• 제목/요약/키워드: brown pigment formation

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A Study on the Formation of Spinel Pigment(Green Pigment based on Magnesium-Chrome) (Spinel Pigment의 생성반응에 관한 연구)

  • 이응상;박철원;황성연
    • Journal of the Korean Ceramic Society
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    • v.12 no.1
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    • pp.29-36
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    • 1975
  • This study was conducted to research the formation, color development and application for colored glazes of the spinel solid solutions of the green pigment. On specimens prepared by calcining the oxide and basic carbonate mixture at 1250℃ for 1.5 hour, the x-ray analysis, measurement of reflectance and the test of their stabiality as a glaze pigment were carried out. The results are summarized as follows 1) Each sample is composed of single spinel and not of mixture of spinel. 2) Formation of continuous soild solution, except for a few instances, pertaining to Vegard's law was confirmed by means of the x-ray analysis. 3) The more difference between absorption and reflectance lies, the lighter colors are. When the absorption occurs at the high-reflectance, the excitation purity becomes low. On the contrary when the absorption takes place at the low-reflectance, the excitation purity becomes low. On the contrary when the absorption takes place at the low-reflectance, the excitation purity is higher. 4) Colors obtained in the CdO-MgO-Cr2O3-Al2O3 system, as the amounts of Al3+ increased, change from green through brown to pink, and the absorption peak shifts towards violet region. 5) An increase in Co2+ in the CoO-MgO-Cr2O3-Al2O3 system, changes the color from blue green to dark blue. The excitation purity is higher, and the absorption peak shifts toward regions. 6) Colors are green in the NiO-MgO-Cr2O3 and CdO-MgO-Cr2O3 systems in general, but in the ZnO-MgO-Cr2O3 system brillant hue is not obtained. 70 According to the results of the colored glaze test, the spinels turn outto be stable as brilliant glaze pigment in the calcium-magnesia glaze.

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Color Formation Mechanism of Ceramic Pigments Synthesized in the TiO2-SnO-ZnO Compounds

  • Kim, Soomin;Kim, Ungsoo;Cho, Woo-Seok
    • Journal of the Korean Ceramic Society
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    • v.55 no.4
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    • pp.368-375
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    • 2018
  • This study deals with the color formation of ceramic pigment in the $TiO_2$-SnO-ZnO system. We designed compounds to control the color formation depending on the composition using the Design of Experiment. The color coordinate values of synthesized pigments, $L^*a^*b^*$ were measured and statistically analyzed color for changing elements depending on its composition. The relationship between the major crystalline phases and chromaticity was examined using XRD, and the oxidation states of each element were analyzed by XPS. The synthesized pigments based on the compound design exhibited various color changes ranging from yellow-orange to green-blue and brown. The statistical analysis on the spectrophotometer results shows that $a^*$ and $b^*$ values decreased with $TiO_2$ content, and increased with SnO content. Yellow-orange color was detected with the main peak of SnO, and the green-blue color developed with the main peak of $Zn_2TiO_4$. The $a^*$ and $b^*$ values increased with increased SnO peak intensity, and decreased with increased $Zn_2TiO_4$ peak intensity. The results revealed that pigment color formation was influenced by changes in the main crystalline phases and crystalline intensity. However, XPS analysis of the oxidation states of each element showed little correlation with the pigment chromaticity result.

Changes in Fatty Acid Composition of Dried Shellfish during Storage (패류 건제품의 저장 중 지방산 조성의 변화)

  • CHO HO-Sung;LEE Kang-HO;SON Byung-Yil;CHO Young-Je;LEE Jong-HO;LIM Sang-Sun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.32 no.4
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    • pp.416-419
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    • 1999
  • To evaluate lipid oxidation in dried shellfish during storage, brown pigment formation and composition of fatty acid were determined. Levels of brown pigment formation occurred at $25^{\circ}C$ were higher than those occurred at $4^{\circ}C$ throughout the storage period. Especially, the formation content of lipophilic brown pigment was 9$\~$10 times higher than that of hydrophilic brown pigment in all samples. Fatty acid composition of total lipid (TL) in fresh sea mussel and baby clam were $34.21\%$ and $32.83\%$ in saturated fatty acid, $19.50\%$ and $20,83\%$ in monoenoic acid, and $46.29\%$ and $46.79\%$ in polyenoic acid, respectively. The prominent fatty acids were 16:0, 16:1 and 20:5 in TL of the both samples. During storage, the contents of saturated fatty acid and monoenoic acid were slightly increased but that of polyenoic acid was decreased. In sea mussel, the content of polyenoic acid was higher in phospholipid (PL) than in neutral lipid (NL), while saturated fatty acid and monoenoic acid content were higher in the latter. The ratios of polyenoic acid/saturated fatty acid (P/S) in NL was similar in all samples. But the ratio of P/S in PL was higher in baby clam ($1.81\%$) than that in sea mussel($1.42\%$).

