• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.81-81
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• 2010

유리기판위에 큰 결정입자를 갖는 실리콘 (폴리 실리콘) 박막을 제조하는 것은 가격저가화 및 대면적화 측면 같은 산업화의 높은 잠재성을 가지고 있기 때문에 그동안 많은 관심을 가지고 연구되어 오고 있다. 다양한 방법을 이용하여 다결정 실리콘 박막을 만들기 위해 노력해 오고 있으며, 태양전지에 응용하기 위하여 연속적이면서 10um이상의 큰 입자를 갖는 다결정 실리콘 씨앗층이 필요하며, 고속증착을 위해서는 (100)의 결정성장방향 등 다양한 조건이 제시될 수 있다. 다결정 실리콘 흡수층의 품질은 고품질의 다결정 실리콘 씨앗층에서 얻어질 수 있다. 이러한 다결정 실리콘의 에피막 성장을 위해서는 유리기판의 연화점이 저압 화학기상증착법 및 아크 플라즈마 등과 같은 고온기반의 공정 적용의 어려움이 있기 때문에 제약 사항으로 항상 문제가 제기되고 있다. 이러한 관점에서 볼때 유리기판위에 에피막을 성장시키는 방법으로 많지 않은 방법들이 사용될 수 있는데 전자 공명 화학기상증착법(ECR-CVD), 이온빔 증착법(IBAD), 레이저 결정화법(LC) 및 펄스 자석 스퍼터링법 등이 에피 실리콘 성장을 위해 제안되는 대표적인 방법으로 볼 수 있다. 이중에서 효율적인 관점에서 볼때 IBAD는 산업화측면에서 좀더 많은 이점을 가지고 있으나, 박막을 형성하는 과정에서 큰 에너지 및 이온크기의 빔 사이즈 등으로 인한 표면으로의 damages가 일어날 수 있어 쉽지 않는 방법이 될 수 있다. 여기에서는 이러한 damage를 획기적으로 줄이면서 저온에서 결정화 시킬 수 있는 cold annealing법을 소개하고자 한다. 이온빔에 비해서 전자빔의 에너지와 크기는 그리드 형태의 렌즈를 통해 전체면적에 조사하는 것을 쉽게 제어할 수 있으며 이러한 전자빔의 생성은 금속 필라멘트의 열전자가 아닌 Ar플라즈마에서 전자의 분리를 통해 발생된다. 유리기판위에 흡수층 제조연구를 위해 DC 및 RF 스퍼터링법을 이용한 비정질실리콘의 박막에 대하여 두께별에 따른 밴드갭, 캐리어농도 등의 변화에 대하여 조사한다. 최적의 조건에서 비정질 실리콘을 2um이하로 증착을 한 후, 전자빔 조사를 위해 1.4~3.2keV의 다양한 에너지세기 및 조사시간을 변수로 하여 실험진행을 한 후 단면의 이미지 및 결정화 정도에 대한 관찰을 위해 SEM과 TEM을 이용하고, 라만, XRD를 이용하여 결정화 정도를 조사한다. 또한 Hall효과 측정시스템을 이용하여 캐리어농도, 이동도 등을 각 변수별로 전기적 특성변화에 대하여 분석한다. 또한, 태양전지용 흡수층으로 응용을 위하여 dark전도도 및 photo전도도를 측정하여 광감도에 대한 결과가 포함된다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.8
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• pp.887-894
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• 2007

In this paper, design and fabrication of the LPF with controllable four transmission zeros using electric coupling and added open stub is presented. Pass-band of the LPF is GSM band, and two transmission zeros are generated by the electric coupling at the WiBro and S-DMB band, And the other two transmission zeros are generated by the open stub at the upper frequencies. Harmonic frequency of the stop-band is suppressed by the realization of the filter using quasi-lumped element with small parasitic values. $C_M$, which is the electric coupling element of the equivalent circuit, is realized by the distance control between the open stubs of the filter structure. The fabricated LPF used teflon substrate with relative permittivity of 2.6. And it has a size of $38{\times}20{\times}0.79 mm^3$, which is including a feed line. The measured 3 dB cut-off frequency is 1.55 GHz, and locations of the transmission zeros are 2.20, 2.43, 4.11 and 6.84 GHz, respectively.

