• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.258-259
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• 2015

$CuInSe_2$(CIS)층에 Na의 첨가는 태양전지 셀의 효율을 향상시키는데 도움을 주는 것으로 알려져 있다. 본 연구에서는 Na이 없는 코닝 유리 기판에 Mo/Mo-Na 이중 박막을 후면 전극으로 이용하여 CIS층의 Na소스로 작용하도록 하였다. CIS/Mo/Mo-Na 다층 박막을 제조한 후, AES분석을 통해 Na은 Mo/Na층과 CIS층의 계면과 CIS층의 표면에 주로 분포하는 것을 알 수 있었다. XRD분석을 통해서 Na함량이 증가할수록 Mo박막의 우선성장면 (110)면의 피크는 감소하였고, CIS의 우선 성장면인 (112)면은 점차 증가하여 Mo-Na층이 200 nm일 때, 최댓값을 가지고 이후로는 감소하는 경향을 보인다. CIS의 결정은 기판에 수직인 방향으로 덴드라이트 성장을 한다. Mo-Na층이 200 nm까지는 밀도가 높은 결정이 성장되지만, 그 이상으로 Na농도가 증가하면 결정 입자의 크기는 다소 성장하지만 밀도가 현저하게 감소한다. 이 결과들로 보아 CIS층의 Na농도조절은 Mo/Mo-Na 이중층의 두께조절을 통해 가능하며, Na이 CIS층에 초과되어 첨가되면 특성이 저하된다.

• Journal of the Mineralogical Society of Korea
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• v.3 no.1
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• pp.7-17
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• 1990

화산 유리질 암석을 출발 물질로 사용하여 저온 ($80^{\circ}C$)에서 수열 처리하여 Na-P Na-X 및 Na-A 제올라이트를 합성하였다. 합성과정은 (1) 유리질 분말 시료와 알칼리 용액과의 용해.변질 반응에 의한 1차적인 Na-P의 합성 방식과 (2) 여기서 잔류된 규산질 모액에 Al(OH)3나 NaAlO2의 수용액을 공급하여 보다 고순도의 Na-P, Na-X 및 Na-A를 효과적으로 합성할 수 있었다. 원암의 암상과 조성은 제올라이트들의 화학 조성과 순도 및 백색도같은 물리적 특성에는 영향을 주지만, 합성된 제올라이트의 광물종을 규제하는 주된 요인은 아닌 것으로 해석된다. 합성된 제올라이트의 광물상은 반응 용액의 pH, Al(OH)4 및 Na+에 대한 농도 조건에 주로 의존되는 경향을 나타낸다. 또한 화산 유리질 암석을 제올라이트 합성원료로 활용하는 데에 있어서 (2)와 같음 합성 방안이 보완적으로 시행되면 그 생산성과 효율성을 제고시킬 수 있을 것으로 여겨진다.

• Journal of the Mineralogical Society of Korea
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• v.13 no.4
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• pp.171-185
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• 2000

Siliceous mudstones are embedded on a large scale in the Tertiary formations of Pohang area. Some useful zeolites such as NsP, (Na, TMA)P, analcime and hydroxysodalite were synthesized from the siliceous mudstones by treating with the variety of solution, i.e ., NaOH, NaOH+NaCl, NaOH, NaOH+$NaAlO_2$and NaOH+TMAOH at the low-temperature hydrothermal system ranging 60~12$0^{\circ}C$. Major precursor of zeolites is found as opal-CT in the zeolite-forming reaction. Smectite, which is included in considerable amounts in the mudstone, appears to play a major role of Al-source in the zeolite synthesis. In comparison, chalcedonic quartz and mica are rather insoluble in alkaline solution, and thus, these are observed as major impurities in the reaction products. An addition of $NaAlO_2$to NaOH solution is effective for eliminating these impurities in the reaction procedure, through these are partly dissolved when elevating the reaction temperature, concentration, and time. Phase change from NaP to hydroxysodalite takes place at the NaOH concentrations of 3.0~4.0 M, and the reaction is not sensitive to the temperature shift. NaP is more stable at lower NaOH concentration and higher activity of $Na_{+}$ whereas analcime is sensitive to the temperature change and stable at higher than $100^{\circ}C$ and 2.0~4.0 M in NaOH concentration. For the pure NaP synthesis without any other products, the treatment of mudstones with 1:1 solution of NaOH and $NaAlO _2$ turns out to be quite effective. NaP was successfully synthesized together with analcime at $100^{\circ}C$ as well as lower concentrations of NaOH+NaCl solution. In addition, the organic type, (Na, TMA)P was formed together with smectite in the 1:1 solution of NaOH and TMAOH.

