• 한국재료학회지
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• 제13권6호
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• pp.365-368
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• 2003

Small amounts of additives such as mol % 0.13 NiO and mol % 0.01 $CaCO_3$were added to Cu-Zn-Mg ferrites. Basic composition of the Cu-Zn-Mg ferrites was $Cu_{Cu}$X/$Fe_{0.054}$ /$Zn_{0.486}$$Mg_{0.407}$ $Fe_{1.946}$ $O_4$(group A) and $Cu_{0.263}$$Fe_{0.027}$ $Zn_{0.503}$ $Mg_{0.262}$ $Fe_{1.973}$ $O_4$(group B). Specimens were sintered at different temperatures (1010, 1030, $1050^{\circ}C$) for 2 hours in air followed by an air cooling. Then, effects of various composition and sintering temperatures on the microstructure and the magnetic properties such as inductions, coercive forces, and initial permeabilities of the Cu-Zn-Mg ferrites were investigated. The average grain size increased with the increase of sintering temperature. The magnetic properties obtained from the aforementioned Cu-Zn-Mg ferrite specimens were 1,724 gauss for the maximum induction, 1.0 oersted for the coercive force, and 802 for the initial permeability. These magnetic properties indicated that the specimens could be utilized as the core of IFT (intermediate frequency transformer) and antenna in the amplitude modulation.

• 대한치과의사협회지
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• 제12권7호
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• pp.521-526
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• 1974

This observation was carried out to investigate the inorganic constituents of dental calculus of varying locations and different ages. Supragingival calculus was obtained from 540 patients with the periodontal disease. The results were as follows : 1. The weight loss rate in ashing by aging was the highest in the 2nd decade (63.7%) and followed in order by 3rd decade (60.8%), seventh decade 959.8%), fourth decade (55.9%), sixth decade (52.6%) and fifth decade (43.2%). 2. The weight loss rate by ashing was more prominent in the buccal surfaces of the upper posterior teeth (62.0%) than in the lingual surface of the lower anterior teeth (59.7%). 3. The difference in contents of the inorganic constituents by sex was not remarkable. (male, Ca:373.0 P:333.9, female, Ca: 380.2, P: 339.6 ㎍/mg dry weight) 4. In the dry calulus, contents of the inorganic constituents were as follows: Ca:325.8 P:269.10 Mg:1.21 Na:8.44 K:1.32, Zn:0.67 ㎍/mg. 5. The Ca/P ratio was the lowest in the upper anterior region (1.11) and the highest in the lower posterior region (1.29) and the average was 1.20.

• Asian-Australasian Journal of Animal Sciences
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• 제17권1호
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• pp.46-52
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• 2004

Hisardale male lambs (n=24, 4-5 month of age) were maintained on a conventional ration for a month, to equilibrate the body mineral status. Six lambs were sacrificed after one month of feeding; the samples of organs were analyzed to ascertain mineral status. The remaining 18 lambs were divided into 3 groups of 6 each on body weight basis. Three dietary treatments containing 100 ($T_1$), 110 ($T_2$) and 120% ($T_3$) of minerals (Ca, P, S, Zn and Mn) as specified by NRC (1985) were formulated and each treatment was alloted ad libitum to a group for 120 days. Blood and wool samples were collected at monthly intervals. At the end of the experiment a balance trial of 5 days duration was conducted to study the balance of mineral elements. The effective intake of minerals was Ca, 111 and 120, P, 110 and 122; S, 112 and 129; Zn, 112 and 126 and Mn, 109 and 123 percent in $T_2$ and $T_3$, respectively, in comparison to $T_1$ (100). The additional mineral supplementation had no significant effect on dry matter intake. The average daily weight gain was higher (p<0.01) in $T_2$ and $T_3$ than the control ($T_1$). The lambs under treatments $T_2$ (8.72) and $T_3$ (8.47 kg) consumed apparently lesser amount of dry matter per unit gain as compared to $T_1$ (10.81 kg). Significantly higher (p<0.05) dry matter and crude protein digestibility (%) were observed in $T_2$ and $T_3$ than in $T_1$. The mean balances for different elements were Ca, 1.14, 1.68 and 1.67 g; P, 1.70, 1.95 and 2.18 g; S, 0.54, 0.92 and 1.11 g; Zn, 22.56, 25.30 and 28.71 mg; Cu, 7.94, 5.71 and 5.53 mg; Fe, 33.19, 32.94 and 31.03 mg and Mn, 8.24, 14.40 and 16.07 mg/lamb/day. The retention of supplemental minerals increased (p<0.01) while that of Cu decreased (p<0.01) due to supplementation of minerals (Ca, P, S, Zn and Mn). Retention as per cent of intake increased statistically for S and Mn while that of Cu decreased. It can be concluded that supplementation of minerals (Ca, P, S, Zn and Mn) higher than the recommended level improved body weight gain and feed to gain ratio. The retention of minerals increased due to supplementation. Therefore, an additional supplementation of deficient minerals (Ca, P, S, Zn and Mn) by 10% was beneficial for Hisardale male lambs under tropical condition in India.

