WorldWideScience

Sample records for beads packed column

  1. Tritium isotope separation by water distillation column packed with silica-gel beads

    International Nuclear Information System (INIS)

    Fukada, Satoshi

    2004-01-01

    Tritium enrichment or depletion by water distillation was investigated using a glass column of 32cm in height packed with silica-gel beads of 3.4mm in average diameter. The total separation factor of the silica-gel distillation column, α H-T , was compared with those of an open column distillation tower and of a column packed with stainless-steel Dixon rings. Depletion of the tritium activity in the distillate was enhanced by isotopic exchange with water absorbed on silica-gel beads that have a higher affinity for HTO than for H 2 O. The value of α H-T -1 of the silica-gel distillation column was about four times larger than that of a column without any packing and about two times larger than that of the Dixon-ring column. The improvement of α H-T by the silica-gel adsorbent indicated that the height of the distillation-adsorption column becomes shorter than that of the height of conventional distillation columns. (author)

  2. Effect of gravity on colloid transport through water-saturated columns packed with glass beads: modeling and experiments.

    Science.gov (United States)

    Chrysikopoulos, Constantinos V; Syngouna, Vasiliki I

    2014-06-17

    The role of gravitational force on colloid transport in water-saturated columns packed with glass beads was investigated. Transport experiments were performed with colloids (clays: kaolinite KGa-1b, montmorillonite STx-1b). The packed columns were placed in various orientations (horizontal, vertical, and diagonal) and a steady flow rate of Q = 1.5 mL/min was applied in both up-flow and down-flow modes. All experiments were conducted under electrostatically unfavorable conditions. The experimental data were fitted with a newly developed, analytical, one-dimensional, colloid transport model. The effect of gravity is incorporated in the mathematical model by combining the interstitial velocity (advection) with the settling velocity (gravity effect). The results revealed that flow direction influences colloid transport in porous media. The rate of particle deposition was shown to be greater for up-flow than for down-flow direction, suggesting that gravity was a significant driving force for colloid deposition.

  3. Column-to-column packing variation of disposable pre-packed columns for protein chromatography.

    Science.gov (United States)

    Schweiger, Susanne; Hinterberger, Stephan; Jungbauer, Alois

    2017-12-08

    In the biopharmaceutical industry, pre-packed columns are the standard for process development, but they must be qualified before use in experimental studies to confirm the required performance of the packed bed. Column qualification is commonly done by pulse response experiments and depends highly on the experimental testing conditions. Additionally, the peak analysis method, the variation in the 3D packing structure of the bed, and the measurement precision of the workstation influence the outcome of qualification runs. While a full body of literature on these factors is available for HPLC columns, no comparable studies exist for preparative columns for protein chromatography. We quantified the influence of these parameters for commercially available pre-packed and self-packed columns of disposable and non-disposable design. Pulse response experiments were performed on 105 preparative chromatography columns with volumes of 0.2-20ml. The analyte acetone was studied at six different superficial velocities (30, 60, 100, 150, 250 and 500cm/h). The column-to-column packing variation between disposable pre-packed columns of different diameter-length combinations varied by 10-15%, which was acceptable for the intended use. The column-to-column variation cannot be explained by the packing density, but is interpreted as a difference in particle arrangement in the column. Since it was possible to determine differences in the column-to-column performance, we concluded that the columns were well-packed. The measurement precision of the chromatography workstation was independent of the column volume and was in a range of±0.01ml for the first peak moment and±0.007 ml 2 for the second moment. The measurement precision must be considered for small columns in the range of 2ml or less. The efficiency of disposable pre-packed columns was equal or better than that of self-packed columns. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  4. The adsorption of copper in a packed-bed of chitosan beads: Modeling, multiple adsorption and regeneration

    OpenAIRE

    Neomagus, Hein W J P; Osifo, Peter O; Everson, Raymond C; Webster, Athena; Gun, Marius A

    2009-01-01

    In this study, exoskeletons of Cape rock lobsters were used as raw material in the preparation of chitin that was successively deacetylated to chitosan flakes. The chitosan flakes were modified into chitosan beads and the beads were cross-linked with glutaraldehyde in order to study copper adsorption and regeneration in a packed-bed column. Five consecutive adsorption and desorption cycles were carried out and a chitosan mass loss of 25% was observed, after the last cycle. Despite the loss of...

  5. Experimental investigation of virus and clay particles cotransport in partially saturated columns packed with glass beads.

    Science.gov (United States)

    Syngouna, Vasiliki I; Chrysikopoulos, Constantinos V

    2015-02-15

    Suspended clay particles in groundwater can play a significant role as carriers of viruses, because, depending on the physicochemical conditions, clay particles may facilitate or hinder the mobility of viruses. This experimental study examines the effects of clay colloids on the transport of viruses in variably saturated porous media. All cotransport experiments were conducted in both saturated and partially saturated columns packed with glass beads, using bacteriophages MS2 and ΦX174 as model viruses, and kaolinite (KGa-1b) and montmorillonite (STx-1b) as model clay colloids. The various experimental collision efficiencies were determined using the classical colloid filtration theory. The experimental data indicated that the mass recovery of viruses and clay colloids decreased as the water saturation decreased. Temporal moments of the various breakthrough concentrations collected, suggested that the presence of clays significantly influenced virus transport and irreversible deposition onto glass beads. The mass recovery of both viruses, based on total effluent virus concentrations, was shown to reduce in the presence of suspended clay particles. Furthermore, the transport of suspended virus and clay-virus particles was retarded, compared to the conservative tracer. Under unsaturated conditions both clay particles facilitated the transport of ΦX174, while hindered the transport of MS2. Moreover, the surface properties of viruses, clays and glass beads were employed for the construction of classical DLVO and capillary potential energy profiles, and the results suggested that capillary forces play a significant role on colloid retention. It was estimated that the capillary potential energy of MS2 is lower than that of ΦX174, and the capillary potential energy of KGa-1b is lower than that of STx-1b, assuming that the protrusion distance through the water film is the same for each pair of particles. Moreover, the capillary potential energy is several orders of

  6. Cotransport of clay colloids and viruses through water-saturated vertically oriented columns packed with glass beads: Gravity effects.

    Science.gov (United States)

    Syngouna, Vasiliki I; Chrysikopoulos, Constantinos V

    2016-03-01

    The cotransport of clay colloids and viruses in vertically oriented laboratory columns packed with glass beads was investigated. Bacteriophages MS2 and ΦX174 were used as model viruses, and kaolinite (ΚGa-1b) and montmorillonite (STx-1b) as model clay colloids. A steady flow rate of Q=1.5 mL/min was applied in both vertical up (VU) and vertical down (VD) flow directions. In the presence of KGa-1b, estimated mass recovery values for both viruses were higher for VD than VU flow direction, while in the presence of STx-1b the opposite was observed. However, for all cases examined, the produced mass of viruses attached onto suspended clay particles were higher for VD than VU flow direction, suggesting that the flow direction significantly influences virus attachment onto clays, as well as packed column retention of viruses attached onto suspended clays. KGa-1b hindered the transport of ΦX174 under VD flow, while STx-1b facilitated the transport of ΦX174 under both VU and VD flow directions. Moreover, KGa-1b and STx-1b facilitated the transport of MS2 in most of the cases examined except of the case where KGa-1b was present under VD flow. Also, the experimental data were used for the estimation of virus surface-coverages and virus surface concentrations generated by virus diffusion-limited attachment, as well as virus attachment due to sedimentation. Both sedimentation and diffusion limited virus attachment were higher for VD than VU flow, except the case of MS2 and STx-1b cotransport. The diffusion-limited attachment was higher for MS2 than ΦΧ174 for all cases examined. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Boiling phenomenon and heat transfer in bead-packed porous structure

    International Nuclear Information System (INIS)

    Zhang Xiaojie; ZHu Yanlei; Bai Bofeng; Yan Xiao; Xiao Zejun

    2009-01-01

    A visual study on pool boiling behavior and phase distribution was conducted on the porous structures made of staggered glass beads at atmospheric pressure. The bead-packed structure was heated on the bottom. The investigations were carried out respectively at different glass bead diameters which were 4 mm, 6 mm and 8 mm. The results show that during subcooled boiling, small isolated bubbles are formed on the heated surface and combine into main-bubbles, the dispersion frequency of the main-bubbles is low and the small bubbles scatter in the bead-packed porous structures. At the initial stage of saturated boiling, the bubble growth rate, the volume of main-bubbles and the range of continuous vapor phase increase. The dispersion frequency of main-bubbles increases with the increasing of heat flux. During film boiling, the heated surface is absolutely covered with vapor film and the porous structure is full of liquid. The larger the diameter of beads is, the higher heat flux is needed for the same phenomenon, and the higher maximum value of heat transfer coefficient will be. During the whole saturated boiling, and the heat transfer enhanced firstly and then weakened. Being opposite to that of the diameters of 4 mm and 8 mm, the heat transfer coefficient in the 6 mm-bead-packed porous structure decreases with the increasing of the heat flux. (authors)

  8. Evaluation of Packed Distillation Columns I - Atmospheric Pressure

    National Research Council Canada - National Science Library

    Reynolds, Thaine

    1951-01-01

    .... Four column-packing combinations of the glass columns and four column-packing combinations of the steel columns were investigated at atmospheric pressure using a test mixture of methylcyclohexane...

  9. The adsorption of copper in a packed-bed of chitosan beads: modeling, multiple adsorption and regeneration.

    Science.gov (United States)

    Osifo, Peter O; Neomagus, Hein W J P; Everson, Raymond C; Webster, Athena; vd Gun, Marius A

    2009-08-15

    In this study, exoskeletons of Cape rock lobsters were used as raw material in the preparation of chitin that was successively deacetylated to chitosan flakes. The chitosan flakes were modified into chitosan beads and the beads were cross-linked with glutaraldehyde in order to study copper adsorption and regeneration in a packed-bed column. Five consecutive adsorption and desorption cycles were carried out and a chitosan mass loss of 25% was observed, after the last cycle. Despite the loss of chitosan material, an improved efficiency in the second and third cycles was observed with the adsorbent utilizing 97 and 74% of its adsorbent capacity in the second and third cycles, respectively. The fourth and fifth cycles, however, showed a decreased efficiency, and breakage of the beads was observed after the fifth cycle. In the desorption experiments, 91-99% of the adsorbed copper was regenerated in the first three cycles. It was also observed that the copper can be regenerated at a concentration of about a thousand fold the initial concentration. The first cycle of adsorption could be accurately described with a shrinking core particle model combined with a plug flow column model. The input parameters for this model were determined by batch characterization methods, with as only fitting parameter, the effective diffusion coefficient of copper in the bead.

  10. The adsorption of copper in a packed-bed of chitosan beads: Modeling, multiple adsorption and regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Osifo, Peter O., E-mail: petero@vut.ac.za [Department of Chemical Engineering, Vaal University of Technology, P/Bag X021, Vanderbijlpark 1900 (South Africa); Neomagus, Hein W.J.P.; Everson, Raymond C. [School of Chemical and Minerals Engineering, North-West University, P/Bag X6001, Potchefstroom 2520 (South Africa); Webster, Athena [University of Utah, Chemistry Department, Salt Lake City, UT 84112 (United States); Gun, Marius A. vd [Sulzer Elbar B.V., Spikweien 36, NL-5943 AD Lomm (Netherlands)

    2009-08-15

    In this study, exoskeletons of Cape rock lobsters were used as raw material in the preparation of chitin that was successively deacetylated to chitosan flakes. The chitosan flakes were modified into chitosan beads and the beads were cross-linked with glutaraldehyde in order to study copper adsorption and regeneration in a packed-bed column. Five consecutive adsorption and desorption cycles were carried out and a chitosan mass loss of 25% was observed, after the last cycle. Despite the loss of chitosan material, an improved efficiency in the second and third cycles was observed with the adsorbent utilizing 97 and 74% of its adsorbent capacity in the second and third cycles, respectively. The fourth and fifth cycles, however, showed a decreased efficiency, and breakage of the beads was observed after the fifth cycle. In the desorption experiments, 91-99% of the adsorbed copper was regenerated in the first three cycles. It was also observed that the copper can be regenerated at a concentration of about a thousand fold the initial concentration. The first cycle of adsorption could be accurately described with a shrinking core particle model combined with a plug flow column model. The input parameters for this model were determined by batch characterization methods, with as only fitting parameter, the effective diffusion coefficient of copper in the bead.

  11. The adsorption of copper in a packed-bed of chitosan beads: Modeling, multiple adsorption and regeneration

    International Nuclear Information System (INIS)

    Osifo, Peter O.; Neomagus, Hein W.J.P.; Everson, Raymond C.; Webster, Athena; Gun, Marius A. vd

    2009-01-01

    In this study, exoskeletons of Cape rock lobsters were used as raw material in the preparation of chitin that was successively deacetylated to chitosan flakes. The chitosan flakes were modified into chitosan beads and the beads were cross-linked with glutaraldehyde in order to study copper adsorption and regeneration in a packed-bed column. Five consecutive adsorption and desorption cycles were carried out and a chitosan mass loss of 25% was observed, after the last cycle. Despite the loss of chitosan material, an improved efficiency in the second and third cycles was observed with the adsorbent utilizing 97 and 74% of its adsorbent capacity in the second and third cycles, respectively. The fourth and fifth cycles, however, showed a decreased efficiency, and breakage of the beads was observed after the fifth cycle. In the desorption experiments, 91-99% of the adsorbed copper was regenerated in the first three cycles. It was also observed that the copper can be regenerated at a concentration of about a thousand fold the initial concentration. The first cycle of adsorption could be accurately described with a shrinking core particle model combined with a plug flow column model. The input parameters for this model were determined by batch characterization methods, with as only fitting parameter, the effective diffusion coefficient of copper in the bead.

  12. A new affinity-HPLC packing for protein separation: Cibacron blue attached uniform porous poly(HEMA-co-EDM) beads.

    Science.gov (United States)

    Unsal, Ender; Durdu, Aysun; Elmas, Begum; Tuncel, Murvet; Tuncel, Ali

    2005-11-01

    In this study, a new affinity high-performance liquid chromatography (HPLC) stationary phase suitable for protein separation was synthesized. In the first stage of the synthesis, uniform porous poly(2-hydroxyethyl methacrylate-co-ethylene dimethacrylate), poly(HEMA-co-EDM), beads 6.2 mum in size were obtained. Homogeneous distribution of hydroxyl groups in the bead interior was confirmed by confocal laser scanning microscopy. The plain poly(HEMA-co-EDM) particles gave very low non-specific protein adsorption with albumin. The selected dye ligand Cibacron blue F3G-A (CB F3G-A) was covalently linked onto the beads via hydroxyl groups. In the batch experiments, albumin adsorption up to 60 mg BSA/g particles was obtained with the CB F3G-A carrying poly(HEMA-co-EDM) beads. The affinity-HPLC of selected proteins (albumin and lysozyme) was investigated in a 25 mm x 4.0-mm inner diameter column packed with CB F3G-A carrying beads and both proteins were successfully resolved. By a single injection, 200 mug of protein was loaded and quantitatively eluted from the column. The protein recovery increased with increasing flow rate and salt concentration of the elution buffer and decreased with the increasing protein feed concentration. During the albumin elution, theoretical plate numbers up to 30,000 plates/m were achieved by increasing the salt concentration.

