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Sample records for mixer-settler extraction column

  1. Mass transfer coefficients in a hanson mixer-settler extraction column

    Directory of Open Access Journals (Sweden)

    M. Torab-Mostaedi

    2008-09-01

    Full Text Available The volumetric overall mass transfer coefficients in a pilot plant Hanson mixer-settler extraction column of seven stages have been measured using toluene-acetone-water system. The effects of agitation speed and dispersed and continuous phases flow rates on volumetric overall mass transfer coefficients have been investigated. The results show that the volumetric overall mass transfer coefficient increases with increase in agitation speed and reaches a maximum. After having reached its maximum, it falls with further increase in agitation speed. It was found that the volumetric overall mass transfer coefficient increases with increase in dispersed phase flow rate, while it decreases with increase in continuous phase flow rate. By using interfacial area, the overall mass transfer coefficients for continuous and dispersed phases are determined from volumetric coefficients. An empirical correlation for prediction of the continuous phase overall mass transfer coefficient is proposed in terms of Sherwood and Reynolds numbers. Also the experimental data of the column investigated are compared with data for various extraction columns. Comparison between theoretical models and experimental results for the dispersed phase mass transfer coefficient shows that these models do not have enough accuracy for column design. Using effective diffusivity in the Gröber equation results in more accurate prediction of overall mass transfer coefficient. The prediction of overall mass transfer coefficients from the presented equations is in good agreement with experimental results.

  2. PULSED MIXER-SETTLER SOLVENT EXTRACTION CONTACTORS

    Science.gov (United States)

    Figg, W.S.

    1958-08-12

    A mixer-settler extractor is described for contacting immiscible liquids having different specific gravities in order to withdraw one or more components from one liquid with the aid of the other liquid. The extractor consists of a hollow column, a rotary drive shafi extending : through the column with a number of impellers spaced thereon, an equal nunnber of separator plate sets each consisting of one fluorothene and one stainless steel plate with peripheral recesses and flow slots mounted on the column, and a pulse generator. This apparatus is particularly useful in solvent extraction processes for recovering plutonium from aqueous acidic solutions of irradiated uranium.

  3. Comparison of SX of uranium using mixer settler and columns

    Energy Technology Data Exchange (ETDEWEB)

    Grinbaum, B., E-mail: baruchgr@bateman.co.il [Bateman Advanced Technologies, Yokneam (Israel); Kotze, M. [Mintek, Randburg (South Africa); Buchalter, E. [Bateman Advanced Technologies, Yokneam (Israel)

    2010-07-01

    Two types of equipment are used in the industry for solvent extraction (SX) of U: mixer-settlers (MS) and columns. Currently the only published type of columns applied in U SX is the Bateman Pulsed Columns (BPC). These columns have been applied for extraction of U for more than 13 years in Olympic Dam plant in Australia and in recent years were also introduced to additional plants in Australia and South Africa. Other plants are using MS of various types. The columns are currently used in the extraction battery only. For stripping and scrubbing only MS are currently used. Although pilot tests prove that the pH gradient required in the stripping may be successfully obtained in the BPC, they have not yet been applied in the industry. The paper compares the extraction and stripping in both types of equipment, regarding the capital cost, operating costs and operating conditions. The capital cost of the BPC is lower by 33-40%, depending on the size of the plant and the quality of the ore. The operating costs with the BPC are slightly lower, due to smaller losses of solvent. From operating point of view the BPC has the ability to recover from phase inversion and precipitation of yellow cake without the need to shut down the plant, if the problem is addressed within a few minutes. (author)

  4. Effect of operational parameters and internal recycle on rhenium solvent extraction from leach liquors using a mixer-settler

    Directory of Open Access Journals (Sweden)

    Mostafa Hosseinzadeh

    2014-06-01

    Full Text Available The extraction of rhenium from molybdenite roasting dust leach solution was performed using a mixer-settler extractor by tributyl phosphate (TBP diluted in kerosene as the extractant. In the single-stage extraction experiments, effect of the aqueous to organic phase ratios, Qa/Qo, and the number of extraction stages, N, on the rhenium extraction was studied. It was found that using the phase ratio of 1:1 in a two-stage extraction, 87.5% depletion of rhenium was obtained. The comparison of experimental results with the continuous co-current extraction showed a good agreement. The effect of internal recycle of organic phase was investigated in the phase ratio of 1:1 by changing the flow rate ratio of recycle-to-fresh organic phase, Qro/Qfo. The optimum performance was achieved in the phase ratio, Qro/Qfo, equal to 3:7. It was found that improvement in the performance of the mixer-settler for the rhenium-TBP system can be obtained in the phase ratio of 1:1when Qro/Qfo = 3:7.

  5. In-process inventory estimation for pulsed columns and mixer-settlers

    Energy Technology Data Exchange (ETDEWEB)

    Cobb, D.D.; Burkhart, L.E.; Beyerlein, A.L.

    1980-01-01

    Nuclear materials accounting and control in fuels reprocessing plants can be improved by near-real-time estimation of the nuclear materials inventory in solvent-extraction contactors. Techniques are being developed for the estimation of the in-process inventory in contactors. These techniques are derived from recent developments in chemical modeling of contactor systems, on-line measurements for materials accounting and control of the Purex process, and computer-based data acquisition and analysis methods.

  6. Analysis of continuous solvent extraction of nickel from spent electroless nickel plating baths by a mixer-settler.

    Science.gov (United States)

    Huang, Ying; Tanaka, Mikiya

    2009-05-30

    It is urgent to develop an effective technique to treat the large amount of spent electroless nickel plating bath and recycle the high concentration nickel. In our previous study, high recycling efficiency of nickel from the model spent bath was obtained by continuous solvent extraction with 2-hydroxy-5-nonylacetophenone oxime (LIX84I) as the extractant and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (PC88A) as the accelerator using a mixer-settler extractor. It was observed that the extraction efficiency was affected by the operation parameters such as the flow rates of the aqueous and organic phases and the total stage number. In the present study, the effects of the operation parameters on the extraction efficiency were quantitatively studied on the basis of the pseudo-first-order interfacial extraction rate equation together with the hydrodynamic properties in the mixer. The organic phase holdup, measured under varying conditions of the flow rates of both phases, was analyzed by the Takahashi-Takeuchi holdup model in order to estimate the specific interfacial area. The overall extraction rate coefficients defined by the product of the interfacial extraction rate constant and the specific interfacial area were evaluated using the experimental data and ranged from 3.5 x 10(-3) to 6.7 x 10(-3)s(-1), which was close to the value of 3.4 x 10(-3)s(-1) obtained by batch extraction. Finally, an engineering simulation method was established for assessing the extraction efficiency of nickel during a multistage operation.

  7. 改进型箱式混合澄清器在提钒新工艺中的应用%APPLICATION OF AN IMPROVED BOX-STYLE MIXER-SETTLER IN VANADIUM EXTRACTION

    Institute of Scientific and Technical Information of China (English)

    宫传文

    2001-01-01

    介绍了一种改进型箱式混合澄清器的结构特点及其在提钒新工艺萃取过程中的应用情况。实际生产运行考察结果表明,该设备完全能满足提钒新工艺的要求并具有效率高、分相快、操作简便、运行稳定、适应能力强等优点。%The structure and application of an improved box-style mixer settler in vanadium extraction are introduced.Practice results show that the mixer-settler meets the demand of vanadium extraction and has the advantages of high efficiency,fast phase separation,easy operation,stable run and high flexibility,etc.

  8. PEMISAHAN Zr – Hf SECARA SINAMBUNG MENGGUNAKAN MIXER SETTLER

    Directory of Open Access Journals (Sweden)

    Dwi Biyantoro

    2017-01-01

    Full Text Available ABSTRAK PEMISAHAN Zr – Hf SECARA SINAMBUNG MENGGUNAKANMIXER SETTLER. Telah dilakukan pemisahanZr – Hf secara sinambung menggunakan pengaduk pengenap (mixer settler 16 stage. Larutan umpan adalah zirkon nitrat dengan kadar Zr = 30786 ppm dan Hf = 499 ppm. Ekstraktan dipakai adalah solven 60 % TBP dalam kerosen dan larutan scrubbingyang dipakai adalah asam nitrat 1 M. Umpan masuk pada stageke 5 dikontakkan secara berlawanan arah dengan solven masuk pada stage ke 16 dan larutan scrubbing masuk pada stage ke 1. Tujuan penelitian ini adalah memisahkan unsur Zr dan Hf dari hasil olah pasir zirkon menggunakan solven TBP dengan alat mixer settler16 stage. Analisis umpan dan hasil proses pemisahan untuk zirkonium (Zr dilakukan dengan menggunakan alat pendar sinar-X, sedangkananalisis unsur hafnium (Hf menggunakan Analisis Pengaktifan Neutron (APN. Parameter penelitian dilakukan dengan variasi keasaman asam nitrat dalam umpan dan variasi waktu pada berbagai laju pengadukan. Hasil penelitian pemisahan unsur Zr dengan Hf diperolehkondisi optimum pada keasaman umpan 4 N HNO3, keseimbangan dicapai setelah 3jam dan laju pengadukan 3300 rpm. Hasil ekstrak  unsur zirkon (Zr diperoleh kadar sebesar 28577 ppm dengan efisiensi 92,76 % serta kadar pengotor hafnium (Hf sebesar 95 ppm. Kata Kunci: pemisahan Zr, Hf, ekstraksi, mixer settler, alat pendar sinar-X, APN. ABSTRACT SEPARATION of Zr - Hf CONTINUOUSLY USE THE MIXER SETTLER. Separation of Zr - Hf continuously using mixer settler 16 stage has been done. The feed solution is zircon nitrate concentration of Zr = 30786 ppm  and Hf = 499 ppm. As the solvent used extractant 60 % TBP in 40 % kerosene. Nitric acid solution used srubbing 1 M. The feed entered into stage to 5 is contacted with solvents direction on the stage to 16 and the scrubbing solution enter the stage to 1. The purpose of this study is to separate Zr and Hf of the results from the process of zircon sand using solvent TBP using 16 stage

  9. Mixer-settler runs for the evaluation of tri-iso-amyl phosphate (TiAP) as an alternate extractant to tri-n-butyl phosphate (TBP) for reprocessing applications

    Energy Technology Data Exchange (ETDEWEB)

    Suresh, A.; Sreenivasulu, B.; Jayalakshmi, S.; Subramaniam, S.; Sabharwal, K.N.; Sivaraman, N.; Nagarajan, K.; Srinivasan, T.G.; Vasudeva Rao, P.R. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

    2015-05-01

    As part of the studies on the development of alternate extractants for fast reactor fuel reprocessing, a mixer-settler facility for performing counter-current solvent extraction runs with radioactive materials has been set up and commissioned in our laboratory for flow sheet development experiments. Mixer-settler runs were carried out with 1.1 M TiAP/Heavy Normal Paraffin (HNP) as the solvent using the above facility to test the equipment as well as the behaviour of the solvent for continuous solvent extraction processes. Stage profile data generated for the extraction and stripping of nitric acid with TiAP based solvent have been reported. Studies carried out on the continuous counter-current extraction and stripping of U(VI) for 1.1 M TiAP/HNP-U(VI)-HNO{sub 3} system under high solvent loading conditions are also reported in this paper. Overall and stage-wise mass balance data for the above runs are also discussed.

  10. Electrolytic partitioning of uranium and plutonium based on a new type of electrolytic mixer-settler

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Z.; Yan, T.; Zheng, W. [China Institute of Atomic Energy, Beijing (China)] [and others

    2013-11-01

    The design of a new type of electroreduction mixer-settler for the partitioning of uranium and plutonium during the Purex process, which is featured with E-shaped cathodes and U-shaped anodes in settling chamber, is described and the operational results achieved using this equipment are presented. The results show that this new type of mixer-settler has excellent separation performances. The flow rate of organic feed solution is 3 mL/min and the flow ratio of feed solution (1BF) to aqueous back extraction stream (1BX) and to organic wash stream (1BS) is 4/1/1. For an organic feed of 84 g/L uranium and 1.40 {proportional_to} 2.64 g/L plutonium, both the separation factor of plutonium from uranium and that of uranium from plutonium are apparently higher than 10{sup 4}. (orig.)

  11. Experimental Study on Aqueous Phase Entrainment in a Mixer-settler with Double Stirring Mode

    Institute of Scientific and Technical Information of China (English)

    Wang Shuchan; Zhang Tingan; Zhao Qiuyue; Liu Yan; Wu Qiuyang

    2013-01-01

    The mixer-settler is a core device of solvent extraction for separating rare earth elements. There are some adverse effects like high rare earth accumulation and poor production efifciency during industrial production. Current researches usually focus on changing the structure of the mixer-settler without making a breakthrough towards gravity clariifcation. In this paper, in order to improve the efifciency of clariifcation, a mixer-settler with double stirring mode was designed and manufactured by adding a stirring device in the settler after reducing the volume of the settler. The innovation of this research involves adopting the ultraviolet-visible spectrophotometer to investigate the quantity of aqueous phase entrainment at the settler outlet in order to measure the clariifcation degree. Experimental results show that the clariifcation effect with stirring is better than that without stirring. The clariifcation effect is ameliorated as the stirring speed increases. Generally, the clariifcation effect shows a best condition when the offset distance is 12.5 cm, making the phase entrainment reduced to less than 0.1%. When the clearance over the tank bottom is 7 cm and 10 cm, respectively, the quantity of aqueous phase entrainment is better than the case with a clearance of 4 cm. The results show that the stirring paddle close to the mixed phase zone can better promote the two-phase separation.

  12. Computational fluid dynamics (CFD) simulation of effect of baffles on separation in mixer settler

    Institute of Scientific and Technical Information of China (English)

    Mohsen Ostad Shabani; Ali Mazahery; Mehdi Alizadeh; Ali Asghar Tofigh; Mohammad Reza Rahimipour; Mansour Razavi; Alireza Kolahi

    2012-01-01

    The main ideas in the development of the solvent extraction mixer settler focused on achieving clean phase separation,minimizing the loss of the reagents and decreasing the surface area of the settlers.The role of baffles in a mechanically agitated vessel is to ensure even distribution,reduce settler turbulence,promote the stability of power drawn by the impeller and to prevent swirling and vortexing of liquid,thus,greatly improving the mixing of liquid.The insertion of the appropriate number of baffles clearly improves the extent of liquid mixing.However,excessive baffling would interrupt liquid mixing and lengthen the mixing time.Computational fluid dynamics (CFD) provides a tool for determining detailed information on fluid flow (hydrodynamics) which is necessary for modeling subprocesses in mixer settler.A total of 54 final CFD runs were carried out representing different combinations of variables like number of baffles,density and impeller speed.CFD data shows that amount of separation increases with increasing baffles number and decreasing impeller speed.

  13. Electrolytic Partitioning of Uranium and Plutonium Based on a New Type of Electrolytic Mixer-Settler

    Institute of Scientific and Technical Information of China (English)

    YUAN; Zhong-wei; YAN; Tai-hong; ZHENG; Wei-fang; ZUO; Chen; LI; Hui-rong

    2012-01-01

    <正>A new type of electroreduction mixer-settler for the partitioning of uranium and plutonium during the Purex process, which is featured with E-shaped cathodes and U-shaped anodes in settling chamber, is designed and the operational results achieved using this equipment are presented. The results show that this new type of mixer-settler has excellent separation performance. The flow rate of organic feed solution

  14. Continuous aqueous two-phase extraction of human antibodies using a packed column.

    Science.gov (United States)

    Rosa, P A J; Azevedo, A M; Sommerfeld, S; Bäcker, W; Aires-Barros, M R

    2012-01-01

    The performance of a pilot scale packed differential contactor was evaluated for the continuous counter-current aqueous two-phase extraction (ATPE) of human immunoglobulin G (IgG) from a Chinese hamster ovary (CHO) cells supernatant (CS) enriched with pure protein. Preliminary studies have been firstly performed in order to select the dispersed phase (phosphate-rich or polyethylene glycol 3350 Da (PEG)-rich phase) and the column packing material. The PEG-rich phase has been selected as the dispersed phase and the stainless steel as the preferred material for the column packing bed since it was not wetted preferentially by the selected dispersed phase. Hydrodynamic studies have been also performed, and the experimental results were successfully adjusted to the Richardson-Zaki and Mísek equations, typically used for the conventional organic-aqueous two-phase systems. An experimental set-up combining the packed column with a pump mixer-settler stage showed to have the best performance and to be advantageous when compared to the IgG batch extraction. An IgG recovery yield of 85% could be obtained with about 50% of total contaminants and more than 85% of contaminant proteins removal. Mass transfer studies have revealed that the mass transfer was controlled by the PEG-rich phase. A higher efficiency could be obtained when using an extra pump mixer-settler stage and higher flow rates.

  15. Mass transfer coeficients in pulsed perforated-plate extraction columns

    Directory of Open Access Journals (Sweden)

    M. Torab-Mostaedi

    2010-06-01

    Full Text Available This study examined the mass transfer performance in a pulsed perforated-plate extraction column with diameter of 50 mm using two different liquid systems. Mass transfer coefficients have been interpreted in terms of the axial diffusion model. The effects of pulsation intensity and dispersed and continuous phase velocities on the mass transfer performance have been investigated. Three different operating regimes, namely mixer-settler, transition, and emulsion regimes, were observed when the input energy was changed. Effective diffusivity is substituted for molecular diffusivity in the Gröber equation for prediction of dispersed phase overall mass transfer coefficients. A single correlation is derived in terms of Reynolds number, Eötvös number and dispersed phase holdup for prediction of the enhancement factor in all operating regimes. The prediction of overall mass transfer coefficients from the presented model is in good agreement with experimental results.

  16. Improvement of Big Flow Ratio Micro-Mixer-Settler Extractor

    Institute of Scientific and Technical Information of China (English)

    CHANG; Shang-wen; CHANG; Li; LI; Rui-xue; LI; Sa; LIU; Li-sheng; WANG; Chang-shui; LI; Hui-rong; OUYANG; Ying-gen

    2012-01-01

    <正>The trace plutonium in the 1BU fluid should be further separated by using 1BXX in Purex process and be re-extracted from the organic phase. To decrease the producing of the waste liquid with trace plutonium, we employed the big flow rate extractor, (15-30)﹕1 of organic to aqueous. The aqueous outlet

  17. Mixer-settler counter-current chromatography with a barricaded spiral disk assembly with glass beads.

    Science.gov (United States)

    Ito, Yoichiro; Qi, Lin; Powell, Jimmie; Sharpnack, Frank; Metger, Howard; Yost, James; Cao, Xue-Li; Dong, Yin-Mao; Huo, Liang-Sheng; Zhu, Xiao-Ping; Li, Ting

    2007-06-01

    A novel spiral disk is designed by placing barricades at 6 mm intervals in the middle of the spiral channel to divide the channel into multiple sections. Glass beads are placed in every other section so that the planetary motion produces repetitive mixing and settling of polymer phase systems. Performance of this mixer-settler spiral disk assembly was examined for separation of lysozyme and myoglobin with a polymer phase system. The best results were obtained with a spiral disk equipped with barricades with openings ranging from 1.2 to 0.4 mm on each side at a high revolution speed up to 1200 rpm.

  18. Mixer-settler counter-current chromatography with multiple spiral disk assembly.

    Science.gov (United States)

    Ito, Yoichiro; Clary, Robert; Sharpnak, Frank; Metger, Howard; Powell, Jimmie

    2007-11-23

    A novel system for performing high-speed counter-current chromatography has been developed for separation of biopolymers using polymer phase systems. The spiral disk assembly consisting of eight units, each equipped with over 300 mixer-settler sets, was constructed and performance evaluated in terms of retention of the stationary phase and separation efficiency. A series of experiments was performed with a polymer phase system composed of polyethylene glycol 1000 (12.5%, w/w) and dibasic potassium phosphate (12.5%, w/w) using two stable protein samples of myoglobin and lysozyme at various experimental conditions of flow rates and revolution speeds. The best results were obtained with revolution speeds of 800-1000rpm at flow rates of 0.25-0.5ml/min where the partition efficiency of several 100 theoretical plates was achieved with over 50% stationary phase retention.

  19. 混合澄清槽吹气测量方法研究%Study on blowing air measurement method of the Mixer-Settler

    Institute of Scientific and Technical Information of China (English)

    董春华

    2013-01-01

    This article presents the Mixer-Settler and measuring method briefly, mainly introduces the solutions of key problems in the period of research on the Mixer-Settler, the solutions of these problems are proved feasible and accurate. So it is showed that using blowing air measures paraments of the Mixer-Settler is achieved.%  本文简要介绍了混合澄清槽及其测量方法,主要介绍了混合澄清槽测量研究过程中一些关键问题的解决,这些问题的解决,经验证是可行的、准确的,表明采用吹气测量混合澄清槽参数是可实现的。

  20. Drop size in a liquid pulsed sieve-plate extraction column

    Directory of Open Access Journals (Sweden)

    M. R. Usman

    2009-12-01

    Full Text Available The (Benzoic acid + kerosene + water system was studied in a 5.0 cm diameter liquid pulsed liquid-liquid extraction column with a total number of 80 sieve plates. The effect of pulsation intensity, dispersed phase superficial velocity, and continuous phase superficial velocity on volume-surface mean diameter was studied. Generally, the mean drop diameter decreased more rapidly with the increase of pulsation intensities and superficial velocities at low pulsation intensities and superficial velocities. However, the effect was not found to be significant at higher pulsation intensities and higher superficial velocities. In the interpretation of the experimental results, the drop size was observed to be a function of the operating regimes (mixer-settler, dispersion, and emulsion of the pulsed sieve-plate extraction column. The experimental mean drop diameters were compared to the most acceptable analytical drop size correlation developed by Kumar and Hartland (1986. The correlation proved to be in good agreement for the column operating in the dispersion regime.

  1. 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.

  2. Influence of main process variables on the treatment of waste waters using a new technology Mixer-Settler based on Phase Inversion (MSPI)

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, N.A.; Paulo, J.B.A.; Medeiros, G.S. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Engenharia Quimica], e-mail: norberto@eq.ufrn.br

    2011-04-15

    The prototype of a device on a semi-industrial scale to treat wastewaters from the oil industry has been widely studied as a viable alternative to conventional equipment. The device, called Mixer-Settler based on Phase Inversion (MSPI), uses the phase inversion method as operating principle. Using experimental planning (2{sup 4} factorial with four repetitions in the central point), it was determined the influence of the main variables on the oil/water separation process for waters containing between 30 and 100 mg of oil per liter of water. The following variables were evaluated: specific throughput, organic/aqueous phase ratio, agitation in the mixing chamber, and coconut oil concentration. The response variable was the oil/water separation efficiency. The results show that the separation efficiency of the device is a function of the effective throughput and the organic/aqueous phase ratio. (author)

  3. Numerical Simulation of Mixing Process in Mixer-settler%萃取混合澄清槽混合过程的数值模拟

    Institute of Scientific and Technical Information of China (English)

    逄启寿; 谢明春

    2012-01-01

    The stirring and mixing process in mixer-settler were simulated and analyzed by means of Fluent software with aqueous phase and organic phase (P507) as the simulation object, and the upper two layer of stirrer adopted straight blade and the lower adopted turbine impeller. The results show that a low pressure area is formed in the stirring axis center, as a result of which the liquid is pumped into the mixing chamber and forms a periodic circular flow, and impeller torques of each layer increase gradually from top to bottom.%应用Fluent软件对混合澄清槽的搅拌混合过程进行模拟分析,以水相和有机相(P507)两种液体为模拟对象,搅拌器采用上两层为平直叶桨和下层为涡轮桨的三层组合桨.结果表明,搅拌轴中心即前室口上方产生低压区,从而使前室液体抽吸至混合室,并在混合室内形成了周期性的上下循环流动;各层叶轮转矩由上而下逐渐递增.

  4. SPIRAL CONTACTOR FOR SOLVENT EXTRACTION COLUMN

    Science.gov (United States)

    Cooley, C.R.

    1961-06-13

    The patented extraction apparatus includes a column, perforated plates extending across the column, liquid pulse means connected to the column, and an imperforate spiral ribbon along the length of the column.

  5. Liquid-Liquid Extraction Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Jack D. Law; Terry A. Todd

    2008-12-01

    Solvent extraction processing has demonstrated the ability to achieve high decontamination factors for uranium and plutonium while operating at high throughputs. Historical application of solvent extraction contacting equipment implies that for the HA cycle (primary separation of uranium and plutonium from fission products) the equipment of choice is pulse columns. This is likely due to relatively short residence times (as compared to mixer-settlers) and the ability of the columns to tolerate solids in the feed. Savannah River successfully operated the F-Canyon with centrifugal contactors in the HA cycle (which have shorter residence times than columns). All three contactors have been successfully deployed in uranium and plutonium purification cycles. Over the past 20 years, there has been significant development of centrifugal contactor designs and they have become very common for research and development applications. New reprocessing plants are being planned in Russia and China and the United States has done preliminary design studies on future reprocessing plants. The choice of contactors for all of these facilities is yet to be determined.

  6. 高效澄清萃取槽内搅拌对液液分离特性的影响%Effect of Stirring on Liquid-Liquid Separation in Modified Mixer-Settlers

    Institute of Scientific and Technical Information of China (English)

    赵秋月; 张廷安; 刘燕; 王淑婵; 谢超亚

    2014-01-01

    针对传统稀土萃取混合澄清槽存在的问题,提出了在澄清室增加搅拌装置以提高澄清效率的方法。通过对四斜叶搅拌桨、Intermig桨及框式搅拌桨等不同桨型搅拌对澄清度影响的研究,证实四斜叶桨是合适的桨型,经搅拌之后,澄清室两相分离效果明显优于传统混合澄清槽,澄清度平均提高30%以上。在转速20,30,40和50 r·min-1条件下,搅拌桨离底距离分别为4.0,5.5,7.0,8.5和10.0 cm,搅拌桨距溢流口距离分别为10,13和16 cm时,对四斜叶桨搅拌澄清度的研究结果表明,低转速下澄清效果更好,搅拌桨距离溢流口越近澄清效果越好,而搅拌桨离底距离8.5 cm,即处于两相混合带附近时澄清效果最佳。在此基础上,根据因次分析原理和试验数据建立了澄清度因次公式。%Addition of agitation device to mixer-settlers was proposed in order to improve separation efficiency. A four-pitched-blade turbine, an Intermig impeller and a frame impeller were selected. Experimental conditions were: rotation speed:20, 30, 40 and 50 r⋅min-1, impeller to bottom distance: 4.0, 5.5, 7.0, 8.5 and 10.0 cm and the distance from paddle to overflow port: 10, 13 and 16 cm. The results show that the pitched blade turbine is applicable and the two-phase separation process is better in the settlers with agitation than in traditional mixer-settlers without agitation. The results show that the separation efficiency is better when the rotation speed is lower and the distance from paddle to overflow port is narrower. When the impeller to bottom distance is 8.5 cm, the separation efficiency is the best. A principle theory formula in the range of the experimental condition is established. The theoretical values have a good agreement with the experimental values.

  7. 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.

  8. Investigations for the reduction of specific power input at the production and downstream processing of antibiotics on the example of penicillin II. Pt. 1. Product formation in loop-type bubble columns. Final report. Untersuchugen zur Minimierung der Energie bei der Produktion und Aufarbeitung von Antibiotika am Beispiel des Penicillins II. T. 1. Produktbildung in Mammut-Schlaufen-Reaktoren. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schuegerl, K.; Lorenz, T.; Likidis, Z.

    1986-08-01

    The concentrations of most important medium components were permanently measured by means of an on-line analyser system consisting of a ultrafiltration probe for continuous sterile sampling of cell-free fermentation broth and a multichannel autoanalyser. An improved process operation was possible by coupling the reactor and its periphery to a process computer to store and evaluate the measured data. The specific power input into the applied airlift tower loop reactor could be considerably reduced by means of pellet morphology and a parameter-adaptive closed loop control of the dissolved oxygen concentration in the broth. Reactive extraction of penicillin from model media and fermentation as well as its reextraction were carried out in different extraction columns, in a mixer-settler and in different centrifugal extractors. By testing several carriers a new inexpensive compound, diisotridecylamin, was found, which proved to be - beside Amberlite LA-2 - as especially suitable for the extraction of penicillin. Extractions were carried out at pH 5 and reextractions at pH 7.5 at different phase-rations, throughputs from 20 l/h up to 1.5 m/sup 3//h and at penicillin concentrations up to 40 g/l with very high degrees of extraction.

  9. Hydrodynamics and Mass Transfer Performance in Supercritical Fluid Extraction Columns

    Institute of Scientific and Technical Information of China (English)

    石冰洁; 张泽廷; 等

    2002-01-01

    New models for describing hydrodynamics and mass transfer performance in supercritical fluid extraction columns were proposed.Those models were proved by experimental data,which were obtained in supercritical fluid extraction packed column,spray column and sieve tray column respectively.The inner diameter of those columns areΦ25mm,These experimental systems include supercritical carbon dioxideisopropanol-water and supercritical carbon dioxide-ethanol-water,in which supercritical carbon dioxide was dispersed phase,and another was continuous phase.The extraction processes were operated with continuous countercurrent flow.The predicted values are agreed well with experimental data.

  10. Study on Micro-extraction Column of Uranium

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Some samples of uranium are very complicated therefore they can not be determined directly by analysis instrument, so pretreatment is necessary. The micro-extraction column of uranium is a kind of

  11. A new model for solvent extraction in columns

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, R.A.; Regalbuto, M.C.; Chamberlain, D.B.; Vandegrift, G.F.

    1989-12-08

    A new model was developed for analyzing solvent extraction processes carried out in columns. Each column is treated as a series of well-defined equilibrium stages where the backmixing (other-phase carryover) between stages can be large. By including all mass transfer effects in the backmixing value, the same number of stages can be used for all extracted components no matter what their distribution coefficients. This greatly simplifies the calculations required when modeling multicomponent solvent extraction processes. Initial testing shows the new model to be better than either the Height of an Equivalent Theoretical Plate (HETP) or the Height of a Transfer Unit (HTU) method.

  12. PERFORMANCE OF A PACKED LIQUID-LIQUID EXTRACTION COLUMN

    Directory of Open Access Journals (Sweden)

    İ. Metin HASDEMİR

    1999-03-01

    Full Text Available The influence of feed ratios ((LE/LR on the performance of a packed liquid-liquid extraction column, with a diameter of 5.86 cm and a column height of 132 cm was investigated. The column is made of borosilicate glass and packed with 10 x 10 mm glass Raschig rings. In this study, a ternary system composed of water + propionic acid + trichloroethylene was used. The data used to triangular diagram were obtained experimentally. The overall mass transfer coefficients, the numbers of overall mass transfer units, the heights of mass transfer units, the numbers of theoretical stages and height equivalent to a theoretical stage (H. E. T. S. values were calculated and compared with each other.

  13. SLIP VELOCITY IN PULSED DISC AND DOUGHNUT EXTRACTION COLUMN

    Directory of Open Access Journals (Sweden)

    Mohammad Outokesh

    2011-09-01

    Full Text Available In the present work, slip velocity has been measured in a 76 mm diameter pulsed disc and doughnut extraction column for four different liquid-liquid systems. The effects of operating variables including pulsation intensity and dispersed and continuous phase flow rates on slip velocity have been investigated. The existence of three different operational regimes, namely mixersettler, transition, and emulsion regimes, was observed when the energy input was changed. Empirical correlations are derived for prediction of the slip velocity in terms of operating variables, physical properties of the liquid systems, and column geometry for different regimes. Good agreement between prediction and experiments was found for all operating conditions that were investigated.

  14. Mass transfer performance in pulsed disc and doughnut extraction columns

    Directory of Open Access Journals (Sweden)

    M Torab-Mostaedi

    2011-09-01

    Full Text Available Mass transfer performance is presented for a 76 mm diameter pulsed disc and doughnut extraction column for the toluene-acetone-water system. The experiments were carried out for both mass transfer directions. The mass transfer data are interpreted in terms of the axial diffusion model, thus accounting for continuous phase axial dispersion. The effect of operating parameters on the overall volumetric mass transfer coefficients has been investigated. The results show that the column performance increases with an increase in pulsation intensity. At high pulsation intensity, however, the overall volumetric mass transfer coefficient decreases due to the production of very fine dispersed droplets. It was also found that the column performance decreases with both an increase in dispersed phase velocity and a decrease in continuous phase velocity. An empirical correlation for prediction of the continuous phase overall mass transfer coefficient is derived in terms of the overall Sherwood number, Reynolds number and dispersed phase holdup for each mass transfer direction. The prediction of continuous phase overall mass transfer coefficients from the presented correlations is in good agreement with experimental data.

  15. REUSABILITY OF BOND ELUT CERTIFY COLUMNS FOR THE EXTRACTION OF DRUGS FROM PLASMA

    NARCIS (Netherlands)

    CHEN, XH; FRANKE, JP; WIJSBEEK, J; DEZEEUW, RA

    1993-01-01

    The reusability of Bond Elut Certify columns for the extraction of toxicologically relevant drugs from plasma has been evaluated. Pentobarbital, hexobarbital, mepivacaine, trimipramine and clonazepam were selected as test drugs to represent various classes of drugs. The columns were regenerated

  16. REUSABILITY OF BOND ELUT CERTIFY COLUMNS FOR THE EXTRACTION OF DRUGS FROM PLASMA

    NARCIS (Netherlands)

    CHEN, XH; FRANKE, JP; WIJSBEEK, J; DEZEEUW, RA

    1993-01-01

    The reusability of Bond Elut Certify columns for the extraction of toxicologically relevant drugs from plasma has been evaluated. Pentobarbital, hexobarbital, mepivacaine, trimipramine and clonazepam were selected as test drugs to represent various classes of drugs. The columns were regenerated imme

  17. Dynamics and control of a heat pump assisted extractive dividing-wall column for bioethanol dehydration

    NARCIS (Netherlands)

    Patraşcu, Iulian; Bildea, Costin Sorin; Kiss, Anton A.

    Recently, a novel heat-pump-assisted extractive distillation process taking place in a dividing-wall column was proposed for bioethanol dehydration. This integrated design combines three distillation columns into a single unit that allows over 40% energy savings and low specific energy requirements

  18. Blue Chitin columns for the extraction of heterocyclic amines from urine samples

    DEFF Research Database (Denmark)

    Bang, J.; Frandsen, Henrik Lauritz; Skog, K.

    2004-01-01

    During normal cooking of meat, a class of mutagenic/carcinogenic compounds called heterocyclic amines is formed. Heterocyclic amines are rapidly absorbed and metabolised in the human body, and for estimation of the intake of heterocyclic amines, it is useful to determinate their levels in the urine....... Blue Chitin columns were used for the extraction and purification of heterocyclic amines from urine samples spiked with 14 different heterocyclic amines. The samples were analysed using LC-MS. The results show that Blue Chitin columns provide a straightforward and rapid means of extracting heterocyclic...... amines from urine samples, and that Blue Chitin column are also useful in the purification of urinary metabolites....

  19. Technical note: Efficiency of total demineralization and ion-exchange column for DNA extraction from bone.

    Science.gov (United States)

    Seo, Seung Bum; Zhang, Aihua; Kim, Hye Yeon; Yi, Jin A; Lee, Hye Young; Shin, Dong Hoon; Lee, Soong Deok

    2010-01-01

    We investigated whether a combination of recently introduced methods, total demineralization and ion-exchange columns, would increase DNA recovery from old bone. Ten bone samples taken after a burial period of approximately 60 years were used in this study. Bone powder was digested using total or incomplete demineralization. DNA was extracted by the standard organic method. The DNA extract was purified with ion-exchange columns or QIAquick spin columns. The efficiency of different DNA extraction methods was compared in terms of DNA concentration, inhibitors generated by real-time PCR, and conventional STR typing results. The mean DNA concentration using the total demineralization method is approximately 3 times higher than that using the incomplete demineralization method. For DNA purification, the method using QIAquick spin columns appeared to yield approximately double the DNA than the method using ion-exchange columns. Furthermore, 2 out of 10 samples showed higher levels of inhibition with C(T) values of IPC > or =30 cycles when using only ion-exchange columns. In STR results, total demineralization yielded more locus profiles by 4.2 loci than incomplete demineralization, and QIAquick spin columns also yielded more locus profiles by 3.5 loci than ion-exchange columns. Total demineralization of bone powder significantly increased DNA yield and improved STR typing results. However, the use of ion-exchange columns was not efficient when compared with the method using QIAquick spin columns. It is suggested that the combination of total demineralization and QIAquick spin columns lead to greatly improved STR typing results.

  20. CFD based extraction column design-Chances and challenges

    Institute of Scientific and Technical Information of China (English)

    Mark W Hlawitschka; Menwer M Attarakih; Samer S Alzyod; Hans-Jrg Bart

    2016-01-01

    This paper shows that one-dimensional (1-D) [and three-dimensional (3-D) computational fluid dynamics (CFD)] simulations can replace the state-of-the-art usage of pseudo-homogeneous dispersion or back mixing models. This is based on standardized lab-scale cel experiments for the determination of droplet rise, breakage, coalescence and mass transfer parameters in addition to a limited number of additional mini-plant experiments with original fluids. Alternatively, the hydrodynamic parameters can also be derived using more sophisticated 3-D CFD simulations. Computational 1-D modeling served as a basis to replace pilot-plant experiments in any column geometry. The combination of 3-D CFD simulations with droplet population balance models (DPBM) increased the accuracy of the hydrodynamic simulations and gave information about the local droplet size. The high computational costs can be reduced by open source CFD codes when using a flexible mesh generation. First combined simulations using a three way coupled CFD/DPBM/mass-transfer solver pave the way for a safer design of industrial-sized columns, where no correlations are available.

  1. Performance of Inclined Baffle Column for Pectin Continuous Extraction Process from Cocoa Peel (Theobromacacao

    Directory of Open Access Journals (Sweden)

    Soemargono

    2016-01-01

    Full Text Available Pectin from cocoa peel was successfully prepared by extraction method in the bubble column reactor. The process could be carried out in batch and continuous, with co-current or counter current flow. Bubble pipe reactor with inclined baffle is expected to reduce the problem from gas flow patterns, jagged sloping bulkhead serves as a bubble breaker that could replace mechanical stirrer. In this study the reactor column sloping bulkhead was used as extractor to recover pectin in the cocoa peel by citric acid (1 N solvent. Cocoa peel paste and citric acid were entered to the top of the column at 1 : 1 rate ratio by streamed using dosing pump. Nitrogen gas as a medium stirrer flowed counter current from the bottom of the column. Once extraction was completed, the liquid then precipitated by acid alcohol. Pectin solids were washed with alcohol (96%. The temperature of extraction process is maintained at 70° C. The residence time in the column material was determined by feed flow rate (cocoa paste and citric acid, and the volume of suspension that remains in the reactor (V. Residence time equation obtained is: t = (7045.86G-0.1275/L. The yield of yellowish white precipitate reached up to 5.2973% and methoxyl concentration reached 5,21% for 72 minutes. The experiment shows that the continuous extraction process of pectin in baffle columns is better than batch process.

  2. Extraction of genomic DNA using a new amino silica monolithic column.

    Science.gov (United States)

    Liu, Lijia; Yu, Shengbing; Yang, Shuixian; Zhou, Ping; Hu, Jiming; Zhang, Yibing

    2009-08-01

    A new amino silica monolithic column was developed for DNA extraction in a miniaturized format. The monolithic column was prepared in situ by polymerization of tetraethoxysilane (TEOS) and N-(beta-aminoethyl)-gamma-aminopropylmethyldimethoxysilane (AEAPMDMS). DNA was loaded in 50 mM tris(hydroxylmethyl)aminomethane-EDTA buffer at pH 7.0 and eluted with 300 mM potassium phosphate solution at pH 10.0. Under optimal condition, a 6.0-cm monolithic column provided a capacity of 56 ng DNA with an extraction efficiency of 71 +/- 5.2% (X +/- RSD). When the amino silica monolithic column was applied to extract genomic DNA from the whole blood of crucian carp, an extraction efficiency of 52 +/- 5.6% (X +/- RSD) was obtained by three extractions. Since the chaotropic-based sample loading and organic solvent wash steps were avoided in this procedure, the purified DNA was suitable for downstream processes such as PCR. This amino silica monolithic column was demonstrated to allow rapid and efficient DNA purification in microscale.

  3. Axial mixing and mass transfer characteristics of pulsed extraction column with discs and doughnuts

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The axial mixing is a key factor for design and scaling up of the pulsed extraction column which has strong influence on the mass transfer performances of the pulsed extraction column with discs and doughnuts. A steady-state concentration profile measurement was used to evaluate the mass transfer and axial mixing coefficients for the nitric acid/water/30%TRPO (in kerosene) system in the pulsed extraction column with the diameter of 38 mm on the condition of the TRPO-kerosene solution as the continuous phase and the flow ratio of 1: 1. Experimental results indicate that Ey evaluated by the experiments is in good agreement with that given by Burratti's correlation; the axial mixing is far smaller for the continuous phase than that for the dispersed phase. However the empirical correlation for Hox is only given based on the present data.

  4. Synergistic Extraction of Gallium for Sulfate Solution

    Institute of Scientific and Technical Information of China (English)

    DENGTong; HUANGLijuan; 等

    2002-01-01

    A novel extractant mixture, di-2-ethylhexyl phosphate (DEHPA) plus HX, was propose and tested for recovering gallium from sulfate solution.It was found that the extraction capacity of DEPHA for gallium from sulfate solution could be enhanced significantly due to the synergistic effect of acidix extractant HX. Gallium extraction is negligible below pH 0 and highly sensitive to pH of aqueous phase in the range from 0 to 1, and satisfactory extraction can be gained at pH>1. More than 96% Ga extraction was obtained using 15% DEHPA plus 2% HX. Although Fe(Ⅲ) was found to be extracted preferentially to Ga (Ⅲ), effective extraction of Ga (Ⅲ) was possible by reducing ferric to the ferrous state prior to extraction. A loaded organic phase containing 0.48g·L-1 Ga could be produced from solution of 0.12g·L-1 Ga at A/O ratio of 4:1 via three mixer-settler operation stages. Gallium was stripped quantitatively from the loaded organic phase with 1.5mol·L-1 of sulfuric acid.

  5. The setup of an extraction system coupled to a hydrogen isotopes distillation column

    Energy Technology Data Exchange (ETDEWEB)

    Zamfirache, M.; Bornea, A.; Stefanescu, I.; Bidica, N.; Balteanu, O.; Bucur, C. [INC-DTCI, ICSIRm. Valcea, Uzinei Street 4, Rm. Valcea (Romania)

    2008-07-15

    Among the most difficult problems of cryogenic distillation one stands apart: the extraction of the heavy fraction. By an optimal design of the cycle scheme, this problem could be avoided. A 'worst case scenario' is usually occurring when the extracted fraction consists of one prevalent isotope such as hydrogen and small amounts of the other two hydrogen isotopes (deuterium and/or tritium). This situation is further complicated by two parameters of the distillation column: the extraction flow rate and the hold-up. The present work proposes the conceptual design of an extraction system associated to the cryogenic distillation column used in hydrogen separation processes. During this process, the heavy fraction (DT, T{sub 2}) is separated, its concentration being the highest at the bottom of the distillation column. From this place the extraction of the gaseous phase can now begin. Being filled with adsorbent, the extraction system is used to temporarily store the heavy fraction. Also the extraction system provides samples for the gas Chromatograph. The research work is focused on the existent pilot plant for tritium and deuterium separation from our institute to validate the experiments carried out until now. (authors)

  6. Evaluation of phytochemical screening & extraction of lycopene from Citrullus lanatus by using column chromatography

    OpenAIRE

    lalitha govindaraj; Suseela vivek

    2015-01-01

    The present study focused on the phytochemical constituents, isolation of lycopene of the Citrullus lanatusis fruits which were collected from the local market in around sulur area, India. The phytochemical analysis of fruit extracts revealed the presence of   bioactive compounds such as phenolics, alkaloids, saponins, tannins, steroids and flavonoids in the extract. The isolation of lycopene were quantified by using column chromatography that depicted (lycopene - 68.0285 mg/k fresh wt) respe...

  7. [Preparation and applications of a supported liquid-liquid extraction column with a composite diatomite material].

    Science.gov (United States)

    Bao, Jianmin; Ma, Zhishuang; Sun, Ying; Wang, Yongzun; Li, Youxin

    2012-08-01

    A rapid and special supported liquid-liquid extraction (SLE) column was developed with a composite diatomite material. The SLE column was evaluated by high performance liquid chromatography (HPLC) with acidic, neutral and alkaline compounds dissolved in water. Furthermore, some real complex samples were also analyzed by HPLC with the SLE method. The recoveries of benzoic acid (acidic), p-nitroaniline (alkaline) and 4-hydroxy-benzoic methyl ester (neutral) treated by the SLE column were 90.6%, 98.1% and 97.7%. However, the recoveries of the three compounds treated by traditional liquid-liquid extraction (LLE) method were 71.9%, 81.9% and 83.9%. The results showed that the SLE technique had higher recoveries than the traditional LLE method. The spiked recoveries of the complex samples, such as benzoic acid in Sprite and dexamethasone acetate, chlorphenamine maleate, indomethacin in bovine serum, were between 80% and 110% and the relative standard deviations (RSDs) were less than 15%. For biological specimen, the results could be accepted. Meantime, many disadvantages associated with traditional LLE method, such as emulsion formation, didn't occur using SLE column. The SLE column technique is a good sample preparation method with many advantages, such as rapid, simple, robust, easily automated, high recovery and high-throughput, which would be widely used in the future.

  8. A machine learning approach to extract spinal column centerline from three-dimensional CT data

    Science.gov (United States)

    Wang, Caihua; Li, Yuanzhong; Ito, Wataru; Shimura, Kazuo; Abe, Katsumi

    2009-02-01

    The spinal column is one of the most important anatomical structures in the human body and its centerline, that is, the centerline of vertebral bodies, is a very important feature used by many applications in medical image processing. In the past, some approaches have been proposed to extract the centerline of spinal column by using edge or region information of vertebral bodies. However, those approaches may suffer from difficulties in edge detection or region segmentation of vertebral bodies when there exist vertebral diseases such as osteoporosis, compression fracture. In this paper, we propose a novel approach based on machine learning to robustly extract the centerline of the spinal column from threedimensional CT data. Our approach first applies a machine learning algorithm, called AdaBoost, to detect vertebral cord regions, which have a S-shape similar to and close to, but can be detected more stably than, the spinal column. Then a centerline of detected vertebral cord regions is obtained by fitting a spline curve to their central points, using the associated AdaBoost scores as weights. Finally, the obtained centerline of vertebral cord is linearly deformed and translated in the sagittal direction to fit the top and bottom boundaries of the vertebral bodies and then a centerline of the spinal column is obtained. Experimental results on a large CT data set show the effectiveness of our approach.

  9. Study on the dynamic holdup distribution of the pulsed extraction column

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.; Chen, J.; Wu, Q. [Tsinghua University, Beijing 100084 (China)

    2013-07-01

    In the study, a CSTR cascade dynamic hydraulic model was developed to investigate the dynamic holdup distribution of the pulsed extraction column. It is assumed that the dynamic process of the dispersed phase holdup of pulsed extraction column has equal effects with the operational process of multiple cascade CSTRs. The process is consistent with the following assumptions: the holdups vary on different stages but maintain uniform on each stage; the changes of the hydraulic parameters have impact initially on the inlet of dispersed phase, and stability will be reached gradually through stage-by-stage blending. The model was tested and verified utilizing time domain response curves of the average holdup. Nearly 150 experiments were carried out with different capillary columns, various feed liquids, and diverse continuous phases and under different operation conditions. The regression curves developed by the model show a good consistency with the experimental results. After linking parameters of the model with operational conditions, the study further found that the parameters are only linearly correlated with pulse conditions and have nothing to do with flow rate for a specific pulsed extraction column. The accuracy of the model is measured by the average holdup, and the absolute error is ±0.01. The model can provide supports for the boundary studies on hydraulics and mass transfer by making simple and reliable prediction of the dynamic holdup distribution, with relatively less accessible hydraulic experimental data. (authors)

  10. Isolation of tetracyclines in milk using a solid-phase extracting column and water eluent.

    Science.gov (United States)

    Furusawa, Naoto

    2003-01-01

    An isolating method using a solid-phase extraction (SPE) ISOLUTE(R) C8 endcapped syringe-column for routine monitoring of residual tetracyclines (TCs) (oxytetracycline (OTC), tetracycline (TC), chlortetracycline (CTC), and doxycycline (DC)) in cow's milk is presented. In the simplest and most environmentally harmless method, milk samples could be applied directly to the SPE column, following which all TCs were eluted with water. No organic solvents were used at all. The purified sample was injected into a high-performance liquid chromatography (HPLC) with a photo-diode array detector (PDAD). For the HPLC determination/identification, a LiChrospher(R) 100 RP-8 endcapped column and a mobile phase of acetonitrile -7% (v v(-1)) acetic acid solution (in water) (35:65, v v(-1)) with a PDAD was used. The total time required for the analysis of one sample was 80 and <5%, respectively.

  11. Regenerated silica gel as stationary phase on vacuum column chromatography to purify temulawak’s extracts

    Energy Technology Data Exchange (ETDEWEB)

    Cahyono, Bambang; Maduwu, Ratna Dewi; Widayat,; Suzery, Meiny [Organic Chemistry Laboratory, Departement of Chemistry, Diponegoro University Jln Prof. Soedharto SH, Tembalang, Semarang 50275, Indonesia Tel / Fax: (024) 7460058 (Indonesia)

    2015-12-29

    Commercial silica gel only used once by many researchers and affected high cost for purification process, also less support the green chemistry program. This research focused in regeneration silica gel that used purification of temulawak’s extracts (Curcuma xanthorrhiza Roxb) by vacuum column chromatography. Sample extracts (contains 10.1195±0.5971% of curcuminoids) was purified by vacuum column chromatography (pressure: 45 kPa, column: 100mm on length and 16mm on diameter). Ethanol 96% and acetone were compared as eluent. The amount of solvent and yield of curcuminoids used as indicator purification. The silica gel was regenerated with heating in 600°C for 8 hours The silica gels were analyzed by IR spectroscopy and X-ray diffraction. Furthermore, regenerated silica gel was used as the stationary phase in vacuum column chromatography under the same conditions with the previous purification. All the purification experiments were performed in three repetitions. Based on regression equation, y=0.132x+0.0011 (r{sup 2}=0.9997) the yield of curcuminoids on purified products using ethanol as the eluent was improved 4.26% (to 14.3724±0.5749%) and by acetone was improved 3,03% (to 13.1450 ±0.6318%). The IR spectrum of both silica gel showed the same vibration profile and also there were three crystallinity peaks missing on its X-ray diffraction. Regenerated silica gel has the same performance with new silica gel in purification of temulawak’s extract: by ethanol has increased 4.08% (14.1947±0.7415%) and 2.93% (13.0447±0.4822) by acetone. In addition, all purification products showed similar TLC profiles. Purification using regenerated silica gel as the adsorbent on vacuum column chromatography has exactly same potential with the new silica gel.

  12. Regenerated silica gel as stationary phase on vacuum column chromatography to purify temulawak's extracts

    Science.gov (United States)

    Cahyono, Bambang; Maduwu, Ratna Dewi; Widayat, Suzery, Meiny

    2015-12-01

    Commercial silica gel only used once by many researchers and affected high cost for purification process, also less support the green chemistry program. This research focused in regeneration silica gel that used purification of temulawak's extracts (Curcuma xanthorrhiza Roxb) by vacuum column chromatography. Sample extracts (contains 10.1195±0.5971% of curcuminoids) was purified by vacuum column chromatography (pressure: 45 kPa, column: 100mm on length and 16mm on diameter). Ethanol 96% and acetone were compared as eluent. The amount of solvent and yield of curcuminoids used as indicator purification. The silica gel was regenerated with heating in 600°C for 8 hours The silica gels were analyzed by IR spectroscopy and X-ray diffraction. Furthermore, regenerated silica gel was used as the stationary phase in vacuum column chromatography under the same conditions with the previous purification. All the purification experiments were performed in three repetitions. Based on regression equation, y=0.132x+0.0011 (r2=0.9997) the yield of curcuminoids on purified products using ethanol as the eluent was improved 4.26% (to 14.3724±0.5749%) and by acetone was improved 3,03% (to 13.1450 ±0.6318%). The IR spectrum of both silica gel showed the same vibration profile and also there were three crystallinity peaks missing on its X-ray diffraction. Regenerated silica gel has the same performance with new silica gel in purification of temulawak's extract: by ethanol has increased 4.08% (14.1947±0.7415%) and 2.93% (13.0447±0.4822) by acetone. In addition, all purification products showed similar TLC profiles. Purification using regenerated silica gel as the adsorbent on vacuum column chromatography has exactly same potential with the new silica gel.

  13. Technical note: improved DNA extraction from ancient bones using silica-based spin columns.

    Science.gov (United States)

    Yang, D Y; Eng, B; Waye, J S; Dudar, J C; Saunders, S R

    1998-04-01

    We describe a simple method for extracting polymerase chain reaction-amplifiable DNA from ancient bones without the use of organic solvents. Bone powders are digested with proteinase K, and the DNA is purified directly using silica-based spin columns (QIAquick3, QIAGEN). The efficiency of this protocol is demonstrated using human bone samples ranging in age from 15 to 5,000 years old.

  14. Evaluation of phytochemical screening & extraction of lycopene from Citrullus lanatus by using column chromatography

    Directory of Open Access Journals (Sweden)

    lalitha govindaraj

    2015-09-01

    Full Text Available The present study focused on the phytochemical constituents, isolation of lycopene of the Citrullus lanatusis fruits which were collected from the local market in around sulur area, India. The phytochemical analysis of fruit extracts revealed the presence of   bioactive compounds such as phenolics, alkaloids, saponins, tannins, steroids and flavonoids in the extract. The isolation of lycopene were quantified by using column chromatography that depicted (lycopene - 68.0285 mg/k fresh wt respectively. Consequently, the watermelon proved as a good source of antioxidant, could be used as a raw material in drug formulation.

  15. Simple, specific analysis of organophosphorus and carbamate pesticides in sediments using column extraction and gas chromatography

    Science.gov (United States)

    Belisle, A.A.; Swineford, D.M.

    1988-01-01

    A simple, specific procedure was developed for the analysis of organophosphorus and carbamate pesticides in sediment. The wet soil was mixed with anhydrous sodium sulfate to bind water and the residues were column extracted in acetone:methylene chloride (1:l,v/v). Coextracted water was removed by additional sodium sulfate packed below the sample mixture. The eluate was concentrated and analyzed directly by capillary gas chromatography using phosphorus and nitrogen specific detectors. Recoveries averaged 93 % for sediments extracted shortly after spiking, but decreased significantly as the samples aged.

  16. The extraction of thorium by calix[6]arene columns for urine analysis.

    Science.gov (United States)

    Mekki, S; Bouvier-Capely, C; Jalouali, R; Rebière, F

    2011-03-01

    Thorium is a natural alpha-emitting element occurring in various ores and has numerous industrial applications. Routine monitoring of potentially exposed workers is generally achieved through radiobioassay (urine and faeces). The procedures currently used for analysing actinides such as thorium in urine require lengthy chemical separation associated with long counting times by alpha-spectrometry due to low activity levels. Thus, their main drawback is that they are time-consuming, which limits the frequency and flexibility of individual monitoring. In this context, this study developed new radiochemical procedures based on the use of tertbutylcalix[6]arenes bearing three carboxylic acid groups or three hydroxamic acid groups. These previous works demonstrated that these macrocyclic molecules immobilised on an inert solid support are excellent extractants for uranium, plutonium and americium. In this study, the authors investigated the thorium extraction by calix[6]arene columns. Experiments were performed on synthetic solutions and on real urine samples. The influence of various parameters, such as the thorium solution pH and the column flow rate on thorium extraction, was studied. The results showed that both calix[6]arenes are efficient to extract thorium. Thorium extraction is quantitative from pH = 2 for synthetic solution and from pH = 3 for real urine samples. This study has demonstrated that the column flow rate is a crucial parameter since its value must not be too high to achieve the steady-state complexation equilibrium. Finally, these results will be compared with those obtained for other actinides (U, Pu and Am) and the conditions of actinides' separation will be discussed.

  17. Molecularly imprinted solid-phase extraction monolithic capillary column for selective extraction and sensitive determination of safranine T in wolfberry.

    Science.gov (United States)

    Su, Zihao; Zhai, Haiyun; Chen, Zuanguang; Zhou, Qing; Li, Jiangmei; Liu, Zhenping

    2014-02-01

    A method was developed to sensitively determine safranine T in wolfberry by molecularly imprinted solid-phase extraction (MISPE) coupled with high-performance liquid chromatography and laser-induced fluorescence detection (HPLC-LIF). The MISPE capillary monolithic column was prepared by water-bath in situ polymerization, using safranine T, methacrylic acid (MAA), and ethylene dimethacrylate (EDMA) as template, functional monomer, and cross-linker, respectively. The properties of the homemade MISPE capillary monolithic column, including capacity and specificity, were investigated under optimized conditions and the morphologies of inner polymers were characterized by scanning electron microscopy (SEM). The mean recoveries of safranine T in wolfberry ranged from 91.2 % to 92.9 % and the intraday and interday relative standard deviation (RSD) values all ranged from 3.4 % to 4.2 %. Good linearity was obtained over 0.001-1.0 μg mL(-1) (r = 0.9999) with a detection limit (S/N = 3) of 0.4 ng g(-1). Under the selected conditions, enrichment factors of over 90-fold were obtained and the extraction on the monolithic column effectively cleaned up the wolfberry matrix. The results demonstrated that the proposed MISPE-HPLC-LIF method could be applied to sensitively determine safranine T in wolfberry.

  18. Micro-column solid phase extraction to determine uranium and thorium in environmental samples.

    Science.gov (United States)

    Tsai, Tsuey-Lin; Lin, Chun-Chih; Chu, Tieh-Chi

    2008-08-01

    Extraction chromatographic separation techniques based on U/TEVA and TEVA resins were utilized to separate uranium and thorium isotopes in complex matrices from environmental samples. This approach has the advantages of ease of quantitative analysis, small sample size, an absence of mixed waste solvents, complete separation of U/Th isotopes, acceptable chemical yields and good energy resolution in the alpha spectrum. The procedure for analyzing alpha-emitting isotopes of uranium and thorium in geothermal water from Peito, Taiwan, is illustrated in detail. It involves sample pre-concentration, filtration and separation by highly selective extraction chromatographic resins, followed by electroplating and alpha-spectroscopy. The analytical results show a chemical recovery exceeding 55% for U and 65% for Th, respectively, under optimized conditions. The efficient and cost-effective use of recyclable columns makes the analytical methods simple, accurate, rapid, reliable and robust.

  19. Chromatographic determination of cyanoglycosides prunasin and amygdalin in plant extracts using a porous graphitic carbon column.

    Science.gov (United States)

    Berenguer-Navarro, V; Giner-Galván, R M; Grané-Teruel, N; Arrazola-Paternina, G

    2002-11-20

    The determination of cyanogenic compounds in plants is often performed by HPLC. However, in this analysis, interferences due to compounds in the matrix, such as tannins and other pigments, are encountered, especially in roots and leaves. A new method is proposed for determining the cyanogenic glycosides amygdalin (D-mandelonitrile beta-D-gentiobioside) and prunasin (D-mandelonitrile beta-D-glucoside) in almond tree tissues, using poly(vinylpyrrolidone) or active carbon as scavengers for extracting cyanogenic compounds from roots or leaves, respectively. A new chromatographic approach for conducting the analysis is also discussed herein. The advantages of a Hypercarb column for the analysis of prunasin in roots are shown. The correlation coefficient with a reference method is high (>0.99), and statistical tests prove that the two methods are equivalent. In addition, the results provide evidence that prunasin is the only cyanoglycoside present in almond tree roots.

  20. [Reparation and application of perfluorodecyl modified silica monolithic capillary column in extraction and enrichment of perfluorooctane sulfonates].

    Science.gov (United States)

    Huang, Ke; Zhou, Naiyuan; Chen, Bo

    2011-10-01

    A perfluorodecyl modified silica monolithic capillary column has been prepared by using sol-gel method. The preparation steps included hydrolysis of alkoxy silane, fasculation of silanol, gelation, aging, meso-pore preparation, drying and surface modification. It could be used as a solid phase extraction (SPE) microcolumn for extraction and enrichment of perfluorooctane sulfonate (PFOS). The enrichment characteristics and efficiency of the perfluorodecyl modified monolithic silica capillary column has been investigated and compared with C18 silica monolithic capillary column. The results indicated that the perfluorodecyl modified silica monolithic capillary column ( 15 cm x 75 microm) had a higher adsorption capacity and a better enrichment selectivity for PFOS. The average adsorption capacity of the perfluorodecyl modified silica monolithic capillary column was 75 ng. And when the PFOS mass concentration in sample was 0. 25 mg/L, the enrichment factor was 29-fold in average. Owing to the good performance of the perfluorodecyl modified silica monolithic capillary column, it can be used for the extraction and enrichment of trace PFOS in water to meet the requirements of water quality monitoring and analysis.

  1. Synergistic Extraction of Gallium from Sulfate Solution%从硫酸盐溶液中协同萃取镓

    Institute of Scientific and Technical Information of China (English)

    邓彤; 黄丽娟; 傅丽

    2002-01-01

    A novel extractant mixture, di-2-ethylhexyl phosphate (DEHPA) plus HX, was proposed and tested for recovering gallium from sulfate solution. It was found that the extraction capacity of DEPHA for gallium from sulfate solution could be enhanced significantly due to the synergistic effect of acidic extractant HX. Gallium extraction is negligible below pH 0 and highly sensitive to pH of aqueous phase in the range from 0 to 1, and satisfactory extraction can be gained at pH>1. More than 96% Ga extraction was obtained using 15% DEHPA plus 2% HX. Although Fe (Ⅲ) was found to be extracted preferentially to Ga (Ⅲ), effective extraction of Ga (Ⅲ) was possible by reducing ferric to the ferrous state prior to extraction. A loaded organic phase containing 0.48g. L-1 Ga could be produced from solution of 0.12g@L-1 Ga at A/O ratio of 4: 1 via three mixer-settler operation stages.Gallium was stripped quantitatively from the loaded organic phase with 1.5 mol@L-1 of sulfuric acid.

  2. Parallel extraction columns and parallel analytical columns coupled with liquid chromatography/tandem mass spectrometry for on-line simultaneous quantification of a drug candidate and its six metabolites in dog plasma.

    Science.gov (United States)

    Xia, Y Q; Hop, C E; Liu, D Q; Vincent, S H; Chiu, S H

    2001-01-01

    A method with parallel extraction columns and parallel analytical columns (PEC-PAC) for on-line high-flow liquid chromatography/tandem mass spectrometry (LC/MS/MS) was developed and validated for simultaneous quantification of a drug candidate and its six metabolites in dog plasma. Two on-line extraction columns were used in parallel for sample extraction and two analytical columns were used in parallel for separation and analysis. The plasma samples, after addition of an internal standard solution, were directly injected onto the PEC-PAC system for purification and analysis. This method allowed the use of one of the extraction columns for analyte purification while the other was being equilibrated. Similarly, one of the analytical columns was employed to separate the analytes while the other was undergoing equilibration. Therefore, the time needed for re-conditioning both extraction and analytical columns was not added to the total analysis time, which resulted in a shorter run time and higher throughput. Moreover, the on-line column extraction LC/MS/MS method made it possible to extract and analyze all seven analytes simultaneously with good precision and accuracy despite their chemical class diversity that included primary, secondary and tertiary amines, an alcohol, an aldehyde and a carboxylic acid. The method was validated with the standard curve ranging from 5.00 to 5000 ng/mL. The intra- and inter-day precision was no more than 8% CV and the assay accuracy was between 95 and 107%.

  3. Determination of phthalate esters in physiological saline solution by monolithic silica spin column extraction method%Determination of phthalate esters in physiological saline solution by monolithic silica spin column extraction method

    Institute of Scientific and Technical Information of China (English)

    Lu Lu; Yuki Hashi; Zhi-Hua Wang; Yuan Ma; Jin- Ming Lin

    2011-01-01

    Monolithic silica spin column extraction (MonoSpin-SPE) was developed as a simple, sensitive, and eco-friendly pretreatment method which combined with ultra-fast liquid chromatography-mass spectrometry (UFLC-MS) to determine the levels of six phthalate es

  4. Liquid-Liquid-Liquid Three Phase Extraction Apparatus: Operation Strategy and Influences on Mass Transfer Efficiency

    Institute of Scientific and Technical Information of China (English)

    何秀琼; 黄昆; 于品华; 张超; 谢铿; 李鹏飞; 王娟; 安震涛; 刘会洲

    2012-01-01

    Abstract A new mixer-settler-mixer three chamber integrated extractor is proposed in this work for liquid-liquid- liquid three phase countercurrent and continuous extraction. Experiments revealed the influences of the structural design of the three-liquid-phase extractor and some key operational parameters on three-phase partition of two phenolic isomers, p-nitrophenol (p-NP) and o-nitrophenol (o-NP). The model three-liquid-phase extraction system used here is nonane (organic top-plaase)-polyethylene glycol (PEG 20UU) (polymer mlddle-phase)-(NH4)2SO4 aqueous solution (aqueous bottom-phase). It is indicated that agitating speed and retention time in three-phase mixer are key parameters to extraction fraction of nitrophenol. Dispersion band behavior is related to agitating intensity, and its occurrence does not affect the extraction fraction of target compounds. The present work highlights the possibility of a feasible approach of scaling up of the proposed three-phase extraction apparatus for future in- dustrial-aimed applications.

  5. Multistage aqueous two-phase extraction of a monoclonal antibody from cell supernatant.

    Science.gov (United States)

    Muendges, Jan; Zalesko, Alexej; Górak, Andrzej; Zeiner, Tim

    2015-01-01

    This article presents results of continuous multistage aqueous two-phase extraction of an immunoglobulin G1 from cell supernatant in a mixer-settler unit. An aqueous two-phase system consisting of polyethylene glycol 2000, phosphate salt, and water was applied without and with sodium chloride (NaCl). Influences of different parameters such as throughput, phase ratio, and stage number on the extraction performance were analyzed. For systems without NaCl, the extraction was carried out as a washing step. An increase of stage number from one to five stages enabled to increase the immunoglobulin G1 purity from 11.8 to 32.6% at a yield of nearly 90%. Furthermore, a reduction of product phase volume due to a higher phase ratio led to an increase of purity from 20.8 to 29.6% in a three-stage countercurrent extraction. For experiments with NaCl moderate partitioning conditions were adjusted by adding 8 wt% NaCl. In that case, the extraction was carried out as a stripping step.

  6. Determination of phenylenediamine isomers in hair dyes by coal cinders micro-column extraction and MEKC.

    Science.gov (United States)

    Wu, Yiwei; Jiang, Feng; Chen, Lin; Zheng, Jing; Deng, Zhenli; Tao, Qing; Zhang, Jing; Han, Lijuan; Wei, Xiaoshu; Yu, Aimin; Zhang, Haili

    2011-06-01

    A new micellar electrokinetic chromatography (MEKC) method using beta-cyclodextrins (β-CDs) and 1-butyl-3-methylimidazolium hexafluorophosphates (ionic liquids) as additives was successfully developed for determination of para-, meta-, and ortho-phenylenediamines isomers (p-P, m-P, and o-P) in hair dyes. To improve the sensitivity of the MEKC-UV, a simple and cheap flow injection (FI) technique using a micro-column packed with coal cinders (the by-products from combustion in a boiler) as solid-phase extractant was also investigated. In the presence of 20 mmol L(-1) phosphates at pH 5.5, addition of 12 mmol L(-1) ionic liquids and 8 mmol L(-1) β-CDs greatly improved the separation efficiency. The three analytes could be quantitatively adsorbed by coal cinders, and desorbed readily with 0.15 mL of 0.01 mol L(-1) NaOH. Under the optimum conditions, an enrichment factor (EF) of 33.3 was obtained, and determination limits of p-P, m-P, and o-P were 1.97 × 10(-7), 0.99 × 10(-7), and 0.61 × 10(-7) mol L(-1), respectively. The adsorption capacities of the coal cinders micro-column for p-P, m-P, and o-P were all 1.20 mg g(-1). The presented procedure was successfully applied to the determination of p-P, m-P, and o-P in hair dyes with satisfactory results.

