• 마이크로전자및패키징학회지
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• 제31권1호
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• pp.43-48
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• 2024

SrTiO₃ (STO) 기판 위에 성장된 LaAlO₃ (LAO) 계면에서의 이차원 전자 가스 (2DEG)의 발견은 복합 산화물 이종 구조를 기반으로 한 혁신적인 전자소자 연구의 장을 제공함으로써 많은 관심을 받아왔다. 하지만 LAO 박막을 형성하기 위하여, 일반적으로 물리기상증착법(PVD)을 기반으로 하는 펄스 레이저 증착 (PLD) 등의 기법이 주로 사용되어 왔으나, 공정 비용이 많이 들며 LAO 내 La와 Al의 정밀한 조성 제어가 어려운 단점이 있다. 본 연구에서는 PVD에 비해 경제적인 대안인 용액 기반 공정을 사용하여 LAO 박막을 제조하였고, 그 전기적 특성을 평가하였다. LAO 전구체 용액의 농도를 다르게 하여 LAO의 두께를 2에서 65 nm까지 변화시켰으며, 각 두께에 따른 면저항 및 캐리어 농도를 도출하였다. 진공 열처리 후 형성된 전도성 채널의 면저항 값은 0.015에서 0.020 Ω·sq^-1 범위로 나타났으며, 이러한 결과는 기존 문헌과 비교하였을 때 LAO와 STO 사이의 계면에서의 전자 이동뿐만 아니라 계면으로부터 떨어져 있는 STO bulk 영역으로의 전자 전도를 시사한다. 본 연구 결과는 용액 기반 공정을 통한 2DEG 형성 및 제어를 구현한 것으로, 공정 비용을 줄이고 전자 소자 제조에서 보다 광범위한 응용 가능성을 제시한다는 점에 그 의의가 있다.

• 한국식품저장유통학회지
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• 제15권2호
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• pp.169-173
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• 2008

Bacillus subtilis subsp. subtilis는 녹조류인 매생이에서 분리되는 총 생균주 중에서 90%를 차지하고 있다. Bacillus subtilis subsp. subtilis에 대한 항미생물 활성을 50 ppm 수준에서 과산화수소와 NaOCl의 각각의 처리가 전해수 (50 ppm) 보다 유의적 수준에서 높았다. 매생이를 50 ppm의 과산화수소, NaOCl 그리고 전해수로 처리한 후 $4^{\circ}C$에서 30일간 일반포장 또는 진공포장에 의한 저장실험 후 총균수를 측정한 결과 과산화수소와 NaOCl를 처리시에는 초기 균수보다 $1.8{\pm}0.4$ log cfu/g 감소함을 보였고 전해수를 처리시에는 $1.7{\pm}0.5$ log cfu/g의 감소를 보였으며, 포장방법에 의한 총균수의 감소에는 영향이 없었다. 매생이를 50ppm의 과산화수수 NaOCl 그리고 전해수에 처리한 후 $4^{\circ}C$에서 20일간 저장실험 후 조직감 (경도)를 측정한 결과, 과산화수소와 NaOCl를 처리시에는 초기 경도 ($7.9{\times}10^6dyne/cm^2$)보다 $1.6{\pm}0.1$배 감소하였으나, 전해수 처리는 $2.1{\pm}0.1$배의 경도의 감소를 보였다. 결론적으로, 본 연구에서는 Bacillus subtilis subsp. subtilis 균주가 일반포장과 진공 포장된 제품에서 우점종으로 나타났고, 매생이의 장기 저온 저장 시 중요 관리요인으로 나타났으며, 이를 제어하는데 과산화수소와 NaOCl이 전해수보다 효율성이 높았다.

• 한국축산식품학회지
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• 제36권6호
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• pp.752-759
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• 2016

The objective of this study was to describe the growth patterns of Staphylococcus aureus in combinations of NaCl and $NaNO_2$, using a probabilistic model. A mixture of S. aureus strains (NCCP10826, ATCC13565, ATCC14458, ATCC23235, and ATCC27664) was inoculated into nutrient broth plus NaCl (0, 0.25, 0.5, 0.75, 1, 1.25, 1.5, and 1.75%) and $NaNO_2$ (0, 15, 30, 45, 60, 75, 90, 105, and 120 ppm). The samples were then incubated at 4, 7, 10, 12 and $15^{\circ}C$ for up to 60 d under aerobic or vacuum conditions. Growth responses [growth (1) or no growth (0)] were then determined every 24 h by turbidity, and analyzed to select significant parameters (p<0.05) by a stepwise selection method, resulting in a probabilistic model. The developed models were then validated with observed growth responses. S. aureus growth was observed only under aerobic storage at $10-15^{\circ}C$. At $10-15^{\circ}C$, NaCl and $NaNO_2$ did not inhibit S. aureus growth at less than 1.25% NaCl. Concentration dependency was observed for NaCl at more than 1.25%, but not for $NaNO_2$. The concordance percentage between observed and predicted growth data was approximately 93.86%. This result indicates that S. aureus growth can be inhibited in vacuum packaging and even aerobic storage below $10^{\circ}C$. Furthermore, $NaNO_2$ does not effectively inhibit S. aureus growth.

