• Title/Summary/Keyword: L/D rate

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Inactivation Kinetics of Listeria innocua ATCC 33090 at Various Temperature Heating-up and Pressure Building-up Rates

  • Ahn, Ju-Hee;Balasubramaniam, V.M.
    • Food Science and Biotechnology
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    • v.16 no.2
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    • pp.255-259
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    • 2007
  • The effects of temperature heating-up rate and pressure building-up phase on the inactivation of Listeria innocua ATCC 33090 were evaluated in buffered peptone water. The number of L. innocua was reduced by 5.57 and 6.52 log CFU/mL during the nonisothermal treatment (the come-up time followed by isothermal process) and the isothermal treatment, respectively, at $60^{\circ}C$. When compared to the isothermal treatment (0.76$33.2^{\circ}C/min$ of temperature heating-rate. The effect of the combined high pressure and thermal processing on the inactivation of L. innocua increased with increasing pressure and temperature. At all temperature levels from 40 to $60^{\circ}C$ under 700 MPa, L. innocua was not detected by enrichment culture (>7 log reduction).

Biological Hydrogen Production from Mixed Waste in a Polyurethane Foam-sequencing Batch Reactor (혼합폐기물 및 폴리우레탄 담체를 충전한 연속회분식공정을 이용한 생물학적 수소생산)

  • Lee, Jung-Yeol;Wee, Daehyun;Cho, Kyung-Suk
    • Microbiology and Biotechnology Letters
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    • v.42 no.3
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    • pp.307-311
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    • 2014
  • This study investigated the effects of polyurethane foam on continuous hydrogen production from mixed wastes. Molasses was co-fermented with non-pretreated sewage sludge in a sequencing batch reactor. The results indicated that the addition of polyurethane foams as a microbial carrier in the reactor mitigated biomass loss at HRT 12 h, while most of the biomass was washed out during the operation period with no carrier. There was a stable hydrogen production rate of $0.4L-H_2/l/d$ in the carrier-sequencing batch reactor. Suspended biomass in the carrier-reactor indicated it possessed the highest specific hydrogen production rate ($241{\pm}4ml-H_2/g\;VSS/d$) when compared to that of biomass on the surface ($133{\pm}10ml-H_2/g\;VSS/d$) or inner carrier ($95{\pm}14ml-H_2/g\;VSS/d$).

Mass Propagation of Dicentra spectabilis L. Lemaire Through In vitro Suspension Culture (현탁배양을 통한 금낭화(Dicentra spectabilis L. Lemaire)의 대량증식)

  • Lee, Kang-Seop;Sim, Ock-Kyeong;Shin, Jeong-Sun;Choi, Yong-Eui;Kim, Ee-Yup
    • Journal of Plant Biotechnology
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    • v.31 no.2
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    • pp.121-126
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    • 2004
  • Bleeding heart (Dicentra spectabilis L. Lemaire) is one of the most valuable wild flower in Korea. This work was conducted for the mass production of somatic embryos through suspension culture and more effective plant regeneration system in Dicentra spectabilis. High-frequency embryogenic callus proliferation was achieved in SH liquid medium supplemented with 1 mg/L 2,4-D. Half-strength SH medium was suitable concentration for somatic embryo induction and germination. About 5,000 embryos were produced per 250$m\ell$ flask after 4 weeks of culture. Germination rate of somatic embryos was decreased when GA$_3$ was added in medium. The plantlets showed a 58% survival rate when transferred to pots after 1 month of culture. The results indicate that micropropagation procedure via somatic embryogenesis can be applied for an efficient mass propagation of Dicentra spectabilis.

