• Title, Summary, Keyword: adsorption yield

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Protein Aggregation and Adsorption upon In vitro Refolding of Recombinant Pseudomonas Lipase

  • Lee, Young-Phil;Rhee, Joon-Shick
    • Journal of Microbiology and Biotechnology
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    • v.6 no.6
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    • pp.456-460
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    • 1996
  • Recombinant Pseudomonas lipase was used to study protein aggregation and adsorption upon in vitro refolding. Protein adsorption as well as aggregation was responsible for major side reactions upon in vitro refolding as a function of protein concentration. The optimal range of protein concentration was determined by the relative contribution of protein aggregation and adsorption. Above the optimal range, the yield of active lipase inversely correlated with protein aggregation, showing a competition between folding and aggregation. However, adsorption of protein rather than protein aggregation is thought to contribute as a major side reaction of the refolding process at sub-optimal concentrations at which the formation of aggregates should be more reduced. Protein aggregation was influenced by the amount of guanidine hydrochloride in the refolding solvent. The refolding temperature was a critical factor determining the extent of protein aggregation. The refolding yield was also affected by the dilution fold and dilution mode, which suggests that the refolding process might kinetically compete with the rate of mixing.

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Production of Activated Carbon from Waste Walnut Shell Using Phosphoric Acid and Its Adsorption Characteristics for Heavy Metal Ion (인산활성화제에 의한 폐호도껍질을 원료로 한 활성탄제조 및 이의 중금속 이온 흡착특성)

  • Lee Go-Eun;Ahn Ju-Hyun;Kim Dong-Su
    • Resources Recycling
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    • v.12 no.3
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    • pp.13-24
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    • 2003
  • The production characteristics of activated carbon from waste walnut shell have been investigated by taking activation temperature, activation time, amount of activating agent, and kind of activating agent as the major influential factors. The adsorption capacity of the activated carbon which was produced using phosphoric acid as the activating agent increased with activation temperature and showed its greatest value at about $550^{\circ}C$. Yield for activated carbon was observed to decrease continuously as the activation temperature was raised. The optimal activation time for the highest adsorption capacity was found to be about 2 hr, and as the activation time increased the yield for activated carbon was showed to decrease continuously. The increase in the amount of activating agent resulted in the increase of the yield for activated carbon, however, excessive amount of activating agent deteriorated its adsorption capacity reversely. The variations of the microstructure of activated carbon observed by SEM with several influential factors, correlated very well with its changes in the adsorbability with the same factors and the kind of activating agent was found to play an important role in the determination of the adsorption capacity of activated carbon. To investigate the adsorption characteristics of the produced activated carbon, the adsorption reactions of $Cu^{2+}$ ion were examined using the produced activated carbon as the adsorbent. In general, the kinetics of the adsorption of $Cu^{2+}$ ion was observed to follow a 2nd-order reaction and the rate constant for adsorption reaction increased as the initial concentration of adsorbate was diminished. The equilibrium adsorption of $Cu^{2+}$ was explained well with Freundlich model and its adsorption reaction was found to be endothermic. The activation energy for adsorption was calculated to be 13.07 kcal/mol, which implied that the adsorption reaction was very irreversible, and several thermodynamic parameters of adsorption reaction were estimated using van't. Hoff equation and thermodynamic relationships.

Adsorption Characteristics of Radionuclides on AMP and $MnO_2$ (AMP와 $MnO_2$에 대한 방사성핵종의 흡착특성)

  • Kim, Chang-Kyu;Kim, Cheol-Su;Kim, Yong-Jae;Rho, Byung-Hwan
    • Journal of Radiation Protection and Research
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    • v.23 no.2
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    • pp.115-121
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    • 1998
  • Adsorption characteristics of the radionuclides and stable elements on AMP and $MnO_2$ in the seawater have been investigated. The adsorption yield of AMP was 97.5% for $^{137}Cs$, 11.8% for $^{85}Sr$, and 15.1% for $^{131}I$, while being less than 6% for other radionuclides and elements. The AMP showed the highest adsorption yield for $^{137}Cs$. The adsorption yields of $MnO_2$ were more than 90% for all radionuclides and elements, except for $^{40}K$, $^{137}Cs$ and $^{203}Hg$ of which the adsorption yields were less than 8%.