  7. Study on separation of minor actinides from HLLW with new extractant of TODGA-DHOA/Kerosene

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Guo-an; Zhu, Wen-bin; Li, Feng-feng; Lin, Ru-shan; Li, Hui-rong [China Institute of Atomic Energy, P.O.Box 275-26, Beijing 102413 (China)

    2013-07-01

    The extraction behavior of U, Np, Pu, Am, rare earth elements and Sr from nitric acid solutions by TODGA/dodecan, DHOA/dodecane and TODGA-DHOA/dodecane were investigated, respectively. Based on experimental results, a separation process was proposed for minor actinide isolation from high level liquid waste (HLLW): the TODGA-DHOA/kerosene system. The multi-stage counter-current cascade experiments were carried out for the purpose by 0.1 mol/l TODGA-1.0 mol/l DHOA/kerosene with miniature mixer- settler contactor rigs (8 stages for extraction, 6 stages for scrubbing, 8 stages for first stripping, 8 stages for second stripping). The results show that the recovery efficiencies of the actinides and lanthanides are more than 99.9%, whereas less than 1% Sr was extracted by 0.1 mol/l TODGA - 1.0 mol/l DHOA/kerosene. The stripping efficiencies of U, Np and Pu are more than 95% in the first stripping step by 0.5 mol/l HNO{sub 3} + 0.5 mol/l AHA(aceto-hydroxamic acid), all of the remained actinides and lanthanides can be stripped by 0.01 mol/l HNO{sub 3} in the second stripping step. 99% Sr was extracted by 0.1 mol/l TODGA/kerosene, so Sr can be recovered efficiently directly from the raffinate by 0.1 mol/l TODGA/kerosene. (authors)

  8. Automatic Vertebral Column Extraction by Whole-Body Bone SPECT Scan

    Directory of Open Access Journals (Sweden)

    Sheng-Fang Huang

    2013-01-01

    Full Text Available Bone extraction and division can enhance the accuracy of diagnoses based on whole-body bone SPECT data. This study developed a method for using conventional SPECT for automatic recognition of the vertebral column. A novel feature of the proposed approach is a novel “bone graph" image description method that represents the connectivity between these image regions to facilitate manipulation of morphological relationships in the skeleton before surgery. By tracking the paths shown on the bone graph, skeletal structures can be identified by performing morphological operations. The performance of the method was evaluated quantitatively and qualitatively by two experienced nuclear medicine physicians. Datasets for whole-body bone SPECT scans in 46 lung cancer patients with bone metastasis were obtained with Tc-99m MDP. The algorithm successfully segmented vertebrae in the thoracolumbar spine. The quantitative assessment shows that the segmentation method achieved an average TP, FP, and FN rates of 95.1%, 9.1%, and 4.9%. The qualitative evaluation shows an average acceptance rate of 83%, where the data for the acceptable and unacceptable groups had a Cronbach’s alpha value of 0.718, which indicated reasonable internal consistency and reliability.

  9. Prediction of dispersed phase holdup in pulsed disc and doughnut solvent extraction columns under different mass transfer conditions

    Institute of Scientific and Technical Information of China (English)

    Yong Wang; Kathryn H. Smith; Kathryn Mumford; Teobaldo F. Grabin; Zheng Li; Geoffrey W. Stevens

    2016-01-01

    Using experimental data from a number of pulsed disc and doughnut solvent extraction columns, a unified correla-tion for the prediction of dispersed phase holdup that considers the effects of mass transfer is presented. Pulsed disc and doughnut solvent extraction columns (PDDC) have been used for a range of important applications such as ura-nium extraction and nuclear fuel recycling. Although the dispersed phase holdup in a PDDC has been presented by some researchers, there is stil the need to develop a robust correlation that can predict the experimental dispersed phase holdup over a range of operating conditions including the effects of mass transfer direction. In this study, dis-persed phase holdup data from different literature sources for a PDDC were used to refit constants for the correlation presented by Kumar and Hartland [Ind. Eng. Chem. Res.,27 (1988),131–138] which did not consider the effect of col-umn geometry. In order to incorporate the characteristic length of the PDDC (i.e. the plate spacing), the unified cor-relation for holdup proposed by Kumar and Hartland based on data from eight different types of columns [Ind. Eng. Chem. Res.,34 (1995) 3925–3940] was refitted to the PDDC data. New constants have been presented for each hold-up correlation for a PDDC based on regression analysis using published holdup data from PDDCs that cover a range of operating conditions and physical properties and consider the direction of mass transfer.

  10. Extraction of red cabbage anthocyanins: optimization of the operation conditions of the column process

    Directory of Open Access Journals (Sweden)

    Marcelo Fonseca Xavier

    2008-02-01

    Full Text Available The aim of this work was to extract anthocyanins from the red cabbage. Batch studies under several extraction conditions indicated that acetic acid in aqueous solution (10% V/V was the best solvent, used in the proportion of 0.25 g of red cabbage mL-1. At this condition, column assays were carried out to evaluate the influence of the ionic force, pH, solvent flow rate, recirculated volume of red cabbage juice and the mass of red cabbage. Results showed that the pH, recirculation and mass of red cabbage had statistically significant effects, where the optimum operation conditions found for the process were pH 2.3, recirculation volume of the solvent 0.83 L and mass of red cabbage 50 g.Desde os primórdios dos tempos as antocianinas são extraídas de vegetais, mas avanços que garantam um processo viável e rentável exigem conhecimento, quantificação e controle das condições de operação. Estudos em batelada sob várias condições de extração indicaram que ácido acético em solução aquosa (10% V/V foi o melhor solvente, quando usado na proporção de 0,25 g de repolho roxo mL-1. Nesta condição de operação foram feitos ensaios em coluna para avaliar a influência da força iônica, pH, taxa de escoamento do solvente, volume recirculado da solução de extração e massa de repolho roxo. Os resultados mostraram que o pH, recirculação e massa de repolho foram estatisticamente significativos, e as condições ótimas de operação encontradas para o processo foram pH 2,3, volume de solvente recirculado de 0,83 L e massa de repolho roxo igual a 50g.

  11. A solvent extraction approach to recover acetic acid from mixed waste acids produced during semiconductor wafer process.

    Science.gov (United States)

    Shin, Chang-Hoon; Kim, Ju-Yup; Kim, Jun-Young; Kim, Hyun-Sang; Lee, Hyang-Sook; Mohapatra, Debasish; Ahn, Jae-Woo; Ahn, Jong-Gwan; Bae, Wookeun

    2009-03-15

    Recovery of acetic acid (HAc) from the waste etching solution discharged from silicon wafer manufacturing process has been attempted by using solvent extraction process. For this purpose 2-ethylhexyl alcohol (EHA) was used as organic solvent. In the pre-treatment stage >99% silicon and hydrofluoric acid was removed from the solution by precipitation. The synthesized product, Na(2)SiF(6) having 98.2% purity was considered of commercial grade having good market value. The waste solution containing 279 g/L acetic acid, 513 g/L nitric acid, 0.9 g/L hydrofluoric acid and 0.030 g/L silicon was used for solvent extraction study. From the batch test results equilibrium conditions for HAc recovery were optimized and found to be 4 stages of extraction at an organic:aqueous (O:A) ratio of 3, 4 stages of scrubbing and 4 stages of stripping at an O:A ratio of 1. Deionized water (DW) was used as stripping agent to elute HAc from organic phase. In the whole batch process 96.3% acetic acid recovery was achieved. Continuous operations were successfully conducted for 100 h using a mixer-settler to examine the feasibility of the extraction system for its possible commercial application. Finally, a complete process flowsheet with material balance for the separation and recovery of HAc has been proposed.

  12. Study of on-line analysis using energy dispersive X-ray fluorescence spectrometry for controlling lanthanum and neodymium extraction

    Energy Technology Data Exchange (ETDEWEB)

    Wenli, Li; Ascenzo, G.D`; Curini, R. [Department of Chemistry, University of Rome `La Sapienza`, Rome (Italy); Gasparini, G.M.; Casarci, M.; Mattia, B.; Traverso, D.M.; Bellisario, F. [ENEA, CRE Casaccia INN-NUMA (Italy)

    1998-05-04

    Many rare-earth extraction processes require frequent control over separation process quality. Ideally, an analysis method for this type should be simple, rapid and reliable. Energy dispersive X-ray fluorescence (EDXRF) spectrometry, due to its relative simplicity of instrumentation, speed of analysis, and non-destructive nature, is well suited to this on-line analysis application. In particular, since the radioisotope energy dispersive XRF method eliminates the need to transport samples to a laboratory which houses the X-ray spectrometry, it is most commonly used for on-line analysis of extraction systems. The present paper describes an attempt to type the radioisotope source {sup 241}Am XRF on-line analysis arrangement coupled with a personal computer for controlling a lanthanum and neodymium separation process. From the HpGe detector (high-purity germanium) response, a continuous spectral signal is observed during loading of the feed samples. The separation process using countercurrent extraction consists of a 16-stage laboratory mixer-settler, a switching valve, and a pumping system. The performance of this control system is illustrated by extracting La, Nd acidic solutions with 100% tributyl phosphate

  13. Recovery of Caprolactam from Waste Water in Caprolactam Production Using Pulsed—sieve—plate Extraction column

    Institute of Scientific and Technical Information of China (English)

    LIUJiangqing; XIEFangyou; 等

    2002-01-01

    Recovery of caprolactam from waste water of caprolactam production factory was investigated using benzence as solvent in a small-scale pulsed-sieve-plate column.First,liquid-liquid equilibrium (LLE) deta were measured,including water-caprolactam-benzene system at low caprolactam concentrations,and waste water-benzene system.Then,the operating regions and mass transfer of the pulsed-sieve-plate column were measured.Finally,the overall apparent heights of a transfer unit based on continuous phase are correlated in terms of the column operation variables.

  14. Extraction and preparation of high-aroma and low-caffeine instant green teas by the novel column chromatographic extraction method with gradient elution.

    Science.gov (United States)

    Li, Qing-Rong; Wu, Min; Huang, Rui-Jie; Chen, Ya-Fei; Chen, Chan-Jian; Li, Hui; Ni, He; Li, Hai-Hang

    2017-06-01

    The lack of aroma and natural taste is a critical problem in production and consumption of instant green teas. A method to prepare instant green teas high in-natural-aroma and low-caffeine by the novel column chromatographic extraction with gradient elution is reported. This method simultaneously extracted aroma (or volatile) and non-aroma compounds from green tea. Green tea was loaded into columns with 2.0-fold of petroleum ether (PE): ethanol (8:2). After standing for 3 h until the aroma compounds dissolved, the column was sequentially eluted with 3.0-fold 40% ethanol and 3.5-fold water. The eluant was collected together and automatically separated into PE and ethanol aqueous phases. The aroma extracts was obtained by vacuum-evaporation of PE phase at 45 °C. The ethanol aqueous phase was vacuum-concentrated to aqueous and partially or fully decaffeinated with 4% or 9% charcoal at 70 °C. A regular instant green tea with epigallocatechin-3-gallate: caffeine of 3.5:1 and a low-caffeine instant green tea (less than 1% caffeine) with excellent aroma and taste were prepared, by combining the aroma and non-aroma extracts at a 1:10 ratio. This work provides a practical approach to solve the low-aroma and low-taste problems in the production of high quality instant green teas.

  15. TOXIC ACTIVITIES OF HEXANE EXTRACT AND COLUMN CHROMATOGRAPHY FRACTIONS OF RODENT TUBER PLANT (Typhonium flagelliforme Lodd. ON Artemia salina

    Directory of Open Access Journals (Sweden)

    Nesti F. Sianipar

    2013-04-01

    Full Text Available Rodent tuber (Typhonium flagelliforme Lodd. is a medicinal plant  particularly found in Java. The plant is used as an ingredient for  conventional cancer treatment. The aim of this study was to determine the toxic activities of crude extracts and column chromatography fractions of  rodent tuber on Artemia salina larvae. Rodent tuber plant was obtained  from the Indonesian Spice and Medicinal Crops Research Institute in  Bogor, West Java. The experiment was conducted in the Biology  Laboratory of Universitas Pelita Harapan, Tangerang, Banten. Leaves and petioles of the plant were macerated with acetone and the filtrates were evaporated (40°C to obtain crude extracts. The crude extracts were partitioned with ethyl acetate, followed with hexane, chloroform and  butanol. Toxicity test of the extracts was performed using the Brine Shrimp Lethality Test (BSLT method on A. salina larvae. Extract showing the most toxic was fractioned using column chromatography and then tested on the larvae. The experiment was designed in a completely randomized  factorial, four replicates for crude extracts and two replicates for the fractions. Treatments were different types of extracts (hexane, chloroform and butanol at various concentrations (500, 1,000 and 1,500 μg ml-1 of 5% Tween solution. Fractions of the column chromatography used were taken from the column number 1, 3 and 10, and tested their toxicities at 200, 400, 600, 800 and 1,000 μg ml-1 of 5% Tween solution. Parameters observed were the death of A. salina expressed as LC50. The study  showed that hexane extract of the petioles had the most toxic to A. salina (LC50 = 762.08 μg ml-1. Fraction number 10 showed the highest toxic (LC50 = 381.07 μg ml-1, whereas the lowest was fraction number 3 (LC50 = 653.13 μg ml-1. The study indicates that rodent tuber plant from Bogor is toxic to A. salina and further test for its cytotoxic activity is justified.

  16. Optimal synthesis and design of extractive distillation systems for bioethanol separation: From simple to complex columns

    DEFF Research Database (Denmark)

    Errico, M.; Rong, B. G.; Tola, G.

    2013-01-01

    Bioethanol has been considered as a green fuel and a valid alternative to reduce the dependence on fossil distillates. The development of an optimal separation process is considered as a key element in the design of an efficient process able to be cost effective and competitive. Despite many...... are investigated. The complex column subspace is generated introducing one or more thermal couplings and considering the possibility to intensify the process combining the column sections performing the same separation task. All the configurations considered, simulated by means of Aspen Plus V 7.3, are compared...... considering the total condenser and reboiler duty as energy index. The capital costs and the solvent consumption are also taken into account in the final selection. Among all the complex configurations considered the two-column sequence can reduce the capital cost above 10% compared to the best simple column...

  17. Molecularly imprinted coated graphene oxide solid-phase extraction monolithic capillary column for selective extraction and sensitive determination of phloxine B in coffee bean

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Haiyun, E-mail: zhaihaiyun@126.com [College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006 (China); Su, Zihao [College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006 (China); Chen, Zuanguang, E-mail: chenzg@mail.sysu.edu.cn [School of Pharmaceutical Science, Sun Yat-sen University, Guangzhou 510006 (China); Liu, Zhenping; Yuan, Kaisong; Huang, Lu [College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006 (China)

    2015-03-20

    Highlights: • A new GO-MISPE monolithic capillary column was prepared. • The column showed ability of impurities removal and excellent selectivity. • Phloxine B existed in real sample was enriched more than 90 times. • The GO-MISPE column presented good recovery and high stability. • The method was prospered to analyze phloxine B and LOD achieved 0.3 ng g{sup −1}. - Abstract: A method was developed to sensitively determine phloxine B in coffee bean by molecularly imprinted polymers (MIPs) coated graphene oxide (GO) solid-phase extraction (GO-MISPE) coupled with high-performance liquid chromatography and laser-induced fluorescence detection (HPLC–LIF). The GO-MISPE capillary monolithic column was prepared by water-bath in situ polymerization, using GO as supporting material, phloxine B, methacrylic acid (MAA), and ethylene dimethacrylate (EDMA) as template, functional monomer, and cross-linker, respectively. The properties of the homemade GO-MISPE capillary monolithic column, including capacity and specificity, were investigated under optimized conditions. The GO-MIPs were characterized by scanning electron microscopy (SEM) and Fourier transform-infrared spectroscopy (FT-IR). The mean recoveries of phloxine B in coffee bean ranged from 89.5% to 91.4% and the intra-day and inter-day relative standard deviation (RSD) values all ranged from 3.6% to 4.7%. Good linearity was obtained over 0.001–2.0 μg mL{sup −1} (r = 0.9995) with the detection limit (S/N = 3) of 0.075 ng mL{sup −1}. Under the selected conditions, enrichment factors of over 90-fold were obtained and extraction on the monolithic column effectively cleaned up the coffee bean matrix. The results demonstrated that the proposed GO-MISPE HPLC–LIF method can be applied to sensitively determine phloxine B in coffee bean.

  18. Extracting Concrete Thermal Characteristics from Temperature Time History of RC Column Exposed to Standard Fire

    OpenAIRE

    Jung J. Kim; Kwang-Soo Youm; Reda Taha, Mahmoud M.

    2014-01-01

    A numerical method to identify thermal conductivity from time history of one-dimensional temperature variations in thermal unsteady-state is proposed. The numerical method considers the change of specific heat and thermal conductivity with respect to temperature. Fire test of reinforced concrete (RC) columns was conducted using a standard fire to obtain time history of temperature variations in the column section. A thermal equilibrium model in unsteady-state condition was developed. The ther...

  19. HA demonstration in the Atalante facility of the Ganex 1. cycle for the selective extraction of Uranium from HLW

    Energy Technology Data Exchange (ETDEWEB)

    Miguirditchian, M.; Sorel, C.; Cames, B.; Bisel, I.; Baron, P.; Espinoux, D.; Calor, J.N.; Viallesoubranne, C.; Lorrain, B.; Masson, M. [CEA/DEN/MAR/DRCP, Marcoule, BP17171, 30207 Bagnols/Ceze (France)

    2009-06-15

    The selective separation of uranium(VI) in the GANEX process (Group Actinide Extraction) is operated by a hydrometallurgical process using a monoamide extractant DEHiBA (N,N-di- (ethyl-2-hexyl)isobutyramide) diluted in an industrial aliphatic solvent HTP. Based on batch experimental results, a physicochemical model was developed to describe the extraction of uranium, neptunium, plutonium, and technetium by DEHiBA. With the help of this model, a flowsheet was designed and tested first in a counter-current process on a surrogate uranium/nitric acid feed in order to validate the computer code calculations and the effective recovery of uranium. After this successful 'cold' demonstration, the flowsheet was tested in 28 mixer-settlers (laboratory scale) on a genuine High Liquid Waste (HLW) in the CBP hot cell (Atalante facility) in June 2008. The HLW was obtained from the dissolution of an irradiated uranium oxide fuel (70 GWd/t). After running 60 hours, high recovery of uranium was achieved with a good purity versus transuranium elements and fission products. The decontamination factors obtained versus the other actinides and the major fission products were around 6000 for Pu, 300 for Np, 10{sup 4} for Cs and Ru, and 40 for Tc. The organic and aqueous profiles of uranium concentration in the different stages were measured and compared to the calculated data. (authors)

  20. Fluidized-bed column method for automatic dynamic extraction and determination of trace element bioaccessibility in highly heterogeneous solid wastes.

    Science.gov (United States)

    Rosende, María; Miró, Manuel; Cerdà, Víctor

    2010-01-18

    Dynamic flow-through extraction/fractionation methods have recently drawn much attention as appealing alternatives to the batchwise steady-state counterparts for the evaluation of environmentally available pools of potentially hazardous trace elements in solid matrices. The most critical weakness of flow-based column approaches lies in the small amount of solid that can be handled, whereby their applicability has been merely limited to date to the extraction of trace elements in highly homogeneous solid substrates; otherwise the representativeness of the test portion might not be assured. To tackle this limitation, we have devised an automated flow-through system incorporating a specially designed extraction column with a large volume capacity, wherein up to 2 g of solid sample could be handled without undue backpressure. The assembled flow setup was exploited for fast screening of potentially hazardous trace elements (namely, Cd, Cr, Cu, Pb, and Zn) in highly inhomogeneous municipal solid waste incineration (MSWI) bottom ashes. The pools of readily mobilizable metal forms were ascertained using the Toxicity Characteristic Leaching Procedure (TCLP) based on the usage of 0.1 mol L(-1) CH(3)COOH as leachant and analysis of extracts by inductively coupled optical emission spectrometry. The application of a two-level full factorial (screening) design revealed that the effect of sample fluidization primarily but other experimental factors such as the solid to liquid ratio and extractant flow rate significantly influenced the leachability of given elements in raw bottom ashes at the 0.05 significance level. The analytical performance of the novel flow-based method capitalized on fluidized-bed extraction was evaluated in terms of accuracy, through the use of mass balance validation, reproducibility and operational time as compared to batchwise extraction and earlier flow injection/sequential injection microcolum-based leaching tests.

  1. Tunable aqueous polymer-phase impregnated resins-technology-a novel approach to aqueous two-phase extraction.

    Science.gov (United States)

    van Winssen, F A; Merz, J; Schembecker, G

    2014-02-14

    Aqueous Two-Phase Extraction (ATPE) represents a promising unit operation for downstream processing of biotechnological products. The technique provides several advantages such as a biocompatible environment for the extraction of sensitive and biologically active compounds. However, the tendency of some aqueous two-phase systems to form intensive and stable emulsions can lead to long phase separation times causing an increased footprint for the required mixer-settler devices or the need for additional equipment such as centrifuges. In this work, a novel approach to improve ATPE for downstream processing applications called 'Tunable Aqueous Polymer-Phase Impregnated Resins' (TAPPIR(®))-Technology is presented. The technology is based on the immobilization of one aqueous phase inside the pores of a solid support. The second aqueous phase forms the bulk liquid around the impregnated solids. Due to the immobilization of one phase, phase emulsification and phase separation of ATPE are realized in a single step. In this study, a biodegradable and sustainable aqueous two-phase system consisting of aqueous polyethylene glycol/sodiumcitrate solutions was chosen. The impregnation of different macroporous glass and ceramic solids was investigated and could be proven to be stable. Additionally, the separation of the dye Patent blue V was successfully performed with the TAPPIR(®)-Technology. Thus, the "proof of principle" of this technology is presented.

  2. Isolation of atropine and scopolamine from plant material using liquid-liquid extraction and EXtrelut(®) columns.

    Science.gov (United States)

    Śramska, Paula; Maciejka, Artur; Topolewska, Anna; Stepnowski, Piotr; Haliński, Łukasz P

    2017-02-01

    Tropane alkaloids are toxic secondary metabolites produced by Solanaceae plants. Among them, plants from Datura genus produce significant amounts of scopolamine and hyoscyamine; the latter undergoes racemization to atropine during isolation. Because of their biological importance, toxic properties and commonly reported food and animal feed contamination by different Datura sp. organs, there is a constant need for reliable methods for the analysis of tropane alkaloids in many matrices. In the current study, three extraction and sample-clean up procedures for the determination of scopolamine and atropine in plant material were compared in terms of their effectiveness and repeatability. Standard liquid-liquid extraction (LLE) and EXtrelut(®) NT 3 columns were used for the sample clean-up. Combined ultrasound-assisted extraction and 24h static extraction using ethyl acetate, followed by multiple LLE steps was found the most effective separation method among tested. However, absolute extraction recovery was relatively low and reached 45-67% for atropine and 52-73% for scopolamine, depending on the compound concentration. The same method was also the most effective one for the isolation of target compounds from Datura stramonium leaves. EXtrelut(®) columns, on the other hand, displayed relatively low effectiveness in isolating atropine and scopolamine from such a complex matrix and hence could not be recommended. The most effective method was also applied to the extraction of alkaloids from roots and stems of D. stramonium. Quantitative analyses were performed using validated method based on gas chromatography with flame ionization detector (GC-FID). Based on the results, the importance of the proper selection of internal standards in the analysis of tropane alkaloids was stressed out.

  3. Extracting Concrete Thermal Characteristics from Temperature Time History of RC Column Exposed to Standard Fire

    Directory of Open Access Journals (Sweden)

    Jung J. Kim

    2014-01-01

    Full Text Available A numerical method to identify thermal conductivity from time history of one-dimensional temperature variations in thermal unsteady-state is proposed. The numerical method considers the change of specific heat and thermal conductivity with respect to temperature. Fire test of reinforced concrete (RC columns was conducted using a standard fire to obtain time history of temperature variations in the column section. A thermal equilibrium model in unsteady-state condition was developed. The thermal conductivity of concrete was then determined by optimizing the numerical solution of the model to meet the observed time history of temperature variations. The determined thermal conductivity with respect to temperature was then verified against standard thermal conductivity measurements of concrete bricks. It is concluded that the proposed method can be used to conservatively estimate thermal conductivity of concrete for design purpose. Finally, the thermal radiation properties of concrete for the RC column were estimated from the thermal equilibrium at the surface of the column. The radiant heat transfer ratio of concrete representing absorptivity to emissivity ratio of concrete during fire was evaluated and is suggested as a concrete criterion that can be used in fire safety assessment.

  4. Phenolic composition of pomegranate peel extracts using an LC-MS approach with silica hydride columns

    Science.gov (United States)

    The peels of different pomegranate cultivars (Molla Nepes, Parfianka, Purple Heart, Wonderful and Vkunsyi) were compared in terms of phenolic composition and total phenolics. Analyses were performed on two silica hydride-based stationary phases: phenyl and undecenoic acid columns. Quantitation was ...

  5. Extracting concrete thermal characteristics from temperature time history of RC column exposed to standard fire.

    Science.gov (United States)

    Kim, Jung J; Youm, Kwang-Soo; Reda Taha, Mahmoud M

    2014-01-01

    A numerical method to identify thermal conductivity from time history of one-dimensional temperature variations in thermal unsteady-state is proposed. The numerical method considers the change of specific heat and thermal conductivity with respect to temperature. Fire test of reinforced concrete (RC) columns was conducted using a standard fire to obtain time history of temperature variations in the column section. A thermal equilibrium model in unsteady-state condition was developed. The thermal conductivity of concrete was then determined by optimizing the numerical solution of the model to meet the observed time history of temperature variations. The determined thermal conductivity with respect to temperature was then verified against standard thermal conductivity measurements of concrete bricks. It is concluded that the proposed method can be used to conservatively estimate thermal conductivity of concrete for design purpose. Finally, the thermal radiation properties of concrete for the RC column were estimated from the thermal equilibrium at the surface of the column. The radiant heat transfer ratio of concrete representing absorptivity to emissivity ratio of concrete during fire was evaluated and is suggested as a concrete criterion that can be used in fire safety assessment.

  6. A new co conversion technology based on liquid/liquid extraction column

    Energy Technology Data Exchange (ETDEWEB)

    Borda, Gilles; Ode, Denis; Duhamet, Jean; Brackx, Emmanuelle [CEA Valrho - Marcoule - BP 17171 - 30207 Bagnols sur Ceze Cedex (France)

    2009-06-15

    The current objective of implementing 'direct' coprecipitation of uranium, plutonium and minor actinides for nuclear fuel re-fabrication leads to reconsider the (co)precipitation step, and more precisely its adaptability to new flowrates' specifications. Indeed, coprecipitation of a uranium fraction together with plutonium results in an appreciable increase in the process flow rates for this step. The technological impact of the increase in capacity could require the development of a different concept for a continuous device capable of ensuring the proposed process. A new type of device designed and patented by the CEA has been tested since 2007. The patent is for organic confinement in a pulsed column (PC) or Couette column (CC). The precipitation reaction between the oxalate complexing agent and a surrogate nitrate-cerium(II) or neodymium(III) alone, or coprecipitated uranium(IV) and cerium(III), occurs within an emulsion created in the device by these two phases flowing with a counter-current chemically inert organic phase (for example TPH) produced by the stirring action of the pulsator (PC) or the central rotor (CC). The precipitate is confined and thus does not form deposits on the vessel walls (which are also water-repellent); it flows downward by gravity and exits the column continuously into a settling tank. This paper describes the recent results obtained with this new technology for precipitation of Ce and Nd and coprecipitation of U + Ce in pulsed column and Couette column. It describes a first modeling allowing further extrapolation of this device to high capacities. (authors)

  7. Continuous-flow fractionation of selenium in contaminated sediment and soil samples using rotating coiled column and microcolumn extraction.

    Science.gov (United States)

    Savonina, Elena Yu; Fedotov, Petr S; Wennrich, Rainer

    2012-01-15

    Dynamic fractionation is considered to be an attractive alternative to conventional batch sequential extraction procedures for partitioning of trace metals and metalloids in environmental solid samples. This paper reports the first results on the continuous-flow dynamic fractionation of selenium using two different extraction systems, a microcolumn (MC) packed with the solid sample and a rotating coiled column (RCC) in which the particulate matter is retained under the action of centrifugal forces. The eluents (leachants) were applied in correspondence with a four-step sequential extraction scheme for selenium addressing "soluble", "adsorbed", "organically bound", and "elemental" Se fractions extractable by distilled water, phosphate buffer, tetramethylammonium hydroxide, and sodium sulphite solutions, respectively. Selenium was determined in the effluent by using an inductively coupled plasma atomic emission spectrometer. Contaminated creek sediment and dumped waste (soil) samples from the abandoned mining area were used to evaluate resemblances and discrepancies of two continuous-flow methods for Se fractionation. In general, similar trends were found for Se distribution between extractable and residual fractions. However, for the dumped waste sample which is rich in organic matter, the extraction in RCC provided more effective recovery of environmentally relevant Se forms (the first three leachable fractions). The most evident deviation was observed for "adsorbed" Se (recoveries by RCC and MC are 43 and 7 mg kg(-1), respectively). The data obtained were correlated with peculiarities of samples under investigation and operational principles of RCC and MC.

  8. Preparation and Application of an Immunoaffinity Column for Direct Extraction of Morphine and its Analogs from Opium

    Institute of Scientific and Technical Information of China (English)

    Xiao Hua QI; Jian Qiu MI; Xin Xiang ZHANG; Wen Bao CHANG

    2004-01-01

    A rapid, simple and accurate method using an immunoaffinity column (IAC) and capillary electrophoresis (CE) for the analysis of the major alkaloids in opium is developed. The IAC was synthesized by coupling specific morphine polyclonal antibodies to CNBr-actived Sepharose 4B. The IAC showed high selectivity and obvious enrichment to morphine, codeine, dionin and thebaine. The extraction solution was analyzed by CE with β-cyclodextrin as an additive. Recoveries of the four alkaloids from PBS were between 93%-105% with RSD value less than 5.0%. The result showed that this method was practical for the determination of morphine analogs in opium.

  9. Monitoring of urine by extraction chromatography with tri-n-octylphosphine oxide supported on a polypropylene column

    Energy Technology Data Exchange (ETDEWEB)

    Bonino, N.; Diodati, J.; Cena, M.R. [Gerencia de Seguridad Radiologica y Nuclear, Comision Nacional de Energia Atomica, Buenos Aires (Argentina)

    1992-07-01

    Monitoring of personnel working with 20% enriched uranium implies development of techniques for excreta analysis, mainly for urine, with very low detection limits. The method described allows the determination of 20% enriched uranium after extraction in tri-n-octylphosphine oxide (TOPO), 0.5 in toluene, supported on polypropylene capillary columns. Alpha activity is later measured in a low background liquid scintillation equipment and the fluorescence in a fluorimeter, with detection limits, for 800 mL of urine, of 15.0 {+-} 4.0 mBq L{sup -1} and 5x10{sup -2} {+-} 10{sup -2} {mu}g L{sup -1}. (author)

  10. A new oxalate co-conversion technology based on liquid/liquid extraction columns

    Energy Technology Data Exchange (ETDEWEB)

    Borda, Gilles; Ode, Denis; Duhamet, Jean; Allegri, Patrick [CEA Nuclear Energy Division - Fuel Cycle Technology Division - System and Chemical Engineering Device Marcoule - 30207 Bagnols sur Ceze (France)

    2008-07-01

    The current objective of fabricating non proliferating nuclear fuel by 'direct' coprecipitation of uranium, plutonium and minor actinides requires a new process to replace the (co)precipitation step. The technological impact of an increased capacity on the work zone could require the development of a different concept for a continuous device capable of ensuring the proposed goal. A new type of device designed and patented by the Cea was tested in 2007. The patent is for organic confinement in a pulsed column. First, precipitation of cerium or neodymium alone has been carried out in this device, with satisfactory results. Moreover, a recent test campaign demonstrated that a uranium-cerium co-precipitate easily forms when the two nitrates are mixed in a pulsed column of the same size operating under very similar process conditions. Qualitatively, the co-precipitate meets the process requirements. (authors)

  11. Development of an immunoaffinity chromatography column for selective extraction of a new agonist phenylethylamine A from feed, meat and liver samples.

    Science.gov (United States)

    Mei, Liyun; Cao, Biyun; Yang, Hong; Xie, Yun; Xu, Shouming; Deng, Anping

    2014-01-15

    Phenylethanolamine A (PA) is a new emerged β-adrenergic agonist that has been illegally used as an animal feed additive for growth promotion in China. In this study, an immunoaffinity chromatography (IAC) column for selective extraction of PA from swine feed, meat and liver samples was developed. The IAC column was constructed by covalently coupling specific polyclonal antibody (Ab) against PA to CNBr-activated Sepharose 4B and packed into a common solid phase extraction (SPE) cartridge. The extraction conditions including loading, washing and eluting solutions were carefully optimized. Under optimal conditions, the IAC column was characterized in terms of maximum capacity, selectivity, extraction recovery and stability. The maximum capacity of the ICA for PA extraction was found to be 239.4ng. For selectivity testing, 100ng of other three β-adrenergic agonists (clenbuterol, ractopamine and salbutamol) was separately loaded onto the column, and it was observed that the tested compounds could not be captured on the column, e.g. the column could only selectively recognize PA. The recovery of the IAC for PA extraction was found within 96.47-101.98% when 10, 50 and 100ng PA were separately loaded onto IAC column. The IAC column was also applied to real sample extraction. Swine feed, meat and liver samples were collected and spiked with PA in range of 1.0-20ngg(-1). The spiked and unspiked samples were extracted by IAC column and measured by high performance liquid chromatography (HPLC). It was found that there was no detectable PA in the blank samples, and the extraction recoveries of the IAC for PA from the spiked samples were within 89.48-104.89%. The stability of the column was also tested. It was showed that after 35 times repeated usage, 60% of the maximum capacity was still remained. The proposed IAC was proven to be a feasible extraction method for PA from different matrices with the properties of high maximum capacity, selectivity, extraction efficiency and

  12. Method Development for Extraction of Butyrylcholin- esterase using Protein-G Agarose Spin Columns

    Directory of Open Access Journals (Sweden)

    Amruta S. Indapurkar

    2015-01-01

    Full Text Available Butyrylcholinesterase (BuChE is a biomarker of organophosphate (OP poisoning and can be used as a diagnostic marker to measure exposure to OP compounds. The purpose of this study was to develop a method to extract BuChE from human plasma. BuChE was extracted from plasma using the NAb protein-G Agarose Spin Kit. Factors affecting extraction like incubation time, plasma volume and cross-linking of antibodies to agarose beads were evaluated. All samples were analyzed for BuChE activity using the Ellman’s assay. The incubation times of plasma and anti-BuChE antibodies marginally affected the extraction efficiency of BuChE whereas a decrease in plasma volume increased the extraction efficiency. Cross-linking of anti-BuChE antibodies on agarose increased the extraction efficiency. The NAb protein-G Spin Kit can be used successfully to extract BuChE from human plasma. This extraction technique may be coupled to downstream analytical analyses for diagnosing exposure to OP compounds.

  13. Online micro-solid-phase extraction based on boronate affinity monolithic column coupled with high-performance liquid chromatography for the determination of monoamine neurotransmitters in human urine.

    Science.gov (United States)

    Yang, Xiaoting; Hu, Yufei; Li, Gongke

    2014-05-16

    Quantification of monoamine neurotransmitters is very important in diagnosing and monitoring of patients with neurological disorders. We developed an online analytical method to selectively determine urinary monoamine neurotransmitters, which coupled the boronate affinity monolithic column micro-solid-phase extraction with high-performance liquid chromatography (HPLC). The boronate affinity monolithic column was prepared by in situ polymerization of vinylphenylboronic acid (VPBA) and N,N'-methylenebisacrylamide (MBAA) in a stainless capillary column. The prepared monolithic column showed good permeability, high extraction selectivity and capacity. The column-to-column reproducibility was satisfactory and the enrichment factors were 17-243 for four monoamine neurotransmitters. Parameters that influence the online extraction efficiency, including pH of sample solution, flow rate of extraction and desorption, extraction volume and desorption volume were investigated. Under the optimized conditions, the developed method exhibited low limit of detection (0.06-0.80μg/L), good linearity (with R(2) between 0.9979 and 0.9993). The recoveries in urine samples were 81.0-105.5% for four monoamine neurotransmitters with intra- and inter-day RSDs of 2.1-8.2% and 3.7-10.6%, respectively. The online analytical method was sensitive, accurate, selective, reliable and applicable to analysis of trace monoamine neurotransmitters in human urine sample.

  14. Development of a CMPO based extraction process for partitioning of minor actinides and demonstration with genuine fast reactor fuel solution (155 GWd/Te)

    Energy Technology Data Exchange (ETDEWEB)

    Antony, M.P.; Kumaresan, R.; Suneesh, A.S. [Indira Gandhi Centre for Atomic Research, Kalpakkam (IN). Fuel Chemistry Div.] (and others)

    2011-07-01

    A method has been developed for partitioning of minor actinides from fast reactor (FR) fuel solution by a TRUEX solvent composed of 0.2 M n-octyl(phenyl)-N,N-diisobutylcarbamoyl-methylphosphine oxide (CMPO)-1.2 M tri-n-butylphosphate (TBP) in n-dodecane (n-DD), and subsequently demonstrated with genuine fast reactor dissolver solution (155 GWd/Te) using a novel 16-stage ejector mixer settler in hot cells. Cesium, plutonium and uranium present in the dissolver solution were removed, prior to minor actinide partitioning, by using ammonium molybdophosphate impregnated XAD-7 (AMP-XAD), methylated poly(4-vinylpyridine) (PVP-Me), and macroporous bifunctional phosphinic acid (MPBPA) resins respectively. Extraction of europium(III) and cerium(III) from simulated and real dissolver solution, and their stripping behavior from loaded organic phase was studied in batch method using various citric acid-nitric acid formulations. Based on these results, partitioning of minor actinides from fast reactor dissolver solution was demonstrated in hot cells. The extraction and stripping profiles of {sup 154}Eu, {sup 144}Ce, {sup 106}Ru and {sup 137}Cs, and mass balance of {sup 241}Am(III) achieved in the demonstration run have been reported in this paper. (orig.)

  15. Treatment of waste waters in oil fields by a new technology-MDIF; Tratamento de aguas de descarte em campos produtores de petroleo atraves de nova tecnologia-MDIF

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes Junior, W.E.; Paulo, J.B.A. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Engenharia Quimica. Programa de Pos-graduacao em Engenharia Quimica]. E-mail: jbosco@eq.ufrn.br; Rolim, T.A.; Chiavenato, M.C.; Lima, A.F. [PETROBRAS, RN/CE (Brazil). Unidade de Negocios

    2004-07-01

    Mixer-settlers are usual equipment for phase separation in liquid-liquid systems. They consist of a mixer and a settling chambers. The critical point of this equipment is the length of the settling chamber. This characteristic is specially relevant where space is limited in lay-out of an industrial plant, for example, in an off-shore platform for oil exploration. An alternative to solve this problem is done by means of 'The Method of Separation by Phase Inversion' which is the base of operation of a new design of mixer-settler named MDIF. The equipment has hybrid characteristics between conventional mixer-settler and extraction columns. This equipment has been used to treat waste waters coming from production oil fields. The laboratory prototype showed an efficiency of separation up to 96% on treating waste waters with oil in a concentration of 100 to 1500 mg/L and total flow of 100 L/h. The effluent on exit of MDIF has approached 20 mg/L of oil (Resolucao CONAMA N. 20). A prototype in a semi-industrial scale of MDIF was designed to operate in real industrial conditions. A hundred times factor of scale laboratory/field was used. In this work a Statistical Experimental Design is carried out to laboratory conditions to get a model to predict the influence of operational variables as: total flow, organic/aqueous ratio on a volumetric basis and speed of agitation into mixer chamber upon efficiency of separation. These data are essential to perform the scale-up of the equipment. (author)

  16. One-step column chromatographic extraction with gradient elution followed by automatic separation of volatiles, flavonoids and polysaccharides from Citrus grandis.

    Science.gov (United States)

    Han, Han-Bing; Li, Hui; Hao, Rui-Lin; Chen, Ya-Fei; Ni, He; Li, Hai-Hang

    2014-02-15

    Citrus grandis Tomentosa is widely used in traditional Chinese medicine and health foods. Its functional components include volatiles, flavonoids and polysaccharides which cannot be effectively extracted through traditional methods. A column chromatographic extraction with gradient elution was developed for one-step extraction of all bioactive substances from C. grandis. Dried material was loaded into a column with petroleum ether: ethanol (8:2, PE) and sequentially eluted with 2-fold PE, 3-fold ethanol: water (6:4) and 8-fold water. The elutes was separated into an ether fraction containing volatiles and an ethanol-water fraction containing flavonoids and polysaccharides. The later was separated into flavonoids and polysaccharides by 80% ethanol precipitation of polysaccharides. Through this procedure, volatiles, flavonoids and polysaccharides in C. grandis were simultaneously extracted at 98% extraction rates and simply separated at higher than 95% recovery rates. The method provides a simple and high-efficient extraction and separation of wide range bioactive substances.

  17. Pressure Drop Measurement of Column Weight in Disc and Doughnut Pulsed Extraction Column by External Air Purge Method%外置吹气杯测量折流板脉冲萃取柱柱重压降

    Institute of Scientific and Technical Information of China (English)

    王悦云; 李少伟; 景山

    2013-01-01

    The pressure drop of column weight was measured in a disc and doughnut pulsed extraction column with the inertial diameter of 0.3 m and height of 5.6 m by in-ternal and external air purge methods ,respectively .The experimental results show that the pressure drops of column weight measured by external air purge method are in good agreement with those by internal air purge method ,therefore ,the external air purge method is recommended to measure the pressure drop of column weight in the pulsed extraction column in plutonium purification cycle .%在内径为0.3m和高度为5.6m的折流板脉冲萃取柱中,分别采用内置吹气杯和外置吹气杯对柱重压降信号进行了测量和比较。实验结果表明,两种吹气杯安装方式所测量的结果一致。因此,为了避免由于内置吹气杯所造成的钚纯化循环脉冲萃取柱异形下澄清段的设计和加工难度,推荐可使用外置吹气杯来测量该工段的脉冲萃取柱柱重压降。

  18. Determination of ricin by nano liquid chromatography/mass spectrometry after extraction using lactose-immobilized monolithic silica spin column.

    Science.gov (United States)

    Kanamori-Kataoka, Mieko; Kato, Haruhito; Uzawa, Hirotaka; Ohta, Shigenori; Takei, Yoshiyuki; Furuno, Masahiro; Seto, Yasuo

    2011-08-01

    Ricin is a glycosylated proteinous toxin that is registered as toxic substance by Chemical Weapons convention. Current detection methods can result in false negatives and/or positives, and their criteria are not based on the identification of the protein amino acid sequences. In this study, lactose-immobilized monolithic silica extraction followed by tryptic digestion and liquid chromatography/mass spectrometry (LC/MS) was developed as a method for rapid and accurate determination of ricin. Lactose, which was immobilized on monolithic silica, was used as a capture ligand for ricin extraction from the sample solution, and the silica was supported in a disk-packed spin column. Recovery of ricin was more than 40%. After extraction, the extract was digested with trypsin and analyzed by LC/MS. The accurate masses of molecular ions and MS/MS spectra of the separated peptide peaks were measured by Fourier transform-MS and linear iontrap-MS, respectively. Six peptides, which were derived from the ricin A-(m/z 537.8, 448.8 and 586.8) and B-chains (m/z 701.3, 647.8 and 616.8), were chosen as marker peptides for the identification of ricin. Among these marker peptides, two peptides were ricin-specific. This method was applied to the determination of ricin from crude samples. The monolithic silica extraction removed most contaminant peaks from the total ion chromatogram of the sample, and the six marker peptides were clearly detected by LC/MS. It takes about 5 h for detection and identification of more than 8 ng/ml of ricin through the whole handling, and this procedure will be able to deal with the terrorism using chemical weapon.

  19. 混合澄清器的专利技术综述%Patent Summarization of Mixer-settler

    Institute of Scientific and Technical Information of China (English)

    许远平

    2015-01-01

    混合澄清器是最早使用且目前仍广泛应用于工业生产的一种萃取设备,它是一种逐级接触式液-液萃取设备.介绍了混合澄清器的发展历程,分析了混合澄清器的国内外专利申请情况,以及专利的发展方向.

  20. Comparison of the Reynolds-averaged Turbulence Models on Single Phase Flow Simulation in Agitated Extraction Columns

    Institute of Scientific and Technical Information of China (English)

    尤学一; H.J.Bart

    2003-01-01

    The flow field of liquid phase (water) of agitated extraction columns is simulated with the help of computational fluid dynamics (CFD). Four kinds of Reynolds-averaged turbulence models, i.e. the standard k-ε model, the RNG (renormaiization group) k-ε model, the realizable k-ε model and the Reynolds stress model, are compared in detail in order to judge which is the best model in terms of the accuracy, less CPU time and memory required. The performance of the realizable k-ε model is obviously improved by reducing the model constant from c2 = 1.90 to c2 = 1.61. It is concluded that the improved realizable k-ε model is the optimal model.

  1. HA demonstration in the Atalante facility of the Ganex 2. cycle for the grouped TRU extraction

    Energy Technology Data Exchange (ETDEWEB)

    Miguirditchian, M.; Roussel, H.; Chareyre, L.; Baron, P.; Espinoux, D.; Calor, J.N.; Viallesoubranne, C.; Lorrain, B.; Masson, M. [CEA/DEN/MAR/DRCP, Marcoule, BP17171, 30207 Bagnols/Ceze (France)

    2009-06-15

    The GANEX process (Group Actinide Extraction), developed by the CEA for the reprocessing of Generation IV spent nuclear fuel, is composed of two extraction cycles following the dissolution of the spent fuel. Once the uranium is selectively extracted from the dissolution solution, the transuranium elements (Np, Pu, Am, and Cm) are separated from the fission products in a second cycle, prior to their co-conversion step and their homogeneous recycling. The DIAMEX-SANEX process, initially developed for the partitioning of trivalent minor actinides (Am and Cm), was adapted to handle neptunium and plutonium along with americium and curium and selected as the reference route for the GANEX 2. cycle process. In the first step, actinides, lanthanides and other extractable fission products are co-extracted at high acidity by a mixture of a malonamide (DMDOHEMA) and an organophosphorous acid (HDEHP) diluted in HTP. In a second step, molybdenum, ruthenium and technetium are stripped from the solvent, before the selective recovery of all actinides by a mixture of HEDTA and citric acid at pH 3. The last step consists in stripping the remaining cations using specific aqueous complexing agents. Distribution ratios of actinides and major fission products were acquired at each step of the process and showed the possibility to adapt the DIAMEX-SANEX process to the group actinide extraction after adjusting experimental conditions (selection of complexing agents, optimization of reagent concentrations). From these batch experiments and from cold and hot counter-current tests, previously performed when studying minor actinide partitioning, a model was developed to describe the behaviour of the target elements. This model was implemented into our liquid-liquid process simulation code in order to design a flowsheet, which was tested in 48 mixer-settlers (laboratory scale) in the CBP hot cell (Atalante facility) on the high active raffinate issued from the GANEX 1. cycle test. (authors)

  2. 超临界流体萃取塔的流体力学和传质性能%Hydrodynamics and Mass Transfer Performance in Supercritical Fluid Extraction Columns

    Institute of Scientific and Technical Information of China (English)

    石冰洁; 张卫东; 张泽廷; 于恩平

    2002-01-01

    New models for describing hydrodynamics and mass transfer performance in supercritical fluid extraction columns were proposed.Those models were proved by experimental data, which were obtained in supercritical fluid extraction packed column, spray column and sieve tray column respectively. The inner diameter of those columns are φ25 mm. These experimental systems include supercritical carbon dioxide-isopropanol-water and supercritical carbon dioxide-ethanol-water, in which supercritical carbon dioxide was dispersed phase, and another was continuous phase. The extraction processes were operated with continuous conntercurrent flow. The predicted values are agreed well with ex-perimental data.

  3. Comparative Studies with N-Methyl-2-Pyrrolidone and Furfural As Solvents for Extraction of Lube Distillates Etude comparative de deux solvants, la n-methyl-2 pyrrolidone et le furfural, pour l'extraction de distillats pour huiles lubrifiantes

    Directory of Open Access Journals (Sweden)

    Krishna R.

    2006-11-01

    Full Text Available Solvent extraction of spindle raw lube distillate from Oman crude using n-methyl pyrrolidone (NMP containing 1. 5wt. % water has been studied using a six-stage all-glass mixer-settler. Results of three operating temperatures with NMP are reported. A 65-55°C extraction temperature appears to be most appropriate for this stock. Data obtained at this temperature have been compared with those for furfural on the basis of phase boundary curves, extraction and lube refining indices and selectivity. Comparison of the results shows NMP to be more selective as far as raffinate yield is concerned. It requires lower operating solvent-to-feed ratios and lower temperatures. On étudie dans cet article l'extraction par solvant de distillats bruts pour huiles lubrifiantes spindles au moyen de n-méthyl pyrrolydone (NMP contenant 1,5 % d'eau en poids, dans une unité en verre constituée par une batterie de six mélangeurs-décanteurs. On présente les résultats relatifs à trois températures de fonctionnement avec la NMP. Une température d'extraction de 66-55°C est celle qui convient le mieux pour cette huile de base. On compare les résultats obtenus à cette température avec ceux du furfural, en ce qui concerne les courbes de solubilité, les indices de raffinage et d'extraction, et les sélectivités. La comparaison des résultats montre que la NMP est plus sélective et conduit à un rendement de raffinat plus élevé. Elle nécessite des taux de solvant par rapport à la charge plus faibles ainsi que des températures d'extraction plus basses.

  4. Phenylboronic acid modified solid-phase extraction column: Preparation, characterization, and application to the analysis of amino acids in sepia capsule by removing the maltose.

    Science.gov (United States)

    Guo, Mengzhe; Yin, Dengyang; Han, Jie; Zhang, Liyan; Li, Xiao; He, Dandan; Du, Yan; Tang, Daoquan

    2016-09-01

    Maltose, a common auxiliary material of pharmaceutical preparation, may disturb the analysis of total amino acids in sepia capsule by aldolization. Therefore, it is necessary to remove the maltose through a convenient method. In this work, a phenylboronic acid modified solid-phase extraction column has been synthesized and used to remove the maltose. The materials were synthesized by one step "thiol-ene" reaction and the parameters of the column such as absorption capacity, recovery, and absorption specificity have been investigated. The results showed the column (0.5 cm of length × 0.5 cm of inner diameter) can absorb 4.6 mg maltose with a linear absorption and absorption specificity. Then this technique was applied in the quantification of amino acids in sepia capsule. After the optimization of the method, four kinds of amino acids, which were the most abundant, were quantified by high-performance liquid chromatography with diode array detection. The amounts of the four kinds of amino acids are 1.5∼2 times more than that without the treatment of solid-phase extraction column, which almost overcomes the influence of the maltose. All the results indicate that the phenylboronic acid modified solid-phase extraction column can successfully help to accurately quantify the total amino acids in sepia capsule.

  5. Wall modified photonic crystal fibre capillaries as porous layer open tubular columns for in-capillary micro-extraction and capillary chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Kazarian, Artaches A. [Australian Centre for Research on Separation Science, School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001 (Australia); W.M. Keck FT-ICR-MS Laboratory, Department of Chemistry, North Carolina State University, Raleigh, NC (United States); Sanz Rodriguez, Estrella; Deverell, Jeremy A. [Australian Centre for Research on Separation Science, School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001 (Australia); McCord, James; Muddiman, David C. [W.M. Keck FT-ICR-MS Laboratory, Department of Chemistry, North Carolina State University, Raleigh, NC (United States); Paull, Brett, E-mail: Brett.Paull@utas.edu.au [Australian Centre for Research on Separation Science, School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001 (Australia); ARC Centre of Excellence for Electromaterials Science, School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001 (Australia)

    2016-01-28

    Wall modified photonic crystal fibre capillary columns for in-capillary micro-extraction and liquid chromatographic separations is presented. Columns contained 126 internal parallel 4 μm channels, each containing a wall bonded porous monolithic type polystyrene-divinylbenzene layer in open tubular column format (PLOT). Modification longitudinal homogeneity was monitored using scanning contactless conductivity detection and scanning electron microscopy. The multichannel open tubular capillary column showed channel diameter and polymer layer consistency of 4.2 ± 0.1 μm and 0.26 ± 0.02 μm respectively, and modification of 100% of the parallel channels with the monolithic polymer. The modified multi-channel capillaries were applied to the in-capillary micro-extraction of water samples. 500 μL of water samples containing single μg L{sup −1} levels of polyaromatic hydrocarbons were extracted at a flow rate of 10 μL min{sup −1}, and eluted in 50 μL of acetonitrile for analysis using HPLC with fluorescence detection. HPLC LODs were 0.08, 0.02 and 0.05 μg L{sup −1} for acenaphthene, anthracene and pyrene, respectively, with extraction recoveries of between 77 and 103%. The modified capillaries were also investigated briefly for direct application to liquid chromatographic separations, with the retention and elution of a standard protein (cytochrome c) under isocratic conditions demonstrated, proving chromatographic potential of the new column format, with run-to-run retention time reproducibility of below 1%. - Highlights: • Novel PS-DVB modified photonic crystal fibres for in-capillary micro-extraction. • New method for micro-extraction of PAHs and HPLC-FL detection at sub-ppb levels. • Demonstration of PS-DVB modified photonic crystal fibres for capillary bioseparations.

  6. Extraction of amphetamines and methylenedioxyamphetamines from urine using a monolithic silica disk-packed spin column and high-performance liquid chromatography-diode array detection.

    Science.gov (United States)

    Namera, Akira; Nakamoto, Akihiro; Nishida, Manami; Saito, Takeshi; Kishiyama, Izumi; Miyazaki, Shota; Yahata, Midori; Yashiki, Mikio; Nagao, Masataka

    2008-10-24

    To overcome the limitations of solid-phase extraction, we developed a device comprising a spin column packed with octadecyl silane-bonded monolithic silica for extracting amphetamines and methylenedioxyamphetamines from urine. Urine (0.5mL), buffer (0.4mL), and methoxyphenamine (internal standard) were directly put into the preactivated column. The column was centrifuged (3000rpm, 5min) for sample loading and washed. The adsorbed analytes were eluted and analyzed by high-performance liquid chromatography, without evaporation. The results were as follows: linear curves (drug concentrations of 0.2-20microg/mL); correlation coefficients >0.99; detection limit, 0.1microg/mL. The proposed method is not only useful for drugs from biological materials but also highly reproducible for the analysis of these drugs in urine.

  7. Determination of Wastewater Compounds in Sediment and Soil by Pressurized Solvent Extraction, Solid-Phase Extraction, and Capillary-Column Gas Chromatography/Mass Spectrometry

    Science.gov (United States)

    Burkhardt, Mark R.; Zaugg, Steven D.; Smith, Steven G.; ReVello, Rhiannon C.

    2006-01-01

    A method for the determination of 61 compounds in environmental sediment and soil samples is described. The method was developed in response to increasing concern over the effects of endocrine-disrupting chemicals in wastewater and wastewater-impacted sediment on aquatic organisms. This method also may be used to evaluate the effects of combined sanitary and storm-sewer overflow on the water and sediment quality of urban streams. Method development focused on the determination of compounds that were chosen on the basis of their endocrine-disrupting potential or toxicity. These compounds include the alkylphenol ethoxylate nonionic surfactants and their degradates, food additives, fragrances, antioxidants, flame retardants, plasticizers, industrial solvents, disinfectants, fecal sterols, polycyclic aromatic hydrocarbons, and high-use domestic pesticides. Sediment and soil samples are extracted using a pressurized solvent extraction system. The compounds of interest are extracted from interfering matrix components by high-pressure water/isopropyl alcohol extraction. The compounds were isolated using disposable solid-phase extraction (SPE) cartridges containing chemically modified polystyrene-divinylbenzene resin. The cartridges were dried with nitrogen gas, and then sorbed compounds were eluted with methylene chloride (80 percent)-diethyl ether (20 percent) through Florisil/sodium sulfate SPE cartridge, and then determined by capillary-column gas chromatography/mass spectrometry. Recoveries in reagent-sand samples fortified at 4 to 72 micrograms averaged 76 percent ?13 percent relative standard deviation for all method compounds. Initial method reporting levels for single-component compounds ranged from 50 to 500 micrograms per kilogram. The concentrations of 20 out of 61 compounds initially will be reported as estimated with the 'E' remark code for one of three reasons: (1) unacceptably low-biased recovery (less than 60 percent) or highly variable method performance

  8. Separation of the Components of a Commercial Analgesic Tablet: A Two-Week Sequence Comparing Purification by Two-Base Extraction and Column Chromatography

    Science.gov (United States)

    Revell, Kevin D.

    2011-01-01

    A new laboratory experiment is described in which students compare two benchtop separation methods to isolate the three active components of the commercial analgesic Excedrin. In the two-week sequence, aspirin, acetaminophen, and caffeine are separated using either a two-base liquid-liquid extraction or silica column chromatography. Students then…

  9. Separation of the Components of a Commercial Analgesic Tablet: A Two-Week Sequence Comparing Purification by Two-Base Extraction and Column Chromatography

    Science.gov (United States)

    Revell, Kevin D.

    2011-01-01

    A new laboratory experiment is described in which students compare two benchtop separation methods to isolate the three active components of the commercial analgesic Excedrin. In the two-week sequence, aspirin, acetaminophen, and caffeine are separated using either a two-base liquid-liquid extraction or silica column chromatography. Students then…

  10. Speciation of Cr(III) and Cr(VI) after column solid phase extraction on Amberlite XAD-2010.

    Science.gov (United States)

    Bulut, V N; Duran, C; Tufekci, M; Elci, L; Soylak, M

    2007-05-08

    A speciation procedure for Cr(III) and Cr(VI) based on column solid phase extraction on Amberlite XAD-2010 and flame atomic absorption spectrometry combination. Cr(VI) was quantitatively recovered on Amberlite XAD-2010 resin at pH range of 2.0-3.0 as its diethyldithiocarbamate complex, while the recoveries of Cr(III) was below 5%. The influences of the various parameters including amounts of the reagents, eluent type and its volume, sample volume, etc., on the quantitative recoveries were examined. The interference of matrix and coexistent elements for method were studied. The detection limit (corresponding to three times the standard deviation of the blank) and the enrichment factor for Cr(VI) were found to be 1.28 microg/L and 25, respectively. To verify the accuracy of the method, drinking water certified reference material (CRM-TMDW-500) was analyzed and the results obtained were in good agreement with the certified value. The proposed method has been successfully applied to the speciation of Cr(III) and Cr(VI) in water samples and preconcentration of total chromium in environmental samples.

  11. Application of tandem column solid phase extraction and flame atomic absorption spectrometry for the determination of inorganic and organically bound forms of iron in wine.

    Science.gov (United States)

    Pohl, Pawel; Prusisz, Bartlomiej

    2009-03-15

    A tandem column solid phase extraction (SPE) procedure has been devised to examine the fractionation of Fe in wine. Wine was filtered through a 0.45 microm filter and then, the filtrate was driven through an adsorbing Amberlite XAD-7HP column followed by a cation exchange Dowex 50 W-x8-200 column. Three different Fe groupings are discriminated and assessed, including hydrophobic species of Fe bound to phenolic substances and related species (phenolic fraction), cationic species comprising simple Fe ions and labile Fe forms (cationic fraction), in addition to anionic and/or neutral Fe complexes with organic acids (residual fraction). The suitability of the procedure has been evaluated analyzing four bottled red wines. The results obtained were verified using another tandem column assemblage in which an adsorbing Amberlite XAD-16 column was exchanged by the Amberlite XAD-7HP column. The fractionation pattern ascertained for Fe in analyzed wines is discussed in reference to previously published works. In addition, a conditioning treatment and preparation of Amberlite XAD resins have been revised.

  12. Determina tion of diacetyl and 2,3-pentanedione in beer by gc/ms using solid-phase extraction columns

    Directory of Open Access Journals (Sweden)

    Pejin Jelena D.

    2002-01-01

    Full Text Available A new GC/MS method for the determination of diacetyl and 2,3-pentanedione was investigated. Diacetyl and 2,3-pentanedione were derivatized with 1,2-diaminobenzene to form 2,3-dimetylquinoxaline and 2-ethyl-3-methylquinoxaline. respectively. The amounts of formed 2.3-dimetylqu:inoxaline and 2-ethyl-3,.methylquinoxaline were proportional to the concentrations of diacetyl and 2,3-penianedione present in the sample. 2,3-Dimetylquinoxaline and 2-ethyl-3-methylquinoxaline were extracted by solid-phase extraction (SPE columns and determined by gas chromatography using a mass selective detector. This method was applied for the determination of diacetyl and 2,3-pentanedione concentrations in beer. Extraction by SPE columns proved to be very simple and reliable. The method can be used for simultaneous determination of diacetyl and 2,3-pentanedione concentrations in beer in a great number of beer samples.

  13. Phytochemical analysis of ethanolic extract of Dichrostachys Cinerea W and Arn leaves by a thin layer chromatography, high performance thin layer chromatography and column chromatography.

    Science.gov (United States)

    Vijayalakshmi, M; Periyanayagam, K; Kavitha, K; Akilandeshwari, K

    2013-04-01

    The leaves of Dichrostachys cinerea are used as laxative, diuretic, painkiller. It is also used in the treatment of gonorrhoea, boils, oedema, gout, veneral diseases and nasopharyngeal affections, etc. The Phytochemical investigation of ethanolic extract of D. cinerea leaves were performed by standard chemical tests, thin layer chromatography (TLC) by using various solvent systems, and by high performance liquid chromatography (HPTLC). Two compounds were isolated by column chromatography and one of the compounds was identified by various spectral studies. Preliminary phytochemical screening of ethanolic extract of D. cinerea leaves showed the presence of Carbohydrates, proteins, Glycosides, Saponins, Tannins, Aminoacids and Terpenoids. The TLC and HPTLC fingerprint of ethanolic extract were studied and various fractions were isolated by column chromatography and one of the fraction contain β-amyrin glucoside which was confirmed by Infra Red[IR] Spectroscopy, (1)H-Nuclear Magnetic Resonance (NMR), C-(13) NMR and Mass spectroscopic (MS) studies.

  14. 带有中间储罐的塔用于间歇萃取精馏%Batch Extractive Distillation in a Column with a Middle Vessel

    Institute of Scientific and Technical Information of China (English)

    崔现宝; 杨志才; 翟亚锐; 潘玉军

    2002-01-01

    Batch extractive distillation was studied in a column with a middle vessel. The process was simulatedby a constant holdup model and solved by two point implicit method. Acetone and methanol mixture was separatedin such a setup using water as solvent. The simulation agrees well with experimental results. The experimental andsimulation results show that the solvent at the bottom and the product at the top of the column can be withdrawnsimultaneously for a long period of time. It needs more time for the solvent to reach high purity than that requiredfor the more volatile component to reach high purity, so that the time to withdraw solvent from the bottom isdelayed.

  15. Solid phase extraction of chromium(VI) from aqueous solutions by adsorption of its diphenylcarbazide complex on an Amberlite XAD-4 resin column.

    Science.gov (United States)

    Rajesh, N; Jalan, Rohit Kumar; Hotwany, Pinky

    2008-02-11

    A method has been developed for the solid phase extraction of chromium(VI) based on the adsorption of its diphenylcarbazide complex on an Amberlite XAD-4 resin column. The influence of acidity, stability of the column, sample volume, flow rate and interfering ions were studied in detail. The adsorbed complex could be eluted using acetone-sulfuric acid mixture and the concentration of chromium was determined using visible spectrophotometry. A detection limit of 6 microg L(-1) could be achieved. A preconcentration factor of 27 could be obtained for 400 mL sample volume. The validity of the method was checked in spiked water samples and electroplating wastewater.

  16. Wall modified photonic crystal fibre capillaries as porous layer open tubular columns for in-capillary micro-extraction and capillary chromatography.

    Science.gov (United States)

    Kazarian, Artaches A; Sanz Rodriguez, Estrella; Deverell, Jeremy A; McCord, James; Muddiman, David C; Paull, Brett

    2016-01-28

    Wall modified photonic crystal fibre capillary columns for in-capillary micro-extraction and liquid chromatographic separations is presented. Columns contained 126 internal parallel 4 μm channels, each containing a wall bonded porous monolithic type polystyrene-divinylbenzene layer in open tubular column format (PLOT). Modification longitudinal homogeneity was monitored using scanning contactless conductivity detection and scanning electron microscopy. The multichannel open tubular capillary column showed channel diameter and polymer layer consistency of 4.2 ± 0.1 μm and 0.26 ± 0.02 μm respectively, and modification of 100% of the parallel channels with the monolithic polymer. The modified multi-channel capillaries were applied to the in-capillary micro-extraction of water samples. 500 μL of water samples containing single μg L(-1) levels of polyaromatic hydrocarbons were extracted at a flow rate of 10 μL min(-1), and eluted in 50 μL of acetonitrile for analysis using HPLC with fluorescence detection. HPLC LODs were 0.08, 0.02 and 0.05 μg L(-1) for acenaphthene, anthracene and pyrene, respectively, with extraction recoveries of between 77 and 103%. The modified capillaries were also investigated briefly for direct application to liquid chromatographic separations, with the retention and elution of a standard protein (cytochrome c) under isocratic conditions demonstrated, proving chromatographic potential of the new column format, with run-to-run retention time reproducibility of below 1%.

  17. Study of axial mixing, holdup and slip velocity of dispersed phase in a pulsed sieve plate extraction column using radiotracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Ghiyas Ud Din [Department of Nuclear Engineering, Pakistan Institute of Engineering and Applied Sciences -PIEAS, P.O Nilore, Islamabad (Pakistan); Isotope Application Division, Pakistan Institute of Nuclear Science and Technology - PINSTECH, P.O Nilore, Islamabad (Pakistan)], E-mail: fac192@pieas.edu.pk; Imran Rafiq Chughtai; Mansoor Hameed Inayat [Department of Chemical and Materials Engineering, Pakistan Institute of Engineering and Applied Sciences - PIEAS, P.O Nilore, Islamabad (Pakistan); Iqbal Hussain Khan [Isotope Application Division, Pakistan Institute of Nuclear Science and Technology - PINSTECH, P.O Nilore, Islamabad (Pakistan)

    2009-07-15

    Axial mixing, holdup and slip velocity of dispersed phase which are parameters of fundamental importance in the design and operation of liquid-liquid extraction pulsed sieve plate columns have been investigated. Experiments for residence time distribution (RTD) analysis have been carried out for a range of pulsation frequency and amplitude in a liquid-liquid extraction pulsed sieve plate column with water as dispersed and kerosene as continuous phase using radiotracer technique. The column was operated in emulsion region and {sup 99m}Tc in the form of sodium pertechnetate eluted from a {sup 99}Mo/{sup 99m}Tc generator was used to trace the dispersed phase. Axial dispersed plug flow model with open-open boundary condition and two points measurement method was used to simulate the hydrodynamics of dispersed phase. It has been observed that the axial mixing and holdup of dispersed phase increases with increase in pulsation frequency and amplitude until a maximum value is achieved while slip velocity decreases with increase in pulsation frequency and amplitude until it approaches a minimum value. Short lived and low energy radiotracer {sup 99m}Tc in the form of sodium pertechnetate was found to be a good water tracer to study the hydrodynamics of a liquid-liquid extraction pulsed sieve plate column operating with two immiscible liquids, water and kerosene. Axial dispersed plug flow model with open-open boundary condition was found to be a suitable model to describe the hydrodynamics of dispersed phase in the pulsed sieve plate extraction column.

  18. Determination of antihyperglycemic biguanides in serum and urine using an ion-pair solid-phase extraction technique followed by HPLC-UV on a pentafluorophenylpropyl column and on an octadecyl column.

