• Title/Summary/Keyword: Residual oxygen content

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Effect of Residual Impurity on Magnetic Properties of the Permalloy Soft Magnet by Powder Injection Molding (분말사출성형으로 제조된 퍼말로이 연자성체에서 잔류 불순물이 자기특성에 미치는 영향)

  • 정원용;최준환;정우상
    • Journal of the Korean Magnetics Society
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    • v.10 no.6
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    • pp.291-296
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    • 2000
  • The manufacturing method of permalloy soft magnet with the Ni contents of 46.6 and 47.2 wt% was investigated by powder injection molding technology. The magnetic properties of permalloy were greatly affected on the residual carbon and oxygen content of the sintered magnet. Solvent extraction and thermal debinding process to minimize the residual carbon content in sintered magnet were developed by controlling the debinding atmosphere. The residual carbon content depends on the debinding condition of the binder system for powder injection molding and the residual oxygen content on the sintering atmosphere. The sintered magnet produced by powder injection molding process had a 50 ppm. residual carbon, 150 ppm. residual oxygen. The coercivity and maximum relative permeability of permalloy soft magnet were 0.46 Oe and 14,600 respectively.

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Impact of Lignin Determination Method on Oxygen Delignification Chemistry

  • Shin Soo-Jeong;Lai Yuan-Zong
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.37 no.5 s.113
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    • pp.50-55
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    • 2005
  • In previous report, we investigated the impact of hexeneuronic acid and some residual extractiveson lignin determination. These non-lignin components severely interfered lignin content determination which also affect on the oxygen delignification comparison between aspen and pine unbleached kraft pulps. Very different pattern was observed whether based on uncorrected conventional kappa number or based on corrected kappa number in oxygen delignification comparison. Lower kappa number aspen pulps showed poor response to oxygen delignification when kappa number was used as lignin determination method but better response with using the acid lignin method. Phenolic hydroxyl group in kraft pulps were also compared based on uncorrected or corrected kappa numberfor lignin content. Based on uncorrected kappa number, lower kappa number oxygen-delignified pulps had lower phenolic hydroxyl group. However, lower kappa number oxygen-delignified pulps showed much higher phenolic hydroxyl group based on the corrected lignin content. For accurate comparison for residual lignin properties from different pulps, lignin determination should be corrected from non-lignin components contribution to lignin.

Deoxidation of Solid Nd Metal by the Metal Calcium Vapour (금속 Ca증기에 의한 고체 Nd 금속의 탈산)

  • Choi, Yonug-Jin;Kim, Sang-Wuk;Jeon, Byung-Seo;Song, Chang-Bin;Oho, Yoon-Seok;Lee, Young-Joo
    • Korean Journal of Materials Research
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    • v.27 no.5
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    • pp.237-241
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    • 2017
  • As a basic study for the removal of oxygen in solid Nd metal by metal Ca vapour, by using the thermodynamic data such as ${\Delta}G-T$ diagrams and Nd-O and Nd-Ca equilibrium diagrams, the amount of residual oxygen in solid Nd metal formed based on deoxidation reaction by Ca vapour, instead of by direct contact of solid Nd metal and Ca solution, was determined. Deoxidation experiments were carried out for solid Nd metal in a temperature range of $890{\sim}970^{\circ}C$ for 1h to 4h and content of addition Ca of 0.6~1.8 g (5~15 wt% of solid Nd metal). As a result, it was found that as deoxidation temperature increased, dissolved oxygen decreased. Especially, it was observed that a small amount of Nd-Ca alloy liquid was formed on the surface of the solid Nd metal sample deoxidized at $970^{\circ}C$ for approximately 1 hour. Also, it was found that if the content of addition Ca was 1.8 g (15 wt% of solid Nd metal) the amount of produced Nd-Ca alloy increased slightly. However, for the Nd sample with which the deoxidation reaction was performed at $930^{\circ}C$ for 4h with content of addition of Ca of 1.5 g (13 wt% of Nd metal), the residual oxygen was found to decreased to 12.00 ppm.

