• Title/Summary/Keyword: degree of oxidation

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The Method of Exposure Determination for Digital Infrared Photography in Forensic Field (법과학 분야에서 디지털 적외선 사진을 위한 노출 결정 방법)

  • Kim, Sang-Ki;Kim, Yoo-Jin
    • The Journal of the Korea Contents Association
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    • v.14 no.2
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    • pp.181-191
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    • 2014
  • In the past, making IR photography needed somewhat complicated process, so its application fields were limited. However, it has become easy to make IR photography with advanced digital technology, so it is expected that the fields of IR photography and existing limit due to difficult making process will be expanded. Therefore, in this study, it is decided that the need of IR standard chart which allows us to manage exposure and tone of IR photography for scientific purpose will increase. Two methods were used to make IR standard chart. First method is to use aluminum. When aluminum has oxide coating through anodic oxidation, it has high durability, corrosion resistance and heat resistance. Also, IR reflectance of aluminum can be controlled in some degree depending on the thickness of oxide coating. Second method is to use pigments. Yellow 10P150 pigment is used for the brightest patch. This pigment is appropriate in this study due to high heat resistance and IR reflectance. Carbon black is used for the darkest patch. Carbon black absorbs much IR, and its color is not faded by any source of light. IR reflectance is adjusted elaborately by mixing two pigments. Finally, 6 patches are selected with consideration for actual IR reflectance of patches. As a result, IR reflectance of random subjects can be known approximately and IR photographs can have appropriate contrast with the IR standard chart.

A Study on Physiochemical Characteristics of Xanthoceras sorbifolia Seeds Oil (문관나무 종자유의 이화학적 특성 분석)

  • Park, Yu Hwa;Lee, Ki Yeon;Hong, Soo Young;Kim, Hee Yeon;Heo, Nam Ki;Kim, Kyung Hee
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.12
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    • pp.1747-1752
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    • 2012
  • This study investigated the physiochemical characteristics of Xanthoceras sorbifolia seed oil. Xanthoceras sorbifolia seed oil was extracted by supercritical fluid extraction (420 atm, $50^{\circ}C$), hexane extraction and heat-pressed extraction ($160^{\circ}C$, $180^{\circ}C$). Acid values and peroxide values were evaluated, as well as the degree of lipid oxidation. The heat-pressed ($160^{\circ}C$) extraction gave a $53.5{\pm}2.5%$ higher yield of oil, compared with the other extraction methods. The acid values from the super critical fluid extraction were the highest, while peroxide values were highest from the heat-pressed extraction at $160^{\circ}C$ (3.10 meq/kg). The contents of linolenic acid and oleic acid were 38.63~41.13% and 26.29~26.85%, respectively. Contents of stigmasterol and ${\beta}$-sitosterol were 6.01~6.49 mg/100 g and 58.19~59.85 mg/100 g, respectively. These results indicate that Xanthoceras sorbifolia seed oil can possibly serve as new edible oils.

Review of Microbially Mediated Smectite-illite Reaction (생지화학적 스멕타이트-일라이트 반응에 관한 고찰)

  • Kim, Jin-Wook
    • Economic and Environmental Geology
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    • v.42 no.5
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    • pp.395-401
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    • 2009
  • The smectite-illite (SI) reaction is a ubiquitous process in siliciclastic sedimentary environments. For the last 4 decades the importance of smectite to illite (S-I) reaction was described in research papers and reports, as the degree of the (S-I) reaction, termed "smectite illitization", is linked to the exploration of hydrocarbons, and geochemical/petrophysical indicators. The S-I transformation has been thought that the reaction, explained either by layer-by-layer mechanism in the solid state or dissolution/reprecipitation process, was entirely abiotic and to require burial, heat, and time to proceed, however few studies have taken into account the bacterial activity. Recent laboratory studies showed evidence suggesting that the structural ferric iron (Fe(III)) in clay minerals can be reduced by microbial activity and the role of microorganisms is to link organic matter oxidation to metal reduction, resulting in the S-I transformation. In abiotic systems, elevated temperatures are typically used in laboratory experiments to accelerate the smectite to illite reaction in order to compensate for a long geological time in nature. However, in biotic systems, bacteria may catalyze the reaction and elevated temperature or prolonged time may not be necessary. Despite the important role of microbe in S-I reaction, factors that control the reaction mechanism are not clearly addressed yet. This paper, therefore, overviews the current status of microbially mediated smectite-to-illite reaction studies and characterization techniques.

