• Title/Summary/Keyword: MgB2

Search Result 4,781, Processing Time 0.03 seconds

A Study on the Diatomaceous Earth Filtration of Settling Basin Effluent (정수장 침전지 유출수의 규조토 여과에 관한 연구)

  • Shin Dae-Yewn;Ji Sung-Nam;Moon Ok-Ran;Kim Ji-Yeong;Suh Dong-Woo;Cho Young-Kwan
    • Journal of Environmental Health Sciences
    • /
    • v.30 no.5 s.81
    • /
    • pp.410-416
    • /
    • 2004
  • The objective of this investigation was to evaluate applicability of precoat filtration that can be substituted for rapid sand filter of conventional water treatment system(CWTS). Precoat filter used in this experiment are candle filter. Element disk of candle are pore size $10{\mu}m(R),\;20{\mu}m(B)$ And diatomaceous earth are cake pore size $3.5{\mu}m$(Standard Super- Cel; A), $7{\mu}m$(Hyflo Super-Cel; B) and $17{\mu}m$(Celite 545RV; C). $2kg/m^2$ diatomaceous earth is used for precoating, it coated candle in $5{\sim}6mm$ thickness. 1. Al adsorption dosages by diatomaceous earth used in experimental we Hyflo Super-Cel 0.843mg/g, Standard Super-Cel 0.782 mg/g and Celite 545RV 0.766 mg/g. 2. Filtrate of precoat filter during 60min are R-C combination 20.7($m^3/m^2$)>B-C 18.3($m^3/m^2$)>B-B 15.0($m^3/m^2$)> R-B 12.9($m^3/m^2$)> R-A 11,093($l/m^2$). 3. Water quality of precoat filter effluent are thus. $KMnO_4$ consumption are $1.10{\sim}2.20mg/l$, removal rate are $30.9{\sim}65.6\%$. They are R-A 1.10(mg/l)(removal rate $65.6\%$). R-C(2.20 mg/l)(removal rate $30.9\%$). 4. $Al^{3+}$ are not detected with all combination, removal rate $100\%$. 5. Considering water quality and flux, continued running time of R-A combination is 7 hr. Accumulated filtrate are $74.4 m^3/m^2$, average flux is $177.2 l/m^2{\cdot}min$. And filtrate per diatomaceous earth 1g are 37.2 l. 6. R-A effluent's water quality are $KMnO_4$ Consumption 1.10(mg/l), DOC 1.161 mg/1, Al 0.0 mg/1, $UV_{254}$ 0.016/cm, Turbidity 0.1(NTU). R-A combination is suitable to precoat filtration for the settling basin effluent treatment.

Thermal Annealing Effect on Ferromagnetic Resonance Properties in CoFeB/MgO Thin Film (CoFeB/MgO 박막 재료의 열처리에 따른 강자성공명 특성)

  • Yoon, Seok-Soo;Kim, Dong-Young
    • Journal of the Korean Magnetics Society
    • /
    • v.21 no.1
    • /
    • pp.10-14
    • /
    • 2011
  • We have measured the ferromagnetic resonance (FMR) signal in as deposited and $400^{\circ}C$ annealed CoFeB/MgO thin film to investigate the annealing effect on magnetic anisotropies and FMR linewidth (${\Delta}H_{PP}$). The uniaxial anisotropy field ($H_{K1}$) was only observed in the as deposited sample. Whereas, in the $400^{\circ}C$ annealed sample, the biaxial anisotropy field ($H_{K2}$) was additionally observed in accompany with uniaxial anisotropy field ($H_{K1}$). The appearance of biaxial anisotropy fields was originated from the crystalline growth of bcc CoFeB(001) from the MgO(001) interface and by the B diffusion during thermal annealing. Also, the ${\Delta}H_{PP}$ of $400^{\circ}C$ annealed sample was increased compared with that of as deposited sample, which was due to the broad distribution of the magnetization axis by the biaxial anisotropy.

Comparision of Chemical Components of Angelica gigas Nakai and Angelica acutiloba Kitagawa (토당귀와 일당귀의 화학성분 비교)

  • Hwang, Jin-Bong;Yang, Mi-Ok
    • Korean Journal of Food Science and Technology
    • /
    • v.29 no.6
    • /
    • pp.1113-1118
    • /
    • 1997
  • Chemical components of domestic Angelica gigas Nakai and Angelica acutiloba Kitagawa were analyzed. Proximate analysis of each species showed crude protein 18.1% and 13.4%, crude lipid 8.9% and 4.3%, crude fiber 8.6% and 9.4%, crude ash 7.4% and 8.2%, and carbohydrate 57.0% and 64.7%, respectively. Contents of potassium which was found to be the most abundant mineral in both species were 2,740.0 mg% and 2,582.8 mg%, and those of sucrose were 0.4 % and 0.3% respectively while neither fructose nor glucose were detected in each species. Major fatty acids in Angelica gigas Nakai and Angelica acutiloba Kitagawa were linoleic acid (60.8% and 59.5%), palmitic acid (17.4% and 15.3%), oleic acid (8.8% and 7.7%) (respectively) but there was no significant difference between two species. Arginine was revealed as the most abundant amino acid in both species with 2,599.8 mg% in Angelica gigas Nakai and 1,543.4 mg% in Angelica acutiloba Kitagawa. Angelica gigas Nakai and Angelica acutiloba Kitagawa also were shown to contained 10.5 mg% and 12.2 mg% $vitamin\;B_1$, 0.1 mg% and 0.04 mg%, $vitamin\;B_2$, 4.3% and 0.8% decursin, and 988.0 mg% and 900.0 mg% tannin, respectively.