    Science.gov (United States)

    Tahara, Kayoko; Yonemoto, Ayumi; Yoshiyama, Yuji; Nakamura, Toshiya; Aizawa, Masaaki; Fujita, Yoshikuni; Nishikawa, Takashi

    2006-11-01

    An HPLC-UV method was established for the determination of metformin and buformin in biological fluids. Metformin was not retained on particles packed in conventional solid-phase extraction cartridges; in contrast, buformin was retained too firmly and not eluted with a solvent for recovery. However, both drugs were retained on particles that had been treated with an ion-pair reagent of heptanesulfonate or dodecylsulfate and recovered almost completely. The recovered fraction was subjected to HPLC on a pentafluorophenylpropyl column which was suitable for the determination of both biguanides in serum and in urine. Limits of quantitation were low enough for clinical use, and reproducibility was high with an RSD of 0.9-2.3%. HPLC on a conventional octadecyl column was suitable only for the determination of buformin in serum since interfering peaks appeared on the chromatograms of urine samples. The method was applied to analysis of some clinical specimens.

  19. CFD simulation and experimental investigation of the copper solvent extraction in a pilot plant pulsed packed column in Sarcheshmeh Copper Complex

    Science.gov (United States)

    Mirzaie, Maryam; Sarrafi, Amir; Hashemipour, Hasan; Baghaie, Ali; Molaeinasab, Mehdi

    2017-06-01

    Present work deals with the development of a computational fluid dynamics (CFD) model for investigate the extraction of copper from leach solution with the Lix84-I. The model is based on Eulerian-Eulerian two phase equations in conjunction with the realizable k-ɛ model for turbulence. Population balance modeling (PBM) is used to describe the dynamics of the time and space variation of droplet sizes in the column. The PBM equation is solved using the class method. The mass transfer is the important parameters which can improve the performance of pulsed column and changes widely with the variation in the droplet number density. Valid empirical correlations were implemented to the CFD model for mass transfer coefficients by user defined functions. To validate the model, the results of CFD model and experimental measurements were compared and there was a good agreement between them. The effects of flow rates and intensity of pulsation on the yield of copper extraction and entrainment of the organic phase were studied. The results shown that increasing the phase ratio (the flow rate of organic phase/aqueous phase) from 0.5 to 1.75, caused yield of copper extraction from leach solution increased from 31 to 91%. The organic entrainment increased with increasing the pulse intensity and phase flow rates. Additionally, the results show that the performance of the pulsed packed column for copper extraction is reasonable.

  20. Spatholobus suberectus Column Extract Inhibits Estrogen Receptor Positive Breast Cancer via Suppressing ER MAPK PI3K/AKT Pathway

    Directory of Open Access Journals (Sweden)

    Jia-Qi Sun

    2016-01-01

    Full Text Available Although Chinese herbal compounds have long been alternatively applied for cancer treatment in China, their treatment effects have not been sufficiently investigated. The Chinese herb Spatholobus suberectus is commonly prescribed to cancer patients. HPLC analysis has shown that the main components of Spatholobus suberectus are flavonoids that can be classified as phytoestrogens, having a structure similar to estrogen. This study was designed to investigate the effects of Spatholobus suberectus column extract (SSCE on the estrogen receptor-positive (ER+ breast cancer cell line MCF-7 and its possible molecular mechanism. In our study, MTT assay was performed to evaluate cell viability. The results show that SSCE (80, 160, and 320 μg/ml significantly decreased the viability of MCF-7 cells. SSCE also triggered apoptosis, arrested the cell cycle at the G0/G1 phase, and inhibited cell migration. A dual-luciferase reporter system showed that SSCE suppressed intranuclear p-ER activity; Western blot analysis confirmed the repressed expression of phosphorylated-ER alpha (p-ERα, ERK1/2, p-ERK1/2, AKT, p-AKT, p-mTOR, PI3K, and p-PI3K, indicating that SSCE suppressed the MAPK PI3K/AKT signaling pathway. Collectively, our results suggest that SSCE causes apoptosis, an arrest in the G0/G1 phase, and a decrease in migration in ER+ MCF-7 cells via hypoactivity of the ER and suppression of the MAPK PI3K/AKT pathway.

  1. Design of an Extractive Distillation Column for the Environmentally Benign Separation of Zirconium and Hafnium Tetrachloride for Nuclear Power Reactor Applications

    Directory of Open Access Journals (Sweden)

    Le Quang Minh

    2015-09-01

    Full Text Available Nuclear power with strengthened safety regulations continues to be used as an important resource in the world for managing atmospheric greenhouse gases and associated climate change. This study examined the environmentally benign separation of zirconium tetrachloride (ZrCl4 and hafnium tetrachloride (HfCl4 for nuclear power reactor applications through extractive distillation using a NaCl-KCl molten salt mixture. The vapor–liquid equilibrium behavior of ZrCl4 and HfCl4 over the molten salt system was correlated with Raoult’s law. The molten salt-based extractive distillation column was designed optimally using a rigorous commercial simulator for the feasible separation of ZrCl4 and HfCl4. The molten salt-based extractive distillation approach has many potential advantages for the commercial separation of ZrCl4 and HfCl4 compared to the conventional distillation because of its milder temperatures and pressure conditions, smaller number of required separation trays in the column, and lower energy requirement for separation, while still taking the advantage of environmentally benign feature by distillation. A heat-pump-assisted configuration was also explored to improve the energy efficiency of the extractive distillation process. The proposed enhanced configuration reduced the energy requirement drastically. Extractive distillation can be a promising option competing with the existing extraction-based separation process for zirconium purification for nuclear power reactor applications.

  2. Direct SX of uranium from low-grade leach solutions

    Energy Technology Data Exchange (ETDEWEB)

    Grinbaum, B., E-mail: baruchgr@bateman.co.il [Bateman Advanced Technologies, Yokneam (Israel)

    2010-07-01

    Historically, recovery of uranium from high-grade (>400 ppm U) pregnant leach solutions (PLS) was done by solvent extraction (SX), while low-grade feed was treated by ion exchange (IX). Significant improvement in the SX technology, especially application of large pulsed columns instead of mixer-settlers (MS), have now made the SX more attractive for PLS with U below 100 ppm. Recently Bateman carried out three test work programs for direct SX of low-grade (<100 ppm) U PLS, using BPC pulsed columns for extraction and MS for stripping and scrubbing. In all 3 cases the results prove that the direct SX is overall more economical that any combination of IX and SX. Based on these results, two industrial plants, in South Africa and Australia, were erected. (author)

  3. Preparation of solvents for extraction of vegetable oils using dividing wall extractive distillation column%间壁塔萃取精馏制取植物油抽提溶剂的研究

    Institute of Scientific and Technical Information of China (English)

    程振华; 李文涛; 戴海林; 陈平文; 刘元直

    2011-01-01

    The coking problems of the solvents for extraction of vegetable oils in the extractive distillation process have been studied. The reason caused coking of the solvents is analyzed. The method using dividing wall extractive distillation column to produce solvents for extraction of vegetable oils is proposed. The process simulation software is applied to compare the dividing wall extractive distillation columns with the traditional distillation ones. The simulatian resullts show that , the optimum operating parameters for dividing wall extractive distillation column are shown as follows:30 of theoretical plates in main column ,1.1 ( volume ratio) of extractant to oil , lateral line discharging plate at 27th plate of the main column. In comparison with direct sequence of conventional distillation , the re-boiler duty and condenser duty of the dividing wall extractive distillation column are reduced by 10% and by 15% , respectively. The capital investment is decreased as well.%针对植物油抽提溶剂萃取精馏系统存在的萃取剂结焦问题展开研究,分析了萃取剂结焦的原因,提出了间壁塔萃取精馏制取植物油抽提溶剂的思路,并应用工艺模拟软件对比了间壁塔萃取精馏工艺和常规精馏工艺.模拟结果表明,间壁塔主塔合适的理论塔板数为30,侧线塔塔板数为10,剂油比为1.1(体积比),侧线采出位置为第27块板.与常规两塔精馏相比,再沸器热负荷降低约10%,冷凝器热负荷降低15%,且设备投资也有所减少.

  4. The effect of temperature and flow rate on the clarification of the aqueous stevia-extract in a fixed-bed column with zeolites

    Directory of Open Access Journals (Sweden)

    Mantovaneli I. C. C.

    2004-01-01

    Full Text Available Stevia is being used as a sweetener due to its low calorific value and its taste, which is very similar to that of sucrose. After extraction from dried leaves, stevia extract is dark in colour so needs to be clarified for better acceptance by consumers. Adsorption is one of the most important processes in this clarification. In this work the clarification of extract stevia extract in fixed-bed columns with calcium zeolites was studied. Two temperatures (10ºC and 30ºC and six different flow rates (2, 5, 9, 12, 16 and 19 mL/min were studied. The results showed that the mass-transfer coeffcient increases with an increase in flow rate and the length of unused bed reaches a maximum at 9 mL/min for both temperatures. The fit of the Thomas model with the breakthrough data was not very good.

  5. Quantitative extraction of methylgermanium species at trace levels and determination by on-column capillary gas chromatography with flame photometric detector

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    A solvent extraction procedure for the quantitativeextraction of trace levels of methylgermanium species as theirchloride complex has been developed and the extract was determinedby an on-column capillary gas chromatography with a lab-modifiedflame phorometric detector(FPD) using quartz surface-inducedgermanium emission after pentylation with Grignard reaction. Theextracted percentages for TMGe, DMGe and MMGe in a 100-ml 9mol/LHCl aqueous solution by a single extraction with 1 ml hexane are86.6%, 87.4% and 96.2%, respectively. The precision for overallprocedure range from 3.9% to 7.5%. The extraction was found to beindependent of the initial concentration of methylgermanium speciesin the aqueous phase, which typically varied from 0.1 to 10 μg. This method is suitable for most types of environmental samples and, are superior to all hydride generation coupled spectrometric andspectrophotometric methods in terms of selectivity and toleranceability to interference.

  6. Selection of Extraction Column in Solid Phase Extraction of Ethyl Carbamate%固相萃取氨基甲酸乙酯过程萃取柱的选择比较

    Institute of Scientific and Technical Information of China (English)

    严敏; 吕昱; 黄云芳

    2015-01-01

    In this study, the extracting effects of each extraction column in the extraction of ethyl carbamate were investigated to obtain the opti-mum extracting conditions and the best extraction column. Meanwhile, the selection method of the extraction column in solid phase EC extrac-tion technique was established and further optimized. Firstly, 5 mL ethyl carbamate was taken, pH value adjusted to 7.5, balancing time was 10 mins, the extracting time was 30 mins, then sample desorption by gas-phase held for 10 mins, then several kinds of extraction columns includ-ing silica gel column, Welchrom Florisil, Welchrom Silica, Aglient Technologies and Welchrom C18 were selected for comparative study. The re-sults suggested that, Welchrom C18 had the best decolorization and impurity-removal effects with more stable baseline and easier quantitative analysis and the highest recovery rate. Finally, Welchrom C18 was selected for sample purification. The study provided foundation for further re-search on ethyl carbamate solid-phase extraction.%以固相萃取前处理技术作为重点研究对象,在固相萃取氨基甲酸乙酯的技术中,检测出各萃取柱的萃取效果,找到最佳的萃取条件和萃取柱,优化建立固相萃取EC萃取柱技术的选择比较的方法。取5 mL的氨基甲酸乙酯,调节pH7.5,平衡时间10 min,萃取时间30 min,气相进样解吸10 min。选用硅胶柱Welchrom Florisil、Wel-chrom Silica、Aglient Technologies和Welchrom C18进行对比研究。结果表明,Welchrom C18脱色除杂效果最好且基线较为平稳,更易定量,回收率最高;最后选择Welchrom C18用于样品净化。研究为固相萃取氨基甲酸乙酯技术中的进一步研究提供前期的基础。

  7. Efficient extraction and preparative separation of four main isoflavonoids from Dalbergia odorifera T. Chen leaves by deep eutectic solvents-based negative pressure cavitation extraction followed by macroporous resin column chromatography.

    Science.gov (United States)

    Li, Lu; Liu, Ju-Zhao; Luo, Meng; Wang, Wei; Huang, Yu-Yan; Efferth, Thomas; Wang, Hui-Mei; Fu, Yu-Jie

    2016-10-15

    In this study, green and efficient deep eutectic solvent-based negative pressure cavitation-assisted extraction (DES-NPCE) followed by macroporous resin column chromatography was developed to extract and separate four main isoflavonoids, i.e. prunetin, tectorigenin, genistein and biochanin A from Dalbergia odorifera T. Chen leaves. The extraction procedure was optimized systematically by single-factor experiments and a Box-Behnken experimental design combined with response surface methodology. The maximum extraction yields of prunetin, tectorigenin, genistein and biochanin A reached 1.204, 1.057, 0.911 and 2.448mg/g dry weight, respectively. Moreover, the direct enrichment and separation of four isoflavonoids in DES extraction solution was successfully achieved by macroporous resin AB-8 with recovery yields of more than 80%. The present study provides a convenient and efficient method for the green extraction and preparative separation of active compounds from plants.

  8. The effect of dilution and the use of a post-extraction nucleic acid purification column on the accuracy, precision, and inhibition of environmental DNA samples

    Science.gov (United States)

    Mckee, Anna M.; Spear, Stephen F.; Pierson, Todd W.

    2015-01-01

    Isolation of environmental DNA (eDNA) is an increasingly common method for detecting presence and assessing relative abundance of rare or elusive species in aquatic systems via the isolation of DNA from environmental samples and the amplification of species-specific sequences using quantitative PCR (qPCR). Co-extracted substances that inhibit qPCR can lead to inaccurate results and subsequent misinterpretation about a species’ status in the tested system. We tested three treatments (5-fold and 10-fold dilutions, and spin-column purification) for reducing qPCR inhibition from 21 partially and fully inhibited eDNA samples collected from coastal plain wetlands and mountain headwater streams in the southeastern USA. All treatments reduced the concentration of DNA in the samples. However, column purified samples retained the greatest sensitivity. For stream samples, all three treatments effectively reduced qPCR inhibition. However, for wetland samples, the 5-fold dilution was less effective than other treatments. Quantitative PCR results for column purified samples were more precise than the 5-fold and 10-fold dilutions by 2.2× and 3.7×, respectively. Column purified samples consistently underestimated qPCR-based DNA concentrations by approximately 25%, whereas the directional bias in qPCR-based DNA concentration estimates differed between stream and wetland samples for both dilution treatments. While the directional bias of qPCR-based DNA concentration estimates differed among treatments and locations, the magnitude of inaccuracy did not. Our results suggest that 10-fold dilution and column purification effectively reduce qPCR inhibition in mountain headwater stream and coastal plain wetland eDNA samples, and if applied to all samples in a study, column purification may provide the most accurate relative qPCR-based DNA concentrations estimates while retaining the greatest assay sensitivity.

  9. Chip-based molecularly imprinted monolithic capillary array columns coated GO/SiO2 for selective extraction and sensitive determination of rhodamine B in chili powder.

    Science.gov (United States)

    Zhai, Haiyun; Huang, Lu; Chen, Zuanguang; Su, Zihao; Yuan, Kaisong; Liang, Guohuan; Pan, Yufang

    2017-01-01

    A novel solid-phase extraction chip embedded with array columns of molecularly imprinted polymer-coated silanized graphene oxide (GO/SiO2-MISPE) was established to detect trace rhodamine B (RB) in chili powder. GO/SiO2-MISPE monolithic columns for RB detection were prepared by optimizing the supporting substrate, template, and polymerizing monomer under mild water bath conditions. Adsorption capacity and specificity, which are critical properties for the application of the GO/SiO2-MISPE monolithic column, were investigated. GO/SiO2-MIP was examined by scanning electron microscopy (SEM) and Fourier transform-infrared spectroscopy. The recovery and the intraday and interday relative standard deviations for RB ranged from 83.7% to 88.4% and 2.5% to 4.0% and the enrichment factors were higher than 110-fold. The chip-based array columns effectively eliminated impurities in chili powder, indicating that the chip-based GO/SiO2-MISPE method was reliable for RB detection in food samples using high-performance liquid chromatography. Accordingly, this method has direct applications for monitoring potentially harmful dyes in processed food.

  10. Sensitive high-performance liquid chromatographic quantitation of gabapentin in human serum using liquid-liquid extraction and pre-column derivatization with 9-fluorenylmethyl chloroformate.

    Science.gov (United States)

    Bahrami, Gholamreza; Kiani, Amir

    2006-05-01

    Most of the published methods for analysis of gabapentin, an antiepileptic agent, in human serum are based on the same approach, involving o-phthaldialdehyde derivatization of deproteinized serum samples. The present paper however, describes a new, simple and sensitive high-performance liquid chromatographic method for determination of gabapentin in human serum using liquid-liquid extraction and 9-fluorenylmethyl chloroformate (FMOC-Cl) as pre-column labeling agent. The drug and an internal standard (azithromycin) were extracted from serum by salting-out approach using a mixture of dichloromethane-2 propanol (1:1, v/v) as the extracting solvent. The extracted analytes were subjected to derivatization with FMOC-Cl in the presence of phosphate buffer (pH 7). A mobile phase consisting of methanol-0.05 M sodium phosphate buffer (73/27, v/v; pH of 3.9) containing 1 ml/l triethylamine was eluted and chromatographic separation was performed on a Shimpack CLC-C18 (150 mm x 4.6 mm) column. The standard curve was linear over the range of 0.03-20 microg/ml and limit of quantification was 0.03 microg/ml. The performance of analysis was studied and the validated method showed excellent performance in terms of selectivity, specificity, sensitivity, precision and accuracy. No interferences were found from commonly co-administered antiepileptic agents.

  11. Monolithic silica spin column extraction and simultaneous derivatization of amphetamines and 3,4-methylenedioxyamphetamines in human urine for gas chromatographic-mass spectrometric detection.

    Science.gov (United States)

    Nakamoto, Akihiro; Nishida, Manami; Saito, Takeshi; Kishiyama, Izumi; Miyazaki, Shota; Murakami, Katsunori; Nagao, Masataka; Namura, Akira

    2010-02-19

    A simple, sensitive, and specific method with gas chromatography-mass spectrometry was developed for simultaneous extraction and derivatization of amphetamines (APs) and 3,4-methylenedioxyamphetamines (MDAs) in human urine by using a monolithic silica spin column. All the procedures, such as sample loading, washing, and elution were performed by centrifugation. APs and MDAs in urine were adsorbed on the monolithic silica and derivatized with propyl chloroformate in the column. Methamphetamine-d(5) was used as an internal standard. The linear ranges were 0.01-5.0 microg mL(-1) for methamphetamine (MA) and 3,4-methylenedioxymethamphetamine (MDMA) and 0.02-5.0 microg mL(-1) for amphetamine (AP) and 3,4-methylenedioxyamphetamine (MDA) (coefficient of correlation > or = 0.995). The recovery of APs and MDAs in urine was 84-94%, and the relative standard deviation of the intra- and interday reproducibility for urine samples containing 0.1, 1.0, and 4.0 microg mL(-1) of APs and MDAs ranged from 1.4% to 13.6%. The lowest detection limit (signal-to-noise ratio > or = 3) in urine was 5 ng mL(-1) for MA and MDMA and 10 ng mL(-1) for AP and MDA. The proposed method can be used to perform simultaneous extraction and derivatization on spin columns that have been loaded with a small quantity of solvent by using centrifugation.

  12. Cold column trapping-cloud point extraction coupled to high performance liquid chromatography for preconcentration and determination of curcumin in human urine.

    Science.gov (United States)

    Rahimi, Marzieh; Hashemi, Payman; Nazari, Fariba

    2014-05-15

    A cold column trapping-cloud point extraction (CCT-CPE) method coupled to high performance liquid chromatography (HPLC) was developed for preconcentration and determination of curcumin in human urine. A nonionic surfactant, Triton X-100, was used as the extraction medium. In the proposed method, a low surfactant concentration of 0.4% v/v and a short heating time of only 2min at 70°C were sufficient for quantitative extraction of the analyte. For the separation of the extraction phase, the resulted cloudy solution was passed through a packed trapping column that was cooled to 0 °C. The temperature of the CCT column was then increased to 25°C and the surfactant rich phase was desorbed with 400μL ethanol to be directly injected into HPLC for the analysis. The effects of different variables such as pH, surfactant concentration, cloud point temperature and time were investigated and optimum conditions were established by a central composite design (response surface) method. A limit of detection of 0.066mgL(-1) curcumin and a linear range of 0.22-100mgL(-1) with a determination coefficient of 0.9998 were obtained for the method. The average recovery and relative standard deviation for six replicated analysis were 101.0% and 2.77%, respectively. The CCT-CPE technique was faster than a conventional CPE method requiring a lower concentration of the surfactant and lower temperatures with no need for the centrifugation. The proposed method was successfully applied to the analysis of curcumin in human urine samples.

  13. SOLID-PHASE EXTRACTION OF MORPHINE FROM WHOLE-BLOOD BY MEANS OF BOND ELUT CERTIFY COLUMNS

    NARCIS (Netherlands)

    CHEN, XH; HOMMERSON, ALC; ZWEIPFENNING, PGM; FRANKE, JP; HARMENBOVERHOF, CW; ENSING, K; DEZEEUW, RA

    1993-01-01

    The use of Bond Elut Certify columns for the isolation of morphine from whole blood was evaluated. In order to monitor possible losses and the elution profile of morphine, a small amount of the tritiated analogue was added to the samples. Four sample pretreatment methods, three protein precipitation

  14. Solid phase extraction and spectrophotometric determination of mercury by adsorption of its diphenylthiocarbazone complex on an alumina column.

    Science.gov (United States)

    Rajesh, N; Gurulakshmanan, G

    2008-02-01

    A simple method has been developed for the preconcentration of mercury based on the adsorption of its diphenylthiocarbazone complex on a neutral alumina column. The influence of acidity, eluting agents, stability of the column, sample volume and interfering ions has been investigated in detail. The adsorbed complex could be eluted using environmentally benign polyethylene glycol (PEG 400) and the concentration of mercury was determined by visible spectrophotometry at a wavelength maximum of 520nm. A detection limit of 4microgL(-1) could be achieved and the developed procedure was successfully applied for the determination of mercury in spiked water samples and city waste incineration ash (CRM176). The preconcentration factor attainable for quantitative recovery (>95%) of mercury(II) was 100 for a 1000mL sample volume.

  15. Manual for the thermal and hdyraulic design of direct contract spray columns for use in extracting heat from geothermal brines

    Science.gov (United States)

    Jacobs, H. R.

    1985-06-01

    This report outlines the current methods being used in the thermal and hydraulic design of spray column type, direct contact heat exchangers. It provides appropriate referenced equations for both preliminary design and detailed performance. The design methods are primarily empirical and are applicable for use in the design of such units for geothermal application and for application with solar ponds. Methods for design, for both preheater and boiler sections of the primary heat exchangers, for direct contact binary powers plants are included.

  16. Impact of the uranium (VI) speciation in mineralised urines on its extraction by calix[6]arene bearing hydroxamic groups used in chromatography columns.

    Science.gov (United States)

    Baghdadi, S; Bouvier-Capely, C; Ritt, A; Peroux, A; Fevrier, L; Rebiere, F; Agarande, M; Cote, G

    2015-11-01

    Actinides determination in urine samples is part of the analyses performed to monitor internal contamination in case of an accident or a terrorist attack involving nuclear matter. Mineralisation is the first step of any of these analyses. It aims at reducing the sample volume and at destroying all organic compounds present. The mineralisation protocol is usually based on a wet ashing step, followed by actinides co-precipitation and a furnace ashing step, before redissolution and the quantification of the actinides by the appropriate techniques. Amongst the existing methods to perform the actinides co-precipitation, alkali-earth (typically calcium) precipitation is widely used. In the present work, the extraction of uranium(VI), plutonium(IV) and americium(III) from the redissolution solutions (called "mineralised urines") on calix[6]arene columns bearing hydroxamic groups was investigated as such an extraction is a necessary step before their determination by ICP-MS or alpha spectrometry. Difficulties were encountered in the transfer of uranium(VI) from raw to mineralised urines, with yield of transfer ranging between 0% and 85%, compared to about 90% for Pu and Am, depending on the starting raw urines. To understand the origin of such a difficulty, the speciation of uranium (VI) in mineralised urines was investigated by computer simulation using the MEDUSA software and the associated HYDRA database, compiled with recently published data. These calculations showed that the presence of phosphates in the "mineralised urines" leads to the formation of strong uranyl-phosphate complexes (such as UO2HPO4) which compete with the uranium (VI) extraction by the calix[6]arene bearing hydroxamic groups. The extraction constant of uranium (VI) by calix[6]arene bearing hydroxamic groups was determined in a 0.04 mol L(-1) sodium nitrate solution (logK=4.86±0.03) and implemented in an extraction model taking into account the speciation in the aqueous phase. This model allowed to

  17. The perils of pathogen discovery: origin of a novel parvovirus-like hybrid genome traced to nucleic acid extraction spin columns.

    Science.gov (United States)

    Naccache, Samia N; Greninger, Alexander L; Lee, Deanna; Coffey, Lark L; Phan, Tung; Rein-Weston, Annie; Aronsohn, Andrew; Hackett, John; Delwart, Eric L; Chiu, Charles Y

    2013-11-01

    Next-generation sequencing was used for discovery and de novo assembly of a novel, highly divergent DNA virus at the interface between the Parvoviridae and Circoviridae. The virus, provisionally named parvovirus-like hybrid virus (PHV), is nearly identical by sequence to another DNA virus, NIH-CQV, previously detected in Chinese patients with seronegative (non-A-E) hepatitis. Although we initially detected PHV in a wide range of clinical samples, with all strains sharing ∼99% nucleotide and amino acid identity with each other and with NIH-CQV, the exact origin of the virus was eventually traced to contaminated silica-binding spin columns used for nucleic acid extraction. Definitive confirmation of the origin of PHV, and presumably NIH-CQV, was obtained by in-depth analyses of water eluted through contaminated spin columns. Analysis of environmental metagenome libraries detected PHV sequences in coastal marine waters of North America, suggesting that a potential association between PHV and diatoms (algae) that generate the silica matrix used in the spin columns may have resulted in inadvertent viral contamination during manufacture. The confirmation of PHV/NIH-CQV as laboratory reagent contaminants and not bona fide infectious agents of humans underscores the rigorous approach needed to establish the validity of new viral genomes discovered by next-generation sequencing.

  18. On-line SPE-UHPLC method using fused core columns for extraction and separation of nine illegal dyes in chilli-containing spices.

    Science.gov (United States)

    Khalikova, Maria A; Satínský, Dalibor; Smidrkalová, Tereza; Solich, Petr

    2014-12-01

    The presented work describes the development of a simple, fast and effective on-line SPE-UHPLC-UV/vis method using fused core particle columns for extraction, separation and quantitative analysis of the nine illegal dyes, most frequently found in chilli-containing spices. The red dyes Sudan I-IV, Sudan Red 7B, Sudan Red G, Sudan Orange G, Para Red, and Methyl Red were separated and analyzed in less than 9 min without labor-consuming pretreatment procedure. The chromatographic separation was performed on Ascentis Express RP-Amide column with gradient elution using mixture of acetonitrile and water, as a mobile phase at a flow rate of 1.0 mL min(-1) and 55°C of temperature. As SPE sorbent for cleanup and pre-concentration of illegal dyes short guard fused core column Ascentis Express F5 was used. The applicability of proposed method was proven for three different chilli-containing commercial samples. Recoveries for all compounds were between 90% and 108% and relative standard deviation ranged from 1% to 4% for within- and from 2% to 6% for between-day. Limits of detection showed lower values than required by European Union regulations and were in the range of 3.3-10.3 µg L(-1) for standard solutions, 5.6-235.6 µg kg(-1) for chilli-containing spices.

  19. APPLICATION OF COLUMN EXTRACTION METHOD FOR IMPURITIES ANALYSIS ON HB-LINE PLUTONIUM OXIDE IN SUPPORT OF MOX FEED PRODUCT SPECIFICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Jones, M.; Diprete, D.; Wiedenman, B.

    2012-03-20

    The current mission at H-Canyon involves the dissolution of an Alternate Feedstocks 2 (AFS-2) inventory that contains plutonium metal. Once dissolved, HB-Line is tasked with purifying the plutonium solution via anion exchange, precipitating the Pu as oxalate, and calcining to form plutonium oxide (PuO{sub 2}). The PuO{sub 2} will provide feed product for the Mixed Oxide (MOX) Fuel Fabrication Facility, and the anion exchange raffinate will be transferred to H-Canyon. The results presented in this report document the potential success of the RE resin column extraction application on highly concentrated Pu samples to meet MOX feed product specifications. The original 'Hearts Cut' sample required a 10000x dilution to limit instrument drift on the ICP-MS method. The instrument dilution factors improved to 125x and 250x for the sample raffinate and sample eluent, respectively. As noted in the introduction, the significantly lower dilutions help to drop the total MRL for the analyte. Although the spike recoveries were half of expected in the eluent for several key elements, they were between 94-98% after Nd tracer correction. It is seen that the lower ICD limit requirements for the rare earths are attainable because of less dilution. Especially important is the extremely low Ga limit at 0.12 {mu}g/g Pu; an ICP-MS method is now available to accomplish this task on the sample raffinate. While B and V meet the column A limits, further development is needed to meet the column B limits. Even though V remained on the RE resin column, an analysis method is ready for investigation on the ICP-MS, but it does not mean that V cannot be measured on the ICP-ES at a low dilution to meet the column B limits. Furthermore, this column method can be applicable for ICP-ES as shown in Table 3-2, in that it trims the sample of Pu, decreasing and sometimes eliminating Pu spectral interferences.

  20. Sensitive Detection of α-Conotoxin GI in Human Plasma Using a Solid-Phase Extraction Column and LC-MS/MS.

    Science.gov (United States)

    Yu, Shuo; Yang, Bo; Yan, Liangping; Dai, Qiuyun

    2017-07-28

    α-conotoxin GI, a short peptide toxin in the venom of Conus geographus, is composed of 13 amino acids and two disulfide bonds. It is the most toxic component of Conus geographus venom with estimated lethal doses of 0.029-0.038 mg/kg for humans. There is currently no reported analytical method for this toxin. In the present study, a sensitive detection method was developed to quantify GI in human plasma using a solid-phase extraction (SPE) column (polystyrene-divinyl benzene copolymer) combined with liquid chromatography/electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) in the multiple reaction monitoring (MRM) mode. The plasma samples were treated with a protein precipitating solvent (methanol: acetonitrile = 50:50, v/v). GI in the solvent was efficiently extracted with an SPE column and was further separated by a Grace Alltima HP C18 (50 × 2.1 mm, 5 μm) column at a flow rate of 0.4 mL/min. Water (with 2% methanol) acetonitrile (with 0.1% acetic acid) was selected as the mobile phase combination used in a linear gradient system. α-Conotoxin GI was analyzed by an API 4000 triple quadrupole mass spectrometer. In the method validation, the linear calibration curve in the range of 2.0 to 300.0 ng/mL had correlation coefficients (r) above 0.996. The recovery was 57.6-66.8% for GI and the internal standard. The lower limit of quantification (LLOQ) was 2 ng/mL. The intra- and inter-batch precisions were below 6.31% and 8.61%, respectively, and the accuracies were all within acceptance. GI was stable in a bench-top autosampler through long-term storage and freeze/thaw cycles. Therefore, this method is specific, sensitive and reliable for quantitative analysis of α-conotoxin GI in human plasma.

  1. Monolithic silica spin column extraction and simultaneous derivatization of amphetamines and 3,4-methylenedioxyamphetamines in human urine for gas chromatographic-mass spectrometric detection

    Energy Technology Data Exchange (ETDEWEB)

    Nakamoto, Akihiro [Scientific Investigation Laboratory, Hiroshima Prefectural Police Headquarters, Kohnan 2-26-3, Naka-ku, Hiroshima 730-0825 (Japan); Nishida, Manami [Hiroshima University Technical Center, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8551 (Japan); Saito, Takeshi [Department of Emergency and Critical Care Medicine, Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1143 (Japan); Kishiyama, Izumi; Miyazaki, Shota [GL Sciences Inc., Sayamagahara 237-2, Iruma, Saitama 358-0032 (Japan); Murakami, Katsunori [Scientific Investigation Laboratory, Hiroshima Prefectural Police Headquarters, Kohnan 2-26-3, Naka-ku, Hiroshima 730-0825 (Japan); Nagao, Masataka [Department of Forensic Medicine, Graduate School of Biomedical Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8551 (Japan); Namura, Akira, E-mail: namera@hiroshima-u.ac.jp [Department of Forensic Medicine, Graduate School of Biomedical Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8551 (Japan)

    2010-02-19

    A simple, sensitive, and specific method with gas chromatography-mass spectrometry was developed for simultaneous extraction and derivatization of amphetamines (APs) and 3,4-methylenedioxyamphetamines (MDAs) in human urine by using a monolithic silica spin column. All the procedures, such as sample loading, washing, and elution were performed by centrifugation. APs and MDAs in urine were adsorbed on the monolithic silica and derivatized with propyl chloroformate in the column. Methamphetamine-d{sub 5} was used as an internal standard. The linear ranges were 0.01-5.0 {mu}g mL{sup -1} for methamphetamine (MA) and 3,4-methylenedioxymethamphetamine (MDMA) and 0.02-5.0 {mu}g mL{sup -1} for amphetamine (AP) and 3,4-methylenedioxyamphetamine (MDA) (coefficient of correlation {>=}0.995). The recovery of APs and MDAs in urine was 84-94%, and the relative standard deviation of the intra- and interday reproducibility for urine samples containing 0.1, 1.0, and 4.0 {mu}g mL{sup -1} of APs and MDAs ranged from 1.4% to 13.6%. The lowest detection limit (signal-to-noise ratio {>=} 3) in urine was 5 ng mL{sup -1} for MA and MDMA and 10 ng mL{sup -1} for AP and MDA. The proposed method can be used to perform simultaneous extraction and derivatization on spin columns that have been loaded with a small quantity of solvent by using centrifugation.

  2. Manual for the thermal and hydraulic design of direct contact spray columns for use in extracting heat from geothermal brines

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, H.R.

    1985-06-01

    This report outlines the current methods being used in the thermal and hydraulic design of spray column type, direct contact heat exchangers. It provides appropriate referenced equations for both preliminary design and detailed performance. The design methods are primarily empirical and are applicable for us in the design of such units for geothermal application and for application with solar ponds. Methods for design, for both preheater and boiler sections of the primary heat exchangers, for direct contact binary powers plants are included. 23 refs., 8 figs.

  3. Column flotation

    Energy Technology Data Exchange (ETDEWEB)

    Kohmuench, J.N.; Norrgran, D.A.; Luttrell, E.; Luttrell, G.H. [Virginia Tech. (United States)

    2008-04-15

    Over the last decade, column flotation has been recognised in the industry to be most efficient and economical means of recovering fine coal while maximizing product grade. When designed properly, flotation columns provide a high combustible recovery while maintaining a low product ash. The paper looks at the benefits of using column flotation for fine coal recovery. 2 refs., 5 figs.

  4. Cation-selective extraction column study for the conception of nuclear medical radionuclide generators; Untersuchung kationenselektiver Extraktionssaeulen zur Konzeption nuklearmedizinischer Radionuklidgeneratoren

    Energy Technology Data Exchange (ETDEWEB)

    Streng, Roman

    2012-07-09

    The topic of the present work is the conception of a Yttrium-90 radionuclide generator for nuclear medicine applications. Due to its physical properties Yttrium-90 is considered as one of the most useful nuclides for radiotherapeutic cancer treatment. The parent nuclide Strontium-90 is gained during reprocessing of fission products. Thus, the sustained availability of large quantities of Yttrium-90 is limited to a number of research facilities. A radionuclide generator provides an independent Yttrium-90 source and enhances the capacities for radiopharmaceutical research and biomedical applications. The present work focussed on the identification of appropriate column materials for the separation of Strontium and Yttrium. The results for two materials are reported: AnaLig {sup registered} Sr-01 and crystalline antimonic acid. Based on the mode of operation of the Technetium-99m generator the aim was to enable the construction of a compact, enclosed apparatus. The projected device comprises a reservoir for the eluant, the ion-exchange column, pipings and radiation shielding. Elution of Yttrium-90 could then be easily performed by connecting evacuated vials to the outlet tube. The prospected concept involves physical and chemical confinements that exclude most of the known processes for Strontium-Yttrium separation. For example no ligands, no oxidizing reactants (e.g. nitric acid) and no organic solvents are to be used, but small volumes of isotonic or buffer solutions and dilute acids respectively. AnaLig {sup registered} Sr-01 is a commercially available resin used in extraction chromatography. Its high selectivity for Strontium cations results from the strictly defined cavity of the imbedded cryptand. Determination of weight distribution coefficients, elution studies and pre-generator experiments were carried out. Quantitative separation of Yttrium from Strontium and Zirconium is possible using small volumes of 0,05 M hydrochloric acid as eluant. Furthermore, high

  5. RNA extraction from ten year old formalin-fixed paraffin-embedded breast cancer samples: a comparison of column purification and magnetic bead-based technologies

    Directory of Open Access Journals (Sweden)

    Zhang Haiyu

    2007-12-01

    Full Text Available Abstract Background The development of protocols for RNA extraction from paraffin-embedded samples facilitates gene expression studies on archival samples with known clinical outcome. Older samples are particularly valuable because they are associated with longer clinical follow up. RNA extracted from formalin-fixed paraffin-embedded (FFPE tissue is problematic due to chemical modifications and continued degradation over time. We compared quantity and quality of RNA extracted by four different protocols from 14 ten year old and 14 recently archived (three to ten months old FFPE breast cancer tissues. Using three spin column purification-based protocols and one magnetic bead-based protocol, total RNA was extracted in triplicate, generating 336 RNA extraction experiments. RNA fragment size was assayed by reverse transcription-polymerase chain reaction (RT-PCR for the housekeeping gene glucose-6-phosphate dehydrogenase (G6PD, testing primer sets designed to target RNA fragment sizes of 67 bp, 151 bp, and 242 bp. Results Biologically useful RNA (minimum RNA integrity number, RIN, 1.4 was extracted in at least one of three attempts of each protocol in 86–100% of older and 100% of recently archived ("months old" samples. Short RNA fragments up to 151 bp were assayable by RT-PCR for G6PD in all ten year old and months old tissues tested, but none of the ten year old and only 43% of months old samples showed amplification if the targeted fragment was 242 bp. Conclusion All protocols extracted RNA from ten year old FFPE samples with a minimum RIN of 1.4. Gene expression of G6PD could be measured in all samples, old and recent, using RT-PCR primers designed for RNA fragments up to 151 bp. RNA quality from ten year old FFPE samples was similar to that extracted from months old samples, but quantity and success rate were generally higher for the months old group. We preferred the magnetic bead-based protocol because of its speed and higher quantity of

  6. "In situ" extraction of essential oils by use of Dean-Stark glassware and a Vigreux column inside a microwave oven: a procedure for teaching green analytical chemistry.

    Science.gov (United States)

    Chemat, Farid; Perino-Issartier, Sandrine; Petitcolas, Emmanuel; Fernandez, Xavier

    2012-08-01

    One of the principal objectives of sustainable and green processing development remains the dissemination and teaching of green chemistry in colleges, high schools, and academic laboratories. This paper describes simple glassware that illustrates the phenomenon of extraction in a conventional microwave oven as energy source and a process for green analytical chemistry. Simple glassware comprising a Dean-Stark apparatus (for extraction of aromatic plant material and recovery of essential oils and distilled water) and a Vigreux column (as an air-cooled condenser inside the microwave oven) was designed as an in-situ extraction vessel inside a microwave oven. The efficiency of this experiment was validated for extraction of essential oils from 30 g fresh orange peel, a by-product in the production of orange juice. Every laboratory throughout the world can use this equipment. The microwave power is 100 W and the irradiation time 15 min. The method is performed at atmospheric pressure without added solvent or water and furnishes essential oils similar to those obtained by conventional hydro or steam distillation. By use of GC-MS, 22 compounds in orange peel were separated and identified; the main compounds were limonene (72.1%), β-pinene (8.4%), and γ-terpinene (6.9%). This procedure is appropriate for the teaching laboratory, does not require any special microwave equipment, and enables the students to learn the skills of extraction, and chromatographic and spectroscopic analysis. They are also exposed to a dramatic visual example of rapid, sustainable, and green extraction of an essential oil, and are introduced to successful sustainable and green analytical chemistry.

  7. Determination of lignin in marine sediment using alkaline cupric oxide oxidation-solid phase extraction-on-column derivatization-gas chromatography

    Science.gov (United States)

    Zhang, Ting; Li, Xianguo; Sun, Shuwen; Lan, Haiqing; Du, Peirui; Wang, Min

    2013-03-01

    Lignin serves as one of the most important molecular fossils for tracing Terrestrial Organic Matters (TOMs) in marine environment. Extraction and derivatization of lignin oxidation products (LOPs) are crucial for accurate quantification of lignin in marine sediment. Here we report a modification of the conventional alkaline cupric oxide (CuO) oxidation method, the modification consisting in a solid phase extraction (SPE) and a novel on-column derivatization being employed for better efficiency and reproducibility. In spiking blanks, recoveries with SPE for the LOPs are between 77.84% and 99.57% with relative standard deviations (RSDs) ranging from 0.57% to 8.04% ( n=3), while those with traditional liquid-liquid extraction (LLE) are from 44.52% to 86.16% with RSDs being from 0.53% to 13.14% ( n=3). Moreover, the reproducibility is greatly improved with SPE, with less solvent consumption and shorter processing time. The average efficiency of on-column derivatization for LOPs is 100.8% ± 0.68%, which is significantly higher than those of in-vial or in-syringe derivatization, thus resulting in still less consumption of derivatizing reagents. Lignin in the surface sediments sampled from the south of Yangtze River estuary, China, was determined with the established method. Recoveries of 72.66% to 85.99% with standard deviation less than 0.01mg/10g dry weight are obtained except for p-hydroxyben-zaldehyde. The lignin content Σ8 (produced from 10 g dry sediment) in the research area is between 0.231 and 0.587 mg. S/V and C/V ratios (1.028 ± 0.433 and 0.192 ± 0.066, respectively) indicate that the TOMs in this region are originated from a mixture of woody and nonwoody angiosperm plants; the high values of (Ad/Al)v suggest that the TOMs has been highly degraded.

  8. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of pesticides in water by C-18 solid-phase extraction and capillary-column gas chromatography/mass spectrometry with selected-ion monitoring

    Science.gov (United States)

    Zaugg, Steven D.; Sandstrom, Mark W.; Smith, Steven G.; Fehlberg, Kevin M.

    1995-01-01

    A method for the isolation of 41 pesticides and pesticide metabolites in natural-water samples using C-18 solid-phase extraction and determination by capillary-column gas chromatography/mass spectrometry with selected-ion monitoring is described. Water samples are filtered to remove suspended particulate matter and then are pumped through disposable solid-phase extraction columns containing octadecyl-bonded porous silica to extract the pesticides. The columns are dried using carbon dioxide or nitrogen gas, and adsorbed pesticides are removed from the columns by elution with 3.0 milliliters of hexane-isopropanol (3:1). Extracted pesticides are determined by capillary- column gas chromatography/mass spectrometry with selected-ion monitoring of three characteristic ions. The upper concentration limit is 4 micrograms per liter (g/L) for most pesticides, with the exception of widely used corn herbicides--atrazine, alachlor, cyanazine, and metolachlor--which have upper concentration limits of 20 g/L. Single- operator method detection limits in reagent-water samples range from 0.001 to 0.018 g/L. Average short-term single-operator precision in reagent- water samples is 7 percent at the 0.1- and 1.0-g/L levels and 8 percent at the 0.01-g/L level. Mean recoveries in reagent-water samples are 73 percent at the 0.1- and 1.0-g/L levels and 83 percent at the 0.01-g/L level. The estimated holding time for pesticides after extraction on the solid-phase extraction columns was 7 days. An optional on-site extraction procedure allows for samples to be collected and processed at remote sites where it is difficult to ship samples to the laboratory within the recommended pre-extraction holding time.

  9. 散相液滴在搅拌萃取塔内的停留时间分布%The Resident Time Distribution of Injected Dispersed Drops in Stirred Extraction Columns

    Institute of Scientific and Technical Information of China (English)

    尤学一; 李丹; 李胜华

    2005-01-01

    A resident time model is proposed to evaluate the performance of agitated extraction columns. In this model, the resident time of dispersed drops is simulated with the discrete phase modeling, where the continuous phase and the dispersed phase (drops) are described by the single-phase Navier-Stokes (turbulence) model and Lagrangian model, respectively. The interaction of dispersed phase and continuous phase is neglected for the low concentration of drop in the cases studied. The statistical parameters of drops (the average resident time and standard deviation) under different operation conditions are computed for four columns. The relation of the above statistical parameters with the performance of columns is discussed and the criterions for an optimal compartment are outlined. Our results indicate that the resident time model is useful to evaluate the performance and optimize the design of extraction columns.

  10. Validated method for bioactive lignans in Schisandra chinensis in vitro cultures using a solid phase extraction and a monolithic column application.

    Science.gov (United States)

    Brezinová, Lenka; Vlasínová, Helena; Havel, Ladislav; Humpa, Otakar; Slanina, Jirí

    2010-09-01

    A simple and rapid method for determination of six lignans found in plant cell cultures of Schisandra chinensis was developed and validated. The lignans were extracted from plant samples with methanol and the extracts were effectively cleaned by solid-phase extraction using Strata C18-E (Phenomenex) cartridges. Chromatographic separation was carried out on a Chromolith Performance RP-18e monolithic column (100 x 4.6 mm, Merck) using an isocratic mobile phase of acetonitrile and water in a 50:50 (v/v) ratio. The eluent was monitored at 220 nm. The baseline separation of schizandrin, gomisin A, deoxyschizandrin, gamma-schizandrin, gomisin N and wuweizisu C was achieved in a relatively short time period (20 min), which was made possible by the relatively high flow rate of the mobile phase (2 mL/min). The lower limit of quantitation was 0.1 mg/L for schizandrin and gomisin A, 0.3 mg/L for deoxyschizandrin, gamma-schizandrin, and gomisin N and 1 mg/L for wuweizisu C. The analysis of spiked samples containing six lignans provided absolute recoveries between 93 and 101% in all cases. The validated method was successfully applied to the determination of lignans in embryogenic plant cell cultures of Schisandra chinensis.

  11. Mobility of arsenic, cadmium and zinc in a multi-element contaminated soil profile assessed by in-situ soil pore water sampling, column leaching and sequential extraction

    Energy Technology Data Exchange (ETDEWEB)

    Beesley, Luke, E-mail: l.beesley@2007.ljmu.ac.u [Faculty of Science, Liverpool John Moores University, Liverpool L3 3AF (United Kingdom); Moreno-Jimenez, Eduardo [Departamento de Quimica Agricola, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Clemente, Rafael [Dep. of Soil and Water Conservation and Organic Waste Management, CEBAS-CSIC, Campus Universitario de Espinardo, PO Box 164, 30100 Espinardo, Murcia (Spain); Lepp, Nicholas; Dickinson, Nicholas [Faculty of Science, Liverpool John Moores University, Liverpool L3 3AF (United Kingdom)

    2010-01-15

    Three methods for predicting element mobility in soils have been applied to an iron-rich soil, contaminated with arsenic, cadmium and zinc. Soils were collected from 0 to 30 cm, 30 to 70 cm and 70 to 100 cm depths in the field and soil pore water was collected at different depths from an adjacent 100 cm deep trench. Sequential extraction and a column leaching test in the laboratory were compared to element concentrations in pore water sampled directly from the field. Arsenic showed low extractability, low leachability and occurred at low concentrations in pore water samples. Cadmium and zinc were more labile and present in higher concentrations in pore water, increasing with soil depth. Pore water sampling gave the best indication of short term element mobility when field conditions were taken into account, but further extraction and leaching procedures produced a fuller picture of element dynamics, revealing highly labile Cd deep in the soil profile. - Mobility of arsenic, cadmium and zinc in a polluted soil can be realistically interpreted by in-situ soil pore water sampling.

  12. Automated determination of total captopril in urine by liquid chromatography with post-column derivatization coupled to on-line solid phase extraction in a sequential injection manifold.

    Science.gov (United States)

    Karakosta, Theano D; Tzanavaras, Paraskevas D; Themelis, Demetrius G

    2012-01-15

    The present study reports a new liquid chromatographic (HPLC) method for the determination of the anti-hypertension drug captopril (CAP) in human urine. After its separation from the sample matrix in a reversed phase HPLC column, CAP reacts with the thiol-selective reagent ethyl-propiolate (EP) in a post-column configuration and the formed thioacrylate derivative is detected at 285 nm. Automated 4-fold preconcentration of the analyte prior to analysis was achieved by an on-line solid phase extraction (SPE) step using a sequential injection (SI) manifold. The Oasis HLB SPE cartridges offered quantitative recoveries and effective sample cleaning by applying a simple SPE protocol. The limits of detection and quantitation were 10 μg L(-1) and 35 μg L(-1) respectively. The percent recoveries for the analysis of human urine samples ranged between 90 and 96% and 95 and 104% using aqueous and matrix matched calibration curves respectively. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Cation-selective extraction column study for the conception of nuclear medical radionuclide generators; Untersuchung kationenselektiver Extraktionssaeulen zur Konzeption nuklearmedizinischer Radionuklidgeneratoren

    Energy Technology Data Exchange (ETDEWEB)

    Streng, Roman

    2012-07-09

    The topic of the present work is the conception of a Yttrium-90 radionuclide generator for nuclear medicine applications. Due to its physical properties Yttrium-90 is considered as one of the most useful nuclides for radiotherapeutic cancer treatment. The parent nuclide Strontium-90 is gained during reprocessing of fission products. Thus, the sustained availability of large quantities of Yttrium-90 is limited to a number of research facilities. A radionuclide generator provides an independent Yttrium-90 source and enhances the capacities for radiopharmaceutical research and biomedical applications. The present work focussed on the identification of appropriate column materials for the separation of Strontium and Yttrium. The results for two materials are reported: AnaLig {sup registered} Sr-01 and crystalline antimonic acid. Based on the mode of operation of the Technetium-99m generator the aim was to enable the construction of a compact, enclosed apparatus. The projected device comprises a reservoir for the eluant, the ion-exchange column, pipings and radiation shielding. Elution of Yttrium-90 could then be easily performed by connecting evacuated vials to the outlet tube. The prospected concept involves physical and chemical confinements that exclude most of the known processes for Strontium-Yttrium separation. For example no ligands, no oxidizing reactants (e.g. nitric acid) and no organic solvents are to be used, but small volumes of isotonic or buffer solutions and dilute acids respectively. AnaLig {sup registered} Sr-01 is a commercially available resin used in extraction chromatography. Its high selectivity for Strontium cations results from the strictly defined cavity of the imbedded cryptand. Determination of weight distribution coefficients, elution studies and pre-generator experiments were carried out. Quantitative separation of Yttrium from Strontium and Zirconium is possible using small volumes of 0,05 M hydrochloric acid as eluant. Furthermore, high

  14. Axial dispersion, holdup and slip velocity of dispersed phase in a pulsed sieve plate extraction column by radiotracer residence time distribution analysis

    Energy Technology Data Exchange (ETDEWEB)

    Din, Ghiyas Ud [Department of Nuclear Engineering, Pakistan Institute of Engineering and Applied Sciences (PIEAS), P.O. Nilore, Islamabad (Pakistan); Isotope Applications Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), P.O. Nilore, Islamabad (Pakistan)], E-mail: fac192@pieas.edu.pk; Chughtai, Imran Rafiq; Inayat, Mansoor Hameed [Department of Chemical and Materials Engineering, Pakistan Institute of Engineering and Applied Sciences (PIEAS), P.O. Nilore, Islamabad (Pakistan); Khan, Iqbal Hussain [Isotope Applications Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), P.O. Nilore, Islamabad (Pakistan)

    2008-12-15

    Axial dispersion, holdup and slip velocity of dispersed phase have been investigated for a range of dispersed and continuous phase superficial velocities in a pulsed sieve plate extraction column using radiotracer residence time distribution (RTD) analysis. Axial dispersion model (ADM) was used to simulate the hydrodynamics of the system. It has been observed that increase in dispersed phase superficial velocity results in a decrease in its axial dispersion and increase in its slip velocity while its holdup increases till a maximum asymptotic value is achieved. An increase in superficial velocity of continuous phase increases the axial dispersion and holdup of dispersed phase until a maximum value is obtained, while slip velocity of dispersed phase is found to decrease in the beginning and then it increases with increase in superficial velocity of continuous phase.

  15. Indirect spectrophotometric determination of small amounts of selenium(IV) and arsenic(V) by simple extraction using flotation columns.

    Science.gov (United States)

    Mostafa, G A; Ghazy, S E

    2001-10-01

    A simple, rapid and selective procedure for the indirect spectrophotometric determination of Se(IV) and As(V) has been developed. It is based on the reduction of Se(IV) to Se(0) and As(V) to As(III) with hydroiodic acid (KI + HCl). The liberated iodine, equivalent to each analyte, is quantitatively extracted with oleic acid (HOL) surfactant. The iodine-HOL system exhibits its maximum absorbance at 435 nm. The different analytical parameters affecting the extraction and determination processes have been examined. The calibration graphs were found to be linear over the ranges 5-120 and 0.25-20 ppm of Se(IV) and As(V), with lower detection limits of 2.5 and 0.15 ppm and molar absorptivities of 1 x 10(4) and 0.5 x 10(4) dm3 mol(-1) cm(-1), respectively. Sandell's sensitivity was calculated to be 0.0078 and 0.0149 microg/cm2 in the same order. The relative standard deviation for five replicate analyses of 40 ppm Se(IV) and 4 ppm As(V) were 1.0 and 0.9%, respectively. The proposed procedure in the presence of EDTA as a masking agent for foreign ions has been successfully applied to the determination of Se(IV) in a reference sample and As(V) in copper metal, in addition to their determination in spiked and polluted water samples.

  16. Sodium desoxycholate-assisted capillary electrochromatography with methacrylate ester-based monolithic column on fast separation and determination of coumarin analogs in Angelica dahurica extract.

    Science.gov (United States)

    Chen, Zhao; Wang, Jiajing; Chen, Danxia; Fan, Guorong; Wu, Yutian

    2012-09-01

    A rapid and sensitive CEC method with methacrylate ester-based monolithic column has been developed for separation and determination of five coumarins (byakangelicin, oxypeucedanin hydrate, xanthotoxol, 5-hydroxy-8-methoxypsoralen and bergapten) in Angelica dahurica extract. Surfactant sodium desoxycholate (SDC) was introduced into the mobile phase as the pseudostationary to dynamically increase the selectivity of analytes instead of increasing the hydrophobicity of stationary phase. In addition, other factors, pH of phosphate buffer, ACN content and applied voltage, for instance, have also an obvious effect on the resolution but little on the retention time. Satisfactory separation of these five coumarins was achieved within 6 min under a 30:70 v/v ACN-buffer containing 20 mM sodium dihydrogen phosphate (NaH(2) PO(4) ) and 0.25 mM SDC at pH 2.51. The RSDs of intraday and interday for relative peak areas were less than 3.0% and 4.7%, respectively; and the recoveries were between 87.5% and 95.0%. The LODs were lower than 0.15 μg/mL and the LOQs were lower than 0.30 μg/mL, respectively, while calibration curves showed a good linearity (r(2) > 0.9979). Finally, five target coumarins from the crude extracts of A. dahurica were separated, purified, and concentrated by D-101 macroporous resin, and were successfully separated and quantitatively determined within 6 min.

  17. Determination of Wastewater Compounds in Whole Water by Continuous Liquid-Liquid Extraction and Capillary-Column Gas Chromatography/Mass Spectrometry

    Science.gov (United States)

    Zaugg, Steven D.; Smith, Steven G.; Schroeder, Michael P.

    2006-01-01

    A method for the determination of 69 compounds typically found in domestic and industrial wastewater is described. The method was developed in response to increasing concern over the impact of endocrine-disrupting chemicals on aquatic organisms in wastewater. This method also is useful for evaluating the effects of combined sanitary and storm-sewer overflow on the water quality of urban streams. The method focuses on the determination of compounds that are indicators of wastewater or have endocrine-disrupting potential. These compounds include the alkylphenol ethoxylate nonionic surfactants, food additives, fragrances, antioxidants, flame retardants, plasticizers, industrial solvents, disinfectants, fecal sterols, polycyclic aromatic hydrocarbons, and high-use domestic pesticides. Wastewater compounds in whole-water samples were extracted using continuous liquid-liquid extractors and methylene chloride solvent, and then determined by capillary-column gas chromatography/mass spectrometry. Recoveries in reagent-water samples fortified at 0.5 microgram per liter averaged 72 percent ? 8 percent relative standard deviation. The concentration of 21 compounds is always reported as estimated because method recovery was less than 60 percent, variability was greater than 25 percent relative standard deviation, or standard reference compounds were prepared from technical mixtures. Initial method detection limits averaged 0.18 microgram per liter. Samples were preserved by adding 60 grams of sodium chloride and stored at 4 degrees Celsius. The laboratory established a sample holding-time limit prior to sample extraction of 14 days from the date of collection.

  18. Improved method for the extraction and chromatographic analysis on a fused-core column of ellagitannins found in oak-aged wine.

    Science.gov (United States)

    Navarro, María; Kontoudakis, Nikolaos; Canals, Joan Miquel; García-Romero, Esteban; Gómez-Alonso, Sergio; Zamora, Fernando; Hermosín-Gutiérrez, Isidro

    2017-07-01

    A new method for the analysis of ellagitannins observed in oak-aged wine is proposed, exhibiting interesting advantages with regard to previously reported analytical methods. The necessary extraction of ellagitannins from wine was simplified to a single step of solid phase extraction (SPE) using size exclusion chromatography with Sephadex LH-20 without the need for any previous SPE of phenolic compounds using reversed-phase materials. The quantitative recovery of wine ellagitannins requires a combined elution with methanol and ethyl acetate, especially for increasing the recovery of the less polar acutissimins. The chromatographic method was performed using a fused-core C18 column, thereby avoiding the coelution of main ellagitannins, such as vescalagin and roburin E. However, the very polar ellagitannins, namely, the roburins A, B and C, still partially coeluted, and their quantification was assisted by the MS detector. This methodology also enabled the analysis of free gallic and ellagic acids in the same chromatographic run. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Development of a silica monolith modified with Fe3O4 nano-particles in centrifugal spin column format for the extraction of phosphorylated compounds.

    Science.gov (United States)

    Alwy, Ali; Clarke, Sarah P; Brougham, Dermot F; Twamley, Brendan; Paull, Brett; White, Blánaid; Connolly, Damian

    2015-01-01

    In this study, citrate-stabilised iron oxide nano-particles (∼16 nm) have been immobilised on commercial silica monolithic centrifugal spin columns (MonoSpin) for the extraction of phosphorylated compounds. Two alternative strategies were adopted involving either direct electrostatic attachment to an aminated MonoSpin (single-layer method) in the first instance, or the use of a layer-by-layer method with poly(diallyldimethylammonium) chloride. Field-emission scanning electron spectroscopy and energy-dispersive X-ray spectroscopy was used for confirming notably higher coverage of nano-particles using the layer-by-layer method (2.49 ± 0.53 wt%) compared with the single-layer method (0.43 ± 0.30 wt%). The modified monolith was used for the selective separation/extraction of adenosine monophosphate, adenosine diphosphate and adenosine triphosphate with elution using a phosphate buffer. A reversed-phase liquid chromatographic assay was used for confirming that adenosine, as a non-phosphorylated control was not retained on the modified MonoSpin devices, whereas recovery of 80% for adenosine monophosphate, 86% for adenosine diphosphate and 82% for adenosine triphosphate was achieved.

  20. Reading Columns

    OpenAIRE

    Coutts, Marion

    2008-01-01

    Reading Columns are twin permanent public sculptures commissioned as part of a £245m scheme for the redevelopment of the Chatham Place area in Reading. Dimensions: 3.5m high x 1.3m diameter each Field of knowledge: The work consists of twin bespoke columns of stainless steel and glass over digital colour transparencies. The piece revisits and reworks the idea of the Morris Column, a 19th C feature characteristic of major European metropolitan centres. A wraparound image on each of ...

  1. Isolation of high-quality DNA in 16 aromatic and medicinal Colombian species using silica-based extraction columns

    Directory of Open Access Journals (Sweden)

    Vega Vela Nelson Enrique

    2011-12-01

    Full Text Available

    Aromatic and medicinal plant species are a valuable resource for research and development of pharmaceutical, cosmetic, crop protection and nutritional agents, due to the high amount of bioactive phytochemicals that they contain. However, these compounds are a major obstacle in the isolation of high-quality DNA suitable for genetic analyses. In this paper, we report a protocol that optimizes the use of the cationic detergent CTAB and the reductant β-mercaptoethanol in cell lysis. The elimination of plant secondary metabolites such as polysaccharides and polyphenols, that typically co-isolate with DNA, was achieved using the chemical denaturing properties of the guanidinium cation, which together with the adsorbent chemical specificity of the silica, resulted in the purification of high-quality DNA suitable for digestion with restriction enzymes and optimal for PCR amplification of AFLP-type molecular markers. This protocol was evaluated on 16 Colombian aromatic and medicinal plant species promising for their essential oils. The results allow suggesting that this procedure might be appropriate for other species, tissues and sample types recalcitrant to DNA extraction.

  2. Novel on-line column extraction apparatus coupled with binary peak focusing for high-performance liquid chromatography determination of rifampicin in human plasma: a strategy for therapeutic drug monitoring.

    Science.gov (United States)

    Li, Wei; Peng, Min; Long, Minghui; Qiu, Ximin; Yang, Liping

    2014-12-01

    In order to develop a method that is completely suitable for the routine therapeutic drug monitoring, a sensitive and fully automated on-line column extraction apparatus in combination with high-performance liquid chromatography allowing binary peak focusing was developed and validated for the determination of rifampicin in human plasma. Rifapentine was used as an internal standard. The analytical cycle started with the injection of 100 μL of the sample pretreated by protein precipitation in a Venusil SCX extraction column. After the elution, the analytes were transferred and concentrated in an Xtimate C18 trap column. Finally, the trapped analytes were separated by an Xtimate C18 analytical column and were analyzed by an ultraviolet detector at 336 nm. With this new strategy, continuous on-line analysis of the compounds was successfully performed. The method showed excellent performance for the analysis of rifampicin in plasma samples, including calibration curve linearity (All r were larger than 0.9996), sensitivity (lowest limit of quantification was 0.12 μg/mL), method accuracy (within 6.6% in terms of relative error), and precision (relative standard deviations of intra- and interday precision were less than 7.8%). These results demonstrated that the simple, reliable, and automatic method based on on-line column extraction and binary peak focusing is a promising approach for therapeutic drug monitoring in complex biomatrix samples.

  3. Comparison of Column Solid-Phase Extraction Procedures for Spectrophotometric Determination of E129 (Allura Red) in Foodstuff, Pharmaceutical, and Energy Drink Samples.

    Science.gov (United States)

    Bişgin, Abdullah Taner; Uçan, Mustafa; Narin, İbrahim

    2015-01-01

    Two novel spectrophotometric determination procedures based on retention of Allura Red onto Amberlite XAD-1180 and XAD-16 resins for its preconcentration, purification, and separation were developed. Analytical parameters of the methods including pH, eluent type, sample volume, and sample and eluent flow rates, were investigated and optimized. Interference effects of some cations, anions, and widely used food dyes were also investigated. Detection limits of the two methods were found to be 1.2 and 1.5 μg/L for XAD-1180 and XAD-16 columns, respectively, under optimum conditions. Linear calibration curve ranges of the methods were 0.4-8.0 and 0.5-6.0 μg/mL of Allura Red for XAD-1180 and XAD-16 resins, respectively. Preconcentration factors were found as 80 for both the XAD-1180 and XAD-16 columns using maximum sample volume and minimum eluent volume. RSDs of the methods were below 6% throughout all experiments. All absorbance measurements were performed at 506 nm. Validations of the methods were performed comparatively with determination of the Allura Red contents of some foodstuff, pharmaceutical, and energy drink samples. Allura Red concentrations in investigated solid and liquid samples ranged from 298 to 501 μg/g and 53.8 to 508 μg/mL, respectively. Satisfactory results were obtained from the real samples analysis. Allura Red contents of samples were determined to be highly similar using the two extraction methods. Comparisons of the methods were performed by analysis of Allura Red contents of the real samples. In addition to analytical parameters, adsorption isotherm studies were performed for the two kinds of Amberlite resins. It was observed that developed methods fit the linear form of the Freundlich adsorption isotherm model. All of the experimental results suggested that the developed SPE procedures are suitable for separation, preconcentration, and determination of Allura Red in solid and liquid matrixes.

  4. Study on a Mixer-Settler of Double Mixer and Flat Settler%双混浅层澄清室的混合澄清器研究

    Institute of Scientific and Technical Information of China (English)

    王春花; 黄桂文

    2007-01-01

    在剖析EC-D混合澄清器结构性能基础上,设计了双混浅层澄清室的混合澄清器.研究表明:该结构萃取器,在各种试验条件下,级效率均大于95.79%;在处理量等工艺条件相同时,混合澄清器的总体积可减少20%~50%;对操作条件响应快,有利于串级萃取体系快速建立平衡和稀土分离过程的自动控制;多级串联用于氯化稀土镧铈分离,分离效果与分液漏斗模拟一致.

  5. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of semivolatile organic compounds in bottom sediment by solvent extraction, gel permeation chromatographic fractionation, and capillary-column gas chromatography/mass spectrometry

    Science.gov (United States)

    Furlong, E.T.; Vaught, D.G.; Merten, L.M.; Foreman, W.T.; Gates, Paul M.

    1996-01-01

    A method for the determination of 79 semivolatile organic compounds (SOCs) and 4 surrogate compounds in soils and bottom sediment is described. The SOCs are extracted from bottom sediment by solvent extraction, followed by partial isolation using high-performance gel permeation chromatography (GPC). The SOCs then are qualitatively identified and quantitative concentrations determined by capillary-column gas chromatography/mass spectrometry (GC/MS). This method also is designed for an optional simultaneous isolation of polychlorinated biphenyls (PCBs) and organochlorine (OC) insecticides, including toxaphene. When OCs and PCBs are determined, an additional alumina- over-silica column chromatography step follows GPC cleanup, and quantitation is by dual capillary- column gas chromatography with electron-capture detection (GC/ECD). Bottom-sediment samples are centrifuged to remove excess water and extracted overnight with dichloromethane. The extract is concentrated, centrifuged, and then filtered through a 0.2-micrometer polytetrafluoro-ethylene syringe filter. Two aliquots of the sample extract then are quantitatively injected onto two polystyrene- divinylbenzene GPC columns connected in series. The SOCs are eluted with dichloromethane, a fraction containing the SOCs is collected, and some coextracted interferences, including elemental sulfur, are separated and discarded. The SOC-containing GPC fraction then is analyzed by GC/MS. When desired, a second aliquot from GPC is further processed for OCs and PCBs by combined alumina-over-silica column chromatography. The two fractions produced in this cleanup then are analyzed by GC/ECD. This report fully describes and is limited to the determination of SOCs by GC/MS.

  6. Determination of copper, lead and iron in water and food samples after column solid phase extraction using 1-phenylthiosemicarbazide on Dowex Optipore L-493 resin.

    Science.gov (United States)

    Yildiz, Ozden; Citak, Demirhan; Tuzen, Mustafa; Soylak, Mustafa

    2011-02-01

    A novel solid phase extraction procedure for determination of copper, lead and iron in natural water and food samples has been established in the presented work. 1-Phenylthiosemicarbazide (1-PTSC) as ligand and Dowex Optipore L-493 resin as adsorbent were used in a mini chromatographic column. Various analytical conditions for the quantitative recoveries of analyte ions including pH, amounts of adsorbent, eluent, sample volume, etc. were investigated. The recovery values for analyte ions were higher than 95%. The determination of copper, lead and iron was performed by flame atomic absorption spectrometry. The influences of some alkali, alkali earth and transition metals on the recoveries of analyte ions were investigated. The preconcentration factor was 62.5. The limit of detections of the understudied analytes (k=3, N=21) were 0.64 μg L(-1) for copper, 0.55 μg L(-1) for lead and 0.82 μg L(-1) for iron. The relative standard deviation was found to be lower than 6%. The accuracy of the method was confirmed with certified reference material (GBW 07605 Tea). The method was successively applied for the determination of copper, lead and iron in water and some food samples including cheese, bread, baby food, pekmez, honey, milk and red wine after microwave digestion.

