• 대한토목학회논문집
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• 제2권2호
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• pp.39-46
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• 1982

회전원판접촉법(回轉圓板接觸法)에 의한 폐수처리(廢水處理)의 이해(理解)를 증진(增進)시키고 여러가지 조건(條件)의 변화(變化)에 따라 달라지는 처리효율(處理效率)을 산정(算定)하기 위하여 모형(模型)을 개발(開發)하고 Simulation을 통하여 정상상태(定常狀態)와 비정상상태(非定常狀態)에서의 모형(模型)을 분석(分析)하였다. 회전원판(回轉圓板)에 의한 기질제거모형(基質除去模型)은 용액(溶液)으로부터 미생물막내부(微生物膜內部)로의 기질전달(基質傳達)과 미생물(微生物)에 의한 기질(基質)의 분해(分解)에 의해 처리(處理)가 이루어진다고 가정(假定)하고 정립(定立)되었고 모형(模型)은 여러개의 요소(要素)로 나뉘어진 액체막(液體膜)과 미생물막(微生物膜), 그리고 용액중(溶液中)의 기질농도(基質濃度)에 관한 일련의 물질수지식(物質收支式)으로 구성(構成)된다. 정상상태(定常狀態)에서 처리효율(處理效率)은 기질(基質)의 확산계수(擴散係數)와 미생물(微生物)의 최대기질분해율(最大基質分解率)에 의해 좌우(左右)되고 확산(擴散)에 의한 영향은 용액중(溶液中)의 기질농도(基質濃度)가 낮고 최대기질분해율(最大基質分解率)이 높을 경우 현저하게 나타난다. 기질제거효율(基質除去效率)은 미생물막(微生物膜)의 두께가 얇을 때는 거의 두께에 비례(比例)하여 증가(增加)하나 두께의 증가(增加)에 따라 효율증가(效率增加)는 둔화(鈍化)되고 한계(限界)두께에 이르면 기질(基質)의 침투(浸透)가 불충분(不充分)하여 효율(效率)은 일정(一定)해진다. 비정상상태(非定常狀態)에서 유출수(流出水)의 수질(水質)은 반응조(反應槽)의 체적(體積)에 의해 영향을 받는다. 반응조(反應槽)의 체적증가(體積增加)는 첨두부하(尖頭負荷)에 대하여 첨두농도(尖頭濃度)를 낮게하는 완충효과(緩衝效果)를 나타내기 때문에 반응조(反應槽)는 균등조(均等槽)의 역할을 한다 할 수 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권6호
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• pp.864-873
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• 2013

In developing countries, biogas energy production is seen as a technology that can provide clean energy in poor regions and reduce pollution caused by animal manure. Laboratories in these countries have little access to advanced gas measuring equipment, which may limit research aimed at improving local adapted biogas production. They may also be unable to produce valid estimates of an international standard that can be used for articles published in international peer-reviewed science journals. This study tested and validated methods for measuring total biogas and methane ($CH_4$) production using batch fermentation and for characterizing the biomass. The biochemical methane potential (BMP) ($CH_4$ NL $kg^{-1}$ VS) of pig manure, cow manure and cellulose determined with the Moller and VDI methods was not significantly different in this test (p>0.05). The biodegradability using a ratio of BMP and theoretical BMP (TBMP) was slightly higher using the Hansen method, but differences were not significant. Degradation rate assessed by methane formation rate showed wide variation within the batch method tested. The first-order kinetics constant k for the cumulative methane production curve was highest when two animal manures were fermented using the VDI 4630 method, indicating that this method was able to reach steady conditions in a shorter time, reducing fermentation duration. In precision tests, the repeatability of the relative standard deviation (RSDr) for all batch methods was very low (4.8 to 8.1%), while the reproducibility of the relative standard deviation (RSDR) varied widely, from 7.3 to 19.8%. In determination of biomethane concentration, the values obtained using the liquid replacement method (LRM) were comparable to those obtained using gas chromatography (GC). This indicates that the LRM method could be used to determine biomethane concentration in biogas in laboratories with limited access to GC.

