• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.312.1-312.1
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• 2014

Chalcopyrite계 화합물 반도체인 $Cu(InGa)Se_2$ (CIGS)는 직접천이형 에너지 밴드갭과 전파장 영역에 대하여 높은 광흡수계수($1{\times}$[10]^5/cm)를 가지므로 두께 $1{\sim}2{\mu}m$인 박막형태으로 고효율의 태양전지 제조가 가능하다. 또한, 박막공정의 저가 가능성을 나타내면서 전세계적으로 많은 연구와 관심을 받고 있고, 현재 상용화되어 있는 결정질실리콘 태양전지를 대체할만한 재료로 주목 받고 있다. 일반적으로, CIGS박막형 태양전지 구성은는 유리를 기판으로 하여 5개의 단위 박막인 Mo 후면전극, p형 반도체 CIGS 광흡수층, n형 반도체 CdS 버퍼층, doped-ZnO 상부 투명전극, $MgF_2$ 반사방지막으로 이루어진다. 이들 중에서 태양전지의 에너지 변환효율에 결정적인 영향을 미치는 구성된다. CIGS 광흡수층의 제조는 크게 진공법과 비진공방법으로 나뉜다. 현재까지 보고된 문헌에 따르면 CIGS 박막형 태양전지의 경우에 동시증발법으로 20.3%의 에너지 변환효율을 보였지만,는데, 이는 진공장비 특성상 공정단가가 높고 대면적화가 어렵다는 단점을 가진다. 따라서, 비진공법을 이용하여 광흡수층 제작하는 것이 기술적으로 진보할 여지가 크다고 볼 수 있다. 반면 현재 상용화되어 있는 결정질실리콘 태양전지를 대체할만한 방법으로 주목 받고 있는 비진공을 이용한 저가공정은 최근 15.5%의 에너지 변환효율이 보고 되었다. 비진공법에는 전계를 이용한 증착법 및 스프레이법으로 나뉘며, 이들 광흡수층 재료의 화학적 합성은 III족 원소인 In, Ga의 함량비에 따라 광흡수층의 에너지 밴드갭(1.04~1.5 eV) 조절이 가능하다. 따라서, 본 연구에서는 비진공법에 사용되는 CIGS재료의 화학적 합성조건을 변화시켜 III족 원소의 조성비 조절을 시도하였다. CIGS 분말 시료의 입자 형태와 크기를 FE-SEM을 이용하여 관찰하였고, 화합물의 성분비를 EDX 및 XRD 분석을 통해 Ga 함량에 따른 구조적 차이를 비교해 보았다.

• Journal of Radiation Protection and Research
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• v.15 no.2
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• pp.57-65
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• 1990

Newly developed LiF(Mg, Cu, Na, Si) thermoluminescence phosphors sealed in a plastic capsules (32mm dia., 0.9mm wall thickness) were used for in-phantom dosimetry of $^{60}Co$ $\gamma$-irradiation. The absorbed doses in water were determined by applying the general cavity theory to the absorbed dose in TLD cavity, which was computed from exposure. The absorbed doses at various sites in the water-phantom were measured by LiF(Mg, Cu, Na, Si) TLD and compared with doses obtained by the ionization method. Both results were consistent within the experimental fluctuation$({\pm}3%)$ Central axis percentage depth doses and phantom-air ratios measured by LiF(Mg. Cu, Na, Si) TLD showed good agreement with the published values[Br. J. Radiology, Suppl. 17(1983)].

• Journal of the Korean Geotechnical Society
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• v.24 no.7
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• pp.17-24
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• 2008

In this study, the triaxial behaviour of an unsaturated soil was analyzed by Bishop stress descriptions. $K_0$ stress paths and those final values were independent of matric suctions after describing by the Bishop stress. The failure criteria could be defined uniquely by the Bishop stress and were also independent of matric suctions. In the low level of matric suctions the failure criteria have a linear relationship and the estimated criterion fits the measured accurately. The variable ${\chi}$ for describing the Bishop stress was a constant theoretically under the low level of matric suctions. The suction stress could be defined at zero deviatoric stress in the failure criteria and increased linearly with respect to matric suctions in both the theory and the experiments.