  13. The general packed column : an analytical solution

    NARCIS (Netherlands)

    Gielen, J.L.W.

    2000-01-01

    The transient behaviour of a packed column is considered. The column, uniformly packed on a macroscopic scale, is multi-structured on the microscopic level: the solid phase consists of particles, which may differ in incidence, shape or size, and other relevant physical properties. Transport in the

  14. Effect of oxygen on ethanol fermentation in packed-bed tapered-column reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hamamci, H.; Ryu, D.D.Y.

    1988-07-01

    In ethanol production with immobilized yeast a major problem is the provision of nutrients to these highly concentrated cells. O/sub 2/ being one of the nutrients of utmost importance to yeast cells, was fed into a column packed with beads with a cell loading of more than 40 g/l. Since addition of large volume of air or O/sub 2/ to a cylindrical column reactor would aggravate the problems of pressure build up and channelling caused by the evolving CO/sub 2/ gas, a tapered-column reactor and pulsed flow of oxygen gas was used. The supplement of O/sub 2/ gas to the tapered column increased the productivity from 21.1 g ethanol x (l gel x h)/sup -1/ to 26.7 g x (l gelxh)/sup -1/, when the ethanol concentration at the outlet was about 80 g/l. The yield coefficient of ethanol was also increased from 0.41 g ethanol/g glucose to 0.43 after O/sub 2/ supplement was started. The effects of frequency and duration of O/sub 2/ supplement were also determined.

  15. Coupling sequential injection on-line preconcentration using a PTFE beads packed column to direct injection nebulization inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald

    2002-01-01

    An automated sequential injection on-line preconcentration procedure for trace metals by using a PTFE bead-packed microcolumn coupled to ICP-MS is described, and used for simultaneous analyses of cadmium and lead. In dilute nitric acid (0.5%, v/v), neutral complexes between the analytes...

  16. A Capillary Electrochromatographic Microchip Packed with Self-Assembly Colloidal Carboxylic Silica Beads

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, In Sun; Kim, Shin Seon; Park, Jong Man [Konkuk University, Seoul (Korea, Republic of)

    2012-04-15

    An electrochromatographic microchip with carboxyl-group-derivatized mono-disperse silica packing was prepared from the corresponding colloidal silica solution by utilizing capillary action and self-assembly behavior. The silica beads in water were primed by the capillary action toward the ends of cross-patterned microchannel on a cyclic olefinic copolymer (COC) substrate. Slow evaporation of water at the front of packing promoted the self-assembled packing of the beads. After thermally binding a cover plate on the chip substrate, reservoirs for sample solutions were fabricated at the ends of the microchannel. The packing at the entrances of the microchannel was silver coated to fix utilizing an electroless silver-plating technique to prevent the erosion of the packed structure caused by the sudden switching of a high voltage DC power source. The electrochromatographic behavior of the microchip was explored and compared to that of the microchip with bare silica packing in basic borate buffer. Electrophoretic migration of Rhodamine B was dominant in the microchip with the carboxyl-derivatized silica packing that resulted in a migration approximated twice as fast, while the reversible adsorption was dominant in the bare silica-packed microchip. Not only the faster migration rates of the negatively charged FITC-derivatives of amino acids but also the different migration due to the charge interaction at the packing surface were observed. The electrochromatographic characteristics were studied in detail and compared with those of the bare silica packed microchip in terms of the packing material, the separation potential, pH of the running buffer, and also the separation channel length

  17. The art and science of forming packed analytical high-performance liquid chromatography columns.

    Science.gov (United States)

    Kirkland, J J; Destefano, J J

    2006-09-08

    Columns of packed particles still are the most popular devices for high-performance liquid chromatography (HPLC) separations because of their great utility, excellent performance and wide variety. However, the forming of packed beds for efficient, stable columns traditionally has been an art where the basics of how to form optimum beds generally was not well understood. The recent development of monolith rods was introduced in part to overcome the difficulty of producing stable beds of packing particles. However, these materials are less versatile than packed particle columns. Technology developments in recent years have produced a better understanding among those skilled in the practice of how to form optimized packed beds, and this has led to widely available, high-quality commercial columns. This presentation discusses the developments that led to the present state of column packing technology. Important steps in the packing of efficient, stable beds are described. The key step of selecting the best solvent for the slurry packing method is emphasized. Factors affecting the mechanical stability of packed columns also are discussed. The early art of packing columns now has evolved into a more scientific approach that allows the packing of good columns with a minimum of effort and time.

  18. EXPERIMENTAL STUDY ON HEAT TRANSFER COEFFICIENT AND FRICTION FACTOR OF Al2O3 NANOFLUID IN A PACKED BED COLUMN

    Directory of Open Access Journals (Sweden)

    G. Srinivasa Rao

    2011-12-01

    Full Text Available The forced convection heat transfer coefficient and friction factor are determined for the flow of water and nanofluid in a vertical packed bed column. The analysis is undertaken in the laminar and transition Reynolds number range. The column is filled with spherical glass beads as the bed material. The heat transfer coefficients with Al2O3 nanofluid increased by 12% to 15% with the increase of volume concentration from 0.02% to 0.5% compared with water. The experimental values of axial temperature are in good agreement with the NTU-ε method proposed by Schumann’s model.

  19. HETP evaluation of structured packing distillation column

    Directory of Open Access Journals (Sweden)

    A. E. Orlando Jr.

    2009-09-01

    Full Text Available Several tests with a hydrocarbon mixture of known composition (C8-C14, obtained from DETEN Chemistry S.A., have been performed in a laboratory distillation column, having 40mm of nominal diameter and 2.2m high, with internals of Sulzer DX gauze stainless steel structured packing. The main purpose of this work was to evaluate HETP of a structured packing laboratory scale distillation column, operating continuously. Six HETP correlations available in the literature were compared in order to find out which is the most appropriate for structured packing columns working with medium distillates. Prior to the experimental tests, simulation studies using commercial software PRO/II® were performed in order to establish the optimum operational conditions for the distillation, especially concerning operating pressure, top and bottom temperatures, feed location and reflux ratio. The results of PRO/II® were very similar to the analysis of the products obtained during continuous operation, therefore permitting the use of the properties calculated by that software on the theoretical models investigated. The theoretical models chosen for HETP evaluation were: Bravo, Rocha and Fair (1985; Rocha, Bravo and Fair (1993, 1996; Brunazzi and Pagliant (1997; Carlo, Olujić and Pagliant (2006; Olujić et al., (2004. Modifications concerning calculation of specific areas were performed on the correlations in order to fit them for gauze packing HETP evaluation. As the laboratory distillation column was operated continuously, different HETP values were found by the models investigated for each section of the column. The low liquid flow rates in the top section of the column are a source of error for HETP evaluation by the models; therefore, more reliable HETP values were found in the bottom section, in which liquid flow rates were much greater. Among the theoretical models, Olujić et al. (2004 has shown good results relative to the experimental tests. In addition, the

  20. Pulse amplitude and frequency effects in a pulsed packed column

    Energy Technology Data Exchange (ETDEWEB)

    Russell, S H

    1954-04-15

    A study has been made of the effect on the efficiency and capacity of applying pulses of varying amplitude and frequency to a packed column. In the efficiency studies, the maximum efficiency was obtained with a pulse having an amplitude of 3/8'' and a frequency of 140 cycles per minute. Under these conditions, the column was about five times as efficient as a simple packed column. Two general types of results were obtained in the capacity studies. Under certain conditions, the capacity increased over that of a simple packed column, but under others, it decreased. Some of the factors causing this were investigated but the fundamental reasons were not determined due to a lack of personnel for the necessary experiments. (author)

  1. Pulse amplitude and frequency effects in a pulsed packed column

    International Nuclear Information System (INIS)

    Russell, S.H.

    1954-04-01

    A study has been made of the effect on the efficiency and capacity of applying pulses of varying amplitude and frequency to a packed column. In the efficiency studies, the maximum efficiency was obtained with a pulse having an amplitude of 3/8'' and a frequency of 140 cycles per minute. Under these conditions, the column was about five times as efficient as a simple packed column. Two general types of results were obtained in the capacity studies. Under certain conditions, the capacity increased over that of a simple packed column, but under others, it decreased. Some of the factors causing this were investigated but the fundamental reasons were not determined due to a lack of personnel for the necessary experiments. (author)

  2. Scalability of pre-packed preparative chromatography columns with different diameters and lengths taking into account extra column effects.

    Science.gov (United States)

    Schweiger, Susanne; Jungbauer, Alois

    2018-02-16

    Small pre-packed columns are commonly used to estimate the optimum run parameters for pilot and production scale. The question arises if the experiments obtained with these columns are scalable, because there are substantial changes in extra column volume when going from a very small scale to a benchtop column. In this study we demonstrate the scalability of pre-packed disposable and non-disposable columns of volumes in the range of 0.2-20 ml packed with various media using superficial velocities in the range of 30-500 cm/h. We found that the relative contribution of extra column band broadening to total band broadening was not only high for columns with small diameters, but also for columns with a larger volume due to their wider diameter. The extra column band broadening can be more than 50% for columns with volumes larger than 10 ml. An increase in column diameter leads to high additional extra column band broadening in the filter, frits, and adapters of the columns. We found a linear relationship between intra column band broadening and column length, which increased stepwise with increases in column diameter. This effect was also corroborated by CFD simulation. The intra column band broadening was the same for columns packed with different media. An empirical engineering equation and the data gained from the extra column effects allowed us to predict the intra, extra, and total column band broadening just from column length, diameter, and flow rate. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

  3. 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.

  4. Flow dynamics in distillation columns packed with Dixon rings as used in isotope separation

    International Nuclear Information System (INIS)

    Gilath, C.; Cohen, H.; Wolf, D.

    1977-01-01

    Packed distillation columns are common in isotope separation. The pressure drop serves as an indication for the hydrodynamic state of the column. Models were formulated for flow and pressure drop dynamics in packed distillation columns. These models were confirmed on columns packed with Dixon rings and operated with water for separation of oxygen isotopes. Liquid holdup displacement is very important in isotope separation practice. Experiments proved that distillation columns packed with Dixon rings exhibit a behaviour close to plug flow. (author)

  5. Micro-fabricated packed gas chromatography column based on laser etching technology.

    Science.gov (United States)

    Sun, J H; Guan, F Y; Zhu, X F; Ning, Z W; Ma, T J; Liu, J H; Deng, T

    2016-01-15

    In this work, a micro packed gas chromatograph column integrated with a micro heater was fabricated by using laser etching technology (LET) for analyzing environmental gases. LET is a powerful tool to etch deep well-shaped channels on the glass wafer, and it is the most effective way to increase depth of channels. The fabricated packed GC column with a length of over 1.6m, to our best knowledge, which is the longest so far. In addition, the fabricated column with a rectangular cross section of 1.2mm (depth) × 0.6mm (width) has a large aspect ratio of 2:1. The results show that the fabricated packed column had a large sample capacity, achieved a separation efficiency of about 5800 plates/m and eluted highly symmetrical Gaussian peaks. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Sequential injection on-line matrix removal and trace metal preconcentration using a PTFE beads packed column as demonstrated for the determination of cadmium by electrothermal atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald

    2002-01-01

    A sequential injection (SI) on-line matrix removal and trace metal preconcentration procedure by using a novel microcolumn packed with PTFE beads is described, and demonstrated for trace cadmium analysis with detection by electrothermal atomic absorption spectrometry (ETAAS). The analyte...

  7. Preparation of diclofenac-imprinted polymer beads for selective molecular separation in water.

    Science.gov (United States)

    Zhou, Tongchang; Kamra, Tripta; Ye, Lei

    2018-03-01

    Molecular imprinting technique is an attractive strategy to prepare materials for target recognition and rapid separation. In this work, a new type of diclofenac (DFC)-imprinted polymer beads was synthesized by Pickering emulsion polymerization using 2-(dimethylamino)ethyl methacrylate as the functional monomer. The selectivity and capacity of the molecularly imprinted polymers (MIPs) were investigated in aqueous solution. Equilibrium binding results show that the MIPs have a high selectivity to bind DFC in a wide range of pH values. Moreover, in liquid chromatography experiment, the imprinted polymer beads were packed into column to investigate the binding selectivity under nonequilibrium conditions. The retention time of DFC on the MIP column is significantly longer than its structural analogues. Also, retention of DFC on the MIP column was significantly longer than on the nonimprinted polymer column under aqueous condition. As the new MIP beads can be used to achieve direct separation of DFC from water, the synthetic method and the affinity beads developed in this work opened new possibilities for removing toxic chemicals from environmental and drinking water. Copyright © 2017 John Wiley & Sons, Ltd.

  8. Micro-fabricated semi-packed column for gas chromatography by using functionalized parylene as a stationary phase

    International Nuclear Information System (INIS)

    Nakai, T; Nishiyama, S; Shuzo, M; Delaunay, J-J; Yamada, I

    2009-01-01

    The conformal coating of effective stationary phases onto micro-fabricated columns having complex geometries such as semi-packed columns poses a real challenge. Here, we report for the first time the conformal coating of a semi-packed column with amino-functionalized parylene diX-AM (poly-aminomethyl-[2,2]-paracyclophane), which was found to be an effective stationary-phase material for the chromatography of short-retention-time compounds. A semi-packed column (consisting of a zigzag array of 30 µm square micro-pillars in a 1.0 m long, 180 µm wide and 230 µm deep channel) and an open tubular column (1.0 m long, 160 µm wide and 230 µm deep channel) used for comparison purposes were micro-fabricated on silicon that was subsequently coated with diX-AM parylene and thermally bonded. The chromatograms recorded on a commercial gas chromatograph demonstrated the usefulness of the conformal diX-AM coating as a stationary phase for semi-packed columns. The separation efficiency of the semi-packed column was found to be more than ten times that of the open tubular column

  9. Adiabatic packed column supercritical fluid chromatography using a dual-zone still-air column heater.

    Science.gov (United States)

    Helmueller, Shawn C; Poe, Donald P; Kaczmarski, Krzysztof

    2018-02-02

    An approach to conducting SFC separations under pseudo-adiabatic condition utilizing a dual-zone column heater is described. The heater allows for efficient separations at low pressures above the critical temperature by imposing a temperature profile along the column wall that closely matches that for isenthalpic expansion of the fluid inside the column. As a result, the efficiency loss associated with the formation of radial temperature gradients in this difficult region can be largely avoided in packed analytical scale columns. For elution of n-octadecylbenzene at 60 °C with 5% methanol modifier and a flow rate of 3 mL/min, a 250 × 4.6-mm column packed with 5-micron Kinetex C18 particles began to lose efficiency (8% decrease in the number of theoretical plates) at outlet pressures below 142 bar in a traditional forced air oven. The corresponding outlet pressure for onset of excess efficiency loss was decreased to 121 bar when the column was operated in a commercial HPLC column heater, and to 104 bar in the new dual-zone heater operated in adiabatic mode, with corresponding increases in the retention factor for n-octadecylbenzene from 2.9 to 6.8 and 14, respectively. This approach allows for increased retention and efficient separations of otherwise weakly retained analytes. Applications are described for rapid SFC separation of an alkylbenzene mixture using a pressure ramp, and isobaric separation of a cannabinoid mixture. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Flooding and mass transfer in Goodloe-packed columns, Part 2

    International Nuclear Information System (INIS)

    Ayala, J.S.; Brian, B.W.; Sharon, A.C.