• 한국동물학회지
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• 제28권1호
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• pp.31-43
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• 1985

$(Ca^{2+}+Mg^{2+})$-ATPase를 쥐의 근소포체로부터 sucrose density gradient centrifugation의 방법을 사용하여 분리 정제하였다. 정제된 효소를 폴리아크릴 아마이드 젤에서 전기영동한 결과, 토끼와 닭의 경우에서와 같이 분자량 115,000인 단일 단백질 띠로 나타났다. 정제된 이 효소의 활설도는 50 $\\muM$의 $Mg^{2+}, Ca^{2+}, Co^{2+}, Fe^{2+}, Min^{2+}$에 의해서는 증가되었고, 같은 농도의 $Zn^{2+}, Cu^{2+}, Hg^{2+}$에 의해서는 감소되었다. Quinine와 quinacrine 같은 antimalarial drug는 이 효소의 활성도에 큰 영향을 주지 않았으나, p-hydroxymercuric benzoate와 phenylmethylsulfonylfluoride는 이 효소의 활성을 억제하였다. 이 효소는 pH 6과 7 사이에서 가장 높은 활성을 나타내었고, ATP를 기질로 사용하였을 때 Km 값은 98 $\\muM$이었다. $(Ca^{2+}+Mg^{2+})$-ATPase는 microsomal fraction에서 선택적으로 분해되었다. $^{3}H-casein$ 이나 ^{125}I-insulin같은 방사성 동위원소로 표지된 기질을 사용하여 단백질 분해에 대한 활성도를 조사해 본 결과, microsomal preparation에 metalloendoprotease가 존재하였다. 그러나 아직까지는 그 효소가 $(Ca^{2+}+Mg^{2+})$-ATPase를 분해하는지는 확실하지 않다.

• 한국식품위생안전성학회지
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• 제25권2호
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• pp.170-179
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• 2010

본 연구는 유용 자원식물인 함초를 식품 및 식물자원으로서 이용가치를 높이는데 있어 그 기초자료로 활용하고자 인천연안 갯벌에서 채취하여 냉동동결건조 분쇄한 함초와 칠면초 분말 시료의 미네랄, 생리활성물질, 항산화 활성을 조사하였다. 1. Na, K는 칠면초보다 함초에 많고, Ca, Fe, Mn은 함초보다 칠면초에 많았으며, Na, K, Mg, Ca는 각각 평균 100,006 mg/kg, 1,385 mg/kg, 3,263 mg/kg, 2.750 mg/kg이며 함초 뿌리는 각각 19,138 mg/kg, 1,260 mg/kg, 1,766 mg/kg, 1,164 mg/kg으로 나타났다. 함초 잎 줄기의 Fe, Mn, Zn, Cu는 각각 평균 90.4 mg/kg 98.9 mg/kg, 33.3 mg/kg, 3.4 mg/kg이며 뿌리는 각각 356.3 mg/kg, 45.3 mg/kg, 27.9 mg/kg, 3.0 mg/kg으로 나타났다. 2. 칠면초의 잎 줄기 부위의 Na, K, Mg, Ca은 각각 평균 85,332 mg/kg, 710 mg/kg, 7,005 mg/kg, 4,344 mg/kg이며 잎 줄기 부위는 각각 1,434.9 mg/kg, 119.1 mg/kg, 19.2 mg/kg, 2.7 mg/kg으로 나타났다. 3. 베타인의 함량은 함초 잎 줄기 평균 15.09 mg/g, 함초 뿌리 평균 7.27 mg/g, 칠면초 잎 줄기 평균 14.64 mg/g으로 나타났다. 4. 콜린은 DPAP-choline으로 유도체화하여 HPLC/PDA로 분석한 결과, 평균 함초 잎 줄기는 20.9 mg/100g, 함초 뿌리는 23.4 mg/100g, 칠면초 잎 줄기는 23.1 mg/100g, 칠면초 뿌리는 23.8 mg/100g으로 나타났다. 5. 폴리페놀화합물은 함초 잎 줄기(28.3 mg/g), 칠면초 잎 줄기(15.5 mg/g), 함초 뿌리(9.2 mg/g), 칠면초 뿌리(5.7 mg/g) 순으로 특히 6월 성장기 함초 잎 줄기에서 총페놀화합물 함량이 36.0 mg/g으로 가장 높았고, 잎 줄기부위와 뿌리부위 모두 함초가 칠면초보다 1.6~1.8배 높았다. 6. DPPH에 대한 항산화활성은 함초와 칠면초 추출물의 시료첨가구와 비첨가구의 흡광도차를 백분율로 표시하였고, 함초 잎 줄기부위의 DPPH free radical 소거 효과가 월등히 높았고, 특히 6우러 성장기 함초 잎 줄기에서 90.1%로 가장 높았다. 7. 상용산화방지제의 DPPH free radical 소거 효과를 비교한 결과, 6월 채취한 함초 잎 줄기 부위를 동결 건조한 분말 1g은 TBHQ 20.32 mg, Ascorbic acid 22.86 mg, BHA 25.86 mg Quercetin 30.26 mg, BHT 40.75 mg, Rutin 42.65 mg에 대응하는 항산화력을 가지고 있다.

