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Sample records for two-phase digestion system

  1. Two-phase (acidogenic-methanogenic) anaerobic thermophilic/mesophilic digestion system for producing Class A biosolids from municipal sludge.

    Science.gov (United States)

    Rubio-Loza, L A; Noyola, A

    2010-01-01

    Two different arrangements of two-phase anaerobic sludge systems were operated treating a mixture of primary and secondary sludge. Two steady state periods were evaluated: the first acidogenic thermophilic phase was operated at hydraulic retention times of 3 and 2 days and the second methanogenic (mesophilic and thermophilic) phases at 13 and 10 days. The two-phase systems had an efficient removal of pathogens and parasites, achieving values lower than those specified for Class A biosolids, according to the Mexican Standard NOM-004-SEMARNAT-2002. The first thermophilic phase achieved almost complete destruction of pathogens and parasites by itself. During the second steady state period, volatile fatty acids accumulated in the second methanogenic phases (HRT of 10 days and an organic load of 3 kg VS/m(3)d) indicating that the systems were overloaded, mainly the mesophilic digester. In this case, the accumulation of propionic acid may be related to a deficiency of micronutrients. The results show that the two-phase thermophilic/mesophilic anaerobic sludge digestion may be considered as an adequate option for the production of Class A biosolids.

  2. Anaerobic digestion of food waste through the operation of a mesophilic two-phase pilot scale digester--assessment of variable loadings on system performance.

    Science.gov (United States)

    Grimberg, S J; Hilderbrandt, D; Kinnunen, M; Rogers, S

    2015-02-01

    Single and two-phase operations were compared at mesophilic operating conditions using a digester system consisting of three 5-m(3) reactors treating food waste generated daily within the university campus kitchens. When normalizing the methane production to the daily feedstock characteristics, significantly greater methane was produced during two-phase mesophilic digestion compared to the single-stage operation (methane yield of 380 vs 446-L CH4 kg VS(-1); 359 vs 481-L CH4 kg COD(-1) removed for single vs two stage operation). The fermentation reactor could be maintained reliably even under very low loading rates (0.79±0.16 kg COD m(-3) d(-1)) maintaining a steady state pH of 5.2. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Comparative performance and microbial community of single-phase and two-phase anaerobic systems co-digesting cassava pulp and pig manure

    DEFF Research Database (Denmark)

    Panichnumsin, P.; Ahring, B.K.; Nopharatana, A.

    2010-01-01

    In this study, we illustrated the performance and microbial community of single- and two-phase systems anaerobically co-digesting cassava pulp and pig manure. The results showed that the volatile solid reduction and biogas productivity of two-phase CSTR were 66 ± 4% and 2000 ± 210 ml l-1 d-1, whi...

  4. High-calorific biogas production from anaerobic digestion of food waste using a two-phase pressurized biofilm (TPPB) system.

    Science.gov (United States)

    Li, Yeqing; Liu, Hong; Yan, Fang; Su, Dongfang; Wang, Yafei; Zhou, Hongjun

    2017-01-01

    To obtain high calorific biogas via anaerobic digestion without additional upgrading equipment, a two-phase pressurized biofilm system was built up, including a conventional continuously stirred tank reactor and a pressurized biofilm anaerobic reactor (PBAR). Four different pressure levels (0.3, 0.6, 1.0 and 1.7MPa) were applied to the PBAR in sequence, with the organic loading rate maintained at 3.1g-COD/L/d. Biogas production, gas composition, process stability parameters were measured. Results showed that with the pressure increasing from 0.3MPa to 1.7MPa, the pH value decreased from 7.22±0.19 to 6.98±0.05, the COD removal decreased from 93.0±0.9% to 79.7±1.2% and the methane content increased from 80.5±1.5% to 90.8±0.8%. Biogas with higher calorific value of 36.2MJ/m(3) was obtained at a pressure of 1.7MPa. Pressure showed a significant effect on biogas production and gas quality in methanogenesis reactor. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Comparative performance and microbial community of single-phase and two-phase anaerobic systems co-digesting cassava pulp and pig manure

    DEFF Research Database (Denmark)

    Panichnumsin, P.; Ahring, B.K.; Nopharatana, A.

    2010-01-01

    In this study, we illustrated the performance and microbial community of single- and two-phase systems anaerobically co-digesting cassava pulp and pig manure. The results showed that the volatile solid reduction and biogas productivity of two-phase CSTR were 66 ± 4% and 2000 ± 210 ml l-1 d-1, while...... predominant in both digesters while the relative abundance of Methanosaeta sp. and Methanospirillum hungatei differed between the two systems......., followed by the Clostridia in singlephase CSTR. In hydrolysis/acidification reactor of two-phase system, the bacteria within the phylum Firmicutes, especially Clostridium, Eubacteriaceae and Lactobacillus were the dominant phylogenetic groups. Among the Archaea, Methanosaeta sp. was the exclusive...

  6. Two phase continuous digestion of solid manure on-farm

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, W.; Lehto, M. [MTT Agrifood Research Finland, Vihti (Finland). Animal Production Research; Evers, L.; Granstedt, A. [Biodynamic Research Inst., Jaerna (Sweden)

    2007-07-01

    Present commercially available biogas plants are mainly suitable for slurry and co-substrates. Cattle, horse and poultry farms using a solid manure chain experience a crucial competitive disadvantage, because conversion to slurry technology requires additional investments. Based on the technological progress of anaerobic digestion of municipal solid waste, so called 'dry fermentation' prototype plants were developed for anaerobic digestion of organic material containing 15-50% total solids (Hoffman, 2001). These plants show added advantages compared to slurry digestion plants: Less reactor volume, less process energy, less transport capacity, less odour emissions. On-farm research (Gronauer and Aschmann, 2004; Kusch and Oechsner, 2004) and prototype research (Linke, 2004) on dry fermentation in batch reactors show that loading and discharging of batch reactors remains difficult and/or time-consuming compared to slurry reactors. Additionally a constant level of gas generation requires offset operation of several batch reactors. Baserga et al. (1994) developed a pilot plant of 9.6 m{sup 3} capacity for continuous digestion of solid beef cattle manure on-farm. However, on-farm dry fermentation plants are not common and rarely commercially available. We assume that lack of tested technical solutions and scarceness of on-farm research results are the main reason for low acceptance of dry fermentation technology on-farm. We report about an innovative two phase farm-scale biogas plant. The plant continuously digests dairy cattle manure and organic residues of the farm and the surrounding food processing units. The two phase reactor technology was chosen for two reasons: first it offers the separation of a liquid fraction and a solid fraction for composting after hydrolysis and secondly the methanation of the liquid fraction using fixed film technology results in a very short hydraulic retention time, reduction in reactor volume, and higher methane content of the

  7. Performance and microbial community dynamics in a two-phase anaerobic co-digestion system using cassava dregs and pig manure.

    Science.gov (United States)

    Ren, Jiwei; Yuan, Xufeng; Li, Jie; Ma, Xuguang; Zhao, Ye; Zhu, Wanbing; Wang, Xiaofen; Cui, Zongjun

    2014-03-01

    The two-phase anaerobic co-digestion of cassava dregs (CD) with pig manure (PM) was evaluated using four sequencing batch reactors (SBRs) and a continuously stirred tank reactor (CSTR). The effect of seven different PM to CD volatile solid ratios (10:0, 8:2, 6:4, 5:5, 4:6, 2:8 and 0:10) on the acidification phase was investigated. Results indicated the concentrations of soluble chemical oxygen demand, NH4-N and volatile fatty acids increased substantially at seven ratios. Co-acidification of PM and CD performed well. Methanogenic fermentation of the acidification products at seven ratios was steady in CSTR. The highest methane yield and VS removal of 0.352m(3)/kg VSadded and 68.5% were achieved at PM:CD (4:6). The microbial population in CSTR was analyzed using molecular methods. Findings revealed that bacteria such as Firmicutes and Bacteroidetes, archaea such as Methanobacteriales and Methanomicrobiales were advantageous populations. Co-digestion of PM and CD supported higher quantity and diversity of methanogens.

  8. Two-phase flow in refrigeration systems

    CERN Document Server

    Gu, Junjie; Gan, Zhongxue

    2013-01-01

    Two-Phase Flow in Refrigeration Systems presents recent developments from the authors' extensive research programs on two-phase flow in refrigeration systems. This book covers advanced mass and heat transfer and vapor compression refrigeration systems and shows how the performance of an automotive air-conditioning system is affected through results obtained experimentally and theoretically, specifically with consideration of two-phase flow and oil concentration. The book is ideal for university postgraduate students as a textbook, researchers and professors as an academic reference book, and b

  9. Two-phase anaerobic digestion of vegetable market waste fraction of municipal solid waste and development of improved technology for phase separation in two-phase reactor.

    Science.gov (United States)

    Majhi, Bijoy Kumar; Jash, Tushar

    2016-12-01

    Biogas production from vegetable market waste (VMW) fraction of municipal solid waste (MSW) by two-phase anaerobic digestion system should be preferred over the single-stage reactors. This is because VMW undergoes rapid acidification leading to accumulation of volatile fatty acids and consequent low pH resulting in frequent failure of digesters. The weakest part in the two-phase anaerobic reactors was the techniques applied for solid-liquid phase separation of digestate in the first reactor where solubilization, hydrolysis and acidogenesis of solid organic waste occur. In this study, a two-phase reactor which consisted of a solid-phase reactor and a methane reactor was designed, built and operated with VMW fraction of Indian MSW. A robust type filter, which is unique in its implementation method, was developed and incorporated in the solid-phase reactor to separate the process liquid produced in the first reactor. Experiments were carried out to assess the long term performance of the two-phase reactor with respect to biogas production, volatile solids reduction, pH and number of occurrence of clogging in the filtering system or choking in the process liquid transfer line. The system performed well and was operated successfully without the occurrence of clogging or any other disruptions throughout. Biogas production of 0.86-0.889m(3)kg(-1)VS, at OLR of 1.11-1.585kgm(-3)d(-1), were obtained from vegetable market waste, which were higher than the results reported for similar substrates digested in two-phase reactors. The VS reduction was 82-86%. The two-phase anaerobic digestion system was demonstrated to be stable and suitable for the treatment of VMW fraction of MSW for energy generation.

  10. One- and two-phase anaerobic digestion of ley crop silage with and without liquid recirculation

    Energy Technology Data Exchange (ETDEWEB)

    Nordberg, Aa.

    1996-10-01

    In this study the effects of liquid recirculation on hydrolysis and methanogenesis in one- and two-phase biogas processes were investigated in comparison with water-diluted processes. The operation of a water-diluted one-phase process resulted in process imbalances at a low loading rate. In a water-diluted two-phase process the fibre degrading capability was lost. The reason for the poor process performance was due to a deficiency in trace elements, since the supplementation of cobalt resulted in an increased conversion rate of acetate. The recirculation of process liquid resulted in an accumulation of different compounds which initially stabilized one-phase processes and stimulated the hydrolysis and the methane production in the liquefaction-acidogenesis stage of a two-phase process. However, upon continuous recirculation the concentration of free ammonia reached toxic levels, which resulted in a decrease in the methane yield both in the methanogenic reactor of the two-phase process and in the one-phase process. Due to the decreased methane production, acids started to accumulate which subsequently inhibited the hydrolysis in the one-phase process. The systematic variation in the processes were evaluated using principal component analysis and principal component regression. The interpretation of the dynamic behaviour of the processes was facilitated by the use of score plots and loading plots. The results indicate that ley crops do not meet the nutrient requirements of the bacteria in anaerobic digestion. Thus, the low content of trace elements and the high content of protein which subsequently will cause toxic levels of ammonia in digesting system with low water consumption, suggests co-digestion with supplementary feedstocks. 95 refs, 5 figs, 3 tabs

  11. Biogasification of steam-exploded wheat straw by a two-phased digestion system%汽爆麦草的两相法生物气化

    Institute of Scientific and Technical Information of China (English)

    陈洪章; 王麾; 张爱军; 李佐虎

    2005-01-01

    蒸汽爆破作为一种新型的预处理方法被初次运用于麦草的两相气化系统,以碳酸氢铵作为补充氮源调节碳氮比,并在相同条件下以未汽爆麦草作对照试验.以汽爆麦草为原料时,水解反应器的pH值低于加入未汽爆麦草的pH值,并且在25 d后慢慢升至7;以两种麦草为原料时,甲烷反应器的pH都稳定在7左右,此时最适合甲烷生成.汽爆麦草的总固形物和挥发性固形物含量分别降低了57.5%和62.1%,下降率差不多是未汽爆麦草的2倍;纤维素和半纤维素的降解率也有了显著的提高,分别为63.0%和67.4%;木质素的降解率变化不大,都在5%左右.汽爆麦草的总产气量高于非汽爆麦草,并且一直保持较高的增长率,而非汽爆麦草的增长率一直较低;两种麦草产生的生物气中的甲烷含量大致相同,在水解反应器中后期为50%左右,在甲烷反应器中为70%左右.以上结果表明,汽爆可以促进麦草的降解,提高生物气的产量,是一种行之有效的预处理技术.%In the study, steam-explosion, a novel pretreatment method of substrate, was firstly introduced in the twophased digestion system. Ammonium bicarbonate was used as added nitrogen source to adjust C/N in the system. Under the same conditions, experiments using NPWS (non-pretreated wheat straw) were processed as the control. Results showed that pH value in the hydrolysis reactor using SEWS (Steam-exploded wheat straw) was lower and increased slowly to 7 in 25 days. In methanogenesis reactors using SEWS and NPWS, pH value was all around 7, which is most suitable to produce methane. In the digestion system using SEWS, the content of TS (Total solid) and VS (Volatile solid) decreased by 57.5% and by 62.1%, respectively, about twice as high as NWPS. The degradation rate of cellulose and semi-cellulose of SEWS were 63.0% and 67.4%, respectively, much higher than NPWS. The degradation rate of the lignin is similar and about 5 %. The total

  12. Two phase continuous digestion of solid manure on-farm: design, mass and nutrient balance

    OpenAIRE

    Schäfer, Winfried; Evers, Lars; Lehto, Marja; Sorvala, Sanna; Teye, Frederick; Granstedt, Artur

    2005-01-01

    During the last decade some so called ‘dry fermentation’ prototype plants were developed for anaerobic digestion of organic material containing 15-50 % total solids. These plants show added advantages com-pared to slurry digestion plants: Less reactor volume, less process energy, less transport capacity, less odour emissions. However on-farm dry fermentation plants are not common and rarely commercially available. This paper reports about an innovative two phase prototype biogas plant designe...

  13. Influence of lactic acid on the two-phase anaerobic digestion of kitchen wastes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bo; CAI Wei-min; HE Pin-jing

    2007-01-01

    To evaluate the influence of lactic acid on the methanogenesis, anaerobic digestion of kitchen wastes was firstly conducted in a two-phase anaerobic digestion process, and performance of two digesters fed with lactic acid and glucose was subsequently compared.The results showed that the lactic acid was the main fermentation products of hydrolysis-acidification stage in the two-phase anaerobic digestion process for kitchen wastes. The lactic acid concentration constituted approximately 50% of the chemical oxygen demand (COD) concentration in the hydrolysis-acidification liquid. The maximum organic loading rate was lower in the digester fed with lactic acid than that fed with glucose. Volatile fatty acids (VFAs) and COD removal were deteriorated in the methanogenic reactor fed with to the high concentration of lactic acid fed. It could be concluded that avoiding the presence of the lactic acid is necessary in the hydrolysis-acidification process for the improvement of the two-phase anaerobic digestion process of kitchen wastes.

  14. Potential and optimization of two-phase anaerobic digestion of oil refinery waste activated sludge and microbial community study

    Science.gov (United States)

    Wang, Qinghong; Liang, Ying; Zhao, Peng; Li, Qing X.; Guo, Shaohui; Chen, Chunmao

    2016-12-01

    Oil refinery waste activated sludge produced from oil wastewater biological treatment is a major industrial sludge. Two-phase anaerobic digestion of oil refinery waste activated sludge was studied for the first time. Thermal pretreatment under 170 °C is effective on sludge solubilization. At the optimum hydrolytic-acidogenic condition which was pH of 6.5, temperature of 55 °C and HRT of 2 days, 2754 mg/L volatile fatty acids (VFAs) were produced and acetic acid and butyric acid were the key components. Comparative studies of single-phase and two-phase anaerobic digestion in terms of organic removal, biogas production and methane concentration were conducted. The cumulative methane production and soluble COD (SCOD) removal efficiency in the two-phase system were 228 mL/g COD added and 77.8%, respectively, which were 1.6 and 2.1 times higher than those in single-phase anaerobic digestion. Such improved performance is attributed to intensification of dominant microbial population in separated reactors. Caloramator, Ureibacillus, Dechloromonas, Petrobacter, and T78 played important roles in hydrolytic-acidification and oil-organics degradation. Syntrophic bacteria in the family Porphyromonadaceae and the genus Anaerobranca provide acetate for methanogen. The results demonstrated the potential and operating condition of two-phase anaerobic digestion in treatment of oil refinery waste activated sludge.

  15. Potential and optimization of two-phase anaerobic digestion of oil refinery waste activated sludge and microbial community study.

    Science.gov (United States)

    Wang, Qinghong; Liang, Ying; Zhao, Peng; Li, Qing X; Guo, Shaohui; Chen, Chunmao

    2016-12-01

    Oil refinery waste activated sludge produced from oil wastewater biological treatment is a major industrial sludge. Two-phase anaerobic digestion of oil refinery waste activated sludge was studied for the first time. Thermal pretreatment under 170 °C is effective on sludge solubilization. At the optimum hydrolytic-acidogenic condition which was pH of 6.5, temperature of 55 °C and HRT of 2 days, 2754 mg/L volatile fatty acids (VFAs) were produced and acetic acid and butyric acid were the key components. Comparative studies of single-phase and two-phase anaerobic digestion in terms of organic removal, biogas production and methane concentration were conducted. The cumulative methane production and soluble COD (SCOD) removal efficiency in the two-phase system were 228 mL/g COD added and 77.8%, respectively, which were 1.6 and 2.1 times higher than those in single-phase anaerobic digestion. Such improved performance is attributed to intensification of dominant microbial population in separated reactors. Caloramator, Ureibacillus, Dechloromonas, Petrobacter, and T78 played important roles in hydrolytic-acidification and oil-organics degradation. Syntrophic bacteria in the family Porphyromonadaceae and the genus Anaerobranca provide acetate for methanogen. The results demonstrated the potential and operating condition of two-phase anaerobic digestion in treatment of oil refinery waste activated sludge.

  16. Potential and optimization of two-phase anaerobic digestion of oil refinery waste activated sludge and microbial community study

    Science.gov (United States)

    Wang, Qinghong; Liang, Ying; Zhao, Peng; Li, Qing X.; Guo, Shaohui; Chen, Chunmao

    2016-01-01

    Oil refinery waste activated sludge produced from oil wastewater biological treatment is a major industrial sludge. Two-phase anaerobic digestion of oil refinery waste activated sludge was studied for the first time. Thermal pretreatment under 170 °C is effective on sludge solubilization. At the optimum hydrolytic-acidogenic condition which was pH of 6.5, temperature of 55 °C and HRT of 2 days, 2754 mg/L volatile fatty acids (VFAs) were produced and acetic acid and butyric acid were the key components. Comparative studies of single-phase and two-phase anaerobic digestion in terms of organic removal, biogas production and methane concentration were conducted. The cumulative methane production and soluble COD (SCOD) removal efficiency in the two-phase system were 228 mL/g COD added and 77.8%, respectively, which were 1.6 and 2.1 times higher than those in single-phase anaerobic digestion. Such improved performance is attributed to intensification of dominant microbial population in separated reactors. Caloramator, Ureibacillus, Dechloromonas, Petrobacter, and T78 played important roles in hydrolytic-acidification and oil-organics degradation. Syntrophic bacteria in the family Porphyromonadaceae and the genus Anaerobranca provide acetate for methanogen. The results demonstrated the potential and operating condition of two-phase anaerobic digestion in treatment of oil refinery waste activated sludge. PMID:27905538

  17. Performances of anaerobic co-digestion of fruit & vegetable waste (FVW) and food waste (FW): single-phase vs. two-phase.

    Science.gov (United States)

    Shen, Fei; Yuan, Hairong; Pang, Yunzhi; Chen, Shulin; Zhu, Baoning; Zou, Dexun; Liu, Yanping; Ma, Jingwei; Yu, Liang; Li, Xiujin

    2013-09-01

    The co-digestion of fruit & vegetable waste (FVW) and food waste (FW) was performed at various organic loading ratios (OLRs) in single-phase and two-phase system, respectively. The results showed that the ethanol-type fermentation dominated in both digestion processes when OLR was at low levels (2.0 g(VS) L(-1) d(-1)), which could cause unstable anaerobic digestion. Single-phase digestion was better than two-phase digestion in term of 4.1% increase in CH4 production at lower OLRs (two-phase digestion achieved higher CH4 production of 0.351-0.455 L(g VS)(-1) d(-1), which were 7.0-15.8% more than that of single-phase. Additionally, two-phase digestion presented more stable operation, and higher OLR treatment capacity. Furthermore, comparison of these two systems with bioenergy recovery revealed that two-phase system overall presented higher bioenergy yield than single-phase.

  18. Syntrophic acetate oxidation in two-phase (acid-methane) anaerobic digesters.

    Science.gov (United States)

    Shimada, T; Morgenroth, E; Tandukar, M; Pavlostathis, S G; Smith, A; Raskin, L; Kilian, R E

    2011-01-01

    The microbial processes involved in two-phase anaerobic digestion were investigated by operating a laboratory-scale acid-phase (AP) reactor and analyzing two full-scale, two-phase anaerobic digesters operated under mesophilic (35 °C) conditions. The digesters received a blend of primary sludge and waste activated sludge (WAS). Methane levels of 20% in the laboratory-scale reactor indicated the presence of methanogenic activity in the AP. A phylogenetic analysis of an archaeal 16S rRNA gene clone library of one of the full-scale AP digesters showed that 82% and 5% of the clones were affiliated with the orders Methanobacteriales and Methanosarcinales, respectively. These results indicate that substantial levels of aceticlastic methanogens (order Methanosarcinales) were not maintained at the low solids retention times and acidic conditions (pH 5.2-5.5) of the AP, and that methanogenesis was carried out by hydrogen-utilizing methanogens of the order Methanobacteriales. Approximately 43, 31, and 9% of the archaeal clones from the methanogenic phase (MP) digester were affiliated with the orders Methanosarcinales, Methanomicrobiales, and Methanobacteriales, respectively. A phylogenetic analysis of a bacterial 16S rRNA gene clone library suggested the presence of acetate-oxidizing bacteria (close relatives of Thermacetogenium phaeum, 'Syntrophaceticus schinkii,' and Clostridium ultunense). The high abundance of hydrogen consuming methanogens and the presence of known acetate-oxidizing bacteria suggest that acetate utilization by acetate oxidizing bacteria in syntrophic interaction with hydrogen-utilizing methanogens was an important pathway in the second-stage of the two-phase digestion, which was operated at high ammonium-N concentrations (1.0 and 1.4 g/L). A modified version of the IWA Anaerobic Digestion Model No. 1 (ADM1) with extensions for syntrophic acetate oxidation and weak-acid inhibition adequately described the dynamic profiles of volatile acid production

  19. Pilot-scale gasification of municipal solid wastes by high-rate and two-phase anaerobic digestion (TPAD).

    Science.gov (United States)

    Ghosh, S; Henry, M P; Sajjad, A; Mensinger, M C; Arora, J L

    2000-01-01

    Bioconversion of municipal solid waste-sludge blend by conventional high-rate and two-phase anaerobic digestion was studied. RDF (refused-derived fuel)-quality feed produced in a Madison, Wisconsin, USA, MRF (materials-recovery facility) was used. High-rate digestion experiments were conducted with bench-scale digesters under target operating conditions developed from an economic feasibility study. The effects of digestion temperature, RDF content of digester feed, HRT, loading rate, RDF particle size, and RDF pretreatment with cellulase or dilute solutions of NaOH or lime on digester performance were studied. A pilot-scale two-phase digestion plant was operated with 80:20 (weight ratio) RDF-sludge blends to show that this process exhibited a higher methane yield, and produced a higher methane-content digester gas than those obtained by single-stage, high-rate anaerobic digestion.

  20. CFD simulation of gas and non-Newtonian fluid two-phase flow in anaerobic digesters.

    Science.gov (United States)

    Wu, Binxin

    2010-07-01

    This paper presents an Eulerian multiphase flow model that characterizes gas mixing in anaerobic digesters. In the model development, liquid manure is assumed to be water or a non-Newtonian fluid that is dependent on total solids (TS) concentration. To establish the appropriate models for different TS levels, twelve turbulence models are evaluated by comparing the frictional pressure drops of gas and non-Newtonian fluid two-phase flow in a horizontal pipe obtained from computational fluid dynamics (CFD) with those from a correlation analysis. The commercial CFD software, Fluent12.0, is employed to simulate the multiphase flow in the digesters. The simulation results in a small-sized digester are validated against the experimental data from literature. Comparison of two gas mixing designs in a medium-sized digester demonstrates that mixing intensity is insensitive to the TS in confined gas mixing, whereas there are significant decreases with increases of TS in unconfined gas mixing. Moreover, comparison of three mixing methods indicates that gas mixing is more efficient than mixing by pumped circulation while it is less efficient than mechanical mixing.

  1. Scaling of Two-Phase Systems Across Gravity Levels Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There is a defined need for long term earth based testing for the development and deployment of two-phase flow systems in reduced-gravity, including lunar gravity,...

  2. High pressure homogenization and two-phased anaerobic digestion for enhanced biogas conversion from municipal waste sludge.

    Science.gov (United States)

    Wahidunnabi, Abdullahil K; Eskicioglu, Cigdem

    2014-12-01

    This study compared advanced anaerobic digestion combining two-phased anaerobic digestion (2PAD) with high pressure homogenization (HPH) pretreatment to conventional anaerobic digestion of municipal sludge at laboratory scale. The study began with examination of thickened waste activated sludge (TWAS) solubilization due to HPH pretreatment at different pressure (0-12,000 psi) and chemical dose (0.009-0.036 g NaOH/g total solids). Homogenizing pressure was found as the most significant factor (p-value production (0.61-1.32 L CH4/Ldigester-d) and VS removals (43-64%). Thermophilic control, 2PAD and HPH + 2PAD systems resulted in significant pathogen removals meeting Class A biosolids requirements according to Organic Matter Recycling Regulations (OMRR) of British Columbia (BC) at 20 d SRT. Energy analysis indicated that all the digestion scenarios attained positive energy balance with 2PAD system operated at 20 d SRT producing the maximum net energy of 4.76 GJ/tonne CODadded.

  3. Chemical characterization of municipal wastewater sludges produced by two-phase anaerobic digestion for biogas production

    Energy Technology Data Exchange (ETDEWEB)

    Francioso, Ornella, E-mail: ornella.francioso@unibo.it [Dipartimento di Scienze e Tecnologie Agroambientali, V.le Fanin 40, 40127 Bologna (Italy); Rodriguez-Estrada, Maria Teresa [Dipartimento di Scienze degli Alimenti, V.le Fanin 40, 40127 Bologna (Italy); Montecchio, Daniela [Dipartimento di Scienze e Tecnologie Agroambientali, V.le Fanin 40, 40127 Bologna (Italy); Salomoni, Cesare; Caputo, Armando [Biotec sys srl, Via Gaetano Tacconi, 59, 40139 Bologna (Italy); Palenzona, Domenico [Dipartimento di Biologia Evoluzionistica Sperimentale, Via Selmi 3, 40126 Bologna (Italy)

    2010-03-15

    In the present study, the chemical features of municipal wastewater sludges treated in two-phase separate digesters (one for acetogenesis and the other one for methanogenesis), were characterized by using chemical analysis, stable carbon isotope ratios ({delta}{sup 13}C), HS-SPME-GC-MS, TG-DTA analysis and DRIFT spectroscopy. The results obtained showed that sludges from acetogenesis and methanogenesis differed from each other, as well as from influent raw sludges. Both processes exhibited a diverse chemical pattern in term of VFA and VOC. Additional variations were observed for {delta}{sup 13}C values that changed from acetogenesis to methanogenesis, as a consequence of fermentation processes that led to a greater fractionation of {sup 12}C with respect to the {sup 13}C isotope. Similarly, the thermal profiles of acetogenesis and methanogenesis sludges greatly differed in terms of heat combustion produced. These changes were also supported by higher lipid content (probably fatty acids) in acetogenesis than in methanogenesis, as also shown by DRIFT spectroscopy.

  4. Optimization of micronutrient supplement for enhancing biogas production from food waste in two-phase thermophilic anaerobic digestion.

    Science.gov (United States)

    Menon, Ajay; Wang, Jing-Yuan; Giannis, Apostolos

    2017-01-01

    The aim of this study was to enhance the biogas productivity of two-phase thermophilic anaerobic digestion (AD) using food waste (FW) as the primary substrate. The influence of adding four trace metals (Ca, Mg, Co, and Ni) as micronutrient supplement in the methanogenic phase of the thermophilic system was investigated. Initially, Response Surface Methodology (RSM) was applied to determine the optimal concentration of micronutrients in batch experiments. The results showed that optimal concentrations of 303, 777, 7 and 3mg/L of Ca, Mg, Co and Ni, respectively, increased the biogas productivity as much as 50% and significantly reduced the processing time. The formulated supplement was tested in continuous two-phase thermophilic AD system with regard to process stability and productivity. It was found that a destabilized thermophilic AD process encountering high VFA accumulation recovered in less than two weeks, while the biogas production was improved by 40% yielding 0.46L CH4/gVSadded/day. There was also a major increase in soluble COD utilization upon the addition of micronutrient supplement. The results of this study indicate that a micronutrient supplement containing Ca, Mg, Co and Ni could probably remedy any type of thermophilic AD process. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Modeling of two-phase anaerobic process treating traditional Chinese medicine wastewater with the IWA Anaerobic Digestion Model No. 1.

    Science.gov (United States)

    Chen, Zhaobo; Hu, Dongxue; Zhang, Zhenpeng; Ren, Nanqi; Zhu, Haibo

    2009-10-01

    The aim of the study was to implement a mathematical model to simulate two-phase anaerobic digestion (TPAD) process which consisted of an anaerobic continuous stirred tank reactor (CSTR) and an upflow anaerobic sludge blanket (UASB) reactor in series treating traditional Chinese medicine (TCM) wastewater. A model was built on the basis of Anaerobic Digestion Model No. 1 (ADM1) while considering complete mixing model for the CSTR, and axial direction discrete model and mixed series connection model for the UASB. The mathematical model was implemented with the simulation software package MATLABTM/Simulinks. System performance, in terms of COD removal, volatile fatty acids (VFA) accumulation and pH fluctuation, was simulated and compared with the measured values. The simulation results indicated that the model built was able to well predict the COD removal rate (-4.8-5.0%) and pH variation (-2.9-1.4%) of the UASB reactor, while failed to simulate the CSTR performance. Comparing to the measured results, the simulated acetic acid concentration of the CSTR effluent was underpredicted with a deviation ratios of 13.8-23.2%, resulting in an underprediction of total VFA and COD concentrations despite good estimation of propionic acid, butyric acid and valeric acid. It is presumed that ethanol present in the raw wastewater was converted into acetic acid during the acidification process, which was not considered by the model. Additionally, due to the underprediction of acetic acid the pH of CSTR effluent was overestimated.

  6. Two-phase flow instability in a parallel multichannel system

    Institute of Scientific and Technical Information of China (English)

    HOU Suxia

    2009-01-01

    The two-phase flow instabilities observed in through parallel multichannel can be classified into three types, of which only one is intrinsic to parallel multichannel systems. The intrinsic instabilities observed in parallel multichannel system have been studied experimentally. The stable boundary of the flow in such a parallel-channel system are sought, and the nature of inlet flow oscillation in the unstable region has been examined experimentally under various conditions of inlet velocity, heat flux, liquid temperature, cross section of channel and entrance throttling. The results show that parallel multichannel system possess a characteristic oscillation that is quite independent of the magnitude and duration of the initial disturbance, and the stable boundary is influenced by the characteristic frequency of the system as well as by the exit quality when this is low, and upon raising the exit quality and reducing the characteristic frequency, the system increases its instability, and entrance throttling effectively contributes to stabilization of the system.

  7. Improved biogas production and biodegradation of oilseed rape straw by using kitchen waste and duck droppings as co-substrates in two-phase anaerobic digestion.

    Science.gov (United States)

    Wang, Chuqiao; Hong, Feng; Lu, Yong; Li, Xianning; Liu, Hengming

    2017-01-01

    Oilseed rape straw (ORS) is a kind of biorefractory waste widely existing in the rural area of China, which is highly suitable to mix with kitchen waste (KW) and duck droppings (DD) in two-phase anaerobic digestion (AD). This research introduced the importance of KW and DD addition to improve the biogas production and biodegradation of ORS. A set of comparative experiments were conducted on two-phase mono- and co-digestion with organic load of 60 g VS/L. The total methane yield (TMY) and the biodegradation of ORS of co-digestions were obviously improving, and the synergistic effect found in the two-phase co-digestions. The optimum mixing ratio of ORS, KW and DD was 50:40:10, and the corresponding TMY and VS degradation rate of ORS were 374.5 mL/g VS and 49.7%, respectively. Addition of KW and DD maintained the pH within the optimal range for the hydrolyzing-acidification, improved the phase separation and buffering capacity of AD system.

  8. Improved biogas production and biodegradation of oilseed rape straw by using kitchen waste and duck droppings as co-substrates in two-phase anaerobic digestion

    Science.gov (United States)

    Wang, Chuqiao; Hong, Feng; Lu, Yong; Liu, Hengming

    2017-01-01

    Oilseed rape straw (ORS) is a kind of biorefractory waste widely existing in the rural area of China, which is highly suitable to mix with kitchen waste (KW) and duck droppings (DD) in two-phase anaerobic digestion (AD). This research introduced the importance of KW and DD addition to improve the biogas production and biodegradation of ORS. A set of comparative experiments were conducted on two-phase mono- and co-digestion with organic load of 60 g VS/L. The total methane yield (TMY) and the biodegradation of ORS of co-digestions were obviously improving, and the synergistic effect found in the two-phase co-digestions. The optimum mixing ratio of ORS, KW and DD was 50:40:10, and the corresponding TMY and VS degradation rate of ORS were 374.5 mL/g VS and 49.7%, respectively. Addition of KW and DD maintained the pH within the optimal range for the hydrolyzing-acidification, improved the phase separation and buffering capacity of AD system. PMID:28767709

  9. Removal of organics and nutrients from food wastewater using combined thermophilic two-phase anaerobic digestion and shortcut biological nitrogen removal.

    Science.gov (United States)

    Cui, Fenghao; Lee, Seungho; Kim, Moonil

    2011-10-15

    A process combining pilot-scale two-phase anaerobic digestion and shortcut biological nitrogen removal (SBNR) was developed to treat organics and nutrients (nitrogen and phosphorus) from food wastewater. The thermophilic two-phase anaerobic digestion process was investigated without adjusting the pH of the wastewater for the pre-acidification process. The digested food wastewater was treated using the SBNR process without supplemental carbon sources or alkalinity. Under these circumstances, the combined system was able to remove about 99% of COD, 88% of TN, and 97% of TP. However, considerable amounts of nutrients were removed due to chemical precipitation processes between the anaerobic digestion and SBNR. The average TN removal efficiency of the SBNR process was about 74% at very low C/N (TCOD/TN) ratio of 2. The SBNR process removed about 39% of TP from the digested food wastewater. Conclusively, application of the combined system improved organic removal efficiency while producing valuable energy (biogas), removed nitrogen at a low C/N ratio, and conserved additional resources (carbon and alkalinity).

  10. A TWO-PHASE APPROACH TO FUZZY SYSTEM IDENTIFICATION

    Institute of Scientific and Technical Information of China (English)

    Ta-Wei HUNG; Shu-Cherng FANG; Henry L.W.NUTTLE

    2003-01-01

    A two-phase approach to fuzzy system identification is proposed. The first phase produces a baseline design to identify a prototype fuzzy system for a target system from a coIlection of input-output data pairs. It uses two easily implemented clustering techniques: the subtractive clustering method and the fuzzy c-means (FCM) clustering algorithm. The second phase (fine tuning)is executed to adjust the parameters identified in the baseline design. This phase uses the steepest descent and recursive least-squares estimation methods. The proposed approach is validated by applying it to both a function approximation type of problem and a classification type of problem. An analysis of the learning behavior of the proposed approach for the two test problems is conducted for further confirmation.

  11. Transient thermohydraulic modeling of two-phase fluid systems

    Science.gov (United States)

    Blet, N.; Delalandre, N.; Ayel, V.; Bertin, Y.; Romestant, C.; Platel, V.

    2012-11-01

    This paper presents a transient thermohydraulic modeling, initially developed for a capillary pumped loop in gravitational applications, but also possibly suitable for all kinds of two-phase fluid systems. Using finite volumes method, it is based on Navier-Stokes equations for transcribing fluid mechanical aspects. The main feature of this 1D-model is based on a network representation by analogy with electrical. This paper also proposes a parametric study of a counterflow condenser following the sensitivity to inlet mass flow rate and cold source temperature. The comparison between modeling results and experimental data highlights a good numerical evaluation of temperatures. Furthermore, the model is able to represent a pretty good dynamic evolution of hydraulic variables.

  12. The influence of the temperature regime on the formation of methane in a two-phase anaerobic digestion process

    Energy Technology Data Exchange (ETDEWEB)

    Schoenberg, Mandy; Linke, Bernd

    2012-06-15

    The influence of different temperature levels on the formation of methane in a two-phase anaerobic digestion process using rye silage and barley straw as feedstocks was investigated in this study. This process comprised a leach-bed reactor (LBR), a reservoir for leachate from the LBR, and a separate downstream fixed-film anaerobic filter (AF), with immobilized micro biocoenosises. The degree of degradation of the volatile solids was similar in both studies and was almost equal at 75 Ma.-%{sub VS}. When both reactor phases were operated at thermophilic conditions, the main substrate turnover was observed in the LBR(58% of the total methane yield, with an average methane content of 41 Vol.-%). Only the excess of organic fraction in the process-liquid was transformed in the AF(42% of the total methane yield, with an average methane content of 74 Vol.-%). When the parts of the reactor system operated at different temperature regimes, thermophilic hydrolysis/acidogenesis phase and mesophilic methanization, a separation of carbon dioxide and methane production, was observed. A total methane yield of 88%, with an average methane content of 85 Vol.-%, was formed in the AF. The generated biogas with high methane concentrations is suitable for feeding the purified biomethane into the natural gas grid. Furthermore, it can be used as fuel for cars and tractors. (copyright 2012 WILEY-VCH Verlag GmbH 8 Co. KGaA, Weinheim)

  13. An automated two-phase system for hydrogel microbead production.

    Science.gov (United States)

    Coutinho, Daniela F; Ahari, Amir F; Kachouie, Nezamoddin N; Gomes, Manuela E; Neves, Nuno M; Reis, Rui L; Khademhosseini, Ali

    2012-09-01

    Polymeric beads have been used for protection and delivery of bioactive materials, such as drugs and cells, for different biomedical applications. Here, we present a generic two-phase system for the production of polymeric microbeads of gellan gum or alginate, based on a combination of in situ polymerization and phase separation. Polymer droplets, dispensed using a syringe pump, formed polymeric microbeads while passing through a hydrophobic phase. These were then crosslinked, and thus stabilized, in a hydrophilic phase as they crossed through the hydrophobic-hydrophilic interface. The system can be adapted to different applications by replacing the bioactive material and the hydrophobic and/or the hydrophilic phases. The size of the microbeads was dependent on the system parameters, such as needle size and solution flow rate. The size and morphology of the microbeads produced by the proposed system were uniform, when parameters were kept constant. This system was successfully used for generating polymeric microbeads with encapsulated fluorescent beads, cell suspensions and cell aggregates proving its ability for generating bioactive carriers that can potentially be used for drug delivery and cell therapy.

  14. Assessment of two-phase olive mill solid waste and microalgae co-digestion to improve methane production and process kinetics.

    Science.gov (United States)

    Fernández-Rodríguez, M J; Rincón, B; Fermoso, F G; Jiménez, A M; Borja, R

    2014-04-01

    Olive mill solid waste (OMSW) is a pollutant waste coming from olive oil elaboration by the two-phase centrifugation system. OMSW has a high organic matter content and unbalanced carbon to nitrogen (C/N) ratio, 31/1, which avoids obtaining high methane yields in the anaerobic digestion of this waste. In the present study a microalgae, Dunaliella salina, was employed as co-substrate for the OMSW anaerobic digestion in order to decrease the C/N ratio and increase its biodegradability. Different co-digestion mixtures (C/N ratios) were studied. The increase of D. salina from 25% to 50% in the co-digestion mixture clearly increased the biodegradability of the sole substrates. The highest biodegradability was found for the co-digestion mixture 50% OMSW-50% D. salina. Nevertheless, the maximum methane production, 330mLCH4/gVSadded, and the highest methane production rate were obtained for the co-digestion mixture 75% OMSW-25% D. salina, keeping a C/N ratio near to 26.7/1.

  15. Single-phase and two-phase anaerobic digestion of fruit and vegetable waste: Comparison of start-up, reactor stability and process performance

    Energy Technology Data Exchange (ETDEWEB)

    Ganesh, Rangaraj [INRA, UR50, Laboratoire de Biotechnologie de l’Environnement, Avenue des Etangs, Narbonne F-11100 (France); Torrijos, Michel, E-mail: michel.torrijos@supagro.inra.fr [INRA, UR50, Laboratoire de Biotechnologie de l’Environnement, Avenue des Etangs, Narbonne F-11100 (France); Sousbie, Philippe [INRA, UR50, Laboratoire de Biotechnologie de l’Environnement, Avenue des Etangs, Narbonne F-11100 (France); Lugardon, Aurelien [Naskeo Environnment, 52 rue Paul Vaillant Couturier, F-92240 Malakoff (France); Steyer, Jean Philippe; Delgenes, Jean Philippe [INRA, UR50, Laboratoire de Biotechnologie de l’Environnement, Avenue des Etangs, Narbonne F-11100 (France)

    2014-05-01

    Highlights: • Single-phase and two-phase systems were compared for fruit and vegetable waste digestion. • Single-phase digestion produced a methane yield of 0.45 m{sup 3} CH{sub 4}/kg VS and 83% VS removal. • Substrate solubilization was high in acidification conditions at 7.0 kg VS/m{sup 3} d and pH 5.5–6.2. • Energy yield was lower by 33% for two-phase system compared to the single-phase system. • Simple and straight-forward operation favored single phase process over two-phase process. - Abstract: Single-phase and two-phase digestion of fruit and vegetable waste were studied to compare reactor start-up, reactor stability and performance (methane yield, volatile solids reduction and energy yield). The single-phase reactor (SPR) was a conventional reactor operated at a low loading rate (maximum of 3.5 kg VS/m{sup 3} d), while the two-phase system consisted of an acidification reactor (TPAR) and a methanogenic reactor (TPMR). The TPAR was inoculated with methanogenic sludge similar to the SPR, but was operated with step-wise increase in the loading rate and with total recirculation of reactor solids to convert it into acidification sludge. Before each feeding, part of the sludge from TPAR was centrifuged, the centrifuge liquid (solubilized products) was fed to the TPMR and centrifuged solids were recycled back to the reactor. Single-phase digestion produced a methane yield of 0.45 m{sup 3} CH{sub 4}/kg VS fed and VS removal of 83%. The TPAR shifted to acidification mode at an OLR of 10.0 kg VS/m{sup 3} d and then achieved stable performance at 7.0 kg VS/m{sup 3} d and pH 5.5–6.2, with very high substrate solubilization rate and a methane yield of 0.30 m{sup 3} CH{sub 4}/kg COD fed. The two-phase process was capable of high VS reduction, but material and energy balance showed that the single-phase process was superior in terms of volumetric methane production and energy yield by 33%. The lower energy yield of the two-phase system was due to the loss of

  16. Effect of biochar addition on hydrogen and methane production in two-phase anaerobic digestion of aqueous carbohydrates food waste.

    Science.gov (United States)

    Sunyoto, Nimas M S; Zhu, Mingming; Zhang, Zhezi; Zhang, Dongke

    2016-11-01

    Effect of biochar addition on hydrogen and methane production in two-phase anaerobic digestion of aqueous carbohydrates was studied using bench-scale bioreactors. The cultures with biochar additions were placed in 100ml reactors and incubated at 35°C and pH 5 for hydrogen production. The residual cultures were then used for methane production, incubated at 35°C and pH 7. Daily yields of hydrogen and methane and weekly yield of volatile fatty acids (VFA) were measured. The hydrogen and methane production potentials, rate and lag phases of the two phases were analysed using the Gompertz model. The results showed that biochar addition increased the maximum production rates of hydrogen by 32.5% and methane 41.6%, improved hydrogen yield by 31.0% and methane 10.0%, and shortened the lag phases in the two phases by 36.0% and 41.0%, respectively. Biochar addition also enhanced VFA generation during hydrogen production and VFA degradation in methane production.

  17. The Effect of pH Difference Between Two Phases on the Partition of Lysozyme in Aqueous Two-Phase System

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In the investigation of effect of KSCN on the partitioning of lysozyme in PEG2000/ammonium sulfate aqueous two-phase system, it was found that the KSCN could alter the pH difference between the two phases, and thus affect the partition of lysozyme. The relationship between partition coefficients of lysozyme and pH differences between two phases was discussed.

  18. Liquefaction and methanization of solid and liquid coffee wastes by two phase anaerobic digestion process.

    Science.gov (United States)

    Houbron, E; Larrinaga, A; Rustrian, E

    2003-01-01

    This study attempted to investigate the feasibility of volatile fatty acid (VFA) production from coffee pulp hydrolyse, and further to determine the potential of methanization of both the pre-acidified effluent and the coffee wastewater. The experiments were carried out in 2 completely mixed reactors, each one with a working volume of 4 litres. Coffee pulp was used as substrate in the acidogenic reactor and different mixtures of pulper and wash-water and pre-acidified effluent in the methanogenic one. The acidogenic and methanogenic reactors were operated at an organic loading rate of 5 COD g x l(-1) x d(-1) and 0.5 COD g x l(-1) x d(-1). The total, soluble and VFA's effluent COD concentrations of the acidogenic reactor present average values of 57.75, 17.00 and 13.92 g x l(-1) respectively. Under these experimental conditions, 23% (COD based) of coffee pulp was hydrolysed with a rate of 1.32 gCOD x l(-1) x d(-1) and the soluble fraction was transformed to VFA's with an acidification efficiency of 82%. Total VFA's concentration reached a value of 13.9 gCOD x l(-1), and acetate, propionate, butyrate and valerate represented 52%, 28%, 9% and 11% respectively of the liquid phase COD. In the methanogenic reactor, COD removal and methanization of fresh coffee wastewater, pre-acidified effluent and both combined occur with an efficiency of 85% to 95% respectively, with a characteristic biogas composition of 80% CH4 and 20% CO2. These results show that a humid coffee "Beneficio" processing daily 23 tons of cherry coffee (fresh fruit), equipped with a two stage anaerobic digestion process could generate at least 1,886 CH4 m3 x d(-1). This represents an increase in methane production by a factor 3 to 5 compared to a "Beneficio" using anaerobic digestion only for the treatment of its wastewater.

  19. Liquefaction and methanization of solid and liquid coffee wastes by two phase anaerobic digestion process

    Energy Technology Data Exchange (ETDEWEB)

    Houbron, E.; Rustrian, E. [Universidad Veracruzana, Orizaba, Ver. (Mexico). Facultad de Ciencias Quimicas; Larrinaga, A. [Instituto tecnologico de Orizaba, Ver. (Mexico)

    2003-07-01

    This study attempted to investigate the feasibility of volatile fatty acid (VFA) production from coffee pulp hydrolyse, and further to determine the potential of methanization of both the pre-acidified effluent and the coffee wastewater. The experiments were carried out in 2 completely mixed reactors, each one with working volume of 4 litres. Coffee pulp was used as substrate in the acidogenic reactor and different mixtures of pulper and wash-water and pre-acidified effluent in the methanogenic one. The acidogenic and methanogenic reactors were operated at an organic loading rate of 5 COD g.l{sup -1}.d{sup -1} and 0.5 COD g.l{sup -1}.d{sup -1}. The total, soluble and VFA's effluent COD concentrations of the acidogenic reactor present average values of 57.75, 17.00 and 13.92 g.l{sup -1} respectively. Under these experimental conditions, 23% (COD based) of coffee pulp was hydrolysed with a rate of 1.32 gCOD.l{sup -1}.d{sup -1} and the soluble fraction was transformed to VFA's with an acidification efficiency of 82%. Total VFA's concentration reached a value of 13.9 gCOD.l{sup -1}, and acetate, propionate, butyrate and valerate represented 52%, 28%, 9% and 11% respectively of the liquid phase COD. In the methanogenic reactor, COD removal and methanization of fresh coffee wastewater, pre-acidified effluent and both combined occur with an efficiency of 85% to 95% respectively, with a characteristic biogas composition of 80% CH{sub 4} and 20% CO{sub 2}. These results show that a humid coffee 'Beneficio' processing daily 23 tons of cherry coffee (fresh fruit), equipped with a two stage anaerobic digestion process could generate at least 1,886 CH{sub 4} m{sup 3}.d{sup -1}. This represents an increase in methane production by a factor 3 to 5 compared to a 'Beneficio' using anaerobic digestion only for the treatment of its wastewater. (author)

  20. Digestive system; Appareil digestif

    Energy Technology Data Exchange (ETDEWEB)

    Moureau-Zabotto, L.; Touboul, E.; Lerouge, D.; Deniaud-Alexandre, E.; Grahek, D.; Foulquier, J.N.; Petegnief, Y.; Gres, B.; El Balaa, H.; Keraudy, K.; Servagi-Vernat, S.S.; Lorchel, F.L.; Crehange, G.C.; Miny, J.M.; Bosset, J.F.B.; Mineur, L.; Chastel, D.; Combescure, C.; Guillot, N.; Garcia, R.; Reboul, F.; Huguet, F.; Andre, T.; Hammel, P.; Artru, P.; Balosso, J.; Ruszniewski, P.; Touboul, E.; Gramont, A. de; Louvet, C.; Moretti, L.; Meert, N.; Magne, N.; Daisne, J.F.; Berben, D.; Bral, S.; Alen, R.; Van Cleef, A.; Florescu, C.; Henry-Amar, M.; Jacob, J.; Ollivier, J.M.; Gallais, M.P.; Guillois, J.M.; Vie, B.; Tournier-Rangeard, L.; Mercier, M.; Gerard, J.P.; Ducreux, M.; Lemanski, C.; Francois, E.; Giovannini, M.; Cvitkovic, F.; Mirabel, X.; Peiffert, D

    2005-11-15

    Seven articles concern the digestive system cancer, mixing of images, toxicity of the chemoradiotherapy, comparison of dosimetry tools, pancreas cancer, rectum cancer, treated by chemoradiotherapy. (N.C.)

  1. Performance evaluation of a two-phase anaerobic digestion process of synthetic domestic wastewater at ambient temperature.

    Science.gov (United States)

    Guerrero, L; Montalvo, S; Coronado, E; Chamy, R; Poirrier, P; Crutchik, D; Sánchez, E; De La Rubia, M A; Borja, R

    2009-06-01

    A two-phase anaerobic digestion process of synthetic domestic wastewater was studied at ambient temperature in mild to cold climates. The hydrolytic stage was carried out in a continuous stirred tank reactor with an effective volume of 1.2 L. The hydrolytic reactor operated at hydraulic retention times (HRTs) in the range of 1.3 to 2.7 h, which allowed for optimum HRT to be obtained in order to achieve a maximum amount of soluble COD. For the methanogenic stage, an up-flow anaerobic filter with a volume of 1.35 L and corrugated plastic rings as biomass immobilization support were used. During the investigation, the ambient temperature ranged between 21 degrees C and 24 degrees C. Synthetic domestic wastewater with a COD of 700 mg/L was used as substrate. The study was performed at total organic loading rates (OLR(T)) of 2.0-4.3 g COD/L. d, with a global HRT (including both hydrolytic and methanogenic stages) of 2.8-5.8 hours. A maximum percentage of organic matter removed of 88% was achieved at a global HRT of 5.8 hours. Under these operating conditions, the production of biogas was 97% higher than that obtained in the one-phase anaerobic digestion process. Additionally, the kinetics involved in the hydrolytic stage was determined using the Contois kinetic model, which adequately predicted the experimental results.

  2. Single-phase and two-phase anaerobic digestion of fruit and vegetable waste: comparison of start-up, reactor stability and process performance.

    Science.gov (United States)

    Ganesh, Rangaraj; Torrijos, Michel; Sousbie, Philippe; Lugardon, Aurelien; Steyer, Jean Philippe; Delgenes, Jean Philippe

    2014-05-01

    Single-phase and two-phase digestion of fruit and vegetable waste were studied to compare reactor start-up, reactor stability and performance (methane yield, volatile solids reduction and energy yield). The single-phase reactor (SPR) was a conventional reactor operated at a low loading rate (maximum of 3.5 kgVS/m3 d), while the two-phase system consisted of an acidification reactor (TPAR) and a methanogenic reactor (TPMR). The TPAR was inoculated with methanogenic sludge similar to the SPR, but was operated with step-wise increase in the loading rate and with total recirculation of reactor solids to convert it into acidification sludge. Before each feeding, part of the sludge from TPAR was centrifuged, the centrifuge liquid (solubilized products) was fed to the TPMR and centrifuged solids were recycled back to the reactor. Single-phase digestion produced a methane yield of 0.45 m3 CH4/kg VS fed and VS removal of 83%. The TPAR shifted to acidification mode at an OLR of 10.0 kgVS/m3 d and then achieved stable performance at 7.0 kgVS/m3 d and pH 5.5-6.2, with very high substrate solubilization rate and a methane yield of 0.30 m3 CH4/kg COD fed. The two-phase process was capable of high VS reduction, but material and energy balance showed that the single-phase process was superior in terms of volumetric methane production and energy yield by 33%. The lower energy yield of the two-phase system was due to the loss of energy during hydrolysis in the TPAR and the deficit in methane production in the TPMR attributed to COD loss due to biomass synthesis and adsorption of hard COD onto the flocs. These results including the complicated operational procedure of the two-phase process and the economic factors suggested that the single-phase process could be the preferred system for FVW.

  3. Aqueous two-phase system based on natural quaternary ammonium compounds for the extraction of proteins.

    Science.gov (United States)

    Zeng, Chao-Xi; Xin, Rui-Pu; Qi, Sui-Jian; Yang, Bo; Wang, Yong-Hua

    2016-02-01

    Aqueous two-phase systems, based on the use of natural quaternary ammonium compounds, were developed to establish a benign biotechnological route for efficient protein separation. In this study, aqueous two-phase systems of two natural resources betaine and choline with polyethyleneglycol (PEG400/600) or inorganic salts (K2 HPO4 /K3 PO4 ) were formed. It was shown that in the K2 HPO4 -containing aqueous two-phase system, hydrophobic interactions were an important driving force of protein partitioning, while protein size played a vital role in aqueous two-phase systems that contained polyethylene glycol. An extraction efficiency of more than 90% for bovine serum albumin in the betaine/K2 HPO4 aqueous two-phase system can be obtained, and this betaine-based aqueous two-phase system provided a gentle and stable environment for the protein. In addition, after investigation of the cluster phenomenon in the betaine/K2 HPO4 aqueous two-phase systems, it was suggested that this phenomenon also played a significant role for protein extraction in this system. The development of aqueous two-phase systems based on natural quaternary ammonium compounds not only provided an effective and greener method of aqueous two-phase system to meet the requirements of green chemistry but also may help to solve the mystery of the compartmentalization of biomolecules in cells.

  4. Metabolic and microbial community dynamics during the anaerobic digestion of maize silage in a two-phase process.

    Science.gov (United States)

    Sträuber, Heike; Lucas, Rico; Kleinsteuber, Sabine

    2016-01-01

    Two-phasic anaerobic digestion processes (hydrolysis/acidogenesis separated from acetogenesis/methanogenesis) can be used for biogas production on demand or a combined chemicals/bioenergy production. For an effective process control, detailed knowledge about the microbial catalysts and their correlation to process conditions is crucial. In this study, maize silage was digested in a two-phase process and interrelationships between process parameters and microbial communities were revealed. In the first-phase reactor, alternating metabolic periods were observed which emerged independently from the feeding frequency. During the L-period, up to 11.8 g L(-1) lactic acid was produced which significantly correlated to lactic acid bacteria of the genus Lactobacillus as the most abundant community members. During the alternating G-period, the production of volatile fatty acids (up to 5.3, 4.0 and 3.1 g L(-1) for propionic, n-butyric and n-caproic acid, respectively) dominated accompanied by a high gas production containing up to 28 % hydrogen. The relative abundance of various Clostridiales increased during this metabolic period. In the second-phase reactor, the metabolic fluctuations of the first phase were smoothed out resulting in a stable biogas production as well as stable bacterial and methanogenic communities. However, the biogas composition followed the metabolic dynamics of the first phase: the hydrogen content increased during the L-period whereas highest CH4/CO2 ratios (up to 2.8) were reached during the G-period. Aceticlastic Methanosaeta as well as hydrogenotrophic Methanoculleus and Methanobacteriaceae were identified as dominant methanogens. Consequently, a directed control of the first-phase stabilizing desired metabolic states can lead to an enhanced productivity regarding chemicals and bioenergy.

  5. Influence of two-phase anaerobic digestion on fate of selected antibiotic resistance genes and class I integrons in municipal wastewater sludge.

    Science.gov (United States)

    Wu, Ying; Cui, Erping; Zuo, Yiru; Cheng, Weixiao; Rensing, Christopher; Chen, Hong

    2016-07-01

    The response of representative antibiotic resistance genes (ARGs) to lab-scale two-phase (acidogenic/methanogenic phase) anaerobic digestion processes under thermophilic and mesophilic conditions was explored. The associated microbial communities and bacterial pathogens were characterized by 16S rRNA gene sequencing. A two-phase thermophilic digestion reduced the presence of tetA, tetG, tetX, sul1, ermB, dfrA1, dfrA12 and intI1 exhibiting 0.1-0.72 log unit removal; in contrast, tetO, tetW, sul3, ermF and blaTEM even increased relative to the feed, and sul2 showed no significant decrease. The acidogenic phase of thermophilic digestion was primarily responsible for reducing the quantity of these genes, while the subsequent methanogenic phase caused a rebound in their quantity. In contrast, a two-phase mesophilic digestion process did not result in reducing the quantity of all ARGs and intI1 except for ermB and blaTEM. ARGs patterns were correlated with Proteobacteria and Actinobacteria during the two-phase anaerobic digestion.

  6. Two-phase anaerobic digestion of mixed waste streams to separate generation of bio-hydrogen and bio-methane

    Energy Technology Data Exchange (ETDEWEB)

    Siddiqui, Z.; Horam, N.J. [Leeds Univ. (United Kingdom). School of Civil Engineering

    2010-07-01

    two phase and sub optimal conditions improves the energy potential to 8.27 MW/tonne VS{sub fed} with VS(removal) efficiency as 80.7% in total 15 days of HRT. The net energy balance results indicated the co-digestion of IFW with waste products of SS treatment plant viz. primary sludge (PS) and waste activated sludge (WAS) are amenable substrates for the two-stage anaerobic bio-hydrogen and biomethane digestion process. (orig.)

  7. Heat transfer studies in a spiral plate heat exchanger for water: palm oil two phase system

    Directory of Open Access Journals (Sweden)

    S. Ramachandran

    2008-09-01

    Full Text Available Experimental studies were conducted in a spiral plate heat exchanger with hot water as the service fluid and the two-phase system of water – palm oil in different mass fractions and flow rates as the cold process fluid. The two phase heat transfer coefficients were correlated with Reynolds numbers (Re in the form h = a Re m, adopting an approach available in literature for two phase fluid flow. The heat transfer coefficients were also related to the mass fraction of palm oil for identical Reynolds numbers. The two-phase multiplier (ratio of the heat transfer coefficient of the two phase fluid and that of the single phase fluid was correlated with the Lockhart Martinelli parameter in a polynomial form. This enables prediction of the two-phase coefficients using single-phase data. The predicted coefficients showed a spread of ± 10 % in the laminar range.

  8. A two-phase system call arguments attribute analyzing method

    Institute of Scientific and Technical Information of China (English)

    LI Hong-jiao; LI Jian-hua

    2008-01-01

    To detect more attacks aiming at key security data in program behavior-based anomaly detection, the data flow properties were formulated as unary and binary relations on system call arguments. A new method named two-phrase analysis (2PA) is designed to analyze the efficient relation dependency, and its description as well as advantages are discussed. During the phase of static analysis, a dependency graph was constructed according to the program's data dependency graph, which was used in the phase of dynamic learning to learn specified binary relations. The constructed dependency graph only stores the information of related arguments and events, thus improves the efficiency of the learning algorithm and reduces the size of learned relation de-pendencies. Performance evaluations show that the new method is more efficient than existing methods.

  9. Influence of two-phase anaerobic digestion on fate of selected antibiotic resistance genes and class I integrons in municipal wastewater sludge

    DEFF Research Database (Denmark)

    Wu, Ying; Cui, Erping; Zuo, Yiru

    2016-01-01

    The response of representative antibiotic resistance genes (ARGs) to lab-scale two-phase (acidogenic/methanogenic phase) anaerobic digestion processes under thermophilic and mesophilic conditions was explored. The associated microbial communities and bacterial pathogens were characterized by 16S r...

  10. Symmetrical components and power analysis for a two-phase microgrid system

    DEFF Research Database (Denmark)

    Alibeik, M.; Santos Jr., E. C. dos; Blaabjerg, Frede

    2014-01-01

    This paper presents a mathematical model for the symmetrical components and power analysis of a new microgrid system consisting of three wires and two voltages in quadrature, which is designated as a two-phase microgrid. The two-phase microgrid presents the following advantages: 1) constant power...

  11. Two-phase aqueous micellar systems: an alternative method for protein purification

    Directory of Open Access Journals (Sweden)

    Rangel-Yagui C. O.

    2004-01-01

    Full Text Available Two-phase aqueous micellar systems can be exploited in separation science for the extraction/purification of desired biomolecules. This article reviews recent experimental and theoretical work by Blankschtein and co-workers on the use of two-phase aqueous micellar systems for the separation of hydrophilic proteins. The experimental partitioning behavior of the enzyme glucose-6-phosphate dehydrogenase (G6PD in two-phase aqueous micellar systems is also reviewed and new results are presented. Specifically, we discuss very recent work on the purification of G6PD using: i a two-phase aqueous micellar system composed of the nonionic surfactant n-decyl tetra(ethylene oxide (C10E4, and (ii a two-phase aqueous mixed micellar system composed of C10E4 and the cationic surfactant decyltrimethylammonium bromide (C10TAB. Our results indicate that the two-phase aqueous mixed (C10E4/C10TAB micellar system can improve significantly the partitioning behavior of G6PD relative to that observed in the two-phase aqueous C10E4 micellar system.

  12. Effect of different pH-values on process parameters in two-phase anaerobic digestion of high-solid substrates.

    Science.gov (United States)

    Lindner, Jonas; Zielonka, Simon; Oechsner, Hans; Lemmer, Andreas

    2015-01-01

    In many publications, primary fermentation is described as a limiting step in the anaerobic digestion of fibre-rich biomass [Eastman JA, Ferguson JF. Solubilization of particulacte carbon during the anaerobic digeston. J WPCF. 1981;53:352-366; Noike T, Endo G, Chang J, Yaguchi J, Matsumoto J. Characteristics of carbohydrate degradation and the rate-limiting step in anaerobic digestion. Biotechnol Bioeng. 1985;27:1482-1489; Arntz HJ, Stoppok E, Buchholz K. Anaerobic hydroysis of beet pulp-discontiniuous experiments. Biotechnol Lett. 1985;7:113-118]. The microorganisms of the primary fermentation process differ widely from the methanogenic microorganisms [Pohland FG, Ghosh S. Developments in anaerobic stabilization of organic wastes-the two-phase concept. Environ Lett. 1971;1:255-266]. To optimize the biogas process, a separation in two phases is suggested by many authors [Fox P, Pohland GK. Anaerobic treatment applications and fundamentals: substrate specificity during phase separation. Water Environ Res. 1994;66:716-724; Cohen A, Zoetemeyer RJ, van Deursen A, van Andel JG. Anaerobic digestion of glucose with separated acid production and methane formation. Water Res. 1979;13:571-580]. To carry out the examination, a two-phase laboratory-scale biogas plant was established, with a physical phase separation. In previous studies, the regulation of the pH-value during the acid formation was usually carried out by the addition of sodium hydroxide [Cohen A, Zoetemeyer RJ, van Deursen A, van Andel JG. Anaerobic digestion of glucose with separated acid production and methane formation. Water Res. 1979;13:571-580; Ueno Y, Tatara M, Fukui H, Makiuchi T, Goto M, Sode K. Production of hydrogen and methane from organic solid wastes by phase separation of anaerobic process. Bioresour Technol. 2007;98:1861-1865; Zoetemeyer RJ, van den Heuvel JC, Cohen A. pH influence on acidogenic dissimilation of glucose in an anaerobic digestor. Water Res. 1982;16:303-311]. A new technology

  13. Ionic liquids for two-phase systems and their application for purification, extraction and biocatalysis.

    Science.gov (United States)

    Oppermann, Sebastian; Stein, Florian; Kragl, Udo

    2011-02-01

    The development of biotechnological processes using novel two-phase systems based on molten salts known as ionic liquids (ILs) got into the focus of interest. Many new approaches for the beneficial application of the interesting solvent have been published over the last years. ILs bring beneficial properties compared to organic solvents like nonflammability and nonvolatility. There are two possible ways to use the ILs: first, the hydrophobic ones as a substitute for organic solvents in pure two-phase systems with water and second, the hydrophilic ones in aqueous two-phase systems (ATPS). To effectively utilise IL-based two-phase systems or IL-based ATPS in biotechnology, extensive experimental work is required to gain the optimal system parameters to ensure selective extraction of the product of interest. This review will focus on the most actual findings dealing with the basic driving forces for the target extraction in IL-based ATPS as well as presenting some selected examples for the beneficial application of ILs as a substitute for organic solvents. Besides the research focusing on IL-based two-phase systems, the "green aspect" of ILs, due to their negligible vapour pressure, is widely discussed. We will present the newest results concerning ecotoxicity of ILs to get an overview of the state of the art concerning ILs and their utilisation in novel two-phase systems in biotechnology.

  14. Bioconversion of apigenin-7-O-β-glucoside in aqueous two-phase system

    OpenAIRE

    Ilić Sanja M.; Đaković Sanja D.; Cvejić Jelena H.; Antov Mirjana G.; Zeković Zoran P.

    2005-01-01

    The study is concerned with the conversion of apigenin-7-O-β-glucoside into apigenin in polyethylene glycol 6000 / dextran 20000 aqueous two-phase system by β-glucosidase. Apigenin was separated from apigenin-7-O-β-glucoside and β-glucosidase by their partition into opposite phases. In 14% PEG / 22.5% DEX aqueous two-phase system obtained yield of apigenin in top phase was 108%.

  15. Bioconversion of apigenin-7-O-β-glucoside in aqueous two-phase system

    Directory of Open Access Journals (Sweden)

    Ilić Sanja M.

    2005-01-01

    Full Text Available The study is concerned with the conversion of apigenin-7-O-β-glucoside into apigenin in polyethylene glycol 6000 / dextran 20000 aqueous two-phase system by β-glucosidase. Apigenin was separated from apigenin-7-O-β-glucoside and β-glucosidase by their partition into opposite phases. In 14% PEG / 22.5% DEX aqueous two-phase system obtained yield of apigenin in top phase was 108%.

  16. Living between two worlds: two-phase culture systems for producing plant secondary metabolites.

    Science.gov (United States)

    Malik, Sonia; Hossein Mirjalili, Mohammad; Fett-Neto, Arthur Germano; Mazzafera, Paulo; Bonfill, Mercedes

    2013-03-01

    The two-phase culture system is an important in vitro strategy to increase the production of secondary metabolites (SMs) by providing an enhanced release of these compounds from plant cells. Whereas the first phase supports cell growth, the second phase provides an additional site or acts as a metabolic sink for the accumulation of SMs and also reduces feedback inhibition. This review is focused on several aspects of the two-phase culture system and aims to show the diverse possibilities of employing this technique for the in vitro production of SMs from plant cells. Depending on the material used in the secondary phase, two-phase culture systems can be broadly categorised as liquid-liquid or liquid-solid. The choice of material for the second phase depends on the type of compound to be recovered and the compatibility with the other phase. Different factors affecting the efficiency of two-phase culture systems include the choice of material for the secondary phase, its concentration, volume, and time of addition. Factors such as cell elicitation, immobilization, and permeabilization, have been suggested as important strategies to make the two-phase culture system practically reliable on a commercial scale. Since there are many possibilities for designing a two-phase system, more detailed studies are needed to broaden the range of secondary phases compatible with the various plant species producing SMs with potential applications, mainly in the food and pharmacology industries.

  17. Study of microbial community and biodegradation efficiency for single- and two-phase anaerobic co-digestion of brown water and food waste.

    Science.gov (United States)

    Lim, J W; Chen, C-L; Ho, I J R; Wang, J-Y

    2013-11-01

    The objective of this work was to study the microbial community and reactor performance for the anaerobic co-digestion of brown water and food waste in single- and two-phase continuously stirred tank reactors (CSTRs). Bacterial and archaeal communities were analyzed after 150 days of reactor operation. As compared to single-phase CSTR, methane production in two-phase CSTR was found to be 23% higher. This was likely due to greater extent of solubilization and acidification observed in the latter. These findings could be attributed to the predominance of Firmicutes and greater bacterial diversity in two-phase CSTR, and the lack of Firmicutes in single-phase CSTR. Methanosaeta was predominant in both CSTRs and this correlated to low levels of acetate in their effluent. Insights gained from this study would enhance the understanding of microorganisms involved in co-digestion of brown water and food waste as well as the complex biochemical interactions promoting digester stability and performance.

  18. Camomile autofermentation in polyethylene glycol/dextran two-phase system

    Directory of Open Access Journals (Sweden)

    Đaković Sanja D.

    2008-01-01

    Full Text Available The objective of this study was the investigation of the extractive bioconversion of apigenin-7-O-β-glucoside in camomile ligulate flowers into apigenin by autofermentation in polyethylene glycol 6000/dextran 200000 two-phase system. In 22.5% polyethylene glycol/14% dextran aqueous two-phase system the obtained yield of apigenin in the top phase was 96.5%. In the presence of plant material that partiotioned to the interphase, the yield of apigenin in the top phase was 3.5 times higher in comparison to the model system.

  19. Optimisation of the two-phase dry-thermophilic anaerobic digestion process of sulphate-containing municipal solid waste: population dynamics.

    Science.gov (United States)

    Zahedi, S; Sales, D; Romero, L I; Solera, R

    2013-11-01

    Microbial population dynamics and anaerobic digestion (AD) process to eight different hydraulic retention times (HRTs) (from 25d to 3.5d) in two-phase dry-thermophilic AD from sulphate-containing solid waste were investigated. Maximum values of gas production (1.9 ± 0.2 l H2/l/d; 5.4 ± 0.3 l CH4/l/d and 82 ± 9 ml H2S/l/d) and microbial activities were obtained at 4.5d HRT; where basically comprised hydrolysis step in the first phase (HRT=1.5d) and acidogenic step finished in the second phase as well as acetogenic-methanogenic steps (HRT=3d). In the first phase, hydrolytic-acidogenic bacteria (HABs) was the main group (44-77%) and Archaea, acetogens and sulphate-reducing bacteria (SRBs) contents were not significant; in the second phase (except to 2d HRT), microbial population was able to adapt to change in substrate and HRTs to ensure the proper functioning of the system and both acetogens and Archaea were dominated over SRBs. Decreasing HRT resulted in an increase in microbial activities.

  20. Affinity partitioning of human antibodies in aqueous two-phase systems

    NARCIS (Netherlands)

    Rosa, P. A. J.; Azevedo, A. M.; Ferreira, I. F.; de Vries, J.; Korporaal, R.; Verhoef, H. J.; Visser, T. J.; Aires-Barros, M. R.

    2007-01-01

    The partitioning of human immunoglobulin (IgG) in a polymer-polymer and polymer-salt aqueous two-phase system (ATPS) in the presence of several functionalised polyethylene glycols (PEGs) was studied. As a first approach, the partition studies were performed with pure IgG using systems in which the t

  1. Selective separation and enrichment of proteins in aqueous two-phase extraction system

    Institute of Scientific and Technical Information of China (English)

    Feng Qu; Hao Qin; Min Dong; Dong Xu Zhao; Xin Ying Zhao; Jing Hua Zhang

    2009-01-01

    A simple aqueous two-phase extraction system(ATPS)of PEG/phosphate was proposed for selective separation and enrichment of proteins.The combination of ATPE with HPLC was applied to identify the partition of proteins in two phases.Five proteins (bovine serum albumin,Cytochrome C,lysozyme,myoglobin,and trypsin)were used as model proteins to study the effect of phosphate concentration and pH on proteins partition.The PEG/phosphate system was firstly applied to real human saliva and plasma samples,some proteins showed obviously different partition in two phases.The primary results manifest the selective separation and enrichment of proteins in ATPS provided the potential for high abundance proteins depletion in proteomics.

  2. Liquid-liquid extraction of enzymes by affinity aqueous two-phase systems

    Directory of Open Access Journals (Sweden)

    Xu Yan

    2003-12-01

    Full Text Available From analytical to commercial scale, aqueous two-phase systems have their application in the purification, characterization and study of biomaterials. In order to improve the selectivity of the systems, the biospecific affinity ligands were introduced. In the affinity partitioning aqueous two-phase system, have many enzymes been purified. This review discusses the partitioning of some enzymes in the affinity aqueous two-phase systems in regard to the different ligands, including reactive dyes, metal ions and other ligands. Some integration of aqueous two-phase system with other techniques for more effective purification of enzymes are also presented.Tanto em escala de laboratório como industrial, os sistemas de duas fases aquosas podem ser utilizados para a purificação, caracterização e estudos de biomateriais. Para aumentar a seletividade desse sistema, ligantes de afinidade bioespecíficos podem ser utilizados. No sistema de duas fases aquosas por afinidade, muitas enzimas podem ser purificadas. Neste artigo de revisão, a partição de algumas enzimas por esse tipo de afinidade, utilizando diferentes ligantes como corantes e íons metálicos, são discutidas. Além disso, a integração desse sistema de duas fases aquosas com outras técnicas de purificação estão sendo apresentados, com o objetivo mostrar a melhoria da eficiência do processo.

  3. Two-phase flow stability structure in a natural circulation system

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Zhiwei [Nuclear Engineering Laboratory Zurich (Switzerland)

    1995-09-01

    The present study reports a numerical analysis of two-phase flow stability structures in a natural circulation system with two parallel, heated channels. The numerical model is derived, based on the Galerkin moving nodal method. This analysis is related to some design options applicable to integral heating reactors with a slightly-boiling operation mode, and is also of general interest to similar facilities. The options include: (1) Symmetric heating and throttling; (2) Asymmetric heating and symmetric throttling; (3) Asymmetric heating and throttling. The oscillation modes for these variants are discussed. Comparisons with the data from the INET two-phase flow stability experiment have qualitatively validated the present analysis.