Effect of Blue Color-deficient Sunlight on the Productivity and Cold Tolerance of Crop Plants II. On the unsaturation of mitochondrial phospholipid (청색파장(靑色波長)영역이 결여된 태양광이 작물(作物)의 생산성(生産性) 및 내냉성(耐冷性)의 향상에 미치는 효과 II. 미토콘드리아막(膜)의 인지질불포화도(燐脂質不飽和度)의 증가)

  • Jung, Jin;Kim, Chang-Sook
    • Korean Journal of Environmental Agriculture
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    • v.5 no.2
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    • pp.149-155
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    • 1986
  • The fatty acid compositions of phospholipids extracted from leaves and leaf mitochondria, which were sampled from several horicultural plants grown under blue color-deficient sunlight (BCDS), were determined and compared with those from plants grown under natural white colored sunlight(WCS). It was found that the mitochondria isolated from plants grown under BCDS contained phospholipid whose degree of unsaturation in unit of number of double bonds per lipid molecule was remarkably higher than that from plants grown under WCS, the relative increment being $8{\sim}49%$. This was significantly larger than the relative increment, $4{\sim}8%$ for total phospholipid extracted from whole leaves grown under BCDS campared to WCS. This observation demonstrated that the blue light effect of sunlight on the chemical property of cellular membranes, as long as it was concerned with fatty acid composition, arose mainly at the mitochondrial membrane. Also observing that the degree of unsaturation of mitochondrial phospholipid was much lower than that of total phospholipid, it was interpreted that this was the consequence of rather active oxidative destruction of lipid-fatty acid components occuring in mitochondrial membrane by the reactive oxygen species, especially superoxide($O_2-$), which was known to be produced in mitochondrial inner membrane through the side reactions of the respiratory electron transport chain and also probably through the photosensitized reaction involving oxygen induced by blue colored light. Thus, it may be tentatively concluded that the extent of photosensitization in mitochondrial membrane could be considerably reduced under BCDS resulting in lowering of the $O_2-$ level in the respirating organelle The possible involvement of photodynamic action in membrane oxidation was also indicated by the fact that the typical fat-soluble antioxidant, ${\alpha}-tocopherol$, was found to be contained on a higher level in leaves under BCDS than those under WCS.

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Application to the Biscuits Manufacture of Processed Amaranth Seeds (아마란스(Amaranth) 종실의 가공에 따른 비스킷 제품에의 적용)

  • 김진수;유희중
    • The Korean Journal of Food And Nutrition
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    • v.15 no.4
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    • pp.321-325
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    • 2002
  • For examination, amaranth was first dried its surface after sufficient soaking in water. Dried amaranth was roasted when the moisture contents reached 30∼50%, its nasty smell disappeared and its color turned to yellow and it was puffed. Pretreated amaranth was added to biscuit for the improvement of apparence and merchandise value. The maximum expansion was reported at the moisture percentage of 130∼160% according to the examination of expansion and moisture percentage. In order to compare gelatinization of different processing, three different amaranth were prepared as follows ; Raw amaranth, steamed/dried amaranth, and roasted amaranth. The degree of gelatinization was increased as the percentage of moisture was increased and the degree of gelatinization of roasted amaranth was higher than the one of steamed/dried amaranth, their moisture contents were 62.10% and 57.59%, respectively In addition, the hardness($\times$10$\^$5/dyn/㎠) of roasted amaranth was showed lower values than that of steamed amaranth and raw amaranth were showed the large values. After examining biscuits containing each amaranth, raw amaranth had problem with nasty smell and bad texture, and streamed/dried amaranth were able to remove viscosity but turned brown. Biscuits containing roasted amaranth had good smell and texture, and besides the color of biscuits became bright because roasted amaranth turned white. Biscuits tasted best when it contained 5% of roasted amaranth. The rancidity of biscuits with 5% roasted amaranth were proceeded slowly while roasted amaranth itself had high acid value and peroxide value. For the safety from oxidation, it was fairly safe for about 6 months.