• 한국재료학회지
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• 제18권5호
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• pp.266-271
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• 2008

Magnesium alloys are alloyed with rare earth elements (Re, Ca, Sr) due to the limited use of magnesium in high-temperature conditions. In this study, the influences of Zr and Zn on the aging behavior of a Mg-Nd-Y alloy were investigated. magnesium alloys containing R.E elements require aging treatments Specifically, Nd, Y and Zr are commonly used for high-temperature magnesium alloys. Various aging treatments were conducted at temperatures of 200, 250 and $300^{\circ}C$ for 0.5, 1, 3, 6, and 10 hours in order to examine the microstructural changes and mechanical properties at a high temperature ($150^{\circ}C$). Hardness and high-temperature ($150^{\circ}C$) tensile tests were carried out under various aging conditions in order to investigate the effects of an aging treatment on the mechanical properties of a Mg-3.05Nd-2.06Y-1.13Zr-0.34Zn alloy. The maximum hardness was 67Hv; this was achieved after aging at $250^{\circ}C$ for 3 hours. The maximum tensile, yield strength and elongation at $150^{\circ}C$ were 237MPa, 145MPa and 13.6%, respectively, at $250^{\circ}C$ for 3 hours. The strengths of the Mg-3.05Nd-2.06Y-1.13Zr-0.34Zn alloy increased as the aging time increased to 3 hours at $250^{\circ}C$ This is attributed to the precipitation of a Nd-rich phase, a Zr-rich phase and $Mg_3Y_2Zn_3$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.277-281
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• 2003

Effects of $CaF_2$ addition as a filler on the high frequency dielectric properties and sintering of CaO-$Al_2O_3-SiO_2-B_2O_3$(CASB) and ZnO-MgO-$B_2O_3-SiO_2$(ZMBS) glass composites were investigated. The optimal glass composition in the CASB system was 33.0CaO-$17.0Al_2O_3-35.0SiO_2-15.0B_O_3$(in wt%). The corresponding dielectric properties were k=8.1 and $Q{\times}fo$=1,200GHz. The sintering temperature was $800{\mu}m$. In case of 2MBS system, 25.0ZnO-25.0MgO-20.0$B_2O_3-30.0SiO_2$(in wt%) glass showed k=6.8 and $Q{\times}fo$=5,200GHz when it was sintered at $750^{\circ}C$. The maximum amount of $CaF_2$ in the CASB and 2MBS glass system without any detrimental effect on the sintering was 25.0 v/o and 15.0 v/o, respectively. The addition of $CaF_2$ in the glass systems improved the high frequency dielectric properties. In case of CASB+$CaF_2$ composite, k was 7.1 and $Q{\times}fo$ was 2,300GHz. And in case of 2MBS+$CaF_2$ composite, k was 5.9 and $Q{\times}fo$ was 8,100GHz. $CaF_2$ addition also reduced sintering temperature. Effects of $CaF_2$ on the dielectric and sintering properties was analyzed in terms of viscosity and crystallization behavior changes due to the interaction between $CaF_2$ and the glass systems.

• 한국환경농학회지
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• 제4권1호
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• pp.11-17
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• 1985

