바이오의약품 시장이 성장함에 따라 분리정제공정의 연구를 통해 비용 절감을 위한 연구가 활발히 진행되고 있 다. 본 연구에서는 새로운 정용여과 장치를 개발하여 바이오의약품 제조 공정에서의 완충액 교환 성능 평가를 수행하였다. 해 당 방법은 가변 부피 정용여과의 방식을 사용하였으며 전량여과 방식을 사용하였다. 이를 통하여, 완충액 사용량을 약 55% 감소시킬 수 있었다. 또한 역흐름을 통해 막의 파울링을 제어하여 초기 유량의 70%를 복구하며 유량의 감소를 완화할 수 있 었으며 교반을 통해 공정시간을 약 52.8% 단축시킬 수 있었다. 또한 새로운 정용여과 장치를 사용하여 연속공정으로의 전환 을 제안한다. 공정의 체류량을 감소시킬 수 있으며, 이는 초소형화 공정을 가능하게 한다. 초소형화 공정을 통해 적은 용량을 사용하여 다양한 조건에서의 신속한 공정 설계를 가능하게 한다. 하지만 고농도에서의 추가 실험을 통해 상업용 공정에서의 사용 가능 여부에 대한 증명이 필요하다.

Because intact FMDV particles (146S) are often unstable in vitro, stabilizing foot-and-mouth disease virus (FMDV) antigens remains a key challenge in studying viral charateristics. Therefore, finding optimal condition to stabilize the FMDV is essential. In this study, we investigated formulations and potentials of several stabilizers such as appropriate buffer, excipients, and storage conditions to enhance the stability of 146S. Inactivated FMDV O-Jincheon (O-JC) was dissolved in various buffer formulations, and stored at 4℃ for two months to evaluate quantity of 146S at every 2-week interval. Among phosphate buffered saline (PBS), Tris buffered saline (TBS), HEPES buffered saline (HBS), and MOPS buffered saline (MBS), PBS showed more effective 146S stabilization that showed 1.3-1.6 fold higher 146S fraction than TBS, HBS, and MBS after storage for 2 weeks. However, constant dissociations of 146S were observed in all formulations at 8 weeks. Compared with other FMDVs, A22 Iraq and SAT-1, in PBS, O-JC proved to be the least stable in PBS. A variety of excipients including carbohydrate, sugar alcohol, cryo-protectant were tested for the capability in protecting O-JC from dissociation. By adding 4-8% sucrose, more than 60% of 146S fractions were maintained at 8 weeks, those were at least 1.8 fold higher than the PBS-only control. Addition of 1% β-cyclodextrin showed synergistic enhancement in O-JC stability. As the results of this study, it could be suggested that the PBS-based buffer together with 4-8% sucrose + 2% sorbitol or 2% sucrose + 2% sorbitol + 1% β-cyclodextrin could help the better stability of the O-JC in vaccine preparation.

Recently, there have been studies on space and time priority queues, where space priorities are given to a class of packets that are sensitive to loss, and time priorities to another class of packets that are sensitive to delay. However, these studies have been restricted to such models with push-out space priorities. In this paper, we extend the studies to the space and time priority M/G/1 model with partial-buffer-sharing (PBS) space priorities, where the whole buffer is divided into two regions: one is shared by packets of all classes and the other is dedicated only for packets of the higher space-priority class. Since the PBS space-priority mechanism can be implemented more readily in communication systems than the push-out one, there have been a lot of contributions on PBS space-priority queues. However, there are no contributions on space and time priority queues with PBS space priorities. To analyze the proposed queueing model, we first study the probabilistic structure of the service time of a packet, which is more involved to analyze than the push-out alternative because it may be divided into three different regimes: a regime (S-period) from the beginning of the service until the shared buffer region becomes full, a second one (P-period) from the end of the S-period until the whole buffer becomes full, a third one (F-period) from the end of the P-period until the end of the service. Using the distributions of the S-, P-, F-periods, we then construct and analyze the embedded Markov chain and the corresponding semi-Markov process governing the system state, and also derive system performance measures such as expected sojourn times and loss probabilities of different priority classes of packets. In numerical examples, we finally explore the effect of the shared buffer size, which is a major system control parameter of PBS priority queues, and the distributions of the service times of packets of different classes on the system performance measures.

