• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.90.1-90.1
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• 2010

Due to the rapidly diminishing energy sources and higher energy production cost, the interest in dye-sensitized solar cells (DSSCs) has been increasing dramatically in recent years. A typical DSSC is constructed of wide band gap semiconductor electrode such as $TiO_2$ or ZnO that are anchored by light-harvesting sensitizer dyes and surrounded by a liquid electrolyte with a iodide ion/triiodide ion redox couple. DSSCs based on one-dimensional nano-structures, such as ZnO nanorods, have been recently attracting increasing attention due to their excellent electrical conductivity, high optical transmittance, diverse and abundant configurations, direct band gap, absence of toxicity, large exiton binding energy, etc. However, solar-to-electrical conversion performances of DSSCs composed of ZnO n-type photo electrode compared with that of $TiO_2$ are not satisfactory. An important reason for the low photovoltaic performance is the dissolution of $Zn^{2+}$ by the adsorption of acidic dye followed by the formation of agglomerates with dye molecules which could block the I-diffusion pathway into the dye molecule on the ZnO surface. In this paper, we prepared the DSSC with the ZnO electrode using the chemical bath deposition (CBD) method under low temperature condition (< $100^{\circ}C$). It was demonstrated that the ZnO seed layers played an important role on the formation of the ZnO nanostructures using CBD. To achieve truly low-temperature growth of the ZnO nanostructures on the substrates, a two-step method was developed and optimized in the present work. Firstly, ZnO seed layer was prepared on the FTO substrate through the spin-coating method. Secondly, the deposited ZnO seed substrate was immersed into an aqueous solution of 0.25M zinc nitrate hexahydrate and 0.25M hexamethylenetetramine at $90^{\circ}C$ for hydrothermal reaction several times.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.11
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• pp.702-706
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• 2016

We demonstrated that self-separation FS-GaN (freestanding-GaN) was grown on MELO (maskless epitaxially lateral overgrowth) GaN template by horizontal HVPE (hydride vapor phase epitaxy). Before thick GaN grwoth, MELO GaN template was grown on patterned GaN template by MOCVD (metal organic chemical vapor deposition). The laterally overgrown GaN would consist of a continuous well coalesced layer. The mixed TDD (threading dislocation density) of seed and wing region were $8{\times}10^8cm^{-2}$ and $7{\times}10^7cm^{-2}$, respectively. After thick GaN grown by HVPE, the self-separation between thick GaN and sapphire substrate was generated at seed region. The regions of self-separation for FS-GaN and sapphire were observed by FE-SEM. Moreover, Raman results indicated that the compressive strain of seed and wing regions at FS-GaN substrate were slightly released compared to that of thick GaN grown on conventional GaN template. The optical properties of the FS-GaN substrate were examined by using PL (photoluminescence). The PL exhibited that donor bound exciton and donor acceptor pair were observed at low temperature. The effects on optical and structural properties of FS-GaN substrate have been discussed in detail.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.12
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• pp.1726-1730
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• 2000

High fibre (CF, 242 g/kg) sunflower seed meal (SSM) was incorporated in standard grower and layer quail diets at 0, 50, 75 or 100 g/kg replacing part of the soybean meal (SBM) and deoiled rice bran (DORB). Each grower diet was offered to 30 quails housed in battery cages from day one to 5 weeks of age. At the end of the growing period, Twelve female quails from each of the four respective dietary groups were transferred to the individual laying cages and their laying performance from 7 to 20 weeks of age were evaluated on diets containing SSM at similar levels as that during the growing period. The results of growth bioassay revealed that the live weight gain, feed intake, nutrient retention and carcass characteristics of quails in different dietary groups did not vary significantly (p>0.05), although the quails fed SSM based diets utilized the feed less (p<0.05) efficiently than those fed the control diet. During the laying period, the egg production and egg quality traits remained unaffected due to dietary treatments but feed required per unit egg production increased (p<0.05) as the level of SSM in diet was increased to 100 g/kg. Although, the cost of feed per kg decreased due to the incorporation of SSM in diet but the same was not reflected in feed cost per unit gain, meat or egg production as such parameters were comparable on all the diets. It could thus be concluded that the SSM can be incorporated in quail diets upto 100 g/kg for part of SBM, an item usually expensive and also in short supply in developing countries including India.