• Tuberculosis and Respiratory Diseases
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• v.58 no.1
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• pp.68-73
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• 2005

Pulmonary sequestration is a very rare congenital malformation in which a mass of pulmonary tissue is detached from the normal lung and receives its blood supply from a systemic artery. It may be clinically asymptomatic or it has a wide spectrum of various clinical manifestations. The clinical therapeutic approach is to resect the sequestered lobe to prevent frequent complication such as infection. The arterial embolization of feeding artery is a new technique and a less invasive treatment than conventional surgical removal. We have experienced a 17-year-old male with pulmonary sequestration whose complaints were pain in left lower chest. He was diagnosed by computed tomography and aortography and successfully treated with embolization of feeding artery. We report a case of pulmonary sequestration treated with arterial embolization instead of surgery.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.2
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• pp.204-211
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• 2023

This study investigated the physicochemical properties and palatability-enhancing effects of the alcohol precipitate, in the enzymatic extracts of Sargassum confusum C. Agardh (SC), obsained using the crude enzyme of Shewanella oneidensis PKA 1008. We analyzed the oligosaccharides recovered from the alcohol precipitate using a thin-layer chromatography for SC-degrading extracts, pH, color, reducing sugar, and viscosity. Thin-layer chromatography showed that after treating with the crude enzyme for 60 h, the polysaccharides were degraded into tetramers, dimers, and trimers and pH increased in the alcohol precipitate (EtOH Sedi). In terms of color, the redness and yellowness of alcohol precipitate/supernatant (EtOH Sedi+Super) and the brightness of EtOH Sedi were the highest among enzyme treated for 0 h and 60 h, EtOH Sedi, and EtOH Sedi+Super. In the reducing sugar analysis, EtOH Sedi showed the lowest value of 13.63 ㎍/mL, and the lowest viscosity of 1.13. In terms of the sensory evaluation, EtOH Sedi+Super showed the highest value with respect to the overall preference. These results suggest that the crude enzyme of S. oneidensis PKA 1008 is effective at degrading polysaccharides, and its recovery increases the palatability of the alcohol precipitate.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.6
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• pp.790-797
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• 2023

Guar gum is an edible starch extracted from Cyamopsis tetragonolobus and used as an auxiliary ingredient to enhance the viscosity and adhesiveness of food and improve its emulsification stability. Here, characteristics of fish surimi mixture with various added amounts (0, 0.23, 0.45, 0.67, and 0.89 wt%) of guar gum were analyzed. In unheated surimi with guar gum, the pH decreased as the content increased. In the color values analysis, only the b^* (yellowness) increased depending on the amount of added guar gum. The firmness increased with increasing guar gum content, and no significant difference in adhesiveness was observed. In heated surimi, a^* (redness) and b^* decreased in a content-dependent manner, and L^* (lightness) was higher than that of unheated surimi. Regarding physical properties, the highest values of hardness, gumminess, and chewiness were observed in the heated surimi with 0.67 wt% of guar gum. However, no significant change was observed in springiness and cohesiveness. Results of sensory evaluation indicated that with higher guar gum content, only the hardness increased slightly, and significant differences were absent in the remaining parameters. Thus, surimi with 0.67 wt% of guar gum is considered to be optimal for 3D printing.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.2
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• pp.109-115
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• 2024

This study investigated the effects of various naked barley starch contents (0, 0.67, 1.34, 2.0, and 2.67 wt%) in surimi mixtures for 3D printing. Adding starch to surimi altered its texture, potentially reducing production costs. Unheated surimi became less firm with higher starch content. After heating, there was an increase in hardness, adhesiveness, springiness, cohesiveness, gumminess, chewiness, and resilience, peaking at 1.34 wt% starch. Compared to the negative control, starch-added heated surimi had a tougher texture. The color values (L^*, a^*, and b^*) decreased after heating, with no significant change in shearing force with increasing starch content. Sensory evaluation indicated improved smell, texture, hardness, elasticity, and preference over the negative control. Higher starch content increased hardness for 3D printing suitability with no significant difference above 1.34 wt% starch indicating this is the most appropriate content. Naked barley starch enhanced surimi strength without affecting smell and preference, suggesting it as a potential surimi additive.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.2
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• pp.116-121
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• 2024

The meats of tuna Thunnus albacares and swordfish Xiphias gladius are ideal for fish patty production, offering high nutrition and other health benefits. Although red fish meat, including tuna, is added for cost-effectiveness, swordfish white meat is also used, as its aroma resembles that of market-sold beef patties. Here, we assessed the different blending ratios of tuna red meat and swordfish white meat (60:40, 40:60, 20:80, and 0:100) to find the optimal combination for fish patty production. Regarding color, the heated fish patties exhibited increased redness (a*) and yellowness (b*) compared with those of non-heated ones, with similar brightness (L*). The heated patties also scored higher concerning hardness, springiness, gumminess, and chewiness. A higher proportion of swordfish white meat resulted in a softer texture, particularly in patties with a ratio of 40% red meat to 60% white meat. Considering the results of the texture comparison analysis, it is recommended that the texture be improved by increasing the physical property "softness." Sensory evaluations revealed that the addition of white meat led to increased scores in terms of smell, beef taste, texture, and elasticity. These results suggest that swordfish white meat, with improved overall quality, is a suitable raw material for fish patties. Accordingly, the recommended ratio of 20% tuna red meat to 80% swordfish white meat is optimal for fish patty production.