• 한국자원식물학회지
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• 제27권1호
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• pp.72-79
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• 2014

본 연구는 마찰과 칼날 박피방식과 저장온도에 따른 박피밤의 품질 변화를 조사하기 위하여 수행되었다. 박피밤의 중량감소율은 저장기간 동안 모든 처리구에서 관찰되었으며, 박피방식에 따른 차이는 관찰할 수 없었다. 그러나 박피밤의 수분함량은 모든 처리구에서 저장기간에 따라 감소하는 경향을 보였는데, 마찰박피밤이 모든 처리구에서 칼날박피밤 보다 수분함량이 높았다. 박피밤 색도의 경우 a, b, ${\Delta}E$값은 모든 처리구에서 저장기간 동안 증가한 반면, L값은 저장기간 동안 감소하였다. 다만, 마찰 박피밤의 갈변정도가 칼날 박피밤보다 높게 나타났다. 과육경도는 마찰박피와 칼날박피에서 $-1^{\circ}C$ 처리구의 밤이 가장 높았으며, 당함량은 저장직후부터 감소하였으나 저장 24일째부터 당함량이 증가하는 경향을 나타내었다. 박피밤의 식미와 식감은 모든 처리구에서 저장기간이 늘어날수록 감소하였으며, 저장 15일 이후로 급격하게 감소하는 경향을 보였다. 따라서 위의 결과를 볼 때 마찰과 칼날 밤피밤의 품질차이는 나타나지 않았다. 하지만 $4^{\circ}C$와 $2^{\circ}C$에서 저장한 박피밤은 15일 이후 품질이 급격하게 감소한 반면 $-1^{\circ}C$에서 저장한 박피밤은 천천히 감소하여 품질을 유지하는데 효과적이었다. 또한 마찰 박피밤의 갈변을 줄일 수 있으면 고품질의 우수한 박피밤이 생산될 수 있을 것이다.

• ETRI Journal
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• 제24권4호
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• pp.290-298
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• 2002

We present, for the first time, a prototype active-matrix field emission display (AMFED) in which an amorphous silicon thin-film transistor (a-Si TFT) and a molybdenum-tip field emitter array (Mo-tip FEA) were monolithically integrated on a glass substrate for a novel active-matrix cathode (AMC) plate. The fabricated AMFED showed good display images with a low-voltage scan and data signals irrespective of a high voltage for field emissions. We introduced a light shield layer of metal into our AMC to reduce the photo leakage and back channel currents of the a-Si TFT. We designed the light shield to act as a focusing grid to focus emitted electron beams from the AMC onto the corresponding anode pixel. The thin film depositions in the a-Si TFTs were performed at a high temperature of above 360°C to guarantee the vacuum packaging of the AMC and anode plates. We also developed a novel wet etching process for $n^+-doped$ a-Si etching with high etch selectivity to intrinsic a-Si and used it in the fabrication of an inverted stagger TFT with a very thin active layer. The developed a-Si TFTs performed well enough to be used as control devices for AMCs. The gate bias of the a-Si TFTs well controlled the field emission currents of the AMC plates. The AMFED with these AMC plates showed low-voltage matrix addressing, good stability and reliability of field emission, and good light emissions from the anode plate with phosphors.

• Fisheries and Aquatic Sciences
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• 제15권4호
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• pp.265-273
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• 2012

The effects of processing and frozen storage conditions on the quality of anchovy Engraulis japonica fried surimi gels were investigated. Protein content decreased after surimi gel processing from 19.6% (raw meat) to 12.1% (kamaboko) due to the added ingredients and change in water content. Lipid content decreased from 2.8% (raw meat) to 1.3% in minced and 0.5% in surimi, but fried kamaboko showed a 6.9 % lipid level. Thiobarbituric acid values and thiobarbituric acid reactive substances levels were highest in kamaboko samples, 89.5 and 1.9 mg/g solid, and increased gradually with storage time to 101.8 and 4.6 mg/g solid, respectively. In vitro protein digestibility increased from 79.2% in raw anchovy to 88.5% in kamaboko samples. Levels of trypsin inhibitor decreased gradually with processing and during storage time from 2.43 in raw anchovy to 0.31 mg/g solid in the kamaboko sample after 60 days of frozen storage. No noticeable changes in total essential amino acid was observed during processing conditions. Computed protein efficiency ratio for kamaboko was highest (2.59) compared with whole anchovy (1.96), minced (1.94) and surimi (2.50). Fresh fried anchovy kamaboko showed similar values of hardness, springiness, gumminess and chewiness to commercial surimi gel, but a higher values were seen for fracturability and adhesiveness, and lower values for cohesiveness and resilience. The frozen and thawed anchovy kamaboko showed higher values for all of these rheological parameters compared with fresh and commercial kamaboko. Anchovy kamaboko showed the lowest lightness (62.9) and redness (0.16) and similar yellowness (11.9) compared with commercial kamaboko. Frozen storage and vacuum packaging were effective maintaining the shelf life of anchovy kamaboko within 30 days, but were not effective after 45 days due to fat oxidation.

