• Title/Summary/Keyword: pellet formation

Search Result 86, Processing Time 0.024 seconds

Bio-capsule Formation for Synchronous Saccharification and Fermentation Process (동시당화발효공정을 위한 바이오캡슐 형성)

  • Shin, Gyeong Yeon;Choi, Hye Jung;Kang, Yang-Rae;Nam, Ki-Du;Song, Ju Yeong;Joo, Woo Hong
    • Microbiology and Biotechnology Letters
    • /
    • v.45 no.2
    • /
    • pp.162-167
    • /
    • 2017
  • For the production of bioethanol by the synchronous saccharification and fermentation (SSF) process, bio-capsule formation was attempted. Many saccharifying fungal strains and fermentative yeast strains were first screened. Aspergillus sp. BCNU 6200, Penicillium sp. BCNU 6201, and P. chrysogenum KACC 44363 were found to be excellent producers of saccharifying enzymes such as ${\alpha}$-amylase and glucoamylase. Saccharomyces cerevisiae IFO-M-07 showed the highest ethanol productivity among the tested strains. Secondly, we determined the optimal conditions for pellet formation, and those for bio-capsule formation. All the tested fungal strains formed pellets, and the optimal conditions for bio-capsule formation were $28^{\circ}C$ and 120 rpm. Lastly, SSF process was performed using a bio-capsule. An ethanol yield of 3.9% was achieved by using the Aspergillus sp. BCNU 6200 bio-capsule (Aspergillus sp. BCNU 6200 + S. cerevisiae IFO-M-07) at $30^{\circ}C$ with shaking at 120 rpm during the 10 days of incubation. The results provide useful information on the application of a bio-capsule in bioethanol production under the SSF process.

Effect of High Temperature Treatment and Subsequent Oxidation anil Reduction on Powder Property of Simulated Spent Fuel

  • Song, Kun-Woo;Kim, Young-Ho;Kim, Bong-Goo;Lee, Jung-Won;Kim, Han-Soo;Yang, Myung-Seung;Park, Hyun-Soo
    • Nuclear Engineering and Technology
    • /
    • v.28 no.4
    • /
    • pp.366-372
    • /
    • 1996
  • The simulated spent PWR fuel pellet which is corresponding to the turnup of 33,000 MWD/MTU is prepared by adding 11 fission-product elements to UO$_2$. The simulated spent fuel pellet is treated at 40$0^{\circ}C$ in air (oxidation), at 110$0^{\circ}C$ in air (high-temperature treatment), and at $600^{\circ}C$ in hydrogen (reduction). The product is treated through additional addition and reduction up to 3 cycles. Pellets are completely pulverized by the first oxidation, and the high-temperature treatment causes particle and crystallite to grow and surface to be smooth, and thus particle size significantly increases and surface area decreases. The reduction following the high-temperature treatment decreases much the particle size by means of the formation of intercrystalline cracks. The particle size decreases a little during the second oxidation and reduction cycle and then remains nearly constant during the third and fourth cycles. Surface area of pounder increases progressively with the repetition of oxidation and reduction cycles, mainly due to the formation of Surface cracks. The degradation of surface area resulting from high-temperature treatment is restored by too subsequent resulting oxidation and reduction cycles.

  • PDF

Bi-electrolyte Carbon Dioxide Gas Sensor Based on Paste Sodium-Beta Alumina and Yttria-stabilized Zirconia

  • Han, Hyeuk Jin;Park, Chong Ook
    • Journal of Sensor Science and Technology
    • /
    • v.23 no.3
    • /
    • pp.170-172
    • /
    • 2014
  • $CO_2$ sensor was used only one solid electrolyte in many cases. To improve the sensing characteristics of $CO_2$ sensors, solid electrolyte $CO_2$ sensor has been developed by bi-electrolyte type sensor using Na-Beta-alumina and YSZ. However, in many further studies, bi-electrolyte type sensor was made by pellet pressed by press machine and additional treatment for formation of interface. In the aspect of mass production, using thick film and additional treatment is not suitable. In this study, $CO_2$ sensor was fabricated by bi-electrolyte structure which was made by an NBA paste layer deposited on YSZ pellet and fired at $1650^{\circ}C$ for 2 hour. The formation of stable interface between YSZ and NBA were confirmed by SEM image. When the type IV electrochemical cell arrangement represented by $CO_2,O_2,Pt{\mid}Li_2CO_3-CaCO_3{\parallel}NBA{\parallel}YSZ{\mid}O_2,Pt$ is used to measure the $CO_2$ concentration in air. This sensor EMF should depend only on the concentration of $CO_2$ by logarithmic. Also, sensor shows $P_{CO_2}$ and EMF relationship like nerstian reaction at a temperature of $450^{\circ}C$.