  • PDF

Growth of $PbMg_{1/3}Nb_{2/3}O_3$ Single Crystals by Flux Method (융제법에 의한 $PbMg_{1/3}Nb_{2/3}O_3$단결정 성장)

  • 임경연;박찬석
    • Korean Journal of Crystallography
    • /
    • v.8 no.2
    • /
    • pp.75-80
    • /
    • 1997
  • A perovskite relaxor ferroelectrics PMN is used as an important material to investigate the diffusive phase transition phenomena. In this study PMN single crystals were grown and the microstructure were observed. For the growth of PMN single crystals, the spontaneous nucleation technique and the TSSG technique were used. 2-5mm single crystals were grown from PbO self flux and it was observed that only PMN crystals were grown when excess MgO was added over 100% as flux. Single crystals with well developed (001) faces were obtained from PbO-B2O3 flux. single crystals larger than 1 cm were grown from PbO-B2O3 flux by TXXG technique. For higher quality crystals, optimization of the variables such as the rotation speed of seed crystal, the orientation of seed crystal, and cooling rate is needed. With grown crystals, it was confirmed by TEM diffraction pattern of thin plate crystal that the 1:1 ordering of Mg2+ and Nb5+ with small volume exists.

  • PDF

Acute Toxicity of $P_2$, $B_1$, $T_{0}$, and $O_1$ in Rats and Mice

  • Yoon, Suh-young;Yoo, Kyeong-seok;Yim, Jae-woong;Kim, Bak-kwang;Cheong, Jae-hoon
    • Proceedings of the Korean Society of Applied Pharmacology
    • /
    • 1998.11a
    • /
    • pp.190-190
    • /
    • 1998
  • $_2$(5,7-dipropoxychrysin), $B_1$(chrysin7-O-toluate), $T_{0}$(5-hydroxy-7-butoxy-chrysin), and $O_1$(5- hydroxy-7 -octoxychrysin) are chrysin derivatives which have isolated from Mori Cortex Radicis. They exhibited strong hypoglycemic effect, so they can be developed for hypoglycemic agents. In this study, we evaluated the acute toxicity of $P_2$, $B_1$, $T_{0}$, and $O_1$ by a single oral administration in rats and mice. The male SD rats and the male ICR mice were divided into 5 groups, and each group was treated orally with 500mg/kg $P_2$, $B_1$, $T_{0}$, and $O_1$, and control respectively. 500mg/kg is the highest dosage which can be administered to mouse. Each group of mice were subdivided as the dosage, 5mg/kg, 20mg/kg, l00mg/kg, and 500mg/kg. After oral administration, we examined food consumption, clinical signs and mortality of each group for 12 days. We also examined body weight increment of animals before and after treatment. Then organ weights were examined on 13th day. There was no toxic effect in mortality, body weight changes, food consumption, clinical signs and organ weights. We found out that the $LD_{50}$ of $P_2$, $B_1$, $T_{0}$, and $O_1$ is more than 500mg/kg in rats.

  • PDF

Effect of ${B_2}{O_3}$on the Adhesion Properties of Electrophoretically Deposited Phosphor Films (${B_2}{O_3}$가 전기영동법으로 제조된 형광막의 접착력에 미치는 영향)

  • 오승목;이현덕;강태식;김강진;변재동
    • Journal of the Korean Ceramic Society
    • /
    • v.37 no.9
    • /
    • pp.927-932
    • /
    • 2000
  • Mg(NO$_3$)$_2$가 용해된 IPA 용액에서 형광 분말의 전기영동법에 의한 증착 과정을 증착 시간, Mg(NO$_3$)$_2$의 농도 및 열처리 조건에 따라 분석하였다. 전기영동법으로 가장 두께가 균일한 형광막을 얻기 위한 Mg(NO$_3$)$_2$의 최적 농도는 $10^{-3}$~$10^{-4}$ M였다. 형광체의 접착력을 향상시키기 위해 새로운 방법을 고안하였다. 즉 전기영동법으로 증착된 형광막에 B$_2$O$_3$가 용해된 IPA 용액을 분사한 후 열처리를 하였다. 그 결과 기존의 PL 특성을 그대로 유지하면서 접착력을 향상시킬 수 있었다. 그러나 CL 휘도는 약간 감소하였다.