Stability of Oil-in-Water Emulsions with Different Saturation Degrees from Beef Tallow Alcoholysis Products (우지 Alcoholysis 반응물을 이용한 Oil-in-Water Emulsion의 포화도에 따른 산화특성 및 안정성 연구)

  • Zhang, Hua;Lee, Young-Hwa;Shin, Jung-Ah;Lee, Ki-Teak;Hong, Soon-Teak
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.6
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    • pp.933-940
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    • 2013
  • In this study, methyl esters with different saturated fatty acids (SFA) were prepared by urea fractionation to make an oil-in-water emulsion. Emulsion characteristics (emulsion stability and oxidative stability) of the methyl ester emulsion were then studied at different percentages of methyl ester saturation (5, 28, 39, 50, and 72%, termed ${\Sigma}$SFA5, ${\Sigma}$SFA28, ${\Sigma}$SFA39, ${\Sigma}$SFA50, and ${\Sigma}$SFA72, respectively). The stability of emulsions (ES) with different SFA content was 46.0 (${\Sigma}$SFA5), 39.5 (${\Sigma}$SFA28), 32.7 (${\Sigma}$SFA39), 32.6 (${\Sigma}$SFA50), and 27.3 (${\Sigma}$SFA72). Results from Turbiscan showed that creaming or clarification, based on the backscattering intensity, was more pronounced with increases in the saturation degree of the emulsion. These results implied that the emulsions with lower saturation were more stable. During 30 days of storage, the lipid peroxide value increased for all emulsions, with the increase less pronounced with the increasing saturation of the emulsion; 1.880 (${\Sigma}$ SFA5), 1.267 (${\Sigma}$SFA28), 1.062 (${\Sigma}$SFA39), 0.342 (${\Sigma}$SFA50) and 0.153 (${\Sigma}$SFA72) mg $H_2O_2/mL$ emulsion. In addition, thiobarbituric acid reactive substances (TBARS) values were significantly lower in emulsions with high saturation (4.419 mg for ${\Sigma}$SFA50 and 4.226 mg for ${\Sigma}$SFA72) than emulsions with low saturation (6.229 mg for ${\Sigma}$SFA5, 6.801 mg for ${\Sigma}$SFA28 and 6.246 mg for ${\Sigma}$SFA39). In conclusion, the emulsions with a higher saturation degree of methyl esters showed lower emulsion stability but better oxidation stability.

Purification and Characterization of Lactate Dehydrogenase Isozymes in Channa argus (가물치(Channa argus) 젖산탈수소효소 동위효소들의 정제 및 특성)

  • Park, Eun-Mi;Yum, Jung-Joo
    • Journal of Life Science
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    • v.20 no.2
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    • pp.260-268
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    • 2010
  • The lactate dehydrogenase (EC 1.1.1.27, LDH) isozymes in tissues from Channa argus were purified and characterized by biochemical, immunochemical and kinetic methods. The activity of LDH in skeletal muscle was the highest at 380.4 units and those in heart, eye and brain tissues were 13.4, 3,5 and 5.4 units, respectively. Citrate synthase (EC 4.1.3.7, CS) activity in heart tissue was the highest at 20.7 units. LDH/CS in skeletal muscle, heart, eye and brain tissues were 172.9, 0.6, 0.32 and 0.47. Protein concentration in skeletal muscle tissue was 14.7 mg/g and specific activities of LDH in skeletal muscle, heart, eye and brain tissues were 25.88, 0.79, 0.31 and 1.38 units/mg, respectively. Therefore, skeletal muscle tissue was anaerobic and heart tissue was aerobic. The LDH isozymes in tissues were identified by polyacrylamide gel electrophoresis, immunoprecipitation and Western blot with antiserum against $A_4$, $B_4$, and eye-specific $C_4$. LDH $A_4$, $A_3B$, $A_2B_2$. $AB_3$ and $B_4$ isozymes were detected in every tissue, $C_4$, $AC_3$, $A_2C_2$ and $A_3C$ were detected in eye tissue, and $A_3C$ was found in brain tissue. LDH $A_4$, $A_3B$, $A_2B_2$, $AB_3$, $B_4$, eye-specific $C_4$ isozymes were purified by affinity chromatography and Preparative PAGE Cells. The LDH $A_4$ isozyme was purified in the fraction from elution with $NAD^+$ containing buffer of affinity chromatography. Eye-specific $C_4$ isozyme was eluted right after $A_4$, after which $B_4$ isozyme was eluted with plain buffer. As a result, one part of molecular structures in $A_4$, $B_4$ and eye-specific $C_4$ were similar, but were different from each other in $B_4$ and $C_4$. Therefore the subunit A may be conservative in evolution, and the evolution of subunit B seems to be faster than that of subunit A. The activity of LDH $A_4$, $A_2B_2$, $B_4$, and eye-specific $C_4$ isozymes remained at 39.98, 21.28, 19.67 and 16.87% as a result of the inhibition by 10 mM of pyruvate, so the degree of inhibition was very high. The $Km^{PYR}$ values were 0.17, 0.27 and 0.133 mM in $A_4$, $B_4$ and eye-specific $C_4$ isozymes, respectively. The optimum pH of LDH $A_4$, $B_4$, eye-specific $C_4$, $A_2B_2$, $A_3B$, and $AB_3$ were pH 6.5, pH 8.5, pH 5.5, pH 6.0-6.5, pH 5.0 and pH 7.5. The $A_4$ and heterotetramer isozymes stabilized a broad range of pH. Especially, LDH activities in skeletal muscle tissue were high, resulting in a high degree of muscle activity.LDH metabolism in eye tissue seems to be converted faster from pyruvate to lactate by eye-specific $C_4$ isozyme as eye-specific $C_4$ have the highest affinity for pyruvate, and right after the conversion, oxidation of lactate was induced by $A_4$ isozyme. It was found that expression of Ldh-C, affinity to substrate and reaction time of $C_4$ isozyme were different according to the ecological environmental and feeding capturing patterns.