    1977-01-01

    Krypton gas is recovered from HTGR off-gas streams by countercurrent absorption in liquid carbon dioxide. Goodloe stainless steel wire mesh packing was chosen for the absorption columns since the process operates at -20 0 C and about 20 atm pressure. Flooding points and an overall mass transfer coefficient for Goodloe-packed columns were determined with a carbon dioxide-air-water system for 6.4 and 15.2-cm-ID columns. Flood points were obtained for liquid-to-gas mass velocity ratios of 20 to 800. A mixing model, assuming plug flow for the gas and dispersed flow for the liquid, was used to calculate an overall mass transfer coefficient, K/sub L/a. K/sub L/a, based on mass concentrations, ranged from 0.01 to 0.08 sec/sup -T/ and was found to increase with increasing liquid flow rate

  11. THE PERFORMANCE ANALYSIS OF A PACKED COLUMN : CALIBRATION OF AN ORIFICE

    Directory of Open Access Journals (Sweden)

    Aynur ŞENOL

    2003-01-01

    Full Text Available Investigations to develop data for this study were made using a pilot scale glass column of 9 cm inside diameter randomly filled to a depth of 1.90 cm with a Raschig type ring at a slightly modified geometry. The geometrical characteristics of packing are: the total area of a single particle ad = 2.3 cm2; specific area ap = 10.37 cm2/cm3; voidage ? = 0.545 m3/m3. The efficiency tests were run using trichloroethylene/n-heptane system under total reflux conditions. Using the modified versions of the Eckert flooding model and the Bravo effective area (ae approach, as well as the Onda wetted area (aw and individual mass transfer coefficient models, it has been attempted to estimate the packing efficiency theoretically. This article also deals with the design strategies attributed to a randomly packed column. Emphasis is mainly placed on the way to formulate an algorithm of designing a pilot scale column through the models being attributed to the film theory. Using the column dry pressure drop properties based on the air flowing it has been achieved a generalized flow rate approach for calibrating of an orifice through which the air passes.

  12. PENGARUH POROSITAS PACKING STEEL WOOL TERHADAP PRESSURE DROP DIDALAM PACKED BED COLUMN PADA DISTILASI CAMPURAN ETANOL-AMIL-ALKOHOL-AIR

    Directory of Open Access Journals (Sweden)

    Trisna Kumala Dhaniswara

    2016-08-01

    Full Text Available Inventories of petroleum fuels are increasingly depleted and will someday run out. These shortcomings can be overcome by using alternative fuels, such as ethanol. Based on this, it is necessary to research and development of ethanol as a fuel. One way is with a separation in a packed distillation column. This study aims to assess the mass transfer phenomena that occur in the process of distilling a mixture of ethanol-water-amyl alcohol packed in column. In addition, this study aims to optimize temperature and reflux to obtain the highest levels of ethanol. This research method uses packed bed distillation system with the batch process. Feed used is synthetic ethanol, water, and solvent. Solvent used were amyl alcohol. Doing distillation with heating temperature is maintained. Distillation is done in the packing of stainless steel wool. Research carried out in a batch process with a variable temperature of  79°C; 84°C; 91°C; and porosity packing 20%; 30%; 40%; 50%; 60%; 70%; 80%.

  13. Laboratory studies of the behavior of undissolved solids in both pulsed and packed column extraction systems

    International Nuclear Information System (INIS)

    Siemer, D.D.

    1989-01-01

    A substantial fraction of the finely divided undissolved solid material found in nuclear fuel reprocessing dissolver-product solutions is hydrophobic and tends to ''seek'' any organic-aqueous interface existing within countercurrent liquid-liquid extraction systems. While passing through pulsed-type columns this material is swept out of the aqueous phase by the combined surface area of the tiny bubbles of dispersed phase. Because these bubbles have a net velocity towards the end of the column where the nominal interface is located, the solids are swept in that direction too. These solids tend to gather in a three-phase ''crud'' layer at the nominal interface point. At equilibrium, about the same amount breaks off from the crud layer and escapes into the liquid exiting from that end of the column as enters it from the other side. If large enough, the crud layer can even interfere with interface detection and control equipment. In packed-column extraction systems, an additional problem is that feed solids can accumulate within the packing material to the point that the column '' floods'' or even totally plugs. The keys to preventing solids-related problems is the correct choice of interface level, and with packed columns, the addition of a ''pulsing leg'' at the bottom of the column. Pulsing packed column systems not only prevents solids from settling onto packing material but it also increses the number of theoretical stages available for extraction. 3 figs., 2 tabs

  14. Development of a mathematical model of a packed column for benzene removal from salt solutions

    International Nuclear Information System (INIS)

    Georgeton, G.K.

    1989-01-01

    A mathematical model of a packed column was developed to describe the removal of benzene from radioactive salt solutions at the Savannah River Site. The model was developed from existing, generalized mass transfer correlations for randomly dumped packing, and the correlations were adapted for structured packing. Thermophysical data specific to the solutions of interest were incorporated into the model. Verification of the code was completed using operating data from stripping columns at other locations

  15. Electrochromatographic performance of graphene and graphene oxide modified silica particles packed capillary columns.

    Science.gov (United States)

    Zhao, Hongyan; Wang, Yizhou; Zhang, Danyu; Cheng, Heyong; Wang, Yuanchao

    2018-04-01

    Graphene oxide functionalized silica microspheres (GO@SiO 2 ) were synthesized based on condensation reaction between amino from aminosilica particles and carboxyl groups from GO. Reduction of GO@SiO 2 with hydrazinium hydroxide generated graphene modified silica particles (G@SiO 2 ). GO@SiO 2 and G@SiO 2 packed capillary columns for capillary electrochromatography were thereafter fabricated by pressure slurry packing with single-particle frits. GO of 0.3 mg/mL in dispersion solution for GO@SiO 2 synthesis was considered as a compromise between retaining and column efficiency whereas GO@SiO 2 of 20 mg/mL in slurries for column packing was chosen for a homogenous and tight bed. Optimum mobile phases were acquired considering both electroosmotic flow and resolution at an applied voltage of -6 kV as the following: acetonitrile/phosphate buffer (10 mM, pH 7.0), 75:25 (v/v) for polycyclic aromatic hydrocarbons and 50:50 (v/v) for aromatic compounds. A comparison was made between electrochromatographic performances for three PAHs (naphthalene, fluorene and phenanthrene) and three aromatic compounds of various polarities (toluene, aniline and phenol) on bare aminosilica, GO@SiO 2 and G@SiO 2 packed columns, which proved the contribution of alone or combinational actions of solvophobic effect and π-π electron stacking as well as hydrogen bonds to retaining behaviors by GO@SiO 2 and G@SiO 2 . Well over-run, over-day and over-column precisions (retention time: 0.3-1.4, 1.1-3.8 and 2.8-5.2%, respectively; peak area: 2.6-6.5, 4.8-8.3 and 6.5-12.6%, respectively) of GO@SiO 2 packed columns were a powerful proof for good reproducibility. Analytical characteristics of GO@SiO 2 packed capillary columns in CEC analysis of fresh water were evaluated with respect to linearity (R 2 = 0.9961-0.9989) over the range 0.1 to 100 mg/L and detection limits of 9.5 for naphthalene, 12.6 for fluorene and 16.2 μg/L for phenanthrene. Further application to fresh water increased the

  16. Fluid dynamics of packed columns principles of the fluid dynamic design of columns for gas/liquid and liquid/liquid systems

    CERN Document Server

    Mackowiak, Jerzy

    2010-01-01

    This book describes the basic design principles of columns equipped with modern lattice packings and structured packed beds, as generally used in industry. It provides support to engineers as well as graduate students in their daily design work.

  17. Super/subcritical fluid chromatography with packed columns: state of the art and applications

    Directory of Open Access Journals (Sweden)

    Carla Grazieli Azevedo da Silva

    2014-07-01

    Full Text Available Separations using supercritical fluid chromatography (SFC with packed columns have been re-discovered and explored in recent years. SFC enables fast and efficient separations and, in some cases, gives better results than high performance liquid chromatography (HPLC. This paper provides an overview of recent advances in SFC separations using packed columns for both achiral and chiral separations. The most important types of stationary phases used in SFC are discussed as well as the most critical parameters involved in the separations and some recent applications.

  18. Axial dispersion of gas and solid phases in a gas—solid packed column at trickle flow

    NARCIS (Netherlands)

    Roes, A.W.M.; van Swaaij, Willibrordus Petrus Maria

    1979-01-01

    Axial dispersion of gas and solid phases in a gas—solid packed column at trickle flow, a promising new countercurrent operation, was evaluated using residence time distribution (RTD) experiments. The column was packed with dumped Pall rings, the gas phase was air at ambient conditions and the solid

  19. Deposition behavior of colloid in filtration process through glass beads packed bed

    International Nuclear Information System (INIS)

    Chinju, Hirofumi; Nagasaki, Shinya; Tanaka, Satoru; Tanaka, Tadao; Takebe, Shinichi; Ogawa, Hiromichi

    1999-01-01

    We investigated the deposition behavior in colloid transport through porous media by conducting column experiments and batch experiments using polystyrene latex particles and spherical glass beads. The conclusion of this present work are summarized as follows: (1) The comparison between the results of the batch and the column experiments indicated that the deposition was enhanced in the column experiments compared with the batch experiments due to particles trapped by the effect of slow field. (2) Colloid BTCs showed three different stages of deposition which can be characterized by the different rate of the change in the C/C O . Three stages can be explained by the existence of large area of weak deposition sites and small area of strong deposition sites on the collector surfaces. (3) The amount of deposited particles until the beginning of the third stage was larger for lower flow velocity. (4) The results of the column experiments revealed that breakthrough behavior of colloidal particles of the second run after back wash process is affected by remaining particles on collector surfaces. (J.P.N.)

  20. Rice Husk Packed Bed Column Reactor To Remove Cadmium From Landfill Leachate

    Directory of Open Access Journals (Sweden)

    Monik Kasman

    2014-06-01

    Full Text Available The landfill leachate can be a major problem due to large variability of high organic, inorganic, heavy metal content and toxicity characteristics from landfill leachate such as  cadmium. Thus, this study was aimed to observe the application of rice husk packed bed column to reduce cadmium from landfill leachate. Experiment was conducted in gravity down flow system by pumping landfill leachate into packed bed column. The effect of influent flow rate to adsorption capacity was studied by varying flow rate (5 mL/min and 10 mL/min. The effluent-influent concentration ratio Ce/C0 (% as a function of throughput volume (L was used to represent the breakthrough curve in column systems. Result shows that the flow rate of 5 mL/min was favorable to achieve higher removal rates with the percentage of cadmium was 57 %. At breakthrough time, the cadmium effluent concentration reached on 0.01 mg/l for both of flow rate.ABSTRAKLindi yang dihasilkan dari TPA (Tempat Pembuangan Akhir menimbulkan permasalahan lingkungan karena kandungan pencemarnya meliputi material organik, material anorganik, logam dan material beracun. Salah satu logam berat yang terdapat dalam lindi tersebut adalah kadmium. Penelitian ini bertujuan untuk mereduksi kadmium dalam lindi dengan menggunakan sekam padi yang diinstal dalam packed bed column. Lindi dipompakan dari tangki penampung lindi ke dalam packed bed column dan dialirkan dari atas ke bawah kolom secara gravitasi. Fokus pada penelitian ini adalah pengaruh laju alir influen terhadap kapasitas adsorpsi. Dimana lindi dialirkan dengan laju alir 5 mL/menit dan 10 mL/menit. Kurva breakthrough (titik jenuh kolom dipresentasikan oleh hubungan antara rasio konsentrasi efluen-influen Ce/C0 (% dan jumlah aliran lindi yang diolah dalam kolom. Hasil eksperimen menunjukkan bahwa persentase reduksi tertinggi dicapai pada laju alir 5 mL/menit yaitu 57%. Waktu jenuh kedua laju alir (5 mL/menit dan 10 mL/menit tercapai saat konsentrasi efluen

  1. Hydrodynamic behaviour of a gas—solid counter-current packed column at trickle flow

    NARCIS (Netherlands)

    Roes, A.W.M.; van Swaaij, Willibrordus Petrus Maria

    1979-01-01

    Trickle flow of a more or less fluidized catalyst through a packed column is a promising new gas—solid counter-current operation. The hydrodynamic, behaviour of such a column, filled with dumped PALL rings, has been investigated, while some results have been obtained with RASCHIG rings and

  2. Improvement for the design of packed moving bed adsorption column

    International Nuclear Information System (INIS)

    Xiao Wei

    2014-01-01

    The problems needed to pay attention to in the physical design of packed moving bed adsorption column were presented. The design of key parts such as the inlet and outlet of liquid phase and gas phase were improved. The expected effect was achieved by the improvement. (author)

  3. Adsorption of zinc ions on bone char using helical coil-packed bed columns and its mass transfer modeling

    DEFF Research Database (Denmark)

    Moreno-Pérez, J.; Bonilla-Petriciolet, A.; Rojas-Mayorga, C. K.

    2016-01-01

    This study reports the assessment of helical coil-packed bed columns for Zn2+ adsorption on bone char. Zn2+ adsorption breakthrough curves have been obtained using helical coil columns with different characteristics and a comparison has been conducted with respect to the results of straight fixed-bed...... columns. Results showed that the helical coil adsorption columns may offer an equivalent removal performance than that obtained for the traditional packed bed columns but using a compact structure. However, the coil diameter, number of turns, and feed flow appear to be crucial parameters for obtaining...... the best performance in this packed-bed geometry. A mass transfer model for a mobile fluid flowing through a porous media was used for fitting and predicting the Zn2+ breakthrough curves in helical coil bed columns. Results of adsorbent physicochemical characterization showed that Zn2+ adsorption on bone...

  4. Hydrodynamic impact of particle shape in slurry packed liquid chromatography columns

    DEFF Research Database (Denmark)

    Lottes, F.; Arlt, W.; Minceva, M.

    2009-01-01

    We report on a series of flow velocity and efficiency profiles, which were measured across the cross section of preparative chromatographic columns packed with different stationary phase materials using computed tomography. It is shown that this non-invasive technique is very useful for visualiza...

