• Korean Journal of Ecology and Environment
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• v.33 no.3 s.91
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• pp.304-310
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• 2000

Enclosure experiments to reduce the growth of Cyanophyceae were carried out using plants in Kyongan stream. Wet plants put into the enclosure at a rate of 2.5 g wet wt/l and at that time, the average concentration of chlorophyll a was ranged from 30 to $50\;{\mu}g/l$. The dominant species was Microcystis aeruginosa. Ginkgo, big cone pine and pine needles significantly inhibited the growth of Microcystis from the early days to the stages of log-Phase. Waterchestnut was the most inhibitory to the growth of Microcystis. Pine needles inhibited in 85% of the algal growth: ginkgo in 80%; big cone pine in 75%; waterchestnut in 78%; wildrice in 59%; and iris in 30%. At the treatment with 0.25 g dried plants/l, algae was declined at a rate of 90% by waterchestnut: 53% by pine needles. Phenolic compounds were purifled from decomposing big cone pine and waterchestnut.

• Fashion & Textile Research Journal
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• v.10 no.6
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• pp.1058-1063
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• 2008

The use of clothes dryers is increasing in Korea and throughout Asia, because of preference for the drum type washer dryer. Clothes dryers consume more energy than almost any other home appliance. This paper suggests efficient ways for drying laundry with condensing clothes drier. We dried cotton fabrics with the condensing clothes dryers and observed the energy input, temperature and RH of the dryer during the drying process. In the early stages of drying process, the air temperature inside the clothes dryer decreased and the RH and the drying time increased as the weight of fabrics increased. We found that it was important to consider the total weight of the fabrics that included heat-sensitive fibers. It took more than half the drying time and the energy input for a 2.5 kg load that it did for a 5 kg load. Therefore, drying larger one load was more efficient than divided smaller loads, because increasing the weight of the fabrics reduced the energy input per kg of drying clothes. The lower the initial moisture regains of the fabrics were, the lower the energy input and the drying time were. The energy input for spinning after washing was much less than that for drying in the dryer. Consequently, it is more efficient to reduce the moisture content of the clothes by lengthening the spinning time of the washer to reduce the energy consumption and the drying time. During the drying process opening the door twice for 30 seconds each time lowered the air temperature and the RH of the dryer, but did not affect the moisture regain of the fabrics, the drying time, and the energy input.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.330-331
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• 2011

희토류 이온이 첨가된 형광체는 조명, 정보 디스플레이, 태양 에너지 변환 소자에 응용 가능하기 때문에 상당한 주목을 받고 있다. 특히, 결정 입자의 형상과 크기는 산업체 응용에 있어서 중요한 변수 중의 하나이다. 구형의 형광체 입자는 형광층의 광학 및 기하학적 구조를 최적화 시킬 수 있고, 결정 입자의 크기는 양질의 코팅을 위해 필요한 결정 입자의 양에 영향을 미친다. 본 연구에서는, $YVO_4$ 모체 결정에 Eu 이온의 농도를 선택적으로 주입하여 발광 효율이 높은 적색 형광체를 합성하고자 한다. 형광체 분말 시료는 활성체인 Eu의 함량을 0.00, 0.05, 0.10, 0.15, 0.20 mol로 변화시키면서 고상 반응법을 사용하여 합성하였다. 볼밀링 작업을 수행한 후에, 60$^{\circ}C$에서 20시간 건조하였고, 잘게 갈아서 체로 걸러낸 다음에 세라믹 도가니에 넣고 전기로에서 서서히 온도를 승온시켜 500$^{\circ}C$에서 10시간 동안 하소를 실시한 후에 1,100$^{\circ}C$에서 5시간 동안 소결하였다. Eu 이온의 함량비를 변화시켜 합성한 $YVO_4$ : Eu 형광체 분말 시료의 발광 세기의 변화, 결정 구조와 표면 형상을 각각 PL과 PLE, XRD, FE-SEM 장치를 사용하여 측정한 결과들을 종합해 볼 때, Eu 이온의 비가 0.15 mol일때 발광 세기가 최대값을 나타냄을 알 수 있었으며, 더욱 Eu의 함량을 증가시키자 농도 억제 현상에 의하여 발광 세기는 급격히 감소함을 보였다. SEM으로 촬영한 결정 입자의 형상의 경우에, Eu 이온의 함량비가 증가함에 따라 결정 입자들이 더욱 조밀하게 구형에 가까운 형상을 나타냄을 관측할 수 있었다(Fig. 1). 형광체 분말의 형광 스펙트럼의 경우에, 619 nm에 주 피크를 갖는 적색 형광 스펙트럼들이 관측되었으며, Eu 이온의 함량비에 따라 형광 세기는 상당한 의존성을 나타내었다(Fig. 2). Eu 함량에 따른 결정입자의 크기, 형광 세기와 회절 피크의 반치폭 사이의 상관 관계를 제시하고자 한다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.108.1-108.1
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• 2012