The Application of Direct Water Quenching Process in Hot Stamping of Boron Steels (보론강 판재 핫스탬핑시 직수분사냉각 공정의 적용성)

  • Park, Hyeon Tae;Kwon, Eui Pyo;Im, Ik-Tae
    • Korean Journal of Materials Research
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    • v.29 no.12
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    • pp.818-824
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    • 2019
  • In this study, the direct water quenching technique is applied to validate the applicability of direct water quenching as a cooling method in the hot stamping process of 3.2 mm thick boron steel sheet. Cooling performance of conventional die quenching and direct water quenching is compared. Higher cooling rate is obtained by hot stamping with direct water quenching compared to die quenching. As the flow rate of cooling water increases, the cooling rate increases, and a high cooling rate of 71 ℃/s is achieved under flow rate conditions of 0.8 L/min. Through direct water quenching, the cooling time required for sufficient cooling of the sheet is reduced. Full martensitic microstructure is obtained under flow rate condition of 0.8 L/min. Hardness increases with increasing flow rate. From these results, it is verified that the direct water quenching is applicable to the hot stamping of thick boron steel sheet.

Influence of Applied Voltage for Bioelectrochemical Anaerobic Digestion of Sewage Sludge (하수슬러지의 생물전기화학 혐기성소화에 대한 인가전압의 영향)

  • Kim, Dong-Hyun;Song, Young-Chae;Qing, Feng
    • Journal of Korean Society of Environmental Engineers
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    • v.37 no.9
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    • pp.542-549
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    • 2015
  • The bioelectrochemical anaerobic digestion for sewage sludge was attempted at different applied voltages ranged from 0.2 V to 0.4 V. At 0.3 V of the applied voltage, pH and VFAs were at 7.32 and 760 mg COD/L, respectively, which were quite stable. The methane production rate was $1.32L\;CH_4/L.d$, and the methane content in biogas was 73.8%, indicating that the performance of the bioelectrochemical anaerobic digestion could be considerably improved by applying a low voltage. At 0.4 V of the applied voltage, however, the contents of the minor VFA components including formic acid and propionic acid were increased. The methane production rate was reduced to $1.24L\;CH_4/L.d$ and the biogas methane content was also reduced to 72.4%. At 0.2 V of the applied voltage, the pH was decreased to 6.3, and VFAs was accumulated to 5,684 mg COD/L. The contents of propionic acid and butyric acid in the VFAs were considerably increased, The performances in terms of the methane production rate and the biogas methane content were deteriorated. The poor performance of the bioelectrochemical reactor at 0.2 V of the applied voltage was ascribed to the thermodynamic potential lack for the driving of the carbon dioxide reduction into methane at cathode.

Callus Formation and Plant Regeneration from Immature Embryos of Eleutherococcus senticosus (가시오갈피 미숙배 배양으로부터 Callus 형성 및 식물체 재분화)

  • Yu, Chang-Yeon;Kim, Jae-Kwang;Ahn, Sang-Deuk
    • Korean Journal of Medicinal Crop Science
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    • v.5 no.1
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    • pp.49-55
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    • 1997
  • This study was conducted to establish mass propagation system from the tissue culture using immature embryos in Eleutherococcus senticosus. Immature embryos from seeds were removed under the microscope and placed on MS, $MSB_5\;and\;B_5$ medium containing several plant growth regulators. While the calli were well formed on media containing 2 mg/l of 2, 4-D, 2 mg/l of 2, 4-D and 0.7 mg/l of TDZ, shoot regeneration was better on MS medium with combinations of high concentrations of TDZ and low concentrations of 2, 4-D. Treatment of 2, 4-D alone was better than treatment of TDZ alone in callus induction, but plant regeneration was reversed. The results of callus formation and shoot regeneration on $MSB_5\;and\;B_5$ media were similar to those of MS media. The rate of callus formation was nearly 100% when 2, 4-D was added to $B_5$, medium on concentration of 2 mg/l or 0.7 mg/l. TDZ showed very significant effect on the formation of multiple shoots.

