• 제목/요약/키워드: biological characteristic

검색결과 584건 처리시간 0.029초

미생물에 의한 발효처리 (Wastewater Treatment by Microorganism)

  • 신석봉
    • 한국미생물·생명공학회지
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    • 제8권2호
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    • pp.135-142
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    • 1980
  • The process of biological treatment of organic wastewater is principally associated with those of self-purification in the natural water environment. The treatment system has e intensive function of stabilizing wastewater more effectively than in natural water, which is like natural water concentrated in a small space. Biological treatment of wastewater involves activated sludge and various modified process, trickling filter, rotating disk, oxidation ditch, etc. for aerobic decomposition and anaerobic processes such as anaerobic decomposition and methane fermentation. The basic characteristic of these processes is the use of mixed culture for the conversion of pollutants. This review forcuses on the various kinds of microorganisms related to each treatment processes. Kinetic analysis of the activated sludge process is discussed in order to understand the basis of control and maintenance of the biological treatment process.

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First Record of Cleantioides planicauda (Crustacea: Isopoda: Holognathidae) from South Korea

  • Song, Ji-Hun;Kim, Min-Seop;Min, Gi-Sik
    • Animal Systematics, Evolution and Diversity
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    • 제30권1호
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    • pp.26-32
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    • 2014
  • Cleantioides planicauda (Benedict, 1899) has previously been recorded in China and Japan. In the present study, to our knowledge, we report for the first time the occurrence of this species in South Korea. Here, we provide detailed descriptions and illustrations of the diagnostic characteristics of C. planicauda. Further, for the first time, we determined the partial sequence of mitochondrial cytochrome c oxidase subunit 1 (CO1) gene of C. planicauda for molecular characteristic. Additionally, we provide a key to the Korean species and distribution of the genus Cleantioides. As a result of this study, four species of the genus Cleantioides, including C. planicauda, have now been recorded in South Korea.

Pilot Plant Study on Biological Nutrient Removal of Wastewater

  • Ahn, Sang-Jin;Kim, Geon-Heung;Ahn, Bok-Kyoun
    • Korean Journal of Hydrosciences
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    • 제1권
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    • pp.99-106
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    • 1990
  • An extensive biological nutrient removal pilot plant study of anoxic/anaerobic/ aerobic treatment process was conducted to eastblish an optimum operational mode using primary dffluent. Two operational modes, (1) Qr/Q was 3.0 and maintaining EMLSS of 3100 mg/L in which the best operational results were obtained from previous bench scale study using synthetic wastewater (2) Qr/Q was 0.5 and EMLSS of 2200 mg/L which was compatible with the main plant, were Compared and evaluated for removal of nitrogen and/or phosphorous under field conditions. The nitrogen removal increased with increasing recycle ratios, but the phosphorous removal revealed more consistent results with 83percent removal efficiency in the second mode compared with 80 percent in the first mode. Above all, the two modes equally showed good BOD and nitrogen removals by nitrification-denitrification processes. It was also observed that no scum formed in the pilot plant and the sludge exhibited excellent settling characteristic all the time. The modified biological nutrient removal train can be adopted to the main plant without any major changes of their operational modes.

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Neriene bovista sp. nov., a new sheet-web spider (Araneae: Linyphiidae) from Korea

  • Lee, Sue Yeon;Yoo, Jung Sun;Kim, Seung Tae
    • Journal of Species Research
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    • 제11권2호
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    • pp.94-97
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    • 2022
  • Linyphiidae Blackwall, 1859 is one of the most diverse and largest families within the order Araneae Clerck, 1757. Of the currently 60 valid species of the genus Neriene Blackwall, 1833 worldwide, 10 species are distributed in Korea. The males of the new sheet-web spider Neriene bovista sp. nov. were recently collected with a sweep net between the shrubs of mixed forests from the hilly valley with well conserved nature in Uljin-gun, Gyeongsangbuk-do (the middle east coast region) during a seasonal survey of the spider fauna in hilly terrains in 2017-2018. The present study describes a new sheet-web spider, Neriene bovista sp. nov. with a diagnosis, detailed description, morphological illustrations, and a distribution map from Korea. The new species has a characteristic mushroom-like tip of the terminal apophysis, the truncated tip of anterior projection, and the bifurcated lateral projection of the lamella compared to the congeners of the genus Neriene Blackwall, 1833.

Bioactivation of Aromatic Amines by Human CYP2W1, An Orphan Cytochrome P450 Enzyme

  • Eun, Chang-Yong;Han, Song-Hee;Lim, Young-Ran;Park, Hyoung-Goo;Han, Jung-Soo;Cho, Kyoung-Sang;Chun, Young-Jin;Kim, Dong-Hak
    • Toxicological Research
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    • 제26권3호
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    • pp.171-175
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    • 2010
  • The human genome contains approximately 13 orphan cytochrome P450 (P450, CYP) genes, of which the apparent function or substrate has not been identified. However, they seem to possess their own biological relevance in some tissues or developmental stages. Here, we characterized the heterologously expressed CYP2W1, an orphan P450 enzyme. The recombinant CYP2W1 protein containing a $6{\times}$(His)-tag at Nterminus has been expressed in Escherichia coli and purified. Expression level of CYP2W1 holoenzyme was around 500 nmol P450 holoenzyme per liter culture medium. The reduced CO difference spectrum of CYP2W1 showed a maximum absorption at 449 nm. CYP2W1 indicated the significant induction to bioactivate Trp-P-1, MeIQ, and IQ in E. coli DJ701 tester strain. However, the bioactivation of B[$\alpha$]P, and NNK by CYP2W1 was relatively low. The model structure of CYP2W1 suggested the characteristic P450 folds with the lengths and orientations of the individual secondary elements. The F-G loop is situated on the distal side of heme to accommodate the flexibility of active site of CYP2W1. These studies can provide useful information for the finding of its biological roles and structure-function relationships of an orphan CYP2W1 enzyme.