높은 균일도의 대면적 OLED 조명을 만들기 위해서는 보조배선이 필요하다. 이 때 보조배선이 노출되면 보조배선에서 발생하는 누설전류로 인하여 디바이스가 효율적으로 구동이 되지 않는다. 그래서 누설전류를 막기 위하여 절연층을 사용하게 된다. 본 연구에서는 그라비아 오프셋 프린팅 방식으로 절연층을 형성 하였다. 그라비아 오프셋 프린팅 방식은 포토리소그래피 공법에 비해 공정이 간단하여 제작비용이 낮아지고, 친환경적인 이점이 있다. 절연층 재료로는 PVP 유기 절연체를 사용하였다. 이 PVP 유기 절연체는 PVP Poly-4-vinylphenol, Propylene glycol monomethyl ether acetate, 그리고 Poly(melamineco-formaldehyde) metylate 재료들을 적절한 비율로 혼합하여 제작하였다. 제작된 용액은 최대 1840cps의 점도를 가지고 있다. 이 PVP용액으로 인쇄 테스트를 진행하였다. 일반적으로 그라비아 오프셋 프린팅 방식에서는 고점도 재료가 사용되지만, 이 PVP용액은 낮은 점도에서도 프린팅이 잘 되는 것을 확인 할 수 있었다. 재료의 열처리는 $100^{\circ}C$에서 10분 건조 후 $200^{\circ}C$에서 15분의 큐어링을 진행하였다. 인쇄에 사용한 패턴의 선폭은 50um~100um로 구현하였으며, 약 120cps의 점도에서 선폭 및 해상도가 패턴과 가장 유사하게 나타났다. 인쇄 후의 절연층은 최종적으로 약 1um의 두께와 낮은 접촉각을 형성하였다. 누설전류는 전압 20V인가시 0.12pA/$cm^2$의 값을 가진다. 이 결과는 동일 두께의 스핀코팅과 비슷하였다. 우리는 이 결과값을 토대로 보조배선과 PVP 유기 절연층을 그라비아 오프셋 프린팅 방식으로 인쇄 한 OLED 조명을 제작하였다.

• Applied Chemistry for Engineering
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• v.7 no.4
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• pp.750-756
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• 1996

$TiO_2$ was dispersed in zeolite and glass filter by soaking them in isopropanol solution of titanium tetraisopropoxide and drying in the air, followed by calcination at $500^{\circ}C$. The analysis of chlorothalnoil was carried out by gas chromatograph with an electron capture detector. Chlorothalnoil was degraded photocatalytically over the matrix-supported $TiO_2$ efficiently and could be completely photodegraded after 3hrs. Production were 5.0ppm of $Cl^-$ for $TiO_2$ supported zeolite, 7.5ppm of $Cl^-$ for $TiO_2$ supported glass filter and 2.0ppm of $Cl^-$ for $TiO_2$ powder. But, $CN^-$ was lower than the detection limit irrespective of matrices.