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Elimination of R-Plasmid in Streptomyces bobili (YS-40) by Ethldium Bromide (Ethidium Bromide에 의한 Streptomyces bobili(YS-40)의 R-Plasmid 제거)

  • 김상달;도재호
    • Microbiology and Biotechnology Letters
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    • v.10 no.4
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    • pp.289-295
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    • 1982
  • Streptomyces bobili (YS-40) isolated from soil was tested that it had drug resistance against penicillin, cephalosporin series antibiotics and other antibiotics in the previous paper. The treatment of Streptomyces bobili, (YS-40) with ethidium bromide (EtBr), acriflavine and sodium dodecyl sulfate. (SDS) resulted in the elimination of R-plasmid from the host strain. Minimum growth inhibitory concentrations (MIC) of Hg, Ag, penicillin-G, ampicillin, chloramphenicol, oxytetracycline, streptomycin and kanamycin were found to be 15, 10, > 3, 000, > 100, > 1, 000, > 100, < 5 and < 5$\mu\textrm{g}$/$m\ell$ respectively. Among the curing agents, EtBr was proved to be the most powerful compound for the elimination of R-plasmid in the strain and the elimination rate with EtBr(10$\mu\textrm{g}$/$m\ell$) was about 98%. Optimal pH to. the elimination of R-plasmid was pH 7.0 and the R-plasmid in the cells incubated for 24 hrs was proved to be eliminated most effectively. Aerial mass color, soluble pigment formation and reverse side color were reported to be often the plasmid associated characteristics of the R-plasmid bearing bacteria. But these characteristics of the uncured and cured Streptomyces bobili, (YS-40) showed no changes in the most of the pigment formation media tested in this work.

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Changes in Physicochemical Properties of Soybean Protein due to Acetylation during Incubation with Glucose

  • Kim, Myung-Hee;Kim, Jin-Hee;Kim, Kang-Sung
    • Journal of Environmental Health Sciences
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    • v.30 no.4
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    • pp.308-313
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    • 2004
  • Native and acetylated soybean protein with acetylation percentage of $25\%$ were incubated with glucose to induce Maillard reaction. Acetylation of ${\varepsilon}$-amino group of lysine residues changed the conformation of soybean protein. The direct uv spectrum of native and acetylated soybean protein showed conformational changes with accessibility of tyrosine and tryptophan residues increased. Acetylation suppressed Maillard reaction between soybean protein and glucose. Acetylated soybean protein showed improved water sorption, fat binding, foam formation, and emulsion activity of the protein, but depressed brown pigment development and trypsin digestion. Thus aceylation prevented deterioration of certain functional characteristics that occurred during storage, besides causing functional characteristics to be improved on its own.

A study on the resistance of saccharomyces cerevisiae to copper sulfate (유산동에 대한 Saccharomyce cerevisiae의 저항성에 관한 연구)

  • 이민재;이진기
    • YAKHAK HOEJI
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    • v.3 no.1
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    • pp.15-20
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    • 1957
  • Resume 1. The toxic effect of $CuSO_4$ on the growth of yeast began in the 0.2mM and colony formation was completely inhibited in the 3mM $CuSO_4$ media. 2. The yeast strain which was trained sucessively from lower concentration media to higher one, could grow even in 10mM $CuSO_4$ media. 3. Rlb strain produced brown pigment in copper media. 4. Resistance of Rlb strain to $CuSO_4$ did not revert in non copper media. 5. The appearance of resistant strain was regarded as the result of "Mutation and Selection". 6. The alcohol fermentation ability of Rlb strain was lower than that of parent strain. 7. Rlb strain yielded some effective substance which induced the parent strain to resist against $CuSO_4$. 8. The dehydrogenase activity of yeast was inhibited by $CuSO_4$.

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Nutritional Regulation of Morphological and Physiological Differentiation on Surface Culture of Streptomyces exfoliatus SMF13

  • KYE JOON LEE;KIM, IN SEOP
    • Journal of Microbiology and Biotechnology
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    • v.5 no.4
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    • pp.200-205
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    • 1995
  • Nutritional factors regulating the morphological differentiation and physiological differentiation of Streptomyces exfoliatus SMF13 on surface cultures were evaluated. S. exfoliatus SMF13 produced leupeptin and chymotrypsin-like protease (CTP) at the stage of substrate mycelium growth, and leupeptin-inactivating enzyme (LIE) and trypsin-like protease (TLP) at the stage of aerial mycelium growth. The activity of leupeptin and CTP was high in the region of active growing substrate mycelium, whereas the activity of LIE and TLP was high in the region of aerial mycelium or spores. The differentiations were induced in glucose-limited conditions or by the addition of glucose anti-metabolite (methyl $\alpha$-glucopyranoside), but repressed by high concentrations of glucose or casamino acids. Morphological differentiation (formation of aerial mycelia and spores) was closely related with physiological differentiation (formation of brown-pigment, LIE and TLP). The local distribution of leupeptin, CTP, LIE, and TLP in a developing colony showed that colony development correlated with the production and functions of the compounds: CTP is essential for providing a nitrogen source for mycelium growth: leupeptin regulates TLP activity: LIE inactivates leupeptin: TLP hydrolyzes nongrowing mycelium.

