A. sativum extract was developed and validated by gas chromatography (GC) mass spectrometry (MS) with head-space sampler. The developed method was validated, and the limit of quantification (LOQ) and recovery rates of AMS, DMDS, and DPS were 0.08, 0.32, and 0.09 mg/L and 90.3-91.3, 86.2-88.3, and 87.6-89.5%, respectively. From the nine commercial biopesticide samples, contents of AMS, DMDS, and DPS were analyzed using the developed method and results showed

Supercapacitive properties of nickel sulfide coated titanium dioxide nanoparticles

  • 강진현;류일환;홍다정;김그린;임상규
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.156.1-156.1
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    • 2016
  • Nickel sulfide (NiS) is one of the most promising candidates as an electrode material for supercapacitors due to its good capacitive properties, high electrical conductivity and low cost. In addition to the development of the new electrode materials, nanostructuring the electrode surface is one of the main issues in enhancing the capacitive performance of the supercapacitors because the increased surface area can improve the charge transfer and energy storage processes occurring at the electrode surface. However, most nanofabrication techniques require complicated and delicate nanoprocesses, and hence are not suitable for practical use. In this work, we developed a simple method to fabricate nanostructured NiS electrodes by depositing NiS onto $TiO_2$ nanoparticles. First, $TiO_2$ nanoparticles were spin-coated on a fluorine-doped tin oxide (FTO) substrate, and then NiS layers were deposited onto the $TiO_2$ nanoparticles by consecutive dip-coatings in the solutions containing nickel and sulfur precursors. This nanostructured NiS electrode showed significantly improved capacitive properties compared to the electrode of NiS films deposited without $TiO_2$ nanoparticles. The asymmetric full-cell supercapacitor with this nanostructured NiS electrode and activated carbon electrode was also fabricated and investigated.

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Waste coffee grounds-derived nanoporous carbon nanosheets for supercapacitors

  • Park, Min Hong;Yun, Young Soo;Cho, Se Youn;Kim, Na Rae;Jin, Hyoung-Joon
    • Carbon letters
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    • 제19권
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    • pp.66-71
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    • 2016
  • The development of nanostructured functional materials derived from biomass and/or waste is of growing importance for creating sustainable energy-storage systems. In this study, nanoporous carbonaceous materials containing numerous heteroatoms were fabricated from waste coffee grounds using a top-down process via simple heating with KOH. The nanoporous carbon nanosheets exhibited notable material properties such as high specific surface area (1960.1 m2 g−1), numerous redox-active heteroatoms (16.1 at% oxygen, 2.7 at% nitrogen, and 1.6 at% sulfur), and high aspect ratios (>100). These unique properties led to good electrochemical performance as supercapacitor electrodes. A specific capacitance of ~438.5 F g−1 was achieved at a scan rate of 2 mV s−1, and a capacitance of 176 F g−1 was maintained at a fast scan rate of 100 mV s−1. Furthermore, cyclic stability was achieved for over 2000 cycles.

Rhodobactor sphaeroides의 수소생산에 미치는 광세기 및 광합성 배양기 영향 (Influence of light intensity and photo-bioreactor design for photo biological hydrogen production by Rhodobactor sphaeroides)

  • 김미선;백진숙
    • 한국수소및신에너지학회논문집
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    • 제15권2호
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    • pp.166-174
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    • 2004
  • Purple non-sulfur bacteria, Rhodobacter sphaeroides KD131 grew to reach the maximum cell concentration in 45 hrs of incubation in the synthetic media containing (NH4)2SO4, L-aspartic acid and succinic acid as the carbon and nitrogen sources, respectively, at 30oC under 8 klux irradiance using halogen lamp. The strain produced hydrogen from the middle of the logarithmic growth phase and continued until the cell growth leveled out. The strain grew and produced hydrogen under the irradiance of 3-30 klux, but cell growth was inhibited over 100 klux. In addition, anaerobic/light culture condition was better than the aerobic/dark on the hydrogen production. Among various photo-bioreactors examined, the flat-vertical reactor manufactured using clear acrylic plastic material showed the best hydrogen production rate at the given culture condition.

