• Korean Chemical Engineering Research
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• 제56권4호
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• pp.600-606
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• 2018

다양한 Si/Al 몰비를 지닌 MTT 제올라이트를 합성하여 methanol-to-olefin(MTO) 반응에서 촉매의 산성도가 미치는 영향을 조사하였다. Si/Al 몰비를 조절하기 위해 N,N,N',N'-테트라메틸-1,3-디아미노프로판을 구조유도물질(SDA)로 사용하였으며, 알루민산나트륨의 함량을 달리하여 $20SiO_2$ : 30SDA : x (=0.25~1.25)$NaAlO_2$ : 2NaOH : $624H_2O$ 조성으로 모액을 제조한 후 433 K에서 4일 동안 수열 합성하였다. 알루민산나트륨의 함량이 감소함에 따라 MTT 제올라이트의 입자 크기가 증가하였으며 또한 산점의 양도 감소하였다. 제조한 MTT 제올라이트의 촉매 활성을 평가하기 위해 673 K에서 공간속도(WHSV)가 $1.2h^{-1}$인 조건으로 MTO 반응을 수행한 결과, Si/Al 몰비가 24인 H-MTT (1.00Al) 촉매가 900분까지 90% 이상의 전환율을 유지함을 확인하였다.

• Preventive Nutrition and Food Science
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• 제17권2호
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• pp.93-100
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• 2012

The purpose of this study was to identify food sources for major minerals such as calcium (Ca), phosphorus (P), sodium (Na) and potassium (K), and to evaluate the relationship between dietary intake of these minerals and serum lipids in healthy Korean adults. A total of 132 healthy men and women completed a physical examination and dietary record and provided blood samples for lipid profile analysis. Results showed the following daily average mineral intakes: 373.4 mg of calcium, 806.0 mg of phosphorous, 3685.8 mg of sodium, and 1938.3 mg of potassium. The calcium-to-phosphorus and sodium-to-potassium ratio was about 0.5 and 2.0, respectively. The primary sources for each mineral were: vegetables (24.9%) and fishes (19.0%) for calcium, grains (31.4%) for phosphorus, seasonings (41.6%) and vegetables (27.0%) for sodium, and vegetables (30.6%) and grains (18.5%) for potassium. The correlation analysis, which has been adjusted for age, gender, total food consumption, and energy intake, showed significantly positive correlations between Ca/P and serum HDL cholesterol levels, between Na intake and the level of serum total cholesterol, and between Na/K and the level of serum cholesterol and LDL cholesterol. Our data indicates that the level of mineral consumption partially contributes to serum lipid profiles and that a diet consisting of a low Ca/P ratio and a high Na/K ratio may have negative impacts on lipid metabolism.

• 한국토양비료학회지
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• 제32권4호
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• pp.333-343
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• 1999

본 연구는 호염성(胡鹽性) 이면서 호칼슘 식물로 알려진 사탕무에서 일가이온인 K와 Na 그리고 이가 이온인 Ca와 Sr 및 Mg의 식물체내 수송과 분포를 밝히고자 수행하였다. Sr의 흡수와 재분배과정은 근권의 이온농도와 생육단계와 밀접한 관계가 있었다. Ca 4 mM과 Sr 1 mM을 처리했을 때 체내 Ca 함량이 가장 높았던 반면 Sr의 함량은 1mM Ca와 4 mM Sr을 혼합처리 했을 때 가장높았다. 즉 낮은 농도의 Sr을 처리했을 때 Ca의 흡수가 가장 높았다. 이러한 결과는 Ca와 Sr의 상가적 흡수기작 때문으로 추정되었다. Mg함량에 대한 Ca와 Sr총 함량은 고도의 부의 상관을 나타냈다. 결과적으로 Mg와 Sr 및 Ca는 상호 길항적으로 흡수되는 것을 알수 있었다. 5mM Sr 존재 하에서만 K와 Na의 흡수가 증가하는 반면 Ca와 Sr의 혼합처리는 이들 이온과는 무관하였다. 따라서 K/Na Ratio 또한 변화되지 않았다. 소량(1mM)의 Sr 첨가는 Chlorophyll 분해를 저지하는 효과를 보였다.

