• 한국수산과학회지
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• 제50권6호
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• pp.684-693
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• 2017

We investigated methods for extracting histidine-containing low-molecular-weight (LMW) peptides such as anserine, carnosine and histidine from the edible meat of tuna byproducts. Extracts were treated by several methods including heat treatment ($80^{\circ}C$, 10 min), DOWEX ion exchange (IEC), ultrafiltration (UF), and carboxymethyl (CM)-cellulose column chromatography (IEC+CMC); then the levels of protein, total iron, histidine, carnosine, and anserine were measured. Extracts treated with IEC+CMC using CM-cellulose were analyzed for total iron, protein, histidine, and anserine content, which were $6.27{\pm}0.26mg/mL$, $5.20{\pm}0.21{\mu}g/mL$, 0.80 mg/mL, 0.208 mg/mL, and 4.40 mg/mL, respectively, in yellowfin tuna; and $9.05{\pm}0.82mg/mL$, $4.06{\pm}0.20{\mu}g/mL$, 1.62 mg/mL, 0.012 mg/mL, and 7.28 mg/mL in bigeye tuna. By comparison in IEC-UF treated extracts, protein, total iron, and histidine content decreased by 43%, 73%, and 27% in yellowfin and 0.4%, 54%, and 23% in bigeye tuna, wheres carnosine and anserine content increased by 22% and 17%, respectively. Freeze-dried (FD) extracts exhibited similar trends as non-dried extracts, i.e., dipeptide content increased with purification steps, whereas pro-oxidant (total iron and protein) content decreased. IEC+CMC treated FD extracts had the highest anserine, content, and the greatest reductuion in pro-oxidants.

• 한국가금학회지
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• 제30권4호
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• pp.245-251
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• 2003

Ferritin 유전자 이식 효모 (FRT, Saccharomyces cerevisiae)를 생균제로 급여시에 육계와 산란계의 생산성과 장기 및 난황의 철분 함량에 미치는 영향을 구명하기 위하여 3회의 사양실험을 실시하였다. FRT의 급여효과는 일반 효모 (W0)와 20mM의 구연산 철을 첨가한 배지에서 배양한 효모(W20)의 급여시와 비교하였다. 실험 1에서는 철분을 첨가급여구(75mg/kg; Fe75), 무첨가구 (Fe0) 효모의 급여(무첨가, W0, FRT)가 육계의 생산성과 장기의 철분함량에 미치는 영향을 구명하기 위하여 1일령 육계 수컷 420수를 이용하여 5주간 사양실험을 실시하였다. 매주 증체량과 사료섭취량, 사료요구율을 측정하였다. 실험 2에서는 33주령 이사브라운 산란계 15수를 산란케이지에 개체수용하여 대조구와 W0, FRT 사료를 3주간 급여하였다. 실험 3은 45주령 이사브라운 산란계 24수를 산란케이지에 개체수용하여 1주간 기초사료를 급여한 뒤 시험사료(대조구, W0, W20, FRT)를 3주간 급여하였다. 모든 실험의 종료시 간과 심장, 비장, 경골의 철분함량을 측정하였으며 주간별로 난황의 철분함량을 측정하였으며 주간별로 난황의 철분함량을 측정하였다.(Expt 2, 3) 실험 1과 2에서 효모의 급여량은 사료에 $1{\times}10^8$cfu/kg이었으며 철분함량은 세포 건물기준 500mg/kg이었다. 실험 3에서는 사료에 $2{\times}10^{10}$cfu/kg을 첨가하였으며 철분함량은 1000mg/kg이었다. 실험 1에서 Fe75의 급여는 Fe0에 비해 증체량이 현저히 증가하였다.(P<0.05). 실험 3에서 FRT의 급여는 간과 비장의 철분함량을 증가시키는 경향을 보였으나 경골의 철분함량은 감소하는 경향을 보였다. 이상의 결과에서 FRT의 급여는 생균제로서 육계와 산란계의 생산성과 장기의 철분함량을 개선하지 못하였다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2000년도 추계학술발표강연 및 논문개요집
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• pp.169-169
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• 2000

• 한국식품과학회지
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• 제25권5호
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• pp.517-520
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• 1993