• Journal of the Korean Wood Science and Technology
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• v.27 no.1
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• pp.18-23
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• 1999

The formation conditions of Na-cellulose II with three fold helix were investigated by an x-ray diffraction method. Na-cellulose II was formed through Na-cellulose I. It seems that the concentration of sodium hydroxide in Na-cellulose II is higher than both those of Na-cellulose I and Na-cellulose III. Na-cellulose II was formed well by different rinsing and drying methods even though the sample treatment was carried out in very short periods of time. Metal-complexed Na-cellulose swollen in the mixture of $Cu(OH)_2$ and sodium hydroxide is stable in wet state, and changed to a different polymorph by drying.

• Membrane Journal
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• v.25 no.1
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• pp.42-47
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• 2015

In this study, PEBAX[poly(ether-block-amide)]-NaY zeolite composite membranes were prepared, and those prepared membranes were studied on permeability of $C_3H_6$ and $C_3H_8$, and selectivity ($C_3H_6/C_3H_8$). NaY zeolite particles in PEBAX-NaY zeolite composite membranes was dispersed as aggregated particles with the size $0.5{\sim}2.5{\mu}m$ by SEM observation. TGA measurement showed the weight loss change resulted from the amount of NaY zeolite when NaY zeolite was added into PEBAX. By gas permeation experiment, the permeabilities of $C_3H_6$ and $C_3H_8$ were decreased by the more addition NaY zeolite in PEBAX. Overall, $C_3H_6$ was having higher permeability than $C_3H_8$. The selectivity $C_3H_6/C_3H_8$ was decreased by the more NaY zeolite in PEBAX.

• Membrane Journal
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• v.20 no.1
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• pp.47-54
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• 2010

The PDMS-NaYzeolite composite membranes were prepared by adding 1~40 wt% NaYzeolite to PDMS. In order to investigate the characteristics of these membranes, we used the analytical methods such as FT-IR, $^1H$-NMR, and SEM. The permselectivity of $H_2$ and $N_2$ gases through the composite membranes was studied as a function of NaYzeolite contents. The permeability and selectivity ($H_2/N_2$) of PDMS membrane increased as the gas permeation pressure increased. The permeability of the PDMS-NaYzeolite composite membranes increased when 1~10 wt% NaYzeolite was added, and then decreased at higher wt% as NaYzeolite content increased. The selectivity ($H_2/_2$) of PDMS-NaYzeolite composite membranes decreased when 1~2 wt% NaYzeolite was added, and then increased as NaYzeolite content increased. As the $H_2$ permeability increased, the selectivity ($H_2/N_2$) of PDMS-NaYzeolite composite membranes decreased at 0~2 wt% and 10~40 wt% NaYzeolite contents, increased at 2~10 wt% NaYzeolite content.

• Clean Technology
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• v.15 no.1
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• pp.60-66
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• 2009

Adsorptive removal of tetrahydrothiophene (THT) and tert-butylmercaptan (TBM) that were widely used sulfur odorants in pipeline natural gas was studied using various ion-exchanged NaY zeolites at ambient temperature and atmospheric pressure. In order to improve the adsorption ability, ion exchange was performed on NaY zeolites with alkali metal cations of $Li^+,\;Na^+,\;K^+$ and transition metal cations of $Cu^{2+},\;Ni^{2+},\;Co^{2+},\;Ag^+$. Among the adsorbents tested, Cu-NaY and Ag-NaY showed good adsorption capacities for THT and TBM. These good behaviors of removal of sulfur compound for Cu-NaY and Ag-NaY zeolites probably was influenced by their acidity. The adsorption capacity for THT and TBM on the best adsorbent Cu-NaY-0.5, which was ion exchanged with 0.5 M copper nitrate solution, was 1.85 and 0.78 mmol-S/g at breakthrough, respectively. It was the best sulfur capacity so far in removing organic sulfur compounds from fuel gas by adsorption on zeolites. While the desorption activation energy of TBM on the Cu-NaY-0.5 was higher than NaY zeolite, the difference of THT desorption activation energy between two zeolites was comparatively small.

