• 대한지하수환경학회지
• /
• 제6권4호
• /
• pp.206-212
• /
• 1999

산성광상배수의 처리를 위한 중화제로서 제강 슬래그의 이용 가능성을 검토하였으며 석회석과의 성능을 비교하였다. 24시간 반응시킨 고정 실험에서는 슬래그가 석회석보다 높은 pH를 나타냈고 Fe. Al 및 기타 중금속에 우수한 제거효율을 보였다. 10일간 진행된 연속단계실험결과 역시 슬레그가 석회석보다 높은 pH를 유지하였고 Fe와 Al의 제거성능의 저하는 나타나지 않았으며 Ni, Co. Cu. Zn 모두 석회석보다 슬래그에서 휠씬 높은 제거효율을 보였다. 황산$({H_2}{SO_4})$으로 pH를 AMD와 동일하게 맞추고 중금속만을 인위적으로 첨가한 증류수(인공산 용액)와의 반응에서는 AMD와의 반응에서보다 중금속의 제거효율이 떨어졌는데, 이는 AMD내에 존재하는 Fe와 Al 산화물이 침전할 때 공침이나 흡착에 의해 중금속이 제거되는데 비해 인공적인 AMD에서는 이러한 효과가 없기 때문인 것으로 판단된다. 슬래그의 크기별(5mm이하. 5~20 mm. 20 mm이상)실험에서는 슬래그의 크기가 작을수록 더 높은 pH 상승과 더 효과적인 금속들의 제거 성능을 보여 비표면적이 중요한 요인임을 제시하였다.

• 대한수의학회지
• /
• 제43권3호
• /
• pp.393-398
• /
• 2003

Simple and rapid sample preparation method for trace elements in foods of animal origin using ultra high pressure microwave digestion system (UHP/MDS) and inductively coupled plasma atomic emission spectrometer (ICP/AES) were developed. 1. For the digestion of sample using UHP-MDS, 20% nitric acid (v/v) was the most suitable solvent for the determination of trace elements in foods of animal origin. 2. The optimal digestion conditions for UHP-MDS were as follows: final temperature $180^{\circ}C$, final pressure 400 PSI, and magnetic power 900 W in the solid sample. For the liquid sample final temperature $170^{\circ}C$, final pressure 300 PSI and magnetic power 700 W were optimal conditions. 3. As result of interlaboratory test, the average recovery rate of the for solid sample were 88.3~99.1% for As, 82.4~93.3% for Cd, 89.2~101.2% for Hg and 86.5~93.8% for Pb, respectively. In liquid sample, it were 87.0~96.8% for As, 80.9~96.6% for Cd, 87.5~91.2% for Hg and 91.4~95.5% for Pb, respectively. 4. The average coefficient variation rate were 3.3~15.9% for solid sample and 2.9~10.8% for liquid sample.

• Ocean and Polar Research
• /
• 제39권4호
• /
• pp.269-277
• /
• 2017

Medium compositions for the hyperthermophilic archaeon, Thermococcus onnurineus NA1 was statistically optimized to enhance formate-driven hydrogen ($H_2$) production by using response surface methodology. From the Plackett-Burman design-based experiment, it was confirmed that among the minor components of medium such as KCl, $MgSO_4$, $NH_4Cl$, Cystein-HCl, trace elements, Fe-EDTA and $CaCl_2$, the trace elements were screened as the only positively effective components with respect to $H_2$ production. Subsequently, the optimal concentrations of the trace elements and the major components of a medium such as NaCl, yeast extract and sodium formate were determined from the five-level central composite design (CCD)-based experiment. The resulting quadratic model predicted the maximum $H_2$ production of 46.6 mmol/L in serum bottle and it was validated experimentally using the optimal medium initially supplemented with 26.70 g/L of NaCl, 9.81 g/L of sodium formate, 3.50 g/L of yeast extract and 4.59 mL/L of trace elements. From the duplicate batch cultivations in the fermentor using the optimized medium, the a maximum $H_2$ production rate up to 71.8 mmol/L/h could be obtained, which was a 65% enhanced value compared with that obtained using the control medium, showing the high efficiency of the optimized medium.