  • PDF

Chemical Components and Pulverization conditions of the Pollens of Pinus rigida and Pinus koraiensis (리기다소나무와 잣나무 화분의 화학적 성분과 파쇄 조건에 관한 연구)

  • 김계환;오혁근;서병수;박준모;김상용
    • Journal of Korea Foresty Energy
    • /
    • v.19 no.1
    • /
    • pp.30-37
    • /
    • 2000
  • This study was to analyze the chamical components of the pollens of Pinus rigida and P. koraensis and to investigate the optimal conditions for pollen pulverization. The results are as follow: (1) The contents of moisture, crude ash, crude protein, crude fat, crude filber and carbohydrate in the pollen of P. rigida were 9.9%, 2.5%, 13.1% 2.9% 7.5% 64.1% respectively, while those of P. koraiensis were 9.8%, 2.1%, 11.1% 2.8% 8.1% 66.1% respectively. All the contents of P. rigida and P. koraiensis were much higher than those of general crop grains. (2) Eighteen different amino acids were detected in the pollen of P. rigida and P. koraiensis. Among them, ten essential amino acids were indentified, which showed high nutritions values. (3) The contents of vitamin A, B1, B2, C, and E in the pollen of P. rigida were 8.7 mg, 10.1 mg, 15.9 mg, 32.9 mg, 1.9 mg, respectively, while those of in the pollen of P. koraiensis were 7.9 mg, 9.7 mg, 14.5 mg, 34.2 mg, and 2.5 mg respectively. Vitamin C among them was abundant. (4)When the pollen grains of P. prigida was pulverized for 50minutes at 5,000rpm and P. koraiensis for 40 minutes at 5,000rpm by Overhead stirrer, the 100% of pollen was pulverized.

  • PDF

Working Environment and Risk Assessment of Gasoline in Workplace (Gasoline 취급 사업장의 작업환경 측정 및 위해성 평가)

  • Kim, Hyeon-Yeong
    • Journal of the Korean Institute of Gas
    • /
    • v.18 no.4
    • /
    • pp.1-7
    • /
    • 2014
  • To protect the workers' health, we evaluated the hazards of gasoline which the large amounts of use and lack of information, and perform the risk assessment through the measurement of working environment. It is estimated the reproductive toxicity, and has germ cell mutagenicity class 1B, also IARC 2B, ACGIH A3 with carcinogenicity. With working environment, it is measured as below the TLV-TWA $900mg/m^3$. It is also calculated $0.3mg/m^3$ as carcinogenicity RfC (worker), $2.7mg/m^3$ as chronic inhalation toxicity RfC (worker), $2.7mg/m^3$ as developmental toxicity RfC (worker). From all of these results, it is calculated that the risks are 459, 51 and 51 as carcinogenicity, chronic inhalation toxicity and developmental toxicity, respectively. It is concluded that the risk of gasoline is evaluated over 1.

Quantitative Analysis of Vitamin B5 and B6 Using High Performance Liquid Chromatography (고속액체크로마토그래피를 이용한 비타민 B5 및 B6의 정량 분석)

  • Kim, Gi-Ppeum;Hwang, Young-Sun;Choung, Myoung-Gun
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.46 no.10
    • /
    • pp.1186-1194
    • /
    • 2017
  • Recently, many people have demanded reliable nutritional data even for minor-components. On the other hand, an analytical method for the analyses of vitamin $B_5$ and $B_6$ is lacking. Therefore, this study attempted to validate with accuracy and precision the analysis of vitamin $B_5$ and $B_6$ using a high-performance liquid chromatography (HPLC) method. The vitamin $B_5$ and $B_6$ contents were analyzed using an Agilent 1260 series HPLC system. YMC-Pack ODS-AM ($250{\times}4.6mm$ I.D.) and YMC-Pack Pro RS $C_{18}$ ($250{\times}4.6mm$ I.D.) columns were used for the analyses of vitamin $B_5$ and $B_6$, respectively. In the case of vitamin $B_5$, the flow rate was set to 1.0 mL/min by isocratic elution using the 50 mM $KH_2PO_4$ solution (pH 3.5)/acetonitrile (ACN) (95:5, v/v) with monitoring at 200 nm using HPLC/DAD, whereas the flow rate for vitamin $B_6$ was set to 1.0 mL/min of flow rate by isocratic elution using a 20 mM $CH_3CO_2Na$ solution (pH 3.6)/ACN (97:3, v/v) with monitoring by excitation at 290 nm and emission at 396 nm using HPLC/FLD. The column temperature was set to $30^{\circ}C$. The injection volume was $20{\mu}L$ for each experiment. The specificity of the accuracy and precision for vitamin $B_5$ and $B_6$ were also validated by HPLC. The results showed high linearity in the calibration curve for vitamin $B_5$ ($R^2=0.9998^{{\ast}{\ast}}$), the limit of detection (LOD) and limit of quantitation (LOQ) were 0.4 mg/L and 1.3 mg/L, respectively, In contrast, for the calibration curve of vitamin $B_6$, which showed high linearity ($R^2=0.9999^{{\ast}{\ast}}$), the LOD and LOQ were 0.006 mg/L and 0.02 mg/L, respectively.