• Journal of Welding and Joining
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• 제13권3호
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• pp.134-146
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• 1995

Aluminium nitride(AlN) is currently under investigation as potential candidate for replacing alumium oxide(Al$_{2}$ $O_{3}$) as a substrate material for for electronic circuit packaging. Brazing of aluminium nitride(AlN) to Cu with Ag base active alloy containing Ti has been investigated in vacuum. Binary Ag$_{98}$ $Ti_{2}$(AT) and ternary At-1wt.%Al(ATA), AT-1wt.%Ni(ATN), AT-1wt.% Mn(ATM) alloys showed good wettability to AlN and led to the development of strong bond between brate alloy and AlN ceramic. The reaction between AlN and the melted brazing alloys resulted in the formation of continuous TiN layers at the AlN side iterface. This reaction layer was found to increase by increase by increasing brazing time and temperature for all filler metals. The bond strength, measured by 4-point bend test, was increased with bonding temperature and showed maximum value and then decreased with temperature. It might be concluded that optimum thickness of the reaction layer was existed for maximum bond strength. The joint brazed at 900.deg.C for 1800sec using binary AT alloy fractured at the maximum load of 35kgf which is the highest value measured in this work. The failure of this joint was initiated at the interface between AlN and TiN layer and then proceeded alternately through the interior of the reaction layer and AlN ceramic itself.

• 생명과학회지
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• 제9권1호
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• pp.44-49
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• 1999

품질이 양호한 참가자미 조미 반건조제품을 제조하기 위한 기초자료를 얻기 위하여, 참가자미를 조미 반건조한 후 나일론＋폴리에틸렌+선형 저밀도폴리에틸렌 (0.0l5/0.045/0.040 mm)의 적층필름으로 진공포장하여 각각 빙결점 동결저장 (-3$\pm$$0.5^{\circ}C$) 및 냉장 (3$\pm$$0.5^{\circ}C$)하면서 저장중의 품질변화를 검토하였다. 참가자미 반건조제품의 제조를 위한 가장 적합한 냉풍 건조온도 및 시간은 상대습도 50$\pm$5$\%$ 및 풍속 2 m/sec의 조건하에서 각각$20^{\circ}C$ 및 4시간이었으며, 진공포장한 제품의 저장수명은 빙결점 동결저장 (-3$\pm$$0.5^{\circ}C$) 시 35일이었고 냉장 (3 $\pm$$0.5^{\circ}C$) 시 16일이었다.

• Journal of Plant Biotechnology
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• 제30권4호
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• pp.369-373
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• 2003

In spite of potential benefits of anther culture, low productivity of plant regeneration in some genotypes; e.g. tonsil and indica rice, is one of the major obstacles for practical use of anther culture. This study was conducted to improve cold shock method and carbohydrate source for increasing the efficiency of anther culture in rice. The most common carbon source, sucrose was replaced to maltose, which has two molecules of glucose. Maltose increased callus induction 1.4-to 1.8-fold higher in japonica rice, 3.2-to 11.6-fold in tongil types and 2.7-fold in indica rice IR50. Callus induction was increased from 0.2％ to 12.5％ in maltose medium compared to the medium supplemented with sucrose plus glucose in indica rice "Tetep". A simple procedure of vacuum packaging of panicles during cold shock treatment prolonged not only anther viability more than 15 days but also increased callus induction more than 2-fold compared to open-air storage (conventional method). Combining of above two methods, callus induction was increased 28 to 56％ in japonica, 13 to 33％ in tonsil type and 12 to 31％ in indica rice. Plant regeneration was increased 14 to 35％ in japonica, 10 to 20％ in tonsil and 4 to 15％ in indica rice, respectively.

• 한국축산식품학회지
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• 제31권2호
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• pp.200-206
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• 2011

Off-flavor and lipid oxidation are possible defects of irradiated bulgogi. This study compared the effects of several physicochemical treatments on microbial safety, volatiles, lipid oxidation, and sensory properties of irradiated beef bulgogi. Samples were separately irradiated with 20 kGy after each treatment such as packaging (aerobic and vacuum), antioxidants (vitamin C + ${\alpha}$-tocopherol (0.0 and 1.0%, w/w)), charcoal teabags (0 and 0.5%), or different temperatures (room temperature, -20, and -70$^{\circ}C$). No bacterial growth was observed (p<0.05) after irradiation of more than 20 kGy during storage at $35^{\circ}C$. Volatiles created by irradiating bulgogi were toluene, heptane, and 1,3-bis(1,1-dimethylethyl)benzene. Irradiation offflavor, lipid oxidation, and deterioration of sensory quality induced by irradiation were effectively reduced (p<0.05) by all physico-chemical treatments tested.