• Title/Summary/Keyword: solid media

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Evaluation of Downflow Granular Media Filtration for Stormwater Treatment (강우유출수에 의한 비점오염 저감을 위한 하향류식 입상여과 효율 평가)

  • Lim, Chan-Su;Kim, Do-Gun;Ko, Seok-Oh
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.10
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    • pp.684-693
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    • 2012
  • The stormwater runoff from the increasing paved roads and vehicles resulted in the increase in the pollutants load to adjacent water bodies. The granular media filtration facilities are the most widely adopted to minimize the non-point source pollution from motorways. It is essential to consider the severe variation of hydraulic condition, suspended solid (SS) characteristics, and the medium characteristics for stormwater management filter. In this study, different types of media, including sand, were tested and the performance of downflow sand filters was investigated under various linear velocity and influent solid particle size. Results showed that the best medium is the coarse sand with large grain size, which showed the specific SS removal before clogging of more than $8.498kg/m^2$, the SS removal of higher than 95%, and minimum head loss. Linear velocity did not affect the total solid removal, while the performance was improved when fine solid was introduced. It is suggested that the life of a downflow sand filter bed can be extended by deep bed filtration when influent particles are fine. However, the captured particles can be washed out after a long period of operation.

Increasing Trend of Isolation of Non-Tuberculous Mycobacteria in a Tertiary University Hospital in South Korea

  • Yoo, Jung-Wan;Jo, Kyung-Wook;Kim, Mi-Na;Lee, Sang-Do;Kim, Woo-Sung;Kim, Dong-Soon;Shim, Tae-Sun
    • Tuberculosis and Respiratory Diseases
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    • v.72 no.5
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    • pp.409-415
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    • 2012
  • Background: The isolation of non-tuberculous mycobacteria (NTM) has been increasing in South Korea. To date, however, the cause of this increase has not been determined, and it remains unclear whether the use of liquid media has contributed to this increase. The aim of this study was to evaluate the factors associated with NTM isolation and the impact of liquid media on NTM culture. Methods: Mycobacterial smear/culture results of respiratory specimens (sputum and bronchial aspirates), obtained during the years 2002, 2005, and 2010, were retrieved and analyzed retrospectively. Results: During the years 2002, 2005, and 2010, 83,096 sputum specimens were collected from 31,104 patients, and were cultured for mycobacteria, using solid media only in the 2002 and 2005 specimens and both solid and liquid media in the 2010. Of these, 3,516 (4.2%) specimens were smear-positive for acid-fast bacilli (AFB). The annual rate of NTM among positive culture specimens increased from 21% in 2002 to 57.8% in 2010 (p<0.001), as did the proportion of NTM, among AFB smear- and culture-positive specimens, from 12.2% in 2002 to 45.2% in 2010 (p<0.001). In 2010, the NTM culture rate was higher in the liquid than in the solid media (13.9% vs. 8.4%, p<0.001). The NTM rate among AFB-positive specimens was higher in patients aged >50 than ${\leq}$50 years. Conclusion: The rate of NTM isolation has steadily been increasing at the hospital in South Korea, likely due in part to the use of liquid media for the culture.

The effect of medium change after pretreating microspores, medium addition, and volume of under solid medium in double layer culture on the production of embryos in isolated microspore culture of hot pepper (Capsicum annuum L.) (고추의 소포자 배양 시 전처리 후 배지의 교환, 배지의 첨가 및 2층배양 시 하층고체 배지의 양이 배의 생산에 미치는 영향)