In this study, corrosion fatigue crack propagation was investigated in pH buffer environment using the giga strength steel and its heat-affected zone, and the results were compared with theoretical model prediction. Also, the pure corrosion effect on fatigue crack propagation in a corrosive environment was compared with the modified Forman equation. As results, the average value of corrosion rate obtained as the ratio of the net corrosion-induced crack length to the total crack length under cyclic loading in the base metal and heat-affected zone under experimental loading conditions. These results exhibit a new theoretical method for corrosion fatigue crack propagation that predicts a purely corrosion effect on the behavior to be determined.

In the recent years, thin film solar cells (TFSCs) have emerged as a viable replacement for crystalline silicon solar cells and offer a variety of choices, particularly in terms of synthesis processes and substrates (rigid or flexible, metal or insulator). Among the thin-film absorber materials, SnS has great potential for the manufacturing of low-cost TFSCs due to its suitable optical and electrical properties, non-toxic nature, and earth abundancy. However, the efficiency of SnS-based solar cells is found to be in the range of 1 ~ 4 % and remains far below those of CdTe-, CIGS-, and CZTSSe-based TFSCs. Aside from the improvement in the physical properties of absorber layer, enormous efforts have been focused on the development of suitable buffer layer for SnS-based solar cells. Herein, we investigate the device performance of SnS-based TFSCs by introducing double buffer layers, in which CdS is applied as first buffer layer and ZnMgO films is employed as second buffer layer. The effect of the composition ratio (Mg/(Mg+Zn)) of RF sputtered ZnMgO films on the device performance is studied. The structural and optical properties of ZnMgO films with various Mg/(Mg+Zn) ratios are also analyzed systemically. The fabricated SnS-based TFSCs with device structure of SLG/Mo/SnS/CdS/ZnMgO/AZO/Al exhibit a highest cell efficiency of 1.84 % along with open-circuit voltage of 0.302 V, short-circuit current density of 13.55 mA cm−2, and fill factor of 0.45 with an optimum Mg/(Mg + Zn) ratio of 0.02.

기존의 L. monocytogenes 증균배지를 개량함으로써 증균배지를 개발하여 L. monocytogenes의 증균 효율을 높이며, DNA 추출에 사용되는 용해버퍼 및 용해조건을 개발함으로써 식육 및 식육가공품에서 L. monocytogenes를 효 율적이고 신속하게 검출하고자 하였다. 식품공전에 등재 되어 있는 L. monocytogenes 증균배지의 증균 효율을 비 교하였으며, Listeria Enrichment Broth (LEB)가 가장 우수한 증균 효율을 보였다. LEB에 탄소원, 질소원, 미네랄 등 다양한 성분을 첨가하여 증균배지를 개발하였으며, 그 결과 LEB에 0.1% pyruvate, 0.1% ferric citrate를 첨가한 개발 증균배지에서 L. monocytogenes가 가장 빠르게 증균되었다. L. monocytogenes의 DNA를 신속하고 효율적으로 추출하기 위해 용해버퍼와 용해조건을 개발하였으며, 그 결과 0.5% 또는 1% N-lauroylsarcosine sodium salt에 0.5 N NaOH와 0.5 M EDTA가 혼합된 용해버퍼를 이용하여 실온에서 30분 간 L. monocytogenes 세포를 용해시키는 것 이 DNA의 순도와 수율, 신규성과 경제적 측면에서 가장 우수한 것으로 확인되었다. 결론적으로 본 연구에서 개발 된 증균배지 및 DNA 추출법을 활용한다면 식육 및 식육 가공품에서 L. monocytogenes를 보다 신속하게 검출할 수 있을 것이다.

Recently, the use of an aluminum nitride(AlN) buffer layer has been actively studied for fabricating a high quality gallium nitride(GaN) template for high efficiency Light Emitting Diode(LED) production. We confirmed that AlN deposition after N2 plasma treatment of the substrate has a positive influence on GaN epitaxial growth. In this study, N2 plasma treatment was performed on a commercial patterned sapphire substrate by RF magnetron sputtering equipment. GaN was grown by metal organic chemical vapor deposition(MOCVD). The surface treated with N2 plasma was analyzed by x-ray photoelectron spectroscopy(XPS) to determine the binding energy. The XPS results indicated the surface was changed from Al2O3 to AlN and AlON, and we confirmed that the thickness of the pretreated layer was about 1 nm using high resolution transmission electron microscopy(HR-TEM). The AlN buffer layer deposited on the grown pretreated layer had lower crystallinity than the as-treated PSS. Therefore, the surface N2 plasma treatment on PSS resulted in a reduction in the crystallinity of the AlN buffer layer, which can improve the epitaxial growth quality of the GaN template.

