• Journal of the Korean Society of Tobacco Science
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• v.1 no.1
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• pp.71-77
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• 1979

The weight of domestic cigarette brands were examined by the three affecting factors, the standard leaf blending and the filling value of each leaf, the length of tobacco rod, and the apparent quality conditions. The calculated cigarette weight we obtained was 760mg, whereas the operation standard weight was established as 790mg ~820mg for the 60mm tobacco rod. In the case of the 64mm rod this value was estimated to be 820mg compared with the operation standard weight of 870mg ~ 900mg. For the 56mm rod it was calculated as 720mg being compared to the standard value of 770mg~ 780mg. These results means that the operation standard weight of the domestic brands can cut down by 5-9 per cent in weight.

• Journal of Hydrogen and New Energy
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• v.9 no.4
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• pp.143-150
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• 1998

The hydriding and dehydriding properties of a Mg-10wt.%Ni mixture, mechanically-alloyed in order to improve the hydriding and dehydriding kinetics of pure Mg, were investigated. The $Mg_2Ni$ phase develops along with hydriding-dehydriding cycling. The principal effects of mechanical alloying in a planetary mill and hydriding-dehydriding cycling are considered to be the augmentation in the density of defects and the enlargement in the specific surface area. The mechanically-alloyed Mg-10wt.%Ni mixture is activated easily. It has much higher hydriding rate and hydrogen-storage capacity and relatively high dehydriding rate as compared with the pure Mg, the Mg-10wt.%Ni alloy, the Mg-25wt.%Ni alloy and the $Mg_2Ni$ alloy.

• Journal of Korea Foundry Society
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• v.17 no.5
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• pp.458-464
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• 1997

Mg-Cu-Si과 Mg-Cu-Ge계 3원 합금에서 비정질 생성범위와 열적, 기계적 성질을 조사하였다. Mg-Cu-Si계에서는 $15{\sim}45%Cu$, $0{\sim}10%Si$, Mg-Cu-Ge계에서는 $15{\sim}45%Cu$, $0{\sim}5%Ge$의 조성범위에서 각각 비정질 단상이 생성되었고, $15{\sim}22.5%Cu$, 2.5%Si(or Ge)의 조성범위에서 생성되는 비정질상은 180도 밀착굽힘을 하여도 파단되지 않는 양호한 인성을 가지고 있었으며, $Mg_{82.5}Cu_{15}Ge_{2.5}$비정질합금의 최대인장강도는 800 MPa로 결정질 Mg기 합금의 최대치인 300 MPa에 비해 월등히 높은 값을 나타내었다. 그러고 비정질합금의 결정화는 다음과 같은 과정으로 일어났다. 1) Si(or Ge) ${\le}$ 2.5%: 비정질 ${\to}$ 비정질+$Mg_2Cu$+Mg ${\to}$ $Mg_2Cu$+Mg+$Mg_2Si$(or Ge), 2) Si(or Ge)=5%: 비정질 ${\to}$ $Mg_2Cu$+Mg+$Mg_2Si$(or Ge), 3) Si=10%: 비정질 ${\to}$ 비정질+$Mg_2Si$ ${\to}$ $Mg_2Si$+$Mg_2Cu$+Mg.

• Progress in Superconductivity and Cryogenics
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• v.24 no.4
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• pp.36-39
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• 2022

Since the MgB₂ superconductor is simply composed of two constituents of Mg and B, its performance can be monitored easily with the change of one ingredient compared to the other. With the powder size of B less than 100 nm, two different sizes of Mg powders are used to investigate the reaction temperature dependence of MgB₂ bulk samples. In the range of 630-700℃ for the duration of 30 min., the un-reacted Mg is seen only at 630℃ with Mg powder size of <5 ㎛, whereas Mg traces are detected at all the temperature range with Mg powder size of <45 ㎛. The reaction temperature dependence of MgB₂ superconducting transition temperature, T_c, shows little difference whether Mg powder size is large or small in this range except for the 630℃. It is worthy of notice that the critical current densities of MgB₂ show higher performance with the small size of Mg compared to the large one at all field ranges. With the Mg powder size of <45 ㎛, flux pinning is enhanced with decreasing the reaction temperature, whereas flux pinning properties is quite similar in the Mg powder size of <5 ㎛ except for the 630℃, where Mg is left behind after the reaction.