  5. Fluid flow profile in a packed bead column using residence time curves and radiotracer techniques

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Ana Paula F. de; Gonçalves, Eduardo Ramos; Brandão, Luis Eduardo B.; Salgado, Cesar M., E-mail: anacamiqui@gmail.com, E-mail: egoncalves@con.ufrj.br, E-mail: brandao@ien.gov.br, E-mail: otero@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    Filling columns are extremely important in the chemical industry and are used for purification, separation and treatment processes of gas or liquid mixtures. The objective of this work is to study the hydrodynamics of the fluid for a characterization of aqueous phase flow patterns in the filling column, associating with the methodology of the Curves of Residence Time Distribution (RTD) to analyze and associate theoretical models that put as conditions column operating. RTD can be obtained by using the pulse-stimulus response technique which is characterized by the instantaneous injection of a radiotracer into the system input. In this work, 68Ga was used as radiotracer. Five shielded and collimated NaI (Tl) 1 x 1″ scintillator detectors were suitably positioned to record the movement of the radiotracer's path in the conveying line and filling column. Making possible the analysis of the RTD curve in the regions of interest. With the data generated by the NaI (Tl) detectors with the passage of the radiotracer in the transport line and inside the column, it was possible to evaluate the flow profile of the aqueous phase and to identify operational failures, such as internal conduit and the existence of a retention zone in the inside the column. Theoretical models were used for different flow flows: the piston flow and perfect mixing. (author)

  6. Fluid flow profile in a packed bead column using residence time curves and radiotracer techniques

    International Nuclear Information System (INIS)

    Almeida, Ana Paula F. de; Gonçalves, Eduardo Ramos; Brandão, Luis Eduardo B.; Salgado, Cesar M.

    2017-01-01

    Filling columns are extremely important in the chemical industry and are used for purification, separation and treatment processes of gas or liquid mixtures. The objective of this work is to study the hydrodynamics of the fluid for a characterization of aqueous phase flow patterns in the filling column, associating with the methodology of the Curves of Residence Time Distribution (RTD) to analyze and associate theoretical models that put as conditions column operating. RTD can be obtained by using the pulse-stimulus response technique which is characterized by the instantaneous injection of a radiotracer into the system input. In this work, 68Ga was used as radiotracer. Five shielded and collimated NaI (Tl) 1 x 1″ scintillator detectors were suitably positioned to record the movement of the radiotracer's path in the conveying line and filling column. Making possible the analysis of the RTD curve in the regions of interest. With the data generated by the NaI (Tl) detectors with the passage of the radiotracer in the transport line and inside the column, it was possible to evaluate the flow profile of the aqueous phase and to identify operational failures, such as internal conduit and the existence of a retention zone in the inside the column. Theoretical models were used for different flow flows: the piston flow and perfect mixing. (author)

  7. Analysis of packing microstructure and wall effects in a narrow-bore ultrahigh pressure liquid chromatography column using focused ion-beam scanning electron microscopy.

    Science.gov (United States)

    Reising, Arved E; Schlabach, Sabine; Baranau, Vasili; Stoeckel, Daniela; Tallarek, Ulrich

    2017-09-01

    Column wall effects are well recognized as major limiting factor in achieving high separation efficiency in HPLC. This is especially important for modern analytical columns packed with small particles, where wall effects dominate the band broadening. Detailed knowledge about the packing microstructure of packed analytical columns has so far not been acquired. Here, we present the first three-dimensional reconstruction protocol for these columns utilizing focused ion-beam scanning electron microscopy (FIB-SEM) on a commercial 2.1mm inner diameter×50mm length narrow-bore analytical column packed with 1.7μm bridged-ethyl hybrid silica particles. Two sections from the packed bed are chosen for reconstruction by FIB-SEM: one from the bulk packing region of the column and one from its critical wall region. This allows quantification of structural differences between the wall region and the center of the bed due to effects induced by the hard, confining column wall. Consequences of these effects on local flow velocity in the column are analyzed with flow simulations utilizing the lattice-Boltzmann method. The reconstructions of the bed structures reveal significant structural differences in the wall region (extending radially over approximately 62 particle diameters) compared to the center of the column. It includes the local reduction of the external porosity by up to 10% and an increase of the mean particle diameter by up to 3%, resulting in a decrease of the local flow velocity by up to 23%. In addition, four (more ordered) layers of particles in the direct vicinity of the column wall induce local velocity fluctuations by up to a factor of three regarding the involved velocity amplitudes. These observations highlight the impact of radial variations in packing microstructure on band migration and column performance. This knowledge on morphological peculiarities of column wall effects helps guiding us towards further optimization of the packing process for analytical

  8. [Analysis of hydrogen isotopes by gas chromatography using a MnCl2 coated γ-Al2O3 capillary packed column].

    Science.gov (United States)

    Chen, Ping; Fu, Xiaolong; Hu, Peng; Xiao, Chengjian; Ren, Xingbi; Xia, Xiulong; Wang, Heyi

    2017-07-08

    The conventional packed column gas chromatographic analysis of hydrogen isotopes has low column efficiency, broad peak and long retention time. In this work, a γ -Al 2 O 3 with MnCl 2 coated capillary packed column was tested at cryogenic temperature. The systematic column efficiency analysis and the hydrogen isotopes analytical technique research had been carried out. The results showed that, the γ -Al 2 O 3 with MnCl 2 coating could greatly improve the surface degree of order, pore structure and adsorption properties. Also the o -H 2 peak and p -H 2 peak were eluted in a single area. The γ -Al 2 O 3 with MnCl 2 coating was packed into a 0.53 mm inner diameter and 1.0 m long fused silica capillary column. It had a good linear relationship used this column with thermal conductivity detector (TCD) to detect the volume concentrations of hydrogen isotopes from 1 to 10 mL/L, and the relative error was less than 5% for low concentration sample testing. For H 2 , HD and D 2 , the retention times can be shortened to 39, 46 and 60 s, respectively. The limits of detection were reduced to 0.046, 0.067 and 0.072 mL/L, respectively. Compared with conventional packed column, capillary packed column had sharper peak form, higher separation degree of adjacent components, shorter retention time and lower detection limits. The above results indicate that the capillary packed column with TCD detector can be used for fast detection of low concentration of hydrogen isotopes and their online analysis.

  9. K Basin sludge/resin bead separation test report

    International Nuclear Information System (INIS)

    Squier, D.M.

    1998-01-01

    The K Basin sludge is an accumulation of fuel element corrosion products, organic and inorganic ion exchange materials, canister gasket materials, iron and aluminum corrosion products, sand, dirt and minor amounts of other organic material. The sludge will be collected and treated for storage and eventual disposal. This process will remove the large solid materials by a 1/4 inch screen. The screened material will be subjected to nitric acid in a chemical treatment process. The organic ion exchange resin beads produce undesirable chemical reactions with the nitric acid. The resin beads must be removed from the bulk material and treated by another process. An effective bead separation method must extract 95% of the resin bead mass without entraining more than 5% of the other sludge component mass. The test plan I-INF-2729, ''Organic Ion Exchange Resin Separation Methods Evaluation,'' proposed the evaluation of air lift, hydro cyclone, agitated slurry and elutriation resin bead separation methods. This follows the testing strategy outlined in section 4.1 of BNF-2574, ''Testing Strategy to Support the Development of K Basins Sludge Treatment Process''. Engineering study BNF-3128, ''Separation of Organic Ion Exchange Resins from Sludge,'' Rev. 0, focused the evaluation tests on a method that removed the fine sludge particles by a sieve and then extracted the beads by means of a elutriation column. Ninety-nine percent of the resin beads are larger than 125 microns and 98.5 percent are 300 microns and larger. Particles smaller than 125 microns make up the largest portion of sludge in the K Basins. Eliminating a large part of the sludge's non-bead component will reduce the quantity that is lifted with the resin beads in the elutriation column. Resin bead particle size distribution measurements are given in Appendix A The Engineering Testing Laboratory conducted measurements of a elutriation column's ability to extract resin beads from a sieved, non-radioactive sludge

  10. Dissolved oxygen removal in a column packed with catalyst

    International Nuclear Information System (INIS)

    Lee, Han Soo; Chung, Hong Suk; Cho, Young Hyun; Ahn, Do Hee; Kim, Eun Kee

    1996-01-01

    The dissolved oxygen removed by H 2 -O 2 reaction in column packed with various catalysts was examined. The catalysts employed were the prepared polymeric catalyst, platinum on activated carbon, and Lewatit OC-1045 which is available commercially. The column experiments with the prepared polymeric catalyst showed the dissolved oxygen reduced to 35 ppb which is below the limit in feel water of power plants. This implies the likely application of the prepared catalyst for practical use. The activated carbon required the pre-treatment for the removed of dissolved oxygen, since the surface of activated carbon contains much oxygen adsorbed initially. The Lewatit catalyst exposed the best performance, however, the aged one showed the gradual loss of catalytic activity due to degradation of resin catalyst. 14 refs., 6 figs., 2 tabs. (author)

  11. Arsenate removal by layered double hydroxides embedded into spherical polymer beads: Batch and column studies.

    Science.gov (United States)

    Nhat Ha, Ho Nguyen; Kim Phuong, Nguyen Thi; Boi An, Tran; Mai Tho, Nguyen Thi; Ngoc Thang, Tran; Quang Minh, Bui; Van Du, Cao

    2016-01-01

    In this study, the performance of poly(layered double hydroxides) [poly(LDHs)] beads as an adsorbent for arsenate removal from aqueous solution was investigated. The poly(LDHs) beads were prepared by immobilizing LDHs into spherical alginate/polyvinyl alcohol (PVA)-glutaraldehyde beads (spherical polymer beads). Batch adsorption studies were conducted to assess the effect of contact time, solution pH, initial arsenate concentrations and co-existing anions on arsenate removal performance. The potential reuse of these poly(LDHs) beads was also investigated. Approximately 79.1 to 91.2% of arsenic was removed from an arsenate solution (50 mg As L(-1)) by poly(LDHs). The adsorption data were well described by the pseudo-second-order kinetics model and the Langmuir isotherm model, and the adsorption capacities of these poly(LDHs) beads at pH 8 were from 1.64 to 1.73 mg As g(-1), as calculated from the Langmuir adsorption isotherm. The adsorption ability of the poly(LDHs) beads decreased by approximately 5-6% after 5 adsorption-desorption cycles. Phosphates markedly decreased arsenate removal. The effect of co-existing anions on the adsorption capacity declined in the following order: HPO4 (2-) > HCO3 (-) > SO4 (2-) > Cl(-). A fixed-bed column study was conducted with real-life arsenic-containing water. The breakthrough time was found to be from 7 to 10 h. Under optimized conditions, the poly(LDHs) removed more than 82% of total arsenic. The results obtained in this study will be useful for further extending the adsorbents to the field scale or for designing pilot plants in future studies. From the viewpoint of environmental friendliness, the poly(LDHs) beads are a potential cost-effective adsorbent for arsenate removal in water treatment.

  12. 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.

  13. Determination of betaine, l-carnitine, and choline in human urine using a self-packed column and column-switching ion chromatography with nonsuppressed conductivity detection.

    Science.gov (United States)

    Wei, Dan; Liu, Junwei; Guo, Ming; Zhu, Yan

    2017-11-01

    A simple method for the determination of betaine, l-carnitine, and choline in human urine was developed based on column-switching ion chromatography coupled with nonsuppressed conductivity detection by using a self-packed column. A pretreatment column (50 mm × 4.6 mm, id) packed with poly(glycidyl methacrylate-divinylbenzene) microspheres was used for the extraction and cleanup of analytes. Chromatographic separation was achieved within 10 min on a cationic exchange column (150 mm × 4.6 mm, id) using maleic anhydride modified poly(glycidyl methacrylate-divinylbenzene) as the particles for packing. The detection was performed by ion chromatography with nonsuppressed conductivity detection. Parameters including column-switching time, eluent type, flow rates of eluent, and interfering effects were optimized. Linearity (r 2 ≥ 0.99) was obtained for the concentration range of 0.50-100, 0.75-100, and 0.25-100 μg/mL for betaine, l-carnitine, and choline, respectively. Detection limits were 0.12, 0.20, and 0.05 μg/mL for betaine, l-carnitine, and choline, respectively. The intra- and interday accuracy and precision for all quality controls were within ±10.11%. Satisfactory recovery was observed between 92.5 and 105.0%. The validated method was successfully applied for the determination of betaine, l-carnitine, and choline in urine samples from healthy people. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Physical properties and structure of fine core-shell particles used as packing materials for chromatography Relationships between particle characteristics and column performance.

    Science.gov (United States)

    Gritti, Fabrice; Leonardis, Irene; Abia, Jude; Guiochon, Georges

    2010-06-11

    The recent development of new brands of packing materials made of fine porous-shell particles, e.g., Halo and Kinetex, has brought great improvements in potential column efficiency, demanding considerable progress in the design of chromatographic instruments. Columns packed with Halo and Kinetex particles provide minimum values of their reduced plate heights of nearly 1.5 and 1.2, respectively. These packing materials have physical properties that set them apart from conventional porous particles. The kinetic performance of 4.6mm I.D. columns packed with these two new materials is analyzed based on the results of a series of nine independent and complementary experiments: low-temperature nitrogen adsorption (LTNA), scanning electron microscopy (SEM), inverse size-exclusion chromatography (ISEC), Coulter counter particle size distributions, pycnometry, height equivalent to a theoretical plate (HETP), peak parking method (PP), total pore blocking method (TPB), and local electrochemical detection across the column exit section (LED). The results of this work establish links between the physical properties of these superficially porous particles and the excellent kinetic performance of columns packed with them. It clarifies the fundamental origin of the difference in the chromatographic performances of the Halo and the Kinetex columns. Copyright 2010 Elsevier B.V. All rights reserved.

  15. Modeling chromatographic columns. Non-equilibrium packed-bed adsorption with non-linear adsorption isotherms

    NARCIS (Netherlands)

    Özdural, A.R.; Alkan, A.; Kerkhof, P.J.A.M.

    2004-01-01

    In this work a new mathematical model, based on non-equilibrium conditions, describing the dynamic adsorption of proteins in columns packed with spherical adsorbent particles is used to study the performance of chromatographic systems. Simulations of frontal chromatography, including axial

  16. Aromatically enhanced pear distillates from blanquilla and conference varieties using a packed column.

    Science.gov (United States)

    Arrieta-Garay, Yanine; García-Llobodanin, Laura; Pérez-Correa, José Ricardo; López-Vázquez, Cristina; Orriols, Ignacio; López, Francisco

    2013-05-22

    Pear distillates are generally produced from the Bartlett variety because of its rich aroma. In this study, a chemical and sensorial comparative examination of pear distillates from the three main varieties grown in Spain (Bartlett, Blanquilla, and Conference) using two distillation systems (copper Charentais alembic and packed column) was undertaken. Volatile compounds were identified by gas chromatography to differentiate the spirits according to pear variety and distillation method. The Bartlett distillates from both distillation systems possessed higher ethyl ester and acetate and lower cis-3-hexen-1-ol and 1-hexanol concentrations. Despite these differences, a sensory analysis panel could distinguish only the Bartlett alembic distillate from the alembic distillates of the other varieties. In contrast, the panel rated the packed-column distillates equally. Therefore, less aromatic pear varieties can be used to produce distillates with aromatic characteristics similar to those of the Bartlett variety if a suitable distillation process is used.

  17. Comparative study of the performance of columns packed with several new fine silica particles. Would the external roughness of the particles affect column properties?