• Journal of Ginseng Research
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• v.2 no.1
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• pp.59-66
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• 1977

Mineral contents of sail in two-year-old ginseng plantation. of the top-dressings for ginseng and of the green grasses (Chung-Cho) were analyzed in order to clarify budget of inorganic nutrients of ginseng Plant. The amount of mineral nutrients contained in soil of two-year-old ginseng plantation had 56 times of nitrogen, 1.2 times of phosphorus and 20 times of potassium as compared with the requisition of two to sin-year-old ginseng plants per $\textrm{m}^2$. In consideration of the lack of phosphorus, it is recommendable to use bone mill as top dressing, which contains higher content of Phosphorus than ether top-dressings.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.1
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• pp.16-25
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• 1992

A pot experiment was conducted to understand effect of soil temperaute on soybean shoot and root growth, and its relations to nutrient uptake including phosporus and potassium. Pregerminated soybean seedlings, Paldal cultivar, were planted for 43 days on the pots with Ihyeon silt loam and Samgag sandy loam in the temperature controled water baths at 17, 25 and $32^{\circ}C$. Shoot and root samples were taken at four times and analyzed. Shoot and root dry matter weights were heavier as higher soil temperaure. The root dry matter increased faster than shoot at earlier period. Shoot dry matter weights grown at 17 and $25^{\circ}C$ showed little difference between two soils, however, those grown in silt loam at $32^{\circ}C$ were heavier than sandy loam. The total lengths of roots were longer as higher soil temperature, and longer in silt loam than sandy loam. The roots grown in sandy loam at low temperature were thicker than the roots grown in silt loam at high temperature. The uptakes of phosphorus and potassium were higher as higher tempeature with same trend with dry matter. The uptake rate of unit root surface area was higher in sandy loam soil than silt loam. The uptake rates showed strong dependence on soil temperature as well as dependence of water uptake rate. Based on Dalton and Gardner model, at high temperature the dependence trend of phosphorus and potassium on soil temperature showed with active uptake model, while at low temperature the dependence showed without active uptake model.

• Journal of Korean Society of Forest Science
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• v.11 no.1
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• pp.1-24
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• 1970

This experiment was carried out to elucidate the behavior of nutrition absorption and the acid tolerance, on varying soil pH levels, of Pinus thunbergii, Pinus densiflora, Pinus rigida, PInus koraiensis, Larix leptolepis and Abies holophylla which are 6 month old seedlings through examinations of the absorption behavior, the acid and alkali tolerance of N,P,K, Ca and Fe in the sand culture media with artificially controlled pH. 1. The increase rate of dry matter conditioned by the behavior of nutrition absorption in a strong acidic condition (pH3) was found in the following decreasing order of Pinus rigida, Pinus thunbergii. This order, therefore, can also be said to apply to the case of acid tolerance. 2. The increase rate of dry matter in a strong alkaline condition (pH9) was found in the following decreasing order of Pinus thunbergii, Pinus rigida, Pinus densiflora, Pinus koraiensis, Abies hoplohylla, Larix leptolepis. This order, therefore can be said to apply to the case of alkali tolerance. 3. Considering the absorption behavior of K and Ca, it is possible to decide the tolerance of acid from the absorption behavior and it can be said that if the absorption quantity is K>Ca the acid tolerance is strong and vice versa. 4. Considering the ratio of K:Fe and Ca:Fe in this experiment, a strong acid tolerance shows a higher ratio of K/Fe and vice versa. And also a strong acid tolerance shows a lower ratio of Ca/Fe and vice versa. It is therefore possible to decide the acid tolerance from the absorption behavior of K, Ca and Fe. 5. Of the tree species subjected to this experiment, Pinus thunbergii was the strongest in both acid and alkali tolerance. 6. In spite of that in all species the dry weight in the root is smailer than that in the top, the quantity of Fe contained in the root was larger than that in the top.

