• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1128-1133
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• 1998

Extrusion cooking treatment was compared with autoclaving/cooling treatment for formation of enzyme resistant starch of high amylose corn starch (HACS). Effects of barrel temperature $(100^{\circ}C,\;120^{\circ}C,\;140^{\circ}C)$ and feed moisture content (25%, 35%, 45%) on extrusion processing in a co-rotating twin-screw extruder under fixed screw speed (100 rpm) were investigated by measuring enzyme resistant starch (RS) yield. RS yield were estimated by in-vitro pancreatin digestion method and enzymatic-gravimetric method using termamyl. Barrel temperature and yield of RS were negatively correlated and feed moisture content and yield of RS was positively correlated as determined by in-vitro pancreatin method. The highest yield (38.4%) of RS was obtained from HACS extrudate processed at the barrel temperature of $100^{\circ}C$ and the feed moisture content of 45%, while the yield of RS by 5 times of autoclaving/cooling was 25%. The yield of RS by in vitro pancreatin digestion method was 20.7% with high amylose corn starch and 8.2% with ordinary corn starch (CS), respectively, under the same extrusion condition (barrel temperature $120^{\circ}C$, feed moisture content 35%). At the same condition, the yields of RS by enzyme-gravimetric method were 14.6% with HACS and 6.8% with CS, respectively. The yield of RS increased during the storage at $4^{\circ}C$ for 4 weeks and the highest yield (60%) was obtained by the storage of HACS extrudates extruded at $100^{\circ}C$ and 45% feed moisture content.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.278-285
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• 2016

The bifunctional PheA protein, having chorismate mutase and prephenate dehydratase (CMPD) activities, is one of the key regulatory enzymes in the aromatic amino acid biosynthesis in Escherichia coli, and is negatively regulated by an end-product, phenyalanine. Therefore, PheA protein has been thought as useful for protein engineering to utilize mass production of essential amino acid phenylalanine. To obtain feedback resistant PheA protein against phenylalanine, we mutated by using random mutagenesis, extensively screened, and obtained $pheA^{FBR}$ gene encoding a feedback resistant PheA protein. The mutant PheA protein contains substitution of Leu to Phe at the position of 118, displaying that higher affinity (about $290{\mu}M$) for prephenate in comparison with that (about $850{\mu}M$) of wild type PheA protein. Kinetic analysis showed that the saturation curve of $PheA^{FBR}$ against phenyalanine is hyperbolic rather than that of $PheA^{WT}$, which is sigmoidal, indicating that the L118F mutant enzyme has no cooperative effects in prephenate binding in the presence of phenylalanine. In vitro enzymatic assay showed that the mutant protein exhibited increased activity by above 3.5 folds compared to the wild type enzyme. Moreover, L118F mutant protein appeared insensitive to feedback inhibition with keeping 40% of enzymatic activity even in the presence of 10 mM phenylalanine at which the activity of wild type $PheA^{WT}$ was not observed. The substitution of Leu to Phe in CMPD may induce significant conformational change for this enzyme to acquire feedback resistance to end-product of the pathway by modulating kinetic properties.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.34-42
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• 2016

In order to prepare for the type approval test for the United States Coast Guard (USCG) Phase-II of Ballast Water Treatment System (BWTS), a phytoplankton mass culture was conducted in a mesocosm enclosure. We evaluated the response of the phytoplankton community after nutrient addition (+N, +P, and +NP) and investigated the development of the species with increasing culture time. After nutrient dosing, the phytoplankton population significantly (p < 0.05) increased from day 1 to day 3, depending on the nutrient treatments In particular, the specific growth rate of the phytoplankton community in the case of +NP treatment and + N treatment were estimated to be $2.47d^{-1}$ and $1.98d^{-1}$, respectively. The phytoplankton population density in the case of + NP treatment was approximately 50 times higher than that of the control group, suggesting that these treatments could be useful for mass culturing phytoplankton (> 75% of natural community) for the approval regulation of USCG Phase-II. In the phytoplankton community of the mesocosm, Pseudo-nitzchia spp. dominated in the logarithmic growth phase. The cell density decreased significantly (p < 0.05) with increasing time, coinciding with the nutrient limitation. At that time, the dominance of Pseudo-nitzchia spp. shifted to that of Cylindrotheca closterium. Therefore, the optimum nutrient concentration ($N:30{\mu}M$, $P:3{\mu}M$) and reasonable harvesting time (after 3 days in summer) found in this study for the mass culturing of phytoplankton may be helpful to meet the USCG Phase-II biological criteria to be used in BWTS.