  4. Extraction of peptide tagged cutinase in detergent-based aqueous two-phase systems

    NARCIS (Netherlands)

    Rodenbrock, A.; Selber, K.; Egmond, M.R.; Kula, M.-R.

    2010-01-01

    Detergent-based aqueous two-phase systems have the advantage to require only one auxiliary chemical to induce phase separation above the cloud point. In a systematic study the efficiency of tryptophan-rich peptide tags was investigated to enhance the partitioning of an enzyme to the detergent-rich p

  5. Design, Modelling and Simulation of Two-Phase Two-Stage Electronic System with Orthogonal Output for Supplying of Two-Phase ASM

    Directory of Open Access Journals (Sweden)

    Michal Prazenica

    2011-01-01

    Full Text Available This paper deals with the two-stage two-phase electronic systems with orthogonal output voltages and currents - DC/AC/AC. Design of two-stage DC/AC/AC high frequency converter with two-phase orthogonal output using single-phase matrix converter is also introduced. Output voltages of them are strongly nonharmonic ones, so they must be pulse-modulated due to requested nearly sinusoidal currents with low total harmonic distortion. Simulation experiment results of matrix converter for both steady and transient states for IM motors are given in the paper, also experimental verification under R-L load, so far. The simulation results confirm a very good time-waveform of the phase current and the system seems to be suitable for low-cost application in automotive/aerospace industries and application with high frequency voltage sources.

  6. Transport, geometrical, and topological properties of stealthy disordered hyperuniform two-phase systems.

    Science.gov (United States)

    Zhang, G; Stillinger, F H; Torquato, S

    2016-12-28

    Disordered hyperuniform many-particle systems have attracted considerable recent attention, since they behave like crystals in the manner in which they suppress large-scale density fluctuations, and yet also resemble statistically isotropic liquids and glasses with no Bragg peaks. One important class of such systems is the classical ground states of "stealthy potentials." The degree of order of such ground states depends on a tuning parameter χ. Previous studies have shown that these ground-state point configurations can be counterintuitively disordered, infinitely degenerate, and endowed with novel physical properties (e.g., negative thermal expansion behavior). In this paper, we focus on the disordered regime (0 two-phase media by circumscribing each point with a possibly overlapping sphere of a common radius a: the "particle" and "void" phases are taken to be the space interior and exterior to the spheres, respectively. The hyperuniformity of such two-phase media depends on the sphere sizes: While it was previously analytically proven that the resulting two-phase media maintain hyperuniformity if spheres do not overlap, here we show numerically that they lose hyperuniformity whenever the spheres overlap. We study certain transport properties of these systems, including the effective diffusion coefficient of point particles diffusing in the void phase as well as static and time-dependent characteristics associated with diffusion-controlled reactions. Besides these effective transport properties, we also investigate several related structural properties, including pore-size functions, quantizer error, an order metric, and percolation thresholds. We show that these transport, geometrical, and topological properties of our two-phase media derived from decorated stealthy ground states are distinctly different from those of equilibrium hard-sphere systems and spatially uncorrelated overlapping spheres. As the extent of short-range order increases, stealthy disordered

  7. Dynamic characteristics of two-phase thermal control system for spacecraft

    Science.gov (United States)

    Malozemov, Vladimir V.; Kudryavtseva, Natal'ya S.; Antonov, Viktor A.; Zagar, Oleg V.; Chernobaev, Nikolaj N.

    1992-07-01

    This paper deals with review of the issues associated with modelling the dynamic processes in the spacecraft two-phase thermal control systems. The work presents the results of modelling the nonstationary conditions of the evaporative and condensation heat exchangers functioning, investigates their response to the characteristic external influences. Disclosed are the results of the computer-aided modelling the two-phase thermal control system with a pump. The dynamic characteristics of the change in the inputs of pressures, temperatures and vapor content of a coolant in various branches of the system, as well as the lengths of the heat transfer zones in the evaporator and condenser under effect of the typical disturbing actions are obtained. The attained transients are analyzed.

  8. Aqueous Two-Phase Systems formed by Biocompatible and Biodegradable Polysaccharides and Acetonitrile.

    Science.gov (United States)

    de Brito Cardoso, Gustavo; Souza, Isabela Nascimento; Pereira, Matheus M; Freire, Mara G; Soares, Cleide Mara Faria; Lima, Álvaro Silva

    2014-11-05

    In this work, it is shown that novel aqueous two-phase systems can be formed by the combination of acetonitrile and polysaccharides, namely dextran. Several ternary phase diagrams were determined at 25 °C for the systems composed of water + acetonitrile + dextran. The effect of the dextran molecular weight (6,000, 40,000 and 100,000 g.mol(-1)) was ascertained toward their ability to undergo liquid-liquid demixing. An increase in the dextran molecular weight favors the phase separation. Furthermore, the effect of temperature (25, 35 and 45 °C) was evaluated for the system constituted by the dextran of higher molecular weight. Lower temperatures are favorable for phase separation since lower amounts of dextran and acetonitrile are required for the creation of aqueous two-phase systems. In general, acetonitrile is enriched in the top phase while dextran is majorly concentrated in the bottom phase. The applicability of this new type of two-phase systems as liquid-liquid extraction approaches was also evaluated by the study of the partition behavior of a well-known antioxidant - vanillin - and used here as a model biomolecule. The optimized conditions led to an extraction efficiency of vanillin of 95% at the acetonitrile-rich phase.

  9. Drop volumes and terminal velocities in aqueous two-phase systems

    Energy Technology Data Exchange (ETDEWEB)

    Bhavasar, P. M.; Jafarabad, K. R.; Pandit, A. B.; Sawant, S. B.; Joshi, J. B. [Bombay Univ. (India). Dept. of Chemical Technology

    1996-12-01

    Two phase aqueous extraction techniques employed in liquid-liquid extraction equipment such as spray columns and plate columns were studied, with particular attention to predicting drop sizes prior to jetting, and their terminal velocity. In the particular system studied, the values obtained by conventional models as found in the literature were considered inapplicable. A generalised model was constructed using video photographic measurements, and a correlation was developed for the terminal velocities of the drops in aqueous two-phase systems. This simplified model was found to be successful in expressing the terminal rise/fall velocities of droplets covering a specific range of Morton numbers (representing physical properties) from 0.00211 to 11050 and Eotvos numbers (representative of drop size) from 0.091 to 288. 22 refs., 6 figs.

  10. Use of two-phase flow heat transfer method in spacecraft thermal system

    Science.gov (United States)

    Hye, A.

    1985-01-01

    In space applications, weight, volume and power are critical parameters. Presently liquid freon is used in the radiator planels of the Space Shuttle to dissipate heat. This requires a large amount of freon, large power for pumps, large volume and weight. Use of two-phase flow method to transfer heat can reduce them significantly. A modified commercial vapor compression refrigerator/freezer was sucessfully flown in STS-4 to study the effect of zero-gravity on the system. The duty cycle was about 5 percent higher in flight as compared to that on earth due to low flow velocity in condenser. The vapor Reynolds number at exit was about 4000 as compared to about 12,000. Efforts are underway to design a refrigerator/freezer using an oil-free compressor for Spacelab Mission 4 scheduled to fly in January 1986. A thermal system can be designed for spacecraft using the two-phase flow to transfer heat economically.

  11. Two-phase distribution in the vertical flow line of a domestic wet central heating system

    Directory of Open Access Journals (Sweden)

    Ge Y.T.

    2013-04-01

    Full Text Available The theoretical and experimental aspects of bubble distribution in bubbly two-phase flow are reviewed in the context of the micro bubbles present in a domestic gas fired wet central heating system. The latter systems are mostly operated through the circulation of heated standard tap water through a closed loop circuit which often results in water supersaturated with dissolved air. This leads to micro bubble nucleation at the primary heat exchanger wall, followed by detachment along the flow. Consequently, a bubbly two-phase flow characterises the flow line of such systems. The two-phase distribution across the vertical and horizontal pipes was measured through a consideration of the volumetric void fraction, quantified through photographic techniques. The bubble distribution in the vertical pipe in down flow conditions was measured to be quasi homogenous across the pipe section with a negligible reduction in the void fraction at close proximity to the pipe wall. Such a reduction was more evident at lower bulk fluid velocities.

  12. Two-phase distribution in the vertical flow line of a domestic wet central heating system

    Science.gov (United States)

    Fsadni, A.-M.; Ge, Y. T.

    2013-04-01

    The theoretical and experimental aspects of bubble distribution in bubbly two-phase flow are reviewed in the context of the micro bubbles present in a domestic gas fired wet central heating system. The latter systems are mostly operated through the circulation of heated standard tap water through a closed loop circuit which often results in water supersaturated with dissolved air. This leads to micro bubble nucleation at the primary heat exchanger wall, followed by detachment along the flow. Consequently, a bubbly two-phase flow characterises the flow line of such systems. The two-phase distribution across the vertical and horizontal pipes was measured through a consideration of the volumetric void fraction, quantified through photographic techniques. The bubble distribution in the vertical pipe in down flow conditions was measured to be quasi homogenous across the pipe section with a negligible reduction in the void fraction at close proximity to the pipe wall. Such a reduction was more evident at lower bulk fluid velocities.

  13. Interfacial Tension Effect on Cell Partition in Aqueous Two-Phase Systems.

    Science.gov (United States)

    Atefi, Ehsan; Joshi, Ramila; Mann, Jay Adin; Tavana, Hossein

    2015-09-30

    Aqueous two-phase systems (ATPS) provide a mild environment for the partition and separation of cells. We report a combined experimental and theoretical study on the effect of interfacial tension of polymeric ATPS on the partitioning of cells between two phases and their interface. Two-phase systems are generated using polyethylene glycol and dextran of specific properties as phase-forming polymers and culture media as the solvent component. Ultralow interfacial tensions of the solutions are precisely measured using an axisymmetric drop shape analysis method. Partition experiments show that two-phase systems with an interfacial tension of 30 μJ/m(2) result in distribution of majority of cells to the bottom dextran phase. An increase in the interfacial tension results in a distribution of cells toward the interface. An independent cancer cell spheroid formation assay confirms these observations: a drop of the dextran phase containing cancer cells is dispensed into the immersion polyethylene glycol phase to form a cell-containing drop. Only at very small interfacial tensions do cells remain within the drop to aggregate into a spheroid. We perform a thermodynamic modeling of cell partition to determine variations of free energy associated with displacement of cells in ATPS with respect to the ultralow interfacial tensions. This modeling corroborates with the experimental results and demonstrates that at the smallest interfacial tension of 30 μJ/m(2), the free energy is a minimum with cells in the bottom phase. Increasing the interfacial tension shifts the minimum energy and partition of cells toward the interfacial region of the two aqueous phases. Examining differences in the partition behavior and minimum free energy modeling of A431.H9 cancer cells and mouse embryonic stem cells shows that the surface properties of cells further modulate partition in ATPS. This combined approach provides a fundamental understanding of interfacial tension role on cell partition in

  14. Optimization of two-phase thermophilic anaerobic digestion of biowaste for hydrogen and methane production through reject water recirculation.

    Science.gov (United States)

    Cavinato, C; Bolzonella, D; Fatone, F; Cecchi, F; Pavan, P

    2011-09-01

    The optimization of a two-phase thermophilic anaerobic process treating biowaste for hydrogen and methane production was carried out at pilot scale using two stirred reactors (CSTRs) and without any physical/chemical pre-treatment of inoculum. During the experiment the hydrogen production at low hydraulic retention time (3d) was tested, both with and without reject water recirculation and at two organic loading rate (16 and 21 kgTVS/m3 d). The better yields were obtained with recirculation where the pH reached an optimal value (5.5) thanks to the buffering capacity of the recycle stream. The specific gas production of the first reactor was 51 l/kgVS(fed) and H2 content in biogas 37%. The mixture of gas obtained from the two reactors met the standards for the biohythane mix only when lower loading rate were applied to the first reactor, with a composition of 6.7% H2, 40.1% CO2 and 52.3% CH4 the overall SGP being 0.78 m3/kgVS(fed).

  15. Simulation of non-equilibrium two-phase flow in single component fluid systems

    Energy Technology Data Exchange (ETDEWEB)

    Hoyer, Norbert [Scandpower A/S, Kjeller (Norway)

    1996-12-31

    Traditionally, two-phase flow has been modelled by separate correlations for void fraction, pressure drop and flow regimes. A more unified approach, which treats flow regimes as an integral part of the two-fluid model is described in this work. A general, transient simulator for steam-water/inert gas systems has been developed. MONA is based on a full two-fluid, three field, nonequilibrium, nonhomogeneous two-phase flow model. It includes further an extensive heat and mass transfer package. The major contribution for MONA validation comes from the FRIGG loop experiments, covering a wide range of parameters like geometry, flow, subcooling, pressure and heat flux. Both validation against steady state and dynamic experiments has been carried out, the former comprising void fractions, pressure drops as well as natural and forced circulation flow rates while the latter consists of boiling instability analysis. 69 refs., 41 figs., 5 tabs.

  16. Preparative crystallization of a single chain antibody using an aqueous two-phase system.

    Science.gov (United States)

    Huettmann, Hauke; Berkemeyer, Matthias; Buchinger, Wolfgang; Jungbauer, Alois

    2014-11-01

    A simultaneous crystallization and aqueous two-phase extraction of a single chain antibody was developed, demonstrating process integration. The process conditions were designed to form an aqueous two-phase system, and to favor crystallization, using sodium sulfate and PEG-2000. At sufficiently high concentrations of PEG, a second phase was generated in which the protein crystallization occurred simultaneously. The single chain antibody crystals were partitioned to the top, polyethylene glycol-rich phase. The crystal nucleation took place in the sodium sulfate-rich phase and at the phase boundary, whereas crystal growth was progressing mainly in the polyethylene glycol-rich phase. The crystals in the polyethylene glycol-rich phase grew to a size of >50 µm. Additionally, polyethylene glycol acted as an anti-solvent, thus, it influenced the crystallization yield. A phase diagram with an undersaturation zone, crystallization area, and amorphous precipitation zone was established. Only small differences in polyethylene glycol concentration caused significant shifts of the crystallization yield. An increase of the polyethylene glycol content from 2% (w/v) to 4% (w/v) increased the yield from approximately 63-87%, respectively. Our results show that crystallization in aqueous two-phase systems is an opportunity to foster process integration.

  17. Enrichment of membrane proteins by partitioning in detergent/polymer aqueous two-phase systems.

    Science.gov (United States)

    Everberg, Henrik; Gustavasson, Niklas; Tjerned, Folke

    2008-01-01

    Methods that combine efficient solubilization with enrichment of proteins and intact protein complexes are of central interest in current membrane proteomics. We have developed methods based on nondenaturing detergent extraction of yeast mitochondrial membrane proteins followed by enrichment of hydrophobic proteins in aqueous two-phase system. Combining the zwitterionic detergent Zwittergent 3-10 and the nonionic detergent Triton X-114 results in a complementary solubilization of proteins, which is similar to that of the anionic detergent sodium dodecyl sulfate (SDS) but with the important advantage of being nondenaturing. Detergent/polymer two-phase system partitioning offers removal of soluble proteins that can be further improved by manipulation of the driving forces governing protein distribution between the phases. Integral and peripheral membrane protein subunits from intact membrane protein complexes partition to the detergent phase while soluble proteins are found in the polymer phase. An optimized solubilization protocol is presented in combination with detergent/polymer two-phase partitioning as a mild and efficient method for initial enrichment of membrane proteins and membrane protein complexes in proteomic studies.

  18. Fractionation of wheat gliadins by counter-current distribution using an organic two-phase system.

    Science.gov (United States)

    Truust, H; Johansson, G

    1998-06-26

    A liquid liquid two-phase system based on N,N-dimethylformamide and the two polymers, poly(ethyleneglycol) and Ficoll, useful for partitioning of hydrophobic proteins, has been developed. The system has been applied to a counter-current distribution process in 56 steps for analysing the heterogeneity of proteins extracted with N,N-dimethylformamide from wheat flour. The counter-current distribution patterns of proteins, extracted from eight kinds of wheat, have been analysed. The minimum number of hypothetical proteins necessary to describe the patterns was found to be seven. The relative amount of these hypothetical components varied among the wheats.

  19. Two-Phase Cryogenic Heat Exchanger for the Thermodynamic Vent System

    Science.gov (United States)

    Christie, Robert J.

    2011-01-01

    A two-phase cryogenic heat exchanger for a thermodynamic vent system was designed and analyzed, and the predicted performance was compared with test results. A method for determining the required size of the Joule-Thomson device was also developed. Numerous sensitivity studies were performed to show that the design was robust and possessed a comfortable capacity margin. The comparison with the test results showed very similar heat extraction performance for similar inlet conditions. It was also shown that estimates for Joule- Thomson device flow rates and exit quality can vary significantly and these need to be accommodated for with a robust system design.

  20. Innovative method for increased methane recovery from two-phase anaerobic digestion of food waste through reutilization of acidogenic off-gas in methanogenic reactor.

    Science.gov (United States)

    Yan, Bing Hua; Selvam, Ammaiyappan; Wong, Jonathan W C

    2016-10-01

    In this study, the performance of a two-phase anaerobic digestion reactor treating food waste with the reutilization of acidogenic off-gas was investigated with the objective to improve the hydrogen availability for the methanogenic reactor. As a comparison a treatment without off-gas reutilization was also set up. Results showed that acidogenic off-gas utilization in the upflow anaerobic sludge blanket (UASB) reactor increased the methane recovery up to 38.6%. In addition, a 27% increase in the production of cumulative chemical oxygen demand (COD) together with an improved soluble microbial products recovery dominated by butyrate was observed in the acidogenic leach bed reactor (LBR) with off-gas reutilization. Of the increased methane recovery, ∼8% was contributed by the utilization of acidogenic off-gas in UASB. Results indicated that utilization of acidogenic off-gas in methanogenic reactor is a viable technique for improving overall methane recovery.

  1. Aqueous Two-Phase Extraction of Polyphenols Using a Microchannel System – Process Optimization and Intensification

    Directory of Open Access Journals (Sweden)

    Ivana Rukavina

    2011-01-01

    Full Text Available Polyphenols are one of the most numerous and widespread groups of compounds in the plant world. Nowadays, organic solvents such as methanol, ethanol, acetone, dimethylformamide, ethyl acetate and diethylether are mainly used for the extraction of polyphenols. These solvents require special process conditions and special care in the disposal of the used solvents. In this paper, the extraction of polyphenols from the model solution was performed using the aqueous two-phase system which contains 80.90 % water and represents low burden on the environment. The aqueous solution of gallic acid (GA was used as a model solution of polyphenols. The extraction was performed in the aqueous two-phase system containing PEG6000/H2O/(NH42SO4 in a macroextractor (V=10 mL and microextractor (V=14 ƒμL. The influence of the process parameters, the concentration of gallic acid, pH and composition of the aqueous two-phase system was investigated in order to maximize the partition coefficient. The method of multifactor experimental planning was used to optimize the extraction process and the results were statistically analysed using the evolutionary operation method (EVOP. Optimal operating conditions of the extraction process were pH=6.50, γGA=4.50 g/L, the mass fraction of polyethylene glycol (PEG wPEG=0.1037 g/g and the mass fraction of ammonium sulphate (AMS wAMS=0.0925 g/g. Under these conditions the maximal partition coefficient of K=5.54 and the extraction efficiency of E=89.11 % were achieved and successfully applied for total phenol extraction from white wine in the macro- and microextractor. Approximately the same partition coefficients and extraction efficiency were achieved in the microextractor within a 60-fold shorter residence time.

  2. Rapid RNA Exchange in Aqueous Two-Phase System and Coacervate Droplets

    Science.gov (United States)

    Jia, Tony Z.; Hentrich, Christian; Szostak, Jack W.

    2014-02-01

    Compartmentalization in a prebiotic setting is an important aspect of early cell formation and is crucial for the development of an artificial protocell system that effectively couples genotype and phenotype. Aqueous two-phase systems (ATPSs) and complex coacervates are phase separation phenomena that lead to the selective partitioning of biomolecules and have recently been proposed as membrane-free protocell models. We show in this study through fluorescence recovery after photobleaching (FRAP) microscopy that despite the ability of such systems to effectively concentrate RNA, there is a high rate of RNA exchange between phases in dextran/polyethylene glycol ATPS and ATP/poly-L-lysine coacervate droplets. In contrast to fatty acid vesicles, these systems would not allow effective segregation and consequent evolution of RNA, thus rendering these systems ineffective as model protocells.

  3. Integration of bioconversion and downstream processing: starch hydrolysis in an aqueous two-phase system.

    Science.gov (United States)

    Larsson, M; Arasaratnam, V; Mattiasson, B

    1989-02-05

    Integration of bioconversion and the first step(s) of down stream processing can be used as a means to increase the productivity of bioprocesses. This integration also gives the possibility to run the bioconversion in a continuous mode. We demonstrate the use of an aqueous two-phase system in combination with ultrafiltration to accomplish this. Conversion of native starch to glucose by alpha-amylase and glucoamylase was carried out in an aqueous two-phase system in connection with a membrane filtration unit. In this way, a continuous stream of glucose in buffer solution was obtained; the phase-forming polymers as well as the starch-degrading enzymes were recycled, and clogging of the ultrafiltration membrane was avoided. The process was carried out continuously in a mixer-settler reactor for a period of 8 days. The enzyme activities in the top and bottom phases and in the mixing chamber were monitored intermittently throughout the experiment. The optimum pH, temperature, and ionic strength for the activity of the enzyme mixture were determined. The settling time of phase systems containing varying amounts of PEG, crude dextran, and solid starch was studied. The activity and stability of enzyme mixtures was studied both in buffer medium and in the medium containing the polymers. The enzymes were found to be more active and stable in medium containing polymers than in the buffer solutions.

  4. Bromelain purification through unconventional aqueous two-phase system (PEG/ammonium sulphate).

    Science.gov (United States)

    Coelho, D F; Silveira, E; Pessoa Junior, A; Tambourgi, E B

    2013-02-01

    This paper focuses on the feasibility of unconventional aqueous two-phase systems for bromelain purification from pineapple processing waste. The main difference in comparison with conventional systems is the integration of the liquid-liquid extraction technique with fractional precipitation, which can decrease the protein content with no loss of biological activity by removing of unwanted molecules. The analysis of the results was based on the response surface methodology and revealed that the use of the desirability optimisation methodology (DOM) was necessary to achieve higher purification factor values and greater bromelain recovery. The use of DOM yielded an 11.80-fold purification factor and 66.38 % biological activity recovery using poly(ethylene glycol) (PEG) with a molar mass of 4,000, 10.86 % PEG concentration (m/m) and 36.21 % saturation of ammonium sulphate.

  5. Analysis of a pneumatic system for a two-phase flow sugar

    Directory of Open Access Journals (Sweden)

    G OteroR

    2016-09-01

    Full Text Available This document shows a complete analysis the transportation of sugar particles by a pneumatic conveying station. This project shows an actual situation presenting in a food plant located in Aragua, Venezuela, where the sugar piping system suffers continuous obstructions. It was achieved an effective analysis of the phenomenon of solid-gas two-phase flow transport which involves a complex physics phenomenon. Two possible obstruction causes was studied: the high temperature at the blower exit that induces changes in the sugar properties caused by the working condition far from the designed operation condition, or the excessive friction losses, due to the system is working out of the dilute phase condition (optimal condition for the flow. The mathematical model described allowed to determine that the cause of the obstruction of the pipeline was the stick of the sugar to the internal wall, as consequence of this high temperature at the outlet of the blower.

  6. Enzymatic hydrolysis of penicillin in mixed ionic liquids/water two-phase system.

    Science.gov (United States)

    Jiang, Yangyang; Xia, Hansong; Guo, Chen; Mahmood, Iram; Liu, Huizhou

    2007-01-01

    In this paper, an integrated process involving the mixed ionic liquids/water two-phase system (MILWS) is proposed to improve the efficiency for enzymatic hydrolysis of penicillin G. First, hydrophilic [C4mim]BF4 (1-butyl-3-methylimidazolium tetrafluoraborate) and NaH2PO4 salt form an ionic liquids aqueous two-phase system (ILATPS), which could extract penicillin from its fermentation broth efficiently. Second, a hydrophobic [C4mim]PF6 (1-butyl-3-methylimidazolium hexafluoraphosphate) is introduced into the ionic liquids-rich phase of ILATPS containing penicillin and converses it into MILWS. Penicillin is hydrolyzed by penicillin acylase in the water phase of MILWS at pH 5. The byproduct phenylacetic acid (PAA) is partitioned into the ionic liquids mixture phase, while the intended product 6-aminopenicillanic acid (6-APA) is precipitated at this pH. In comparison with a similar butyl acetate/water system (BAWS) at pH 4, MILWS exhibits two advantages. (1) The selectivity between PAA and penicillin is greatly optimized at pH 5 by varying the mole ratio of [C4mim]PF6/[C4mim]BF4 in MILWS, whereas in BAWS the unalterable nature of the organic solvent restricts the optimized pH for maximum selectivity between PAA and penicillin at pH 4. (2) The pH for 6-APA precipitation in BAWS is 4, whereas it shifts to pH 5 in MILWS due to the complexation between negatively charged 6-APA and the cationic surface of the ionic liquids micelle. As a result, the removal of the two products from the enzyme sphere at relatively high pH is permitted in MILWS, which is beneficial for enzymatic activity and stability in comparison with the acidic pH 4 environment in BAWS.

  7. Ionic Liquid-salt Aqueous Two-phase System, a Novel System for the Extraction of Abused Drugs

    Institute of Scientific and Technical Information of China (English)

    She Hong LI; Chi Yang HE; Hu Wei LIU; Ke An LI; Feng LIU

    2005-01-01

    A 1-butyl-3-methylimidazolium chloride-salt aqueous two-phase system was studied on extraction of abused drugs. The effects of sorts of salts, temperature, concentration of salt and drugs on system were investigated systematically. A satisfactory extraction efficiency of 93%was obtained for papaverine while that of morphine was 65%. The extraction mechanism was primarily discussed.

  8. Optimizing steam flood performance utilizing a new and highly accurate two phase steam measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Huff, B. D.; Warren, P. B. [CalResources LLC (Canada); Whorff, F. [ITT Barton (Canada)

    1995-11-01

    The development of a two phase steam measurement system was documented. The system consists of a `V` cone differential pressure device and a vortex meter velocity device in series through which the steam flows. Temperature and pressure sensors are electronically interfaced with a data logging system. The design was described as being very simple and rugged, consequently, well suited to monitoring in the field.. Steam quality measurements were made in the Kern River Field and the Coalinga Field thermal projects using a surface steam separator. In steam flood operations, steam cost is very high, hence appropriate distribution of the steam can result in significant cost reduction. This technology allows the measurement of steam flow and quality at any point in the steam distribution system. The metering system`s orifice meter was found to have a total average error of 45%, with 25% of that attributable to `cold leg` problem. Installation of the metering system was expected to result in a steam use reduction of 8%, without any impact on production. Steam re-distribution could result in a potential oil production increase of 10%. 12 refs., 8 tabs., 9 figs.

  9. Reaction Mechanisms and Particle Interaction in Burning Two-Phase Systems

    Science.gov (United States)

    Dreizin, Edward L.; Shoshin, Yuriy L.; Murdyy, Ruslan S.; Hoffmann, Vern K.

    2001-01-01

    The main objective of this research is to understand the mechanisms by which particle interactions affect ignition and combustion in the two-phase systems. Combustion of metal aerosols representing the two-phase systems is carried out in the microgravity environment enabling one to avoid the buoyant flows that mask the particle motion due to the particle-particle interaction effects. In addition, relatively large, e.g., 100 micron diameter particles can be used, that remain aerosolized (i.e., do not fall down as they would at normal gravity) so that their behavior ahead, behind, and within the propagating flame can be resolved optically. An experimental apparatus exploiting this approach has been designed for the 2.2-s drop tower microgravity experiments. A typical experiment includes fluidizing metal particles under microgravity in an acoustic field, turning off the acoustic exciter, and igniting the created aerosol at a constant pressure using a hot wire igniter. The flame propagation and details of the individual particle combustion and particle interactions are studied using high-speed movie and video cameras coupled with microscope lenses to resolve individual particles. Recorded flame images are digitized and various image processing techniques including flame position tracking, color separation, and pixel by pixel image comparisons are employed to understand the processes occurring in the burning aerosols. Condensed combustion products are collected after each experiment for the phase, composition, and morphology analyses. New experiments described in this paper address combustion of Ti and Al particle clouds in air and combustion of Mg particle clouds in CO2. In addition, microgravity combustion experiments have been conducted with the particles of the newly produced Al-Mg mechanical alloys aerosolized in air.

  10. A green deep eutectic solvent-based aqueous two-phase system for protein extracting

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Kaijia; Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn; Huang, Yanhua; Li, Na; Wen, Qian

    2015-03-15

    Highlights: • A strategy for the protein purification with a deep eutectic solvent(DES)-based aqueous two-phase system. • Choline chloride-glycerin DES was selected as the extraction solvent. • Bovine serum albumin and trypsin were used as the analytes. • Aggregation phenomenon was detected in the mechanism research. - Abstract: As a new type of green solvent, deep eutectic solvent (DES) has been applied for the extraction of proteins with an aqueous two-phase system (ATPS) in this work. Four kinds of choline chloride (ChCl)-based DESs were synthesized to extract bovine serum albumin (BSA), and ChCl-glycerol was selected as the suitable extraction solvent. Single factor experiments have been done to investigate the effects of the extraction process, including the amount of DES, the concentration of salt, the mass of protein, the shaking time, the temperature and PH value. Experimental results show 98.16% of the BSA could be extracted into the DES-rich phase in a single-step extraction under the optimized conditions. A high extraction efficiency of 94.36% was achieved, while the conditions were applied to the extraction of trypsin (Try). Precision, repeatability and stability experiments were studied and the relative standard deviations (RSD) of the extraction efficiency were 0.4246% (n = 3), 1.6057% (n = 3) and 1.6132% (n = 3), respectively. Conformation of BSA was not changed during the extraction process according to the investigation of UV–vis spectra, FT-IR spectra and CD spectra of BSA. The conductivity, dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to explore the mechanism of the extraction. It turned out that the formation of DES–protein aggregates play a significant role in the separation process. All the results suggest that ChCl-based DES-ATPS are supposed to have the potential to provide new possibilities in the separation of proteins.

  11. Space qualification of an experimental two-phase flow thermal management system

    Science.gov (United States)

    Koonmen, James P.; Carswell, Lisa C.; Kvansnak, Michael A.

    1991-01-01

    The Weapons Laboratory will launch a space experiment in March 1991 to investigate the effects of extended microgravity on two-phase (liquid/vapor) flow. The qualification process for the experimental flight system hardware differs significantly from the process used for complex, high cost, long life space systems. Some development, qualification, and acceptance tests normally included in the test program of an operational space system were omitted because of the low program cost and low consequence of experiment failure. Key environment and functional qualification tests were performed, however, in an effort to reduce the risk of failure inherent in any space mission. The environmental qualification program included short duration vacuum chamber tests, reduced gravity missions onboard a National Aeronautics and Space Administration (NASA) test aircraft, and a complete series of shock and vibration tests. The functional qualification program centered on thermal-hydraulic system performance tests and a complete check-out of the unique telemetry system used to retrieve the experimental data from the payload. The test program also contains a number of acceptance and prelaunch validation tests to be performed as final verification of payloads readiness for spaceflight.

  12. Two-phase equilibrium and molecular hydrogen formation in damped Lyman-alpha systems

    CERN Document Server

    Liszt, H S

    2002-01-01

    Molecular hydrogen is quite underabundant in damped Lyman-alpha systems at high redshift, when compared to the interstellar medium near the Sun. This has been interpreted as implying that the gas in damped Lyman-alpha systems is warm. like the nearby neutral intercloud medium, rather than cool, as in the clouds which give rise to most H I absorption in the Milky Way. Other lines of evidence suggest that the gas in damped Lyman-alpha systems -- in whole or part -- is actually cool; spectroscopy of neutral and ionized carbon, discussed here, shows that the damped Lyman-alpha systems observed at lower redshift z $$ 2.8 are warm (though not devoid of H2). To interpret the observations of carbon and hydrogen we constructed detailed numerical models of H2 formation under the conditions of two-phase thermal equilibrium, like those which account for conditions near the Sun, but with varying metallicity, dust-gas ratio, $etc$. We find that the low metallicity of damped Lyman-alpha systems is enough to suppress H2 form...

  13. 餐厨垃圾与污泥两相中温厌氧消化试验研究%Experimental Study on Two-Phase Mesophilic Anaerobic Co-Digestion for Kitchen Waste and Sewage Sludge

    Institute of Scientific and Technical Information of China (English)

    王国华; 王磊; 谭学军; 王逸贤; 王峰

    2014-01-01

    研究了混合比例和污泥停留时间对餐厨垃圾与污泥联合两相中温厌氧消化过程的影响。相较于餐厨垃圾与污泥TS比为1∶3的条件,TS比为1∶1时两相系统具有更好的产气效果、有机物去除效果和运行稳定性。随着SRT的延长,两相系统有机负荷逐步降低,产甲烷速率相应降低,单位体积进料产沼气量以及有机物去除率逐步提高。在餐厨垃圾与污泥TS比为1∶1的条件下,两相厌氧消化系统最佳SRT为25 d(产酸相和产甲烷相分别为5 d和20 d);此时,沼气中甲烷含量高达71%,产甲烷速率和甲烷产率分别为0.7 L/L·d和0.69 L/gVS去除,两相系统VS去除率达到64.7%。%The impact of mixing proportion and sludge retention time on two-phase mesophilic anaerobic co-digestion for kitchen waste and sewage sludge was studied under mixing ratios of 1∶3 and 1∶1 on TS basis. Under the mixing ratio of 1∶1,more biogas was produced and more organic pollutants were removed,while better operation stability was observed,simultaneously. With the increase of sludge retention time,organic load and methane production rate of the two-phase co-digestion system decreased accordingly,while the biogas yield as well as organic pollutants removal rate increased,gradually. Under the mixing ratio of 1∶1,25 d was proved to be the optimum SRT of two-phase anaerobic co-digestion system while methane content,methane production rate,special methane production and VS removal rate reached 71%,0. 7 L/L·d,0. 69 L/gVSremoved and 64. 7%,respectively.

  14. Effective extraction of elastase from Bacillus sp. fermentation broth using aqueous two-phase system

    Institute of Scientific and Technical Information of China (English)

    XU Ying; HE Guo-qing; LI Jing-jun

    2005-01-01

    This paper presents the evaluation of an aqueous two-phase system (ATPS) for extracting elastase produced by Bacillus sp. EL31410. The elastase and cell partition behavior in polyethylene glycol (PEG)/salt systems was investigated. The suitable system for elastase extraction was PEG/KH2PO4-K2HPO4, in which elastase is mainly partitioned into the PEG-rich phase,while the cells remained in the other phase. The influence of defined system parameters (e.g. PEG molecular mass, pH, NaCl addition) on the partitioning behavior of elastase is described. The concentration of phase forming components, PEG and KH2PO4-K2HPO4, was optimized for elastase recovery by means of response surface methodology, and it was found that they greatly influenced extraction recovery. The optimal ATPS was 23.1% (w/w) PEG 2 000 and 11.7% (w/w) KH2PO4-K2HPO4. The predicted recovery was about 89.5%, so this process is suggested to be a rapid and convenient method for elastase extraction.

  15. Effective extraction of elastase from Bacillus sp. fermentation broth using aqueous two-phase system.

    Science.gov (United States)

    Xu, Ying; He, Guo-qing; Li, Jing-jun

    2005-11-01

    This paper presents the evaluation of an aqueous two-phase system (ATPS) for extracting elastase produced by Bacillus sp. EL31410. The elastase and cell partition behavior in polyethylene glycol (PEG)/salt systems was investigated. The suitable system for elastase extraction was PEG/KH(2)PO(4)-K(2)HPO(4), in which elastase is mainly partitioned into the PEG-rich phase, while the cells remained in the other phase. The influence of defined system parameters (e.g. PEG molecular mass, pH, NaCl addition) on the partitioning behavior of elastase is described. The concentration of phase forming components, PEG and KH(2)PO(4)-K(2)HPO(4), was optimized for elastase recovery by means of response surface methodology, and it was found that they greatly influenced extraction recovery. The optimal ATPS was 23.1% (w/w) PEG 2 000 and 11.7% (w/w) KH(2)PO(4)-K(2)HPO(4). The predicted recovery was about 89.5%, so this process is suggested to be a rapid and convenient method for elastase extraction.

  16. Molecular features determining different partitioning patterns of papain and bromelain in aqueous two-phase systems.

    Science.gov (United States)

    Rocha, Maria Victoria; Nerli, Bibiana Beatriz

    2013-10-01

    The partitioning patterns of papain (PAP) and bromelain (BR), two well-known cysteine-proteases, in polyethyleneglycol/sodium citrate aqueous two-phase systems (ATPSs) were determined. Polyethyleneglycols of different molecular weight (600, 1000, 2000, 4600 and 8000) were assayed. Thermodynamic characterization of partitioning process, spectroscopy measurements and computational calculations of protein surface properties were also carried out in order to explain their differential partitioning behavior. PAP was observed to be displaced to the salt-enriched phase in all the assayed systems with partition coefficients (KpPAP) values between 0.2 and 0.9, while BR exhibited a high affinity for the polymer phase in systems formed by PEGs of low molecular weight (600 and 1000) with partition coefficients (KpBR) values close to 3. KpBR values resulted higher than KpPAP in all the cases. This difference could be assigned neither to the charge nor to the size of the partitioned biomolecules since PAP and BR possess similar molecular weight (23,000) and isoelectric point (9.60). The presence of highly exposed tryptophans and positively charged residues (Lys, Arg and His) in BR molecule would be responsible for a charge transfer interaction between PEG and the protein and, therefore, the uneven distribution of BR in these systems.

  17. Impact of microwave pre-treatment on the batch anaerobic digestion of two-phase olive mill solid residue: a kinetic approach

    Directory of Open Access Journals (Sweden)

    B. Rincón

    2016-12-01

    Full Text Available The effect of a microwave (MW pre-treatment on two-phase olive mill solid residue (OMSR or alperujo with a view to enhancing its anaerobic digestibility was studied. The MW pre-treatment was carried out at a power of 800 W and at a targeted temperature of 50 °C using different heating rates and holding times. The following specific energies were applied: 4377 kJ·kg TS-1 (MW1, 4830 kJ·kg TS-1 (MW2, 7170 kJ·kg TS-1 (MW3 and 7660 kJ·kg TS-1 (MW4. The maximum methane yield, 395±1 mL CH4·g VSadded-1, was obtained for MW4. The effect of the pre-treatment on the kinetics of the process was also studied. The methane production curves generated during the batch tests showed a first exponential stage and a second sigmoidal stage for all the cases studied. In the first stage, the kinetic constant for the pre-treatment MW1 was 54.8% higher than that obtained for untreated OMSR.

  18. Stability of clavulanic acid in PEG/citrate and liquid–liquid extraction in aqueous two-phase system

    OpenAIRE

    Carneiro-da-Cunha, M. N.; Souza, K. P. S.; Mota, A; J.A. Teixeira; Porto, C S; Porto, Tatiana Souza; Porto, Ana L. F.

    2014-01-01

    β-Lactamases are enzymes responsible for the hydrolysis of β-lactam antibiotics, being produced by several pathogenic bacteria. Clavulanic acid is a commercially and clinically important β-lactamase inhibitor, its extraction being possible by the application of aqueous two-phase system. In this study, clavulanic acid stability was investigated at different molar mass PEG (400, 1 000 and 20 000 g mol−1) and at different citrate concentrations (5 and 20%) PEG/citrate aqueous-two phase systems (...

  19. LPS removal from an E. coli fermentation broth using aqueous two-phase micellar system.

    Science.gov (United States)

    Lopes, André M; Magalhães, Pérola O; Mazzola, Priscila G; Rangel-Yagui, Carlota O; de Carvalho, João C M; Penna, Thereza C V; Pessoa, Adalberto

    2010-01-01

    In biotechnology, endotoxin (LPS) removal from recombinant proteins is a critical and challenging step in the preparation of injectable therapeutics, as endotoxin is a natural component of bacterial expression systems widely used to manufacture therapeutic proteins. The viability of large-scale industrial production of recombinant biomolecules of pharmaceutical interest significantly depends on the separation and purification techniques used. The aim of this work was to evaluate the use of aqueous two-phase micellar system (ATPMS) for endotoxin removal from preparations containing recombinant proteins of pharmaceutical interest, such as green fluorescent protein (GFPuv). Partition assays were carried out initially using pure LPS, and afterwards in the presence of E. coli cell lysate. The ATPMS technology proved to be effective in GFPuv recovery, preferentially into the micelle-poor phase (K(GFPuv) 98.00%). Therefore, this system can be exploited as the first step for purification in biotechnology processes for removal of higher LPS concentrations. Copyright © 2010 American Institute of Chemical Engineers (AIChE).

  20. 农业有机废弃物两相厌氧消化影响因素的稳定性调控%Stable Control of Influence Factor during Two-phase Anaerobic Digestion for Agricultural Organic Waste

    Institute of Scientific and Technical Information of China (English)

    尹芳; 张无敌; 柳静; 杨红

    2014-01-01

    Two-phase anaerobic digestion process is influenced by acid control for hydrogen production, reaction temperature, substrate detention time, sludge activity, and granular formation. Al of these technological parameters are directly related to success or failure of the system operation and treatment effect.%两相厌氧消化工艺受产氢调酸、反应温度、底物滞留时间、活性污泥的形成及其颗粒化程度调控,其工艺参数的选取直接关系到系统运行的成败和处理效果的优劣。

  1. Drift flux modelling for a two-phase system in a flotation column

    Energy Technology Data Exchange (ETDEWEB)

    Vandenberghe, J.; Choung, J.; Xu, Z.; Masliyah, J. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering

    2005-04-01

    Mineral and coal industries use flotation columns to improve recovery, upgrade products, save energy and reduce scale. Flotation columns are a proven process equipment that are adaptable to computer process control and offer flexible operation. Once gas is introduced to the bottom of the flotation column, bubbles form and rise throughout the pulp. Hydrophobic particles in the pulp attache to the bubbles, making the density of the bubble particle aggregates less than that of the medium. The bubble zone and the froth zone are the 2 main zones of a flotation column. This study applied the drift flux analysis to a wide range of operating conditions of a two-phase system column in order develop a better empirical relation that can predict the bubbly and froth zone characteristics. Tests were performed with process water taken from a bitumen extraction process at Syncrude Canada Limited with aqueous solutions having low concentrations of methyl isobutyl carbinol at 7.8 or 15.5 ppm. A new correlation for the drift flux system characteristic curve was discovered in this study. The new correlation is applicable for a bubble Reynolds number range of 5 to 70. The numerical equation for this correlation was presented. The bubble and froth zones have different hydrodynamics. Therefore, the method for calculating the Reynolds number in the bubble zone may not be suitable for the froth zone. Therefore, a new equation was proposed to accommodate a wider operating range. 16 refs., 1 tab., 13 figs.

  2. LPS-protein aggregation influences protein partitioning in aqueous two-phase micellar systems.

    Science.gov (United States)

    Lopes, André Moreni; Santos-Ebinuma, Valéria de Carvalho; Novaes, Leticia Celia de Lencastre; Molino, João Vitor Dutra; Barbosa, Leandro Ramos Souza; Pessoa, Adalberto; Rangel-Yagui, Carlota de Oliveira

    2013-07-01

    Lipopolysaccharide endotoxins (LPS) are the most common pyrogenic substances in recombinant peptides and proteins purified from Gram-negative bacteria, such as Escherichia coli. In this respect, aqueous two-phase micellar systems (ATPMS) have already proven to be a good strategy to purify recombinant proteins of pharmaceutical interest and remove high LPS concentrations. In this paper, we review our recent experimental work in protein partitioning in Triton X-114 ATPMS altogether with some new results and show that LPS-protein aggregation can influence both protein and LPS partitioning. Green fluorescent protein (GFPuv) was employed as a model protein. The ATPMS technology proved to be effective for high loads of LPS removal into the micelle-rich phase (%REM(LPS) > 98 %) while GFPuv partitioned preferentially to the micelle-poor phase (K GFP(uv) system. Nonetheless, ATPMS can still be considered as an efficient strategy for high loads of LPS removal, but being aware that the excluded-volume partitioning theory available might overestimate partition coefficient values due to the presence of protein-LPS aggregation.

  3. Effective thermal conductivity of real two-phase systems using resistor model with ellipsoidal inclusions

    Indian Academy of Sciences (India)

    Jagjiwanram; Ramvir Singh

    2004-08-01

    A theoretical model has been developed for real two-phase system assuming linear flow of heat flux lines having ellipsoidal particles arranged in a three-dimensional cubic array. The arrangement has been divided into unit cells, each of which contains an ellipsoid. The resistor model has been applied to determine the effective thermal conductivity (ETC) of the unit cell. To take account of random packing of the phases, non-uniform shape of the particles and non-linear flow of heat flux lines in real systems, incorporating an empirical correction factor in place of physical porosity modifies an expression for ETC. An effort is made to correlate it in terms of the ratio of thermal conductivities of the constituents and the physical porosity. Theoretical expression so obtained has been tested on a large number of samples cited in the literature and found that the values predicted are quite close to the experimental results. Comparison of our model with different models cited in the literature has also been made.

  4. Recovery of crocins from saffron stigmas (Crocus sativus) in aqueous two-phase systems.

    Science.gov (United States)

    Montalvo-Hernández, Bertha; Rito-Palomares, Marco; Benavides, Jorge

    2012-05-04

    Crocins are carotenoid derivates that have recently attracted the interest of the scientific community due to their nutraceutical properties. Saffron (dry Crocus sativus stigmas) is one of the main known sources of crocins. In this study the potential use of aqueous two-phase system (ATPS) for the extraction of crocins from C. sativus stigmas was evaluated. The partitioning behavior of crocins in different types of ATPS (polymer-polymer, polymer-salt, alcohol-salt and ionic liquid-salt) was evaluated. Ethanol-potassium phosphate ATPS were selected based on their high top phase recovery yield and low cost of system constituents. The evaluation and optimization of system parameters rendered conditions (V(R)=3.2, ethanol 19.8% (w/w), potassium phosphate 16.5% (w/w), TLL of 25% (w/w), 0.1M NaCl and 2% (w/w) of sample load) under which more than 75% of total crocins were recovered in the top (ethanol rich) phase, whereas the wasted stigmas accumulated in the bottom phase. Lastly, a comparison between an optimized solid-liquid extraction using ethanol:water as solvent and ATPS was conducted demonstrating that similar yields are achieved with both strategies (76.89 ± 18% and 79.27 ± 1.6%, respectively). However, ATPS rendered a higher extraction selectivity of 1.3 ± 0.04 mg of crocins for each mg of phenolic compound, whereas ethanolic extraction showed a selectivity of 0.87 ± 0.01. The results reported herein demonstrate the potential application of ATPS, particularly ethanol-potassium phosphate systems, for the recovery of crocins from C. sativus stigmas.

  5. Aqueous two phase system based on ionic liquid for isolation of quinine from human plasma sample.

    Science.gov (United States)

    Flieger, J; Czajkowska-Żelazko, A

    2015-01-01

    Aqueous two phase system was applied for selective extraction of quinine from human plasma. Bi-phase was constructed from ionic liquid: butyl-methyl-imidazolium chloride after addition kosmotropic salts K₃PO₄ or KH₂PO₄. Quinine was determined in plasma samples after drinking of tonic containing quinine. Determination was performed by HPLC on 5-μm Zorbax SB-CN column and eluent containing 40% acetonitrile (v/v), 20 mM phosphate buffer at pH 3 and 40 mM NaPF₆ using external standard method. The spectrophotometric detection was set λ=214 nm. Selective fluorescence detection was performed at excitation of 325 nm and emission of 375 nm. Proposed strategy provides suitable sample purification and gives extraction yields in the range of 89-106%. The determination coefficient (R(2)) has a value ≥0.997 in the range of 50-800 ng/ml quinine concentration. The limit of quantification was set at 27.9 ng/ml and the detection limit was found to be 8.4 ng/ml under fluorescence detection.

  6. Extraction of proteins with ionic liquid aqueous two-phase system based on guanidine ionic liquid.

    Science.gov (United States)

    Zeng, Qun; Wang, Yuzhi; Li, Na; Huang, Xiu; Ding, Xueqin; Lin, Xiao; Huang, Songyun; Liu, Xiaojie

    2013-11-15

    Eight kinds of green ionic liquids were synthesized, and an ionic liquid aqueous two-phase system (ILATPS) based on 1,1,3,3-tetramethylguandine acrylate (TMGA) guanidine ionic liquid was first time studied for the extraction of proteins. Single factor experiments proved that the extraction efficiency of bovine serum albumin (BSA) was influenced by the mass of IL, K2HPO4 and BSA, also related to the separation time and temperature. The optimum conditions were determined through orthogonal experiment by the five factors described above. The results showed that under the optimum conditions, the extraction efficiency could reach up to 99.6243%. The relative standard deviations (RSD) of extraction efficiencies in precision experiment, repeatability experiment and stability experiment were 0.8156% (n=5), 1.6173% (n=5) and 1.6292% (n=5), respectively. UV-vis and FT-IR spectra confirmed that there were no chemical interactions between BSA and ionic liquid in the extraction process, and the conformation of the protein was not changed after extraction. The conductivity, DLS and TEM were combined to investigate the microstructure of the top phase and the possible mechanism for the extraction. The results showed that hydrophobic interaction, hydrogen bonding interaction and the salt out effect played important roles in the transferring process, and the aggregation and embrace phenomenon was the main driving force for the separation. All these results proved that guanidine ionic liquid-based ATPSs have the potential to offer new possibility in the extraction of proteins.

  7. Study of organic compounds-water interactions by partition in aqueous two-phase systems.

    Science.gov (United States)

    Madeira, Pedro P; Bessa, Ana; Teixeira, Miguel A; Álvares-Ribeiro, Luís; Aires-Barros, M Raquel; Rodrigues, Alírio E; Zaslavsky, Boris Y

    2013-12-27

    Partition coefficients of fourteen organic compounds were determined in 10 or 20 different polymer/polymer aqueous two-phase systems (ATPS) all at physiological pH (0.15M NaCl in 0.01M phosphate buffer, pH 7.4). Solute-specific coefficients characterizing different types of solute-water interactions for the compounds examined were determined by the multiple linear regression analysis. It is shown that (i) the partition behavior for the polar organic compounds is affected not only by dipole-dipole and hydrogen-bond interactions with aqueous environment but, notably, in most cases also by dipole-ion interactions; (ii) it is possible to predict partition behavior for compounds with pre-determined solute-specific coefficients in ATPS with characterized solvent features; and (iii) linear combinations of the solute-specific coefficients for the organic compounds might be useful in the development of quantitative structure-activity relationship (QSAR) analysis to describe their odor detection threshold.

  8. What are the structural features that drive partitioning of proteins in aqueous two-phase systems?

    Science.gov (United States)

    Wu, Zhonghua; Hu, Gang; Wang, Kui; Zaslavsky, Boris Yu; Kurgan, Lukasz; Uversky, Vladimir N

    2017-01-01

    Protein partitioning in aqueous two-phase systems (ATPSs) represents a convenient, inexpensive, and easy to scale-up protein separation technique. Since partition behavior of a protein dramatically depends on an ATPS composition, it would be highly beneficial to have reliable means for (even qualitative) prediction of partitioning of a target protein under different conditions. Our aim was to understand which structural features of proteins contribute to partitioning of a query protein in a given ATPS. We undertook a systematic empirical analysis of relations between 57 numerical structural descriptors derived from the corresponding amino acid sequences and crystal structures of 10 well-characterized proteins and the partition behavior of these proteins in 29 different ATPSs. This analysis revealed that just a few structural characteristics of proteins can accurately determine behavior of these proteins in a given ATPS. However, partition behavior of proteins in different ATPSs relies on different structural features. In other words, we could not find a unique set of protein structural features derived from their crystal structures that could be used for the description of the protein partition behavior of all proteins in all ATPSs analyzed in this study. We likely need to gain better insight into relationships between protein-solvent interactions and protein structure peculiarities, in particular given limitations of the used here crystal structures, to be able to construct a model that accurately predicts protein partition behavior across all ATPSs. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Aqueous Two-phase Systems with Ultrasonic Extraction Used for Extracting Phenolic Compounds from Inonotus obliquus

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yan-xia; LIU Yu-bing; LIU Feng; ZHENG Wei-fa

    2013-01-01

    Objective To optimize the extracting technology of assessing the maximum yield of phenolic compounds (PC)from Inonotus obliquus by single factor experiments and orthogonal array design methods through aqueous two-phase systems combined with ultrasonic extraction.Methods The range of the independent variables,namely levels of acetone and ammonium sulfate,and ultrasonic time were identified by a first set of single factor experiments.The actual values of the independent variables coded at four levels and three factors were selected based on the results of the single factor experiments.Subsequently,the levels of acetone and ammonium sulfate,and ultrasonic time were optimized using the orthogonal array method.Results The optimum conditions for the extraction of PC were found to use 7.0 mL acetone,5.5 mg ammonium sulfate,with ultrasonic time for 5 min.Under these optimized conditions,the experimental maximum yield of PC was 37.8 mg/g,much higher than that of the traditional ultrasonic extraction (UE,29.0 mg/g).And the PC obtained by this method had stronger anti-oxidative activities than those by traditional UE method.Conclusion These results indicate the suitability of the models developed and the success in optimizing the extraction conditions.This is an economical and efficient method for extracting polyphenols from Ⅰ.obliquus.

  10. Ultrasound-Assisted Aqueous Two-Phase System for Extraction and Enrichment of Zanthoxylum armatum Lignans

    Directory of Open Access Journals (Sweden)

    Tao Guo

    2015-08-01

    Full Text Available In the study, an aqueous two phase system (ATPS coupled with ultrasound was employed to extract lignans from Zanthoxylum armatum. Three standard lignans, namely (−-fargesin, sesamin and L-asarinin, were used as marker compounds, and extraction was optimized and projected by response surface methodology (RSM and artificial neural network (ANN. The optimal condition for ATPS with 20% n-propanol and 24% (NH42SO4 coupled with ultrasonic-assisted extraction including a solvent to solid ratio of 15:1, a temperature of 40 °C, and a treatment time of 55 min was obtained. Under the condition, the yield of (−-fargesin increased 15.12%, and the purities of (−-fargesin, sesamin and L-asarinin reached 2.222%, 1.066%, and 1.583%, with an increase of 44.38%, 25.70%, and 26.34% compared to those extracted with 95% ethanol, respectively. Coefficient of the determined (0.9855 and mean squared error (0.0018 of ANN model suggested good fitness and generalization of the ANN. Taken together, the results showed that ultrasonic-assisted ATPS can be a suitable method for extraction and enrichment of lignans from Z. armatum.

  11. Partitioning in aqueous two-phase systems: Analysis of strengths, weaknesses, opportunities and threats.

    Science.gov (United States)

    Soares, Ruben R G; Azevedo, Ana M; Van Alstine, James M; Aires-Barros, M Raquel

    2015-08-01

    For half a century aqueous two-phase systems (ATPSs) have been applied for the extraction and purification of biomolecules. In spite of their simplicity, selectivity, and relatively low cost they have not been significantly employed for industrial scale bioprocessing. Recently their ability to be readily scaled and interface easily in single-use, flexible biomanufacturing has led to industrial re-evaluation of ATPSs. The purpose of this review is to perform a SWOT analysis that includes a discussion of: (i) strengths of ATPS partitioning as an effective and simple platform for biomolecule purification; (ii) weaknesses of ATPS partitioning in regard to intrinsic problems and possible solutions; (iii) opportunities related to biotechnological challenges that ATPS partitioning may solve; and (iv) threats related to alternative techniques that may compete with ATPS in performance, economic benefits, scale up and reliability. This approach provides insight into the current status of ATPS as a bioprocessing technique and it can be concluded that most of the perceived weakness towards industrial implementation have now been largely overcome, thus paving the way for opportunities in fermentation feed clarification, integration in multi-stage operations and in single-step purification processes.

  12. Microfluidic generation of aqueous two-phase system (ATPS) droplets by controlled pulsating inlet pressures.

    Science.gov (United States)

    Moon, Byeong-Ui; Jones, Steven G; Hwang, Dae Kun; Tsai, Scott S H

    2015-06-07

    We present a technique that generates droplets using ultralow interfacial tension aqueous two-phase systems (ATPS). Our method combines a classical microfluidic flow focusing geometry with precisely controlled pulsating inlet pressure, to form monodisperse ATPS droplets. The dextran (DEX) disperse phase enters through the central inlet with variable on-off pressure cycles controlled by a pneumatic solenoid valve. The continuous phase polyethylene glycol (PEG) solution enters the flow focusing junction through the cross channels at a fixed flow rate. The on-off cycles of the applied pressure, combined with the fixed flow rate cross flow, make it possible for the ATPS jet to break up into droplets. We observe different droplet formation regimes with changes in the applied pressure magnitude and timing, and the continuous phase flow rate. We also develop a scaling model to predict the size of the generated droplets, and the experimental results show a good quantitative agreement with our scaling model. Additionally, we demonstrate the potential for scaling-up of the droplet production rate, with a simultaneous two-droplet generating geometry. We anticipate that this simple and precise approach to making ATPS droplets will find utility in biological applications where the all-biocompatibility of ATPS is desirable.

  13. Purification and in situ immobilization of papain with aqueous two-phase system.

    Science.gov (United States)

    Li, Mingliang; Su, Erzheng; You, Pengyong; Gong, Xiangyu; Sun, Ming; Xu, Diansheng; Wei, Dongzhi

    2010-12-13

    Papain was purified from spray-dried Carica papaya latex using aqueous two-phase system (ATPS). Then it was recovered from PEG phase by in situ immobilization or preparing cross-linked enzyme aggregates (CLEAs). The Plackett-Burman design and the central composite design (CCD) together with the response surface methodology (RSM) were used to optimize the APTS processes. The highly purified papain (96-100%) was achieved under the optimized conditions: 40% (w/w) 15 mg/ml enzyme solution, 14.33-17.65% (w/w) PEG 6000, 14.27-14.42% (w/w) NaH2PO4/K2HPO4 and pH 5.77-6.30 at 20°C. An in situ enzyme immobilization approach, carried out by directly dispersing aminated supports and chitosan beads into the PEG phase, was investigated to recover papain, in which a high immobilization yield (>90%) and activity recovery (>40%) was obtained. Moreover, CLEAs were successfully used in recovering papain from PEG phase with a hydrolytic activity hundreds times higher than the carrier-bound immobilized papain.

  14. Aqueous Two-phase Systems with Ultrasonic Extraction Used for Extracting Phenolic Compounds from Inonotus obliquus

    Institute of Scientific and Technical Information of China (English)

    ZHAO; Yan-xia; LIU; Yu-bing; LIU; Feng; ZHENG; Wei-fa

    2013-01-01

    Objective To optimize the extracting technology of assessing the maximum yield of phenolic compounds (PC) from Inonotus obliquus by single factor experiments and orthogonal array design methods through aqueous two-phase systems combined with ultrasonic extraction. Methods The range of the independent variables, namely levels of acetone and ammonium sulfate, and ultrasonic time were identified by a first set of single factor experiments. The actual values of the independent variables coded at four levels and three factors were selected based on the results of the single factor experiments. Subsequently, the levels of acetone and ammonium sulfate, and ultrasonic time were optimized using the orthogonal array method. Results The optimum conditions for the extraction of PC were found to use 7.0 mL acetone, 5.5 mg ammonium sulfate, with ultrasonic time for 5 min. Under these optimized conditions, the experimental maximum yield of PC was 37.8 mg/g, much higher than that of the traditional ultrasonic extraction (UE, 29.0 mg/g). And the PC obtained by this method had stronger anti-oxidative activities than those by traditional UE method. Conclusion These results indicate the suitability of the models developed and the success in optimizing the extraction conditions. This is an economical and efficient method for extracting polyphenols from I. obliquus.

  15. Selective separation of protein and saccharides by ionic liquids aqueous two-phase systems

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In the present work,it was found that aqueous solution of a hydrophilic ionic liquid (IL),1-butyl-3-methylimidazolium dicyanamide ([C4mim][N(CN)2]),could be separated into an aqueous two-phase system (ATPS) by inorganic salts such as K2HPO4 and K3PO4.The top phase is IL-rich,while the bottom phase is phosphate-rich.It was shown that 82.7%-100% bovine serum albumin (BSA) could be enriched into the top phase and almost quantitative saccharides (arabinose,glucose,sucrose,raffinose or dextran) were preferentially extracted into the bottom phase in a single-step extraction by [C4mim][N(CN)2] + K2HPO4 ATPS.The extraction efficiency of BSA from the aqueous saccharide solutions was influenced by the molecular structure of saccharides.The conductivity,dynamic light scattering (DLS) and transmission electron microscopy (TEM) were combined to investigate the microstructure of the IL-rich top phase and the possible mechanism for the selective separation.It is suggested that the formation of the IL aggregate and the IL aggregate-BSA complex plays a significant role in the separation of BSA from aqueous saccharide solutions.This is the first example for the selective separation by ILs-based ATPSs.It is expected that these findings would have potential applications in bio-analysis,separation,and IL recycle.

  16. Prostaglandin H synthase kinetics in the two-phase aqueous-micellar system.

    Science.gov (United States)

    Ponomareva, Olga A; Trushkin, Nikita A; Filimonov, Ivan S; Krivoshey, Alexandr V; Barkhatov, Vladimir I; Mitrofanov, Sergey I; Vrzheshch, Petr V

    2016-09-01

    Reaction mixture for PGHS (prostaglandin-H-synthase) is a two-phase system including micellar hydrophobic phase and hydrophilic aqueous phase. Reagents added to the mixture are distributed between phases, thus concentrations of reagents dissolved in phases can differ significantly from their overall contents. Using dynamic light scattering we found that the hydrophobic phase produced by tween-20 consists of micelles, which radius (4-5nm) does not depend on either tween-20 overall content (0.1%-1% v/v) or arachidonic acid (AA) addition (10-1000μM) or PGHS addition (1μM). Tween-20 overall content changing from 0.1% to 2% v/v dramatically affected COX kinetic, but accounting AA distribution between phases allowed us to estimate "true" parameters, independent of the tween-20 overall content and the concentration of another substrate: KM(Ox) equals 9.8μM O2 in the aqueous phase or 0.0074bar in the gaseous phase, KM(AA) equals 5400μM AA in the phase of tween-20 micelles and 5400/PμM AA in the aqueous phase (P is the distribution ratio for the AA between the aqueous phase and the hydrophobic phase (P≫1000)). This approach allowed to evaluate PS, the distribution ratio for the AA between the hydrophobic phase and the PGHS active center (PS ~310). This coefficient indicates the AA selectivity toward the cyclooxygenase active center.

  17. Ultralow interfacial tensions of aqueous two-phase systems measured using drop shape.

    Science.gov (United States)

    Atefi, Ehsan; Mann, J Adin; Tavana, Hossein

    2014-08-19

    Aqueous solutions of different polymers can separate and form aqueous two-phase systems (ATPS). ATPS provide an aqueous, biocompatible, and mild environment for separation and fractionation of biomolecules. The interfacial tension between the two aqueous phases plays a major role in ATPS-mediated partition of biomolecules. Because of the structure of the two aqueous phases, the interfacial tensions between the phases can be 3-4 orders of magnitude smaller than conventional fluid-liquid systems: ∼1-100 μJ/m(2) for ATPS compared to ∼72 mJ/m(2) for the water-vapor interface. This poses a major challenge for the experimental measurements of reproducible interfacial tension data for these systems. We address the need for precise determination of ultralow interfacial tensions by systematically studying a series of polymeric ATPS comprising of polyethylene glycol (PEG) and dextran (DEX) as the phase-forming polymers. Sessile and pendant drops of the denser DEX phase are formed within the immersion PEG phase. An axisymmetric drop shape analysis (ADSA) is used to determine interfacial tensions of eight different ATPS. Specific criteria are used to reproducibly determine ultralow interfacial tensions of the ATPS from pendant and sessile drops. Importantly, for a given ATPS, pendant drop and sessile drop experiments return values within 0.001 mJ/m(2) indicating reliability of our measurements. Then, the pendant drop technique is used to measure interfacial tensions of all eight ATPS. Our measured values range from 0.012 ± 0.001 mJ/m(2) to 0.381 ± 0.006 mJ/m(2) and vary with the concentration of polymers in equilibrated phases of ATPS. Measurements of ultralow interfacial tensions with such reproducibility will broadly benefit studies involving partition of different biomolecules in ATPS and elucidate the critical effect of interfacial tension.

  18. Characteristics of high-sulfate wastewater treatment by two-phase anaerobic digestion process with Jet-loop anaerobic fluidized bed

    Institute of Scientific and Technical Information of China (English)

    WEI Chao-hai; WANG Wen-xiang; DENG Zhi-yi; WU Chao-fei

    2007-01-01

    A new anaerobic reactor,Jet-loop anaerobic fluidized bed(JLAFB),was designed for treating high-sulfate wastewater.The treatment characteristics,including the effect of influent COD/SO42- ratio and alkalinity and sulfide inhibition in reactors,were discussed for a JLAFB and a general anaerobic fluidized bed(AFB)reactor used as sulfate-reducing phase and methane-producing phase,respectively,in two-phase anaerobic digestion process.The formation of granules in the two reactors was also examined.The results indicated that COD and sulfate removal had different demand of influent COD/S042- ratios.When total COD removal Was up to 85%,the ratio was only required up to 1.2,whereas,total sulfate removal up to 95%required it exceeding 3.0.The alkalinity in the two reactors increased linearly with the growth of influent alkalinity.Moreover,the change of influent alkalinity had no significant effect on pH and volatile fatty acids(VFA)in the two reactors.Influent alkalinity kept at 400-500 mg/t,could meet the requirement of the treating process.The JLAFB reactor had great advantage in avoiding sulfide and free-H2S accumulation and toxicity inhibition on microorganisms.When sulfate loading rate was up to 8.1 kg/(m3·d),the sulfide and free-H2S concentrations in JLAFB reactor were 58.6 and 49.7 mg/L,respectively.Furthermore,the granules,with offwhite color,ellipse shape and diameters of 1.0-3.0 mm,could be developed in JLAFB reactor.In granules,different groups of bacteria were distributed in different layers,and some inorganic metal compounds such as Fe,Ca,Mg etc.were found.

  19. Extraction of amylase from fermentation broth in poly (Ethylene Glycol salt aqueous two-phase system

    Directory of Open Access Journals (Sweden)

    Raquel Pedrosa Bezerra

    2006-07-01

    Full Text Available Studies were carried out on the partition of amylase from Bacillus subtilis in a minimal medium at 37 ºC and 110 rpm. Enzyme recovery was carried out in aqueous two-phase system PEG-Phosphate salt were carried out. The best purification factor (5.4 was obtained in system PEG 1000 (16.7% w/w with potassium phosphate (14.8% w/w, at pH 6.0, resulting in a recovery of 45.2% activity enzymatic in the salt-rich phase.Enzimas amilolíticas têm sido amplamente investigadas com a finalidade de melhorar os processos industriais para a degradação do amido. Foi determinado que a extração da enzima em sistema bifásico aquosos é um método aplicável para separação e purificação de biomoléculas em misturas. Vários sistemas compostos de soluções aquosas de polietilenoglicol e fosfato foram avaliados. Estudos de produção em meio mínimo suplementado, à 37ºC, com uma velocidade de agitação de 110rpm e recuperação da amilase a partir do Bacillus subtilis em sistema bifásico aquoso PEG-fosfato foram avaliados. O melhor fator de purificação (5.4 foi obtido no sistema PEG 1000 (16.7% w/w com fosfato de potássio (14.8% w/w, a pH 6.0, resultando na recuperação da atividade enzimática de 45.2% na fase rica em sal.

  20. Model description of bactrial 3-methylcatechol production in one- and two-phase systems

    NARCIS (Netherlands)

    Husken, L.E.; Hoogakker, J.; Bont, de J.A.M.; Tramper, J.; Beeftink, H.H.

    2003-01-01

    Pseudomonas putida MC2 produces 3-methylcatechol from toluene in aqueous medium. A second phase of 1-octanol may improve total product accumulation. To optimise the design of such a biphasic process, a process model was developed, both for one- and two-phase applications. The insights obtained by th

  1. Your Digestive System and How It Works

    Science.gov (United States)

    ... the GI tract, also called gut flora or microbiome, help with digestion. Parts of the nervous and circulatory systems also play roles in the digestive process. Together, a combination of nerves, hormones, bacteria, blood, and the organs ...

  2. Measurement and Correlation of Equilibrium Data for Aqueous Two-phase System Ethanol+Water+K2HPO4

    Institute of Scientific and Technical Information of China (English)

    LIN Jin-qing; TAN Ping-hua; JIN Chun-ying; LI Ming-chun

    2004-01-01

    The isothermal solubility data of aqueous two-phase system ethanol+water+K2HPO4 were determined with the turbidity titration method at 303.2 K. The binodal curves were described by using the Mistry equation very well. An experimental procedure for measuring the liquid-liquid equilibrium data of the aqueous two-phase system was proposed, in which the concentrations of the coexisting phases were determined with the corresponding densities of the solution. The tie lines were satisfactorily described by using the Othmer Tobias and Bancroft equations.

  3. Individual extraction constants of some univalent anions in the two-phase water-phenyltrifluoromethyl sulfone system.

    Science.gov (United States)

    Makrlík, Emanuel; Selucký, Pavel; Vaňura, Petr

    2011-12-01

    From extraction experiments and g-activity measurements, the extraction constants corresponding to the general equilibrium Cs+(aq) + A- (aq) Cs+(org) + A- (org) taking place in the two-phase water-phenyltrifluoromethyl sulfone (FS 13) system (A-= I-, ClO4-, MnO4-, Br-3, I-3, picrate, tetraphenylborate (BPh-4); aq = aqueous phase, org = FS 13 phase) were evaluated. Furthermore, the individual extraction constants of these 7 anions in the mentioned two-phase system were calculated; they were found to increase in the series of I-< ClO4- < Br-3 < MnO4-, picrate < I-3 < BPh-4.

  4. Two-phase experimental heat transfer studies on a water-diesel system in a shell and tube heat exchanger

    Directory of Open Access Journals (Sweden)

    V. Alagesan

    2012-06-01

    Full Text Available Two-phase heat transfer involving two immiscible systems is gaining importance in petrochemical and allied industries. Varying compositions of diesel and water were experimentally studied in a 1:2 shell and tube heat exchanger. The data on pure water and diesel were fitted to an equation of the form. h1φ = a NmRe.The two-phase multiplier, Φ L, was related to the Lockhart Martinelli (L-M parameter, χtt², using the two-phase data and a correlation Φ L = b+c(χtt²+d/(χtt²² was established. The two-phase heat transfer coefficient was calculated based on the coefficients 'a' and 'm' for pure diesel and pure water along with ФL and the L-M parameter. The calculated values of the two-phase heat transfer coefficient h2φ based on pure diesel and pure water suggest that diesel is a better reference fluid since the average error is much smaller compared to pure water as reference.

  5. A numerical method for a model of two-phase flow in a coupled free flow and porous media system

    KAUST Repository

    Chen, Jie

    2014-07-01

    In this article, we study two-phase fluid flow in coupled free flow and porous media regions. The model consists of coupled Cahn-Hilliard and Navier-Stokes equations in the free fluid region and the two-phase Darcy law in the porous medium region. We propose a Robin-Robin domain decomposition method for the coupled Navier-Stokes and Darcy system with the generalized Beavers-Joseph-Saffman condition on the interface between the free flow and the porous media regions. Numerical examples are presented to illustrate the effectiveness of this method. © 2014 Elsevier Inc.

  6. A simple method to optimize the HSCCC two-phase solvent system by predicting the partition coefficient for target compound.

    Science.gov (United States)

    Han, Quan-Bin; Wong, Lina; Yang, Nian-Yun; Song, Jing-Zheng; Qiao, Chun-Feng; Yiu, Hillary; Ito, Yoichiro; Xu, Hong-Xi

    2008-04-01

    A simple method was developed to optimize the solvent ratio of the two-phase solvent system used in the high-speed counter-current chromatography (HSCCC) separation. Some mathematic equations, such as the exponential and the power equations, were established to describe the relationship between the solvent ratio and the partition coefficient. Using this new method, the two-phase solvent system was easily optimized to obtain a proper partition coefficient for the CCC separation of the target compound. Furthermore, this method was satisfactorily applied in determining the two-phase solvent system for the HSCCC preparation of pseudolaric acid B from the Chinese herb Pseudolarix kaempferi Gordon (Pinaceae). The two-phase solvent system of n-hexane/EtOAc/MeOH/H(2)O (5:5:5:5 by volume) was used with a good partition coefficient K = 1.08. As a result, 232.05 mg of pseudolaric acid B was yielded from 0.5 g of the crude extract with a purity of 97.26% by HPLC analysis.

  7. Ionic interaction of oral streptococcal bacteria studied by partition in an aqueous polymer two-phase system.

    Science.gov (United States)

    Westergren, G

    1981-01-01

    The net surface charge of various oral streptococci were assessed by aqueous two-phase partitioning in a dextran-polyethylene glycol system. Great variability was found among individual strains within all species tested. Type 1 strains of Streptococcus sanguis serotypes which have been found to be more adherent, exposed a lower negative net surface charge than Type 2 strains.

  8. Two-phase plate-fin heat exchanger modeling for waste heat recovery systems in diesel engines

    NARCIS (Netherlands)

    Feru, E.; de Jager, B.; Willems, F.; Steinbuch, M.

    2014-01-01

    This paper presents the modeling and model validation for a modular two-phase heat exchanger that recovers energy in heavy-duty diesel engines. The model is developed for temperature and vapor quality prediction and for control design of the waste heat recovery system. In the studied waste heat reco

  9. Design of aqueous two-phase systems supporting animal cell growth: a first step toward extractive bioconversions.

    NARCIS (Netherlands)

    Zijlstra, G.M.; Gooijer, de C.D.; Pol, van der L.A.; Tramper, J.

    1996-01-01

    The design of aqueous two-phase systems (ATPSs) which support the long-term growth of animal cells is described in this paper. It was found that the increase in osmolality caused by the ATPS-forming polymers could be compensated by reducing the NaCl concentration of the culture medium. Cell growth

  10. Use of multifactorial analysis to develop aqueous two-phase systems for isolation of non-native IGF-I.

    Science.gov (United States)

    Hart, R A; Ogez, J R; Builder, S E

    1995-04-01

    A high yield procedure was developed to solubilize and extract IGF-I from recombinant E. coli by adding chaotrope and disulfide reductant to alkaline fermentation broth. To enhance centrifugation performance and recovery yield, a salt/polymer aqueous two-phase extraction procedure was developed whereby soluble non-native IGF-I and biomass solids are enriched in separate liquid phases. To develop this extraction system a multifactorial experimental approach was used to simultaneously map the phase diagram and identify conditions to suitably partition IGF-I and cell remnants. The presence of urea in these systems tended to disrupt two-phase formation and solids sedimentation. This, in turn, constrained the concentrations of phase forming solutes which could be effectively used. Systems containing low levels of salt (less than about 4% w/w) and polymer (less than about 10% w/w) did not form two phases. Systems containing high levels of salt (greater than about 7% w/w) and polymer (greater than about 18% w/w) formed two phases with floating solids. Intermediate levels of salt (between about 4% and 7% w/w) and polymer (between about 10% and 18% w/w) formed two phases in which solids were enriched in the heavy phase. Systems in this latter desired category were produced with a variety of different salts and polymers and all enriched non-native IGF-I in the light phase. Highest recovery yield (about 90%) was obtained with systems composed of 5% sodium sulfate and 14% PEG-8000.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Cloud Point and Liquid-Liquid Equilibrium Behavior of Thermosensitive Polymer L61 and Salt Aqueous Two-Phase System.