• 생약학회지
• /
• 제13권3호
• /
• pp.102-105
• /
• 1982

Nine trace elements in Bear Galls(Fel Ursi) studied in this paper are Na, Mg, K, Ca, Cu, Zn, Fe, Pb and Ge. The contents of Na, Mg, K, Ca, Cu, Zn, Fe, Pb are determined by atomic absorption spectrometry and Ge is determined by graphite atomic absorption spectrometry. In both methods, the sample is digested with nitric-perchloric acid and then ashed. The results of analysis are shown in table and the result obtained from this study are as follows. a. The highest content of trace element of Bear Gall is Na and other elements are getting lower in order of K, Mg, Ca, Ge, Zn, Fe, Cu, and Pb. b. Particularly the content of Ge in Bear Gall was determined.

• 자원환경지질
• /
• 제25권3호
• /
• pp.245-258
• /
• 1992

The variations of certain major and trace elements of the Onjong granite mass was studied on the basis of petrological and geochemical characteristics and compared with those of the Eonyang-Yucheon granite masses in order to investigate the geochemical differences of the granitic rocks in relation to mineralization between Pb-Zn ore district and Pb-Zn-Mo-W ore district in Kyeongsang basin. The Onjong granite mass is classified into granodiorite and monzo-granite, and the Eonyang-Yucheon granite masses into monzo-granite by the Streckeisen's diagram. Between both granite masses there are clear differences in contents of certain major elements and lithophile trace elements. The former have high contents of Ca (2.94%), Mg (1.66%) and Sr (365 ppm), and low contents of K (3.52%), Na (3.51%), Rb (116 ppm), Ba (640 ppm) and Li (18.9 ppm), whereas the latter have high contents of K (4.02%), Na (4.28%), Rb (145 ppm), Ba (695 ppm) and Li (19.3 ppm), and low contents of Ca (1.42%), Mg (0.43%) and Sr (161 ppm). Except for Mo, there are not clear differences in chalcophile trace elements between two granite masses: the Onjong granite mass has higher Mo content (7.1 ppm) lnan that (1.7 ppm) of the Eonyang-Yucheon granite masses, but Pb and Zn contents are similar between the Onjong granite mass (Pb=8.7 ppm, Zn=37.1 ppm) and the Eonyang-Yucheon granite masses (Pb=7.8 ppm, Zn=39.8 ppm). Ca and Sr contents of the Onjong granite mass (Ca> 1.5%, Sr> 270 ppm) are higher than those of the Eonyang- Yucheon granite masses (Ca<1.5%, Sr<270ppm), and Rb/Sr, Rb-Rb/Sr and K-Rb/Sr ratios are clearly distinguishable between the Onjong granite mass(Rb/Sr<0.51, Rb-Rb/Sr>250 and K-Rb/Sr>5.2) and the Eonyang- Yucheon granite masses (Rb/Sr>0.51, Rb-Rb/Sr<250 and K-Rb/Sr<5.0). Thus, variations of certain major and trace elements and ratios are applicable as geochemical index to distinguish the types of mineralization of the ore districts related to the Cretaceous granitic rocks in the Kyeongsang basin.

• 대한화학회지
• /
• 제52권6호
• /
• pp.637-648
• /
• 2008

• 한국대기환경학회지
• /
• 제20권2호
• /
• pp.143-151
• /
• 2004

The chemical composition of PM$_{2.5}$ was measured at Gosan, Jeju for two weeks each in November 2001 and spring 2002. In the latter part of the measurement period of November 2001, designated as the polluted period in this work, secondarily formed ion components as well as primarily emitted elemental carbon were high. PM$_{2.5}$ mass concentration was also high in this polluted period compared with the yellow sand period, in which daily average of PM $_{10}$ peaked up to 520 $\mu\textrm{g}$/㎥. Increase of major components of anthropogenic origin in the polluted period was not correlated with the variation in sea salt components while increase of crustal components in the yellow sand period was highly correlated with the variation in sea salt components. Trace elements were generally higher in the yellow sand period; however, toxic heavy metals such as zinc, cadmium and lead were the highest in the polluted period.d.d.d.