• Analytical Science and Technology
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• v.11 no.6
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• pp.448-451
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• 1998

The feasibility of using FT-NIR (Fourier Transform Near Infrared) spectrometer to measure NaOH, $Na_2CO_3$ and $Na_2S$ concentration in a naphtha cracking process, and an outline of the method development to identify spectral feature of the hydroxide whose band is overlapped by a strong water absorption were demonstrated. For measuring NaOH, $Na_2CO_3$ and $Na_2S$, FT-NIR spectrometer is a rapid and possible alternative to the current titration method with a standard deviation of 0.1.

• Journal of Food Hygiene and Safety
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• v.6 no.3
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• pp.139-145
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• 1991

In order to observe the Na contents, Korean common foods, especially processed foods were analyzed by Atomic Absorption Spectrophotometer. 1. The Na contents of instant noodle (ramen) was 400-900 mg/100 g and Na contents of their soup powder was 10000-16000 mg/100 g. 2. The Na contents of corns and beans was very low but their processed foods, com Dake and soybean milk, had relatively high Na contents. 3. The Na contents of meats was 40-60 mg/100 g but the Na contents of meats products was 700-900 mg/100 g. 4. The Na contents of Davoring salt was 12000-38000 mg/100 g, those of soybean products was 3000-6OOO mg/100 g, and that of seasoning MSG was 8000-17000 mg/100 g. 5. There was no statistical difference between the results of wet ash method and dry ash method in the Na contents of all food groups.

• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 1987.06a
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• pp.92-106
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• 1987

$Na^{+}$는 체내에서 세포외액 (extracellular fluid)의 주요 양이온으로 세포내액과 세포외액은 세포막을 사이에 두고 $Na^{+}$와 $K^{+}$의 높은 농도의 차이를 유지하고 있다. 이러한 농도차이는 세포막에 있는 $Na^{+}$-K$^{+}$ATP ase의 활동에 의하여 유지되며 $Na^{+}$는 체액의 osmolarity와 혈장의 부피 유지, 신경흥분, 근육수축 및 영양소등의 이동에도 중요한 역할을 한다. 체내의 Na balance는 renin-aldosterone system에 의하여 신장에서의 배설조절로 이루어지며, 최근 Na대사에 관여하는 natriuretic hormone이 발견되고 있다. Na의 과잉섭취는 역학적 연구와 동물실험에서 고혈압의 유발인자로 제시되고 있으나, 임상적 연구에서는 Na제한이 혈압강하효과가 있다는 보고와 없다는 보고가 있어 결과가 뚜렷하지 않다. 이는 고혈압 환자중에는 salt-sensitive한 group자 salt-resistant group이 있다는 것과 산업화된 사회들의 Na 섭취량이 이미 너무 높은 수준으로 Na섭취증가와 혈압상승간의 관계를 현재의 연구 방법들로는 찾아내기 어렵다는 ‘saturation effect’로 설명한다. 그러나 Na섭취를 1일 70~100mEq.(NaCl 4.0~5.8g)이하로 줄이면 고혈압 발생이 현저히 감소하고 Na 섭취량이 1일 30mEq.(NaCl 1.7g)이하이면 고혈압은 거의 발생하지 않는다. 그러나 Na섭취가 1일 400mEq.(NaCl 23.2g)이상이 되더라도 인구 중 50~80%는 고혈압에 걸리지 않아 고혈압의 발생은 유전적 인자, 신장 기능의 부족에 의해 지배되고, Na이외에도 K, Ca등의 식이 인자 및 stress, 운동등의 환경적 요인들이 영향을 미친다. Na 섭취량은 자연식품에 들어있는 양 뿐 아니라, 가공과정, 조리가정, 식사 중에 첨가되는 양에 의하여 좌우되므로, Na 섭취량을 측정하기 매우 어렵다. 가장 널리 사용되는 방법은 24시간 소변 중 배설되는 Na의 양으로부터 추정하는 방법으로 우리나라의 경우, 이러한 방법으로 섭취량을 환산할 경우 1일 200~260mEq. (NaCl 11.6~15.1g) 정도이며 이중 80% 이상이 discretionary intake인 것으로 추정된다. 따라서 앞으로 Na섭취를 줄이도록 많은 노력을 기울여야 하겠다.