• Korean Journal of Agricultural Science
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• v.20 no.1
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• pp.25-33
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• 1993

This study was conducted to obtain necessary informations for improving of wildlife rearing management. The data was gathered by surveying with questionaire. One hundred and eighty farmers which was 60 of deer and pheasant, 30 of wild boar and fox rearing farmers respectively were investigated during the summer in 1992. The results of this study are as follows : 1. Most of managers considered their rearing as a side job but agriculture was appointed as a main job from most of them except wild boar managers. 2. The major cost items were breeding stock and feeding which occupied over than half. 3. The yearly profit was the highest in deer(25.5%) but the lowest in wild boar(10.3%). 4. The break-even point was the highest in wild boar(24 mil. won) but the lowest in pheasant(7.3 mil. won). 5. The optimum sales scale for a year was deer(11 heads), Pheasant(1,027 heads), Wild boar(69 heads) and Fox (102 heads).

• Korean Journal of Optics and Photonics
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• v.27 no.1
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• pp.1-17
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• 2016

Over the past two decades, fiber-based lasers have made remarkable progress, now having reached power levels exceeding kilowatts and drawing a huge amount of attention from academy and industry as a replacement technology for bulk lasers. In this paper we review the significant factors that have led to the progress of fiber lasers, such as gain-fiber regimes based on ytterbium-doped silica, optical pumping schemes through the combination of laser diodes and double-clad fiber geometries, and tandem schemes for minimizing quantum defects. Furthermore, we discuss various power-limitation issues that are expected to incur with respect to the ultimate power scaling of fiber lasers, such as efficiency degradation, thermal hazard, and system-instability growth in fiber lasers, and various relevant methods to alleviate the aforementioned issues. This discussion includes fiber nonlinear effects, fiber damage, and modal-instability issues, which become more significant as the power level is scaled up. In addition, we also review beam-combining techniques, which are currently receiving a lot of attention as an alternative solution to the power-scaling limitation of high-power fiber lasers. In particular, we focus more on the discussion of the schematics of a spectral beam-combining system and their individual requirements. Finally, we discuss prospects for the future development of fiber laser technologies, for them to leap forward from where they are now, and to continue to advance in terms of their power scalability.

• Korean Journal of Agricultural Science
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• v.12 no.1
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• pp.75-85
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• 1985

This study is intended to find out the influence of Lignosulfonic Acid Type Admixture on compressive, tensile, flexural strength and dispersing action of mortar, and fixation of by-product of pulp industry. 1. The more Pozzolith-84 is added, the larger flow value is. The admixture of lignosulfonic acid type adhere to cement particles and the surface potential of particles is generated. On account of the repulsion among the cement particles, they are dispersed and the mortar get workable, so the production cost of precast product is curtailed and the amount of cement is reduced in a certain workability of mortar. 2. The strength of mortar is greater than plain mortar when P/C added is 0.2 and 0.4%. As time passed the potential energy is reduced and the distance of particles which lignosulfonic acid adhered to get near according as the amount of adhesion is increased. The setting and hardening reaction of morter is occurred in close state, so the strength of mortar is increased a little. The strength of mortar is less than plain mortar when amount P/C added is 0.8%. Pozzolith-84 is mainly composed of lignosulfonic acid and lignin does not influence the hardening of mortar, therefore the remained $SO_3$, $SO_3H$ are the reason of decrease of strength. 3. There is high significance between specific gravity and compressive strength. The larger specific gravity is, the more compressive strength is increased. There is high significance between 7 day's strength and 28 day's strength. The larger compressive strength is, the more tensile and flexural strength are increased. 4. Since Pozzolith-84 is a by-product of pulp industry, by using the Pozzolith-84 admixture the concreate quality is improved. The water pollusion is reduced according to fix by-products in concrete structure.

• Korean Journal of Veterinary Pathology
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• v.6 no.2
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• pp.101-104
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• 2002