Phase Transitions of $LiMn_2O_4$ on $CO_2$ Decomposition (($CO_2$ 분해시 $LiMn_2O_4$의 상변화)

  • Kwoen, Tae-Hwan;Yang, Chun-Mo;Park, Young-Goo;Cho, Young-Koo;Rim, Byung-O
    • Journal of the Korean Applied Science and Technology
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    • v.20 no.1
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    • pp.33-43
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    • 2003
  • $LiMn_2O_4$ catalyst for $CO_2$ decomposition was synthesized by oxidation method for 30 min at 600$^{\circ}C$ in an electric furnace under air condition using manganese(II) nitrate $(Mn(NO_3)_2{\cdot}6H_2O)$, Lithium nitrate ($LiNO_3$) and Urea $(CO(NH_2)_2)$. The synthesized catalyst was reduced by $H_2$ at various temperatures for 3 hr. The reduction degree of the reduced catalysts were measured using the TGA. And then $CO_2$ decomposition rate was measured using the reduced catalysts. Phase-transitions of the catalysts were observed after $CO_2$ decomposition reaction at an optimal decomposition temperature. As the result of X-ray powder diffraction analysis, the synthesized catalyst was confirmed that the catalyst has the spinel structure, and also confirmed that when it was reduced by $H_2$, the phase of $LiMn_2O_4$ catalyst was transformed into $Li_2MnO_3$ and $Li_{1-2{\delta}}Mn_{2-{\delta}}O_{4-3{\delta}-{\delta}'}$ of tetragonal spinel phase. After $CO_2$ decomposition reaction, it was confirmed that the peak of $LiMn_2O_4$ of spinel phase. The optimal reduction temperature of the catalyst with $H_2$ was confirmed to be 450$^{\circ}C$(maximum weight-increasing ratio 9.47%) in the case of $LiMn_2O_4$ through the TGA analysis. Decomposition rate(%) using the $LiMn_2O_4$ catalyst showed the 67%. The crystal structure of the synthesized $LiMn_2O_4$ observed with a scanning electron microscope(SEM) shows cubic form. After reduction, $LiMn_2O_4$ catalyst became condensed each other to form interface. It was confirmed that after $CO_2$ decomposition, crystal structure of $LiMn_2O_4$ catalyst showed that its particle grew up more than that of reduction. Phase-transition by reduction and $CO_2$ decomposition ; $Li_2MnO_3$ and $Li_{1-2{\delta}}Mn_{2-{\delta}}O_{4-3{\delta}-{\delta}'}$ of tetragonal spinel phase at the first time of $CO_2$ decomposition appear like the same as the above contents. Phase-transition at $2{\sim}5$ time ; $Li_2MnO_3$ and $Li_{1-2{\delta}}Mn_{2-{\delta}}O_{4-3{\delta}-{\delta}'}$ of tetragonal spinel phase by reduction and $LiMn_2O_4$ of spinel phase after $CO_2$ decomposition appear like the same as the first time case. The result of the TGA analysis by catalyst reduction ; The first time, weight of reduced catalyst increased by 9.47%, for 2${\sim}$5 times, weight of reduced catalyst increased by average 2.3% But, in any time, there is little difference in the decomposition ratio of $CO_2$. That is to say, at the first time, it showed 67% in $CO_2$ decomposition rate and after 5 times reaction of $CO_2$ decomposition, it showed 67% nearly the same as the first time.