• Proceedings of the Korea Contents Association Conference
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• 2005.05a
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• pp.107-111
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• 2005

As Internet grows rapidly and next electronic commerce applications increase, the security is getting more important. Information security to provide secure and reliable information transfer is based on cryptography technique. The proposed ISEED(Improved SEED) algorithm based on block cryptography algorithm which belongs to secret-key algorithm. In terms of efficiency, the round key generation algorithm has been proposed to reduces the time required in encryption and decryption. The algorithm has been implemented as follow. 128-bit key is divided into two 64-bit group to rotate each of them 8-bit on the left side and right side, and then basic arithmetic operation and G function have been applied to 4-word outputs. In the process of converting encryption key which is required in decryption and encryption of key generation algorithm into sub key type, the conversion algorithm is analyzed. As a result, the time consumed to encryption and decryption is reduced by minimizing the number of plain text required differential analysis.

• Journal of the Korean Magnetics Society
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• v.2 no.1
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• pp.22-28
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• 1992

Barium ferrite thin films were reactively deposited with Fe and BaO composite targets by a facing tergects sputtering unit. When thermally oxidized silicon wafers were used as substrates, minimum substrate heating of $750^{\circ}C$ was necessary for the perfect c-axis alignment in barium ferrite films. To lower the critical substrate temperature for the good c-axis alignment, such seed layers as ZnO, ${\alpha}-Fe_{2}O_{3}$ and ${\gamma}-Fe_{2}O_{3}$ were tested. The excellent c-axis algnment of BaM was obtained at a substrate temperature of $600^{\circ}C$ on ZnO seed layer whose (002) plane was parallel to the substrate surface. The magnetic properties of the BaM film showed saturation magnetization of 295 emu/cc, perpendicular coercivity of 1.7 kOe and squareness of 0.75. Optimum deposition rate of $230\;{\AA}/min$ was obtained with the composite target and this was 5 to 20 times higher than those of other investigators with oxide targets.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.6
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• pp.72-85
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• 2002

This study was conducted to investigate the germination rates and ground coverage rates of the 16 native wild flower, herbaceous, shrub and woody plants according to temperature and seeding timing for the revegetation and rehabilitation of the roadside slopes. Also, this study was conducted to suggest design criteria to select revegetation plants and to decide proper seed mixture for ecological restoration of the disturbed manmade slopes as a environmentally friendly construction. The results are summarized as follows. 1. Most of the plants germinated after 10~14 days. Woody plants germinated more slowly than wild flowers and herbaceous plants because of the hard seed. 2. Most of the plants showed the highest percentage of the germination rates under $15/25^{\circ}C$ temperature. The next was in order of under the $20/30^{\circ}C$ temperature, normal temperature(October) and $25/35^{\circ}C$ temperature. 3. At the chamber experiment, the Sorbaria sorbifolia var. stellipila showed the highest germination rates. Most of the native wild flowers germinated well and showed high germination rates under the various temperature. 4. As the field germination experiments, the seeding at August shows higher germination rates than that of the seeding at September, but showed lower surviving percentage of the germinated seedlings and lower ground coverage percentage than those of the seeding at September. After one year, Chionanthus retusus, Acer palmatum, Albizzia julibrissin are germinated and showed 10% coverage rates. So, they can be used as revegetation plants for the restoration works. 5. As seed mixture experiment, it was not effective only to increase the proportion of the ratio of the tree seeds, relatively high price, for making woody vegetation. It would be more successful to make vegetation structure by natural competition among wild flowers, shrubs and trees. 6. The excessive dominance of trees in revegetation works may destroy the lower layer of vegetation and it will be undesirable on the species diversity. It is more important to recover the species diversity of the plant community by seed mixture with the considering the germination, the growth characteristics and the correlation effect among revegetation plants. 7. To recover the manmade slopes quickly, increasing the ratio of the wild flower was recommended.

• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.524-531
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• 1996

The objective of this study was to determine the important factors affecting the early natural regeneration of Pinus densiflora S. et Z. Seed germination, survival and height growth of the pine seedlings were examined at four experimental plots of P. densiflora forests including forest roadside. Plots I and III were thinned in 1992, plot II was treated with hexazinone in 1993 after seed tree method was applied in 1982 and 1989. Seedlings emerged after thinning and the rate of their emergence depended on forest floor conditions. Seedling survival was related with light conditions, herbaceous vegetation, and degrees of rainfall. More seedlings emerged in forest hauling roads than within the forest because soil scarification due to logging provided better conditions for seed germination and seedling growth. Seed supply was enough, but germination rate was very low in the forest compared with that in the greenhouse because micro-environments such as organic layer and herbaceous plant acted as limiting factors. Weed control was needed for 4 to 5 years until seedlings grew upto about 50cm in height which was similar to that of herbaceous plants. But 10-40% coverage of herbaceous vegetation was needed to protect small seedlings from heavy rain. Forest works such as thinning and logging, over 40% of light were important factors to help the pine regeneration. However, over 70% coverage of herbaceous vegetation, and heavy rain inhibited rather survival and growth of pine seedlings.

• Korean Journal of Food Science and Technology
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• v.17 no.4
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• pp.248-252
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• 1985

Prunus tomentosa Thunberg seed was investigated to evaluate its possibility for use as food resources of fats and proteins. The seed contained 40.38% of crude fat and 26.59% of crude protein. The lipid fractions obtained by silicic acid column chromatography were mainly composed of 95.49% of neutral lipids, whereas compound lipids were only 4.51%. Among the neutral lipid components by thin-layer chromatography, triglycerides were 89.86%, sterols, monoglycerides, sterol esters, free fatty acids and diglycerides were 4.14%, 2.98%, 1.77%, 1.07%, and 0.18%, respectively. Oleic acid (65.06-66.05%) and linoleic acid (26.56-28.40%) were the main fatty acids in the total lipid, neutral lipid and triglyceride fractions. In the glycolipid and phospholipid fractions, predominant fatty acids were oleic acid (40.55-51.46%), linoleic acid (20.26-30.89%) and palmitic acid (17.64-21.43%). The extractability of salt soluble protein of seed was 60%, and recovery rate of main protein fraction separated by Sephadex G-200 was about 46.5%. The electrophoretic analysis showed 7 bands in seed protein.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.4
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• pp.359-368
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• 2008

Black soybean has been widely utilized as foods and oriental medicinal materials. The pigmentation in the seed coat of black soybean is due to accumulate anthocyanins in the epidermis palisade layer. The anthocyanins of black soybean seed coat are considered as a parameter of quality evaluation of black soybean. Therefore, the purpose of this study was to investigate the most suitable HPLC condition for simultaneous determination of anthocyanins in black soybean seed coats extracts. The efficient HPLC analytical condition of D3G, C3G, and Pt3G contained extracts of black soybean seed coats was developed. The gradient elution employed a $250\;mm\;{\times}\;4.6\;mm$ i.d. YMC-pak ODS-AM 303 column. The gradient system was used two mobile phases. A gradient elution was performed with mobile phase A, consisting of 5% aqueous formic acid, and mobile phase B, comprising 5% formic acid - acetonitrile, and delivered at a flow rate of 0.7 mL/min as follows: $0{\sim}35\;min$, $90%\;A{\sim}60%\;A$; 36 min, 90% A; 46 min, 90% A. The UV-VIS. detection wavelength was set at 520 nm. The limit of detection (LOD) for D3G, C3G, and Pt3G were under 10 ng/mL.

• Applied Microscopy
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• v.41 no.1
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• pp.61-67
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• 2011

The purpose of this study is to investigate the hemp (Cannabis sativa cv. Chungsam) seed structure and ultrastructure of food reserves by scanning and transmission electron microscopy. We examined the seed coat and embryo consisting of a hypocotyl-radicle axis and two cotyledons. The seed coat consisted of exotesta and endotesta. The exotesta was a mechanical layer with lignified and elongated cells, while endotesta of the underlying layers of the exotesta was consisted of two separated cell layers. The collapsed outer layer of endotesta showed the unique reticulate structures. In cotyledon cells, protein and lipid bodies occupied most of cytoplasm. Protein bodies varied in diameter from 1.8 to $5.0{\mu}m$ and possessed a protein matrix containing electron-dense globoid crystals. Numerous lipid bodies ranged from 0.8 to $3.0{\mu}m$ in diameter were distributed around the protein bodies. During the early stages of breakdown, protein bodies rapidly changed their shape into the granular feature, however, lipid bodies were gradually degradated and fused each other. The degeneration process of protein bodies and lipid bodies of cotyledon cells might be correlated with the reports which hemp seeds rapidly lose their ability to germinate.