닭의 전신장기에 림프종 발생이 특정인 마렉병(Marek's disease; MD)은 림프구성 백혈병(Lymphoid leukosis; LL)과 병리학적 소견이 매우 유사하여 감별이 요구된다. 마렉병 바이러스(Marek's disease virus; MDV)는 질병초기에서 후기에 이르기까지 모낭상피세포에 세포용해성 감염을 지속적으로 일으킨다. 세포용해성 감염이 있는 모낭상피세포는 변성내지 괴사되어 있고 핵내봉입체가 관찰된다. 또한 세포용해성 감염이 있는 모낭상피세포 바로 밑의 진피와 깃털 수질(feather pulp)내의 혈관주위에 림프구 침윤이 관찰된다. 이러한 피부병변은 MD의 특징적인 병변들로서 LL과 감별할 수 있는 결정적인 단서이다. 본 고에서는 MD에 관한 전반적인 것과 특히 MD 진단을 위한 피부병변의 유용성에 대해서 자세히 논하고자 한다. 양계산업에 문제를 야기하고 있는 림프구 증식성 종양은 크게 마렉병(Marek’s disease; MD)과 백혈병(Lymphoid leukosis; LL)이 있다. 이들 질환의 원인체들이 분리되기 전까지는 이들 질병들은 발병부위에 따라 질병명을 붙였다. 즉, 내부장기냐 근육에 발생한 것은 visceral lymphomatosis, 피부에 발생한 것은 skin leukosis, 말초신경의 병변은 poly­n neuritis, neuritis, neurolymphomatosis gallinarum, range paralyis로 불리었다. 또한 눈에 발생한 것은 blindness, gray eye, iritis, uveitis, ocular lymphomatosis라고 불리었다. 1961년에 Biggs는 이러한 림프구 증식성 질병을 마렉병과 백혈병 으로 분류하자는 제안을 하였고, 드디어 1960년대 중반에 림프구 증식성 병변 중의 일부에서 herpesvirus가 분리되어서 Biggs가 제안한 병명인 마렉병을 본격적으로 사용하게 되었다. MD는 마렉병 바이러스(Marek’s disease virus; MDV)가 원 인제로서 닭에 전염성이 강한 염증성에서 종양성의 병변을 내부장기, 피부, 근육, 안구, 중추신경계, 말초신경계 등에 일 으킨다. MDV는 림프종을 유발하기 때문에 처음에는 사람에서 림프종을 유발하는 Epstein-Bar 바이러스와 관련이 있을 것으로 생각되어 gamma-herpesvirus로 분류되었지만, MDV의 게놈 구조와 세포배양에서 빠르게 성장한다는 점 때문에 지금은 alpha-herpesvirus로 재분류 되었다. MDV는 바이러스 중화시험과 한천 겔 침강법에 의해서 3개의 혈청형으로 분류 된다. 혈청형 1은 종양원성 바이러스와 종양원성 바이러스의 계대배양에 의한 약독주가 있다. 혈청형 2는 자연적으로 발 생하는 비종양원성 닭의 MDV이고, 혈정형 3은 바종양원성 칠면조 herpesvirus (HVT)이다. 림프종을 유발하는 MDV 감염은 4개의 과정, 즉 초기 세포용해성 감염, 잠복감염, 후기 세포용해성 감염, 마지막으로 종양화로 나눌 수 있다. 감염의 경로를 보면, 흡입된 MDV는 폐의 대식세포에 감염한 후 전선 장기로 MDV를 전파 시킨다. 특히, 흉선, F냥, 비장 등의 림프구에 초기 세포용해성 감염을 일으키는데, B 림프구가 주로 감염된다. 세포용해성 감염음 방어하기 위해 몰려든 T 림프구가 활성화가 되면, T 세포도 감염되게 된다. 잠복감염은 여러 가지 사이토카인 등 을 포함한 면역반응에 의해서 일어나며, 이 때 잠복감염된 세포는 특히 혈중의 T 세포라고 한다. 혈중 MDV 감염세포 는 피부 모낭상피세포, 선장 등 상피세포 유래의 조직에 MDV를 전파 시켜서 이들 조직에서 후기 세포용해성 감염이 일어나게 한다. 후기 세포용해성 감염을 유발하는 것은 이러한 MDV가 감염된 혈중 림프구라는 증거는 혈중의 세포 외에는 감염성 바이러스가 없기 때문이다. 후기 세포용해성 감염이 있는 후 육안적 혹은 현미경적으로 검출이 가능한 림프종이 여러 장기에서 관찰된다. MDV가 감염되면 병변 발생부위에 따라서 다양한 임상증상이 발생한다. 즉 내부장기에 병변이 있을 경우는 침울, 체중감소, 산란율 저하 등이 발생하며, 신경계는 발생부위별 신경증상이 일어난다. 이러한 장기나 조직에서는 육안적으로 백색에서 회백색의 종양성 병변이 관찰된다. 말초신경에 병변이 발생한 경우에는 특히 좌골신경 및 신경총에서 호발하는데, 이들 조직은 편측성 혹은 양측성으로 종창되어 있다. 안구는 간혹 육안적으로 식별이 가능한 홍채 퇴색 및 증식 병변이 관찰된다. 피부형 MD는 특히 육용계에서 문제가 되고 있으며, 산란계의 내장형 MD가 발생한 경우에도 피부를 자세히 설펴보면 피부형 MD를 간혹 관찰할 수 있다. 피부형 MD는 모낭주위에 원형의 결절형태로 발생하는데, 이들 병변이 커지면 바로 옆의 병변과 융합 되어 큰 결절을 형성하기도 한다. (중략)

• Journal of Life Science
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• v.23 no.4
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• pp.501-509
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• 2013