    Science.gov (United States)

    Gritti, Fabrice; Guiochon, Georges

    2007-09-28

    We measured and compared the characteristics and performance of columns packed with particles of five different C(18)-bonded silica, 3 and 5 microm Luna, 3 microm Atlantis, 3.5 microm Zorbax, and 2.7 microm Halo. The average particle size of each material was derived from the SEM pictures of 200 individual particles. These pictures contrast the irregular morphology of the external surface of the Zorbax and Halo particles and the smooth surface of the Luna and Atlantis particles. In a wide range of mobile phase velocities (from 0.010 to 3 mL/min) and at ambient temperature, we measured the first and second central moments of the peaks of naphthalene, insulin, and bovine serum albumin (BSA). These moments were corrected for the contributions of the extra-column volumes to calculate the reduced HETPs. The C-terms of naphthalene and insulin are largest for the Halo and Zorbax materials and the A-term smallest for the Halo-packed column. The Halo column performs the best for the low molecular weight compound naphthalene (minimum reduced HETP, 1.4) but is not as good as the Atlantis or Luna columns for the large molecular weight compound insulin. The Zorbax column is the least efficient column because of its large C-term. The lowest sample diffusivity through these particles, alone, does not account for the results. It is most likely that the roughness of the external surface of the Halo and Zorbax particles limit the performance of these columns at high flow rates generating an unusually high film mass transfer resistance.

  18. Effect of chemical and physical heterogeneities on colloid-facilitated cesium transport

    Science.gov (United States)

    Rod, Kenton; Um, Wooyong; Chun, Jaehun; Wu, Ning; Yin, Xialong; Wang, Guohui; Neeves, Keith

    2018-06-01

    A set of column experiments was conducted to investigate the chemical and physical heterogeneity effect on colloid facilitated transport under slow pore velocity conditions. Pore velocities were kept below 100 cm d-1 for all experiments. Glass beads were packed into columns establishing four different conditions: 1) homogeneous, 2) mixed physical heterogeneity, 3) sequentially layered physical heterogeneity, and 4) chemical heterogeneity. The homogeneous column was packed with glass beads (diameter 500-600 μm), and physical heterogeneities were created by sequential layering or mixing two sizes of glass bead (500-600 μm and 300-400 μm). A chemical heterogeneity was created using 25% of the glass beads coated with hydrophobic molecules (1H-1H-2H-2H-perfluorooctyltrichlorosilane) mixed with 75% pristine glass beads (all 500-600 μm). Input solution with 0.5 mM CsI and 50 mg L-1 colloids (1-μm diameter SiO2) was pulsed into columns under saturated conditions. The physical heterogeneity in the packed glass beads retarded the transport of colloids compared to homogeneous (R = 25.0), but showed only slight differences between sequentially layered (R = 60.7) and mixed heterogeneity(R = 62.4). The column with the chemical, hydrophobic/hydrophilic, heterogeneity removed most of the colloids from the input solution. All column conditions stripped Cs from colloids onto the column matrix of packed glass beads.

  19. Flooding characteristics of Goodloe packing

    International Nuclear Information System (INIS)

    Begovich, J.M.; Watson, J.S.

    1976-08-01

    Experimental flooding data for the countercurrent flow of air and water in a 7.62-cm-diam glass column filled with Goodloe packing were compared with a correlation reported by the packing manufacturer. Flooding rates observed in this study were as low as one-half those predicted by the correlation. Rearranging the packing by inverting the column and removing some packing segments yielded results similar to the correlation for liquid-to-gas (L/G) mass flow rate ratios greater than 10, but the experimental flooding curve fell significantly below the correlation at lower L/G ratios. When the column was repacked with new packing, the results were essentially the same as those obtained in the inverted column. Thus, it is believed that a carefully packed column is more likely to yield flooding rates similar to those obtained in the new or inverted columns rather than rates predicted by the original correlation

  20. Height determination at the transfer unit in isotopic distillation of hydrogen on type B7 ordered column packing

    International Nuclear Information System (INIS)

    Pop, F.; Croitoru, C.; Peculea, M.

    2001-01-01

    Owing to the low pressure drop implied by ordered column packings these are often utilized for vacuum distillations and separation of mixtures in which the important component occurs at a very low concentration, as for instance is the case of water, deuterium or oxygen isotopic distillation. The paper presents a model for determination of the height of transfer unit (HTU) in the hydrogen isotopic distillation installation, equipped with ordered column packing of B7 type. The computed values for HUT based on the analogy between heat, moment and mass transfer, were compared with the experimental data

  1. Multiple steady states detection in a packed-bed reactive distillation column using bifurcation analysis

    DEFF Research Database (Denmark)

    Ramzan, Naveed; Faheem, Muhammad; Gani, Rafiqul

    2010-01-01

    A packed reactive distillation column producing ethyl tert-butyl ether from tert-butyl alcohol and ethanol was simulated for detection of multiple steady states using Aspen Plus®. A rate-based approach was used to make the simulation model more realistic. A base-case was first developed and fine...

  2. Two-Phase Flow in Packed Columns and Generation of Bubbly Suspensions for Chemical Processing in Space

    Science.gov (United States)

    Motil, Brian J.; Green, R. D.; Nahra, H. K.; Sridhar, K. R.

    2000-01-01

    For long-duration space missions, the life support and In-Situ Resource Utilization (ISRU) systems necessary to lower the mass and volume of consumables carried from Earth will require more sophisticated chemical processing technologies involving gas-liquid two-phase flows. This paper discusses some preliminary two-phase flow work in packed columns and generation of bubbly suspensions, two types of flow systems that can exist in a number of chemical processing devices. The experimental hardware for a co-current flow, packed column operated in two ground-based low gravity facilities (two-second drop tower and KC- 135 low-gravity aircraft) is described. The preliminary results of this experimental work are discussed. The flow regimes observed and the conditions under which these flow regimes occur are compared with the available co-current packed column experimental work performed in normal gravity. For bubbly suspensions, the experimental hardware for generation of uniformly sized bubbles in Couette flow in microgravity conditions is described. Experimental work was performed on a number of bubbler designs, and the capillary bubble tube was found to produce the most consistent size bubbles. Low air flow rates and low Couette flow produce consistent 2-3 mm bubbles, the size of interest for the "Behavior of Rapidly Sheared Bubbly Suspension" flight experiment. Finally the mass transfer implications of these two-phase flows is qualitatively discussed.

  3. Effect of the structured packing height on efficiency of freons mixture separation in a large-scale model of distillation column

    Directory of Open Access Journals (Sweden)

    Pavlenko Aleksandr

    2017-01-01

    Full Text Available Results of experimental studies of heat-and-mass transfer and hydrodynamic processes at distillation on a regular packing are presented. The mixture of freons R114–R21 at the pressure of 0.3 MPa was used as a working mixture. The mixture was separated on the Mellapak 350Y structured packing with the diameter of 0.9 m under the conditions of complete reflux (L/V = 1 at different packing heights. A specially designed liquid distributor with a possibility to change the density and pattern of drip points was used to irrigate the packing. The experimental data on the efficiency of mixture separation (height of transfer unit HTU and distribution of the local flow rate density over the column cross-section were compared. It is shown that an increase in the height of the structured packing from 2.1 m to 4.0 m leads to a significant decrease in the efficiency of mixture separation in the distillation column.

  4. Application of a Fast Separation Method for Anti-diabetics in Pharmaceuticals Using Monolithic Column: Comparative Study With Silica Based C-18 Particle Packed Column.

    Science.gov (United States)

    Hemdan, A; Abdel-Aziz, Omar

    2018-04-01

    Run time is a predominant factor in HPLC for quality control laboratories especially if there is large number of samples have to be analyzed. Working at high flow rates cannot be attained with silica based particle packed column due to elevated backpressure issues. The use of monolithic column as an alternative to traditional C-18 column was tested for fast separation of pharmaceuticals, where the results were very competitive. The performance comparison of both columns was tested for separation of anti-diabetic combination containing Metformin, Pioglitazone and Glimepiride using Gliclazide as an internal standard. Working at high flow rates with less significant backpressure was obtained with the monolithic column where the run time was reduced from 6 min in traditional column to only 1 min in monolithic column with accepted resolution. The structure of the monolith contains many pores which can adapt the high flow rate of the mobile phase. Moreover, peak symmetry and equilibration time were more efficient with monolithic column.

  5. Kinetic investigation of narrow-bore columns packed with prototype sub-2 μm superficially porous particles with various shell thickness.

    Science.gov (United States)

    Gritti, Fabrice; Omamogho, Jesse; Guiochon, Georges

    2011-10-07

    The recent successful breakthrough of sub-3 μm shell particles in HPLC has triggered considerable research efforts toward the design of new brands of core-shell particles. We investigated the mass transfer mechanism of a few analytes in narrow-bore columns packed with prototype 1.7 μm shell particles, made of 1.0, 1.2, and 1.4 μm solid nonporous cores surrounded by porous shells 350, 250, and 150 nm thick, respectively. Three probe solutes, uracil, naphthalene, and insulin, were chosen to assess the kinetic performance of these columns. Inverse size exclusion chromatography, peak parking experiments, and the numerical integration of the experimental peak profiles were carried out in order to measure the external, internal, and total column porosities, the true bulk diffusion coefficients of these analytes, the height equivalent to a theoretical plate, the longitudinal diffusion term, and the trans-particle mass transfer resistance term. The residual eddy diffusion term was measured by difference. The results show the existence of important trans-column velocity biases (7%) possibly due to the presence of particle multiplets in the slurry mixture used during the packing process. Our results illustrates some of the difficulties encountered by scientists preparing and packing shell particles into narrow-bore columns. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Hydrogen extraction from Pb-17Li: results with a 800 mm high packed column

    International Nuclear Information System (INIS)

    Alpy, N.; Terlain, A.; Lorentz, V.

    2000-01-01

    Within the framework of the studies carried out for the development of a gas-liquid alloy contactor for the extraction of hydrogen from Pb-17Li, the behaviour of a 800 mm high packed column has been investigated on the Melodie loop. The previous contactor technology, a structured packing supplied by the Sulzer Company, has been retained since it had shown satisfying efficiency, likely due to the beneficial effect, on the mass transfer, of the liquid flow division that it involves. The best results of the present study have been achieved via a reduction of the liquid load on the packing: an efficiency of up to 30% was reached at 673 K for an inlet hydrogen pressure in Pb-17Li of 1000 Pa. The impact of the hydrogen pressure in the inlet Pb-17Li flow and on the extraction efficiency has been experimentally assessed: this study allowed us to evaluate the potential of the process in terms of packing height. Finally, a future experimental facility, which should allow us to observe the hydraulic behaviour of liquid mercury (simulating Pb-17Li) on the packing is presented

  7. Analysis of the Conditions for the Inception of Natural Pulsing Flow in Cocurrent Packed Columns

    Czech Academy of Sciences Publication Activity Database

    Akramov, T. A.; Stavárek, Petr; Jiřičný, Vladimír; Staněk, Vladimír

    2008-01-01

    Roč. 47, č. 19 (2008), s. 7424-7432 ISSN 0888-5885 R&D Projects: GA MPO FT-TA/039 Institutional research plan: CEZ:AV0Z40720504 Keywords : natural pulsing flow * cocurrent flow * packed columns Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.895, year: 2008

  8. Adsorption of ochratoxin A from grape juice by yeast cells immobilised in calcium alginate beads.

    Science.gov (United States)

    Farbo, Maria Grazia; Urgeghe, Pietro Paolo; Fiori, Stefano; Marceddu, Salvatore; Jaoua, Samir; Migheli, Quirico

    2016-01-18

    Grape juice can be easily contaminated with ochratoxin A (OTA), one of the known mycotoxins with the greatest public health significance. Among the different approaches to decontaminate juice from this mycotoxin, microbiological methods proved efficient, inexpensive and safe, particularly the use of yeast or yeast products. To ascertain whether immobilisation of the yeast biomass would lead to successful decontamination, alginate beads encapsulating Candida intermedia yeast cells were used in our experiments to evaluate their OTA-biosorption efficacy. Magnetic calcium alginate beads were also prepared by adding magnetite in the formulation to allow fast removal from the aqueous solution with a magnet. Calcium alginate beads were added to commercial grape juice spiked with 20 μg/kg OTA and after 48 h of incubation a significant reduction (>80%), of the total OTA content was achieved, while in the subsequent phases (72-120 h) OTA was slowly released into the grape juice by alginate beads. Biosorption properties of alginate-yeast beads were tested in a prototype bioreactor consisting in a glass chromatography column packed with beads, where juice amended with OTA was slowly flowed downstream. The adoption of an interconnected scaled-up bioreactor as an efficient and safe tool to remove traces of OTA from liquid matrices is discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Holdup of O/W emulsion in a packed column for liquid membrane separation of hydrocarbon; Tankasuiso no ekimaku bunri ni okeru jutento nai no emarushon horudo appu

    Energy Technology Data Exchange (ETDEWEB)

    Egashira, R.; Sugimoto, T.; Kawasaki, J. [Tokyo Inst. of Technology, Tokyo (Japan). Faculty of Engineering

    1993-07-10

    Liquid membrane separation of hydrocarbon is an energy saving separation method that is expected of practical use. If the method uses a packed column, the holdup of O/W emulsion affects the effective contact area and residence time of the emulsion. Therefore, this paper describes an attempt to correlate the dynamic emulsion holdup in a packed column in liquid membrane separation of hydrocarbon with property values of the emulsion and external oil phase, and operation variables. The experiment used a mixture of toluene + n - heptane + n - decane for oil phase in the O/W emulsion and saponin aqueous solution for liquid phase (liquid membrane phase). The packed column with an inner diameter of 37 mm used stainless steel McMahon packing. As a result of the experiment, the dynamic emulsion holdup showed a correlation according to the Reynolds number and Galilei number, regardless of whether the emulsion permeates the liquid membrane. The correlation made it possible to estimate in a simple manner the emulsion holdup in the packed column when this separation method is used. 5 refs., 3 figs., 3 tabs.

  10. Effects of the gas-liquid ratio on the optimum catalyst quantity for the CECE process with a homogeneously packed LPCE column

    International Nuclear Information System (INIS)

    Sugiyama, T.; Ushida, A.; Yamamoto, I.