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Microbial Control of Forest Insect Pests (II) (산림해충의 미생물적 방제 2)

  • 이응래;황계성
    • Korean Journal of Microbiology
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    • v.9 no.2
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    • pp.69-73
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    • 1971
  • On June in 1970 the authors discovered a pathogenecity, cytoplasmic polyhedrosis virus, of the Smithia virus in the larvae of Liparis dispay L. appeared on quercus forest in Chung-Neung district and had carried out a experiment to detect the pathogenecity of Smithia virus through the inoculation of it into the larvase, such as Liparis dispay L. Hyphantrea cunea DRURY, and Dendrolinus spectabilis BUTLER. The results obtained were as follows ; 1) Death rate of L.dispay and D.spectabilis treated by 10$^{6}$ /ml cytoplasmic polyhedrosis virus of Smithis virus were 88.0% and 85.5% respectively, when the larvaes of these insects are big enough. But there were none of pathogenecity in case of Hyphantrea cunea DRURY. 20 Dead larvae caused by the injection of Smithia virus had begum to find out about on 10 days after inoculation. Miximum death rate of L. didpay and D. spectabilis appeared on 20-25days nad on 25-30days, respectively, after the incoulation. 3) In the cytoplasm of Mid-gut cylindrical cells of both of these insects, polyhedrosis, such s hexagonal (0.5-2.0-6.0 micron) were found out and in these insects, polyhedrosis, such as hexaginal (0.5-2.0-6.0 mivton) were found out and in case of D.spectabilis were a few polyhedrosis, such as tetragonal, trianglar polyhedrosis. 4) Diluted concentration of `0$^{6}$ /ml cytoplasmic polyhedrosis virus of Smithia virus were spread out in the field conditions. The corrected mortality was confirmed as about 87.8%.

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The study for Biological nutrient removal of High-strength nitrogen loading rate using B3 pilot plant (B3 Pliot plant를 이용한 고농도 질소부하에서의 고도처리에 관한 연구)

  • Eorn Tae-Kyu;Han Dong-Yueb;Kim Boo-Gil
    • Journal of Environmental Science International
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    • v.14 no.8
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    • pp.771-775
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    • 2005
  • The purpose of this research was to investigate applicative possibility of field. Pilot-scale experiments were conducted, at outdoor temperature, HRT l0hour, IR(Internal Recycle) $150\%$ and used $2.8m^3$ Reactor. External carbon source was varied 80 to 120 mg/L. When External carbon source and Alkalinity were injected to the B3 pilot plant, the removal efficiencies of COD and BOD were not decreased. Nitrification rate were 5.95, 5.40, 4.08 $mgNH_4^+-N/gSS/d$ during operation periods and denitrification rate was $3.l2mgNO_3^--N/gSS/d.$ When we surveyed the relationship between loading rate of nitrogen and nitrogen removal quantity, this data was 0.949, B3 process will be possible application process of field.

Multiple Shoots Regeneration and In vitro Bulblet Formation from Garlic Callus

  • Kim Soon-Seob;Guo De-Ping;Jung Do-Cheol;Kwon Soon-Tae
    • Journal of Plant Biotechnology
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    • v.5 no.2
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    • pp.95-99
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    • 2003
  • The leaf segments of garlic (Allium sativum L.) were cultured in vitro and determined optimal concentration of plant growth regulators and sugars for callus induction, multiple shoots regeneration and in vitro bulblet formation. Highest yield of callus was observed in the leaf segment culture on Murashige and Skoog (MS) medium supplemented with 1.0 mg/L 2,4-D, 30 g/L sucrose and 8 g/L agar. Regeneration rate of multiple shoots from callus was high in the MS medium supplemented with kinetin 3.0 + NAA 3.0 mg/L or SA 1.0 + NAA 3.0 mg/L, containing 30 g/L sucrose. High rate of bulblet formation was observed as the concentration of jasmonic acid increased from 0.5 to 2.0 mg/L in medium, whereas addition of gibberellic acid significantly suppressed bulblet formation. The rate of in vitro bulbing was as high as $96\%$ in MS medium supplemented with 2.0 mg/L jasmonic acid and 120 g/l sucrose after two month culture at $25{\pm}1^{\circ}C$ under 16 hours day light.