황화광의 침출반응 및 중간생성물의 안정도 (Leaching of Metal Sulfides and the Stability of Reaction Intermediates)

  • 이만승;최승훈
    • 자원리싸이클링
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    • 제27권3호
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    • pp.3-7
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    • 2018
  • 고품위 산화광의 고갈로 인해 금속황화광의 제련공정의 개발이 중요해지고 있다. 금속황화광의 침출은 대부분 전기화학반응으로 크게 $H_2S$, S, ${SO_4}^{2-}$ 발생형으로 분류된다. 침출용액의 산도와 산화제의 종류 및 농도는 황의 중산생성물 형성에 큰 영향을 미친다. 산화성이 강한 침출용액에서 황 옥소음이온의 Frost도는 황의 산화수가 증가할수록 열역학적으로 안정함을 나타낸다.

IMO Type C LNG 저장 탱크의 단열성능 및 구조적 건전성 평가 (Evaluation of Insulation Performance and Structural Integrity of an IMO Type C LNG Storage Tank)

  • 박희우;박진성;조종래
    • 한국기계가공학회지
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    • 제20권7호
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    • pp.1-7
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    • 2021
  • Restrictions on the emissions of nitrogen oxides, sulfur oxides, carbon dioxide, and particulate matter from marine engines are being tightened. Each of these emissions requires different reduction technologies, which are costly and require many pieces of equipment to meet the requirements. Liquefied natural gas (LNG) fuel has a great advantage in reducing harmful emissions emitted from ships. Therefore, the marine engine application of LNG fuel is significantly increasing in new ship buildings. Accordingly, this study analyzed the internal support structure, insulation type, and fuel supply piping system of a 35 m3 International Maritime Organization C type pressurized storage tank of an LNG-fueled ship. Analysis of the heat transfer characteristics revealed that A304L stainless steel has a lower heat flux than A553 nickel steel, but the effect is not significant. The heat flux of pearlite insulation is much lower than that of vacuum insulation. Moreover, the analysis results of the constraint method of the support ring showed no significant difference. A553 steel containing 9% nickel has a higher strength and lower coefficient of thermal expansion than A304L, making it a suitable material for cryogenic containers.

Tetramethylthiuram monosulfide를 ionophore로 이용한 납 이온 선택성 poly(aniline) 고체 접촉 전극 (Lead Ion Selective Solid Contact Electrode based on Tetramethylthiuram monosulfide ionophore)

  • 한원식;박운석;권혜영;이영훈;홍태기
    • 한국응용과학기술학회지
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    • 제30권2호
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    • pp.356-361
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    • 2013
  • Lead (II) ion selective poly(aniline) solid contact electrode based on Tetramethylthiuram monosulfide ionophore as a sulfur containing sensing material is successfully developed. The electrode exhibits good linear response of 25.6 mV / decade (at $20{\pm}0.2^{\circ}C$, r2=0.995) within the concentration range of $1.0{\times}10^{-1}{\sim}4.0{\times}10^{-7}$ M Pb (II). The composition of this electrode was Ionophore : PVC : dioctylphthalate : potassiumtetrakis(4-chlorophenyl)borate : Oleic acid = 5.0 : 20.0 : 25.0 : 4.0 : 5.0. When we consider the results of using different composition electrodes based on only one potassiumtetrakis(4-chlorophenyl)borate or Oleic acid liphophlic additive, poly(aniline) solid contact electrode based on Tetramethylthiuram monosulfide ionophore with potassiumtetrakis(4-chlorophenyl)borate and Oleic acid liphophlic additive had the best result in response characteristics. The electrode shows good selectivity for lead (II) ion in comparison with alkali, alkaline earth, transition and heavy metal ions. This electrode is suitable for use with aqueous solutions of pH 3.0 ~ 7.0 and their standard deviation in the measured emf differences was ${\pm}2.94$ mV at Tris buffered lead sample solution of $1.0{\times}10^{-2}$ M and ${\pm}2.82$ mV at Tris buffered lead sample solution of $1.0{\times}10^{-3}$ M. Their stabilization time was less than 710 s. and response time was less than 16 s.