  7. Comprehensive characterization of Annonaceous acetogenins within a complex extract by HPLC-ESI-LTQ-Orbitrap® using post-column lithium infusion.

    Science.gov (United States)

    Le Ven, Jessica; Schmitz-Afonso, Isabelle; Lewin, Guy; Laprévote, Olivier; Brunelle, Alain; Touboul, David; Champy, Pierre

    2012-11-01

    Annonaceous acetogenins (AAGs) are a homogenous class of polyketides proposed as environmental neurotoxins. Previous dereplication studies of AAGs were limited by the use of low-resolution mass spectrometers. Only poor information in terms of structures was provided due to the limited fragmentation of protonated or sodium cationized species. An innovative approach, using reversed-phase high-performance liquid chromatography coupled to a hybrid linear ion trap/orbitrap mass spectrometer (LTQ-Orbitrap®), was therefore performed. Sensitivity was enhanced by post-column infusion of lithium, since AAGs have a high affinity for this cation. High level of structural information was obtained from low-energy-collision-induced dissociation fragmentation experiments of lithium-cationized AAGs ([M + Li](+) ions) as demonstrated with purified standards. The method was then applied to a total ethyl-acetate extract prepared from commercial soursop nectar (Annona muricata L.). The sensitivity, mass accuracy and specific fragmentation patterns proved to be particularly useful for characterization of the AAGs. Typical structural identification procedure and unexpected observations for specific structural types are illustrated, with major and minor compounds.

  8. Sequential extraction of inorganic arsenic compounds and methyl arsenate in human urine using mixed-mode monolithic silica spin column coupled with gas chromatography-mass spectrometry.

    Science.gov (United States)

    Namera, Akira; Takeuchi, Akito; Saito, Takeshi; Miyazaki, Shota; Oikawa, Hiroshi; Saruwatari, Tatsuro; Nagao, Masataka

    2012-09-01

    A sequential analytical method was developed for the detection of arsenite, arsenate, and methylarsenate in human urine by gas chromatography-mass spectrometry (GC-MS). The combination of a derivatization of trivalent arsenic compounds by 2,3-dithio-1-propanol (British antilewisite; BAL) and a reduction of pentavalent arsenic compounds (arsenate and methylarsenate) were accomplished to carry out the analysis of arsenic compounds in urine. The arsenic derivatives obtained using BAL were extracted in a stepwise manner using a monolithic spin column and analyzed by GC-MS. A linear curve was observed for concentrations of arsenic compounds of 2.0 to 200 ng/mL, where the correlation coefficients of calibration curves were greater than 0.996 (for a signal-to-noise (S/N) ratio >10). The detection limits were 1 ng/mL (S/N > 3). Recoveries of the targets in urine were in the range 91.9-106.5%, and RSDs of the intra- and interday assay for urine samples containing 5, 50, and 150 ng/mL of arsenic compounds varied between 2.95 and 13.4%. The results from real samples obtained from a patient suspected of having ingested As containing medications using this proposed method were in good agreement with those obtained using high-performance liquid chromatography with inductively coupled plasma mass spectrometry.

  9. PULSE COLUMN

    Science.gov (United States)

    Grimmett, E.S.

    1964-01-01

    This patent covers a continuous countercurrent liquidsolids contactor column having a number of contactor states each comprising a perforated plate, a layer of balls, and a downcomer tube; a liquid-pulsing piston; and a solids discharger formed of a conical section at the bottom of the column, and a tubular extension on the lowest downcomer terminating in the conical section. Between the conical section and the downcomer extension is formed a small annular opening, through which solids fall coming through the perforated plate of the lowest contactor stage. This annular opening is small enough that the pressure drop thereacross is greater than the pressure drop upward through the lowest contactor stage. (AEC)

  10. [Determination of five avermectins in bovine liver by on-line solid-phase extraction with hydrophobic monolithic column coupled with high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Li, Xin; Zhang, Yaoqin; Ai, Lianfeng; Wang, Xuesheng; Wang, Manman; Xu, Houjun; Hao, Yulan

    2015-06-01

    A method based on on-line solid-phase extraction (SPE) with hydrophobic monolithic column coupled with high performance liquid chromatography-tandem mass spectrometry was developed for the simultaneous determination of five avermectins in bovine liver. A poly(butyl methacrylate-co-ethylene dimethacrylate) monolithic column was used as the sorbent. The parameters influenced on on-line SPE and separation process such as the loading mobile phase, the eluting flow rate and the solvent for the separation were investigated in detail. Blank samples, spiked samples, matrix effect and recovery experiments were investigated to evaluate the extraction efficiency and potential interfering compounds originating from the matrix. Under the optimized conditions, the method showed a linear range of 1-100 µg/L and the quantification limit of 5 µg/kg for each analyte. The presented method gave recoveries of 77.4%-98.4%. The relative standard deviations of intra-day and inter-day were 4.46%-8.03% and 4.79%-8.68%, respectively. Moreover, no significant changes were found in the extraction performance after more than 400 usages on one monolithic column, and even on the monoliths with various batches. The feasibility of the developed poly (butyl methacrylate-coethylene dimethacrylate) monolithic column based on the on-line SPE method for the determination of avermectins was further demonstrated by the analysis of real samples.

  11. Experimental studies and tests on An(III)/Ln(III) separation using the TODGA extractant

    Energy Technology Data Exchange (ETDEWEB)

    Heres, Xavier; Sorel, Christian; Miguirditchian, Manuel; Cames, Beatrice; Hill, Clement; Bisel, Isabelle; Espinoux, Denis; Viallesoubranne, Carole; Baron, Pascal; Lorrain, Brigitte [CEA/DEN/MAR/DRCP, Marcoule, BP17171, 30207 Bagnols/Ceze (France)

    2009-06-15

    Minor actinide recycling by separation and transmutation is worldwide considered as one of the most promising strategies to reduce the inventory of radioactive waste, thus contributing to make nuclear energy more sustainable. One of the different options investigated at the CEA Marcoule and within the ACSEPT project (a European collaborative project partly funded by the 7. EURATOM Framework Program) to separate trivalent minor actinide (Am(III)-Cf(III)) from the fission and activation products contained in PUREX raffinates is the TODGA process, which consists in: 1. Co-extracting trivalent 4f and 5f elements from highly acidic PUREX raffinates by a mixture of TODGA (tetraoctyl-diglycolamide) and TBP (tributyl-phosphate), dissolved in HTP (hydrogenated tetra-propene). 2. Selectively stripping the trivalent minor actinides by a hydrophilic poly-aminocarboxylic acid used as a complexing agent in a buffered aqueous solution, while the trivalent lanthanides are kept in the organic solvent thanks to a sodium nitrate salting-out effect. 3. Stripping the lanthanides in a diluted nitric acid solution. The major difficulty of this TODGA separation process is to tune the pH in a very narrow range of operating conditions in the second step, because of the high sensitivity of the performances of the flow-sheet vs pH. This difficulty was however overcome. This paper describes the development of the TODGA process from experimental studies to hot test implementation in shielded cells of the ATALANTE facility, including (i) the optimization of the extraction system (both the formulation of the organic solvent and those of the aqueous scrubbing and stripping solutions), (ii) the implementation of a cold test in small scale mixer-settlers in the G1 facility (MARCEL loop), using a surrogate feed composed of major fission products, (iii) the validation of some steps of the process, using a surrogate feed, spiked with Am-241 and Eu-152, and similar laboratory contactors (medium activity

  12. Column: lef

    NARCIS (Netherlands)

    Reep, Frans van der

    2012-01-01

    1e alinea column: Ook in je beleggingsbeslissingen is het voor echte performance wellicht tijd om eens voorbij best practices (dan word je namelijk hoogstens tweede) te kijken naar next practices. Als je op zeker speelt, verdien je weinig geld. Want anderen gingen je al voor. Maar kun je nog meer op

  13. Optimized determination of trace jet fuel volatile organic compounds in human blood using in-field liquid-liquid extraction with subsequent laboratory gas chromatographic-mass spectrometric analysis and on-column large-volume injection.

    Science.gov (United States)

    Liu, S; Pleil, J D

    2001-03-05

    A practical and sensitive method to assess volatile organic compounds (VOCs) from JP-8 jet fuel in human whole blood was developed by modifying previously established liquid-liquid extraction procedures, optimizing extraction times, solvent volume, specific sample processing techniques, and a new on-column large-volume injection method for GC-MS analysis. With the optimized methods, the extraction efficiency was improved by 4.3 to 20.1 times and the detection sensitivity increased up to 660 times over the standard method. Typical detection limits in the parts-per-trillion (ppt) level range were achieved for all monitored JP-8 constituents; this is sufficient for assessing human fuels exposures at trace environmental levels as well as occupational exposure levels. The sample extractions are performed in the field and only solvent extracts need to be shipped to the laboratory. The method is implemented with standard biological laboratory equipment and a modest bench-top GC-MS system.

  14. Determination of co-administrated opioids and benzodiazepines in urine using column-switching solid-phase extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Xiong, Lingjuan; Wang, Rong; Liang, Chen; Teng, Xiaomei; Jiang, Fengli; Zeng, Libo; Ye, Haiying; Ni, Chunfang; Yuan, Xiaoliang; Rao, Yulan; Zhang, Yurong

    2015-05-22

    Co-administration of opioids with benzodiazepines is very common around the world. A semi-automated method was developed for the determination of four opioids and two benzodiazepines as well as their metabolites (including glucuronide metabolites) in human urine, based on on-line column-switching-solid-phase extraction (CS-SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The CS-SPE was performed by loading 200μL of urine sample to an Oasis HLB cartridge. Detection was achieved using a LC-MS/MS system equipped with an electrospray ionization source (ESI). For unequivocal identification and confirmation, two selected reaction monitoring transitions were registered for each compound, and no co-elution of interferences was observed at the expected retention time. Significant ion suppressions were observed for most analytes during chromatographic runs, but isotope-labeled internal standards (ISs) were used and found to be useful to compensate for the determination error caused by the matrix effect. The assay's linearity ranged from 1-20ng/mL to 800-1000ng/mL for 23 compounds, except for lorazepam (LOR), whose linearity was in the range of 1-100ng/mL. This method showed to be precise and accurate. The relative standard deviation (RSD) % values of within-run precision, between-run precision and total precision were not greater than 10.4% (n=3), 12.9% (n=5) and 15.1% (n=15), respectively. Accuracy values were in the range of 87.5-110%. Limits of detection (LODs) ranged from 0.2ng/mL to 5ng/mL, and limits of quantification (LOQs) ranged from 1ng/mL to 20ng/mL. The method was applied to the assay of 12 samples from forensic cases, which exemplified the co-administration of benzodiazepines (BZDs) by some heroin abusers. This method was of high sensitivity, selectivity and reliability, minimum sample manipulation, semi-automation, and fairly high throughput (analysis time per sample was 20min). The method developed will be useful for the detection of co

  15. Application of an online post-column derivatization HPLC-DPPH assay to detect compounds responsible for antioxidant activity in Sonchus oleraceus L. leaf extracts

    DEFF Research Database (Denmark)

    Ou, Zong-Quan; Schmierer, David M; Rades, Thomas;

    2013-01-01

    To use an online assay to identify key antioxidants in Sonchus oleraceus leaf extracts and to investigate the effect of leaf position and extraction conditions on antioxidant concentration and activity.......To use an online assay to identify key antioxidants in Sonchus oleraceus leaf extracts and to investigate the effect of leaf position and extraction conditions on antioxidant concentration and activity....

  16. Rapid simultaneous determination of eperisone, tolperisone, and tizanidine in human serum by using a MonoSpin® C18 extraction column and liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Miura, Naoya; Saito, Takeshi; Taira, Takayuki; Yamagiwa, Takeshi; Morita, Sein; Inokuchi, Sadaki

    2014-01-01

    A method was developed for rapid toxicological analysis of eperisone, tolperisone, and tizanidine in human serum using a MonoSpin® C18 extraction column and LC/MS/MS. The method was validated for LOD, linearity, precision, and extraction recovery. This method was rapid with an LOD of 0.5 ng/mL, linearity range 1-500.0 ng/mL (r2 = 0.999), and RSD value below 14.6%. Extraction recovery from the sample was greater than 98.6, 98.8, and 88.5% for eperisone, tolperisone, and tizanidine, respectively. Results showed that combination of the MonoSpin C18 extraction column and LC/MS/MS is a simple and rapid method for the analysis of these three analytes, and a method is described for simultaneous quantitative determination of the analytes in human serum by LC/MSIMS. This method was used to determine the serum levels of eperisone in a patient with eperisone poisoning, and could be successfully applied for screening analyses in clinical cases other than poisoning.

  17. STUDY OF LOT-TO-LOT REPRODUCIBILITIES OF BOND ELUT CERTIFY AND CLEAN SCREEN DAU MIXED-MODE SOLID-PHASE EXTRACTION COLUMNS IN THE EXTRACTION OF DRUGS FROM WHOLE-BLOOD

    NARCIS (Netherlands)

    CHEN, XH; FRANKE, JP; WIJSBEEK, J; DEZEEUW, RA

    1993-01-01

    The lot-to-lot reproducibilities of Bond Elut Certify and Clean Screen DAU columns are described. The recoveries of five test drugs obtained from twelve lots of Bond Elut Certify columns ranged from 84 to 104% with standard deviations of less than 9%. The recoveries of five test drugs obtained from

  18. Development of an immunoaffinity column method using broad-specificity monoclonal antibodies for simultaneous extraction and cleanup of quinolone and sulfonamide antibiotics in animal muscle tissues

    Science.gov (United States)

    This paper describes a novel mixed-bed immunoaffinity column (IAC) method. The IAC was produced by coupling anti-fluoroquinolone and anti-sulfonamide broad-specificity monoclonal antibodies (Mabs) to Sepharose 4B for simultaneously isolating 13 fluoroquinolones (FQs) and 6 sulfonamides (SAs) from s...

  19. Advances in Simulation of Liquid-Liquid Two-phase Flow in Extraction Columns with CFD-PBM%萃取柱内液-液两相流CFD-PBM模拟研究进展

    Institute of Scientific and Technical Information of China (English)

    李少伟; 景山; 张琦; 吴秋林

    2012-01-01

    对萃取柱内CFD-PBM模拟研究进行了较详细的综述,包括其基本理论、不同的求解方法及模拟研究现状等.CFD-PBM模拟的基本方程包括流动方程和群体平衡方程,其相互耦合,群体平衡方程涉及破碎与聚并2个关键模型.群体平衡模型的求解方法包括直接离散化方法、矩量法、正交矩量法、直接正交矩量法、分段正交矩量法等,对这些方法的原理、优点和缺点进行了综述.目前国际上关于萃取柱内CFD模拟采用较多的是简单的欧拉-欧拉两相流模拟,考虑液滴尺寸分布和进一步的浓度分布的群体平衡模型应用较少.完善伴随传质的液-液分散体系的群体平衡模型,并将其应用于不同类型的萃取柱中,是萃取分离学科的重要任务.%A detailed review on the CFD-PBM research in the extraction columns is presented, including the fundamental theory, different solution methods, and status of the simulation research. The basic equations in the CFD-PBM simulation contain the flow equations and the population balance equation, which are coupled with each other. Coalescence and break-up models are two important models in the population equation. The methods to solve the population balance equation include the class method, the method of moments, the quadrature method of moments, the direct quadrature method of moments, and the sectional quadrature method of moments. The fundamental, advantages and disadvantaged of these methods were reviewed. The Eulerian-Eulerian method is mainly used in the CFD simulation of the two-phase flow in extraction columns to date. The PBM which considers the droplet size distribution and further the concentration distribution is relatively less used in extraction columns. To improve the PBM in a liquid-liquid dispersion system with mass transfer and to use the model in different types of extraction columns are important issues for extraction research.

  20. Methods of analysis by the U. S. Geological Survey National Water Quality Laboratory - determination of organonitrogen herbicides in water by solid-phase extraction and capillary-column gas chromatography/mass spectrometry with selected-ion monitoring

    Science.gov (United States)

    Sandstrom, Mark W.; Wydoski, Duane S.; Schroeder, Michael P.; Zamboni, Jana L.; Foreman, William T.

    1992-01-01

    A method for the isolation of organonitrogen herbicides from natural water samples using solid-phase extraction and analysis by capillary-column gas chromatography/mass spectrometry with selected-ion monitoring is described. Water samples are filtered to remove suspended particulate matter and then are pumped through disposable solid-phase extraction cartridges containing octadecyl-bonded porous silica to remove the herbicides. The cartridges are dried using carbon dioxide, and adsorbed herbicides are removed from the cartridges by elution with 1.8 milliliters of hexaneisopropanol (3:1). Extracts of the eluants are analyzed by capillary-column gas chromatography/mass spectrometry with selected-ion monitoring of at least three characteristic ions. The method detection limits are dependent on sample matrix and each particular herbicide. The method detection limits, based on a 100-milliliter sample size, range from 0.02 to 0.25 microgram per liter. Recoveries averaged 80 to 115 percent for the 23 herbicides and 2 metabolites in 1 reagent-water and 2 natural-water samples fortified at levels of 0.2 and 2.0 micrograms per liter.

  1. Continuous biosorption of Pb/Cu and Pb/Cd in fixed-bed column using algae Gelidium and granulated agar extraction algal waste

    Energy Technology Data Exchange (ETDEWEB)

    Vilar, Vitor J.P. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: vilar@fe.up.pt; Loureiro, Jose M. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: loureiro@fe.up.pt; Botelho, Cidalia M.S. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: cbotelho@fe.up.pt; Boaventura, Rui A.R. [LSRE-Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: bventura@fe.up.pt

    2008-06-15

    Continuous metal ions biosorption from Pb/Cu and Pb/Cd solutions onto seaweed Gelidium sesquipedale and a composite material prepared from an industrial algal waste was performed in a packed bed column. A binary Langmuir equation describes well the equilibrium data and indicates a good adsorption capacity. In the sorption process, Cd and Cu break through the column faster than Pb due to its lower affinity for the biosorbent. An overshoot in the outlet Cd concentration was observed and explained by competitive adsorption between Pb and Cd, whereby the higher Pb affinity for the biosorbent displaces bound Cd ions. A small overshoot happens for Cu adsorption in the presence of Pb ions. Desorption using 0.1 M HNO{sub 3} as eluant, was 100% effective. A mass transfer model for the adsorption and desorption processes, considering an external and intraparticle film resistance, adequately simulates the column performance. A binary Langmuir equation was used to describe equilibrium for the saturation process and a mass action law for the desorption process. Elution process is defined as an ion exchange mechanism, between protons and metal ions.

  2. Continuous biosorption of Pb/Cu and Pb/Cd in fixed-bed column using algae Gelidium and granulated agar extraction algal waste.

    Science.gov (United States)

    Vilar, Vítor J P; Loureiro, José M; Botelho, Cidália M S; Boaventura, Rui A R

    2008-06-15

    Continuous metal ions biosorption from Pb/Cu and Pb/Cd solutions onto seaweed Gelidium sesquipedale and a composite material prepared from an industrial algal waste was performed in a packed bed column. A binary Langmuir equation describes well the equilibrium data and indicates a good adsorption capacity. In the sorption process, Cd and Cu break through the column faster than Pb due to its lower affinity for the biosorbent. An overshoot in the outlet Cd concentration was observed and explained by competitive adsorption between Pb and Cd, whereby the higher Pb affinity for the biosorbent displaces bound Cd ions. A small overshoot happens for Cu adsorption in the presence of Pb ions. Desorption using 0.1 M HNO3 as eluant, was 100% effective. A mass transfer model for the adsorption and desorption processes, considering an external and intraparticle film resistance, adequately simulates the column performance. A binary Langmuir equation was used to describe equilibrium for the saturation process and a mass action law for the desorption process. Elution process is defined as an ion exchange mechanism, between protons and metal ions.

  3. Sensitive fluorimetric determination of gentamicin sulfate in biological matrices using solid-phase extraction, pre-column derivatization with 9-fluorenylmethyl chloroformate and reversed-phase high-performance liquid chromatography.

    Science.gov (United States)

    Stead, D A; Richards, R M

    1996-01-26

    A high-performance liquid chromatographic method is described for the determination of gentamicin in bacterial culture medium or plasma with increased sensitivity and improved separation of the C1 component. Gentamicin was extracted from the biological matrix with high efficiency using carboxypropyl (CBA)-bonded silica. Derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl) followed by C18 reversed-phase chromatography allowed the fluorimetric detection of gentamicins C1, C1a and C2. A fourth component, considered to be gentamicin C2a, was partially resolved from the C2 peak. Optimal conditions for the extraction and derivatization of gentamicin are described. The detection limit was below 50 micrograms/l, the assay was linear to 5 mg/l and showed good reproducibility. It is concluded that pre-column derivatization with FMOC-Cl substantially improves the analysis of gentamicin compared with present methods based on reaction with o-phthaldialdehyde.

  4. Simulation and optimization of the methylal purification by extractive dividing wall column%分壁式萃取精馏塔制取高纯度甲缩醛的模拟与优化

    Institute of Scientific and Technical Information of China (English)

    朱登磊; 任根宽

    2015-01-01

    A novel process of methylal purification by extractive dividing wall column was developed. Simulation and optimization were carried out by Aspen Plus software. The optimized parameters were as fellow: plate number was 39, bottom of dividing wall was placed on 31 stage, feed stage was 17, extractant feed stage was 4, reflux ratio was 0.9, ratio of solvent was 1.0 and vapor split ratio was 0.12. Rigorous simulation results in the optimized parameters showed that 99.96 % methylal and 99.24 % methanol in mass fraction could be obtained by this process. Compared with conventional extractive distillation process, reboiler load saving of extractive dividing wall column was 14.8 % and condenser load saving was 16.9 %. This showed that the methylal purification by extractive dividing wall column is not only feasible in technology,but also has significant economic advantage because of lower capital costs and saving energy.%建立一种利用分壁式萃取精馏塔制取高纯度甲缩醛的新工艺,并用Aspen Plus软件对该工艺进行模拟和优化。最优工艺参数为:主塔塔板数39,隔板底端位置在第31块板,原料进料在第17块板,萃取剂进料在第4块板,回流比为0.9,溶剂比为1.0,气相分配比为0.12。最优参数下的严格模拟结果显示:本工艺可得到质量分数99.96%的甲缩醛和99.24%的甲醇;与常规萃取精馏工艺相比,再沸器和冷凝器热负荷分别降低14.8%和16.9%。说明分壁式萃取精馏塔制取高纯度甲缩醛不仅技术上可行,而且能减少一个塔的投资和节约分离过程的能耗,在经济上也具有显著的优势。

  5. 分隔壁萃取精馏塔分离C4烯烃与烷烃的模拟%Simulation of Separation of C40lefins and Alkanes Through Dividing Wall Extractive Distillation Column

    Institute of Scientific and Technical Information of China (English)

    高思亮; 田龙胜; 唐文成; 赵明; 吴巍

    2013-01-01

    A novel single column extractive distillation process for the separation of n-butane and trans-2-butene was proposed and simulated by means of the MultiFrac module of Aspen Plus software.The influences of solvent ratio,reflux ratio and distribution ratio of vapor phase on the separation efficiency and energy consumption were investigated.The simulation results show that under the conditions of the number of theoretical plates of main column and side column 40 and 10 respectively,solvent ratio 2.5,reflux ratio 3.5,and distribution ratio of vapor phase 2.5,the purities of the products n-butane and trans-2-butene can reach 99.0%(w),99.9%(w),respeetively which can meet the requirement of the separation.It was found that the novel process had higher energy efficiency than conventional extractive distillation process,the reboiler and condenser can save energy up to 17.31% and 25.81%,respectively.The reason for the energy saving was discussed based on the analysis of the component concentration distributions in the dividing wall extractive distillation column.%采用Aspen Plus化工流程模拟软件中的MultiFrac模块,对分隔壁萃取精馏塔分离正丁烷和反-2-丁烯混合物的过程进行模拟,分析了溶剂比、回流比、汽相分配比对分离效果及能耗的影响.模拟结果表明,当分离要求为正丁烷纯度大于99.0%(w),反-2-丁烯纯度大于99.9%(w)时,分隔壁萃取精馏塔主塔理论板数40,副塔理论板数10;最佳工艺条件为溶剂比2.5,主塔回流比3.5,汽相分配比2.5;分隔壁萃取精馏塔能有效避免常规萃取精馏塔内的返混效应,因此节能效果显著.与常规萃取精馏塔相比,分隔壁萃取精馏塔再沸器和冷凝器可分别节能17.31%,25.81%.

  6. EPA Method 525.3 - Determination of Semivolatile Organic Chemicals in Drinking Water by Solid Phase Extraction and Capillary Column Gas Chromatography/Mass Spectrometry (GC/MS)

    Science.gov (United States)

    Method 525.3 is an analytical method that uses solid phase extraction (SPE) and gas chromatography/mass spectrometry (GC/MS) for the identification and quantitation of 125 selected semi-volatile organic chemicals in drinking water.

  7. Impact of backmixing of the aqueous phase on two-component rare earth separation process

    Institute of Scientific and Technical Information of China (English)

    WU Sheng; CHENG Fuxiang; LIAO Chunsheng; YAN Chunhua

    2013-01-01

    Solvent extraction based on mixer-settler is the major industrial method of rare earth (RE) separation.In the mixer-settler extraction process,due to the insufficient settling time in normal circumstances,backmixing of the aqueous phase could have significant impact on the process of RE extraction separation.Therefore on the basis of the extraction equilibrium and mass balance of the mixer-settler extraction process,here we developed a mathematic expression of the aqueous phase backmixing in a two-component separation process,and obtained a quantitative analysis of the backmixing effect on the purification process by the approximations according to certain hypotheses.Two extraction systems of La/Ce and Pr/Nd separation were chosen as the examples to analyze the backmixing effect,and the results showed that the aqueous backmixing had greater influence in the scrubbing segment than in the extraction segment,especially in the system with a high separation factor such as La/Ce separation.Therefore it was suggested that the aqueous backmixing effect should be well attended in the design and application of RE extraction separation.

  8. Development and validation of a high-performance liquid chromatography method for determination of ractopamine residue in pork samples by solid phase extraction and pre-column derivatization.

    Science.gov (United States)

    Ding, Guanglong; Li, Deguang; Qin, Jiao; Zhu, Juanli; Wang, Baitao; Geng, Qianqian; Guo, Mingcheng; Punyapitak, Darunee; Cao, Yongsong

    2015-08-01

    Ractopamine (RAC) has been approved as a feed additive for swine, cattle or turkey, and is likely to have residue in edible animal products and may pose a potential risk for consumer health. Therefore, it is essential to establish a method to detect the residue of RAC in animal products. This work presents a rapid and sensitive HPLC method for the determination of RAC in pork samples with pre-column derivatization. The RAC derivative was separated on a kromasil C18 column and detected at 284nm with a UV detector. The detection capability (CCβ) was 0.078μgg(-1) and the linearity was established over the concentration range of 0.15-100.0μgg(-1). The overall mean recovery in spike range of 0.2μgg(-1) to 100μgg(-1) was 89.9% with the overall mean relative standard deviation of 4.1%. This method can be used for the quantification of RAC in pork samples and help to establish adequate monitoring of the residue of RAC.

  9. Batch and fixed-bed column studies for biosorption of Zn(II) ions onto pongamia oil cake (Pongamia pinnata) from biodiesel oil extraction.

    Science.gov (United States)

    Shanmugaprakash, M; Sivakumar, V

    2015-12-01

    The present work, analyzes the potential of defatted pongamia oil cake (DPOC) for the biosorption of Zn(II) ions from aqueous solutions in the both batch and column mode. Batch experiments were conducted to evaluate the optimal pH, effect of adsorbent dosage, initial Zn(II) ions concentration and contact time. The biosorption equilibrium and kinetics data for Zn(II) ions onto the DPOC were studied in detail, using several models, among all it was found to be that, Freundlich and the second-order model explained the equilibrium data well. The calculated thermodynamic parameters had shown that the biosorption of Zn(II) ions was exothermic and spontaneous in nature. Batch desorption studies showed that the maximum Zn(II) recovery occurred, using 0.1 M EDTA. The Bed Depth Service Time (BDST) and the Thomas model was successfully employed to evaluate the model parameters in the column mode. The results indicated that the DPOC can be applied as an effective and eco-friendly biosorbent for the removal of Zn(II) ions in polluted wastewater.

  10. Solid phase extraction method for the determination of iron, lead and chromium by atomic absorption spectrometry using Amberite XAD-2000 column in various water samples

    Energy Technology Data Exchange (ETDEWEB)

    Elci, Latif [Chemistry Department, Science and Arts Faculty, Pamukkale University, Denizli (Turkey)], E-mail: elci@pamukkale.edu.tr; Kartal, Aslihan A. [Chemistry Department, Science and Arts Faculty, Pamukkale University, Denizli (Turkey); Soylak, Mustafa [Chemistry Department, Science and Arts Faculty, Erciyes University, Kayseri (Turkey)

    2008-05-01

    This work describes a procedure for the separation-preconcentration of Fe(III), Pb(II) and Cr(III) from some water samples using a column-filled Amberlite XAD-2000 resin. The analyte ions retained on the column were eluted with 0.5 mol L{sup -1} HNO{sub 3}. The analytes in the effluent were determined by atomic absorption spectrometry. Several parameters governing the efficiency of the method were evaluated including pH, resin amount, sample volume, flow rates, eluent type and divers ion effects. The recoveries under the optimum working conditions were found to be as 100 {+-} 1% Fe, 96 {+-} 1% Pb and 93 {+-} 2% Cr. The relative standard deviations and errors were less than 2% and 5%, respectively. The detection limit based on three standard deviations of the blank was found to be 0.32, 0.51 and 0.81 {mu}g L{sup -1}, for Fe, Pb and Cr, respectively. The procedure was applied to the determination of Fe, Cr and Pb in hot spring water and drinking water samples.

  11. Solid phase extraction method for the determination of iron, lead and chromium by atomic absorption spectrometry using Amberite XAD-2000 column in various water samples.

    Science.gov (United States)

    Elci, Latif; Kartal, Aslihan A; Soylak, Mustafa

    2008-05-01

    This work describes a procedure for the separation-preconcentration of Fe(III), Pb(II) and Cr(III) from some water samples using a column-filled Amberlite XAD-2000 resin. The analyte ions retained on the column were eluted with 0.5 mol L(-1) HNO(3). The analytes in the effluent were determined by atomic absorption spectrometry. Several parameters governing the efficiency of the method were evaluated including pH, resin amount, sample volume, flow rates, eluent type and divers ion effects. The recoveries under the optimum working conditions were found to be as 100+/-1% Fe, 96+/-1% Pb and 93+/-2% Cr. The relative standard deviations and errors were less than 2% and 5%, respectively. The detection limit based on three standard deviations of the blank was found to be 0.32, 0.51 and 0.81 microg L(-1), for Fe, Pb and Cr, respectively. The procedure was applied to the determination of Fe, Cr and Pb in hot spring water and drinking water samples.

  12. 超声萃取一柱色谱法分离鉴定乌桕叶抑螺活性成分%Separation and determination of molluscicidal composition from Sapium sebiferum by supersonic extraction-column chromatography

    Institute of Scientific and Technical Information of China (English)

    罗坤水; 余能富; 邹峥嵘; 徐林初

    2013-01-01

    Based on previous research, ethyl acetate extraction of ethanol extract of Sapium sebiferum had strong molluscicidal activity. In order to separate and determine molluscicidal composition from Sapium sebiferum leaves, supersonic extraction, fractional solvent extraction and column chromatography were used to separate many constituent. According to their physicochemical properties and spectroscopic characteristics, three flavonoids were seperated, and were identified as kaempferol, quercetin, isoquercitrin. Three compounds were all separated from this plant.%根据笔者前期研究结果,乌桕叶乙醇提取物的乙酸乙酯萃取部位具有较强的抑螺活性.为分离鉴定乌桕叶中的抑螺活性物质,采用超声波辅助溶剂提取、溶剂分步萃取和多种柱层析联用等方法从乌桕叶乙醇提取物中分离得到多个单体化合物,依据化合物的理化性质和波谱学特征,鉴定出3个黄酮类化合物,分别为山柰酚、槲皮素和异槲皮苷,均为首次从该植物中得到.

  13. Automated Composite Column Wrapping

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    The Automated Composite Column Wrapping is performed by a patented machine known as Robo-Wrapper. Currently there are three versions of the machine available for bridge retrofit work depending on the size of the columns being wrapped. Composite column retrofit jacket systems can be structurally just as effective as conventional steel jacketing in improving the seismic response characteristics of substandard reinforced concrete columns.

  14. Column flotation testing at Suncor Energy Inc.

    Energy Technology Data Exchange (ETDEWEB)

    Cleyle, P.; Lee, L. [Suncor Energy Inc. Oil Sands, Fort McMurray, AB (Canada)

    2006-07-01

    The operations at Suncor's primary extraction plant were reviewed with reference to the column flotation process and the history of column flotation testing at Suncor. Tertiary bitumen recovery processes were also reviewed. In March and August 2005, an in-plant pilot scale column flotation test was conducted at Suncor's Millennium Primary Extraction plant near Fort McMurray, Alberta. The purpose was to evaluate the feasibility of using column flotation for tertiary bitumen recovery from cyclone overflow. The test was performed in a 4 ft diameter by 25 ft high column to determine the effects of column feed flow rate, froth wash water supply, and froth depth. The feed ranged from 0.14 to 3.79 wt per cent bitumen. Feed flow rate ranged from 59 to 237 USGPM. The test results indicated that wash water reduced froth mineral content. Increasing the wash water did not make any difference in mineral rejection. Although bitumen upgrading improved when the test column was operated at a deeper froth depth, the mineral content was not reduced. Both mechanical cell and flotation column tailings samples were collected in the flotation column tests. The average tailings composition for the last cell in the tertiary mechanical bank was 0.22 per cent bitumen, 12.10 per cent mineral, and 87.66 per cent water. At an average test column feed rate of 158 USGPM, the average tailings composition was 0.23 per cent bitumen, 12.13 per cent mineral, and 87.62 per cent water. It was concluded that flotation columns are capable of producing a tailings product similar to that of the tertiary mechanical bank. Therefore, it is feasible to use flotation columns as an alternative to mechanical cells. In fact, since there are no rotating parts requiring off-line maintenance work, flotation columns may be a better alternative from a maintenance and operations perspective. tabs., figs.

  15. Solid phase extraction for multiresidue analysis of anabolic steroids and related substances from calf urine using C18 and alumina columns

    NARCIS (Netherlands)

    Koole, A; Franke, JP; de Zeeuw, RA

    1999-01-01

    A solid phase extraction method for anabolic steroids and related substances in calf urine is reported, that is suitable as a screening method for illegal growth promoters. Two types of sorbent were used: a reversed phase C18 material and a polar alumina material. After overnight enzymatic deconjuga

  16. Nanofibers Solid Phase Extraction Column for Determination of Cortisol in Hair Samples%纳米纤维固相萃取柱萃取-高效液相荧光法分析头发皮质醇

    Institute of Scientific and Technical Information of China (English)

    陈利琴; 康学军; 晏嫣; 顾忠泽; 陆祖宏

    2012-01-01

    In recent years, many studies found that hair cortisol can serve as a good biomarker of chronic stress. A high performance liquid chromatography-fluorescence (HPLC-Flu) method for the determination of hair cortisol based on novel packed nanofiber solid phase extraction (PFSPE) was established. The incubation solution of hair samples was extracted by the new PFSPE column. The column was eluted with 100 μL ethanol, and then 230 μL concentrated sulfuric acid was add in the eluant and retained for 2 min. The mixture of reactants and water was secondly extracted by the PFSPE column, which was eluted with 50 μL methanol directly. The detection limit of cortisol was 0.5 ng/g(signal-to-noise ratio of 3). The within-run and between-day precisions (RSD) were below 6.8% and 8. 9%, and the average recovery of cortisol spiked into hair samples was 88. 9%. The method of pretreatment is simple, fast and green. Moreover, the established method can accurately determine the level of cortisol in hair samples, which provides a simple, inexpensive determination method for physiology, psychiatry, sports medicine, cognitive science, psychology and other researches.%采用基于纳米纤维固相萃取的高效液相色谱-荧光测定(HPLC-Flu)法测定头发中的皮质醇水平.以新型纳米纤维萃取柱(PFSPE)提取头发样本浸出液,用100 μL乙醇洗脱,再加入230μL浓H2SO4反应2 min,反应物加水混合后用PFSPE柱提取,最后用50 μL甲醇直接洗脱后注入色谱体系进行分析.此方法的检出限为0.05 ng/g( S/N=3),日内精密度和日间精密度分别低于6.8%和8.9%,平均方法回收率为88.9%.本方法提取过程简便、快速、环保,而且可以准确测定头发样本中的皮质醇水平.

  17. EXTRACT

    DEFF Research Database (Denmark)

    Pafilis, Evangelos; Buttigieg, Pier Luigi; Ferrell, Barbra

    2016-01-01

    The microbial and molecular ecology research communities have made substantial progress on developing standards for annotating samples with environment metadata. However, sample manual annotation is a highly labor intensive process and requires familiarity with the terminologies used. We have the...... and text-mining-assisted curation revealed that EXTRACT speeds up annotation by 15-25% and helps curators to detect terms that would otherwise have been missed.Database URL: https://extract.hcmr.gr/....

  18. Phytochemical analysis of ethanolic extract of Dichrostachys Cinerea W and Arn leaves by a thin layer chromatography, high performance thin layer chromatography and column chromatography

    OpenAIRE

    M.Vijayalakshmi; Periyanayagam, K.; K Kavitha; Akilandeshwari, K.

    2013-01-01

    Background: The leaves of Dichrostachys cinerea are used as laxative, diuretic, painkiller. It is also used in the treatment of gonorrhoea, boils, oedema, gout, veneral diseases and nasopharyngeal affections, etc. Materials and Methods: The Phytochemical investigation of ethanolic extract of D. cinerea leaves were performed by standard chemical tests, thin layer chromatography (TLC) by using various solvent systems, and by high performance liquid chromatography (HPTLC). Two compounds were...

  19. Phytochemical analysis of ethanolic extract of Dichrostachys Cinerea W and Arn leaves by a thin layer chromatography, high performance thin layer chromatography and column chromatography

    OpenAIRE

    Vijayalakshmi, M; K Periyanayagam; Kavitha, K; K Akilandeshwari

    2013-01-01

    Background: The leaves of Dichrostachys cinerea are used as laxative, diuretic, painkiller. It is also used in the treatment of gonorrhoea, boils, oedema, gout, veneral diseases and nasopharyngeal affections, etc. Materials and Methods: The Phytochemical investigation of ethanolic extract of D. cinerea leaves were performed by standard chemical tests, thin layer chromatography (TLC) by using various solvent systems, and by high performance liquid chromatography (HPTLC). Two compounds were...

  20. Mass Transfer and Axial Mixing Characteristics in a Coalescence-Dispersion Pulsed-Sieve-Plate Extraction Column%聚并-分散脉冲筛板萃取塔的传质与轴向混合特性

    Institute of Scientific and Technical Information of China (English)

    唐晓津; 骆广生; 汪家鼎

    2004-01-01

    A new configuration of coalescence-dispersed pulsed-sieve-plate extraction column (CDPSEC) was developed, and the mass transfer and axial mixing characteristics were evaluated with the two-point dynamic method.The influence of operation conditions was discussed with experimental results, showing that the mass transfer performance of CDPSEC mainly depends on the energy input and the holdup of dispersed phase. Higher energy input results in higher holdup of the dispersed phase, the axial mixing of the continuous phase is suppressed, and the true height of mass transfer unit decreases markedly. On the other hand, higher energy input leads to more serious forward mixing of the dispersed phase, so the energy input should be limited. Accordingly the operation conditions were divided into two regions, and empirical correlations for predicting the mass transfer and axial mixing characteristics in different regions with a satisfactory accuracy were suggested.

  1. A model for a liquid membrane separation stage

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    The coupled mixer-settlers having a common settling zone suggested for use to extract fission products from a conversion reactor blanket are analogues of membrane apparatuses and at a first glance in terms of hydrodynamics do not differ from conventional mixer-settlers. However, the common settling zone complicates both the design solutions and their modelling. For example, different emulsion types can result in mixers and it is not known how this fact will affect phenomena such as separation rates, disperse phase entrainment under conditions close to flooding. For initial studies of the feasibility of the process in principle and the primary optimization of the structure of the transfer scheme one needs to have a model and a program to calculate the statics of a multistage membrane facility of this type.

  2. Continuous enzymatic biodiesel production from coconut oil in two-stage packed-bed reactor incorporating an extracting column to remove glycerol formed as by-product.

    Science.gov (United States)

    Costa E Silva, William; Freitas, Larissa; Oliveira, Pedro C; de Castro, Heizir F

    2016-10-01

    The transesterification of coconut oil with ethanol catalyzed by Burkholderia cepacia lipase immobilized on polysiloxane-polyvinyl alcohol was performed in a continuous flow. The experimental design consisted of a two-stage packed-bed reactor incorporating a column with cationic resin (Lewatit GF 202) to remove the glycerol formed as by-product and the reactor performance was quantified for three different flow rates corresponding to space-times from 10 to 14 h. The influence of space-time on the ethyl ester (FAEE) concentrations, yields and productivities was determined. The reactor operation was demonstrated for space-time of 14 h attaining FAEE concentrations of 58.5 ± 0.87 wt%, FAEE yields of 97.3 ± 1.9 % and productivities of 41.6  ± 1.0 mgester g medium (-1)  h(-1). Biodiesel purified samples showed average kinematic viscosity values of 5.5 ± 0.3 mm(2) s(-1) that meet the criteria established by the American National Standard ASTM (D6751). The immobilized lipase was found to be stable regarding its morphological and catalytic characteristics, showing half-life time (t 1/2) around 1540 h. The continuous packed-bed reactor connected in series with simultaneous glycerol removal has a great potential to attain high level of transesterification yields, raising biodiesel productivity.

  3. Modeling Stone Columns

    Directory of Open Access Journals (Sweden)

    Jorge Castro

    2017-07-01

    Full Text Available This paper reviews the main modeling techniques for stone columns, both ordinary stone columns and geosynthetic-encased stone columns. The paper tries to encompass the more recent advances and recommendations in the topic. Regarding the geometrical model, the main options are the “unit cell”, longitudinal gravel trenches in plane strain conditions, cylindrical rings of gravel in axial symmetry conditions, equivalent homogeneous soil with improved properties and three-dimensional models, either a full three-dimensional model or just a three-dimensional row or slice of columns. Some guidelines for obtaining these simplified geometrical models are provided and the particular case of groups of columns under footings is also analyzed. For the latter case, there is a column critical length that is around twice the footing width for non-encased columns in a homogeneous soft soil. In the literature, the column critical length is sometimes given as a function of the column length, which leads to some disparities in its value. Here it is shown that the column critical length mainly depends on the footing dimensions. Some other features related with column modeling are also briefly presented, such as the influence of column installation. Finally, some guidance and recommendations are provided on parameter selection for the study of stone columns.

  4. Modeling Stone Columns

    Science.gov (United States)

    2017-01-01

    This paper reviews the main modeling techniques for stone columns, both ordinary stone columns and geosynthetic-encased stone columns. The paper tries to encompass the more recent advances and recommendations in the topic. Regarding the geometrical model, the main options are the “unit cell”, longitudinal gravel trenches in plane strain conditions, cylindrical rings of gravel in axial symmetry conditions, equivalent homogeneous soil with improved properties and three-dimensional models, either a full three-dimensional model or just a three-dimensional row or slice of columns. Some guidelines for obtaining these simplified geometrical models are provided and the particular case of groups of columns under footings is also analyzed. For the latter case, there is a column critical length that is around twice the footing width for non-encased columns in a homogeneous soft soil. In the literature, the column critical length is sometimes given as a function of the column length, which leads to some disparities in its value. Here it is shown that the column critical length mainly depends on the footing dimensions. Some other features related with column modeling are also briefly presented, such as the influence of column installation. Finally, some guidance and recommendations are provided on parameter selection for the study of stone columns. PMID:28773146

  5. Development of an Inclined Plate Extractor-Separator for Immiscible Liquids

    Directory of Open Access Journals (Sweden)

    Syed Zahoor ul Hassan Rizvi

    2009-10-01

    Full Text Available A new inclined plates extractor-separator is developed for operation with immiscible liquids in which extraction and separation is achieved in one unit contrary to mixer settlers. The inclined plates extractor-separator combines turbulent jets for contacting, and an inclined plate for separation of the two phases. The inclined plates extractor-separator does not have any moving part inside the vessel. This feature makes it free from the mechanical problems associated with conventional apparatus. The proposed inclined plates extractor-separator was operated in batch mode under various operating conditions to evaluate its performance on the basis of extraction efficiency. Water (light phase was used as solvent to extract ethyl acetate from a heavy phase pool of tetrachloroethylene and ethyl acetate. The ethyl acetate content was analysed using chromatography. A hydrodynamic study was carried out using high speed photography to understand the mechanisms occurring during mass transfer across the two phases. Furthermore, it was found that the proposed inclined plate extractor-separator reduces the overall operating time by 67% and consumes only 13% of the power in comparison to a mixer-settler. A hydraulic power consumption comparison with a mixer settler and a gullwing extractor-separator is also presented.

  6. Development of an inclined plate extractor-separator for immiscible liquids

    Energy Technology Data Exchange (ETDEWEB)

    Munir, A.; Daood, S. S. [School of Process, Environmental and Materials Engineering, University of Leeds, LS2 9JT (United Kingdom); Rizvi, H.; Butt, M. A. [Institute of Chemical Engineering and Technology, University of the Punjab Lahore (Pakistan)

    2009-07-01

    A new inclined plates extractor-separator is developed for operation with immiscible liquids in which extraction and separation is achieved in one unit contrary to mixer settlers. The inclined plates extractor-separator combines turbulent jets for contacting, and an inclined plate for separation of the two phases. The inclined plates extractor-separator does not have any moving part inside the vessel. This feature makes it free from the mechanical problems associated with conventional apparatus. The proposed inclined plates extractor-separator was operated in batch mode under various operating conditions to evaluate its performance on the basis of extraction efficiency. Water (light phase) was used as solvent to extract ethyl acetate from a heavy phase pool of tetrachloroethylene and ethyl acetate. The ethyl acetate content was analysed using chromatography. A hydrodynamic study was carried out using high speed photography to understand the mechanisms occurring during mass transfer across the two phases. Furthermore, it was found that the proposed inclined plate extractor-separator reduces the overall operating time by 67% and consumes only 13% of the power in comparison to a mixer settler. A hydraulic power consumption comparison with a mixer settler and a gull wing extractor-separator is also presented. (author)

  7. Column Liquid Chromatography.

    Science.gov (United States)

    Majors, Ronald E.; And Others

    1984-01-01

    Reviews literature covering developments of column liquid chromatography during 1982-83. Areas considered include: books and reviews; general theory; columns; instrumentation; detectors; automation and data handling; multidimensional chromatographic and column switching techniques; liquid-solid chromatography; normal bonded-phase, reversed-phase,…

  8. Application of solid phase extraction column chromatography in organic compounds analysis in soy sauce%固相萃取技术在酱油有机物分析中的应用进展

    Institute of Scientific and Technical Information of China (English)

    任敏; 汪雨

    2015-01-01

    ABSTRACT:Soy sauce is a condiment which widely used in daily life. The organic compounds analysis in soy sauce is become more important due to food safety reasons. In this paper, the advances in application of solid phase extraction (SPE) column chromatography in organic compounds analysis in soy sauce in last 10 years were summarized, including SPE methods which were used in analysis of soy sauce, the organic compounds which could be analyzed by SPE, and summarization and classification of adsorbents used in SPE for soy sauce analysis.%酱油是日常生活中较为常用的调味品。随着社会对食品安全的重视,酱油中的有机物分析也日益受到关注。本文对近10年来国内外在酱油有机物分析中固相萃取(solid phase extraction, SPE)法的应用进行概述,归纳总结了主要用于酱油有机物分析的 SPE 法,可使用 SPE 法分析的酱油中的有机物种类,并对应用到酱油分析中的SPE方法使用的吸附剂进行总结和分类。

  9. Methods of analysis and quality-assurance practices of the U.S. Geological Survey organic laboratory, Sacramento, California; determination of pesticides in water by solid-phase extraction and capillary-column gas chromatography/mass spectrometry

    Science.gov (United States)

    Crepeau, Kathryn L.; Domagalski, Joseph L.; Kuivila, Kathryn M.

    1994-01-01

    Analytical method and quality-assurance practices were developed for a study of the fate and transport of pesticides in the Sacramento-San Joaquin Delta and the Sacramento and San Joaquin River. Water samples were filtered to remove suspended parti- culate matter and pumped through C-8 solid-phase extraction cartridges to extract the pesticides. The cartridges were dried with carbon dioxide, and the pesticides were eluted with three 2-milliliter aliquots of hexane:diethyl ether (1:1). The eluants were analyzed using capillary-column gas chromatography/mass spectrometry in full-scan mode. Method detection limits for analytes determined per 1,500-milliliter samples ranged from 0.006 to 0.047 microgram per liter. Recoveries ranged from 47 to 89 percent for 12 pesticides in organic-free, Sacramento River and San Joaquin River water samples fortified at 0.05 and 0.26 microgram per liter. The method was modified to improve the pesticide recovery by reducing the sample volume to 1,000 milliliters. Internal standards were added to improve quantitative precision and accuracy. The analysis also was expanded to include a total of 21 pesticides. The method detection limits for 1,000-milliliter samples ranged from 0.022 to 0.129 microgram per liter. Recoveries ranged from 38 to 128 percent for 21 pesticides in organic-free, Sacramento River and San Joaquin River water samples fortified at 0.10 and 0.75 microgram per liter.

  10. Interfacing on-line solid phase extraction with monolithic column multisyringe chromatography and chemiluminescence detection: An effective tool for fast, sensitive and selective determination of thiazide diuretics.

    Science.gov (United States)

    Maya, Fernando; Estela, José Manuel; Cerdà, Víctor

    2010-01-15

    A new, multisyringe flow injection set-up has been developed for the completely automated determination of trace thiazide compounds with diuretic action in different types of samples. The proposed instrumental set-up exploits for the first time, a low pressure on-line solid phase extraction-liquid chromatography-chemiluminescence detection method. This novel combination of sample treatments in flow systems expands the current applicability of low pressure liquid chromatography due to the isolation/preconcentration of the target compounds, besides high selectivity and sensitivity. For the determination of three thiazide compounds named hydroflumethiazide, furosemide and bendroflumethiazide, the proposed set-up provided with the preconcentration of only 1mL of sample, limits of detection of 3, 60 and 40microgL(-1), respectively. Furthermore wide linear dynamic ranges of 6-4000, 140-20,000 and 90-40,000microgL(-1), respectively, were obtained. Besides of this, a high injection throughput of 12h(-1) was also achieved. As in sports, thiazide diuretics are prohibited substances, the proposed method has been applied to their determination in urine samples. Furthermore the potential of the proposed method as a fast-screening approach for emerging contaminants in waters has been also tested by applying it to well water and leachates from a solid waste landfill.

  11. Analysis of protein phosphorylation by monolithic extraction columns based on poly(divinylbenzene) containing embedded titanium dioxide and zirconium dioxide nano-powders.

    Science.gov (United States)

    Rainer, Matthias; Sonderegger, Harald; Bakry, Rania; Huck, Christian W; Morandell, Sandra; Huber, Lukas A; Gjerde, Douglas T; Bonn, Günther K

    2008-11-01

    The potential of an organic monolith with incorporated titanium dioxide (TiO(2)) and zirconium dioxide (ZrO(2)) nanoparticles was evaluated for the selective enrichment of phosphorylated peptides from tryptic digests. A pipette tip was fitted with a monolith based on divinylbenzene (DVB) of highly porous structure, which allows sample to pass through the monolithic bed. The enrichment of phosphopeptides was enhanced by increasing the pipetting cycles during the sample preparation and a higher recovery could be achieved with adequate buffer systems. A complete automated process was developed for enrichment of phosphopeptides leading to high reproducibility and resulting in a robust method designed to minimize analytical variance while providing high sensitivity at high sample throughput. The effect of particle size on the selectivity of phosphopeptides was investigated by comparative studies with nano- and microscale TiO(2) and ZrO(2) powders. Eleven phosphopeptides from alpha-casein digest could be recovered by an optimized mixture of microscale TiO(2)/ZrO(2) particles, whereas nine additional phosphopeptides could be retained by the same mixture of nano-structured material. When compared to conventional immobilized metal-ion affinity chromatography and commercial phosphorylation-enrichment kits, higher selectivity was observed in case of self fabricated tips. About 20 phosphopeptides could be retained from alpha-casein and five from beta-casein digests by using TiO(2) and ZrO(2) based extraction tips. Further selectivity for phosphopeptides was demonstrated by enriching a digest of in vitro phosphorylated extracellular signal regulated kinase 1 (ERK1). Two phosphorylated peptides of ERK1 could be identified by MALDI-MS/MS measurements and a following MASCOT database search.

  12. Tantalum: A strategic metal; Tantalo: Un metal estrategico

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Lopez, G.; Lopez-Lopez, J.; Garcia-Yagues, M. R.

    2009-07-01

    In nature, the main source of tantalum is an isomorphous series of minerals containing oxides of tantalum, niobium, iron and manganese, which are collectively known as columbine-tantalite (coltan). Upgraded Ta{sub 2}O{sub 5}-containing tin slags are also used as a secondary source of tantalum. Coltan, either naturally occurring or synthetically produced as concentrates from tin slags, are digested with hydrofluoric and sulphuric acid at an elevated temperature. the aqueous solution of ta-Nb in hydrofluoric acid is extracted in several continuously operating mixer-settler systems or extraction columns with an organic solvent like methyl isobutyl ketone. The organic phase is then scrubbed with 6-15 N H{sub 2}SO{sub 4} to separate the niobium from the tantalum by selective stripping. The tantalum salt is extracted from the organic phase with water or diluted aqueous ammonium fluoride solution, the demands of the solid tantalum capacitor industry for high quality, high surface area tantalum powders have driven improvements in the sodium reduction of K{sub 2}TaF{sub 7}. The much-improved chemistry reflects the many modifications to the process put in place after 1990 and the subsequent improvements in the electrical quality as measured by the performance of tantalum capacitors. (Author) 5 refs.

  13. Tung FDG Test Facility. Phase 2, Pilot plant demonstration. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    The Tung FGD Process is a regenerative process which extracts SO{sub 2} from a scrubbing liquor into an organic medium using mixer-settlers followed by steam-stripping the SO{sub 2} off from the organic medium. For the process to operate satisfactorily, (1) the organic must be stable, (2) phase separation must be relatively fast, (3) crud (i.e. solids in-between two phases) must not form and (4) SO{sub 2} must be able to be stripped off from the organic medium readily. The demonstration confirmed that the first three conditions can be met satisfactorily. Much lower stripping efficiency was attained in the pilot plant demonstration than what was previously attained in a bench-scale demonstration. Engineering analysis showed that the pilot plant stripping column was scaled up from the bench-scale column incorrectly. A new scale-up criterion for stripping a relatively viscous liquid medium is proposed based upon pilot plant data.

  14. Studies and research concerning BNFP pilot-scale pulsed columns: column profile and holdup studies

    Energy Technology Data Exchange (ETDEWEB)

    Cermak, A. F.

    1980-11-01

    Experimental studies were conducted on pilot-scaled pulsed columns for the purpose of obtaining data for verification of contactor computer programs. This work is in support of safeguards programs related to determination of near real-time inventories in pulsed columns. Holdup tests were performed resulting in the derivation of an empirical equation for estimation of the dispersed phase holdup in a column. Uranium solvent extraction mass-transfer tests were conducted in which all four process cycles were simulated under coprocessing flowsheet conditions. Extensive data were obtained during these tests on uranium profiles and inventories within the columns. Transient profile data were also determined between selected runs under the tested operating conditions. No concentration peaks could be observed during the transient period. Based on the extensive inventory data taken, empirical equations were developed for relating uranium inventory in a column to the test parameters. These equations were found useful for predicting and estimating the column inventory under the known run conditions.

  15. Spiral multicapillary columns

    Science.gov (United States)

    Efimenko, A. P.; Naumenko, I. I.; Soboleva, V. K.

    2008-08-01

    It was shown in a theoretical study and confirmed by experiment that a spiral multicapillary column had maximum efficiency if the bunch of capillaries was additionally coiled around its longitudinal axis to produce an integral number of coils. This technique made it possible to manufacture gas-chromatographic columns with performance as high as 12 to 16 thousand theoretical plates. These columns can find various applications, especially if quick separation is required.

  16. Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory - Determination of Wastewater Compounds by Polystyrene-Divinylbenzene Solid-Phase Extraction and Capillary-Column Gas Chromatography/Mass Spectrometry

    Science.gov (United States)

    Zaugg, Steven D.; Smith, Steven G.; Schroeder, Michael P.; Barber, Larry B.; Burkhardt, Mark R.

    2002-01-01

    A method for the determination of 67 compounds typically found in domestic and industrial wastewater is described. The method was developed in response to increasing concern over the impact of endocrine-disrupting chemicals in wastewater on aquatic organisms. This method also may be useful for evaluating the impact of combined sanitary and storm-sewer overflow on the water quality of urban streams. The method focuses on the determination of compounds that are an indicator of wastewater or that have been chosen on the basis of their endocrine-disrupting potential or toxicity. These compounds include the alkylphenol ethoxylate nonionic surfactants and their degradates, food additives, fragrances, antioxidants, flame retardants, plasticizers, industrial solvents, disinfectants, fecal sterols, polycyclicaromatic hydrocarbons, and high-use domestic pesticides. Water samples are filtered to remove suspended particulate matter and then are extracted by vacuum through disposable solid-phase cartridges that contain polystyrene-divinylbenzene resin. Cartridges are dried with nitrogen gas, and then sorbed compounds are eluted with dichloromethane-diethyl ether (4:1) and determined by capillary-column gas chromatography/mass spectrometry. Recoveries in reagent-water samples fortified at 4 micrograms per liter averaged 74 percent ? 7 percent relative standard deviation for all method compounds. Initial method detection limits for single-component compounds (excluding hormones and sterols) averaged 0.15 microgram per liter. Samples are preserved by filtration, the addition of 60 grams NaCl, and storage at 4 degrees Celsius. The laboratory has established a sample-holding time (prior to sample extraction) of 14 days from the date of sample collection until a statistically accepted method can be used to determine the effectiveness of these sample-preservation procedures.

  17. Simultaneous speciation of inorganic arsenic and antimony in water samples by hydride generation-double channel atomic fluorescence spectrometry with on-line solid-phase extraction using single-walled carbon nanotubes micro-column

    Energy Technology Data Exchange (ETDEWEB)

    Wu Hong, E-mail: wuhong1968@hotmail.com; Wang Xuecui; Liu Bing; Liu Yueling; Li Shanshan; Lu Jusheng; Tian Jiuying; Zhao Wenfeng; Yang Zonghui

    2011-01-15

    A new method was developed for the simultaneous speciation of inorganic arsenic and antimony in water by on-line solid-phase extraction coupled with hydride generation-double channel atomic fluorescence spectrometry (HG-DC-AFS). The speciation scheme involved the on-line formation and retention of the ammonium pyrrolidine dithiocarbamate complexes of As(III) and Sb(III) on a single-walled carbon nanotubes packed micro-column, followed by on-line elution and simultaneous detection of As(III) and Sb(III) by HG-DC-AFS; the total As and total Sb were determined by the same protocol after As(V) and Sb(V) were reduced by thiourea, with As(V) and Sb(V) concentrations obtained by subtraction. Various experimental parameters affecting the on-line solid-phase extraction and determination of the analytes species have been investigated in detail. With 180 s preconcentration time, the enrichment factors were found to be 25.4 for As(III) and 24.6 for Sb(III), with the limits of detection (LODs) of 3.8 ng L{sup -1} for As(III) and 2.1 ng L{sup -1} for Sb(III). The precisions (RSD) for five replicate measurements of 0.5 {mu}g L{sup -1} of As(III) and 0.2 {mu}g L{sup -1} of Sb(III) were 4.2 and 4.8%, respectively. The developed method was validated by the analysis of standard reference materials (NIST SRM 1640a), and was applied to the speciation of inorganic As and Sb in natural water samples.

  18. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory : determination of organophosphate pesticides in whole water by continuous liquid-liquid extraction and capillary-column gas chromatography with flame photometric detection

    Science.gov (United States)

    Jha, Virendra K.; Wydoski, Duane S.

    2003-01-01

    A method for the isolation of 20 parent organophosphate pesticides and 5 organophosphate pesticide degradates from natural-water samples is described. Compounds are extracted from water samples with methylene chloride using a continuous liquid-liquid extractor for 6 hours. The solvent is evaporated using heat and a flow of nitrogen to a volume of 1 milliliter and solvent exchanged to ethyl acetate. Extracted compounds are determined by capillary-column gas chromatography with flame photometric detection. Single-operator derived method detection limits in three water-matrix samples ranged from 0.003 to 0.009 microgram per liter. Method performance was validated by spiking all compounds in three different matrices at three different concentrations. Eight replicates were analyzed at each concentration in each matrix. Mean recoveries of most method compounds spiked in surface-water samples ranged from 54 to 137 percent and those in ground-water samples ranged from 40 to 109 percent for all pesticides. Recoveries in reagent-water samples ranged from 42 to 104 percent for all pesticides. The only exception was O-ethyl-O-methyl-S-propylphosphorothioate, which had variable recovery in all three matrices ranging from 27 to 79 percent. As a result, the detected concentration of O-ethyl-O-methyl-S-propylphosphorothioate in samples is reported in this method with an estimated remark code. Based on the performance issue, two more compounds, disulfoton and ethion monoxon, also will be reported in this method with an estimated remark code. Estimated-value compounds, which are ?E-coded? in the data base, do not meet the performance criteria for unqualified quantification, but are retained in the method because the compounds are important owing to high use or potential environmental effects and because analytical performance has been consistent and reproducible.

  19. A rapid HPLC post-column reaction analysis for the quantification of ergothioneine in edible mushrooms and in animals fed a diet supplemented with extracts from the processing waste of cultivated mushrooms.

    Science.gov (United States)

    Nguyen, The Han; Giri, Anupam; Ohshima, Toshiaki

    2012-07-15

    For establishing an efficient and sensitive method for the quantitative determination of 2-thiol-l-histidine-betaine (ergothioneine, ERG) in edible mushrooms and the blood and muscles of animals, a technique using reversed-phase separation and post-column reaction between 2'-dipyridyl disulphide and ERG was developed. A corresponding derivative 2-thiopyridone, detected at 343 nm, was used for estimating ERG concentration. The flow rate, temperature, pH, and composition of the solution were optimised. A low limit of quantification (1.41 ppm) and a simpler sample preparation made this technique more rapid compared to other methods using liquid chromatography-mass spectrometry. The coefficient of variation (CV) values for the reproducibility and recovery of ERG were within the acceptable values of 6% and 97.5-100.0%, respectively. The efficiency of this methodology was compared with that of spectrophotometric and mass-spectrometric quantitative methods, and was assessed in the light of previous studies. The ERG contents in different mushrooms were 12.69-234.85 mg/kg wet weight basis. Dietary supplementation with extracts from mushroom processing waste significantly improved ERG bioavailability in the blood of yellowtail fish and muscle tissue of cattle.

  20. JCE Feature Columns

    Science.gov (United States)

    Holmes, Jon L.

    1999-05-01

    The Features area of JCE Online is now readily accessible through a single click from our home page. In the Features area each column is linked to its own home page. These column home pages also have links to them from the online Journal Table of Contents pages or from any article published as part of that feature column. Using these links you can easily find abstracts of additional articles that are related by topic. Of course, JCE Online+ subscribers are then just one click away from the entire article. Finding related articles is easy because each feature column "site" contains links to the online abstracts of all the articles that have appeared in the column. In addition, you can find the mission statement for the column and the email link to the column editor that I mentioned above. At the discretion of its editor, a feature column site may contain additional resources. As an example, the Chemical Information Instructor column edited by Arleen Somerville will have a periodically updated bibliography of resources for teaching and using chemical information. Due to the increase in the number of these resources available on the WWW, it only makes sense to publish this information online so that you can get to these resources with a simple click of the mouse. We expect that there will soon be additional information and resources at several other feature column sites. Following in the footsteps of the Chemical Information Instructor, up-to-date bibliographies and links to related online resources can be made available. We hope to extend the online component of our feature columns with moderated online discussion forums. If you have a suggestion for an online resource you would like to see included, let the feature editor or JCE Online (jceonline@chem.wisc.edu) know about it. JCE Internet Features JCE Internet also has several feature columns: Chemical Education Resource Shelf, Conceptual Questions and Challenge Problems, Equipment Buyers Guide, Hal's Picks, Mathcad

  1. Glass-silicon column

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Conrad M.

    2003-12-30

    A glass-silicon column that can operate in temperature variations between room temperature and about 450.degree. C. The glass-silicon column includes large area glass, such as a thin Corning 7740 boron-silicate glass bonded to a silicon wafer, with an electrode embedded in or mounted on glass of the column, and with a self alignment silicon post/glass hole structure. The glass/silicon components are bonded, for example be anodic bonding. In one embodiment, the column includes two outer layers of silicon each bonded to an inner layer of glass, with an electrode imbedded between the layers of glass, and with at least one self alignment hole and post arrangement. The electrode functions as a column heater, and one glass/silicon component is provided with a number of flow channels adjacent the bonded surfaces.

  2. Distillation Column Flooding Predictor

    Energy Technology Data Exchange (ETDEWEB)

    George E. Dzyacky

    2010-11-23

    The Flooding Predictor™ is a patented advanced control technology proven in research at the Separations Research Program, University of Texas at Austin, to increase distillation column throughput by over 6%, while also increasing energy efficiency by 10%. The research was conducted under a U. S. Department of Energy Cooperative Agreement awarded to George Dzyacky of 2ndpoint, LLC. The Flooding Predictor™ works by detecting the incipient flood point and controlling the column closer to its actual hydraulic limit than historical practices have allowed. Further, the technology uses existing column instrumentation, meaning no additional refining infrastructure is required. Refiners often push distillation columns to maximize throughput, improve separation, or simply to achieve day-to-day optimization. Attempting to achieve such operating objectives is a tricky undertaking that can result in flooding. Operators and advanced control strategies alike rely on the conventional use of delta-pressure instrumentation to approximate the column’s approach to flood. But column delta-pressure is more an inference of the column’s approach to flood than it is an actual measurement of it. As a consequence, delta pressure limits are established conservatively in order to operate in a regime where the column is never expected to flood. As a result, there is much “left on the table” when operating in such a regime, i.e. the capacity difference between controlling the column to an upper delta-pressure limit and controlling it to the actual hydraulic limit. The Flooding Predictor™, an innovative pattern recognition technology, controls columns at their actual hydraulic limit, which research shows leads to a throughput increase of over 6%. Controlling closer to the hydraulic limit also permits operation in a sweet spot of increased energy-efficiency. In this region of increased column loading, the Flooding Predictor is able to exploit the benefits of higher liquid

  3. Optimisation and application of accelerated solvent extraction and flash chromatography for quantification of PCBs in tree barks and XAD-2 passive samplers using GC-ECD with dual columns.

    Science.gov (United States)

    Guéguen, Florence; Stille, Peter; Millet, Maurice

    2013-07-15

    An analytical method for the quantification of Polychlorinated biphenyls (PCBs) concentrations in XAD-2 passive air samplers (PAS) and tree barks collected close to the Rhine River between France and Germany was developed. This method used Accelerated Solvent Extraction (ASE) followed by a purification step by flash chromatography using a 4gr cartridge (3 g of silica gel and 1 g of 44% acidified silica) and analysis by GC-ECD with dual columns. Quantification (QL) and detection (DL) limits varied 0.5 from and 5.7 ng PAS(-1) and from 0.5 and 3.0 ng PAS(-1) respectively. For tree barks, quantification and detection limits were calculated for each congener on washed tree bark sample with a signal to noise ratio of 3:1 and 10:1 (corresponding to a LQ in the range of 1-4 ng per bark sample by congeners). Uncertainties on each congener concentration were calculated to be in the range of 3-20% XAD-2 passive samplers were field calibrated by using Hi-vol. Samplers. Sampling rates of 4.2, 11.5, 1.6, and 7.9 m(3) PAS(-1) d(-1) for tri-, tetra-, penta- hexa-PCBs, respectively were obtained and are comparable to those already obtained with PUF-PAS for gas phase only (gas/particle distribution was 90/10). Method was applied to real atmospheric samples collected by XAD-2 passive samplers and tree barks in the east of France.

