수소 생산과 세균 군집구조에 미치는 PVA-포괄고정화의 영향

윤정희 ( Jeong Hee Yun ),김태관 ( Tae Gwan Kim ),조경숙 ( Kyung Suk Cho ) 한국미생물생명공학회(구 한국산업미생물학회) 2014 한국미생물·생명공학회지 Vol.42 No.1

수소생산 유효세균을 유지하기 위해 열처리한 혐기소화슬러지를 접종원으로 하여 PVA 담체를 활용한 고정화와 비고 정화 방법에 의한 수소생산능 및 세균 군집을 비교분석 하였다. 고정화에 의한 수소생산성은 비고정화 방법과 비교하여 수소생산성에 영향을 미치지 않았다. 그러나 고정화 방법은 유기물 분해결과 발생하는 유기산 축적 및 pH 강하 등의 환경변화에 있어 세균의 성장과 활성에 안정적 환경을 제공할 수 있는 가능성을 나타내었다. DGGE 분석에 의한 세균군집분석에서는 비고정화와 고정화 반응조간에 형성된 세균군집이 차이가 있는 것으로 나타났으며, 상대적으로 고정화 반응조내의 유효 수소생산 세균 군집이 좀 더 안정적으로 유지되는 것으로 확인되었다. Droplet digital PCR에 의한 6종의 유효한 수소생산 세균 절대정량 분석결과, encapsulation 에 관계없이 두 반응기에서의 우점세균수는 유사하였다. Firmicutes, Clostridium, Enterobacter, Ruminococcus 및 Escherichia가 1 × 105-1 × 106 copy number of ml-sample 수준에서 존재하였다. In this study, the performances of PVA-encapsulation and non-encapsulation in a fed-batch bioreactor system were compared for biohydrogen production. Hydrogen production in the PVA-encapsulation bioreactor was not significantly different in comparison to the non-encapsulation bioreactor. However, the hydrogen gas in the encapsulation bioreactor could be stably produced when it was exposed to environmental difficulties such as pH impact by the accumulation of organic acids as fermentative metabolic products. Bacterial communities by DGGE analysis were differently shifted between the PVA-encapsulation and nonencapsulation bioreactors from the initial sludge. The community of hydrogen producing bacteria was stable during the experimental period in the PVA-encapsulation bioreactor compared to the non-encapsulation method. The absolute quantitation of the DNA copy number by a high-throughput droplet digital PCR system for six genera contributed to hydrogen production showing that the numbers of dominant bacteria existed at similar levels in the two bioreactors regardless of encapsulation. In both of two bioreactors, not only Clostridium and Enterobacter, which are known as anaerobic hydrogen producing bacteria, but also Firmicutes, Ruminococcus and Escherichia existed with 1 × 105 -1 × 106 copy numbers of ml-samples exhibiting rapid growth during the initial operation period.

A Case Study of Paraffin Double-walled Microencapsulation Preparation Using Acrylic Polymer and Melamine Polymer for Thermal Energy Storage

Hang Vo-Minh Nguyen,Kim Chae-Hyun,김종국 한국태양에너지학회 2019 한국태양에너지학회 논문집 Vol.39 No.5

In this study, we investigated the paraffin encapsulation using double-walled encapsulation technique. The first encapsulation used methyl methacrylic acid as the main component in acrylic polymer and the second encapsulation used melamine polymer. Particles size and distribution of the capsules were analyzed using scanning electron microscopy. In the first encapsulation, the stable capsules were obtained at 67% of phase change material ratio to methyl methacrylic acid monomer and the size of the capsule was from 0.2 to 0.3μm. In the second encapsulation, the size of the capsules was almost the same with those capsules prepared in the first encapsulation. The particle size of single wall and double wall was about 0.3μm. As a result of the encapsulation of paraffin using double-walled encapsulation technique, it was confirmed that the particle size was determined in the process of encapsulating using the acrylic polymer at the first wall material, and the physical and thermal stability of the capsules were imparted using melamine at the secondary wall material.