• ALGAE
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• 제33권3호
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• pp.279-290
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• 2018

Microalgae have been utilized in diverse industries including aquaculture. Among the microalgae, dinoflagellates are known to have various bioactive compounds, and thus the interest in their application to industry has increased. In order to test their potential as food materials for aquaculture animals, the crude protein contents and compositions of amino acids of six dinoflagellates Heterocapsa rotundata (family Heterocapsaceae), Ansanella granifera (Suessiaceae), Alexandrium andersonii (Ostreopsidaceae), Takayama tasmanica (Brachidiniaceae), Takayama helix, and Gymnodinium smaydae (Gymnodiniaceae) belonging to diverse families were analyzed. The percentage of the amount of the crude protein relative to dry weight of T. tasmanica was the highest (65%) and that of A. andersonii was the lowest (26%). However, the highest percentage of total detected amino acids in crude protein was found in A. andersonii (98.2%). In all six dinoflagellates, glutamic acid was the most dominant amino acid in crude protein. However, the second main amino acid was aspartic acid for H. rotundata, A. granifera, T. helix, and G. smaydae, but were arginine and leucine for A. andersonii and T. tasmanica, respectively. Furthermore, T. tasmanica and T. helix did not have taurine and gamma-aminobutyric acid, whereas the other dinoflagellates possessed them. The percentages of essential amino acid contents of the dinoflagellates met the requirement levels for juvenile shrimps. In addition, the dinoflagellates were not toxic to the brine shrimp Artemia salina. Compared with the other microalgae reported so far, H. rotundata and A. andersonii can be used for arginine-rich diets, T. tasmanica for valine and leucine-rich diets, A. granifera for histidine-rich diets, T. helix for threonine-rich diets, and G. smaydae for lysine-rich diets. Therefore, based on their biochemical composition and toxicity to Artemia, the dinoflagellates could be used as essential amino acid sources for cultivating animals in the aquaculture industry.

• 한국균학회지
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• 제36권1호
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• pp.45-50
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• 2008

잣버섯 균사체의 액체배양을 촉진하기 위해 소나무 목분의 첨가배양 조건을 구명하고자 하였다. 소나무의 여러 부위 중 목부의 목분에서 균사체 생장이 양호한 것으로 조사되었다. 목분을 액체 배양에 첨가하기 위한 전처리로서는 알카리 처리 조건에서 균사체 생장이 우수하였으나, 전처리를 하지 않아도 균사체 배양 촉진에 효과가 있는 것으로 나타났다. 액체배양 배지에 적정한 목분의 분말도 $200\;{\mu}m$ 이하로 낮을수록, 목분의 첨가 농도는 0.5%(w/v)로 또한 배지내의 탄소원인 glucose 농도는 10 g/l로 하는 조건에서 균사체 생장 촉진 효과가 큰 것으로 나타났다. 이러한 배양 조건에서 표고버섯 균사체를 배양한 결과도 균사배양 촉진 결과가 우수하여 액체배지에 목분 첨가에 의한 다른 목재부후균의 균사체 배양 촉진에도 효과가 있을 것으로 추정된다.

• Journal of Microbiology and Biotechnology
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• 제21권7호
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• pp.686-696
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• 2011

To deal with pathogens, plants have evolved sophisticated mechanisms including constitutive and induced defense mechanisms. Phytohormones play important roles in plant growth and development, as well as in the systemic response induced by beneficial and pathogen microorganisms. In this work, we identified an Aspergillus ustus isolate that promotes growth and induces developmental changes in Solanum tuberosum and Arabidopsis thaliana. A. ustus inoculation on A. thaliana and S. tuberosum roots induced an increase in shoot and root growth, and lateral root and root hair numbers. Assays performed on Arabidopsis lines to measure reporter gene expression of auxin-induced/ repressed or cell cycle controlled genes (DR5 and CycB1, respectively) showed enhanced GUS activity, when compared with mock-inoculated seedlings. To determine the contribution of phytohormone signaling pathways in the effect elicited by A. ustus, we evaluated the response of a collection of hormone mutants of Arabidopsis defective in auxin, ethylene, cytokinin, or abscisic acid signaling to the inoculation with this fungus. All mutant lines inoculated with A. ustus showed increased biomass production, suggesting that these genes are not required to respond to this fungus. Moreover, we demonstrated that A. ustus synthesizes auxins and gibberellins in liquid cultures. In addition, A. ustus induced systemic resistance against the necrotrophic fungus Botrytis cinerea and the hemibiotrophic bacterium Pseudomonas syringae DC3000, probably through the induction of the expression of salicylic acid, jasmonic acid/ethylene, and camalexin defense-related genes in Arabidopsis.