  4. Study of clean up procedures using Charcoal-Alumina-Celite column, immunoaffinity column and strata x column to determine deoxynivalenol by high performance liquid chromatography in wheat

    Directory of Open Access Journals (Sweden)

    Jacqueline Cea

    2011-04-01

    Full Text Available Fusarium graminearum is the most common toxic fungal species affecting grains in Uruguay. Since 1977, due to favorable climate conditions, there have been harvests with prominent Fusarium Head Blight in wheat. This were in 1984, 1990, 1993, 1996 and 2001.Natural Toxin Department of Technological Laboratory of Uruguay as National Reference Laboratory, is continuously improving the analytical methods in order to have a good response to the industry requirements and to the monitoring programs for import and exports commodities. The objective of this work was to compare different clean up methods in order to select the best one for routine determination of deoxynivalenol (DON in wheat (grain and flour.  Charcoal-alumina-celite (7+5+3,  immunoaffinity columns DONPREP R-Biopharm Rhone and Strata X 33 m polymeric sorbent  Phenomenex columns were used to perform the study. Considering as reference analytical method the internal protocol  PEC.TOX.063 accredited by United Kingdom Accreditation Service (UKAS  following the ISO 17025 requirements, and  based on AOAC method 986.17( chapter 49, 2002 for extraction and clean-up  and on J.AOAC 70(3, 1987:479-483 for the high performance liquid chromatography (HPLC detection, two more clean up methods were evaluated. In all of them PEC.TOX.063 detection procedure was carried out. PEC.TOX.063 used for the clean up an in house column chromatography prepared with charcoal-alumina-celite (7+5+3 . Extraction was performed using acetonitrile- water (84+16 and an aliquot of the extract was passed through the column. Extract was dryed under vacuum and DON detected by HPLC using photodiode array detector. For the method that used immunoaffinity columns, water was the extraction solvent, and manufacture protocol was followed up. An aliquot of the extract was passed through the column. Column was washed using water and DON eluated using methanol 100%. For the method that used Strata X column for the clean up, the

  5. Eruption column physics

    Energy Technology Data Exchange (ETDEWEB)

    Valentine, G.A.

    1997-03-01

    In this paper the author focuses on the fluid dynamics of large-scale eruption columns. The dynamics of these columns are rooted in multiphase flow phenomena, so a major part of the paper sets up a foundation on that topic that allows one to quickly assess the inherent assumptions made in various theoretical and experimental approaches. The first part is centered on a set of complex differential equations that describe eruption columns, but the focus is on a general understanding of important physical processes rather than on the mathematics. The author discusses briefly the relative merits and weaknesses of different approaches, emphasizing that the largest advances in understanding are made by combining them. He then focuses on dynamics of steady eruption columns and then on transient phenomena. Finally he briefly reviews the effects of varying behavior of the ambient medium through which an eruption column moves. These final sections will emphasize concepts and a qualitative understanding of eruption dynamics. This paper relies on principles of continuum mechanics and transport processes but does not go into detail on the development of those principles. 36 refs., 36 figs., 3 tabs.

  6. Enhanced reductive dechlorination in columns treated with edible oil emulsion

    Science.gov (United States)

    Long, Cameron M.; Borden, Robert C.

    2006-09-01

    The effect of edible oil emulsion treatment on enhanced reductive dechlorination was evaluated in a 14 month laboratory column study. Experimental treatments included: (1) emulsified soybean oil and dilute HCl to inhibit biological activity; (2) emulsified oil only; (3) emulsified oil and anaerobic digester sludge; and (4) continuously feeding soluble substrate. A single application of emulsified oil was effective in generating strongly reducing, anaerobic conditions for over 14 months. PCE was rapidly reduced to cis-DCE in all three live columns. Bioaugmentation with a halorespiring enrichment culture resulted in complete dechlorination of PCE to ethene in the soluble substrate column (yeast extract and lactate). However, an additional treatment with a pulse of yeast extract and bioaugmentation culture was required to stimulate complete dechlorination in the emulsion treated columns. Once the dechlorinating population was established, the emulsion only column degraded PCE from 90-120 μM to below detection with concurrent ethene production in a 33 day contact time. The lower biodegradation rates in the emulsion treated columns compared to the soluble substrate column suggest that emulsified oil barriers may require a somewhat longer contact time for effective treatment. In the HCl inhibited column, partitioning of PCE to the retained oil substantially delayed PCE breakthrough. However, reduction of PCE to more soluble degradation products ( cis-DCE, VC and ethene) greatly reduced the impact of oil-water partitioning in live columns. There was only a small decline in the hydraulic conductivity ( K) of column #1 (low pH + emulsion, Kfinal/ Kinitial = 0.57) and column #2 (live + emulsion, Kfinal/ Kinitial = 0.73) indicating emulsion injection did not result in appreciable clogging of the clayey sand. However, K loss was greater in column #3 (sludge +emulsion, Kfinal/ Kinitial = 0.12) and column #4 (soluble substrate, Kfinal/ Kinitial = 0.03) indicating clogging due

  7. Columns in Clay

    Science.gov (United States)

    Leenhouts, Robin

    2010-01-01

    This article describes a clay project for students studying Greece and Rome. It provides a wonderful way to learn slab construction techniques by making small clay column capitols. With this lesson, students learn architectural vocabulary and history, understand the importance of classical architectural forms and their influence on today's…

  8. Slender CRC Columns

    DEFF Research Database (Denmark)

    Aarup, Bendt; Jensen, Lars Rom; Ellegaard, Peter

    2005-01-01

    CRC is a high-performance steel fibre reinforced concrete with a typical compressive strength of 150 MPa. Design methods for a number of structural elements have been developed since CRC was invented in 1986, but the current project set out to further investigate the range of columns for which...

  9. Experiment and Simulation Study on Extractive Distillation of Anhydrous n-Propyl Alcohol by Dividing Wall Column%分壁式萃取精馏塔制取无水正丙醇的实验与模拟研究

    Institute of Scientific and Technical Information of China (English)

    刘树丽; 赵俊明; 齐鸣斋

    2012-01-01

    A dividing wall column was applied in extractive distillation in order to gain anhydrous n-propyl alcohol with ethanediol as extractant.When the solvent ratio was 3, the reflux ratio of main column was 2.5, the mass fraction of n-propyl alcohol in the top product was 96.03%, the mass fraction of ethanediol in the bottom product was 99.44% and it could be recycling used as extraction solvent.It showed that the experiment results were basically in agreement with the simulation results obtained by Aspen Plus. The DWC column could reduce energy by 22.5% compared with conventional extractive distillation process, the equipment cost and energy consumption could also be reduced.%采用分壁式萃取精馏塔制取无水正丙醇,以乙二醇为萃取剂,在溶剂比为3、主塔回流比为2.5时,实验测得塔顶正丙醇的质量分数达到96.03%,塔釜乙二醇的质量分数达到99.44%,可作萃取剂直接循环利用。利用AspenPIus对该工艺进行模拟计算,其结果与实验基本一致。模拟对比该工艺和常规双塔萃取精馏工艺,结果显示分壁式萃取精馏塔节能22.5%,降低了能耗和设备投资。

  10. Column flotation of bitumen at Fort Hills

    Energy Technology Data Exchange (ETDEWEB)

    Lizama, H.M. [Teck Cominco, Vancouver, BC (Canada); Romero, D. [UTS Energy Corp., Calgary, AB (Canada); Armour, M. [Petro-Canada, Calgary, AB (Canada)

    2008-05-15

    Flotation columns are used by mineral processors to separate mineral species. The separation is based on the premise that different mineral particles have different surface hydrophobicities. There are 2 carrier phases, notably air bubbles moving up and aqueous pulp moving down. Hydrophobic particles predominantly adhere to rising air bubbles and form a froth, while hydrophilic particles remain in aqueous suspension and flow down and out the bottom of the column. This paper described a demonstration plant near Fort McMurray where bitumen extraction was tested. The plant included 2 columns for bitumen flotation. Oil sands material was passed through a roll sizer and fed to a countercurrent drum separator, where it was mixed with water at 75 degrees C. Column data from the demonstration plant provided the opportunity to examine the separation behaviour during flotation of bitumen. The bitumen grade was described only in terms of bitumen content and solids content in order to simplify the interpretation of the bitumen flotation data. Bitumen/solids separation in the first column was successful at 50 to 60 degrees C, with feeds having bitumen grades between 1 and 19 per cent, and where the solids had about 60 per cent fines. Bitumen/solids separation did not occur in the second column at 50 to 60 degrees C, with feeds having bitumen grades between 8 and 63 per cent, and where the solids had about 90 per cent fines. The lack of separation was probably due to high solids entrainment in the flotation froth. It was concluded that bitumen column flotation data can be analyzed and interpreted by adopting mineral processing principles. Bitumen/solids separation can be evaluated and predicted by plotting solids recovery as a function of bitumen recovery. 7 refs., 1 tab., 6 figs.

  11. OPTIMIZED DETERMINATION OF TRACE JET FUEL VOLATILE ORGANIC COMPOUNDS IN HUMAN BLOOD USING IN-FIELD LIQUID-LIQUID EXTRACTION WITH SUBSEQUENT LABORATORY GAS CHROMATOGRAPHIC-MASS SPECTROMETRIC ANALYSIS AND ON-COLUMN LARGE VOLUME INJECTION

    Science.gov (United States)

    A practical and sensitive method to assess volatile organic compounds (VOCs) from JP-8 jet fuel in human whole blood was developed by modifying previously established liquid-liquid extraction procedures, optimizing extraction times, solvent volume, specific sample processing te...

  12. Slurry bubble column hydrodynamics

    Science.gov (United States)

    Rados, Novica

    Slurry bubble column reactors are presently used for a wide range of reactions in both chemical and biochemical industry. The successful design and scale up of slurry bubble column reactors require a complete understanding of multiphase fluid dynamics, i.e. phase mixing, heat and mass transport characteristics. The primary objective of this thesis is to improve presently limited understanding of the gas-liquid-solid slurry bubble column hydrodynamics. The effect of superficial gas velocity (8 to 45 cm/s), pressure (0.1 to 1.0 MPa) and solids loading (20 and 35 wt.%) on the time-averaged solids velocity and turbulent parameter profiles has been studied using Computer Automated Radioactive Particle Tracking (CARPT). To accomplish this, CARPT technique has been significantly improved for the measurements in highly attenuating systems, such as high pressure, high solids loading stainless steel slurry bubble column. At a similar set of operational conditions time-averaged gas and solids holdup profiles have been evaluated using the developed Computed Tomography (CT)/Overall gas holdup procedure. This procedure is based on the combination of the CT scans and the overall gas holdup measurements. The procedure assumes constant solids loading in the radial direction and axially invariant cross-sectionally averaged gas holdup. The obtained experimental holdup, velocity and turbulent parameters data are correlated and compared with the existing low superficial gas velocities and atmospheric pressure CARPT/CT gas-liquid and gas-liquid-solid slurry data. The obtained solids axial velocity radial profiles are compared with the predictions of the one dimensional (1-D) liquid/slurry recirculation phenomenological model. The obtained solids loading axial profiles are compared with the predictions of the Sedimentation and Dispersion Model (SDM). The overall gas holdup values, gas holdup radial profiles, solids loading axial profiles, solids axial velocity radial profiles and solids

  13. Behavior of Columns During Earthquakes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The behavior of columns during earthquakes is very important since column failures may lead to additional structural failures and result in total building collapses....

  14. Determination of Two Columns Performance

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    When protein is analyzed by high performance liquid chromatography (HPLC), the selection of column is one of the most important factors. There are four quality control parameters for the column, which are theoretical plates n, capacity facto

  15. NMFS Water Column Sonar Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water column sonar data are an important component of fishery independent surveys, habitat studies and other research. NMFS water column sonar data are archived here.

  16. 固相萃取-双柱气相色谱法测定水中多种有机磷农药残留%Determination of multiple organophosphorous pesticide residues in water by dual-column gas chromatography coupled with solid phase extraction

    Institute of Scientific and Technical Information of China (English)

    陈烨; 许秀艳; 吕怡兵; 滕恩江; 邢冠华; 王超

    2011-01-01

    针对单一气相色谱柱定性分析易出现假阳性误判的情况,采用固相萃取-气相色谱双柱技术测定环境水体中多种有机磷农药的残留量.水样中的有机磷农药通过HLB固相萃取小柱富集,经洗脱浓缩后,用DB-35MS和HP-5毛细管气相色谱柱、火焰光度检测器测定.方法的平均加标回收率为86.1%~118%,相对标准偏差为3.2%~6.8%,最低检出限为20~40 ng/L,可满足环境水体中痕量有机磷农药残留的分析需要.%To avoid the case of false positive when analyzing by single column, the dual-column gas chromatography coupled with solid phase extraction was applied to the multi -residue determination of organophosphorous pesticides in environmental water. The organophosphorous pesticides were extracted from water with HLB solid phase extraction cartridges and then eluted. After concentrated, the eluents were detected by GC-FPD with DB-35MS and HP-5 capillary columns. The average recoveries of 5 replicates for analytes ranged from 86.1% to 118%, with relative standard deviations between 3.2% and 6.8%. And the method detection limits were within the range of 20 ng/L to 40 ng/L. The results showed that the proposed method is suitable for the determination of trace amounts of multiple organophosphorous pesticide residues in environmental water.

  17. Dynamic optimization of the benzene extractive distillation unit

    National Research Council Canada - National Science Library

    Ghaee, A; Sotudeh-Gharebagh, R; Mostoufi, N

    2008-01-01

    A mathematical model has been developed for describing the dynamic operation of the N-formylmorpholine extractive distillation column and the corresponding solvent recovery column in the benzene extraction plant...

  18. Column: Every Last Byte

    Directory of Open Access Journals (Sweden)

    Simson Garfinkel

    2011-06-01

    Full Text Available Inheritance powder is the name that was given to poisons, especially arsenic, that were commonly used in the 17th and early 18th centuries to hasten the death of the elderly. For most of the 17th century, arsenic was deadly but undetectable, making it nearly impossible to prove that someone had been poisoned. The first arsenic test produced a gas—hardly something that a scientist could show to a judge. Faced with a growing epidemic of poisonings, doctors and chemists spent decades searching for something better.(see PDF for full column

  19. Automated mini-column solid-phase extraction cleanup for high-throughput analysis of chemical contaminants in foods by low-pressure gas chromatography – tandem mass spectrometry

    Science.gov (United States)

    This study demonstrated the application of an automated high-throughput mini-cartridge solid-phase extraction (mini-SPE) cleanup for the rapid low-pressure gas chromatography – tandem mass spectrometry (LPGC-MS/MS) analysis of pesticides and environmental contaminants in QuEChERS extracts of foods. ...

  20. SENSITIVITY ANALYSIS FOR SALTSTONE DISPOSAL UNIT COLUMN DEGRADATION ANALYSES

    Energy Technology Data Exchange (ETDEWEB)

    Flach, G.

    2014-10-28

    PORFLOW related analyses supporting a Sensitivity Analysis for Saltstone Disposal Unit (SDU) column degradation were performed. Previous analyses, Flach and Taylor 2014, used a model in which the SDU columns degraded in a piecewise manner from the top and bottom simultaneously. The current analyses employs a model in which all pieces of the column degrade at the same time. Information was extracted from the analyses which may be useful in determining the distribution of Tc-99 in the various SDUs throughout time and in determining flow balances for the SDUs.

  1. Why Hexagonal Basalt Columns?

    Science.gov (United States)

    Hofmann, Martin; Anderssohn, Robert; Bahr, Hans-Achim; Weiß, Hans-Jürgen; Nellesen, Jens

    2015-10-09

    Basalt columns with their preferably hexagonal cross sections are a fascinating example of pattern formation by crack propagation. Junctions of three propagating crack faces rearrange such that the initial right angles between them tend to approach 120°, which enables the cracks to form a pattern of regular hexagons. To promote understanding of the path on which the ideal configuration can be reached, two periodically repeatable models are presented here involving linear elastic fracture mechanics and applying the principle of maximum energy release rate. They describe the evolution of the crack pattern as a transition from rectangular start configuration to the hexagonal pattern. This is done analytically and by means of three-dimensional finite element simulation. The latter technique reproduces the curved crack path involved in this transition.

  2. Column: File Cabinet Forensics

    Directory of Open Access Journals (Sweden)

    Simson Garfinkel

    2011-12-01

    Full Text Available Researchers can spend their time reverse engineering, performing reverse analysis, or making substantive contributions to digital forensics science. Although work in all of these areas is important, it is the scientific breakthroughs that are the most critical for addressing the challenges that we face.Reverse Engineering is the traditional bread-and-butter of digital forensics research. Companies like Microsoft and Apple deliver computational artifacts (operating systems, applications and phones to the commercial market. These artifacts are bought and used by billions. Some have evil intent, and (if society is lucky, the computers end up in the hands of law enforcement. Unfortunately the original vendors rarely provide digital forensics tools that make their systems amenable to analysis by law enforcement. Hence the need for reverse engineering.(see PDF for full column

  3. European Analytical Column

    DEFF Research Database (Denmark)

    Karlberg, B.; Grasserbauer, M.; Andersen, Jens Enevold Thaulov

    2009-01-01

    The European Analytical Column has once more invited a guest columnist to give his views on various matters related to analytical chemistry in Europe. This year, we have invited Professor Manfred Grasserbauer of the Vienna University of Technology to present some of the current challenges...... for European analytical chemistry. During the period 2002–07, Professor Grasserbauer was Director of the Institute for Environment and Sustainability, Joint Research Centre of the European Commission (EC), Ispra, Italy. There is no doubt that many challenges exist at the present time for all of us representing...... a major branch of chemistry, namely analytical chemistry. The global financial crisis is affecting all branches of chemistry, but analytical chemistry, in particular, since our discipline by tradition has many close links to industry. We have already noticed decreased industrial commitment with respect...

  4. Method of analysis and quality-assurance practices for determination of pesticides in water by solid-phase extraction and capillary-column gas chromatography/mass spectrometry at the U.S. Geological Survey California District Organic Chemistry Laboratory, 1996-99

    Science.gov (United States)

    Crepeau, Kathryn L.; Baker, Lucian M.; Kuivila, Kathryn M.

    2000-01-01

    A method of analysis and quality-assurance practices were developed to study the fate and transport of pesticides in the San Francisco Bay-Estuary by the U.S. Geological Survey. Water samples were filtered to remove suspended-particulate matter and pumped through C-8 solid-phase extraction cartridges to extract the pesticides. The cartridges were dried with carbon dioxide and the pesticides were eluted with three cartridge volumes of hexane:diethyl ether (1:1) solution. The eluants were analyzed using capillary-column gas chromatography/mass spectrometry in full-scan mode. Method detection limits for pesticides ranged from 0.002 to 0.025 microgram per liter for 1-liter samples. Recoveries ranged from 44 to 140 percent for 25 pesticides in samples of organic-free reagent water and Sacramento-San Joaquin Delta and Suisun Bay water fortified at 0.05 and 0.50 microgram per liter. The estimated holding time for pesticides after extraction on C-8 solid-phase extraction cartridges ranged from 10 to 257 days.

  5. Compact electron beam focusing column

    Energy Technology Data Exchange (ETDEWEB)

    Persaud, Arun; Leung, Ka-Ngo; Reijonen, Jani

    2001-07-13

    A novel design for an electron beam focusing column has been developed at LBNL. The design is based on a low-energy spread multicusp plasma source which is used as a cathode for electron beam production. The focusing column is 10 mm in length. The electron beam is focused by means of electrostatic fields. The column is designed for a maximum voltage of 50 kV. Simulations of the electron trajectories have been performed by using the 2-D simulation code IGUN and EGUN. The electron temperature has also been incorporated into the simulations. The electron beam simulations, column design and fabrication will be discussed in this presentation.

  6. Determination of Aflatoxin B1, M1 in Foods Using Homemade Mixed Solid Phase Extraction Column Coupled with High Performance Liquid Chromatography%自制混合型固相萃取柱-高效液相色谱法同时测定食品中黄曲霉毒素B1、M1

    Institute of Scientific and Technical Information of China (English)

    彭晓俊; 曾勚; 庞晋山; 邓爱华; 谌瑜

    2013-01-01

    A novel method for the determination of aflatoxin B1,M1 in foods was developed using homemade mixed solid phase extraction column coupled with high performance liquid chromatography.The sample was extracted with 60% acetonitrile solution,and cleaned up on a homemade mixed solid phase extraction column.The separation was performed on a Shim-pack VP-ODS C18 column with acetonitrile-water(20 ∶ 80) as mobile phase within 13 min.The contents of two aflatoxins were detected with fluorescence detector,and quantified by the external standard method.The effects of column type,column capacity,sample amount,extraction solution and flow rate on the determination of aflatoxin residue were investigated.Under the optimized conditions,there were good linearities between peak areas and aflatoxins concentrations in the range of 0.40-100 μg/L with correlation coefficients of 0.999 4-0.999 7.The limits of detection(S/N =3) of aflatoxin B1,M1 were both 0.050 μg/kg.The recoveries of aflatoxins in different samples at three spiked levels of 0.40,1.0,100 μg/L were in the range of 53%-112% with relative standard deviations(RSDs) of 2.7%-7.1%.The proposed method showed the advantages of sensitivity,simplicity and fastness,and was successfully applied in the determination of low aflatoxins residues in peanut,pistachio and milk samples.%建立了基于自制混合型固相萃取柱的样品净化/高效液相色谱测定食品中黄曲霉毒素B1、M1的方法.样品经60%乙腈水溶液提取、离心后,通过自制固相萃取柱排除杂质干扰,流出液以Shim-pack VP-ODS C18色谱柱为分离柱,水和乙腈为流动相,用荧光检测器检测,外标法定量.考察了柱类型、柱容量、取样量、提取溶液和流速等对检测的影响,优化了实验条件.在优化条件下,2种毒素在0.40~100 μg/L质量浓度范围内与峰面积呈良好的线性关系,相关系数为0.9994~0.9997,检出限(S/N=3)为0.050 μg/kg.在样品中分别加入0.40、1

  7. From Single Droplet to Column Design

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The technique state to design counter-current extraction columns is based on the performance of pilot plant experiments. The modelling is then either with the equilibrium or dispersion model, whereas in the latter the dispersion coefficient accounts for all hydrodynamic non-idealities. A new approach uses single droplet experiments to obtain the basic laws and functions governing droplet breakage, coalescence,relative velocity, and axial dispersion when using droplet populance balance models (DPBM). The hydrodynamics simulation results show that the mean Sauter diameter, hold-up, and concentration profiles could be well predicted, which promotes the use of DPBM models for further applications in industrial scale.

  8. Practical design of stepped columns

    NARCIS (Netherlands)

    Girao Coelho, A.M.; Simao, P.D.; Bijlaard, F.S.K.

    2012-01-01

    This paper deals with buckling aspects of the design of stepped columns in heavy mill buildings. In these structures, columns have to carry significant axial loads that usually act eccentrically and strength reducing bending moments due to lateral loads. A simple physical model for buckling behaviou

  9. An Undergraduate Column Chromatography Experiment.

    Science.gov (United States)

    Danot, M.; And Others

    1984-01-01

    Background information, list of materials needed, and procedures used are provided for an experiment designed to introduce undergraduate students to the theoretical and technical aspects of column chromatography. The experiment can also be shortened to serve as a demonstration of the column chromatography technique. (JN)

  10. Mush Column Magma Chambers

    Science.gov (United States)

    Marsh, B. D.

    2002-12-01

    Magma chambers are a necessary concept in understanding the chemical and physical evolution of magma. The concept may well be similar to a transfer function in circuit or time series analysis. It does what needs to be done to transform source magma into eruptible magma. In gravity and geodetic interpretations the causative body is (usually of necessity) geometrically simple and of limited vertical extent; it is clearly difficult to `see' through the uppermost manifestation of the concentrated magma. The presence of plutons in the upper crust has reinforced the view that magma chambers are large pots of magma, but as in the physical representation of a transfer function, actual magma chambers are clearly distinct from virtual magma chambers. Two key features to understanding magmatic systems are that they are vertically integrated over large distances (e.g., 30-100 km), and that all local magmatic processes are controlled by solidification fronts. Heat transfer considerations show that any viable volcanic system must be supported by a vertically extensive plumbing system. Field and geophysical studies point to a common theme of an interconnected stack of sill-like structures extending to great depth. This is a magmatic Mush Column. The large-scale (10s of km) structure resembles the vertical structure inferred at large volcanic centers like Hawaii (e.g., Ryan et al.), and the fine scale (10s to 100s of m) structure is exemplified by ophiolites and deeply eroded sill complexes like the Ferrar dolerites of the McMurdo Dry Valleys, Antarctica. The local length scales of the sill reservoirs and interconnecting conduits produce a rich spectrum of crystallization environments with distinct solidification time scales. Extensive horizontal and vertical mushy walls provide conditions conducive to specific processes of differentiation from solidification front instability to sidewall porous flow and wall rock slumping. The size, strength, and time series of eruptive behavior

  11. Employing anatomical knowledge in vertebral column labeling

    Science.gov (United States)

    Yao, Jianhua; Summers, Ronald M.

    2009-02-01

    The spinal column constitutes the central axis of human torso and is often used by radiologists to reference the location of organs in the chest and abdomen. However, visually identifying and labeling vertebrae is not trivial and can be timeconsuming. This paper presents an approach to automatically label vertebrae based on two pieces of anatomical knowledge: one vertebra has at most two attached ribs, and ribs are attached only to thoracic vertebrae. The spinal column is first extracted by a hybrid method using the watershed algorithm, directed acyclic graph search and a four-part vertebra model. Then curved reformations in sagittal and coronal directions are computed and aggregated intensity profiles along the spinal cord are analyzed to partition the spinal column into vertebrae. After that, candidates for rib bones are detected using features such as location, orientation, shape, size and density. Then a correspondence matrix is established to match ribs and vertebrae. The last vertebra (from thoracic to lumbar) with attached ribs is identified and labeled as T12. The rest of vertebrae are labeled accordingly. The method was tested on 50 CT scans and successfully labeled 48 of them. The two failed cases were mainly due to rudimentary ribs.

  12. Determination of oxytocin in biological samples by isocratic high-performance liquid chromatography with coulometric detection using C18 solid-phase extraction and polyclonal antibody-based immunoaffinity column purification.

    Science.gov (United States)

    Kukucka, M A; Misra, H P

    1994-03-04

    A specific high-performance liquid chromatographic (HPLC) method is described for the reliable quantitation of oxytocin using culture media supernatants. The procedure employs solid-phase extraction, antibody-based immunoaffinity purification and isocratic HPLC with dual channel coulometric detection (ED). The lower limit of detection for this cyclic nonapeptide was 40 pg (40 fmol). Due to its relative simplicity, specificity and precision, the HPLC-ED of oxytocin is an accurate and attractive alternative to many existing quantitative methods.

  13. 自制双层固相萃取柱在新会陈皮及其制品中11种有机磷农药测定中的应用%Application of homemade double solid phase extraction column for determination of 11 organophosphorus pesticides in Xinhui dried orange peel and its products

    Institute of Scientific and Technical Information of China (English)

    彭晓俊; 秦汉; 温绮靖; 梁伟华; 梁优珍

    2016-01-01

    By packing N-propylethylenediamine ( PSA ) and multi-walled carbon nanotubes (MWNTs) separately,a homemade double solid phase extraction purification column was made. A gas chromatographic method was developed for the simultaneous determination of 11 kinds of organophosphorus pesticides,including dichlorovos,methamidophos,acephate,phor-ate,omethoate,dimethoate,chlorpyrifos,malathion,parathion-ethyl,quinalphos and ethion in Xinhui dried orange peel and its products. The samples were centrifuged after extracted by ethyl acetate,and then cleaned up with a homemade double PSA/MWNTs solid phase extrac-tion column. The separation of target compounds was performed on an Agilent RTS-1701 capil-lary column with temperature programmed within 25 min,then determined by a flame photo-metric detector and quantified by using external standard method. The factors affecting the determination,such as packing type,amount of packing,elution mode,extraction solution and ultrasonic time,were investigated. Under the optimized experimental conditions,the novel method showed a good linearity in the range of 0. 020-1. 0 mg/L with correlation coefficients of 0. 999 0-0. 999 8,the limits of detection were 3. 5-9. 6 μg/kg for the pesticides. The new method was successfully applied to the analyses of organophosphorus pesticides in Xinhui dried orange peel and its products. The recoveries spiked with organophosphorus pesticides standards at three concentration levels of 10,25 and 100 μg/kg in samples were 50. 8%-109% with relative standard deviations of 2. 7%-8. 5%. The established method is accurate,sensitive,simple and fast. The detection limits of the method meet the limited requirements of organophosphorus pesticide residues. The homemade column is cost saving and worthy of popularization and application. The study provides a useful method for the analysis of trace substance.%以自制改性多壁碳纳米管(MWNTs)和 N-丙基乙二胺(PSA)填料分层填装的双层固相萃取

  14. 熔化提取-毛细管气相色谱法测定乙二醇硬脂酸酯中乙二醇的残留量%Capillary Column-GC Determination of Residual Amount of Ethylene Glycol in Ethylene Glycol Stearate with Fusion Extraction

    Institute of Scientific and Technical Information of China (English)

    张晨辉; 贾埂美; 唐福伟; 王月芬; 王新荣

    2011-01-01

    Residual amount of ethylene glycol in ethylene glycol stearate was determined by capillary column (242. The sample was melted at 50 ;C ultrasonically and extracted with methanol. Propylene glycol was used as internal standard. An aliquot of the extract was separated on HP-5 capillary column and determined with FID. Linearity range of ethylene glycol was kept from 102.6 to 1 026.0 mg · L-1 , with value of detection limit (3S/N) of 30 mg · L-1. The proposed method was applied to the analysis of ethylene glycol stearate, values of recovery found were in the range of 93.7%-103.2%.%提出了毛细管气相色谱法测定乙二醇硬脂酸酯中乙二醇残留量的方法。样品在50。C熔化,经甲醇超声浸提,以丙二醇为内标,采用HP5毛细管色谱柱分离,用火焰离子化检测器测定。乙二醇的质量浓度在102.6~1026.0mg·L叫范围内呈线性,方法的检出限(3S/N)为30mg·L。应用此方法分析乙二醇硬脂酸酯,回收率在93.7%~103.2%之间。

  15. 一种以含硅藻土的复合材料为介质的支撑液液萃取柱的制备及其应用%Preparation and applications of a supported liquid-liquid extraction column with a composite diatomite material

    Institute of Scientific and Technical Information of China (English)

    包建民; 马志爽; 孙莹; 王勇尊; 李优鑫

    2012-01-01

    以含硅藻土的复合材料为支撑介质,开发了一种独特的支撑液液萃取柱;以一系列酸性、碱性和中性水溶液样品为模型化合物,结合高效液相色谱法( HPLC)对该萃取柱进行了系统评价,同时将其用于复杂基质样品的分析.结果表明:经该支撑液液萃取柱预处理的苯甲酸、对硝基苯胺和对羟基苯甲酸甲酯水溶液的萃取回收率分别为90.6%、98.1%和97.7%,远超过对应样品经传统液液萃取法处理后的回收率(分别为71.9%、81.9%和83.9%).对于复杂基质样品的分析,如雪碧中的防腐剂苯甲酸以及牛血清中的中性药物醋酸地塞米松、碱性药物马来酸氯苯那敏及酸性药物吲哚美辛等,样品的加标回收率均在80%和110%之间,相对标准偏差(RSD)均小于15%,符合生物样品的分析要求,且未出现传统液液萃取技术中常见的问题(如乳化现象).所开发的支撑液液萃取柱具有快速、简单、耐受性好、易于实现自动化和高通量的特点,具有广泛的应用前景.%A rapid and special supported liquid-liquid extraction (SLE) column was developed with a composite diatomite material. The SLE column was evaluated by high performance liquid chromatography (HPLC) with acidic, neutral and alkaline compounds dissolved in water. Furthermore, some real complex samples were also analyzed by HPLC with the SLE method. The recoveries of benzoic acid ( acidic) , p-nitroaniline ( alkaline) and 4-hydroxy-benzoic methyl ester (neutral) treated by the SLE column were 90.6%, 98.1% and 97.7%. However, the recoveries of the three compounds treated by traditional liquid-liquid extraction (LLE) method were 71. 9%, 81. 9% and 83. 9%. The results showed that the SLE technique had higher recoveries than the traditional LLE method. The spiked recoveries of the complex samples, such as benzoic acid in Sprite and dexamethasone acetate, chlorphenamine maleate, indomethacin in bovine serum, were

  16. Solid-phase extraction of galloyl- and caffeoylquinic acids from natural sources (Galphimia glauca and Arnicae flos) using pure zirconium silicate and bismuth citrate powders as sorbents inside micro spin columns.

    Science.gov (United States)

    Hussain, Shah; Schönbichler, Stefan A; Güzel, Yüksel; Sonderegger, Harald; Abel, Gudrun; Rainer, Matthias; Huck, Christian W; Bonn, Günther K

    2013-10-01

    Galloyl- and caffeoylquinic acids are among the most important pharmacological active groups of natural compounds. This study describes a pre-step in isolation of some selected representatives of these groups from biological samples. A selective solid-phase extraction (SPE) method for these compounds may help assign classes and isomer designations within complex mixtures. Pure zirconium silicate and bismuth citrate powders (325 mesh) were employed as two new sorbents for optimized SPE of phenolic acids. These sorbents possess electrostatic interaction sites which accounts for additional interactions for carbon acid moieties as compared to hydrophilic and hydrophobic sorbents alone. Based on this principle, a selective SPE method for 1,3,4,5-tetragalloylquinic acid (an anti-HIV and anti-asthamatic agent) as a starting compound was developed and then deployed upon other phenolic acids with success. The recoveries and selectivities of both sorbents were compared to most commonly applied and commercially available sorbents by using high performance liquid chromatography. The nature of interaction between the carrier sorbent and the acidic target molecules was investigated by studying hydrophilic (silica), hydrophobic (C18), mixed-mode (ionic and hydrophobic: Oasis(®) MAX) and predominantly electrostatic (zirconium silicate) materials. The newly developed zirconium silicate and bismuth citrate stationary phases revealed promising results for the selective extraction of galloyl- and caffeoylquinic acids from natural sources. It was observed that zirconium silicate exhibited maximum recovery and selectivity for tetragalloylquinic acid (84%), chlorogenic acid (82%) and dicaffeoylquinic acid (94%) among all the tested sorbents.

  17. Water Column Sonar Data Collection

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The collection and analysis of water column sonar data is a relatively new avenue of research into the marine environment. Primary uses include assessing biological...

  18. Rapid Preparation Methods of Biological Samples for Ionic Compounds Using Ion Exchange Type Monolithic Silica Spin Column

    OpenAIRE

    宮崎, 将太; 山田, 智子; 太田, 茂徳; 斉藤, 剛; 奈女良, 昭; 大平, 真義

    2010-01-01

    We developed a device comprising a spin column packed with ion exchange type (SCX and SAX) monolithic silica for extracting ionic compounds from biological samples. The methods involving the use of these spin column are not useful for the extraction of ionic analytes, but are highly reproducible for the analysis in serum and urine. This spin column enabled sample preparation in less than 10 min. Handling such as sample loading, washing, and elution of analytes, was exhibited by the centrifuga...

  19. Optimization of silica gel column chromatography extraction process of oryzanol from rice bran oil soap stock by response surface methodology%响应面法优化柱层析工艺提取米糠油皂脚中的谷维素

    Institute of Scientific and Technical Information of China (English)

    沈鸿; 张培培; 庞敏; 姜绍通

    2016-01-01

    以米糠油加工所得的副产物皂脚为原料,用乙酸乙酯索氏抽提得到皂脚浸提物,采用硅胶柱层析的方法对皂脚浸提物分离纯化谷维素,采用单因素和响应面方法进行优化,确定浸提液的谷维素浓度为4.00%,上样量为8.70 g,硅胶用量为60.00 g。结果表明,此工艺得到的谷维素纯度88.5%,皂脚中谷维素的总提取率达到58.7%。%Soapstock,the byproduct of rice bran oil procossing,was used as raw material. Oryzanol was extracted with ethyl acetate from rice bran oil soap stock and purified by silica gel column chromatography methods. Based on single factor experiments and response surface methodology,the optimum conditions were as follows:oryzanol concentration of sample forsilica gelcolumn chromatography was 4.00%,the sample volume was 8.70 g,the amount of silica gel was 60 g. The results showed that the total extraction rate of oryzanol could reached 58.7% while oryzanol purity was 88.5%.

  20. Radiotracer Imaging of Sediment Columns

    Science.gov (United States)

    Moses, W. W.; O'Neil, J. P.; Boutchko, R.; Nico, P. S.; Druhan, J. L.; Vandehey, N. T.

    2010-12-01

    Nuclear medical PET and SPECT cameras routinely image radioactivity concentration of gamma ray emitting isotopes (PET - 511 keV; SPECT - 75-300 keV). We have used nuclear medical imaging technology to study contaminant transport in sediment columns. Specifically, we use Tc-99m (T1/2 = 6 h, Eγ = 140 keV) and a SPECT camera to image the bacteria mediated reduction of pertechnetate, [Tc(VII)O4]- + Fe(II) → Tc(IV)O2 + Fe(III). A 45 mL bolus of Tc-99m (32 mCi) labeled sodium pertechnetate was infused into a column (35cm x 10cm Ø) containing uranium-contaminated subsurface sediment from the Rifle, CO site. A flow rate of 1.25 ml/min of artificial groundwater was maintained in the column. Using a GE Millennium VG camera, we imaged the column for 12 hours, acquiring 44 frames. As the microbes in the sediment were inactive, we expected most of the iron to be Fe(III). The images were consistent with this hypothesis, and the Tc-99m pertechnetate acted like a conservative tracer. Virtually no binding of the Tc-99m was observed, and while the bolus of activity propagated fairly uniformly through the column, some inhomogeneity attributed to sediment packing was observed. We expect that after augmentation by acetate, the bacteria will metabolically reduce Fe(III) to Fe(II), leading to significant Tc-99m binding. Imaging sediment columns using nuclear medicine techniques has many attractive features. Trace quantities of the radiolabeled compounds are used (micro- to nano- molar) and the half-lives of many of these tracers are short (Image of Tc-99m distribution in a column containing Rifle sediment at four times.

  1. Extraction of aflatoxins from food samples using graphene-based magnetic nanosorbents followed by high-performance liquid chromatography: a simple solution to overcome the problems of immunoaffinity columns.

    Science.gov (United States)

    Es'haghi, Zarrin; Beheshti, Hamed Reza; Feizy, Javad

    2014-09-01

    In this research, magnetic graphene nanoparticles were prepared and used as adsorbents for preconcentrating the aflatoxins in rice, wheat, and sesame samples. For this purpose, graphene was synthesized by Hummer's method. Magnetically modified graphene formed by the deposition of magnetite (Fe3O4) on graphene was used for the separation of aflatoxins B1, B2, G1, and G2 from the samples. The extractants were subsequently analyzed with high-performance liquid chromatography and fluorescence detection. Parameters affecting the efficiency of the method were thoroughly investigated. The measurements were done under the optimized conditions. For aflatoxins B1, B2, G1, and G2, limits of detection were 0.025, 0.05, 0.05, and 0.075 ng/g and limits of quantification were 0.083, 0.16, 0.16, and 0.23 ng/g, respectively. Accuracy was examined by the determination of the relative recovery of the aflatoxins. The relative recovery of aflatoxins B1, B2, G1, and G2 were quite satisfactory (between 64.38 and 122.21% for food samples). Relative standard deviations for within laboratory repeatability (n = 6) were in the range from 1.3 to 3.2. The application of this sorbent for the separation and concentration of the mentioned aflatoxins from food samples was examined.

  2. A novel convenient process to obtain a raw decaffeinated tea polyphenol fraction using a lignocellulose column.

    Science.gov (United States)

    Sakanaka, Senji

    2003-05-07

    Lignocellulose prepared from sawdust was investigated for its potential application in obtaining a raw decaffeinated tea polyphenol fraction from tea extract. Tea polyphenols having gallate residues, namely, (-)epigallocatechin gallate (EGCg) and (-)epicatechin gallate (ECg), were adsorbed on the lignocellulose column, while caffeine was passed through it. Adsorbed polyphenols were eluted with 60% ethanol, and the elute was found to consist mainly of EGCg and ECg. The caffeine/EGCg ratio was 0.696 before lignocellulose column treatment, but it became 0.004 after the column treatment. These results suggest that the lignocellulose column provides a useful and convenient process of purification of tea polyphenol fraction accompanied by decaffeination.

  3. Coupling purification and on-column PEGylation of tumor necrosis factor alpha analogue.

    Science.gov (United States)

    Milunović, Tatjana; Kunstelj, Menči; Fidler, Katarina; Anderluh, Gregor; Gaberc Porekar, Vladka

    2012-11-15

    Trends in preparation of PEGylated protein drugs strive for simple, fast, and cheap processes, resulting in well-defined homogeneous products. We investigated the on-column PEGylation of tumor necrosis factor alpha (TNF-α), where purification and conjugation were performed in one step by using immobilized metal affinity chromatography (IMAC). The same quality of the PEGylated product was obtained by the on-column approach starting from either the crude Escherichia coli protein extract or the purified protein. In comparison with the PEGylation in solution, the on-column approach resulted in more homogeneous PEGylated product. The on-column PEGylation reduces the number of production steps, costs, and preparation time.

  4. Microwave rapid extraction of free fatty acids from Zanthoxylum bungeanum Maxim and their HPLC fluorescence detection by pre-column derivatization%花椒游离脂肪酸的微波快速提取与衍生化HPLC荧光检测方法研究

    Institute of Scientific and Technical Information of China (English)

    郑振佳; 席兴军; 赵先恩; 赵镭; 张璐璐; 郑佳佳

    2013-01-01

    建立了花椒中游离脂肪酸的微波快速提取技术,并采用苯并[b]吖啶酮-5-乙基对甲苯磺酸酯(BAETS)作为柱前衍生试剂,建立了19种长链饱和与不饱和游离脂肪酸的衍生化HPLC荧光检测分析方法.微波提取功率700W,溶剂为体积比1∶1的氯仿/甲醇,70℃提取10min,可达近100%提取率.采用色谱柱Eclipse XDB-C8(4.6mm× 150mm,5μm),酸性乙腈/水流动相进行梯度洗脱,HPLC荧光激发和发射波长分别为273nm和505nm.同时进行在线质谱辅助鉴定(APCI-MS),更提高了HPLC荧光定量的准确度.结果表明,微波提取快速高效,分析方法线性良好,线性范围14.286~0.0139μmol/L,最低检出限为0.636nmol/L,回收率在87.60%~ 106.59%之间.本方法快速、准确、高灵敏,可作为花椒相关样品的标准化检测方法.%Free fatty acids (FFAs) in Zanthoxylum bungeanum Maxim were extracted by microwave-assisted extraction and derivatized using 2-(12-oxobenzo[b]acridin-5 (12H)-yl) ethyl-4-toluenesulfonate (BAETS) as derivatization reagent.This method was proposed to detect 19 long-chain saturated and unsaturated FFA derivatives by HPLC fluorescence detection using pre-column derivatization.Microwave-assisted extract percentages almost reached 100% when FFAs were extracted at microwave power 700W,70℃ and 10min using chloroform/methanol(1∶1,v∶v).Good chromatographic separation was achieved using acidic acetonitrile/ water as mobile phase on Eclipse XDB-C8 column(4.6mm×150mm,5μm) by gradient elution.On-line APCI-MS identification was used for producing more accurate HPLC fluorescence quantitation.Fluorescence excitation and emission wavelengths for HPLC detection were 273nm and 505nm,respectively.The results indicated that microwave-assisted extraction was fast and efficient,and the developed analytical method had good linearity.Linear range was from 14.286 to 0.0139μmol/L,the lowest detection limits was 0.636nmol/L,the recovery was in the range of 87

  5. Experimental validation of pulsed column inventory estimators

    Energy Technology Data Exchange (ETDEWEB)

    Beyerlein, A.L.; Geldard, J.F. (Clemson Univ., SC (United States)); Weh, R. (Gesellschaft fuer Nuklear-Service mbH, Hannover (Germany)); Eiben, K.; Dander, T. (Wiederaufbereitungsanlage Karlsruhe Betriebsgesellschaft mbH (WAK), Eggenstein-Leopoldshafen (Germany)); Hakkila, E.A. (Los Alamos National Lab., NM (United States))

    1991-01-01

    Near-real-time accounting (NRTA) for reprocessing plants relies on the timely measurement of all transfers through the process area and all inventory in the process. It is difficult to measure the inventory of the solvent contractors; therefore, estimation techniques are considered. We have used experimental data obtained at the TEKO facility in Karlsruhe and have applied computer codes developed at Clemson University to analyze this data. For uranium extraction, the computer predictions agree to within 15% of the measured inventories. We believe this study is significant in demonstrating that using theoretical models with a minimum amount of process data may be an acceptable approach to column inventory estimation for NRTA. 15 refs., 7 figs.

  6. Column Holdup Formula of Soil Solute Transport

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The shortcomings of the present two formulae for describing column holdup are analyzed and deductions are made to find a new formula. The column holdup, Hw, described by the new formula is dimensional,and related to soil solute transport kinesis and column physical properties. Compared with the other two column holdups, Hw is feasible to describe dimensional column holdup during solute transport process. The relationships between Hw and retardation factor, R, in different solute transport boundary conditions are established.

  7. Partially saturated granular column collapse

    Science.gov (United States)

    Turnbull, Barbara; Johnson, Chris

    2017-04-01

    Debris flows are gravity-driven sub-aerial mass movements containing water, sediments, soil and rocks. These elements lead to characteristics common to dry granular media (e.g. levee formation) and viscous gravity currents (viscous fingering and surge instabilities). The importance of pore fluid in these flows is widely recognised, but there is significant debate over the mechanisms of build up and dissipation of pore fluid pressure within debris flows, and the resultant effect this has on dilation and mobility of the grains. Here we specifically consider the effects of the liquid surface in the flow. We start with a simple experiment constituting a classical axisymmetric granular column collapse, but with fluid filling the column up to a depth comparable to the depth of grains. Thus, as the column collapses, capillary forces may be generated between the grains that prevent dilation. We explore a parameter space to uncover the effects of fluid viscosity, particle size, column size, aspect ratio, grain shape, saturation level, initial packing fraction and significantly, the effects of fine sediments in suspension which can alter the capillary interaction between wetted macroscopic grains. This work presents an initial scaling analysis and attempts to relate the findings to current debris flow modelling approaches.

  8. NucleoSpin(®) XS Columns for DNA Concentration and Clean-Up.

    Science.gov (United States)

    Hudlow, William R

    2016-01-01

    The phenol-chloroform (organic) extraction method continues to be a preferred method for extraction of DNA from forensic evidence samples that may contain low quantities of DNA and polymerase chain reaction (PCR) inhibitors. The aqueous extracts from the organic extraction of DNA require subsequent concentration and cleanup, which has traditionally been performed with microdialysis filter units, including the Centricon(®) and Microcon(®) centrifugal filter devices. Here, we describe the use of the NucleoSpin(®) XS silica columns as an alternative for the concentration and purification of the aqueous extracts from the organic extraction and for the removal of PCR inhibitors from existing DNA extracts.

  9. Monolithic molecularly imprinted polymeric capillary columns for isolation of aflatoxins.

    Science.gov (United States)

    Szumski, Michał; Grzywiński, Damian; Prus, Wojciech; Buszewski, Bogusław

    2014-10-17

    Monolithic molecularly imprinted polymers extraction columns have been prepared in fused-silica capillaries by UV or thermal polymerization in a two-step process. First, a poly-(trimethylolpropane trimethacrylate) (polyTRIM) core monolith was synthesized either by UV or thermal polymerization. Then it was grafted with the mixture of methacrylic acid (MAA) as a functional monomer, ethylene dimethacrylate (EDMA) as a cross-linking agent, 5,7-dimethoxycoumarin (DMC) as an aflatoxin-mimicking template, toluene as a porogen solvent and 2,2-azobis-(2-methylpropionitrile) (AIBN) as an initiator of the polymerization reaction. Different thermal condition of the photografting and different concentrations of the grafting mixture were tested during polymerization. The extraction capillary columns were evaluated in the terms of their hydrodynamic and chromatographic properties. Retention coefficients for aflatoxin B1 and DMC were used for assessment of the selectivity and imprinting factor. The obtained results indicate that the temperature of photografting and concentration of the grafting mixture are key parameters that determine the quality of the prepared MIPs. From the MIP columns characterized by the highest permeability the column of the highest imprinting factor was applied for isolation of aflatoxins B1, B2, G1 and G2 from the model aqueous sample followed by on-line chromatographic separation. The process was performed using a micro-MISPE-microLC-LIF system of a novel design, which allowed for detection of the eluates from the sample preparation part as well as from the chromatographic separation.

  10. Columns

    Institute of Scientific and Technical Information of China (English)

    于晓悠; 丁燕燕; 韩多妮; Ray; Carrie; 未冉

    2010-01-01

    <正>New York Whitney艺术双年展今年第75届纽约Whitney双年展不设题目,但以"2010"指示策展方向,继续以发掘年轻艺术家、展示创作实验为目标。参展的55位艺术家,最年轻的是23岁摄影师Tam Tran,最老资历的是75岁的概念艺术家Lorraine O’Grady。这届的另一先创性,是每位艺术家只限一件或一个系列的作品,避免了去届双年展的"小型个人回顾展"现象,而五层楼的展场各有特色,如录像及短片将独立于三楼展出,而美术馆馆藏则移师五楼。这届双年展由著名的意大利策展人Francesco Bonami联同助手Gary Carrion-Murayarn共同制作,两位策展人说明,双年展的重要性是预示未来,创新及前瞻性依然是取决原则。

  11. Columns

    Institute of Scientific and Technical Information of China (English)

    Carrie Tsang; 丁燕燕; 韩多妮; RAY

    2009-01-01

    <正>Paris承诺的展现33岁的墨西哥艺术家Mario Garcia Torres是近年国际艺坛炙手可热的新星,他以录象、摄影、幻灯及装置为创作形式,透过个人视点及独特演绎手法来重新思考历史。他是一个思考型艺术家,同时又是一个淘气的大孩子,作品往往反映了他的双重性格——嬉戏中带有深沉的历史感。这次是GarciaTorres首次在法国的国家博物馆举行展览,整合出版了他过往两年间在

  12. Revised Thermal Analysis of LANL Ion Exchange Column

    Energy Technology Data Exchange (ETDEWEB)

    Laurinat, J

    2006-04-11

    This document updates a previous calculation of the temperature distributions in a Los Alamos National Laboratory (LANL) ion exchange column.1 LANL operates two laboratory-scale anion exchange columns, in series, to extract Pu-238 from nitric acid solutions. The Defense Nuclear Facilities Safety Board has requested an updated analysis to calculate maximum temperatures for higher resin loading capacities obtained with a new formulation of the Reillex HPQ anion exchange resin. The increased resin loading capacity will not exceed 118 g plutonium per L of resin bed. Calculations were requested for normal operation of the resin bed at the minimum allowable solution feed rate of 30 mL/min and after an interruption of flow at the end of the feed stage, when one of the columns is fully loaded. The object of the analysis is to demonstrate that the decay heat from the Pu-238 will not cause resin bed temperatures to increase to a level where the resin significantly degrades. At low temperatures, resin bed temperatures increase primarily due to decay heat. At {approx}70 C a Low Temperature Exotherm (LTE) resulting from the reaction between 8-12 M HNO{sub 3} and the resin has been observed. The LTE has been attributed to an irreversible oxidation of pendant ethyl benzene groups at the termini of the resin polymer chains by nitric acid. The ethyl benzene groups are converted to benzoic acid moities. The resin can be treated to permanently remove the LTE by heating a resin suspension in 8M HNO{sub 3} for 30-45 minutes. No degradation of the resin performance is observed after the LTE removal treatment. In fact, heating the resin in boiling ({approx}115-120 C) 12 M HNO{sub 3} for 3 hr displays thermal stability analogous to resin that has been treated to remove the LTE. The analysis is based on a previous study of the SRS Frames Waste Recovery (FWR) column, performed in support of the Pu-238 production campaign for NASA's Cassini mission. In that study, temperature transients

  13. Mass transport coefficients from liquid thermal diffusion columns

    Energy Technology Data Exchange (ETDEWEB)

    Ecenarro, O.; Madariaga, J.A.; Navarro, J.L.; Santamaria, C.M. (Universidad del Pais Vasco, Bilbao (Spain). Dept. de Fisica Aplicada 2); Carrion, J.A.; Saviron, J.M. (Zaragoza Univ. (Spain). Facultad da Ciencias)

    1990-03-01

    Experimental data on ordinary diffusion coefficient and thermal diffusion for binary liquid systems containing hexane, heptane, benzene, toluene and carbon tetrachloride are obtained from steady and non-steady separation measurements in a thermal diffusion column. The data extraction uses a time evolution theory previously developed by the authors that accounts for density effects (the 'forgotten effect'). The comparison of the diffusion data with those of the literature provides a powerful test of the derived thermal diffusion factors. (orig.).

  14. Transformations of Carotenoids in the Oceanic Water Column.

    Science.gov (United States)

    1982-11-01

    products. A subsequent study by Nitsche (1974) confirmed this hypothesis. Nitsche extracted 150 kg (wet weight) of Fucus vesiculosus and purified the...1974) Neoxanthin and Fucoxanthinol in Fucus Vesiculosus . Biochim. Biophys. Acta 338, 572-576. Nitache H. (1972) Mimulaxanthin - A New Allenic Xanthophyll...AD-AI21 499 TRANSFORMATIONS OF CROTENOIDS IN THE OCEANIC WATER 1/3 COLUMN(U) WOODS HOLE OCEANOGRAPHIC INSTITUTION MR D J REPETA NOY 92 MWHOI-82-46

  15. Modeling of column apparatus processes

    CERN Document Server

    Boyadjiev, Christo; Boyadjiev, Boyan; Popova-Krumova, Petya

    2016-01-01

    This book presents a new approach for the modeling of chemical and interphase mass transfer processes in industrial column apparatuses, using convection-diffusion and average-concentration models. The convection-diffusion type models are used for a qualitative analysis of the processes and to assess the main, small and slight physical effects, and then reject the slight effects. As a result, the process mechanism can be identified. It also introduces average concentration models for quantitative analysis, which use the average values of the velocity and concentration over the cross-sectional area of the column. The new models are used to analyze different processes (simple and complex chemical reactions, absorption, adsorption and catalytic reactions), and make it possible to model the processes of gas purification with sulfur dioxide, which form the basis of several patents.

  16. Comparison of drug substance impurity profiles generated with extended length columns during packed-column SFC.

    Science.gov (United States)

    Roston, D A; Ahmed, S; Williams, D; Catalano, T

    2001-10-01

    The current study assesses the effect of extending column length during gradient packed column sub/supercritical fluid chromatography (PCSFC) experiments on the detection of known and unknown impurities in a drug substance sample. Quantitative drug substance impurity profiles were generated and compared using multiple column PCSFC and HPLC conditions. Also, chromatographic figures of merit were estimated and compared for components of a standard mixture during PCSFC experiments, which used one column, four columns, and six columns in series.

  17. Beam Studies with Electron Columns

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, V.; Valishev, A.; Kuznetsov, G.; /Fermilab; Kamerdzhiev, V.; /Julich, Forschungszentrum; Romanov, A.; /Novosibirsk, IYF

    2009-04-01

    We report preliminary results of experimental studies of 'electron columns' in the Tevatron and in a specialized test setup. In the Tevatron, a beam of 150 GeV protons ionizes residual gas and ionization electrons are stored in an electrostatic trap immersed into strong longitudinal magnetic field. Shifts of proton betatron frequencies are observed. In the test setup, we observe effects pointing to accumulation and escape of ionization electrons.

  18. 柱前衍生-萃取阻断反应-高效液相色谱法测定化妆品中游离甲醛%Determination of free formaldehyde in cosmetics by pre-column derivatization, extraction inhibition and high performance liquid chromatography

    Institute of Scientific and Technical Information of China (English)

    吕春华; 黄超群; 陈梅; 谢文; 陈笑梅

    2012-01-01

    Pre-column derivatization and inhibition by solvent extraction were applied to determine free formaldehyde in cosmetics by high performance liquid chromatography (HPLC). Due to the rapid decomposition of formaldehyde donors in the derivatization, it is hard to detect the amount of the free formaldehyde in cosmetics. The formaldehyde directly reacted with 2,4-dini-trophenylhydrazine in acetonitrile-phosphate buffer (pH 2) (1:1, v/v) solution for 2 min, then dichloromethane extraction was used to induce the decomposition of formaldehyde donors. The extract was diluted with acetonitrile and then determined by HPLC. The formaldehyde derivative was separated on an Agilent C18 column (250 mm ×4. 6 mm, 5 μm) at 30 ℃ with acetonitrile-water (60=40, v/v) as mobile phase at a flow rate of 1.0 mL/min, and detected at the wavelength of 355 nm. The recoveries were from 81% to 106% at the spiked levels of 50, 100, 500, 1 000 μg/g of formaldehyde in shampoo, milk, cream, hand cleaner, toothpaste, nail polish, powder separately, and the relative standard deviations (n =6) were less than 5. 0%. The limit of quantification of the formaldehyde in cosmetics was 50 μg/g. The method has been applied to the determination of free formaldehyde in real samples and the results showed that the release by formaldehyde donors was inhibited. The method has the advantages of simple operation, good accuracy and meets the requirement of determination of free formaldehyde in cosmetics.%建立了柱前衍生化-萃取阻断反应-高效液相色谱(HPLC)测定化妆品中甲醛的方法.化妆品中甲醛检测的难点是:甲醛缓释剂类防腐剂在衍生过程中释放甲醛,影响游离甲醛的准确测定.以2,4-二硝基苯肼(DNPH)乙腈溶液-磷酸盐缓冲液(pH2)(1∶1,v/v)为提取溶液,于室温下快速衍生2 min后,立即加入二氯甲烷萃取,阻断衍生反应,经乙腈稀释后进行HPLC测定.以Agilent C18柱(250 mm ×4.6 mm,5μm)为分离柱,乙腈-水(60∶40,v

  19. Water Column Methylation in Estuaries

    Science.gov (United States)

    Schartup, A. T.; Calder, R.; Soerensen, A. L.; Mason, R. P.; Balcom, P. H.; Sunderland, E. M.

    2014-12-01

    Methylmercury (MeHg) is a neurotoxin that bioaccumulates in aquatic food webs and affects humans and wildlife through fish consumption. Many studies have measured active methylation/demethylation in ocean margin sediments but few have reported similar rates for the marine water column. This presentation will review available evidence for water column methylation in estuaries, including new experimental measurements of methylation/demethylation rates from a deep subarctic fjord in Labrador Canada collected in Spring and Fall of 2012-2013. We used these and other data to construct a mass budget for MeHg in the estuary and show that water column methylation (with rates ranging from 1.5 to 2.8 % day-1), is the largest contributor, followed by inputs from rivers (4.9 mol year-1), to the in situ pool of MeHg available for uptake by biota. By contrast, the sediment in this system is a net sink for MeHg (-1.5 mol year-1). We discuss the relationship between observed MeHg and other ancillary environmental factors (organic carbon, sulfur and nutrients) as well as implications for the response time of fish to future changes in mercury inputs.

  20. Effects of a malfunctional column on conventional and FeedCol-simulated moving bed chromatography performance.

    Science.gov (United States)

    Song, Ji-Yeon; Oh, Donghoon; Lee, Chang-Ha

    2015-07-17

    The effects of a malfunctional column on the performance of a simulated moving bed (SMB) process were studied experimentally and theoretically. The experimental results of conventional four-zone SMB (2-2-2-2 configuration) and FeedCol operation (2-2-2-2 configuration with one feed column) with one malfunctional column were compared with simulation results of the corresponding SMB processes with a normal column configuration. The malfunctional column in SMB processes significantly deteriorated raffinate purity. However, the extract purity was equivalent or slightly improved compared with the corresponding normal SMB operation because the complete separation zone of the malfunctional column moved to a lower flow rate range in zones II and III. With the malfunctional column configuration, FeedCol operation gave better experimental performance (up to 7%) than conventional SMB operation because controlling product purity with FeedCol operation was more flexible through the use of two additional operating variables, injection time and injection length. Thus, compared with conventional SMB separation, extract with equivalent or slightly better purity could be produced from FeedCol operation even with a malfunctional column, while minimizing the decrease in raffinate purity (less than 2%). Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Fast HPLC for quality control of Harpagophytum procumbens by using a monolithic silica column: method transfer from conventional particle-based silica column.

    Science.gov (United States)

    Schmidt, Alexander H

    2005-05-06

    The applicability of a monolithic C18-bonded silica column for the rapid HPLC separation of ingredients in medicinal plants and their phytopharmaceutical preparations has been evaluated in the author's laboratory. In this presentation, an existing method for the determination of the iridoid glycoside harpagoside in Harpagophytum procumbens (Devil's Claw) was successfully transferred from a conventional particle-based C18 silica column to a monolithic silica column. The very high porosity of the stationary phase allows chromatography with a much lower backpressure than on conventional columns. Therefore, the flow rate could be easily increased from 0.8 mL/min (particle-based column) to 5 mL/min (monolithic column) and the run-time reduced from 30 to 5 min (that is a reduction about 85% !), without losing any chromatographic resolution of the compound of interest. The amount of harpagoside was measured with the original method on a conventional particle-based silica column and on the adapted method on a monolithic silica column. The statistical mean t-test showed no significant differences of the variances and the means indicating that the fast HPLC method is an acceptable alternative. The shorter analysis time makes the method very valuable for commercial quality control of Harpagophytum extracts and its pharmaceutical preparations.

  2. "Supermarket Column Chromatography of Leaf Pigments" Revisited: Simple and Ecofriendly Separation of Plant Carotenoids, Chlorophylls, and Flavonoids from Green and Red Leaves

    Science.gov (United States)

    Dias, Alice M.; Ferreira, Maria La Salete

    2015-01-01

    A simple and ecofriendly procedure was developed in order to prepare extracts from red and green leaves. This procedure enables the separation of yellow, green, and red band pigments and optimizes the previously reported baking soda "supermarket column". The same extract also led to a novel and colorful potato starch column, which can…

  3. "Supermarket Column Chromatography of Leaf Pigments" Revisited: Simple and Ecofriendly Separation of Plant Carotenoids, Chlorophylls, and Flavonoids from Green and Red Leaves

    Science.gov (United States)

    Dias, Alice M.; Ferreira, Maria La Salete

    2015-01-01

    A simple and ecofriendly procedure was developed in order to prepare extracts from red and green leaves. This procedure enables the separation of yellow, green, and red band pigments and optimizes the previously reported baking soda "supermarket column". The same extract also led to a novel and colorful potato starch column, which can…

  4. 一种改进的异硫氰酸胍法结合硅胶膜离心吸附柱提取孕妇外周血微量胎儿RNA的方法%Extraction of Trace Fetal RNA from Peripheral Blood of Pregnant Women by Improved Metuod of Guanidinium Isothiocyanate Combination with Absorptive Spin Column

    Institute of Scientific and Technical Information of China (English)

    杨利丽; 刘红英; 杨和军; 刘顺梅

    2012-01-01

    Recently, a number of investigators have shown that in addition to DNA, circulating fetal RNA is also present in the maternal plasma. Its presence has opened up new possibilities for noninvasive prenatal diagnosis. But it is difficult to extract fetal RNA from plasma of pregnant women because of abundant Rnase and trace fetal RNA. An improved method were used for extracting total RNA from whole peripheral blood of pregnant women. Thirty blood samples from normal pregnancies and nine samples from non-pregnant women were studded. The blood samples were collected in EDTA-containing Rnase free plain tubes. For plasma samples, the improved method of guanidinium isothiocyanatecombined with spin column and the reagent kit method were applied to extract total RNA. Then RT-PCR was used for the target genes mRNA, e hemoglobin gene and PLAC4 (placenta-specific 4) gene. The extracted total RNA showed three bright bands in agarose gel electrophoresis, 28S, 18S and 5. 8S. The band of 28S was twice than that of 18S. Ratio of A260/A2S0 was 1. 97; (A260 - A320)/(A 280 - A 320) was 1. 86. Seven positive and 23 negative e hemoglobin gene mRNA were obtained from 30 samples. The minimum concentration of e hemoglobin gene mRNA was 0. 537 μg/mL,the maximum concentration was 1.79 μg/mL,the median was 1.24 μg/mL. There was a negative correlation between the amount of e hemoglobin gene mRNA and gestation age durine 7 ~ 10 weeks; Also, PLAC4 mRNA is present in peripheral blood of pregnant women but not in 9 cases of non-pregnant women ( P < 0. 01 ). The minimum concentration of PLAC4 mRNA was 2. 105 x 103 copies/mL, the maximum concentration was 12.760 x 10 copies/mL, the average was 6.612 x 10 copies/mL. The results proposed that improved guanidinium isothiocyanate combined with spin column method is a swift and efficient method for extracting total RNA from whole blood. The potential achievement of these goals would allow us to make a significant step toward the development of a

  5. A technique using a stellar spectrographic plate to measure terrestrial ozone column depth

    Energy Technology Data Exchange (ETDEWEB)

    Wong, A.Y.

    1995-08-01

    This thesis examines the feasibility of a technique to extract ozone column depths from photographic stellar spectra in the 5000--7000 Angstrom spectral region. A stellar spectrographic plate is measured to yield the relative intensity distribution of a star`s radiation after transmission through the earth`s atmosphere. The amount of stellar radiation absorbed by the ozone Chappuis band is proportional to the ozone column depth. The measured column depth is within 10% the mean monthly value for latitude 36{degree}N, however the uncertainty is too large to make the measurement useful. This thesis shows that a 10% improvement to the photographic sensitivity uncertainty can decrease the column depth uncertainty to a level acceptable for climatic study use. This technique offers the possibility of measuring past ozone column depths.

  6. A technique using a stellar spectrographic plate to measure terrestrial ozone column depth

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Alec Y. [Univ. of California, Berkeley, CA (United States)

    1995-08-01

    This thesis examines the feasibility of a technique to extract ozone column depths from photographic stellar spectra in the 5000--7000 Angstrom spectral region. A stellar spectrographic plate is measured to yield the relative intensity distribution of a star`s radiation after transmission through the earth`s atmosphere. The amount of stellar radiation absorbed by the ozone Chappuis band is proportional to the ozone column depth. The measured column depth is within 10% the mean monthly value for latitude 36{degree}N, however the uncertainty is too large to make the measurement useful. This thesis shows that a 10% improvement to the photographic sensitivity uncertainty can decrease the column depth uncertainty to a level acceptable for climatic study use. This technique offers the possibility of measuring past ozone column depths.

  7. Water column correction for coral reef studies by remote sensing.

    Science.gov (United States)

    Zoffoli, Maria Laura; Frouin, Robert; Kampel, Milton

    2014-09-11

    Human activity and natural climate trends constitute a major threat to coral reefs worldwide. Models predict a significant reduction in reef spatial extension together with a decline in biodiversity in the relatively near future. In this context, monitoring programs to detect changes in reef ecosystems are essential. In recent years, coral reef mapping using remote sensing data has benefited from instruments with better resolution and computational advances in storage and processing capabilities. However, the water column represents an additional complexity when extracting information from submerged substrates by remote sensing that demands a correction of its effect. In this article, the basic concepts of bottom substrate remote sensing and water column interference are presented. A compendium of methodologies developed to reduce water column effects in coral ecosystems studied by remote sensing that include their salient features, advantages and drawbacks is provided. Finally, algorithms to retrieve the bottom reflectance are applied to simulated data and actual remote sensing imagery and their performance is compared. The available methods are not able to completely eliminate the water column effect, but they can minimize its influence. Choosing the best method depends on the marine environment, available input data and desired outcome or scientific application.

  8. Elastic stability of non-uniform columns

    Science.gov (United States)

    Lee, S. Y.; Kuo, Y. H.