  • Park, Eun-Joon;Lee, Jong-Suk;An, Dong-Joo;Kim, Moon-Za
    • Journal of Plant Biotechnology
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    • v.37 no.4
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    • pp.494-504
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    • 2010
  • The effect of the addition of the fresh medium, volume of under solid medium in double layer culture as well as the medium change after pretreating microspores on the production of embryos in microspore culture of hot pepper (Capsicum annuum L.) has been studied. When cultured after heat pre-treatment, changing pretreatment media with fresh culture media proved to be more effective for embryo production rather than supplementing additional culture media. Heat-pretreating for 3 days turned out more effective for embryo production than pretreating for 1 or 2 days. In the case of anther pretreatment, the addition of fresh medium after culture was not effective for embryo production. In pretreating microspores, however, supplementing additional fresh culture media greatly improved embryo yield and quality. The best time point of media addition was 4 days after culture commenced, and the most effective number of times of media addition was one time addition. Moreover, the effective volume of added medium in double layer culture for embryo production was 1.5 ml. The addition of media more than 1.5 ml reduced both embryo yield and quality. Double layer medium was more effective for embryo development than liquid medium. When the volume of under solid medium increased ranging from 3 ml to 7 ml, more cotyledonary embryos were produced in either 5 ml or 7 ml compared to 3 ml, even though the total number of embryos were highest in 3 ml. These results can be used as an important data for establishing an efficient microspore culture system for producing high frequency of normal embryos in hot pepper.

Culture Characteristics of Streptomyces spp. on Improved Polyacrylamide Gel and Agar Media

  • Han, Hong ui;Baek, Ji-Ho;Yang, Moon
    • Journal of Microbiology
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    • v.34 no.4
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    • pp.384-386
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    • 1996
  • Application of polyacrylamide gel (PAG) instead of agar to solid cultures of Streptomyces spp. was studied. The improved media were prepared by 1) gelling 20 ml of 5% acrylamide in a glass petri dish at room temperature, 2) washing by running water for more than 8 hr to remove residual reaction reagents, 3) drying at 5$0^{\circ}C$ for 12 hr to make a gel film, 4) autoclaving at 121$^{\circ}C$ for 15 min, and 5) swelling gel for about 4 hr by adding sterile liquid medium. In PAG media there were no differences from the observation of morphological characteristics showing during the cellular differentiation on agar media, whereas the ability to utilize carbohydrates differed somewhat from agar media. Agar media thus were little favorable for biochemical tests which the growth was determined depending on the formation of colony, but washed PAG was superior to serve as a solidifying agent.

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Sawdust cultures of Lepista nuda (민자주방망이버섯 (Lepista nuda)의 톱밥배양)

  • Lee, Sang-Sun;Choi, Kyoung-Jin;Oh, Chang-Ho
    • The Korean Journal of Mycology
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    • v.24 no.4 s.79
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    • pp.274-279
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    • 1996
  • An isolate of Lepista nuda was cultivated on the solid media consisted of various cereal grains or those of the acacia sawdust mixed with other cereal grains. The mycelia grew well on the solid cultures made from millet cereals, but did not on those from sorghum or corn cereals. Thus, the millet and the acacia sawdust, as the solid media, were employed for the next experiments related to mycelial growths. For growth of this isolate, it was shown that the nitrogen source is needed for those of millet. Also, the rice bran or minerals were considered to be needed for the acacia sawdust. As minerals, however, the rice bran is shown as the best additive in the solid cultures of the acacia sawdust. The mycelia of L. nuda were cultivated directly through the solid cultures. Their growths were measured' by the production of carbon dioxide with gas chromatography.

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Enhancement of Nitrendipine Bioavailability in Rats by its Solid Dispersion with $Hydroxypropyl-{\beta}-Cyclodextrin$ after Oral Administration (흰쥐에 경구 투여시 히드록시프로필-베타-시클로덱스트린과 니트렌디핀 고체분산에 의한 생체이용률 증가)

  • Yong, Chul-Soon
    • Journal of Pharmaceutical Investigation
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    • v.27 no.4
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    • pp.295-301
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    • 1997
  • Nitrendipine, a slightly soluble calcium channel blocking agent forms a solid dispersion system with $hydroxypropyl-{\beta}-cyclodextrin$, which exhibits better dissolution characteristics than the uncomplexed drug. The dissolution rate of nitrendipine was markedly increased in solid dispersion system in pharmacopeial disintegration media at pH 1.2 and pH 6.8. Four different dosage forms of nitrendipine were administered to rats: (a) nitrendipine in the solution of PEG 400; (b) nitrendipine solid dispersion system with $hydroxypropyl-{\beta}-cyclodextrin$ in a molar ratio of 1:2 by solvent evaporation method and administered in capsule form; (c) physical mixture of nitrendipine with $hydroxypropyl-{\beta}-cyclodextrin$ in a molar ratio of 1:2 and administered in capsule form; (d) nitrendipine alone administered in capsule form. Relative bioavailability after the oral administration of various dosage forms to rats with a dose of 10 mg/kg equivalent to nitrendipine was compared with that of nitrendipine in the solution of PEG 400. The AUC of solid dispersion was significantly bigger than that of nitrendipine powder. $T_{max}$ of solid dispersion was significantly shorter and $C_{max}$ was higher than that of nitrendipine powder. These results indicate that the bioavailability of nitrendipine could be improved markedly by inclusion complexation. An interesting correlation also appears to exist between the in vitro dissolution data and the area under the plasma concentration-time curves.