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Effects of Dilute Acid Pretreatment on Enzyme Adsorption and Surface Morphology of Liriodendron tulipifera

  • Min, Byeong-Cheol;Koo, Bon-Wook;Gwak, Ki-Seob;Yeo, Hwan-Myeong;Choi, Joon-Weon;Choi, In-Gyu
    • Journal of the Korean Wood Science and Technology
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    • v.39 no.2
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    • pp.187-195
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    • 2011
  • In this study, dilute acid pretreatment of $Liriodendron$ $tulipifera$ was performed for enzymatic hydrolysis. As the pretreatment temperature was increased, enzymatic hydrolysis and enzyme adsorption yield also increased. The highest enzymatic hydrolysis yield was 57% (g/g) and enzyme adsorption was 44% (g/g). Enzymatic hydrolysis yield was determined with weight loss of pretreated biomass by enzyme, and enzyme adsorption was a percentage of enzyme weight attaching on pretreated biomass compared with input enzyme weight. When $L.$ $tulipifera$ was pretreated with 1% sulfuric acid at $160^{\circ}C$ for 5 min., hemicellulose was significantly removed in pretreatment, but the lignin contents were constant. Other changes in surface morphology were detected on biomass pretreated at $160^{\circ}C$ by a field emission scanning electron microscope (FESEM). A large number of spherical shapes known as lignin droplets were observed over the entire biomass surface after pretreatment. Hemicellulose removal and morphological changes improved enzyme accessibility to cellulose by increasing cellulose exposure to enzyme. It is thus evidence that enzyme adsorption is a significant factor to understand pretreatment effectiveness.

Synthesis of Sulfonated Hollow PP-g-Styrene Fibrous Ion-exchange Membrane and Separation of BSA Protein (술폰화 PP-g-Styrene 중공사 이온교환막의 합성과 BSA 단백질 분리에 관한 연구)

  • 황택성;이진혁
    • Polymer(Korea)
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    • v.26 no.4
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    • pp.415-421
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    • 2002
  • A sulfonated PP-g-styrene ion-exchange hollow fiber membrane was prepared by pre-irradiation method with E-beam followed by sulfonation reaction. Degree of grafting increased with the increase of styrene monomer concentration and showed the maximum value of 128% at 80% of styrene monomer composition. Sulfonation yield increased with the degree of grafting. At 100% degree of grafting, sulfonation yield showed the maximum value of 13.4%. Ion exchange capacity of sulfonated HPP-g-styrene of 3.42 meq/g was attained, resulting in the remarkable increase of adsorption ability BET analysis proved that the surface area of sulfonated HPP-g-styrene was 62.54 $m^2/g$ and the mean pore size was 25 $\AA$. From the BSA adsorption experiments, the adsorption amount of BSA was increased with sulfonation. At 13.4% sulfonation yield the adsorption amount of BSA was maximum as 3.8 mg/g. Sulfonated HPP-g-styrene was synthesized successfully and suitable for the adsorption and separation of BSA.

Adsorption and Desorption Characteristics of Fission Molybdenum on Alumina (알루미나에 의한 Fission 몰리브덴의 흡착과 탈착 특성)

  • 조경태;정원명;이종대
    • Journal of the Korean Society of Safety
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    • v.12 no.3
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    • pp.97-105
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    • 1997
  • Mo-99(Molybdenum) is the only source of Tc-99m(Technetium) which is most frequently used in nuclear medical diagnostics and the demand is on the increase recently. Separation and refining of Mo-99 was investigated by adsorption and desorption on alumina. At pH=0.63, adsorption isotherm of Mo was fitted by Redlich & Peterson equation using the adsorption experimental data. It was found that the pore diffusion model ($D_p=1.4{\times}10^{-6}cm^2/s, K_f/=0.4 cm/s$) agreed well with batch adsorption experimental data. RTDs(Residence Time Distributions ) were measured and axial dispersion coefficients were obtained in the fixed bed absorber according to the changes of the flow rate using 0.05% -NaCl. From the adsorption experimental data, it was shown that the behavior of breakthroughs depended on flow rate. Mo recovery yield was increased as adsorption flow rate was increased and desorption flow rate was decreased.

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Comparative Evaluation of Three Purification Methods for the Nucleocapsid Protein of Newcastle Disease Virus from Escherichia coli Homogenates

  • Tan Yan Peng;Ling Tau Chuan;Yusoff Khatijah;Tan Wen Siang;Tey Beng Ti
    • Journal of Microbiology
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    • v.43 no.3
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    • pp.295-300
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    • 2005
  • In the present study, the performances of conventional purification methods, packed bed adsorption (PBA), and expanded bed adsorption (EBA) for the purification of the nucleocapsid protein (NP) of Newcastle disease virus (NDV) from Escherichia coli homogenates were evaluated. The conventional methods for the recovery of NP proteins involved multiple steps, such as centrifugation, precipitation, dialysis, and sucrose gradient ultracentrifugation. For the PBA, clarified feedstock was used for column loading, while in EBA, unclarified feedstock was used. Streamline chelating immobilized with $Ni^{2+}$ ion was used as an affinity ligand for both PBA and EBA. The final protein yield obtained in conventional and PBA methods was $1.26\%$ and $5.56\%$, respectively. It was demonstrated that EBA achieved the highest final protein yield of $9.6\%$ with a purification factor of 7. Additionally, the total processing time of the EBA process has been shortened by 8 times compared to that of the conventional method.