    1991-07-01

    A simple and efficient method is proposed to investigate the elastic stability of three different tapered columns subjected to uniformly distributed follower forces. The influences of the boundary conditions and taper ratio on critical buckling loads are investigated. The critical buckling loads of columns of rectangular cross section with constant depth and linearly varied width ( T1), constant width and linearly varied depth ( T2) and double taper ( T3) are investigated. Among the three different non-uniform columns considered, taper ratio has the greatest influence on the critical buckling load of column T3 and the lowest influence on that of column T1. The types of instability mechanisms for hinged-hinged and cantilever non-uniform columns are divergence and flutter respectively. However, for clamped-hinged and clamped-clamped non-uniform columns, the type of instability mechanism for column T1 is divergence, while that for columns T2 and T3 is divergence only when the taper ratio of the columns is greater than certain critical values and flutter for the rest value of taper ratio. When the type of instability mechanism changes from divergence to flutter, there is a finite jump for the critical buckling load. The influence of taper ratio on the elastic stability of cantilever column T3 is very sensitive for small values of the taper ratio and there also exist some discontinieties in the critical buckling loads of flutter instability. For a hinged-hinged non-uniform column ( T2 or T3) with a rotational spring at the left end of the column, when the taper ratio is less than the critical value the instability mechanism changes from divergence to flutter as the rotational spring constant is increased. For a clamped-elastically supported non-uniform column, when the taper ratio is greater than the critical value the instability mechanism changes from flutter to divergence as the translational spring constant is increased.

  9. Integrated Multiscale Latent Variable Regression and Application to Distillation Columns

    Directory of Open Access Journals (Sweden)

    Muddu Madakyaru

    2013-01-01

    Full Text Available Proper control of distillation columns requires estimating some key variables that are challenging to measure online (such as compositions, which are usually estimated using inferential models. Commonly used inferential models include latent variable regression (LVR techniques, such as principal component regression (PCR, partial least squares (PLS, and regularized canonical correlation analysis (RCCA. Unfortunately, measured practical data are usually contaminated with errors, which degrade the prediction abilities of inferential models. Therefore, noisy measurements need to be filtered to enhance the prediction accuracy of these models. Multiscale filtering has been shown to be a powerful feature extraction tool. In this work, the advantages of multiscale filtering are utilized to enhance the prediction accuracy of LVR models by developing an integrated multiscale LVR (IMSLVR modeling algorithm that integrates modeling and feature extraction. The idea behind the IMSLVR modeling algorithm is to filter the process data at different decomposition levels, model the filtered data from each level, and then select the LVR model that optimizes a model selection criterion. The performance of the developed IMSLVR algorithm is illustrated using three examples, one using synthetic data, one using simulated distillation column data, and one using experimental packed bed distillation column data. All examples clearly demonstrate the effectiveness of the IMSLVR algorithm over the conventional methods.

  10. Produced fluids separation using a coalascer column

    Energy Technology Data Exchange (ETDEWEB)

    Renouf, G.; Soveran, D.; Soveran, L. [Saskatchewan Research Council, Saskatoon, SK (Canada)

    2005-07-01

    This paper reports the results of a laboratory study in which a coalescer column was used to successfully remove water from produced heavy oil emulsions. The coalescer column is a simple, inexpensive, and environmentally friendly technology that can improve basic sediment and water values after 4 hours of settling time by about 38 per cent. The laboratory study tested the use of the column, and the effects of column length, column packing size, temperature, flow rate, demulsifier concentration, and water addition. More than 100 tests were conducted and 24 pairs of tests compared the treating effects with and without the column. The use of the coalescer column in the treatment facility resulted in a a reduction of demulsifier concentration from 250 ppm to 70 ppm, translating to an annual cost savings of $320,000 to $1,100,000 per battery. Incorporating the coalescer column also allowed operators to reduce both temperatures and demulsifier concentrations. The column also promoted faster treating. Water droplets grew by as much as 34 per cent, suggesting that treating time could be faster by 21 to 80 per cent. It was concluded that the coalescer column was very successful at improving water removal from heavy oil battery emulsions. 22 refs., 9 tabs., 7 figs.

  11. Oscillating water column structural model

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, Guild [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bull, Diana L [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jepsen, Richard Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gordon, Margaret Ellen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    An oscillating water column (OWC) wave energy converter is a structure with an opening to the ocean below the free surface, i.e. a structure with a moonpool. Two structural models for a non-axisymmetric terminator design OWC, the Backward Bent Duct Buoy (BBDB) are discussed in this report. The results of this structural model design study are intended to inform experiments and modeling underway in support of the U.S. Department of Energy (DOE) initiated Reference Model Project (RMP). A detailed design developed by Re Vision Consulting used stiffeners and girders to stabilize the structure against the hydrostatic loads experienced by a BBDB device. Additional support plates were added to this structure to account for loads arising from the mooring line attachment points. A simplified structure was designed in a modular fashion. This simplified design allows easy alterations to the buoyancy chambers and uncomplicated analysis of resulting changes in buoyancy.

  12. Exergetic and economic analysis of an industrial distillation column

    Directory of Open Access Journals (Sweden)

    A. C. B. Araújo

    2007-09-01

    Full Text Available In this work, applications of exergy and economic concepts to compression, heat exchange, and separation processes were used for calculation of the irreversibility rate, thermodynamic efficiency, and internal rate of return (IRR of the profitability. A case study based on a real process, the purification of 1,2-dichloroethane (DCE in a high-purity distillation column, is presented. This column has the highest steam flow rate in any vinyl chloride monomer (VCM plant. A configuration using a vapor compression heat pump is proposed for improvement of the energy efficiency without having to make important process modifications. Existing and proposed configurations were implemented using the Aspen Plus™ commercial simulator; the results of the existing configuration were validated with data extracted from the plant. The objective of this work was to compare the existing configuration with the proposed one, using a thermodynamic and an economic approach.

  13. Study on a continuous heat integrated distillation column

    Energy Technology Data Exchange (ETDEWEB)

    Glenchur, T.; Govind, R.

    1987-12-01

    A novel continuous heat integrated distillation column called a concentric column has been studied using computer simulation. It is shown that a concentric column is a novel implementation of a thermodynamically reversible distillation column and has a lower energy loss than an ordinary distillation column. Their studies show that a concentric column has reduced column height, since the stripping section is configured concentrically around the rectifying section, and uses less utilities than a conventional column.

  14. The system uranyl nitrate-dietyl ether-water. Extraction by water in spray and packed columns from uranyl nitrate-either solutions; El sistema nitrato de uranilo-eter dietilico-agua, extraccion de nitrato de uranilo con agua a partir de disoluciones etereas en columnas de pulverizacion y de relleno

    Energy Technology Data Exchange (ETDEWEB)

    Perez Luina, A.; Gutierrez Jodra, L.

    1960-07-01

    This paper is a continuation of the one published in Chemical Engineering Progress. Symposium Series, 50, n. 12, 127 (1954). New runs for spray columns, are given and other concentrations in uranyl nitrate for the packed columns. New correlations for the overall H.T.U. are also given. The individual H.T.U. have been grapycally calculated and show that the film resistances have similar values, being independent of the concentration of the ether phase. (Author) 24 refs.

  15. The jet flotation column control system

    Energy Technology Data Exchange (ETDEWEB)

    Xu Zhiqiang; Ming Shangzhi; Liu Lijian; Huangfu Jinghua; Huo Sen; Zhang Rongzeng [China Univ. of Mining and Technology, Beijing (China). Mineral Processing Dept.; Yang Hongjun [Hebi Coal Mine Administrative (China)

    1998-12-31

    Compared with the conventional mechanical flotation column, the jet flotation column has the advantages of high selectivity of separation, low investment and production cost, low floor space requirement, low dosage of reagent, easy control; it is more suitable to process fine particles. Recently, many new types of flotation columns have been developed with new methods. Mineral Processing Dept., China University of Mining and Technology (Beijing) designed an aerated, double-jet flotation column in the lab and the industrial trial will be put into operation. One of the significant characteristics of the new type of flotation column is high selectivity of separation, fast bubble mineralization speed. As it is sensitive to various factors, a control system for flotation column has been developed to stabilize the working condition, and this set of control system has been operated in the lab experiment.

  16. SNAP-TITE Composite Column Reinforcement

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    Recent earthquakes throughout the world have demonstrated the vulnerabilities of older reinforced concrete columns to seismic deformation demands. The Snap Tite Composite Column Reinforcement strengthens a concrete column by confining it in an external composite jacket, which prevents the concrete from expanding during seismic activity or prolonged freeze-thaw cycles. The pre-manufactured fiberglass jacket is comprised of glass fibers and corrosion resistant isopolyester resins.

  17. Parametric resonance in concrete beam-columns

    OpenAIRE

    Sharma,Mamta R.; Singh,Arbind K; Benipal,Gurmail S

    2014-01-01

    A dynamic instability, called parametric resonance, is exhibited by undampedelastic beam-columns when under the action of pulsating axial force. The scope of the existing theory of parametric resonance is restricted to physically linear beam-columns undergoing finite lateral displacements. In this Paper, the dynamic behaviour of physically nonlinear elastic cracked concrete beam-columns under pulsating axial force and constant lateral force is investigated. The constitutive equations derived ...

  18. Enzyme activities in the water column and in shallow permeable sediments from the northeastern Gulf of Mexico

    Science.gov (United States)

    Arnosti, C.; Ziervogel, K.; Ocampo, L.; Ghobrial, S.

    2009-09-01

    The activities of extracellular enzymes that initiate the microbial remineralization of high molecular weight organic matter were investigated in the water column and sandy surface sediments at two sites in the northeastern Gulf of Mexico. Six fluorescently labeled polysaccharides were hydrolyzed rapidly in the water column as well as in permeable sediments. This result contrasts with previous studies carried out in environments dominated by fine-grained muds, in which the spectrum of enzymes active in the water column is quite limited compared to that of the underlying sediments. Extracts of Spirulina, Isochrysis, and Thalassiosira were also used to measure hydrolysis rates in water from one of the sites. Rates of hydrolysis of the three plankton extracts were comparable to those of the purified polysaccharides. The broad spectrum and rapid rates of hydrolysis observed in the water column at both sites in the northeastern Gulf of Mexico may be due to the permeable nature of the sediments. Fluid flux through the sediments is sufficiently high that the entire 1.5 m deep water column could filter though the sediments on timescales of a few days to two weeks. Movement of water through sediments may also transport dissolved enzymes from the sediment into the water column, enhancing the spectrum as well as the rate of water column enzymatic activities. Such interaction between the sediments and water column would permit water column microbial communities to access high molecular weight substrates that might otherwise remain unavailable as substrates.

  19. Column: Factors Affecting Data Decay

    Directory of Open Access Journals (Sweden)

    Kevin Fairbanks

    2012-06-01

    Full Text Available In nuclear physics, the phrase decay rate is used to denote the rate that atoms and other particles spontaneously decompose. Uranium-235 famously decays into a variety of daughter isotopes including Thorium and Neptunium, which themselves decay to others. Decay rates are widely observed and wildly different depending on many factors, both internal and external. U-235 has a half-life of 703,800,000 years, for example, while free neutrons have a half-life of 611 seconds and neutrons in an atomic nucleus are stable.We posit that data in computer systems also experiences some kind of statistical decay process and thus also has a discernible decay rate. Like atomic decay, data decay fluctuates wildly. But unlike atomic decay, data decay rates are the result of so many different interplaying processes that we currently do not understand them well enough to come up with quantifiable numbers. Nevertheless, we believe that it is useful to discuss some of the factors that impact the data decay rate, for these factors frequently determine whether useful data about a subject can be recovered by forensic investigation.(see PDF for full column

  20. Extraction chromatography: Progress and opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, M.L.; Horwitz, E.P.; Bond, A.H. [Argonne National Lab., IL (United States). Chemistry Div.

    1997-10-01

    Extraction chromatography provides a simple and effective method for the analytical and preparative-scale separation of a variety of metal ions. Recent advances in extractant design, particularly the development of extractants capable of metal ion recognition or of strong complex formation in highly acidic media, have significantly improved the utility of the technique. Advances in support design, most notably the introduction of functionalized supports to enhance metal ion retention, promise to yield further improvements. Column instability remains a significant obstacle, however, to the process-scale application of extraction chromatography. 79 refs.

  1. Rasch models with exchangeable rows and columns

    DEFF Research Database (Denmark)

    Lauritzen, Steffen Lilholt

    The article studies distributions of doubly infinite binary matrices with exchangeable rows and columns which satify the further property that the probability of any $m \\times n$ submatrix is a function of the row- and column sums of that matrix. We show that any such distribution is a (unique...... of existence of measures with given marginals....

  2. Circulation in gas-slurry column reactors

    Energy Technology Data Exchange (ETDEWEB)

    Clark, N.; Kuhlman, J.; Celik, I.; Gross, R.; Nebiolo, E.; Wang, Yi-Zun.

    1990-08-15

    Circulation in bubble columns, such as those used in fischer-tropsch synthesis, detracts from their performance in that gas is carried on average more rapidly through the column, and the residence time distribution of the gas in the column is widened. Both of these factors influence mass-transfer operations in bubble columns. Circulation prediction and measurement has been undertaken using probes, one-dimensional models, laser Doppler velocimetry, and numerical modeling. Local void fraction was measured using resistance probes and a newly developed approach to determining air/water threshold voltage for the probe. A tall column of eight inch diameter was constructed of Plexiglas and the distributor plate was manufactured to distribute air evenly through the base of the column. Data were gathered throughout the volume at three different gas throughputs. Bubble velocities proved difficult to measure using twin probes with cross-correlation because of radial bubble movement. A series of three-dimensional mean and RMS bubble and liquid velocity measurements were also obtained for a turbulent flow in a laboratory model of a bubble column. These measurements have been made using a three-component laser Doppler velocimeter (LDV), to determine velocity distributions non-intrusively. Finally, the gas-liquid flow inside a vertically situated circular isothermal column reactor was simulated numerically. 74 refs., 170 figs., 5 tabs.

  3. Influence of tray hydraulics on tray column

    NARCIS (Netherlands)

    Betlem, Bernardus H.L.; Rijnsdorp, J.E.; Rijnsdorp, J.E.; Azink, R.F.

    1998-01-01

    To column control, in contrast to column design, tray hold-up and dependencies of tray hold-up on the operating conditions play an important role. The essence of this article is the development of an improved model of tray hydraulics over a broad operating range and its experimental validation by

  4. nduced hyperlipidemic rats. Methods: Column chromatographic fractionation of butanol fraction of total methanol extract of leaves of Bauhinia variegata (Linn. yields four sub-fractions (sub-fraction A-D. All sub-fractions tested for their anti-hyperlipidemic activity. Sub-fractions administered at a dose of 65 mg/kg (oral to the Triton WR-1339 induced hyperlipidemic rats and total cholesterol, triglycerides, HDL, LDL and VLDL

    Directory of Open Access Journals (Sweden)

    Deepak Kumar

    2012-10-01

    Full Text Available Objective: To investigate the effect and evaluation of Anti-hyperlipidemic activity guided subfraction isolated from total methanolic extract of Bauhinia variegata (Linn. leaves on Triton WR-1339 induced hyperlipidemic rats. Methods: Column chromatographic fractionation of butanol fraction of total methanol extract of leaves of Bauhinia variegata (Linn. yields four subfractions (sub-fraction A-D. All sub-fractions tested for their anti-hyperlipidemic activity. Subfractions administered at a dose of 65 mg/kg (oral to the Triton WR-1339 induced hyperlipidemic rats and total cholesterol, triglycerides, HDL, LDL and VLDL level in the blood were checked. Results: Sub-fraction D showed significant reduction (P<0.05 among four sub-fraction in comparison with standard drug fenofibrate. Conclusions: From the above study it could be concluded that butanol sub-fraction D of Bauhinia variegata (Linn. not only have resulted in significant reduction in cholesterol, triglyceride, LDL, VLDL level but also increases the HDL level at a reduced dose level.

  5. Simulation study on vertical transport of atrazine in soil column

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A simulation experiment on vertical transport of herbicide atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) in soil column was conducted using lysimeter system. The atrazine concentrations in leaching water and soil samples in column at 8 layers with 10 cm thick of each layer were detected by high-performance liquid chromatography. The results show total atrazine amount in leaching water increases nonlinearly with the leaching time and the herbicide application rate, and the atrazine concentrations in column soil decrease with the vertical depth after water leaching. The distribution of atrazine mass in the system after 154 days were that among the applied atrazine, 0.3 % is out through leaching water, 1% is methanol extractable residues in soil, 46 % is methanol nonextractable residues in soil, and 52 % is other loss (including volatilization and degradation). The study indicates movement of atrazine in agriculture soil may not only have relation to the properties of herbicide, but also to the herbicide application history.

  6. Simulation study on vertical transport of atrazine in soil column

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A simulation experiment on vertical transport of herbicide atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) in soil column was conducted using lysimeter system. The atrazine concentrations in leaching water and soil samples in column at 8 layers with 10 cm thick of each layer were detected by high-performance liquid chromatography. The results show total atrazine amount in leaching water increases nonlinearly with the leaching time and the herbicide application rate, and the atrazine concentrations in column soil decrease with the vertical depth after water leaching. The distribution of atrazine mass in the system after 154 days were that among the applied atrazine, 0.3 % is out through leaching water, 1% is methanol extractable residues in soil, 46 % is methanol nonextractable residues in soil, and 52 % is other loss (including volatilization and degradation). The study indicates movement of atrazine in agriculture soil may not only have relation to the properties of herbicide, but also to the herbicide application history.

  7. Highly efficient capillary columns packed with superficially porous particles via sequential column packing.

    Science.gov (United States)

    Treadway, James W; Wyndham, Kevin D; Jorgenson, James W

    2015-11-27

    Highly efficient capillary columns packed with superficially porous particles were created for use in ultrahigh pressure liquid chromatography. Superficially porous particles around 1.5μm in diameter were packed into fused silica capillary columns with 30, 50, and 75μm internal diameters. To create the columns, several capillary columns were serially packed from the same slurry, with packing progress plots being generated to follow the packing of each column. Characterization of these columns using hydroquinone yielded calculated minimum reduced plate heights as low as 1.24 for the most efficient 30μm internal diameter column, corresponding to over 500,000plates/m. At least one highly efficient column (minimum reduced plate height less than 2) was created for all three of the investigated column inner diameters, with the smallest diameter columns having the highest efficiency. This study proves that highly efficient capillary columns can be created using superficially porous particles and shows the efficiency potential of these particles.

  8. ISOLATION AND PURIFICATION OF ALKALOIDS FROM PLUMULA NELUMBINIS BY DOUBLE-COLUMN ADSORPTION CHROMOTOGRAPHY

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The performance of adsorption and separation for liensinine, isoliensinine and neferine was studied by double-column adsorption chromatography using macroporous adsorption and cation exchange resins. The alkaloid extract with 49.2% total contents by mass representing 10.6% liensinine, 10.6% isoliensinine and 28.0% neferine respectively was prepared by D72 cation exchange resins, in which most of the impurities were water-soluble alkaloids. Furthermore,the alkaloid extract with 82.6% total contents by mass containing 33.1%, 15.0% and 34.5% of the three adsorbates respectively was prepared by double-column adsorption chromatography using AKS-W macroporous adsorption and D72 cation exchange resins. As a result, the content of single and total alkaloids has been greatly increased by the double-column adsorption chromatography.

  9. ISOLATION AND PURIFICATION OF ALKALOIDS FROM PLUMULA NELUMBINIS BY DOUBLE-COLUMN ADSORPTION CHROMOTOGRAPHY

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jixiang; GUO Jinsheng; OU Lailiang

    2007-01-01

    The performance of adsorption and separation for liensinine, isoliensinine and neferine was studied by double-column adsorption chromatography using macroporous adsorption and cation exchange resins. The alkaloid extract with 49.2% total contents by mass representing 10.6% liensinine, 10.6% isoliensinine and 28.0% neferine respectively was prepared by D72 cation exchange resins, in which most of the impurities were water-soluble alkaloids. Furthermore, the alkaloid extract with 82.6% total contents by mass containing 33.1%, 15.0% and 34.5% of the three adsorbates respectively was prepared by double-column adsorption chromatography using AKS-W macroporous adsorption and D72 cation exchange resins. As a result, the content of single and total alkaloids has been greatly increased by the double-column adsorption chromatography.

  10. Pretreatment method for immunoassay of polychlorinated biphenyls in transformer oil using multilayer capillary column and microfluidic liquid-liquid partitioning.

    Science.gov (United States)

    Aota, Arata; Date, Yasumoto; Terakado, Shingo; Ohmura, Naoya

    2013-01-01

    Polychlorinated biphenyls (PCBs) are persistent organic pollutants that are present in the insulating oil inside a large number of transformers. To aid in eliminating PCB-contaminated transformers, PCBs in oil need to be measured using a rapid and cost-effective analytical method. We previously reported a pretreatment method for the immunoassay of PCBs in oil using a large-scale multilayer column and a microchip with multiple microrecesses, which permitted concentrated solvent extraction. In this paper, we report on a more rapid and facile pretreatment method, without an evaporation process, by improving the column and the microchip. In a miniaturized column, the decomposition and separation of oil were completed in 2 min. PCBs can be eluted from the capillary column at concentrations seven-times higher than those from the previous column. The total volume of the microrecesses was increased by improving the microrecess structure, the enabling extraction of four-times the amount of PCBs achieved with the previous system. By interfacing the capillary column with the improved microchip, PCBs in the eluate from the column were extracted into dimethyl sulfoxide in microrecesses with high enrichment and without the need for evaporation. Pretreatment was completed within 20 min. The pretreated oil was analyzed using a flow-based kinetic exclusion immunoassay. The limit of detection of PCBs in oil was 0.15 mg kg(-1), which satisfies the criterion set in Japan of 0.5 mg kg(-1).

  11. Dynamic Effects of Diabatization in Distillation Columns

    DEFF Research Database (Denmark)

    Bisgaard, Thomas; Huusom, Jakob Kjøbsted; Abildskov, Jens

    2012-01-01

    The dynamic eects of diabatization in distillation columns are investigated in simulation with primary focus on the heat-integrated distillation column (HIDiC). A generic, dynamic, rst-principle model has been formulated, which is exible to describe various diabatic distillation congurations....... Dynamic Relative Gain Array and Singular Value Analysis have been applied in a comparative study of a conventional distillation column and a HIDiC. The study showed increased input-output coupling due to diabatization. Feasible SISO control structures for the HIDiC were also found. Control...

  12. Dynamic effects of diabatization in distillation columns

    DEFF Research Database (Denmark)

    Bisgaard, Thomas; Huusom, Jakob Kjøbsted; Abildskov, Jens

    2013-01-01

    The dynamic effects of diabatization in distillation columns are investigated in simulation emphasizing the heat-integrated distillation column (HIDiC). A generic, dynamic, first-principle model has been formulated, which is flexible enough to describe various diabatic distillation configurations....... Dynamic Relative Gain Array and Singular Value Analysis have been applied in a comparative study of a conventional distillation column and a HIDiC. The study showed increased input-output coupling due to diabatization. Feasible SISO control structures for the HIDiC were also found and control...

  13. A SINGLE-COLUMN PROCEDURE ON BOND ELUT CERTIFY FOR SYSTEMATIC TOXICOLOGICAL ANALYSIS OF DRUGS IN PLASMA AND URINE

    NARCIS (Netherlands)

    CHEN, XH; WIJSBEEK, J; FRANKE, JP; DEZEEUW, RA

    A single-column solid-phase extraction procedure was developed for the screening of acidic, neutral, and basic drugs from plasma. The recoveries of all 25 tested drugs exceeded 82%. After the plasma had been diluted with phosphate buffer (pH 6.0), the drugs were extracted using a single Bond Elut

  14. A SINGLE-COLUMN PROCEDURE ON BOND ELUT CERTIFY FOR SYSTEMATIC TOXICOLOGICAL ANALYSIS OF DRUGS IN PLASMA AND URINE

    NARCIS (Netherlands)

    CHEN, XH; WIJSBEEK, J; FRANKE, JP; DEZEEUW, RA

    1992-01-01

    A single-column solid-phase extraction procedure was developed for the screening of acidic, neutral, and basic drugs from plasma. The recoveries of all 25 tested drugs exceeded 82%. After the plasma had been diluted with phosphate buffer (pH 6.0), the drugs were extracted using a single Bond Elut Ce

  15. 29 CFR 1926.756 - Beams and columns.

    Science.gov (United States)

    2010-07-01

    ... (.46 m) from the extreme outer face of the column in each direction at the top of the column shaft. (e) Perimeter columns. Perimeter columns shall not be erected unless: (1) The perimeter columns extend a minimum of 48 inches (1.2 m) above the finished floor to permit installation of perimeter safety cables prior...

  16. Electroosmotic Driving Liquid Using Nanosilica Packed Column

    Institute of Scientific and Technical Information of China (English)

    Ling Xin CHEN; Guo An LUO; Tao WEN

    2005-01-01

    The electroosmotic pump (EOP) using nanosilica particles packed-bed column was experimentally studied. The relationship between flowrate, pressure and applied voltage of the pump, and pressure-flowrate (P-Q) characteristic were investigated.

  17. Early development of the vertebral column.

    Science.gov (United States)

    Scaal, Martin

    2016-01-01

    The segmental organization of the vertebrate body is most obviously visible in the vertebral column, which consists of a series of vertebral bones and interconnecting joints and ligaments. During embryogenesis, the vertebral column derives from the somites, which are the primary segments of the embryonic paraxial mesoderm. Anatomical, cellular and molecular aspects of vertebral column development have been of interest to developmental biologists for more than 150 years. This review briefly summarizes the present knowledge on early steps of vertebral column development in amniotes, starting from sclerotome formation and leading to the establishment of the anatomical bauplan of the spine composed of vertebral bodies, vertebral arches, intervertebral discs and ribs, and their specific axial identities along the body axis.

  18. Modeling Tropical Precipitation in a Single Column.

    Science.gov (United States)

    Sobel, Adam H.; Bretherton, Christopher S.

    2000-12-01

    A modified formulation of the traditional single column model for representing a limited area near the equator is proposed. This formulation can also be considered a two-column model in the limit as the area represented by one of the columns becomes very large compared to the other. Only a single column is explicitly modeled, but its free tropospheric temperature, rather than its mean vertical velocity, is prescribed. This allows the precipitation and vertical velocity to be true prognostic variables, as in prior analytical theories of tropical precipitation. Two models developed by other authors are modified according to the proposed formulation. The first is the intermediate atmospheric model of J. D. Neelin and N. Zeng, but with the horizontal connections between columns broken, rendering it a set of disconnected column models. The second is the column model of N. O. Rennó, K. A. Emanuel, and P. H. Stone. In the first model, the set of disconnected column models is run with a fixed temperature that is uniform in the Tropics, and insolation, SST, and surface wind speed taken from a control run of the original model. The column models produce a climatological precipitation field that is grossly similar to that of the control run, despite that the circulation implied by the column models is not required to conserve mass. The addition of horizontal moisture advection by the wind from the control run substantially improves the simulation in dry regions. In the second model the sensitivity of the modeled steady-state precipitation and relative humidity to varying SST and wind speed is examined. The transition from shallow to deep convection is simulated in a `Lagrangian' calculation in which the column model is subjected to an SST that increases in time. In this simulation, the onset of deep convection is delayed to a higher SST than in the steady-state case, due to the effect of horizontal moisture advection (viewed in a Lagrangian reference frame). In both of the

  19. Nonlinear control of high purity distillation columns

    OpenAIRE

    Groebel, Markus; Allgöwer, Frank; Storz, Markus; Gilles, Ernst Dieter

    1994-01-01

    Two simple models of distillation columns are studied to investigate their suitability for the practical use with exact I/O-linearization. An extension of exact I/O-linearization, the asymptotically exact I/O-linearization is applied to the control of a high purity distillation column, using one of these models to derive the static state feedback law. Simulation studies demonstrate the advantage of asymptotically exact I/O-linearization versus classical exact I/O-linearization techniques. Exp...

  20. The Dissipative Column: A New Hysteretic Damper

    OpenAIRE

    Bruno Palazzo; Paolo Castaldo; Ivana Marino

    2015-01-01

    A new replaceable hysteretic damper to better control seismic building damage, consisting of two or more adjacent steel vertical elements connected to each other with continuous mild/low strength steel shear links, is proposed and investigated in this paper. New Dampers, called Dissipative Columns (DC), continuously linked with X-shaped steel plates, provide additional stiffness and damping to a lateral system by using a basic and minimally invasive construction element: the column. Working i...

  1. Fuzzy Based composition Control of Distillation Column

    Directory of Open Access Journals (Sweden)

    Guru.R

    2013-04-01

    Full Text Available This paper proposed a control scheme based on fuzzy logic for a methanol - water system of bubble cap distillation column. Fuzzy rule base and Inference System of fuzzy (FIS is planned to regulatethe reflux ratio (manipulated variable to obtain the preferred product composition (methanol for a distillation column. Comparisons are made with conventional controller and the results confirmed the potentials of the proposed strategy of fuzzy control.

  2. The handedness of historiated spiral columns.

    Science.gov (United States)

    Couzin, Robert

    2016-11-17

    Trajan's Column in Rome (AD 113) was the model for a modest number of other spiral columns decorated with figural, narrative imagery from antiquity to the present day. Most of these wind upwards to the right, often with a congruent spiral staircase within. A brief introductory consideration of antique screw direction in mechanical devices and fluted columns suggests that the former may have been affected by the handedness of designers and the latter by a preference for symmetry. However, for the historiated columns that are the main focus of this article, the determining factor was likely script direction. The manner in which this operated is considered, as well as competing mechanisms that might explain exceptions. A related phenomenon is the reversal of the spiral in a non-trivial number of reproductions of the antique columns, from Roman coinage to Renaissance and baroque drawings and engravings. Finally, the consistent inattention in academic literature to the spiral direction of historiated columns and the repeated publication of erroneous earlier reproductions warrants further consideration.

  3. Gas Chromatograph Method Optimization Trade Study for RESOLVE: 20-meter Column v. 8-meter Column

    Science.gov (United States)

    Huz, Kateryna

    2014-01-01

    RESOLVE is the payload on a Class D mission, Resource Prospector, which will prospect for water and other volatile resources at a lunar pole. The RESOLVE payload's primary scientific purpose includes determining the presence of water on the moon in the lunar regolith. In order to detect the water, a gas chromatograph (GC) will be used in conjunction with a mass spectrometer (MS). The goal of the experiment was to compare two GC column lengths and recommend which would be best for RESOLVE's purposes. Throughout the experiment, an Inficon Fusion GC and an Inficon Micro GC 3000 were used. The Fusion had a 20m long column with 0.25mm internal diameter (Id). The Micro GC 3000 had an 8m long column with a 0.32mm Id. By varying the column temperature and column pressure while holding all other parameters constant, the ideal conditions for testing with each column length in their individual instrument configurations were determined. The criteria used for determining the optimal method parameters included (in no particular order) (1) quickest run time, (2) peak sharpness, and (3) peak separation. After testing numerous combinations of temperature and pressure, the parameters for each column length that resulted in the most optimal data given my three criteria were selected. The ideal temperature and pressure for the 20m column were 95 C and 50psig. At this temperature and pressure, the peaks were separated and the retention times were shorter compared to other combinations. The Inficon Micro GC 3000 operated better at lower temperature mainly due to the shorter 8m column. The optimal column temperature and pressure were 70 C and 30psig. The Inficon Micro GC 3000 8m column had worse separation than the Inficon Fusion 20m column, but was able to separate water within a shorter run time. Therefore, the most significant tradeoff between the two column lengths was peak separation of the sample versus run time. After performing several tests, it was concluded that better

  4. 固相萃取-分散液液微萃取-柱前衍生法测定水样中痕量雌激素%Combination of Solid Phase Extraction-Dispersive Liquid Liquid Microextraction and Pre-column Derivatization Method for Determination of Trace Level Estrogens in Water Sample

    Institute of Scientific and Technical Information of China (English)

    李鱼; 刘建林; 张琛; 王夏娇

    2012-01-01

    建立了碳纳米管的固相萃取-分散液液微萃取-柱前荧光衍生化(SPE-DLLME-PFD)测定水体中痕量雌三醇(E3)、双酚A(BPA)、17α-乙炔基雌二醇(EE2)及17β-雌二醇(E2)的高效液相色谱方法.采用中心复合设计和响应曲面法分析并优化SPE、DLLME及PLD条件,最佳条件为210 mL水样以2.0 mL/min的流速过固相萃取柱(碳纳米管量30 mg),甲醇洗脱,氮气浓缩并定容至0.6 mL(分散剂),将100 μL C6MIM[PF6]与分散剂的混合液注入到NaCl含量为25%的2.0 mL去离子水中,离心,移取20 μL下层有机相于样品瓶中,与4.0 mg衍生剂混合,在40℃水浴中衍生25 min;用0.1mL甲醇溶解过量的衍生剂颗粒,取20 μL进样分析.在优化条件下.4种雌激素的线性范围为0.05~5.00 μg/L,相关系数R2=0.9966~0.9999;,检出限介于0.13~6.33 ng/L(S/N=3)之间.不同加标浓度条件下,雌激素的加标回收率在83.1%~122.4%范围内(RSD=1.7%~9.6%).在实际水样中E3和BPA检出率较高.与其它方法相比,本方法虽然萃取时间长、水样量大、步骤多,但具有检出限低、操作简便、环境友好等优点.%A method, carbon nanotubes assisted solid phase extraction combined with dispersive liquid-liquid microextration and pre-column derivatization (SPE-DLLME-PFD) , was developed for the determination of estriol (E3), bisphenol A (BPA), 17α-ethinyl estradiol (EE2) and 17β-estradiol (E2) in water samples. SPE, DLLME and PFD process was studied and optimized using central composite design and response surface plot. The optimized conditions were as follows: target estrogens were adsorbed from 210 mL aqueous samples into 30 mg carbon nanotubes at 2. 0 mL/min; methanol used as elution solution was concentrated to a volume of 0. 6 mL, which was mixed with 100 μL of C6MIM[PF6] and the blend was added to 2. 0 mL of deionized water (25. 0% NaCl, g/L). After centrifugation, 20 μL of the settled organic phase was mixed with 4. 0 mg derivating

  5. Structural Decoupling and Disturbance Rejection in a Distillation Column

    DEFF Research Database (Denmark)

    Bahar, Mehrdad; Jantzen, Jan; Commault, C.

    1996-01-01

    Introduction, distillation column model, input-output decoupling, disturbance rejection, concluding remarks, references.......Introduction, distillation column model, input-output decoupling, disturbance rejection, concluding remarks, references....

  6. One column operation for (90)Sr/(90)Y separation by using a functionalized-silica.

    Science.gov (United States)

    Lee, Jun Sig; Park, Ul-Jae; Son, Kwang-Jae; Han, Hyon-Soo

    2009-01-01

    Organo-ceramic hybrid materials have been developed as the separation media for a (90)Sr/(90)Y generator system. Currently available (90)Y is generally extracted from a mother solution by a solvent extraction or a successive column operation. Both processes are successfully applied to produce (90)Y with a high quality standard. However, such processes are highly dependent on what kind of extracting materials are employed. Hence, some of the previously developed technologies are not adequate for a (90)Y production because of a waste generation or leaching of radiolytic end-products from the extracting materials. In this study, high performance organo-ceramic hybrid materials have been applied for the extraction of (90)Y. The hybrid materials have properties of both a ceramic and a solvent extractant by molecularly implanting the extracting molecules on to the ceramic surfaces. In this study, organo-phosphorus functionalized hybrid materials are synthesized and tested as the separation media for the (90)Y/(90)Sr generator system. An adsorptive extraction with a small Sep-Pak type column can recover more than 92% of (90)Y with a contamination ratio of (90)Sr/(90)Y=1.2x10(-5) from the mother solution and 70% with 5x10(-7).

  7. Column Selection for Biomedical Analysis Supported by Column Classification Based on Four Test Parameters.

    Science.gov (United States)

    Plenis, Alina; Rekowska, Natalia; Bączek, Tomasz

    2016-01-21

    This article focuses on correlating the column classification obtained from the method created at the Katholieke Universiteit Leuven (KUL), with the chromatographic resolution attained in biomedical separation. In the KUL system, each column is described with four parameters, which enables estimation of the FKUL value characterising similarity of those parameters to the selected reference stationary phase. Thus, a ranking list based on the FKUL value can be calculated for the chosen reference column, then correlated with the results of the column performance test. In this study, the column performance test was based on analysis of moclobemide and its two metabolites in human plasma by liquid chromatography (LC), using 18 columns. The comparative study was performed using traditional correlation of the FKUL values with the retention parameters of the analytes describing the column performance test. In order to deepen the comparative assessment of both data sets, factor analysis (FA) was also used. The obtained results indicated that the stationary phase classes, closely related according to the KUL method, yielded comparable separation for the target substances. Therefore, the column ranking system based on the FKUL-values could be considered supportive in the choice of the appropriate column for biomedical analysis.

  8. Post Column Derivatization Using Reaction Flow High Performance Liquid Chromatography Columns.

    Science.gov (United States)

    Jones, Andrew; Pravadali-Cekic, Sercan; Hua, Stanley; Kocic, Danijela; Camenzuli, Michelle; Dennis, Gary; Shalliker, Andrew

    2016-04-26

    A protocol for the use of reaction flow high performance liquid chromatography columns for methods employing post column derivatization (PCD) is presented. A major difficulty in adapting PCD to modern HPLC systems and columns is the need for large volume reaction coils that enable reagent mixing and then the derivatization reaction to take place. This large post column dead volume leads to band broadening, which results in a loss of observed separation efficiency and indeed detection in sensitivity. In reaction flow post column derivatization (RF-PCD) the derivatization reagent(s) are pumped against the flow of mobile phase into either one or two of the outer ports of the reaction flow column where it is mixed with column effluent inside a frit housed within the column end fitting. This technique allows for more efficient mixing of the column effluent and derivatization reagent(s) meaning that the volume of the reaction loops can be minimized or even eliminated altogether. It has been found that RF-PCD methods perform better than conventional PCD methods in terms of observed separation efficiency and signal to noise ratio. A further advantage of RF-PCD techniques is the ability to monitor effluent coming from the central port in its underivatized state. RF-PCD has currently been trialed on a relatively small range of post column reactions, however, there is currently no reason to suggest that RF-PCD could not be adapted to any existing one or two component (as long as both reagents are added at the same time) post column derivatization reaction.

  9. Robust Matrix Completion with Corrupted Columns

    CERN Document Server

    Chen, Yudong; Caramanis, Constantine; Sanghavi, Sujay

    2011-01-01

    This paper considers the problem of matrix completion, when some number of the columns are arbitrarily corrupted, potentially by a malicious adversary. It is well-known that standard algorithms for matrix completion can return arbitrarily poor results, if even a single column is corrupted. What can be done if a large number, or even a constant fraction of columns are corrupted? In this paper, we study this very problem, and develop an efficient algorithm for its solution. Our results show that with a vanishing fraction of observed entries, it is nevertheless possible to succeed in performing matrix completion, even when the number of corrupted columns grows. When the number of corruptions is as high as a constant fraction of the total number of columns, we show that again exact matrix completion is possible, but in this case our algorithm requires many more -- a constant fraction -- of observations. One direct application comes from robust collaborative filtering. Here, some number of users are so-called mani...

  10. Retrieval of tropospheric column densities of NO2 from combined SCIAMACHY nadir/limb measurements

    Directory of Open Access Journals (Sweden)

    T. Wagner

    2009-11-01

    Full Text Available The SCIAMACHY instrument onboard the ESA satellite ENVISAT allows the retrieval of column densities of various trace gases, among them NO2. As only instrument of its kind, SCIAMACHY measures in an alternating limb/nadir mode. The limb measurements allow a direct determination of stratospheric column densities, which are needed to extract tropospheric from the total column density measurements performed in (quasi simultaneous nadir geometry. Here we discuss the potential and limitations of SCIAMACHY limb measurements for estimating stratospheric column densities of NO2 in comparison to a simple reference sector method, and the consequences for the resulting tropospheric column densities. A direct, absolute limb correction scheme improves spatial patterns of tropospheric NO2 column densities at high latitudes compared to the simple reference sector method. However, it results in artificial zonal stripes at low latitudes. Thus, also a relative limb correction scheme was defined, which turned out to successfully reduce stratospheric artefacts in the resulting tropospheric data product without introducing new ones. This relative limb correction scheme is rather simple, robust, and, in essence, based on measurements alone. The effect of the different stratospheric estimation schemes on tropospheric column densities is discussed with respect to zonal and temporal dependencies. In addition, error quantities are defined from the nadir/limb measurements which indicate remaining systematic errors as function of latitude and day. Our new suggested stratospheric estimation scheme, the relative limb correction, improves monthly mean tropospheric slant column densities significantly, e.g. from −1×1015 molec/cm2 (using a simple reference sector method to ≈0 in the Atlantic ocean, and from +1×1015 molec/cm2 to ≈0 over Siberia, at 50° N in January.

  11. Fingerprinting of traditional Chinese medicines on the C18-Diol mixed-mode column in online or offline two-dimensional liquid chromatography on the single column modes.

    Science.gov (United States)

    Wang, Qing; Tong, Ling; Yao, Lin; Zhang, Peng; Xu, Li

    2016-06-01

    In the present study, a mixed-mode stationary phase, C18-Diol, was applied for fingerprint analysis of traditional Chinese medicines. Hydrophobic, hydrogen bonding and electrostatic interactions were demonstrated to contribute the retention separately or jointly, which endowed the C18-Diol stationary phase with distinct selectivity compared to the bare C18 one. The separation of total alkaloids extracted from Fritillaria hupehensis was compared on the C18-Diol and conventional C18 column with the greater resolving power and better symmetry responses on the former one. Besides, a novel two-dimensional liquid chromatography on the single column (2D-LC-1C) was realized on C18-Diol with the offline mode for the alcohol extract of Fritillaria hupehensis and online mode for Ligusticum chuanxiong Hort. The early co-eluted extracted components with great polarity on the first dimension were reinjected on the same column and well separated on the second dimension. The results exhibited that the two complementary RPLC and HILIC modes on C18-Diol stationary phase enhanced the separation capacity and revealed more abundant chemical information of the sample, which was a powerful tool in analyzing complex herbal medicines.

  12. Buckling driven debonding in sandwich columns

    DEFF Research Database (Denmark)

    Østergaard, Rasmus Christian

    2008-01-01

    A compression loaded sandwich column that contains a debond is analyzed using a geometrically non-linear finite element model. The model includes a cohesive zone along one face sheet/core interface whereby the debond can extend by interface crack growth. Two geometrical imperfections are introduced......; a global imperfection of the sandwich column axis and a local imperfection of the debonded face sheet axis. The model predicts the sandwich column to be very sensitive to the initial debond length and the local face sheet imperfection. The study shows that the sensitivity to the face sheet imperfection...... results from two mechanisms: (a) interaction of local debond buckling and global buckling and (b) the development of a damaged zone at the debond crack tip. Based on the pronounced imperfection sensitivity, the author predicts that an experimental measurement of the strength of sandwich structures may...

  13. Non-planar microfabricated gas chromatography column

    Science.gov (United States)

    Lewis, Patrick R.; Wheeler, David R.

    2007-09-25

    A non-planar microfabricated gas chromatography column comprises a planar substrate having a plurality of through holes, a top lid and a bottom lid bonded to opposite surfaces of the planar substrate, and inlet and outlet ports for injection of a sample gas and elution of separated analytes. A plurality of such planar substrates can be aligned and stacked to provide a longer column length having a small footprint. Furthermore, two or more separate channels can enable multi-channel or multi-dimensional gas chromatography. The through holes preferably have a circular cross section and can be coated with a stationary phase material or packed with a porous packing material. Importantly, uniform stationary phase coatings can be obtained and band broadening can be minimized with the circular channels. A heating or cooling element can be disposed on at least one of the lids to enable temperature programming of the column.

  14. Computational analysis of ozonation in bubble columns

    Energy Technology Data Exchange (ETDEWEB)

    Quinones-Bolanos, E. [Univ. of Guelph, School of Engineering, Guelph, Ontario (Canada)]|[Univ. de Cartagena, Facultad de Ciencias e Ingenieria, Cartagena de Indias (Colombia); Zhou, H.; Otten, L. [Univ. of Guelph, School of Engineering, Guelph, Ontario (Canada)]. E-mail: hzhou@uoguelph.ca

    2002-06-15

    This paper presents a new computational ozonation model based on the principle of computational fluid dynamics along with the kinetics of ozone decay and microbial inactivation to predict the performance of ozone disinfection in fine bubble columns. The model can be represented using a mixture two-phase flow model to simulate the hydrodynamics of the water flow and using two transport equations to track the concentration profiles of ozone and microorganisms along the height of the column, respectively. The applicability of this model was then demonstrated by comparing the simulated ozone concentrations with experimental measurements obtained from a pilot scale fine bubble column. One distinct advantage of this approach is that it does not require the prerequisite assumptions such as plug flow condition, perfect mixing, tanks-in-series, uniform radial or longitudinal dispersion in predicting the performance of disinfection contactors without carrying out expensive and tedious tracer studies. (author)

  15. Methylmercury production in the marine water column

    Science.gov (United States)

    Topping, G.; Davies, I. M.

    1981-03-01

    Although the biosynthesis of methylmercury in sediments is well established1, this is not necessarily the exclusive natural source of methylmercury entering the marine food chain, particularly commercial fish and shellfish species for human consumption. An examination of mercury levels in freshwater fish2, collected from a lake with a history of industrial mercury contamination, suggested that levels in fish are controlled in part by mercury in suspension and it followed that methylation should occur in the water column. Although methylmercury is present in seawater in coastal areas receiving discharges of waste containing either inorganic mercury3 or methylmercury4 there is no evidence that methylmercury is actually formed in the water column. We now present data which demonstrate that inorganic mercury can be methylated in the water column and we compare this production with that known to occur in marine sediments.

  16. Neutron camera employing row and column summations

    Science.gov (United States)

    Clonts, Lloyd G.; Diawara, Yacouba; Donahue, Jr, Cornelius; Montcalm, Christopher A.; Riedel, Richard A.; Visscher, Theodore

    2016-06-14

    For each photomultiplier tube in an Anger camera, an R.times.S array of preamplifiers is provided to detect electrons generated within the photomultiplier tube. The outputs of the preamplifiers are digitized to measure the magnitude of the signals from each preamplifier. For each photomultiplier tube, a corresponding summation circuitry including R row summation circuits and S column summation circuits numerically add the magnitudes of the signals from preamplifiers for each row and for each column to generate histograms. For a P.times.Q array of photomultiplier tubes, P.times.Q summation circuitries generate P.times.Q row histograms including R entries and P.times.Q column histograms including S entries. The total set of histograms include P.times.Q.times.(R+S) entries, which can be analyzed by a position calculation circuit to determine the locations of events (detection of a neutron).

  17. Studies on Behavior and Trend Controlling of Technetium in 1A and Scrubbing Extractor

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effect of the concentration of HNO3 on distribution ratio of Tc (Ⅶ) between 30% TBP-kerosene and HNO3 solution at various ratio of U, Zr, Tc is determined. The trend and extraction behavior of Tc in 1A extractor with mixer-settler is studied. The results show that 14.4% and 27.0% of Tc is in 1AP, respectively while the concentrations of HNO3 in 1AF solution are 2 mol/L and 3 mol/L which prepared by chemicals. However after heating pretreatment of 1AF solution , 99.8% of Tc is in 1Ap while concentration of HNO3 in 1AF is 3 mol/L.Meanwhile, The HNO3 driving out method of U-Tc-Zr in efflux 1AP is studied. The aim is

  18. Accelerating selected columns of the density matrix computations via approximate column selection

    CERN Document Server

    Damle, Anil; Ying, Lexing

    2016-01-01

    Localized representation of the Kohn-Sham subspace plays an important role in quantum chemistry and materials science. The recently developed selected columns of the density matrix (SCDM) method [J. Chem. Theory Comput. 11, 1463, 2015] is a simple and robust procedure for finding a localized representation of a set of Kohn-Sham orbitals from an insulating system. The SCDM method allows the direct construction of a well conditioned (or even orthonormal) and localized basis for the Kohn-Sham subspace. The SCDM procedure avoids the use of an optimization procedure and does not depend on any adjustable parameters. The most computationally expensive step of the SCDM method is a column pivoted QR factorization that identifies the important columns for constructing the localized basis set. In this paper, we develop a two stage approximate column selection strategy to find the important columns at much lower computational cost. We demonstrate the effectiveness of this process using a dissociation process of a BH$_{3}...

  19. Final Report, Distillation Column Flooding Predictor

    Energy Technology Data Exchange (ETDEWEB)

    George E. Dzyacky

    2003-05-31

    The Flooding Predictor is an advanced process control strategy comprising a patented pattern-recognition methodology that identifies pre-flood patterns discovered to precede flooding events in distillation columns. The grantee holds a U.S. patent on the modeling system. The technology was validated at the Separations Research Program, The University of Texas at Austin under a grant from the U. S. Department of Energy, Inventions & Innovation Program. Distillation tower flooding occurs at abnormally high vapor and/or liquid rates. The loss in tray efficiencies is attributed to unusual behavior of liquid inventories inside the column leading to conditions of flooding of the space in between trays with liquid. Depending on the severity of the flood condition, consequences range from off spec products to equipment damage and tower shutdown. This non-intrusive pattern recognition methodology, processes signal data obtained from existing column instrumentation. Once the pattern is identified empirically, it is modeled and coded into the plant's distributed control system. The control system is programmed to briefly "unload" the tower each time the pattern appears. The unloading takes the form of a momentary reduction in column severity, e.g., decrease bottom temperature, reflux or tower throughput. Unloading the tower briefly at the pre-flood state causes long-term column operation to become significantly more stable - allowing an increase in throughput and/or product purity. The technology provides a wide range of value between optimization and flooding. When a distillation column is not running at capacity, it should be run in such a way ("pushed") that optimal product purity is achieved. Additional benefits include low implementation and maintenance costs, and a high level of console operator acceptance. The previous commercial applications experienced 98% uptime over a four-year period. Further, the technology is unique in its ability to distinguish between

  20. Retention Models on Core-Shell Columns.

    Science.gov (United States)

    Jandera, Pavel; Hájek, Tomáš; Růžičková, Marie

    2017-07-13

    A thin, active shell layer on core-shell columns provides high efficiency in HPLC at moderately high pressures. We revisited three models of mobile phase effects on retention for core-shell columns in mixed aqueous-organic mobile phases: linear solvent strength and Snyder-Soczewiński two-parameter models and a three-parameter model. For some compounds, two-parameter models show minor deviations from linearity due to neglect of possible minor retention in pure weak solvent, which is compensated for in the three-parameter model, which does not explicitly assume either the adsorption or the partition retention mechanism in normal- or reversed-phase systems. The model retention equation can be formulated as a function of solute retention factors of nonionic compounds in pure organic solvent and in pure water (or aqueous buffer) and of the volume fraction of an either aqueous or organic solvent component in a two-component mobile phase. With core-shell columns, the impervious solid core does not participate in the retention process. Hence, the thermodynamic retention factors, defined as the ratio of the mass of the analyte mass contained in the stationary phase to its mass in the mobile phase in the column, should not include the particle core volume. The values of the thermodynamic factors are lower than the retention factors determined using a convention including the inert core in the stationary phase. However, both conventions produce correct results if consistently used to predict the effects of changing mobile phase composition on retention. We compared three types of core-shell columns with C18-, phenyl-hexyl-, and biphenyl-bonded phases. The core-shell columns with phenyl-hexyl- and biphenyl-bonded ligands provided lower errors in two-parameter model predictions for alkylbenzenes, phenolic acids, and flavonoid compounds in comparison with C18-bonded ligands.

  1. Complex osteotomies vertebral column resection and decancellation.

    Science.gov (United States)

    Obeid, Ibrahim; Bourghli, Anouar; Boissière, Louis; Vital, Jean-Marc; Barrey, Cédric

    2014-07-01

    Pedicle subtraction osteotomy (PSO) is nowadays widely used to treat sagittal imbalance. Some complex malalignment cases cannot be treated by a PSO, whereas the imbalance is coronal or mixed or the sagittal imbalance is major and cannot be treated by a single PSO. The aim of this article was to review these complex situations--coronal imbalance, mixed imbalance, two-level PSO, vertebral column resection, and vertebral column decancellation, and to focus on their specificities. It wills also to evoke the utility of navigation in these complex cases.

  2. Column flotation in coal: does it make `cents?`

    Energy Technology Data Exchange (ETDEWEB)

    Laurila, M.J.

    1997-01-01

    Column flotation technology was introduced into the coal industry in 1986. The column can produce higher grade concentrates than conventional cells. This has created a niche market for columns in recovering ultrafine (-100 mesh) coal from waste streams. However, column flotation is much more expensive than froth flotation and columns can only process a maximum of 20 tons per hour per unit and consume more reagents than conventional cells. Researchers at Michigan Technological University have found that baffles along the axis of a column vastly improved performance. Today only two companies in the US participate in the column flotation market, ICF Kaiser and Deister.

  3. Bioretention column studies of phosphorus removal from urban stormwater runoff.

    Science.gov (United States)

    Hsieh, Chi-hsu; Davis, Allen P; Needelman, Brian A

    2007-02-01

    This study investigated the effectiveness of bioretention as a stormwater management practice using repetitive bioretention columns for phosphorus removal. Bioretention media, with a higher short-term phosphorus sorption capacity, retained more phosphorus from infiltrating runoff after 3 mg/L phosphorus loading. A surface mulch layer prevented clogging after repetitive total suspended solids input. Evidence suggests that long-term phosphorus reactions will regenerate active short-term phosphorus adsorption sites. A high hydraulic conductivity media overlaying one with low hydraulic conductivity resulted in a higher runoff infiltration rate, from 0.51 to 0.16 cm/min at a fixed 15-cm head, and was more efficient in phosphorus removal (85% mass removal) than a profile with low conductivity media over high (63% mass removal). Media extractions suggest that most of the retained phosphorus in the media layers is available for vegetative uptake and that environmental risk thresholds were not exceeded.

  4. The industrial practice and development of flotation column in China

    Energy Technology Data Exchange (ETDEWEB)

    Liu Jiongtian; Zhang Shuangquan [China Univ. of Mining and Technology, Xuzhou (China). Dept. of Energy Utilization and Chemical Engineering

    1997-12-31

    This paper reviewed the developing course of the flotation column since the 1960`s in China. Based on the practical data from several coal preparation plants, two types of flotation columns (the pressure aerated column and the jetting-cyclone column) were compared by their operation, performance and the reasons why they succeeded in the coal industry in China. The paper points out that the flotation column has come into commercial use and has good application prospects in China.

  5. A New Statistical Parameter for Identifying the Main Transition Velocities in Bubble Columns.

    Science.gov (United States)

    Nedeltchev, Stoyan; Rabha, Swapna; Hampel, Uwe; Schubert, Markus

    2015-11-01

    The identification of the main flow regime boundaries in bubble columns is essential since the degrees of mixing and mass and heat transfer vary with the flow regime. In this work, a new statistical parameter was extracted from the time series of the cross-sectional averaged gas holdup. The measurements were performed in bubble columns by means of conductivity wire-mesh sensors at very high sampling frequency. The columns were operated with an air/deionized water system under ambient conditions. As a flow regime indicator, a new dimensionless statistical parameter called "relative maximum number of visits in a region" was introduced. This new parameter is a function of the difference between the maximum numbers of visits in a region, calculated from two different division schemes of the signal range.

  6. Reducing axial mixing in flotation columns

    Energy Technology Data Exchange (ETDEWEB)

    Al Taweel, A.M.; Ramadan, A.M. [Technical Univ. of Nova Scotia, Halifax (Canada). Chemical Engineering Dept.; Moharam, M.R.; Hassan, T.A. [Al Azhar Univ., Cairo (Egypt); El Mofty, S.M. [Cairo Univ., Giza (Egypt)

    1995-10-01

    The axial mixing characteristics of a pilot-scale flotation column were investigated with the objective of identifying means to mitigate the extent of axial mixing that adversely affects its grade/recovery performance. A wide range of design and operating conditions wa investigated and the experimental results, obtained using the dynamic response method, were analyzed using three axial mixing models. The dynamic response of the column can best be described using the axial dispersion model. The results obtained suggest that the value of the axial dispersion coefficient, E{sub L}, can be significantly reduced by judicial selection of hydrodynamic conditions and/or the use of column inserts that suppress the onset of hydrodynamic instabilities inherent to the operation of conventional flotation columns. Up to 40% reduction in the value of E{sub L} was thus obtained by using spargers that produce more uniform bubble sizes, while up to 30% reductions were obtained by controlling the residual frother concentration. 33 refs., 7 figs.

  7. On Row Rank Equal Column Rank

    Science.gov (United States)

    Khalili, Parviz

    2009-01-01

    We will prove a well-known theorem in Linear Algebra, that is, for any "m x n" matrix the dimension of row space and column space are the same. The proof is based on the subject of "elementary matrices" and "reduced row-echelon" form of a matrix.

  8. Robust Geometric Control of a Distillation Column

    DEFF Research Database (Denmark)

    Kymmel, Mogens; Andersen, Henrik Weisberg

    1987-01-01

    A frequency domain method, which makes it possible to adjust multivariable controllers with respect to both nominal performance and robustness, is presented. The basic idea in the approach is that the designer assigns objectives such as steady-state tracking, maximum resonance peaks, bandwidth, m...... is used to examine and improve geometric control of a binary distillation column....

  9. The Special Column of Primate Behavior

    Institute of Scientific and Technical Information of China (English)

    Baoguo LI; Guest Editor

    2010-01-01

    @@ It is a long-term policy to publish SPECIAL COLUMNs in Current Zoology, and I am delighted that the journal is publishing this special colunm devoted to the topic of Primate Behavior. The eight papers in this seetion present significant new data and synthesize these findings with existing information on sexual selection of human-being and behaviors of living primates.

  10. Thermal Analysis of LANL Ion Exchange Column

    Energy Technology Data Exchange (ETDEWEB)

    Laurinat, J.E.

    1999-06-16

    This document reports results from an ion exchange column heat transfer analysis requested by Los Alamos National Laboratory (LANL). The object of the analysis is to demonstrate that the decay heat from the Pu-238 will not cause resin bed temperatures to increase to a level where the resin significantly degrades.

  11. "Dry-column" chromatography of plant pigments

    Science.gov (United States)

    Woeller, F. H.; Lehwalt, M. F.; Oyama, V. I.

    1973-01-01

    Separation of plant pigments which can be accomplished on thin-layer silica plates with mixture of petroleum ether, halocarbon, acetone, and polar solvent can be readily translated into dry-column technique that yields reproducible chromatograms after elution in fashion of liquid chromatography with fluorimeter as detector. Best solvent system was found to be mixture of petroleum ether, dichloromethane, acetone, and ethyl acetate.

  12. WATER COLUMN DATA AND SPECTRAL IRRADIANCE MODEL

    Science.gov (United States)

    Water samples collected monthly, for 18 months, from six sites in the Laguna Madre were analyzed to identify and quantify phytopigments using High Performance Liquid Chromatography (HPLC). In addition, water column pigment and nutrient data were acquired at 12 stations in Upper ...

  13. Flexural buckling of fire exposed aluminium columns

    NARCIS (Netherlands)

    Maljaars, J.; Twilt, L.; Soetens, F.

    2009-01-01

    In order to study buckling of fire exposed aluminium columns, a finite element model is developed. The results of this model are verified with experiments. Based on a parametric study with the finite element model, it is concluded that the simple calculation model for flexural buckling of fire expos

  14. Contexts for Column Addition and Subtraction

    Science.gov (United States)

    Lopez Fernandez, Jorge M.; Velazquez Estrella, Aileen

    2011-01-01

    In this article, the authors discuss their approach to column addition and subtraction algorithms. Adapting an original idea of Paul Cobb and Erna Yackel's from "A Contextual Investigation of Three-Digit Addition and Subtraction" related to packing and unpacking candy in a candy factory, the authors provided an analogous context by…

  15. Contexts for Column Addition and Subtraction

    Science.gov (United States)

    Lopez Fernandez, Jorge M.; Velazquez Estrella, Aileen

    2011-01-01

    In this article, the authors discuss their approach to column addition and subtraction algorithms. Adapting an original idea of Paul Cobb and Erna Yackel's from "A Contextual Investigation of Three-Digit Addition and Subtraction" related to packing and unpacking candy in a candy factory, the authors provided an analogous context by…

  16. Stabilization of Regional Column Models by Parameterized Dynamical Tendencies

    Science.gov (United States)

    Bergman, J. W.

    2002-12-01

    Atmospheric Single Column Models (SCMs) provide an efficient modeling framework for regional studies. In these models, vertical profiles of temperature and humidity evolve in response to diabatic interactions within the column and adiabatic tendencies produced by by the large scale circulation. The adiabatic tendencies are either prescribed or neglected and,thus, decoupled from the diabatic tendencies. This decoupling can lead to the rapid development of unrealistic atmospheric states. In particular, the temperature profiles from a SCM can become unrealistic enough within just a few hours to render any meaningful diagnosis difficult, if not impossible. We have implemented an SCM framework in which the adiabatic tendencies are coupled to the column physics through a formula that links vertical temperature advection to the time-history of diabatic heating rates. The parameters in any such coupling formula should depend in principle depend upon the zonal, meridional, vertical and temporal scales of the heating. In practice, however, we find that the dependence is weak over a wide range of zonal and meridional scales; the vertical dependence is accounted for in the formula itself, as is also the temporal dependence by considering the time history of the diabatic forcing rather than just instantaneous values. The effect of this dynamical coupling on the behavior of an SCM extracted from the NCAR CCM is investigated here. Because of the coupling, only the mean temperature and humidity profiles for the environment in which the column is embedded need to be explicitly specified; all other quantities are generated by the model. The coupled SCM is tested in tropical conditions during the TOGA COARE period. Control runs and 100-member ensembles, in which initial temperature and humidity profiles are perturbed, are run for environmental conditions taken from 85 sets of observed temperature and humidity profiles. The same data are also used to force the original, dynamically

  17. Determination of the sediment oxidation capacity by column and field experiments with reactive tracers

    Energy Technology Data Exchange (ETDEWEB)

    Dethlefsen, F.; Bliss, F.; Wachter, T.; Dahmke, A. [Kiel Univ. (Germany). Inst. fuer Geowissenschaften; Meckenstock, R. [Tuebingen Univ. (Germany). Zentrum fuer Angewandte Geowissenschaften

    2003-07-01

    The oxidation capacity of ferric iron in column studies was determined by phosphate tracer tests and validated by biodegradation experiments with toluene as a carbon source and the iron(III)-oxide reducing bacterium Geobacter metallireducens as well as with wet chemical extraction. Toluene mass balance, Fe(II) production and tracer test results showed that about 1/3 of the total Fe(III) mass had been reduced during the biodegradation experiment. The redox reactive tracer sulfide is supposed to be more practicable for field purposes, because a sulfide mass or electron balance enables evaluation of the tracer test. In this way, consideration of mineral specific sorption parameters and long residence periods of a sorptive reactive tracer can be avoided. Laboratory column experiments were performed with an artificially composed sediment (quartz sand and ferrihydrite) as well as with natural sediments from the margin of the benzene contaminated RETZINA test site in Zeitz (Germany). Fast reaction kinetics of sulfide with iron(III) minerals allowed the observation of a successive fixation of black iron sulfides in all the glas columns. Depending on the mineral iron content, the sedimentary oxidation capacity of the column material was used up in few days to weeks. Mass of sulfide reacted in the tracer test and sulfide mass recovered by sediment extraction after the experiment were in very good agreement. Evaluation of the column experiments confirmed the calculated ratio that 3 molar equivalents sulfide were used to reduce and fix 2 molar equivalents of Fe(III). Mean Fe(III) content of natural sediment samples (drilling SafZz 28/02 in Zeitz) was 0.35 mg/g sediment determined by laboratory sulfide tracer test and 5 M HCl extractions. Finally, a single well push-pull test was performed at the RETZINA test site Zeitz to test the applicability of the sulfide tracer in a field-scale experiment. (orig.)

  18. Isolation of lactoperoxidase using different cation exchange resins by batch and column procedures.

    Science.gov (United States)

    Fweja, Leonard Wt; Lewis, Michael J; Grandison, Alistair S

    2010-08-01

    Lactoperoxidase (LP) was isolated from whey protein by cation-exchange using Carboxymethyl resin (CM-25C) and Sulphopropyl Toyopearl resin (SP-650C). Both batch and column procedures were employed and the adsorption capacities and extraction efficiencies were compared. The resin bed volume to whey volume ratios were 0.96:1.0 for CM-25C and 0.64:1.0 for SP-650 indicating higher adsorption capacity of SP-650 compared with CM-25C. The effluent LP activity depended on both the enzyme activity in the whey and the amount of whey loaded on the column within the saturation limits of the resin. The percentage recovery was high below the saturation point and fell off rapidly with over-saturation. While effective recovery was achieved with column extraction procedures, the recovery was poor in batch procedures. The whey-resin contact time had little impact on the enzyme adsorption. SDS PAGE and HPLC analyses were also carried out, the purity was examined and the proteins characterised in terms of molecular weights. Reversed phase HPLC provided clear distinction of the LP and lactoferrin (LF) peaks. The enzyme purity was higher in column effluents compared with batch effluents, judged on the basis of the clarity of the gel bands and the resolved peaks in HPLC chromatograms.

  19. 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.

  20. Proteins Associated with the Termination of Ocular Dominance Column Plasticity in Long Evans Rats

    Institute of Scientific and Technical Information of China (English)

    Junping Yao; Zhengqin Yin; Shijun Wang

    2007-01-01

    Purpose: To investigate the mechanism of the termination of ocular dominance column plasticity by electrophysiologic analysis and 2-dimensional electrophoresis-mass spectrography (2-DE/MS).Methods: The changes in ocular dominance columns following monocular deprivation were electrophysiologically detected in 22-day-old, 100-day-old and chondroitinaseperfused 100-day-old rats. Total protein of grey matter of the primary visual cortex was extracted and studied by 2-DE/MS from the three groups of rats.Results: Monocular deprivation may lead to shifts in ocular dominance columns in 22-day-old and chondroitinase-perfused 100-day-old rats, but not in 100-day-old rats. Four protein spots present in grey matter of the primary visual cortex in 100-day-old, but not in that of 22-day-old and chondroitinase-perfused rats, and mass spectrography identified two of these proteins.Conclusions: The electrophysiologic results show that ocular dominance column plasticity presents in 22-day-old rats, ends up in 100-day-old rats and restored in chondroitinaseperfused 100-day-old rats. 2-DE/MS results show that phosphatidylethanolamine binding protein and glial fibrillary acidic protein delta may be associated with the termination of ocular dominance column plasticity in the rat, but need more evidence to confirm it.

  1. Comparison of IMAC and MOAC for phosphopeptide enrichment by column chromatography.

    Science.gov (United States)

    Negroni, Luc; Claverol, Stephane; Rosenbaum, Jean; Chevet, Eric; Bonneu, Marc; Schmitter, Jean-Marie

    2012-04-01

    Automated phosphopeptide enrichment prior to MS analysis by means of Immobilized Metal Affinity Chromatography (IMAC) and Metal Oxide Affinity Chromatography (MOAC) has been probed with packed columns. We compared POROS-Fe³⁺ and TiO₂ (respectively IMAC and MOAC media), using a simple mixture of peptides from casein-albumin and a complex mixture of peptides isolated from mouse liver. With theses samples, selectivity of POROS-Fe³⁺ and TiO₂ were pH dependant. In the case of liver extract, selectivity increased from 12-18% to 58-60% when loading buffer contained 0.1 M acetic acid or 0.1 M trifluoroacetic acid, respectively. However, with POROS-Fe³⁺ column, the number of identifications decreased from 356 phosphopeptides with 0.1 M acetic acid to 119 phosphopeptides with 0.1 M TFA. This decrease of binding capacity of POROS-Fe³⁺ was associated with strong Fe³⁺ leaching. Furthermore, repetitive use of IMAC-Fe³⁺ with the 0.5 M NH₄OH solution required for phosphopeptide elution induced Fe₂O₃ accumulation in the column. By comparison, MOAC columns packed with TiO₂ support do not present any problem of stability in the same conditions and provide a reliable solution for packed column phosphopeptide enrichment.