Heavy Metal Contamination around the Abandoned Au-Ag and Base Metal Mine Sites in Korea (국내 전형적 금은 및 비(base)금속 폐광산지역의 중금속 오염특성)

  • Chon Hyo-Taek;Ahn Joo Sung;Jung Myung Chae
    • Economic and Environmental Geology
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    • v.38 no.2 s.171
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    • pp.101-111
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    • 2005
  • The objectives of this study we to assess the extent and degree of environmental contamination and to draw general conclusions on the fate of toxic elements derived from mining activities in Korea. 인t abandoned mines with four base-metal mines and four Au-Ag mines were selected and the results of environmental surveys in those areas were discussed. In the base-metal mining areas, the Sambo Pb-Zn-barite, the Shinyemi Pb-Zn-Fe, the Geodo Cu-Fe and the Shiheung Cu-Pb-Zn mine, significant levels of Cd, Cu, Pb and Zn were found in mine dump soils developed over mine waste materials, tailings and slag. Furthermore, agricultural soils, stream sediments and stream water near the mines were severely contaminated by the metals mainly due to the continuing dispersion downstream and downslope from the sites, which was controlled by the feature of geography, prevailing wind directions and the distance from the mine. In e Au-Ag mining areas, the Kubong, the Samkwang, the Keumwang and the Kilkok mines, elevated levels of As, Cd, Cu, Pb and Zn were found in tailings and mine dump soils. These levels may have caused increased concentrations of those elements in stream sediments and waters due to direct dis-charge downstream from tailings and mine dumps. In the Au-Ag mines, As would be the most characteristic contaminant in the nearby environment. Arsenic and heavy metals were found to be mainly associated with sulfide gangue minerals, and mobility of these metals would be enhanced by the effect of oxidation. According to sequential extraction of metals in soils, most heavy metals were identified as non-residual chemical forms, and those are very susceptible to the change of ambient conditions of a nearby environment. As application of pollution index (PI), giving data on multi-element contamination in soils, over 1.0 value of the PI was found in soils sampled at and around the mining areas.

Characterization of Platycodon grandiflorum Seeds Oil Extracted by Supercritical Carbon Dioxide (초임계 이산화탄소를 이용하여 추출된 도라지 종자유의 특성)

  • Kim, Yangji;Imm, Jee-Young;Kim, Seok Joong
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.1
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    • pp.99-110
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    • 2018
  • In this study, oil of Platycodon grandiflorum seeds was prepared using supercritical carbon dioxide extraction (SCE) and its physicochemical indices as a new edible oil were investigated. Compared to Soxhlet solvent extraction, SCE under the condition of 6,000 psi at $40^{\circ}C$ produced more oil, especially from the roasted seeds to 32.7%. TLC analysis showed triacylglycerols accounted for most of the oil obtained from roasted Platycodon grandiflorum seeds by SCE similarly to commercial soybean oil or perilla seeds oil. The oil had highly unsaturated lipid with considerable amount of linoleic acid(73.27%) much more than two commercial oils followed by oleic acid(13.16%). Physicochemical properties of the oil were as follows; specific gravity, 0.92; dynamic viscosity, 45.37 cP; refractive index, 1.48; color, L=47.30, a=-3.69, b=25.72; iodine value, 141.57 g $I_2/100g$ oil; saponification value, 191.21 mg of KOH/g of oil; acid value, 2.60 mg of KOH/g of oil. Among those, refractive index, viscosity and iodine value, which were related to unsaturation degree of lipid, were ranged between those of two commercial oils. The oxidation stability of oil(2.03 hr) was also ranged between less stable perilla seeds oil(1.79 hr) and more stable soybean oil(2.94 hr) based on the induction time measured by Rancimat assay. In addition to extraction yield increase, seeds roasting provided further benefits such as reductions of cholesterol ester content and acid value without change in fatty acid composition. In conclusion, oil was extracted from the roasted Platycodon grandiflorum seeds at high yield by supercritical carbon dioxide and it seemed to have proper characteristics as a edible oil.