    Science.gov (United States)

    Rao, Wenwei; Wang, Yun; Han, Juan; Wang, Lei; Chen, Tong; Liu, Yan; Ni, Liang

    2015-06-25

    The cloud point of thermosensitive triblock polymer L61, poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO), was determined in the presence of various electrolytes (K2HPO4, (NH4)3C6H5O7, and K3C6H5O7). The cloud point of L61 was lowered by the addition of electrolytes, and the cloud point of L61 decreased linearly with increasing electrolyte concentration. The efficacy of electrolytes on reducing cloud point followed the order: K3C6H5O7 > (NH4)3C6H5O7 > K2HPO4. With the increase in salt concentration, aqueous two-phase systems exhibited a phase inversion. In addition, increasing the temperature reduced the concentration of salt needed that could promote phase inversion. The phase diagrams and liquid-liquid equilibrium data of the L61-K2HPO4/(NH4)3C6H5O7/K3C6H5O7 aqueous two-phase systems (before the phase inversion but also after phase inversion) were determined at T = (25, 30, and 35) °C. Phase diagrams of aqueous two-phase systems were fitted to a four-parameter empirical nonlinear expression. Moreover, the slopes of the tie-lines and the area of two-phase region in the diagram have a tendency to rise with increasing temperature. The capacity of different salts to induce aqueous two-phase system formation was the same order as the ability of salts to reduce the cloud point.

  12. Two-phase Flow of Liquid-gas in Diesel Fuel Injection System and Their Effect on Engine Performances

    Institute of Scientific and Technical Information of China (English)

    Yongling He; Zhihe Zhao; Jianxin Liu; Huiyong Du; Min Li; Yongping Zong

    2001-01-01

    In this paper, by using high-speed camera, CCD camera, signal and graph acquisition system, and other experimental instruments, investigation on liquid-gas two-phase flow in diesel fuel injection system and their effect on engine performances were made. Emerging and bursting of cavitation in the cavity above pump delivery valve, in injection pipe, and in fuel trough of injector of the fuel injection system were observed and mechanism of cavitation were discussed. Effects of liquid-gas two-phase flow on propagation velocity of pressure wave of the system and on irregular injection were analyzed. Two types of cavitation, long living time cavitation and short living time cavitation, in the cavity above pump delivery valve of diesel fuel injection system were observed.

  13. Two-phase flows and heat transfer within systems with ambient pressure above the thermodynamic critical pressure

    Science.gov (United States)

    Hendricks, R. C.; Braun, M. J.; Mullen, R. L.

    1986-01-01

    In systems where the design inlet and outlet pressure P sub amb are maintained above the thermodynamic critical pressure P sub c, it is often assumed that heat and mass transfer are governed by single-phase relations and that two-phase flows cannot occur. This simple rule of thumb is adequate in many low-power designs but is inadequate for high-performance turbomachines, boilers, and other systems where two-phase regions can exist even though P sub amb P sub c. Heat and mass transfer and rotordynamic-fluid-mechanic restoring forces depend on momentum differences, and those for a two-phase zone can differ significantly from those for a single-phase zone. By using a laminar, variable-property bearing code and a rotating boiler code, pressure and temperature surfaces were determined that illustrate nesting of a two-phase region within a supercritical pressure region. The method of corresponding states is applied to bearings with reasonable rapport.

  14. Low Energy Consumption Technique for Processing Rapeseed with Two-phase Extraction System without Ammonia

    Institute of Scientific and Technical Information of China (English)

    Shi Meiren; Qin Jinping; SQian Renyuan

    2000-01-01

    the mother liquid of methanol phase obtained from rapeseed two-phase extraction process can directly be reused in large amounts to process rapeseed again together with some fresh methanol phase, so long as it is treated with a litter of proper additives in advance. The ratio of the reused mother liquid may be more than 3/ 4 of the total amount of the methanol phase needed for processing rapeseed, so the energy consumption can be decreased tremendously. The meal obtained by use of the reused mother liquid keeps the quality as good as those obtained by use of totally fresh methanol phase with light color, weak taste, crispness, good palatability, high protein content, and a low level of glucosinolates much more less than that stipulated by the State for the fodder of grade A.

  15. [Autoimmune Diseases of Digestive System].

    Science.gov (United States)

    Ivashkinl, V T; Sheptulina, A F; Raĭkhelson, K L; Losik, E A; Ivashkin, K V; Okhlobystin, A V; Baranskaia, E K; Polouvektova, E A; Shifrin, O S

    2015-01-01

    Autoimmune diseases of digestive system refer to pathological conditions, caused by autoimmune mechanisms, and their etiology remains unknown. This is a group of relatively rare diseases, however, during the last years a marked tendency towards the raise in incidence andprevalence is observed, which led to an increase in number of clinical investigations on etiology, pathogenesis, and, accordingly, development of new diagnostic methods and therapies. Results of such trials shown, for example, that the pathogenesis of chronic cholestatic liver diseases is associated with nuclear receptors function, while the main etiological and pathogenic factor of inflammatory bowel diseases represents gut microbiota. Despite new achievements in autoinmune diseases of digestive system research, therapies are low effective and are accompanied by a huge number of adverse events. The fact that these diseases may lead to malignant tumors is also worth noting. For example, patients with primary sclerosing cholangitis have a 160 times higher risk of cholangiocellular carcinoma, while 10-14% ofpatients with celiac disease may develop malignancies of esophagus, small and large intestine. Thus, these diseases require further investigation with a purpose of more accurate diagnostic methods for the detection of disease at early stages and new effective and safe therapies development.

  16. Facile synthesis and properties of CdSe quantum dots in a novel two-phase liquid/liquid system

    Science.gov (United States)

    Wang, Jidong; Wang, Xiaoyu; Tang, Hengshan; Gao, Zehua; He, Shengquan; Ke, Dandan; Zheng, Yue; Han, Shumin

    2017-10-01

    High-quantity CdSe QDs were synthesized in a novel two-phase liquid/liquid system. This system, ODE/water was stable and as-used solvents were almost nontoxic. The methodology leading to the successful synthesis of CdSe QDs was a typical, one-pot approach and the obtained CdSe QDs with zinc-blende phase structure exhibited excellent optical properties, narrow size distribution, higher particle uniformity and crystallinity. The mechanism of nucleation and growth of CdSe QDs were discussed by the possible thermodynamic equilibrium existing in ODE/water interface. This two-phase liquid/liquid system would broaden the synthesis of other semiconductor QDs.

  17. Study on PEG-(NH4)2SO4 Aqueous Two-Phase System and Distribution Behavior of Drugs

    Institute of Scientific and Technical Information of China (English)

    LI, Lei(李蕾); HE, Chi-Yang(何池洋); LI, She-Hong(李社红); LIU, Feng(刘锋); SU, Shun(苏顺); KONG, Xiang-Xu(孔祥旭); LI, Na(李娜); LI, Ke-An(李克安)

    2004-01-01

    The distribution behavior of chlorpromazine hydrochloride (CPZ), procaine hydrochloride (PCN) and procaine amide hydrochloride (PCNA) in polyethylene glycol (PEG800 or PEG1500)-(NH4)2SO4 aqueous two-phase systems has been investigated. The result shows that the PEG-(NH4)2SO4 aqueous two-phase system has potential extraction capability in small molecular drug separation. In PEG800-(NH4)2SO4 system, the extraction efficiencies (E)of CPZ, PCN and PCNA amount to 92.8%, 74.5% and 74.4%, respectively, with the distribution coefficients (KD)being 25.7, 5.9 and 5.8, correspondingly. In PEG1500-(NH4)2SO4 system, the extraction efficiencies (E) of CPZ,PCN and PCNA are 93.7%, 71.3% and 63.2%, respectively, with distribution coefficients (KD) of 39.6, 6.6 and 5.0,correspondingly. Based on the study on ultraviolet and fluorescence spectra and also distribution behavior of the drugs in PEG-(NH4)2SO4 aqueous two-phase system, extraction mechanism was further proposed that both hydrogen bond and hydrophobic interaction are involved in extraction.

  18. Recyclable hydroformylation catalysts of higher alkenes using immobilized catalysts and two-phase systems

    Energy Technology Data Exchange (ETDEWEB)

    Reek, J.N.H.; Sandee, A.J.; Schreuder Goedheijt, M.; Kamer, P.C.J.; Leeuwen, P.W.N.M. van [Amsterdam Univ. (Netherlands). Inst. of Molecular Chemistry, Homogeneous Catalysis

    2001-03-01

    This article reports on the use of recyclable catalysts, using different concepts, in the hydroformylation of 1-octene employing diphosphine ligands based on the xantene backbone. Amphiphilic diphosphines were developed for the aqueous two-phase catalysis, which spontaneously form aggregates that are remarkably thermostable. The observed TOF's in the hydroformylation of 1-octene using ligands that form vesicles are up to 14 times higher compared to analogue ligands that do not form aggregates. A water-soluble ligand based on the xantene backbone was used to form a stable and recyclable supported aqueous phase catalyst (SAPC). A xanthene-based ligand, N-(3-trimethoxysilane-n-propyl)-4,5-bis(diphenyl-phosphino)-phenoxazine (Siloxantphos) was anchored covalently to a silica support by the sol-gel technique. All concepts demonstrated that the rhodium complexes of these ligands form very selective hydroformylation catalysts producing linear aldehydes. Under similar conditions the activity of the silica-immobilized catalysts is higher than that of the aggregates (by a factor 2) of which the activity is higher than the SAP catalyst (factor 12). (orig.)

  19. Quantitative study on experimentally observed poroelastic behavior of Berea sandstone in two-phase fluid system

    Science.gov (United States)

    Goto, Hiroki; Aichi, Masaatsu; Tokunaga, Tomochika; Yamamoto, Hajime; Ogawa, Toyokazu; Aoki, Tomoyuki

    2014-08-01

    Coupled two-phase fluid flow and poroelastic deformation of Berea sandstone is studied through laboratory experiment and numerical simulation. In the experiment, compressed air was infiltrated from the bottom of a water-saturated cylindrical Berea sandstone sample under hydrostatic external stress condition. Both axial and circumferential strains at half the height of the sample showed sudden extension and monotonic and gradual extension afterward. Numerical simulation based on thermodynamically consistent constitutive equations was conducted in order to quantitatively analyze the experimental results. In a simulation assuming isotropy of material properties, the volumetric discharge rate of water at the outlet and one of the axial, circumferential, and volumetric strains at half the height of the sample were reproduced well by each parameter set, while the other two strains were not. When introducing transverse isotropy, all the experimental data were reproduced well. In addition, the effect of saturation dependency of Bishop's effective stress coefficient on the deformation behavior of porous media was discussed, and it was found that strains, both axial and circumferential, are sensitive to the coefficient.

  20. Transformation of Geniposide into Genipin by Immobilized β-Glucosidase in a Two-Phase Aqueous-Organic System

    Directory of Open Access Journals (Sweden)

    Duo Jin

    2011-05-01

    Full Text Available Genipin is the bioactive compound of geniposide and a natural cross-linking agent. In order to improve the preparation process of genipin, the hydrolysis of geniposide to genipin by immobilized β-glucosidase in an aqueous-organic two-phase system was studied. β-Glucosidase was immobilized by the crosslinking-embedding method using sodium alginate as the carrier. The optimum reaction temperature, pH value and time were 55 °C, 4.5 and 2.5 h, respectively. To reduce genipin hydrolysis and byproduct production the reaction was carried out in an aqueous-organic two-phase system comprising ethyl acetate and sodium acetate buffer. The product was analyzed by HPLC, UV, IR, and NMR. The yield of genipin was 47.81% and its purity was over 98% (HPLC.

  1. Aqueous two-phase extraction of 2,3-butanediol from fermentation broths by isopropanol/ammonium sulfate system.

    Science.gov (United States)

    Sun, Li-Hui; Jiang, Bo; Xiu, Zhi-Long

    2009-03-01

    A novel aqueous two-phase system consisted of 2-propanol/ammonium sulfate was used for the extraction of 2,3-butanediol from fermentation broths. The maximum partition coefficient and recovery of 2,3-butanediol reached 9.9 and 93.7%, respectively, and more than 99% of the cells and about 85% of the soluble proteins were removed when 34% (w/w) 2-propanol and 20% (w/w) ammonium sulfate were used. The separated cells could be re-used as inocula for subsequent fermentations. The aqueous two-phase system described in this study may have potential application in the extraction of 2,3-butanediol produced by industrial fermentation processes.

  2. Optimized Enzymatic Synthesis of Hesperidin Fatty Acid Esters in a Two-Phase System Containing Ionic Liquid

    Directory of Open Access Journals (Sweden)

    Yollanda Edwirges Moreira Franco

    2011-08-01

    Full Text Available Response surface methodology (RSM based on a five-level, three-variable central composite design (CCD was employed for modeling and optimizing the conversion yield of the enzymatic acylation of hesperidin with decanoic acid using immobilized Candida antarctica lipase B (CALB in a two-phase system containing [bmim]BF4. The three variables studied (molar ratio of hesperidin to decanoic acid, [bmim]BF4/acetone ratio and lipase concentration significantly affected the conversion yield of acylated hesperidin derivative. Verification experiments confirmed the validity of the predicted model. The lipase showed higher conversion degree in a two-phase system using [bmim]BF4 and acetone compared to that in pure acetone. Under the optimal reaction conditions carried out in a single-step biocatalytic process when the water content was kept lower than 200 ppm, the maximum acylation yield was 53.6%.

  3. Application of surface response analysis to the optimization of penicillin acylase purification in aqueous two-phase systems

    OpenAIRE

    2002-01-01

    Penicillin acylase purification from an Escherichia coli crude extract using PEG 3350 – sodium citrate aqueous two phase systems was optimized. An experimental design was used to evaluate the influence of PEG, sodium citrate and sodium chloride on the purification parameters. A central composite design was defined centred on the previously found conditions for highest purification from an osmotic shock extract. Mathematical models for the partition coefficient of protein and enzyme, balance o...

  4. Effect of Mechanical Stress on Magnetic States and Hysteresis Characteristics of a Two-Phase Nanoparticles System

    Directory of Open Access Journals (Sweden)

    Leonid Lazarevich Afremov

    2013-01-01

    Full Text Available In terms of the two-phase nanoparticles model, the effect of mechanical stress on the magnetic state of both uniaxial and multiaxial heterophase magnetic is investigated. The spectrum of critical fields of reversal of phases' magnetic moments was calculated and phase diagrams were drawn to assess the effect of mechanical stress on the degree of metastability of two-phase nanoparticles' magnetic states. By the example of epitaxial cobalt-coated -Fe2O3 particles, a theoretical analysis of the effect of uniaxial mechanical stress on the magnetization of a system of noninteracting heterophase nanoparticles is investigated. It was shown that tension reduced and compression increased coercive force , while the residual saturation magnetization was not changed under the influence of mechanical stress.

  5. Influence of system and process parameters on partitioning of cheese whey proteins in aqueous two-phase systems.

    Science.gov (United States)

    Rito-Palomares, M; Hernandez, M

    1998-06-26

    A practical study is described to characterise some problems encountered in the application of aqueous two-phase systems (ATPS) to protein recovery. These factors include practical design of extraction stages and the impact of ATPS compounding methods and biological suspension upon process performance. They were addressed using the recovery of whey proteins as a model. The known effects of system parameters (i.e. tie-line length, volume ratio and system pH) were exploited to define the specific operating conditions of a two-stage ATPS process for the recovery of whey proteins. The partition of whey proteins in ATPS assembled using different methods resulted in changes in the partition coefficient of the proteins. Such changes were associated with the initial location of the proteins in the polymer or salt-rich solutions of the ATPS. Cheese whey loaded into the ATPS caused the displacement of the binodal curve from the origin. Such behaviour was attributed to the residual fat present in the whey. These findings highlight those factors perceived as negative constraints on the wider adoption of ATPS processes for protein recovery from complex biological systems.

  6. 不同有机质含量剩余污泥的两相厌氧消化研究%Two-phase Anaerobic Digestion of Waste Activated Sludge with Different Organic Contents

    Institute of Scientific and Technical Information of China (English)

    刘蕾; 张立国; 尹军; 刘春峰

    2011-01-01

    分别采用两种不同来源的剩余污泥以及剩余污泥与厨余垃圾的混合物进行两相厌氧消化,考察了不同有机质含量污泥的中温厌氧消化性能.结果表明,添加厨余垃圾后系统产酸相的VFA/BA值约为0.05,三个系统产甲烷相的稳定性较好.随着HRT的延长,各系统对VS和TCOD的去除率均逐渐升高,当 HRT为20 d时,混合系统对VS与TCOD的去除率达到最大,分别为47.9%和49.2%,显著高于其他两个系统.随着HRT的延长,各系统的SMA活性逐渐提高,而且产气中的甲烷含量也随之增加.研究表明,在有机质含量偏低的剩余污泥中添加有机固体废物,不仅可以提高对有机质的去除率,还可以提高沼气产量.%Two types of waste activated sludge ( WAS) and kitchen garbage were used to prepare the WAS samples with different organic contents, and the digestion efficiencies of prepared samples were investigated using mesophilic two-phase anaerobic digestion (TPAD) process. The experimental results show that the ratio of volatile fatty acids and bicarbonate alkalinity (VFA/BA) in acidogenic phase is 0.05 for the system with the addition of kitchen garbage, and the three systems have good stability in methanogenic phase. The removal rates of VS and total COD are increased with increasing hydraulic retention time ( HRT) . The maximum removal rates of VS and total COD in the mixed system are achieved (47.9% and 49.2% respectively) when the HRT is 20 d, significantly higher than those in other two systems. The specific methanogenic activity (SMA) and methane content in biogas are both increased with increasing HRT. The addition of kitchen garbage into the low organic WAS can improve both organic removal efficiency and biogas yield.

  7. Efficient hydrolysis of tuna oil by a surfactant-coated lipase in a two-phase system.

    Science.gov (United States)

    Ko, Wen-Ching; Wang, Hsiu-Ju; Hwang, Jyh-Sheng; Hsieh, Chang-Wei

    2006-03-08

    A surfactant-coated lipase (SCL) prepared by mixing Candida rugosa lipase with emulsifier in ethanol was used to hydrolyze tuna oil in a two-phase aqueous-organic system. Both enzyme (SCL) and substrate (tuna oil) were soluble in the organic phase, and the hydrolysis could occur with water molecules from the aqueous phase. This hydrolysis could promptly proceed compared to that catalyzed by native lipases which only occurred at the interface between the two phases. Michaelis-Menten kinetics in the two-phase reactions showed that the K(m) value of the SCL was half that of the native lipase, while the maximum velocity (V(max)) was 11.5 times higher. The hydrolysis method resulted in enrichment of n-3 polyunsaturated fatty acid (n-3 PUFA) content in glyceride mixtures from 26.4% to 49.8% and DHA from 19.1% to 38.9%. The SCL acted as an efficient hydrolytic catalyst for tuna oil.

  8. Enzymatic hydrolysis of cellulose in aqueous two-phase systems. 1. Partition of cellulases from Trichoderma reesei

    Energy Technology Data Exchange (ETDEWEB)

    Tjerneld, F.; Persson, J.; Albertsson, P.A.; Hahn-Haegerdal, B.

    1985-07-01

    The partitioning of endo-..beta..-glucanase, exo-..beta..-glucananse, and ..beta..-glucosidase from Trichoderma reesei QM 9414 in aqueous two-phase systems has been studied with the object of designing a phase system for continuous bioconversion of cellulose. The partitioning of the enzymes in two-phase systems composed of various water soluble polymeric compounds were studied. Systems based on dextran and polyethylene glycol (PEG) were optimal for one sidedly partitioning of the enzymes to the bottom phase. The influence of polymer molecular weights, polymer concentration, ionic composition of the medium, pH, temperature, and adsorption of the enzymes to cellulose on the enyzme partition coefficients (K) were studied. By combining the effects of polymer molecular weight and adsorption to cellulose, K values could be reduced for endo-..beta..-glucanase to 0.02 and for ..beta..-glucosidase to 0.005 at 20 degrees C in a phase system of Dvalues could be reduced for endo-..beta..-glucanase to 0.02 and for ..beta..-glucosidase to 0.005 at 20 degrees C in a phase system of Dextran 40-PEG 40000 in the presence of excess cellulose. At 50 degrees C, K values were increased by a factor of two. In a phase system based on inexpensive crude dextran and PEG, the partition coefficient for endo-..beta..-glucanase was 0.16 and for beta-glucosidase was 0.14 at 20 degrees C with excess cellulose present.

  9. Slug flow transitions in horizontal gas/liquid two-phase flows. Dependence on channel height and system pressure for air/water and steam/water two-phase flows

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Hideo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-05-01

    The slug flow transitions and related phenomena for horizontal two-phase flows were studied for a better prediction of two-phase flows that typically appear during the reactor loss-of-coolant accidents (LOCAs). For better representation of the flow conditions experimentally, two large-scaled facility: TPTF for high-pressure steam/water two-phase flows and large duct test facility for air/water two-phase flows, were used. The visual observation of the flow using a video-probe was performed in the TPTF experiments for good understanding of the phenomena. The currently-used models and correlations based mostly on the small-scale low-pressure experiments were reviewed and improved based on these experimental results. The modified Taitel-Dukler model for prediction of transition into slug flow from wavy flow and the modified Steen-Wallis correlation for prediction of onset of liquid entrainment from the interfacial waves were obtained. An empirical correlation for the gas-liquid interfacial friction factor was obtained further for prediction of liquid levels at wavy flow. The region of slug flow regime that is generally under influences of the channel height and system pressure was predicted well when these models and correlations were applied together. (author). 90 refs.

  10. Modeling Two-Phase Flow and Vapor Cycles Using the Generalized Fluid System Simulation Program

    Science.gov (United States)

    Smith, Amanda D.; Majumdar, Alok K.

    2017-01-01

    This work presents three new applications for the general purpose fluid network solver code GFSSP developed at NASA's Marshall Space Flight Center: (1) cooling tower, (2) vapor-compression refrigeration system, and (3) vapor-expansion power generation system. These systems are widely used across engineering disciplines in a variety of energy systems, and these models expand the capabilities and the use of GFSSP to include fluids and features that are not part of its present set of provided examples. GFSSP provides pressure, temperature, and species concentrations at designated locations, or nodes, within a fluid network based on a finite volume formulation of thermodynamics and conservation laws. This paper describes the theoretical basis for the construction of the models, their implementation in the current GFSSP modeling system, and a brief evaluation of the usefulness of the model results, as well as their applicability toward a broader spectrum of analytical problems in both university teaching and engineering research.

  11. Separated two-phase flow regime parameter measurement by a high speed ultrasonic pulse-echo system.

    Science.gov (United States)

    Masala, Tatiana; Harvel, Glenn; Chang, Jen-Shih

    2007-11-01

    In this work, a high speed ultrasonic multitransducer pulse-echo system using a four transducer method was used for the dynamic characterization of gas-liquid two-phase separated flow regimes. The ultrasonic system consists of an ultrasonic pulse signal generator, multiplexer, 10 MHz (0.64 cm) ultrasonic transducers, and a data acquisition system. Four transducers are mounted on a horizontal 2.1 cm inner diameter circular pipe. The system uses a pulse-echo method sampled every 0.5 ms for a 1 s duration. A peak detection algorithm (the C-scan mode) is developed to extract the location of the gas-liquid interface after signal processing. Using the measured instantaneous location of the gas/liquid interface, two-phase flow interfacial parameters in separated flow regimes are determined such as liquid level and void fraction for stratified wavy and annular flow. The shape of the gas-liquid interface and, hence, the instantaneous and cross-sectional averaged void fraction is also determined. The results show that the high speed ultrasonic pulse-echo system provides accurate results for the determination of the liquid level within +/-1.5%, and the time averaged liquid level measurements performed in the present work agree within +/-10% with the theoretical models. The results also show that the time averaged void fraction measurements for a stratified smooth flow, stratified wavy flow, and annular flow qualitatively agree with the theoretical predictions.

  12. A Novel Flow Measurement System for Cryogenic Two-Phase Flow Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Flow rate measurements for cryogenic propellants are required for spacecraft and space exploration systems. Such a requirement has been hampered by lack of fast and...

  13. Interfacial Area and Interfacial Transfer in Two-Phase Flow Systems (Volume II. Chapters 6-10)

    Energy Technology Data Exchange (ETDEWEB)

    Guo, T.; Park, J.; Kojasoy, G.

    2003-03-15

    Experiments were performed on horizontal air-water bubbly two-phase flow, axial flow, stratified wavy flow, and annular flow. Theoretical studies were also undertaken on interfacial parameters for a horizontal two-phase flow.

  14. Interfacial Area and Interfacial Transfer in Two-Phase Flow Systems (Volume III. Chapters 11-14)

    Energy Technology Data Exchange (ETDEWEB)

    Guo, T.; Park, J.; Kojasoy, G.

    2003-03-15

    Experiments were performed on horizontal air-water bubbly two-phase flow, axial flow, stratified wavy flow, and annular flow. Theoretical studies were also undertaken on interfacial parameters for a horizontal two-phase flow.

  15. Interfacial Area and Interfacial Transfer in Two-Phase Flow Systems (Volume IV. Chapters 15-19)

    Energy Technology Data Exchange (ETDEWEB)

    Guo, T.; Park, J.; Kojasoy, G.

    2003-03-15

    Experiments were performed on horizontal air-water bubbly two-phase flow, axial flow, stratified wavy flow, and annular flow. Theoretical studies were also undertaken on interfacial parameters for a horizontal two-phase flow.

  16. Interfacial Area and Interfacial Transfer in Two-Phase Flow Systems (Volume I. Chapters 1-5)

    Energy Technology Data Exchange (ETDEWEB)

    Guo, T.; Park, J.; Kojasoy, G.

    2003-03-15

    Experiments were performed on horizontal air-water bubbly two-phase flow, axial flow, stratified wavy flow, and annular flow. Theoretical studies were also undertaken on interfacial parameters for a horizontal two-phase flow.

  17. Thermodynamic modelling of phase equilibrium for water + poly(Ethylene glycol + salt aqueous two-phase systems

    Directory of Open Access Journals (Sweden)

    R.A.G. Sé

    2002-04-01

    Full Text Available The NRTL (nonrandom, two-liquid model, expressed in mass fraction instead of mole fraction, was used to correlate liquid-liquid equilibria for aqueous two-phase polymer-salt solutions. New interaction energy parameters for this model were determined using reported data on the water + poly(ethylene glycol + salt systems, with different molecular masses for PEG and the salts potassium phosphate, sodium sulfate, sodium carbonate and magnesium sulfate. The correlation of liquid-liquid equilibrium is quite satisfactory.

  18. Studies of efficiency in a perforated rotating disc contactor using a polymer-polymer aqueous two-phase systems

    Directory of Open Access Journals (Sweden)

    L. A. Sarubbo

    2005-09-01

    Full Text Available The mass transfer process in a perforated rotating disc contactor (PRDC using a polymer-polymer aqueous two-phase system was investigated. The results show that the efficiency did not show a regular trend with the increase of the dispersed phase velocity and increased with the rotation velocity. The separation efficiency was higher for three rotating discs than for four discs. The increase in tie-line length decreased the efficiency. The separation efficiency reached high values, about 96% under conditions studied in this work.

  19. Partition Coefficients of Amino Acids, Peptides, and Enzymes in Dextran + Poly(Ethylene Glycol) + Water Aqueous Two-Phase Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kakisaka, Keijiro.; Shindo, Takashi.; Iwai, Yoshio.; Arai, Yasuhiko. (Kyushu University, Fukuoka (Japan). Department of Chemical Systems and Engineering)

    1998-12-01

    Partition coefficients are measured for five amino acids(aspartic acid, asparagine, methionine, cysteine and histidine) and tow peptides(glycyl-glycine and hexa-glycine) in dextran + poly(ethylene glycol) + water aqueous two-phase system. The partition coefficients of the amino acids and peptides are aorrelated using the osmotic virial equation. The interaction coefficients contained in the equation can be calculated by hydrophilic group parameters. The partition coefficients of [alpha]-amylase calculated by the osmotic virial equation with the hydrophilic group parameters are in fairly good agreement with the experimental data, though a relatively large discrepancy is shown for [beta]-amylase. (author)

  20. Partition Coefficients of Amino Acids, Peptides, and Enzymes in Dextran + Poly(Ethylene Glycol) + Water Aqueous Two-Phase Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kakisaka, Keijiro.; Shindo, Takashi.; Iwai, Yoshio.; Arai, Yasuhiko. [Kyushu University, Fukuoka (Japan). Department of Chemical Systems and Engineering

    1998-12-01

    Partition coefficients are measured for five amino acids(aspartic acid, asparagine, methionine, cysteine and histidine) and tow peptides(glycyl-glycine and hexa-glycine) in dextran + poly(ethylene glycol) + water aqueous two-phase system. The partition coefficients of the amino acids and peptides are aorrelated using the osmotic virial equation. The interaction coefficients contained in the equation can be calculated by hydrophilic group parameters. The partition coefficients of {alpha}-amylase calculated by the osmotic virial equation with the hydrophilic group parameters are in fairly good agreement with the experimental data, though a relatively large discrepancy is shown for {beta}-amylase. (author)

  1. COUPLING MODEL OF TWO PHASE FLOW IN A FRACTURE-ROCK MATRIX SYSTEM AND ITS STOCHASTIC FEATURE ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    王经明; 李竞生; 高智联; 杨保禹

    1998-01-01

    This study is concerned with developing a two-dimensional two-phase model thatsimulate the movement of non-aqueous phase liquid (NAPL) in a fracture-rock matrix system. Theintrinsic permeability and the fracture aperture are represented in the model via its Karhunen-Loeve expansion. Other parameters and the nodal unknowns, water saturations and waterpressures, are represented by their stochastic spectral expanions. The errors resulting fromtruncation of Karhunen - Loeve and polynomial chaos expansions to a finite number of terms areanalyzed. The eigenvalues of stochastic process is found out for any point in the special domain ofthe problem at any instant in time.

  2. Local existence and stability for a hyperbolic-elliptic system modeling two-phase reservoir flow

    Directory of Open Access Journals (Sweden)

    H. J. Schroll

    2000-01-01

    Full Text Available A system arising in the modeling of oil-recovery processes is analyzed. It consists of a hyperbolic conservation law governing the saturation and an elliptic equation for the pressure. By an operator splitting approach, an approximate solution is constructed. For this approximation appropriate a-priori bounds are derived. Applying the Arzela-Ascoli theorem, local existence and uniqueness of a classical solution for the original hyperbolic-elliptic system is proved. Furthermore, convergence of the approximation generated by operator splitting towards the unique solution follows. It is also proved that the unique solution is stable with respect to perturbations of the initial data.

  3. Partition of Chiral pharmaceutical intermediate R(-)-Mandelic Acid in Aqueous Two-Phase System of Poly(ethylene glycol)-Ammonium Sulfate

    Institute of Scientific and Technical Information of China (English)

    Xu Xiaoping; Li Zhongqin; Chen Jiebo; Huang Xinghua

    2004-01-01

    An aqueous two-phase system of poly (ethylene glycol)-ammonium sulfate was employed to separate R (-)-mandelic acid.The result showed that R (-)-mandelic acid has priority to partition in PEG-rich top phase. This indicated that aqueous two-phase is a very suitable system for separation of R(-)-mandelic acid.

  4. Energetic Efficiency of Mixing and Mass Transfer in Single Phase and Two-Phase Systems

    Directory of Open Access Journals (Sweden)

    Bałdyga Jerzy

    2017-03-01

    Full Text Available In this work a concept of energetic efficiency of mixing is presented and discussed; a classical definition of mixing efficiency is modified to include effects of the Schmidt number and the Reynolds number. Generalization to turbulent flows is presented as well. It is shown how the energetic efficiency of mixing as well as efficiencies of drop breakage and mass transfer in twophase liquid-liquid systems can be identified using mathematical models and test chemical reactions. New expressions for analyzing efficiency problem are applied to identify the energetic efficiency of mixing in a stirred tank, a rotor stator mixer and a microreactor. Published experimental data and new results obtained using new systems of test reactions are applied. It has been shown that the efficiency of mixing is small in popular types of reactors and mixers and thus there is some space for improvement.

  5. Two-Phase Thermal Switching System for a Small, Extended Duration Lunar Science Platform

    Science.gov (United States)

    Bugby, D.; Farmer, J.; OConnor, B.; Wirzburger, M.; Abel, E.; Stouffer, C.

    2010-01-01

    Issue: extended duration lunar science platforms, using solar/battery or radioisotope power, require thermal switching systems that: a) Provide efficient cooling during the 15-earth-day 390 K lunar day; b) Consume minimal power during the 15-earth-day 100 K lunar night. Objective: carry out an analytical study of thermal switching systems that can meet the thermal requirements of: a) International Lunar Network (ILN) anchor node mission - primary focus; b) Other missions such as polar crater landers. ILN Anchor Nodes: network of geophysical science platforms to better understand the interior structure/composition of the moon: a) Rationale: no data since Apollo seismic stations ceased operation in 1977; b) Anchor Nodes: small, low-power, long-life (6-yr) landers with seismographic and a few other science instruments (see next chart); c) WEB: warm electronics box houses ILN anchor node electronics/batteries. Technology Need: thermal switching system that will keep the WEB cool during the lunar day and warm during the lunar night.

  6. Purification of papain by metal affinity partitioning in aqueous two-phase polyethylene glycol/sodium sulfate systems.

    Science.gov (United States)

    Jiang, Zhi-Guo; Zhang, Hai-De; Wang, Wei-Tao

    2015-05-01

    A simple and inexpensive aqueous two-phase affinity partitioning system using metal ligands was introduced to improve the selectivity of commercial papain extraction. Polyethylene glycol 4000 was first activated using epichlorohydrin, then it was covalently linked to iminodiacetic acid. Finally, the specific metal ligand Cu(2+) was attached to the polyethylene glycol-iminodiacetic acid. The chelated Cu(2+) content was measured by atomic absorption spectrometry as 0.88 mol/mol (polyethylene glycol). The effects on the purification at different conditions, including polyethylene glycol molecular weight (2000, 4000, and 6000), concentration of phase-forming components (polyethylene glycol 12-20% w/w and sodium sulfate 12-20%, w/w), metal ligand type, and concentration, system pH and the commercial papain loading on papain extraction, were systematically studied. Under optimum conditions of the system, i.e. 18% w/w sodium sulfate, 18% w/w polyethylene glycol 4000, 1% w/w polyethylene glycol-iminodiacetic acid-Cu(2+) and pH 7, a maximum yield of 90.3% and a degree of purification of 3.6-fold were obtained. Compared to aqueous two phase extraction without ligands, affinity partitioning was found to be an effective technique for the purification of commercial papain with higher extraction efficiency and degree of purification.

  7. Effect of sodium chloride on solute-solvent interactions in aqueous polyethylene glycol-sodium sulfate two-phase systems.

    Science.gov (United States)

    da Silva, Nuno R; Ferreira, Luisa A; Madeira, Pedro P; Teixeira, José A; Uversky, Vladimir N; Zaslavsky, Boris Y

    2015-12-18

    Partition behavior of eight small organic compounds and six proteins was examined in poly(ethylene glycol)-8000-sodium sulfate aqueous two-phase systems containing 0.215M NaCl and 0.5M osmolyte (sorbitol, sucrose, TMAO) and poly(ethylene glycol)-10000-sodium sulfate-0.215M NaCl system, all in 0.01M sodium phosphate buffer, pH 6.8. The differences between the solvent properties of the coexisting phases (solvent dipolarity/polarizability, hydrogen bond donor acidity, and hydrogen bond acceptor basicity) were characterized with solvatochromic dyes using the solvatochromic comparison method. Differences between the electrostatic properties of the phases were determined by analysis of partitioning of sodium salts of dinitrophenylated (DNP-) amino acids with aliphatic alkyl side-chain. The partition coefficients of all compounds examined (including proteins) were described in terms of solute-solvent interactions. The results obtained in the study show that solute-solvent interactions of nonionic organic compounds and proteins in polyethylene glycol-sodium sulfate aqueous two-phase system change in the presence of NaCl additive.

  8. Two-Phase Thermal Switching System for a Small, Extended Duration Lunar Surface Science Platform

    Science.gov (United States)

    Bugby, David C.; Farmer, Jeffery T.; OConnor, Brian F.; Wirzburger, Melissa J.; Abel, Elisabeth D.; Stouffer, Chuck J.

    2010-01-01

    This paper describes a novel thermal control system for the Warm Electronics Box (WEB) on board a small lunar surface lander intended to support science activities anywhere on the lunar surface for an extended duration of up to 6 years. Virtually all lander electronics, which collectively dissipate about 60 W in the reference mission, are contained within the WEB. These devices must be maintained below 323 K (with a goal of 303 K) during the nearly 15-earth-day lunar day, when surface temperatures can reach 390K, and above 263 K during the nearly 15-earth-day lunar night, when surface temperatures can reach 100K. Because of the large temperature swing from lunar day-to-night, a novel thermal switching system was required that would be able to provide high conductance from WEB to radiator(s) during the hot lunar day and low (or negligible) conductance during the cold lunar night. The concept that was developed consists of ammonia variable conductance heat pipes (VCHPs) to collect heat from WEB components and a polymer wick propylene loop heat pipe (LHP) to transport the collected heat to the radiator(s). The VCHPs autonomously maximize transport when the WEB is warm and autonomously shut down when the WEB gets cold. The LHP autonomously shuts down when the VCHPs shut down. When the environment transitions from lunar night to day, the VCHPs and LHP autonomously turn back on. Out of 26 analyzed systems, this novel arrangement was able to best achieve the combined goals of zero control power, autonomous operation, long life, low complexity, low T, and landed tilt tolerance.

  9. Measurement of two-phase particle flow based on the characteristics of particle-system scattering

    Science.gov (United States)

    Li, Min; Zhang, Yang; Wang, Yuan; Yang, Bin

    2017-02-01

    Precise measurement of the mass of moving particles (MPM) is fundamental to the research on particle flows. In non-intrusive optical measurements, traditional discrete methods obtain the MPM by determining the connected domains on experimental pictures, leading to inevitable errors. In this study, the constitutive relationship between the MPM and the foreground grey scale value of the experimental picture is investigated on the basis of the working principle of digital cameras and the scattering theory of particle systems. This relationship is confirmed to be effective in wind-blown sand particle flow experiments using high-speed photography.

  10. Chemiluminescence detection of organic peroxides in a two-phase system.

    Science.gov (United States)

    Baj, Stefan; Krawczyk, Tomasz

    2007-02-28

    Potential application of chemiluminescence (CL) reaction of luminol for detection of organic peroxides by HPLC post-column reaction using an immiscible apolar eluent (hexane) with aqueous solution of luminol has been proposed. The positive influence of the addition of an anionic surface-active agent--sodium dodecyl sulphate (SDS) to the luminol solution on the CL intensity has been observed. The sensitivity of the method is greater for peroxyacid and hydroperoxide tested, and lesser for diacyl peroxide as compared to system with polar eluent miscible with solution of luminol. Our interpretation of observed results based on the extraction efficiency, CL kinetics and microemulsion formation has been suggested.

  11. Partition of volatile compounds in pea globulin-maltodextrin aqueous two-phase system.

    Science.gov (United States)

    Nguyen, Thanh Dat; Lafarge, Céline; Murat, Chloé; Mession, Jean-Luc; Cayot, Nathalie; Saurel, Rémi

    2014-12-01

    This study is based on the assumption that the off-flavour of pea proteins might be decreased using the retention of volatile compounds by a mixture with another biopolymer. The partition of volatile compounds in an aqueous system containing pea protein and maltodextrins was followed under thermodynamic incompatibility conditions. Firstly, the phase diagram of the system was established. Then, the partition of aroma compounds between the phase rich in protein and the phase rich in maltodextrin was measured by SPME-GC-MS. There was a transfer of volatile compounds during phase separation. Variations of pH were also used to vary the retention of volatile compounds by proteins. The concentration of volatile compounds in protein solution at pH 2.4 was higher than at pH 7.2. It was possible to increase the transfer of volatile compounds from the phase rich in protein to the phase rich in maltodextrin using the effect of pH on protein denaturation.

  12. Numerical Simulation of One- and Two-Phase Flows in Propulsion Systems

    Science.gov (United States)

    Gilinsky, Mikhail; Verma, Arun; Hardin, Jay C.; Banerjee, Debrup; Blankson, Isaiah M.; Hendricks, Robert C.; Shvets, Alexander I.

    2003-01-01

    Four subprojects were conducted using analytical methods, numerical simulation and experimental tests: (A) Shock wave mitigation by spike-shaped blunt bodies with application for the purpose of drag, lift and longitudinal momentum optimization. The main result in this subproject is: application of a single needle against a supersonic flow provides higher benefits for blunt body drag reduction and heat transfer to the body than the application of multiple needles. (B) Solid particles, liquid and air jet injection through the front of a blunt body against a supersonic flow. In this case, the research conducted and analysis of multiple previous investigations in this area have shown essential benefits and preferable application of solid particle injection. (C) Comparison of different methods of fuel injection into supersonic duct flows. Preliminary numerical simulations and theoretical analysis show promising results for Telescope-shaped inlet applications in SCRAMJET; and (D) Development of an acoustic source location method for different applications including propulsion systems.

  13. Can affinity interactions influence the partitioning of glucose-6-phosphate dehydrogenase in two-phase aqueous micellar systems?

    Directory of Open Access Journals (Sweden)

    André M. Lopes

    2008-01-01

    Full Text Available In this work, we provide an investigation of the role and strength of affinity interactions on the partitioning of the glucose-6-phosphate dehydrogenase in aqueous two-phase micellar systems. These systems are constituted of micellar surfactant solutions and offer both hydrophobic and hydrophilic environments, providing selectivity to biomolecules. We studied G6PD partitioning in systems composed of the nonionic surfactants, separately, in the presence and absence of affinity ligands. We observed that G6PD partitions to the micelle-poor phase, owing to the strength of excluded-volume interactions in these systems that drive the protein to the micelle-poor phase, where there is more free volume available.

  14. Isolation and fractionation of CHO chromosomes in aqueous two phase systems using charged polymers and base specific macroligands.

    Science.gov (United States)

    Klaar, J; Kula, M R

    1986-02-01

    Chromosomes were isolated in a preparative scale by synchronisation of CHO cells with a double Thymidine block followed by an arrest in the metaphase by addition of Colcemid. Under proper cultivation conditions a mitotic index of 77% total cells could be routinely achieved. Bulk chromosome preparations free of nuclei and other subcellular particles have been obtained by low speed centrifugation followed by a 60 transfer countercurrent distribution using aqueous two phase systems composed of polyethylenglycol and dextran. The partition of CHO chromosomes previously purified in aqueous two phase systems were studied further to develop a protocol for the separation and isolation of individual chromosomes. Partition experiments with chromosomes changing the electrostatic phase potential by addition of charged PEG-derivatives suggest the existence of relatively highly charged chromosome groups. Most promising results with regard to separation were obtained using two PEG-derivatives, which interact specifically with the bases in DNA. For this affinity partitioning a GC- and AT-specific macroligand were employed. Comparing CCD's using each of these ligands information on the GC and AT content of exposed DNA in the chromosomes groups could be derived, demonstrating that specific sequences of DNA are accessible at the surface of metaphase chromosomes.

  15. Influence of ultrasonic condition on phase transfer catalyzed radical polymerization of methyl methacrylate in two phase system - A kinetic study.

    Science.gov (United States)

    Marimuthu, Elumalai; Murugesan, Vajjiravel

    2017-09-01

    An ultrasonic condition assisted phase transfer catalyzed radical polymerization of methyl methacrylate was investigated in an ethyl acetate/water two phase system at 60±1°C and 25kHz, 300W under inert atmosphere. The influence of monomer, initiator, catalyst and temperature, volume fraction of aqueous phase on the rate of polymerization was examined in detail. The reaction order was found to be unity for monomer, initiator and catalyst. Generally, the reaction rate was relatively fast in two phase system, when a catalytic amount of phase transfer catalyst was used. The combined approach, use of ultrasonic and PTC condition was significantly enhances the rate of polymerization. An ultrasonic and phase transfer catalyzed radical polymerization of methyl methacrylate has shown about three fold enhancements in the rate compared with silent polymerization of MMA using cetyltrimethylammonium bromide as PTC. The resultant kinetics was evaluated with silent polymerization and an important feature was discussed. The activation energy and other thermodynamic parameters were computed. Based on the obtained results an appropriate radical mechanism has been derived. TGA showed the polymer was stable up to 150°C. The FT-IR and DSC analysis validates the atactic nature of the obtained polymer. The XRD pattern reveals the amorphous nature of polymer was dominated. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. A resolution approach of racemic phenylalanine with aqueous two-phase systems of chiral tropine ionic liquids.

    Science.gov (United States)

    Wu, Haoran; Yao, Shun; Qian, Guofei; Yao, Tian; Song, Hang

    2015-10-30

    Aqueous two-phase systems (ATPS) based on tropine type chiral ionic liquids and inorganic salt solution were designed and prepared for the enantiomeric separation of racemic phenylalanine. The phase behavior of IL-based ATPS was comprehensive investigated, and phase equilibrium data were correlated by Merchuk equation. Various factors were also systematically investigated for their influence on separation efficiency. Under the appropriate conditions (0.13g/g [C8Tropine]pro, 35mg/g Cu(Ac)2, 20mg/g d,l-phenylalanine, 0.51g/g H2O and 0.30g/g K2HPO4), the enantiomeric excess value of phenylalanine in solid phase (mainly containing l-enantiomer) was 65%. Finally, the interaction mechanism was studied via 1D and 2D NMR. The results indicate that d-enantiomer of phenylalanine interacts more strongly with chiral ILs and Cu(2+) based on the chiral ion-pairs space coordination mechanism, which makes it tend to remain in the top IL-rich phase. By contrast, l-enantiomer is transferred into the solid phase. Above chiral ionic liquids aqueous two-phase systems have demonstrated obvious resolution to racemic phenylalanine and could be promising alterative resolution approach for racemic amino acids in aqueous circumstance.

  17. A novel anaerobic two-phase system for biohydrogen production and in situ extraction of organic acid byproducts.

    Science.gov (United States)

    Sarma, Saurabh Jyoti; Brar, Satinder Kaur; Le Bihan, Yann; Buelna, Gerardo

    2015-06-01

    Owing to CO2-free emission, hydrogen is considered as a potential green alternative of fossil fuels. Water is the major emission of hydrogen combustion process and gravimetric energy density of hydrogen is nearly three times more than that of gasoline and diesel fuel. Biological hydrogen production, therefore, has commercial significance; especially, when it is produced from low-cost industrial waste-based feedstock. Light independent anaerobic fermentation is simple and mostly studied method of biohydrogen production. During hydrogen production by this method, a range of organic acid byproducts are produced. Accumulation of these byproducts is inhibitory for hydrogen production as it may result in process termination due to sharp decrease in medium pH or by possible metabolic shift. For the first time, therefore, a two-phase anaerobic bioreactor system has been reported for biohydrogen production which involves in situ extraction of different organic acids. Among different solvents, based on biocompatibility oleyl alcohol has been chosen as the organic phase of the two-phase system. An organic:aqueous phase ratio of 1:50 has been found to be optimum for hydrogen production. The strategy was capable of increasing the hydrogen production from 1.48 to 11.65 mmol/L-medium.

  18. Numerical Simulation of One- and Two-Phase Flows in Propulsion Systems

    Science.gov (United States)

    Gilinsky, Mikhail; Patel, Kaushal; Alexander, Casey; Thompson, Tyesha; Blankson, Isaiah M.; Shvets, Alexander I.; Gromov, Valery G.; Sakharov, Vladimir I.

    2001-01-01

    In this report, we present some results of problems investigated during joint research between the Hampton University Fluid Mechanics and Acoustics Laboratory (HU/FM&AL), NASA GRC, and the LaRC Hyper-X Program. This work is supported by joint research between the NASA GRC and the Institute of Mechanics at Moscow State University (IM/MSU) in Russia under a CRDF grant. The main areas of current scientific interest of the HU/FM&AL include an investigation of the proposed and patented advanced methods for aircraft engine thrust and noise benefits. These methods are based on nontraditional 3D corrugated and composite nozzle, inlet, propeller and screw designs such as a Bluebell and Telescope nozzle, Mobius-shaped screw, etc. This is the main subject of our other projects, of which one is presented at the current conference. Here we analyze additional methods for exhaust jet noise reduction without essential thrust loss and even with thrust augmentation. Such additional approaches are: (1) to add some solid, fluid, or gas mass at discrete locations to the main supersonic gas stream to minimize the negative influence of strong shock waves formed in propulsion systems. This mass addition may be accompanied by heat addition to the main stream as a result of the fuel combustion or by cooling of this stream as a result of the liquid mass evaporation and boiling; (2) Use of porous or permeable nozzles and additional shells at the nozzle exit for preliminary cooling of the hot jet exhaust and pressure compensation for off-design conditions (so-called continuous ejector with small mass flow rate); and (3) to propose and analyze new effective methods of fuel injection into the flow stream in air-breathing engines. The research is focused on a wide regime of problems in the propulsion field as well as in experimental testing and theoretical and numerical simulation analyses for advanced aircraft and rocket engines. The FM&AL Team uses analytical methods, numerical simulations, and

  19. Smoking and Your Digestive System

    Science.gov (United States)

    ... the risk of H. pylori infection, slows the healing of peptic ulcers, and increases the likelihood that peptic ulcers will recur. The stomach and duodenum contain acids, enzymes, and other substances that help digest food. However, these substances may also harm the lining ...

  20. Design of aqueous two-phase systems for purification of hyaluronic acid produced by metabolically engineered Lactococcus lactis.

    Science.gov (United States)

    Rajendran, Vivek; Puvendran, Kirubhakaran; Guru, Bharath Raja; Jayaraman, Guhan

    2016-02-01

    Hyaluronic acid has a wide range of biomedical applications and its commercial value is highly dependent on its purity and molecular weight. This study highlights the utility of aqueous two-phase separation as a primary recovery step for hyaluronic acid and for removal of major protein impurities from fermentation broths. Metabolically engineered cultures of a lactate dehydrogenase mutant strain of Lactococcus lactis (L. lactis NZ9020) were used to produce high-molecular-weight hyaluronic acid. The cell-free fermentation broth was partially purified using a polyethylene glycol/potassium phosphate system, resulting in nearly 100% recovery of hyaluronic acid in the salt-rich bottom phase in all the aqueous two-phase separation experiments. These experiments were optimized for maximum removal of protein impurities in the polyethylene glycol rich top phase. The removal of protein impurities resulted in substantial reduction of membrane fouling in the subsequent diafiltration process, carried out with a 300 kDa polyether sulfone membrane. This step resulted in considerable purification of hyaluronic acid, without any loss in recovery and molecular weight. Diafiltration was followed by an adsorption step to remove minor impurities and achieve nearly 100% purity. The final hyaluronic acid product was characterized by Fourier-transform IR and NMR spectroscopy, confirming its purity.

  1. Comparative assessment of olive oil mill effluents from three-phase and two-phase systems, treated for hydrogen production.

    Science.gov (United States)

    Rouvalis, A; Iliopoulou-Georgudaki, J

    2010-10-01

    By-products of a two-phase and a three-phase olive oil mill process treated in an anaerobic fermentation system for hydrogen production, were evaluated by three bioassays: the zebrafish Danio rerio embryo test and two microbiotests, Thamnotoxkit F and Daphtoxkit F™ pulex. Samples from both processes were classified as "very toxic" with LC(50) values ranging from 1.52% (T. platyurus 24 h test) to 4.48% (D. pulex 48 h-LC₅₀). Toxicity values were differently correlated to physicochemical parameters showing different degree of influence. The treated effluents of both process systems remained very toxic showing the necessity for further treatment, aiming to environmentally safe discharges.

  2. Measurement and Correlation of Partition Coefficients of Baicalin in EOPO/Salt Aqueous Two-Phase Systems

    Institute of Scientific and Technical Information of China (English)

    李伟; 朱自强

    2002-01-01

    The partition coefficients of baicalin were measured in ethylene oxide and propylene oxide(EOPO)/salt aqueous two-phase systems at 298.15K,It was found that most of baicalin partitioned into EOPO-rich phase.The partition coefficients of baicalin varied from 10 to 120.The effect of various factors,including tie-line lngth,salt composition,molecular weight of EOPO,and solution pH,on the partition behavior was investigated on EOPO/salt systems.Furthermore the partition coefficients of baicalin were correlated using the modified Diamond-Hsu model.Good agreement with experimental data is obtained.The average relative deviations are less than 5.0%.

  3. Design of functional guanidinium ionic liquid aqueous two-phase systems for the efficient purification of protein

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Xueqin; Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn; Zeng, Qun; Chen, Jing; Huang, Yanhua; Xu, Kaijia

    2014-03-01

    Graphical abstract: - Highlights: • A series of novel cationic functional hexaalkylguanidinium ionic liquids and anionic functional tetraalkylguanidinium ionic liquids have been synthesized. • Functional guanidinium ionic liquid aqueous two-phase systems have been first designed for the purification of protein. • Mechanisms and performances of the process were researched. • Simple, green, safety and presents better purified ability than ordinary process. • A potential efficient platform for protein purification and related studies. - Abstract: A series of novel cationic functional hexaalkylguanidinium ionic liquids and anionic functional tetraalkylguanidinium ionic liquids have been devised and synthesized based on 1,1,3,3-tetramethylguanidine. The structures of the ionic liquids (ILs) were confirmed by {sup 1}H nuclear magnetic resonance ({sup 1}H NMR) and 13C nuclear magnetic resonance (13C NMR) and the production yields were all above 90%. Functional guanidinium ionic liquid aqueous two-phase systems (FGIL-ATPSs) have been first designed with these functional guanidinium ILs and phosphate solution for the purification of protein. After phase separation, proteins had transferred into the IL-rich phase and the concentrations of proteins were determined by measuring the absorbance at 278 nm using an ultra violet visible (UV–vis) spectrophotometer. The advantages of FGIL-ATPSs were compared with ordinary ionic liquid aqueous two-phase systems (IL-ATPSs). The proposed FGIL-ATPS has been applied to purify lysozyme, trypsin, ovalbumin and bovine serum albumin. Single factor experiments were used to research the effects of the process, such as the amount of ionic liquid (IL), the concentration of salt solution, temperature and the amount of protein. The purification efficiency reaches to 97.05%. The secondary structure of protein during the experimental process was observed upon investigation using UV–vis spectrophotometer, Fourier-transform infrared

  4. Energetic and exploitation characteristics of a two-phase ejecting vacuum system built in the paper machine at A.D. Komuna Skopje

    Directory of Open Access Journals (Sweden)

    Šarevski Milan

    2004-01-01

    Full Text Available This work presents the concept of a two-phase ejecting vacuum system. The energetic characteristics of these systems were analyzed and compared to those with mechanical pumps with water ring and turbo compressor vacuum pumps. A method for optimizing a two-phase thermo compressor vacuum systems is presented. The analysis included the exploitation characteristics of the system developed at A.D. "Komuna" Skopje.

  5. Aqueous two-phase systems: A simple methodology to obtain mixtures enriched in main toxins of Bothrops alternatus venom.

    Science.gov (United States)

    Gomez, Gabriela; Leiva, Laura; Nerli, Bibiana Beatriz

    2016-08-01

    Phospholipase A2 (PLA2) and protease (P) are enzymes responsible of myotoxic, edematogenic and hemostasis disorder effects observed in the envenomation by Bothrops alternatus pitviper. Their partitioning coefficient (Kp) in different polyethyleneglycol/potassium phosphate aqueous two-phase systems (ATPSs) was determined in order to both achieve a better understanding of the partitioning mechanism and define optimal conditions for toxin isolation. Polyethyleneglycols (PEGs) of molecular weights 1000; 3350; 6000 and 8000; different temperatures (5, 20 and 37 °C) and phase volume ratios of 0.5; 1 and 2 were assayed. PLA2 partitioned preferentially to the top phase while P mainly distributed to the bottom phase. Either entropically- or enthalpically-driven mechanisms were involved in each case (PLA2 and P). The aqueous two-phase system formed by PEG of MW 3350 (12.20% wt/wt) and KPi pH 7.0 (11.82% wt/wt) with a volume ratio of one and a load of 1.25 mg of venom/g of system showed to be the most efficient to recover both enzymes. It allowed obtaining the 72% of PLA2 in the top phase with a purification factor of 2 and the 82% of P at the bottom phase simultaneously. A further adsorption batch step with DEAE-cellulose was used to remove satisfactorily the PEG from the top phase and recover the active PLA2. The proposed methodology is simple, inexpensive, and only requires professionals trained in handling basic laboratory equipment. It could be easily adoptable by developing countries in which the snakebite accidents cause considerable morbidity and mortality.

  6. Abdomen, digestive system; Abdomen, appareil digestif

    Energy Technology Data Exchange (ETDEWEB)

    Pradel, J. [Hopital Saint-Eloi, 34 - Montpellier (France); Siauve, N. [Hopital Laennec, 75 - Paris (France); Alexandre, M. [Centre Hospitalier Universitaire, 06 - Nice (France); Lorenzetti, J. [Centre Hospitalier Universitaire, 63 - Clermont Ferrand (France)

    1997-03-01

    The Radiological Society of North America (RNSA) ` 96 has devoted a broad part to abdomen and digestive imaging. we find hepatic pathology and comparative evaluation between computed tomography and NMR imaging. The question of contrast products and their advance in hepatic pathology are studied. The biliary tracts and MRI do not present any surprise. The pancreas with the computerized tomography and finally the digestive system, always with computerized tomography are exposed. (N.C.).

  7. Phase Diagrams of the Aqueous Two-Phase Systems of Poly(ethylene glycol/Sodium Polyacrylate/Salts

    Directory of Open Access Journals (Sweden)

    Adalberto Pessoa Junior

    2011-03-01

    Full Text Available Aqueous two-phase systems consisting of polyethylene glycol (PEG, sodium polyacrylate (NaPAA, and a salt have been studied. The effects of the polymer size, salt type (NaCl, Na2SO4, sodium adipate and sodium azelate and salt concentrations on the position of the binodal curve were investigated. The investigated PEG molecules had a molar mass of 2,000 to 8,000 g/mol, while that of NaPAA was 8,000 g/mol. Experimental phase diagrams, and tie lines and calculated phase diagrams, based on Flory-Huggins theory of polymer solutions are presented. Due to strong enthalpic and entropic balancing forces, the hydrophobicity of the added salt has a strong influence on the position of the binodal, which could be reproduced by model calculations.

  8. Design of functional guanidinium ionic liquid aqueous two-phase systems for the efficient purification of protein.

    Science.gov (United States)

    Ding, Xueqin; Wang, Yuzhi; Zeng, Qun; Chen, Jing; Huang, Yanhua; Xu, Kaijia

    2014-03-07

    A series of novel cationic functional hexaalkylguanidinium ionic liquids and anionic functional tetraalkylguanidinium ionic liquids have been devised and synthesized based on 1,1,3,3-tetramethylguanidine. The structures of the ionic liquids (ILs) were confirmed by (1)H nuclear magnetic resonance ((1)H NMR) and 13C nuclear magnetic resonance (13C NMR) and the production yields were all above 90%. Functional guanidinium ionic liquid aqueous two-phase systems (FGIL-ATPSs) have been first designed with these functional guanidinium ILs and phosphate solution for the purification of protein. After phase separation, proteins had transferred into the IL-rich phase and the concentrations of proteins were determined by measuring the absorbance at 278 nm using an ultra violet visible (UV-vis) spectrophotometer. The advantages of FGIL-ATPSs were compared with ordinary ionic liquid aqueous two-phase systems (IL-ATPSs). The proposed FGIL-ATPS has been applied to purify lysozyme, trypsin, ovalbumin and bovine serum albumin. Single factor experiments were used to research the effects of the process, such as the amount of ionic liquid (IL), the concentration of salt solution, temperature and the amount of protein. The purification efficiency reaches to 97.05%. The secondary structure of protein during the experimental process was observed upon investigation using UV-vis spectrophotometer, Fourier-transform infrared spectroscopy (FT-IR) and circular dichroism spectrum (CD spectrum). The precision, stability and repeatability of the process were investigated. The mechanisms of purification were researched by dynamic light scattering (DLS), determination of the conductivity and transmission electron microscopy (TEM). It was suggested that aggregation and embrace phenomenon play a significant role in the purification of proteins. All the results show that FGIL-ATPSs have huge potential to offer new possibility in the purification of proteins.

  9. Establishment of total ammonia-nitrogen accumulation prediction modelin two-phase anaerobic digestion of OFMSW and its verification%有机垃圾两相厌氧消化氨氮累积模型的建立及验证

    Institute of Scientific and Technical Information of China (English)

    贾传兴; 彭绪亚; 刘国涛

    2011-01-01

    Nitrogen transformation characteristic experiments of organic fraction of municipal solid waste (OFMSW) in a batch hydrolysis-UASB two-phase anaerobic digestion are carried out to solve the problems of total ammonia-nitrogen (TAN) accumulation and obtain appropriate key process control parameters. Based on the experiment results, TAN accumulation prediction model in the two-phase anaerobic digestion of OFMSW with digestive effluent reuse is established. And then with the prediction model analyzed, reflux ratio is obtained as a key process control parameter to prevent TAN accumulation. In the end, verification tests are designed to validate the feasibility and practicability of resolving TAN accumulation by controlling reflux ratio. In verifying experiment, when reflux ratio is set at 0.85, TAN concentration of UASB effluent is increased to a constant value, which is 1 900 mg/L. Furthermore, the accumulated TAN has no negative influence on the population and activity of methanogens, on the contrary, it develops the buffer capacity to acid and alkaline and keeps the anaerobic system more steadily. To sum up, a method of resolving the problem of TAN accumulation by controlling reflux ratio of digestive effluent has been ascertained radically, and the method can be used in the preventing of ammonia inhibition in two-phase anaerobic digestion process.%为解决消化液回用带来的氨氮累积问题,寻求关键控制参数,在序批式水解-UASB两相厌氧消化体系中对有机垃圾中各种氮素转化特性进行了试验研究;基于上述研究分析结果建立了消化液回用时有机垃圾两相厌氧消化氨氮累积模型,找出了消化液回用中氨氮累积的关键控制参数-回流比;并通过试验验证了当回流比为0.85时,系统内UASB出水氨氮浓度最终趋于一定值,约为1 900mg/L;此氨氮浓度并未对产甲烷反应器产生负面影响,反而提高了系统对酸碱的缓冲能力,保证了系统的稳定运行;从而

  10. Isolation of natural red colorants from fermented broth using ionic liquid-based aqueous two-phase systems.

    Science.gov (United States)

    Ventura, Sónia P M; Santos-Ebinuma, Valéria C; Pereira, Jorge F B; Teixeira, Maria F S; Pessoa, Adalberto; Coutinho, João A P

    2013-05-01

    There is a growing demand for natural colorants. This is prompting the search for new alternative and "benign" separation systems allowing higher recoveries, extraction yields, and selectivities. This work investigates the use of aqueous two-phase systems (ATPS) based on ionic liquids as extraction processes for the recovery of red colorants from the fermented broth of Penicillium purpurogenum DPUA 1275. Several ATPS based on quaternary ammonium and imidazolium were studied in this work aiming at separating the red colorants produced from the remaining colorants and contaminant proteins present in the fermented broth. The results suggest that the red colorants can be isolated by an appropriate manipulation of some of the process conditions, such as the use of quaternary ammonium with short alkyl chains, alkaline media, and short tie-line lengths (extraction point systems with lower concentrations of ionic liquid). These conditions allow large partition coefficients for the red colorants (K red = 24.4 ± 2.3), high protein removal (60.7 ± 2.8 %) and selectivity parameters (S red/prot = 10.05).

  11. Extraction and purification of anthraquinones derivatives from Aloe vera L. using alcohol/salt aqueous two-phase system.

    Science.gov (United States)

    Tan, Zhi-jian; Li, Fen-fang; Xu, Xue-lei

    2013-08-01

    An alcohol/salt aqueous two-phase system (ATPS) composed of 1-propanol and (NH4)2SO4 was employed to purify anthraquinones (AQs) extracted from Aloe vera L. The main influencing system parameters such as type of alcohol, type and concentration of salt, temperature and pH were investigated in detail. Under the optimal extraction conditions, AQs can be extracted into alcohol-rich phase with high extraction efficiency, meanwhile majority polysaccharides, proteins, mineral substances and other impurities were extracted into salt-rich phase. Partitioning of AQs is dependent on hydrophobic interaction, hydrogen bond interaction, and salting-out effect in ATPS. Temperature also played a great role in the partitioning. After ATPS extraction, alcohol can be recycled by evaporation; moreover, salt can be recycled by dilution crystallization method. Compared with other liquid-liquid extractions, this alcohol/salt system is much simpler, lower in cost with easier recovery of phase-forming components, which has the potential scale-up in down-processing of active ingredients in plant.

  12. Modeling and investigation of refrigeration system performance with two-phase fluid injection in a scroll compressor

    Science.gov (United States)

    Gu, Rui

    Vapor compression cycles are widely used in heating, refrigerating and air-conditioning. A slight performance improvement in the components of a vapor compression cycle, such as the compressor, can play a significant role in saving energy use. However, the complexity and cost of these improvements can block their application in the market. Modifying the conventional cycle configuration can offer a less complex and less costly alternative approach. Economizing is a common modification for improving the performance of the refrigeration cycle, resulting in decreasing the work required to compress the gas per unit mass. Traditionally, economizing requires multi-stage compressors, the cost of which has restrained the scope for practical implementation. Compressors with injection ports, which can be used to inject economized refrigerant during the compression process, introduce new possibilities for economization with less cost. This work focuses on computationally investigating a refrigeration system performance with two-phase fluid injection, developing a better understanding of the impact of injected refrigerant quality on refrigeration system performance as well as evaluating the potential COP improvement that injection provides based on refrigeration system performance provided by Copeland.

  13. Purification of C-phycocyanin from Spirulina platensis in aqueous two-phase systems using an experimental design

    Directory of Open Access Journals (Sweden)

    Francine Silva Antelo

    2015-02-01

    Full Text Available C-phycocyanin from Spirulina platensis was purified in aqueous two-phase systems (ATPS of polyethylene glycol (PEG/potassium phosphate, varying the molar mass of the PEG. Results using a full factorial design showed that an increase in the concentration of salt and decrease in the concentration of PEG caused an increment in the purification factor for all the ATPS studied. Optimization of the conditions of the purification was studied using a central composite rotatable design for each molar mass of PEG. The ATPS composed of 7% (w/w PEG 1500 or 4% (w/w PEG 8000 (g/gmol and 23 or 22.5% (w/w of phosphate resulted a purification factor of 1.6-fold for C-phycocyanin, with total and 57% recovery, respectively. Process conditions were optimized for the purification factor for the system with PEG 1500. The ATPS with 4% (w/w PEG 4000 or 4% (w/w PEG 6000 and 21% (w/w phosphate resulted purification factors of 2.1 and 2.2-fold, recovering 100% and 73.5%, respectively of C-phycocyanin in the top phase.

  14. Partitioning of L-methionine in aqueous two-phase systems containing poly(propylene glycol) and sodium phosphate salts

    Energy Technology Data Exchange (ETDEWEB)

    Salabat, Alireza, E-mail: a-salabat@araku.ac.ir [Chemistry Department, Arak University, P.O. Box 38156-879, Arak (Iran, Islamic Republic of); Sadeghi, Rahmat [Department of Chemistry, University of Kurdistan, Sanandaj, Kurdistan 66135 (Iran, Islamic Republic of); Moghadam, Somayeh Tiani [Chemistry Department, Arak University, P.O. Box 38156-879, Arak (Iran, Islamic Republic of); Jamehbozorg, Bahman [Department of Chemistry, University of Kurdistan, Sanandaj, Kurdistan 66135 (Iran, Islamic Republic of)

    2011-10-15

    Highlights: > Thermodynamics parameters for partitioning of L-methionine in ATPS. > Investigation of different effects on partition coefficient of the amino acid. > Propose the best condition for L-methionine partitioning. - Abstract: The partitioning behavior of L-methionine has been studied in aqueous two-phase systems of (poly(propylene glycol) + sodium phosphate salts + H{sub 2}O) at different temperatures. The salts used were sodium di-hydrogen phosphate (NaH{sub 2}PO{sub 4}), di-sodium hydrogen phosphate (Na{sub 2}HPO{sub 4}) and tri-sodium phosphate (Na{sub 3}PO{sub 4}). The effects of tie line length, salt type, and temperature on the partition coefficient of this amino acid have been studied. In addition, thermodynamic parameters ({Delta}H{sup o}, {Delta}S{sup o} and {Delta}G{sup o}) as a function of temperature were calculated. The results showed that increasing tie line length led to decreasing of the partition coefficient. We also showed that the partition coefficients of the amino acid in the systems containing Na{sub 3}PO{sub 4} are greater than the other two salts. Moreover, it is verified that increasing temperature led to decreasing the partition coefficient. The experimental partition coefficient data are correlated using a modified virial-type model.

  15. Extraction and purification of wheat-esterase using aqueous two-phase systems of ionic liquid and salt.

    Science.gov (United States)

    Jiang, Bin; Feng, Zhibiao; Liu, Chunhong; Xu, Yingcao; Li, Dongmei; Ji, Guo

    2015-05-01

    To explore a new and simple rapid extraction and purification technique for wheat-esterase, an ionic liquids (ILs)-based aqueous two-phase system (ATPS) was developed for the purification of wheat-esterase from wheat extracts. Effects of various process parameters such as the concentrations of [Bmim]BF4, the types and concentrations of phase-forming salt, the system pH and the temperature on partitioning of wheat-esterase were evaluated. The obtained data indicated that wheat-esterase was preferentially partitioned into the ILs-rich phase and the ATPS composed of 20 % [Bmim]BF4 (w/w) and 25 % (w/w) NaH2PO4(pH = 4.8) showed good selectivity on wheat-esterase. Under the optimum conditions, wheat-esterase was purified with an acceptable yield (88.93 %), but produced wheat-esterase was 4.23 times as pure. It was obvious that temperature shows little influence on the purification between 10 and 50 °C. Sephadex G-150FF revealed that the band intensity of contaminating proteins in ATPS fraction almost disappeared. Therefore, ILs-based ATPS was an effective method for partitioning and recovery of wheat-esterase from wheat crude extracts.

  16. Development of tropine-salt aqueous two-phase systems and removal of hydrophilic ionic liquids from aqueous solution.

    Science.gov (United States)

    Wu, Haoran; Yao, Shun; Qian, Guofei; Song, Hang

    2016-08-26

    A novel aqueous two-phase systems (ATPS) composed of a small molecule organic compound tropine and an organic or inorganic salt aqueous solution has been developed for the first time. The phase behavior of tropine-salt ATPS was systemically investigated and the phase equilibrium data were measured in different temperatures and concentrations and correlated by the Merchuk equation with satisfactory results. The detection of the conductivity and particle size proved the formation of micelle in the process of forming tropine-salt ATPS. The separation application of the ATPS was assessed with the removal of hydrophilic benzothiazolium-based ionic liquids (ILs) from aqueous solution. The result showed that ILs were effectively extracted into the top tropine-rich phase. Finally, ILs in the top tropine-rich phase were further separated by the means of adsorption-desorption with DM301 macroporous resin and ethanol. The method of novel tropine-salt ATPS combined with adsorption-desorption is demonstrated a promising alternative thought and approach for the removal or recovery of hydrophilic compounds from aqueous media and also could provide a potential application for bio-separation.

  17. Characterization of aqueous two phase systems by combining lab-on-a-chip technology with robotic liquid handling stations.

    Science.gov (United States)

    Amrhein, Sven; Schwab, Marie-Luise; Hoffmann, Marc; Hubbuch, Jürgen

    2014-11-07

    Over the last decade, the use of design of experiment approaches in combination with fully automated high throughput (HTP) compatible screenings supported by robotic liquid handling stations (LHS), adequate fast analytics and data processing has been developed in the biopharmaceutical industry into a strategy of high throughput process development (HTPD) resulting in lower experimental effort, sample reduction and an overall higher degree of process optimization. Apart from HTP technologies, lab-on-a-chip technology has experienced an enormous growth in the last years and allows further reduction of sample consumption. A combination of LHS and lab-on-a-chip technology is highly desirable and realized in the present work to characterize aqueous two phase systems with respect to tie lines. In particular, a new high throughput compatible approach for the characterization of aqueous two phase systems regarding tie lines by exploiting differences in phase densities is presented. Densities were measured by a standalone micro fluidic liquid density sensor, which was integrated into a liquid handling station by means of a developed generic Tip2World interface. This combination of liquid handling stations and lab-on-a-chip technology enables fast, fully automated, and highly accurate density measurements. The presented approach was used to determine the phase diagram of ATPSs composed of potassium phosphate (pH 7) and polyethylene glycol (PEG) with a molecular weight of 300, 400, 600 and 1000 Da respectively in the presence and in the absence of 3% (w/w) sodium chloride. Considering the whole ATPS characterization process, two complete ATPSs could be characterized within 24h, including four runs per ATPS for binodal curve determination (less than 45 min/run), and tie line determination (less than 45 min/run for ATPS preparation and 8h for density determination), which can be performed fully automated over night without requiring man power. The presented methodology provides

  18. Salt effect on the (polyethylene glycol 8000 + sodium sulfate) aqueous two-phase system: Relative hydrophobicity of the equilibrium phases

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Luisa A., E-mail: laferreira@deb.uminho.pt [IBB - Institute for Biotechnology and Bioengineering, Centre for Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Teixeira, Jose A. [IBB - Institute for Biotechnology and Bioengineering, Centre for Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal)

    2011-08-15

    Highlights: > Gibbs free energy of transfer of a methylene group on PEG 8000 - Na{sub 2}SO{sub 4} ATPS. > Influence of salt additive on the hydrophobic character of the coexisting phases. > Partitioning behavior of a series of five sodium salts of DNP-amino acids. > A relationship between {Delta}G(CH{sub 2}), TLL and I of the salt additive was established. - Abstract: The relative hydrophobicity of the phases of several {l_brace}polyethylene glycol (PEG) 8000 + sodium sulfate (Na{sub 2}SO{sub 4}){r_brace} aqueous two-phase systems (ATPSs), all containing 0.01 mol . L{sup -1} sodium phosphate buffer (NaPB, pH 7.4) and increasing concentration of a salt additive, NaCl or KCl, up to 1.0 mol . L{sup -1}, was measured by the free energy of transfer of a methylene group between the phases, {Delta}G(CH{sub 2}). The {Delta}G(CH{sub 2}) of the systems was determined by partitioning of a homologous series of five sodium salts of dinitrophenylated (DNP) - amino acids with aliphatic side chains in three different tie-lines of each biphasic system. The relative hydrophobicity of the phases ranged from -0.125 to -0.183 kcal . mol{sup -1}, being the NaCl salt the one to provide the more effective changes. The results show that, within each system, there is a linear relationship between the {Delta}G(CH{sub 2}) and the tie-line length (TLL), and biphasic systems with high salt additive concentration present the most negative {Delta}G(CH{sub 2}) values. Therefore, the feasibility of establishing a relationship between the relative hydrophobicity of the phases in a given TLL and the ionic strength of the salt additive was investigated and a satisfactory correlation was found for each salt.