Arthrobacter subterraneus sp. nov., Isolated from Deep Subsurface Water of the South Coast of Korea

  • Chang, Ho-Won;Bae, Jin-Woo;Nam, Young-Do;Kwon, Hyuk-Yong;Park, Ja-Ryeong;Shin, Kee-Sun;Kim, Kyoung-Ho;Quan, Zhe-Xue;Rhee, Sung-Keun;An, Kwang-Guk;Park, Yong-Ha
    • Journal of Microbiology and Biotechnology
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    • 제17권11호
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    • pp.1875-1879
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    • 2007
  • Strain $CH7^T$, a pale yellow-pigmented bacterium and new isolate from deep subsurface water of the South Coast of Korea, was subjected to a polyphasic taxonomic study. $CH7^T$ grew between 5 and $37^{\circ}C$, pH 5.3-10.5, and tolerated up to 13% NaCl. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain $CH7^T$ was associated with the genus Arthrobacter and phylogenetically closely related to the type strains Arthrobacter tumbae (99.4%) and Arthrobacter parietis (99.1%). However, DNA-DNA hybridization experiments revealed 2.1% and 12% between strain $CH7^T$ and Arthrobacter tumbae and Arthrobacter parietis, respectively. Thus, the phenotypic and phylogenetic differences suggested that $CH7^T$ should be placed in the genus Arthrobacter as a novel species, for which the name Arthrobacter subterraneus sp. novo is proposed. In addition, the type strain for the new species is $CH7^T$ ($=KCTC\;9997^T=DSM\;17585^T$).

펄스변조의 듀티비 변경에 따른 DBD 대기압 플라즈마 특성 연구 (Study on the Atmospheric Plasma Characteristics of Dielectric Barrier Discharge due to a Variation of the Duty Ratio of Pulse Modulation)

  • 박종인;황상혁;조태훈;윤명수;곽형신;진기남;전부일;최은하;권기청
    • 한국재료학회지
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    • 제25권11호
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    • pp.616-621
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    • 2015
  • Atmospheric pressure plasma is used in the biological and medical fields. Miniaturization and safety are important in the application of apply atmospheric plasma to bio devices. In this study, we made a small, pocket-sized inverter for the discharge of atmospheric plasma. We used pulse power to control the neutral gas temperature at which the, when plasma was discharged. We used direct current of 5 V of bias(voltage). The output voltage is about 1 to 2 kilo volts the frequency is about 80 kilo hertz. We analyzsed the characteristics of the atmospheric plasma using OES(Optical emission spectroscopy) and the Current-Voltage characteristic of pulse power. By calculating of the current voltage characteristics, we were able to determine that, when the duty ratio increased, the power that actually effects the plasma discharge also increased. To apply atmospheric plasma to human organisms, the temperature is the most important factor, we were able to control the temperature by modulating the pulse power duty ratio. This means we can use atmospheric plasma on the human body or in other areas of the medical field.

얼굴의 특이점 검출 및 실시간 추적을 이용한 e-Book 제어 (Unconstrained e-Book Control Program by Detecting Facial Characteristic Point and Tracking in Real-time)

  • 김현우;박주용;이정직;윤영로
    • 대한의용생체공학회:의공학회지
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    • 제35권2호
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    • pp.14-18
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    • 2014
  • This study is about e-Book program based on human-computer interaction(HCI) system for physically handicapped person. By acquiring background knowledge of HCI, we know that if we use vision-based interface we can replace current computer input devices by extracting any characteristic point and tracing it. We decided betweeneyes as a characteristic point by analyzing facial input image using webcam. But because of three-dimensional structure of glasses, the person who is wearing glasses wasn't suitable for tracing between-eyes. So we changed characteristic point to the bridge of the nose after detecting between-eyes. By using this technique, we could trace rotation of head in real-time regardless of glasses. To test this program's usefulness, we conducted an experiment to analyze the test result on actual application. Consequently, we got 96.5% rate of success for controlling e-Book under proper condition by analyzing the test result of 20 subjects.

형태학적 특징을 이용한 향상된 치아 검출 방법 (Improved Tooth Detection Method for using Morphological Characteristic)

  • 나승대;이기현;이정현;김명남
    • 한국멀티미디어학회논문지
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    • 제17권10호
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    • pp.1171-1181
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    • 2014
  • In this paper, we propose improved methods which are image conversion and extraction method of watershed seed using morphological characteristic of teeth on complement image. Conventional tooth segmentation methods are occurred low detection ratio at molar region and over, overlap segmentation owing to specular reflection and morphological feature of molars. Therefore, in order to solve the problems of the conventional methods, we propose the image conversion method and improved extraction method of watershed seed. First, the image conversion method is performed using RGB, HSI space of tooth image for to extract boundary and seed of watershed efficiently. Second, watershed seed is reconstructed using morphological characteristic of teeth. Last, individual tooth segmentation is performed using proposed seed of watershed by watershed algorithm. Therefore, as a result of comparison with marker controlled watershed algorithm and the proposed method, we confirmed higher detection ratio and accuracy than marker controlled watershed algorithm.