In this experiment, we determined the effect of curcumin supplementation in freezing buffer for miniature pig sperm cryopreservation. Each ejaculate was diluted with modified Modena B extender and mixed with lactose-egg yolk (LEY extender, 80% v/v lactose solution [310 mM], 20% v/v egg yolk, and100 μg/mL kanamycin sulfate) and LEY-glycerol Orvus ES Paste (LEYGO, 89.5% v/v LEY, 5% v/v glycerol, 1.5% v/v Orvus ES Paste), 100 mM trehalose supplemented with 0, 10, 50, 100, and 500 μM of curcumin from turmeric, respectively. Following equilibration, the 0.5 mL French straws were frozen and plunged into LN2 tank for 7 days at least. Sperm parameter and oxidative byproducts were determined by the computer assisted sperm motility analysis (CASA) and fluorescence-activated cell sorting (FACS) as compared with each groups.Supplementation of curcumin had no effect on sperm motility, progressive motility and curvilinear velocity. However, average-path velocity and straight-line velocity were significantly higher in 10 μM curcumin group (100.9±8.8 μm/s, 61.7±2.9 μm/s, respectively) than control group (77.8±3.9 μm/s, 46.4±3.0 μm/s, respectively) (p < 0.05). In addition, the level of the O2 radical and H2O2 were comparatively decreased in curcumin groups by evaluation of ethidium and DCF fluorescence. According to the results, curcumin can improve sperm kinetic variables and alleviate ROS induced cryoinjury to pig sperm.

We investigated the effect of ZnO buffer layer on the formation of ZnO thin film by ultrasonic assisted spray pyrolysis deposition. ZnO buffer layer was formed by wet solution method, which was repeated several times. Structural and optical properties of the ZnO thin films deposited on the ZnO buffer layers with various cycles and at various temperatures were investigated by field-emission scanning electron microscopy, X-ray diffraction, and photoluminescence spectrum analysis. The structural investigations showed that three-dimensional island shaped ZnO was formed on the bare Si substrate without buffer layers, while two-dimensional ZnO thin film was deposited on the ZnO buffer layers. In addition, structural and optical investigations showed that the crystalline quality of ZnO thin film was improved by introducing the buffer layers. This improvement was attributed to the modulation of the surface energy of the Si surface by the ZnO buffer layer, which finally resulted in a modification of the growth mode from three to two-dimensional.

The buffer green space of Sihwa industrial complex is located on the boundary of residential areas and industrial areas, and this regions have been the ability to mitigate environmental impact of noise, vibration, atmospheric. In this area, the survey of vegetation and bird was conducted to understand the biology structures and function of buffer green space from biology habitats and natural recovery for ecology restoration. The survey was performed four times according to the season. As a result, vegetation were distributed to the most widely Pinus thunbergii community (72.2%) in the whole survey area (approximately 0.32 km2), and grasslands (6.6%), Amorpha fruticosa community (4.1%), Koelreuteria paniculata community (4.0%), Acer buergerianum community (3.9%) in the order of distribution. The characteristics of vegetation distribution were mainly planted Pinus thunbergii in outlying areas, and Koelreuteria paniculata, Acer buergerianum, Sophora japonica, Quercus acutissima were planted in the middle areas. The birds observed in this area were a total of 37 species, 912 individuals, the species of legal protection were observed Falco tinnunculus 1 individuals. The most of birds observed in this area were the resident that can be observed easily in the park and greenland surrounding urban. The waterfowl almost were not observed because of lacking water space. Thus, as providing safe habitats and movement passageway of wildlife, the connection of ecological green areas will be strengthened.

Bacterial Cellulose (BC) produced from Acetobacter sp. is used in a wide variety of applications including paper, textile, food, cosmetic, and medicine due to its high mechanical strength, purity, and water holding capacity. In Southeast Asia, coconut water is commonly used as a carbon source for producing BC called “nata de coco”. However, there have been very few attempts to produce BC from juices of other fruit sources, such as pear, apple, and grape, which are major fruits produced in East Asia including South Korea. Since those fruits have relatively low pH because of a large quantity of organic acids, the control of pH is necessary to achieve the maximum BC production yield. The objective of this study was to investigate the BC fermentation characteristics of various fruit juices as media and to determine optimum conditions for the BC production. Sodium acetate was added to each fruit juice medium and the pH was adjusted to pH 5 with acetic acid. Acetobacter xylinus KCCM 41431 was inoculated and BC fermentation was performed for 10 days. The total sugar levels of pear, apple, and grape were 102.31, 155.10, 131.70 g/l and the pHs were 4.72, 4.04, and 3.08, respectively. In buffered fruit juice media, BC production yields were 1.98, 1.44 and 2.55 fold higher than those of pure fruit juice, probably due to the reduction of acid stress. However, the BC production was inhibited at high sodium acetate concentration (>150mM).