고분자 기판의 휨 스트레스에 대한 Encapsulation층의 효과

박준백,서대식,이상극,이준웅,김영훈,문대규,한정인 한국전기전자재료학회 2004 전기전자재료학회논문지 Vol.17 No.4

In this study, we investigated the necessity of encapsulation layer to maximize flexibility of brittle indium-tin-oxide (ITO) on polymer substrates. And, Young's modulus (E) of encapsulation layer han a significant effect on external bending stress and the coefficient of thermal expansion (CTE) of that han a significant effect on internal thermal stress. To compare the magnitude of total mechanical stress including both bending stress and thermal stress, the mechanical stress of triple-layer structure (substrate / ITO / encapsulation layer or substrate / buffer layer / ITO) can be quantified and numerically analyzed through the farthest cracked island position. As a result, it should be noted that multi-layer structures with more elastic encapsulation material have small mechanical stress compared to that of buffer and encapsulation structure of large Young's modulus material when they were externally bent.

Molecular cloning and functional properties of two early-stage encapsulation-relating proteins from the coleopteran insect, Tenebrio molitor larvae

Cho, Mi Young,Lee, Hyun Seong,Lee, Kwang Moon,Homma, Ko-ichi,Natori, Shunji,Lee, Bok Luel 부산대학교 유전공학연구소 1999 분자생물학 연구보 Vol.15 No.-

Encapsulation is a major defensive reaction against foreign materials that are too large to be phagocytosed by individual hemocytes: however, the biochemical process of encapsulation is still obscure. To isolate and characterize the early-stage encapsulation-relating protein (ERP), we used the coleopteran insect. Tenebrio molitor larvae, injecting three differing kinds of bead or inserting pieces of surgical suture into the abdomen of T. molitor larvae. The resulting proteins from the injected beads or the inserted pieces of surgical suture were recovered 10 min after injection or insertion, and were analyzed on SDS/PAGE under reducing conditions. Four different proteins (86, 78, 56 and 48 kDa) were enriched compared with the crude hemolymph. Among them, we purified 56-kDa and 48-kDa ERPs to homogeneity and raised polyclonal antibodies against each protein. Immunoblotting analysis showed that the affinity-purified antibodies of the 56-kDa ERP consisted of 579 amino acid residues and showed a novel glutamine-rich protein. Positive clones of the 48-kDa ERP showed the same DNA sequence as 56-kDa ERP. Interestingly, the chemically determined N-terminal amino acid sequence and the three partial amino acid sequences of the 48-kDa protein were found in the 56-kDa ERP, suggesting that the 48 kDa ERP was produced by the cleavage of Arg101-Gly102 of the 56-kDa ERP by a limited proteolysis. Western blotting analysis showed that these ERPs were detected exclusively on membrane fractions of hemocytes. Also, when the early-stage encapsulated beads were coated with both the 56-kDa and 48-kDa ERP antibodies and re-injected into larvae, no further encapsulation reaction was observed. However, when the early-stage encapsulated beads were incubated with 56-kDa ERP antibody, 48-kDa ERP antibody or nonimmunized rabbit igG and re-injected into larvae, further encapsulation did occur.

Encapsulation of polyvinyl alcohol based flexible temperature sensor through spatial atmospheric atomic layer deposition system to enhance its lifetime

Kim, Soo Wan,Rehman, Muhammad Muqeet,Sajid, Memoon,Rehman, Mohammad Mutee ur,Gul, Jahanzeb,Jo, Jeong Dai,Choi, Kyung Hyun Elsevier 2019 THIN SOLID FILMS - Vol.673 No.-

<P><B>Abstract</B></P> <P>Printed organic sensors are of significant importance owing to their simplicity, low cost, easy fabrication and solution processability. However, organic sensors often suffer from the drawback of performance degradation when exposed to ambient environment. In this study, polyvinyl alcohol (PVA) is used as the functional layer of a temperature sensor and is encapsulated by aluminum oxide (Al<SUB>2</SUB>O<SUB>3</SUB>) deposited through spatial atmospheric atomic layer deposition system (SAALD). The encapsulating layer of Al<SUB>2</SUB>O<SUB>3</SUB> was pure, atomically thin and highly reliable. Fabricated organic temperature sensor is based on a conductive and uniform interdigitated pattern deposited on a flexible polyethylene naphthalate substrate through advanced printing technology of reverse offset. Thin film of PVA is used as the temperature sensitive functional layer deposited through electrohydrodynamic atomization followed by Al<SUB>2</SUB>O<SUB>3</SUB> encapsulation. The developed sensors were tested in the temperature range of 25 °C to 90 °C with relative humidity reaching up to 75% relative humidity. The obtained results exhibited that Al<SUB>2</SUB>O<SUB>3</SUB> encapsulation deposited through SAALD significantly enhanced the linearity, repeatability, endurance (50 cycles), retention (2 months) and lifetime of PVA based temperature sensor as compared with the non-encapsulated sensor hence, protecting the organic device from performance degradation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Lifetime of organic temperature sensor has been enhanced through encapsulation. </LI> <LI> Electrical, mechanical, chemical, and morphological characterizations are included. </LI> <LI> The device is encapsulated with Al<SUB>2</SUB>O<SUB>3</SUB> thin film deposited through SAALD system. </LI> <LI> Encapsulated sensor displayed better results than non-encapsulated sensor. </LI> <LI> The obtained results were highly stable and reproducible. </LI> </UL> </P>