• Korean Chemical Engineering Research
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• 제60권3호
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• pp.414-422
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• 2022

본 연구의 목적은 국내 대표적인 농경잔류물인, 볏짚과 보릿짚을 이용하여 헤미셀룰로오스 부분의 최대 가용화를 위한 산 촉매 열수 분별공정의 타당성을 조사한 것이다. 1.2-2.9 범위의 반응가혹도(CS; Combined reaction severity)에서 다양한 분별 조건들을 사용하여 초기 반응조건 기준을 설정했다. 볏짚의 경우, 160 ℃의 반응온도, 0.75%(w/v)의 H₂SO₄, 20분의 반응시간, 그리고 1:15의 고체/액체 비율을 가진 반응 조건에서 56.6%의 헤미셀룰로스 당 수율을 얻을 수 있었으며, 보릿짚의 경우, 150 ℃ 반응온도, 0.75%(w/v) H₂SO₄, 15분의 반응시간, 1:10의 고체/액체 비율에서 83.0%의 헤미셀룰로스 당 수율을 얻었다. 따라서, 볏짚과 비교하여 보릿짚의 경우 산촉매 열수분획을 효과적으로 수행할 수 있었다. 분별과정 후 남은 분획된 고형분은 볏짚과 보릿짚에서 각각 48.5%와 57.5%였다. 분별된 볏짚과 보릿짚의 XMG(Xylan+Mannan+Galactan) 함량은 17.3% 및 17.6%에서 6.0% 및 2.6%로 각각 감소하였으며, 이는 원료 짚 기준으로 각각 16.7% 및 8.5%에 해당한다. 또한, 보리 짚의 산촉매 열수분별 과정에서 과도한 분해로 인해 셀룰로오스 및 XMG의 5.6% 및 8.5%만 손실된 반면, 볏짚의 셀룰로오스 및 XMG 손실은 6.4% 및 26.6%이었다. 볏짚의 헤미셀룰로스 당은 산 촉매 열수 분별공정중, 다소 높은 반응가혹도로 인해 심하게 과분해된 것에 기인한다.

• 한국분무공학회지
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• 제19권3호
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• pp.115-122
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• 2014

As a demand for an automobile increases, air pollution and a problem of the energy resources come to the fore in the world. Consequently, governments of every country established ordinances for green-house gas reduction and improvement of air pollution problem. Especially, as international oil price increases, engine using clean energy are being developed competitively with alternative transportation energy sources development policy as the center. Bio ethanol, one of the renewable energy produced from biomass, gained spotlight for transportation energy sources. Studies are in progress to improve fuel supply methods and combustion methods which are key features, one of the engine technologies. DI(Direct Injection), which can reduce fuel consumption rate by injecting fuel directly into the cylinder, is being studied for Green-house gas reduction and fuel economy enhancement at SI(Spark Ignition). GDI(Galoine Direct Injection) has an advantage to meet the regulations for fuel efficiency and $CO_2$ emissions. However it produces increased number of ultrafine particles, that yet received attention in the existing port-injection system, and NOX. As fuel is injected into the cylinder with high-pressure, a proper injection strategy is required by characteristics of a fuel. Especially, when alcohol type fuel is considered. In this study, we tried to get a base data bio-ethanol mixture in GDI, and combustion for optimization. We set fuel mixture rate and fuel injection pressure as parameters and took a picture with a high speed camera after gasoline-ethanol mixture fuel was injected into a constant volume combustion chamber. We figured out spraying characteristic according to parameters. Also, we determine combustion characteristics by measuring emissions and analyzing combustion.