• 한국작물학회지
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• 제43권4호
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• pp.234-238
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• 1998

To select new germplasm for salinity tolerance from new plant type (NPT) breeding lines, the sixty F$_4$ lines selected from the crosses between Korean cultivars and IRRI's NPT lines were evaluated for salinity tolerance at the seedling stage with salinized culture solution (EC=12 dS/m) in the controlled conditions. Two NTP lines derived from a cross between 'Ilmibyeo' and 'IR66152-AC5-1', 'HR15258-7-1' and 'HR15258-27-1', were found to have good tolerance. The salinity tolerance of the lines was compared to their parents and the sensitive ('IR29') and tolerant ('Pokkali') checks in three salinity levels, no salinity (control) and an EC of 12 and 16 dS/m. Visual salinity score, shoot Na+ and Na-K ratio in two NPT lines was significantly low compared with the parents and IR29. Indicating that salinity tolerance of the lines might be derived from a transgressive segregation. The relative water content of the lines was higher than Pokkali, and the dry weight of shoot and root was proportionally decreased to salinity score and salinizing concentration. The visual salinity scores were significantly correlated with shoot Na concentration, Na-K ratio, relative water content, and reduction of dry weight (P<0.01). Their tolerance was attributed to root and shoot characteristics that led to high shoot water content, thus diluting the toxic effect of salts.

• Bulletin of the Korean Chemical Society
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• 제28권10호
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• pp.1675-1682
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• 2007

Large colorless single crystals of faujasite-type zeolite with diameters up to 200 μm have been synthesized from gels with the composition of 3.58SiO2:2.08NaAlO2:7.59NaOH:455H2O:5.06TEA:1.23TCl. Two of these, colorless octahedron about 200 μm in cross-section have been treated with aqueous 0.1 M TlC2H3O2 and KNO3 in order to prepare Tl+- and K+-exchanged faujasite-type zeolites, respectively, and then determined the Si/Al ratio of the zeolite framework. The crystal structures of |Tl71|[Si121Al71O384]-FAU and |K53Na18|[Si121Al71O384]-FAU per unit cell, a = 24.9463(2) and 24.9211(16) A, respectively, dehydrated at 673 K and 1 × 10-6 Torr, have been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd m at 294 K. The two single-crystal structures were refined using all intensities to the final error indices (using only the 905 and 429 reflections for which Fo > 4σ(Fo)) R1/R2 = 0.059/0.153 and 0.066/0.290, respectively. In the structure of fully Tl+-exchanged faujasite-type zeolite, 71 Tl+ ions per unit cell are located at four different crystallographic sites. Twenty-nine Tl+ ions fill site I' in the sodalite cavities on 3-fold axes opposite double 6-rings (Tl-O = 2.631(12) A and O-Tl-O = 93.8(4)o). Another 31 Tl+ ions fill site II opposite single 6-rings in the supercage (Tl-O = 2.782(12) A and O-Tl-O = 87.9(4)o). About 3 Tl+ ions are found at site III in the supercage (Tl-O = 2.91(6) and 3.44(3) A), and the remaining 8 occupy another site III (Tl-O = 2.49(5) and 3.06(3) A). In the structure of partially K+-exchanged faujasite-type zeolite, 53 K+ ions per unit cell are found at five different crystallographic sites and 18 Na+ ions per unit cell are found at two different crystallographic sites. The 4 K+ ions are located at site I, the center of the hexagonal prism (K-O = 2.796(8) A and O-K-O = 89.0(3)o). The 10 K+ ions are found at site I' in the sodalite cavity (K-O = 2.570(19) A and O-KO = 99.4(9)o). Twenty-two K+ ions are found at site II in the supercage (K-O = 2.711(9) A and O-K-O = 94.7(3)o). The 5 K+ ions are found at site III deep in the supercage (K-O = 2.90(5) and 3.36(3) A), and 12 K+ ions are found at another site III' (K-O = 2.55(3) and 2.968(18) A). Twelve Na+ ions also lie at site I' (Na-O = 2.292(10) and O-Na-O = 117.5(5)o). The 6 Na+ ions are found at site II in the supercage (Na-O = 2.390(17) A and O-Na-O = 113.1(11)o). The Si/Al ratio of synthetic faujasite-type zeolite is 1.70 determined by the occupations of cations, 71, in two single-crystal structures.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권7호
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• pp.103-111
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• 2015