  19. Two phase sampling

    CERN Document Server

    Ahmad, Zahoor; Hanif, Muhammad

    2013-01-01

    The development of estimators of population parameters based on two-phase sampling schemes has seen a dramatic increase in the past decade. Various authors have developed estimators of population using either one or two auxiliary variables. The present volume is a comprehensive collection of estimators available in single and two phase sampling. The book covers estimators which utilize information on single, two and multiple auxiliary variables of both quantitative and qualitative nature. Th...

  20. Extraction of natural red colorants from the fermented broth of Penicillium purpurogenum using aqueous two-phase polymer systems.

    Science.gov (United States)

    Santos-Ebinuma, Valéria Carvalho; Lopes, André Moreni; Pessoa, Adalberto; Teixeira, Maria Francisca Simas

    2015-01-01

    Safety concerns related to the increasing and widespread application of synthetic coloring agents have increased the demand for natural colorants. Fungi have been employed in the production of novel and safer colorants. In order to obtain the colorants from fermented broth, suitable extraction systems must be developed. Aqueous two-phase polymer systems (ATPPS) offer a favorable chemical environment and provide a promising alternative for extracting and solubilizing these molecules. The aim of this study was to investigate the partitioning of red colorants from the fermented broth of Penicillium purpurogenum using an ATPPS composed of poly(ethylene glycol) (PEG) and sodium polyacrylate (NaPA). Red colorants partitioned preferentially to the top (PEG-rich phase). In systems composed of PEG 6,000 g/mol/NaPA 8,000 g/mol, optimum colorant partition coefficient (KC ) was obtained in the presence of NaCl 0.1 M (KC  = 10.30) while the PEG 10,000 g/mol/NaPA 8,000 g/mol system in the presence of Na2 SO4 0.5 M showed the highest KC (14.78). For both polymers, the mass balance (%MB) and yield in the PEG phase (%ηTOP ) were close to 100 and 79%, respectively. The protein selectivity in all conditions evaluated ranged from 2.0-3.0, which shows a suitable separation of the red colorants and proteins present in the fermented broth. The results suggest that the partitioning of the red colorants is dependent on both the PEG molecular size and salt type. Furthermore, the results obtained support the potential application of ATPPS as the first step of a purification process to recover colorants from fermented broth of microorganisms.

  1. Phase behavior and molecular dynamics simulation studies of new aqueous two-phase separation systems induced by HEPES buffer.

    Science.gov (United States)

    Taha, Mohamed; Khoiroh, Ianatul; Lee, Ming-Jer

    2013-01-17

    Here, for the first time, we show that with addition of a biological buffer, 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES), into aqueous solutions of tetrahydrofuran (THF), 1,3-dioxolane, 1,4-dioxane, 1-propanol, 2-propanol, tert-butanol, acetonitrile, or acetone, the organic solvent can be excluded from water to form a new liquid phase. The phase diagrams have been determined at ambient temperature. In order to understand why and how a zwitterion solute (HEPES) induced phase separation of the investigated systems, molecular dynamics (MD) simulation studies are performed for HEPES + water + THF system. The MD simulations were conducted for the aqueous mixtures with 12 different compositions. The reliability of the simulation results of HEPES in pure water and beyond the phase separation mixtures was justified by comparing the densities obtained from MD with the experimental values. The simulation results of HEPES in pure THF and in a composition inside the phase separation region were justified qualitatively. Interestingly, all HEPES molecules entirely aggregated in pure THF. This reveals that HEPES is insoluble in pure THF, which is consistent with the experimental results. Even more interestingly, the MD simulation for the mixture with composition inside the phase separation region showed the formation of two phases. The THF molecules are squeezed out from the water network into a new liquid phase. The hydrogen bonds (HBs), HB lifetime, HB Gibbs energy (ΔG), radial distribution functions (RDFs), coordination numbers (CNs), electrostatic interactions, and the van der Waals interactions between the different species have been analyzed. Further, MD simulations for the other phase separation systems by choosing a composition inside the two liquids region for each system were also simulated. Our findings will therefore pave the way for designing new benign separation auxiliary agents.

  2. Microcalorimetric Study on the Oscillating System of Two-phase Reaction of Aqueous Acid with Primary Amine in Chloroform

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Hong-Lin; YU,Xiu-Fang; LU,Cheng-Xue; SUN,Si-Xiu; GUO,Guo-Hua; FU,Xun

    2003-01-01

    It has been found that the two-phase reactions of aqueous HCl,HOAc or H3PO4 with primary amine N1923 in chloroform are oscillating reactions. Their power-time curves were measured by the titration microcalorimetric method, and the induction period (tin).The first oscillating period (tp.1) and the second oscillating period(tp.2 ) were determined.The apparent activating parameters and the orders of the oscillating systems were calculated and the following relationships were established: for the oscillating system of hydrochloric acid tin∝c0.147HCIexp(1.35×103/T),.tp.1∝c0.241HCI·exp(4.33×103/T),tp.2∝c0.290HCIexp(5.59×103/T);for the oscillating system of acetic acid, tm∝c0.883HOAcexp(2.32×103/T),tp.1∝c0.399HOAc·exp(4.50×103/T),tp.2∝c0.301HOAcexp(5.88×103/T),for the oscillating system of phosphoric acid, tim∝c1.14H3PO4exp(7.70×104]T),tp.1∝c1.42H3PO4exp(1.14×104/T),tp.2∝c1.47H3PO4exp(1.27×104/T).

  3. Separation of active laccases from Pleurotus sapidus culture supernatant using aqueous two-phase systems in centrifugal partition chromatography.

    Science.gov (United States)

    Schwienheer, C; Prinz, A; Zeiner, T; Merz, J

    2015-10-01

    For the production of bio active compounds, e.g., active enzymes or antibodies, a conserved purification process with a minimum loss of active compounds is necessary. In centrifugal partition chromatography (CPC), the separation effect is based on the different distribution of the components to be separated between two immiscible liquid phases. Thereby, one liquid phase is kept stationary in chambers by a centrifugal field and the mobile phase is pumped through via connecting ducts. Aqueous two phase systems (ATPS) are known to provide benign conditions for biochemical products and seem to be promising when used in CPC for purification tasks. However, it is not known if active biochemical compounds can "survive" the conditions in a CPC where strong shear forces can occur due to the two-phasic flow under centrifugal forces. Therefore, this aspect has been faced within this study by the separation of active laccases from a fermentation broth of Pleurotus sapidus. After selecting a suitable ATPS and operating conditions, the activity yield was calculated and the preservation of the active enzymes could be observed. Therefore, CPC could be shown as potentially suitable for the purification of bio-active compounds.

  4. Development of green betaine-based deep eutectic solvent aqueous two-phase system for the extraction of protein.

    Science.gov (United States)

    Li, Na; Wang, Yuzhi; Xu, Kaijia; Huang, Yanhua; Wen, Qian; Ding, Xueqin

    2016-05-15

    Six kinds of new type of green betaine-based deep eutectic solvents (DESs) have been synthesized. Deep eutectic solvent aqueous two-phase systems (DES-ATPS) were established and successfully applied in the extraction of protein. Betaine-urea (Be-U) was selected as the suitable extractant. Single factor experiments were carried out to determine the optimum conditions of the extraction process, such as the salt concentration, the mass of DES, the separation time, the amount of protein, the temperature and the pH value. The extraction efficiency could achieve to 99.82% under the optimum conditions. Mixed sample and practical sample analysis were discussed. The back extraction experiment was implemented and the back extraction efficiency could reach to 32.66%. The precision experiment, repeatability experiment and stability experiment were investigated. UV-vis, FT-IR and circular dichroism (CD) spectra confirmed that the conformation of protein was not changed during the process of extraction. The mechanisms of extraction were researched by dynamic light scattering (DLS), the measurement of the conductivity and transmission electron microscopy (TEM). DES-protein aggregates and embraces phenomenon play considerable roles in the separation process. All of these results indicated that betaine-based DES-ATPS may provide a potential substitute new method for the separation of proteins.

  5. Evidence for Two Phases of Galaxy Formation from Radial Trends in the Globular Cluster System of NGC 1407

    CERN Document Server

    Forbes, Duncan; Strader, Jay; Romanowsky, Aaron; Brodie, Jean; Foster, Caroline

    2011-01-01

    Here we present the colours of individual globular clusters (GCs) around the massive elliptical galaxy NGC 1407 out to a projected galactocentric radius of 140 kpc or 17 galaxy effective radii (R$_e$). Such data are a proxy for the halo metallicity. We find steep, and similar, metallicity gradients of ~ -0.4 dex per dex for both the blue (metal-poor) and red (metal-rich) GC subpopulations within 5-8.5 R_e (40-70 kpc). At larger radii the mean GC colours (metallicity) are constant. A similar behaviour is seen in a wide-field study of M87's GC system, and in our own Galaxy. We interpret these radial metallicity trends to indicate an inner region formed by early in-situ dissipative processes and an outer halo formed by ongoing accretion of low mass galaxies and their GCs. These results provide observational support for the model of galaxy formation whereby massive galaxies form inside-out in two phases. We have also searched the literature for other massive early-type galaxies with reported GC metallicity gradie...

  6. Relative hydrophobicity between the phases and partition of cytochrome-c in glycine ionic liquids aqueous two-phase systems.

    Science.gov (United States)

    Wu, Changzeng; Wang, Jianji; Li, Zhiyong; Jing, Jun; Wang, Huiyong

    2013-08-30

    In this work, glycine ionic liquids tetramethylammonium glycine ([N1111][Gly]), tetraethylammonium glycine ([N2222][Gly]), tetra-n-butylammonium glycine ([N4444][Gly]), tetra-n-butylphosphonium glycine ([P4444][Gly]) and tetra-n-pentylammonium glycine ([N5555][Gly]) were synthesized and used to prepare aqueous two-phase systems (ATPSs) in the presence of K2HPO4. Binodal curves of such ATPSs and partition coefficients of a series of dinitrophenylated (DNP) amino acids in these ATPSs were determined at 298.15K to understand the effect of cationic structure of the ionic liquids on the phase-forming ability of glycine ionic liquids, relative hydrophobicity between the phases in the ionic liquids ATPSs, and polarity of the ionic liquids-rich phases. With the attempt to correlate the relative hydrophobicity of the phases in the ATPSs with their extraction capability for proteins, partition coefficients of cytochrome-c in the ATPSs were also determined. It was shown that partition coefficients of cytochrome-c were in the range from 2.83 to 20.7 under the studied pH conditions. Then, hydrophobic interactions between cytochrome-c and the ionic liquid are suggested to be the main driving force for the preferential partition of cytochrome-c in the glycine ionic liquid-rich phases of the ATPSs. Result derived from polarity of the ionic liquids-rich phases supports this mechanism.

  7. Formation and characteristics of aqueous two-phase systems formed by a cationic surfactant and a series of ionic liquids.

    Science.gov (United States)

    Wei, Xi-Lian; Wang, Xiu-Hong; Ping, A-Li; Du, Pan-Pan; Sun, De-Zhi; Zhang, Qing-Fu; Liu, Jie

    2013-11-15

    Aqueous two-phase systems (ATPS) were obtained in the aqueous mixtures of a cationic surfactant and a series of ionic liquids (ILs). The effects of IL structure, temperature and additives on the phase separation were systematically investigated. The microstructures of some ATPS were observed by freeze-fracture replication technique. Lyotropic liquid crystal was found in the bottom phase besides micelles under different conditions. Remarkably, both IL structure and additives profoundly affected the formation and properties of the ATPSs. The phase separation can be attributed to the existence of different aggregates and the cation-π interactions of the cationic surfactant with the ILs, which has a significant role in the formation of ATPS. The extraction capacity of the studied ATPS was also evaluated through their application in the extraction of two biosubstances. The results indicate that the ILs with BF4(-) as anion show much better extraction efficiencies than the corresponding ILs with Br(-) as anion do under the same conditions. l-Tryptophan was mainly distributed into the NPTAB-rich phase, while methylene blue and capsochrome were mainly in the IL-rich phase.

  8. Aqueous two-phase system patterning of detection antibody solutions for cross-reaction-free multiplex ELISA

    Science.gov (United States)

    Frampton, John P.; White, Joshua B.; Simon, Arlyne B.; Tsuei, Michael; Paczesny, Sophie; Takayama, Shuichi

    2014-05-01

    Accurate disease diagnosis, patient stratification and biomarker validation require the analysis of multiple biomarkers. This paper describes cross-reactivity-free multiplexing of enzyme-linked immunosorbent assays (ELISAs) using aqueous two-phase systems (ATPSs) to confine detection antibodies at specific locations in fully aqueous environments. Antibody cross-reactions are eliminated because the detection antibody solutions are co-localized only to corresponding surface-immobilized capture antibody spots. This multiplexing technique is validated using plasma samples from allogeneic bone marrow recipients. Patients with acute graft versus host disease (GVHD), a common and serious condition associated with allogeneic bone marrow transplantation, display higher mean concentrations for four multiplexed biomarkers (HGF, elafin, ST2 and TNFR1) relative to healthy donors and transplant patients without GVHD. The antibody co-localization capability of this technology is particularly useful when using inherently cross-reactive reagents such as polyclonal antibodies, although monoclonal antibody cross-reactivity can also be reduced. Because ATPS-ELISA adapts readily available antibody reagents, plate materials and detection instruments, it should be easily transferable into other research and clinical settings.

  9. Modeling the Dynamic Digestive System Microbiome

    Directory of Open Access Journals (Sweden)

    Anne M. Estes

    2015-08-01

    Full Text Available “Modeling the Dynamic Digestive System Microbiome” is a hands-on activity designed to demonstrate the dynamics of microbiome ecology using dried pasta and beans to model disturbance events in the human digestive system microbiome. This exercise demonstrates how microbiome diversity is influenced by: 1 niche availability and habitat space and 2 a major disturbance event, such as antibiotic use. Students use a pictorial key to examine prepared models of digestive system microbiomes to determine what the person with the microbiome “ate.” Students then model the effect of taking antibiotics by removing certain “antibiotic sensitive” pasta. Finally, they add in “environmental microbes” or “native microbes” to recolonize the digestive system, determine how resilient their model microbome community is to disturbance, and discuss the implications. Throughout the exercise, students discuss differences in the habitat space available and microbiome community diversity. This exercise can be modified to discuss changes in the microbiome due to diet shifts and the emergence of antibiotic resistance in more depth.

  10. Partitioning and purification of extracellular β-1,3-1,4-glucanase in aqueous two-phase systems

    Institute of Scientific and Technical Information of China (English)

    HE Guo-qing; ZHANG Xiu-yan; TANG Xing-jun; CHEN Qi-he; RUAN Hui

    2005-01-01

    The partition behaviors of β-1,3-1,4-glucanase, α-amylase and neutral proteases from clarified and whole fermentation broths of Bacillus subtilis ZJF-1A5 were investigated. An aqueous two-phase system (polyethylene glycol (PEG)/MgSO4)was examined with regard to the effects of PEG molecular weight (MW) and concentration, MgSO4 concentration, pH and NaCl concentration on enzyme partition and extraction. The MW and concentration of PEG were found to have significant effects on enzyme partition and extraction with low MW PEG showing the greatest benefit in the partition and extraction of β-glucanase with the PEG/MgSO4 system. MgSO4 concentration influenced the partition and extraction of β-glucanase significantly. pH had little effect on β-glucanase or proteases partition but affected α-amylase partition when pH was over 7.0. The addition of NaCl had little effect on the partition behavior of β-glucanase but had very significant effects on the partitioning of α-amylase and on the neutral proteases. The partition behaviors of β-glucanase, α-amylase and proteases in whole broth were also investigated and results were similar to those obtained with clarified fermentation broth. A two-step process for purifying β-glucanase was developed, which achieved β-glucanase recovery of 65.3% and specific activity of 14027 U/mg, 6.6 times improvement over the whole broth.

  11. Determination of partition coefficients of biomolecules in a microfluidic aqueous two phase system platform using fluorescence microscopy.

    Science.gov (United States)

    Silva, D F C; Azevedo, A M; Fernandes, P; Chu, V; Conde, J P; Aires-Barros, M R

    2017-03-03

    Aqueous two phase systems (ATPS) offer great potential for selective separation of a wide range of biomolecules by exploring differences in molecular solubility in each of the two immiscible phases. However, ATPS use has been limited due to the difficulty in predicting the behavior of a given biomolecule in the partition environment together with the empirical and time-consuming techniques that are used for the determination of partition and extraction parameters. In this work, a fast and novel technique based on a microfluidic platform and using fluorescence microscopy was developed to determine the partition coefficients of biomolecules in different ATPS. This method consists of using a microfluidic device with a single microchannel and three inlets. In two of the inlets, solutions containing the ATPS forming components were loaded while the third inlet was fed with the FITC tagged biomolecule of interest prepared in milli-Q water. Using fluorescence microscopy, it was possible to follow the location of the FITC-tagged biomolecule and, by simply varying the pumping rates of the solutions, to quickly test a wide variety of ATPS compositions. The ATPS system is allowed 4min for stabilization and fluorescence micrographs are used to determine the partition coefficient.The partition coefficients obtained were shown to be consistent with results from macroscale ATPS partition. This process allows for faster screening of partition coefficients using only a few microliters of material for each ATPS composition and is amenable to automation. The partitioning behavior of several biomolecules with molecular weights (MW) ranging from 5.8 to 150kDa, and isoelectric points (pI) ranging from 4.7 to 6.4 was investigated, as well as the effect of the molecular weight of the polymer ATPS component. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Influence of salts on the coexistence curve and protein partitioning in nonionic aqueous two-phase micellar systems

    Directory of Open Access Journals (Sweden)

    A. M. Lopes

    2014-12-01

    Full Text Available Aqueous two-phase micellar systems (ATPMS can be exploited in separation science for the extraction/purification of desired biomolecules. Prior to phase separation the surfactant solution reaches a cloud point temperature, which is influenced by the presence of electrolytes. In this work, we provide an investigation on the cloud point behavior of the nonionic surfactant C10E4 in the presence of NaCl, Li2SO4 and KI. We also investigated the salts' influence on a model protein partitioning. NaCl and Li2SO4 promoted a depression of the cloud point. The order of salts and the concentration that decreased the cloud point was: Li2SO4 0.5 M > NaCl 0.5 M ≈ Li2SO4 0.2 M. On the other hand, 0.5 M KI dislocated the curve to higher cloud point values. For our model protein, glucose-6-phosphate dehydrogenase (G6PD, partitioning experiments with 0.5 M NaCl or 0.2 M Li2SO4 at 13.85 ºC showed similar results, with K G6PD ~ 0.46. The lowest partition coefficient was obtained in the presence of 0.5 M KI (K G6PD = 0.12, with major recovery of the enzyme in the micelle-dilute phase (%Recovery = 90%. Our results show that choosing the correct salt to add to ATPMS may be useful to attain the desired partitioning conditions at more extreme temperatures. Furthermore, this system can be effective to separate a target biomolecule from fermented broth contaminants.

  13. One-Step Generation of Cell-Encapsulating Compartments via Polyelectrolyte Complexation in an Aqueous Two Phase System.

    Science.gov (United States)

    Hann, Sarah D; Niepa, Tagbo H R; Stebe, Kathleen J; Lee, Daeyeon

    2016-09-28

    Diverse fields including drug and gene delivery and live cell encapsulation require biologically compatible encapsulation systems. One widely adopted means of forming capsules exploits cargo-filled microdroplets in an external, immiscible liquid phase that are encapsulated by a membrane that forms by trapping of molecules or particles at the drop surface, facilitated by the interfacial tension. To eliminate the potentially deleterious oil phase often present in such processes, we exploit the aqueous two phase system of poly(ethylene glycol) (PEG) and dextran. We form capsules by placing dextran-rich microdroplets in an external PEG-rich phase. Strong polyelectrolytes present in either phase form complexes at the drop interface, thereby forming a membrane encapsulating the fluid interior. This process requires considerable finesse as both polyelectrolytes are soluble in either the drop or external phase, and the extremely low interfacial tension is too weak to provide a strong adsorption site for these molecules. The key to obtaining microcapsules is to tune the relative fluxes of the two polyelectrolytes so that they meet and complex at the interface. We identify conditions for which complexation can occur inside or outside of the drop phase, resulting in microparticles or poor encapsulation, respectively, or when properly balanced, at the interface, resulting in microcapsules. The resulting microcapsules respond to the stimuli of added salts or changes in osmotic pressure, allowing perturbation of capsule permeability or triggered release of capsule contents. We demonstrate that living cells can be sequestered and interrogated by encapsulating Pseudomonas aeruginosa PAO1 and using a Live/Dead assay to assess their viability. This method paves the way to the formation of a broad variety of versatile functional membranes around all aqueous capsules; by tuning the fluxes of complexing species to interact at the interface, membranes comprising other complexing

  14. Numerical modelling of the impact of a liquid drop on the surface of a two-phase fluid system

    Science.gov (United States)

    Sochan, Agata; Lamorski, Krzysztof; Bieganowski, Andrzej; Ryżak, Magdalena

    2014-05-01

    The aim of the study was validation of a numerical model of the impact of a liquid drop on the surface of a two-phase system of immiscible fluids. The drop impact phenomenon was recorded using a high-speed camera (Vision Research MIRO M310) and the data were recorded at 2000 frames per second. The numerical calculations were performed with the Finite Volume Method (FVM) solving the three-dimensional Navier-Stokes equations for three phases: air and two selected immiscible fluids. The Volume of Fluid (VOF) technique was employed for modelling of the boundaries between the phases. Numerical modelling was done with the Finite Volume Method using an available OpenFOAM software. The experiment was based on three variables: • the height from which the drop of the selected fluids fell (the speed of the drop), • the thickness of the layers of the two selected immiscible fluids (a thin layer of the fluid with a lower density was spread over the higher-density fluid), • the size of the fluid droplet. The velocity and radius of the falling drop was calculated based on the recorded images. The used parameters allowed adequate projection of the impact of fluid droplets on a system of two immiscible liquids. Development of the numerical model of splash may further have practical applications in environmental protection (spraying of hazardous fluids, spread of fuels and other hazardous substances as a result of disasters, spraying (water cooling) of hot surfaces), and in agriculture (prevention of soil erosion). The study was partially funded from the National Science Centre (Poland) based on the decision no. DEC-2012/07/N/ST10/03280.

  15. 废弃食用油脂两相厌氧发酵酸化条件优化%Process optimization of wasted edible oil hydrolytic acidification in two-phase anaerobic digestion

    Institute of Scientific and Technical Information of China (English)

    贺静; 邓雅月; 李凛; 李政伟; 尹小波; 邓宇

    2015-01-01

    It was reported that in China the annual consumption of edible oil was 21×106 tons which consequently produced waste oil of about 6×106 tons. The waste oil can be recycled to produce biodiesel, bulk chemicals, surfactant, fine chemicals and biogas. The recycling and bioconversion of waste edible oil into biogas will be beneficial to energy crisis and environmental pollution, and promote sustainable economic development. Because of the suppression of long chain fatty acid that is one of intermediate metabolites, waste edible oil that is directly used in anaerobic fermentation often causes digestion inhibition or system crash. The two-phase anaerobic digestion process can avoid the accumulation of long chain fatty acid and volatile acid in the methanogenesis process. Waste edible oil hydrolysis and long chain fatty acid degradation are critical steps in anaerobic digestion of waste edible oil. Improving the production rate of volatile fatty acid (VFA) in hydrolysis acidification phase will raise the subsequent methanogenesis reaction. The response surface methodology (RSM) can obtain the best combination of the factors in a given area and the optimal value of response values, which has been widely used in the optimization of culture conditions and technology conditions in the areas of food processing, water treatment and so on. Therefore, the RSM was used to optimize waste oil biological hydrolysis to produce volatile acid (including acetic acid, propionic acid and butyric acid). By adopting the method of central composite design (CCD) line design of experiment, using the soft Design Expert to analyze the experiment result, we established the quadratic polynomial in which volatile acid concentration was taken as the response value. The effects of initial pH value, raw material load, reaction time and inoculation rate on volatile acid concentration were investigated. The mathematical model and optimized parameters of process were also acquired. The results showed

  16. Integrated Library Systems. ERIC Digest.

    Science.gov (United States)

    Lopata, Cynthia L.

    An automated library system usually consists of a number of functional modules, such as acquisitions, circulation, cataloging, serials, and an online public access catalog (OPAC). An "integrated" library system is an automated system in which all of the function modules share a common bibliographic database. There are several ways the…

  17. Partition separation and characterization of the polyhydroxyalkanoates synthase produced from recombinant Escherichia coli using an aqueous two-phase system.

    Science.gov (United States)

    Lan, John Chi-Wei; Yeh, Chun-Yi; Wang, Chih-Chi; Yang, Yu-Hsuan; Wu, Ho-Shing

    2013-10-01

    Polyhydroxyalkanoates (PHAs) are renewable and biodegradable polyesters which can be synthesized either by numerous of microorganisms in vivo or synthase in vitro. The synthesis of PHAs in vitro requires an efficient separation for high yield of purified enzyme. The recombinant Escherichia coli harboring phaC gene derived from Ralstonia eutropha H16 was cultivated in the chemically defined medium for overexpression of synthase in the present work. The purification and characteristics of PHA synthase from clarified feedstock by using aqueous two-phase systems (ATPS) was investigated. The optimized concentration of ATPS for partitioning PHA synthase contained polyethylene glycol 6000 (30%, w/w) and potassium phosphate (8%, w/w) with 3.25 volume ratio in the absence of NaCl at pH 8.7 and 4°C. The results showed that the partition coefficient of enzyme activity and protein content are 6.07 and 0.22, respectively. The specific activity, selectivity, purification fold and recovery of phaC(Re) achieved 1.76 U mg⁻¹, 29.05, 16.23 and 95.32%, respectively. Several metal ions demonstrated a significant effect on activity of purified enzyme. The purified enzyme displayed maximum relative activity as operating condition at pH value of 7.5 and 37°C. As compared to conventional purification processes, ATPS can be a promising technique applied for rapid recovery of PHA synthase and preparation of large quantity of PHA synthase on synthesis of P(3HB) in vitro.

  18. Enabling two-phase microfluidic thermal transport systems using a novel thermal-flux degassing and fluid charging approach

    Science.gov (United States)

    Singh Dhillon, Navdeep; Pisano, Albert P.

    2014-03-01

    A novel two-port thermal-flux method has been proposed and demonstrated for degassing and charging two-phase microfluidic thermal transport systems with a degassed working fluid. In microscale heat pipes and loop heat pipes (mLHPs), small device volumes and large capillary forces associated with smaller feature sizes render conventional vacuum pump-based degassing methods quite impractical. Instead, we employ a thermally generated pressure differential to purge non-condensable gases from these devices before charging them with a degassed working fluid in a two-step process. Based on the results of preliminary experiments studying the effectiveness and reliability of three different high temperature-compatible device packaging approaches, an optimized compression packaging technique was developed to degas and charge a mLHP device using the thermal-flux method. An induction heating-based noninvasive hermetic sealing approach for permanently sealing the degassed and charged mLHP devices has also been proposed. To demonstrate the efficacy of this approach, induction heating experiments were performed to noninvasively seal 1 mm square silicon fill-hole samples with donut-shaped solder preforms. The results show that the minimum hole sealing induction heating time is heat flux limited and can be estimated using a lumped capacitance thermal model. However, further continued heating of the solder uncovers the hole due to surface tension-induced contact line dynamics of the molten solder. It was found that an optimum mass of the solder preform is required to ensure a wide enough induction-heating time window for successful sealing of a fill-hole.

  19. 餐厨垃圾SBMR-ASBR两相厌氧消化产气性能研究%Performances of two-phase SBMR-ASBR anaerobic digestion for biogas production of kitchen waste

    Institute of Scientific and Technical Information of China (English)

    钟起隆; 李秀金; 李兵; 邹德勋; 朱保宁; 袁海荣

    2012-01-01

    以学校食堂餐厨垃圾为原科,考察餐厨垃圾在SBMR-ASBR反应器中产酸和产甲烷性能.结果表明:高负荷下启动酸化相有利于系统快速形成稳定的乙醇型发酵,且可以避开丙酸型发酵,在10 g/(L·d)负荷(以VS计)下,稳定状态产酸率平均达到55 000 mg/L,VFA中乙醇和乙酸分别平均稳定在27 000 mg/L和23 000mg/L,两者共占总VFA的91%;甲烷相可以稳定运行的最高负荷为5g/(L·d)(以VS计),此时,系统整体处理能力为3.3 g/(L·d),单位容积产气率达到2.3 L/(L·d),甲烷含量在65%~70%,TS,VS去除率分别达到77%,83%.在实际工程中可以高负荷启动酸化相,有利于系统形成稳定的乙醇型发酵和高负荷运行的甲烷相.%The performances of two-phase SBMR-ASBR anaerobic digestion for biogas production of kitchen waste was investigated. To find out the acid production performances of acidification phase and the methane production performance of methanogenic phase, kitchen waste from campus restaurant was used as feedstock. The results showed that the acidification phase of kitchen waste . entered into a stable ethanol-type fermentation rapidly and avoid the propionate-type fermentation at a high OLR. The acid yield was 55 000 mg/L with 10 g/(L·d) of OLR at the stable state. Ethanol and acetic acid were 27 000 mg/L and 23 000 mg/L in VFA, respectively. Ethanol and acetic acid were 91% of VFA. The stable OLR of the methanation phase was 5 g/(L·d) in this condition. The OLR of the system was 3.3 g/(L·d). The volume gas production rate arrived at 23 L/(L·d). Methane content was 65%~70%. Removal rate of TS and VS reached 77% and 83%, respectively. It is suggested that the acidification be started at a high OLR, and this is beneficial to the system to build a stable ethanol-type fermentation and a methane phase running at a high OLR. The acidification phase running at high OLR would be recommended in facility of municipal organic solid waste.

  20. The formation and physical stability of two-phase solid dispersion systems of indomethacin in supercooled molten mixtures with different matrix formers.

    Science.gov (United States)

    Semjonov, Kristian; Kogermann, Karin; Laidmäe, Ivo; Antikainen, Osmo; Strachan, Clare J; Ehlers, Henrik; Yliruusi, Jouko; Heinämäki, Jyrki

    2017-01-15

    Amorphous solid dispersions (SDs) are a promising approach to improve the dissolution rate of and oral bioavailability of poorly water-soluble drugs. In some cases multi-phase, instead of single-phase, SD systems with amorphous drug are obtained. While it is widely assumed that one-phase amorphous systems are desirable, two-phase systems may still potentially exhibit enhanced stability and dissolution advantages over undispersed systems. The objective of the present study was to understand the solid-state properties of two-phase SDs with amorphous drug and their relation to physical stability. Two different types of excipients for SD formation were used, one being a polymer and the other a small molecule excipient. The supercooled molten SDs of a poorly water-soluble indomethacin (IND) with a graft copolymer, Soluplus® (SOL) and sugar alcohol, xylitol (XYL) were prepared. Supercooled molten SDs of IND with SOL were two-phase glassy suspension in which the amorphous drug was dispersed in an amorphous polymer matrix. A short-term aging of the SDs led to the formation of glassy suspensions where the crystalline drug was dispersed in an amorphous polymer matrix. These were physically stable at room temperature for the time period studied (RT, 23±2°C), but aging at high-humidity conditions (75% RH) recrystallization to metastable α-IND occurred. Interestingly, the SDs with XYL were two-phase amorphous precipitation systems in which the drug was in an amorphous form in the crystalline sugar alcohol matrix. The SDs of IND and XYL exhibited fast drug recrystallization. In conclusion, the preparation method of two-phase systems via co-melting in association with the rapid quench cooling is a feasible method for the formulation of poorly water-soluble drugs. The physical stability of these two-phase systems, however, is dependent on the carrier material and storage conditions.

  1. 双水相体系在无机盐分离中的应用%Application of Aqueous - two Phase System in the Separation of Inorganic Salts

    Institute of Scientific and Technical Information of China (English)

    史许娜; 韩清华

    2016-01-01

    Different separation methods of potassium chloride and ammonium chloride mixture are ana-lyzed. The present situation for separating mixed solution of potassium chloride and ammonium chloride by aqueous two - phase system(1 - propanol - KCl - NH4 Cl - H2 O aqueous two - phase system)is intro-duced,and the application of aqueous two - phase system is expanded.%分析了氯化钾和氯化铵混合溶液的不同分离方法,介绍了双水相体系(正丙醇—氯化钾—氯化铵—水双水相体系)对该混合溶液的分离现状,拓展了双水相体系的应用范围。

  2. Thermal-gravitational modeling and scaling of two-phase heat transport systems from micro-gravity to super-gravity levels

    Science.gov (United States)

    Delil, A. A. M.

    2001-02-01

    Earlier publications extensively describe NLR research on thermal-gravitational modeling and scaling of two-phase heat transport systems for spacecraft applications. These publications on mechanically and capillary pumped two-phase loops discuss pure geometric scaling, pure fluid to fluid scaling, and combined (hybrid) scaling of a prototype system by a model at the same gravity level, and of a prototype in micro-gravity environment by a scale-model on earth. More recent publications include the scaling aspects of prototype two-phase loops for Moon or Mars applications by scale-models on earth. Recent work, discussed here, concerns extension of thermal-gravitational scaling to super-g acceleration levels. This turned out to be necessary, since a very promising super-g application for (two-phase) heat transport systems will be cooling of high-power electronics in spinning satellites and in military combat aircraft. In such aircraft, the electronics can be exposed during maneuvres to transient accelerations up to 120 m/s2. The discussions focus on ``conventional'' (capillary) pumped two-phase loops. It can be considered as introduction to the accompanying article, which focuses on pulsating and oscillating devices. .

  3. Development of a Thermal Control System with Mechanically Pumped CO2 Two-Phase Loops for the AMS-02 Tracker on the ISS

    CERN Document Server

    Alberti, G; Ambrosi, G; Bardet, M; Battiston, R; Borsini, S; Cao, J F; Chen, Y; van Es, J; Gargiulo, C; Guo, K H; Guo, L; He, Z H; Huang, Z C; Koutsenko, V; Laudi, E; Lebedev, A; Lee, S C; Li, T X; Lin, Y L; Lv, S S; Menichelli, M; Miao, J Y; Mo, D C; Ni, J Q; Pauw, A; Qi, X M; Shue, G M; Sun, D J; Sun, X H; Tang, C P; Verlaat, B; Wang, Z X; Weng, Z L; Xiao, W J; Xu, N S; Yang, F K; Yeh, C C; Zhang, Z; Zwartbol, T

    2013-01-01

    To provide a stable thermal environment for the AMS-Tracker, a thermal control system based on mechanically pumped CO2 two-phase loops was developed. It has been operating reliably in space since May 19, 2011. In this article, we summarize the design, construction, tests, and performance of the AMS-Tracker thermal control system (AMS-TTCS).

  4. Recovery of ascorbic oxidoreductase from crude extract with an aqueous two-phase system in a perforated rotating disc contactor

    Directory of Open Access Journals (Sweden)

    Ana Lúcia Figueiredo Porto

    2004-09-01

    Full Text Available A continuous perforated rotating disc contactor was used to extract the enzyme ascorbic oxidoreductase (E.C.1.10.3.3 from crude extract of Curcubita maxima with an aqueous two-phase system of poly (ethylene glycol and phosphate salts. The effect of dispersed phase velocity on either protein mass transfer coefficients or separation efficiency at 1, 2 and 3 mL/min was studied. An increase of the mass transfer coefficients was observed with the dispersed phase velocity, while the separation efficiency showed a small decrease with the increase of this parameter. The experimental results obtained during continuous extraction showed that the ascorbic oxidoreductase activity was partitioned preferentially into the salt-rich phase in all conditions studied. The best recovery of enzyme activity was 236%, with a purification factor of 34 in flow rates of 1 mL/min for dispersed phase.Uma coluna de discos perfurados rotativos foi utilizada na extração da enzima ascorbato oxidorredutase (E.C.1.10.3.3, obtida do extrato bruto de Curcubita maxima, através da utilização do sistema bifásico aquoso Polietilenoglicol-sais de fosfato. Os efeitos da velocidade da fase dispersa nos coeficientes de transferência de massa e na eficiência de separação para valores de 1, 2 e 3 mL/min foram estudados. Observou-se um aumento da transferência de massa com a velocidade da fase dispersa, enquanto que a eficiência de separação demonstrou uma ligeira redução com o aumento deste parâmetro. Os resultados experimentais obtidos durante a extração contínua demonstraram que a atividade da ascorbato oxidorredutase se concentrou preferencialmente na fase rica em sal para todas as condições estudadas. A maior recuperação da atividade enzimática foi de 236%, com um fator de purificação de 34 para o valor de 1 mL/min para a fase dispersa.

  5. Maximizing the utilization of Laminaria japonica as biomass via improvement of alginate lyase activity in a two-phase fermentation system.

    Science.gov (United States)

    Oh, Yuri; Xu, Xu; Kim, Ji Young; Park, Jong Moon

    2015-08-01

    Brown seaweed contains up to 67% of carbohydrates by dry weight and presents high potential as a polysaccharide feedstock for biofuel production. To effectively use brown seaweed as a biomass, degradation of alginate is the major challenge due to its complicated structure and low solubility in water. This study focuses on the isolation of alginate degrading bacteria, determining of the optimum fermentation conditions, as well as comparing the conventional single fermentation system with the two-phase fermentation system which is separately using alginate and mannitol extracted from Laminaria japonica. Maximum yield of organic acids production and volatile solids reduction obtained were 0.516 g/g and 79.7%, respectively, using the two-phase fermentation system in which alginate fermentation was carried out at pH 7 and mannitol fermentation at pH 8. The two-phase fermentation system increased the yield of organic acids production by 1.14 times and led to a 1.45-times reduction of VS when compared to the conventional single fermentation system at pH 8. The results show that the two-phase fermentation system improved the utilization of alginate by separating alginate from mannitol leading to enhanced alginate lyase activity.

  6. Preparation of aqueous two-phase systems composed of two pH-response polymers and liquid-liquid extraction of demeclocycline.

    Science.gov (United States)

    Yan, Bo; Cao, Xuejun

    2012-07-06

    Aqueous two-phase systems have potential applications for separation and purification of bioproducts in bio-industry. However, a key problem is the recovery of the polymers forming aqueous two-phase systems. In this study, two novel random copolymers (P(ADB) and P(ADBA)) were synthesized using acrylic acid, dimethylamino-ethyl methacrylate, butyl methacrylate and allyl alcohol as monomers and used to form pH response aqueous two-phase systems. The recoveries of P(ADB) and P(ADBA) are 97.18% and 98.87% and the pI of P(ADB) and P(ADBA) are 2.79 and 4.01, respectively. Demeclocycline was partitioned in the P(ADB)/P(ADBA) aqueous two-phase systems and the partition coefficient reached 0.085, in the presence of MgSO₄ (60 mmol/L) at pH 5.28. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Liquid-liquid equilibrium of water + PEG 8000 + magnesium sulfate or sodium sulfate aqueous two-phase systems at 35°C: experimental determination and thermodynamic modeling

    Directory of Open Access Journals (Sweden)

    B. D. Castro

    2005-09-01

    Full Text Available Liquid-liquid extraction using aqueous two-phase systems is a highly efficient technique for separation and purification of biomolecules due to the mild properties of both liquid phases. Reliable data on the phase behavior of these systems are essential for the design and operation of new separation processes; several authors reported phase diagrams for polymer-polymer systems, but data on polymer-salt systems are still relatively scarce. In this work, experimental liquid-liquid equilibrium data on water + polyethylene glycol 8000 + magnesium sulfate and water + polyethylene glycol 8000 + sodium sulfate aqueous two-phase systems were obtained at 35°C. Both equilibrium phases were analyzed by lyophilization and ashing. Experimental results were correlated with a mass-fraction-based NRTL activity coefficient model. New interaction parameters were estimated with the Simplex method. The mean deviations between the experimental and calculated compositions in both equilibrium phases is about 2%.

  8. In vitro digestion testing of lipid-based delivery systems

    DEFF Research Database (Denmark)

    Devraj, Ravi; Williams, Hywel D; Warren, Dallas B

    2012-01-01

    In vitro digestion testing is of practical importance to predict the fate of drugs administered in lipid-based delivery systems. Calcium ions are often added to digestion media to increase the extent of digestion of long-chain triglycerides (LCTs), but the effects they have on phase behaviour...... of the products of digestion, and consequent drug solubilization, are not well understood. This study investigates the effect of calcium and bile salt concentrations on the rate and extent of in vitro digestion of soybean oil, as well as the solubilizing capacity of the digestion products for two poorly water......-soluble drugs, fenofibrate and danazol. In the presence of higher concentrations of calcium ions, the solubilization capacities of the digests were reduced for both drugs. This effect is attributed to the formation of insoluble calcium soaps, visible as precipitates during the digestions. This reduces...

  9. Transformation of Vesicles in Aqueous Two-Phase System of an Anionic Gemini Surfactant and a Cationic Conventional Surfactant Mixture

    Institute of Scientific and Technical Information of China (English)

    JIANG Rong; HUANG Yi-Xiong; ZHAO Jian-Xi; HUANG Chang-Cang

    2008-01-01

    Transformation of vesicles formed in DTAB/C11-p-PhCNa aqueous surfactant two-phase (ASTP) was observed by the transmission electron microscopy (TEM). The trans-conformation of the gemini surfactant in the aggregates was considered to be the important factor for constructing the multi-lamellar structure of the vesicle wall. The cation-π interaction between the quaternary ammonium cation and the aromatic ring in the spacer was determined by the UV-Vis spectrum analysis, which, as well as the general electrostatic attraction and hydrophobic force, contributes to the stability of the multi-lamellar structure. The concentrations of the surface-active ions were measured for understanding the mechanism of vesicle transformation. The results show that isoelectric mixing of the two components benefits the growth of vesicles both in size and wall thickness.

  10. Increased production of megakaryocytes near purity from cord blood CD34+ cells using a short two-phase culture system.

    Science.gov (United States)

    Boyer, Lucie; Robert, Amélie; Proulx, Chantal; Pineault, Nicolas

    2008-03-20

    Expansion of hematopoietic progenitor cells (HPC) ex vivo remains an important focus in fundamental and clinical research. The aim of this study was to determine whether the implementation of such expansion phase in a two-phase culture strategy prior to the induction of megakaryocyte (Mk) differentiation would increase the yield of Mks produced in cultures. Toward this end, we first characterized the functional properties of five cytokine cocktails to be tested in the expansion phase on the growth and differentiation kinetics of CD34+-enriched cells, and on their capacity to expand clonogenic progenitors in cultures. Three of these cocktails were chosen based on their reported ability to induce HPC expansion ex vivo, while the other two represented new cytokine combinations. These analyses revealed that none of the cocktails tested could prevent the differentiation of CD34+ cells and the rapid expansion of lineage-positive cells. Hence, we sought to determine the optimum length of time for the expansion phase that would lead to the best final Mk yields. Despite greater expansion of CD34+ cells and overall cell growth with a longer expansion phase, the optimal length for the expansion phase that provided greater Mk yield at near maximal purity was found to be 5 days. Under such settings, two functionally divergent cocktails were found to significantly increase the final yield of Mks. Surprisingly, these cocktails were either deprived of thrombopoietin or of stem cell factor, two cytokines known to favor megakaryopoiesis and HPC expansion, respectively. Based on these results, a short resource-efficient two-phase culture protocol for the production of Mks near purity (>95%) from human CD34+ CB cells has been established.

  11. A microdevice assisted approach for the preparation, characterization and selection of continuous aqueous two-phase systems: from micro to bench-scale.

    Science.gov (United States)

    Vázquez-Villegas, Patricia; Ouellet, Eric; González, Claudia; Ruiz-Ruiz, Federico; Rito-Palomares, Marco; Haynes, Charles A; Aguilar, Oscar

    2016-07-05

    Aqueous two-phase systems (ATPS) have emerged as an alternative strategy for the recovery and purification of a wide variety of biological products. Typical process development requires a large screening of experimental conditions towards industrial adoption where continuous processes are preferred. In this work, it was proved that under certain flow conditions, ATPS could be formed continuously inside a microchannel, starting from stocks of phase components. Staggered herringbone chaotic micromixers included within the device sequentially and rapidly prepare two-phase systems across an entire range of useful phase compositions. Two-phase diagrams (binodal curves) were easily plotted using the cloud-point method for systems of different components and compared with previously reported curves for each system, proving that phase formation inside the device correlated with the previously reported diagrams. A proof of concept for sample partitioning in such a microdevice was performed with two different experimental models: BSA and red blood cells. Finally, the microdevice was employed to obtain information about the recovery and partition coefficient of invertase from a real complex mixture of proteins (yeast extract) to design a process for the recovery of the enzyme selecting a suitable system and composition to perform the process at bench-scale.

  12. Testing low cost anaerobic digestion (AD) systems

    Science.gov (United States)

    To evaluate the potential for low technology and low cost digesters for small dairies, BARC and researchers from the University of Maryland installed six modified Taiwanese-model field-scale (FS) digesters near the original dairy manure digester. The FS units receive the same post-separated liquid ...

  13. A Novel Aqueous Two Phase System Composed of Surfactant and Xylitol for the Purification of Lipase from Pumpkin (Cucurbita moschata) Seeds and Recycling of Phase Components.

    Science.gov (United States)

    Amid, Mehrnoush; Manap, Mohd Yazid; Hussin, Muhaini; Mustafa, Shuhaimi

    2015-06-17

    Lipase is one of the more important enzymes used in various industries such as the food, detergent, pharmaceutical, textile, and pulp and paper sectors. A novel aqueous two-phase system composed of surfactant and xylitol was employed for the first time to purify lipase from Cucurbita moschata. The influence of different parameters such as type and concentration of surfactants, and the composition of the surfactant/xylitol mixtures on the partitioning behavior and recovery of lipase was investigated. Moreover, the effect of system pH and crude load on the degree of purification and yield of the purified lipase were studied. The results indicated that the lipase was partitioned into the top surfactant rich phase while the impurities partitioned into the bottom xylitol-rich phase using an aqueous two phase system composed of 24% (w/w) Triton X-100 and 20% (w/w) xylitol, at 56.2% of tie line length (TLL), (TTL is one of the important parameters in this study and it is determined from a bimodal curve in which the tie-line connects two nodes on the bimodal, that represent concentration of phase components in the top and bottom phases) and a crude load of 25% (w/w) at pH 8.0. Recovery and recycling of components was also measured in each successive step process. The enzyme was successfully recovered by the proposed method with a high purification factor of 16.4 and yield of 97.4% while over 97% of the phase components were also recovered and recycled. This study demonstrated that the proposed novel aqueous two phase system method is more efficient and economical than the traditional aqueous two phase system method for the purification and recovery of the valuable enzyme lipase.

  14. [Phase transfer catalyzed bioconversion of penicillin G to 6-APA by immobilized penicillin acylase in recyclable aqueous two-phase systems with light/pH sensitive copolymers].

    Science.gov (United States)

    Jin, Ke-ming; Cao, Xue-jun; Su, Jin; Ma, Li; Zhuang, Ying-ping; Chu, Ju; Zhang, Si-liang

    2008-03-01

    Immobilized penicillin acylase was used for bioconversion of penicillin PG into 6-APA in aqueous two-phase systems consisting of a light-sensitive polymer PNBC and a pH-sensitive polymer PADB. Partition coefficients of 6-APA was found to be about 5.78 in the presence of 1% NaCl. Enzyme kinetics showed that the reaction reached equilibrium at roughly 7 h. The 6-APA mole yields were 85.3% (pH 7.8, 20 degrees C), with about 20% increment as compared with the reaction of single aqueous phase buffer. The partition coefficient of PG (Na) varied scarcely, while that of the product, 6-APA and phenylacetic acid (PA) significantly varied due to Donnan effect of the phase systems and hydrophobicity of the products. The variation of the partition coefficients of the products also affected the bioconversion yield of the products. In the aqueous two-phase systems, the substrate, PG, the products of 6-APA and PA were biased in the top phase, while immobilized penicillin acylase at completely partitioned at the bottom. The substrate and PG entered the bottom phase, where it was catalyzed into 6-APA and PA and entered the top phase. Inhibition of the substrate and products was removed to result in improvement of the product yield, and the immobilized enzyme showed higher efficiency than the immobilized cells and occupied smaller volume. Compared with the free enzyme, immobilized enzyme had greater stability, longer life-time, and was completely partitioned in the bottom phase and recycle. Bioconversion in two-phase systems using immobilized penicillin acylase showed outstanding advantage. The light-sensitive copolymer forming aqueous two-phase systems could be recovered by laser radiation at 488 nm or filtered 450 nm light, while pH-sensitive polymer PADB could be recovered at the isoelectric point (pH 4.1). The recovery of the two copolymers was between 95% and 99%.

  15. A Novel Aqueous Two Phase System Composed of Surfactant and Xylitol for the Purification of Lipase from Pumpkin (Cucurbita moschata Seeds and Recycling of Phase Components

    Directory of Open Access Journals (Sweden)

    Mehrnoush Amid

    2015-06-01

    Full Text Available Lipase is one of the more important enzymes used in various industries such as the food, detergent, pharmaceutical, textile, and pulp and paper sectors. A novel aqueous two-phase system composed of surfactant and xylitol was employed for the first time to purify lipase from Cucurbita moschata. The influence of different parameters such as type and concentration of surfactants, and the composition of the surfactant/xylitol mixtures on the partitioning behavior and recovery of lipase was investigated. Moreover, the effect of system pH and crude load on the degree of purification and yield of the purified lipase were studied. The results indicated that the lipase was partitioned into the top surfactant rich phase while the impurities partitioned into the bottom xylitol-rich phase using an aqueous two phase system composed of 24% (w/w Triton X-100 and 20% (w/w xylitol, at 56.2% of tie line length (TLL, (TTL is one of the important parameters in this study and it is determined from a bimodal curve in which the tie-line connects two nodes on the bimodal, that represent concentration of phase components in the top and bottom phases and a crude load of 25% (w/w at pH 8.0. Recovery and recycling of components was also measured in each successive step process. The enzyme was successfully recovered by the proposed method with a high purification factor of 16.4 and yield of 97.4% while over 97% of the phase components were also recovered and recycled. This study demonstrated that the proposed novel aqueous two phase system method is more efficient and economical than the traditional aqueous two phase system method for the purification and recovery of the valuable enzyme lipase.

  16. pH recycling aqueous two-phase systems applied in extraction of Maitake β-Glucan and mechanism analysis using low-field nuclear magnetic resonance.

    Science.gov (United States)

    Hou, Huiyun; Cao, Xuejun

    2015-07-31

    In this paper, a recycling aqueous two-phase systems (ATPS) based on two pH-response copolymers PADB and PMDM were used in purification of β-Glucan from Grifola frondosa. The main parameters, such as polymer concentration, type and concentration of salt, extraction temperature and pH, were investigated to optimize partition conditions. The results demonstrated that β-Glucan was extracted into PADB-rich phase, while impurities were extracted into PMDM-rich phase. In this 2.5% PADB/2.5% PMDM ATPS, 7.489 partition coefficient and 96.92% extraction recovery for β-Glucan were obtained in the presence of 30mmol/L KBr, at pH 8.20, 30°C. The phase-forming copolymers could be recycled by adjusting pH, with recoveries of over 96.0%. Furthermore, the partition mechanism of Maitake β-Glucan in PADB/PMDM aqueous two-phase systems was studied. Fourier transform infrared spectra, ForteBio Octet system and low-field nuclear magnetic resonance (LF-NMR) were introduced for elucidating the partition mechanism of β-Glucan. Especially, LF-NMR was firstly used in the mechanism analysis in partition of aqueous two-phase systems. The change of transverse relaxation time (T2) in ATPS could reflect the interaction between polymers and β-Glucan.

  17. Measurement and simulation of the turbulent dispersion of a radioactive tracer in a two-phase flow system

    Energy Technology Data Exchange (ETDEWEB)

    Hensel, F.; Rohde, U.

    1998-10-01

    The turbulent dispersion of a radiotracer in an experimental setup with a natural convection liquid-gaseous flow was investigated. A liquid-gaseous bubbly flow was generated in a narrow tank by injection of pressurized air into water or by catalytic disintegration of H{sub 2}O{sub 2}. Turbulent Prandtl numbers for gas and tracer dispersion were varied. In the case of higher gas superficial velocities (J{sub gas}{approx}5-15 mm/s), a reasonable agreement was achieved between calculated and measured tracer transport velocity and dispersion coefficient values. A nearly linear correlation between j{sub gas} and D was found in agreement with other authors. The calculation results contribute to a better understanding of the phenomena and interpretation of the measurement results as well as to the validation of the CFD code for turbulent two-phase flow applications. Further investigations are necessary to improve the agreement in the cases of H{sub 2}O{sub 2} disintegration and low gas superficial velocities. (orig.)

  18. Production of dry Lactobacillus rhamnosus GG preparations by spray drying and lyophilization in aqueous two-phase systems

    Directory of Open Access Journals (Sweden)

    Katarzyna Leja

    2009-12-01

    Full Text Available Background. Drying is the oldest method of food preservation. It works by removing water from the food, which prevents the growth of microorganisms and decay. Moreover, spray or freeze drying is also used for the preservation of probiotic cultures. The aim of this study was to compare a survival rate of probiotic bacteria Lactobacillus rhamnosus during spray and freeze drying in ATPS. These results were also compared with survival rate of cells dried under the same conditions but suspended only in skim milk, 6% solution of PVP or 6% solution of dextran. Material and methods. The bacteria Lactobacillus rhamnosus GGwere suspended and spray or freeze dried in various types of aqueous two-phase emulsions: PVP/dextran, PEG4000/dextran and PEG8000/dextran. These emulsions consisted of different types of polymers and had varying ratio of polymers in dispersed (dextran and dispersing (PEG and PVP phases. Results. The research demonstrated that survival rate of bacteria directly after drying depended mainly on protective reagent, rather than on drying method. After 30-day-storage of the dried bacteria cell specimens, the highest survival rate was noted in case of freeze dried cells in milk. In case of spray drying the highest cell survival rate was observed when emulsion PVP3.6%/dextran2.4% was used as a drying medium. Conclusions. Finally, it has been found that cell survival rate was not strongly influenced by the storage temperature of the powder but it depended on the drying medium.  

  19. Design and development of single stage purification of papain using Ionic Liquid based aqueous two phase extraction system and its Partition coefficient studies

    Directory of Open Access Journals (Sweden)

    Senthilkumar Rathnasamy

    2013-04-01

    Full Text Available As an emerging trend in bioseparation, aqueous two phase extractions based on phosponium ionic liquid have been utilized in this work to extract papain from Carica papaya fruit latex and the same wascompared with conventional aqueous two phase extraction system. Factors affecting the partition coefficient of papain such as ionic liquid concentration, pH of the extraction system and temperature have been investigated. The optimization studies show that ionic liquid concentrations and pH are majorly influencing the phaseformations and papain partitioning. It reveals the importance of electrostatic and hydrophobic interactions in the papain partitioning. Purification studies performed on Gel Filtration Chromatography shows that 96% of the papain enzyme could be extracted with the phosponium based ionic liquid in a single stage extraction. The final fraction containing papain enzyme was confirmed by SDS Page analysis.

  20. Extraction of penicillin G by aqueous two-phase system of [Bmim]BF4/NaH2PO4

    Institute of Scientific and Technical Information of China (English)

    LIU Qingfen; HU Xuesheng; WANG Yuhong; YANG Ping; XIA Hansong; YU Jiang; LIU Huizhou

    2005-01-01

    A novel approach for the extraction of penicillin G by aqueous two-phase system comprised of hydrophilic ionic liquid [Bmim]BF4 (1-butyl-3- methylimidazolium tetrafluoroborate) and NaH2PO4 is reported. The effects of some important parameters involving the concentration of NaH2PO4, the concentration of penicillin G, the amount of [Bmim]BF4 on the formation of aqueous two-phase system and the extraction yield of penicillin were investigated. The primary result shows that the ATPS can take advantage of penicillin concentrated in upper phase at higher pH value for penicillin extraction from its aqueous solution without emulsification.

  1. Study on constant-pressure specific heat of non-equi- librium phase change process in gas-liquid two-phase flow system

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, the air-water vapor-water system is taken as an example, and the formula of constantpressure specific heat during non-equilibrium phase change process in the two-phase flow system is deduced using the theory of two-phase flow and thermophysics. The constant-pressure specific heat of non-equilibrium phase change process is calculated with the corresponding numerical model, and the numerical results are compared to those of the equilibrium phase change process. It is shown that in evaporation process, the variational rate of the non-equilibrium specific heat increases with increasing initial fluid temperature and particle mass fraction. The smaller particle radius is, the faster the variational rate is. Meanwhile, the constant-pressure specific heat of equilibrium process is higher than that of the non-equilibrium process all the time.

  2. Contribution to the thermodynamics of sc3+, y3+, la3+ and trivalent lanthanide cations in the two-phase water-nitrobenzene extraction system.

    Science.gov (United States)

    Makrlík, Emanuel; Vaňura, Petr

    2011-06-01

    From the exchange extraction constants corresponding to the general equilibrium M3+(aq) + 3H+(nb) M3+(nb) + 3H+(aq) occurring in the two-phase water-nitrobenzene system (M3+ = Sc3+, Y3+, La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, Yb3+, Lu3+; aq = aqueous phase, nb = nitrobenzene phase), the individual extraction constants of 16 trivalent metal cations were calculated. It was found that these individual extraction constants in the mentioned two-phase system increase in the following cation order: Sc3+ < Yb3+< Ho3+ < Er3+ < Tm3+, Lu3+ < Y3+, Dy3+ < Tb3+ < Gd3+ < Eu3+ < Sm3+ < Nd3+ < Pr3+ < La3+, Ce3+.

  3. Simultaneous separation/enrichment and detection of trace ciprofloxacin and lomefloxacin in food samples using thermosensitive smart polymers aqueous two-phase flotation system combined with HPLC.

    Science.gov (United States)

    Lu, Yang; Chen, Bo; Yu, Miao; Han, Juan; Wang, Yun; Tan, Zhenjiang; Yan, Yongsheng

    2016-11-01

    Smart polymer aqueous two phase flotation system (SPATPF) is a new separation and enrichment technology that integrated the advantages of the three technologies, i.e., aqueous two phase system, smart polymer and flotation sublation. Ethylene oxide and propylene oxide copolymer (EOPO)-(NH4)2SO4 SPATPF is a pretreatment technique, and it is coupled with high-performance liquid chromatography to analyze the trace ciprofloxacin and lomefloxacin in real food samples. The optimized conditions of experiment were determined in the multi-factor experiment by using response surface methodology. The flotation efficiency of lomefloxacin and ciprofloxacin was 94.50% and 98.23% under the optimized conditions. The recycling experimentsshowed that the smart polymer EOPO could use repeatedly, which will reduce the cost in the future application. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Predicting the influence of compressibility and thermal and flow distribution asymmetry on the frequency-response characteristics of multitube two-phase condensing flow systems

    Energy Technology Data Exchange (ETDEWEB)

    Kobus, C.J.; Wedekind, G.L.; Bhatt, B.L.

    2000-02-01

    An equivalent single-tube model concept was extended to predict the frequency-response characteristics of multitube two-phase condensing flow systems, complete with the ability to predict the influence of compressibility and thermal and flow distribution asymmetry. The predictive capability of the equivalent single-tube model was verified experimentally with extensive data that encompassed a three-order-of-magnitude range of frequencies, and a wide range of operating parameters.

  5. Experimental study on two-phase flow natural circulation in a core catcher cooling channel for EU-APR1400 using air-water system

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ki Won [Division of Advanced Nuclear Engineering, POSTECH, Pohang 790-784 (Korea, Republic of); Korea Atomic Energy Research Institute, Daejeon 34057 (Korea, Republic of); Nguyen, Thanh Hung [School of Nuclear Engineering, Purdue University, West Lafayette, IN 47906 (United States); Ha, Kwang Soon; Kim, Hwan Yeol; Song, Jinho [Korea Atomic Energy Research Institute, Daejeon 34057 (Korea, Republic of); Park, Hyun Sun [Division of Advanced Nuclear Engineering, POSTECH, Pohang 790-784 (Korea, Republic of); Revankar, Shripad T., E-mail: shripad@postech.ac.kr [Division of Advanced Nuclear Engineering, POSTECH, Pohang 790-784 (Korea, Republic of); School of Nuclear Engineering, Purdue University, West Lafayette, IN 47906 (United States); Kim, Moo Hwan [Division of Advanced Nuclear Engineering, POSTECH, Pohang 790-784 (Korea, Republic of); Korea Institute of Nuclear Safety, Daejeon 305-338 (Korea, Republic of)

    2017-05-15

    Highlights: • Two-phase flow regimes and transition behavior were observed in the coolant channel. • Test were conducted for natural circulation with air-water. • Data were obtained on flow regime, void fraction, flow rates and re-wetting time. • The data were related to a cooling capability of core catcher system. - Abstract: Ex-vessel core catcher cooling system driven by natural circulation is designed using a full scaled air-water system. A transparent half symmetric section of a core catcher coolant channel of a pressurized water reactor was designed with instrumentations for local void fraction measurement and flow visualization. Two designs of air-water top separator water tanks are studied including one with modified ‘super-step’ design which prevents gas entrainment into down-comer. In the experiment air flow rates are set corresponding to steam generation rate for given corium decay power. Measurements of natural circulation flow rate, spatial local void fraction distribution and re-wetting time near the top wall are carried out for various air flow rates which simulate boiling-induced vapor generation. Since heat transfer and critical heat flux are strongly dependent on the water mass flow rate and development of two-phase flow on the heated wall, knowledge of two-phase flow characteristics in the coolant channel is essential. Results on flow visualization showing two phase flow structure specifically near the high void accumulation regions, local void profiles, rewetting time, and natural circulation flow rate are presented for various air flow rates that simulate corium power levels. The data are useful in assessing the cooling capability of and safety of the core catcher system.

  6. Partitioning of Cephalexin in Ionic Liquid Aqueous Two-Phase System Composed of 1-Butyl-3-Methylimidazolium Tetrafluoroborate and ZnSO4

    Directory of Open Access Journals (Sweden)

    Yan Fang Li

    2013-01-01

    Full Text Available Ionic liquid aqueous two-phase system (ILATPS was applied in the extraction and separation of hydrosoluble antibiotics. The partitioning behavior of cephalexin (CEX in 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4-ZnSO4 aqueous two-phase system was studied by the partitioning parameter of the extraction efficiency. The effect of the volume of [Bmim]BF4, the concentration of ZnSO4, temperature, pH, and the volume of ZnSO4 solution was discussed concretely. When the volume of [Bmim]BF4 was 2 mL and the concentration of ZnSO4 was 35%, the extraction efficiency of CEX could reach 92.64% with pH unadjusted. The effect of the volume of [Bmim]BF4 on the extraction efficiency was higher than that of the concentration of ZnSO4. The temperature influenced not only the formation of aqueous two-phase system but also the extraction efficiency of CEX. The target was found to be preferentially extracted to the [Bmim]BF4-rich phase at the pH below 4.3. The partition of CEX to the top phase was enhanced by increasing the volume of [Bmim]BF4, the concentration of ZnSO4, and temperature; however, the partition of CEX to the top phase increased by decreasing the pH.

  7. An Experimental Study of Air-Solid Two-Phase Flow in a 90° Bend Using LDV System

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    The measurements of he mean streamwise and radial velocities,the associated turbulence and the relative particle densities were made in an air-solid two-phase flow in square sectioned(30mm×30mm) 90° vertical to horizontal bend using laser Doppler velocimetry.The radius ratio of the bedn was 2.0.Glass beads of 100um in diameter were employed to form the solid phase.The measurements of air and solid phases were performed separately at the same bulk velocity 19.34m/s,correaponding to a Reynolds number of 3.87×104.The mass ratio of solid to air was 1.6%,The results indicate that the particle trajectories are very close to straight lines.The streamwise velocity profiles for the gas and the solids cross over near the outer wall with the solids having the higher speed.At θ=30° and 45°,particle-wall collisions happen mostly in the region fromθ=30°to θ=75°,and cause a sudden change in solid velocity,The particles tned to move towards the outer wall in 90°bend,The particle concentration near the outer wall is umch higher than that near the inner wall in the bend,and there are few particles in the inside of the bend.The bend leads to apparent phase separation.atθ=45°,the solids concentrate in the half of the duct near the outer wall,After θ=60° the second peak concentration appears,and goes gradually towards the inner wall.

  8. Pilot Scale Study on Two-phase Anaerobic Digestion Performance of Kitchen Waste%餐厨垃圾两相厌氧消化特性试验研究

    Institute of Scientific and Technical Information of China (English)

    熊杰; 袁海荣; 王奎升; 朱保宁; 刘研萍; 邹德勋; 党峰; 李秀金

    2012-01-01

    Two-phase anaerobic digestion performance of kitchen waste was investigated with different organic loading rate (OLR) of 10, 30, 50 and 70 gVS/L, inoculums dosages of 5, 10, 15 and 20 gVS/L, acidification times of 3, 5, 7 and 9 d by orthogonal experiment design. Kitchen waste from campus restaurant was used as feedstock. Results showed that kitchen waste obtained the best acidification results with 30 gVS/L of OLR, 15 gVS/L of inoculums dosage and 5 day of acidification time. The acid yield of kitchen waste was 561.0 mg acetic acid.gVS/L mainly acetate and butyrate. Total biogas yield was 826.7 mL/gVS, which was 8.2% and 1,070.3% higher than ethanol type fermentation of 763.8 mL/gVS in the best condition, and butyrate type fermentation of 70.6 mL/gVS in the worst condition respectively. Therefore OLR, acidification time and inoculums dosage have important influence on acidification and methane of kitchen waste. The study would provide parameters for effective operation and optimal design of anaerobic digestion facility of municipal organic solid waste.%研究了餐厨垃圾两相厌氧消化特性.以北京化工大学餐厨垃圾为原料,分别以不同有机负荷(10、30、50和70 gVS/L)、接种量(5、10、15和20 gVS/L)、酸化时间(3、5、7和9d)考察其对酸化效果的影响,并对酸化出料进行甲烷化产气实验.结果表明,餐厨垃圾最优酸化条件为有机负荷30 gVS/L,酸化时间5d,接种量15 gVS/L.在此条件下,单位负荷产酸率为561.0 mg乙酸gVS,酸化末端产物主要为乙酸和丁酸,单位负荷累积产气量达到826.7 mL/gVS,比乙醇型最佳条件单位负荷累积产气量763.8 mL/gVS高8.2%,比丁酸型最低单位负荷累积产气量70.6 mL/gVS高1 070.3%.有机负荷、酸化时间、接种量依次对餐厨垃圾酸化有重要的影响,并且餐厨垃圾酸化效果和产气性能具有一致性.研究结果可为城市生活垃圾厌氧消化提供设计和运行依据.

  9. Sophisticated digestive systems in early arthropods

    National Research Council Canada - National Science Library

    Vannier, Jean; Liu, Jianni; Lerosey-Aubril, Rudy; Vinther, Jakob; Daley, Allison C

    2014-01-01

    .... Here we describe exceptionally well-preserved complex digestive organs in early arthropods from the early Cambrian of China and Greenland with functional similarities to certain modern crustaceans...

  10. Hydrolysis of triglyceride by the whole cell of Pseudomonas putida 3SK in two-phase batch and continuous reactors systems.

    Science.gov (United States)

    Lee, S Y; Rhee, J S

    1994-08-05

    Batch and continuous hydrolysis of olive oil in an organic-aqueous two-phase system using the live whole cell of Pseudomonas putida 3SK as a source of a lipase is investigated. The strain was not only fully viable and grown well, but also produced extracellular lipase simultaneously. The degree of hydrolysis, depending on olive oil concentration in the solvents, was maximal at 13.5% (w/v) and decreased with the increase of the substrate concentration. At the optimal condition, a degree of hydrolysis higher than 95% was achieved with 24 h at 30 degrees C when the reaction was carried out in a two-phase batch stirred reactor. For long-term operation a continuous stirred reactor was designed. When the reaction was carried out in a continuous stirred reactor, the degree was hydrolysis reached 86% at a dilution rate of 0.2 h(-1). Satisfactory performance of a two-phase bioreactor was obtained in a long-term continous operation, which lasted for at least 30 days by feeding organic solvent containing olive oil and aqueous media separately. (c) 1994 John Wiley & Sons, Inc.

  11. Dependence of chymosin and pepsin partition coefficient with phase volume and polymer pausidispersity in polyethyleneglycol-phosphate aqueous two-phase system.

    Science.gov (United States)

    Spelzini, Darío; Picó, Guillemo; Farruggia, Beatriz

    2006-08-01

    The influence of the phase volume ratio and polymer pausidispersity on chymosin and pepsin partition in polyethylenglycol-phosphate aqueous two-phase systems was studied. Both proteins showed a high affinity for the polyethylenglycol rich phase with a partition coefficient from 20 to 100 for chymosin and from 20 to 180 for pepsin, when the polyethyleneglycol molecular mass in the system varied between 1450 and 8000. The partition coefficient of chymosin was not affected by the volume phase ratio, while the pepsin coefficient showed a significant decrease in its partition coefficient with the increase in the top/bottom phase volume ratio.

  12. Prediction of liquid-liquid equilibria for polyethylene glycol based aqueous two-phase system by ASOG and UNIFAC method

    Directory of Open Access Journals (Sweden)

    M. Perumalsamy

    2009-03-01

    Full Text Available Liquid-Liquid equilibrium data were obtained for the polyethylene glycol2000(PEG2000-sodium citrate-water system at 298.15, 308.15 and 318.15 K. The effect of temperature on binodal and tie line data was studied and published in a previous article (Murugesan and Perumalsamy, 2005. The interaction parameters of ASOG and UNIFAC models were estimated using the LLE data of PEG2000-sodium citrate-water system and are used to predict the LLE data for PEG6000-sodium citrate-water system at 298.15, 308.15 and 318.15 K (literature data. The predicted LLE data by both ASOG and UNIFAC models showed good agreement with the experimental and literature data.

  13. Cooling the dark energy camera CCD array using a closed-loop two-phase liquid nitrogen system

    Science.gov (United States)

    Cease, H.; DePoy, D.; Derylo, G.; Diehl, H. T.; Estrada, J.; Flaugher, B.; Kuk, K.; Kuhlmann, S.; Lathrop, A.; Schultz, K.; Reinert, R. J.; Schmitt, R. L.; Stefanik, A.; Zhao, A.

    2010-07-01

    The Dark Energy Camera (DECam) is the new wide field prime-focus imager for the Blanco 4m telescope at CTIO. This instrument is a 3 sq. deg. camera with a 45 cm diameter focal plane consisting of 62 2k × 4k CCDs and 12 2k × 2k CCDs and was developed for the Dark Energy Survey that will start operations at CTIO in 2011. The DECam CCD array is inside the imager vessel. The focal plate is cooled using a closed loop liquid nitrogen system. As part of the development of the mechanical and cooling design, a full scale prototype imager vessel has been constructed and is now being used for Multi-CCD readout tests. The cryogenic cooling system and thermal controls are described along with cooling results from the prototype camera. The cooling system layout on the Blanco telescope in Chile is described.

  14. Analysis of partitioning of organic compounds and proteins in aqueous polyethylene glycol-sodium sulfate aqueous two-phase systems in terms of solute-solvent interactions.

    Science.gov (United States)

    da Silva, Nuno R; Ferreira, Luisa A; Madeira, Pedro P; Teixeira, José A; Uversky, Vladimir N; Zaslavsky, Boris Y

    2015-10-09

    Partition behavior of nine small organic compounds and six proteins was examined in poly(ethylene glycol)-8000-sodium sulfate aqueous two-phase systems containing 0.5M osmolyte (sorbitol, sucrose, trehalose, TMAO) and poly(ethylene glycol)-10000-sodium sulfate system, all in 0.01M sodium phosphate buffer, pH 6.8. The differences between the solvent properties of the coexisting phases (solvent dipolarity/polarizability, hydrogen bond donor acidity, and hydrogen bond acceptor basicity) were characterized with solvatochromic dyes using the solvatochromic comparison method. Differences between the electrostatic properties of the phases were determined by analysis of partitioning of sodium salts of dinitrophenylated (DNP-) amino acids with aliphatic alkyl side-chain. It was found out that the partition coefficient of all compounds examined (including proteins) may be described in terms of solute-solvent interactions. The results obtained in the study show that solute-solvent interactions of nonionic organic compounds and proteins in polyethylene glycol-sodium sulfate aqueous two-phase system differ from those in polyethylene glycol-dextran system.

  15. Influence of the temperature and type of salt on the phase equilibrium of peg 1500 + potassium phosphate and peg 1500 + sodium citrate aqueous two-phase systems

    Directory of Open Access Journals (Sweden)

    Carolina P. Carvalho

    2008-01-01

    Full Text Available The present work analyzed the effect of the temperature and type of salt on the phase equilibrium of aqueous two-phase systems (ATPS formed by poly (ethylene glycol (PEG 1500 + potassium phosphate, from (278.15 to 318.15 K, and PEG 1500 + sodium citrate, from (278.15 to 298.15 K. The rise of the temperature normally increased the slope of the tie line (STL. With respect to the influence of the type of salt, sodium citrate showed better capability to induce phase separation, when compared to potassium phosphate.

  16. Liquid-liquid equilibrium and partitioning features of bovine trypsin in Ucon 50 HB5100 /sodium citrate aqueous two phase systems

    OpenAIRE

    Tubío, Gisela; Venâncio, Armando; Teixeira, J. A.; Nerli, Bibiana B.; Picó, Guillermo A.

    2008-01-01

    The phase diagrams of Ucon 50-HB-5100, a non-ionic random copolymer of ethylene oxide and propylene oxide (EOPO) and sodium citrate aqueous two-phase systems were determined at different pHs (5.20 and 8.20) and temperatures (5, 20 and 40º C). The binodal curves were determined by refractive index and enzymatic assay of the solution and described using a four-parameter sigmoidal equation, the reliability of the measured tie line compositions was ascertained by correlation equations...

  17. Lactose hydrolysis in aqueous two-phase system by whole-cell {beta}-galactosidase of Kluyveromyces marxianus. Semicontinuous and continuous processes

    Energy Technology Data Exchange (ETDEWEB)

    Tomaska, M. [Slovak Technical Univ., Bratislava (Slovakia). Dept. of Biochemical Technology; Stredansky, M. [Slovak Technical Univ., Bratislava (Slovakia). Dept. of Biochemical Technology; Tomaskova, A. [Slovak Technical Univ., Bratislava (Slovakia). Dept. of Biochemical Technology; Sturdik, E. [Slovak Technical Univ., Bratislava (Slovakia). Dept. of Biochemical Technology

    1995-01-01

    Semicontinuous and continuous hydrolysis of lactose in aqueous two-phase systems (polyethylene glycol 20000/ dextran 40) with whole-cell {beta}-galactosidase of K. marxianus were studied. Both phase polymers had no effect on {beta}-galactosidase activity confined in cells. Good operational stability of the biocatalyst during 55 cycles of semicontinuous process was observed without appreciable decrease in product concentration. Continuous hydrolysis of lactose was performed in the stirred bioreactor, connected with the phase separator. The satisfactory degree of hydrolysis (between 82-88%) and volumetric productivity (21.6 g/l/h) were reached during 72 hours of continuous hydrolysis of 5% (w/w) lactose. (orig.)