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Effect of fractional order on energy ratios at the boundary surface of elastic-piezothermoelastic media

  • Kumar, Rajneesh;Sharma, Poonam
    • Coupled systems mechanics
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    • v.6 no.2
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    • pp.157-174
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    • 2017
  • In the present investigation reflection and transmission of plane waves at an elastic half space and piezothermoelastic solid half space with fractional order derivative is discussed. The piezothermoelastic solid half space is assumed to have 6 mm type symmetry and assumed to be loaded with an elastic half space. It is found that the amplitude ratios of various reflected and refracted waves are functions of angle of incidence, frequency of incident wave and are influenced by the piezothermoelastic properties of media. The expressions of amplitude ratios and energy ratios are obtained in closed form. The energy ratios are computed numerically using amplitude ratios for a particular model of graphite and Cadmium Selenide (CdSe). The variations of energy ratios with angle of incidence are shown graphically. The conservation of energy across the interface is verified. Some cases of interest are also deduced from the present investigation.

The Introduction of Polycrylamide Gel into the Solid Culture of Streptomyces spp

  • Han, Hong-Ui;Yang, Moon
    • Korean Journal of Microbiology
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    • v.30 no.1
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    • pp.65-69
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    • 1992
  • It is proposed the polyacrylamide gel, instead of agar, could be used for the solid cultures of microorganisms including Streptomyces strains. Polymerization and gellation of 5% acrylamide solution were done by autoclaving for 5 min at 121.deg.C and no hindered by the addition of nutrient-rich media. In particular, pH buffer solution suitable for corresponding microorganisms must be used in the preparation of culture media. Comparing with agar, it was discussed that polycrylamide gel had many advantages such as gellation within the wide range of strong acid Carbon and Nitrogen sources, requirement tests of growth factors and minerals, sterization at high temperature, diffusion assays of products depending on the pore size of gel, and stability and standarization of microbial cultures.

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Analysis on Phase and Amplitude Apodization in SIL Based Near-Field Recording Optics (SIL 응용 광 기록계에서 발생하는 위상 및 진폭 Apodization 해석)

  • Kim Wan-Chin;Choe Hyeon;Song TaeSun;Park No-Cheol;Park Young-Pil
    • 정보저장시스템학회:학술대회논문집
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    • 2005.10a
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    • pp.14-15
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    • 2005
  • In near-field recording (NFR) optics using solid immersion lens (SIL), near-field air gap induces unwanted spherical aberration, defocus and astigmatism. This phenomenon can be explained with the apodization of phase and amplitude between each linearly polarized light. In this paper, we analyzed the effect of phase and amplitude apodization with the fundamental multiple beam interference theory, and we compared resultant diffracted patterns on the image plane for the Si-disk first surface media structure and cover-layer incident media structure.

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Design of Soft RAID Storage System for SSD(Solid State Disk) (SSD를 위한 Soft RAID 저장 시스템 설계)

  • Byun, Si-Woo;Hur, Moon-Hang;Roh, Chang-Bae;Kim, Deog-Tae
    • Proceedings of the KAIS Fall Conference
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    • 2008.05a
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    • pp.218-219
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    • 2008
  • Solid State Disks(SSD) are one of the best candidates to support next storage technology in desktop and server computing environment. The features of non-volatility, low power consumption, and fast access time for read operations are sufficient grounds to support SSD as major components of future storages. This paper describes a technical trend of HDD based RAID technology and proposes a new RAID system for SSD.

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