Soil washing with ethylenediaminetetraacetic acid (EDTA) is highly effective in the remediation of soils contaminated with heavy metals. The EDTA recycling process is a requisite for reducing the operating cost. The applicability of Na₂S addition on the precipitation of heavy metals from the spent soil washing solution and thereby recycling of EDTA was investigated. Addition of Na₂S into the single metal-EDTA and the mixed metal-EDTA solutions ([Na₂S]/[metal-EDTA] ratio = 30, reaction time = 30 min and pH = 7~9) was highly effective in the separation of Cu and Pb from metal-EDTA complexes, but not for Ni. The Zn removal efficiency varied with pH and slightly increased upto 40% as the reaction time increased from 0 to 240 min which was longer than those for Cu and Pb. Ca(OH)₂ was subsequently added to induce further precipitation of Zn and Ni and to reduce the Na₂S dose. At the [Na₂S]/[metal-EDTA] ratio of 10, the removal efficiencies of all heavy metals excluding Ni were above 98% with the dose of Ca(OH)₂ at 0.002, 0.006 and 0.008 g into 100 mL of Cu-, Pb- and Zn-EDTA solutions, respectively. However, Ca(OH)₂ addition was not effective for Ni-EDTA solution. A further research is needed to improve metal removal efficiency and subsequent EDTA recycling for the real application in field-contaminated soils.

• Current Photovoltaic Research
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• 제1권1호
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• pp.38-43
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• 2013

$Cu(In,Ga)_3Se_5$ is a candidate material for the top cell of $Cu(In,Ga)Se_2$ tandem cells. This phase is often found at the surface of the $Cu(In,Ga)Se_2$ film during $Cu(In,Ga)Se_2$ cell fabrication, and plays a positive role in $Cu(In,Ga)Se_2$ cell performance. However, the exact properties of the $Cu(In,Ga)_3Se_5$ film have not been extensively studied yet. In this work, $Cu(In,Ga)_3Se_5$ films were fabricated on Mo-coated soda-lime glass substrates by a three-stage co-evaporation process. The Cu content in the film was controlled by varying the deposition time of each stage. X-ray diffraction and Raman spectroscopy analyses showed that, even though the stoichiometric Cu/(In+Ga) ratio is 0.25, $Cu(In,Ga)_3Se_5$ is easily formed in a wide range of Cu content as long as the Cu/(In+Ga) ratio is held below 0.5. The optical band gap of $Cu_{0.3}(In_{0.65}Ga_{0.35})_3Se_5$ composition was found to be 1.35eV. As the Cu/(In+Ga) ratio was decreased further below 0.5, the grain size became smaller and the band gap increased. Unlike the $Cu(In,Ga)Se_2$ solar cell, an external supply of Na with $Na_2S$ deposition further increased the cell efficiency of the $Cu(In,Ga)_3Se_5$ solar cell, indicating that more Na is necessary, in addition to the Na supply from the soda lime glass, to suppress deep level defects in the $Cu(In,Ga)_3Se_5$ film. The cell efficiency of $CdS/Cu(In,Ga)_3Se_5$ was improved from 8.8 to 11.2% by incorporating Na with $Na_2S$ deposition on the CIGS film. The fill factor was significantly improved by the Na incorporation, due to a decrease of deep-level defects.

• Journal of the Korean Wood Science and Technology
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• 제24권3호
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• pp.51-56
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• 1996

The Bark lignin(alkali- and acid lignin), bark extractives(hot water-and $Na_2SO_3$ extractives) of Quercus acutissima and Pinus densiflora, and flavonoids were used to detect heavy metal adsorption. The adsorption ratio of heavy metals by lignin was assigned for 40 to 50%, but was not dependent on lignin kinds. However, in case of the addition of light metals such as $Ca^{++}$ and $Mg^{++}$ to lignin the adsorption ratio was increased by 20 to 40%, and $Pb^{++}$ was almost completely adsorbed. On hot water extractives, the adsorption ratio was very low because the substrate was water-soluble, so the substrate should be water-insoluble to adsorb the heavy metals. However, the adsorption ratios of $Cd^{++}$ and $Pb^{++}$ on $Na_2SO_3$ extractives were significantly increased, while those of $Zn^{++}$ and $Cu^{++}$, were similar to lignin. When four kinds of heavy metals were treated to $Na_2SO_3$ extractives together, more than 97% of $Pb^{++}$ and $Cu^{++}$ was adsorbed_ and $Zn^{++}$ was more adsorbed by 40%, and $Cd^{++}$ was not changed, comparing with the case that on kind of heavy metal was treated. There were differences between adsorption ratio of the kinds of flavonoids and heavy metals, and the adsorption ratio of heavy metals was assigned to 20 to 45% per 0.1g flavonoid.