• Journal of Microbiology and Biotechnology
• /
• 제12권3호
• /
• pp.490-496
• /
• 2002

The production of E. coli WC7 phytase from a recombinant E. coli strain was optimized using a statistical experimental design approach. Two-level complete factorial designs with seven variables were used for the media optimization. In the first optimization step, the influence of disodium succinate, yeast extract, $K_2HPO_4,\;NH_4H_2PO_4,\;MgSO_4$, NaCl, and trace elements on phytase production was evaluated. As a result, disodium succinate, yeast extract, $NH_4H_2PO_4$, NaCl, and the trace elements were found to have a positive influence on the phytase production, while $K_2HPO_4\;and\;MgSO_4$ had a negative influence. In the second step, the concentrations of disodium succinate and yeast extract were further optimized using central composite designs. The maximum phytase activity obtained was 234 U/ml using 15.9 g/1 disodium succinate, 20 g/1 yeast extract, 5 g/1 K_2HPO_4,\;10 g/1 NH_4H_2PO_4,\;1.5 g/1 MgSO_4$, 4 g/1 NaCl, and 1.5 m1/1 trace elements, which was about a 14-fold increase in comparison with that obtained using the basal medium.

• Asian-Australasian Journal of Animal Sciences
• /
• 제14권11호
• /
• pp.1523-1526
• /
• 2001

To study the secretion of trace elements during early lactation, twelve lactating Murrah buffaloes were selected from the herd of the institute. The buffaloes were divided into two groups of six each. Buffaloes of group I were not injected and served as control. Buffaloes of group II received oxytocin injection (2.5 I.U.) intramuscularly for a period of five days for let down of milk. Milk samples were collected from both groups of buffaloes five days before, during and after the administration of oxytocin. Aliquots of milk samples from each buffalo were composited in proportion to their milk yield and used for analysis of trace elements in milk. In both the groups of buffaloes Cu, Mg, Fe, Zn and Mn contents did not vary significantly between animals. However, Ca levels varied significantly (p<0.01) between animals. Administration of oxytocin influenced (p<0.01) Cu, Mg, Zn, Fe and Mn secretion in milk. However, Ca secretion was not affected by oxytocin administration. Secretion of these elements also varied significantly during different days of the study. Zinc content of milk in the control group also varied significantly (p<0.01) during different days and periods of study indicating thereby no effect of oxytocin. The study indicated that administration of oxytocin increases Cu and Mn content and decreases Mg, Fe and Zn content without altering the Ca concentration of milk.

• 대한지역사회영양학회지
• /
• 제2권2호
• /
• pp.133-140
• /
• 1997

The serum concentrations of the major minerals(calcium, phosphorus, magnesium, sodium, potassium) and trace elements(iron, Zinc, copper manganese)were datermined in 23 breast fed infants living in Eumsung, Choong-buk region. The results obtained are summarized as follows: 1)The mean levels of calcium, phosphorus, magnesium, sodium and potassium of the serum of total subjects were 8.15$\pm$0.33mg/dI, 11.06$\pm$0.16mg/dI, 2.00$\pm$0.14mg/dI, 3.4476$\pm$17.99mg/dI and 9.06$\pm$2.04mg/dI respectively. 2)The serum concentrations of iron, zinc, copper and manganese in total subjects averaged 95.83$\pm$0.33mg/dI, 93.79$\pm$7.06$\mu$g/dI and 98.57$\pm$7.06 $\mu$g/dI and 4.93$\pm$0.62$\mu$g/dI respecitively. 3)Breast fed infants had significantly higher serum calcim, magnesium, sodium and iron concentrations than the formula fed groups. Otherwise, serum potassium, copper and manganese levels in breast milk fed infants were significantly lower than those in formula fed infants. 4) In formula fed infants, serum potassium and copper levels increased increased significantly with months after birth.