    2008-01-01

    In order to improve the separative performance of a combined electrolysis catalytic exchange (CECE) process, we have carried out experimental studies on hydrogen isotope separation by a CECE process using a liquid phase catalytic exchange (LPCE) column of trickle-type packed beds. Two types of trickle beds were tested in our previous study. One was the layered bed, where layers of Kogel catalysts and Dixon gauze rings were alternately filled in the column. The other was the homogeneous bed, where Kogel catalysts and Dixon gauze rings were homogeneously mixed and filled in the column. We found that (1) the homogeneously packed bed was more efficient than the layered packed bed, and (2) the catalyst quantity was optimal, which resulted in the highest separative performance. In this study, the effect of the gas-liquid ratio (G/L) on the optimum catalyst quantity was studied experimentally in a homogeneously packed bed. When the value of G/L was 1.7, total separation factors were relatively small and the optimum catalyst quantity could not be determined. On the other hand, when the values of G/L were 0.9 and 0.7, the values of the total separation factors had maximums and the optimal quantities of the catalyst were clearly obtained

  11. A stochastic view on column efficiency.

    Science.gov (United States)

    Gritti, Fabrice

    2018-03-09

    A stochastic model of transcolumn eddy dispersion along packed beds was derived. It was based on the calculation of the mean travel time of a single analyte molecule from one radial position to another. The exchange mechanism between two radial positions was governed by the transverse dispersion of the analyte across the column. The radial velocity distribution was obtained by flow simulations in a focused-ion-beam scanning electron microscopy (FIB-SEM) based 3D reconstruction from a 2.1 mm × 50 mm column packed with 2 μm BEH-C 18 particles. Accordingly, the packed bed was divided into three coaxial and uniform zones: (1) a 1.4 particle diameter wide, ordered, and loose packing at the column wall (velocity u w ), (2) an intermediate 130 μm wide, random, and dense packing (velocity u i ), and (3) the bulk packing in the center of the column (velocity u c ). First, the validity of this proposed stochastic model was tested by adjusting the predicted to the observed reduced van Deemter plots of a 2.1 mm × 50 mm column packed with 2 μm BEH-C 18 fully porous particles (FPPs). An excellent agreement was found for u i  = 0.93u c , a result fully consistent with the FIB-SEM observation (u i  = 0.95u c ). Next, the model was used to measure u i  = 0.94u c for 2.1 mm × 100 mm column packed with 1.6 μm Cortecs-C 18 superficially porous particles (SPPs). The relative velocity bias across columns packed with SPPs is then barely smaller than that observed in columns packed with FPPs (+6% versus + 7%). u w =1.8u i is measured for a 75 μm × 1 m capillary column packed with 2 μm BEH-C 18 particles. Despite this large wall-to-center velocity bias (+80%), the presence of the thin and ordered wall packing layer has no negative impact on the kinetic performance of capillary columns. Finally, the stochastic model of long-range eddy dispersion explains why analytical (2.1-4.6 mm i.d.) and capillary (columns can all be

  12. Two-phase mixed media dielectric with macro dielectric beads for enhancing resistivity and breakdown strength

    Science.gov (United States)

    Falabella, Steven; Meyer, Glenn A; Tang, Vincent; Guethlein, Gary

    2014-06-10

    A two-phase mixed media insulator having a dielectric fluid filling the interstices between macro-sized dielectric beads packed into a confined volume, so that the packed dielectric beads inhibit electro-hydrodynamically driven current flows of the dielectric liquid and thereby increase the resistivity and breakdown strength of the two-phase insulator over the dielectric liquid alone. In addition, an electrical apparatus incorporates the two-phase mixed media insulator to insulate between electrical components of different electrical potentials. And a method of electrically insulating between electrical components of different electrical potentials fills a confined volume between the electrical components with the two-phase dielectric composite, so that the macro dielectric beads are packed in the confined volume and interstices formed between the macro dielectric beads are filled with the dielectric liquid.

  13. Effect of Promoter Concentration on CO2 Separation Using K2CO3 With Reactive Absorption Method in Reactor Packed Column

    Directory of Open Access Journals (Sweden)

    Monde Junety

    2018-01-01

    Full Text Available The presence of carbon dioxide (CO2 in the gas is not expected because CO2 can reduce heating value and CO2 is the major emission contributor into the atmosphere. Various separation technologies can be used to reduce CO2 content and improve quality of gas. Chemical or reactive absorption is most widely used because it provides higher removal rate. This paper will study the effect of the addition di ethanolamine (DEA concentration into aqueous 30wt.% potassium carbonate(K2CO3 with reactive absorption method in a reactor packed column at temperature from 40°C to 80°C, DEA concentration range of (1% - 3% and absorbent flow rate (0.5, 0.75 and 1 L. min1. Contacting the gas and absorbent are countercurrent flow in packed column with 1.5 m high and 50 mm in diameter. The absorption column was randomly packed with a packing material raschig rings 5 mm in diameter. The CO2 loading in the liquid samples was determined by titration. It is found that the best result of CO2 loading is 0.065594 mole/mole K2CO3 and CO2 removal 28%. The result show that the loading capacity (mole CO2/mole K2CO3 and CO2 removal increased with the increase of DEA concentration.

  14. ETHANOL DEHYDRATION IN PACKED DISTILLATION COLUMN USING GLYCEROL AS ENTRAINER: EXPERIMENTS AND HETP EVALUATION

    Directory of Open Access Journals (Sweden)

    W. L. R. Souza

    Full Text Available Abstract The ethanol-water separation is very important because ethanol is widely applied in the chemical industry and its use as a fuel can reduce the pollution emitted to the air. However, anhydrous ethanol production using conventional distillation is impossible, at atmospheric pressure, due to the presence of an azeotrope. In the present work, experimental tests were carried out in order to evaluate the use of glycerol as an entrainer, in substitution of ethylene glycol in an extractive distillation. The use of glycerol is motivated by the biodiesel production units, due to the fact that it is the main byproduct and a new market is necessary to consume its overproduction. The experiments were carried out in a distillation column packed with Raschig rings, varying the glycerol/feed (ethanol and water ratio, S/F, from 0.5 to 0.9. The samples were analyzed using a digital densimeter. The results showed that glycerol was effective to promote ethanol dehydration and the presence of an azeotrope was not observed using a solvent to feed ratio (S/F equal to 0.9. Some empirical correlations were investigated to evaluate the HETP (Height Equivalent to a Theoretical Plate, and the results provided a useful tool for designing a packed bed column for ethanol-water separation.

  15. Enabling Microliquid Chromatography by Microbead Packing of Microchannels

    Science.gov (United States)

    Balvin, Manuel; Zheng, Yun

    2014-01-01

    The microbead packing is the critical element required in the success of on-chip microfabrication of critical microfluidic components for in-situ analysis and detection of chiral amino acids. In order for microliquid chromatography to occur, there must be a stationary phase medium within the microchannel that interacts with the analytes present within flowing fluid. The stationary phase media are the microbeads packed by the process discussed in this work. The purpose of the microliquid chromatography is to provide a lightweight, low-volume, and low-power element to separate amino acids and their chiral partners efficiently to understand better the origin of life. In order to densely pack microbeads into the microchannels, a liquid slurry of microbeads was created. Microbeads were extracted from a commercially available high-performance liquid chromatography column. The silica beads extracted were 5 microns in diameter, and had surface coating of phenyl-hexyl. These microbeads were mixed with a 200- proof ethanol solution to create a microbead slurry with the right viscosity for packing. A microfilter is placed at the outlet via of the microchannel and the slurry is injected, then withdrawn across a filter using modified syringes. After each injection, the channel is flushed with ethanol to enhance packing. This cycle is repeated numerous times to allow for a tightly packed channel of microbeads. Typical microbead packing occurs in the macroscale into tubes or channels by using highly pressurized systems. Moreover, these channels are typically long and straight without any turns or curves. On the other hand, this method of microbead packing is completed within a microchannel 75 micrometers in diameter. Moreover, the microbead packing is completed into a serpentine type microchannel, such that it maximizes microchannel length within a microchip. Doing so enhances the interactions of the analytes with the microbeads to separate efficiently amino acids and amino acid

  16. New approaches to the preparation of PαMS beads as mandrels for NIF-scale target capsules

    International Nuclear Information System (INIS)

    Cook, R.; Buckley, S.R.; Fearon, E.; Letts, S.A.

    1999-01-01

    The authors report on a new method using heated density gradient columns for preparing spherical poly(αmethylstyrene) (PαMS) bead mandrels for inertial confinement fusion spherical shell targets. Using 1,2 propane diol/glycerol mixtures, stable density gradient columns for supporting PαMS beads can be prepared at temperatures as high as 150 C. At these temperatures plasticized commercial beads become fluid and spherical, however loss of the plasticizer and very low molecular weight components of the bead due to limited solubility in the column fluid leads to surface finish problems. The authors also present results on PαMS beads prepared in an aqueous bath batch mode. Using these techniques beads with maximum out-of-rounds less than 5 microm have been produced

  17. Sequential injection-bead injection-lab-on-valve schemes for on-line solid phase extraction and preconcentration of ultra-trace levels of heavy metals with determination by electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Wang Jianhua; Hansen, Elo Harald; Miro, Manuel

    2003-01-01

    This communication presents an overview of the state-of-the-art of the exploitation of sequential injection (SI)-bead injection (BI)-lab-on-valve (LOV) schemes for automatic on-line sample pre-treatments interfaced with ETAAS and ICPMS detection as conducted in the authors' group. The discussions are focused on the applications of SI-BI-LOV protocols for on-line microcolumn based solid phase extraction of ultra-trace levels of heavy metals, employing the so-called renewable surface separation and preconcentration manipulatory scheme. Two types of sorbents have been employed as packing material, that is, the hydrophilic SP Sephadex C-25 cation exchange and iminodiacetate based Muromac A-1 chelating resins, and the hydrophobic poly(tetrafluoroethylene) (PTFE) and poly(styrene-divinylbenzene) copolymer alkylated with octadecyl groups (C 18 -PS/DVB). Using ETAAS as detection device, the easy-to-handle hydrophilic renewable reactors hold the features of improved R.S.D.s and LODs as compared to those operated in the conventional, permanent mode, in addition to the elimination of flow resistance. The hydrophobic columns fall into two categories, that is, the renewable one packed with C 18 -PS/DVB beads entails analogous R.S.D.s and LODs with respect to the conventional approach, while those with PTFE beads result in slightly inferior R.S.D.s and LODs by similar comparison, yet offering a wider dynamic range than when using an external permanent column. Moreover, the hydrophilic materials result in much higher enrichment of the analyte than the hydrophobic ones, although PTFE is the packing material that exhibits the best retention efficiency

  18. Prevention and suppression of metal packing fires.

    Science.gov (United States)

    Roberts, Mark; Rogers, William J; Sam Mannan, M; Ostrowski, Scott W

    2003-11-14

    Structured packing has been widely used because of large surface area that makes possible columns with high capacity and efficiency. The large surface area also contributes to fire hazards because of hydrocarbon deposits that can easily combust and promote combustion of the thin metal packing materials. Materials of high surface area that can fuel fires include reactive metals, such as titanium, and materials that are not considered combustible, such as stainless steel. Column design and material selection for packing construction is discussed together with employee training and practices for safe column maintenance and operations. Presented also are methods and agents for suppression of metal fires. Guidance for prevention and suppression of metal fires is related to incidents involving packing fires in columns.

  19. Treatment of ammonia in waste air using packed column coupling with chemical reaction

    Directory of Open Access Journals (Sweden)

    Thepchai, R.

    2007-05-01

    Full Text Available Ammonia is a common chemical used in various industries. Emission of air contaminated with ammonia to the atmosphere without any treatment causes several effects on human health and environment.A high efficiency method for ammonia removal from waste air is then necessary. In this research, an absorption coupling with chemical reaction was investigated for ammonia removal from waste air using a packedcolumn. The packed column of 10 cm diameter and 200 cm height was packed with 1.4x1.4 cm Raschig rings. Three liquids including water, NaOCl and H2SO4 solution were used as an absorbent for the investigation.The objectives of this research were to determine a suitable absorbent and the optimum condition for ammonia removal from waste air. The packed column was operated at room temperature and atmosphericpressure. The tested conditions were as follows: the gas to liquid ratio (G:L ratio was 35-90 m3 gas/m3 liquid, the inlet concentration of ammonia was 150-500 ppm and the air flow rate was 18 m3/h. The results showedthat the ammonia removal efficiency depends on type of the absorbent and the operating condition. The efficiencies increased with decreasing of G:L ratio and with increasing absorbent concentration. They were70%, 80-92%, and 95-100% for pure water, sodium hypochlorite solution and sulphuric acid solution, respectively. The efficiency decreased with time when water was used as an absorbent while it was almostconstant when NaOCl and H2SO4 solution were applied. The ammonia removal efficiency when using H2SO4 as the absorbent was not dependent on G:L ratio and inlet ammonia concentration, in the range used in thisinvestigation. Since H2SO4 solution gave the highest removal efficiency and can reduce ammonia concentration in waste air to levels which meet the TLV-TWA standard, it is recommended as an absorbent solution forammonia removal from waste air.

  20. Head holder using negative pressure bag packed with plastic beads in xenon CT CBF study

    International Nuclear Information System (INIS)

    Araki, Yuzo; Sakai, Noboru

    2003-01-01

    Employing analysis of cerebral blood flow (CBF) confidence maps, we investigated the usefulness of a head holder using a negative pressure bag packed with plastic beads in a xenon CT CBF study. A total of 272 consecutive patients for the CBF study were enrolled and classified into 3 groups: 88 patients with a negative pressure bag (M group), 87 patients with an air pillow (A group), and 97 patients with a sponge pillow (S group). The degree of effect of head movements on the CBF measurement in each patient was expressed as a confidence value (mean of the confidence values at one CT slice). The mean of confidence value in the M group (0.461) was statistically lower than that in the A group (0.866) and that in the S group (1.043). These findings showed that the head holder described here was useful for obtaining CBF maps of high quality in a xenon CT CBF study. (author)

  1. Recovery of Filtered Graphene Oxide Residue Using Elastic Gel Packed in a Column by Cross Flow

    Directory of Open Access Journals (Sweden)

    Yuji Takaoka

    2018-04-01

    Full Text Available To recover the filtered residues on a gel layer in a column, the method using the elasticity of the gel layer and flowing water in a cross-flow manner is proposed. Polymerized spherical gel (40 μm was packed in a column to a set height of 0.7 cm. The suspensions of graphene oxide at various sizes and shapes were injected on the top of the gel layer and then water was flowed at a flow rate of 1000 mL·h−1 until 0.10 MPa. By releasing the applied pressure, the elastic gel layer rose up, and the filtered graphene oxide also rose above the layer. This rise of the gel layer is due to the difference of pressure between the gel layer, including the filtered graphene oxide, and the open bottom of the column, using the flow of water. The cross flow of water through the column carried away the larger-sized filtered graphene oxide floating above the gel layer. The elasticity of the gel layer and cross flow through the column has the potential to recover the filtered particles.

  2. Retardation characteristics of radionuclides in geologic media through batch and packed column experiments

    International Nuclear Information System (INIS)

    Park, Hun Hwee; Han, Kyung Won; Han, Pil Soo; Lee, Jae Owan; Park, Chung Kyun; Yang, Ho Yeon

    1988-03-01

    Batch and packed column experiments are performed to investigate the retardation characteristics of radionuclide,i.e, Cs-137 in geologic media. In batch experiment, the effects of important parameters on the sorption of radionuclide in geologic media, such as nuclide concentration, pH, and particle size are examined. The Kd value obtained from breakthrough curve was compared with that from the batch sorption experiment to investigate the applicability of the Kd value from batch experiment to prediction of radionuclide migration in dynamic flow through porous media. The proposed model of radionuclide migration in porous media is also verified using the experimental results. (Author)

  3. Simple determination of betaine, l-carnitine and choline in human urine using self-packed column and column-switching ion chromatography with nonsuppressed conductivity detection.