• Korean Journal of Materials Research
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• v.10 no.1
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• pp.15-20
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• 2000

The hydrogen-storage properties of a mechanically-alloyed Mg-18wt.%Ni mixture were investigated. Among the mixtures mechanically alloyed for 1h, 3h, and 6h, the mixture mechanically alloyed for 6h(MA 6h sample) shows the best properties of activation, hydriding, and dehydriding. The $Mg_2Ni$ phase forms in the mechanically-alloyed Mg-18wt.%Ni mixture along with hydriding-dehydriding cycling. The MA 6h sample is relatively easily activated and has higher hydriding rate than the pure Mg, the Mg-10wt.%Ni alloy, and a little lower hydriding rate than the $Mg_2Ni$alloy. The MA 6h sample lower dehydriding rate than the $Mg_2$Ni alloy but higher dehydriding rate than the pure Mg and the Mg-25wt.%Ni alloy. The MA 6h sample has larger hydrogen-storage capacity than the pure Mg and the other alloys.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.88-88
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• 2017

Zn코팅은 우수한 내식성과 경제성을 바탕으로 자동차나 건축자재 등 산업의 전반적인 분야에서 광범위하게 사용되고 있다. 하지만 최근 한정된 Zn의 매장량으로 인한 원자제의 가격상승과 습식 도금과정의 환경오염 물질 배출 문제가 기존 Zn 코팅의 약점으로 지적되고 있다. 따라서 새로운 원소의 첨가로 인한 Zn의 사용량 감소나 친환경적인 공정방법을 적용하는 연구가 대두되고 있다. 최근의 연구 결과에 따르면 Zn-Mg 합금이 다른 Zn계 합금에 비해 내식성이 우수하며, 이와 같은 우수한 내식성은 $Mg_2Zn_{11}$, $MgZn_2$와 같은 Mg-Zn 이원계의 합금상에 의한 것으로 알려져 있다. 따라서 본 연구에서는 친환경적인 비대칭 마그네트론 스퍼터 공정을 활용하여 다양한 공정조건 하에서 Zn-Mg 박막을 합성하여 최적의 공정 조건을 도출하고자 하였다. Zn-Mg 박막 합성 시 Mg타겟의 조성은 3~10 wt.%로 변화하였으며 Zn-Mg 합금 타겟의 온도를 제어하여 박막의 Mg 조성과 타겟 온도가 Zn-Mg 도금강의 내식성 및 밀착성에 미치는 영향을 평가하였다. 합성된 Zn-Mg 박막은 FE-SEM, EDS, XRD를 사용하여 미세조직, 두께, Mg 조성, 합금상 등을 분석하였으며, 염수분무시험 및 0T 굽힘 시험을 활용하여 Zn-Mg 박막의 내식성 및 내식성을 비교 분석하였다. FE-SE및 EDS분석 결과 Zn-Mg 박막의 Mg 조성은 합금 타겟의 조성이 증가함에 따라 증가하였으며, Mg 함량이 증가할수록 미세구조가 치밀하게 변화하였다. 또한 Zn-Mg 박막 합성 중 타겟의 온도가 상승할수록 박막의 치밀도는 감소하였다. XRD분석 결과 박막을 이루는 주요 합금상은 Zn상과 $Mg_2Zn_{11}$상이며 본 연구에서는 증착 조건에 따른 합금상의 큰 변화는 보이지 않았다. 염수분무실험 및 밀착성 평가 결과 박막의 미세조직이 치밀할수록 Zn-Mg 도금강의 내식성은 향상되었으나, 밀착성은 오히려 감소하는 경향을 나타내었다. 이러한 결과는 Zn-Mg 박막이 치밀한 미세구조일수록 부식환경에서의 강판에 대한 보호 효과는 증가하는 반면, 변형 시 박막의 파괴로 인한 박리 현상이 가속되기 때문으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.2
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• pp.217-224
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• 1992