  18. LITERATURE REVIEW: HEAT TRANSFER THROUGH TWO-PHASE INSULATION SYSTEMS CONSISTING OF POWDERS IN A CONTINUOUS GAS PHASE

    Science.gov (United States)

    The report, a review of the literature on heat flow through powders, was motivated by the use of fine powder systems to produce high thermal resistivities (thermal resistance per unit thickness). he term "superinsulations" has been used to describe this type of material, which ha...

  19. Existence and stability of weak solutions for a degenerate parabolic system modelling two-phase flows in porous media

    CERN Document Server

    Escher, Joachim; Matioc, Bogdan-Vasile

    2011-01-01

    We prove global existence of nonnegative weak solutions to a degenerate parabolic system which models the interaction of two thin fluid films in a porous medium. Furthermore, we show that these weak solutions converge at an exponential rate towards flat equilibria.

  20. Two-phase flow studies. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kestin, J.; Maeder, P.F.

    1980-08-01

    Progress on the following is reported: literature survey, design of two-phase flow testing facility, design of nozzle loop, thermophysical properties, design manual, and advanced energy conversion systems. (MHR)

  1. Countercurrent Chromatographic Separation of Lipophilic Ascorbic Acid Derivatives and Extract from Kadsura Coccinea Using Hydrophobic Organic-Aqueous Two-Phase Solvent Systems.

    Science.gov (United States)

    Shinomiya, Kazufusa; Li, Heran; Kitanaka, Susumu; Ito, Yoichiro

    2009-01-01

    Countercurrent chromatographic (CCC) separation of lipophilic ascorbic acid derivatives and the crude extract from Kadsura Coccinea was performed using the type-J multilayer coil planet centrifuge with a hydrophobic organic-aqueous two-phase solvent system composed of n-hexane/ethyl acetate/ethanol/aqueous 0.1% trifluoroacetic acid at the volume ratio of (5 : 5 : 6 : 2). The lipophilic ascorbic acid derivatives were separated in the order of L-ascrobyl 2,6-dibutyrate, L-ascorbyl 6-palmitate and L-ascorbyl 6-stearate by eluting the lower phase as the mobile phase, and L-ascorbyl 2,6-dipalmitate was separated by eluting the upper phase at the opposite direction. The above solvent system was then applied to the CCC separation of the extract prepared from K. coccinea. With lower phase mobile, the extract was mainly separated into two peaks corresponding to lignans and triterpenoids accordingly. The HPLC analysis of the fractions showed that the former peak contained Kadsulignan N, Schizandrin H and Neokadsuranin as lignans, and the latter peak, Micranoic acid A, Neokadsuranic acid B and beta-Sitosterol as triterpenoids. The overall results indicate that the hydrophobic organic-aqueous two-phase solvent system used in the present studies was useful for the CCC separation of lignans and triterpenoids present in the natural products.

  2. High resolution of racemic phenylalanine with dication imidazolium-based chiral ionic liquids in a solid-liquid two-phase system.

    Science.gov (United States)

    Huang, Xiaoxia; Wu, Haoran; Wang, Zhixia; Luo, Yingjie; Song, Hang

    2017-01-06

    A novel solid-liquid two-phase system was developed for the chiral separation of racemic phenylalanine with new dication imidazolium-based chiral ionic liquids. Preliminary experiments showed distinct enantioselectivity in amino acid extraction with the novel solid-liquid two-phase system, more L-enantiomer of amino acid cooperatively interacted with ionic liquids and copper ions to be the solid phase. Various factors, including the alkyl chain length of cations of ionic liquids, the amount of copper acetate, the ratio of n(ILs)/n(Cu(2+)), the amount of water and racemic phenylalanine, the resolution time together with the resolution temperature, were systematically investigated for their influence on resolution efficiency. The results showed that, under a certain condition, the enantiomeric excess value and the yield of phenylalanine in liquid phase (mainly containing D-enantiomer) were 67.8% and 96.5%, the enantiomeric excess value and the yield of phenylalanine in solid phase (mainly containing L-enantiomer) were 99.2% and 85.2%. Finally, 2D NMR technology, infrared spectroscopy and molecular simulation method were used to study the interaction mechanism. The results indicated that L-enantiomer of phenylalanine interacts more strongly with chiral ILs and Cu(2+). The novel system has characteristics of free-organic solvent, simple operation, fast separation process and very high resolution efficiency for racemic phenylalanine. This work could provide a new and alternative resolution approach for other chiral separations.

  3. Photochemical oxidation of thiophene by O2 in an oil/acetonitrile two-phase extraction system.

    Science.gov (United States)

    Li, Fa-Tang; Zhao, Di-Shun; Li, Hong-Xia; Liu, Rui-Hong

    2008-10-01

    Photochemical oxidation of thiophene in an n-octane/acetonitrile extraction system using O(2) as oxidant was studied. Results obtained here can be used as a reference for desulfurization of gasoline, because thiophene is one of the main components containing sulfur in fluid catalytic cracking gasoline. A 500-W high-pressure mercury lamp was used as a light source for irradiation, and air was introduced by a gas pump to supply O(2). Thiophene dissolved in nopolar n-octane solvent was photodecomposed and removed into the polar acetonitrile phase. The desulfurization rate of thiophene in n-octane was 65.2% under photoirradiation for 5 h under the conditions of air flow at 150 mL min(-1), and V(n-octane):V(acetonitrile) = 1:1. This can be improved to 96.5% by adding 0.15 g Na-ZSM-5 zeolite into the 100-mL reaction system, which is the absorbent for O(2) and thiophene. Under such conditions, the photooxidation kinetics of thiophene with O(2) and Na-ZSM-5 zeolite is first-order with an apparent rate constant of 0.6297 h(-1) and half-time of 1.10 h. The sulfur content can be reduced from 800 microL L(-1) to 28 microL L(-1).

  4. Microstructure Formations in the Two-Phase Region of the Binary Peritectic Organic System TRIS-NPG

    Science.gov (United States)

    Mogeritsch, Johann; Ludwig, Andreas

    2012-01-01

    In order to prepare for an onboard experiment on the International Space Station (ISS), systematic directional solidification experiments with transparent hypoperitectic alloys were carried out at different solidification rates around the critical velocity for morphological stability of both solid phases. The investigations were done in the peritectic region of the binary transparent organic TRIS-NPG system where the formation of layered structures is expected to occur. The transparent appearance of the liquid and solid phase enables real time observations of the dynamic of pattern formation during solidification. The investigations show that frequently occurring nucleation events govern the peritectic solidification morphology which occurs at the limit of morphological stability. As a consequence, banded structures lead to coupled growth even if the lateral growth is much faster compared to the growth in pulling direction.

  5. Polarity, selectivity and performance of hydrophilic organic/salt-containing aqueous two-phase system on counter-current chromatography for polar compounds.

    Science.gov (United States)

    Liu, Dan; Hong, Zhilai; Gao, Mingzhe; Wang, Zhixin; Gu, Ming; Zhang, Xiaozhe; Xiao, Hongbin

    2016-05-27

    The essential attributes of a solvent system for separation polar compounds on CCC are polarity, selectively and performance. Here, hydrophilic organic/salt-containing aqueous two-phase system (HO/S TPS) was evaluated as an alternative solvent system for CCC separation of polar compounds. Polarity measurements based on Rohrschneider-Snyder parameter was developed as quantitative assessing the polarity of HO/S TPS and comparing with an organic/aqueous system. All investigated 1-butanol/ethanol/saturated ammonium sulfate solution/water (BEAsWat) and 1-butanol/ethanol/saturated dipotassium hydrogen phosphate solution/water (BEDhpWat) systems with polarity values of organic phase from 4.5 to 6.8, were more polar than chloroform/methanol/water (1/1/1). The considerable water content of BEAsWat and BEDhpWat (0/1/1/1/) was 45.4 and 42.6% (w%) of hydrophilic organic phase, and 66.4 and 51.2% (w%) of salt-containing aqueous phase, respectively, closed to conventional aqueous two-phase system. Therefore, the polarity of HO/S TPS is in the middle of organic/aqueous and aqueous two-phase system. The LogKC values of twenty four polar compounds as model mixture confirmed that the polarities of HO/S TPSs were matched to that of the polar compounds and shown to be a very selective technique capable of separating positional isomers. Moreover, BEAsWat and BEDhpWat systems can be easily retained in CCC column with suitable elution mode. The hydrodynamic behavior reversion of HO/S TPS on hydrodynamic CCC was observed and was tentatively explained based on the density difference. Finally, caffeoylquinic acid isomers and dihydroxybenzoic acid isomers were successfully separated with HO/S TPS on CCC, respectively. Those results demonstrate that HO/S TPS on CCC is a performant and stable way to separate polar compounds from natural products.

  6. Cloning of Toluene 4-Monooxygenase Genes and Application of Two-Phase System to the Production of the Anticancer Agent, Indirubin.

    Science.gov (United States)

    Wongsaroj, Lampet; Sallabhan, Ratiboot; Dubbs, James M; Mongkolsuk, Skorn; Loprasert, Suvit

    2015-08-01

    Indirubin is a strong inhibitor of several eukaryotic cell signaling pathways and shows promise as a treatment for myelocytic leukemia and Alzheimer's disease. The tmoABCDEF operon, encoding the components of a novel toluene 4-monooxygenase from the paint factory soil isolate, Pseudomonas sp. M4, was cloned and expressed in Escherichia coli. E. coli::pKSR12 expressing the tmo genes was used to develop a two-phase [dioctyl phthalate (DOP)/aqueous medium] culture system that was optimized to obtain maximal yields of indirubin from the starting substrate, indole. DOP was used as the organic phase to solubilize and sequester the toxic indole substrate, making possible the use of high indole concentrations that would otherwise interfere with growth in aqueous media. A 50 % (v/v) DOP two-phase system using tryptophan medium containing 3 mM cysteine, 5 mM indole, and 1 mM isatin yielded 102.4 mg/L of indirubin with no conversion of indole to the less valuable alternate product, indigo.

  7. Chelate-Modified Fenton Reaction for the Degradation of Trichloroethylene in Aqueous and Two-Phase Systems

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Scott [Univ of KY, dept of chemical and materials engineering; lynch, Andrew [Univ of KY, dept of chemical and materials engineering; Bachas, Leonidas [Univ of KY, Dept of Chemistry; hampson, Steve [Univ of KY Center for Applied Energy Research - KY Research Consortium of Energy and Environment; Ormsbee, Lindelle [Univ of KY Center for Applied Energy Research - KY Research Consortium of Energy and Environment; Bhattacharyya, Dibakar [Univ of KY, dept of chemical and materials engineering

    2008-06-01

    The Standard Fenton reaction has been used for In-Situ Chemical Oxidation (ISCO) of toxic organics in groundwater. However, it requires low pH operating conditions, and thus has limitations for in situ applications. In addition, hydroxyl radicals are rapidly consumed by hydroxyl scavengers found in the subsurface. These problems are alleviated through the chelate-modified Fenton (hydroxyl radical) reaction, which includes the addition of nontoxic chelate (L) such as citrate or gluconic acid. This chelate allows the reaction to take place at bear neutral pH and control hydrogen peroxide consumption by binding to Fe(II), forming an FeL complex. The chelate also binds to Fe(III), preventing its precipitation as ferric hydroxide and thus prevents problems associated with injection well plugging. The rate of TCE dechlorination in chelate-modified Fenton systems is a function of pH, H2O2 concentration, and FE:L ratio. The primary objective of this research is to model and apply this process to the destruction of trichloroethylene (TCE) present in both the aqueous and organic (in the form of droplets) phases. Experimentation proved the chelate-modified Fenton reaction effectively dechlorinates TCE in both the aqueous and organic phases at near-neutral pH. Other focuses of this work include determining the effect of [L]:[Fe] ratios on H2O2 and TCE degradation as well as reusability of the FE citrate solution under repeated H2O2 injections. Generalized models were developed to predict the concentration of TCE in the aqueous phase and TCE droplet radius as a function of time using established hydroxyl radial kinetics and mass transfer relationships.

  8. Study and Implementation of a Two-Phase Interleaved Bidirectional DC/DC Converter for Vehicle and DC-Microgrid Systems

    Directory of Open Access Journals (Sweden)

    Ching-Ming Lai

    2015-09-01

    Full Text Available The objective of this paper is to implement a two-phase, interleaved, bidirectional DC/DC converter topology with an improved voltage conversion ratio for electric vehicle (EV and DC-microgrid systems. In this study, a two-phase interleaved charge-pump topology is introduced to achieve a high voltage conversion ratio with very simple control circuits. In discharge mode, the circuit topology acts as a voltage-multiplier boost converter to achieve a high step-up conversion ratio (48 V to 240 V. In charge mode, the circuit topology acts as a voltage-divider buck converter to achieve a high voltage step-down conversion ratio (240 V to 48 V. The circuit configuration, operating principle, steady-state analysis and the closed-loop control of the proposed converter are presented. Experiments conducted on a laboratory prototype with 500 W power-rating are presented to verify the effectiveness. The maximum efficiency levels in discharge and charge modes are about 97.7% and 98.4% respectively.

  9. Extraction of Theanine from Waste Liquid of Tea Polyphenol Production in Aqueous Two-phase Systems with Cationic and Anionic Surfactants

    Institute of Scientific and Technical Information of China (English)

    ZHANG Junwei; WANG Yan; PENG Qijun

    2013-01-01

    Extraction of theanine from waste liquid of tea polyphenol production was studied in aqueous surfactant two-phase system (ASTP) with cationic suffactant (CTAB) and anionic surfactant (SDS).Results indicate that the region of ASTP is narrow and there is only a two-phase region of cationic surfactant.The increase in concentrations of NaBr and Na2SO4 are beneficial to the formation of ASTP.Theanine concentration in the bottom phase increases with increasing concentration of theanine,whereas the partition coefficient and extraction rate only change a little when the concentration of theanine is above 0.2 g· L-1.With the increase of SDS concentration,the phase ratio and the partition coefficient decrease,while the extraction efficiency of theanine increases and the concentration of theaninc changes a little in the range from 2.4/7.5 to 2.8/7.2 for SDS/CTAB ratio.The temperature has a notable effect on the concentration of theanine in the bottom phase,partition coefficient and extraction rate of theanine.The increase of waste liquid decreases the phase ratio,increases the concentration and extraction rate of theanine in the bottom phase,since the protein and the saccharide enter the bottom phase with theanine.

  10. Knudsen effusion mass spectrometric studies over (USn3+U3Sn7) two-phase region of U-Sn system

    Science.gov (United States)

    Manikandan, P.; Trinadh, V. V.; Bera, Suranjan; Narasimhan, T. S. Lakshmi; Ananthasivan, K.; Joseph, M.; Mudali, U. Kamachi

    2017-08-01

    Vaporisation studies over (USn3+U3Sn7) ;two-phase; field have been carried out by employing Knudsen effusion mass spectrometry (KEMS) in the temperature range of 1050-1226 K. Sn(g) was the species observed in the mass spectrum of the equilibrium vapour phase over the samples (71.5 at% Sn and 73.0 at% Sn). The partial pressure of Sn(g) was measured as a function of temperature over (USn3+U3Sn7) ;two-phase; field and the p-T relation was derived as log (pSn/Pa) = ((-14580 ± 91)/(T/K)) + (8.82 ± 0.08) (1050-1226 K). The vaporisation reaction 3USn3(s) = U3Sn7(s) + 2Sn(g) was evaluated by second law method. The Gibbs energy of formation of USn3(s) was derived as ΔfGm°(U Sn3 , s , T) (±1.8) = -173.4 + 0.055 T (K) (kJ mol-1) (1050-1226 K). The mass spectrometric studies on this system have been carried out for the first time.

  11. Sophisticated digestive systems in early arthropods.

    Science.gov (United States)

    Vannier, Jean; Liu, Jianni; Lerosey-Aubril, Rudy; Vinther, Jakob; Daley, Allison C

    2014-05-02

    Understanding the way in which animals diversified and radiated during their early evolutionary history remains one of the most captivating of scientific challenges. Integral to this is the 'Cambrian explosion', which records the rapid emergence of most animal phyla, and for which the triggering and accelerating factors, whether environmental or biological, are still unclear. Here we describe exceptionally well-preserved complex digestive organs in early arthropods from the early Cambrian of China and Greenland with functional similarities to certain modern crustaceans and trace these structures through the early evolutionary lineage of fossil arthropods. These digestive structures are assumed to have allowed for more efficient digestion and metabolism, promoting carnivory and macrophagy in early arthropods via predation or scavenging. This key innovation may have been of critical importance in the radiation and ecological success of Arthropoda, which has been the most diverse and abundant invertebrate phylum since the Cambrian.

  12. Multi-stage mixer-settler planet centrifuge. Preliminary studies on partition of macromolecules with organic-aqueous and aqueous-aqueous two-phase solvent systems.

    Science.gov (United States)

    Ito, Y; Zhang, T Y

    1988-03-11

    A rotary-seal-free planetary centrifuge holds a separation column which consists of multiple partition units (ca. 200) connected in series with transfer tubes. In the cavity of each partition unit the transfer tube extends to form a mixer which vibrates to stir the contents under an oscillating force field generated by the planetary motion of the centrifuge. Consequently, solutes locally introduced at the inlet of the column are subjected to an efficient partition process in each partition unit and separated according to their partition coefficients. The mixer tube equipped with a flexible silicone rubber joint was found to produce excellent results for partition with viscous polymer phase systems. The capability of the method was demonstrated on separation of cytochrome c and lysozyme using a PEG-aqueous dibasic potassium phosphate-aqueous two-phase solvent system.

  13. Genetic engineering of the Fusarium solani pisi lipase cutinase for enhanced partitioning in PEG-phosphate aqueous two-phase systems.

    Science.gov (United States)

    Bandmann, N; Collet, E; Leijen, J; Uhlén, M; Veide, A; Nygren, P A

    2000-04-28

    The Fusarium solani pisi lipase cutinase has been genetically engineered to investigate the influence of C-terminal peptide extensions on the partitioning of the enzyme in PEG-salt based aqueous two-phase bioseparation systems. Seven different cutinase lipase variants were constructed containing various C-terminal peptide extensions including tryptophan rich peptide tags ((WP)(2) and (WP)(4)), positively ((RP)(4)) and negatively ((DP)(4)) charged tags as well as combined tags with tryptophan together with either positively ((WPR)(4)) or negatively ((WPD)(4)) charged amino acids. The modified cutinase variants were stably produced in Escherichia coli as secreted to the periplasm from which they were efficiently purified by IgG-affinity chromatography employing an introduced N-terminal IgG-binding ZZ affinity fusion partner present in all variants. Partitioning experiments performed in a PEG 4000/sodium phosphate aqueous two-phase system showed that for variants containing either (WP)(2) or (WP)(4) peptide extensions, 10- to 70-fold increases in the partitioning to the PEG rich top-phase were obtained, when compared to the wild type enzyme. An increased partitioning was also seen for cutinase variants tagged with both tryptophans and charged amino acids, whereas the effect of solely charged peptide extensions was relatively small. In addition, when performing partitioning experiments from cell disintegrates, the (WP)(4)-tagged cutinase showed a similarly high PEG-phase partitioning, indicating that the effect from the peptide tag was unaffected by the background of the host proteins. Taken together, the results show that the partitioning of the recombinantly produced cutinase model enzyme could be significantly improved by relatively minor genetic engineering and that the effects observed for purified proteins are retained also in an authentic whole cell disintegrate system. The results presented should be of general interest also for the improvement of the

  14. Development of the Digestive System-Experimental Challenges and Approaches of Infant Lipid Digestion.

    Science.gov (United States)

    Abrahamse, Evan; Minekus, Mans; van Aken, George A; van de Heijning, Bert; Knol, Jan; Bartke, Nana; Oozeer, Raish; van der Beek, Eline M; Ludwig, Thomas

    2012-12-01

    At least during the first 6 months after birth, the nutrition of infants should ideally consist of human milk which provides 40-60 % of energy from lipids. Beyond energy, human milk also delivers lipids with a specific functionality, such as essential fatty acids (FA), phospholipids, and cholesterol. Healthy development, especially of the nervous and digestive systems, depends fundamentally on these. Epidemiological data suggest that human milk provides unique health benefits during early infancy that extend to long-lasting benefits. Preclinical findings show that qualitative changes in dietary lipids, i.e., lipid structure and FA composition, during early life may contribute to the reported long-term effects. Little is known in this respect about the development of digestive function and the digestion and absorption of lipids by the newborn. This review gives a detailed overview of the distinct functionalities that dietary lipids from human milk and infant formula provide and the profound differences in the physiology and biochemistry of lipid digestion between infants and adults. Fundamental mechanisms of infant lipid digestion can, however, almost exclusively be elucidated in vitro. Experimental approaches and their challenges are reviewed in depth.

  15. Bile acid nuclear receptor FXR and digestive system diseases

    Directory of Open Access Journals (Sweden)

    Lili Ding

    2015-03-01

    Full Text Available Bile acids (BAs are not only digestive surfactants but also important cell signaling molecules, which stimulate several signaling pathways to regulate some important biological processes. The bile-acid-activated nuclear receptor, farnesoid X receptor (FXR, plays a pivotal role in regulating bile acid, lipid and glucose homeostasis as well as in regulating the inflammatory responses, barrier function and prevention of bacterial translocation in the intestinal tract. As expected, FXR is involved in the pathophysiology of a wide range of diseases of gastrointestinal tract, including inflammatory bowel disease, colorectal cancer and type 2 diabetes. In this review, we discuss current knowledge of the roles of FXR in physiology of the digestive system and the related diseases. Better understanding of the roles of FXR in digestive system will accelerate the development of FXR ligands/modulators for the treatment of digestive system diseases.

  16. An alternative method to isolate protease and phospholipase A2 toxins from snake venoms based on partitioning of aqueous two-phase systems

    Directory of Open Access Journals (Sweden)

    GN Gómez

    2012-01-01

    Full Text Available Snake venoms are rich sources of active proteins that have been employed in the diagnosis and treatment of health disorders and antivenom therapy. Developing countries demand fast economical downstream processes for the purification of this biomolecule type without requiring sophisticated equipment. We developed an alternative, simple and easy to scale-up method, able to purify simultaneously protease and phospholipase A2 toxins from Bothrops alternatus venom. It comprises a multiple-step partition procedure with polyethylene-glycol/phosphate aqueous two-phase systems followed by a gel filtration chromatographic step. Two single bands in SDS-polyacrylamide gel electrophoresis and increased proteolytic and phospholipase A2 specific activities evidence the homogeneity of the isolated proteins.

  17. Separation of clavulanic acid from fermented broth of amino acids by an aqueous two-phase system and ion-exchange adsorption.

    Science.gov (United States)

    da Silva, Clovis Sacardo; Cuel, Maressa Fabiano; Barreto, Verônica Orlandin; Kwong, Wu Hong; Hokka, Carlos O; Barboza, M

    2012-02-15

    The clavulanic acid is a substance which inhibits the β-lactamases used with penicillins for therapeutic treatment. After the fermentation, by-products of low molecular weight such as amino acids lysine, histidine, proline and tyrosine are present in the fermented broth. To remove these impurities the techniques of extraction by an aqueous two-phase system of 17% polyethylene glycol molecular weight 600 and 15% potassium phosphate were used for a partial purification. A subsequent ion-exchange adsorption was used for the recuperation of the clavulanic acid of the top phase and purification getting a concentration factor of 2 and purification of 100% in relation to the amino acids lysine, histidine, proline and tyrosine.

  18. Surfactant-coated Candida rugosa Lipase as Catalyst for Hydrolysis of Olive Oil in Solvent-Free Two-Phase System

    Institute of Scientific and Technical Information of China (English)

    宋宝东; 丁辉; 吴金川; HayashiY.; TalukderMMR; 王世昌

    2003-01-01

    The surfactant-coated Candida rugosa lipase was used as catalyst for hydrolysis of olive oil in two-phase system consisting of olive oil and phosphate buffer without organic solvent. For both the coated and native lipases,the optimal buffer/oil volume ratio of 1.0, aqueous pH 6.8 and reaction temperature 30℃ were determined. The maximum activity of the coated lipase was ca 1.3 times than that of the native lipase. The half-life of the coated lipase in olive oil and the native lipase in phosphate buffer was ca 9 h and 12 h, and the final residual activity was 27% and 20% of their initial values, respectively. The final substrate conversion by the coated lipase was ca 20% higher than that of the native lipase.

  19. Calculation of liquid-liquid equilibrium of aqueous two-phase systems using a chemical-theory-based excess Gibbs energy model

    Directory of Open Access Journals (Sweden)

    Pessôa Filho P. A.

    2004-01-01

    Full Text Available Mixtures containing compounds that undergo hydrogen bonding show large deviations from ideal behavior. These deviations can be accounted for through chemical theory, according to which the formation of a hydrogen bond can be treated as a chemical reaction. This chemical equilibrium needs to be taken into account when applying stability criteria and carrying out phase equilibrium calculations. In this work, we illustrate the application of the stability criteria to establish the conditions under which a liquid-phase split may occur and the subsequent calculation of liquid-liquid equilibrium using a chemical-theory-modified Flory-Huggins equation to describe the non ideality of aqueous two-phase systems composed of poly(ethylene glycol and dextran. The model was found to be able to correlate ternary liquid-liquid diagrams reasonably well by simple adjustment of the polymer-polymer binary interaction parameter.

  20. The tendency of smooth and rough Salmonella typhimurium bacteria and lipopolysaccharide to hydrophobic and ionic interaction, as studied in aqueous polymer two-phase systems.

    Science.gov (United States)

    Magnusson, K E; Stendahl, O; Tagesson, C; Edebo, L; Johansson, G

    1977-06-01

    In aqueous two-phase system, the partition of bacteria and lipopolysaccharide from a rough (R) strain (Rd-mutant) of Salmonella typhimurium is influenced by polymers with covalently linked hydrophobic groups indicating hydrophobic structures accessible at the cell surface. Furthermore, the partition of the R bacteria is influenced by a number of inorganic positive and negative ions, presumably as a consequence of interaction with negatively charged surface structures. In contrast, smooth (S) bacteria and lipopolysaccharide from the parent strain do not seem to participate in either hydrophobic or charge interaction indicating extensive hydrophilicity without charge. Thus, the S-specific polysaccharide side chain of S. typhimurium might serve the purpose of blindfolding aspecific host defence mechanisms dependent on hydrophobicity and charge. On the contrary, the R bacteria and R lipopolysaccharide have physico-chemical properties which predispose to interaction with several types of cells, organelles and molecules.

  1. Determination of sunset yellow and tartrazine in food samples by combining ionic liquid-based aqueous two-phase system with high performance liquid chromatography.

    Science.gov (United States)

    Sha, Ou; Zhu, Xiashi; Feng, Yanli; Ma, Weixing

    2014-01-01

    We proposed a simple and effective method, by coupling ionic liquid-based aqueous two-phase systems (IL-ATPSs) with high performance liquid chromatography (HPLC), for the analysis of determining tartrazine and sunset yellow in food samples. Under the optimized conditions, IL-ATPSs generated an extraction efficiency of 99% for both analytes, which could then be directly analyzed by HPLC without further treatment. Calibration plots were linear in the range of 0.01-50.0 μg/mL for both Ta and SY. The limits of detection were 5.2 ng/mL for Ta and 6.9 ng/mL for SY. This method proves successful for the separation/analysis of tartrazine and sunset yellow in soft drink sample, candy sample, and instant powder drink and leads to consistent results as obtained from the Chinese national standard method.

  2. Determination of Sunset Yellow and Tartrazine in Food Samples by Combining Ionic Liquid-Based Aqueous Two-Phase System with High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Ou Sha

    2014-01-01

    Full Text Available We proposed a simple and effective method, by coupling ionic liquid-based aqueous two-phase systems (IL-ATPSs with high performance liquid chromatography (HPLC, for the analysis of determining tartrazine and sunset yellow in food samples. Under the optimized conditions, IL-ATPSs generated an extraction efficiency of 99% for both analytes, which could then be directly analyzed by HPLC without further treatment. Calibration plots were linear in the range of 0.01–50.0 μg/mL for both Ta and SY. The limits of detection were 5.2 ng/mL for Ta and 6.9 ng/mL for SY. This method proves successful for the separation/analysis of tartrazine and sunset yellow in soft drink sample, candy sample, and instant powder drink and leads to consistent results as obtained from the Chinese national standard method.

  3. Releasing intracellular product to prepare whole cell biocatalyst for biosynthesis of Monascus pigments in water-edible oil two-phase system.

    Science.gov (United States)

    Hu, Minglue; Zhang, Xuehong; Wang, Zhilong

    2016-11-01

    Selective releasing intracellular product in Triton X-100 micelle aqueous solution to prepare whole cell biocatalyst is a novel strategy for biosynthesis of Monascus pigments, in which cell suspension culture exhibits some advantages comparing with the corresponding growing cell submerged culture. In the present work, the nonionic surfactant Triton X-100 was successfully replaced by edible plant oils for releasing intracellular Monascus pigments. High concentration of Monascus pigments (with absorbance nearly 710 AU at 470 nm in the oil phase, normalized to the aqueous phase volume approximately 142 AU) was achieved by cell suspension culture in peanut oil-water two-phase system. Furthermore, the utilization of edible oil as extractant also fulfills the demand for application of Monascus pigments as natural food colorant.

  4. Optimization of ultrasound-assisted aqueous two-phase system extraction of polyphenolic compounds from Aronia melanocarpa pomace by response surface methodology.

    Science.gov (United States)

    Xu, Yan-Yang; Qiu, Yang; Ren, Hui; Ju, Dong-Hu; Jia, Hong-Lei

    2017-03-16

    Aronia melanocarpa berries are abundant in polyphenolic compounds. After juice production, the pomace of pressed berries still contains a substantial amount of polyphenolic compounds. For efficient utilization of A. melanocarpa berries and the enhancement of polyphenolic compound yields in Aronia melanocarpa pomace (AMP), total phenolics (TP) and total flavonoids (TF) from AMP were extracted, using ultrasound-assisted aqueous two-phase system (UAE-ATPS) extraction method. First, the influences of ammonium sulfate concentration, ethanol-water ratio, ultrasonic time, and ultrasonic power on TP and TF yields were investigated. On this basis, process variables such as ammonium sulfate concentration (0.30-0.35 g mL(-1)), ethanol-water ratio (0.6-0.8), ultrasonic time (40-60 min), and ultrasonic power (175-225 W) were further optimized by implementing Box-Benhnken design with response surface methodology. The experimental results showed that optimal extraction conditions of TP from AMP were as follows: ammonium sulfate concentration of 0.324 g mL(-1), ethanol-water ratio of 0.69, ultrasonic time of 52 min, and ultrasonic power of 200 W. Meanwhile, ammonium sulfate concentration of 0.320 g mL(-1), ethanol-water ratio of 0.71, ultrasonic time of 50 min, and ultrasonic power of 200 W were determined as optimum extraction conditions of TF in AMP. Experimental validation was performed, where TP and TF yields reached 68.15 ± 1.04 and 11.67 ± 0.63 mg g(-1), respectively. Close agreement was found between experimental and predicted values. Overall, the present results demonstrated that ultrasound-assisted aqueous two-phase system extraction method was successfully used to extract total phenolics and flavonoids in A. melanocarpa pomace.

  5. Whole genome sequence of Clostridium bornimense strain M2/40 isolated from a lab-scale mesophilic two-phase biogas reactor digesting maize silage and wheat straw.

    Science.gov (United States)

    Hahnke, Sarah; Wibberg, Daniel; Tomazetto, Geizecler; Pühler, Alfred; Klocke, Michael; Schlüter, Andreas

    2014-08-20

    The bacterium Clostridium bornimense M2/40 is a mesophilic, anaerobic bacterium isolated from a two-phase biogas reactor continuously fed with maize silage and 5% wheat straw. Grown on glucose, it produced H2, CO2, formiate, lactate and propionate as the main fermentation products, of which some compounds serve as substrates for methanogenic Archaea to form methane. Here, the whole genome sequence of the bacterium consisting of two circular replicons is reported. This genome information provides the basis for further studies addressing metabolic features of the isolate and its role in anaerobic biomass degradation.

  6. (Liquid + liquid) and (liquid + solid) equilibrium of aqueous two-phase systems containing poly ethylene glycol di-methyl ether 2000 and di-sodium hydrogen phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Zafarani-Moattar, Mohammed Taghi, E-mail: zafarani47@yahoo.co [Physical Chemistry Department, University of Tabriz, Tabriz 51664 (Iran, Islamic Republic of); Nasiri, Saeed [Physical Chemistry Department, University of Tabriz, Tabriz 51664 (Iran, Islamic Republic of)

    2010-09-15

    (Liquid + liquid) equilibrium (LLE) for the {l_brace}poly ethylene glycol di-methyl ether 2000 (PEGDME{sub 2000}) + Na{sub 2}HPO{sub 4} + H{sub 2}O{r_brace} system have been determined experimentally at T = (298.15, 308.15, 313.15, and 318.15) K. The effects of temperature on the binodals and tie-lines for the investigated aqueous two-phase system (ATPS) have been studied. An empirical non-linear expression developed by Merchuk was used for reproducing the experimental binodal data. In this work, the three fitting parameters of the Merchuk equation were obtained with the temperature dependence expressed in the linear form with (T - T{sub 0}) K as a variable. Furthermore, the modified local composition segment-based NRTL and Wilson models and also osmotic virial equation were used to describe the LLE data of the studied system. Also, the effects of the type of salt on LLE are discussed. In addition, the effects of end groups of the polymers PEGDME{sub 2000} and poly ethylene glycol 2000 on phase forming ability were studied. The complete phase diagram for the poly ethylene {l_brace}glycol di-methyl ether 2000 (PEGDME{sub 2000}) + Na{sub 2}HPO{sub 4} + H{sub 2}O{r_brace} system has also been determined at T = 298.15 K.

  7. 手性药物扁桃酸的双水相分离%Study on partition of D(-)-mandelic acid in aqueous two-phase systems

    Institute of Scientific and Technical Information of China (English)

    许小平; 李忠琴; 陈杰波

    2004-01-01

    Studies on the partition of D (-)-mandelic acid were performed in polyethylene glycol (PEG) with molecular masses of 2000, 4000, 6000, 10000, 20000- ammonium sulfate systems. The effect of various parameters such as molecular mass of PEG, phase composition, pH of the system and temperature were investigated in this work. The results indicate that the molecular mass of PEG is a key factor affecting the partitioning behaviors of D(-)-mandelic acid in the PEG -(NH4)2SO4 systems. The influence of pH on the partition shows that the partition coefficient of D(-)-mandelic acid decreases with the increase of pH value. D(-)-mandelic acid partition is only slightly influenced by the temperature. All these indicate that the aqueous two-phase is a very suitable alternative system for the separation of D(-)-mandelic acid.%采用聚乙二醇-硫酸铵双水相系统分离手性药物扁桃酸.研究了聚乙二醇分子量、相组成、pH值和温度对扁桃酸分离的影响.结果表明,聚乙二醇分子量对双水相分离扁桃酸的影响最大;温度对扁桃酸的分离几乎没有影响;随pH增大,扁桃酸分配系数减少.

  8. The influence of molecular weight of polyethylene glycol on separation and purification of pectinases from Penicillium cyclopium in aqueous two-phase system

    Directory of Open Access Journals (Sweden)

    Prodanović Jelena M.

    2008-01-01

    Full Text Available In this study the possibility of the partitioning and purification of pectinases from Penicillium cyclopium by their partitioning in polymer/polymer and polymer/salt aqueous two-phase systems was investigated. In the system with 10% (w/w polyethylene glycol 1500/5% (w/w dextran 500 000/85% (w/w crude enzyme, the highest values for partitioning parameters were achieved - the partition coefficient was 2.11, followed by the top phase yield of 85.68% and purification factor 1.28 for the endo-pectinase activity. The partition coefficient, yield in the top phase and purification factor for the exo-pectinase activity in the same system were 1.89, 84.28% and 3.82, respectively. In the system with 10% (w/w polyethylene glycol 6000/15% (w/w (NH42SO4/75% (w/w crude enzyme purification factor 37.85 for exo-pectinase, and 19.52 for endo-pectinase in the bottom phase were obtained.

  9. Direct Purification of Pectinase from Mango (Mangifera Indica Cv. Chokanan Peel Using a PEG/Salt-Based Aqueous Two Phase System

    Directory of Open Access Journals (Sweden)

    Abdul Manap Mohd Yazid

    2011-10-01

    Full Text Available An Aqueous Two-Phase System (ATPS was employed for the first time for the separation and purification of pectinase from mango (Mangifera Indica Cv. Chokanan peel. The effects of different parameters such as molecular weight of the polymer (polyethylene glycol, 2,000–10,000, potassium phosphate composition (12–20%, w/w, system pH (6–9, and addition of different concentrations of neutral salts (0–8%, w/w on partition behavior of pectinase were investigated. The partition coefficient of the enzyme was decreased by increasing the PEG molecular weight. Additionally, the phase composition showed a significant effect on purification factor and yield of the enzyme. Optimum conditions for purification of pectinase from mango peel were achieved in a 14% PEG 4000-14% potassium phosphate system using 3% (w/w NaCl addition at pH 7.0. Based on this system, the purification factor of pectinase was increased to 13.2 with a high yield of (97.6%. Thus, this study proves that ATPS can be an inexpensive and effective method for partitioning of pectinase from mango peel.

  10. Direct purification of pectinase from mango (Mangifera Indica Cv. Chokanan) peel using a PEG/salt-based Aqueous Two Phase System.

    Science.gov (United States)

    Mehrnoush, Amid; Sarker, Md Zaidul Islam; Mustafa, Shuhaimi; Yazid, Abdul Manap Mohd

    2011-10-10

    An Aqueous Two-Phase System (ATPS) was employed for the first time for the separation and purification of pectinase from mango (Mangifera Indica Cv. Chokanan) peel. The effects of different parameters such as molecular weight of the polymer (polyethylene glycol, 2,000-10,000), potassium phosphate composition (12-20%, w/w), system pH (6-9), and addition of different concentrations of neutral salts (0-8%, w/w) on partition behavior of pectinase were investigated. The partition coefficient of the enzyme was decreased by increasing the PEG molecular weight. Additionally, the phase composition showed a significant effect on purification factor and yield of the enzyme. Optimum conditions for purification of pectinase from mango peel were achieved in a 14% PEG 4000-14% potassium phosphate system using 3% (w/w) NaCl addition at pH 7.0. Based on this system, the purification factor of pectinase was increased to 13.2 with a high yield of (97.6%). Thus, this study proves that ATPS can be an inexpensive and effective method for partitioning of pectinase from mango peel.

  11. Aqueous two-phase system cold-set gelation using natural and recombinant probiotic lactic acid bacteria as a gelling agent.

    Science.gov (United States)

    Léonard, Lucie; Husson, Florence; Langella, Philippe; Châtel, Jean-Marc; Saurel, Rémi

    2016-05-01

    The present study aimed to entrap probiotic lactic acid bacteria (LAB) in a sodium alginate and sodium caseinate aqueous two-phase gel system. The natural acidifying properties of two therapeutic probiotic LAB were exploited to liberate calcium ions progressively from calcium carbonate (CaCO3), which caused the gelation of the co-existing phases. Bi-biopolymeric matrix gelation of GDL/CaCO3 or LAB/CaCO3 was monitored by dynamic rheological measurements, and the final gels were characterized by frequency dependence measurements and confocal laser scanning microscopy. Weak to strong gels were formed with an elastic modulus G' from 10 to 1.000Pa, respectively. After cold-set gelation of our system, confocal laser scanning microscopy showed spherical protein microdomains trapped within a calcium alginate network. LAB cells were stained to study their partition in the self-gelling matrices. Our LAB strains showed two different behaviors, which may relate to the exopolysaccharide production: (i) Lactobacillus plantarum CNRZ1997 cells were found mainly in continuous alginate networks, whereas (ii) Lactococcus lactis cells were localized in protein microdomains. This alginate-caseinate phase-separated system that was self-gelled by LAB cells may be an innovative approach for immobilizing and protecting LAB cells.

  12. Optimization of serine protease purification from mango (Mangifera indica cv. Chokanan) peel in polyethylene glycol/dextran aqueous two phase system.

    Science.gov (United States)

    Mehrnoush, Amid; Mustafa, Shuhaimi; Sarker, Md Zaidul Islam; Yazid, Abdul Manap Mohd

    2012-01-01

    Mango peel is a good source of protease but remains an industrial waste. This study focuses on the optimization of polyethylene glycol (PEG)/dextran-based aqueous two-phase system (ATPS) to purify serine protease from mango peel. The activity of serine protease in different phase systems was studied and then the possible relationship between the purification variables, namely polyethylene glycol molecular weight (PEG, 4000-12,000 g·mol(-1)), tie line length (-3.42-35.27%), NaCl (-2.5-11.5%) and pH (4.5-10.5) on the enzymatic properties of purified enzyme was investigated. The most significant effect of PEG was on the efficiency of serine protease purification. Also, there was a significant increase in the partition coefficient with the addition of 4.5% of NaCl to the system. This could be due to the high hydrophobicity of serine protease compared to protein contaminates. The optimum conditions to achieve high partition coefficient (84.2) purification factor (14.37) and yield (97.3%) of serine protease were obtained in the presence of 8000 g·mol(-1) of PEG, 17.2% of tie line length and 4.5% of NaCl at pH 7.5. The enzymatic properties of purified serine protease using PEG/dextran ATPS showed that the enzyme could be purified at a high purification factor and yield with easy scale-up and fast processing.

  13. Validation and comparison of two-phase flow modeling capabilities of CFD, sub channel and system codes by means of post-test calculations of BFBT transient tests

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, Wadim; Manes, Jorge Perez; Imke, Uwe; Escalante, Javier Jimenez; Espinoza, Victor Sanchez, E-mail: victor.sanchez@kit.edu

    2013-10-15

    Highlights: • Simulation of BFBT turbine and pump transients at multiple scales. • CFD, sub-channel and system codes are used for the comparative study. • Heat transfer models are compared to identify difference between the code predictions. • All three scales predict results in good agreement to experiment. • Sub cooled boiling models are identified as field for future research. -- Abstract: The Institute for Neutron Physics and Reactor Technology (INR) at the Karlsruhe Institute of Technology (KIT) is involved in the validation and qualification of modern thermo hydraulic simulations tools at various scales. In the present paper, the prediction capabilities of four codes from three different scales – NEPTUNE{sub C}FD as fine mesh computational fluid dynamics code, SUBCHANFLOW and COBRA-TF as sub channels codes and TRACE as system code – are assessed with respect to their two-phase flow modeling capabilities. The subject of the investigations is the well-known and widely used data base provided within the NUPEC BFBT benchmark related to BWRs. Void fraction measurements simulating a turbine and a re-circulation pump trip are provided at several axial levels of the bundle. The prediction capabilities of the codes for transient conditions with various combinations of boundary conditions are validated by comparing the code predictions with the experimental data. In addition, the physical models of the different codes are described and compared to each other in order to explain the different results and to identify areas for further improvements.

  14. Water-head-driven microfluidic oscillators for autonomous control of periodic flows and generation of aqueous two-phase system droplets.

    Science.gov (United States)

    Dang, Van Bac; Kim, Sung-Jin

    2017-01-17

    Generating periodic flows with an oscillator driven only by water-head pressure has potential for the operation of microfluidic systems without any dynamic off-chip controllers. However, its operational characteristic is not well understood due to complex dynamic interactions of the microfluidic components. Here, we focus on the mechanism of a water-head-driven oscillator and analyze the functions of its flow-switching period (T) and flow rate (Q) in a wide range (0.1 s-5.9 h and 2 μL min(-1)-2 mL min(-1)). We show linear control of T and Q by their corresponding fluidic resistors even with the complex and nonlinear relation of the microfluidic components. This allows independent regulation of T and Q within their operational ranges but we found the two parameters mutually constrain their ranges via fluidic resistance. Also, we characterize the control of T by water-head pressure and present operational ranges of input water-head pressure decrease with increasing output water-head pressure. To show its utility, we apply the oscillator to generate droplets with low interfacial tension aqueous two-phase systems. Our study would be useful and provide the foundation for various functions of water-head-driven microfluidic circuits.

  15. Potential application of aqueous two-phase systems and three-phase partitioning for the recovery of superoxide dismutase from a clarified homogenate of Kluyveromyces marxianus.

    Science.gov (United States)

    Simental-Martínez, Jesús; Rito-Palomares, Marco; Benavides, Jorge

    2014-01-01

    Superoxide dismutase (SOD; EC 1.15.1.1) is an antioxidant enzyme that represents the primary cellular defense against superoxide radicals and has interesting applications in the medical and cosmetic industries. In the present work, the partition behavior of SOD in aqueous two-phase systems (ATPS) (using a standard solution and a complex extract from Kluyveromyces marxianus as sample) was characterized on different types of ATPS (polymer-polymer, polymer-salt, alcohol-salt, and ionic liquid (IL)-salt). The systems composed of PEG 3350-potassium phosphate, 45% TLL, 0.5 M NaCl (315 U/mg, 87% recovery, and 15.1-fold purification) and t-butanol-20% ammonium sulfate (205.8 U/mg, 80% recovery and 9.8-fold purification), coupled with a subsequent 100 kDa ultrafiltration stage, allowed the design of a prototype process for the recovery and partial purification of the product of interest. The findings reported herein demonstrate the potential of PEG-salt ATPS for the potential recovery of SOD.

  16. A novel aqueous micellar two-phase system composed of surfactant and sorbitol for purification of pectinase enzyme from Psidium guajava and recycling phase components.

    Science.gov (United States)

    Amid, Mehrnoush; Murshid, Fara Syazana; Manap, Mohd Yazid; Hussin, Muhaini

    2015-01-01

    A novel aqueous two-phase system composed of a surfactant and sorbitol was employed for the first time to purify pectinase from Psidium guajava. The influences of different parameters, including the type and concentration of the surfactant and the concentration and composition of the surfactant/sorbitol ratio, on the partitioning behavior and recovery of pectinase were investigated. Moreover, the effects of system pH and the crude load on purification fold and the yield of purified pectinase were studied. The experimental results indicated that the pectinase was partitioned into surfactant-rich top phase, and the impurities were partitioned into the sorbitol-rich bottom phase with the novel method involving an ATPS composed of 26% (w/w) Triton X-100 and 23% (w/w) sorbitol at 54.2% of the TLL crude load of 20% (w/w) at pH 6.0. The enzyme was successfully recovered by this method with a high purification factor of 15.2 and a yield of 98.3%, whereas the phase components were also recovered and recycled at rates above 96%. This study demonstrated that this novel ATPS method can be used as an efficient and economical alternative to the traditional ATPS for the purification and recovery of the valuable enzyme.

  17. Extraction protease expressed by Penicillium fellutanum from the Brazilian savanna using poly(ethylene glycol)/sodium polyacrylate/NaCl aqueous two-phase system.

    Science.gov (United States)

    Barros, Kleber V G; Souza, Paula M; Cardoso, Samuel L; Borges, Leonardo L; Filho, Edivaldo X F; Junior, Adalberto P; Magalhães, Pérola O

    2015-01-01

    The partitioning of protease expressed by Penicillium fellutanum from the Brazilian savanna in a novel inexpensive and stable aqueous two-phase system (ATPS) composed of poly(ethylene glycol) (PEG) and sodium polyacrylate (NaPA) was studied in this work using factorial design. The ATPS is formed by mixing both polymers with a salt (NaCl) and fermented broth of P. fellutanum. The effects of molar mass (2,000, 4,000, and 6,000 g ⋅ mol(-1)) and concentration (6, 8, and 10 wt%) of PEG and that of NaPA concentration (6, 8, and 10 wt%) on protease partitioning (K) at 25 °C were studied. A two-level factorial design (2(3)) was implemented. The effect of Na2 SO4 concentration (5, 10, and 15 wt%) on the reextraction of the enzyme was also analyzed. The partition coefficient K ranged from 77.51 to 1.21, indicating the versatility of the method. The reextraction was achieved with the addition of 5% Na2 SO4 , allowing the partitioning of the protease to the upper phase, whereas total proteins were directed to the bottom phase. The results of partitioning using the PEG/NaPA/NaCl system and that of the subsequent reextraction with Na2 SO4 suggest that this method can be used to purify proteases from fermented broth of P. fellutanum.

  18. Rapid, highly efficient extraction and purification of membrane proteins using a microfluidic continuous-flow based aqueous two-phase system.

    Science.gov (United States)

    Hu, Rui; Feng, Xiaojun; Chen, Pu; Fu, Meng; Chen, Hong; Guo, Lin; Liu, Bi-Feng

    2011-01-07

    Membrane proteins play essential roles in regulating various fundamental cellular functions. To investigate membrane proteins, extraction and purification are usually prerequisite steps. Here, we demonstrated a microfluidic aqueous PEG/detergent two-phase system for the purification of membrane proteins from crude cell extract, which replaced the conventional discontinuous agitation method with continuous extraction in laminar flows, resulting in significantly increased extraction speed and efficiency. To evaluate this system, different separation and detection methods were used to identify the purified proteins, such as capillary electrophoresis, SDS-PAGE and nano-HPLC-MS/MS. Swiss-Prot database with Mascot search engine was used to search for membrane proteins from random selected bands of SDS-PAGE. Results indicated that efficient purification of membrane proteins can be achieved within 5-7s and approximately 90% of the purified proteins were membrane proteins (the highest extraction efficiency reported up to date), including membrane-associated proteins and integral membrane proteins with multiple transmembrane domains. Compared to conventional approaches, this new method had advantages of greater specific surface area, minimal emulsification, reduced sample consumption and analysis time. We expect the developed method to be potentially useful in membrane protein purifications, facilitating the investigation of membrane proteomics.

  19. Investigation of the thermal performance of a vertical two-phase closed thermosyphon as a passive cooling system for a nuclear reactor spent fuel storage pool

    Energy Technology Data Exchange (ETDEWEB)

    Kusuma, Mukhsinun Hadi; Putra, Nandy; Imawan, Ficky Augusta [Heat Transfer Laboratory, Department of Mechanical Engineering Universitas Indonesia, Kampus (Indonesia); Antariksawan, Anhar Riza [Centre for Nuclear Reactor Safety and Technology, National Nuclear Energy Agency of Indonesia (BATAN), Kawasan Puspiptek Serpong (Indonesia)

    2017-04-15

    The decay heat that is produced by nuclear reactor spent fuel must be cooled in a spent fuel storage pool. A wickless heat pipe or a vertical two-phase closed thermosyphon (TPCT) is used to remove this decay heat. The objective of this research is to investigate the thermal performance of a prototype model for a large-scale vertical TPCT as a passive cooling system for a nuclear research reactor spent fuel storage pool. An experimental investigation and numerical simulation using RELAP5/MOD 3.2 were used to investigate the TPCT thermal performance. The effects of the initial pressure, filling ratio, and heat load were analyzed. Demineralized water was used as the TPCT working fluid. The cooled water was circulated in the water jacket as a cooling system. The experimental results show that the best thermal performance was obtained at a thermal resistance of 0.22°C/W, the lowest initial pressure, a filling ratio of 60%, and a high evaporator heat load. The simulation model that was experimentally validated showed a pattern and trend line similar to those of the experiment and can be used to predict the heat transfer phenomena of TPCT with varying inputs.

  20. Pressure Loss across Tube Bundles in Two-phase Flow

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Woo Gun; Banzragch, Dagdan [Hannam Univ., Daejon (Korea, Republic of)

    2016-03-15

    An analytical model was developed by Sim to estimate the two-phase damping ratio for upward two-phase flow perpendicular to horizontal tube bundles. The parameters of two-phase flow, such as void fraction and pressure loss evaluated in the model, were calculated based on existing experimental formulations. However, it is necessary to implement a few improvements in the formulations for the case of tube bundles. For the purpose of the improved formulation, we need more information about the two-phase parameters, which can be found through experimental test. An experiment is performed with a typical normal square array of cylinders subjected to the two-phase flow of air-water in the tube bundles, to calculate the two-phase Euler number and the two-phase friction multiplier. The pitch-to-diameter ratio is 1.35 and the diameter of cylinder is 18mm. Pressure loss along the flow direction in the tube bundles is measured with a pressure transducer and data acquisition system to calculate the two-phase Euler number and the two-phase friction multiplier. The void fraction model by Feenstra et al. is used to estimate the void fraction of the two-phase flow in tube bundles. The experimental results of the two phase friction multiplier and two-phase Euler number for homogeneous and non-homogeneous two-phase flows are compared and evaluated against the analytical results given by Sim's model.

  1. Enhanced thermionic emission properties in textured two-phase LaB{sub 6}–BaB{sub 6} system prepared by spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Shen Lin, E-mail: shenlinz@sina.com [College of Mathematics and Physics, Jinggangshan University, Jian 343409 (China); Shanghai Key Laboratory of Special Artificial Microstructure and Pohl Institute of Solid State Physics and School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Zhang, Jiu Xing, E-mail: zjiuxing@hfut.edu.cn [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Bao, Li Hong [Inner Mongolia Key Laboratory for Physics and Chemistry of Functional Materials, Inner Mongolia Normal University, Hohhot 010022 (China); Yu, Xiao Guang; Hu, Qiang Lin; Hu, Dong Qiang [College of Mathematics and Physics, Jinggangshan University, Jian 343409 (China)

    2014-10-25

    Graphical abstract: Room temperature XRD patterns of the nominal composition (La{sub 0.6}Ba{sub 0.4})B{sub 6} synthesized by SPS at 1400 °C for 5 min under 50 MPa. The XRD patterns reveal that the (La{sub 0.6}Ba{sub 0.4})B{sub 6} is a two-phase mixture of LaB{sub 6} and BaB{sub 6}. The inset is a macroscopic picture of the obtained (La{sub 0.6}Ba{sub 0.4})B{sub 6}. - Highlights: • (La{sub 0.6}Ba{sub 0.4})B{sub 6} has been successfully prepared by spark plasma sintering. • The obtained (La{sub 0.6}Ba{sub 0.4})B{sub 6} compound is a two-phase mixture of LaB{sub 6} and BaB{sub 6}. • The (0 0 1) texture is favorable for the decrease of work function. • The addition of BaB{sub 6} to LaB{sub 6} improves the electron emission performance. • (La{sub 0.6}Ba{sub 0.4})B{sub 6} is shown to be promising candidate for cathode applications. - Abstract: Structure, crystallographic orientation, and thermionic emission properties of the two-phase LaB{sub 6}–BaB{sub 6} system fabricated by a combined process of evaporation–condensation and spark plasma sintering (SPS) were investigated systematically. The powder X-ray diffraction (XRD) reveals that the obtained nominal composition (La{sub 0.6}Ba{sub 0.4})B{sub 6} compound exhibits coexistence of two isostructural phases of LaB{sub 6} and BaB{sub 6}. The electron backscatter diffraction (EBSD) confirms that the surface of the (La{sub 0.6}Ba{sub 0.4})B{sub 6} forms a clear (0 0 1) texture, which favors reduction in work function. Thermionic emission properties were measured in the temperature range between 1500 and 1873 K. The results indicated that the (La{sub 0.6}Ba{sub 0.4})B{sub 6} emitter displayed a low work function of 1.95 eV, and a high zero field emission current density of 10 A cm{sup −2} at 1773 K. Compared to the reported LaB{sub 6} and (La{sub 0.6}Sm{sub 0.4})B{sub 6} prepared for identical synthesis conditions, (La{sub 0.6}Ba{sub 0.4})B{sub 6} is shown to have the most excellent thermionic emission

  2. PEG-salt aqueous two-phase systems: an attractive and versatile liquid-liquid extraction technology for the downstream processing of proteins and enzymes.

    Science.gov (United States)

    Glyk, Anna; Scheper, Thomas; Beutel, Sascha

    2015-08-01

    Nowadays, there is an increasing demand to establish new feasible, efficient downstream processing (DSP) techniques in biotechnology and related fields. Although several conventional DSP technologies have been widely employed, they are usually expensive and time-consuming and often provide only low recovery yields. Hence, the DSP is one major bottleneck for the commercialization of biological products. In this context, polyethylene glycol (PEG)-salt aqueous two-phase systems (ATPS) represent a promising, efficient liquid-liquid extraction technology for the DSP of various biomolecules, such as proteins and enzymes. Furthermore, ATPS can overcome the limitations of traditional DSP techniques and have gained importance for applications in several fields of biotechnology due to versatile advantages over conventional DSP methods, such as biocompatibility, technical simplicity, and easy scale-up potential. In the present review, various practical applications of PEG-salt ATPS are presented to highlight their feasibility to operate as an attractive and versatile liquid-liquid extraction technology for the DSP of proteins and enzymes, thus facilitating the approach of new researchers to this technique. Thereby, single- and multi-stage extraction, several process integration methods, as well as large-scale extraction and purification of proteins regarding technical aspects, scale-up, recycling of process chemicals, and economic aspects are discussed.

  3. [Isolation and purification of alpha-glycerophosphate oxidase in a polyethylene glycol/(NH4 )2SO4 aqueous two-phase system].

    Science.gov (United States)

    Meng, Yao; Jin, Jiagui; Liu, Shuangfeng; Yang, Min; Zhang, Qinglian; Wan, Li; Tang, Kun

    2014-02-01

    Alpha-glycerophosphate oxidase (alpha-GPO) from Enterococcus casseli flavus was successfully isolated and purified by using polyethylene glycol (PEG)/(NH4)2SO4 aqueous two-phase system (ATPS). The results showed that the chosen PEG/(NH4)2SO4 ATPS could be affected by PEG molecular weight, pH, concentration of PEG and (NH4)2SO4, and inorganic salt as well as additional amount of crude enzyme. After evaluating these influencing factors, the final optimum purification strategy was formed by 16.5% (m/m) PEG2000, 13.2% (m/m) (NH4)2SO4, pH 7.5 and 30% (m/m) additive crude enzyme, respectively. The NaCl was a negative influencing factor which would lead to lower purification fold and activity recovery. These conditions eventually resulted in the activity recovery of 89% (m/m), distribution coefficient of 1.2 and purification fold of 7.0.

  4. Interrelationship between partition behavior of organic compounds and proteins in aqueous dextran-polyethylene glycol and polyethylene glycol-sodium sulfate two-phase systems.

    Science.gov (United States)

    Ferreira, Luisa A; da Silva, Nuno R; Wlodarczyk, Samarina R; Loureiro, Joana A; Madeira, Pedro P; Teixeira, José A; Uversky, Vladimir N; Zaslavsky, Boris Y

    2016-04-22

    Partition behavior of adenosine and guanine mononucleotides was examined in aqueous dextran-polyethylene glycol (PEG) and PEG-sodium sulfate two-phase systems. The partition coefficients for each series of mononucleotides were analyzed as a functions of the number of phosphate groups and found to be dependent on the nature of nucleic base and on the type of ATPS utilized. It was concluded that an average contribution of a phosphate group into logarithm of partition coefficient of a mononucleotide cannot be used to estimate the difference between the electrostatic properties of the coexisting phases of ATPS. The data obtained in this study were considered together with those for other organic compounds and proteins reported previously, and the linear interrelationship between logarithms of partition coefficients in dextran-PEG, PEG-Na2SO4 and PEG-Na2SO4-0.215M NaCl (all in 0.01M Na- or K/Na-phosphate buffer, pH 7.4 or 6.8) was established. Similar relationship was found for the previously reported data for proteins in Dex-PEG, PEG-600-Na2SO4, and PEG-8000-Na2SO4 ATPS. It is suggested that the linear relationships of the kind established in ATPS may be observed for biological properties of compounds as well.

  5. Reconstruction of electrical capacitance tomography images based on fast linearized alternating direction method of multipliers for two-phase flow system

    Institute of Scientific and Technical Information of China (English)

    Chongkun Xia; Chengli Su⁎; Jiangtao Cao; Ping Li

    2016-01-01

    Electrical capacitance tomography (ECT) has been applied to two-phase flow measurement in recent years. Image reconstruction algorithms play an important role in the successful applications of ECT. To solve the il-posed and nonlinear inverse problem of ECT image reconstruction, a new ECT image reconstruction method based on fast lin-earized alternating direction method of multipliers (FLADMM) is proposed in this paper. On the basis of theoretical analysis of compressed sensing (CS), the data acquisition of ECT is regarded as a linear measurement process of permittivity distribution signal of pipe section. A new measurement matrix is designed and L1 regularization method is used to convert ECT inverse problem to a convex relaxation problem which contains prior knowledge. A new fast alternating direction method of multipliers which contained linearized idea is employed to minimize the objective function. Simulation data and experimental results indicate that compared with other methods, the quality and speed of reconstructed images are markedly improved. Also, the dynamic experimental results in-dicate that the proposed algorithm can fulfil the real-time requirement of ECT systems in the application.

  6. High-throughput downstream process development for cell-based products using aqueous two-phase systems (ATPS) - A case study.

    Science.gov (United States)

    Zimmermann, Sarah; Scheeder, Christian; Zimmermann, Philipp K; Bogsnes, Are; Hansson, Mattias; Staby, Arne; Hubbuch, Jürgen

    2017-02-01

    The availability of preparative-scale downstream processing strategies for cell-based products presents a critical juncture between fundamental research and clinical development. Aqueous two-phase systems (ATPS) present a gentle, scalable, label-free, and cost-effective method for cell purification, and are thus a promising tool for downstream processing of cell-based therapeutics. Here, the application of a previously developed robotic screening platform that enables high-throughput cell partitioning analysis in ATPS is reported. In the present case study a purification strategy for two model cell lines based on high-throughput screening (HTS)-data and countercurrent distribution (CCD)-modeling, and validated the CCD-model experimentally is designed. The obtained data are shown an excellent congruence between CCD-model and experimental data, indicating that CCD-models in combination with HTS-data are a powerful tool in downstream process development. Finally, the authors are shown that while cell cycle phase significantly influences cell partitioning, cell type specific differences in surface properties are the main driving force in charge-dependent separation of HL-60 and L929 cells. In order to design a highly robust purification process it is, however, advisable to maintain constant growth conditions. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Optimization of fibrinolytic enzyme production by Bacillus subtilis DC-2 in aqueous two-phase system (poly-ethylene glycol 4000 and sodium sulfate).

    Science.gov (United States)

    Ashipala, Onesmus K; He, Qian

    2008-07-01

    The central composite rotable design (CCRD) was used to determine optimal conditions for fibrinolytic enzyme production by Bacillus subtilis DC-2 in poly-ethylene glycol 4000 (PEG 4000) and sodium sulfate (Na(2)SO(4)) aqueous two-phase system (ATPS). PEG 4000 and Na(2)SO(4) concentration, fermentation time and temperature, and pH were selected as variables to evaluate the fibrinolytic activity in PEG phase. Using response surface methodology (RSM), a second-order polynomial equation was obtained by multiple regression analysis. The predicted maximal fibrinolytic activity in PEG phase was 1241.02 IU/ml with 9.05% PEG 4000 concentration, 5.06% Na(2)SO(4) concentration, 118.77 h fermentation time, 37.57 degrees C fermentation temperature and pH 6.52. The validity of the response model was verified by a good agreement between predicted and experimental results. The fibrinolytic activity obtained from experimental results in PEG phase (1223.61 IU/ml) was higher than that produced in homogeneous fermentation (1165.58 IU/ml).

  8. Ionic liquid-based ultrasound-assisted extraction and aqueous two-phase system for analysis of caffeoylquinic acids from Flos Lonicerae Japonicae.

    Science.gov (United States)

    Tan, Ting; Lai, Chang-Jiang-Sheng; OuYang, Hui; He, Ming-Zhen; Feng, Yulin

    2016-02-20

    In this work, an ionic liquid-based ultrasonic-assisted extraction (ILUAE) method was developed to extract caffeoylquinic acids (CQAs) from Flos Lonicerae Japonicae (FLJ). ILUAE parameters were optimized by response surface methodology, including IL concentration, ultrasonic time, and liquid-solid ratio. Optimized ILUAE approach gained the highest extraction yields of 28.53, 18.21, 3.84mg/g for 3-O-caffeoylquinic acid (C1), 3,5-di-O-caffeoylquinic acid (C2), 3,4-di-O-caffeoylquinic acid (C3), respectively. C1-C3 are the three most abundant CQAs compounds in FLJ. The method showed comparable extraction yield and shorter extraction time compared with conventional extraction techniques. Subsequently, an aqueous two-phase system (ATPS) was applied in extraction solutions. Two trace CQAs, 5-O-caffeoylquinic acid (C4) and 4,5-di-O-caffeoylquinic acid (C5), were significantly enriched with signal to noise values increasing from less than 10 to higher than 1475. The results indicated that ILUAE and ATPS are efficient and environmentally-friendly sample extraction and enrichment techniques for CQAs from herbal medicines.

  9. Ionic Liquid-Based Ultrasonic-Assisted Extraction of Secoisolariciresinol Diglucoside from Flaxseed (Linum usitatissimum L.) with Further Purification by an Aqueous Two-Phase System.

    Science.gov (United States)

    Tan, Zhi-Jian; Wang, Chao-Yun; Yang, Zi-Zhen; Yi, Yong-Jian; Wang, Hong-Ying; Zhou, Wan-Lai; Li, Fen-Fang

    2015-09-30

    In this work, a two-step extraction methodology of ionic liquid-based ultrasonic-assisted extraction (IL-UAE) and ionic liquid-based aqueous two-phase system (IL-ATPS) was developed for the extraction and purification of secoisolariciresinol diglucoside (SDG) from flaxseed. In the IL-UAE step, several kinds of ILs were investigated as the extractants, to identify the IL that affords the optimum extraction yield. The extraction conditions such as IL concentration, ultrasonic irradiation time, and liquid-solid ratio were optimized using response surface methodology (RSM). In the IL-ATPS step, ATPS formed by adding kosmotropic salts to the IL extract was used for further separation and purification of SDG. The most influential parameters (type and concentration of salt, temperature, and pH) were investigated to obtain the optimum extraction efficiency. The maximum extraction efficiency was 93.35% under the optimal conditions of 45.86% (w/w) IL and 8.27% (w/w) Na₂SO₄ at 22 °C and pH 11.0. Thus, the combination of IL-UAE and IL-ATPS makes up a simple and effective methodology for the extraction and purification of SDG. This process is also expected to be highly useful for the extraction and purification of bioactive compounds from other important medicinal plants.

  10. Performance of a UASB-digester system treating domestic wastewater.

    Science.gov (United States)

    Alvarez, J A; Armstrong, E; Presas, J; Gómez, M; Soto, M

    2004-10-01

    The anaerobic treatment of raw domestic wastewater by a novel technology consisting of an Up-flow Anaerobic Sludge Bed (UASB) reactor combined with a completely mixed digester for the stabilisation of the UASB sludge was assessed. A pilot-scale plant of the so-called UASB-Digester system was located at the municipal wastewater treatment facility of Santiago de Compostela (Northwest of Spain). The main aim of the Digester was to enhance the biodegradation of influent solids retained in the UASB reactor at low temperatures, then increasing its specific methanogenic activity. The sludge drawn from the middle zone of the UASB entered the upper zone of the Digester and then circulated from the bottom of the Digester to the UASB bottom. Circulating in an automated semi-continuous way, the flow of this sludge stream was selected in order to set a previously defined hydraulic retention time (HRT) (16-27 d) in the digester. The Digester temperature was set at an optimum value ranging from 25 to 35 degrees C. The steady state efficiency of the UASB system, at 6-8 h of HRT, 15-16 degrees C of temperature and 330-360 mg l(-1) of influent total chemical oxygen demand (TCOD) was 79% of total suspended solids (TSS) removal, 52% of TCOD removal and 60% of biological oxygen demand (BOD5) removal. The hydrolysis of retained solids reached 85%, while excess sludge generation was only 7% of influent TCOD. A stable anaerobic (pre)treatment of diluted domestic wastewater was reached as the sludge concentration in the reactor remained mainly constant and the specific methanogenic activity showed a slight increase.

  11. Digestive system manifestations in patients with severe acute respiratory syndrome

    Institute of Scientific and Technical Information of China (English)

    詹俊; 陈为宪; 李楚强; 伍卫; 李建军; 江山平; 王景峰; 曾志勇; 黄子通; 黄洪章

    2003-01-01

    Objective To explore digestive system manifestations in patients with severe acute respiratory syndrome (SARS).Method The clinical data of 96 cases with SARS admitted into our hospital from February 6, 2003 to March 28, 2003 were retrospectively analyzed.Results Among the 96 cases, 26 cases (27%) had diarrhea, 17 (18%) had nausea, 6 (6%) had vomiting, 16 (17%) had bellyache, and 8 (8%) had ALT elevation.Conclusions Patients with SARS may have digestive system manifestations; diarrhea is the most common symptom.

  12. Application of an aqueous two-phase micellar system to extract bromelain from pineapple (Ananas comosus) peel waste and analysis of bromelain stability in cosmetic formulations.

    Science.gov (United States)

    Spir, Lívia Genovez; Ataide, Janaína Artem; De Lencastre Novaes, Letícia Celia; Moriel, Patrícia; Mazzola, Priscila Gava; De Borba Gurpilhares, Daniela; Silveira, Edgar; Pessoa, Adalberto; Tambourgi, Elias Basile

    2015-01-01

    Bromelain is a set of proteolytic enzymes found in pineapple (Ananas comosus) tissues such as stem, fruit and leaves. Because of its proteolytic activity, bromelain has potential applications in the cosmetic, pharmaceutical, and food industries. The present study focused on the recovery of bromelain from pineapple peel by liquid-liquid extraction in aqueous two-phase micellar systems (ATPMS), using Triton X-114 (TX-114) and McIlvaine buffer, in the absence and presence of electrolytes CaCl2 and KI; the cloud points of the generated extraction systems were studied by plotting binodal curves. Based on the cloud points, three temperatures were selected for extraction: 30, 33, and 36°C for systems in the absence of salts; 40, 43, and 46°C in the presence of KI; 24, 27, and 30°C in the presence of CaCl2 . Total protein and enzymatic activities were analyzed to monitor bromelain. Employing the ATPMS chosen for extraction (0.5 M KI with 3% TX-114, at pH 6.0, at 40°C), the bromelain extract stability was assessed after incorporation into three cosmetic bases: an anhydrous gel, a cream, and a cream-gel formulation. The cream-gel formulation presented as the most appropriate base to convey bromelain, and its optimal storage conditions were found to be 4.0 ± 0.5°C. The selected ATPMS enabled the extraction of a biomolecule with high added value from waste lined-up in a cosmetic formulation, allowing for exploration of further cosmetic potential.

  13. Optimization of Serine Protease Purification from Mango (Mangifera indica cv. Chokanan Peel in Polyethylene Glycol/Dextran Aqueous Two Phase System

    Directory of Open Access Journals (Sweden)

    Abdul Manap Mohd Yazid

    2012-03-01

    Full Text Available Mango peel is a good source of protease but remains an industrial waste. This study focuses on the optimization of polyethylene glycol (PEG/dextran-based aqueous two-phase system (ATPS to purify serine protease from mango peel. The activity of serine protease in different phase systems was studied and then the possible relationship between the purification variables, namely polyethylene glycol molecular weight (PEG, 4000–12,000 g·mol−1, tie line length (−3.42–35.27%, NaCl (−2.5–11.5% and pH (4.5–10.5 on the enzymatic properties of purified enzyme was investigated. The most significant effect of PEG was on the efficiency of serine protease purification. Also, there was a significant increase in the partition coefficient with the addition of 4.5% of NaCl to the system. This could be due to the high hydrophobicity of serine protease compared to protein contaminates. The optimum conditions to achieve high partition coefficient (84.2 purification factor (14.37 and yield (97.3% of serine protease were obtained in the presence of 8000 g·mol−1 of PEG, 17.2% of tie line length and 4.5% of NaCl at pH 7.5. The enzymatic properties of purified serine protease using PEG/dextran ATPS showed that the enzyme could be purified at a high purification factor and yield with easy scale-up and fast processing.

  14. An Aqueous Two-Phase System for the Concentration and Extraction of Proteins from the Interface for Detection Using the Lateral-Flow Immunoassay.

    Directory of Open Access Journals (Sweden)

    Ricky Y T Chiu

    Full Text Available The paper-based immunoassay for point-of-care diagnostics is widely used due to its low cost and portability over traditional lab-based assays. Lateral-flow immunoassay (LFA is the most well-established paper-based assay since it is rapid and easy to use. However, the disadvantage of LFA is its lack of sensitivity in some cases where a large sample volume is required, limiting its use as a diagnostic tool. To improve the sensitivity of LFA, we previously reported on the concentration of analytes into one of the two bulk phases of an aqueous two-phase system (ATPS prior to detection. In this study, we preserved the advantages of LFA while significantly improving upon our previous proof-of-concept studies by employing a novel approach of concentrating gold nanoparticles, a common LFA colorimetric indicator. By conjugating specific antibodies and polymers to the surfaces of the particles, these gold nanoprobes (GNPs were able to capture target proteins in the sample and subsequently be concentrated within 10 min at the interface of an ATPS solution comprised of polyethylene glycol, potassium phosphate, and phosphate-buffered saline. These GNPs were then extracted and applied directly to LFA. By combining this prior ATPS interface extraction with LFA, the detection limit of LFA for a model protein was improved by 100-fold from 1 ng/μL to 0.01 ng/μL. Additionally, we examined the behavior of the ATPS system in fetal bovine serum and synthetic urine to more closely approach real-world applications. Despite using more complex matrices, ATPS interface extraction still improved the detection limit by 100-fold within 15 to 25 min, demonstrating the system's potential to be applied to patient samples.

  15. Recovery of lignin peroxidase from submerged liquid fermentation of Amauroderma rugosum (Blume & T. Nees) Torrend using polyethylene glycol/salt aqueous two-phase system.

    Science.gov (United States)

    Jong, Wan Yng Linda; Show, Pau Loke; Ling, Tau Chuan; Tan, Yee Shin

    2017-07-01

    Amauroderma rugosum is a wild mushroom species widely distributed in tropics and is classified under the class of Basidiomycetes. Basidiomycetes are well-known for their abilities of producing lignocellulolytic enzymes such as lignin peroxidase (LiP), laccase (Lac) and manganese peroxidase (MnP). Different factors such as nutrient sources, incubation period and agitation affect the production of lignocellulolytic enzymes. The A. rugosum produced LiP in the medium supplemented with potato dextrose broth (PDB), 0.5% yeast and 1.0% saw dust at 26.70±3.31 U/mL. However, the LiP activity was increased to 106.32±5.32 U/mL when supplemented with 150 μm of copper (CuSO4). The aqueous two-phase system (ATPS) is a simple, rapid and low cost method for primary extraction and recovery of LiP. A total of 25 systems made from five different molecular weights of polyethylene glycol (PEG)/dipotassium hydrogen phosphate (K2HPO4) were tested. PEG 600 produced the highest top phase purification factor (PFT) of 1.33±0.62 with yield of 72.18±8.50%. The optimization of the ATPS parameters, such as volume ratio VR, pH and crude enzyme loading are the factors controlling the phase partition. Our results showed that significant improvement (PFT of 6.26±2.87 with yield of 87.31±3.14%) of LiP recovery can be achieved by optimized the parameters. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  16. Coupling two-phase fluid flow with two-phase darcy flow in anisotropic porous media

    KAUST Repository

    Chen, J.