    Science.gov (United States)

    Wei, Dan; Zhu, Yan; Guo, Ming

    2018-02-01

    A sequential online extraction, clean-up and separation system for the determination of betaine, l-carnitine and choline in human urine using column-switching ion chromatography with nonsuppressed conductivity detection was developed in this work. A self-packed pretreatment column (50 × 4.6 mm, i.d.) was used for the extraction and clean-up of betaine, l-carnitine and choline. The separation was achieved using self-packed cationic exchange column (150 × 4.6 mm, i.d.), followed by nonsuppressed conductivity detection. Under optimized experimental conditions, the developed method presented good analytical performance, with excellent linearity in the range of 0.60-100 μg mL -1 for betaine, 0.75-100 μg mL -1 for l-carnitine and 0.50-100 μg mL -1 for choline, with all correlation coefficients (R 2 ) >0.99 in urine. The limits of detection were 0.15 μg mL -1 for betaine, 0.20 μg mL -1 for l-carnitine and 0.09 μg mL -1 for choline. The intra- and inter-day accuracy and precision for all quality controls were within ±10.32 and ±9.05%, respectively. Satisfactory recovery was observed between 92.8 and 102.0%. The validated method was successfully applied to the detection of urinary samples from 10 healthy people. The values detected in human urine using the proposed method showed good agreement with the measurement reported previously. Copyright © 2017 John Wiley & Sons, Ltd.

  4. Separative analyses of a chromatographic column packed with a core-shell adsorbent for lithium isotope separation

    International Nuclear Information System (INIS)

    Sugiyama, T.; Sugura, K.; Enokida, Y.; Yamamoto, I.

    2015-01-01

    Lithium-6 is used as a blanket material for sufficient tritium production in DT fueled fusion reactors. A core-shell type adsorbent was proposed for lithium isotope separation by chromatography. The mass transfer model in a chromatographic column consisted of 4 steps, such as convection and dispersion in the column, transfer through liquid films, intra-particle diffusion and and adsorption or desorption at the local adsorption sites. A model was developed and concentration profiles and time variation in the column were numerically simulated. It became clear that core-shell type adsorbents with thin porous shell were saturated rapidly relatively to fully porous one and established a sharp edge of adsorption band. This is very important feature because lithium isotope separation requires long-distance development of adsorption band. The values of HETP (Height Equivalent of a Theoretical Plate) for core-shell adsorbent packed column were estimated by statistical moments of the step response curve. The value of HETP decreased with the thickness of the porous shell. A core-shell type adsorbent is, then, useful for lithium isotope separation. (authors)

  5. Breakthrough analysis for water disinfection using silver nanoparticles coated resin beads in fixed-bed column

    International Nuclear Information System (INIS)

    Mthombeni, Nomcebo H.; Mpenyana-Monyatsi, Lizzy; Onyango, Maurice S.; Momba, Maggie N.B.

    2012-01-01

    Highlights: ► Performance of silver nanoparticles coated resin in water disinfection is presented. ► Sigmoidal models are used to describe breakthrough curves. ► The performance of the media in water disinfection is affected by process variables. ► Test with environmental water shows the media is effective in water disinfection. - Abstract: This study demonstrates the use of silver nanoparticles coated resin beads in deactivating microbes in drinking water in a column filtration system. The coated resin beads are characterized using X-ray diffraction (XRD), Fourier transform infra-red (FT-IR), scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive spectroscopy (EDS) to confirm the functional groups, morphology and the presence of silver nanoparticles on the surface of the resin. The performance of the coated resin is evaluated as a function of bed mass, initial bacterial concentration and flow rate using Escherichia coli as model microbial contaminant in water. The survival curves of E. coli are expressed as breakthrough curves (BTCs), which are modeled using sigmoidal regression equations to obtain relevant rate parameters. The number of bed volumes processed at breakthrough point and capacity of the bed are used as performance indicators. Results show that performance increases with a decrease in initial bacterial concentration, an increase in flow rate and an increase in bed mass.

  6. Application of a two-dimensional model for predicting the pressure-flow and compression properties during column packing scale-up.

    Science.gov (United States)

    McCue, Justin T; Cecchini, Douglas; Chu, Cathy; Liu, Wei-Han; Spann, Andrew

    2007-03-23

    A two-dimensional model was formulated to describe the pressure-flow behavior of compressible stationary phases for protein chromatography at different temperatures and column scales. The model was based on the assumption of elastic deformation of the solid phase and steady-state Darcy flow. Using a single fitted value for the empirical modulus parameters, the model was applied to describe the pressure-flow behavior of several adsorbents packed using both fluid flow and mechanical compression. Simulations were in agreement with experimental data and accurately predicted the pressure-flow and compression behavior of three adsorbents over a range of column scales and operating temperatures. Use of the described theoretical model potentially improves the accuracy of the column scale-up process, allowing the use of limited laboratory scale data to predict column performance in large scale applications.

  7. The system uranyl nitrate-dietyl ether-water. Extraction by water in spray and packed columns from uranyl nitrate-either solutions

    International Nuclear Information System (INIS)

    Perez Luina, A.; Gutierrez Jodra, L.

    1960-01-01

    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

  8. Development of the Mo loading apparatus for adsorbing high level 99Mo to PZC and packing in 99mTc generator column

    International Nuclear Information System (INIS)

    Hishinuma, Yukio; Ohmori, Hiroyuki; Noguchi, Tuneyuki; Tatenuma, Katsuyoshi; Genka, Tsuguo; Machi, Sueo

    2006-01-01

    For developing the automatic system to produce the PZC- 99m Tc generator column based on (n, gamma) method, we developed and fabricated the proto-type apparatus for semi hot test to prepare and pack PZC adsorbed 99 Mo produced by (n, gamma) method into the generator column; PZC is Mo adsorbent with practical performance for (n, gamma) 99m Tc generator with high 99 Mo adsorption and high 99m Tc elution. For conducting the constant supply and delivery of 99m Tc generator, it is necessary to establish the technology of (n, gamma) method 99m Tc generator using PZC and to develop the fabrication system for 99 Mo loading to PZC and packing the 99m Tc generator column. By the reason, we are developing the Mo loading apparatus. In order to automatically conduct the process of 99 Mo adsorption to PZC and PZC- 99 Mo packing into the generator column, based on one channel system developed by JAERI-KAKEN at 3 years ago, an advanced automatic loading system functioned with 8 channels was developed as FNCA project proceeded by the core with Kaken Co. and JAIF for realizing a mass production of 99m Tc generators, and moreover the Japanese patent regarding the PZC- 99m Tc generator including the automatic loading system of 99 Mo to PZC and making 99m Tc generator columns has already been applied with joint applicants of BATAN and Kaken Co. Regarding the multi-type Mo loading apparatus mentioned above, we set it up in a hot of BATAN at December 2003 year. In this report, we will introduce mainly about the multi-channel automatic loading system of 99 Mo. (author)

  9. Experimental Study of the Flooding and Appearance of a Bubble Bed on Top of a Countercurrent Packed-Bed Column

    Czech Academy of Sciences Publication Activity Database

    Jiřičný, Vladimír; Staněk, Vladimír; Svoboda, Petr; Ondráček, Jakub

    2001-01-01

    Roč. 40, č. 1 (2001), s. 407-412 ISSN 0888-5885 R&D Projects: GA ČR GA203/97/1174 Institutional research plan: CEZ:AV0Z4072921 Keywords : appearance * bubble-bed * packed bed column Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.351, year: 2001

  10. Column-Oriented Database Systems (Tutorial)

    NARCIS (Netherlands)

    D. Abadi; P.A. Boncz (Peter); S. Harizopoulos

    2009-01-01

    textabstractColumn-oriented database systems (column-stores) have attracted a lot of attention in the past few years. Column-stores, in a nutshell, store each database table column separately, with attribute values belonging to the same column stored contiguously, compressed, and densely packed, as

  11. Longitudinal dispersion coefficient depending on superficial velocity of hydrogen isotopes flowing in column packed with zeolite pellets at 77.4 K

    Energy Technology Data Exchange (ETDEWEB)

    Kotoh, K. [Faculty of Engineering, Kyushu University, Nishi-ku, Fukuoka (Japan); Graduate School of Engineering, Kyushu University, Nishi-ku, Fukuoka (Japan); Kubo, K.; Takashima, S.; Moriyama, S.T. [Graduate School of Engineering, Kyushu University, Nishi-ku, Fukuoka (Japan); Tanaka, M. [National Institute for Fusion Science, Oroshi-cho, Toki, Gifu (Japan); Sugiyama, T. [Faculty of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya (Japan)

    2015-03-15

    Authors have been developing a cryogenic pressure swing adsorption system for hydrogen isotope separation. In the problem of its design and operation, it is necessary to predict the concentration profiles developing in packed beds of adsorbent pellets. The profiling is affected by the longitudinal dispersion of gas flowing in packed beds, in addition to the mass transfer resistance in porous media of adsorbent pellets. In this work, an equation is derived for estimating the packed-bed dispersion coefficient of hydrogen isotopes, by analyzing the breakthrough curves of trace D{sub 2} or HD replacing H{sub 2} adsorbed in synthetic zeolite particles packed columns at the liquefied nitrogen temperature 77.4 K. Since specialized for hydrogen isotopes, this equation can be considered to estimate the dispersion coefficients more reliable for the cryogenic hydrogen isotope adsorption process, than the existing equations. (authors)

  12. Biosorption of lead(II) and cadmium(II) by protonated Sargassum glaucescens biomass in a continuous packed bed column

    International Nuclear Information System (INIS)

    Naddafi, Kazem; Nabizadeh, Ramin; Saeedi, Reza; Mahvi, Amir Hossein; Vaezi, Forough; Yaghmaeian, Kamyar; Ghasri, Azar; Nazmara, Shahrokh

    2007-01-01

    Biosorption of lead(II) and cadmium(II) from aqueous solutions by protonated Sargassum glaucescens biomass was studied in a continuous packed bed column. The selective uptake of Pb 2+ and Cd 2+ was investigated in a binary system with initial concentration of 1 mM for each metal ion. The selective uptake capacities of Pb 2+ and Cd 2+ at complete exhaustion point were obtained 1.18 and 0.22 mmol/g, respectively; therefore, the biosorbent showed much higher relative affinity for Pb 2+ than for Cd 2+ . The optimum range of empty bed contact time (EBCT) was identified as 5-10 min in the packed bed column. The efficiency of biosorbent regeneration by 0.1 M HCl was achieved about 60%, so that the maximum uptake capacity of Pb 2+ by the regenerated biomass was determined to be 0.75 mmol/g while the same value for the original biomass was 1.24 mmol/g. The Thomas model was found in a suitable fitness with the experimental data (R 2 > 0.90 and ε% + with the uptake of heavy metals; hence, ion exchange was confirmed to be one of the main biosorption mechanisms

  13. Experimental engineering section off-gas decontamination facility's fractionator column: installation and performance

    International Nuclear Information System (INIS)

    Gilliam, T.M.; Fowler, V.L.; Inman, D.J.

    1978-03-01

    A detailed description of the third column recently installed in the Experimental Engineering Section Off-Gas Decontamination Facility (EES-ODF) is presented. The EES-ODF is being used to provide engineering-scale experiments (nominal gas and liquid flows of 5 scfm and 0.5 gpm, respectively) in the development of the Krypton Absorption in Liquid CO 2 (KALC) process. A detailed discussion of the column's construction is provided. This discussion includes the peripherals associated with the column, such as refrigeration, heat exchangers, instrumentation, etc. The compressibility of Goodloe packing (the packing in the other columns) and the possible reduced throughput due to this compression have revealed the desirablility of a random (i.e., noncompressible) packing. Toward this end, the third column is packed with a new random packing (PRO-PAK). A preliminary comparison between this packing and the woven wire mesh packing (Goodloe) used in the other two columns has been made. Experiments comparing the throughput capacity indicate that the PRO-PAK packing has approximately 60% the capacity of Goodloe for a CO 2 system. When used as a fractionator or stripper with the basic O 2 -Kr-CO 2 KALC system, the PRO-PAK column produced HTU values less than or equal to the GOODLOE columns under similar operating conditions

  14. Highly efficient high-performance liquid chromatographic separation of xylene isomers and phthalate acid esters on a homemade DUT-67(Zr) packed column.

    Science.gov (United States)

    Chen, Sha; Li, Xiao-Xin; Feng, Fan; Li, Sumei; Han, Jia-Hui; Jia, Zi-Yi; Shu, Lun; Somsundaran, P; Li, Jian-Rong

    2018-04-16

    In this study, the baseline separations of xylene isomers and phthalate acid esters on a homemade DUT-67(Zr) packed column were achieved, respectively. The high selectivity for xylene isomers and phthalate acid esters was obtained with the increase of temperature and decrease of the retention time. The hydrophobicity of xylene isomers and phthalate acid esters caused the different separation time on the DUT-67(Zr) packed column. The relative standard deviation values of retention time, peak area, peak height and half peak width for five repeat separation of the xylene isomers were 0.26-0.35, 2.11-2.26, 1.51-2.03, and 0.29-0.77%, and the values of the phthalate acid esters on DUT-67(Zr) column were 0.1-0.4, 4.4-5.2, 3.9-6.3, and 0.6-2.1%, respectively. The thermodynamic properties indicated that the separation of xylene isomers was controlled by ΔH and ΔS, but the separation of phthalate acid esters was mainly controlled by ΔS. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  15. Separation of rate processes for isotopic exchange between hydrogen and liquid water in packed columns 10

    International Nuclear Information System (INIS)

    Butler, J.P.; Hartog, J. den; Goodale, J.W.; Rolston, J.H.

    1977-01-01

    Wetproofed platinum catalysts in packed columns promote isotopic exchange between counter-current streams of hydrogen saturated with water vapour and liquid water. The net rate of deuterium transfer from isotopically enriched hydrogen has been measured and separated into two rate processes involving the transfer of deuterium from hydrogen to water vapour and from water vapour to liquid. These are compared with independent measurements of the two rate processes to test the two-step successive exchange model for trickle bed reactors. The separated transfer rates are independent of bed height and characterize the deuterium concentrations of each stream along the length of the bed. The dependences of the transfer rates upon hydrogen and liquid flow, hydrogen pressure, platinum loading and the effect of dilution of the hydrophobic catalyst with inert hydrophilic packing are reported. The results indicate a third process may be important in the transfer of deuterium between hydrogen and liquid water. (author)

  16. Plasmid pVAX1-NH36 purification by membrane and bead perfusion chromatography.

    Science.gov (United States)

    Franco-Medrano, Diana Ivonne; Guerrero-Germán, Patricia; Montesinos-Cisneros, Rosa María; Ortega-López, Jaime; Tejeda-Mansir, Armando

    2017-03-01

    The demand for plasmid DNA (pDNA) has increased in response to the rapid advances in vaccines applications to prevent and treat infectious diseases caused by virus, bacteria or parasites, such as Leishmania species. The immunization protocols require large amounts of supercoiled plasmid DNA (sc-pDNA) challenging the development of efficient and profitable processes for capturing and purified pDNA molecules from large volumes of lysates. A typical bioprocess involves four steps: fermentation, primary recovery, intermediate recovery and final purification. Ion-exchange chromatography is one of the key operations in the purification schemes of pDNA owing the chemical structure of these macromolecules. The goal of this research was to compare the performance of the final purification step of pDNA using ion-exchange chromatography on columns packed with Mustang Q membranes or perfusive beads POROS 50 HQ. The experimental results showed that both matrixes could separate the plasmid pVAX1-NH36 (3936 bp) from impurities in clarified Escherichia coli lysates with an adequate resolution. In addition, a 24- and 21-fold global purification factor was obtained. An 88 and 63% plasmid recuperation was achieved with ion-exchange membranes and perfusion beads, respectively. A better understanding of perfusion-based matrices for the purification of pDNA was developed in this research.