Anti-pyretic and anti-inflammatory activity of chloroform extract of Croton roxburghii in standard animal models

  • Sivakumar, T;Rajavel, R;Karthikeyan, D;Duraisamy, R;Srinivasan, K;Kumar, S Suresh;Karki, Subhas S
    • Advances in Traditional Medicine
    • /
    • v.8 no.3
    • /
    • pp.252-259
    • /
    • 2008
  • The chloroform extract of Croton roxburghii (Family: Euphorbiaceae) was evaluated for its antipyretic effects in Brewer's yeast induced hyperthermia in rats. The anti-inflammatory effect of the Croton roxburghii was also evaluated by using carrageenan, dextran, histamine, serotonin induced rat paw oedema and cotton pellet induced granuloma (chronic) models in rats. The chloroform extract of Croton roxburghii (CECR) exhibited significant anti-pyretic and anti-inflammatory effect at the dose 50, 100 and 200 mg/kg. Maximum inhibition (55.32%) was notedat the dose of 200 mg/kg after 3 h of drug treatment in carrageenan induced paw oedema, whereas the Indomethacin (standard drug) produced 61.33% of inhibition. The extract exhibited significant anti-inflammatory activity in dextran induced paw edema in a dose dependent manner. In the chronic model (cotton pellet induced granuloma) the CECR (200 mg/kg) and Indomethacin (10 mg/kg) showed decreased formation of granuloma tissue by 52.32% and 56.32% respectively. The extract also exhibited a significant antipyretic response in Brewer's yeast induced pyrexia in rats. Thus, the present study revealed that the CECR exhibited significant antipyretic and anti-inflammatory activity in the tested animal models.

The Interface Reaction Between Molten Converter Slag and $C_3A(3CaO{\cdot}Al_2O_3)$ Pellet (용융전로(熔融轉爐)슬래그와 $C_3A(3CaO{\cdot}Al_2O_3)$ 펠렛사이의 계면반응(界面反應))

  • Kim, Young-Hwan;Ko, In-Yong
    • Resources Recycling
    • /
    • v.14 no.5 s.67
    • /
    • pp.13-17
    • /
    • 2005
  • As a basic study for recycling molten converter slag as an ordinary portland cement (OPC) by a conversion process, the reaction mechanism and the rate of the formation of $C_4AF$ which is one of the main components of OPC were investigated. The converter slag whose basicity was controlled by adding reagent grade $SiO_2$ was melted and hold for 30 minutes in MgO crucible at $1300^{\circ}C{\sim}1350^{\circ}C$. Then, the sintered CaO pellet heated at the same temperature was dipped into the molten slag and hold for $10{\sim}30$minutes. After the reaction, the crucible was cooled in air and the specimen was cut off to the horizontal direction of the crucible. The dissolution rate of $C_3A$ pellet was measured by the change of radius of the sintered $C_3A$ pellet, and the formed phase of $C_4AF$ was observed by SEM/EDX. As a result, the dissolution rate of $C_3A$ pellet into molten slag was increased from $0.75{\times}10^{-4}(cm/sec)$ at $1300^{\circ}C$ to $1.67{\times}10^{-4}(cm/sec)$ at $1350^{\circ}C$, and the mixed layer of $C_4AF$ and $C_{12}A_7$ was found between slag and $C_3A$ pellet.

Evaluation of anti-inflammatory activity of Solanum trilobatum roots

  • Pandurangan, A;Khosa, RL;Hemalatha, S
    • Advances in Traditional Medicine
    • /
    • v.8 no.4
    • /
    • pp.416-422
    • /
    • 2008
  • This study evaluated the anti-inflammatory potential of the crude alkaloidal fraction (CAF) of methanol extract of Solanum trilobatum Linn. (Solanacea) root in animal models of inflammation. Crude alkaloidal fraction at doses of 25, 50 and 100 mg/kg significantly (p < 0.01) reduced carrageenan induced rat paw volume at 3 h after carrageenan challenge as compared to control group of animals. CAF (25, 50 and 100 mg/kg) significantly (p < 0.01) and dose dependently suppressed cotton pellet induced granuloma formation. Topical application of CAF (1, 5 and 10 mg/ear) markedly inhibited multiple application of TPA in mice. CAF elicited pronounced inhibitory effects on formaldehyde and adjuvant induced arthritis in rats. These results indicate that CAF of methanol extract of the Solanum trilobatum has anti-inflammatory activity in acute and chronic inflammation.