Multi-functional Finish of Polypropylene Nonwoven by Photo-induced Graft Polymerization (II) - Grafting of Styrene and Its Ammonia Adsorption Behavior - (광그라프팅에 의한 폴리프로필렌 부직포의 복합기능화 가공(II) -스티렌의 그라프트 반응 및 암모니아 흡착거동 -)

  • 김상률;최창남
    • Polymer(Korea)
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    • v.25 no.5
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    • pp.642-648
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    • 2001
  • An attempt was made to synthesize an ammonia adsorbent by the photo-induced grafting of styrene (St) onto polypropylene (PP) nonwoven using benzoin ethyl ether (BEE) as a photosensitizer with urea and trimethylol propane triacrylate in methanol medium. As styrene concentration was increased, the graft yield was increased. It was also found that the graft yield increased with reaction time. The polypropylene grafted with styrene (PP-g-St) was sulfonated by chlorosulfonic acid in dichloroethane and complexed with several metal ion, such as $cO^{+2}$, $nI^{+2}$, $cU^{+2}$, $Zn^{+2}$. The amount of ammonia gas adsorbed by these sample was dependent on the degree of sulfonation, adsorption time, and ammonia gas pressure. The adsorption capacity of ammonia gas by the sulfonated PP-g-St(SPP-g-St) nonwoven with 4. 25 mmol $H^+$/g was 6.61 mmol/g. Metal ion complexed SPP-g-St nonwovens had higher adsorption capacity than SPP-g-St nonwoven and the $Co^{+2}$ complexed SPP-g-St showed 9.90 mmol $NH_3$/g, which was much higher than that of active carbon or silica gel.

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Analysis of the Behavior of Tubular-Type Equipment for Nuclear Waste Treatment : Sensitivities of the Parameters Affecting Mass Transfer Yield (방사성폐기물의 화학처리공정에 사용되는 유동관식 장치의 해석 : 물질전달 수율에 미치는 매개변수들의 민감도)

  • Yoo, Jae-Hyung;Lee, Byung-Jik;Shim, Joon-Bo;Kim, Eung-Ho
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.5 no.1
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    • pp.91-99
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    • 2007
  • It was intended in this study to investigate the effects of various parameters on the chemical reaction or mass transfer yield in a tubular-type nuclear waste treatment equipment. Since such equipments, as a tubular reactor, multistage solvent extractor, and adsorption column, accompany chemical reaction or mass transfer along the fluid-flowing direction, mathematical modeling for each equipment was carried out first. Then their behaviors of the chemical reaction or mass transfer were predicted through computer simulations. The inherent major parameters for each equipment were chosen and their sensitivities. affecting the reaction or mass transfer yield were analyzed. For the tubular reactor, the effects of axial diffusion coefficient and reaction rate constant on the reaction yield were investigated. As for the multistage solvent extractor, the backmixing of continuous phase and the distribution coefficient between fluid and solvent were considered as the major parameters affecting the extraction yield as well as concentration profiles throughout the axial direction of the extractor. For the adsorption column, the equilibrium constant between fluid and adsorbent surface, and the overall mass transfer coefficient between the two phases were taken as the major factors that affect the adsorption rate.

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Purification of Isoflavone from Soybean Hypocotyls using Various Resins

  • Choi Yeon-Bae;Kim Kang-Sung
    • Journal of Environmental Health Sciences
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    • v.31 no.3
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    • pp.221-226
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    • 2005
  • Isoflavone was extracted with various concentration of aqueous methanol using whole hypocotyls as the starting material. Whole hypocotyls were preferred as the raw material because the residue could be easily removed from the solvent after the extraction process. Extraction yield was almost constant at the methanol concentration of $20-80\%$. Most of the isoflavone was extracted within 1 hr, and the extraction yield remained almost constant thereafter. When the concentration of methanol was $80\%$, the content of total solid was reduced due to the reduced extraction of contaminating protein as the result of protein insolubilization. Among resins tested, Diaion HP-20, Amberlite XAD-16, and Amberlite IRC-50 showed the highest capacity to absorb the compound. Open column chromatography with Diaion HP-20 showed that $80\%$ aqueous ethanol was most efficient as the eluting solvent with final recovery of the phytochemical being more than $95\%$. Maximum adsorption of the phytochemical occurred at the acidic pH 2-4. When the spatial velocity was increased to 15 and more, the degree of adsorption was decreased, whereas below spatial velocity of 15, the adsorption capacity of isoflavone to the resin was almost constant. The purity of the isoflavone purified by column chromatography was $78\%$.