The study was undertaken to determine the effect of dietary magnesium on the eggshell quality and other performance in laying Tsaiya ducks and Leghorn hens. Twenty-five Tsaiya ducks and 25 Leghorn hens were raised in individual cages. The basal diet was mainly consisted of corn starch and isolated soybean protein. At the beginning of the experiments, birds were fed for 10 days with the basal diet supplemented with 500 mg/kg Mg (1070 mg/kg in total by analysis) in order to allow the birds adapting to the new diet. Both Tsaiya ducks and Leghorn hens were then each randomly divided into five groups and each group of five birds were fed with the experimental diets containing 690, 1070, 1690, 2150 or 2380 mg/kg Mg, respectively for 21 days. Eggs were collected in order to measure eggshell quality, Mg and Ca content of the eggshell. At the end of the experiments, blood samples of all birds were taken from their brachial veins for measuring the concentration of Mg and Ca in the plasma. Experimental results appeared that the dietary Mg content did not significantly affect egg production, egg weight, eggshell breaking strength and thickness in both Tsaiya ducks and Leghorn hens. In Tsaiya ducks, however, the plasma Mg concentration was affected by the dietary Mg content, but the plasma Mg almost reached a plateau (4.66 mg/dl) as long as the dietary Mg level was over 1070 mg/kg. In Leghorn hens, the plasma Mg level was significantly increased from 1.66 mg/dl to 4.03 mg/dl when the dietary Mg content in the diet had been increased from 690 mg/kg to 2380 mg/kg, suggesting that the plasma Mg concentration seems to be directly influenced by the Mg absorbed in the intestine. In the Tsaiya ducks, however, the dietary Mg level did not significantly affect the eggshell Mg content (from 0.113% to 0.123%). Whereas, there was a negative correlation between the eggshell thickness and eggshell Mg content (r = -0.50, p<0.01), revealing that the increase in eggshell Mg content probably associated with the impairment of eggshell quality in Tsaiya ducks. In Leghorn hens, however, there was no significant correlation between eggshell quality and eggshell Mg content, although the Mg content in the eggshell was also increased from 0.279% to 0.427% when the dietary Mg had been elevated from 690 mg/kg to 2380 mg/kg.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.415-422
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• 2016

In this research, the total polyphenol and flavonoid contents in the hot water extract (HE) and methanol extract (ME) of the Coriolus versicolor fruiting body and their partial bioactivities were investigated from March, 2015 to February, 2016. For the analysis of the data, the software used was SPSS 2.0. The results indicate that the total polyphenol content in the HE (129.60 mg/dl) was 85,8 mg/dl higher than that in the ME (43.80 mg/dl). The total flavonoid content in the HE (30.50 mg/dl) was 9.5 mg/dl higher than that in the ME (20.90 mg/dl). The DPPH scavenging activities of the HE and ME at a concentration of 3 mg/ml were 41.03% and 16.36% higher than those at a concentration of 1 mg/ml. The tyrosinase inhibitory activities of the HE and ME at a concentration of 3 mg/ml were 8.29% and 10.32% higher than those at a concentration of 1 mg/ml. The elastase inhibitory activities of the HE and ME at a concentration of 3 mg/ml were 3.12% and 21.53% higher than those at a concentration of 1 mg/ml. The collagenase inhibitory activities of the HE and ME at a concentration of 3 mg/ml were 5.44% and 4.07% higher than those at a concentration of 1 mg/ml. In conclusion, these two kinds of extracts are judged to be useful as skin wrinkle relaxants, due to their anti-oxidative and bioactive functions.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.177-177
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• 2016