  2. Recent Advances and Uses of Monolithic Columns for the Analysis of Residues and Contaminants in Food

    Directory of Open Access Journals (Sweden)

    Mónica Díaz-Bao

    2015-02-01

    Full Text Available Monolithic columns are gaining interest as excellent substitutes to conventional particle-packed columns. These columns show higher permeability and lower flow resistance than conventional liquid chromatography columns, providing high-throughput performance, resolution and separation in short run times. Monoliths possess also great potential for the clean-up and preparation of complex mixtures. In situ polymerization inside appropriate supports allows the development of several microextraction formats, such as in-tube solid-phase and pipette tip-based extractions. These techniques using porous monoliths offer several advantages, including miniaturization and on-line coupling with analytical instruments. Additionally, monoliths are ideal support media for imprinting template-specific sites, resulting in the so-called molecularly-imprinted monoliths, with ultra-high selectivity. In this review, time-saving LC columns and preparative applications applied to the analysis of residues and contaminants in food in 2010–2014 are described, focusing on recent improvements in design and with emphasis in automated on-line systems and innovative materials and formats.

  3. Composite support column assembly for offshore drilling and production platforms

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, R.H.

    1989-04-18

    This patent describes a support column assembly for an offshore drilling and/or production comprising: means for anchoring the column assembly on the seabed; an elongated cylindrical support column including at least one generally cylindrical column member having a cylindrical wall formed of a composite of elongated filaments of at least one of carbon and boron bonded in a resin matrix, the support column including a plurality of the column members coupled end to end by coupling means at opposite ends of the column members, the coupling means including a plurality of radially project pins for coupling the composite wall to a coupling member interposed between the column members, respectively; and means for connecting the column to a platform for transmitting platform loads between the platform and the anchor means.

  4. Separation of rare earth by column chromatography using organic resins XAD/DEPHA

    Energy Technology Data Exchange (ETDEWEB)

    Zini, J.; Ferreira, J.C.; Bergamaschi, V.S.; Santos, I.; Carvalho, F.M.S., E-mail: jcferrei@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (CCCH/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Celulas a Combustivel e Hidrogenio

    2013-07-01

    The designation of light and heavy rare earth was used the fractionation used in separation processes. In this study the process of separation of rare earth, in groups, by chromatographic column consisting in fixing of cations these elements in an organic resin Amberlite XAD16 functionalized with the extracting agent DEPHA and another portion functionalized with a mixture of extractors DEPHA/TOP. The preparation of these resins was performed in two forms, one directly as the extracting agent to the resin and the other to be used in ethyl alcohol. Conditioned resins were introduced in chromatographic columns in separation of groups, light and heavy, using a standard solution of cerium nitrate and standard solution of holmium nitrate groups to represent light and heavy respectively. The characterization technique used to identify the rare earth elements was Spectrometry X-Ray Fluorescence (XRF). The results using the technique of chromatography were satisfactory, obtaining 100% separation of the elements. (author)

  5. Do column frits contribute to the on-column, flow-induced degradation of macromolecules?

    Science.gov (United States)

    Striegel, André M

    2014-09-12

    Flow-induced, on-column degradation is a major hindrance to the accurate characterization of ultra-high molar mass macromolecules and colloids. This degradation is a direct result of the large shear rates which are generated within the column, which cause chain scission to occur both in the interstitial medium and, it has been postulated, at the packing particle pore boundary. An additional putative source of degradation has been the column frits, though little experimental evidence exists to either support or refute this claim. To this effect, the present experiments examine the role of the frits in the degradation of high molar mass macromolecules. Two narrow dispersity polystyrene standards, the molar mass of which differs by a factor of two, were analyzed on three different size-exclusion chromatography (SEC) columns, each with frits of different pore size, at various flow rates. In the smallest pore size column, which also contained the smallest frits and which was packed with the smallest diameter particles, the larger standard was forced to degrade by increasing the flow rate of the mobile phase. During the course of the latter portion of the study, the inlet and the outlet frits were removed from the column, in stepwise fashion. It was concluded that neither frit played any appreciable role in the degradation. Results of our studies were applied to explain previously observed degradation in ultra-high pressure liquid chromatography of polymers. The general conclusion arrived at herein is that the column frits are likely to have a secondary role (as compared to interstitial and pore boundary stresses), or no role at all, in polymer degradation for cases where the frit radius is larger than or equal to the hydraulic radius rcof the column.

  6. Separation of Oil from Wastewater by Column Flotation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new type of device, a dissolved-air flotation column, was developed for separation of oily wastewater.The unique design idea of the dissolved-air flotation column is the combined use of dissolved-air flotation and column flotation.The dissolved air release occurred within the column separation system.As a potential application the column was investigated for its performance in separating emulsified oil droplets in oily wastewater.A high separation efficiency was obtained in a series of tests.The aeration performance of the bubble generator used in the dissolved-air flotation column was also studied in particular.

  7. Synchronized oscillation in a modular neural network composed of columns

    Institute of Scientific and Technical Information of China (English)

    LI; Su; QI; Xianglin; HU; Hong; WANG; Yunjiu

    2005-01-01

    The columnar organization is a ubiquitous feature in the cerebral cortex. In this study, a neural network model simulating the cortical columns has been constructed. When fed with random pulse input with constant rate, a column generates synchronized oscillations, with a frequency varying from 3 to 43 Hz depending on parameter values. The behavior of the model under periodic stimulation was studied and the input-output relationship was non-linear. When identical columns were sparsely interconnected, the column oscillator could be locked in synchrony. In a network composed of heterogeneous columns, the columns were organized by intrinsic properties and formed partially synchronized assemblies.

  8. Flow injection with in-line reduction column and conductometric detection for determination of total inorganic nitrogen in soil.

    Science.gov (United States)

    Yanu, Pattama; Jakmunee, Jaroon

    2015-11-01

    A cost effective flow injection (FI) conductometric system has been developed for determination of total inorganic nitrogen (TIN). The system is aimed for evaluation of nitrogen nutrient in soil for agricultural application. Inorganic nitrogen compounds were extracted from soil according to the standard method by using potassium chloride solution as an extractant, and the extracted solution was then injected into the FI system. Nitrate and nitrite are converted to ammonium ion by an in-line reduction column packed with a Devarda's alloy. A gas diffusion unit was incorporated into the FI system to separate ammonium ion from other ions in a donor stream by forming ammonia gas that can diffuse through a PTFE membrane to re-dissolve in an acceptor stream. Conductance of the acceptor stream was directly proportional to ammonium ion concentration. Various parameters affecting reduction efficiency of the column, e.g., column diameter, column packing procedure, and column length was investigated and optimized. A linear calibration graph in the range of 2.00-60.00 mg L(-1) N-NH4(+) (y=0.123x+0.039, R(2) =0.997) was obtained with a limit of detection of 0.47 mg L(-1). Sample throughput of 20 samples h(-1) was achieved. The result of developed method was correlated with total Kjeldahl nitrogen (TKN) obtained from the Kjeldahl digestion method. The proposed method could be used as an alternative method to the Kjeldahl method for determination of TIN in soil.

  9. Operation of a Batch Stripping Distillation Column

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A stripping batch distillation column is preferred when the amount of the light component in the feed is small and the products are to be recovered at high purity. The operation modes of a batch stripping are believed to be the same as those of a rectifier. However, the control system of a stripper is different. In this paper, we explore three different control methods with Hysys (Hyprotech Ltd. 1997) for a batch stripper. The main difference is the control scheme for reboiler liquid level: (a) controlled by reflux flow; (b) controlled by reboiler heat duty; (c) controlled by bottom product flow. The main characteristics of operating a batch stripper with different control scheme are presented in this paper. Guidelines are provided for the startup of a batch stripper, the effects of somecontrol tuning parameters on the column performance are discussed.

  10. The Dissipative Column: A New Hysteretic Damper

    Directory of Open Access Journals (Sweden)

    Bruno Palazzo

    2015-02-01

    Full Text Available A new replaceable hysteretic damper to better control seismic building damage, consisting of two or more adjacent steel vertical elements connected to each other with continuous mild/low strength steel shear links, is proposed and investigated in this paper. New Dampers, called Dissipative Columns (DC, continuously linked with X-shaped steel plates, provide additional stiffness and damping to a lateral system by using a basic and minimally invasive construction element: the column. Working in a way similar to coupled shear walls, the proposed element behavior is theoretically analyzed at linear and non-linear ranges. In fact, considering different restrained cases, a parametric analysis is developed in order both to evaluate the effect of the main geometrical and structural parameters and to provide the design capacity curves of this new damper. The DC can be considered a new damping device, easy to install in new as well as existing buildings in order to protect them from seismic damage.

  11. Pressure drop in CIM disk monolithic columns.

    Science.gov (United States)

    Mihelic, Igor; Nemec, Damjan; Podgornik, Ales; Koloini, Tine

    2005-02-11

    Pressure drop analysis in commercial CIM disk monolithic columns is presented. Experimental measurements of pressure drop are compared to hydrodynamic models usually employed for prediction of pressure drop in packed beds, e.g. free surface model and capillary model applying hydraulic radius concept. However, the comparison between pressure drop in monolith and adequate packed bed give unexpected results. Pressure drop in a CIM disk monolithic column is approximately 50% lower than in an adequate packed bed of spheres having the same hydraulic radius as CIM disk monolith; meaning they both have the same porosity and the same specific surface area. This phenomenon seems to be a consequence of the monolithic porous structure which is quite different in terms of the pore size distribution and parallel pore nonuniformity compared to the one in conventional packed beds. The number of self-similar levels for the CIM monoliths was estimated to be between 1.03 and 2.75.

  12. Modeling of Crystalline Silicotitanate Ion Exchange Columns

    Energy Technology Data Exchange (ETDEWEB)

    Walker, D.D.

    1999-03-09

    Non-elutable ion exchange is being considered as a potential replacement for the In-Tank Precipitation process for removing cesium from Savannah River Site (SRS) radioactive waste. Crystalline silicotitanate (CST) particles are the reference ion exchange medium for the process. A major factor in the construction cost of this process is the size of the ion exchange column required to meet product specifications for decontaminated waste. To validate SRS column sizing calculations, SRS subcontracted two reknowned experts in this field to perform similar calculations: Professor R. G. Anthony, Department of Chemical Engineering, Texas A&038;M University, and Professor S. W. Wang, Department of Chemical Engineering, Purdue University. The appendices of this document contain reports from the two subcontractors. Definition of the design problem came through several meetings and conference calls between the participants and SRS personnel over the past few months. This document summarizes the problem definition and results from the two reports.

  13. Bioleaching of low grade nickel sulfide mineral in column reactor

    Institute of Scientific and Technical Information of China (English)

    ZHEN Shi-jie; QIN Wen-qing; YAN Zhong-qiang; ZHANG Yan-sheng; WANG Jun; REN Liu-yi

    2008-01-01

    Jinchuan low grade nickel (0.4%-0.6% Ni,mass fraction) sulfide mineral ore contains a remarkably high content of magnesia (30%-35% MgO,mass fraction) present in the main gangue minerals.Bioleaching was performed to investigate the feasibility to process the mineral due to its relative simplicity,eco-friendly operation and low capital cost requirements.The mixed mesophiles were enriched from acid mine drainage samples collected from several acid mines in China.Considering that the magnesia is easily extracted by acid solution and the excessive Mg2+ will exceed the tolerance of the mixed mesophiles,three effective means were used to reduce the disadvantage of magnesia during the bioleaching operation.They were adaptation of the mixed mesophiles to improve the tolerance; pre-leaching to remove most leachable magnesia and periodic bleeds of a portion of the pregnant leaching solution to control the level of Mg2+ based on the tolerance of the mixed mesophiles.An extraction of nickel (90.3%) and cobalt (88.6%) was successfully achieved within a 300 d leaching process from the Jinchuan low grade nickel sulfide mineral ore using a column reactor at ambient temperature.

  14. Heavy Metals in a Sulfidic Minespoil: Fractions and Column Leaching

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Fractions of various heavy metals in a sulfidic minespoil were investigated. Column leaching experimentwas also conducted to simulate "acid mine drainage" (AMD) from the minespoil. The results show thatleaching of heavy metals from the minespoil was extremely significant during the initial water flushing.The amounts of heavy metals leached out dramatically reduced after leaching twice. It is worthwhile tonote that in this study, Zn, Mn, Fe, As and Ni in the first leachate exceeded the total amount of eachcorresponding water-extractable (1:5, soil:water) metal contained in the minespoil sample. This appears tosuggest that 1:5 water extraction did not allow accurate estimation of water-leachable concentrations of theabove heavy metals. This work has implications for the management of sulfidic minespoils. Acid drainageof great environmental concerns is likely to occur only during heavy rainfall events after substantial solubleand readily exchangeable acid and metals are accumulated in the minespoils. The slow-reacting fractionsother than water-soluble and readily exchangeable fractions may pose little environmental hazards. This isparticularly true for Pb, As and Ni.

  15. Water Column Variability in Coastal Regions

    Science.gov (United States)

    2016-06-07

    offshore waters of energy, mass, and biota. OBJECTIVES Our objective is to determine the processes that cause water column variations in coastal regions...meteorological conditions (solar radiation, wind velocity, and heat fluxes), (iv) tidal mixing, stratification, water mass variations, (v) runoff from land...air-sea gas exchange and biological activity in these offshore waters. Two papers are being submitted to Limnology and Oceanography on the annual

  16. COLLISIONS OF ROAD VEHICLES WITH BRIDGE COLUMNS

    OpenAIRE

    2015-01-01

    As speed limits and traffic on city roads continue to increase, collisions between road vehicles and bridge columns are becoming more common. Current regulations analyze collision with one major simplification: replacing dynamic action with the equivalent static force. In the present paper, we develop a numerical model of a typical Croatian overpass and loaded it with an equivalent static load according to the EN1991-7 and ASSHTO LRFD provisions, analyzing the differences in overpass behavior...

  17. Using Dividing Wall Columns (DWC) in LNG Production: deviding wall column, double dividing wall column, prefractionator arrangement, Petlyuk column, NGL recovery, distillation

    OpenAIRE

    Ashrafian, Roohollah

    2014-01-01

    The Dividing Wall Columns (DWC) distillation has attracted growing interest for fractionation of multicomponent mixture due to reduction of energy consumption, auxiliary equipment and space within fractionation process. Recent developments of the process show considerable energy saving, up to 30%-40%, compared to conventional fractionation schemes. The objective of this thesis is to introduce DWC configurations, governing equations and applications in LNG and gas processing as well as explana...

  18. [Cervical vertebral column--anatomy, fractures, treatment].

    Science.gov (United States)

    Kłosiński, Michał; Sienkiewicz-Zawilińska, Justyna; Lipski, Marcin; Zawiliński, Jarosław; Matyja, Andrzej; Walocha, Jerzy

    2009-01-01

    The paper deals with anatomy of human cervical spine. It shows close relation between knowledge on the normal structure and methods of treatment of different kinds of spine injuries. It describes detailed anatomy and mechanical features of cervical vertebral column, including the structure of distinct vertebrae, their joints and arrangement of muscles. It reviews also historical methods of treatment of fractures in this region considering current methods.

  19. SVD row or column symmetric matrix

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new architecture for row or column symmetric matrix called extended matrix is defined, and a precise correspondence of the singular values and singular vectors between the extended matrix and its original (namely, the mother matrix) is derived. As an illustration of potential, we show that, for a class of extended matrices, the singular value decomposition using the mother matrix rather than the extended matrix per se can save the CPU time and memory without loss of numerical precision.

  20. Plant practices in fine coal column flotation

    Energy Technology Data Exchange (ETDEWEB)

    Davis, V.L. Jr.; Bethell, P.J.; Stanley, F.L. [Pittston Coal Management Co., Lebanon, VA (United States); Luttrell, G.H. [Virginia Polytechnic Institute and State Univ., Blacksburg, VA (United States). Dept. of Mining and Minerals Engineering

    1995-10-01

    Five 3 m (10 ft) diameter Microcel{trademark} flotation columns were installed at Clinchfield Coal Company`s Middle Fork preparation facility in order to reduce product ash and increase recovery and plant capacity. The Middle Fork facility is utilized for the recovery of fine coal from a feed stream that consists primarily of 1.5 mm x 0 material. The columns replaced conventional flotation cells for the treatment of the minus 150 {micro}m fraction while spirals are used to upgrade the plus 150 {micro}m material in the plant feed. The addition of the column flotation circuit resulted in an increase in plant capacity in excess of 20 percent while reducing the flotation product ash content by approximately 7 percentage points. Flotation circuit combustible recovery wa increased by 17 percentage points. This paper discusses circuit design, commissioning, and sparging system design. Circuit instrumentation, level control, reagent system control, performance comparisons with conventional flotation, and general operating procedures are also discussed.

  1. Seepage characteristics of collapse column fillings

    Institute of Scientific and Technical Information of China (English)

    Zhang Boyang; Bai Haibo; Zhang Kai

    2016-01-01

    With concealment and hysteresis, water-inrush from Karst collapse column has become an important security hazard of lower group coal mining in North China. Based on the MTS815.02 seepage test system, we analyzed the impact of consolidation pressure, initial moisture content and confining pressure on the permeability of fillings in order to study the seepage characteristics of collapse column fillings. The results show that:(1) The permeability of collapse column fillings is of the order of 10?16–10?15 magni-tude and decreases with an increase in consolidation pressure and decrease in initial moisture content. (2) The essence of filling seepage law change is the change in porosity, and a power function relationship exists between the permeability ratio and porosity ratio. (3) With increasing confining pressure, the per-meability of fillings decreases. However, under low confining pressure (1.2–4 MPa), the change of confin-ing pressure has no obvious influence on the permeability.

  2. SPEEDUP{trademark} ion exchange column model

    Energy Technology Data Exchange (ETDEWEB)

    Hang, T.

    2000-03-06

    A transient model to describe the process of loading a solute onto the granular fixed bed in an ion exchange (IX) column has been developed using the SpeedUp{trademark} software package. SpeedUp offers the advantage of smooth integration into other existing SpeedUp flowsheet models. The mathematical algorithm of a porous particle diffusion model was adopted to account for convection, axial dispersion, film mass transfer, and pore diffusion. The method of orthogonal collocation on finite elements was employed to solve the governing transport equations. The model allows the use of a non-linear Langmuir isotherm based on an effective binary ionic exchange process. The SpeedUp column model was tested by comparing to the analytical solutions of three transport problems from the ion exchange literature. In addition, a sample calculation of a train of three crystalline silicotitanate (CST) IX columns in series was made using both the SpeedUp model and Purdue University's VERSE-LC code. All test cases showed excellent agreement between the SpeedUp model results and the test data. The model can be readily used for SuperLig{trademark} ion exchange resins, once the experimental data are complete.

  3. Modular evolution of the Cetacean vertebral column.

    Science.gov (United States)

    Buchholtz, Emily A

    2007-01-01

    Modular theory predicts that hierarchical developmental processes generate hierarchical phenotypic units that are capable of independent modification. The vertebral column is an overtly modular structure, and its rapid phenotypic transformation in cetacean evolution provides a case study for modularity. Terrestrial mammals have five morphologically discrete vertebral series that are now known to be coincident with Hox gene expression patterns. Here, I present the hypothesis that in living Carnivora and Artiodactyla, and by inference in the terrestrial ancestors of whales, the series are themselves components of larger precaudal and caudal modular units. Column morphology in a series of fossil and living whales is used to predict the type and sequence of developmental changes responsible for modification of that ancestral pattern. Developmental innovations inferred include independent meristic additions to the precaudal column in basal archaeocetes and basilosaurids, stepwise homeotic reduction of the sacral series in protocetids, and dissociation of the caudal series into anterior tail and fluke subunits in basilosaurids. The most dramatic change was the novel association of lumbar and anterior caudal vertebrae in a module that crosses the precaudal/caudal boundary. This large unit is defined by shared patterns of vertebral morphology, count, and size in all living whales (Neoceti).

  4. Dynamics of a Tapped Granular Column

    Science.gov (United States)

    Rosato, Anthony; Blackmore, Denis; Zuo, Luo; Hao, Wu; Horntrop, David

    2015-11-01

    We consider the behavior of a column of spheres subjected to a time-dependent vertical taps. Of interest are various dynamical properties, such as the motion of its mass center, its response to taps of different intensities and forms, and the effect of system size and material properties. The interplay between diverse time and length scales are the key contributors to the column's evolving dynamics. Soft sphere discrete element simulations were conducted over a very wide parameter space to obtain a portrait of column behavior as embodied by the collective dynamics of the mass center motion. Results compared favorably with a derived reduced-order paradigm of the mass center motion (surprisingly analogous to that for a single bouncing ball on an oscillating plate) with respect to dynamical regimes and their transitions. A continuum model obtained from a system of Newtonian equations, as a locally averaged limit in the transport mode along trajectories is described, and a numerical solution protocol for a one-dimensional system is outlined. Typical trajectories and density evolution profiles are shown. We conclude with a discussion of our investigations to relate predictions of the continuum and reduced dynamical systems models with discrete simulations.

  5. Behavior of high strength concrete columns under eccentric loads

    Directory of Open Access Journals (Sweden)

    Hany A. Kottb

    2015-04-01

    Full Text Available In recent decades, high strength concrete (HSC has been widely accepted by designers and contractors to be used in concrete structures, especially in high compressive stress elements. The research aims to study the behavior of high strength concrete columns under eccentric compression using experimental and analytical programs. The research is divided into two main parts; the first part is an experimental investigation for ten square columns tested at the Cairo University Concrete Research Laboratory. The main studied parameters were eccentricity of the applied load, column slenderness ratio; and ratios of longitudinal and transverse reinforcement. The second part is analytical analysis using nonlinear finite element program ANSYS11 on nineteen columns (ten tested square columns and nine rectangular section columns to study the effect of the previous parameters on the column ultimate load, mid-height displacement, and column cracking patterns. The analyzed columns revealed a good agreement with the experimental results with an average difference of 16% and 17% for column ultimate load and mid-height displacement respectively. Results showed an excellent agreement for cracking patterns. Predictions of columns capacities using the interaction diagrams based on ACI 318-08 stress block parameters indicated a safe design procedure of HSC columns under eccentric compression, with ACI 318-08 being more conservative for moderate reinforced HSC columns.

  6. Separation optimization of long porous-layer open-tubular columns for nano-LC-MS of limited proteomic samples.

    Science.gov (United States)

    Rogeberg, Magnus; Vehus, Tore; Grutle, Lene; Greibrokk, Tyge; Wilson, Steven Ray; Lundanes, Elsa

    2013-09-01

    The single-run resolving power of current 10 μm id porous-layer open-tubular (PLOT) columns has been optimized. The columns studied had a poly(styrene-co-divinylbenzene) porous layer (~0.75 μm thickness). In contrast to many previous studies that have employed complex plumbing or compromising set-ups, SPE-PLOT-LC-MS was assembled without the use of additional hardware/noncommercial parts, additional valves or sample splitting. A comprehensive study of various flow rates, gradient times, and column length combinations was undertaken. Maximum resolution for LC conditions or long silica monolith nanocolumns. Nearly 500 proteins (1958 peptides) could be identified in just one single injection of an extract corresponding to 1000 BxPC3 beta catenin (-/-) cells, and ~1200 and 2500 proteins in extracts of 10,000 and 100,000 cells, respectively, allowing detection of central members and regulators of the Wnt signaling pathway.

  7. Tooth extraction

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007630.htm Tooth extraction To use the sharing features on this page, please enable JavaScript. A tooth extraction is a procedure to remove a tooth from ...

  8. Supercritical fluid extraction of vapor-deposited pyrene from carbonaceous coal stack ash.

    Science.gov (United States)

    Mauldin, R F; Vienneau, J M; Wehry, E L; Mamantov, G

    1990-11-01

    The efficiencies of extraction of vapor-deposited pyrene from a high-carbon coal stack ash by Soxhlet extraction with methanol, ultrasonic extraction with toluene, acid pretreatment and subsequent ultrasonic extraction with toluene, batch extraction with toluene, and supercritical fluid extraction (SFE) are compared. SFE using CO(2) or isobutane yielded extraction recoveries virtually identical with those obtained using ultrasonic or Soxhlet extraction processes. Collection of the SFE extract was performed by expansion into a solvent or onto the head of a gas chromatography (GC) column. No loss of extracted pyrene was observed upon collection of methanol-modified CO(2) SFE by expansion into methanol. Also, no loss of pure CO(2) SFE extract was observed upon collection on the head of a GC column. However, use of a methanol or toluene modifier for CO(2) SFE directly coupled to GC effected complete loss of extracted pyrene.

  9. Experimental Testing Of Partially Encased Composite Beam Columns

    Directory of Open Access Journals (Sweden)

    Ehab M. Hanna

    2016-01-01

    Full Text Available The past few decades have seen outstanding advances in the use of composite materials in structural applications. There can be little doubt that, within engineering circles, composites have revolutionized traditional design concepts and made possible an unparalleled range of new and exciting possibilities as viable materials for construction. In addition to the well-known advantages of composite columns, partially encased composite columns offered simplified beam-to-column connection as well as reduced or omitted shuttering thus achieved more cost effective construction. Some companies have patented these new types of partially encased composite column made of light welded steel shapes; moreover, the Canadian Institute of Steel construction CISC has recognized and codified this type of columns. In This paper, Partially Encased Composite Beam Columns is introduced; experimental studies are made on five partially encased beam columns to investigate the behavior of eccentrically loaded partially encased composite columns using different parameters.

  10. Composition Estimation in Dividing-Wall Columns Using Temperature Measurements

    OpenAIRE

    Ghadrdan, Maryam; Ivar J. Halvorsen; Skogestad, Sigurd

    2011-01-01

    In this work, we propose a method to estimate the product compositions in a distillation column section based on a combination of a number of temperature measurements from different locations in the column stages.

  11. TOXICOLOGICAL ANALYSIS OF WHOLE-BLOOD SAMPLES BY MEANS OF BOND-ELUT CERTIFY COLUMNS AND GAS-CHROMATOGRAPHY WITH NITROGEN-PHOSPHORUS DETECTION

    NARCIS (Netherlands)

    ZWEIPFENNING, PGM; WILDERINK, AHCM; HORSTHUIS, P; FRANKE, JP; DEZEEUW, RA

    1994-01-01

    The application of Bond-Elut Certify solid-phase extraction columns to the systematic toxicological analysis of whole blood was evaluated. The reproducibility of the extraction was tested with thirteen drugs varying in physico-chemical properties. Analysis was performed with capillary gas chromatogr

  12. TOXICOLOGICAL ANALYSIS OF WHOLE-BLOOD SAMPLES BY MEANS OF BOND-ELUT CERTIFY COLUMNS AND GAS-CHROMATOGRAPHY WITH NITROGEN-PHOSPHORUS DETECTION

    NARCIS (Netherlands)

    ZWEIPFENNING, PGM; WILDERINK, AHCM; HORSTHUIS, P; FRANKE, JP; DEZEEUW, RA

    1994-01-01

    The application of Bond-Elut Certify solid-phase extraction columns to the systematic toxicological analysis of whole blood was evaluated. The reproducibility of the extraction was tested with thirteen drugs varying in physico-chemical properties. Analysis was performed with capillary gas

  13. Numerical Simulations of Settlement of Jet Grouting Columns

    Directory of Open Access Journals (Sweden)

    Juzwa Anna

    2016-03-01

    Full Text Available The paper presents the comparison of results of numerical analyses of interaction between group of jet grouting columns and subsoil. The analyses were conducted for single column and groups of three, seven and nine columns. The simulations are based on experimental research in real scale which were carried out by authors. The final goal for the research is an estimation of an influence of interaction between columns working in a group.

  14. Anchoring FRP laminates for the seismic strengthening of RC columns

    OpenAIRE

    Sadone, Raphaëlle; Quiertant, Marc; FERRIER, Emmanuel; Chataigner, Sylvain; Mercier, Julien

    2012-01-01

    This paper aims to examine the effectiveness of seismic strengthening of reinforced concrete (RC) columns by externally bonded Fibre Reinforced Polymer (FRP). Particularly, a novel strengthening system, designed for the flexural strengthening of columns is studied. This flexural strengthening is achieved by FRP plates bonded longitudinally and anchored at the column-stub junction. The proposed system is validated through an experimental campaign carried out on full-scale RC columns. Different...

  15. Flexural strength enhancement of confined reinforced concrete columns

    OpenAIRE

    Pam, HJ; Ho, JCM

    2001-01-01

    As part of a continuing research study, this paper proposes a new design aid to calculate the actual moment capacity of confined reinforced concrete columns. Up to now the moment capacity of a reinforced concrete column is calculated based on the code's guidelines for an unconfined section. As most reinforced concrete columns contain transverse or confining reinforcement, which will enhance the column moment capacity, the actual moment capacity will be much higher than the unconfined moment c...

  16. QR factorization for row or column symmetric matrix

    Institute of Scientific and Technical Information of China (English)

    ZOU; Hongxing(邹红星); WANG; Dianjun(王殿军); DAI; Qionghai(戴琼海); LI; Yanda(李衍达)

    2003-01-01

    The problem of fast computing the QR factorization of row or column symmetric matrix isconsidered. We address two new algorithms based on a correspondence of Q and R matrices between the rowor column symmetric matrix and its mother matrix. Theoretical analysis and numerical evidence show that, fora class of row or column symmetric matrices, the QR factorization using the mother matrix rather than therow or column symmetric matrix per se can save dramatically the CPU time and memory without loss of anynumerical precision.

  17. Enhanced phytoremediation in the vadose zone: Modeling and column studies

    Science.gov (United States)

    Sung, K.; Chang, Y.; Corapcioglu, M.; Cho, C.

    2002-05-01

    Phytoremediation is a plant-based technique with potential for enhancing the remediation of vadoese zone soils contaminated by pollutants. The use of deep-rooted plants is an alternative to conventional methodologies. However, when the phytoremediation is applied to the vadose zone, it might have some restrictions since it uses solely naturally driven energy and mechanisms in addition to the complesxity of the vadose zone. As a more innovative technique than conventional phytoremediation methods, air injected phytoremediation technique is introduced to enhance the remediation efficiency or to apply at the former soil vapor extraction or bio venting sites. Effects of air injection, vegetation treatment, and air injection with vegetation treatments on the removal of hydrocarbon were investigated by column studies to simulate the field situation. Both the removal efficiency and the microbial activity were highest in air-injected and vegetated column soils. It was suggested that increased microorganisms activity stimulated by plant root exudates enhanced biodegradation of hydrocarbon compounds. Air injection provided sufficient opportunity for promoting the microbial activity at depths where the conditions are anaerobic. Air injection can enhance the physicochemical properties of the medium and contaminant and increase the bioavailability i.e., the plant and microbial accessibility to the contaminant. A mathematical model that can be applied to phytoremediation, especially to air injected phytoremediation, for simulating the fate and the transport of a diesel contaminant in the vadose zone is developed. The approach includes a two-phase model of water flow in vegetated and unplanted vadose zone soil. A time-specific root distribution model and a microbial growth model in the rhizosphere of vegetated soil were combined with an unsaturated soil water flow equation as well as with a contaminant transport equation. The proposed model showed a satisfactory representation of

  18. 45Ti extraction using hydroxamate resin

    DEFF Research Database (Denmark)

    Gagnon, K.; Severin, Gregory; Barnhart, T. E.

    2012-01-01

    As an attractive radionuclide for positron emission tomography, this study explores the extraction and reactivity of 45Ti produced via the 45Sc(p,n)45Ti reaction on a GE PETtrace. Using a small hydroxamate column, we have demonstrated an overall recovery of >50% of 45Ti in ~1 mL of 1M oxalic acid...

  19. DNA extraction from keratin and chitin.

    Science.gov (United States)

    Campos, Paula F; Gilbert, Thomas M P

    2012-01-01

    DNA extracted from keratinous and chitinous materials can be a useful source of genetic information. To effectively liberate the DNA from these materials, buffers containing relatively high levels of DTT, proteinase K, and detergent are recommended, followed by purification using either silica-column or organic methods.

  20. Behavior of reinforced concrete columns strenghtened by partial jacketing

    Directory of Open Access Journals (Sweden)

    D. B. FERREIRA

    Full Text Available This article presents the study of reinforced concrete columns strengthened using a partial jacket consisting of a 35mm self-compacting concrete layer added to its most compressed face and tested in combined compression and uniaxial bending until rupture. Wedge bolt connectors were used to increase bond at the interface between the two concrete layers of different ages. Seven 2000 mm long columns were tested. Two columns were cast monolithically and named PO (original column e PR (reference column. The other five columns were strengthened using a new 35 mm thick self-compacting concrete layer attached to the column face subjected to highest compressive stresses. Column PO had a 120mm by 250 mm rectangular cross section and other columns had a 155 mm by 250mm cross section after the strengthening procedure. Results show that the ultimate resistance of the strengthened columns was more than three times the ultimate resistance of the original column PO, indicating the effectiveness of the strengthening procedure. Detachment of the new concrete layer with concrete crushing and steel yielding occurred in the strengthened columns.

  1. Self-organizing strategies for a column-store database

    NARCIS (Netherlands)

    Ivanova, M.G.; Kersten, M.L.; Nes, N.J.

    2008-01-01

    Column-store database systems open new vistas for improved maintenance through self-organization. Individual columns are the focal point, which simplify balancing conflicting requirements. This work presents two workload-driven self-organizing techniques in a column-store, i.e. adaptive segmentation

  2. Mechanistic model for dispersion coefficients in bubble column

    CSIR Research Space (South Africa)

    Skosana, PJ

    2015-05-01

    Full Text Available A mechanistic model describing the mass and momentum exchange in bubble columns is proposed that is based on the observations that the gas distribution in a bubble column is not uniform across the column and that as a consequence large liquid...

  3. Quantitative determination of 11-nor-9-carboxy-tetrahydrocannabinol in hair by column switching LC-ESI-MS(3).

    Science.gov (United States)

    Park, Meejung; Kim, Jihyun; Park, Yuran; In, Sanghwan; Kim, Eunmi; Park, Yonghoon

    2014-02-01

    Hair analysis has been regarded as an alternative method to urine analysis in forensic and criminal cases. Cannabis (marijuana) is one of the most widely used drugs in the world and it has been controlled in South Korea since 1976. Identification of 11-nor-9-carboxy-tetrahydrocannabinol (THCCOOH) in hair can be an important proof of cannabis use because it can exclude the possibility of passive cannabis smoke exposure. In this study, we described a quantitative method of THCCOOH in hair using simple liquid-liquid extraction (LLE), selective column switching liquid chromatography with electrospray ionization (ESI)-MS(3). For the column switching system three columns (precolumn, trap column and analytical column) were used. Valve switch from the precolumn to the trap column was set from 3.0 to 4.0 min because THCCOOH appeared around 3.5 min with this precolumn. After 4.0 min the valve was switched to the original position and the analytes in the trap column were eluted onto the analytical column. Resolution occurred in this column and eluted into the ESI-MS(3) system. The internal standard was THCCOOH-d3. We used ESI-negative-MS(3) transition of ions at m/z 343 to 299 to 245 (343/299/245) and m/z 346 to 302 to 248 (346/302/248) for quantification of THCCOOH and THCCOOH-d3, respectively. The validation results of selectivity, matrix effect, recovery, linearity, precision and accuracy, and processed sample stability were satisfactory. The limit of detection (LOD) was 0.05 pg/mg and the limit of quantification (LOQ) was 0.10 pg/mg. The range of concentration of THCCOOH from 98 authentic human hair was 0.13-15.75 pg/mg. This method was successfully applied in the analysis of authentic human hair samples.

  4. Comparison between a spray column and a sieve tray column operating as liquid-liquid heat exchangers

    Science.gov (United States)

    Keller, A. S.; Jacobs, H. R.; Boehm, R. F.

    The reported investigation was conducted in connection with research intended to improve the efficiency of direct contact devices for geothermal and solar applications. The investigation had the objective to evaluate the effect of adding sieve trays to the laboratory column used in studies concerned with the development of models for spray column heat transfer. Hot water is pumped from a supply vessel into the top of the heat exchanger column where, as the continuous phase, it flows down through the column. The dispersed phase is kerosene. Using an identical pump to that used for the water, the kerosene flows into a dispersion plate in the bottom of the column. The droplets rise through the column and coalesce at the top. It was found that the heat transfer performance of the perforated plate column was significantly improved over that in a spray column for similar operating conditions.

  5. Enhanced nitrobenzene removal and column longevity by coupled abiotic and biotic processes in zero-valent iron column

    DEFF Research Database (Denmark)

    Yin, Weizhao; Wu, Jinhua; Huang, Weilin;

    2015-01-01

    /or co-precipitation and the reduction of NB to aniline (AN) via abiotic reaction in the abiotic column and via both abiotic and biotic reactions in the biotic column. Due to the interactive effect of ZVI and microorganisms, more effective iron consumption and more reactive minerals such as green rust......In this study, abiotic zero-valent iron (ZVI) column and biotic ZVI column were employed to investigate abiotic and biotic effects between iron and microorganisms on NB removal and column longevity. Physical removal and kinetics analysis revealed that NB was largely removed through adsorption and...... and iron sulfide were found in the biotic column. This led to approximately 50% higher total NB removal and 6 times higher AN production in the biotic column as compared to the abiotic column during the entire operation. According to the NB breakthrough curves, longer stability and longer life...

  6. Column: The Physics of Digital Information

    Directory of Open Access Journals (Sweden)

    Fred Cohen

    2011-09-01

    Full Text Available One of the interesting questions underlying creating a science of digital forensics is what form that science might take. At the end of the IEEE Oakland Conference in 2011, I presented some of the underlying questions and identified my approach and why I favored it.2 My basic position is that science is about causality and a scientific theory should require that cause(C produces effect (E via mechanism M (written C→ME. The scientific method then identifies the criteria for rejecting (refuting or accepting (for a time a scientific theory.(see PDF for full column

  7. Lattice approaches to packed column simulations

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This work presents a review of the findings into the ability of a digitally based particle packing algorithm, called DigiPac, to predict bed structure in a variety of packed columns, for a range of generic pellet shapes frequently used in the chemical and process engineering industries.Resulting macroscopic properties are compared with experimental data derived from both invasive and non-destructive measurement techniques.Additionally, fluid velocity distributions, through samples of the resulting bed structures, are analysed using lattice Boltzmann method (LBM) simulations and are compared against experimental data from the literature.

  8. Hydrodynamic Study Of Column Bioleaching Processes

    Directory of Open Access Journals (Sweden)

    Sadowski Zygmunt

    2015-06-01

    Full Text Available The modelling of flow leaching solution through the porous media has been considered. The heap bioleaching process can be tested using the column experimental equipment. This equipment was employed to the hydrodynamic studies of copper ore bioleaching. The copper ore (black shale ore with the support, inertial materials (glass small balls and polyethylene beads was used to the bioleaching tests. The packed beds were various composition, the ore/support ratio was changed. The correlation between the bed porosity and bioleaching kinetics, and copper recovery was investigated.

  9. Preinjector for Linac 1, accelerating column

    CERN Multimedia

    1974-01-01

    For a description of the Linac 1 preinjector, please see first 7403070X. High up on the wall of the Faraday cage (7403073X) is this drum-shaped container of the ion source (7403083X). It is mounted at the HV end of the accelerating column through which the ions (usually protons; many other types of ions in the course of its long history) proceed through the Faraday cage wall to the low-energy end (at ground potential) of Linac 1. The 520 kV accelerating voltage was supplied by a SAMES generator (7403074X).

  10. EMERGING TECHNOLOGY BULLETIN: NEW JERSEY INSTITUTE OF TECHNOLOGY - GHEA ASSOCIATES PROCESS

    Science.gov (United States)

    The GHEA Associates process applies surfactants and additives to soil washing and wastewater treatment to make organic and metal contaminants soluble (figure 1). The process components include a 25-gal extractor, solid liquid separation, rinse, mixer-settler, and ultrafiltration ...

  11. The maximum force in a column under constant speed compression

    CERN Document Server

    Kuzkin, Vitaly A

    2015-01-01

    Dynamic buckling of an elastic column under compression at constant speed is investigated assuming the first-mode buckling. Two cases are considered: (i) an imperfect column (Hoff's statement), and (ii) a perfect column having an initial lateral deflection. The range of parameters, where the maximum load supported by a column exceeds Euler static force is determined. In this range, the maximum load is represented as a function of the compression rate, slenderness ratio, and imperfection/initial deflection. Considering the results we answer the following question: "How slowly the column should be compressed in order to measure static load-bearing capacity?" This question is important for the proper setup of laboratory experiments and computer simulations of buckling. Additionally, it is shown that the behavior of a perfect column having an initial deflection differ significantlys form the behavior of an imperfect column. In particular, the dependence of the maximum force on the compression rate is non-monotoni...

  12. Frontal crash simulation of vehicles against lighting columns using FEM

    Directory of Open Access Journals (Sweden)

    Yehia A. Abdel-Nasser

    2013-09-01

    Full Text Available There are many severe and fatal crashes that result from vehicles colliding with street columns such as lighting columns. These cause extremely high impact forces and deformation on the frontal area of the car. The objective of the study is to demonstrate the frontal crash simulation of vehicle against lighting columns to examine injury risk and potential of safety. In particular, various FE models are used to perform contact–impact nonlinear dynamic analysis of lighting columns with vehicle. In this paper Abaqus explicit code is used to numerically simulate the crash of the vehicle with present columns and other lighting columns fabricated from a new suggested material. The acceleration, contact force and deformed energy at the frontal region of the vehicle are traced. It is found that the lighting columns with new suggested material have impact properties to decelerate the vehicle and absorb higher energy during impact.

  13. Monolithic columns in plant proteomics and metabolomics.

    Science.gov (United States)

    Rigobello-Masini, Marilda; Penteado, José Carlos Pires; Masini, Jorge Cesar

    2013-03-01

    Since "omics" techniques emerged, plant studies, from biochemistry to ecology, have become more comprehensive. Plant proteomics and metabolomics enable the construction of databases that, with the help of genomics and informatics, show the data obtained as a system. Thus, all the constituents of the system can be seen with their interactions in both space and time. For instance, perturbations in a plant ecosystem as a consequence of application of herbicides or exposure to pollutants can be predicted by using information gathered from these databases. Analytical chemistry has been involved in this scientific evolution. Proteomics and metabolomics are emerging fields that require separation, identification, and quantification of proteins, peptides, and small molecules of metabolites in complex biological samples. The success of this work relies on efficient chromatographic and electrophoretic techniques, and on mass spectrometric detection. This paper reviews recent developments in the use of monolithic columns, focusing on their applications in "top-down" and "bottom-up" approaches, including their use as supports for immobilization of proteolytic enzymes and their use in two-dimensional and multidimensional chromatography. Whereas polymeric columns have been predominantly used for separation of proteins and polypeptides, silica-based monoliths have been more extensively used for separation of small molecules of metabolites. Representative applications in proteomics and in analysis of plant metabolites are given and summarized in tables.

  14. Faster Energy Efficient Column Compression Multiplication

    CERN Document Server

    Ramkumar, B

    2011-01-01

    In this work we demonstrate that faster, energy efficient, column compression multiplication, can be achieved by using a combination of two design techniques: partitioning of the partial products into two parts for independent parallel column compression and acceleration of the final addition using a hybrid adder proposed in this work. In order to demonstrate the efficacy of the techniques we have chosen the Dadda multiplier as an example. Based on the proposed techniques 8, 16, 32 and 64-bit Dadda multipliers are developed and compared with the regular Dadda multiplier. The performance of the proposed multiplier is analyzed by evaluating the delay, area and power, with 180 nm process technologies on interconnect and layout using industry standard design and layout tools. The result analysis shows that the 64-bit regular Dadda multiplier is as much as 41.1% slower than the proposed multiplier and requires only 1.4% and 3.7% less area and power respectively. Also the power-delay product of the proposed design ...

  15. Observations of iodine monoxide columns from satellite

    Directory of Open Access Journals (Sweden)

    A. Schönhardt

    2008-02-01

    Full Text Available Iodine species in the troposphere are linked to ozone depletion and new particle formation. In this study, a full year of iodine monoxide (IO columns retrieved from measurements of the SCIAMACHY satellite instrument is presented, coupled with a discussion of their uncertainties and the detection limits. The largest amounts of IO are found near springtime in the Antarctic. A seasonal variation of iodine monoxide in Antarctica is revealed with high values in springtime, slightly less IO in the summer period and again larger amounts in autumn. In winter, no elevated IO levels are found in the areas accessible to satellite measurements. This seasonal cycle is in good agreement with recent ground-based measurements in Antarctica. In the Arctic region, no elevated IO levels were found in the period analysed. This implies that different conditions with respect to iodine release exist in the two Polar Regions. To investigate possible release mechanisms, comparisons of IO columns with those of tropospheric BrO, and ice coverage are described and discussed. Some parallels and interesting differences between IO and BrO temporal and spatial distributions are identified. Overall, the large spatial coverage of satellite retrieved IO data and the availability of a long-term dataset provide new insight about the abundances and distributions of iodine compounds in the troposphere.

  16. Bioretention column study of bacteria community response to salt-enriched artificial stormwater.

    Science.gov (United States)

    Endreny, Theodore; Burke, David J; Burchhardt, Kathleen M; Fabian, Mark W; Kretzer, Annette M

    2012-01-01

    Cold climate cities with green infrastructure depend on soil bacteria to remove nutrients from road salt-enriched stormwater. Our research examined how bacterial communities in laboratory columns containing bioretention media responded to varying concentrations of salt exposure from artificial stormwater and the effect of bacteria and salt on column effluent concentrations. We used a factorial design with two bacteria treatments (sterile, nonsterile) and three salt concentrations (935, 315, and 80 ppm), including a deionized water control. Columns were repeatedly saturated with stormwater or deionized and then drained throughout 5 wk, with the last week of effluent analyzed for water chemistry. To examine bacterial communities, we extracted DNA from column bioretention media at time 0 and at week 5 and used molecular profiling techniques to examine bacterial community changes. We found that bacterial community taxa changed between time 0 and week 5 and that there was significant separation between taxa among salt treatments. Bacteria evenness was significantly affected by stormwater treatment, but there were no differences in bacterial richness or diversity. Soil bacteria and salt treatments had a significant effect on the effluent concentration of NO, PO, Cu, Pb, and Zn based on ANOVA tests. The presence of bacteria reduced effluent NO and Zn concentrations by as much as 150 and 25%, respectively, while having a mixed effect on effluent PO concentrations. Our results demonstrate how stormwater can affect bacterial communities and how the presence of soil bacteria improves pollutant removal by green infrastructure.

  17. Open tubular lab-on-column/mass spectrometry for targeted proteomics of nanogram sample amounts.

    Directory of Open Access Journals (Sweden)

    Hanne Kolsrud Hustoft

    Full Text Available A novel open tubular nanoproteomic platform featuring accelerated on-line protein digestion and high-resolution nano liquid chromatography mass spectrometry (LC-MS has been developed. The platform features very narrow open tubular columns, and is hence particularly suited for limited sample amounts. For enzymatic digestion of proteins, samples are passed through a 20 µm inner diameter (ID trypsin + endoproteinase Lys-C immobilized open tubular enzyme reactor (OTER. Resulting peptides are subsequently trapped on a monolithic pre-column and transferred on-line to a 10 µm ID porous layer open tubular (PLOT liquid chromatography LC separation column. Wnt/ß-catenein signaling pathway (Wnt-pathway proteins of potentially diagnostic value were digested+detected in targeted-MS/MS mode in small cell samples and tumor tissues within 120 minutes. For example, a potential biomarker Axin1 was identifiable in just 10 ng of sample (protein extract of ∼1,000 HCT15 colon cancer cells. In comprehensive mode, the current OTER-PLOT set-up could be used to identify approximately 1500 proteins in HCT15 cells using a relatively short digestion+detection cycle (240 minutes, outperforming previously reported on-line digestion/separation systems. The platform is fully automated utilizing common commercial instrumentation and parts, while the reactor and columns are simple to produce and have low carry-over. These initial results point to automated solutions for fast and very sensitive MS based proteomics, especially for samples of limited size.

  18. Development Of ABEC Column For Separation Of Tc-99 From Northstar Dissolved Target Solution

    Energy Technology Data Exchange (ETDEWEB)

    Stepinski, Dominique C. [Argonne National Lab. (ANL), Argonne, IL (United States); Bennett, Megan E. [Argonne National Lab. (ANL), Argonne, IL (United States); Naik, Seema R. [Argonne National Lab. (ANL), Argonne, IL (United States); ling, lei [Argonne National Lab. (ANL), Argonne, IL (United States); Wang, N-H. Linda [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-12-01

    Batch and column breakthrough experiments were performed to determine isotherms and mass-transfer parameters for adsorption of Tc on aqueous biphasic extraction chromatographic (ABEC) sorbent in two solutions: 200 g/L Mo, 5.1 M K+, 1 M OH-, and 0.1 M NO3- (Solution A) and 200 g/L Mo, 9.3 M K+, 5 M OH-, and 0.1 M NO3- (Solution B). Good agreement was found between the isotherm values obtained by batch and column breakthrough studies for both Solutions A and B. Potassium-pertechnetate intra-particle diffusivity on ABEC resin was estimated by VERSE simulations, and good agreement was found among a series of column-breakthrough experiments at varying flow velocities, column sizes, and technetium concentrations. However, testing of 10 cc cartridges provided by NorthStar with Solutions A and B did not give satisfactory results, as significant Tc breakthrough was observed and ABEC cartridge performance varied widely among experiments. These different experimental results are believed to be due to inconsistent preparation of the ABEC resin prior to packing and/or inconsistent packing.

  19. Multiresidue analysis of pesticides in vegetables and fruits using two-layered column with graphitized carbon and water absorbent polymer.

    Science.gov (United States)

    Obana, H; Akutsu, K; Okihashi, M; Hori, S

    2001-09-01

    A high-throughput multiresidue analysis of pesticides in non-fatty vegetables and fruits was developed. The method consisted of a single extraction and a single clean-up procedure. Food samples were extracted with ethyl acetate and the mixture of extract and food dregs were poured directly into the clean-up column. The clean-up column consisted of two layers of water-absorbent polymer (upper) and graphitized carbon (lower), which were packed in a reservoir (75 ml ) of a cartridge column. The polymer removed water in the extract while the carbon performed clean-up. In a recovery test, 110 pesticides were spiked and average recoveries were more than 95% from spinach and orange. Most pesticides were recovered in the range 70-115% with RSD usually < 10% for five experiments. The residue analyses were performed by the extraction of 12 pesticides from 13 samples. The two methods resulted in similar residue levels except chlorothalonil in celery, for which the result was lower with the proposed method. The results confirmed that the proposed method could be applied to monitoring of pesticide residue in foods.

  20. Leaching of Salmonella Senftenberg and Cryptosporidium Parvum in Intact Clay Columns

    Science.gov (United States)

    Bech, T. B.; Forslund, A.; Dalsgaard, A.; Jacobsen, O.; Jacobsen, C. S.

    2008-12-01

    Manure application on land has been associated with both environmental and public health problems, even when management is within the current guidelines. Outbreaks of infection have been associated with water or food, including processed fruits and vegetables, contaminated with animal manure. A wide range of pathogenic microorganisms can be found in animal waste, including bacteria, protozoan, and viruses. When animal waste is disposed on agricultural land different factors will influence the risk for contaminating the groundwater. 1) Animal waste application method, rate, volume and frequency will have an effect on contamination. 2) Survival of the pathogens in the soil will e.g. depend on soil water content, temperature and pH. Salmonella species can survive up to 332 days and Cryptosporidium species can remain viable for several years in the soil environment. In the present study we compared the transport between the pathogenic bacteria S. senftenberg and the pathogenic protozoan C. parvum in intact clay columns. Furthermore, we compared the effect from surface and sub-surface manure application on the transport potential. 15 intact clay columns were placed in an outdoor multi-column lysimeter for 36 days. Manure inoculated with S. senftenberg, C. parvum and chloride was added to the soil surface or injected 8 cm into the columns. Drainage water was collected from the soil columns and DNA was extracted to quantify S. senftenberg and C. parvum by quantitative PCR. In addition S. senftenberg was enumerated by plate counting. Acid yellow was applied to selected columns to visualize the pathway down through the soil column. The highest concentration of S. senftenberg was in the first drainage sample ranging from 100-10000 CFU/ml. Breakthrough curves for chloride and S. senftenberg indicates the importance of preferential flow as well as a faster transport for the bacteria compared to chloride. C. parvum is retained to a higher degree in the soil but is still found

  1. Refreshment topics II: Design of distillation columns

    Directory of Open Access Journals (Sweden)

    Milojević Svetomir

    2006-01-01

    Full Text Available For distillation column design it is necessary to define all the variable parameters such as component concentrations in different streams temperatures, pressures, mass and energy flow, which are used to represent the separation process of some specific system. They are related to each other according to specific laws, and if the number of such parameters exceeds the number of their relationships, in order to solve a problem some of them must be specified in advance or some constraints assumed for the mass balance, the balance of energy, phase equilibria or chemical equilibria. Knowledge of specific elements which are the constituents of a distillation unit must be known to define the number of design parameters as well as some additional apparati also necessary to realize the distilation. Each separate apparatus might be designed and constructed only if all the necessary and variable parameters for such a unit are defined. This is the right route to solve a distilation unit in many different cases. The construction of some distillation unit requires very good knowledge of mass, heat and momentum transfer phenomena. Moreover, the designer needs to know which kind of apparatus will be used in the distillation unit to realize a specific production process. The most complicated apparatus in a rectification unit is the distillation column. Depending on the complexity of the separation process one, two or more columns are often used. Additional equipment are heat exchangers (reboilers, condensers, cooling systems, heaters, separators, tanks for reflux distribution, tanks and pumps for feed transportation, etc. Such equipment is connected by pipes and valves, and for the normal operation of a distillation unit other instruments for measuring the flow rate, temperature and pressure are also required. Problems which might arise during the determination and selection of such apparati and their number requires knowledge of the specific systems which must

  2. Group separation and analysis of a carbon disulfide-soluble fraction from Shenfu coal by column chromatography

    Institute of Scientific and Technical Information of China (English)

    DING Ming-jie; WEI Xian-yong; ZONG Zhi-min; ZONG Ying; OUYANG Xiao-dong; HUANG Yao-guo; ZHOU Lei; ZHENG Yu-xuan; ZHOU Xiao; WEI Yan-bin

    2008-01-01

    A carbon disulfide-soluble fraction (CDSSF) from Shenfu coal was separated into five fractions by silica-gel column chromatography using hexane and n-hexane/ethyl acetate binary eluent. The five fractions include four clear group fractions and a nonpolar fraction. All the fractions were analyzed by GC/MS. A total of 204 compounds were detected from the original CDSSF and its further separated fractions, with 173 compounds more than those detected by studying the original CDSSF directly. The results demonstrate a clear group separation by column chromatography in coal organic components and a more accessibility to coal components compared with the solvent extraction only.

  3. Ibuprofen metabolite profiling using a combination of SPE/column-trapping and HPLC-micro-coil NMR.

    Science.gov (United States)

    Djukovic, Danijel; Appiah-Amponsah, Emmanuel; Shanaiah, Narasimhamurthy; Gowda, G A Nagana; Henry, Ian; Everly, Mike; Tobias, Brian; Raftery, Daniel

    2008-06-09

    Solid-phase extraction and column-trapping preconcentration are combined to enhance HPLC-nuclear magnetic resonance (HPLC-NMR) and applied to metabolite profiling in biological samples. Combining the two signal enhancement techniques improved the NMR signal substantially such that we were able to identify 2-hydroxyibuprofen, carboxyibuprofen, and unmetabolized ibuprofen molecules from a small urine sample after a therapeutic dose of ibuprofen. The hyphenated SPE/column-trapping method resulted in an excellent overall signal enhancement of up to 90-fold.

  4. A Sensitive Liquid Chromatographic Method for the Analysis of Clarithromycin with Pre-Column Derivatization: Application to a Bioequivalence Study

    OpenAIRE

    Amir Farshchi; Golbarg Ghiasi; Gholamreza Bahrami

    2009-01-01

    Objective(s)A sensitive liquid chromatographic method for the analysis of clarithromycin- a macrolide antibiotic- in human serum, using pre-column derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl) is described. Materials and MethodsThe method involved liquid–liquid extraction of the drug and an internal standard (amantadine) followed by pre-column derivatization of the analytes with FMOC-Cl. A mixture of 0.05 M phosphate buffer containing triethylamine (2 ml/l; pH 3.8) and methano...

  5. Supercritical fluid extraction of Beauvericin from maize.

    Science.gov (United States)

    Ambrosino, P; Galvano, F; Fogliano, V; Logrieco, A; Fresa, R; Ritieni, A

    2004-02-27

    Beauvericin (BEA), a supercritical fluid extraction with supercritical carbon dioxide from maize was investigated. Extraction efficiencies under several different extraction conditions were examined. Pressure, temperature, extraction time, organic modifier and water matrix content (10%) were investigated. The best extraction conditions were at a temperature of 60 degrees C, 3200psi, for 30min static extraction time and methanol as modifier solvent. Extraction recovery of 36% without modifier by adding water to the matrix in the extraction vessel (reproducibility relative standard deviations (R.S.D.)=3-5%) were recorded. Extraction recovery of 76.9% with methanol as co-solvent (reproducibility R.S.D.=3-5%) was obtained. Data shows that SFE gives a lower BEA recovery compared to conventional extraction protocol with organic solvents while SFE with modifier and conventional extraction yields are comparable. BEA extract contents were determined by high pressure liquid chromatography (HPLC) with a diode array detector (DAD) at 205nm and BEA peak confirmed by LC-MS. Acetonitrile-water as mobile phase and column C-18 were both tested. Instrumental and analytical parameters were optimized in the range linear interval from 1 to 500mgkg(-1) and reached a detection limit of 2ng.

  6. Direct probing of chromatography columns by laser-induced fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    McGuffin, V.L.

    1992-12-07

    This report summarizes the progress and accomplishments of this research project from September 1, 1989 to February 28, 1993. During this period, we have accomplished all of the primary scientific objectives of the research proposal: (1) constructed and evaluated a laser-induced fluorescence detection system that allows direct examination of the chromatographic column, (2) examined nonequilibrium processes that occur upon solute injection and elution, (3) examined solute retention in liquid chromatography as a function of temperature and pressure, (4) examined solute zone dispersion in liquid chromatography as a function of temperature and pressure, and (5) developed appropriate theoretical models to describe these phenomena. In each of these studies, substantial knowledge has been gained of the fundamental processes that are responsible for chromatographic separations. In addition to these primary research objectives, we have made significant progress in three related areas: (1) examined pyrene as a fluorescent polarity probe insupercritical fluids and liquids as a function of temperature and pressure, (2) developed methods for the class-selective identification of polynuclear aromatic hydrocarbons in coal-derived fluids by microcolumn liquid chromatography with fluorescence quenching detection, and (3) developed methods for the determination of saturated and unsaturated (including omega-3) fatty acids in fish oil extracts by microcolumn liquid chromatography with laser-induced fluorescence detection. In these studies, the advanced separation and detection techniques developed in our laboratory are applied to practical problems of environmental and biomedical significance.

  7. Direct probing of chromatography columns by laser-induced fluorescence

    Science.gov (United States)

    McGuffin, V. L.

    1992-12-01

    This report summarizes the progress and accomplishments of this research project from 1 Sep. 1989 to 28 Feb. 1993. During this period, we have accomplished all of the primary scientific objectives of the research proposal: (1) constructed and evaluated a laser-induced fluorescence detection system that allows direct examination of the chromatographic column, (2) examined nonequilibrium processes that occur upon solute injection and elution, (3) examined solute retention in liquid chromatography as a function of temperature and pressure, (4) examined solute zone dispersion in liquid chromatography as a function of temperature and pressure, and (5) developed appropriate theoretical models to describe these phenomena. In each of these studies, substantial knowledge has been gained of the fundamental processes that are responsible for chromatographic separations. In addition to these primary research objectives, we have made significant progress in three related areas: (1) examined pyrene as a fluorescent polarity probe in supercritical fluids and liquids as a function of temperature and pressure, (2) developed methods for the class-selective identification of polynuclear aromatic hydrocarbons in coal-derived fluids by microcolumn liquid chromatography with fluorescence quenching detection, and (3) developed methods for the determination of saturated and unsaturated (including omega-3) fatty acids in fish oil extracts by microcolumn liquid chromatography with laser-induced fluorescence detection. In these studies, the advanced separation and detection techniques developed in our laboratory are applied to practical problems of environmental and biomedical significance.

  8. Strengthening of Steel Columns under Load: Torsional-Flexural Buckling

    Directory of Open Access Journals (Sweden)

    Martin Vild

    2016-01-01

    Full Text Available The paper presents experimental and numerical research into the strengthening of steel columns under load using welded plates. So far, the experimental research in this field has been limited mostly to flexural buckling of columns and the preload had low effect on the column load resistance. This paper focuses on the local buckling and torsional-flexural buckling of columns. Three sets of three columns each were tested. Two sets corresponding to the base section (D and strengthened section (E were tested without preloading and were used for comparison. Columns from set (F were first preloaded to the load corresponding to the half of the load resistance of the base section (D. Then the columns were strengthened and after they cooled, they were loaded to failure. The columns strengthened under load (F had similar average resistance as the columns welded without preloading (E, meaning the preload affects even members susceptible to local buckling and torsional-flexural buckling only slightly. This is the same behaviour as of the tested columns from previous research into flexural buckling. The study includes results gained from finite element models of the problem created in ANSYS software. The results obtained from the experiments and numerical simulations were compared.

  9. Comparison of sulfuric acid treatment and multi-layer silica gel column chromatography in cleanup methods for determination of PCDDs, PCDFs and dioxin-like PCBs in foods.

    Science.gov (United States)

    Amakura, Yoshiaki; Tsutsumi, Tomoaki; Sasaki, Kumiko; Toyoda, Masatake; Maitani, Tamio

    2002-10-01

    Two typical cleanup methods, sulfuric acid treatment and multi-layer silica gel column chromatography, for the determination of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dioxin-like PCBs) in seventeen food samples were examined and compared. Vegetables, fruits, cereals, fish, meat and dairy foods were extracted by conventional methods (shaking with acetone/n-hexane or with n-hexane after alkaline treatment). The extracts were cleaned up by sulfuric acid treatment or multi-layer silica gel column chromatography, followed by several column chromatographic steps. Of the samples treated, the vegetable, fruit and cereal samples could be directly applied to the multi-layer silica gel column after extraction. However, the samples containing fats and oils such as fish, meat and dairy foods needed to be treated several times with concentrated sulfuric acid before multi-layer column chromatography, because these samples plugged the column with oily residues. Both cleanup methods gave similar values of isomeric concentrations and showed similar efficiency of purification, and the recoveries ranged from 40 to 120%. These results are considered to provide useful data for the efficient analysis of dioxins in foods which have wide-ranging compositions.

  10. Electromembrane extraction

    DEFF Research Database (Denmark)

    Huang, Chuixiu; Chen, Zhiliang; Gjelstad, Astrid

    2017-01-01

    Electromembrane extraction (EME) was inspired by solid-phase microextraction and developed from hollow fiber liquid-phase microextraction in 2006 by applying an electric field over the supported liquid membrane (SLM). EME provides rapid extraction, efficient sample clean-up and selectivity based...

  11. Maximum Variance Hashing via Column Generation

    Directory of Open Access Journals (Sweden)

    Lei Luo

    2013-01-01

    item search. Recently, a number of data-dependent methods have been developed, reflecting the great potential of learning for hashing. Inspired by the classic nonlinear dimensionality reduction algorithm—maximum variance unfolding, we propose a novel unsupervised hashing method, named maximum variance hashing, in this work. The idea is to maximize the total variance of the hash codes while preserving the local structure of the training data. To solve the derived optimization problem, we propose a column generation algorithm, which directly learns the binary-valued hash functions. We then extend it using anchor graphs to reduce the computational cost. Experiments on large-scale image datasets demonstrate that the proposed method outperforms state-of-the-art hashing methods in many cases.

  12. Permutation Analysis of Track and Column Braiding

    Institute of Scientific and Technical Information of China (English)

    李毓陵; 丁辛; 胡良剑

    2004-01-01

    The positions of braiding carrier in track and column braiding are represented by a diagrammatic braiding plan and a corresponding lattice-array is defined. A set is then formed so that the permutation analysis can be performed to represent the movement of carriers in a braiding process. The process of 4-step braiding is analyzed as an example to describe the application of the proposed method by expressing a braiding cycle as a product of disjoint cycles. As a result, a mapping relation between the disjoint cycles and the movement of carriers is deduced. Following the same analysis principles, a process of 8-step braiding and the corresponding initial state of the lattice-array is developed. A successful permutation analysis to the process manifests the general suitability of the proposed method.

  13. Education and training column: the learning collaborative.

    Science.gov (United States)

    MacDonald-Wilson, Kim L; Nemec, Patricia B

    2015-03-01

    This column describes the key components of a learning collaborative, with examples from the experience of 1 organization. A learning collaborative is a method for management, learning, and improvement of products or processes, and is a useful approach to implementation of a new service design or approach. This description draws from published material on learning collaboratives and the authors' experiences. The learning collaborative approach offers an effective method to improve service provider skills, provide support, and structure environments to result in lasting change for people using behavioral health services. This approach is consistent with psychiatric rehabilitation principles and practices, and serves to increase the overall capacity of the mental health system by structuring a process for discovering and sharing knowledge and expertise across provider agencies. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

  14. Near shore floating oscillating wave column

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    Three different types of floating buoys, using oscillating wave columns, have been considered for generating electric power in an Atlantic environment. The study considered the situation close to the shore, but in the ultimate it was hoped to deploy units offshore. Although other designs would have greater power capture efficiency, the Spar Buoy was studied in greatest depth as it was expected to have the edge in terms of building cost and operating economics. A risk assessment was carried out for both concrete and steel buoys. The report covers (1) history of the project development; (2) project definition; (3) power generation and sensitivities and (4) lessons learned. The study was sponsored by Great Britain's DTI.

  15. Column: Putting the Science in Digital Forensics

    Directory of Open Access Journals (Sweden)

    Fred Cohen

    2011-03-01

    Full Text Available In a recent study, digital forensics was found to lack a consensus around even the most basis notions and terminology of the field. To quote: “These two preliminary studies individually suggest that scientific consensus in the area of digital forensic evidence examination is lacking in the broad sense, but that different groups within that overall community may have limited consensus around areas in which they have special expertise, and that the current peerreviewed publication process is not acting to bring about the sorts of elements typically found in the advancement of a science toward such a consensus. ... perhaps the most significant challenge may be in the development of a common language to describe the field...”(see PDF for full column

  16. The vertebral column of Australopithecus sediba.

    Science.gov (United States)

    Williams, Scott A; Ostrofsky, Kelly R; Frater, Nakita; Churchill, Steven E; Schmid, Peter; Berger, Lee R

    2013-04-12

    Two partial vertebral columns of Australopithecus sediba grant insight into aspects of early hominin spinal mobility, lumbar curvature, vertebral formula, and transitional vertebra position. Au. sediba likely possessed five non-rib-bearing lumbar vertebrae and five sacral elements, the same configuration that occurs modally in modern humans. This finding contrasts with other interpretations of early hominin regional vertebral numbers. Importantly, the transitional vertebra is distinct from and above the last rib-bearing vertebra in Au. sediba, resulting in a functionally longer lower back. This configuration, along with a strongly wedged last lumbar vertebra and other indicators of lordotic posture, would have contributed to a highly flexible spine that is derived compared with earlier members of the genus Australopithecus and similar to that of the Nariokotome Homo erectus skeleton.

  17. Vacuum extraction

    DEFF Research Database (Denmark)

    Maagaard, Mathilde; Oestergaard, Jeanett; Johansen, Marianne

    2012-01-01

    Objectives. To develop and validate an Objective Structured Assessment of Technical Skills (OSATS) scale for vacuum extraction. Design. Two part study design: Primarily, development of a procedure-specific checklist for vacuum extraction. Hereafter, validationof the developed OSATS scale for vacuum...... extraction in a prospective observational study. Setting. Rigshospitalet, University Hospital of Copenhagen. Population. For development an obstetric expert from each labor ward in Denmark (28 departments) were invited to participate. For validation nine first-year residents and ten chief physicians...... with daily work in the obstetric field were tested. Methods. The Delphi method was used for development of the scale. In a simulated vacuum extraction scenario first-year residents and obstetric chief physicians were rated using the developed OSATS scale for vacuum extraction to test construct validity...