The present in vitro study was conducted to examine the effect of buffer solubility of eight protein feeds (coconut meal, distillers grain, sesame meal, perilla meal, soy source cake, rape seed meal, soybean meal and lupine) on the fermentation characteristics, degradability of dry matter (DM) and crude protein (CP), and methane (CH4) production by rumen microbes. Buffer extraction increased pH (P<0.05 ~ p<0.001) of the culture solution but tended to lower ammonia- N concentration for all protein feeds. Total volatile fatty acids(VFAs) and each VFAs concentrations in all incubation was decreased by buffer extraction (P<0.01 ~ P<0.001). Also, molar proportion of acetate in 1h (P<0.001), 3h (P<0.01) and 12h (P<0.05) incubations and molar proportion of propionate in 1h (P<0.001), 3h (P<0.01), 6h (P<0.05) and 12h (P<0.05) were decreased by buffer extraction. But molar proportion of butyrate in 1h (P<0.001), 3h (P<0.01) and 6h (P<0.05) were increased by buffer extraction. The in vitro effective degradability of dry matter (P<0.001) and CP (P<0.001) was decreased by buffer extraction. The methane production (P<0.01~P<0.001) in all incubation was decreased by buffer extraction. The results from in the current study might be useful for diet formulation to improve the feed efficiency of the ruminant animals without massive loss of major nutrients.

본 연구는 기업 조직 내에서 일어나는 사회적 상황의 중요성을 토대로 직장 내 따돌림, 공정성, 조직시 민행동, 일탈행동, 그리고 역할행동을 연구 하였다. 직장 내 따돌림이 야기한 결과와 관련된 연구들은 어 느 정도 나와 있지만, 아직까지 이러한 연구들은 직장 내 따돌림이 야기 시키는 행동적 결과의 조절 변수 효과를 포함 하고 있지 않다. 본 연구는 근로자 246명을 대상으로 종단 적 연구 되었으며, 연구 결과에서 는 직장 내 따돌림이 조직시민행동과 역할행동 사이의 부적 관계를 보여준 반면에, 직장 내 따돌림과 일 탈행동은 정적 관계를 갖는 것으로 나타났다. 더 나아가, 공정성은 따돌림이 갖는 조직시민행동과 일탈행 동 사이의 부적 관계를 줄일 수 있는 것으로 나타났다. 따라서 공정성 인지도가 직장 내 따돌림이 야기 시키는 부정적인 행동적 결과를 완화 시킬 수 있다는 것을 본 연구에서 제시하고 있다.

GaN is most commonly used to make LED elements. But, due to differences of the thermal expansion coefficient and lattice mismatch with sapphire, dislocations have occurred at about 109~1010/cm2. Generally, a low temperature GaN buffer layer is used between the GaN layer and the sapphire substrate in order to reduce the dislocation density and improve the characteristics of the thin film, and thus to increase the efficiency of the LED. Further, patterned sapphire substrate (PSS) are applied to improve the light extraction efficiency. In this experiment, using an AlN buffer layer on PSS in place of the GaN buffer layer that is used mainly to improve the properties of the GaN film, light extraction efficiency and overall properties of the thin film are improved at the same time. The AlN buffer layer was deposited by using a sputter and the AlN buffer layer thickness was determined to be 25 nm through XRD analysis after growing the GaN film at 1070˚C on the AlN buffer CPSS (C-plane Patterned Sapphire Substrate, AlN buffer 25 nm, 100 nm, 200 nm, 300 nm). The GaN film layer formed by applying a 2 step epitaxial lateral overgrowth (ELOG) process, and by changing temperatures (1020~1070˚C) and pressures (85~300 Torr). To confirm the surface morphology, we used SEM, AFM, and optical microscopy. To analyze the properties (dislocation density and crystallinity) of a thin film, we used HR-XRD and Cathodoluminescence.