우수한 내식성을 가지는 Zn 박막은 자동차, 가전제품, 전자제품 등에 사용되는 철 생산품의 수명 연장을 위하여 널리 사용되어 왔다. 최근 개발된 Zn-Mg 합금 박막은 Zn나 Mg에 비해 우수한 내식성을 나타내는 Zn-Mg 합금상을 형성하기 때문에 순수한 Zn 박막이나 다른 Zn 계 합금 박막에 비해 우수한 내식성을 가진다고 보고된 바 있다. 본 연구에서는 다양한 합금상의 형성을 위해 Mg 중간층 두께를 제어하며 Zn/Mg/Zn 다층 박막들을 합성하였으며 열처리를 통한 합금상의 변화, 그에 따른 박막의 내식성에 관해 연구하였다. Zn/Mg/Zn 다층 박막은 총 $4{\mu}m$의 두께로 Mg 중간층의 두께를 변화하였으며 비대칭 마그네트론 스퍼터링 공정을 이용하여 냉연강판 위에 합성하였다. 합성된 다층 박막은 다양한 Zn-Mg 합금상을 형성하기 위하여 진공로를 이용하여 $200^{\circ}C$에서 1시간 동안 어닐링 열처리를 실시하였다. 열처리 전, 후 Zn/Mg/Zn 다층 박막의 미세조직과 조성은 X선 회절 분석기 (XRD)와 전계방출형 주사전자현미경 (FE-SEM)과 글로우 방전 분광분석기 (GDEOES)를 사용하여 분석하였다. 어닐링 열처리를 통한 Zn-Mg 합금상 형성이 Zn/Mg/Zn 다층 박막의 내식성에 미치는 영향을 평가하기 위하여 동전위 분극시험과 EIS(Electrochemical impedance spectroscopy) 분석 실시하였다. FE-SEM과 GDOES 분석 결과, Zn/Mg/Zn 다층 박막들 각각의 중간층 Mg 두께는 1.5, 2.0, $2.5{\mu}m$ 였으며, 어닐링 열처리 후 중간층의 Mg이 상, 하부의 Zn 층으로 확산되면서 박막을 치밀한 구조로 변화시키는 것으로 확인되었다. XRD 분석 결과, 열처리를 하지 않은 Zn/Mg/Zn 다층 박막들에서는 Mg 상의 피크의 강도 차이만 존재할 뿐 Zn-Mg 합금상은 형성되지 않았다. 그러나 열처리를 후 Zn/Mg/Zn 다층 박막들에서 $MgZn_2$ 합금상이 형성되었으며, 중간층 Mg 두께가 $1.5{\mu}m$ 이하인 박막에서는 Zn 상이, 초과하는 박막에서는 Mg 상이 잔존하는 것을 확인하였다. EIS 분석 결과, 열처리 후 박막의 전하이동저항 값은 증가하며 박막의 어드미턴스 값이 감소하였으며 Bode phase plot을 통해 열처리 후 시정수(time constant)가 높은 주파수 영역에서 형성 되는 것을 확인하였다. 이는 열처리 후 Zn/Mg/Zn 다층 박막이 치밀해지고 내식성이 향상되었음을 나타낸다. 동전위 분극시험 결과에서도 마찬가지로 열처리 한 Zn/Mg/Zn 다층 박막들은 열처리 전 대비 내식성이 향상되는 것을 확인하였다. 열처리를 통한 Zn/Mg/Zn 다층 박막의 내식성의 향상은 우수한 내식성의 합금상의 형성과 박막 미세구조의 치밀화에 기인한다고 판단하였다. 또한 열처리 한 Zn/Mg/Zn 다층 박막들에서는 Zn와 $MgZn_2$ 상들이 공존 할 경우 가장 우수한 내식성을 나타내었으며, 이는 $MgZn_2$와 Zn 사이의 적은 전위 차이로 인해 갈바닉 부식 효과가 감소되었기 때문으로 판단된다.

• The Korean Journal of Zoology
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• v.23 no.2
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• pp.69-76
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• 1980

Mice were dosed with $HgCl_2$ (5, 10 and 20 mg per kilogram body weight) and $CdCl_2$ (10, 15 and 20 mg per kilogram body weight) by the abdominal injection. Acid phosphatase activites of the liver at 24, 48 and 72 hours following the injection were measured by the Mundry colorimetric method using disodium p-nitrophenyl phosphate as the substrate, and the following results were obtained. The enzyme activities measured were 3.47 mg Pi/ml/0.5 hr at 24 hr and 5.00mg/ml/0.5 hr at 72hr respectively following the injection of 5 mg/kg body weight of $HgCl_2$ and 6.79 mg Pi/ml0.5 hr at 24 hr and 3.47 mg Pi/ml/0.5 hr respectively following the injection of 20 mg/kg body weight of the mercury compound, as compared with the activity of 8.3 mg Pi/ml/0.5 hr for the control. With the cadmium treatment, about 50% of the animals injected with 10mg/kg body weight, and none of the animals injected with 15 and 20mg/kg body weight, survived. Of the surviving animals, the sublethal concentration of cadmium was shown to activate the enzyme: the activities at 24, 48 and 72hr following the injection were around 11.2 mg Pi/ml/0.5 hr as compared with 8.63 mg Pi/ml/0.5 hr for the control.