  18. Vacuum extraction

    DEFF Research Database (Denmark)

    Maagaard, Mathilde; Oestergaard, Jeanett; Johansen, Marianne

    2012-01-01

    Objectives. To develop and validate an Objective Structured Assessment of Technical Skills (OSATS) scale for vacuum extraction. Design. Two part study design: Primarily, development of a procedure-specific checklist for vacuum extraction. Hereafter, validationof the developed OSATS scale for vacuum...... extraction in a prospective observational study. Setting. Rigshospitalet, University Hospital of Copenhagen. Population. For development an obstetric expert from each labor ward in Denmark (28 departments) were invited to participate. For validation nine first-year residents and ten chief physicians...... with daily work in the obstetric field were tested. Methods. The Delphi method was used for development of the scale. In a simulated vacuum extraction scenario first-year residents and obstetric chief physicians were rated using the developed OSATS scale for vacuum extraction to test construct validity...

  19. Thermogravitational column as a technique for thermal diffusion factor measurement in liquid mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Ecenarro, O.; Madariaga, J.A.; Navarro, J.; Santamaria, C.M. (Universidad Pais Vasco, Bilbao (Spain)); Carrion, J.A.; Saviron, J.M. (Universidad de Zaragoza (Spain))

    Thermogravitational thermal diffusion separations are studied for benzene-n-heptane, benzene-n-hexane, toluene-n-heptane, toluene-n-hexane, carbon tetrachloride-n-hexane, and cyclohexane-n-hexane mixtures at a mean temperature of 37.5{degree}C. The column used was of 90 cm length with a 0.095 cm gap. Despite its length, this column can be used as a standard for the value of {alpha}{sub T} extraction when the separation factor is extrapolated to {Delta}t = 0{degree}C. Thermal diffusion factors are calculated for benzene-n-heptane and benzene-n-hexane mixtures in different concentrations. For the rest of the systems investigated, {alpha}{sub T}D{sub 12} values (D{sub 12} being the ordinary diffusion coefficient) are calculated.

  20. Spectrophotometric determination of lead after preconcentration of its diphenylthiocarbazone complex on an Amberlite XAD-1180 column

    Science.gov (United States)

    Rajesh, N.; Manikandan, S.

    2008-09-01

    A simple methodology has been developed for the solid phase extraction of lead based on the adsorption of its diphenylthiocarbazone complex on an Amberlite XAD-1180 column. The effect of various parameters such as eluting agents, stability of the column, sample volume, interfering ions, etc. were studied in detail. The adsorbed complex could be eluted using acetone and the concentration of lead was determined using visible spectrophotometry at a wavelength maximum of 486 nm. A detection limit of 3.5 μg L -1 could be achieved and the validity of the proposed method was checked in spiked tap water, well water and industrial wastewater samples. The relative standard deviation of the method was found to be 3.0%. The highest preconcentration factor attainable for quantitative recovery (>95%) of lead was 25 for a 250 mL sample volume.

  1. Separation and concentration of lanthanoids using microcapsules containing acidic organophosphorus compounds as an extractant

    Energy Technology Data Exchange (ETDEWEB)

    Kamio, Eiji; Kondo, Kazuo [Doshisha Univ., Department of Chemical Engineering and Materials Science, Kyoto (Japan)

    2002-06-01

    In this study, we measured the extraction equilibria of lanthanoids with microcapsules containing acidic organophosphorus compound as an extractant and discuss their mutual separation by using a column packed with the microcapsules. The extraction equilibria of lanthanoids into the microcapsules containing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (EHPNA) were elucidated and the extraction equilibrium constants were calculated by slope-analysis method. It was suggested that the lanthanoid ions are extracted in the microcapsules in a high loading state. Furthermore, the adsorption behavior of lanthanoids into the column packed with the microcapsules containing EHPNA was observed. It was found that adsorption and elution of lanthanoids are briefly achieved by selecting pH of the feed aqueous solution. However, it was impossible to separate them only in adsorption or elution operation. So, the mutual separation of lanthanoids was investigated using the adsorption column connected to the development column containing microcapsules. By selecting pH of the eluent, each metal was separated mutually in more than 95% of purity. The metal ions in the eluent from the development column could be concentrated by treating it with a column packed with the microcapsules containing di(2-ethylhexyl) phosphoric acid (D2EHPA). Considering these information, it will be possible to design a continuous extracting, separating and concentrating reactor of lanthanoids using a column packed with the microcapsules. (author)

  2. Suspension column for recovery and separation of substances using ultrasound-assisted retention of bead sorbents.

    Science.gov (United States)

    Spivakov, Boris Ya; Shkinev, Valeriy M; Danilova, Tatiana V; Knyazkov, Nikolai N; Kurochkin, Vladimir E; Karandashev, Vasiliy K

    2012-12-15

    A novel approach to sorption recovery and separation of different substances is proposed which is based on the use of suspended bead sorbents instead of conventional packed beds of such sorbents. This makes it possible to employ small-sized beads which are trapped in a low-pressure column due to ultrasound-assisted retention, without any frits to hold the sorption material. A flow system including a separation mini-column, named herein a suspension column, has been developed and tested by the studies of solid phase extraction (SPE) of trace metals from bi-distilled water and sea water using a 150-μL column with a silica-based sorbent containing iminodiacetic groups (DIAPAK IDA) and having a grain size of 6 μm. The adsorption properties of DIAPAK IDA suspension (9.5mg) were evaluated through adsorption/desorption experiments, where the effect of solution pH and eluent on the SPE of trace metals were examined by ICP-MS or ICP-AES measurements. When sample solution was adjusted to pH 8.0 and 1 mol L(-1) nitric acid was used as eluent, very good recoveries of more than 90% were obtained for a number of elements in a single-step extraction. To demonstrate the versatility of the approach proposed and to show another advantage of ultrasonic field (acceleration of sorbate/sorbent interaction), a similar system was used for heterogeneous immunoassays of some antigens in ultrasonic field using agarose sorbents modified by corresponding antibodies. It has been shown that immunoglobulins, chlamidia, and brucellos bacteria can be quantitatively adsorbed on 15-μm sorbent (15 particles in 50 μL) and directly determined in a 50-μL mini-chamber using fluorescence detection.

  3. Temperature-compensated 8-bit column driver for AMLCD

    Science.gov (United States)

    Dingwall, Andrew G. F.; Lin, Mark L.

    1995-06-01

    An all-digital, 5 V input, 50 Mhz bandwidth, 10-bit resolution, 128- column, AMLCD column driver IC has been designed and tested. The 10-bit design can enhance display definition over 6-bit nd 8-bit column drivers. Precision is realized with on-chip, switched-capacitor DACs plus transparently auto-offset-calibrated, opamp outputs. Increased resolution permits multiple 10-bit digital gamma remappings in EPROMs over temperature. Driver IC features include externally programmable number of output column, bi-directional digital data shifting, user- defined row/column/pixel/frame inversion, power management, timing control for daisy-chained column drivers, and digital bit inversion. The architecture uses fewer reference power supplies.

  4. Effect of axial mixing on RDC and PSE columns performance

    CERN Document Server

    Bastani, D

    2001-01-01

    Using the experimental data obtained from two RDC columns at two different sizes (7.62 and 21.9 cm) and one PSE column with 21.5 cm size, the effect of axial mixing on the performance of these columns was studied. Comparison between the experimental and theoretical (neglecting the axial mixing) number of transfer units indicates that, this effect in PSE columns is more than RDC columns (400% and 200% respectively). These results show that this effect can increase the height of the PSE column up to 4 times for a specific efficiency. Also the results show that this effect is more in law interfacial tension systems, which shows no need of application of agitation facilities when these systems are used.

  5. Multiple column high-throughput e-beam inspection (EBI)

    Science.gov (United States)

    Lam, David K.; Monahan, Kevin M.; Liu, Enden D.; Tran, Cong; Prescop, Ted

    2012-03-01

    Single-column e-beam systems are used in production for the detection of electrical defects, but are too slow to be used for the detection of small physical defects, and can't meet future inspection requirements. This paper presents a multiplecolumn e-beam technology for high throughput wafer inspection. Multibeam has developed all-electrostatic columns for high-resolution imaging. The elimination of magnetic coils enables the columns to be small; e-beam deflection is faster in the absence of magnetic hysteresis. Multiple miniaturecolumns are assembled in an array. An array of 100 columns covers the entire surface of a 300mm wafer, affording simultaneous cross-wafer sampling. Column performance simulations and system architecture are presented. Also provided are examples of high throughput, more efficient, multiple-column wafer inspection.

  6. Simulating a fuzzy level controller for flotation columns

    Institute of Scientific and Technical Information of China (English)

    Liao Yinfei; Liu Jiongtian; Wang Yongtian; Cao Yijun

    2011-01-01

    Level control in flotation columns is an important factor that influences the recovery and the grade of concentrate from the column.A flotation column is a nonlinear,multi-variable problem with changeable parameters that traditional methods have difficulty controlling.We have applied fuzzy control methods to the flotation column and tested the performance of the design by Matlab/Simulink simulation.The simulations show that level control in the flotation column becomes smoother and more rapid with the fuzzy controller.Compared to PID control methods the overshoot in valve position,the adjustment time,and the robustness of the controller are all improved.This indicates that it is suitable to model fuzzy controllers in applications for the study of automatic control of flotation column.

  7. Two-dimensional ion chromatography using tandem ion-exchange columns with gradient-pulse column switching.

    Science.gov (United States)

    Johns, Cameron; Shellie, Robert A; Pohl, Christopher A; Haddad, Paul R

    2009-10-09

    A two-dimensional ion chromatography (2D-IC) approach has been developed which provides greater resolution of complex samples than is possible currently using a single column. Two columns containing different stationary phases are connected via a tee-piece, which enables an additional eluent flow and independent control of eluent concentration on each column. The resultant mixed eluent flow at the tee-piece can be varied to produce a different eluent concentration on the second column. This allows analytes strongly retained on the first column to be separated rapidly on the second column, whilst maintaining a highly efficient, well resolved separation of analytes retained weakly on the first column. A group of 18 inorganic anions has been separated to demonstrate the utility of this approach and the proposed 2D-IC method provided separation of this mixture with resolution of all analytes greater than 1.3. Careful optimisation of the eluent profiles on both columns resulted in run times of less than 28 min, including re-equilibration. Separations were performed using isocratic or gradient elution on the first column, with an isocratic separation being used on the second column. Switching of the analytes onto the second column was performed using a gradient pulse of concentrated eluent to quickly elute strongly retained analytes from the first column onto the second column. The separations were highly repeatable (RSD of 0.01-0.12% for retention times and 0.08-2.9% for peak areas) and efficient (typically 8000-260,000 plates). Detection limits were 3-80 ppb.

  8. Effect of nitrification on movement of trace metals in soil columns

    Energy Technology Data Exchange (ETDEWEB)

    Chang, F.; Broadbent, F.E.

    1980-01-01

    Soil column experiments were conducted with sludge-treated and untreated samples of two soils, Omni silty clay and Delhi loamy sand, to determine whether protons generated during the nitrification process would affect the mobility of the trace metals Cd, Cr, Cu, Mn, Pb, and Zn. Columns 5 cm x 100 cm were leached bi- or tri-weekly with 7.5-cm applications of solutions of CaCl/sub 2/, NH/sub 4/Cl, or KCl. Trace metals in effluents from the columns were analyzed after each application of leaching solution. After 11 appications over a period of several months-the columns were sectioned and the vertical distribution of 2N NCl-extractable metals determined. Average concentrations of metals in column effluents were well below 1 ppM in all cases except Zn eluted from untreated Delhi loamy sand where 20 mM NH/sub 4/Cl or KCl leaching solutions produced effluent concentrations slightly above 1 ppM. There was evidence of nitrification affecting movement of several of the metals, particularly in the cases of Mn, Zn, Cu, and Cd in the untreated Delhi soil. The presence of sludge had a pronounced stabilizing influence of Cd and Zn, and to a lesser degree on other metals, probably as a result of organo-metal complexes. Much of the input labeled NH/sub 4/-N was denitrified, as shown by recoveries of N ranging from 14 to 20% in the Omni soil and 40 to 78% in the Delhi soil. Proton generation during denitrification. It was concluded that nitrification had relatively little effect on metal mobility under the conditions of the experiment.

  9. Method for determination of aflatoxin M₁ in cheese and butter by HPLC using an immunoaffinity column.

    Science.gov (United States)

    Sakuma, Hisako; Kamata, Yoichi; Sugita-Konishi, Yoshiko; Kawakami, Hiroshi

    2011-01-01

    A rapid, sensitive convenient method for determination of aflatoxin M₁ (AFM₁) in cheese and butter by HPLC was developed and validated. The method employs a safe extraction solution (mixture of acetonitrile, methanol and water) and an immunoaffinity column (IAC) for clean-up. Compared with the widely used method employing chloroform and a Florisil column, the IAC method has a short analytical time and there are no interference peaks. The limits of quantification (LOQ) of the IAC method were 0.12 and 0.14 µg/kg, while those of the Florisil column method were 0.47 and 0.23 µg/kg in cheese and buffer, respectively. The recovery and relative standard deviation (RSD) for cheese (spiked at 0.5 µg/kg) in the IAC method were 92% and 7%, respectively, while for the Florisil column method the corresponding values were 76% and 10%. The recovery and RSD for butter (spiked at 0.5 µg/kg) in the IAC method were 97% and 9%, and those in the Florisil method were 74% and 9%, respectively. In the IAC method, the values of in-house precision (n=2, day=5) of cheese and butter (spiked at 0.5 µg/kg) were 9% and 13%, respectively. The IAC method is superior to the Florisil column method in terms of safety, ease of handling, sensitivity and reliability. A survey of AFM₁ contamination in imported cheese and butter in Japan was conducted by the IAC method. AFM₁ was not detected in 60 samples of cheese and 30 samples of butter.

  10. Completing electron scattering studies with the inert gas column:e - Rn scattering and Ionization

    CERN Document Server

    Joshi, Foram M; Chaudhari, Asha S; Modi, Hitesh S; Pindaria, Manish J

    2016-01-01

    Interest in the inert or noble- gas atoms in general arises because they are ideal as test systems for various theoretical models of electron scattering and also since their interaction processes serve as reference for the determination of instrumental responses in electron scattering experiments. The ionization cross section data of ground state inert gas atoms He through Xe are considered to be benchmark data. Our aim in this paper is to provide theoretical results on electron scattering with Radon atoms, as it would complete the studies on the entire inert gas column. That is possible with this particular column only, in view of the preceding literature on He through Xe . Inert gas radon is radioactive, and would be a difficult target for electron scattering experiments. In the present calculations, the complications arising from radioactivity are not considered. We provide hitherto unavailable cross sections on atomic radon, and also provide opportunity of the comparison of electron impact cross sections ...

  11. Mini-columns for Conducting Breakthrough Experiments. Design and Construction

    Energy Technology Data Exchange (ETDEWEB)

    Dittrich, Timothy M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reimus, Paul William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ware, Stuart Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-11

    Experiments with moderately and strongly sorbing radionuclides (i.e., U, Cs, Am) have shown that sorption between experimental solutions and traditional column materials must be accounted for to accurately determine stationary phase or porous media sorption properties (i.e., sorption site density, sorption site reaction rate coefficients, and partition coefficients or Kd values). This report details the materials and construction of mini-columns for use in breakthrough columns to allow for accurate measurement and modeling of sorption parameters. Material selection, construction techniques, wet packing of columns, tubing connections, and lessons learned are addressed.

  12. Tubular composite columns in a non-symmetrical fire

    OpenAIRE

    Markku Heinisuo; Timo Jokinen

    2014-01-01

    A considerable number of studies have been conducted worldwide on fires that act on all four sides of a column (symmetrical fire). These cases are used for the validation of the analysis models developed in this study. In real buildings the columns are often embedded. If the fire does not act similarly on all surfaces of the column (non-symmetrical fire), it is extremely difficult to predict how the column will behave. The key research questions are: Is resistance stronger in non-symmetri...

  13. Morphological modularity in the vertebral column of Felidae (Mammalia, Carnivora)

    National Research Council Canada - National Science Library

    Marcela Randau; Anjali Goswami

    2017-01-01

    Background Previous studies have demonstrated that the clear morphological differences among vertebrae across the presacral column are accompanied by heterogeneous functional signals in vertebral shape...

  14. Analysis of sugar phosphates in plants by ion chromatography on a titanium dioxide column with pulsed amperometric detection.

    Science.gov (United States)

    Sekiguchi, Yoko; Mitsuhashi, Naoto; Inoue, Yoshinori; Yagisawa, Hitoshi; Mimura, Tetsuro

    2004-06-11

    This paper describes the development of a practical method for the analysis of sugar phosphates from the model higher plant Arabidopsis thaliana by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The extraction method of sugar phosphates from higher plants was first optimized for HPAEC-PAD analysis. In order to improve the resolution in HPAEC-PAD, a column packed with titanium dioxide resin was used. The titanium dioxide column was used as a trap-column for sugar phosphates and nucleotides, for the removal of sample matrices. Sample pretreatment was achieved in-line and automatically using a six-port valve placed after the injection valve.

  15. ANALYSIS OF FERRIC AND FERROUS IONS IN SOIL EXTRACTS BY ION CHROMATOGRAPHY

    Science.gov (United States)

    A method using ion chromatography (IC) for the analysis of ferrous (Fe 2+) and ferric (Fe 3+) ions in soil extracts has been developed. This method uses an ion exchange column with detection at 520 nm after post-column derivatization. Selectivity is achieved by using an anionic...

  16. ANALYSIS OF FERRIC AND FERROUS IONS IN SOIL EXTRACTS BY ION CHROMATOGRAPHY

    Science.gov (United States)

    A method using ion chromatography (IC) for the analysis of ferrous (Fe 2+) and ferric (Fe 3+) ions in soil extracts has been developed. This method uses an ion exchange column with detection at 520 nm after post-column derivatization. Selectivity is achieved by using an anionic...

  17. Protein Extractability

    African Journals Online (AJOL)

    human nutrition, particularly in developing ... studied the effect of NaCl on the extractability of ... significant influence on the functional properties ..... Malaka, S. L. O. and Amund, O. O. Studies on the Life Cycle and Morphometrics of Honeybees,.

  18. Bevalac extraction

    Energy Technology Data Exchange (ETDEWEB)

    Kalnins, J.G.; Krebs, G.; Tekawa, M.; Cowles, D.; Byrne, T.

    1992-02-01

    This report will describe some of the general features of the Bevatron extraction system, primarily the dependence of the beam parameters and extraction magnet currents on the Bevalac field. The extraction magnets considered are: PFW, XPl, XP2, XS1, XS2, XM1, XM2, XM3, XQ3A and X03B. This study is based on 84 past tunes (from 1987 to the present) of various ions (p,He,O,Ne,Si,S,Ar,Ca,Ti,Fe,Nb,La,Au and U), for Bevalac fields from 1.749 to 12.575 kG, where all tunes included a complete set of beam line wire chamber pictures. The circulating beam intensity inside the Bevalac is measured with Beam Induction Electrodes (BIE) in the South Tangent Tank. The extracted beam intensity is usually measured with the Secondary Emission Monitor (SEM) in the F1-Box. For most of the tunes the extraction efficiency, as given by the SEM/BIE ratio, was not recorded in the MCR Log Book, but plotting the available Log Book data as a function of the Bevalac field, see Fig.9, we find that the extraction efficiency is typically between 30->60% with feedback spill.

  19. Selective detachment process in column flotation froth

    Energy Technology Data Exchange (ETDEWEB)

    Honaker, R.Q.; Ozsever, A.V.; Parekh, B.K. [University of Kentucky, Lexington, KY (United States). Dept. of Mining Engineering

    2006-05-15

    The selectivity in flotation columns involving the separation of particles of varying degrees of floatability is based on differential flotation rates in the collection zone, reflux action between the froth and collection zones, and differential detachment rates in the froth zone. Using well-known theoretical models describing the separation process and experimental data, froth zone and overall flotation recovery values were quantified for particles in an anthracite coal that have a wide range of floatability potential. For highly floatable particles, froth recovery had a very minimal impact on overall recovery while the recovery of weakly floatable material was decreased substantially by reductions in froth recovery values. In addition, under carrying-capacity limiting conditions, selectivity was enhanced by the preferential detachment of the weakly floatable material. Based on this concept, highly floatable material was added directly into the froth zone when treating the anthracite coal. The enriched froth phase reduced the product ash content of the anthracite product by five absolute percentage points while maintaining a constant recovery value.

  20. Temperature of Steel Columns under Natural Fire

    Directory of Open Access Journals (Sweden)

    F. Wald

    2004-01-01

    Full Text Available Current fire design models for time-temperature development within structural elements as well as for structural behaviour are based on isolated member tests subjected to standard fire regimes, which serve as a reference heating, but do not model natural fire. Only tests on a real structure under a natural fire can evaluate future models of the temperature developments in a fire compartment, of the transfer of heat into the structure and of the overall structural behaviour under fire.To study overall structural behaviour, a research project was conducted on an eight storey steel frame building at the  Cardington Building Research Establishment laboratory on January 16, 2003. A fire compartment 11×7 m was prepared on the fourth floor. A fire load of 40 kg/m2 was applied with 100 % permanent mechanical load and 65 % of imposed load. The paper summarises the experimental programme and shows the temperature development of the gas in the fire compartment and of the fire protected columns bearing the unprotected floors.

  1. SPR Hydrostatic Column Model Verification and Validation.

    Energy Technology Data Exchange (ETDEWEB)

    Bettin, Giorgia [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lord, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rudeen, David Keith [Gram, Inc. Albuquerque, NM (United States)

    2015-10-01

    A Hydrostatic Column Model (HCM) was developed to help differentiate between normal "tight" well behavior and small-leak behavior under nitrogen for testing the pressure integrity of crude oil storage wells at the U.S. Strategic Petroleum Reserve. This effort was motivated by steady, yet distinct, pressure behavior of a series of Big Hill caverns that have been placed under nitrogen for extended period of time. This report describes the HCM model, its functional requirements, the model structure and the verification and validation process. Different modes of operation are also described, which illustrate how the software can be used to model extended nitrogen monitoring and Mechanical Integrity Tests by predicting wellhead pressures along with nitrogen interface movements. Model verification has shown that the program runs correctly and it is implemented as intended. The cavern BH101 long term nitrogen test was used to validate the model which showed very good agreement with measured data. This supports the claim that the model is, in fact, capturing the relevant physical phenomena and can be used to make accurate predictions of both wellhead pressure and interface movements.

  2. GPR Diagnostics of columns in archaeological contexts

    Science.gov (United States)

    Soldovieri, Francesco; Masini, Nicola; Persico, Raffaele; Catapano, Ilaria

    2017-04-01

    In the last decade the use of Ground Penetrating radar (GPR) applied to cultural heritage has been strongly increasing thanks to both technological development of sensors and softwares for data processing and cultural reasons such as the increasing awareness of conservators and archaeologist of the benefits of this method in terms of reduction of costs and time and risk associated with restoration works. This made GPR a mature technique for investigating different types of works of art and building elements of historical interest, including masonry structures, frescoes, mosaics [1-3], in the context of scientific projects, decision support activities aimed at the diagnosis of decay pathologies, and educational activities. One of the most complex building elements to be investigated by GPR are the columns both for the geometry of the object and for the several expected features to be detected including fractures, dishomogeneities and metallic connection elements. The work deals with the Ground Penetrating Radar diagnostic surveys at the prestigious archaeological site of Pompei. In particular, GPR surveys were carried out in two different areas, Palestra Grande and Tempio di Giove. The first campaign was carried out also as educational activity of the "International School "GEOPHYSICS AND REMOTE SENSING FOR ARCHAEOLOGY". The School aimed at giving the opportunity to scholars, PhD students, researchers and specialists in Geophysics, Remote Sensing and Archaeology to deepen their knowledge and expertise with geophysical and remote sensing techniques for archaeology and cultural heritage documentation and management. This survey was carried on two kinds of columns, with circular and rectangular section in order to detect possible hidden defects affecting their integrity. The second survey was carried out at Tempio di Giove, on request of the Soprintendenza Pompei, in order to gain information about the presence of reinforcement structures, which may be put inside the

  3. Transport and deposition of suspended soil colloids in saturated sand columns

    DEFF Research Database (Denmark)

    Sharma, Anu; Kawamoto, Ken; Møldrup, Per;

    2011-01-01

    Understanding colloid mobilization, transport and deposition in the subsurface is a prerequisite for predicting colloid‐facilitated transport of strongly adsorbing contaminants and further developing remedial activities. This study investigated the transport behavior of soil‐colloids extracted from...... a red‐yellow soil from Okinawa, Japan. Different concentrations of suspended‐soil colloids (with diameter ....21 mm) sands. The transport and retention of colloids were studied by analyzing colloid effluent breakthrough curves (BTCs), particle size distribution in the effluent, and colloid deposition profiles within the column. The results showed a significant influence of flow velocity: Low flow velocity...

  4. Linearized potential flow analysis of a 40 chamber, oscillating water column wave energy device

    DEFF Research Database (Denmark)

    Bingham, Harry B.; Read, Robert

    coefficient to represent the air turbine Power Take Off (PTO) system is found for each condition by iterating to find the consistent response-damping pair for a given frequency and incident wave ampli- tude. The absorbed power is estimated based on the pressure in each chamber and the PTO damping coefficient......This abstract presents an analysis of an attenuator-type Wave Energy Converter (WEC) with 40 Os- cillating Water Column (OWC) chambers for the extraction of wave energy. Linearized potential flow calculations are made in the frequency-domain using WAMIT [8]. An equivalent linearized damping...

  5. SIMULTANEOUS REACTION AND LIQUID-LIQUID EXTRACTION IN THE HYDROGEN PEROXIDE PRODUCTION

    Institute of Scientific and Technical Information of China (English)

    Shuxiang L(u); Li Wang; Zhentao Mi; Yaquan Wang

    2004-01-01

    The gas-liquid-liquid reactive extraction system for preparing hydrogen peroxide via anthraquinone was investigated. The oxidation reaction of hydrogenated working solution was combined with the extraction of hydrogen peroxide from working solution in a sieve plate column. The reaction of 2-ethylanthrahydroquionone with oxygen and the liquid-liquid extraction of hydrogen peroxide take place simultaneously. The oxygen was introduced with hydrogenated working solution through a nozzle in the bottom of the column, which worked as agitated air as well as oxidation reagent. The results showed the oxidation and extraction do not hamper each other, on the contrary, the presence of oxidation gas in the column can promote the transfer of hydrogen peroxide from organic phase to aqueous phase, thus the reaction efficiency and extraction efficiency increased with increasing gas superficial velocity. Furthermore, the oxidation efficiency is almost 100% and the extraction efficiency is higher than 90% in this process.

  6. SIMULTANEOUS REACTION AND LIQUID-LIQUID EXTRACTION IN THE HYDROGEN PEROXIDE PRODUCTION

    Institute of Scientific and Technical Information of China (English)

    ShuxiangLǖ; LiWang; ZhentaoMi; YaquanWang

    2004-01-01

    The gas-liquid-liquid reactive extraction system for preparing hydrogen peroxide via anthraquinone was investigated. The oxidation reaction of hydrogenated working solution was combined with the extraction of hydrogen peroxide from working solution in a sieve plate column. The reaction of 2-ethylanthrahydroquionone with oxygen and the liquid-liquid extraction of hydrogen peroxide take place simultaneously. The oxygen was introduced with hydrogenated working solution through a nozzle in the bottom of the column, which worked as agitated air as well as oxidation reagent. The results showed the oxidation and extraction do not hamper each other, on the contrary, the presence of oxidation gas in the column can promote the transfer of hydrogen peroxide fi'om organic phase to aqueous phase, thus the reaction efficiency and extraction efficiency increased with increasing gas superficial velocity. Furthermore, the oxidation efficiency is almost 100% and the extraction efficiency is higher than 90% in this process.

  7. Extraction, purification and antioxidant activity of polysaccharides from bamboo leaves

    Institute of Scientific and Technical Information of China (English)

    GAO Ya-ni; TIAN Cheng-rui; ZHAO Li-li

    2012-01-01

    Ultrasonic extraction (UE) was employed for the extraction of bamboo leaf polysaccharides (BLP).The influential parameters of UE procedure including extraction time,ultrasonic power and solid/liquid ratio were optimized by orthogonal experiments.DEAE-cellulose column chromatography was applied to purify BLP and then the radical scavenging activity of BLP was also evaluated.Optimal extraction conditions were:extraction time of 15 min,ultrasonic power of 300 W,and solid/liquid ratio of 1:15.Four kinds of polysaccharides were obtained by DEAE-cellulose column chromatography; the maximum superoxide radical scavenging rate (20.4%) of BLP was inferior to that of vitamin C (Vc,the control) and the hydroxyl radical scavenging rate (50%) was equivalent to that of Vc.

  8. The dynamic response of prone-to-fall columns to ambient vibrations: comparison between measurements and numerical modelling

    Science.gov (United States)

    Valentin, J.; Capron, A.; Jongmans, D.; Baillet, L.; Bottelin, P.; Donze, F.; Larose, E.; Mangeney, A.

    2017-02-01

    Seismic noise measurements (ambient vibrations) have been increasingly used in rock slope stability assessment for both investigation and monitoring purposes. Recent studies made on gravitational hazard revealed significant spectral amplification at given frequencies and polarization of the wave-field in the direction of maximum rock slope displacement. Different properties (resonance frequencies, polarization and spectral ratio amplitudes) can be derived from the spectral analysis of the seismic noise to characterize unstable rock masses. The objective here is to identify the dynamic parameters that could be used to gain information on prone-to-fall rock columns' geometry. To do so, the dynamic response of prone-to-fall columns to seismic noise has been studied on two different sites exhibiting cliff-like geometry. Dynamic parameters (main resonance frequency and spectral ratio amplitudes) that could characterize the column decoupling were extracted from seismic noise and their variations were studied taking into account the external environmental parameter fluctuations. Based on this analysis, a two-dimensional numerical model has been set up to assess the influence of the rear vertical fractures identified on both sites on the rock column motion response. Although a simple relation was found between spectral ratio amplitudes and the rock column slenderness, it turned out that the resonance frequency is more stable than the spectral ratio amplitudes to characterize this column decoupling, provided that the elastic properties of the column can be estimated. The study also revealed the effect of additional remote fractures on the dynamic parameters, which in turn could be used for detecting the presence of such discontinuities.

  9. Graph Modelling Approach: Application to a Distillation Column

    DEFF Research Database (Denmark)

    Hovelaque, V.; Commault, C.; Bahar, Mehrdad

    1997-01-01

    Introduction, structured systems and digraphs, distillation column model, generic input-output decoupling problem, generic disturbance rejection problem, concluding remarks.......Introduction, structured systems and digraphs, distillation column model, generic input-output decoupling problem, generic disturbance rejection problem, concluding remarks....

  10. A Modeling Framework for Conventional and Heat Integrated Distillation Columns

    DEFF Research Database (Denmark)

    Bisgaard, Thomas; Huusom, Jakob Kjøbsted; Abildskov, Jens

    2013-01-01

    In this paper, a generic, modular model framework for describing fluid separation by distillation is presented. At present, the framework is able to describe a conventional distillation column and a heat-integrated distillation column, but due to a modular structure the database can be further ex...

  11. A Better Method for Filling Pasteur Pipet Chromatography Columns

    Science.gov (United States)

    Ruekberg, Ben

    2006-01-01

    An alternative method for the preparation of Pasteur pipet chromatography columns is presented that allows the column to be filled with solvent without bubbles and allows greater control of fluid flow while the materials to be separated are added. Students are required to wear gloves and goggles and caution should be used while handling glass…

  12. SURFACTANT ENHANCED REMEDIATION OF SOIL COLUMNS CONTAMINATED BY RESIDUAL TETRACHLOROETHYLENE

    Science.gov (United States)

    The ability of aqueous surfactant solutions to recover tetrachloroethylene (PCE) entrapped in Ottawa sand was evaluated in four column experiments. Residual PCE was emplaced by injecting 14C-labeled PCE into water-saturated soil columns and displacing the free product ...

  13. Trend analysis of performance parameters of pre-packed columns for protein chromatography over a time span of ten years.

    Science.gov (United States)

    Scharl, Theresa; Jungreuthmayer, Christian; Dürauer, Astrid; Schweiger, Susanne; Schröder, Tim; Jungbauer, Alois

    2016-09-23

    Pre-packed small scale chromatography columns are increasingly used for process development, for determination of design space in bioprocess development, and for post-licence process verifications. The packing quality of 30,000 pre-packed columns delivered to customers over a period 10 years has been analyzed by advanced statistical tools. First, the data were extracted and checked for inconsistencies, and then were tabulated and made ready for statistical processing using the programming language Perl (https://www.perl.org/) and the statistical computing environment R (https://www.r-project.org/). Reduced HETP and asymmetry were plotted over time to obtain a trend of packing quality over 10 years. The obtained data were used as a visualized coefficient of variation analysis (VCVA), a process that has often been applied in other industries such as semiconductor manufacturing. A typical fluctuation of reduced HETP was seen. A Tsunami effect in manufacturing, the effect of propagation of manufacturing deviations leading to out-of-specification products, was not observed with these pre-packed columns. Principal component analysis (PCA) showed that all packing materials cluster. Our data analysis showed that the current commercially available chromatography media used for biopharmaceutical manufacturing can be reproducibly and uniformly packed in polymer-based chromatography columns, which are designed for ready-to-use purposes. Although the number of packed columns has quadrupled over one decade the packing quality has remained stable.

  14. Nonlinear model predictive control of a packed distillation column

    Energy Technology Data Exchange (ETDEWEB)

    Patwardhan, A.A.; Edgar, T.F. (Univ. of Texas, Austin, TX (United States). Dept. of Chemical Engineering)

    1993-10-01

    A rigorous dynamic model based on fundamental chemical engineering principles was formulated for a packed distillation column separating a mixture of cyclohexane and n-heptane. This model was simplified to a form suitable for use in on-line model predictive control calculations. A packed distillation column was operated at several operating conditions to estimate two unknown model parameters in the rigorous and simplified models. The actual column response to step changes in the feed rate, distillate rate, and reboiler duty agreed well with dynamic model predictions. One unusual characteristic observed was that the packed column exhibited gain-sign changes, which are very difficult to treat using conventional linear feedback control. Nonlinear model predictive control was used to control the distillation column at an operating condition where the process gain changed sign. An on-line, nonlinear model-based scheme was used to estimate unknown/time-varying model parameters.

  15. Design, testing, and simulation of microscale gas chromatography columns

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, M.L.; Kottenstette, R.; Matzke, C.M.; Frye-Mason, G.C.; Shollenberger, K.A.; Adkins, D.R.; Wong, C.C.

    1998-08-01

    A microscale gas chromatography column is one component in a microscale chemistry laboratory for detecting chemical agents. Several columns were fabricated using the Bosch etch process which allows deep, high aspect ratio channels of rectangular cross-section. A design tool, based on analytical models, was developed to evaluate the effects of operating conditions and column specifications on separation resolution and time. The effects of slip flow, channel configuration, and cross-sectional shape were included to evaluate the differences between conventional round, straight columns and the microscale rectangular, spiral columns. Experimental data were obtained and compared with the predicted flowrates and theoretical number of plates. The design tool was then employed to select more optimum channel dimensions and operating conditions for high resolution separations.

  16. HEAT TRANSFER ANALYSIS FOR ION-EXCHANGE COLUMN SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.; King, W.

    2011-05-23

    Models have been developed to simulate the thermal characteristics of Crystalline Silicotitanate (CST) ion exchange media fully loaded with radioactive cesium in a column configuration and distributed within a waste storage tank. This work was conducted to support the Small Column Ion Exchange (SCIX) program which is focused on processing dissolved, high-sodium salt waste for the removal of specific radionuclides (including Cs-137, Sr-90, and actinides) within a High Level Waste (HLW) storage tank at the Savannah River Site. The SCIX design includes CST columns inserted and supported in the tank top risers for cesium removal. Temperature distributions and maximum temperatures across the column were calculated with a focus on process upset conditions. A two-dimensional computational modeling approach for the in-column ion-exchange domain was taken to include conservative, bounding estimates for key parameters such that the results would provide the maximum centerline temperatures achievable under the design configurations using a feed composition known to promote high cesium loading on CST. The current full-scale design for the CST column includes one central cooling pipe and four outer cooling tubes. Most calculations assumed that the fluid within the column was stagnant (i.e. no buoyancy-induced flow) for a conservative estimate. A primary objective of these calculations was to estimate temperature distributions across packed CST beds immersed in waste supernate or filled with dry air under various accident scenarios. Accident scenarios evaluated included loss of salt solution flow through the bed, inadvertent column drainage, and loss of active cooling in the column. The modeling results demonstrate that the baseline design using one central and four outer cooling tubes provides a highly efficient cooling mechanism for reducing the maximum column temperature.

  17. Boron and Zinc Transport Through Intact Columns of Calcareous Soils

    Institute of Scientific and Technical Information of China (English)

    M. MAHMOOD-UL-HASSAN; M. S. AKHTAR; G. NABI

    2008-01-01

    Leaching of boron (B) and zinc (Zn) can be significant in some pedomorphic conditions, which can cause contamination of shallow groundwater and economic losses. Boron and Zn adsorption and transport was studied using 8.4 cm diameter ×28 cm long intact columns from two calcareous soil series with differing clay contents and vadose zone structures:Lyallpur soil series, clay loam (fine-silty, mixed, hyperthermic Ustalfic Haplargid), and Sultanpur soil series, sandy loam (coarse-silty, mixed, hyperthermic Ustollic Camborthid). The adsorption isotherms were developed by equilibrating soil with 0.01 mol L-1 CaCl2 aqueous solution containing varying amounts of B and Zn and were fitted to the Langmuir equation. The B and Zn breakthrough curves were fitted to the two-domain convective-dispersive equation. At the end of the leaching experiment, 0.11 L 10 g L-1 blue dye solution was also applied to each column to mark the flow paths.The Lyallpur soil columns had a slightly greater adsorption partition coefficient both for B and Zn than the Sultanpur soil columns. In the Lyallpur soil columns, B arrival was immediate but the peak concentration ratio (the concentration in solution at equilibrium/concentration applied) was lower than that in the Sultanpur soil columns. The breakthrough of B in the Sultanpur soil columns occurred after about 10 cm of cumulative drainage in both the columns; the rise in effluent concentration was fast and the peak concentration ratio was almost 1. Zinc leaching through the soil columns was very limited as only one column from the Lyallpur soil series showed Zn breakthrough in the effluent where the peak concentration ratio was only 0.05. This study demonstrates the effect of soil structure on B transport and has implications for the nutrient management in field soils.

  18. Mitigation of Liquefaction in Sandy Soils Using Stone Columns

    Science.gov (United States)

    Selcuk, Levent; Kayabalı, Kamil

    2010-05-01

    Soil liquefaction is one of the leading causes of earthquake-induced damage to structures. Soil improvement methods provide effective solutions to reduce the risk of soil liquefaction. Thus, soil ground treatments are applied using various techniques. However, except for a few ground treatment methods, they generally require a high cost and a lot of time. Especially in order to prevent the risk of soil liquefaction, stone columns conctructed by vibro-systems (vibro-compaction, vibro-replacement) are one of the traditional geotechnical methods. The construction of stone columns not only enhances the ability of clean sand to drain excess pore water during an earthquake, but also increases the relative density of the soil. Thus, this application prevents the development of the excess pore water pressure in sand during earthquakes and keeps the pore pressure ratio below a certain value. This paper presents the stone column methods used against soil liquefaction in detail. At this stage, (a) the performances of the stone columns were investigated in different spacing and diameters of columns during past earthquakes, (b) recent studies about design and field applications of stone columns were presented, and (c) a new design method considering the relative density of soil and the capacity of drenage of columns were explained in sandy soil. Furthermore, with this new method, earthquake performances of the stone columns constructed at different areas were investigated before the 1989 Loma Prieta and the 1994 Northbridge earthquakes, as case histories of field applications, and design charts were compiled for suitable spacing and diameters of stone columns with consideration to the different sandy soil parameters and earhquake conditions. Key Words: Soil improvement, stone column, excess pore water pressure

  19. Novel techniques for slurry bubble column hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Dudukovic, M.P.

    1999-05-14

    The objective of this cooperative research effort between Washington University, Ohio State University and Exxon Research Engineering Company was to improve the knowledge base for scale-up and operation of slurry bubble column reactors for syngas conversion and other coal conversion processes by increased reliance on experimentally verified hydrodynamic models. During the first year (July 1, 1995--June 30, 1996) of this three year program novel experimental tools (computer aided radioactive particle tracking (CARPT), particle image velocimetry (PIV), heat probe, optical fiber probe and gamma ray tomography) were developed and tuned for measurement of pertinent hydrodynamic quantities, such as velocity field, holdup distribution, heat transfer and bubble size. The accomplishments were delineated in the First Technical Annual Report. The second year (July, 1996--June 30, 1997) was spent on further development and tuning of the novel experimental tools (e.g., development of Monte Carlo calibration for CARPT, optical probe development), building up the hydrodynamic data base using these tools and comparison of the two techniques (PIV and CARPT) for determination of liquid velocities. A phenomenological model for gas and liquid backmixing was also developed. All accomplishments were summarized in the Second Annual Technical Report. During the third and final year of the program (July 1, 1997--June 30, 1998) and during the nine months no cost extension, the high pressure facility was completed and a set of data was taken at high pressure conditions. Both PIV, CT and CARPT were used. More fundamental hydrodynamic modeling was also undertaken and model predictions were compared to data. The accomplishments for this period are summarized in this report.

  20. Column Grid Array Rework for High Reliability

    Science.gov (United States)

    Mehta, Atul C.; Bodie, Charles C.

    2008-01-01

    Due to requirements for reduced size and weight, use of grid array packages in space applications has become common place. To meet the requirement of high reliability and high number of I/Os, ceramic column grid array packages (CCGA) were selected for major electronic components used in next MARS Rover mission (specifically high density Field Programmable Gate Arrays). ABSTRACT The probability of removal and replacement of these devices on the actual flight printed wiring board assemblies is deemed to be very high because of last minute discoveries in final test which will dictate changes in the firmware. The questions and challenges presented to the manufacturing organizations engaged in the production of high reliability electronic assemblies are, Is the reliability of the PWBA adversely affected by rework (removal and replacement) of the CGA package? and How many times can we rework the same board without destroying a pad or degrading the lifetime of the assembly? To answer these questions, the most complex printed wiring board assembly used by the project was chosen to be used as the test vehicle, the PWB was modified to provide a daisy chain pattern, and a number of bare PWB s were acquired to this modified design. Non-functional 624 pin CGA packages with internal daisy chained matching the pattern on the PWB were procured. The combination of the modified PWB and the daisy chained packages enables continuity measurements of every soldered contact during subsequent testing and thermal cycling. Several test vehicles boards were assembled, reworked and then thermal cycled to assess the reliability of the solder joints and board material including pads and traces near the CGA. The details of rework process and results of thermal cycling are presented in this paper.

  1. Improved column-based radiochemical processing of the generator produced {sup 68}Ga

    Energy Technology Data Exchange (ETDEWEB)

    Loktionova, N.S. [Institute of Nuclear Chemistry, University of Mainz, 55128 Mainz (Germany); Belozub, A.N.; Filosofov, D.V. [Joint Institute of Nuclear Research, DLNP, 141980 Dubna (Russian Federation); Zhernosekov, K.P. [Chair of Radiochemistry, Technical University of Munich, 85748 Garching (Germany); Center for Radiopharmaceutical Science, Paul Scherrer Institute, 5232 Villigen, PSI (Switzerland); Laboratory of Radiochemistry and Environmental Chemistry, Paul Scherrer Institute, 5232 Villigen, PSI (Switzerland); Wagner, T. [Chair of Radiochemistry, Technical University of Munich, 85748 Garching (Germany); Tuerler, A. [Chair of Radiochemistry, Technical University of Munich, 85748 Garching (Germany); Laboratory of Radiochemistry and Environmental Chemistry, Paul Scherrer Institute, 5232 Villigen, PSI (Switzerland); Labor fuer Radio- und Umweltchemie Departement Chemie und Biochemie Universitaet Bern, 3012 Bern (Switzerland); Roesch, F., E-mail: frank.roesch@uni-mainz.d [Institute of Nuclear Chemistry, University of Mainz, 55128 Mainz (Germany)

    2011-07-15

    An improved chemical strategy for processing of the generator produced {sup 68}Ga was developed based on processing of the original {sup 68}Ge/{sup 68}Ga generator eluate on a micro-column. Direct pre-concentration and purification of the eluted {sup 68}Ga is performed on a cation-exchange resin in hydrochloric acid/acetone media. A supplementary step based on a second micro-column filled with a second resin allows direct re-adsorption of {sup 68}Ga eluted from the cation exchanger. {sup 68}Ga is finally striped from the second resin with a small volume of pure water. For this purpose a strong anion exchanger and a novel extraction chromatographic resin based on tetraalkyldiglycolamides are characterized. The strategy allows online pre-concentration and purification of {sup 68}Ga from the original generator eluate. The supplementary column allows transferring {sup 68}Ga with high radionuclide and chemical quality in the aqueous solution with small volume and low acidity useful for direct radiolabeling reactions.

  2. Selective isolation of β-glucan from corn pericarp hemicelluloses by affinity chromatography on cellulose column.

    Science.gov (United States)

    Yoshida, Tomoki; Honda, Yoichi; Tsujimoto, Takashi; Uyama, Hiroshi; Azuma, Jun-ichi

    2014-10-13

    A combination of anion-exchange chromatography and affinity chromatography on a cellulose column was found to be effective for the isolation of β-(1,3;1,4)-glucan (BG) from corn pericarp hemicelluloses (CPHs). CPHs containing 6.6% BG were extracted from corn pericarp with 6M urea-2 wt% NaOH solution and initially fractionated into neutral and acidic parts by anion exchange chromatography to remove acidic arabinoxylan consisting of arabinose (35.6%) and xylose (50.9%). The neutral fraction (yield; 10.1% on the basis of CPHs) consisting of 1.0% arabinose, 10.1% xylose and 80.3% glucose containing 28.4% BG was then applied to a cellulose column of Whatman CF-11. BG could be recovered from the adsorbed fraction on the cellulose column by elution with 2% NaOH in a yield of 2.6% on the basis of CPHs with a purity of 84.7%. The chemical structure of the isolated corn pericarp BG was confirmed by (13)C NMR spectroscopic, methylation and lichenase treatment analyses. The results indicate that the ratios of (1,4)/(1,3) linkage and cellotriosyl/cellotetraosyl segments of the BG were 2.60 and 2.5, respectively.

  3. Experimental design and statistical analysis in Rotating Disc Contactor (RDC) column

    Science.gov (United States)

    Ismail, Wan Nurul Aiffah; Zakaria, Siti Aisyah; Noor, Nor Fashihah Mohd; Ariffin, Wan Nor Munirah

    2015-12-01

    The purpose of this paper is to examine the performance of the liquid-liquid extraction in Rotating Disc Contactor (RDC) Column that being used in industries. In this study, the performance of small diameter column RDC using the chemical system involving cumene/isobutryric asid/water are analyzed by the method of design of the experiments (DOE) and also Multiple Linear Regression (MLR). The DOE method are used to estimated the effect of four independent. Otherwise, by using Multiple Linear Regression (MLR) is to justify the relationship between the input variables and output variables and also to determine which variable are more influence for both output variable. The input variables for both method include rotor speed (Nr); ratio of flow (Fd); concentration of continuous inlet (Ccin); concentration of dispersed inlet (Cdin); interaction between Nr with Fd; interaction between Nr with Ccin; interaction Nr with Cdin. Meanwhile the output variables are concentration of continuous outlet (Ccout) and concentration of dispersed outlet (Cdout) on RDC column performance. By using this two method, we have two linear model represent two output of Ccout and Cdout for MLR. Lastly, the researcher want to determine which input variable that give more influence to output variable by using this two method. Based on the result, we obtained that rotor speed (Nr) more influence to dependent variable, Ccout and concentration of continuous inlet (Ccin) more influence to dependent variable, Cdout according the two method that was used.

  4. Column-by-column compositional mapping by Z-contrast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Molina, S.I. [Departamento de Ciencia de los Materiales e I.M. y Q.I., Facultad de Ciencias, Universidad de Cadiz, Campus Rio San Pedro, s/n, 11510 Puerto Real, Cadiz (Spain)], E-mail: sergio.molina@uca.es; Sales, D.L. [Departamento de Ciencia de los Materiales e I.M. y Q.I., Facultad de Ciencias, Universidad de Cadiz, Campus Rio San Pedro, s/n, 11510 Puerto Real, Cadiz (Spain); Galindo, P.L. [Departamento de Lenguajes y Sistemas Informaticos, CASEM, Universidad de Cadiz, Campus Rio San Pedro, s/n, 11510 Puerto Real, Cadiz (Spain); Fuster, D.; Gonzalez, Y.; Alen, B.; Gonzalez, L. [Instituto de Microelectronica de Madrid (CNM, CSIC), Isaac Newton 8, 28760 Tres Cantos, Madrid (Spain); Varela, M.; Pennycook, S.J. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

    2009-01-15

    A phenomenological method is developed to determine the composition of materials, with atomic column resolution, by analysis of integrated intensities of aberration-corrected Z-contrast scanning transmission electron microscopy images. The method is exemplified for InAs{sub x}P{sub 1-x} alloys using epitaxial thin films with calibrated compositions as standards. Using this approach we have determined the composition of the two-dimensional wetting layer formed between self-assembled InAs quantum wires on InP(0 0 1) substrates.

  5. Improved high performance liquid chromatographic separation of anthocyanin compounds from grapes using a novel mixed-mode ion-exchange reversed-phase column.

    Science.gov (United States)

    McCallum, Jason L; Yang, Raymond; Young, J Christopher; Strommer, Judith N; Tsao, Rong

    2007-04-27

    A novel mixed mode HPLC method using a column combining both ion-exchange and reversed-phase separation mechanisms has been developed to facilitate analysis of anthocyanins in grapes. Chromatographic performance and subsequent analysis of anthocyanidin diglucosides and acylated compounds are significantly improved using the new column, compared to those associated with conventional C18 reversed-phase methods. The mixed mode column produces a distinctive eluting pattern for the different anthocyanin subgroups, avoiding overlaps found with C18 columns. The enhanced chromatographic resolution provides nearly complete separation of 37 anthocyanin types, and permits detection of delphinidin 3-O-(6''-O-caffeoyl) beta-D-glucoside for the first time in extracts of skins from Concord grapes.

  6. Studies on the feasibility of using completely incinerable reagents for the single-cycle separation of americium(III) from simulated high-level liquid waste

    Energy Technology Data Exchange (ETDEWEB)

    Nayak, P.K.; Kumaresan, R.; Venkatesan, K.A.; Subramanian, G.G.S.; Prathibha, T.; Syamala, K.V.; Selvan, B. Robert; Rajeswari, S.; Antony, M.P.; Rao, P.R. Vasudeva [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Fuel Chemistry Div.; Chaurasia, Shivkumar; Bhanage, B.M. [Institute of Chemical Technology, Mumbai (India)

    2015-06-01

    The extraction and stripping behavior of various metal ions present in the fast reactor simulated high-level liquid waste (FR-SHLLW) was studied using a solvent phase composed of a neutral extractant, N,N,-didodecyl-N',N'-dioctyl-3-oxapentane-1,5-diamide (D{sup 3}DODGA) and an acidic extractant, di-2-ethylhexyl diglycolamic acid (HDEHDGA) in n-dodecane (n-DD). The third phase formation behavior of the solvent formulation D{sup 3}DODGA + HDEHDGA/n-DD, was studied when it was contacted with FR-SHLLW, and the concentration of neutral and acidic extractant needed to avoid the third phase formation was optimized. The distribution ratio of various metal ions present in FR-SHLLW was measured in a solution of 0.1 M D{sup 3}DODGA + 0.2 M HDEHDGA/n-DD. The extraction of Am(III) was accompanied by the co-extraction of lanthanides and unwanted metal ions such as Zr(IV), Y(III), and Pd(II). A procedure was developed to minimize the extraction of unwanted metal ions by using aqueous soluble complexing agents in FR-SHLLW. Based on those results, the counter-current mixer-settler run was performed in a 20-stage mixer-settler. Quantitative extraction of Am(III), Ln(III), Y(III), and Sr(II) in 0.1 M D{sup 3}DODGA + 0.2 M HDEHDGA/n-DD was observed. The recovery of Am(III) from the loaded organic phase was carried out by the optimized aqueous formulation composed of 0.01 M diethylenetriaminepentaacetic acid (DTPA) + 0.5 M citric acid (CA) at pH 1.5. The stripping of Am(III) was accompanied by co-stripping of some early lanthanides. However the later lanthanides (Eu(III) and beyond) were not back extracted to Am(III) product. Therefore, the studies foresee the possibility of intra-lanthanides as well as lanthanide-actinide separation in a single-processing cycle.

  7. Information extraction

    NARCIS (Netherlands)

    Zhang, Lei; Hoede, C.

    2002-01-01

    In this paper we present a new approach to extract relevant information by knowledge graphs from natural language text. We give a multiple level model based on knowledge graphs for describing template information, and investigate the concept of partial structural parsing. Moreover, we point out that

  8. EXPANDING EXTRACTIONS

    NARCIS (Netherlands)

    Dietzenbacher, Erik; Lahr, Michael L.

    2013-01-01

    In this paper, we generalize hypothetical extraction techniques. We suggest that the effect of certain economic phenomena can be measured by removing them from an input-output (I-O) table and by rebalancing the set of I-O accounts. The difference between the two sets of accounts yields the phenomeno

  9. NEW DESIGNS OF COLUMNS, INHABITED, INDUSTRIAL AND ADMINISTRATIVE BUILDINGS

    Directory of Open Access Journals (Sweden)

    Belokur K. A.

    2016-01-01

    Full Text Available Original screw designs of buildings and columns are offered. Frameworks of these buildings and columns are the bearing elements and means of external and internal decoration of buildings and constructions. Originality of such buildings and columns frameworks is ensured by the fact that their design is decorated on the outer surface with broken or smooth screw edges and screw surfaces. Versatility of the offered screw columns trunks designs, as well as the possibility of performance of their left or right screwing allows reaching certain symmetry or their repeatability in the form of harmonious alternation of the bearing trunks of screw columns and spaces between them. Giving to numerous sides of trunks of screw columns of a certain invoice, or their coloring in different colors, will contribute even more to their expressiveness and beauty. Durability and vibration resistance (including seismic of such trunks of screw columns at the same volumes of construction materials, in comparison with round and rectangular trunks is higher

  10. Modeling atrazine transport in soil columns with HYDRUS-1D

    Directory of Open Access Journals (Sweden)

    John Leju CELESTINO LADU

    2011-09-01

    Full Text Available Both physical and chemical processes affect the fate and transport of herbicides. It is useful to simulate these processes with computer programs to predict solute movement. Simulations were run with HYDRUS-1D to identify the sorption and degradation parameters of atrazine through calibration from the breakthrough curves (BTCs. Data from undisturbed and disturbed soil column experiments were compared and analyzed using the dual-porosity model. The study results show that the values of dispersivity are slightly lower in disturbed columns, suggesting that the more heterogeneous the structure is, the higher the dispersivity. Sorption parameters also show slight variability, which is attributed to the differences in soil properties, experimental conditions and methods, or other ecological factors. For both of the columns, the degradation rates were similar. Potassium bromide was used as a conservative non-reactive tracer to characterize the water movement in columns. Atrazine BTCs exhibited significant tailing and asymmetry, indicating non-equilibrium sorption during solute transport. The dual-porosity model was verified to best fit the BTCs of the column experiments. Greater or lesser concentration of atrazine spreading to the bottom of the columns indicated risk of groundwater contamination. Overall, HYDRUS-1D successfully simulated the atrazine transport in soil columns.

  11. Analysis of Cordyceps by multi-column liquid chromatography

    Directory of Open Access Journals (Sweden)

    Zhengming Qian

    2017-03-01

    Full Text Available Cordyceps is a famous traditional Chinese medicine (TCM that has been used in China for hundreds of years. In the present study a multi-column liquid chromatography (MC-LC system was developed for the qualitative analysis of macromolecules and micromolecules in Cordyceps. The MC-LC system includes a size exclusion pre-column, a size exclusion column (SEC and a reversed phase column (RP which were controlled by column-switching valves. The sample was separated by the size exclusion pre-column into two fractions (macromolecules and micromolecules. These fractions were further separated on SEC and RP columns, respectively. A diode array detector (DAD and a mass spectrometer (MS were used to detect the components. This MC-LC method was utilized for analysis of Cordyceps samples. Two macromolecular peaks and 15 micromolecular peaks were found in Cordyceps, and 11 of the micromolecular peaks were identified as adenosine-5′-monophosphate (AMP, phenylalanine, uridine, hypoxanthine, inosine, guanine, guanosine, deoxyadenosine-5′-monophosphate (dAMP, adenosine, adenine and cordycepin (or its isomer. This method is useful for quality control of Cordyceps.

  12. Analysis of Cordyceps by multi-column liquid chromatography.

    Science.gov (United States)

    Qian, Zhengming; Li, Shaoping

    2017-03-01

    Cordyceps is a famous traditional Chinese medicine (TCM) that has been used in China for hundreds of years. In the present study a multi-column liquid chromatography (MC-LC) system was developed for the qualitative analysis of macromolecules and micromolecules in Cordyceps. The MC-LC system includes a size exclusion pre-column, a size exclusion column (SEC) and a reversed phase column (RP) which were controlled by column-switching valves. The sample was separated by the size exclusion pre-column into two fractions (macromolecules and micromolecules). These fractions were further separated on SEC and RP columns, respectively. A diode array detector (DAD) and a mass spectrometer (MS) were used to detect the components. This MC-LC method was utilized for analysis of Cordyceps samples. Two macromolecular peaks and 15 micromolecular peaks were found in Cordyceps, and 11 of the micromolecular peaks were identified as adenosine-5'-monophosphate (AMP), phenylalanine, uridine, hypoxanthine, inosine, guanine, guanosine, deoxyadenosine-5'-monophosphate (dAMP), adenosine, adenine and cordycepin (or its isomer). This method is useful for quality control of Cordyceps.

  13. Interpreting satellite column observations of formaldehyde over tropical South America.

    Science.gov (United States)

    Palmer, Paul I; Barkley, Michael P; Kurosu, Thomas P; Lewis, Alastair C; Saxton, Julie E; Chance, Kelly; Gatti, Luciana V

    2007-07-15

    Space-borne column measurements of formaldehyde (HCHO), a high-yield oxidation product of volatile organic compounds (VOCs), represent important constraints for quantifying net regional fluxes of VOCs. Here, we interpret observed distributions of HCHO columns from the Global Ozone Monitoring Experiment (GOME) over tropical South America during 1997-2001. We present the first comparison of year-long in situ isoprene concentrations and fire-free GOME HCHO columns over a tropical ecosystem. GOME HCHO columns and in situ isoprene concentrations are elevated in the wet and dry seasons, with the highest values in the dry season. Previous analysis of the in situ data highlighted the possible role of drought in determining the elevated concentrations during the dry season, inferring the potential of HCHO columns to provide regional-scale constraints for estimating the role of drought on isoprene emissions. The agreement between the observed annual cycles of GOME HCHO columns and Along-Track Scanning Radiometer firecount data over the Amazon basin (correlations typically greater than 0.75 for a particular year) illustrates the potential of HCHO column to provide quantitative information about biomass burning emissions.

  14. Water column particulate matter: A key contributor to phosphorus regeneration in a coastal eutrophic environment, the Chesapeake Bay: Particulate phosphorus in the Chesapeake Bay

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jiying [Department of Plant and Soil Sciences, University of Delaware, Newark Delaware USA; Reardon, Patrick [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland Washington USA; Now at NMR Facility, Oregon State University, Corvallis Oregon USA; McKinley, James P. [Geochemistry Group, Pacific Northwest National Laboratory, Richland Washington USA; Joshi, Sunendra R. [Department of Plant and Soil Sciences, University of Delaware, Newark Delaware USA; Bai, Yuge [Department of Plant and Soil Sciences, University of Delaware, Newark Delaware USA; Bear, Kristi [Department of Plant and Soil Sciences, University of Delaware, Newark Delaware USA; Jaisi, Deb P. [Department of Plant and Soil Sciences, University of Delaware, Newark Delaware USA

    2017-04-01

    Particulate phosphorus (PP) in the water column is an essential component of phosphorus (P) cycling in aquatic ecosystems yet its composition and transformations remain largely uncharacterized. To understand the roles of suspended particulates on regeneration of inorganic P (Pi) into the water column as well as sequestration into more stable mineral precipitates, we studied seasonal variation in both organic and inorganic P speciation in suspended particles in three sites in the Chesapeake Bay using sequential P extraction, 1D (31P) and 2D (1H-31P) nuclear magnetic resonance (NMR) spectroscopies, and electron microprobe analyses (EMPA). Remineralization efficiency of particulate P average 8% and 56% in shallow and deep sites respectively, suggesting the importance of PP remineralization is in resupplying water column Pi. Strong temporal and spatial variability of organic P composition, distributions, and remineralization efficiency were observed relating to water column parameters such as temperature and redox conditions: concentration of orthophosphate monoesters and diesters, and diester-to-monoester (D/M) ratios decreased with depth. Both esters and the D/M ratios were lower in the hypoxic July and September. In contrast, pyrophosphate and orthophosphate increased with depth, and polyphosphates was high in the anoxic water column. Sequential extraction and EMPA analyses of the suspended particles suggest presence of Ca-bound phosphate in the water column. We hypothesize authigenic precipitation of carbonate fluorapatite and/or its precursor mineral(s) in Pi rich water column, supported by our thermodynamic calculations. Our results, overall, reveal the important role suspended particles play in P remineralization and P sequestration in the Chesapeake Bay water column, provide important implications on P bioavailability and P sinks in similar eutrophic coastal environments.

  15. Inner-pipe structure to improve column heterogeneity and peak shape.

    Science.gov (United States)

    Hu, Di; Mei, Xiang; Shi, Pengchao; Zhou, Xin

    2015-04-01

    Column heterogeneity plays an important role in peak tailing and asymmetric profiles. We have designed a novel column structure (concentric column structure) that has a concentric inner-pipe nested in a column. This structure was studied by a number calculation method and wider diameter column experiments. The results showed that column heterogeneity and column efficiency were improved by inner-pipe structure. Moreover, the results showed that high-efficiency columns were stronger influenced by inner-pipe structure than low-efficiency columns. The influence of an inner-pipe was related to its size. The optimal inner-pipe diameter was nearly 0.625 times of column diameter. By using inner-pipe structure in this way, it was possible to decrease column heterogeneity and increase column efficiency of a wide-diameter column. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Miniature electron microscope beam column optics

    Science.gov (United States)

    Loyd, Jody Stuart

    This investigation is in the area of electrostatic lens design with the overarching goal of contributing to the creation of a miniaturized scanning electron microscope (SEM) for use in mineralogical analysis or detection of signs of life on the surface of Mars. Such an instrument could also have application in the exploration of Earth's moon, planetary moons, asteroids, or comets. Other embodiments could include tabletop or field portable SEMs for use on Earth. The scope of this research is in the design of a beam column that attains focusing, demagnification, and aberration control within the smallest achievable package. The goals of planetary exploration and of spaceflight in general impose severe constraints on the instrument's mass and electrical power consumption, while favoring a robust design of small size and high rigidity that is also simple to align. To meet these requirements a design using electrostatic lenses was favored because of the lower power requirement and mass of electrostatic versus magnetic lenses, their relatively simple construction, as well as inherently easier shielding from extraneous fields. In modeling the lens field, a hybrid of a Boundary Element Method (BEM) and a Fourier series solution was employed, whereby an initial solution from the BEM is used to derive the bounding potential of a cylindrical subdomain for the subsequent Fourier series solution. The approach is applicable to many problems in physics and combines the inherent precision of this series solution with the flexibility of BEM to describe practical, non-idealized electrode shapes. The resulting lens field in the Fourier series subdomain is of higher precision, thereby allowing smaller errors in subsequent calculations of electron ray paths. The effects of aberrations are thus easier to observe in tracing non-paraxial rays. A significant speed increase in tracing rays is also observed. The modeling technique has been validated by reproducing example ray-traces through

  17. Numerical models of Plinian eruption columns and pyroclastic flows

    Science.gov (United States)

    Valentine, Greg A.; Wohletz, Kenneth H.

    1989-02-01

    Numerical simulations of physical processes governing the large-scale dynamics of Plinian eruption columns reveal conditions contributing to column collapse and emplacement of pyroclastic flows. The simulations are based on numerical solution of the time-dependent, two-phase, compressible Navier-Stokes equations for jets in a gravitational field. This modeling effort is directed toward studying the steady discharge phase of eruptions in contrast to our previous models of the initial, unsteady blast phase. Analysis of 51 eruption models covers a wide range of vent exit pressures, inertial and buoyancy driving forces, and coupling of energy and momentum between gas and pyroclasts. Consideration of three dimensionless groups (Richardson and Rouse numbers and thermogravitational parameter) facilitates this analysis and defines conditions leading to column collapse. For eruptions with similar particle size characteristics, exit pressure ratios are also very important in determining column behavior; column behavior is much more sensitive to exit pressure ratio than to the density ratio between the column and the atmosphere. Model eruption columns with exit pressures exceeding atmospheric pressure have diamond-shaped patterns at their bases with internal dynamics that correspond closely to observations of overpressured jets in laboratory experiments. Collapsing fountains form pyroclastic flows that consist of low-concentration fronts, relatively thick heads, vortex development along the top surfaces, and rising clouds of buoyant ash. The presence of coarse-grained proximal deposits primarily reflects tephra size sorting within the eruption column before collapse, as opposed to that which occurs during lateral transport of the material in pyroclastic flows. The dynamics and particle behavior in the proximal zone around collapsing eruption columns is examined; the modeling indicates that flow within a few kilometers of a vent will be at its highest particle concentration

  18. Fast simultaneous determination of prominent polyphenols in vegetables and fruits by reversed phase liquid chromatography using a fused-core column

    OpenAIRE

    Marti, R.; Valcarcel, M.; Herrero-Martinez, J.M.; Cebolla Cornejo, Jaime; ROSELLO RIPOLLES, SALVADOR

    2015-01-01

    A reversed-phase high-performance liquid chromatography method with photodiode array detection has been developed enabling the joint determination of 17 prominent flavonoids and phenolic acids in vegetables and fruits. A multi-segmented gradient program using a fused-core column for the separation of several phenolic classes (phenolic acids and flavonoids) has been optimised. The influence of extraction conditions (sample freeze-drying, ultrasound extraction, solvent composition and extractio...

  19. Antibacterial activity of Citrus reticulata peel extracts.

    Science.gov (United States)

    Jayaprakasha, G K; Negi, P S; Sikder, S; Rao, L J; Sakariah, K K

    2000-01-01

    Citrus peels were successively extracted with hexane, chloroform and acetone using a soxhlet extractor. The hexane and chloroform extracts were fractionated into alcohol-soluble and alcohol-insoluble fractions. These fractions were tested against different gram positive and gram negative bacteria. The EtOH-soluble fraction was found to be most effective. Fractionation of EtOH-soluble fraction on silica gel column yielded three polymethoxylated flavones, namely desmethylnobiletin, nobiletin and tangeretin. Their structures were confirmed by UV, 1H, 13C NMR and mass spectral studies. The findings indicated a potential of these natural compounds as biopreservatives in food applications.

  20. Confined High Strength Concrete Columns: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Jagannathan Saravanan

    2010-01-01

    Full Text Available Problem statement: An experimental study on GFRP confined high strength concrete columns has been carried out with a view to evaluate its performances under uni-axial compression in terms of load and deformation capacity. Approach: High strength concrete columns strengthened with different configuration and stiffness of GFRP wraps were tested under axial compression until failure. Their response evaluated at different load levels. Results: The test results clearly indicated GFRP wrapped high strength concrete columns exhibit enhances performance. Conclusion: The study concluded that the three GFRP materials attempted UDC GFRP provided the maximum benefit with respect to load and deformation.