    2014-06-03

    This paper reports a numerical study of coupling two-phase fluid flow in a free fluid region with two-phase Darcy flow in a homogeneous and anisotropic porous medium region. The model consists of coupled Cahn-Hilliard and Navier-Stokes equations in the free fluid region and the two-phase Darcy law in the anisotropic porous medium region. A Robin-Robin domain decomposition method is used for the coupled Navier-Stokes and Darcy system with the generalized Beavers-Joseph-Saffman condition on the interface between the free flow and the porous media regions. Obtained results have shown the anisotropic properties effect on the velocity and pressure of the two-phase flow. 2014 Jie Chen et al.

  17. Synthesis of thermo-responsive polymers recycling aqueous two-phase systems and phase formation mechanism with partition of ε-polylysine.

    Science.gov (United States)

    Xu, Chengning; Dong, Wenying; Wan, Junfen; Cao, Xuejun

    2016-11-11

    Aqueous two-phase systems (ATPS) have the potential application in bioseparation and biocatalysis engineering. In this paper, a recyclable ATPS was developed by two thermo-responsive copolymers, PVBAm and PN. Copolymer PVBAm was copolymerized using N-vinylcaprolactam, Butyl methacrylate and Acrylamide as monomers, and PN was synthesized by N-isopropylacrylamide. The lower critical solution temperature (LCST) of PVBAm and PN were 45.0°C and 33.5°C, respectively. The recoveries of both polymers could achieve over 95.0%. The phase behavior and formation mechanism of PVBAm/PN ATPS was studied. Low-field nuclear magnetic resonance (LF-NMR) was applied in the phase-forming mechanism study in ATPS. In addition, combining the analysis results of surface tension, transmission electron microscopy and dynamic light scattering, the phase-forming of the PVBAm/PN ATPS was proved. The application was performed by partition of ε-polylysine in the 2% PVBAm/2% PN (w/w) ATPS. The results demonstrated that ε-polylysine was extracted into the PN-rich phase, the maximal partition coefficient (1/K) and extraction recovery of pure ε-polylysine were 6.87 and 96.36%, respectively, and 7.41 partition coefficient and 97.85% extraction recovery for ε-polylysine fermentation broth were obtained in the presence of 50mM (NH4)2SO4 at room temperature. And this method can effectively remove the most impurities from fermentation broth when (NH4)2SO4 exists in the ATPS. It is believed that the thermo-responsive recycling ATPS has a good application prospect in the field of bio-separation.

  18. Separation of curcuminoids using ionic liquid based aqueous two-phase system coupled with in situ dispersive liquid-liquid microextraction.

    Science.gov (United States)

    Shu, Yang; Gao, Mingcen; Wang, Xueying; Song, Rusheng; Lu, Jun; Chen, Xuwei

    2016-01-01

    An aqueous two-phase extraction system (ATPS) combined with an in situ dispersive liquid-liquid microextraction (DLLME) method using imidazolium ionic liquids (ILs) for the separation of curcuminoids is developed. The influence of structure of IL, the type of metathesis reagents, and the back extraction agents on the extraction efficiency is investigated. 2.0mg of curcuminoids are extracted by an IL ATPS composed of 0.4g 1,3-diethylimidazolium iodine (EeimI), 0.6g potassium hydrogen phosphate, 1.0g water. Then the bis[(trifluoromethyl)sulfonyl]imide lithium (LiNTf2) aqueous solution is added to the EeimI-rich phase of the ATPS. The water-immiscible ionic liquids, 1,3-diethylimidazole bis[(trifluoromethyl)sulfonyl]imide (EeimNTf2), forms by the metathesis reaction. The in situ DLLME is triggered simultaneously and further purifies the curcuminoids. 92% of EeimI transforms into EeimNTf2 and thus the Eeim(+) cation is used for twice in this method. Finally, 0.1mol/L NaOH aqueous solution is used as the back extraction reagent. The curcuminoids precipitate is achieved with 93% of recovery when the aqueous solution is adjusted to pH 3.0. This ATPS-DLLME method is successfully applied to the separation of curcuminoids from Curcuma Longa (0.96±0.02% of extraction yield, a purity of >51% with respect to the total dry mass of the product).

  19. Magnetic ionic liquid aqueous two-phase system coupled with high performance liquid chromatography: A rapid approach for determination of chloramphenicol in water environment.

    Science.gov (United States)

    Yao, Tian; Yao, Shun

    2017-01-20

    A novel organic magnetic ionic liquid based on guanidinium cation was synthesized and characterized. A new method of magnetic ionic liquid aqueous two-phase system (MILATPs) coupled with high-performance liquid chromatography (HPLC) was established to preconcentrate and determine trace amount of chloramphenicol (CAP) in water environment for the first time. In the absence of volatile organic solvents, MILATPs not only has the excellent properties of rapid extraction, but also exhibits a response to an external magnetic field which can be applied to assist phase separation. The phase behavior of MILATPs was investigated and phase equilibrium data were correlated by Merchuk equation. Various influencing factors on CAP recovery were systematically investigated and optimized. Under the optimal conditions, the preconcentration factor was 147.2 with the precision values (RSD%) of 2.42% and 4.45% for intra-day (n=6) and inter-day (n=6), respectively. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.14ngmL(-1) and 0.42ngmL(-1), respectively. Fine linear range of 12.25ngmL(-1)-2200ngmL(-1) was obtained. Finally, the validated method was successfully applied for the analysis of CAP in some environmental waters with the recoveries for the spiked samples in the acceptable range of 94.6%-99.72%. Hopefully, MILATPs is showing great potential to promote new development in the field of extraction, separation and pretreatment of various biochemical samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Extraction and separation of tungsten (VI) from aqueous media with Triton X-100-ammonium sulfate-water aqueous two-phase system without any extractant.

    Science.gov (United States)

    Yongqiang Zhang; Tichang Sun; Tieqiang Lu; Chunhuan Yan

    2016-11-25

    An aqueous two-phase system composed of Triton X-100-(NH4)2SO4-H2O was proposed for extraction and separation of tungsten(VI) from aqueous solution without using any extractant. The effects of aqueous pH, concentration of ammonium sulfate, Triton X-100 and tungsten, extracting temperature on the extraction of tungsten were investigated. The extraction of tungsten has remarkable relationship with aqueous pH and are to above 90% at pH=1.0-3.0 under studied pH range (pH=1.0-7.0) and increases gradually with increasing Triton X-100 concentration, but decreases slightly with increasing ammonium sulfate concentration. The extraction percentage of tungsten is hardly relevant to temperature but its distribution coefficient linearly increases with increasing temperature within 303.15-343.15K. The distribution coefficient of tungsten increases with the increase of initial tungsten concentration (0.1-3%) and temperature (303.15 K-333.15K). The solubilization capacity of tungsten in Triton X-100 micellar phase is independent of temperature. FT-IR analysis reveals that there is no evident interaction between polytungstate anion and ether oxygen unit in Triton X-100, and DLS analysis indicates that zeta potential of Triton X-100 micellar phase have a little change from positive to negative after extracting tungsten. Based on the above-mentioned results, it can be deduced that polytungstate anions are solubilized in hydrophilic outer shell of Triton X-100 micelles by electrostatic attraction depending on its relatively high hydrophobic nature. The stripping of tungsten is mainly influenced by temperature and can be easily achieved to 95% in single stage stripping. The tungsten (VI) is separated out from solution containing Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Al(III), Cr(III) and Mn(II) under the suitable conditions.

  1. Contrasted Fitness Costs of Docking and Antibacterial Constructs in the EE and EVida3 Strains Validates Two-Phase Anopheles gambiae Genetic Transformation System.

    Directory of Open Access Journals (Sweden)

    Doug Paton

    Full Text Available The deployment of transgenic mosquitoes carrying genes for refractoriness to malaria has long been seen as a futuristic scenario riddled with technical difficulties. The integration of anti-malarial effector genes and a gene-drive system into the mosquito genome without affecting mosquito fitness is recognized as critical to the success of this malaria control strategy. Here we conducted detailed fitness studies of two Anopheles gambiae s.s. transgenic lines recently developed using a two-phase targeted genetic transformation system. In replicated cage-invasion experiments, males and females of the EE Phase-1 docking strain and EVida3 Phase-2 strain loaded with an antimicrobial peptide (AMP expressed upon blood-feeding, were mixed with individuals of a recently-colonized strain of the Mopti chromosomal form. The experimental design enabled us to detect initial strain reproductive success differences, assortative mating and hybrid vigor that may characterize mosquito release situations. In addition, the potential fitness costs of the unloaded Phase-1 and loaded Phase-2 genetic constructs, independent of the strains' original genetic backgrounds, were estimated between the 1(st instar larvae, pupae and adult stages over 10 generations. The Phase-1 unloaded docking cassette was found to have significantly lower allelic fitness relative to the wild type allele during larval development. However, overall genotypic fitness was comparable to the wild type allele across all stages leading to stable equilibrium in all replicates. In contrast, the Phase-2 construct expressing EVida3 disappeared from all replicates within 10 generations due to lower fitness of hemi- and homozygous larvae, suggesting costly background AMP expression and/or of the DsRed2 marker. This is the first study to effectively partition independent fitness stage-specific determinants in unloaded and loaded transgenic strains of a Phase-1-2 transformation system. Critically, the high

  2. Contrasted Fitness Costs of Docking and Antibacterial Constructs in the EE and EVida3 Strains Validates Two-Phase Anopheles gambiae Genetic Transformation System.

    Science.gov (United States)

    Paton, Doug; Underhill, Anne; Meredith, Janet; Eggleston, Paul; Tripet, Frederic

    2013-01-01

    The deployment of transgenic mosquitoes carrying genes for refractoriness to malaria has long been seen as a futuristic scenario riddled with technical difficulties. The integration of anti-malarial effector genes and a gene-drive system into the mosquito genome without affecting mosquito fitness is recognized as critical to the success of this malaria control strategy. Here we conducted detailed fitness studies of two Anopheles gambiae s.s. transgenic lines recently developed using a two-phase targeted genetic transformation system. In replicated cage-invasion experiments, males and females of the EE Phase-1 docking strain and EVida3 Phase-2 strain loaded with an antimicrobial peptide (AMP) expressed upon blood-feeding, were mixed with individuals of a recently-colonized strain of the Mopti chromosomal form. The experimental design enabled us to detect initial strain reproductive success differences, assortative mating and hybrid vigor that may characterize mosquito release situations. In addition, the potential fitness costs of the unloaded Phase-1 and loaded Phase-2 genetic constructs, independent of the strains' original genetic backgrounds, were estimated between the 1(st) instar larvae, pupae and adult stages over 10 generations. The Phase-1 unloaded docking cassette was found to have significantly lower allelic fitness relative to the wild type allele during larval development. However, overall genotypic fitness was comparable to the wild type allele across all stages leading to stable equilibrium in all replicates. In contrast, the Phase-2 construct expressing EVida3 disappeared from all replicates within 10 generations due to lower fitness of hemi- and homozygous larvae, suggesting costly background AMP expression and/or of the DsRed2 marker. This is the first study to effectively partition independent fitness stage-specific determinants in unloaded and loaded transgenic strains of a Phase-1-2 transformation system. Critically, the high fitness of the

  3. Performances of Two-phase CSTR-ASBR with Enhanced Hydrolysis and Acidification for Anaerobic Digestion of Fruit and Vegetable Wastes%果蔬废物CSTR-ASBR强化酸化分相厌氧消化产气性能研究

    Institute of Scientific and Technical Information of China (English)

    蔡文婷; 朱保宁; 李兵; 袁海荣; 邹德勋; 李秀金

    2012-01-01

    采用CSTR-ASBR强化酸化分相工艺对果蔬废物厌氧消化产气性能进行研究.通过先将果蔬废物榨汁,果蔬渣水解酸化后再进入到甲烷相,果蔬汁直接进行甲烷化的方式,实现强化酸化与分相厌氧消化.结果表明:采用此种厌氧消化方式,可以使酸化相稳定运行的最高负荷达到16 gVS·L-1d-1,将酸化相的末端产物均换算成乙酸后,负荷产酸率平均在800 mg·gVS-1d-1以上,并形成稳定的乙醇发酵类型.甲烷相的有机负荷可从1 gVS·L-1d-1上升到5.5 gVS·L-1d-1,负荷产气率平均在500 mL·gVS-1 d-以上,CH4含量稳定在55%~60%之间.甲烷相运行的最优负荷为4 gVS·L-1d-1,负荷产气率与VS去除率分别可达557 mL·gVS-1d-1和83%,且系统稳定性能良好.%Two-phase CSTR-ASBR system with enhanced hydrolysis and acidification was advanced and used for anaerobic digestion of fruit and vegetable wastes( FVW) for biogas production. The performance of the system was investigated. FVW was firstly separated by extrusion. The solid fraction was hydrolyzed and acidified in acidogenic phase and then added into methanogenic phase and co-digested with liquid fraction. The results showed that the acidogenic phase reached maximum OLR of 16 gVS ? L-1d-1, the VFA yield was 800 mg CH3COOH ? gVS-1d-1, and the phase maintained a stable ethanol type fermentation. The methanogenic phase reached maximum OLR of 5. 5 gVS ? L-1 d-1 with biogas yield of 500 mL ? gyS-1d on average. Methane content in biogas was in range of 55% ~ 60%. At the optimum OLR of methanogenic phase (4 gVS ? L-1d-1 ) , the biogas yield and the VS removal rate were 557 mL ? gVS-1d-1 and 83% .respectively. The system was operated in stable state.

  4. A method for dye extraction using an aqueous two-phase system: Effect of co-occurrence of contaminants in textile industry wastewater.

    Science.gov (United States)

    Borges, Gabriella Alexandre; Silva, Luciana Pereira; Penido, Jussara Alves; de Lemos, Leandro Rodrigues; Mageste, Aparecida Barbosa; Rodrigues, Guilherme Dias

    2016-12-01

    This paper reports a green and efficient procedure for extraction of the dyes Malachite Green (MG), Methylene Blue (MB), and Reactive Red 195 (RR) using an aqueous two-phase system (ATPS). An ATPS consists mainly of water, together with polymer and salt, and does not employ any organic solvent. The extraction efficiency was evaluated by means of the partition coefficients (K) and residual percentages (%R) of the dyes, under different experimental conditions, varying the tie-line length (TLL) of the system, the pH, the type of ATPS-forming electrolyte, and the type of ATPS-forming polymer. For MG, the best removal (K = 4.10 × 10(4), %R = 0.0069%) was obtained with the ATPS: PEO 1500 + Na2C4H4O6 (TLL = 50.21% (w/w), pH = 6.00). For MB, the maximum extraction (K = 559.9, %R = 0.258%) was achieved with the ATPS: PEO 400 + Na2SO4 (TLL = 50.31% (w/w), pH = 1.00). Finally for RR, the method that presented the best results (K = 3.75 × 10(4), %R = 0.237%) was the ATPS: PEO 400 + Na2SO4 (TLL = 50.31% (w/w), pH = 6.00). The method was applied to the recovery of these dyes from a textile effluent sample, resulting in values of K of 1.17 × 10(4), 724.1, and 3.98 × 10(4) for MG, MB, and RR, respectively, while the corresponding %R values were 0.0038, 0.154, and 0.023%, respectively. In addition, the ATPS methodology provided a high degree of color removal (96.5-97.95%) from the textile effluent. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Digestion of frozen/thawed food waste in the hybrid anaerobic solid-liquid system.

    Science.gov (United States)

    Stabnikova, O; Liu, X Y; Wang, J Y

    2008-01-01

    The hybrid anaerobic solid-liquid (HASL) system, which is a modified two-phase anaerobic digester, is to be used in an industrial scale operation to minimize disposal of food waste at incineration plants in Singapore. The aim of the present research was to evaluate freezing/thawing of food waste as a pre-treatment for its anaerobic digestion in the HASL system. The hydrolytic and fermentation processes in the acidogenic reactor were enhanced when food waste was frozen for 24h at -20 degrees C and then thawed for 12h at 25 degrees C (experiment) in comparison with fresh food waste (control). The highest dissolved COD concentrations in the leachate from the acidogenic reactors were 16.9 g/l on day 3 in the control and 18.9 g/l on day 1 in the experiment. The highest VFA concentrations in the leachate from the acidogenic reactors were 11.7 g/l on day 3 in the control and 17.0 g/l on day 1 in the experiment. The same volume of methane was produced during 12 days in the control and 7 days in the experiment. It gave the opportunity to diminish operational time of batch process by 42%. The effect of freezing/thawing of food waste as pre-treatment for its anaerobic digestion in the HASL system was comparable with that of thermal pre-treatment of food waste at 150 degrees C for 1h. However, estimation of energy required either to heat the suspended food waste to 150 degrees C or to freeze the same quantity of food waste to -20 degrees C showed that freezing pre-treatment consumes about 3 times less energy than thermal pre-treatment.

  6. Microscopic anatomy of pycnogonida: II. Digestive system. III. Excretory system.

    Science.gov (United States)

    Fahrenbach, W H; Arango, Claudia P

    2007-11-01

    The digestive system of several species of sea spiders (Pycnogonida, Arthropoda) was studied by electron microscopy. It is composed of the foregut inside a long proboscis, a midgut and a hindgut. Lips near the three jaws at the tip of the proboscis receive several hundred ductules originating from salivary glands. These previously undetected glands open on the lips, a fluted, projecting ridge at the external hinge line of the jaws, i.e., to the outside of the mouth. This disposition suggests affinities to the chelicerate line. The trigonal esophagus within the proboscis contains a complex, setose filter device, operated by dedicated muscles, that serves to reduce ingested food to subcellular dimensions. The midgut has diverticula into the bases of all legs. Its cells differentiate from the basal layer and contain a bewildering array of secretion droplets, lysosomes and phagosomes. In the absence of a hepatopancreas, the midgut serves both digestive and absorptive functions. The cuticle-lined hindgut lies in the highly reduced, peg-like abdomen. Traditionally, pycnogonids have been claimed to have no excretory organ at all. Such a structure, however, has been located in at least one ammotheid, Nymphopsis spinosissima, in which a simple, but standard, excretory gland has been found in the scape of the chelifore. It consists of an end sac, a straight proximal tubule, a short distal tubule, and a raised nephropore. The end sac is a thin-walled and polygonal chamber, about 150 microm in cross section, suspended in the hemocoel of the appendage, its edges radially tethered to the cuticle at more than half a dozen locations. This wall consists of a filtration basement membrane, 1-4 microm thick, facing the hemocoel, and internally of a continuous carpet of podocytes and their pedicels. The podocytes, measuring maximally 10 by 15 microm, have complex contents, of which a labyrinthine system of connected intracellular channels stands out. These coated cisternae open into a

  7. McClellan Air Force Base operable unit B, two-phase extraction system demonstration test, work implementation plan for McClellan AFB, California. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-03

    This document is an integrated demonstration and work plan that presents the technical approach for design, implementation, and testing of two-phase extraction as compared with pump and treat technology in Operable Unit B, investigative cluster IC1 at the McClellan Air Force Base. This work is being coordinated with Clean Sites under a cooperative agreement with EPA's Technology Innovation Office and Superfund Innovative Technology Evaluation Program.

  8. Molecular physiology of vesicular glutamate transporters in the digestive system

    Institute of Scientific and Technical Information of China (English)

    Tao Li; Fayez K. Ghishan; Liqun Bai

    2005-01-01

    Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system (CNS). Packaging and storage of glutamate into glutamatergic neuronal vesicles require ATP-dependent vesicular glutamate uptake systems, which utilize the electrochemical proton gradient as a driving force. Three vesicular glutamate transporters (VGLUT1-3) have been recently identified from neuronal tissue where they play a key role to maintain the vesicular glutamate level. Recently, it has been demonstrated that glutamate signaling is also functional in peripheral neuronal and non-neuronal tissues, and occurs in sites of pituitary, adrenal, pineal glands, bone, GI tract, pancreas,skin, and testis. The glutamate receptors and VGLUTs in digestivesystem have been found in both neuronal and endocrinal cells. The glutamate signaling in the digestive system may have significant relevance to diabetes and GI tract motility disorders. This review will focus on the most recent update of molecular physiology of digestive VGLUTs.

  9. [Mental disorders in digestive system diseases - internist's and psychiatrist's insight].

    Science.gov (United States)

    Kukla, Urszula; Łabuzek, Krzysztof; Chronowska, Justyna; Krzystanek, Marek; Okopień, BogusŁaw

    2015-05-01

    Mental disorders accompanying digestive system diseases constitute interdisciplinary yet scarcely acknowledged both diagnostic and therapeutic problem. One of the mostly recognized examples is coeliac disease where patients endure the large spectrum of psychopathological symptoms, starting with attention deficit all the way down to the intellectual disability in extreme cases. It has not been fully explained how the pathomechanism of digestive system diseases affects patient's mental health, however one of the hypothesis suggests that it is due to serotonergic or opioid neurotransmission imbalance caused by gluten and gluten metabolites effect on central nervous system. Behavioral changes can also be invoked by liver or pancreatic diseases, which causes life-threatening abnormalities within a brain. It occurs that these abnormalities reflexively exacerbate the symptoms of primary somatic disease and aggravate its course, which worsens prognosis. The dominant mental disease mentioned in this article is depression which because of its effect on a hypothalamuspituitary- adrenal axis and on an autonomic nervous system, not only aggravates the symptoms of inflammatory bowel diseases but may accelerate their onset in genetically predisposed patients. Depression is known to negatively affects patients' ability to function in a society and a quality of their lives. Moreover, as far as children are concerned, the occurrence of digestive system diseases accompanied by mental disorders, may adversely affect their further physical and psychological development, which merely results in worse school performance. All those aspects of mental disorders indicate the desirability of the psychological care for patients with recognized digestive system disease. The psychological assistance should be provided immediately after diagnosis of a primary disease and be continued throughout the whole course of treatment.

  10. Two-phase viscoelastic jetting

    Energy Technology Data Exchange (ETDEWEB)

    Yu, J-D; Sakai, S.; Sethian, J.A.

    2008-12-10

    A coupled finite difference algorithm on rectangular grids is developed for viscoelastic ink ejection simulations. The ink is modeled by the Oldroyd-B viscoelastic fluid model. The coupled algorithm seamlessly incorporates several things: (1) a coupled level set-projection method for incompressible immiscible two-phase fluid flows; (2) a higher-order Godunov type algorithm for the convection terms in the momentum and level set equations; (3) a simple first-order upwind algorithm for the convection term in the viscoelastic stress equations; (4) central difference approximations for viscosity, surface tension, and upper-convected derivative terms; and (5) an equivalent circuit model to calculate the inflow pressure (or flow rate) from dynamic voltage.

  11. Role of microRNA-7 in digestive system malignancy

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    There are several malignancies of the digestive system(including gastric, pancreatic and colorectal cancers, andhepatocellular carcinoma), which are the most commontypes of cancer and a major cause of death worldwide.MicroRNA (miR)-7 is abundant in the pancreas, playingan important role in pancreatic development andendocrine function. Expression of miR-7 is downregulatedin digestive system malignancies compared with normaltissue. Although there are contrasting results for miR-7expression, almost all research reveals that miR-7 is atumor suppressor, by targeting various genes in specificpathways. Moreover, miR-7 can target different genessimultaneously in different malignancies of the digestivesystem. By acting on many cytokines, miR-7 is alsoinvolved in many gastrointestinal inflammatory diseasesas a significant carcinogenic factor. Consequently, miR-7might be a biomarker or therapeutic target gene indigestive system malignancies.

  12. Expression of nesfatin-1/NUCB2 in rodent digestive system

    Institute of Scientific and Technical Information of China (English)

    Yutaka; Oomura

    2010-01-01

    AIM: To observe the regional distributions and morphological features of nesfatin-1/nucleobindin-2 (NUCB2) immunoreactive (IR) cells in the rodent digestive system. METHODS: Paraffin-embedded sections of seven organs (pancreas, stomach, duodenum, esophagus, liver, small intestine and colon) dissected from sprague-dawley (SD) rats and institute of Cancer Research (ICR) mice were prepared. The regional distributions of nesfatin-1/NUCB2 IR cells were observed by immunohistochemical staining. The morphological ...

  13. Pectinases partitioning in aqueous two-phase systems: an integration of the systems poly(ethylene glycol/crude dextran and poly(ethylene glycol/ammonium sulphate

    Directory of Open Access Journals (Sweden)

    STANA N. PEJIN

    2004-04-01

    Full Text Available The partitioning of pectinases in the poly(ethylene glucol4000/ammonium sulpohate system was studied and also its application for enzymes extraction from the top phase of the poly(ethylene glucol4000/crude dextran system. Almost complete one-sided partition of endo-pectinase and exo-pectinase to the bottom phase of the polymer/salt system was achieved at a tie-line length of 37.16 %. The concentration factors were 1.73 and 3.25, respectively. The highest total endo- and exo-pectinase yields (72.41 % and 69.46 %, respectively were obtained by integration of the polymer/polymer system at a tie-line of 8.61 % and a high phase volume ratio and the polymer/salt system at a tie-line of 30.23 % and a low phase volume ratio. Integration of the partitioning at a high tie-line length in the polymer/polimer and a low tie-line length in the polymer/salt system resulted in a total concentration factor of 1.5 and a purification of 1.66 fold for exo-pectinase. The addition of phosphate to this integrated system improved the total concentration factor and purification fold of the activity to 1.73 and 2.14, respectively.

  14. Time-resolved fast-neutron radiography of air-water two-phase flows in a rectangular channel by an improved detection system

    CERN Document Server

    Zboray, Robert; Mor, Ilan; Bromberger, Benjamin; Tittelmeier, Kai

    2015-01-01

    In a previous work we have demonstrated the feasibility of high-frame-rate, fast-neutron radiography of generic air-water two-phase flows in a 1.5 cm thick, rectangular flow channel. The experiments have been carried out at the high-intensity, white-beam facility of the Physikalisch-Technische Bundesanstalt, Germany, using an multi-frame, time-resolved detector developed for fast neutron resonance radiography. The results were however not fully optimal and therefore we have decided to modify the detector and optimize it for the given application, which is described in the present work. Furthermore, we managed to improve the image post-processing methodology and the noise suppression. Using the tailored detector and the improved post-processing significant increase in the image quality and an order of magnitude lower exposure times, down to 3.33 ms, have been achieved with minimized motion artifacts. Similar to the previous study, different two-phase flow regimes such as bubbly slug and churn flows have been e...

  15. The influence of secondary flow in a two-phase gas-solid system in straight channels with a non-circular cross-section

    Directory of Open Access Journals (Sweden)

    Milanović Saša M.

    2016-01-01

    Full Text Available The paper considers two-phase gas-solid turbulent flow of pneumatic transport in straight horizontal channels with a non-circular cross-section. During turbulent flow, a specific flow phenomenon, known as secondary flow, occurs in these channels in the cross-sectional plane. The existence of strong temperature gradients in the cross-sectional plane of the channel or the cases of curved channels result in the appearance of the secondary flow of the first kind. However, in straight channels with a non-circular cross-section, in the developed turbulent flow mode, a secondary flow, known as Prandtl’s secondary flow of the second kind, is induced. The paper presents a numerical simulation of a developed two-phase turbulent flow by using the PHOENICS 3.3.1 software package. Reynolds stress model was used to model the turbulence. The paper provides the data on the changes in turbulent stresses in the channel cross-section as well as the velocities of solid particles transported along the channel.

  16. Review of two-phase instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Han Ok; Seo, Han Ok; Kang, Hyung Suk; Cho, Bong Hyun; Lee, Doo Jeong

    1997-06-01

    KAERI is carrying out a development of the design for a new type of integral reactors. The once-through helical steam generator is important design features. The study on designs and operating conditions which prevent flow instability should precede the introduction of one-through steam generator. Experiments are currently scheduled to understand two-phase instability, evaluate the effect of each design parameter on the critical point, and determine proper inlet throttling for the prevention of instability. This report covers general two-phase instability with review of existing studies on this topics. The general classification of two phase flow instability and the characteristics of each type of instability are first described. Special attention is paid to BWR core flow instability and once-through steam generator instability. The reactivity feedback and the effect of system parameters are treated mainly for BWR. With relation to once-through steam generators, the characteristics of convective heating and dryout point oscillation are first investigated and then the existing experimental studies are summarized. Finally chapter summarized the proposed correlations for instability boundary conditions. (author). 231 refs., 5 tabs., 47 figs

  17. Next steps in two-phase flow: executive summary

    Energy Technology Data Exchange (ETDEWEB)

    DiPippo, R.

    1980-09-01

    The executive summary includes the following topics of discussion: the state of affairs; the fundamental governing equations; the one-dimensional mixture model; the drift-flux model; the Denver Research Institute two-phase geothermal flow program; two-phase flow pattern transition criteria; a two-fluid model under development; the mixture model as applied to geothermal well flow; DRI downwell instrumentation; two-phase flow instrumentation; the Sperry Research Corporation downhole pump and gravity-head heat exchanger systems; and the Brown University two-phase flow experimental program. (MHR)

  18. Two-Phase Technology at NASA/Johnson Space Center

    Science.gov (United States)

    Ungar, Eugene K.; Nicholson, Leonard S. (Technical Monitor)

    1999-01-01

    Since the baseline International Space Station (ISS) External Active Thermal Control System (EATCS) was changed from a two-phase mechanically pumped system to a single phase cascade system in the fall of 1993, two-phase EATCS research has continued at a low level at JSC. One of-the lessons of the ISS EATCS selection was that two-phase thermal control systems must have significantly lower power than comparable single phase systems to overcome their larger radiator area, larger line and fluid mass, and perceived higher technical risk. Therefore, research at JSC has concentrated on low power mechanically pumped two-phase EATCSs. In the presentation, the results of a study investigating the trade of single and two-phase mechanically pumped EATCSs for space vehicles will be summarized. The low power two-phase mechanically pumped EATCS system under development at JSC will be described in detail and the current design status of the subscale test unit will be reviewed. Also, performance predictions for a full size EATCS will be presented. In addition to the discussion of two-phase mechanically pumped EATCS development at JSC, two-phase technologies under development for biological water processing will be discussed. These biological water processor technologies are being prepared for a 2001 flight experiment and subsequent usage on the TransHab module on the International Space Station.

  19. The ctenophore Mnemiopsis leidyi has a flow-through system for digestion with three consecutive phases of extracellular digestion.

    Science.gov (United States)

    Bumann, D; Puls, G

    1997-01-01

    The ctenophore (comb jelly) Mnemiopsis leidyi is a periodically abundant and voracious predator in U.S. coastal waters. Mnemiopsis leidyi is especially competitive at high prey concentrations because of its very efficient extracellular digestion. We investigated the functional basis for these outstanding digestion capabilities. Extracellular digestion takes place in the pharynx and consists of three distinct and consecutive phases. The three phases take place in different regions of the pharynx so that various prey items can be treated simultaneously in each phase. The first phase is acidic, while the second and the third are alkaline. Extracellular digestion is completed by ciliary currents that mechanically disrupt the predigested food. Bulky indigestible food fragments are expelled through the mouth. Except for a small area, the paths for ingestion and egestion are separate. Hence, both ingestion and egestion can occur simultaneously. The flattened and elongated shape of the pharynx provides the morphological basis for this flow-through system with various regions for different digestive treatments of the food. This system is highly elaborated compared with those of other lower invertebrates and allows for an efficient, fast, and simultaneous digestion of many prey items, which accounts for the outstanding feeding capabilities of M. leidyi.

  20. Anaerobic digestion of solid agroindustrial waste in semi-continuous mode: Evaluation of mono-digestion and co-digestion systems.

    Science.gov (United States)

    Pellera, Frantseska-Maria; Gidarakos, Evangelos

    2017-10-01

    The present study aimed at investigating the anaerobic digestion of four agroindustrial waste, namely cotton gin waste, winery waste, olive pomace and juice industry waste, in semi-continuous mode, conducting mono-digestion and co-digestion assays, using an artificial organic fraction sample as co-substrate. These assays were divided into two groups, in which different conditions were applied. Group I investigated the variation in two operational parameters, i.e. the organic loading rate (OLR) and the hydraulic retention time (HRT), while in Group II, the assays were fed with different substrates in a sequential order. Results showed more elevated specific methane yields for co-digestion assays compared with mono-digestion assays. Maximum yields were achieved at an OLR of 1.0gVS/(L·d) and a HRT reduced to half of the initial. Further reduction of the HRT coupled to an increase of the OLR generally caused a significant decrease of specific methane yields, as well as one case of severe overloading, i.e. the mono-digestion of juice industry waste, which resulted in instability and ultimately system failure. Sequential feeding with different substrates led to a more equilibrated operation, especially for co-digestion systems, with higher specific methane yields being observed during the phases corresponding to winery waste and juice industry waste substrates. Overall more positive results were obtained in the cases in which the latter substrates were fed to the reactors at process startup. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Response of two-phase droplets to intense electromagnetic radiation

    Science.gov (United States)

    Spann, James F.; Maloney, Daniel J.; Lawson, William F.; Casleton, Kent H.

    1993-04-01

    The behavior of two-phase droplets subjected to high intensity radiation pulses is studied. Droplets are highly absorbing solids in weakly absorbing liquid medium. The objective of the study was to define heating thresholds required for causing explosive boiling and secondary atomization of the fuel droplet. The results point to mechanisms for energy storage and transport in two-phase systems.

  2. TWO PHASE FLOW SPLIT MODEL FOR PARALLEL CHANNELS

    African Journals Online (AJOL)

    Ifeanyichukwu Onwuka

    The equations are solved using the Broyden'smethod ... channel system subjected to a two-phase flow transient, and the results have been very .... system pressure, the heat addition rates inside ... three dimensional flows in the LP.

  3. Microalgal Cultivation in Treating Liquid Digestate from Biogas Systems.

    Science.gov (United States)

    Xia, Ao; Murphy, Jerry D

    2016-04-01

    Biogas production via anaerobic digestion (AD) has rapidly developed in recent years. In addition to biogas, digestate is an important byproduct. Liquid digestate is the major fraction of digestate and may contain high levels of ammonia nitrogen. Traditional processing technologies (such as land application) require significant energy inputs and raise environmental risks (such as eutrophication). Alternatively, microalgae can efficiently remove the nutrients from digestate while producing high-value biomass that can be used for the production of biochemicals and biofuels. Both inorganic and organic carbon sources derived from biogas production can significantly improve microalgal production. Land requirement for microalgal cultivation is estimated as 3% of traditional direct land application of digestate.

  4. CFD Analysis and Visualization of the Two Phase Flow in a Thermosyphon for a Passive Heat Removal System of a Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Joseph; Lee, Jae Young [Handong Global University, Pohang (Korea, Republic of)

    2016-05-15

    A thermosyphon, wickless heat pipe, is a heat transfer device of high thermal conductance that functions passively on the principle of evaporation and condensation of a working fluid. The heat-pipe concept was first proposed by Gaugler in 1942. After its independent invention by Grover in the early 1960s, serious development progress was made, and the heat pipe concept was studied intensively for both space and terrestrial applications, because of its beneficial characteristics. Annamalai and Ramalingam developed a CFD modeling for wick part of heat pipe using commercial code, ANSYS CFX. Khurram Kafeel numerically studied thermal hydraulic characteristics of thermosyphon in both transient and steady state. Bandar Fadhl et al. built a CFD modeling for boiling and condensing of thermosyphon using VOF method of ANSYS Fluent. They made user defined function (UDF) to define source term based on Lee model. In this study, CFD model of 1m-thermosyphon has been studied using VOF model. Unlike formal studies, vacuum pressure condition was applied because thermosyphon with vacuum inner pressure is much generally used. Furthermore, to check out hydraulic characteristics of the model, transparent thermosyphon experiment also has been conducted. The main purpose of this research is the investigation of CFD model of thermosyphon. Simulations using VOF method were performed to analyze evaporating, condensing and two phase flow of a thermosyphon. The simulation results show that complex phenomena inside of thermosyphon can be modeled using VOF method. Flow visualizations of working fluid matched well with transparent heat pipe experiment.

  5. Two phase decision algorithm of replica allocation

    Institute of Scientific and Technical Information of China (English)

    Zuo Chaoshu; Liu Xinsong; Wang Zheng; Li Yi

    2006-01-01

    In distributed parallel server system, location and redundancy of replicas have great influence on availability and efficiency of the system. In order to improve availahility and efficiency of the system, two phase decision algorithm of replica allocation is proposed. The algorithm which makes use of auto-regression model dynamically predicts the future count of READ and WRITE operation, and then determines location and redundancy of replicas by considering availability, CPU and bands of the network. The algorithm can not only ensure the requirement of availability, but also reduce the system resources consumed by all the operations in a great scale. Analysis and test show that communication complexity and time complexity of the algorithm satisfy O( n ), resource optimizing scale increases with the increase of READ count.

  6. Thermo-Fluid Dynamics of Two-Phase Flow

    CERN Document Server

    Ishii, Mamrou

    2011-01-01

    "Thermo-fluid Dynamics of Two-Phase Flow, Second Edition" is focused on the fundamental physics of two-phase flow. The authors present the detailed theoretical foundation of multi-phase flow thermo-fluid dynamics as they apply to: Nuclear reactor transient and accident analysis; Energy systems; Power generation systems; Chemical reactors and process systems; Space propulsion; Transport processes. This edition features updates on two-phase flow formulation and constitutive equations and CFD simulation codes such as FLUENT and CFX, new coverage of the lift force model, which is of part

  7. Microgravity Two-Phase Flow Transition

    Science.gov (United States)

    Parang, M.; Chao, D.

    1999-01-01

    Two-phase flows under microgravity condition find a large number of important applications in fluid handling and storage, and spacecraft thermal management. Specifically, under microgravity condition heat transfer between heat exchanger surfaces and fluids depend critically on the distribution and interaction between different fluid phases which are often qualitatively different from the gravity-based systems. Heat transfer and flow analysis in two-phase flows under these conditions require a clear understanding of the flow pattern transition and development of appropriate dimensionless scales for its modeling and prediction. The physics of this flow is however very complex and remains poorly understood. This has led to various inadequacies in flow and heat transfer modeling and has made prediction of flow transition difficult in engineering design of efficient thermal and flow systems. In the present study the available published data for flow transition under microgravity condition are considered for mapping. The transition from slug to annular flow and from bubbly to slug flow are mapped using dimensionless variable combination developed in a previous study by the authors. The result indicate that the new maps describe the flow transitions reasonably well over the range of the data available. The transition maps are examined and the results are discussed in relation to the presumed balance of forces and flow dynamics. It is suggested that further evaluation of the proposed flow and transition mapping will require a wider range of microgravity data expected to be made available in future studies.

  8. Recombinant Saccharomyces cerevisiae expressing P450 in artificial digestive systems : A model for biodetoxication in the human digestive environment

    NARCIS (Netherlands)

    Blanquet, S.; Meunier, J.P.; Minekus, M.; Marol-Bonnin, S.; Alric, M.

    2003-01-01

    The use of genetically engineered microorganisms such as bacteria or yeasts as live vehicles to carry out bioconversion directly in the digestive environment is an important challenge for the development of innovative biodrugs. A system that mimics the human gastrointestinal tract was combined with

  9. Recombinant Saccharomyces cerevisiae expressing P450 in artificial digestive systems : A model for biodetoxication in the human digestive environment

    NARCIS (Netherlands)

    Blanquet, S.; Meunier, J.P.; Minekus, M.; Marol-Bonnin, S.; Alric, M.

    2003-01-01

    The use of genetically engineered microorganisms such as bacteria or yeasts as live vehicles to carry out bioconversion directly in the digestive environment is an important challenge for the development of innovative biodrugs. A system that mimics the human gastrointestinal tract was combined with

  10. Two Phase Technology Development Initiatives

    Science.gov (United States)

    Didion, Jeffrey R.

    1999-01-01

    Three promising thermal technology development initiatives, vapor compression thermal control system, electronics cooling, and electrohydrodynamics applications are outlined herein. These technologies will provide thermal engineers with additional tools to meet the thermal challenges presented by increased power densities and reduced architectural options that will be available in future spacecraft. Goddard Space Flight Center and the University of Maryland are fabricating and testing a 'proto- flight' vapor compression based thermal control system for the Ultra Long Duration Balloon (ULDB) Program. The vapor compression system will be capable of transporting approximately 400 W of heat while providing a temperature lift of 60C. The system is constructed of 'commercial off-the-shelf' hardware that is modified to meet the unique environmental requirements of the ULDB. A demonstration flight is planned for 1999 or early 2000. Goddard Space Flight Center has embarked upon a multi-discipline effort to address a number of design issues regarding spacecraft electronics. The program addressed the high priority design issues concerning the total mass of standard spacecraft electronics enclosures and the impact of design changes on thermal performance. This presentation reviews the pertinent results of the Lightweight Electronics Enclosure Program. Electronics cooling is a growing challenge to thermal engineers due to increasing power densities and spacecraft architecture. The space-flight qualification program and preliminary results of thermal performance tests of copper-water heat pipes are presented. Electrohydrodynamics (EHD) is an emerging technology that uses the secondary forces that result from the application of an electric field to a flowing fluid to enhance heat transfer and manage fluid flow. A brief review of current EHD capabilities regarding heat transfer enhancement of commercial heat exchangers and capillary pumped loops is presented. Goddard Space Flight

  11. Extraction of endo-pectinase activity from the culture filtrate of Polyporus squamosus by aqueous two-phase systems composed of low molecular mass polyethylene glycol and phosphate salt

    Directory of Open Access Journals (Sweden)

    Peričin Draginja M.

    2004-01-01

    Full Text Available Separation of endo-pectinase activity from the culture filtrate of Polyporus squamosus - strain MMOL76, by aqueous two-phase partitioning technique in polyethylene glycol/sodium dihydrogen phosphate system was investigated as the first operation in the downstream processing of enzyme. The best results concerning the partitioning coefficient and the top phase yield were achieved in the polyethylene glycol 400/sodium dihydrogen phosphate system at the tie-line length 78.9 % at pH 3.8 (K = 8, with a 90% yield.

  12. Critical transport velocity in two-phase, horizontal pipe flow

    Energy Technology Data Exchange (ETDEWEB)

    Sommerville, D. (U.S. Army Chemical Research, Development and Engineering Center, Aberdeen Proving Grounds, MD (US))

    1991-02-01

    This paper reports on the suspension of solid particles or entrainment of liquid droplets in two- phase flow. Theoretical and empirical relationships have been derived for both instances without any consideration to the similarities between the two. However, a general relation for two-phase flow is desirable since there are systems that cannot be readily defined due to the dual (solid/liquid) nature of the transported material, such as colloids, pulp, slurries, and sludge. Using turbulence theory, one general equation can be derived to predict critical transport velocities for two-phase horizontal flow.

  13. Autogenerative high pressure digestion: anaerobic digestion and biogas upgrading in a single step reactor system

    NARCIS (Netherlands)

    Lindeboom, R.E.F.; Fermoso, F.G.; Weijma, J.; Zagt, K.; Lier, van J.B.

    2011-01-01

    Conventional anaerobic digestion is a widely applied technology to produce biogas from organic wastes and residues. The biogas calorific value depends on the CH4 content which generally ranges between 55 and 65%. Biogas upgrading to so-called ‘green gas’, with natural gas quality, generally proceeds

  14. Autogenerative high pressure digestion: anaerobic digestion and biogas upgrading in a single step reactor system

    NARCIS (Netherlands)

    Lindeboom, R.E.F.; Fermoso, F.G.; Weijma, J.; Zagt, K.; Lier, van J.B.

    2011-01-01

    Conventional anaerobic digestion is a widely applied technology to produce biogas from organic wastes and residues. The biogas calorific value depends on the CH4 content which generally ranges between 55 and 65%. Biogas upgrading to so-called ‘green gas’, with natural gas quality, generally proceeds

  15. Control System of Two-Phase Brushless DC Gyro Motor Based on DSP%基于DSP的两相无刷直流陀螺电机稳速系统

    Institute of Scientific and Technical Information of China (English)

    吴梅锡; 付鲁华; 林玉池

    2013-01-01

    The research of the influence of gyro motor speed stability on the north-finding result is studied in order to improve the gyro north-finding precision. The paper introduces a two-phase brushless DC gyro motor control system based on TMS320LF2407A. First,it expounds the two-phase brushless DC motor's working principle. Then through the design of the hardware and software system, the close-loop control of two-phase brushless DC gyro motor is realized. The experimental results show that,the system can drive the brushless DC gyro motor well starting,braking and smooth running. The precision of the steady speed is less than 10~6 and the characteristics of the system satisfy the gyroscope demand.%为了进一步提高陀螺仪的寻北精度,分析研究了陀螺电机转速大小和转速精度对寻北结果的影响.在此基础上设计了一种基于TMS320LF2407A的两相无刷直流陀螺电机控制系统,阐述了两相无刷直流电机的工作原理,给出了电机的简化结构及数学模型,并通过对硬件系统和软件算法的设计实现了两相无刷直流陀螺电机的闭环控制.实验结果表明:系统可以很好地完成电机的启动、制动和平稳运行,转速精度优于10-6,满足陀螺仪的工作要求.

  16. 基于AT89C52单片机的步进电机控制系统研究%Research of Control System of Two-phase Hybrid Stepping Motor Based on AT89C52 Microcontrollers

    Institute of Scientific and Technical Information of China (English)

    何冲; 王淑红; 侯胜伟; 牛慧文

    2012-01-01

    The design scheme Based on AT89C52 Microcontrollers of two phase hybrid stepping motor control system is introduced, reflects two phase hybrid stepping motor control method in principle, increase the flexibility of stepping motor control system design. The control system adopts AT89C52 as controller, use BUW49 power tube of double H bridge type circuit as driver, join button control and LCD1602 display. The circuit structure of control system is simple and the thinking design is clearly. Experimental results shows that the control system operation is simple and reliable, it has strong practicability.%本文介绍了基于AT89C52单片机的两相混合式步进电机控制系统的设计方案,增加了步进电机控制系统设计的灵活性。控制系统采用AT89C52单片机作为控制器,由达林顿功率管BUW49组成的双H桥式电路作为驱动器,加入按键控制及LCD1602显示。控制系统的电路结构简单、设计思路清晰。实验表明,控制系统操作简单、运行可靠,具有较强的实用性。

  17. Sulphonamide porphyrins in the biomimetic oxidation by H{sub 2}O{sub 2}. An efficient two-phase system

    Energy Technology Data Exchange (ETDEWEB)

    Rocha Gonsalves, A.M. d`A.; Pereira, M.M.; Serra, A.C. [Departamento de Quimica: Universidade de Coimbra. Coimbra (Portugal)

    1996-12-31

    A catalytic biphasic aqueous/organic system for hydrogen peroxide oxidations was studied and improved, and a new metalloporphyrins derived from meso-tetrakis-2,6-dichlorophenylprophyr in bearing five sulphonamide side chains in the meso-phenyl and in one of the Beta-positions was synthesised and established as an highly efficient and stable catalyst working in the newly developed system. An interface mechanism is proposed to interpret the role of lipophilic acids as co-catalysts, the efficiency of the catalysis and the stability of the catalyst in the new system. (Author) 16 refs.

  18. EFFECT OF ALCOHOL ON AQUEOUS TWO-PHASE SYSTEM PROPERTIES OF SDS/CTAB/H2O/Na2SO4 SYSTEM%醇对正负离子表面活性剂双水相性质的影响

    Institute of Scientific and Technical Information of China (English)

    滕弘霓; 王利

    2004-01-01

    The effect of alcohol on the aqueous two-phase system properties of SDS/CTAB/H2O/Na2SO4 system was studied by the pseudo ternary phase diagram. The electrostatic forces (both attraction and repulsion) between cationic surfactant and anionic surfactant decreased because of the interaction of alcohol hydroxyl group and surfactant polar group. As a result, the phase area width of aqueous two-phase system increased. Long chain alcohol (more than five carbonatoms), which was in high concentration in the SDS/CTAB/H2O/Na2SO4) system, caused the anionic aqueous two-phase system area to vanish and the cationic aqueous two-phase system area to become wider. The CTAB rich phase turned from top phase to bottom phase.

  19. Extraction of doxycycline hydrochloride using anhydrous alcohol and acetone binary aqueous two phase system%醇和小分子有机物二元双水相体系萃取盐酸多西环素

    Institute of Scientific and Technical Information of China (English)

    关卫省; 邓江华; 韩娟

    2012-01-01

    基于小分子醇双水相体系和小分子有机物双水相体系,建立了乙醇与丙酮和( NH4) 2SO4形成的二元双水相体系萃取盐酸多西环素的新方法.研究了(NH4)2SO4浓度、pH值、温度、乙醇与丙酮用量和盐酸多西环素浓度对盐酸多西环素分配行为的影响.结果表明,体系的(NH4)2SO4浓度为41%,pH值在4.5 ~5.0,温度25℃,且盐酸多西环素的质量浓度70 mg/L时,萃取率可达93.61%,分配系数可达83.081.%Based on the molecular alcohol aqueous two-phase system and the small molecular organic two-phase system,the new method of using anhydrous alcohol and small molecular organic (acetone) with ( NH4)2SO4 binary aqueous two phase system for extracting doxycycline hydrochloride was set up. The influence factors on partition behaviors of doxycycline hydrochloride were studied, including the concentration of (NH4)2SO4,anhydrous alcohol and acetone consumption,pH value,temperature and doxycycline hydrochloride. The results showed that when (NH4)2SO4 concentration of 41% ,pH value of 4.5~5.0, and the temperature of 25℃ ,mass concentration of doxycycline hydrochloride 70 mg/L,the extraction rate up to 93.61% and 83.081 .respectively.

  20. Two-phase cooling fluids; Les fluides frigoporteurs diphasiques

    Energy Technology Data Exchange (ETDEWEB)

    Lallemand, A. [Institut National des Sciences Appliquees (INSA), 69 - Lyon (France)

    1997-12-31

    In the framework of the diminution of heat transfer fluid consumption, the concept of indirect refrigerating circuits, using cooling intermediate fluids, is reviewed and the fluids that are currently used in these systems are described. Two-phase cooling fluids advantages over single-phase fluids are presented with their thermophysical characteristics: solid fraction, two-phase mixture enthalpy, thermal and rheological properties, determination of heat and mass transfer characteristics, and cold storage through ice slurry

  1. 黄芩甙在EOPO/盐双水相系统中的分配系数测定及关联%Measurement and Correlation of Partition Coefficients of Baicalin in EOPO/Salt Aqueous Two-Phase Systems

    Institute of Scientific and Technical Information of China (English)

    李伟; 朱自强

    2002-01-01

    The partition coefficients of baicalin were measured in ethylene oxide and propylene oxide (EOPO)/salt aqueous two-phase systemsat 298.15K. It was found that most of baicalin partitioned into EOPO-rich phase. The partition coefficients of baicalin varied from 10 to 120.The effect of various factors, including tie-line length, salt composition, molecular weight of EOPO, and solution pH, on the partition behaviorwas investigated in EOPO/salt systems. Furthermore the partition coefficients of baicalin were correlated using the modified Diamond-Hsumodel. Good agreement with experimental data is obtained. The average relative deviations are less than 5.0%.

  2. Separation, concentration and determination of chloramphenicol in environment and food using an ionic liquid/salt aqueous two-phase flotation system coupled with high-performance liquid chromatography.

    Science.gov (United States)

    Han, Juan; Wang, Yun; Yu, Cuilan; Li, Chunxiang; Yan, Yongsheng; Liu, Yan; Wang, Liang

    2011-01-31

    Ionic liquid-salt aqueous two-phase flotation (ILATPF) is a novel, green, non-toxic and sensitive samples pretreatment technique. ILATPF coupled with high-performance liquid chromatography (HPLC) was developed for the analysis of chloramphenicol, which combines ionic liquid aqueous two-phase system (ILATPS) based on imidazolium ionic liquid (1-butyl-3-methylimidazolium chloride, [C(4)mim]Cl) and inorganic salt (K(2)HPO(4)) with solvent sublation. In ILATPF systems, phase behaviors of the ILATPF were studied for different types of ionic liquids and salts. The sublation efficiency of chloramphenicol in [C(4)mim]Cl-K(2)HPO(4) ILATPF was influenced by the types of salts, concentration of K(2)HPO(4) in aqueous solution, solution pH, nitrogen flow rate, sublation time and the amount of [C(4)mim]Cl. Under the optimum conditions, the average sublation efficiency is up to 98.5%. The mechanism of ILATPF contains two principal processes. One is the mechanism of IL-salt ILATPS formation, the other is solvent sublation. This method was practical when applied to the analysis of chloramphenicol in lake water, feed water, milk, and honey samples with the linear range of 0.5-500 ng mL(-1). The method yielded limit of detection (LOD) of 0.1 ng mL(-1) and limit of quantification (LOQ) of 0.3 ng mL(-1). The recovery of CAP was 97.1-101.9% from aqueous samples of environmental and food samples by the proposed method. Compared with liquid-liquid extraction, solvent sublation and ionic liquid aqueous two-phase extraction, ILATPF can not only separate and concentrate chloramphenicol with high sublation efficiency, but also efficiently reduce the wastage of IL. This novel technique is much simpler and more environmentally friendly and is suggested to have important applications for the concentration and separation of other small biomolecules.

  3. Study on aqueous two-phase extraction of L-phenylalanine by polyethylene glycol/salt system%聚乙二醇/盐双水相萃取L-苯丙氨酸的研究

    Institute of Scientific and Technical Information of China (English)

    孙晨; 刘文举; 刘宁宁

    2012-01-01

    研究了聚乙二醇/盐双水相体系的成相行为及L-苯丙氨酸在双水相中的分配规律,其中包括聚乙二醇的分子量、聚乙二醇质量分数、盐的种类及加入量、L-苯丙氨酸初始浓度和pH对萃取分离的影响。当聚乙二醇1000的质量分数为27%,磷酸氢二钾的质量浓度为O.15g/mL,L-苯丙氨酸的质量浓度为10g/L,体系的pH为8.5时,L-苯丙氨酸的萃取率最高为99.5%,分配系数最大为186.5。%An aqueous two- phase system of polyethylene glycol (PEG)/salt with the behavior of forming aqueous two-phase and the distribution rules of L-phenylalanine in the aqueous two-phase system were studied.Effects of the molecular weight of polyethylene glycol ,the mass fraction of polyethylene glycol ,the types and concentrations of salts,the initial concentration of L-phenylalanine and pH value were investigated.When the mass fraction of PEG1000 was 27% ,the mass concentration of K2HPO4was 0.]5g/mL,the initial concentration of L-phenylalanine was 10g/L and pH value was about 8.5,the highest extraction yield of L-phenylalanine could reach 99.5 %, partition coefficient of L-phenylalanine could reach 186.5.

  4. Markedly improving asymmetric oxidation of 1-(4-methoxyphenyl) ethanol with Acetobacter sp. CCTCC M209061 cells by adding deep eutectic solvent in a two-phase system

    OpenAIRE

    Wei, Ping; Liang, Jing; Cheng, Jing; Zong, Min-Hua; Lou, Wen-Yong

    2016-01-01

    Background Enantiopure (S)-1-(4-methoxyphenyl) ethanol {(S)-MOPE} can be employed as an important synthon for the synthesis of cycloalkyl [b] indoles with the treatment function for general allergic response. To date, the biocatalytic resolution of racemic MOPE through asymmetric oxidation in the biphasic system has remained largely unexplored. Additionally, deep eutectic solvents (DESs), as a new class of promising green solvents, have recently gained increasing attention in biocatalysis for...

  5. Gibbs free energy of transfer of a methylene group on {UCON + (sodium or potassium) phosphate salts} aqueous two-phase systems: Hydrophobicity effects

    OpenAIRE

    Silvério, Sara C.; Rodríguez, Oscar; Teixeira, J. A.; Macedo, Eugénia

    2010-01-01

    The Gibbs free energy of transfer of a suitable hydrophobic probe can be regarded as a measure of the relative hydrophobicity of the different phases. The methylene group (CH2) can be considered hydrophobic, and thus be a suitable probe for hydrophobicity. In this work, the partition coefficients of a series of five dinitrophenylated-amino acids were experimentally determined, at 23 °C, in three different tie-lines of the biphasic systems: (UCON + K2HPO4), (UCON + potassium phosph...

  6. Use of hydrophilic ionic liquids in a two-phase system to improve Mung bean epoxide hydrolases-mediated asymmetric hydrolysis of styrene oxide.

    Science.gov (United States)

    Chen, Wen-Jing; Lou, Wen-Yong; Yu, Chun-Yang; Wu, Hong; Zong, Min-Hua; Smith, Thomas J

    2012-12-31

    A comparative study was made of Mung bean epoxide hydrolases-catalyzed asymmetric hydrolysis of styrene oxide to (R)-1-phenyl-1,2-ethanediol in an n-hexane/buffer biphasic system containing various hydrophilic ionic liquids (ILs). Compared to the n-hexane/buffer biphasic system alone, addition of a small amount of hydrophilic ILs reduced the amount of non-enzymatic hydrolysis, and improved the reaction rate by up to 22%. The ILs with cation containing an alkanol group, namely [C(2)OHMIM][BF(4)] and [C(2)OHMIM][TfO], and the choline amino acid ILs [Ch][Arg] and [Ch][Pro] were found to be the most suitable co-solvents for the reaction, owing to their good biocompatibility with the enzyme, which led to high initial rates (0.99-1.25 μmol/min) and high product e.e.s (95%). When substrate concentration was around 30 mM, where optimal performance was observed with the IL-containing systems, the product e.e. was improved from 90% without ILs to ≥95% in the presence of ILs.

  7. Synthesis of octyl-β-D-glucopyranoside catalyzed by Thai rosewood β-glucosidase-displaying Pichia pastoris in an aqueous/organic two-phase system.

    Science.gov (United States)

    Guo, DongHeng; Xu, YanShan; Kang, YaJun; Han, ShuangYan; Zheng, SuiPing

    2016-04-01

    We explored the ability of a Thai rosewood β-glucosidase-displaying P. pastoris whole-cell biocatalyst (Pp-DCBGL) system to synthesize alkyl β-D-glucosides. The primary investigation centered on the synthesis of octyl-β-D-glucopyranoside (octyl-glu, OG). OG could be synthesized through reverse hydrolysis reaction with very low efficiency. Then, OG was synthesized between BG and octanol by a transglycosylation reaction. In a 2-ml reaction system, OG was synthesized with a conversion rate of 51.1% in 3h when 5 mg/ml BG was utilized as the glucosyl donor under optimized conditions. And, even after being reused four times, the Pp-DCBGL was relatively stable. Additionally, a 500-ml-scale reaction system was conducted in a 2-L stirred reactor with a conversion rate of 47.5% in 1.5 h. Moreover, the conversion rate did not decrease after the whole-cell catalyst was reused two times. In conclusion, Pp-DCBGL has high reaction efficiency and operational stability, which is a powerful biocatalyst available for industrial synthesis. Copyright © 2015. Published by Elsevier Inc.

  8. Two-phase flow simulation inside a tubing string with artificial lift system PCP based; Simulacao do escoamento bifasico em uma coluna de producao com sistema de elevacao artificial por BCP

    Energy Technology Data Exchange (ETDEWEB)

    Vidal, F.J.T.; Salazar, A.O.; Maitelli, A.L. [Rio Grande do Norte Univ., Natal, RN (Brazil). Programa de Pos-graduacao em Engenharia Eletrica]. E-mail: francisco@dca.ufrn.br; andres@dca.ufrn.br; maitelli@dca.ufrn.br; Assmann, B.W. [PETROBRAS S.A., Natal/Fortaleza, RN/CE (Brazil). Unidade de Negocios]. E-mail: benno@petrobras.com.br; Lima, J.A. [Rio Grande do Norte Univ., Natal, RN (Brazil). Dept. de Engenharia Mecanica. Programa de Pos-graduacao em Engenharia Mecanica]. E-mail: jalima@dem.ufrn.br

    2005-07-01

    The main goal of the present work is the computational simulation of the vertical two-phase flow within a tubing string in the production of oil equipped with a PCP artificial lift system (Progressive Cavity Pumping). By initially adopting the homogeneous model for the two-phase mixture (oil and gas), the fields of velocity and pressure are evaluated for prediction of pressure loss along the tubing, as well as the spatial and temporal behavior of typical parameters as gas-oil ratio, bubble pressure, solubility ratio, void fraction, gas and oil formation volume factors, among others. Prediction of these properties is an integral part of pressure loss calculations, as well as they constitute essential parameters for optimization of any artificial lift system. The numerical simulation is based on the transport equations (continuity and momentum equations) for a pseudo-fluid through the finite difference method, and the mixture properties are evaluated by employing the black-oil fluid model. Behavior analyses of the main flow variables are made and results for a typical artificial lift system PCP based are discussed. (author)

  9. Features of the milk whey protein partitioning in polyethyleneglycol-sodium citrate aqueous two-phase systems with the goal of isolating human alpha-1 antitrypsin expressed in bovine milk.

    Science.gov (United States)

    Boaglio, Andrea; Bassani, Georgina; Picó, Guillermo; Nerli, Bibiana

    2006-06-06

    Partitioning behaviour of the bovine whey proteins (bovine serum albumin, alpha-lactoalbumin and beta-lactoglobulin) and human alpha-1 antitrypsin in aqueous two-phase systems prepared with polyethyleneglycol (molecular masses: 1000, 1450 and 3350)-sodium citrate was analysed at pH 5.2, 6.2 and 8.2. Alpha lactoalbumin concentrated in the polyethyleneglycol rich-phase, while beta-lactoglobulin, bovine serum albumin and alpha-1 antitrypsin showed affinity for the citrate rich-phase. In aqueous two-phase systems of high medium pH and high polyethyleneglycol molecular mass the protein partitioning equilibrium is displaced to the citrate rich-phase. The polyethyleneglycol 1450-pH 5.2 system with a top/bottom phase-volume ratio of 3 showed to have the best capability of recovering the alpha-1 antitrypsin from a mixture prepared with natural milk whey and human alpha-1 antitrypsin. The recovery of this protein in the bottom phase was of 90% and the purity of the obtained product was of 98%. The method appears to be suitable as a starting point to isolate other human proteins expressed in transgenic bovine milk.

  10. Two-phases-service queuing system with server breakdown and vacations%带有服务台故障和两阶段服务的休假排队系统

    Institute of Scientific and Technical Information of China (English)

    曾慧; 岳德权

    2011-01-01

    为了解决现实生产生活中的具有两阶段服务性质的休假排队问题,利用马尔可夫过程理论建立系统稳态概率方程组,并利用分块矩阵解法,得到了稳态概率的矩阵解.由此得出系统的平均队长、平均等待队长等性能指标.该成果对解决两阶段服务排队模型具有重要的理论意义和应用价值.%In order to solve the vacation queue problems with a two-phase of service in real-life production, the equations of steady-state probability were derived by applying the Markov process theory in this study. Subsequently, the matrix form solution of steady-state probability was found by using block matrix method. Furthermore, some performance measures of the system, such as the expected number of customers in the system and the expected number of customers in the queue, were also obtained. The study on the queuing systems with two-phase of service is of theoretical significance and application value.

  11. Efficacy and Safety of Epratuzumab in Moderately to Severely Active Systemic Lupus Erythematosus: Results From Two Phase III Randomized, Double‐Blind, Placebo‐Controlled Trials

    Science.gov (United States)

    Wallace, Daniel J.; Furie, Richard A.; Petri, Michelle A.; Pike, Marilyn C.; Leszczyński, Piotr; Neuwelt, C. Michael; Hobbs, Kathryn; Keiserman, Mauro; Duca, Liliana; Kalunian, Kenneth C.; Galateanu, Catrinel; Bongardt, Sabine; Stach, Christian; Beaudot, Carolyn; Kilgallen, Brian; Gordon, Caroline; Batalov, A.; Bojinca, M.; Djerassi, R.; Duca, L.; Horak, P.; Kolarov, Z.; Milasiene, R.; Monova, D.; Otsa, K.; Pileckyte, M.; Popova, T.; Radulescu, F.; Rashkov, R.; Rednic, S.; Repin, M.; Stoilov, R.; Tegzova, D.; Vezikova, N.; Vitek, P.; Zainea, C.; East, Far; Baek, H.; Chen, Y.; Chiu, Y.; Cho, C.; Chou, C.; Choe, J.; Huang, C.; Kang, Y.; Kang, S.; Lai, N.; Lee, S.; Park, W.; Shim, S.; Suh, C.; Yoo, W.; Armengol, H. Avila; Zapata, F. Avila; Santiago, M. Barreto; Cavalcanti, F.; Chahade, W.; Costallat, L.; Keiserman, M.; Alcala, J. Orozco; Remus, C. Ramos; Roimicher, L.; Abu‐Shakra, M.; Agarwal, V.; Agmon‐Levin, N.; Kadel, J.; Levy, Y.; Mevorach, D.; Paran, D.; Reitblat, T.; Rosner, I.; Shobha, V.; Sthoeger, Z.; Zisman, D.; Ayesu, K.; Berney, S.; Box, J.; Busch, H.; Buyon, J.; Carter, J.; Chi, J.; Clowse, M.; Collins, R.; Dao, K.; Diab, I.; Dikranian, A.; El‐Shahawy, M.; Gaylis, N.; Grossman, J.; Halpert, E.; Huff, J.; Jarjour, W.; Kao, A.; Katz, R.; Kennedy, A.; Khan, M.; Kivitz, A.; Kohen, M.; Lawrence‐Ford, T.; Lawson, J.; Levesque, M.; Lowenstein, M.; Majjhoo, A.; Mcarthur, R.; McLain, D.; Merrill, J.; Murillo, A.; Neucks, S.; Niemer, G.; Noaiseh, G.; Parker, C.; Pantojas, C.; Pattanaik, D.; Petri, M.; Pickrell, P.; Reveille, J.; Roman‐Miranda, A.; Rothfield, N.; Sankoorikal, A.; Sayers, M.; Singhal, A.; Snyder, A.; Striebich, C.; Vo, Q.; von Feldt, J.; Wallace, D.; Wasko, M.; Young, C.; Adelstein, S.; Hall, S.; Littlejohn, G.; Nicholls, D.; Suranyi, M.; Amoura, Z.; Bannert, B.; Behrens, F.; Perez, L.Carreno; Chakravarty, K.; Gonzales, F. Diaz; Davies, K.; Doria, A.; Emery, P.; Fernández‐Nebro, A.; Govoni, M.; Hachulla, E.; Hellmich, B.; Houssiau, F.; Malaise, M.; Margaux, J.; Maugars, Y.; Muñoz‐Fernández, S.; Navarro, F.; Ordi‐Ros, J.; Pellerito, R.; Pena‐Sagredo, J.; Roussou, E.; Schmidt, R. E.; Ucar‐Angulo, E.; Viallard, J‐F.; Westhovens, R.; Worm, M.; Yee, C. S.; Nayiager, S.; Reuter, H.; Spargo, C.; Bazela, B.; Brzosko, M.; Chudzik, D.; Gasztonyi, B.; Geher, P.; Ionescu, R.; Jeka, S.; Kemeny, L.; Kiss, E.; Kotyla, P.; Kovacs, L.; Kovalenko, V.; Kucharz, E.; Kwiatkowska, B.; Leszczynski, P.; Levchenko, E.; Lysenko, G.; Majdan, M.; Mihailov, C.; Nalotov, S.; Nedelciu, M.; Pavel, M.; Raskina, T.; Rebrov, B.; Rezus, E.; Semen, T.; Smakotina, S.; Stanislavchuk, M.; Stanislav, M.; Szombati, I.; Szucs, G.; Udrea, G.; Zajdel, J.; Zon‐Giebel, A.; Bonfiglioli, R.; Bustamante, R.; Klumb, E.; Ramirez, G. Medrano; Neiva, C.; Olguin, M.; Gonzaga, J.Reyes; Scotton, A.; Ayala, S. Sicsik; Ximenes, A.; Sharma, R.; Srikantiah, C.; Aelion, J.; Aranow, C.; Baker, M.; Chadha, A.; Chao, J.; Chatham, W.; Chow, A.; Clay, C.; Cohen‐Gadol, S.; Conaway, D.; Denburg, J.; Escalante, A.; Espinoza, L.; Fiechtner, J.; Fortin, I.; Fraser, A.; Furie, R.; Gladman, D.; Goddard, D.; Goldberg, M.; Gonzalez‐Rivera, R.; Gorman, J.; Griffin, R.; Haaland, D.; Halter, D.; Hemaiden, A.; Hobbs, K.; Joshi, V.; Lim, S.; Kalunian, K.; Karpouzas, G.; Khraishi, M.; Lafyatis, R.; Lee, S.; Lidman, R.; Lue, C.; Mohan, M.; Mease, P.; Mehta, C.; Mizutani, W.; Nami, A.; Nascimento, J.; Neuwelt, C.; Pappas, J.; Pope, J.; Porges, A.; Roane, G.; Rosenberg, D.; Ross, S.; Saadeh, C.; Scoville, C.; Sherrer, Y.; Solomon, M.; Surbeck, W.; Valenzuela, G.; Waller, P.; Alten, R.; Baerwald, C.; Bienvenu, B.; Bombardieri, S.; Braun, J.; Dival, L.; Espinosa, G.; Fernandez, I. Figueroa; Gomez‐Reino, J.; Gordon, C.; Hiepe, F.; Hopkinson, N.; Isenberg, D.; Jacobi, A.; Jorgensen, C.; Guern, V. Le; Paul, C.; Pego‐Reigosa, J. M.; Heredia, J. Rodriguez; Rubbert‐Roth, A.; Sabbadini, M.; Schroeder, J.; Schwarting, A.; Spieler, W.; Valesini, G.; Wollenhaupt, J.; Mendoza, A. Zea; Zouboulis, C.

    2017-01-01

    Objective Epratuzumab, a monoclonal antibody that targets CD22, modulates B cell signaling without substantial reductions in the number of B cells. The aim of this study was to report the results of 2 phase III multicenter randomized, double‐blind, placebo‐controlled trials, the EMBODY 1 and EMBODY 2 trials, assessing the efficacy and safety of epratuzumab in patients with moderately to severely active systemic lupus erythematosus (SLE). Methods Patients met ≥4 of the American College of Rheumatology revised classification criteria for SLE, were positive for antinuclear antibodies and/or anti–double‐stranded DNA antibodies, had an SLE Disease Activity Index 2000 (SLEDAI‐2K) score of ≥6 (increased disease activity), had British Isles Lupus Assessment Group 2004 index (BILAG‐2004) scores of grade A (severe disease activity) in ≥1 body system or grade B (moderate disease activity) in ≥2 body systems (in the mucocutaneous, musculoskeletal, or cardiorespiratory domains), and were receiving standard therapy, including mandatory treatment with corticosteroids (5–60 mg/day). BILAG‐2004 grade A scores in the renal and central nervous system domains were excluded. Patients were randomized 1:1:1 to receive either placebo, epratuzumab 600 mg every week, or epratuzumab 1,200 mg every other week, with infusions delivered for the first 4 weeks of each 12‐week dosing cycle, for 4 cycles. Patients across all 3 treatment groups also continued with their standard therapy. The primary end point was the response rate at week 48 according to the BILAG‐based Combined Lupus Assessment (BICLA) definition, requiring improvement in the BILAG‐2004 score, no worsening in the BILAG‐2004 score, SLEDAI‐2K score, or physician's global assessment of disease activity, and no disallowed changes in concomitant medications. Patients who discontinued the study medication were classified as nonresponders. Results In the EMBODY 1 and EMBODY 2 trials of epratuzumab, 793

  12. Intermediate-scale high-solids anaerobic digestion system operational development

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, C.J.

    1995-02-01

    Anaerobic bioconversion of solid organic wastes represents a disposal option in which two useful products may be produced, including a medium Btu fuel gas (biogas) and a compost-quality organic residue. The application of high-solids technology may offer several advantages over conventional low-solids digester technology. Operation of the anaerobic digestion process at high solids reduces the level of process water and thereby the size and capital costs for the digester system. In addition, by virtue of the lack of available water, the microbial catalysts are more productive in feedstock polymer hydrolysis. The National Renewable Energy Laboratory (NREL) has developed a unique digester system capable of uniformly mixing high-solids materials at low cost. Information gained from laboratory-scale digester research was used to develop die intermediate-scale digester system. This system represents a 50-fold scale-up of the original digester system and includes continuous feed addition and computer monitoring and control. During the first 1.15 years of operation, a variety of modifications and improvements were instituted to increase the safety, reliability, and performance of the system. Those improvements -- which may be critical in further scale-up efforts using the NREL high-solids digester design -- are detailed in this report.

  13. Partition of proteins in aqueous two-phase systems based on Cashew-nut tree gum and poly(ethylene glycol

    Directory of Open Access Journals (Sweden)

    Leonie Asfora Sarubbo

    2004-09-01

    Full Text Available The partitioning of two proteins, bovine serum albumin (BSA and trypsin was studied in an aqueous poly(ethylene glycol(PEG- Cashew-nut tree gum system. The phase diagram was provided for Cashew-nut tree gum and PEG molecular weight of 1500 at two different temperatures. The influence of several parameters including concentrations of polymers, pH, salt addition and temperature on the partitioning of these proteins were investigated.. The results of this research demonstrated the importance of the protein characteristics for partitioning in aqueous biphasic system.A partição de duas proteínas, albumina de soro bovino (BSA e tripsina foi estudada no sistema bifásico aquoso Polietileno glicol(PEG - Goma do cajueiro. O diagrama de fases foi estabelecido para a Goma do Cajueiro e para PEG de peso molecular 1500 em duas diferentes temperaturas. A influência de vários parâmetros na partição destas proteínas, incluindo concentração dos polímeros, pH, adição de sal e temperatura foi investigada. Os resultados desta pesquisa demonstraram a importância das características da proteína na partição em sistemas bifásicos aquosos.

  14. CO-DIGESTION OF SEWAGE SLUDGE AND MATURE LANDFILL LEACHATE IN PRE-BIOAUGMENTED SYSTEM

    OpenAIRE

    Agnieszka Montusiewicz

    2014-01-01

    The study examined the effects of co-digestion of sewage sludge and mature landfill leachate at the volumetric ratio of 95:5% in primarily bioaugmented system. Bioaugmentation was carried out with the use of commercial product Arkea® in the volumetric dose of 5% and lasted three months prior to the co-digestion start-up. Co-digestion was undergone without bioaugmentation. The results indicated that in the first period (of three months) following bioaugmentation, co-digestion led to biogas/met...

  15. Validation of an in vitro digestive system for studying macronutrient decomposition in humans.

    Science.gov (United States)

    Kopf-Bolanz, Katrin A; Schwander, Flurina; Gijs, Martin; Vergères, Guy; Portmann, Reto; Egger, Lotti

    2012-02-01

    The digestive process transforms nutrients and bioactive compounds contained in food to physiologically active compounds. In vitro digestion systems have proven to be powerful tools for understanding and monitoring the complex transformation processes that take place during digestion. Moreover, the investigation of the physiological effects of certain nutrients demands an in vitro digestive process that is close to human physiology. In this study, human digestion was simulated with a 3-step in vitro process that was validated in depth by choosing pasteurized milk as an example of a complex food matrix. The evolution and decomposition of the macronutrients was followed over the entire digestive process to the level of intestinal enterocyte action, using protein and peptide analysis by SDS-PAGE, reversed-phase HPLC, size exclusion HPLC, and liquid chromatography-MS. The mean peptide size after in vitro digestion of pasteurized milk was 5-6 amino acids (AA). Interestingly, mostly essential AA (93.6%) were released during in vitro milk digestion, a significantly different relative distribution compared to the total essential AA concentration of bovine milk (44.5%). All TG were degraded to FFA and monoacylglycerols. Herein, we present a human in vitro digestion model validated for its ability to degrade the macronutrients of dairy products comparable to physiological ranges. It is suited to be used in combination with a human intestinal cell culture system, allowing ex vivo bioavailability measurements and assessment of the bioactive properties of food components.