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Influence of NiO, $TiO_2$ for MgO-$SnO_2$ System Spinel Pigment (MgO-$SnO_2$계 Spinel 채요에 대한 NiO, $TiO_2$의 영향)

  • 이응상;박철원;황성윤
    • Journal of the Korean Ceramic Society
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    • v.13 no.2
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    • pp.24-30
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    • 1976
  • To observe the influence of tetrahedral and octahedral preference of cations of Ni2+, Ti4+ upon the formation and the color development of the MgO-SnO2 spinel containing Ni2+ and Ti4+ ions, the gradual substitution of Ni2+ ions for Mg2+ ions and of Ti4+ ions for Sn4+ ions of the spinel in NiO-MgO-SnO2-TiO2 system was carried out. On samples prepared by calcining the oxide and basic carbonate mixtures at 130$0^{\circ}C$ for 1.5 hour, the X-ray analysis, measurement of reflectance and the test of their stability as a glaze pigment were also carried out. On samples prepared by calcining the oxide and basic carbonate mixtures at 130$0^{\circ}C$ for 1.5 hour, the X-ray analysis, measurement of reflectance and the test of their stabiality as a glaze pigment were also carried out. The results are summarized as follows. 1) As increasing the amounts of Ni2+ ions in the xNiO.(2-x)MgO.SnO2 system, spinel was not formed easily, and the mixed-spinel was formed in NiO.MgO.SnO2 of x=1 but the spinels was not formed completely in the range of x>1.5 2) The spinels was not more formed in NiO-MgO-TiO2 system than NiO-MgO-SnO2 system. Therefore, Ti4+ ions have strong octahedral preference than Sn4+ ions. The color changed the yellow region little. The mixed-spinel or non-spinel was formed easily NiO.TiO2, MgO.TiO2 of illmenite type as the gradual substitution of Ti4+ ions for Sn4+ ions. 3) The results of glaze test. The color changed from white through graish brown to brown as the gradual substitution of Ni2+ ions for Mg2+ ions in calcium-zinc glaze and calcium glaze, and from white through light yellowish beige to dull beige in tile glaze. Also, the color did not change generally as the gradual substitution of Ti4+ ions for Sn4+ ions in NiO-MgO-SnO2-TiO2 system.

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Cold Storage and Quality Stability of Ascidian, Halocynthia roretzi (우렁쉥이 저온저장 및 품질안정성에 관한 연구)

  • Lee, Kang-Ho;Lee, Min-Ju;Jung, Byung-Chun;Hong, Byeong-Il;Cho, Ho-Sung;Lee, Dong-Ho;Jung, Woo-Jin
    • Korean Journal of Food Science and Technology
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    • v.26 no.4
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    • pp.382-388
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    • 1994
  • Because of its restrictive harvest from spring to summer, It is necessary to preserve raw ascidians, Halocynthia roretzi, for the purpose of processing regardless of season. We evaluated low Temperature tolerance of ascidian and conditions for cold storage to secure the quality of the stock. To retard the browning of meat rapidly occurred after sucking, ascidians were blanched for 10 seconds in 10% boiling salt solution or dipped for 60 seconds in 0.2% $NaHSO_3$ solution, respectively. The samples were stored in ice, at $-17^{\circ}C$ or $-35^{\circ}C$ for 85 days, respectively. Changes in VBN, glycogen, brown pigment formation, total carotenoid, nucleotides and their related compounds during the storage were determined, and sensory evaluation of quality was also practiced. VBN and brown pigment formation were rapidly increased. Glycogen was gradually decreased and then not detectable after 85 days in case of ice storage. Lipophilic brown pigment was higher than hydrophilic and rapidly increased during storage. The result of sensory evaluation showed that the ascidian treated in 0.2% $NaHSO_3$ was good for 85 days of storage at $-35^{\circ}C$ . Judging from the results of chemical experiment and sensory evaluation, the quality of ascidian treated in 0.2% $NaHSO_3$ and stored at $-35^{\circ}C$ was better than that of other samples.

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Effect of Starvation on Kidney Melano-macrophage Centre in Sub-adult Rock Bream, Oplegnathus fasciatus (Temminck and Schlegel)

  • Seol, Dong-Won;Hur, Jun-Wook;Kim, Dong-Soo;Nam, Yoon-Kwon;Bang, In-Chul;Park, In-Seok
    • Fisheries and Aquatic Sciences
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    • v.12 no.1
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    • pp.49-53
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    • 2009
  • We conducted a histological analysis to investigate the influence of nutritional changes on melano-macrophages (MMs) accumulation in the kidney of sub-adult rock bream (Oplegnathus fasciatus). Four experimental groups were established (initial control, control, fed and starved), and fed commercial feed amounting to 1-3% of their body weight for 2 weeks prior to initiation of experiments. Kidney MMs with dark brown pigment were randomly observed in the kidneys of starved fish, increasing rapidly after 4 weeks, while deposition levels remained low throughout the experiment in the control and fed groups. These results suggest that catabolic tissue breakdown is a major factor contributing to the formation of pigments within MMs. Results also suggest that the degree of MMs deposition in the kidney can be used as alternative indicators in identifying starvation in wild and cultured rock bream.