• 한국환경과학회지
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• 제28권6호
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• pp.561-570
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• 2019

A zeolitic material (Z-Y2) was synthesized from Coal Fly Ash (CFA) using a fusion/hydrothermal method under low-alkali condition (NaOH/CFA = 0.6). The adsorption performance of the prepared zeolite was evaluated by monitoring its removal efficiencies for Sr and Cs ions, which are well-known as significant radionuclides in liquid radioactive waste. The XRD (X-ray diffraction) patterns of the synthesized Z-Y2 indicated that a Na-A type zeolite was formed from raw coal fly ash. The SEM (scanning electron microscope) images also showed that a cubic crystal structure of size $1{\sim}3{\mu}m$ was formed on its surface. In the adsorption kinetic analysis, the adsorption of Sr and Cs ions on Z-Y2 fitted the pseudo-second-order kinetic model well, instead of the pseudo-first-order kinetic model. The second-order kinetic rate constant ($k_2$) was determined to be $0.0614g/mmol{\cdot}min$ for Sr and $1.8172g/mmol{\cdot}min$ for Cs. The adsorption equilibria of Sr and Cs ions on Z-Y2 were fitted successfully by Langmuir model. The maximum adsorption capacity ($q_m$) of Sr and Cs was calculated as 1.6846 mmol/g and 1.2055 mmol/g, respectively. The maximum desorption capacity ($q_{dm}$) of the Na ions estimated via the Langmuir desorption model was 2.4196 mmol/g for Sr and 2.1870 mmol/g for Cs. The molar ratio of the desorption/adsorption capacity ($q_{dm}/q_m$) was determined to be 1.44 for Na/Sr and 1.81 for Na/Cs, indicating that the amounts of desorbed Na ions and adsorbed Sr and Cs ions did not yield an equimolar ratio when using Z-Y2.

• Journal of Preventive Medicine and Public Health
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• 제24권1호
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• pp.8-15
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• 1991

전라북도 완주군의 북부 5개면 지역에서 Na, K의 요중 배설의 양상을 파악하고 일일 식염 섭취량을 추정하며 Na, K 배설과 혈압과의 상관관계를 파악하기 위해, 1987년 1월부터 3월에 걸쳐 40개 마을을 순회하며 30세 이상의 성인에 대한 건강검진을 실시하고 537명으로 부터 12시간 야간뇨를 수집하였다. creatinine의 체중당 일일 배설량이, 일정한 연령층에서는 비교적 일정하다는 성질을 이용하여 수집된 시료를 선발하였다. 이 검사값이 피검자가 속한 연령층의 신뢰범위에 포함되는 소변만을 정확한 12시간 야간뇨로 인정하였는데 537명 중 345명의 소변이 이에 해당되었다. 연구의 결과를 요약하면 다음과 같다. 1. 12시간 동안 소변으로 배설된 전해질의 양은 Na의 경우 고혈압군에서는 179.5 mEq, 정상혈압군에서는 203.8 mEq였고 전체의 평균값은 193.5 mEq였다. Na 배설에 있어서는 두 군 사이에 유의한 차이를 발견할 수 없었다. 그러나 12시간 동안 배설된 K의 양에서는 고혈압군이 정상혈압군에 비해 통계적으로 유의하게 낮은 값을 보였고 (고혈압군이 17.5 mEq, 정상혈압군 23.1 mEq, p<0.01) 전해질 간의 비율에서도 K/creatinine에서 고혈압군이 정상혈압군보다 통계적으로 유의하게 낮은 값을 보였다(고혈압군 0.040, 정상혈압군 0.050, p<0.05). 2. Na의 일일 배설량은 386.9 mEq였으며 이를 NaCl의 양으로 환산한 값은 22.4 g이었다. 1일간 섭취된 Na의 90%만이 소변으로 배설된다고 가정할 때 NaCl의 1일 섭취량은 평균 24.9 g으로 추정되었다. 추정된 1일 NaCl 섭취량에서 고혈압군과 정상혈압군 사이에 통계적으로 유의한 차이는 없었으나(23.2g vs 26.3g) 고혈압군의 평균 식염 섭취량이 정상혈압군의 평균값보다 다소 적은 결과를 얻었다. 3. 전체 조사 대상자 중 수축기 혈압이 120 mmHg 이상인 집단에 한하여 혈압이 높아질수록 K 배설량이 감소하는 부분적 역(逆) 상관관계를 볼 수 있었고 Na/K 비(比)는 대상자 전체에서 혈압의 증가와 함께 증가하였다 (p<0.05).