• Journal of Plant Biotechnology
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• 제43권1호
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• pp.110-118
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• 2016

We compared germination efficiency for somatic embryos (SE) of Liriodendron tulipifera using semi-solid (SS), temporary immersion bioreactors (TIB), and continuous immersion bioreactors (CIB) to produce vigorous plants. The bioreactors were designed to be immersed in liquid media with plantlets with an adjustable immersion time. TIB and CIB improved germination rates up to 80.86% and 95.21%, respectively, however, CIB produced more hyperhydric plantlets than TIB. The height of plantlets in TIB was significantly higher than for those in CIB. Fresh weights of plantlets grown in CIB of were significantly lower than for those grown in TIB. The lowest chlorophyll concentration was found in in vitro plantlets from CIB. We examined abnormally developed leaves, stems, and apical zones of in vitro plantlets that were produced in CIB. Among the three types, SS showed the highest stomatal density and the shortest stomatal length in in vitro plantlets. After acclimatization, plants from CIB exhibited the lowest values in biomass, such as height, root collar diameter, leaf fresh weight, leaf length, leaf width, petiole length, petiole diameter, and leaf area. Photosynthesis and transpiration rates of ex vitro plants were not significantly different among the three culture types, but stomatal conductance was higher in TIB than in the SS and CIB. Therefore, the results suggest that TIB is the preferable bioreactor to improve in vitro plantlet regeneration of L. tulipifera. TIB-originated plants showed higher growth rate than SS and CIB after transferring to soil.

• Journal of Microbiology and Biotechnology
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• 제17권2호
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• pp.207-217
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• 2007

The Saccharomyces0 cerevisiae KNU5377 strain, which was isolated from spoilage in nature, has the ability to convert biomass to alcohol at high temperatures and it can resist against various stresses [18, 19]. In order to understand the defense mechanisms of the KNU5377 strain under menadione (MD) as oxidative stress, we used several techniques for study: peptide mass fingerprinting (PMF) by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS) followed by two-dimensional (2D) gel electrophoresis, liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS), and surface-enhanced laser desorption ionization-time of flight (SELDI-TOF) technology. Among the 35 proteins identified by MALDI-TOF MS, 19 proteins including Sod1p, Sod2p, Tsa1p, and Ahp1p were induced under stress condition, while 16 proteins were augmented under normal condition. In particular, five proteins, Sod1p, Sod2p, Ahp1p, Rib3p, Yaf9p, and Mnt1p, were induced in only stressed cells. By LC-ESI-MS/MS analysis, 37 proteins were identified in normal cells and 49 proteins were confirmed in the stressed cells. Among the identified proteins, 32 proteins were found in both cells. Five proteins including Yel047cp and Met6p were only upregulated in the normal cells, whereas 17 proteins including Abp1P and Sam1p were elevated in the stressed cells. It was interesting that highly hypothetical proteins such as Ynl281wp, Ygr279cp, Ypl273wp, Ykl133cp, and Ykr074wp were only expressed in the stressed cells. SELDI-TOF analysis using the SAX2 and WCX2 chips showed that highly multiple-specific protein patterns were reproducibly detected in ranges from 2.9 to 27.0 kDa both under normal and stress conditions. Therefore, induction of antioxidant proteins, hypothetical proteins, and low molecular weight proteins were revealed by different proteomic techniques. These results suggest that comparative analyses using proteomics might contribute to elucidate the defense mechanisms of KNU5377 under MD stress.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권3호
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• pp.270-274
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• 2005

A reactor-scale hydrogen (H2) production via the water-gas shift reaction of carbon monoxide (CO) and water was studied using the purple nonsulfur bacterium, Rhodopseudomonas palustris P4. The experiment was conducted in a two-step process: an aerobic/chemoheterotrophic cell growth step and a subsequent anaerobic $H_2$ production step. Important parameters investigated included the agitation speed. inlet CO concentration and gas retention time. P4 showed a stable $H_2$ production capability with a maximum activity of 41 mmol $H_2$ g $cell^{-1}h^{-1}$ during the continuous reactor operation of 400 h. The maximal volumetric H2 production rate was estimated to be 41 mmol $H_2 L^{-1}h^{-1}$, which was about nine-fold and fifteen-fold higher than the rates reported for the photosynthetic bacteria Rhodospirillum rubrum and Rubrivivax gelatinosus, respectively. This is mainly attributed to the ability of P4 to grow to a high cell density with a high specific $H_2$ production activity. This study indicates that P4 has an outstanding potential for a continuous H2 production via the water-gas shift reaction once a proper bioreactor system that provides a high rate of gas-liquid mass transfer is developed.