  16. PEG-modified Penicillin Acylase and Its Partitioning in Aqueous Two-phase Bioconversion System%PEG修饰青霉素酰化酶及其在两水相生物转化体系中的分配

    Institute of Scientific and Technical Information of China (English)

    何汉平; 刘叶青; 曹学君; 张秀萍

    2001-01-01

    Polyethyleneglycol (PEG) activated by tosyl chloride was used to modify penicillin acylase (PAC). The stability of the PEG-PAC was much better than the free PAC. The activity of the modified enzyme was 75% of free enzyme. The partition of PEG-PAC in aqueous two-phase system was investigated. The modified penicillin acylase was mainly present in the PEG phase in a PEG-dextran aqueous two-phase system, and the partition coefficient was 25.%采用对甲苯磺酰氯法,用聚乙二醇对青霉素酰化酶进行化学修饰,修饰酶的比活为未修饰酶的75%,稳定性比游离酶有了很大提高。酶在带修饰酶的聚乙二醇与葡聚糖组成的两水相体系中的分配系数为25。

  17. Liquid–liquid equilibria in the quinary aqueous two-phase system of poly(ethylene glycol) 6000 + sodium sulfate + water in the presence of glucose and ethanol: Experimental investigation and thermodynamic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Hekayati, Javad; Roosta, Aliakbar, E-mail: aa.roosta@sutech.ac.ir; Javanmardi, Jafar

    2016-02-10

    Highlights: • Quinary LLE phase equilibria involving PEG 6000 + Na{sub 2}SO{sub 4} + H{sub 2}O + glucose + ethanol. • Favorable partition coefficients of ethanol and glucose. • Satisfactory correlation of the LLE experimental data with the original NRTL model. • Root mean squared deviations (RMSDs) of less than 0.6%. - Abstract: Extractive fermentation processes involving aqueous two-phase systems (ATPSs) are considered as viable means of overcoming the problems associated with product inhibition. Practical development of these processes requires accurate knowledge of the liquid–liquid equilibrium (LLE) of the ATPS forming components alongside the substrate and product of the fermentation process. In this work, the quinary aqueous two-phase LLE of poly(ethylene glycol) 6000 + sodium sulfate + water in the presence of glucose and ethanol have been experimentally determined at 298.15 K using spectrophotometric methods. The resulting LLE data were then satisfactorily correlated by the non-random two-liquid (NRTL) activity coefficient model based on mass fractions. In doing so, the binary energy interaction parameters of the NRTL activity coefficient model were obtained and reported. Calculated RMS deviations below 0.6% demonstrate that the original NRTL activity coefficient model can accurately correlate the LLE data of the quinary aqueous biphasic system of interest.

  18. Mechanical behavior of shock-wave consolidated nano and micron-sized aluminum/silicon carbide and aluminum/aluminum oxide two-phase systems characterized by light and electron metallography

    Science.gov (United States)

    Alba-Baena, Noe Gaudencio

    This dissertation reports the results of the exploratory study of two-phase systems consisting of 150 microm diameter aluminum powder mechanically mixed with 30 nm and 30 microm diameter SiC and Al2O3 powders (in volume fractions of 2, 4, and 21 percent). Powders were mechanically mixed and green compacted to ˜80% theorical density in a series of cylindrical fixtures (steel tubes). The compacted arrangements were explosively consolidated using ammonium nitrate-fuel oil (ANFO) to form stacks of two-phase systems. As result, successfully consolidated cylindrical monoliths of 50 mm (height) x 32 mm (in diameter) were obtained. By taking advantage of the use of SWC (shock wave consolidation) and WEDM (wire-electric discharge machining), the heterogeneous systems were machined in a highly efficiency rate. The sample cuts used for characterization and mechanical properties testing, require the use of less that 10cc of each monolith, in consequence there was preserved an average of 60% of the obtained system monoliths. Consolidated test cylinders of the pure Al and two-phase composites were characterized by optical metallography and TEM. The light micrographs for the five explosively consolidated regimes: aluminum powder, nano and micron-sized Al/Al2O3 systems, and the nano and micron-sized Al/SiC systems exhibit similar ductility in the aluminum grains. Low volume fraction systems exhibit small agglomerations at the grain boundaries for the Al/Al2O3 system and the Al/SiC system reveal a well distributed phase at the grain boundaries. Large and partially bonded agglomerations were observable in the nano-sized high volume fraction (21%) systems, while the micron-sized Al/ceramic systems exhibit homogeneous distribution along the aluminum phase grains. TEM images showed the shock-induced dislocation cell structure, which has partially recrystallized to form a nano grain structure in the consolidated aluminum powder. Furthermore, the SiC nano-agglomerates appeared to have

  19. Ecoulements diphasiques instables dans les systèmes pipeline/riser Unsteady Two-Phase Flows in Pipeline/Riser Systems

    Directory of Open Access Journals (Sweden)

    Fabre J.

    2006-11-01

    Full Text Available Les instabilités hydrodynamiques de l'écoulement dans les systèmes pipeline/riser ont été étudiées sur une boucle d'essais en tubes transparents de diamètre intérieur 0,053 m, longueur 25 m pour la partie pipeline et 13,5 m pour la partie riser. Les expériences effectuées sur de l'eau et de l'air, à différentes pentes du pipeline et pour plusieurs valeurs du débit d'entrée, ont permis l'observation d'instabilités à grande échelle à faible débit de liquide et de gaz. Les cartes de configuration d'écoulement ont été établies pour trois pentes différentes du pipeline. Le modèle numérique développé à partir de ces données résout les équations locales instantanées de bilan de masse et de quantité de mouvement de ces écoulements par la méthode des caractéristiques. L'évolution des pressions, fraction de vide, débit de gaz et de liquide au cours du temps, prévue par le modèle, est généralement en bon accord avec les données expérimentales. Hydrodynamic instabilities of flow in pipeline/riser systems were studied on a test loop made of transparent tubes with an ID of 0. 053 m and 25 m long for the pipeline part and 13. 5 m long for the riser. Experiments performed with water and air, with different slopes of the pipeline and with several inlet flow rates, reveal large-scale instabilities at low liquid and gas flow rates. Flow configuration maps were compiled for three different pipeline slopes. The numerical model developed from these data solves instantaneous local equations for the mass balance and amount of movement of such flows by the method of characteristics. Variations in pressures, in the void fraction and in gas and liquid flow in the time forecast by the model are generally in good agreement with experimental data.

  20. Evaluation of the dual digestion system 1: overview of the Milnerton experience

    CSIR Research Space (South Africa)

    Messenger, JR

    1993-07-01

    Full Text Available A number of advantages are claimed for dual digestion as a system for sewage sludge pasteurisation and stabilisation. In this paper, the first of a series of 4, an overview of a 4-year full-scale (45 m3 aerobic reactor and 500 m3 anaerobic digester...

  1. Design and experiment of household biogas system in alpine region based on two-phase anaerobic fermentation%高寒地区两相厌氧户用沼气系统设计与试验

    Institute of Scientific and Technical Information of China (English)

    孙勇; 李文哲; 张鸿琼

    2012-01-01

    摘要;针对高寒地区农村户用沼气发酵周期过长、产气量少的状况,该文提出并设计了适用于高寒地区农村户用的两相厌氧发酵装置,通过确立合理的工艺方案,控制两相厌氧发酵中产酸相、料液温度和pH值、水力滞留时间等因素,探讨了在哈尔滨地区最寒冷季节,所设计的新型农村户用沼气发酵装置产气量与维持发酵罐体内料液温度所消耗沼气量之间的关系.结果表明:基于两相厌氧发酵的高寒地区高效户用沼气发酵装置最高产气率为1.35m3/(m3·d),是传统沼气池产气率( 0.35 m3/(m3·d))的4倍.冬季1月份日均结余4.08 m3沼气量足以满足三口之家照明、炊事所需能源,实现高寒地区户用沼气全年正能输出,可以取代传统沼气池.该文研究成果为今后寒地户用沼气的发展提供技术支持和参考依据.%According to the problems of long fermentation period and low gas production in the alpine region, a two-phase anaerobic fermentation device was designed for rural household biogas production in the alpine region. The fermentation parameters such as acid production, temperature and pH value of feed and hydraulic retention time were controlled during two-phase anaerobic fermentation. The relationship between the quantity of produced biogas during fermentation and the quantity of consumed biogas to maintain the biogas slurry temperature in most cold season in Harbin was discussed. Results showed that the highest methan production was 1.35 m3/(m3d) using the two-phase anaerobic fermentation process, which was four times higher than the traditional process of 0.35 m3/(m3-d). There was 4.08 m3 daily balance biogas to satisfy lighting and cooking for three people family in January of winter, which could operate in alpine region year-round. In addition, the equipment structure is reasonable and perfect, which might replace the traditional digester. The research can provide a technical support

  2. Effect of organic loading on the microbiota in a temperature-phased anaerobic digestion (TPAD) system co-digesting dairy manure and waste whey.

    Science.gov (United States)

    Li, Yueh-Fen; Abraham, Christopher; Nelson, Michael C; Chen, Po-Hsu; Graf, Joerg; Yu, Zhongtang

    2015-10-01

    Temperature-phased anaerobic digestion (TPAD) has gained increasing attention because it provides the flexibility to operate digesters under conditions that enhance overall digester performance. However, research on impact of organic overloading rate (OLR) to microbiota of TPAD systems was limited. In this study, we investigated the composition and successions of the microbiota in both the thermophilic and the mesophilic digesters of a laboratory-scale TPAD system co-digesting dairy manure and waste whey before and during organic overloading. The thermophilic and the mesophilic digesters were operated at 50 and 35 °C, respectively, with a hydraulic retention time (HRT) of 10 days for each digester. High OLR (dairy manure with 5 % total solid and waste whey of ≥60.4 g chemical oxygen demand (COD)/l/day) resulted in decrease in pH and in biogas production and accumulation of volatile fatty acids (VFAs) in the thermophilic digester, while the mesophilic digester remained unchanged except a transient increase in biogas production. Both denaturant gradient gel electrophoresis (DGGE) and Illumina sequencing of 16S ribosomal RNA (rRNA) gene amplicons showed dramatic change in microbiota composition and profound successions of both bacterial and methanogenic communities. During the overloading, Thermotogae was replaced by Proteobacteria, while Methanobrevibacter and archaeon classified as WCHD3-02 grew in predominance at the expense of Methanoculleus in the thermophilic digester, whereas Methanosarcina dominated the methanogenic community, while Methanobacterium and Methanobrevibacter became less predominant in the mesophilic digester. Canonical correspondence analysis (CCA) revealed that digester temperature and pH were the most influential environmental factors that explained much of the variations of the microbiota in this TPAD system when it was overloaded.

  3. Structure and Function of the Digestive System of Solen Grandis Dunker

    Institute of Scientific and Technical Information of China (English)

    SHENG Xiuzhen; ZHAN Wenbin; REN Sulian

    2003-01-01

    Structure and function of the digestive system of a bivalve mollusc, Solen grandis, were studied using light microscopy and histochemical methods. The wall of digestive tube consists of four layers: the mucosal epithelium, connective tissue, muscular and fibrosa or serosa (only in the portion of rectum) from the inner to the outer. The ciliated columnar epithelial cells, dispersed by cup-shaped mucous cells, rest on a thin base membrane. There are abundant blood spaces in connective tissue layer. The digestive diverticula are composed of multi-branched duct and digestive tubules. The digestive tubules are lined with digestive and basophilic secretory cells, and surrounded by a layer of smooth muscle fibers and connective tissues. Activities of acid and alkaline phosphatases, esterase and lipase are detected in the digestive cells, and the epithelia of stomach and intestine, suggesting that these cells are capable of intracellular digesting of food materials and absorbing.Besides, acid phosphatase and esterase activities are present in the posterior portion of esophagus. Phagocytes are abundant in blood spaces and the lumens of stomach and intestine, containing brown granules derived from the engulfed food materials. The present work indicates that phagocytes play important roles in ingestion and digestion of food materials, which is supported as well by the activities of acid phosphatase, esterase and lipase detected in blood spaces.

  4. Silica nanoparticles to control the lipase-mediated digestion of lipid-based oral delivery systems.

    Science.gov (United States)

    Tan, Angel; Simovic, Spomenka; Davey, Andrew K; Rades, Thomas; Boyd, Ben J; Prestidge, Clive A

    2010-04-05

    We investigate the role of hydrophilic fumed silica in controlling the digestion kinetics of lipid emulsions, hence further exploring the mechanisms behind the improved oral absorption of poorly soluble drugs promoted by silica-lipid hybrid (SLH) microcapsules. An in vitro lipolysis model was used to quantify the lipase-mediated digestion kinetics of a series of lipid vehicles formulated with caprylic/capric triglycerides: lipid solution, submicrometer lipid emulsions (in the presence and absence of silica), and SLH microcapsules. The importance of emulsification on lipid digestibility is evidenced by the significantly higher initial digestion rate constants for SLH microcapsules and lipid emulsions (>15-fold) in comparison with that of the lipid solution. Silica particles exerted an inhibitory effect on the digestion of submicrometer lipid emulsions regardless of their initial location, i.e., aqueous or lipid phases. This inhibitory effect, however, was not observed for SLH microcapsules. This highlights the importance of the matrix structure and porosity of the hybrid microcapsule system in enhancing lipid digestibility as compared to submicrometer lipid emulsions stabilized by silica. For each studied formulation, the digestion kinetics is well correlated to the corresponding in vivo plasma concentrations of a model drug, celecoxib, via multiple-point correlations (R(2) > 0.97). This supports the use of the lipid digestion model for predicting the in vivo outcome of an orally dosed lipid formulation. SLH microcapsules offer the potential to enhance the oral absorption of poorly soluble drugs via increased lipid digestibility in conjunction with improved drug dissolution/dispersion.

  5. CO-DIGESTION OF SEWAGE SLUDGE AND MATURE LANDFILL LEACHATE IN PRE-BIOAUGMENTED SYSTEM

    Directory of Open Access Journals (Sweden)

    Agnieszka Montusiewicz

    2014-10-01

    Full Text Available The study examined the effects of co-digestion of sewage sludge and mature landfill leachate at the volumetric ratio of 95:5% in primarily bioaugmented system. Bioaugmentation was carried out with the use of commercial product Arkea® in the volumetric dose of 5% and lasted three months prior to the co-digestion start-up. Co-digestion was undergone without bioaugmentation. The results indicated that in the first period (of three months following bioaugmentation, co-digestion led to biogas/methane yields only 5-8% lower as compared to anaerobic digestion of sewage sludge, and the differences were not statistically significant. Moreover, a comparable value of volatile solids removal was obtained. However, the effects became worse over time, i.e. a lower organics removal efficiency of 16% as well as 9.5–13% decreases of biogas/methane yields were achieved by applying co-digestion for a further period (of the same duration. Co-digestion of sewage sludge and mature landfill leachate could be recognized as quite efficient in the system that was primarily bioaugmented with the use of Arkea®. However, the beneficial impact of bioaugmentation remained for the limited period of three months after its completion. To sustain the favourable effects a periodical, repeatable bioaugmentation of the co-digestion system is required.

  6. Involvement of Ghrelin-Growth Hormone Secretagogue Receptor System in Pathoclinical Profiles of Digestive System Cancer

    Institute of Scientific and Technical Information of China (English)

    Zhigang WANG; Weigang WANG; Wencai QIU; Youben FAN; Jun ZHAO; Yu WANG; Qi ZHENG

    2007-01-01

    Ghrelin receptor has been shown to be expressed along the human gastrointestinal tract.Recent studies showed that ghrelin and a synthetic ghrelin receptor agonist improved weight gain and lean body mass retention in a rat model of cancer cachexia by acting on ghrelin receptor, that is, growth hormone secretagogue receptor (GHS-R). This study aims to explore the expression and the distribution of ghrelin receptor in human gastrointestinal tract cancers and to investigate the possible involvement of the ghrelin-GHS-R system in human digestive cancers. Surgical human digestive cancer specimens were obtained from various portions of the gastrointestinal tract from different patients. The expression of ghrelin receptor in these tissues was detected by tissue microarray technique. Our results showed that ghrelin receptor was expressed in cancers throughout the gastrointestinal tract, mainly in the cytoplasm of mucosal layer cells.Its expression level possibly correlated with organ type, histological grade, tumor-nodes-metastases stage,and nutrition status (weight loss) of the patients. For the first time, we identified the distribution of ghrelin receptor in digestive system cancers. Our results implied that the ghrelin-GHS-R system might be involved in the pathoclinical profiles of digestive cancers.

  7. Assessment of by-products of bioenergy systems (anaerobic digestion and gasification) as potential crop nutrient.

    Science.gov (United States)

    Kataki, Sampriti; Hazarika, Samarendra; Baruah, D C

    2017-01-01

    Alternative fertilizer resources have drawn attention in recent times in order to cope up with ever increasing demand for fertilizer. By-products of bioenergy system are considered favourable as organic fertilizer due to their ability to recycle plant nutrients. Present study evaluates fertilizer suitability of by-products of two bioenergy systems viz. 3 types of anaerobic digestion by-products (digestate) from local surplus biomass such as cowdung, Ipomoea carnea:cowdung (60:40) and ricestraw:green gram stover:cowdung (30:30:40) and one gasification by-product (biochar) from rice husk. Digestates were assessed considering 4 different application options of each viz. whole, solid, liquid and ash from solid digestates. Digestate characteristics (organic matter, macronutrients, micronutrients and heavy metal content) were found to be a function of feedstock and processing (solid liquid separation and ashing). Ipomoea carnea based digestates in all application options showed comparatively higher N, P, K, NH4(+)-N, Ca, Mg, S and micro nutrient content than other digestates. Separation concentrated plant nutrients and organic matter in solid digestates, making these suitable both as organic amendments and fertilizer. Separated liquid digestate shared larger fraction of ammonium nitrogen (61-91% of total content), indicating their suitability as readily available N source. However, fertilizer application of liquid digestate may not match crop requirements due to lower total nutrient concentration. Higher electrical conductivity of the liquid digestates (3.4-9.3mScm(-1)) than solid digestates (1.5-2mScm(-1)) may impart phyto-toxic effect upon fertilization due to salinity. In case of by-products with unstable organic fraction i.e. whole and solid digestates of rice straw:green gram stover:cowdung digestates (Humification index 0.7), further processing (stabilization, composting) may be required to maximize their fertilizer benefit. Heavy metal contents of the by

  8. Extraction of Doxycycline Hydrochloride Using Alcohol and Ionic Liquid Binary Aqueous Two Phase System%醇与离子液体二元双水相体系萃取盐酸多西环素

    Institute of Scientific and Technical Information of China (English)

    关卫省; 黎文娟; 韩娟

    2012-01-01

    Based on the molecular alcohol aqueous two-phase system and the ionic liquid aqueous two-phase system, the new method of using n-propanol and hydrophilic ionic liquid(1-butyl-3-methylimidazolium tetrafluoroborate, [Bmim]BF4) with (NH4)2SO4 binary aqueous two phase system for the extraction of doxycycline hydrochloride was developed. The influence factors on partition behaviors of doxycycline hydrochloride were studied, including concentration of (NH4)2SO4, n-propanol con-sumption, pH value, concentration of ionic liquid and doxycycline hydrochloride. The results showed that when using pH value of 4. 0 - 5. 0, (NH4) 2SO4 concentration of 34% and doxycycline hydrochloride concentration between 25 -95 mg/L, the extraction rate and distribution coefficient of doxycycline hydrochloride will be up to 90. 26% -95. 71% and 62. 452 - 149. 401, respectively.%基于小分子醇双水相体系和离子液体双水相体系,建立了正丙醇与亲水性离子液体1-丁基-3-甲基咪唑四氟硼酸[ Bmim]BF4和(NH4 )2SO4形成的二元双水相体系萃取盐酸多西环素的新方法.考察了(NH4)2SO4含量、正丙醇用量、pH值、离子液体含量以及盐酸多西环素含量对盐酸多西环素分配行为的影响.结果表明:当醇和离子液体二元双水相体系的pH值在4.0~5.0范围内,(NH4)2SO4含量为34%,且盐酸多西环素的质量浓度在25 ~ 95 mg/L之间时,该体系对盐酸多西环素的萃取率可达90.26% ~95.71%,分配系数可达62.452 ~ 149.401.

  9. Development of two-phase measuring systems for comparative invstigations of transient flow in pipelines. Final report; Entwicklung von Zweiphasenmesstechnik fuer vergleichende Untersuchungen zur Beschreibung von transienten Stroemungen in Rohrleitungen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Prasser, H.M.; Boettger, A.; Zschau, J.

    1999-02-01

    Transient two-phase flow phenomena in pipelines and pipe segments were investigated in an open-air shock pressure test facility specially constructed by the Fraunhofer Insitute of Environmental, Safety and Energy Engineering, Oberhausen (Fraunhofer-Institut fuer Umelt, Sicherheits- und Energietechnik e.V. - UMSICHT). For a better measurement of pressure shock phenomena, the plant was equipped with pressure and power meters. FZR constructed and installed the two-phase measuring sstems, i.e. conductivity and ultrasonic measuring systems, and cooperated in the experiments and their interpretation. To this end, the FZR facility was equipped with 16 needle-shaped conductivity sensors, a novel grid sensor measuring system, and ultrasonic probes. The report describes the technical systems, the trial operation at the Rossendorf test facility, and the experiments in the Oberhausen facility. The experimental results are presented and interpreted. [Deutsch] Fuer die Untersuchung von transienten Zweiphasenstroemungen in Rohrleitungen, bzw. Rohrleitungssegmenten wurde im Fraunhofer-Institut fuer Umwelt, Sicherheits- und Energietechnik e.V. Oberhausen (UMSICHT) eine Druckstossanlage als Freiluftanlage errichtet. Zur experimentellen Beschreibung der Druckstossphaenomene wurde die Anlage neben der Betriebsinstrumentierung zur Einstellung der Betriebsparameter von UMSICHT mit Druck- und Kraftmessgebern ausgeruestet. Aufgabe des FZR war die Instrumentierung der Anlage mit Zweiphasenmesstechnik bestehend aus Leitfaehigkeits- und Ultraschallmesstechnik sowie der Mitwirkung bei den experimentellen Untersuchungen und deren Interpretation. Dazu wurde die Anlage von FZR mit 16 nadelfoermigen Leitfaehigkeitssonden, einem neuartigen Gittersensor-Messsystem und Ultraschall-Aufnehmern ausgeruestet. In dem Bericht wird die eingesetzte Messtechnik und deren Erprobung an der Rossendorfer Versuchsschleife, sowie der Einsatz an der Anlage in Oberhausen beschrieben. Anhand in Zusammenarbeit mit

  10. Dissipation of bentazone, pyrimethanil and boscalid in biochar and digestate based soil mixtures for biopurification systems

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Santanu, E-mail: s.mukherjee@fz-juelich.de [Institute of Bio- and Geosciences (IBG-3), Agrosphere Institute, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Tappe, Wolfgang; Weihermueller, Lutz; Hofmann, Diana; Köppchen, Stephan [Institute of Bio- and Geosciences (IBG-3), Agrosphere Institute, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Laabs, Volker; Schroeder, Tom [BASF SE, Crop Protection, 67117, Limburgerhof (Germany); Vereecken, Harry [Institute of Bio- and Geosciences (IBG-3), Agrosphere Institute, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Burauel, Peter [Sustainable Campus, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany)

    2016-02-15

    Biopurification systems, such as biofilters, are biotechnological tools to prevent point sources of pesticide pollution stemming from on-farm operations. For the purification processes pesticide sorption and mineralization and/or dissipation are essential and both largely depend on the type of filling materials and the pesticide in use. In this paper the mineralization and dissipation of three contrasting {sup 14}C-labeled pesticides (bentazone, boscalid, and pyrimethanil) were investigated in laboratory incubation experiments using sandy soil, biochar produced from Pine woodchips, and/or digestate obtained from anaerobic digestion process using maize silage, chicken manure, beef and pig urine as feedstock. The results indicate that the addition of digestate increased pesticide mineralization, whereby the mineralization was not proportional to the digestate loads in the mixture, indicating a saturation effect in the turnover rate of pesticides. This effect was in correlation with the amount of water extractable DOC, obtained from the digestate based mixtures. Mixing biochar into the soil generally reduced total mineralization and led to larger sorption/sequestration of the pesticides, resulting in faster decrease of the extractable fraction. Also the addition of biochar to the soil/digestate mixtures reduced mineralization compared to the digestate alone mixture but mineralization rates were still higher as for the biochar/soil alone. In consequence, the addition of biochar to the soil generally decreased pesticide dissipation times and larger amounts of biochar led to high amounts of non-extractable residues of pesticide in the substrates. Among the mixtures tested, a mixture of digestate (5%) and biochar (5%) gave optimal results with respect to mineralization and simultaneous sorption for all three pesticides. - Highlights: • Biochar and digestate significantly affects the dissipation pattern of pesticides. • Addition of digestate enhanced mineralization of

  11. Experimental and CFD-PBM approach coupled with a simplified dynamic analysis of mass transfer in phenol biodegradation in a three phase system of an aerated two-phase partitioning bioreactor for environmental applications

    Science.gov (United States)

    Moradkhani, Hamed; Anarjan Kouchehbagh, Navideh; Izadkhah, Mir-Shahabeddin

    2017-03-01

    A three-dimensional transient modeling of a two-phase partitioning bioreactor, combining system hydrodynamics, two simultaneous mass transfer and microorganism growth is modeled using computational fluid dynamics code FLUENT 6.2. The simulation is based on standard "k-ɛ" Reynolds-averaged Navier-Stokes model. Population balance model is implemented in order to describe gas bubble coalescence, breakage and species transport in the reaction medium and to predict oxygen volumetric mass transfer coefficient (kLa). Model results are verified against experimental data and show good agreement as 13 classes of bubble size is taking into account. Flow behavior in different operational conditions is studied. Almost at all impeller speeds and aeration intensities there were acceptable distributions of species caused by proper mixing. The magnitude of dissolved oxygen percentage in aqueous phase has a direct correlation with impeller speed and any increasing of the aeration magnitude leads to faster saturation in shorter periods of time.

  12. Experimental and CFD-PBM approach coupled with a simplified dynamic analysis of mass transfer in phenol biodegradation in a three phase system of an aerated two-phase partitioning bioreactor for environmental applications

    Science.gov (United States)

    Moradkhani, Hamed; Anarjan Kouchehbagh, Navideh; Izadkhah, Mir-Shahabeddin

    2016-07-01

    A three-dimensional transient modeling of a two-phase partitioning bioreactor, combining system hydrodynamics, two simultaneous mass transfer and microorganism growth is modeled using computational fluid dynamics code FLUENT 6.2. The simulation is based on standard "k-ɛ" Reynolds-averaged Navier-Stokes model. Population balance model is implemented in order to describe gas bubble coalescence, breakage and species transport in the reaction medium and to predict oxygen volumetric mass transfer coefficient (kLa). Model results are verified against experimental data and show good agreement as 13 classes of bubble size is taking into account. Flow behavior in different operational conditions is studied. Almost at all impeller speeds and aeration intensities there were acceptable distributions of species caused by proper mixing. The magnitude of dissolved oxygen percentage in aqueous phase has a direct correlation with impeller speed and any increasing of the aeration magnitude leads to faster saturation in shorter periods of time.

  13. Effects of Geometric Parameter on Performance of Ejector and Two-phase Ejector Refrigeration System%几何参数对引射器及两相流引射制冷系统性能的影响

    Institute of Scientific and Technical Information of China (English)

    裴文伟; 郭宪民; 王善云; 郭欣炜

    2013-01-01

    In order to increase the coefficient of performance (COP) of the refrigeration system , the expansion valve is replaced by a two-phase ejector in the two-phase ejector refrigeration cycle to recover the potential energy of the high pressure refrigerant. The performance of two-phase ejector refrigeration system with refrigerant R134a as working fluid is experimentally investigated. The effects of the throat diameter of the nozzle and the diameter of the mixing chamber on the performance of the ejector and the two-phase ejector refrigeration cycle system were analyzed. The experimental results indicate that there is an optimal combination of the nozzle throat diameter and the mixing chamber diameter to maximize the entrainment ratio under a fixed working condition. The entrainment ratio of the ejector reaches to the maximum value with the throat diameter of 2.0mm and the mixing chamber diameter of 16mm under the conditions of 3℃ evaporating temperature and 55℃ condensing temperature. Under a fixed working condition, the optimal combination of the nozzle throat diameter and the mixing chamber diameter for maximum of the entrainment ratio is not consistent with the one for maximum of the COP of the refrigeration system. This may be caused by the shocks in the ejector, which should be investigated deeply.%  用两相流引射器代替膨胀阀,可回收两相流引射制冷循环中高压工质的压力能,提高制冷系统效率.对以R134a为工质的两相流引射制冷系统性能进行了实验研究,分析了喷嘴喉部直径和混合室直径对R134a两相流引射器及引射制冷系统性能的影响.实验结果表明,在固定工况条件下,存在使引射比达到最大的最佳喷嘴喉部直径和混合室直径组合.在蒸发温度为3℃、冷凝温度为55℃的工况下,当喷嘴喉部直径为2.0mm、混合室直径为16mm时引射器的引射比最大.在固定工况条件下,使引射比达到最大值的喷嘴喉部直

  14. Study on treatment of phenolic compounds in cokery wastewater by propyl-alcohol ammonium sulfate aqueous two-phase system%醇-盐双水相技术去除废水中的酚类物质

    Institute of Scientific and Technical Information of China (English)

    曹文; 高云涛; 王红斌; 李孔明; 马存娇

    2009-01-01

    A novel method for treatment of phenolic compounds in cokery wastewater by propyl-alcohol ammonium sulfate aqueous two-phase system was investigted.The effects of the amount of ammonium sulfate used,the amount of propyl-alcohol used,pH value on extractield was studied.Extraction was optimized using a L9(34)orthogonal test.The results indicated optimum extraction conditions were the amount of ammonium sulfate used of 18.0 g,the amount of propyl-alcohol used of 16 mL,and pH value of 3.0.A extraction yield of 99.37% was achived under optimum extraction conditions and via secondary extraction.

  15. 异丙醇/盐双水相分离制备高色价栀子黄%Separation of Gardenia Yellow by Isopropanol Alcohol/Salt Aqueous Two-Phase System

    Institute of Scientific and Technical Information of China (English)

    郭晶莹; 张红萍

    2016-01-01

    Abstrat:Gardenia yellow was separated by employing isopropanol-salt aqueous two-phase system. The factors such as kinds of salt, concentration of the salt, pH and temperture on the gardenia yellow separation efficiency were investigated, and the gardenia yellow was analyzed by spectrophotometric method and HPLC. The results showed that the aqueous two-phase system which was formed by isopropanol alcohol(2mL) and sodium citrate (1.6g)was effective for the separation of gardenia yellow from gardenia fruit in 35℃and pH=8.7,and the color value and the OD of the gardenia yellow were 542 and 0.382,respectively.%采用异丙醇/盐组成的双水相体系分离栀子黄。综合考察了盐的种类、浓度、pH值和温度等因素对栀子黄分离效果的影响,并且采用紫外-可见分光光度法和HPLC对异丙醇/盐双水相体系分离得到的栀子黄进行评价。结果表明,在35℃条件下由1.6g的柠檬酸三钠和2mL的异丙醇组成双水相体系,pH等于8.7,分离得到栀子黄和OD值分别为0.382、542。

  16. Study on Extraction Process Conditions of Rice Bran Polysaccharide by Aqueous Two-phase System%双水相萃取米糠多糖工艺条件的探究

    Institute of Scientific and Technical Information of China (English)

    秦微微; 金婷; 宋学东; 丁振铎; 张衡

    2014-01-01

    旨在探究聚乙二醇/硫酸铵双水相体系萃取米糠中多糖成分的最佳条件。以双水相系统的相比、分配系数、收率等为参数,探究了PEG 的相对分子质量、PEG 的质量分数以及硫酸铵质量分数对米糠多糖在两相系统中的分配行为的影响。结果表明:萃取最佳条件为PEG分子量为6000,硫酸铵质量分数为14.8%,PEG 6000质量分数为14.3%,多糖得率为0.826388。%The aqueous two-phase system of polyethylene glycol (PEG)/ammonium sulfate for extrac-tion of polysaccharide in rice bran is studied.Use the parameters such as the volume ratio of two pha-ses,the distribution coefficient and the yield to explore the effects of the molecular weight of PEG, the mass fraction of ammonium sulfate and PEG on distribution behavior of polysaccharide of rice bran in two-phase system.It is demonstrated that the optimum conditions of extraction are as follows:the molecular weight of PEG is 6000,the mass fraction of ammonium sulfate is 14.8%,the mass fraction of PEG 6000 is 14.3%,and the yield of polysaccharide is 0.826388.

  17. Study of two-phase flows in reduced gravity

    Science.gov (United States)

    Roy, Tirthankar

    Study of gas-liquid two-phase flows under reduced gravity conditions is extremely important. One of the major applications of gas-liquid two-phase flows under reduced gravity conditions is in the design of active thermal control systems for future space applications. Previous space crafts were characterized by low heat generation within the spacecraft which needed to be redistributed within the craft or rejected to space. This task could easily have been accomplished by pumped single-phase loops or passive systems such as heat pipes and so on. However with increase in heat generation within the space craft as predicted for future missions, pumped boiling two-phase flows are being considered. This is because of higher heat transfer co-efficients associated with boiling heat transfer among other advantages. Two-phase flows under reduced gravity conditions also find important applications in space propulsion as in space nuclear power reactors as well as in many other life support systems of space crafts. Two-fluid model along with Interfacial Area Transport Equation (IATE) is a useful tool available to predict the behavior of gas-liquid two-phase flows under reduced gravity conditions. It should be noted that considerable differences exist between two-phase flows under reduced and normal gravity conditions especially for low inertia flows. This is because due to suppression of the gravity field the gas-liquid two-phase flows take a considerable time to develop under reduced gravity conditions as compared to normal gravity conditions. Hence other common methods of analysis applicable for fully developed gas-liquid two-phase flows under normal gravity conditions, like flow regimes and flow regime transition criteria, will not be applicable to gas-liquid two-phase flows under reduced gravity conditions. However the two-fluid model and the IATE need to be evaluated first against detailed experimental data obtained under reduced gravity conditions. Although lot of studies

  18. 48 CFR 36.301 - Use of two-phase design-build selection procedures.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Use of two-phase design... ACQUISITION REGULATION SPECIAL CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Two-Phase Design-Build Selection Procedures 36.301 Use of two-phase design-build selection procedures....

  19. Computer-aided design model for anaerobic-phased-solids digester system

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z.; Zhang, R. [University of California, Davis, CA (United States); Tiangco, V. [California Energy Commission, Sacramento, CA (United States)

    1999-07-01

    The anaerobic-phased-solids (APS) digester system is a newly developed anaerobic digestion system for converting solid wastes, such as crop residues and food wastes, into biogas for power and heat generation. A computer-aided engineering design model has been developed to design the APS-digester system and study the heat transfer from the reactors and energy production of the system. Simulation results of a case study are presented by using the model to predict the heating energy requirement and biogas energy production for anaerobic digestion of garlic waste. The important factors, such as environmental conditions, insulation properties, and characteristics of the wastes, on net energy production are also investigated. (author)

  20. Relationships among the brain, the digestive system, and eating behavior: workshop summary

    National Research Council Canada - National Science Library

    Pray, Leslie A

    2015-01-01

    "On July 9-10, 2014, the Institute of Medicine's Food Forum hosted a public workshop to explore emerging and rapidly developing research on relationships among the brain, the digestive system, and eating behavior...

  1. Digestive system-related pathophysiological symptoms of Sasang typology: Systematic review

    Directory of Open Access Journals (Sweden)

    Mi Suk Lee

    2013-06-01

    Full Text Available The purpose of this study was to review clinical studies on digestive system-related pathophysiological symptoms of each Sasang type to obtain the generalizable typespecific clinical features, which are important for the diagnosis of the Sasang type and subsequent disease treatment. Sasang typology and digestive system symptom-related keywords were used to search through eight domestic and foreign databases up to March 2012. The results were organized and analyzed based on four categories [digestive function, appetite, eating pattern, and body mass index (BMI] to elucidate type-specific symptoms. Sasang type-specific digestive system-related symptoms were identified by reviewing 30 related articles that were gathered by searching through the databases. The Tae-Eum (TE type had the highest digestive functions and the So-Eum (SE type had the lowest. The TE type appeared to have larger volume with fast eating speed compared with the SE type and individuals in the TE category preferred fatty or salty food, which is responsible for the high occurrence rates of organic digestive diseases such as gastritis. Moreover, BMI was higher in the TE type and lower in the SE type. We systematically reviewed previously published clinical reports on digestive functions, which can be used to meet the objective of Sasang-type differentiation and pathophysiological pattern identification.

  2. The prognostic significance of UCA1 for predicting clinical outcome in patients with digestive system malignancies.

    Science.gov (United States)

    Liu, Fang-Teng; Dong, Qing; Gao, Hui; Zhu, Zheng-Ming

    2017-06-20

    Urothelial Carcinoma Associated 1 (UCA1) was an originally identified lncRNA in bladder cancer. Previous studies have reported that UCA1 played a significant role in various types of cancer. This study aimed to clarify the prognostic value of UCA1 in digestive system cancers. The meta-analysis of 15 studies were included, comprising 1441 patients with digestive system cancers. The pooled results of 14 studies indicated that high expression of UCA1 was significantly associated with poorer OS in patients with digestive system cancers (HR: 1.89, 95 % CI: 1.52-2.26). In addition, UCA1 could be as an independent prognostic factor for predicting OS of patients (HR: 1.85, 95 % CI: 1.45-2.25). The pooled results of 3 studies indicated a significant association between UCA1 and DFS in patients with digestive system cancers (HR = 2.50; 95 % CI = 1.30-3.69). Statistical significance was also observed in subgroup meta-analysis. Furthermore, the clinicopathological values of UCA1 were discussed in esophageal cancer, colorectal cancer and pancreatic cancer. A comprehensive retrieval was performed to search studies evaluating the prognostic value of UCA1 in digestive system cancers. Many databases were involved, including PubMed, Web of Science, Embase and Chinese National Knowledge Infrastructure and Wanfang database. Quantitative meta-analysis was performed with standard statistical methods and the prognostic significance of UCA1 in digestive system cancers was qualified. Elevated level of UCA1 indicated the poor clinical outcome for patients with digestive system cancers. It may serve as a new biomarker related to prognosis in digestive system cancers.

  3. Velocity and energy relaxation in two-phase flows

    CERN Document Server

    Meyapin, Yannick; Gisclon, Marguerite

    2009-01-01

    In the present study we investigate analytically the process of velocity and energy relaxation in two-phase flows. We begin our exposition by considering the so-called six equations two-phase model [Ishii1975, Rovarch2006]. This model assumes each phase to possess its own velocity and energy variables. Despite recent advances, the six equations model remains computationally expensive for many practical applications. Moreover, its advection operator may be non-hyperbolic which poses additional theoretical difficulties to construct robust numerical schemes |Ghidaglia et al, 2001]. In order to simplify this system, we complete momentum and energy conservation equations by relaxation terms. When relaxation characteristic time tends to zero, velocities and energies are constrained to tend to common values for both phases. As a result, we obtain a simple two-phase model which was recently proposed for simulation of violent aerated flows [Dias et al, 2010]. The preservation of invariant regions and incompressible li...

  4. On-line digestion system for protein characterization and proteome analysis.

    Science.gov (United States)

    López-Ferrer, Daniel; Petritis, Konstantinos; Lourette, Natacha M; Clowers, Brian; Hixson, Kim K; Heibeck, Tyler; Prior, David C; Pasa-Tolić, Ljiljana; Camp, David G; Belov, Mikhail E; Smith, Richard D

    2008-12-01

    An efficient on-line digestion system that reduces the number of sample manipulation steps has been demonstrated for high-throughput proteomics. By incorporating a pressurized sample loop into a liquid chromatography-based separation system, both sample and enzyme (e.g., trypsin) can be simultaneously introduced to produce a complete, yet rapid digestion. Both standard proteins and a complex Shewanella oneidensis global protein extract were digested and analyzed using the automated online pressurized digestion system coupled to an ion mobility time-of-flight mass spectrometer, an ion trap mass spectrometer, or both. The system denatured, digested, and separated product peptides in a manner of minutes, making it amenable to on-line high-throughput applications. In addition to simplifying and expediting sample processing, the system was easy to implement and no cross-contamination was observed among samples. As a result, the online digestion system offers a powerful approach for high-throughput screening of proteins that could prove valuable in biochemical research (rapid screening of protein-based drugs).

  5. Development of an in vitro system simulating bucco-gastric digestion to assess the physical and chemical changes of food.

    Science.gov (United States)

    Hoebler, C; Lecannu, G; Belleville, C; Devaux, M-F; Popineau, Y; Barry, J-L

    2002-09-01

    The release of nutrients from solid food depends on the physical and chemical characteristics of substrates, and on dynamic physiological events including pH, gastric emptying and enzymatic secretion. Our laboratory has developed an in vitro digestive system mimicking mouth and stomach processes to determine physical and chemical changes of bread during digestion. To simulate oral-phase digestion, bread was minced and subjected to in vitro amylase digestion, releasing 219 +/- 11 g oligosaccharides/kg total carbohydrate. During the gastric phase, bread proteins, which are converted into insoluble aggregated proteins during breadmaking, were emptied in various states of peptic digestion: undigested aggregated proteins and degraded proteins of intermediate and low molecular weight. The mean particle size of ground bread decreased progressively to the end of the gastric digestion (from 292 to 109 microm). The in vitro digestive system proved to be a useful tool for understanding the dynamic digestion of various food components held within the structure of a food matrix.

  6. Optimisation of sewage sludge anaerobic digestion through co-digestion with OFMSW: Effect of collection system and particle size

    Energy Technology Data Exchange (ETDEWEB)

    Silvestre, Gracia [IRTA, GIRO Joint Research Unit IRTA-UPC, Torre Marimon, Barcelona (Spain); Ainia, Departamento de Medio Ambiente, Bioenergía e Higiene Industrial, Paterna, Valencia (Spain); Bonmatí, August [IRTA, GIRO Joint Research Unit IRTA-UPC, Torre Marimon, Barcelona (Spain); Fernández, Belén, E-mail: belen.fernandez@irta.cat [IRTA, GIRO Joint Research Unit IRTA-UPC, Torre Marimon, Barcelona (Spain)

    2015-09-15

    Highlights: • Methane production rate increased between 56% and 208% during OFMSW–SS codigestion. • The OFMSW particle size reduction from 20 to 8 mm did not affect the methane yield. • OFMSW–SS codigestion promoted β-oxidation and acetoclastic methanogenic activity. • The evolution of specific activity was a feasible tool to control the process. - Abstract: The effect of organic fraction of municipal solid waste (OFMSW) loading rate and particulate size on the sewage sludge (SS) mesophilic anaerobic co-digestion was assessed in continuous stirred tank reactor at hydraulic retention time of 20 days. The SS–OFMSW mixture composed by 54% of the volatile solids fed (inlet-VS), at OLR of 3.1 kg{sub COD} m{sup −3} d{sup −1} (1.9 kg{sub VS} m{sup −3} d{sup −1}), showed the highest increment on the volumetric methane production and yield of +200% and +59% respectively, under stable conditions. The effect of particulate size was assessed with the same mixture and same operational conditions but reducing the OFMSW particulate size from 20 mm to 8 mm with the aim to improve the hydrolysis step, but the results showed any influence in the OFMSW particulate size range analysed. In addition, specific biomass activity was assessed at the end of each co-digestion period. Results showed that OFMSW promoted β-oxidation syntrophic acetogens and the acetoclastic methanogens activity; although the last increase of the OFMSW percentage (from 47% to 54% inlet-VS) affected negatively the specific substrate activity, but not inhibitory effect was observed. Therefore, the results obtained in the continuous experiment could be related with some inhibitory or toxic effect and not due to hydrolysis limitation. The specific biomass activity test was demonstrated to be an interesting tool to evaluate and control the co-digestion process, especially when conventional parameters did not explain the behaviour of the biological system.

  7. Two-phase methanization of food wastes in pilot scale.

    Science.gov (United States)

    Lee, J P; Lee, J S; Park, S C

    1999-01-01

    A 5 ton/d pilot scale two-phase anaerobic digester was constructed and tested to treat Korean food wastes in Anyang city near Seoul. The easily degradable presorted food waste was efficiently treated in the two-phase anaerobic digestion process. The waste contained in plastic bags was shredded and then screened for the removal of inert materials such as fabrics and plastics, and subsequently put into the two-stage reactors. Heavy and light inerts such as bones, shells, spoons, and plastic pieces were again removed by gravity differences. The residual organic component was effectively hydrolyzed and acidified in the first reactor with 5 d space time at pH of about 6.5. The second, methanization reactor converted the acids into methane with pH between 7.4 and 7.8. The space time for the second reactor was 15 d. The effluent from the second reactor was recycled to the first reactor to provide alkalinities. The process showed stable steady-state operation with the maximum organic loading rate of 7.9 kg volatile solid (VS)/m3/d and the volatile solid reduction efficiency of about 70%. The total of 3.6 tons presorted MSW containing 2.9 tons of food organic was treated to produce about 230 m3 of biogas with 70% (v/v) of methane and 80 kg of humus. This process is extended to full-scale treating 15 tons of food waste a day in Euiwang city and the produced biogas is utilized for the heating/cooling of adjacent buildings.

  8. Dietary Sodium Suppresses Digestive Efficiency via the Renin-Angiotensin System.

    Science.gov (United States)

    Weidemann, Benjamin J; Voong, Susan; Morales-Santiago, Fabiola I; Kahn, Michael Z; Ni, Jonathan; Littlejohn, Nicole K; Claflin, Kristin E; Burnett, Colin M L; Pearson, Nicole A; Lutter, Michael L; Grobe, Justin L

    2015-06-11

    Dietary fats and sodium are both palatable and are hypothesized to synergistically contribute to ingestive behavior and thereby obesity. Contrary to this hypothesis, C57BL/6J mice fed a 45% high fat diet exhibited weight gain that was inhibited by increased dietary sodium content. This suppressive effect of dietary sodium upon weight gain was mediated specifically through a reduction in digestive efficiency, with no effects on food intake behavior, physical activity, or resting metabolism. Replacement of circulating angiotensin II levels reversed the effects of high dietary sodium to suppress digestive efficiency. While the AT1 receptor antagonist losartan had no effect in mice fed low sodium, the AT2 receptor antagonist PD-123,319 suppressed digestive efficiency. Correspondingly, genetic deletion of the AT2 receptor in FVB/NCrl mice resulted in suppressed digestive efficiency even on a standard chow diet. Together these data underscore the importance of digestive efficiency in the pathogenesis of obesity, and implicate dietary sodium, the renin-angiotensin system, and the AT2 receptor in the control of digestive efficiency regardless of mouse strain or macronutrient composition of the diet. These findings highlight the need for greater understanding of nutrient absorption control physiology, and prompt more uniform assessment of digestive efficiency in animal studies of energy balance.

  9. Solid anaerobic digestion batch with liquid digestate recirculation and wet anaerobic digestion of organic waste: Comparison of system performances and identification of microbial guilds.

    Science.gov (United States)

    Di Maria, Francesco; Barratta, Martino; Bianconi, Francesco; Placidi, Pisana; Passeri, Daniele

    2017-01-01

    Solid anaerobic digestion batch (SADB) with liquid digestate recirculation and wet anaerobic digestion of organic waste were experimentally investigated. SADB was operated at an organic loading rate (OLR) of 4.55kgVS/m(3)day, generating about 252NL CH4/kgVS, whereas the wet digester was operated at an OLR of 0.9kgVS/m(3)day, generating about 320NL CH4/kgVS. The initial total volatile fatty acids concentrations for SADB and wet digestion were about 12,500mg/L and 4500mg/L, respectively. There were higher concentrations of ammonium and COD for the SADB compared to the wet one. The genomic analysis performed by high throughput sequencing returned a number of sequences for each sample ranging from 110,619 to 373,307. More than 93% were assigned to the Bacteria domain. Seven and nine major phyla were sequenced for the SADB and wet digestion, respectively, with Bacteroidetes, Firmicutes and Proteobacteria being the dominant phyla in both digesters. Taxonomic profiles suggested a methanogenic pathway characterized by a relevant syntrophic acetate-oxidizing metabolism mainly in the liquid digestate of the SADB. This result also confirms the benefits of liquid digestate recirculation for improving the efficiency of AD performed with high solids (>30%w/w) content. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Two-Phase Cavitating Flow in Turbomachines

    Directory of Open Access Journals (Sweden)

    Sandor I. Bernad

    2012-11-01

    Full Text Available Cavitating flows are notoriously complex because they are highly turbulent and unsteady flows involving two species (liquid/vapor with a large density difference. These features pose a unique challenge to numerical modeling works. The study briefly reviews the methodology curently employed for industrial cavitating flow simulations using the two-phase mixture model. The two-phase mixture model is evaluated and validated using benchmark problem where experimental data are available. A 3D cavitating flow computation is performed for the GAMM Francis runner. The model is able to qualitatively predict the location and extent of the 3D cavity on the blade, but further investigation are needed to quatitatively assess the accuracy for real turbomachinery cavitating flows.

  11. A Novel Aqueous Two Phase System Composed of a Thermo-Separating Polymer and an Organic Solvent for Purification of Thermo-Acidic Amylase Enzyme from Red Pitaya (Hylocereus polyrhizus Peel

    Directory of Open Access Journals (Sweden)

    Mehrnoush Amid

    2014-05-01

    Full Text Available The purification of thermo-acidic amylase enzyme from red pitaya (Hylocereus polyrhizus peel for the first time was investigated using a novel aqueous two-phase system (ATPS consisting of a thermo-separating copolymer and an organic solvent. The effectiveness of different parameters such as molecular weight of the thermo-separating ethylene oxide-propylene oxide (EOPO copolymer and type and concentration of organic solvent on the partitioning behavior of amylase was investigated. In addition, the effects of phase components, volume ratio (VR, pH and crude load of purification factor and yield of amylase were evaluated to achieve the optimum partition conditions of the enzyme. In the novel ATPS method, the enzyme was satisfactorily partitioned into the polymer-rich top phase in the system composed of 30% (w/w EOPO 2500 and 15% (w/w 2-propanol, at a volume ratio of 1.94 and with a crude load scale of 25% (w/w at pH 5.0. Recovery and recycling of components was also measured in each successive step of the ATPS process. The enzyme was successfully recovered by the method with a high purification factor of 14.3 and yield of 96.6% and copolymer was also recovered and recycled at a rate above 97%, making the method was more economical than the traditional ATPS method.

  12. On the modelling and the analysis of two-phase flow instabilities in pipeline-riser systems; Modelisation et analyse des instabilites d'ecoulements diphasiques dans les conduites petrolieres du type pipeline-riser

    Energy Technology Data Exchange (ETDEWEB)

    Zakarian, E.

    2000-03-10

    Recent estimations predict that over half the remaining offshore oil and gas reserves are located in deep water and marginal fields. For such reserves, economic recovery methods are required. Then, multiphase flows are transported within pipelines and separated on treatment platforms built in shallow water or processed in onshore facilities. Unfortunately, hydrodynamic instabilities may occur whenever gas and liquid flow in a pipeline, generating serious operating problems. This dissertation presents a new way to model two-phase flows in pipelines such as pipeline-riser systems. Equations are algebraic and differential. Their smoothness depends on the closure laws of the problem such as slip or friction laws. Smooth forms of these closure laws are presented for the first time in this dissertation. Therefore, a mathematical analysis of our model fits into a classical frame: a linear analysis leads to an analytical expression of the boundary between stable and unstable flows. A nonlinear analysis provides for the first time, the bifurcation curves of gas-liquid flows in pipe-riser systems, locally round their stability boundary. (author)

  13. A novel aqueous two phase system composed of a thermo-separating polymer and an organic solvent for purification of thermo-acidic amylase enzyme from red pitaya (Hylocereus polyrhizus) peel.

    Science.gov (United States)

    Amid, Mehrnoush; Manap, Yazid; Zohdi, Nor Khanani

    2014-05-22

    The purification of thermo-acidic amylase enzyme from red pitaya (Hylocereus polyrhizus) peel for the first time was investigated using a novel aqueous two-phase system (ATPS) consisting of a thermo-separating copolymer and an organic solvent. The effectiveness of different parameters such as molecular weight of the thermo-separating ethylene oxide-propylene oxide (EOPO) copolymer and type and concentration of organic solvent on the partitioning behavior of amylase was investigated. In addition, the effects of phase components, volume ratio (VR), pH and crude load of purification factor and yield of amylase were evaluated to achieve the optimum partition conditions of the enzyme. In the novel ATPS method, the enzyme was satisfactorily partitioned into the polymer-rich top phase in the system composed of 30% (w/w) EOPO 2500 and 15% (w/w) 2-propanol, at a volume ratio of 1.94 and with a crude load scale of 25% (w/w) at pH 5.0. Recovery and recycling of components was also measured in each successive step of the ATPS process. The enzyme was successfully recovered by the method with a high purification factor of 14.3 and yield of 96.6% and copolymer was also recovered and recycled at a rate above 97%, making the method was more economical than the traditional ATPS method.

  14. An integrated practical implementation of continuous aqueous two-phase systems for the recovery of human IgG: From the microdevice to a multistage bench-scale mixer-settler device.

    Science.gov (United States)

    Espitia-Saloma, Edith; Vâzquez-Villegas, Patricia; Rito-Palomares, Marco; Aguilar, Oscar

    2016-05-01

    Aqueous two-phase systems (ATPS) are a liquid-liquid extraction technology with clear process benefits; however, its lack of industrial embracement is still a challenge to overcome. Antibodies are a potential product to be recovered by ATPS in a commercial context. The objective of this work is to present a more integral approach of the different isolated strategies that have arisen in order to enable a practical, generic implementation of ATPS, using human immunoglobulin G (IgG) as experimental model. A microfluidic device is used for ATPS parameters preselection for product recovery. ATPS were continuously operated in a mixer-settler device in one stage, multistage and multistage with recirculation configuration. Single-stage pure IgG extraction with a polyethylene glycol (PEG) 3350-phophates ATPS within continuous operation allowed a 65% recovery. Further implementation of a multistage platform promoted a higher particle partitioning reaching a 90% recovery. The processing of IgG from a cell supernatant culture harvest in a multistage system with top phase recirculation resulted in 78% IgG recovery in bottom phase. This work conjugates three not widely spread methodologies for ATPS: microfluidics, continuous and multistage operation.

  15. Extraction of Solanesol and Nicotine from Inferior Tobacco Leaves by Aqueous Two-phase System%双水相同时提取次烟叶中茄尼醇和烟碱的研究

    Institute of Scientific and Technical Information of China (English)

    刘宝亮; 曹桂萍; 张金涛

    2012-01-01

    The feasibility and technical conditions of the extraction of solanesol and nicotine from inferior tobacco leaves by a new aqueous two-phase system were investigated. An Acetone-DHP (Dipotassium Hydrogen Phosphate) aqueous two-phase system was applied. Factors including the different volume ratio of acetone to water, the addition amount of phosphate,the material liquid ratio,extraction temperature, extraction time and the pH value on the influences of the yield of two substances were studied. The optimized extraction conditions were described as follows: the volume ratio of acetone to water was 5:5,addition amount of phosphate was 3.0 g,material liquid ratio was 0.025 g/mL (0.5 g/20.0 mL) .extraction temperature was 50℃ .extraction time was 4 h and pH was 10.%研究新型双水相体系同时从次等烟丝中提取茄尼醇和烟碱的可行性和工艺条件.新型双水相体系为丙酮-磷酸氢二钾双水相体系,主要研究了丙酮与水不同体积比、磷酸氢二钾的加入量、料液比、浸提温度、浸提时间、双水相体系pH值对茄尼醇和烟碱得率的影响,确定了最佳提取条件:丙酮与水的体积为5:5,磷酸氢二钾的加入量为3.0g,料液比为0.025 g/mL(0.5 g/20.0 mL),浸提温度为50℃,浸提时间为4h,pH值为10.

  16. Critical thinking: a two-phase framework.

    Science.gov (United States)

    Edwards, Sharon L

    2007-09-01

    This article provides a comprehensive review of how a two-phase framework can promote and engage nurses in the concepts of critical thinking. Nurse education is required to integrate critical thinking in their teaching strategies, as it is widely recognised as an important part of student nurses becoming analytical qualified practitioners. The two-phase framework can be incorporated in the classroom using enquiry-based scenarios or used to investigate situations that arise from practice, for reflection, analysis, theorising or to explore issues. This paper proposes a two-phase framework for incorporation in the classroom and practice to promote critical thinking. Phase 1 attempts to make it easier for nurses to organise and expound often complex and abstract ideas that arise when using critical thinking, identify more than one solution to the problem by using a variety of cues to facilitate action. Phase 2 encourages nurses to be accountable and responsible, to justify a decision, be creative and innovative in implementing change.

  17. [NADPH-diaphorase activity in digestive system of gastropod molluscs Achatina fulica and Littorina littorea].

    Science.gov (United States)

    Zaĭtseva, O V; Kuznetsova, T V; Markosova, T G

    2009-01-01

    Localization and peculiarities of NO-ergic elements were studied for he first time throughout the entire length of digestive tract of the marine gastropod mollusc Achatina fulica (Prosobranchia) and the terrestrial molusc Littorina littorea (Pulmonata) by using histochemical method of detection of NADPH-diaphorase (NADPHd). NO-ergic cells and fibers were revealed in all parts of the mollusc digestive tract beginning from pharynx. An intensive NADPHd activity was found in many intraepithelial cells of the open type and in their processes in intra- and subepithelial nerve plexuses, single subepithelial neurons, granular connective tissue cells, and numerous nerve fibers among muscle elements of he digestive tract wall as well as in nerves innervating the tract. NADPHd was also present in receptor cells of he oral area and in the central A. fulica ganglia participating in innervation of the digestive tract. The digestive tract NO-ergic system ofA. fulica has a more complex organization that that of L. littorea. In the A. fulica pharynx, stomach, and midgut, directly beneath epithelium, there is revealed a complex system of glomerular structures formed by thin NADPHd-positive nerve fibers coming from the side of epithelium. More superficially under the main groups of muscle elements, small agglomerations of NADPHd-positive neurons are seen, which could be considered as primitive, non-formed microganglia. Peculiarities of distribution and a possible functional role of NO-ergic elements in the digestive tract of molluscs are discussed as compared with other invertebrate and vertebrate animals.

  18. Effects of Hydrophobicity of Ethylene Oxide-Propylene Oxide Copolymers on Phase Diagrams of Aqueous Two-Phase Systems and Partition Behaviors of Cephalexin and 7-Aminodeacetoxicephalos Doranic Acid

    Institute of Scientific and Technical Information of China (English)

    朱建航; 魏东芝; 曹学君

    2002-01-01

    A series of ethylene oxide (EO)-propylene oxide (PO) random co-polymers (EOPO) were used to formaqueous two-phase systems (ATPS) with ammonium sulfate. Effects of EOPO's properties on the phase separationbehaviors and on the partition of cephalexin and 7-aminodesacetoxicephalosporanic acid (7-ADCA) in ATPS wereinvestigated. Both the molar mass and molar ratio of EO to PO of EOPO could greatly influence partition behaviorsof cephalexin and 7-ADCA as well as the binodal curve of ATPS. With the increase of molar mass of co-polymeror the decrease of molar ratio of EO to PO, the critical point of ATPS decreased, the binodal curve became moreasymmetry, and both cephalexin and 7-ADCA followed the same tendency to partition into the polymer-poorbottom phase. The experimental results shows that it is feasible to partition cephalexin and 7-ADCA in either thepolymer-rich top phase or the polymer-poor bottom phase by choosing a specific phase-forming EOPO.

  19. The Digestive System and Nutritional Considerations for Individuals with Rett Syndrome

    Directory of Open Access Journals (Sweden)

    Meir Lotan

    2006-01-01

    Full Text Available Rett syndrome (RS is a neurodevelopmental syndrome of genetic origin that mainly affects females. Individuals diagnosed with RS exhibit a variety of functional difficulties that impair their quality of life. One of the affected systems is the digestive system, where 74% of persons with RS have abnormal functioning. The affected digestive system causes this population to present an array of problems, such as gastroesophageal reflux (GER, constipation, and malnutrition, leading to failure to thrive (FTT, which resolves in reduced functional ability. Due to the severe effects of the dysfunctional digestive system of individuals with RS, this article will describe the problems common to this population, as well as propose some clinical suggestions for intervention. .

  20. Dynamics of digestive proteolytic system during blood feeding of the hard tick Ixodes ricinus

    Directory of Open Access Journals (Sweden)

    Sojka Daniel

    2010-12-01

    Full Text Available Abstract Background Ticks are vectors of a wide variety of pathogens causing severe diseases in humans and domestic animals. Intestinal digestion of the host blood is an essential process of tick physiology and also a limiting factor for pathogen transmission since the tick gut represents the primary site for pathogen infection and proliferation. Using the model tick Ixodes ricinus, the European Lyme disease vector, we have previously demonstrated by genetic and biochemical analyses that host blood is degraded in the tick gut by a network of acidic peptidases of the aspartic and cysteine classes. Results This study reveals the digestive machinery of the I. ricinus during the course of blood-feeding on the host. The dynamic profiling of concentrations, activities and mRNA expressions of the major digestive enzymes demonstrates that the de novo synthesis of peptidases triggers the dramatic increase of the hemoglobinolytic activity along the feeding period. Overall hemoglobinolysis, as well as the activity of digestive peptidases are negligible at the early stage of feeding, but increase dramatically towards the end of the slow feeding period, reaching maxima in fully fed ticks. This finding contradicts the established opinion that blood digestion is reduced at the end of engorgement. Furthermore, we show that the digestive proteolysis is localized intracellularly throughout the whole duration of feeding. Conclusions Results suggest that the egressing proteolytic system in the early stage of feeding and digestion is a potential target for efficient impairment, most likely by blocking its components via antibodies present in the host blood. Therefore, digestive enzymes are promising candidates for development of novel 'anti-tick' vaccines capable of tick control and even transmission of tick-borne pathogens.

  1. Histological Study on the Digestive System Development of Takifugu rubripes Larvae and Juvenile

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The digestive tract of Takifugu rubripes during early life stages was studied with light microscopy. At the beginning of hatching, the digestive tract is represented by a simple and undifferentiated straight tube and does not communicate with the exterior, as the mouth and anus are not open yet. At 2 d after hatching, a constriction between intestine and rectum that will become the intestino-rectal valve is visible. During the endogenous feeding phase, the yolk sac is resorbed and the digestive tract becomes functional and differentiated. The liver and pancreas also become apparent at this time. At onset of exogenous feeding (3 d after hatching), yolk sac resesves are not completely depleted, suggesting a period of mixed nutrition. The digestive tract differentiates fully into buccopharynx, esophagus, stomach, intestine and rectum. At 9 d after hatching, the yolk sac reserves are completely depleted. The most noticeable events occurring from 5 to 17 d after hatching are the transformation of the epithelia type, the differentiation of the pneumatic sac, the epithelial cell, gut convolution, mucosal fold increase, and the growth of liver and pancreas. From 18 to 27 d after hatching, the numbers of intestine folds and mucus cells increase progressively. From then on, morphological changes of digestive features are almost completed. At 27 d after hatching, the morphology and function of digestive system are similar to that of the adult.

  2. The effect of 1-week feed restriction on performance, digestibility of nutrients and digestive system development in the growing rabbit.

    Science.gov (United States)

    Tůmová, E; Volek, Z; Chodová, D; Härtlová, H; Makovický, P; Svobodová, J; Ebeid, T A; Uhlířová, L

    2016-01-01

    A 3 to 4 week feed restriction of about 20% to 25% of the free intake is widely applied in rabbit breeding systems to reduce post-weaning digestive disorders. However, a short intensive feed restriction is described in few studies and can be beneficial for growing rabbits due to a longer re-alimentation period. The aim of this study was to evaluate the effect of ad libitum (AL) and two restriction levels of feeding (50 and 65 g/rabbit per day) applied for 1 week on performance, gastrointestinal morphology and physiological parameters during the restriction and during the re-alimentation period. Rabbits were divided into three experimental groups: AL rabbits were fed AL, R1 rabbits were restricted from 42 to 49 days of age and received 50 g daily (29% of AL) and R2 rabbits were restricted at the same age and were fed 65 g of feed daily (37% of AL). In the 1(st) week after weaning and in the weeks after restriction, all the groups were fed AL. During the restriction period, daily weight gain (DWG) in R1 significantly dropped to 11% (experiment 1) and 5% (experiment 2) compared with rabbits in the AL group, although they were fed 29% of AL, whereas in the R2 group it decreased to 20% (experiment 1) and 10% (experiment 2). In the week following feed restriction, DWG in the restricted groups increased (Prabbits in both the experiments reached up to 90% to 93% of the final live weight (70 days) of the AL group. Over the entire experimental period, feed restriction significantly decreased feed intake to 85% to 88% of the AL group; however, the feed conversion ratio was lower (P<0.05) only in experiment 1 (-6% in R1 and -4% in R2). Digestibilities of CP and fat were not significantly higher during the restriction period and during the 1(st) week of re-alimentation compared with the AL group. Significant interactions between feeding regime and age revealed the shortest large intestine in the AL group at 49 days of age and the longest at 70 days in the AL and R1 groups

  3. Partitioning behavior and structural characterization of papain in ionic liquid aqueous two-phase system%木瓜蛋白酶在离子液体双水相中的分配行为

    Institute of Scientific and Technical Information of China (English)

    王伟涛; 蒋志国; 张海德; 彭健; 许英豪; 董安华; 杨雪芳; 蒋欣欣

    2015-01-01

    Papain was extracted by ionic liquid aqueous two-phase system. Firstly,the influence of concentration, pH, and temperature of ionic liquid on the activity of papain was investigated. Secondly, the effects of different ionic liquid aqueous two-phase systems, alkyl chain lengths and concentrations of the ionic liquid, dosage of papain, pH, temperature on the partitioning behavior of papain were discussed. [C4mim]Cl and [C4mim]Br systems were better than [C4mim]BF4 system in extraction of papain, and it was disadvantageous to extract papain at a high temperature (60℃or higher). Activity recovery of enzyme reached 95.16%and purification factor reached 1.5 under the optimum conditions:[C4mim]Cl 0.25 g·ml−1, K2HPO4 0.35 g·ml−1, pH 8.0, enzyme addition 2.0 mg·ml−1, 30℃. The result laid the experimental basis for further scale-up research and commercial production.%采用离子液体双水相提取木瓜蛋白酶。首先考察不同浓度、pH、温度的离子液体对木瓜蛋白酶活性的影响,其次考察不同离子液体双水相体系、离子液体侧烷基链长度及浓度、酶添加量、pH、温度对木瓜蛋白酶分配行为的影响。结果表明:[C4mim]Cl 和[C4mim]Br 体系萃取木瓜蛋白酶的效果比[C4mim]BF4体系好;高温(≥60℃)对离子液体双水相体系萃取木瓜蛋白酶不利。离子液体双水相萃取木瓜蛋白酶的最佳工艺条件:0.25 g·ml−1的[C4mim]Cl,0.35 g·ml−1的K2HPO4,pH 8.0,酶添加量2.0 mg·ml−1,30℃。此条件下木瓜蛋白酶的酶活性回收率达到95.16%,纯化因子达到1.5。为今后进一步研究该体系的放大实验或规模化生产奠定了基础。

  4. Anaerobic co-digestion in the Netherlands. A system analysis on greenhouse gas emissions from Dutch co-digesters.

    NARCIS (Netherlands)

    Groenewold, Henk

    2013-01-01

    Summary Anaerobic digestion (AD) is a biological process whereby, in the absence of oxygen, organic matter is transformed into biogas and digestate. In recent years AD has received new attention in the Dutch agricultural sector by introducing the co-dige

  5. Anaerobic co-digestion in the Netherlands. A system analysis on greenhouse gas emissions from Dutch co-digesters.

    NARCIS (Netherlands)

    Groenewold, Henk

    2013-01-01

    Summary Anaerobic digestion (AD) is a biological process whereby, in the absence of oxygen, organic matter is transformed into biogas and digestate. In recent years AD has received new attention in the Dutch agricultural sector by introducing the co-dige

  6. Partial purification of glucose-6-phosphate dehydrogenase by aqueous two-phase poly(ethyleneglycol/phosphate systems Purificação parcial de glucose-6-fosfato desidrogenase por sistemas de duas fases aquosas poli (etilenoglicol/fosfato

    Directory of Open Access Journals (Sweden)

    Marcela Zanella Ribeiro

    2007-03-01

    Full Text Available Glucose-6-phosphate dehydrogenase (G6PDH is an important enzyme used in biochemical and medical studies and in several analytical methods that have industrial and commercial application. This work evaluated the extraction of G6PDH in aqueous two-phase system (ATPS of poly(ethyleneglycol (PEG/phosphate buffer, using as enzyme source a medium prepared through commercial baker's yeast disruption. Firstly, the effects of PEG molar mass on the enzyme partition and of homogenization and rest on the system equilibrium were investigated. Afterwards, several ATPS were prepared using statistical analysis (2² factorial design. The results, including kinetic and thermodynamic parameters for the G6PDH activity, showed partial purification of this enzyme in ATPS composed of 17.5% (w/w PEG400 and 15.0% (w/w phosphate. A high enzymatic recovery value (97.7%, a high partition coefficient (351, and an acceptable purification factor (2.28 times higher than in cell homogenate were attained from the top phase. So, it was possible to attain an effective enzyme pre-purification by separating some contaminants with a simple method such as liquid-liquid extraction in aqueous two-phase systems (ATPS.Glicose-6-fosfato desidrogenase (G6PDH é uma importante enzima usada em estudos bioquímicos e médicos, bem como em diversos métodos analíticos com aplicação comercial e industrial. Neste trabalho foi avaliado a extração da G6PDH em sistemas de duas fases aquosas (ATPS constituídos por poli(etilenoglicol (PEG/tampão fosfato, usando como fonte de enzima um meio preparado por rompimento de leveduras de panificação comercial. Inicialmente foram investigados os efeitos da massa molar do PEG na partição da enzima e da homogeneização e repouso no equilíbrio do sistema. Na sequência, diversos ATPS foram preparados usando análise estatística (planejamento fatorial 2². Os resultados, incluindo parâmetros cinéticos e termodinâmicos para a atividade da G6PDH

  7. Saccharomyces cerevisiae in the respiratory system, digestive system and on the skin in humans

    Directory of Open Access Journals (Sweden)

    Maria Dynowska

    2013-12-01

    Full Text Available The results of observations on the occurrence of S. cerevisiae in the respiratory and digestive systems and on the skin in hospitalised individuals, mostly belonging to so-called risk groups of fungal infections, conducted over a period of five years (1999-2004, are described and discussed. The participation of S. cerevisiae in the mycocoenoses studied was 11.04% of all the recorded fungi. A significant increase in its prevalence, especially on the skin, was noticed. The fungus was mostly isolated with fungi of the genera Candida and Trichosporon, as well as separately in the last two years of the study.

  8. The Digestive System [and] Instructor's Guide. Instructional Materials in Anatomy and Physiology for Pennsylvania Health Occupations Programs.

    Science.gov (United States)

    National Evaluation Systems, Inc., Amherst, MA.

    This instructional modular unit wlth instructor's guide provides materials on important aspects of one of the major systems of the human body--the digestive system. Its purpose is to introduce the student to the structures and functions of the human digestive system--and the interrelationships of the two--and to familiarize the student with some…

  9. Response Surface Methodology Modelling of an Aqueous Two-Phase System for Purification of Protease from Penicillium candidum (PCA 1/TT031 under Solid State Fermentation and Its Biochemical Characterization

    Directory of Open Access Journals (Sweden)

    Amaal M. Alhelli

    2016-11-01

    Full Text Available Penicillium candidum (PCA 1/TT031 synthesizes different types of extracellular proteases. The objective of this study is to optimize polyethylene glycol (PEG/citrate based on an aqueous two-phase system (ATPS and Response Surface Methodology (RSM to purify protease from Penicillium candidum (PCA 1/TT031. The effects of different PEG molecular weights (1500–10,000 g/mol, PEG concentration (9%–20%, concentrations of NaCl (0%–10% and the citrate buffer (8%–16% on protease were also studied. The best protease purification could be achieved under the conditions of 9.0% (w/w PEG 8000, 5.2% NaCl, and 15.9% sodium citrate concentration, which resulted in a one-sided protease partitioning for the bottom phase with a partition coefficient of 0.2, a 6.8-fold protease purification factor, and a yield of 93%. The response surface models displayed a significant (p ≤ 0.05 response which was fit for the variables that were studied as well as a high coefficient of determination (R2. Similarly, the predicted and observed values displayed no significant (p > 0.05 differences. In addition, our enzyme characterization study revealed that Penicillium candidum (PCA 1/TT031 produced a slight neutral protease with a molecular weight between 100 and 140 kDa. The optimal activity of the purified enzyme occurred at a pH of 6.0 and at a temperature of 50 °C. The stability between different pH and temperature ranges along with the effect of chemical metal ions and inhibitors were also studied. Our results reveal that the purified enzyme could be used in the dairy industry such as in accelerated cheese ripening.

  10. Application of aqueous two-phase systems for the development of a new method of cobalt(II), iron(III) and nickel(II) extraction: a green chemistry approach.

    Science.gov (United States)

    Patrício, Pamela da Rocha; Mesquita, Maiby Cabral; da Silva, Luis Henrique Mendes; da Silva, Maria C Hespanhol

    2011-10-15

    We have investigated the extraction behavior of the metallic ions Co(II), Fe(III) and Ni(II) as a function of the amount of potassium thiocyanate used as an extracting agent, using the following aqueous two-phase systems (ATPS): PEO + (NH(4))(2)SO(4) + H(2)O, PEO + Li(2)SO(4) + H(2)O, L35 + (NH(4))(2)SO(4) + H(2)O and L35 + (Li)(2)SO(4)+H(2)O. Metal extraction from the salt-rich phase to the polymer-rich phase is affected by the following parameters: amount of added extractant, pH, and the nature of the electrolyte and polymer that forms the ATPS. Maximal extraction percentages were obtained for Co(II) (99.8%), Fe(III) (12.7%) and Ni(II) (3.17%) when the ATPS was composed of PEO1500 + (NH(4))(2)SO(4) + H(2)O containing 1.4 mmol of KSCN at pH 4.0, providing separation factors as high as S(Co, Fe) = 3440 and S(Co, Ni) = 15,300. However, when the same ATPS was used at pH 2.0, the maximal extraction percentages for iron and nickel were 99.5% and 4.34%, respectively, with S(Fe, Ni) equal to 4380. The proposed technique was shown to be efficient in the extraction of Co(II) and Fe(III), with large viability for the selective separation of Co(II) and Fe(III) ions in the presence of Ni(II).