• Journal of Food Hygiene and Safety
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• v.6 no.3
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• pp.127-131
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• 1991

${\alpha}-amylase\;and\;{\beta}-amylase$ were extracted from barley and wheat malt, respectively. Their kinetic parameters on gultinous and nonglutinous rice starch were examined. During the germination of barley and wheat, the increaments of ATP levels were significant after 2-day germination and the levels were reduced after 5 days. The dry weights were decreased after 3 days. The activities of amylases were the highest for 6 days in the barley and wheat malt. As for ${\alpha}-amylase$, that the substrate affinity of barley malt on nonglutionous rice starch was greater than other cases. The $V_{max}$ values of ${\alpha}-amylase$ from wheat malt on either type of rice starch showed high, and from barley malt on nonglutinous rice starch were high. The ${\beta}-amylse$ from barley malt showed high substrate affinity on the glutinous rice starch, and $V_{max}$ value of the enzyme from wheat malt on glutinous rice starch was higher than other. The substrate efficiency ($V_{max}/K_{m}$) of ${\beta}-amylase$ on the non glutinous rice strach was better than other cases.

• Journal of Food Hygiene and Safety
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• v.35 no.4
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• pp.304-311
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• 2020

Galacto-oligosaccharides (GOS) are prebiotics that have a beneficial effect on human health by promoting the growth of probiotic bacteria in the gut, in addition to having various applications in the food industry. GOS are generally produced from lactose in a reaction catalyzed by β-galactosidase. Synthesis of GOS from whey permeate (WP) (ultrafiltration of whey, concentrated then spray dried) using surface engineered β-galactosidase in Pichia pastoris (P. pastoris) is a novel method to convert waste into a valuable product. Cell-surface display is the expression of peptides and proteins on the surface of living cells by fusing them to functional components of cells. Surface engineered cells have many potential uses. The Flo1p flocculation functional domain, thought to be located near the N terminus, recognizes and adheres non-covalently to cell-wall components such as α-mannan carbohydrates, causing reversible aggregation of cells into flocs.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.1
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• pp.41-47
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• 2012

Recently, due to the rapid rise of the international oil price, the burden of fuel oil expense is relatively increasing in a ship. And the international restriction of the greenhouse gas which was generated from the burning of fuel oil is also rapidly strengthened. Therefore, to reduce the greenhouse gas and fuel oil consumption, many shipping company adopted the low speed navigation and it was focused on the improvement of fuel consumption efficiency and the usage of alternative energy in the marine engine development field. In this paper, the fuel oil consumption according to the ship's speed was measured in the actual seas and analyzed the shop test results in the shipyard and the ship navigation data from the abstract log. And then it was proposed that the ship's economic speed was 14~15kts and the optimum rpm was 140~150 in specific sea conditions.

• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.133-138
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• 2006

In order to enhance the components of bioactive ginsenosides and the manufacturing process of red ginseng, we developed the simplified method for red ginseng production. The red ginseng extract was prepared from red ginseng produced with the simplified method, and the production rate of extract ($62^{\circ}$ brix) was more than 60%. The ginsenosides of red ginseng were purified and analyzed by HPLC using ELSD. Ginsenoside-$Rg_3,\;Rh_2$ and $Rh_1$, specific artifacts found only in red ginseng, were detected by HPLC. Especially, contents of ginsenoside-$Rg_3$ and Rh1 were detected high than two times in red ginseng produced the simplified method compared to commercial products.

• Applied Biological Chemistry
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• v.50 no.2
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• pp.116-120
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• 2007

Seasoned and dried squid slice (SDSS) was prepared with surimi and squid, and investigated on the food component characteristics. The moisture and water activity of the SDSS slightly increased with increasing addition ratio of squid. According to the increase of addition ratio of squid, sensory scores of SDSS decreased in the color, whereas increased in the taste. There was, however, no difference in sensory flavor and texture between SDSS prepared with various ratios of squid. The results of physical properties and sensory evaluation suggested that the desirable addition ratio of squid was more than 70% based on the mix for preparing SDSS. There was no difference in total amino acid content between seasoned and dried slices with, which was prepared by a ratio of squid(70): surimi (30), and without squid. The major amino acids of SDSS were glutamic acid, leucine, lysine and threonine. The calcium and phosphorus contents of SDSS were 85.9 mg/100g and 458.3 mg/100g, respectively. The total free amino acid content and taste value of SDSS were 3,1991mg/100g and 402.00, respectively. The taste values of SDSS suggested that the major taste-active compounds were glutamic acid and aspartic acid.