돈육의 pH가 5.0에서 7.0으로 증가할수록 저장중 산패치는 유의차 있게 감소하였다. 본 실험 결과 고 pH 돈육의 낮은 유리철 함량과 높은 GPx 활성은 저장중 돈육의 산패 억제에 관여하는 중요한 요인들인 것으로 밝혀졌다. 그러나 pH 조절에 의한 산패 억제에 관여할 수 있는 그 밖의 다른 가능한 인자들을 찾는 연구 또한 중요하다고 하겠다. 나아가서 유리철 ion의 방출 억제나 불활성화 방안, GPx의 또 다른 활성화 방안 및 천연항산화제로서의 활용 가능성등이 계속 연구, 검토되어야 할 것이다. 본 연구의 결과는 돈육의 저장성 증진은 물론, 규명된 항산화 기작들을 다른 작품 system에 응용하는 데에도 이용될 수 있을 것으로 본다.

• 한국식품과학회지
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• 제47권5호
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• pp.561-566
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• 2015

350 ppm 농도로 물/카놀라 기름 에멀션에 첨가된 달걀 노른자 위 레시틴은 에멀션 기름의 철 이온에 의한 자동산화와 클로로필에 의한 감광산화에 유의한 영향을 나타내지 않았다. 에멀션의 산화 중 달걀 노른자위 레시틴으로부터 유래한 인지방질은 분해되었으며 감광산화에 비해 자동산화에서 분해 속도가 높았다. 그러나 PC와 PE 사이의 분해 속도는 두 종류의 산화에서 모두 유의한 차이를 보이지 않았다(p>0.05).

• 한국주조공학회지
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• 제8권3호
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• pp.296-309
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• 1988

In this study the mechanical properties of ferritic ductile cast iron in as-cast are discussed by metallographic considering the effect of phosphorus content(about 0 - 0.8wt.%). In ferritic S.G. cast iron containing about 4.2wt.% Si, 0.5wt.% Ni, 0.02wt.%B, these samples are investigated for castability, microstructure, machinability, wear resistance, mechanical and thermal properties. The main results are summarized as follows. 1) The chill depth increased greatly with P addition up to about 0.6wt.% but the tensile strength and the elongation are decreased smoothly. 2) The size of S.G. and the amount of steadite increase with increasing P content. This means the tendency of increasing the number of S.G. 3) The maximum value of wear by mechanical fracture was appeared at the abrasion speed of 1.14m/sec and the plastic Flow layers are stretched longly on the wear surface with decreasing P content. 4) Although the coefficient of thermal expansion increased with P addition, the cast iron growth was slowing down extremely at 0.6w.% P or more.

• Journal of Magnetics
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• 제9권4호
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• pp.105-108
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• 2004

The attempt for the addition of double-phase nanocomposite $Nd_2Fe_{14}BFe_3B$ powders, respectively, into several $RE_2Fe_{14}B$(RE=Pr, Nd) powders with high magnetic properties was carried out. The powders were compounded and compressed to take shape bonded magnets. By means of investigating the variation of compound magnet $B_r$, the interaction between magnetic powders was revealed. The result shows that not chemical just but physical interaction exists between elements. The compound effect of $Nd_2Fe_{14}BFe_3B$-ferrite bonded magnets was detailed studied. The functional relation was revealed between magnetic properties and ferrite content. That is $Y = 5.42 x^2 -11.34x + 6.62$. The variation of $_iH_c$ temperature coefficient ${\beta}_{iHc}$ with ferrite content was investigated. Following the ferrite content increased, ${\beta}_{iHc}$ and $h_{irr}$ were obviously decreased, compression-resistant strength was enhanced.

• 환경위생공학
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• 제7권1호
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• pp.57-66
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• 1992