Formaldehyde (FA) is widely used in industries, and it is an indoor and outdoor pollutant. Exposure to FA may cause inflammation and respiratory oxidative stress. Studies have demonstrated that FA can cause cancer in animal models. During the regeneration process of injured starfish (Asterina pectinifera), several changes have been observed in the expression of cytokines. In particular, higher TGF-${\beta}1$ expression has been detected in arm cut starfish extract after eight days. The current study was designed to elucidate the in-vitro and the in-vivo pharmacological effects of starfish extract on FA exposure. We investigated the protective effects of intact starfish extract and arm cut starfish extract on an IMR-90 cell line and on mouse lung injury in response to FA exposure. In the presence of FA, inhalation of the arm cut starfish extract was associated with more promising cell proliferation, TNF-${\alpha}$, NF-${\kappa}B$ decrement, and $I{\kappa}-B{\alpha}$ increment. In the experimental group, the pulmonary structure of the arm cut starfish extract-treated group in the presence of FA exposure was similar to the control group, whereas the FA exposure group showed damage to the pulmonary structure. Moreover, the arm cut starfish extracts was more effective than the intact starfish extracts in terms of the expression of TNF-${\alpha}$, NF-${\kappa}B$, $I{\kappa}-B{\alpha}$, and surfactant protein A. The results obtained in this study demonstrate that arm cut starfish extracts are more effective in protecting pulmonary structure and function against FA exposure than intact starfish extracts.

• Cartoon and Animation Studies
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• s.28
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• pp.235-263
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• 2012

Regarding the theme park business as an area of cultural content business, this study focuses on the trend of pursuing indoor theme parks as a small-scale small capital strategy escaped from the existing approach oriented to large-scale outdoor complex theme parks. It is because although existing large-scale outdoor complex theme parks require the capital with the scale of hundreds of billion won and also high-level technique and the latest operational know-how that they have a great barrier for new entry as well as enormous risk, the rent indoor theme parks succeed in market entry with efficient risk management and flexible market strategies. Thereupon, this study examines the current status of the children's indoor theme park market with Korean characters as their theme as a new market among the indoor theme parks and also investigates the market strategies of this market in the two aspects of expansion: the expansion of Korean characters' property value and the expansion of the local theme park market. For that, this article reviewed the advanced researches on theme parks and divided the types of theme parks existing in Korea with the criteria of classification by space and theme or classification by main users. Also, among the children's indoor theme parks with Korean characters as their theme, this study visited five ones located in the capital area to examine the current status. And about two located in the capital area and also four in the local area, the current data were received from the persons in charge of the companies for analysis. Also, with the subjects of spectators visiting the 'DIBO VILLAGE, Cheonggye-cheon' newly opened on April 25th, 2012, the research on satisfaction was conducted for analysis. Through that, this study analyzed the structure of the existing children's indoor theme park business with Korean characters as their theme and suggested the ground to analyze the effectiveness of market strategies being implemented. It is expected that this study will establish the clues of systematic and profound discussion for the indoor theme park business that can be said to be the niche market of the theme park business and allow the small-scale areal indoor theme parks to be examined as a significant business model for the local theme park industry. In the aspect of character business as well, it is expected that this will give a chance to establish a new model of spatial storytelling expansion in terms of the property value of Korean animation characters.

• Journal of the Microelectronics and Packaging Society
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• v.19 no.1
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• pp.61-66
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• 2012

Chemical Mechanical Planarization (CMP) is a polishing process used in the microelectronic fabrication industries to achieve a globally planar wafer surface for the manufacturing of integrated circuits. Pad conditioning plays an important role in the CMP process to maintain a material removal rate (MRR) and its uniformity. For metal CMP process, highly acidic slurry containing strong oxidizer is being used. It would affect the conditioner surface which normally made of metal such as Nickel and its alloy. If conditioner surface is corroded, diamonds on the conditioner surface would be fallen out from the surface. Because of this phenomenon, not only life time of conditioners is decreased, but also more scratches are generated. To protect the conditioners from corrosion, thin organic film deposition on the metal surface is suggested without requiring current conditioner manufacturing process. To prepare the anti-corrosion film on metal conditioner surface, vapor SAM (self-assembled monolayer) and FC (Fluorocarbon) -CVD (SRN-504, Sorona, Korea) films were prepared on both nickel and nickel alloy surfaces. Vapor SAM method was used for SAM deposition using both Dodecanethiol (DT) and Perfluoroctyltrichloro silane (FOTS). FC films were prepared in different thickness of 10 nm, 50 nm and 100 nm on conditioner surfaces. Electrochemical analysis such as potentiodynamic polarization and impedance, and contact angle measurements were carried out to evaluate the coating characteristics. Impedance data was analyzed by an electrical equivalent circuit model. The observed contact angle is higher than 90o after thin film deposition, which confirms that the coatings deposited on the surfaces are densely packed. The results of potentiodynamic polarization and the impedance show that modified surfaces have better performance than bare metal surfaces which could be applied to increase the life time and reliability of conditioner during W CMP.