Studies on the Improvement of Packaging of Retorted Samgyetang (레토르트 삼계탕의 포장 개선을 위한 연구)

  • Lee, Jin-Hwan;Lee, Keun-Taik
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.15 no.2
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    • pp.49-54
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    • 2009
  • The effects of filling temperatures of broth and degassing method on the residual oxygen content and gas composition in the pouch and physical strength of packaging material for Samgyetang depending on the contamination of broth on the sealing layer and sterilization process were investigated. The residual oxygen content in the broth and the oxygen proportion in the headspace of package were decreased with the increase of broth temperature at filling into the pouch from 50 to 100. When the products were packaged as air-contained (Air), manually squeezed the upper side of package out to minimize the headspace (Degas) and flushed with nitrogen gas ($N_2$-Flushing) while maintaining the broth temperatures of Samgyetang at 50 or 85. The residual oxygen content and oxygen proportion were increased in the order of $N_2$-Flushing

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Impact of Residual Extractives and Hexenuronic Acid on Lignin Determination of Kraft pulps

  • Shin Soo Jeong;Schroeder Leland R;Lai Yuan Zong
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.36 no.5 s.108
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    • pp.62-68
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    • 2004
  • The amount of non-lignin components in unbleached and oxygen-delignified kraft pulps and their impact on lignin determinations was investigated. The lignin analyses investigated were kappa number and Klason lignin in conjunction with acid-soluble lignin. The species investigated were loblolly pine, and aspen. The non-lignin components that impacted on lignin determination were residual extractives and hexenuronic acid in unbleached and oxygen-delignified kraft pulps. In the hardwoods, significant amounts of extractives remained after kraft pulping and oxygen delignification. These residual extractives in the hardwood pulps had an impact on the lignin determination, more so on the acid lignin method than kappa number. Hexenuronic acid only impacts on kappa number determination both softwood and hardwood pulps, not on acid lignin. Hexeneuronic acid contributed as lignin content more in aspen than pine pulps, and more in oxygen-delignified than unbleached kraft pulps. Impact of hexenuronic acid on should be corrected both softwood and hardwood pulps for accurate kappa number.

Study on Co-incineration of Municipal Solid Waste and Organic Sludges (도시쓰레기와 유기성 하수 슬러지 혼합소각에 관한 연구)

  • Jurng, Jong-Soo;Chin, Sung-Min
    • 한국연소학회:학술대회논문집
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    • 2005.10a
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    • pp.238-244
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    • 2005
  • This study performs the pilot-plant experiments to evaluate the effect of the oxygen enrichment on the co-incineration of municipal solid waste and organic sludge from a wastewater treatment facility. The design capacity of the stoker-type incinerator pilot-plant is 150 kg/h. Combustion chamber temperatures were measured as well as the stack gas concentrations, i.e., NOx, CO, and the residual oxygen. The maximum ratio of organic sludge waste to the total waste input is 30%. Also the oxygen-enriched air with 23% of oxygen in supplied air is used for stable combustion. As the co-incineration ratio of the sludge increased up to 30% of the total waste input, the primary and the secondary combustion chamber temperature was decreased $to900^{\circ}C$ (primary combustion chamber), $750^{\circ}C$(secondary combustion chamber), respectively, approximately $200^{\circ}C$ below the incineration temperature of the domestic waste only (primary: $1,100^{\circ}C$, secondary: $950^{\circ}C$). However, if the supplied air was enriched to 22% oxygen content in air, the incinerator temperature was high enough to burn the waste mixture with 30% sludge, which has the heating value of 1,600 kcal/kg.

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Effect of Dissolved Oxygen on the Growth of Azotobacter vinelandii UWD and Production of PHBV in the Mixture of Organic Acids and Glucose (유기산 및 포도당 혼합배지에서 Azotobacter vinelandii UWD의 생장 및 PHBV 생산에 대한 용존산소의 영향)

  • 박창호
    • KSBB Journal
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    • v.13 no.6
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    • pp.675-680
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    • 1998
  • In both 7L and 20L fermentor experiments the level of dissolved oxygen (D.O) strongly affected growth and PHBV production of Azotobacter vinelandii UWD. A higher D.O. increased carbon substrate consumption rate and cell growth rate with a similar residual biomass production. However, a lower D.O. was a much better condition for PHBV production. In a 20L fermentor experiments controlled at 5% D.O. cell growth rate was about twice faster(0.555 hr-1 and 0.260 hr-1 at the acid and the glucose phase, respectively) with an equal amount(4.5 g/L) of residual biomass production. However, PHBV content in the cell(62.3 wt%) increased 17.3 times at 1% D.O.