To investigate on the element content of twelve edible mushrooms and Aloe arborescent, i.e., Lentinus edodes, Ganoderma lucidum (culturing in wood and soil), Tricholoma matsutake, Agaricus auricula-Jude (produced in Korea and China), sarcodon asparatus, Pleurotus ostreatus, Coriolus bisporus, Cyrophora esculenta, Auricularia auricula-Jude (produced in Korea and China), Sarcodon asparatus, Pleurotus ostreatus, Coriolus rersicolor, Smilax rotundifolia and Aloe arborescenstyl were analyzed by Atomic absorption spectrometer. The obtained results were summarized as follows : 1. Potassium, sodium, magnesium and iron content for the most part samples were in large quantities, especi phosphorus content of those was highest ammount for the all samples. 2. Sodium content f·as much ammount in the Lentinus edodes(39 mg, and Ganoderma lucidum(20 mg) , Culturing in wood and soil, while potassium was very high ammount in the Aloe arborescens and other samples. Mush ammount of magnesium as compared with others was Lentinus edodes(144 mg) , Ganoderma lucidum(128 mg), Aloe arborescens(50 mg) and Pleurotus ostreatus (60 mg) . 3, Phosphorus content of Lentinus edodes, Gyrophora esculenta, Auricularia polytricha and Agaricus bisporus was much ammount while iron content of all samples equality higher ammount. Sodium content of Aloe arborescens was not analyzed out for almost all, its potassium(82 mg), magnesium(50 mg) and iron(18 mg) content comparatively higher quentity than others nllnerals and phosphorus volume (4.9 mg) as compared with others, was conspicuously lower detect. 4. Cadimium and lead content of harmful metal element were detected on trace quantity for the most part samples. 5. Organic acids of samples i.e., Lentinus edodes, Agaricus bisporus, Pleuritus ostreatus and Ganoderma lucidum were Citrate, Malate, Fumalate, Succinate, Oxalate, Acetate, Lactate, and Tartarate and Citrate, Malate and Fumarate contents were higher amount remarkbly than other organic acids. Tartarate content was trace amount.

• Advances in materials Research
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• 제13권3호
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• pp.161-171
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• 2024

This study aimed to investigate the effect of physicochemical properties and mix ratios of iron ore (oxide feed): coke (reductant) on the carbothermic reductions of iron ore. Coke size was fixed at ≤63 ㎛ while iron ore size varied between 150-63 ㎛ and ≤63 ㎛ respectively. Mix ratios were changed from 100:0 (reference) to 80:20 and 60:40 while the temperature, heating rate and soaking duration in muffle furnace were fixed at 1100 ℃, 10 ℃/min and 1 hour. Particle size analyzer, XRF, CHNS and XRD analyses were used for determination of raw feed characteristics. The occurrence of phase transformations from various forms of iron oxides to iron during the carbothermal reductions were identified through XRD profiles and supported with weight loss (%). XRF analysis proved that iron ore is of high grade with 93.4% of Fe₂O₃ content. Other oxides present in minor amounts are 2% Al₂O₃ and 1.8% SiO₂ with negligible amounts of other compounds such as MnO, K₂O and CuO. Composite pellet with finer size iron particles (≤63 ㎛) and higher carbon content of 60:40 exhibited 45.13% weight lost compared to 32.30% and 3.88% respectively for 80:20 and 100:0 ratios. It is evident that reduction reactions can only occur with the presence of coke, the carbon supply. The small weight loss of 3.88% at 100:0 ratio occurs due to the removal of moisture and volatiles and oxidations of iron ore. Higher carbon supply at 60:40 leads into better heat and mass transfer and diffusivity during carbothermic reductions. Overall, finer particle size and higher carbon supply improves reactivity and gas-solid interactions resulting in increased reductions and phase transformations.

• 열처리공학회지
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• 제14권6호
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• pp.330-335
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• 2001

Flake graphite cast irons with the high damping capacity have been used for the control of vibration and noise occurring in the members of various mechanical structures under vibrating conditions. However, the damping capacity which Is morphological characteristics of graphite is one of the important factors in reducing the vibration and noise, but hardly any work has deal with this problem. Therefore, the authors have examined the damping capacity of various cast irons with alloying elements and studied the influences of the matrix structures, mechanical properties and morphological characteristics of graphite. The main results obtained are as follows: Effects of Sb on the damping capacities and mechanical properties have been investigated in 3.6%C-0.2%Ni gray cast iron. At 0.02%Sb, specific damping capacity showed the maximum value, and decreased with further increase in Sb content. Mechanical properties showed opposite trend with the damping capacity. And then, effects of Ti on the damping capacities and mechanical properties have been investigated in 3.6%C-0.2%Ni-0.02%Sb gray cast iron. Specific damping capacity increased with increase in Ti content. Graphite length also showed same behavior. Tensile strength increased with Ti content due to refinement of pearlite. In the case of 0.14%Ti addition in 3.6%C-0.2%Ni-0.02%Sb cast iron, specific damping capacity and tensile strength was 36% and 25 $kgf/mm^2$ which are higher than 32% and 15 $kgf/mm^2$ at 3.6%C-0.2%Ni cast iron respectively.