Controlled Release of Doxazosin in Multi-layered Pellet Using Polymer Blending (고분자 블렌딩을 이용하여 제조된 독사조신 다중층 펠렛의 약물방출제어)

  • Youn, Ju-Yong;Park, Sang-Wook;Lee, Soo-Young;Kim, Moon-Suk;Lee, Bong;Khang, Gil-Son;Lee, Hai-Bang
    • Polymer(Korea)
    • /
    • v.32 no.4
    • /
    • pp.322-327
    • /
    • 2008
  • In this study, a multi-layered pellet was composed of a seed layer including a water-swellable agent and a drug layer containing doxazosin as a model drug, a porous membrane and a castor oil layer to control drug release. The pellet is prepared by a fluidized bed coating method. To confirm drug release from polymer blending in multi-layered pellet system, it is prepared by containing different ratio such as hydroxypropylmethylcellulose (HPMC) : ethyl cellulose (EC) in drug layer and cellulose acetate(CA) : Eudragit RS in membrane. Also, to confirm the effect of oil in drug release, castor oil is coated. As a result, we observed regularly spherical pellet with diameter of $1500{\mu}m$. Release pattern of drug is confirmed by dissolution tester in aqueous media. The more the ratio of EC in drug layer, CA in membrane, and castor oil layer in pellet, the less the drug release is observed. Formation and the amount of pores in membrane is observed by SEM.

Microstructure Development during Sintering of $Nb_2O_5$-doped $UO_2$ pellets under $H_2$ and $CO_2$ atmospheres ($Nb_2O_5$ 첨가 $UO_2$ pellet의 수소 분위기와 이산화탄소 분위기 소결 중 미세조직의 형성에 대한 연구)

  • Song, K.W.;Kim, S.H.;Kim, B.G.;Lee, Y.W.;Yang, M.S.;Park, H.S.
    • Nuclear Engineering and Technology
    • /
    • v.26 no.4
    • /
    • pp.484-492
    • /
    • 1994
  • Microstructures of Nb$_2$O$_{5}$-doped UO$_2$ pellets have been investigated during sintering under H$_2$ and $CO_2$ atmospheres. Pellets are sintered at 1$700^{\circ}C$ in H$_2$ atmosphere and at 130$0^{\circ}C$ in $CO_2$ atmosphere for 1 to 41 hr. The addison of Nb$_2$O$_{5}$ causes the formation of large pores, which shrink to some extent in H$_2$ atmosphere but very little in $CO_2$. Fine pores in the Nb$_2$O$_{5}$-doped UO$_2$ pellet are almost annihilated when sintered under H$_2$ atmosphere but little changed under $CO_2$ atmosphere. The increase in grain size due to Nb$_2$O$_{5}$ addition is much larger in H$_2$ atmosphere than in $CO_2$. Thus the enhancement of uranium diffusion in UO$_2$ due to the Nb$_2$O$_{5}$ addition is thought to be more significant in H$_2$ atmosphere. Microstructures of Nb$_2$O$_{5}$-doped UO$_2$ pellets sintered in H$_2$ atmosphere are discussed from the viewpoint of in-reactor performance. Possible defects formation due to Nb$_2$O$_{5}$ addition is discussed to explain the enhancement of uranium diffusion in H$_2$ and $CO_2$ atmospheres.> atmospheres.

  • PDF

Modeling of central void formation in LWR fuel pellets due to high-temperature restructuring

  • Khvostov, Grigori
    • Nuclear Engineering and Technology
    • /
    • v.50 no.7
    • /
    • pp.1190-1197
    • /
    • 2018
  • Analysis of the GRSW-A model coupled into the FALCON code is extended by simulation of central void formation in fuel pellets due to high-temperature fuel restructuring. The extended calculation is verified against published, well-known experimental data. Good agreement with the data for a central void diameter in pellets of the rod irradiated in an Experimental Breeder Reactor is shown. The new calculation methodology is employed in comparative analysis of modern BWR fuel behavior under assumed high-power operation. The initial fuel porosity is shown to have a major effect on the predicted central void diameter during the operation in question. Discernible effects of a central void on peak fuel temperature and Pellet-Cladding Mechanical Interaction (PCMI) during a simulated power ramp are shown. A mitigating effect on PCMI is largely attributed to the additional free volume in the pellets into which the fuel can creep due to internal compressive stresses during a power ramp.