Functional Design of Dielectric–Metal–Dielectric-Based Thin-Film Encapsulation with Heat Transfer and Flexibility for Flexible Displays

Kwon, Jeong Hyun,Choi, Seungyeop,Jeon, Yongmin,Kim, Hyuncheol,Chang, Ki Soo,Choi, Kyung Cheol American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.32

<P>In this study, a new and efficient dielectric-metal-dielectric-based thin-film encapsulation (DMD-TFE) with an inserted Ag thin film is proposed to guarantee the reliability of flexible displays by improving the barrier properties, mechanical flexibility, and heat dissipation, which are considered to be essential requirements for organic light-emitting diode (OLED) encapsulation. The DMD-TFE, which is composed of Al2O3, Ag, and a silica nanoparticle-embedded sol-gel hybrid nanocomposite, shows a water vapor transmission rate of 8.70 X 10(-6) g/m(2)/day and good mechanical reliability at a bending radius of 30 mm, corresponding to 0.41% strain for 1000 bending cycles. The electrical performance of a thin-film encapsulated phosphorescent organic light-emitting diode (PHOLED) was identical to that of a glass-lid encapsulated PHOLED. The operational lifetimes of the thin-film encapsulated and glass-lid encapsulated PHOLEDs are 832 and 754 h, respectively. After 80 days, the thin-film encapsulated PHOLED did not show performance degradation or dark spots on the cell image in a shelf-lifetime test. Finally, the difference in lifetime of the OLED devices in relation to the presence and thickness of a Ag film was analyzed by applying various TFE structures to fluorescent organic light-emitting diodes (FOLEDs) that could generate high amounts of heat. To demonstrate the difference in heat dissipation effect among the TFE structures, the saturated temperatures of the encapsulated FOLEDs were measured from the back side surface of the glass substrate, and were found to be 67.78, 65.12, 60.44, and 39.67 degrees C after all encapsulated FOLEDs were operated at an initial luminance of 10 000 cd/m(2) for sufficient heat generation. Furthermore, the operational lifetime tests of the encapsulated FOLED devices showed results that were consistent with the measurements of real-time temperature profiles taken with an infrared camera. A multifunctional hybrid thin-film encapsulation based on a dielectric-metal-dielectric structure was thus effectively designed considering the transmittance, gas-permeation barrier properties, flexibility, and heat dissipation effect by exploiting the advantages of each separate layer.</P>

캡슐화된 과일껍질의 첨가가 냉장저장 동안 프레스햄 품질 안정성에 미치는 영향

박경미,강근호,조수현,박범영,김동훈,Hoa Van Ba,강선문,성필남 강원대학교 동물생명과학연구소(구 강원대학교 동물자원공동연구소) 2014 동물자원연구 Vol.25 No.2

Fruit peels are potential sources of proteases which can help to the proteins digestion and the encapsulation technique is widely used in food industry, which preserves active ingredients in food products by forming coating membrane. In the present study, the effect of addition of encapsulated fruit peels (kiwi, T1; pineapple, T2; pear, T3; fig, T4) on the quality stability of press ham was studied during refrigerated storage (1, 15 and 30 days). In the first experiment, the press ham was prepared with either encapsulated fruit peels or fruit peels powder (without encapsulation) and we observed that the press ham formulated with fruit peels powder showed a texture defect, but no change with encapsulated fruit peels probably due to the proteolytic activity of proteases were prevented by the encapsulation. In the second experiment, the press ham were made with 0.1% encapsulated fruit peels or normal press ham (control) and stored at different days as mentioned above. Our results revealed that T2 showed the highest moisture content, while the control had the highest fat content. The press hams made with all types of encapsulated fruit peels had significantly higher hardness value than the control throughout the storage. Additionally, higher taste, texture and acceptability scores were found in the press ham with encapsulated fruit peels than those in the control. Overall, it is suggested that the addition of encapsulated fruit peels into meat products may enhance the protein digestion and absorption during the digestive processes without the negative effect on texture and sensory traits.