  11. Response Surface Methodology Modelling of an Aqueous Two-Phase System for Purification of Protease from Penicillium candidum (PCA 1/TT031) under Solid State Fermentation and Its Biochemical Characterization

    Science.gov (United States)

    Alhelli, Amaal M.; Abdul Manap, Mohd Yazid; Mohammed, Abdulkarim Sabo; Mirhosseini, Hamed; Suliman, Eilaf; Shad, Zahra; Mohammed, Nameer Khairulla; Meor Hussin, Anis Shobirin

    2016-01-01

    Penicillium candidum (PCA 1/TT031) synthesizes different types of extracellular proteases. The objective of this study is to optimize polyethylene glycol (PEG)/citrate based on an aqueous two-phase system (ATPS) and Response Surface Methodology (RSM) to purify protease from Penicillium candidum (PCA 1/TT031). The effects of different PEG molecular weights (1500–10,000 g/mol), PEG concentration (9%–20%), concentrations of NaCl (0%–10%) and the citrate buffer (8%–16%) on protease were also studied. The best protease purification could be achieved under the conditions of 9.0% (w/w) PEG 8000, 5.2% NaCl, and 15.9% sodium citrate concentration, which resulted in a one-sided protease partitioning for the bottom phase with a partition coefficient of 0.2, a 6.8-fold protease purification factor, and a yield of 93%. The response surface models displayed a significant (p ≤ 0.05) response which was fit for the variables that were studied as well as a high coefficient of determination (R2). Similarly, the predicted and observed values displayed no significant (p > 0.05) differences. In addition, our enzyme characterization study revealed that Penicillium candidum (PCA 1/TT031) produced a slight neutral protease with a molecular weight between 100 and 140 kDa. The optimal activity of the purified enzyme occurred at a pH of 6.0 and at a temperature of 50 °C. The stability between different pH and temperature ranges along with the effect of chemical metal ions and inhibitors were also studied. Our results reveal that the purified enzyme could be used in the dairy industry such as in accelerated cheese ripening. PMID:27845736

  12. Extraction of Tartrazine from Food Colorants by PEG/Salt Aqueous Two-Phase System%PEG/盐双水相萃取食用色素柠檬黄的研究

    Institute of Scientific and Technical Information of China (English)

    姜彬; 李冬梅; 冯志彪

    2014-01-01

    采用PEG/盐双水相体系萃取食用色素柠檬黄。考察了成相物质对柠檬黄吸光度的影响,在此基础上考察了PEG相对分子量、PEG浓度、盐的种类及浓度、p H 对萃取效果的影响,确定了萃取柠檬黄的最佳条件:18% PEG2000,15%(NH4)2SO4,pH 为6。该体系对柠檬黄色萃取效果不受外加无机盐的影响,但表面活性剂的存在对萃取效果有较大影响。%An aqueous two-phase system (ATPS )is presented with polyethylene glycol (PEG )and salt for the extraction of tartrazine in this paper.The extraction of tartrazine in ATPS is investigated. Concentration of (NH4 )2 SO4 and PEG,pH value and other factors are evaluated to determine their effects on the extraction yield of tartrazine.The results show that the extraction yield strongly de-pends on the concentration of PEG and (NH4 )2 SO4 .A high extraction yield around 98% is achieved with the following parameters:(NH4)2SO4 15%,PEG2000 18%,pH 6.It is found that the extrac-tion yield undepends on the additional salt,but the presence of surfactant influences the extraction yield evidently.

  13. Partition efficiencies of newly fabricated universal high-speed counter-current chromatograph for separation of two different types of sugar derivatives with organic-aqueous two-phase solvent systems.

    Science.gov (United States)

    Shinomiya, Kazufusa; Sato, Kazuki; Yoshida, Kazunori; Tokura, Koji; Maruyama, Hiroshi; Yanagidaira, Kazuhiro; Ito, Yoichiro

    2013-12-27

    A new design of universal high-speed counter-current chromatograph (HSCCC) was fabricated in our laboratory. It holds a set of four column holders symmetrically around the rotary frame at a distance of 11.2cm from the central axis. By engaging the stationary gear on the central axis of the centrifuge to the planetary gears on the column holder shaft through a set of idle gears, two pairs of diagonally located column holders simultaneously rotate about their own axes in the opposite directions: one forward (type-J planetary motion) and the other backward (type-I planetary motion) each synchronously with the revolution. Using the eccentric coil assembly, partition efficiencies produced by these two planetary motions were compared on the separation of two different types of sugar derivatives (4-methylumbelliferyl and 5-bromo-4-chloro-3-indoxyl sugar derivatives) using organic-aqueous two-phase solvent systems composed of n-hexane/ethyl acetate/1-butanol/methanol/water and aqueous 0.1M sodium tetraborate, respectively. With lower phase mobile, better peak resolution was obtained by the type-J forward rotation for both samples probably due to higher retention of the stationary phase. With upper phase mobile, however, similar peak resolutions were obtained between these two planetary motions for both sugar derivatives. The overall results indicate that the present universal HSCCC is useful for counter-current chromatographic separation since each planetary motion has its specific applications: e.g., vortex CCC by the type-I planetary motion and HSCCC by the type-J planetary motion both for separation of various natural and synthetic products.

  14. Intermediate-Scale High-Solids Anaerobic Digestion System Operational Development

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, C. J.

    1995-02-01

    Anaerobic bioconversion of solid organic wastes represents a disposal option in which two useful products may be produced, including a medium Btu fuel gas (biogas) and a compost-quality organic residue. The application of high-solids technology may offer several advantages over conventional low-solids digester technology. The National Renewable Energy Laboratory (NREL) has developed a unique digester system capable of uniformly mixing high-solids materials at low cost. During the first 1.5 years of operation, a variety of modifications and improvements were instituted to increase the safety, reliability, and performance of the system. Those improvements, which may be critical in further scale-up efforts using ,the NREL high-solids digester design are detailed in this report.

  15. Early warning indicators for monitoring the process failure of anaerobic digestion system of food waste.

    Science.gov (United States)

    Li, Lei; He, Qingming; Wei, Yunmei; He, Qin; Peng, Xuya

    2014-11-01

    To determine reliable state parameters which could be used as early warning indicators of process failure due to the acidification of anaerobic digestion of food waste, three mesophilic anaerobic digesters of food waste with different operation conditions were investigated. Such parameters as gas production, methane content, pH, concentrations of volatile fatty acid (VFA), alkalinity and their combined indicators were evaluated. Results revealed that operation conditions significantly affect the responses of parameters and thus the optimal early warning indicators of each reactor differ from each other. None of the single indicators was universally valid for all the systems. The universally valid indicators should combine several parameters to supply complementary information. A combination of total VFA, the ratio of VFA to total alkalinity (VFA/TA) and the ratio of bicarbonate alkalinity to total alkalinity (BA/TA) can reflect the metabolism of the digesting system and realize rapid and effective early warning.

  16. 一种新型两相励磁开关磁阻电机驱动系统的静态特性%STATIC PERFORMANCE OF A NEW SRD SYSTEM WITH TWO-PHASE EXCITATION

    Institute of Scientific and Technical Information of China (English)

    郭伟; 詹琼华; 丘亦慧

    2002-01-01

    该文主要分析了一种两相同时励磁的开关磁阻电机(SRM)的静态特性.文中首先简要介绍了这种两相励磁系统的结构,然后提出了两相励磁下SRM的磁链模型.基于详细的非线性有限元分析(FEA)的结果,建立了简化的线性模型且利用此线性模型导出了SRM的转矩--转角特性,并和非线性FEA模型下的结果进行了比较.最后,根据FEA的结果,提出了一种优化的控制策略来提高这种SRM的性能.%This paper provides an analysis of a switched reluctance motor (SRM) under two-phase excitation. After a brief introduction of the two-phase excitation scheme, the flux linkage model of a SRM under two-phase excitation is developed using FEA. A linearized model is then established based on the detailed flux linkage analysis. The torque-angle characteristics of such a linear model are compared with that derived from the detailed and nonlinear FEA model. Based on theFEA model, an optimized control strategy is proposed to improve the performanceof the SRM under two-phase excitation.

  17. Droplet Manipulations in Two Phase Flow Microfluidics

    Directory of Open Access Journals (Sweden)

    Arjen M. Pit

    2015-11-01

    Full Text Available Even though droplet microfluidics has been developed since the early 1980s, the number of applications that have resulted in commercial products is still relatively small. This is partly due to an ongoing maturation and integration of existing methods, but possibly also because of the emergence of new techniques, whose potential has not been fully realized. This review summarizes the currently existing techniques for manipulating droplets in two-phase flow microfluidics. Specifically, very recent developments like the use of acoustic waves, magnetic fields, surface energy wells, and electrostatic traps and rails are discussed. The physical principles are explained, and (potential advantages and drawbacks of different methods in the sense of versatility, flexibility, tunability and durability are discussed, where possible, per technique and per droplet operation: generation, transport, sorting, coalescence and splitting.

  18. Morphological changes in the digestive system of 93 human immunodeficiency virus positive patients: an autopsy study

    Directory of Open Access Journals (Sweden)

    Lucinda Calheiros Guimarães

    2012-04-01

    Full Text Available Involvement of the digestive system in patients with acquired immunodeficiency syndrome (AIDS is frequent and many changes in these patients are diagnosed only at autopsy. There are few studies of autopsy with detailed analysis of this system and only one was conducted in Brazil. We evaluated each segment of the digestive system in 93 consecutive autopsies of patients infected with human immunodeficiency virus (HIV and the importance of these lesions to death. Of these, 90 (96.8% patients had AIDS. We reviewed medical records, autopsy reports and histological sections from tongue to rectum stained with hematoxylin-eosin. When necessary, we analyzed special stains and immunohistochemistry to investigate infections. There was damage to the digestive system in 73 (78.5% cases. The most common infections were candidiasis (42%, cytomegalovirus (29%, histoplasmosis (11.8%, toxoplasmosis (9.7% and mycobacterial infection (9.7%. Malignancies were rare, present in four (4.3% cases (two Kaposi's sarcoma, one adenocarcinoma and one metastatic embryonal carcinoma. All segments showed lesions: tongue (48.6%, esophagus (44.8%, stomach (44.7%, colon (43.2% and small intestine (28.9%. The lesions found were immediate cause of death in five (5.4% cases. In another 36 (38.7% cases the basic disease was systemic and also compromised the digestive system.

  19. Digestible lysine for broiler chickens with lower genetic potential grown on free-range system

    Directory of Open Access Journals (Sweden)

    Eduardo Souza do Nascimento

    Full Text Available ABSTRACT Determining the actual lysine requirement is crucial as it is an essential amino acid and plays animportant role in the metabolism of broilers. In addition, it is the second limiting amino acid for broilers fed with rations formulated basedon corn and soybean meal. The aim of this study was to determine the digestible lysine requirement for male broilers with lower genetic potential for growth in a semi-confined system as well as to evaluate the effects of different values of digestible lysine on performance and carcass characteristics. A total of 300 broiler chickensfrom a commercial lineage EMBRAPA 041 were used with an average initial weight of 987 g. The broilers were distributed into 20 experimental units in a completely randomized design with five treatments (0.586; 0.746; 0.906; 1.066, and 1.226% digestible lysine, four replicates and 15 broilers per experimental unit.In both periods, there were linear effect of digestible lysine values on the lysine intake and lysine utilization efficiency and quadratic effect on final body weight, weight gain and feed: gain ratio.There was a quadratic effect on the absolute weight of carcasses, breast, thigh + drumstick and income gizzard.For rearing of male broilers with lesser genetic growth potential reared in semi-confinement, rations with 1.040% and 1.103% digestible lysine can be recommended for maximum weight gain in periods from 35 to 70 and 35 to 84 days of age, respectively.

  20. Biomethanation and microbial community changes in a digester treating sludge from a brackish aquaculture recirculation system.

    Science.gov (United States)

    Zhang, Xuedong; Tao, Yu; Hu, Jianmei; Liu, Gang; Spanjers, Henri; van Lier, Jules B

    2016-08-01

    Using a high-salinity-adapted inoculum and a moderate stepwise-increased organic loading rate (OLR), a stable digester performance was achieved in treating sludge from a brackish aquaculture recirculation system. The specific methane yield was distinctly enhanced, reaching 0.203LCH4/gCODadded, compared to literature values (0.140-0.154LCH4/gCODadded) from the salty sludges. OLR adjustment and the fecal substrate substantially influenced population changes in the digester. Within the bacterial subpopulations, the relative abundance of Bacillus and Bacteroides declined, accompanied by the increase of Clostridium and Trigonala over time. The results show Trigonala was derived from the substrate and accumulated inside the digester. The most abundant methanogen was Methanosarcina in the inoculum and the digestates. The Methanosarcina proliferation can be ascribed to its metabolic versatility, probably a feature of crucial importance for high-salinity environments. Other frequently observed methanogens were outcompeted. The population similarity at the genus level between inoculum and digestates declined during the initial stage and afterwards increased.

  1. Assessing the treatment costs and the fertilizing value of the output products in digestate treatment systems.

    Science.gov (United States)

    Golkowska, K; Vázquez-Rowe, I; Lebuf, V; Accoe, F; Koster, D

    2014-01-01

    The objective of this paper was to advance towards finding sustainable solutions to deal with biogas digestate and contribute to faster development of the market for digestate treatment products. The study compares digestate treatment costs through four different treatment plants, estimates the potential fertilizing and humus value (PFHV) of the derived products and allocates the cash flows to show the possible regional benefits. The treatment costs for the pre-dried solid fraction of digestate ranged from €19 to €23/tonne output. These costs may be covered by vending treatment products at a price reaching at least 34-41% of their PFHV (ca €55/tonne). Treatment of raw digestate generates high operating costs (€216-247/tonne output), much higher than the PFHV of the products (ca €35-51/tonne). For such systems either the treatment has to be financially subsidized by the authorities or €13-32/tonne input should be covered by the substrate deliverers as a disposal fee. Nevertheless, a well-prepared investment concept in this field may allow the local binding of up to 80% of total cash flows. Finally, the current difficult market situation of the treatment products can be primarily improved by clearing their legal status at European level.

  2. Partitioning of Bovine Serum Albumin in Polyethylene Glycol(PEG)/Phosphate Aqueous Two-Phase System%PEG/磷酸盐双水相系统萃取BSA的研究

    Institute of Scientific and Technical Information of China (English)

    胡松青; 李琳; 李冰; 肖蕾

    2002-01-01

    BSA partitioning was performed in the PEG/phosphate aqueous two-phase system. The effects of the phase compositions concentrations, addition of NaCl and the initial concentration of BSA on the partition coefficient K and the fraction of BSA in the bottom phase Y were investigated. The results showed that BSA was enriched to the bottom phase. The phase compositions of PEG 6000 mass fraction is 10%/PO3-4 mass fraction is 6% and PEG 10000 mass fraction is 6%/PO3-4 mass fraction is 6% respectively were desirable for partitioning. The addition of NaCl showed no influence on BSA partitioning in PEG 6000 mass fraction is 10% /PO3-4 mass fraction is 6% system. The mathematical model for K was derived from the initial mass concentration of BSA and well fitting with the experimental data.%以PEG/磷酸盐双水相系统萃取BSA为对象,研究了双水相系统成相浓度、外加盐NaCl、BSA起始浓度等对BSA在两相间的分配系数和BSA下相萃取率的影响.结果发现,BSA大部分被萃取入双水相体系的下相,成相组成为PEG 6000 10% (质量分数)/ PO3-4 6% (质量分数)和PEG 10000 6% (质量分数)/ PO3-4 6% (质量分数)的双水相系统有利于BSA的萃取分配;外加NaCl对PEG 6000 10%(质量分数)/PO3-4 6%(质量分数)系统萃取BSA的影响不大;得出了上、下相BSA浓度和BSA在两相间分配系数K与系统BSA起始浓度之间的表达式,与实验结果有较好的拟合.

  3. For solid-liquid two phase softness abrasive flow embedded real-time monitoring and control system%面向固-液两相软性磨粒流嵌入式实时测控系统

    Institute of Scientific and Technical Information of China (English)

    计时鸣; 兰信鸿

    2012-01-01

    In order to solve the problems of flow pipe is to small to the conventional sensor for solid-liquid two phase softness abrasive flow,a monitoring method based on the vibration signal was proposed. Through the wavelet packet analysis of vibration signal, extraction signal characteristics were gotten. Using object-oriented technology, a kind of measurement and control software framework was developed, combined with finite state machine theory and embedded real-time operating system and programming methods of multitasking. Using Linux and DSP/BIOS RTOS, the double operating system signal processing technology was implemented,a multi-channel high speed data acquisition function was implemented on the intelligence embedded real-time measurement and control platform. The results indicate that it is easy to expand and interactive.%针对固-液两相软性磨粒流精密抛光方法中流道微小,无法采用常规直接信号传感器的问题,提出了一种基于二次信号-加速度振动信号的软性磨粒流监测方法.通过小波包分析提取了振动信号的特征.结合基于有限状态机理论与基于嵌入式实时操作系统的并发多任务的程序设计方法,采用面向对象技术开发了一种测控软件框架.采用Linux和DSP/BIOS RTOS实施了双操作系统信号处理技术,开发实现了一个面向软性磨粒流的,具有通用多通道高速数据采集功能的智能化嵌入式实时测控平台.研究结果表明,该系统具有易扩展与易交互的优点.

  4. Validation of a new in vitro dynamic system to simulate infant digestion.

    Science.gov (United States)

    Ménard, Olivia; Cattenoz, Thomas; Guillemin, Hervé; Souchon, Isabelle; Deglaire, Amélie; Dupont, Didier; Picque, Daniel

    2014-02-15

    Understanding the mechanisms of infant formula disintegration in the infant gastrointestinal tract is a key step for developing new formulas with health benefits for the neonate. For ethical reasons, the access to in vivo data obtained on infants is limited. The use of animal models can be an alternative but these experiments are labour intensive, expensive and results obtained show high inter-individual variability, making their interpretation difficult. The aim of this work was to develop a simple in vitro dynamic gastrointestinal digestion system, for studying infant formula digestion, and to validate it by comparing the kinetics of proteolysis obtained in vitro with in vivo data collected from piglets. Results showed a good correlation between in vitro and in vivo data and confirmed the rapid hydrolysis of caseins in gastric conditions, whereas whey proteins appeared more resistant to digestion.

  5. Modification of digestive system microbiome of lactating dairy cows by feeding Bovamine: effect on ruminal fermentation

    Science.gov (United States)

    We evaluated the immune modulatory effects as well as effects on productivity of Bovamine® (Lactobacillus acidophilus strain NP51 and Probionibacterium freudenreichii) on the digestive system microbiome of dairy cattle during late lactation (average DIM = 202). To unveil the underlying mechanisms, ...

  6. Design of a coil satellite centrifuge and its performance on counter-current chromatographic separation of 4-methylumbelliferyl sugar derivatives with polar organic-aqueous two-phase solvent systems.

    Science.gov (United States)

    Shinomiya, Kazufusa; Tokura, Koji; Kimura, Emiru; Takai, Midori; Harikai, Naoki; Yoshida, Kazunori; Yanagidaira, Kazuhiro; Ito, Yoichiro

    2015-05-01

    A new high-speed counter-current chromatograph, named coil satellite centrifuge (CSC), was designed and fabricated in our laboratory. The CSC apparatus produces the satellite motion such that the coiled column simultaneously rotates around the sun axis (the angular velocity, ω1), the planet axis (ω2) and the satellite axis (the central axis of the column) (ω3). In order to achieve this triplicate rotary motion without twisting of the flow tube, the rotation of each axis was determined by the following formula: ω1=ω2+ω3. This relation enabled to lay out the flow tube without twisting by the simultaneous rotation of three axes. The flow tube was introduced from the bottom side of the apparatus into the sun axis of the first rotary frame reaching the upper side of the planet axis and connected to the column in the satellite axis. The performance of the apparatus was examined on separation of 4-methylumbelliferyl (MU) sugar derivatives as test samples with organic-aqueous two-phase solvent systems composed of ethyl acetate/1-butanol/water (3:2:5, v/v) for lower phase mobile and (1:4:5, v/v) for upper phase mobile. With lower phase mobile, five 4-MU sugar derivatives including β-D-cellobioside (Cel), β-D-glucopyranoside, α-D-mannopyranoside, β-D-fucopyranoside and α-L-fucopyranoside (α-L-Fuc) were separated with the combined rotation around each axis at counterclockwise (CCW) (ω1) - CCW (ω2) - CCW (ω3) by the flow tube distribution. With upper phase mobile, three 4-MU sugar derivatives including α-L-Fuc, β-D-galactopyranoside and Cel were separated with the combined rotation around each axis at clockwise (CW) (ω1) - CW (ω2) - CW (ω3) by the flow tube distribution. A series of experiments on peak resolution and stationary phase retention revealed that better partition efficiencies were obtained at the flow rate of 0.5 mL/min (column 1) and 0.8 mL/min (column 2) for lower phase mobile and 0.2 mL/min (column 1) and 0.4 mL/min (column 2) for upper phase

  7. 离子液体双水相萃取山楂黄酮和多糖的研究%Study on the Extraction of Hawthorn Flavonoids and Polysaccharide in Ionic Liquid Aqueous Two-Phase System

    Institute of Scientific and Technical Information of China (English)

    巩育军; 牛盛童; 黄学锋; 王键

    2014-01-01

    Partition behaviors of hawthorn flavonoids and polysaccharide in ionic liquid aqueous two-phase system(ILATPS)were studied by spectrophotometry.Effects of concentration of ionic liquid and ammonium sulfate,dosage of hawthorn and ultrasonic time on the extraction rate of hawthorn flavonoids and polysaccharide were investigated.The optimal extraction conditions were as follows:concentration of ionic liquid [Bmim]BF4 was 0.26~0.30 g·mL-1,concentration of ammonium sulfate was 0.08~0.10 g·mL-1,dosage of hawthorn was 0.14~0.17 g,ultrasonic time was 15~20 min.Under these conditions,extraction rate of hawthorn fla-vonoids was 86.4%~96.0% in the up phase,and extraction rate of polysaccharide was 75.2%~76.0% in the down phase.%采用分光光度法研究了山楂黄酮和多糖在[Bmim]BF4/(NH4)2 SO4双水相体系的分配行为,探讨了离子液体浓度、(NH4)2 SO4浓度、山楂用量和超声时间等因素对山楂黄酮和多糖萃取率的影响。确定最佳萃取条件为:离子液体[Bmim]BF4浓度0.26~0.30 g·mL-1,(NH4)2 SO4浓度0.08~0.10 g·mL-1,山楂用量0.14~0.17 g,超声时间15~20 min,在此优化条件下,双水相上相中黄酮的萃取率为86.4%~96.0%、下相中多糖的萃取率为75.2%~76.0%。

  8. Extraction of spirulina platensis polysaccharide by ethanol/(NH4)2SO4 aqueous two-phase system%乙醇/硫酸铵双水相体系萃取螺旋藻多糖的研究

    Institute of Scientific and Technical Information of China (English)

    刘杨; 冯元琦; 陈美欣; 吴景淳; 黄海根

    2012-01-01

    Extraction of spirulina platensis polysaccharide by ethanol/( NH4 ) 2SO4 aqueous two-phase system(ATPS)was investigated. To remove and recycle the proteins, salting-out precipitation protein was carried out after spirulina platensis cells disruption. Spirulina platensis polysaccharide was extracted by traditional hot water diffusion and the polysaccharide dissolution rate reached 38.44 ± 1. 12mg/g spirulina platensis powder. Spirulina platensis polysaccharide was purified deeply by ethanol/ (NH4)2SO4 ATPS. The yield and enrichment factor of the polysaccharide were 84. 5±1. 45% and 6. 2 respectively,on the condition that the tie line length, volume ratio and pH of ATPS were 42. 9,1. 05 and 7. 0, respectively. The results indicated that spirulina platensis polysaccharide would be purified by a simple, efficient and low cost extraction technology using inexpensive ethanol/ (NH4)2SO4 ATPS.%考察了低分子有机溶剂与无机盐-乙醇/硫酸铵双水相体系萃取螺旋藻多糖的可行性及影响因素.研究结果表明:为除去并有效回收螺旋藻细胞中的蛋白质成分,在藻细胞破碎后进行盐析沉淀蛋白质,再采用传统的热水浸提法,可得到螺旋藻多糖的溶出率为38.44±1.12mg/g干燥粉;通过乙醇/硫酸铵双水相体系的萃取分配,在w(乙醇)=19%,w(硫酸铵)=27.5%(即双水相体系系线长度TLL =42.9),体系相比VR=1.05,pH=7.0时,螺旋藻多糖的收率可达84.5±1.45%,富集因子可达6.2.该研究结果表明廉价的乙醇/硫酸铵双水相萃取螺旋藻多糖将有望开发成为一条简洁、高效、低成本的螺旋藻多糖分离提取工艺.

  9. Two-Phase Quality/Flow Meter

    Science.gov (United States)

    Moerk, J. Steven (Inventor); Youngquist, Robert C. (Inventor); Werlink, Rudy J. (Inventor)

    1999-01-01

    A quality and/or flow meter employs a capacitance probe assembly for measuring the dielectric constant of flow stream, particularly a two-phase flow stream including liquid and gas components.ne dielectric constant of the flow stream varies depending upon the volume ratios of its liquid and gas components, and capacitance measurements can therefore be employed to calculate the quality of the flow, which is defined as the volume ratio of liquid in the flow to the total volume ratio of gas and liquid in the flow. By using two spaced capacitance sensors, and cross-correlating the time varying capacitance values of each, the velocity of the flow stream can also be determined. A microcontroller-based processing circuit is employed to measure the capacitance of the probe sensors.The circuit employs high speed timer and counter circuits to provide a high resolution measurement of the time interval required to charge each capacitor in the probe assembly. In this manner, a high resolution, noise resistant, digital representation of each of capacitance value is obtained without the need for a high resolution A/D converter, or a high frequency oscillator circuit. One embodiment of the probe assembly employs a capacitor with two ground plates which provide symmetry to insure that accurate measurements are made thereby.

  10. Influence of Two-phase Ejector on Performance of Compression/Ejection rRefrigeration System%两相喷射器对压缩-喷射制冷系统性能的影响研究

    Institute of Scientific and Technical Information of China (English)

    魏新利; 汤本凯; 马新灵; 孟祥睿

    2014-01-01

    采用等面积混合模型,以 R134a 制冷剂为工质,对两相喷射器建立热力学模型,并用 Matlab7.1软件进行编程计算,相关的工质热物性参数,通过调用Refprop7软件获取。分析比较了各混合压力下喷射器内压力变化趋势,喷射器混合压力、系统蒸发温度、冷凝温度以及喷射器等熵效率的变化对两相喷射器性能、制冷系统性能的影响。结果表明:对于所研究的工质和工况,热力学分析方法采用等面积混合模型比较合理;混合压力在理论取值范围内存在一个最优点;随蒸发温度的升高或冷凝温度的降低,喷射器最优混合压力的取值点越靠近引射压力,喷射系数增加,系统COP升高,但是相对于传统压缩制冷循环的性能提高率减小;喷射器及系统性能对喷射器进口段等熵效率的变化较敏感。因而,选取恰当的混合压力值,设计制造等熵效率较高的工作喷嘴对于压缩-喷射制冷系统的性能优化至关重要。%This paper establishes a thermodynamic model of two-phase ejector, having the mixing area in the mixing chamber constant and R134a refrigerant as working medium. Matlab7.1 is used in programming and calculating. Thermo-physical properties of the refrigerant involved are obtained through application of Refprop7. Pressure changes in the ejector at various mixing pressures are analyzed. How changes in mixing pressure, evaporation temperature, condensation temperature and isentropic efficiency can influence the performance of the ejector and the refrigeration system is studied. The results show that under the operational conditions in this study, the constant area model for mixing chamber is appropriate for thermodynamic analysis. Within the theoretical value range, there is an optimum value for mixing pressure. As the evaporation temperature increases or the condensation temperature decreases, the optimum mixing pressure comes closer to

  11. Development of the digestive system in larvae of the Neotropical fish Prochilodus argenteus (Characiformes, Prochilodontidae

    Directory of Open Access Journals (Sweden)

    Alcione Eneida Santos

    2016-01-01

    Full Text Available The development of the digestive system in larvae of the Neotropical fish P. argenteus was analyzed histologically. On the 3rd day after hatching, the digestive system comprised oropharyngeal cavity, esophagus and simple undifferentiated tube. Since secreting cells, positive to Alcian Blue (AB, were found in the esophagus, digestive activity in the initial phase had occurred. On the 18 and 28th days after hatching, the esophagus was positive for AB and Periodic Acid Schiff (PAS stain. The stomach was fully differentiated, with the cardiac, fundic and pyloric regions. Different regions of the epithelium were characterized by basic and acidic secreting cells (AB and PAS positive. On the 18 and 28th days after hatching, the intestine was long, coiled and divided into proximal, middle and distal segments with pyloric ceca. Secreting cells in different regions of the gut were either positive or negative for AB and PAS. Results showed that larvae of P. argenteus exhibited digestive activity on the third day after hatching, with fully differentiated stomach and intestines on the 18 and 28th days and their different regions featuring secreting cells.

  12. 48 CFR 570.105-2 - Two-phase design-build selection procedures.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Two-phase design-build... ADMINISTRATION SPECIAL CONTRACTING PROGRAMS ACQUIRING LEASEHOLD INTERESTS IN REAL PROPERTY General 570.105-2 Two..., you must use the two-phase design-build selection procedures in section 303M of the Federal Property...

  13. Anaerobic Digestion and its Applications

    Science.gov (United States)

    Anaerobic digestion is a natural biological process. The initials "AD" may refer to the process of anaerobic digestion, or the built systems of anaerobic digesters. While there are many kinds of digesters, the biology is basically the same for all. Anaerobic digesters are built...

  14. Anaerobic Digestion and its Applications

    Science.gov (United States)

    Anaerobic digestion is a natural biological process. The initials "AD" may refer to the process of anaerobic digestion, or the built systems of anaerobic digesters. While there are many kinds of digesters, the biology is basically the same for all. Anaerobic digesters are built...

  15. Efficiency of a novel "Food to waste to food" system including anaerobic digestion of food waste and cultivation of vegetables on digestate in a bubble-insulated greenhouse.

    Science.gov (United States)

    Stoknes, K; Scholwin, F; Krzesiński, W; Wojciechowska, E; Jasińska, A

    2016-10-01

    At urban locations certain challenges are concentrated: organic waste production, the need for waste treatment, energy demand, food demand, the need for circular economy and limited area for food production. Based on these factors the project presented here developed a novel technological approach for processing organic waste into new food. In this system, organic waste is converted into biogas and digester residue. The digester residue is being used successfully as a stand-alone fertilizer as well as main substrate component for vegetables and mushrooms for the first time - a "digeponics" system - in a closed new low energy greenhouse system with dynamic soap bubble insulation. Biogas production provides energy for the process and CO2 for the greenhouse. With very limited land use highly efficient resource recycling was established at pilot scale. In the research project it was proven that a low energy dynamic bubble insulated greenhouse can be operated continuously with 80% energy demand reduction compared to conventional greenhouses. Commercial crop yields were achieved based on fertilization with digestate; in individual cases they were even higher than the control yields of vegetables such as tomatoes, cucumber and lettuce among others. For the first time an efficient direct use of digestate as substrate and fertilizer has been developed and demonstrated.

  16. Vapor Compressor Driven Hybrid Two-Phase Loop Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will demonstrate a vapor compressor driven hybrid two-phase loop technology. The hybrid two-phase loop...

  17. Environmental assessment of energy and waste systems based on anaerobic digestion

    Energy Technology Data Exchange (ETDEWEB)

    Rehl, Torsten

    2013-08-01

    The results of the studies show that biogas production brings about many or environmental improvements compared to energy generation based on fossil sources when designed and managed properly. Environmental advantages are found for GWP (Global Warming Potential) and energy consumption, disadvantages however for EP (Eutrophication Potential), AP (Acidification Potential) and POCP (Photochemical Ozone Creation Potential). However the large amount of technologies and measures indicate that there is a large potential to reduce the environmental impacts. Another finding is that all life cycle phases and subsystems must be carefully considered, as no single dominating item or aspect in the life cycle can be identified. The most environmentally relevant phases are found to be storage, treatment and field application of manure and digestate. This result is to a large part due to the emission of ammonia, nitrous oxide and nitrate. It can therefore be concluded that from a lifecycle perspective, control and mitigation of nitrogen related emissions will be of utmost importance in the future to improve the environmental performance of biogas systems. Considerable emission reduction potentials are exposed when proper technological modifications (e.g. storage covers, filter technologies, digestate treatment or field application technologies) or adopted management practices (early soil incorporation of digestate) are applied. The environmental analysis also shows that whenever possible the focus of anaerobic digestion should be on the use of organic residues from households, agriculture or food industry instead of using energy crops. In this case conventional waste management systems are replaced and manifold positive effects of anaerobic digestion such as waste stabilization, nutrient recycling and energy generation emerge.

  18. Microbial distribution and abundance in the digestive system of five shipworm species (Bivalvia: Teredinidae.

    Directory of Open Access Journals (Sweden)

    Meghan A Betcher

    Full Text Available Marine bivalves of the family Teredinidae (shipworms are voracious consumers of wood in marine environments. In several shipworm species, dense communities of intracellular bacterial endosymbionts have been observed within specialized cells (bacteriocytes of the gills (ctenidia. These bacteria are proposed to contribute to digestion of wood by the host. While the microbes of shipworm gills have been studied extensively in several species, the abundance and distribution of microbes in the digestive system have not been adequately addressed. Here we use Fluorescence In-Situ Hybridization (FISH and laser scanning confocal microscopy with 16S rRNA directed oligonucleotide probes targeting all domains, domains Bacteria and Archaea, and other taxonomic groups to examine the digestive microbiota of 17 specimens from 5 shipworm species (Bankia setacea, Lyrodus pedicellatus, Lyrodus massa, Lyrodus sp. and Teredo aff. triangularis. These data reveal that the caecum, a large sac-like appendage of the stomach that typically contains large quantities of wood particles and is considered the primary site of wood digestion, harbors only very sparse microbial populations. However, a significant number of bacterial cells were observed in fecal pellets within the intestines. These results suggest that due to low abundance, bacteria in the caecum may contribute little to lignocellulose degradation. In contrast, the comparatively high population density of bacteria in the intestine suggests a possible role for intestinal bacteria in the degradation of lignocellulose.

  19. Thermo-fluid dynamics of two-phase flow

    CERN Document Server

    Ishii, Mamoru; Ishii, Mamoru; Ishii, M

    2006-01-01

    Provides a very systematic treatment of two phase flow problems from a theoretical perspectiveProvides an easy to follow treatment of modeling and code devlopemnt of two phase flow related phenomenaCovers new results of two phase flow research such as coverage of fuel cells technology.

  20. Marine biomass system: anaerobic digestion and production of methane

    Energy Technology Data Exchange (ETDEWEB)

    Haven, K.F.; Henriquez, M.; Ritschard, R.L.

    1979-04-01

    Two approaches to kelp conversion to methane are described. First, a large (10.56 mi/sup 2/) oceanic farm using an artificial substrate and an upwelling system to deliver nutrient-rich deep ocean water to the kelp bed is described. This system can yield as much as 50 tons of kelp (dry ash free - DAF) per acre-year. Kelp are harvested by a specially designed 30,000 DWT ship and delivered to an onshore processing plant as a ground kelp slurry. The second system involves the use of a natrual coastal kelp bed. Growth rates in this bed are stimulated by a nutrient rich sewer outfall. A conceptual model is presented for calculation of the growth rate of kelp in this natural bed which can reach 15 tons (DAF) per acre-year. The harvest activity and processing plant are similar to those for oceanic farm system. In the next section of this report, the overall concept of kelp production and conversion to methane is discussed. In Section III the general design of the ocean farm system is presented and discussed while Section IV contains a similar description for the natural bed system. Section V presents the capital requirements and operational labor, resources and material requirements. Section VI describes the environmental residuals created by the operation of either system and, to the extent possible, quantifies the rate at which these residuals are generated. In addition to the technical data reported herein, cost data have been generated for the various processes and components utilized in each solar technology. The requirements for costing information basically arise from the need to compute parameters such as investment demands, employment patterns, material demands and residual levels associated with each technology for each of several national and regional scenarios.

  1. Experimental and numerical investigation on two-phase flow instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Ruspini, Leonardo Carlos

    2013-03-01

    Two-phase flow instabilities are experimentally and numerically studied within this thesis. In particular, the phenomena called Ledinegg instability, density wave oscillations and pressure drop oscillations are investigated. The most important investigations regarding the occurrence of two-phase flow instabilities are reviewed. An extensive description of the main contributions in the experimental and analytical research is presented. In addition, a critical discussion and recommendations for future investigations are presented. A numerical framework using a hp-adaptive method is developed in order to solve the conservation equations modelling general thermo-hydraulic systems. A natural convection problem is analysed numerically in order to test the numerical solver. Moreover, the description of an adaptive strategy to solve thermo-hydraulic problems is presented. In the second part of this dissertation, a homogeneous model is used to study Ledinegg, density wave and pressure drop oscillations phenomena numerically. The dynamic characteristics of the Ledinegg (flow excursion) phenomenon are analysed through the simulation of several transient examples. In addition, density wave instabilities in boiling and condensing systems are investigated. The effects of several parameters, such as the fluid inertia and compressibility volumes, on the stability limits of Ledinegg and density wave instabilities are studied, showing a strong influence of these parameters. Moreover, the phenomenon called pressure drop oscillations is numerically investigated. A discussion of the physical representation of several models is presented with reference to the obtained numerical results. Finally, the influence of different parameters on these phenomena is analysed. In the last part, an experimental investigation of these phenomena is presented. The designing methodology used for the construction of the experimental facility is described. Several simulations and a non

  2. Biogas production from poultry rendering plant anaerobic digesters: systems comparison

    Science.gov (United States)

    Animal wastes can serve as the feedstock for biogas production (mainly methane) that could be used as alternative energy source. The green energy derived from animal wastes is considered to be carbon neutral and offsetting those generated from fossil fuels. In this study, an evaluation of system p...

  3. Evolution of holometabola insect digestive systems: physiological and biochemical aspects

    Directory of Open Access Journals (Sweden)

    Walter R. Terra

    1987-01-01

    Full Text Available This review takes into account primarily the work done in our laboratory with insects from the major Holometabola orders. Only the most significant data for each insect will be presented and a proposal on the evolution of Holometabola insect digstive systems will be advanced.

  4. The digestive tract as the origin of systemic inflammation

    NARCIS (Netherlands)

    de Jong, Petrus R.; Gonzalez-Navajas, Jose M.; Jansen, Nicolaas J. G.

    2016-01-01

    Failure of gut homeostasis is an important factor in the pathogenesis and progression of systemic inflammation, which can culminate in multiple organ failure and fatality. Pathogenic events in critically ill patients include mesenteric hypoperfusion, dysregulation of gut motility, and failure of the

  5. Effect of raw material source, processing systems, and processing temperatures on amino acid digestibility of meat and bone meals.

    Science.gov (United States)

    Wang, X; Parsons, C M

    1998-06-01

    Experiments were conducted to evaluate amino acid digestibility of 32 commercial meat and bone meals (MBM) varying in raw material source and produced in seven different commercial cooking systems and at two processing temperatures (low vs high) that differed by 15 to 20 C. Raw material sources included all beef, all pork, mixed species, and high bone MBM. True digestibilities of amino acids were determined using the precision-fed cecectomized rooster assay. Protein efficiency ratio (PER) of six MBM varying greatly in amino acid digestibility was determined with chicks fed 10% CP diets containing a MBM as the sole source of dietary protein. The 32 MBM samples averaged 53.2% CP, 2.73% Lys, 0.6% Cys, and 0.75% Met on a DM basis. True digestibility averaged 82% for Lys, 87% for Met, and 47% for Cys. True digestibilities of amino acids varied substantially among processing systems and temperatures, particularly for Lys and Cys. For example, Lys and Cys digestibility ranged from 68 to 92% and from 20 to 71%, respectively, among different MBM. The higher processing temperature generally yielded lower amino acid digestibility than did the low processing temperature. A smaller, less consistent, effect was observed for raw material source. The PER values of the six selected MBM varied from 0.97 to 2.68 and were highly correlated with amino acid digestibility. These results indicated that very high amino acid digestibility MBM can be produced in commercial rendering systems. However, differences in processing systems and temperatures can cause substantial variability in amino acid digestibilities.

  6. Reynolds transport theorem for a two-phase flow

    Science.gov (United States)

    Collado, Francisco J.

    2007-01-01

    Transport equations for one-dimensional (1d), steady, two-phase flow have been proposed based on the fact that if the phases have different velocities, they cannot cover the same distance (the control volume length) in the same time. Thus, working in the same control volume for the two phases, the time scales of the phases have to be different. From this approach, transport balances for 1D, steady, two-phase flow have been already derived, supplying acceptable correlations for two-phase flow. Here, based on the strict application of the Reynolds transport theorem, general transport balances for two-phase flow are suggested.

  7. [Digestive system disease as manifestation of the pleiotropic action of genes in mitochondrial dysfunction].

    Science.gov (United States)

    Hrechanina, O Ia; Hrechanina, Iu B; Husar, V A; Molodan, L V

    2014-11-01

    Defined involvement lesions of the digestive system of clinical manifestations of mitochondrial dysfunction associated with both point mutations and polymorphism of mitochondrial DNA. The nature of the clinical signs of mtDNA polymorphisms carriers--multi organical, a progressive, clinical polymorphism, genetic heterogeneity with predominant involvement of energotropic bodies (cerebrum, cordis, hepatic). Set individual nosological forms of mitochondrial dysfunctions--syndromes Leia, Leber, Cairns, Sarah, MERRF, MELAS, NARP, MNGIE confirmed by clinical and genetic, morphological, biochemical, enzymatic, molecular genetics methods. It was found that 84-88% of these syndromes involving the violation of the digestive system with varying degrees of injury. This damage will be the first in the complex chain signs recovery which determines the direction of early rehabilitation.

  8. Experimental and modeling study of a two-stage pilot scale high solid anaerobic digester system.

    Science.gov (United States)

    Yu, Liang; Zhao, Quanbao; Ma, Jingwei; Frear, Craig; Chen, Shulin

    2012-11-01

    This study established a comprehensive model to configure a new two-stage high solid anaerobic digester (HSAD) system designed for highly degradable organic fraction of municipal solid wastes (OFMSW). The HSAD reactor as the first stage was naturally separated into two zones due to biogas floatation and low specific gravity of solid waste. The solid waste was retained in the upper zone while only the liquid leachate resided in the lower zone of the HSAD reactor. Continuous stirred-tank reactor (CSTR) and advective-diffusive reactor (ADR) models were constructed in series to describe the whole system. Anaerobic digestion model No. 1 (ADM1) was used as reaction kinetics and incorporated into each reactor module. Compared with the experimental data, the simulation results indicated that the model was able to well predict the pH, volatile fatty acid (VFA) and biogas production.

  9. Anaerobic Digestion: Process

    DEFF Research Database (Denmark)

    Angelidaki, Irini; Batstone, Damien J.

    2011-01-01

    Organic waste may degrade anaerobically in nature as well as in engineered systems. The latter is called anaerobic digestion or biogasification. Anaerobic digestion produces two main outputs: An energy-rich gas called biogas and an effluent. The effluent, which may be a solid as well as liquid...... with very little dry matter may also be called a digest. The digest should not be termed compost unless it specifically has been composted in an aerated step. This chapter describes the basic processes of anaerobic digestion. Chapter 9.5 describes the anaerobic treatment technologies, and Chapter 9.......6 addresses the mass balances and environmental aspects of anaerobic digestion....

  10. Experimental study of two-phase natural circulation circuit

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Wanderley Freitas; Su, Jian, E-mail: wlemos@lasme.coppe.ufrj.br, E-mail: sujian@nuclear.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Faccini, Jose Luiz Horacio, E-mail: faccini@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), RIo de Janeiro, RJ (Brazil). Lab. de Termo-Hidraulica Experimental

    2012-07-01

    This paper reports an experimental study on the behavior of fluid flow in natural circulation under single-and two-phase flow conditions. The natural circulation circuit was designed based on concepts of similarity and scale in proportion to the actual operating conditions of a nuclear reactor. This test equipment has similar performance to the passive system for removal of residual heat presents in Advanced Pressurized Water Reactors (A PWR). The experiment was carried out by supplying water to primary and secondary circuits, as well as electrical power resistors installed inside the heater. Power controller has available to adjust the values for supply of electrical power resistors, in order to simulate conditions of decay of power from the nuclear reactor in steady state. Data acquisition system allows the measurement and control of the temperature at different points by means of thermocouples installed at several points along the circuit. The behavior of the phenomenon of natural circulation was monitored by a software with graphical interface, showing the evolution of temperature measurement points and the results stored in digital format spreadsheets. Besides, the natural circulation flow rate was measured by a flowmeter installed on the hot leg. A flow visualization technique was used the for identifying vertical flow regimes of two-phase natural circulation. Finally, the Reynolds Number was calculated for the establishment of a friction factor correlation dependent on the scale geometrical length, height and diameter of the pipe. (author)

  11. Biometry, histology, and morphometry of the digestive system of wild crab-eating fox (Cerdocyon thous)

    OpenAIRE

    Andreíza Ramos Heleno; Luiz Michel Santos; Maria Angélica Miglino; Jayme Augusto Peres; Ricardo Romão Guerra

    2011-01-01

    The crab-eating fox (Cerdocyon thous) is found throughout Brazil. It has a nocturnal habit and can be seen on roadsides, where it looks for remains of run over animals and, therefore, it is also a victim of roadkill. This study aimed to characterize the macro and microscopic anatomy of the digestive system of the crab-eating fox. It helps to carry out medical and surgical procedures, besides important information on the feeding strategies, especially for wild individuals needing veterinary ca...

  12. Prognostic Value of MACC1 in Digestive System Neoplasms: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Wu, Zhenzhen; Zhou, Rui; Su, Yuqi; Sun, Li; Liao, Yulin; Liao, Wangjun

    2015-01-01

    Metastasis associated in colon cancer 1 (MACC1), a newly identified oncogene, has been associated with poor survival of cancer patients by multiple studies. However, the prognostic value of MACC1 in digestive system neoplasms needs systematic evidence to verify. Therefore, we aimed to provide further evidence on this topic by systematic review and meta-analysis. Literature search was conducted in multiple databases and eligible studies analyzing survival data and MACC1 expression were included for meta-analysis. Hazard ratio (HR) for clinical outcome was chosen as an effect measure of interest. According to our inclusion criteria, 18 studies with a total of 2,948 patients were identified. Pooled HRs indicated that high MACC1 expression significantly correlates with poorer OS in patients with digestive system neoplasms (HR = 1.94; 95% CI: 1.49-2.53) as well as poorer relapse-free survival (HR = 1.94, 95% CI: 1.33-2.82). The results of subgroup studies categorized by methodology, anatomic structure, and cancer subtype for pooled OS were all consistent with the overall pooled HR for OS as well. No publication bias was detected according to test of funnel plot asymmetry and Egger's test. In conclusion, high MACC1 expression may serve as a prognostic biomarker to guide individualized management in clinical practice for digestive system neoplasms.

  13. A proposed food breakdown classification system to predict food behavior during gastric digestion.

    Science.gov (United States)

    Bornhorst, Gail M; Ferrua, Maria J; Singh, R Paul

    2015-05-01

    The pharmaceutical industry has implemented the Biopharmaceutics Classification System (BCS), which is used to classify drug products based on their solubility and intestinal permeability. The BCS can help predict drug behavior in vivo, the rate-limiting mechanism of absorption, and the likelihood of an in vitro-in vivo correlation. Based on this analysis, we have proposed a Food Breakdown Classification System (FBCS) framework that can be used to classify solid foods according to their initial hardness and their rate of softening during physiological gastric conditions. The proposed FBCS will allow for prediction of food behavior during gastric digestion. The applicability of the FBCS framework in differentiating between dissimilar solid foods was demonstrated using four example foods: raw carrot, boiled potato, white rice, and brown rice. The initial hardness and rate of softening parameter (softening half time) were determined for these foods as well as their hypothesized FBCS class. In addition, we have provided future suggestions as to the methodological and analytical challenges that need to be overcome prior to widespread use and adoption of this classification system. The FBCS gives a framework that may be used to classify food products based on their material properties and their behavior during in vitro gastric digestion, and may also be used to predict in vivo food behavior. As consumer demand increases for functional and "pharma" food products, the food industry will need widespread testing of food products for their structural and functional performance during digestion.

  14. Prediction of digestible energy of feed ingredients for growing pigs using a computer-controlled simulated digestion system.

    Science.gov (United States)

    Chen, L; Gao, L X; Huang, Q H; Lu, Q P; Sa, R N; Zhang, H F

    2014-09-01

    The objectives of this experiment were to evaluate in vitro DE (IVDE) of selected feed ingredients using a computer-controlled simulated digestion system (CCSDS) and predict DE of ingredients for growing pigs. Samples of 6 ingredients with a wide range in energy and nutrient profile were collected. The CP and GE contents ranged from 9.9 to 50.9% and 4,493 to 4,841 kcal/kg (DM basis), respectively. Two control diets were formulated to achieve different CP contents (12.5 and 20.0%). Three experimental diets were formulated by replacing 20% of the high-CP control diet with corn, wheat, or wheat bran, whereas 3 additional diets were formulated by replacing 20% of the low-CP control diet with soybean meal, rapeseed meal, or cottonseed meal. The DE was determined using barrows (n = 24; initial BW = 35.9 ± 1.9 kg) in 2 periods with 6 observations per diet treatment and ranged from 2,769 to 4,368 kcal/kg. The equation for the DE content (kcal/kg of DM) using chemical components as independent variables was DE = 4,186 + 0.06 × CP + 79.33 × ether extract - 14.57 × NDF - 47.99 × ADF, with R(2) = 0.995, residual SD (RSD) = 89.5 kcal/kg, CV = 2.4%, and P = 0.10 (chemical component values; %). The IVDE ranged from 2,289 to 3,724 kcal/kg and was highly related to the determined DE content of the ingredients (R(2) = 0.91, RSD = 193 kcal/kg, and CV = 5.2%). The relationship between IVDE:GE and DE:GE was very high (R(2) = 0.93, RSD = 3.8%, and CV = 4.7%). The average values of CV for IVDE (0.75%) and IVDE:GE (0.73%) were less than that for determined DE (2.58%) and DE:GE (2.54%), respectively. In conclusion, the IVDE content determined, using a CCSDS with relatively high accuracy and acceptable repeatability, might be used to predict DE of feed ingredients for growing pigs.

  15. Evaluation of systems for purification of fuel gas from anaerobic digestion. Engineering report

    Energy Technology Data Exchange (ETDEWEB)

    Ashare, E.; Augenstein, D. C.; Yeung, J. C.; Hossan, R. J.; Duret, G. L.

    1978-07-30

    Fuel gas obtained from the anaerobic digestion of waste materials usually needs to be treated before being transmitted in existing pipeline systems. The purification scheme involves the removal of carbon dioxide, hydrogen sulfide, and moisture from the digester gas to meet pipeline specifications. Gas treatment systems for the handling of 0.1, 1.0, and 3.0 MM Scfd of raw feed gas and product delivery pressures of 125 and 1000 psia were considered in this study. From the results of an economic and technical analysis of these systems, physical absorption systems, particularly water scrubbing, were found to be the most economical system for the treatment of digester gas with the flow streams considered. The Fluor Solvent process was economically comparable with the water scrubbing process for high pressure applications, but the value presented had a large uncertainty. The commercial chemical absorption systems were less economical due to high heat requirements for solvent regeneration. Among the chemical absorption processes, the hot potassium systems were found to be more economical than the amine system. The molecular sieve adsorption process was economically similar to the chemical absorption process. The GE membrane separation process was economically comparable for both high and low pressure apllications, but this system has not been evaluated in real-life conditions. Since no kinetic and equilibrium data were available for the phosphate buffer system, estimates had to be assumed. Using what were believed to be very conservative estimates, this chemical absorption process was found to be economically competitive with the water scrubbing process for treating gas with a delivery pressure of 125 psia.The cost analyses in this study were based on the assumption of no recovery of the CO/sub 2/ by-product. It was found that credits for the recovery of the CO/sub 2/ could be significant.

  16. A real two-phase submarine debris flow and tsunami

    Energy Technology Data Exchange (ETDEWEB)

    Pudasaini, Shiva P.; Miller, Stephen A. [Department of Geodynamics and Geophysics, Steinmann Institute, University of Bonn Nussallee 8, D-53115, Bonn (Germany)

    2012-09-26

    The general two-phase debris flow model proposed by Pudasaini is employed to study subaerial and submarine debris flows, and the tsunami generated by the debris impact at lakes and oceans. The model, which includes three fundamentally new and dominant physical aspects such as enhanced viscous stress, virtual mass, and generalized drag (in addition to buoyancy), constitutes the most generalized two-phase flow model to date. The advantage of this two-phase debris flow model over classical single-phase, or quasi-two-phase models, is that the initial mass can be divided into several parts by appropriately considering the solid volume fraction. These parts include a dry (landslide or rock slide), a fluid (water or muddy water; e.g., dams, rivers), and a general debris mixture material as needed in real flow simulations. This innovative formulation provides an opportunity, within a single framework, to simultaneously simulate the sliding debris (or landslide), the water lake or ocean, the debris impact at the lake or ocean, the tsunami generation and propagation, the mixing and separation between the solid and fluid phases, and the sediment transport and deposition process in the bathymetric surface. Applications of this model include (a) sediment transport on hill slopes, river streams, hydraulic channels (e.g., hydropower dams and plants); lakes, fjords, coastal lines, and aquatic ecology; and (b) submarine debris impact and the rupture of fiber optic, submarine cables and pipelines along the ocean floor, and damage to offshore drilling platforms. Numerical simulations reveal that the dynamics of debris impact induced tsunamis in mountain lakes or oceans are fundamentally different than the tsunami generated by pure rock avalanches and landslides. The analysis includes the generation, amplification and propagation of super tsunami waves and run-ups along coastlines, debris slide and deposition at the bottom floor, and debris shock waves. It is observed that the

  17. Spatial decision support system to evaluate crop residue energy potential by anaerobic digestion.

    Science.gov (United States)

    Escalante, Humberto; Castro, Liliana; Gauthier-Maradei, Paola; Rodríguez De La Vega, Reynel

    2016-11-01

    Implementing anaerobic digestion (AD) in energy production from crop residues requires development of decision tools to assess its feasibility and sustainability. A spatial decision support system (SDSS) was constructed to assist decision makers to select appropriate feedstock according to biomethanation potential, identify the most suitable location for biogas facilities, determine optimum plant capacity and supply chain, and evaluate associated risks and costs. SDSS involves a spatially explicit analysis, fuzzy multi-criteria analysis, and statistical and optimization models. The tool was validated on seven crop residues located in Santander, Colombia. For example, fique bagasse generates about 0.21millionm(3)CH4year(-1) (0.329m(3)CH4kg(-1) volatile solids) with a minimum profitable plant of about 2000tonyear(-1) and an internal rate of return of 10.5%. SDSS can be applied to evaluate other biomass resources, availability periods, and co-digestion potential.

  18. Microscopic anatomy of the digestive system in normal and regenerating specimens of the brittlestar Amphipholis kochii.

    Science.gov (United States)

    Frolova, Lidia T; Dolmatov, Igor Yu

    2010-06-01

    The morphology and regeneration of the digestive system of the ophiuroid Amphipholis kochii were investigated. The epithelia of the esophagus and stomach of A. kochii were composed of typical enterocytes and mucous cells. The digestive epithelium of the stomach contained two types of granular secretory cells. After autotomy of the disk, the animals retained the esophagus and a small part of the stomach. The dedifferentiation of enterocytes and mucous cells began on the first day after autotomy. On day 3 the cells formed an anlage of stomach around the mouth opening. Later, the stomach anlage grew as a result of cell proliferation. The opening on the aboral side of the body was closed by day 7. By this time differentiating cells were already observed in the stomach lining. The stomach mesothelium was formed by peritoneocytes and myoepithelial cells, which migrated from other coelomic epithelia of the body. Our study showed that the formation of the digestive system in A. kochii during regeneration depended on cells from the esophagus and the stomach remnant. Both enterocytes and mucous cells were able to dedifferentiate, migrate, and proliferate to give rise to the luminal epithelium. The basic mechanism of stomach formation was epithelial morphogenesis.

  19. Engineering Digestion: Multiscale Processes of Food Digestion.

    Science.gov (United States)

    Bornhorst, Gail M; Gouseti, Ourania; Wickham, Martin S J; Bakalis, Serafim

    2016-03-01

    Food digestion is a complex, multiscale process that has recently become of interest to the food industry due to the developing links between food and health or disease. Food digestion can be studied by using either in vitro or in vivo models, each having certain advantages or disadvantages. The recent interest in food digestion has resulted in a large number of studies in this area, yet few have provided an in-depth, quantitative description of digestion processes. To provide a framework to develop these quantitative comparisons, a summary is given here between digestion processes and parallel unit operations in the food and chemical industry. Characterization parameters and phenomena are suggested for each step of digestion. In addition to the quantitative characterization of digestion processes, the multiscale aspect of digestion must also be considered. In both food systems and the gastrointestinal tract, multiple length scales are involved in food breakdown, mixing, absorption. These different length scales influence digestion processes independently as well as through interrelated mechanisms. To facilitate optimized development of functional food products, a multiscale, engineering approach may be taken to describe food digestion processes. A framework for this approach is described in this review, as well as examples that demonstrate the importance of process characterization as well as the multiple, interrelated length scales in the digestion process. © 2016 Institute of Food Technologists®

  20. Flooding in counter-current two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Ragland, W.A.; Ganic, E.N.

    1982-01-01

    Flooding is a phenomenon which is best described as the transition from counter-current to co-current flow. Early notice was taken of this phenomenon in the chemical engineering industry. Flooding also plays an important role in the field of two-phase heat transfer since it is a limit for many systems involving counter-current flow. Practical applications of flooding limited processes include wickless thermosyphons and the emergency core cooling system (ECCS) of pressurized water nuclear reactors. The phenomenon of flooding also is involved in the behavior of nuclear reactor core materials during severe accident conditions where flooding is one of the mechanisms governing the motion of the molten fuel pin cladding.

  1. Digestibility of sorghum proteins.

    OpenAIRE

    Axtell, J D; Kirleis, A. W.; Hassen, M M; D'Croz Mason, N; Mertz, E T; Munck, L.

    1981-01-01

    Published information indicates that rice, maize, and wheat proteins are much more digestible in children than sorghum proteins are (66-81% compared with 46%). However, this digestibility difference cannot be demonstrated with the weanling rat, which gave digestibility values of 80% for cooked and 85% for uncooked sorghum gruels. Therefore, a search was made for a laboratory system sensitive to the digestibility differences between sorghum and other cereals. We found that porcine pepsin in vi...

  2. Digestive System

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    2009080 A study on the light microscopic measurement of intercellular space of squamous epithelium in lower esophagus to diagnose gastroesophageal reflux disease. CUI Ronli(崔荣丽), et al. Dept Gastroenterol, Peking Univ 3rd Hosp, Beijing 100191. Chin J Intern Med 2009; 48(3):208-212. Objective To evaluate the significance of dilated intercellular space (DIS) of squamous epithelium in lower-esophagus which was measured at light microscopy (LM) in the diagnosis of gastroesophageal reflux disease (GERD).

  3. Digestive System

    Science.gov (United States)

    ... abdominal pain, fever, loss of appetite, and vomiting. Gastritis and peptic ulcers arise when a bacterium, Helicobacter ... irritate and inflame the lining of the stomach (gastritis) or cause peptic ulcers, which are sores or ...

  4. Digestive System

    Science.gov (United States)

    ... absorbable atoms and molecules. During the process of absorption, nutrients that come from the food (including carbohydrates, proteins, fats, vitamins, and minerals) pass through channels in the intestinal wall and into the bloodstream. The blood works ...

  5. High-rate two-phase process for the anaerobic degradation of cellulose, employing rumen microorganisms for an efficient acidogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Gijzen, H.J.; Zwart, K.B.; Verhagen, F.J.M.; Vogels, G.D.

    1988-04-05

    A novel two-stage anaerobic process for the microbial conversion of cellulose into biogas has been developed. In the first phase, a mixed population of rumen bacteria and ciliates was used in the hydrolysis and fermentation of cellulose. The volatile fatty acids (VFA) produced in this acidogenic reactor were subsequently converted into biogas in a UASB-type methanogenic reactor. A stepwise increase of the loading rate from 11.9 to 25.8 g volatile solids/L reactor volume/day (g VS/L/day) did not affect the degradation efficiency in the acidogenic reactor, whereas the methanogenic reactor appeared to be overloaded at the highest loading rate. Cellulose digestion was almost complete at all loading rates applied. The two-stage anaerobic process was also tested with a closed fluid circuit. In this instance total methane production was 0.438 L CH/sub 4//g VS added, which is equivalent to 98% of the theoretical value. The application of rumen microorganisms in combination with a high-rate methane reactor is proposed as a means of efficient anaerobic degradation of cellulosic residues to methane. Because this newly developed two-phase system is based on processes and microorganisms from the ruminant, it will be referred to as Rumen Derived Anaerobic Digestion (RUDAD)-process.

  6. Phenotypic flexibility in digestive system structure and function in migratory birds and its ecological significance.

    Science.gov (United States)

    McWilliams, S R; Karasov, W H

    2001-03-01

    Birds during migration must satisfy the high energy and nutrient demands associated with repeated, intensive flight while often experiencing unpredictable variation in food supply and food quality. Solutions to such different challenges may often be physiologically incompatible. For example, increased food intake and gut size are primarily responsible for satisfying the high energy and nutrient demands associated with migration in birds. However, short-term fasting or food restriction during flight may cause partial atrophy of the gut that may limit utilization of ingested food energy and nutrients. We review the evidence available on the effects of long- and short-term changes in food quality and quantity on digestive performance in migratory birds, and the importance of digestive constraints in limiting the tempo of migration in birds. Another important physiological consequence of feeding in birds is the effect of diet on body composition dynamics during migration. Recent evidence suggests that birds utilize and replenish both protein and fat reserves during migration, and diet quality influences the rate of replenishment of both these reserves. We conclude that diet and phenotypic flexibility in both body composition and the digestive system of migratory birds are important in allowing birds to successfully overcome the often-conflicting physiological challenges of migration.

  7. The Effect of Effluent Recirculation in a Semi-Continuous Two-Stage Anaerobic Digestion System

    Directory of Open Access Journals (Sweden)

    Karthik Rajendran

    2013-06-01

    Full Text Available The effect of recirculation in increasing organic loading rate (OLR and decreasing hydraulic retention time (HRT in a semi-continuous two-stage anaerobic digestion system using stirred tank reactor (CSTR and an upflow anaerobic sludge bed (UASB was evaluated. Two-parallel processes were in operation for 100 days, one with recirculation (closed system and the other without recirculation (open system. For this purpose, two structurally different carbohydrate-based substrates were used; starch and cotton. The digestion of starch and cotton in the closed system resulted in production of 91% and 80% of the theoretical methane yield during the first 60 days. In contrast, in the open system the methane yield was decreased to 82% and 56% of the theoretical value, for starch and cotton, respectively. The OLR could successfully be increased to 4 gVS/L/day for cotton and 10 gVS/L/day for starch. It is concluded that the recirculation supports the microorganisms for effective hydrolysis of polyhydrocarbons in CSTR and to preserve the nutrients in the system at higher OLRs, thereby improving the overall performance and stability of the process.

  8. Stability of stratified two-phase flows in horizontal channels

    CERN Document Server

    Barmak, Ilya; Ullmann, Amos; Brauner, Neima; Vitoshkin, Helen

    2016-01-01

    Linear stability of stratified two-phase flows in horizontal channels to arbitrary wavenumber disturbances is studied. The problem is reduced to Orr-Sommerfeld equations for the stream function disturbances, defined in each sublayer and coupled via boundary conditions that account also for possible interface deformation and capillary forces. Applying the Chebyshev collocation method, the equations and interface boundary conditions are reduced to the generalized eigenvalue problems solved by standard means of numerical linear algebra for the entire spectrum of eigenvalues and the associated eigenvectors. Some additional conclusions concerning the instability nature are derived from the most unstable perturbation patterns. The results are summarized in the form of stability maps showing the operational conditions at which a stratified-smooth flow pattern is stable. It is found that for gas-liquid and liquid-liquid systems the stratified flow with smooth interface is stable only in confined zone of relatively lo...

  9. Mathematical model of two-phase flow in accelerator channel

    Directory of Open Access Journals (Sweden)

    О.Ф. Нікулін

    2010-01-01

    Full Text Available  The problem of  two-phase flow composed of energy-carrier phase (Newtonian liquid and solid fine-dispersed phase (particles in counter jet mill accelerator channel is considered. The mathematical model bases goes on the supposition that the phases interact with each other like independent substances by means of aerodynamics’ forces in conditions of adiabatic flow. The mathematical model in the form of system of differential equations of order 11 is represented. Derivations of equations by base physical principles for cross-section-averaged quantity are produced. The mathematical model can be used for estimation of any kinematic and thermodynamic flow characteristics for purposely parameters optimization problem solving and transfer functions determination, that take place in  counter jet mill accelerator channel design.

  10. Phase appearance or disappearance in two-phase flows

    CERN Document Server

    Cordier, Floraine; Kumbaro, Anela

    2011-01-01

    This paper is devoted to the treatment of specific numerical problems which appear when phase appearance or disappearance occurs in models of two-phase flows. Such models have crucial importance in many industrial areas such as nuclear power plant safety studies. In this paper, two outstanding problems are identified: first, the loss of hyperbolicity of the system when a phase appears or disappears and second, the lack of positivity of standard shock capturing schemes such as the Roe scheme. After an asymptotic study of the model, this paper proposes accurate and robust numerical methods adapted to the simulation of phase appearance or disappearance. Polynomial solvers are developed to avoid the use of eigenvectors which are needed in usual shock capturing schemes, and a method based on an adaptive numerical diffusion is designed to treat the positivity problems. An alternate method, based on the use of the hyperbolic tangent function instead of a polynomial, is also considered. Numerical results are presente...

  11. Emerging Two-Phase Cooling Technologies for Power Electronic Inverters

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, J.S.

    2005-08-17

    In order to meet the Department of Energy's (DOE's) FreedomCAR and Vehicle Technologies (FVCT) goals for volume, weight, efficiency, reliability, and cost, the cooling of the power electronic devices, traction motors, and generators is critical. Currently the power electronic devices, traction motors, and generators in a hybrid electric vehicle (HEV) are primarily cooled by water-ethylene glycol (WEG) mixture. The cooling fluid operates as a single-phase coolant as the liquid phase of the WEG does not change to its vapor phase during the cooling process. In these single-phase systems, two cooling loops of WEG produce a low temperature (around 70 C) cooling loop for the power electronics and motor/generator, and higher temperature loop (around 105 C) for the internal combustion engine. There is another coolant option currently available in automobiles. It is possible to use the transmission oil as a coolant. The oil temperature exists at approximately 85 C which can be utilized to cool the power electronic and electrical devices. Because heat flux is proportional to the temperature difference between the device's hot surface and the coolant, a device that can tolerate higher temperatures enables the device to be smaller while dissipating the same amount of heat. Presently, new silicon carbide (SiC) devices and high temperature direct current (dc)-link capacitors, such as Teflon capacitors, are available but at significantly higher costs. Higher junction temperature (175 C) silicon (Si) dies are gradually emerging in the market, which will eventually help to lower hardware costs for cooling. The development of high-temperature devices is not the only way to reduce device size. Two-phase cooling that utilizes the vaporization of the liquid to dissipate heat is expected to be a very effective cooling method. Among two-phase cooling methods, different technologies such as spray, jet impingement, pool boiling and submersion, etc. are being developed. The

  12. Equations of two-phase flow in spray chamber

    Institute of Scientific and Technical Information of China (English)

    李新禹; 张志红; 金星; 徐杰

    2009-01-01

    The downstream water-air heat and moisture transfer system in a moving coordinate was studied. The relationship between the diameter of the misted droplets and the spray pressure was determined. Based on the theory of the relative velocity,the two-phase flow mode of the spray chamber and the efficiency equation for heat and moisture exchange were established. Corrections were carried out for the efficiency equation with spray pressure of 157 kPa. The results show that the pressure plays an important part in determining the efficiency of heat and moisture exchange. When the spray pressure is less than 157 kPa,better coincidence is noticed between the theoretical analysis and the test results with the error less than 6%. Greater error will be resulted in the case when the spray pressure is beyond 157 kPa. After the correction treatment,the coincidence between the theoretical and the experimental results is greatly improved.

  13. Thirty-two phase sequences design with good autocorrelation properties

    Indian Academy of Sciences (India)

    S P Singh; K Subba Rao

    2010-02-01

    Polyphase Barker Sequences are finite length, uniform complex sequences; the magnitude of their aperiodic autocorrelation sidelobes are bounded by 1. Such sequences have been used in numerous real-world applications such as channel estimation, radar and spread spectrum communication. In this paper, thirty-two phase Barker sequences up to length 24 with an alphabet size of only 32 are presented. The sequences from length 25 to 289 have autocorrelation properties better than well-known Frank codes. Because of the complex structure the sequences are very difficult to detect and analyse by an enemy’s electronic support measures (ESMs). The synthesized sequences are promising for practical application to radar and spread spectrum communication systems. These sequences are found using the Modified Simulated Annealing Algorithm (MSAA). The convergence rate of the algorithm is good.

  14. Correct numerical simulation of a two-phase coolant

    Science.gov (United States)

    Kroshilin, A. E.; Kroshilin, V. E.

    2016-02-01

    Different models used in calculating flows of a two-phase coolant are analyzed. A system of differential equations describing the flow is presented; the hyperbolicity and stability of stationary solutions of the system is studied. The correctness of the Cauchy problem is considered. The models' ability to describe the following flows is analyzed: stable bubble and gas-droplet flows; stable flow with a level such that the bubble and gas-droplet flows are observed under and above it, respectively; and propagation of a perturbation of the phase concentration for the bubble and gas-droplet media. The solution of the problem about the breakdown of an arbitrary discontinuity has been constructed. Characteristic times of the development of an instability at different parameters of the flow are presented. Conditions at which the instability does not make it possible to perform the calculation are determined. The Riemann invariants for the nonlinear problem under consideration have been constructed. Numerical calculations have been performed for different conditions. The influence of viscosity on the structure of the discontinuity front is studied. Advantages of divergent equations are demonstrated. It is proven that a model used in almost all known investigating thermohydraulic programs, both in Russia and abroad, has significant disadvantages; in particular, it can lead to unstable solutions, which makes it necessary to introduce smoothing mechanisms and a very small step for describing regimes with a level. This does not allow one to use efficient numerical schemes for calculating the flow of two-phase currents. A possible model free from the abovementioned disadvantages is proposed.

  15. Innovative bioelectrochemical-anaerobic-digestion integrated system for ammonia recovery and bioenergy production from ammonia-rich residues

    OpenAIRE

    Zhang, Yifeng; Angelidaki, Irini

    2015-01-01

    Ammonia (NH4+/NH3) inhibition during anaerobic digestion process is one of the most frequent problems existing in biogas plants, resulting in unstable process and reduced biogas production. In this study, we developed a novel hybrid system, consisted of a submersed microbial resource recovery cell (SMRC) and a continuous stirred tank reactor (CSTR), to prevent ammonia toxicity during anaerobic digestion by in-situ ammonia recovery and electricity production (Figure 1). In batch experiment, th...

  16. [Anaerobic digestion of lignocellulosic biomass with animal digestion mechanisms].

    Science.gov (United States)

    Wu, Hao; Zhang, Pan-Yue; Guo, Jian-Bin; Wu, Yong-Jie

    2013-02-01

    Lignocellulosic material is the most abundant renewable resource in the earth. Herbivores and wood-eating insects are highly effective in the digestion of plant cellulose, while anaerobic digestion process simulating animal alimentary tract still remains inefficient. The digestion mechanisms of herbivores and wood-eating insects and the development of anaerobic digestion processes of lignocellulose were reviewed for better understanding of animal digestion mechanisms and their application in design and operation of the anaerobic digestion reactor. Highly effective digestion of lignocellulosic materials in animal digestive system results from the synergistic effect of various digestive enzymes and a series of physical and biochemical reactions. Microbial fermentation system is strongly supported by powerful pretreatment, such as rumination of ruminants, cellulase catalysis and alkali treatment in digestive tract of wood-eating insects. Oxygen concentration gradient along the digestive tract may stimulate the hydrolytic activity of some microorganisms. In addition, the excellent arrangement of solid retention time, digesta flow and end product discharge enhance the animal digestion of wood cellulose. Although anaerobic digestion processes inoculated with rumen microorganisms based rumen digestion mechanisms were developed to treat lignocellulose, the fermentation was more greatly limited by the environmental conditions in the anaerobic digestion reactors than that in rumen or hindgut. Therefore, the anaerobic digestion processes simulating animal digestion mechanisms can effectively enhance the degradation of wood cellulose and other organic solid wastes.

  17. Analysis of Bioenergy Residues (biochar and digestate) to Study the Fate of Pesticides for Biopurification Systems

    Science.gov (United States)

    Mukherjee, S.

    2015-12-01

    To overcome the problem of on farm point sources of pollution, environmental friendly and low cost technology filter systems are under development. Processes like sorption-desorption, dissipation behavior of three radiolabeled pesticides (Bentazone, Boscalid and Pyrimethanil) has been investigated at lab scale. Biochar and digestate mixtures with two types of soil (sandy and silt loam) had been used as a biofilter test material for a respiration study (over three month's time period) instead of conventional soil, peat and straw mixtures. The results show that digestate is an easily available C-source leading to highest release of CO2-C. It was found that with the addition of even a small amount (1 % W/W) of biochar there is a profound suppression in the CO2-C release.The driving mechanism for this suppression can be manifold like negative priming, chemisorption of CO2-C on biochar or combinations of all. Further, the fate of applied organic contaminants to biomixtures depends on factors like soil properties as well as biological degradation by soil microbes. To analyze the degradation potential of the different soil/amendment mixtures on pesticides a degradation study was performed. The results from the 14C labelled pesticides study indicated that a mixture of digestate (5%) and biochar (5%) well balanced the mineralization (~20% for bentazone, ~6% for boscalid and ~2% for pyrimethanil) and sorption process (>85% non-extractable residues for all pesticides) resulting in favorable dissipation process. To investigate the sorption-desorption potential of the above pesticides a batch equilibrium study was carried out with selected biomixtures. A higher Kd (>1500 L kg-1), kf (>400 μM1-1/nf L1/nfkg-1) and KL (>40 L kg-1) was obtained for all pesticides for the soil/digestate/biochar mixtures, which had a higher organic matter content. SUVA254 values justified the aromatic character of digestate (5%) and biochar (5%) mixture which showed highest Koc values among all

  18. Two Phases of Coherent Structure Motions in Turbulent Boundary Layer

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-Hua; JIANG Nan

    2007-01-01

    Two phases of coherent structure motion are acquired after obtaining conditional phase-averaged waveforms for longitudinal velocity of coherent structures in turbulent boundary layer based on Harr wavelet transfer. The correspondences of the two phases to the two processes (i.e. ejection and sweep) during a burst are determined.

  19. Clinical analysis of multiple primary malignancies in the digestive system: A hospital-based study

    Institute of Scientific and Technical Information of China (English)

    Hui-Yun Cheng; Cheng-Hsin Chu; Wen-Hsiung Chang; Tzu-Chi Hsu; Shee-Chan Lin; Chuan-Chuan Liu; An-Ming Yang; Shou-Chuan Shih

    2005-01-01

    AIM: To analyze the characteristics of multiple primary malignancies (MPMs) of digestive system; including incidence, types of tumor combinations, time intervals between development of mult