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Effect of Oxygen on the Magnetic and Recording Characteristics of Magneto-Optical Disk (광자기 디스크의 기록 및 자기적 특성에 산소가 미치는 영향)

  • Choe, G.
    • Journal of the Korean Magnetics Society
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    • v.3 no.3
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    • pp.229-233
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    • 1993
  • The effects of differential partial pressures of oxygen during sputtering on the magnetic and recording characteristics of magneto-optical disks were investigated. Different flows of oxygen were deliberately introduced into the sputtering chamber to have a variety of partial pressures of oxygen during sputtering. A residual gas analyzer was employed to monitor the oxygen peak before, during, and after sputtering and to estimate the reacted oxygen amount. Most of the oxygen introduced into the chamaber was reacted during sputtering. As the partial pressure of oxygen increased, the oxygen content of the TbFeCoCr film increased also. The oxygen appeared to be bound as Tb-O, effectively decreasing the magnetically active Tb content of the film The coercivity decreased but the squareness of the Kerr hysteresis loops was still excellent. The perpendicular anisotropy was not significantly affected by oxygen amount. The carrier-to-noise ratio, includi!1g the write power sensitivity and bias field sensitivity did not change too much with oxygen content in the film The disks sputtered with oxygen showed better bias field sensitivity with lower write power threshold than the disk sputtered without oxygen, due to high demagnetization during domain formation. No significant degradation of coercivity for the disk sputtered oxygen was observed during an accelerated aging test.

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Thermal Degradation Pattern of Tocopherols on Heating without Oxygen in a Model Food System (모델식품계에서 무산소 가열시 토코페롤의 열분해 패턴)

  • 정혜영
    • The Korean Journal of Food And Nutrition
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    • v.11 no.6
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    • pp.635-639
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    • 1998
  • The thermal degradation pattern of $\alpha$-, ${\gamma}$-and $\delta$-tocopherols in glycerol was investigated during heating at 100~25$0^{\circ}C$ for 5-60 min in the absence of oxyge. The tocopherols and thermally decomposed products were separated by HPLC with a reversed phase $\mu$-Bondapak C18-column. The degradation pattern of $\alpha$-tocopherol during the heating in the absence of oxygen was different from those of ${\gamma}$-and $\delta$-tocopherols. But the degradation patterns of ${\gamma}$-and $\delta$-tocopherols were similar to each other. The residual content of $\alpha$-tocopherol during the heating in the absence of oxygen decreased to the range 12~65% and those of ${\gamma}$-and $\delta$-tocopherols decreased to the range 4~96%. The thermal degradation of tocopherols in the absence of oxygen was less than that in the presence of oxygen.

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Stress Determination in Epitaxial Lead Titanate Films by Asymmetric X-ray Diffraction Method

  • Uchida, Hiroshi;Kiguchi, Takanori;Wakiya, Naoki;Shinozaki, Kazuo;Mizutani, Nobuyasu
    • The Korean Journal of Ceramics
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    • v.6 no.4
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    • pp.385-389
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    • 2000
  • Residual stresses in epitaxial films were measured by X-ray diffraction method. Lattice strains of the (hkl) planes measured along particular Ψ-angles were converted to the in-plane stress according to the equation of stress-strain tensor conversion. Residual tensile stresses were observed in epitaxial PbTiO$_3$ films deposited on (100) SrTiO$_3$ substrate. Tensile stresses approximately 0.9 GPa were measured in Pb-rich films, while it increased to approximately 2.0 GPa with the decreasing of Pb content in the case of Pb-poor films, which ascribed to the formation of lead and oxygen vacancies (expressed as x in Pb$_1-x$TiO$_3-x$).

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