반추위 pH 조정제로서 일반적으로 중조가 많이 사용되고 있으나 사료에 중조의 첨가량을 증가시키는 경우에 기호성을 저하시키는 경향이 있다. 따라서 본 연구에서는 사료의 기호성에 영향을 미치지 않으면서 반추위 완충효과를 나타내도록 개발된 액상형 완충제의 젖소사료 첨가제로서의 이용효과를 구명하기 위하여 수행되었다. 시험축으로 착유 중기 젖소 27두를 공시하였으며, 처리는 대조구와 중조 첨가구, 그리고 액상형 완충제 첨가구로 하여 처리별 9두씩 배치하였다. 대조구는 착유우용 자가배합 TMR 사료를 급여하였으며, 중조 첨가구는 대조 사료에 중조를 두당 1일 150g 추가하여 급여하였고, 액상형 완충제 첨가구는 같은 방식으로 액상형 완충제를 두당 15㎖ 추가하여 사양시험을 수행하였다. 시험결과 산유량은 대조구, 중조 및 액상형 완충제 첨가구의 경우에 각각 23.82, 23.91, 24.91kg으로 대조구에 비하여 액상형 완충제 처리구에서 다소 증가하는 경향이었으나 처리 간에 뚜렷한 유의 있는 결과를 보여주지는 않았다. 처리에 따른 유성분 변화에서는 유단백질 및 무지고형분에서 액상형 완충제를 첨가한 경우에 대조구에 비해 유의 있는 증가(p < 0.05)를 보여주었고, 유지율에서도 대조구에 비하여 처리구가 다소 증가하는 경향을 보였다. 혈액성분 중 포도당과 콜레스테롤은 대조구에 비해 액상형 완충제의 첨가구에서 다소 증가하였으나, 처리 간에 유의 있는 차이를 나타내지는 않았다. 따라서 개발된 액상형 완충제의 추가급여 시 생산성 증대, 특히 유성분 증가 효과가 있어 반추위 pH 조정을 위하여 일반적으로 이용되고 있는 중조를 대체하여 반추동물의 사료첨가제로 이용이 가능할 것으로 평가되었다.

바이러스 입자를 감지하는 역전사 핵산 연쇄 증폭법 (VC/RT-PCR)은 감염된 식물종들로부터 핵산 추출 없이 식물바이러스들을 검출 할 수 있다. 본 연구는 VC/RT-PCR 분석법을이용하여 고추를 감염시키는 바이러스들을 효과적으로 진단하기 위하여 새로운 즙액 추출 완충액들이 제작하였다.토마토반점위조바이러스 (Tomato spotted wilt virus;TSWV), 고추약한모틀바이러스 (Pepper mild mottle virus;PMMoV) 및 고추모틀바이러스 (Pepper mottle virus;PepMoV) 진단을 위한 가장 최적화된 추출 완충액은 0.5%sodium sulfate를 포함하는 1.0M Tris (pH 8.0) buffer 였다.고추 바이러스들은 담배 즙액 추출 후 7일까지 검출이 되었으며, 마쇄 직후와 검출 감도는 유의한 차이가 없었다. 반면에,3가지 고추 바이러스들은 고추 즙액 추출 후 2일까지만 바이러스들이 검출되었으며, 검출 감도는 크게 감소하였다.국내 고추 재배 농가들에서 수집한 고추 시료들에서 TSWV,PMMoV, PepMoV의 단독 감염 및 PMMoV와 PepMoV의중복 감염을 선발된 최적 즙액 완충액과 VC/RT-PCR의 조합을 이용하여 동시 진단이 가능하였다.

본 연구는 경관조명 시뮬레이션 기법을 활용하여 야간 보행자의 보행안전 확보를 위해 대로변에 조성된 완충녹지 공간을 고려한 조명기구 배치의 적절성을 평가하여 효율적 경관조명 설계 방법론을 제시하고 있다. 이를 위해 도로조명기준에 부합하는 가로 조명환경을 구현하고 일정 수준 성장이 이루어진 가로수를 배치하여 가로수에 의한 조명감소환경을 구현한 후 이를 개선하기 위해 배광이 제어되지 않은 보조 조명기구를 가로등 하단부와 보행로와 완충녹지경계에 위치시켜 설치 위치에 따른 조도 개선효과를 비교하였다. 결과에서 보행로의 조명환경 개선 효과와 동시에완충녹지의 조명환경 역시 크게 개선됨을 보여주고 있다. 또한 보조 조명기구를 가로등 간 보행로와 완충녹지의 경계에설치할 경우 배광이 제어되지 않은 조명기구보다 배광이 적절히 제어된 조명기구의 개선효과가 조도의 측면에서 우수함을알 수 있었다. 결과를 바탕으로 야간 보행자의 안전을 고려하기 위해 조명설계와 완충녹지 설계 시 경관조명 시뮬레이션기법을 활용하는 것이 필요함을 알 수 있다.