Cryopreservation of Zygotic Embryos of Herbaceous Peony (Paeonia lactiflora Pall.) by Encapsulation-Dehydration

Kim Hyun-Mi,Shin Jong-Hee,Sohn Jea-Keun The Korean Society of Crop Science 2004 Korean journal of crop science Vol.49 No.4

A simplified technique which cryoprotects zygotic embryos by encapsulation-dehydration was developed for the germplasm conservation of herbaceous peony (Paeonia lactiflora Pall.). The highest survival rate $(85\%)$ was obtained from embryos treated by encapsulation-dehydration. The zygotic embryos were precultured on MS medium containing 0.3mg/L $GA_3$ for 1 day. The precultured embryos were encapsulated in $3\%$ (w/v) alginate beads and immersed for 1 h in MS medium containing 2 M glycerol and 0.5 M sucrose. The encapsulated embryos were dehydrated for 5h by air drying prior to direct immersion in liquid nitrogen. This encapsulation-dehydration method appears to be a promising technique for germplasm cryopreservation of a herbaceous peony.

OLED의 Thin Film Encapsulation을 위한 MgO 박막의 원자층 증착 장치 및 공정에 관한 연구

조의식,권상직,Cho, Eou Sik,Kwon, Sang Jik 한국반도체디스플레이기술학회 2021 반도체디스플레이기술학회지 Vol.20 No.3

Thin-film encapsulation (TFE) technology is most effective in preventing water vapor and oxygen permeation in the organic light emitting diodes (OLED). Of those, a laminated structure of Al₂O₃ and MgO were applied to provide efficient barrier performance for increasing the stability of devices in air. Atomic layer deposition (ALD) method is known as the most promising technology for making the laminated Al₂O₃/MgO and is used to realize a thin film encapsulation technology in organic light-emitting diodes. Atomic layer deposited inorganic films have superior barrier performance and have advantages of excellent uniformity over large scales at relatively low deposition temperatures. In this study, the control system of the MgCP₂ precursor for the atomic layer deposition of MgO was established in order to deposit the MgO layer stably by the injection time of second level and the stable heating temperature. The deposition rate was obtained stably to be from 4 to 10 Å/cycle using the injection pulse times ranging from 3 to 12 sec and a substrate temperature ranging from 80 to 150 ℃.

Correlation of Drug and Carbon Nanotube Size in Encapsulation and Free Energy Calculation: A Molecular Insight

Maryam Ghadamgahi,Davood Ajloo 대한화학회 2015 Bulletin of the Korean Chemical Society Vol.36 No.1

Spontaneous encapsulation of drugs into carbon nanotubes (CNTs) has attracted great interest because of their importance in biological and biomedical devices. In this work, the diameter dependence of 20 drugs on the carbon nanotube size was explored via molecular dynamics (MD) simulation. Negative free energy of interaction, reduced potential of mean force, reduced CNT–drug distance, and reduced number of water molecules after encapsulation confirm the encapsulation of the drug into the smallest possible size of CNT. The variations of the radius of gyration of the CNTs and drugs were compared to explore the correlation trend. One of the factors influencing the encapsulation and insertion of drug is the size of the nanotube. In addition, the linear correlation between the drug and the nanotube size was confirmed by quantitative structure–property relationship (QSPR) analysis, and themultiple linear regression (MLR) method was applied to develop the correlation model. The regression parameter provided by the MLR method was R2 = 0.99 for prediction of the drug gyration radius. The MLR prediction confirms that the larger drug molecule prefers to locate inside a larger CNT, which agrees with MD data. It was found that there is π–π interaction between the oxygen atoms and the aromatic ring of some of the drugs and the aromatic rings of CNTs are conjugated; this helps the drug molecule to locate inside the CNT. These theoretical methods provide a simple, detailed, and alternative method to obtain optimal tube size for encapsulation.