Zn와 Cd을 무저(無底)폿트(${\phi}30cm{\times}70cm$)에 Cd는 5, 10, 30ppm, Zn은 150, 300, 600ppm으로 처리(處理)하고 옥수수(수원(水原) 19호(號))를 파종(播種)하여 발아후(發芽後) 15일(日), 30일(日), 45일(日)의 식물체(植物體) 생육(生育), 엽중(葉中) peroxidase활성(活性), 엽녹소(葉綠素) 합량(合量), 무기성분(無機成分) 함량(含量) 및 중김속(重金屬) 함량(含量)을 조사(調査)한 결과(結果)는 다음과 같다. 1) 토양중(土壤中) Cd, Zn의 첨가농도(添加濃度)가 높아질수록 간장(稈長) 및 건물중(乾物重)이 유의성(有意性)있게 감소하였다. 2) 식물체중(植物體中) Cd함량(含量)이 높아질수록 엽중(葉中) peroxidase 활성(活性)은 증가(增加)하나, Zn은 함량(含量)이 높아질수록 감소(減少)하는 경향(減少)이었다. 3) 식물체중(植物體中) Cd, Zn 농도(濃度)가 증가(增加)할수록 chlorophyll함량(含量)은 감소(減少)되었다. 4) 토양중 Cd 첨가농도(添加濃度)가 높아질수록 식물체중(植物體中) N함량(含量)은 증가(增加)되나 P, K, Ca, Mg, $SiO_2$함량(含量)은 감소(減少)되었다. 반면(反面) 토양중(土壤中) Zn첨가농도(添加濃度)가 높아질수록 P 및 SiO함양(含量)은 증가(增加)되나 N, Ca, Mg함양(含量)은 감소(減少)되는 경향(傾向)이었다. 5) 식물체중(植物體中) Cd, Zn흡수량(吸收量)은 시기(時期)가 경과할수록 증가(增加)하나 이들 함양(含量)은 일정(一定)한 경향(傾向)이 없었다. 6) 시일(時日)이 경과함에 따라 식물체중(植物體中) Cd흡수(吸收)는 Zn의 첨가농도(添加濃度)가 높아질수록 감소(減少)된 반면(反面) 식물체중(植物體中) Zn흡수(吸收) Cd의 낮은 첨가농도(添加濃度)에서 감소(減少)되었다.

• 한국식품영양과학회지
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• 제29권1호
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• pp.99-105
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• 2000

The purpose of this study was to evaluat the Zn, Cu, Mn and Ni status and correlation of their concentrations in serum, urine, hair and fingernail in female college students. As the results are follows; The mean age of subjects was 22.5 years and height, weight and BMI were 160.1 cm, 51.0 kg and 20.0 respectively. The daily intake of energy 1769.5 kcal and the ratio of carbohydrate, fat and protein for energy is 60 : 20 : 15. The daily intake of energy (88.5%), vitamin B2 (86.1%), Ca (75.4%), Fe (58.3%) and Zn (63.0%) of subjects did not reach to Korean Recommended Dietary Allowance (RDA). The daily mean intake of Zn, Cu, Mn and Ni were 7.56 mg, 2.30 mg, 3.81 mg and 0.18 mg respectively. The concentrations of Zn in serum, urine, hair and nail were 85.6$\mu\textrm{g}$/dL, 391.2$\mu\textrm{g}$/day, 174.6$\mu\textrm{g}$/g and 102.4$\mu\textrm{g}$/g respectively and those Cu were 84.2$\mu\textrm{g}$/dL, 56.6 $\mu\textrm{g}$/day, 20.3$\mu\textrm{g}$/g and 4.3$\mu\textrm{g}$/g respectively. The concentrations of Mn in serum, urine, hari and nail were 0.2$\mu\textrm{g}$/dL, 1.1$\mu\textrm{g}$/day, 1.8$\mu\textrm{g}$/g and 1.6$\mu\textrm{g}$/g respectively and those of Ni were 0.6$\mu\textrm{g}$/dL, 24.5$\mu\textrm{g}$/day, 3.5$\mu\textrm{g}$/g and 3.1$\mu\textrm{g}$/g respectively. The daily intake of Mn showed the positive correlations with concentration of Mn in hair (p<0.05) and the daily intake of Ni was positively correlated with urinary exretion (p<0.05) and hair contents (p<0.001) of Ni. The more detailed studies about these trace mineral status should be required.

• 한국토양비료학회지
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• 제31권3호
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• pp.253-258
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• 1998

마이크로파 시료 분해법이 식물체와 퇴비 중의 K, Ca, Mg, Cu, Zn, Mn등을 분석하는데 적합한가를 검정하기 위하여 기존의 습식분해법과 비교하였다. 분석시간은 기존의 습식분해법이 4~6시간 걸리던 것에 비하여 마이크로파 분해법에서는 1시간 이하로 단축할 수 있었으며, 두 분석법간의 각 성분별 분석값의 상관계수($R^2$)는 각각 K 0.98, Ca 0.97, Mg 0.91, Zn 0.94, Mn 0.99, Cu 0.99를 나타내었다. 칼륨과 칼슘의 경우 기존 습식분해법의 분석값이 더 높은 경향을 나타내었고 구리, 망간, 아연의 경우는 마이크로파 분해법의 분석값이 더 높은 경향을 나타내었으나 마그네슘의 경우 일정한 경향이 없었다. 그러나 칼슘의 경우를 제외한 그 외 성분들의 편기도(biases)는 10% 이내였다.