• Korean Journal of Environmental Agriculture
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• v.25 no.4
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• pp.382-385
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• 2006

To know the effect of water treatment sludge (WTS) as a rice seedling culture soil, rice seeds are sown, germinated and grown on the culture soils mixed with different ratios of WTS to sand (100:0, 50:50, 30:70, respectively), and their growth effects was compared to that of control, commercial culture soil. When WTS is used as a culture soil for rice, the length and weight of the top part of rice seedling somewhat decreased than those of control treatment while their root length and weight in all WTS treatments significantly increased. Although phosphorus and potassium uptake of rice seedling in WTS treatments was slightly decreased, WTS treatment showed to develop root growth which is necessary in the seedling stage of all plane. Such a stimulatory effect on root growth of rice seedling was significant in the mixture ratio of 50% WTS to 50% sand.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.630-638
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• 2021

In this study, we investigated the effects of dissolved inorganic and organic nutrient on the growth of dinoflagellate Alexandrium affine (LIMS-PS-2345). The maximum uptake rates (ρ_max) and half saturation constants (Ks) calculated from the uptake kinetics experiment were 77.0 pmol/cell/hr, 17.6 μM for nitrate and 15.5 pmol/cell/hr, 3.88 μM for phosphate, respectively. These results suggested that this species has high inorganic nutrient demand and a low affinity for inorganic nutrients. During the utilization of organic nutrients for A. affine, growth rates of experimental groups added by organic nitrogen (urea and glycine) and phosphorus (adenosine triphosphate and glycerol phosphate) were above 70 %, compared to the experimental groups added by inorganic nutrients. Thus, A. affine may need to utilize organic nutrients to understand the dominant strategy and advantageous position in the interspecific competition within low inorganic nutrient environments.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.1
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• pp.41-45
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• 2004

A phosphate solubilizig bacterium, Pantoea agglomerans, was isolated from rhizosphere soils collected from Chungbuk area. A greenhouse experiment was conducted to study the effect of combined application of rock phosphate and P. agglomerans inoculation on plant growth and phosphate accumulation of rice (Oryza sativa L.). Apart from control that received no inputs, six treatments were planned as follows; 1) seed bacterization, 2) free cell inoculation and 3) bacteria immobilized beads inoculation, individually and in combination with 1 and 2.5 g of rock phosphate per pot. The results showed that plant growth and phosphate uptake were significantly enhanced as a result of bacterial inoculation. Bacterial inoculation in the form of immobilized beads and 1 g of rock phosphate was found to affect positively the rice plant growth and phosphorus accumulation than other treatments. The available phosphate concentration of the pot mixture also found improved as a result of P. agglomerans inoculation. A positive correlation was observed between the phosphate concentration in the pot mixture and phosphate accumulation in plant.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.1
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• pp.81-88
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• 1983

This experiment was conducted to study about influenced inorganic element contents of flag leaf and chaff with different nitrogen and silicate application in Jinan (sea level 303m). The recommended rate of fertilizer application above N 15kg/10a was poor for dry production increment in cold in July elevation and was demanded increment of silicate. In the elevation of cold in July high rates of nitrogen application produced more incomplete grain and a reduced cold tolerance. These effects were due to over-content of soluble nitrogen within flag leaf and disturbance of uptaking potassium and silicate. On the other hand, the application of silicate could increase yield by promoting resistance to cold- damage. The application of increasing level of nitrogen resulted in increasing the contents of total nitrogen and phosphate in both sterile and fertile glumes. The contents of potassium and calcium were the highest at the level of nitrogen 10 - 15kg/10a, but magnessium was rather high at low nitrogen levels. It is interesting that at any level of nitrogen, over 6% higher silicate contents were noted in the fertile chaff than in the sterile chaff. Application of increasing level of silicate fertilizer decreased total nitrogen contents, but increased the contents of phosphate, potassium. and silicate in the chaff. Increasing rate of silicate content by increasing silicate addition was remarkably higher in the fertile chaff than in the sterile chaff.