  17. Magnetic resonance velocity imaging of liquid and gas two-phase flow in packed beds.

    Science.gov (United States)

    Sankey, M H; Holland, D J; Sederman, A J; Gladden, L F

    2009-02-01

    Single-phase liquid flow in porous media such as bead packs and model fixed bed reactors has been well studied by MRI. To some extent this early work represents the necessary preliminary research to address the more challenging problem of two-phase flow of gas and liquid within these systems. In this paper, we present images of both the gas and liquid velocities during stable liquid-gas flow of water and SF(6) within a packing of 5mm spheres contained within columns of diameter 40 and 27 mm; images being acquired using (1)H and (19)F observation for the water and SF(6), respectively. Liquid and gas flow rates calculated from the velocity images are in agreement with macroscopic flow rate measurements to within 7% and 5%, respectively. In addition to the information obtained directly from these images, the ability to measure liquid and gas flow fields within the same sample environment will enable us to explore the validity of assumptions used in numerical modelling of two-phase flows.

  18. Application of four novel fungal strains to remove arsenic from contaminated water in batch and column modes.

    Science.gov (United States)

    Jaiswal, Virendra; Saxena, Sangeeta; Kaur, Ispreet; Dubey, Priya; Nand, Sampurna; Naseem, Mariya; Singh, Suman B; Srivastava, Pankaj Kumar; Barik, Saroj Kanta

    2018-08-15

    Immobilized biomass of novel indigenous fungal strains FNBR_3, FNBR_6, FNBR_13, and FNBR_19 were evaluated for arsenic (As) removal from aqueous solution. Alginate beads containing 0.1 g biomass were used in a batch experiment (200 mg l -1 As; pH 6). Biosorption equilibrium established in first 2 h with As adsorption (mg g -1 ) as 70, 68, 113 and 90 by FNBR_3, FNBR_6, FNBR_13 and FNBR_19, respectively. The equilibrium was fitted to the Langmuir model (r 2  = 0. 90-0.97). The absorption kinetic followed the pseudo second order. Changes in the surface of fungal cells and intracellular As-uptake by fungal biomass were also confirmed by scanning electron microscopy combined with X-ray energy dispersive spectrometer. The presence of different functional groups on fungal cells capable of As-binding was investigated by FTIR. The As-removal by immobilized fungal beads tested in the packed columns also. The As-adsorption by biomass (qe as mg g -1 ) were recorded as 59.5 (FNBR_3 and FNBR_6), 74.8 (FNBR_13), and 66.3 (FNBR_19) in the column and validated by Thomas model. This is the first report concerning the arsenic removal by immobilized biomass of these novel fungal strains from aqueous solution both in batch and column studies with a prospect of their further industrial application. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. ADVANCED DIAGNOSTIC TECHNIQUES FOR THREE-PHASE SLURRY BUBBLE COLUMN REACTORS(SBCR)

    Energy Technology Data Exchange (ETDEWEB)

    M.H. Al-Dahhan; L.S. Fan; M.P. Dudukovic

    2002-07-25

    This report summarizes the accomplishment made during the third year of this cooperative research effort between Washington University, Ohio State University and Air Products and Chemicals. Data processing of the performed Computer Automated Radioactive Particle Tracking (CARPT) experiments in 6 inch column using air-water-glass beads (150 {micro}m) system has been completed. Experimental investigation of time averaged three phases distribution in air-Therminol LT-glass beads (150 {micro}m) system in 6 inch column has been executed. Data processing and analysis of all the performed Computed Tomography (CT) experiments have been completed, using the newly proposed CT/Overall gas holdup methodology. The hydrodynamics of air-Norpar 15-glass beads (150 {micro}m) have been investigated in 2 inch slurry bubble column using Dynamic Gas Disengagement (DGD), Pressure Drop fluctuations, and Fiber Optic Probe. To improve the design and scale-up of bubble column reactors, a correlation for overall gas holdup has been proposed based on Artificial Neural Network and Dimensional Analysis.

  20. Centrifugal sedimentation for selectively packing channels with silica microbeads in three-dimensional micro/nanofluidic devices.

    Science.gov (United States)

    Gong, Maojun; Bohn, Paul W; Sweedler, Jonathan V

    2009-03-01

    Incorporation of nanofluidic elements into microfluidic channels is one approach for adding filtration and partition functionality to planar microfluidic devices, as well as providing enhanced biomolecular separations. Here we introduce a strategy to pack microfluidic channels with silica nanoparticles and microbeads, thereby indirectly producing functional nanostructures; the method allows selected channels to be packed, here demonstrated so that a separation channel is packed while keeping an injection channel unpacked. A nanocapillary array membrane is integrated between two patterned microfluidic channels that cross each other in vertically separated layers. The membrane serves both as a frit for bead packing and as a fluid communication conduit between microfluidic channels. Centrifugal force-assisted sedimentation is then used to selectively pack the microfluidic channels using an aqueous silica bead suspension loaded into the appropriate inlet reservoirs. This packing approach may be used to simultaneously pack multiple channels with silica microbeads having different sizes and surface properties. The chip design and packing method introduced here are suitable for packing silica particles in sizes ranging from nanometers to micrometers and allow rapid (approximately 10 min) packing with high quality. The liquid/analyte transport characteristics of these packed micro/nanofluidic devices have potential utility in a wide range of applications, including electroosmotic pumping, liquid chromatographic separations, and electrochromatography.

  1. Degradation of nitrobenzene in simulated wastewater by iron-carbon micro-electrolysis packing.

    Science.gov (United States)

    Li, Meng; Zou, Donglei; Zou, Haochen; Fan, Dongyan

    2011-12-01

    The reductive degradation of nitrobenzene (NB) by iron-carbon micro-electrolysis packing was investigated. The influence of initial NB concentration, pH value and packing amount on the removal rate of NB were studied. The results showed that the reaction with packing followed the pseudo-first-order reaction. The optimum pH was 3.0 for the degradation of NB in the tested pH ranges of 3-9 and the optimum packing amount was 40 g/200 ml. The flow-through column packed with packing was designed to remove NB from simulated wastewater for approximately 68 days. The removal rate was over 90% within initial periods. It could be seen that after running for 68 days, the packing still had good performance after the long-term column experiment. In addition, the changes of the packing surfaces morphologies and matters before, during and after the column experiment were analysed by scanning electron microscopy in conjunction with energy-dispersion spectroscopy (EDS).

  2. Biosorption of copper by marine algae Gelidium and algal composite material in a packed bed column.

    Science.gov (United States)

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

    2008-09-01

    Marine algae Gelidium and algal composite material were investigated for the continuous removal of Cu(II) from aqueous solution in a packed bed column. The biosorption behaviour was studied during one sorption-desorption cycle of Cu(II) in the flow through column fed with 50 and 25 mg l(-1) of Cu(II) in aqueous solution, at pH 5.3, leading to a maximum uptake capacity of approximately 13 and 3 mg g(-1), respectively, for algae Gelidium and composite material. The breakthrough time decreases as the inlet copper concentration increases, for the same flow rate. The pH of the effluent decreases over the breakthrough time of copper ions, which indicates that ion exchange is one of the mechanisms involved in the biosorption process. Temperature has little influence on the metal uptake capacity and the increase of the ionic strength reduces the sorption capacity, decreasing the breakthrough time. Desorption using 0.1M HNO(3) solution was 100% effective. After two consecutive sorption-desorption cycles no changes in the uptake capacity of the composite material were observed. A mass transfer model including film and intraparticle resistances, and the equilibrium relationship, for adsorption and desorption, was successfully applied for the simulation of the biosorption column performance.

  3. Effect of Temperature on Granulocyte and Monocyte Adsorption to Cellulose Acetate Beads.

    Science.gov (United States)

    Nishise, Shoichi; Takeda, Yuji; Abe, Yasuhiko; Sasaki, Yu; Nara, Hidetoshi; Asao, Hironobu; Ueno, Yoshiyuki

    2017-06-01

    Granulocyte and monocyte (GM) adsorptive apheresis (GMA) is an effective therapy for inflammatory disorders including inflammatory bowel disease (IBD). During GMA, the blood of a patient with IBD passes through a column to contact cellulose acetate (CA) beads at a temperature below body temperature, likely close to room temperature. Here we investigated the effect of temperature on GM adsorption to CA beads in vitro. We incubated peripheral blood with and without CA beads at 5°C, 25°C, 37°C, and 43°C and calculated the ratios of adsorbed GMs. The ratios of adsorbed GMs increased as the temperature was raised. Additionally, we measured complement activation fragment concentrations. C3a and C5a concentrations also increased as the temperature was raised, and C5a concentrations had a positive correlation with the ratios of adsorbed GMs. These results suggest that warming the column during GMA might increase GM adsorption to CA beads, thereby enhancing the clinical efficacy of GMA. © 2017 International Society for Apheresis, Japanese Society for Apheresis, and Japanese Society for Dialysis Therapy.

  4. Effect of algal density in bead, bead size and bead concentrations ...

    African Journals Online (AJOL)

    Effect of algal density in bead, bead size and bead concentrations on wastewater nutrient removal. ... African Journal of Biotechnology ... The bioreactor containing algal beads (4 mm diameter) with 1.5 x 106 cells bead-1 (cell stocking) at concentration of 10.66 beads ml-1 wastewater (1:3 bead: wastewater, v/v) achieved ...

  5. Deuterium exchange reaction in a trickle bed packed with a mixture of hydrophobic catalyst and hydrophilic packings

    International Nuclear Information System (INIS)

    Seungwoo Paek; Heui-Joo Choi; DO-Hee Ahn; Kwang-Rag Kim; Minsoo Lee; Sung-Paal Yim; Hongsuk Chung

    2006-01-01

    Full text of publication follows: The isotopic exchange reaction between hydrogen and water on the platinum supported catalysts provides a useful step for separating hydrogen isotopes such as deuterium and tritium. The CECE (Combined Electrolysis Catalytic Exchange) with a hydrophobic catalyst is a very effective method to remove small quantities of tritium from light or heavy waste water streams because of its high separation factor and mild operating conditions. The CECE column is composed of an electrolysis cell and a liquid phase catalytic exchange column. This paper deals with the experiments for the hydrogen isotopic exchange reaction in a trickle bed reactor packed with a hydrophobic catalyst in order to develop the catalytic column of the CECE. Hydrophobic Pt/SDBC catalyst which has been developed for the LPCE column of WTRF (Wolsong Tritium Removal Facility) was tested in a trickle bed reactor. The catalyst column was packed with a mixture of hydrophobic catalyst and hydrophilic packing (Dixon gauze ring) to improve liquid distribution and vapor/liquid transfer area. An experimental apparatus was built for the test of the catalyst at various temperatures and gas velocities. The catalyst was packed wet into the column and water was injected at the top through a liquid distributor and trickled through a catalyst mixture. Hydrogen gas passed up the column and deuterium was transferred to water stream flowing counter currently. The temperature of the column was controlled to maintain at 60 deg. C using water jackets around the reactor and equilibrator, a feed waster heater, and a circulation water heater. A metal bellows pump was used to circulate the hydrogen gas at the typical flow rate of 60 LPM.The reactor pressure was controlled to maintain at 135 kPa (abs) by a water column. Gas samples were drawn off from the top and bottom of the column. The difference in deuterium concentration between the inlet and outlet gas samples was analyzed using Gas

  6. Column-Oriented Database Systems (Tutorial)

    OpenAIRE

    Abadi, D.; Boncz, Peter; Harizopoulos, S.

    2009-01-01

    textabstractColumn-oriented database systems (column-stores) have attracted a lot of attention in the past few years. Column-stores, in a nutshell, store each database table column separately, with attribute values belonging to the same column stored contiguously, compressed, and densely packed, as opposed to traditional database systems that store entire records (rows) one after the other. Reading a subset of a table’s columns becomes faster, at the potential expense of excessive disk-head s...

  7. Post column derivatisation analyses review. Is post-column derivatisation incompatible with modern HPLC columns?

    Science.gov (United States)

    Jones, Andrew; Pravadali-Cekic, Sercan; Dennis, Gary R; Shalliker, R Andrew

    2015-08-19

    Post Column derivatisation (PCD) coupled with high performance liquid chromatography or ultra-high performance liquid chromatography is a powerful tool in the modern analytical laboratory, or at least it should be. One drawback with PCD techniques is the extra post-column dead volume due to reaction coils used to enable adequate reaction time and the mixing of reagents which causes peak broadening, hence a loss of separation power. This loss of efficiency is counter-productive to modern HPLC technologies, -such as UHPLC. We reviewed 87 PCD methods published from 2009 to 2014. We restricted our review to methods published between 2009 and 2014, because we were interested in the uptake of PCD methods in UHPLC environments. Our review focused on a range of system parameters including: column dimensions, stationary phase and particle size, as well as the geometry of the reaction loop. The most commonly used column in the methods investigated was not in fact a modern UHPLC version with sub-2-micron, (or even sub-3-micron) particles, but rather, work-house columns, such as, 250 × 4.6 mm i.d. columns packed with 5 μm C18 particles. Reaction loops were varied, even within the same type of analysis, but the majority of methods employed loop systems with volumes greater than 500 μL. A second part of this review illustrated briefly the effect of dead volume on column performance. The experiment evaluated the change in resolution and separation efficiency of some weak to moderately retained solutes on a 250 × 4.6 mm i.d. column packed with 5 μm particles. The data showed that reaction loops beyond 100 μL resulted in a very serious loss of performance. Our study concluded that practitioners of PCD methods largely avoid the use of UHPLC-type column formats, so yes, very much, PCD is incompatible with the modern HPLC column. Copyright © 2015. Published by Elsevier B.V.

  8. Removal of H2S from Biogas by Iron (Fe3+ Doped MgO on Ceramic Honeycomb Catalyst using Double Packed Columns System

    Directory of Open Access Journals (Sweden)

    Juntima Chungsiriporn

    2010-03-01

    Full Text Available Hydrogen sulfide is a toxic and corrosive in nature, gas should be safely removed from the biogas streams before subjecting into the fuel cell. Fe3+ doped magnesium oxide was synthesized using sol-gel technique and dip coating process of Fe3+ doped MgO on foam ceramic honeycomb. XRD and SEM indicate that Fe3+ in Fe3+ doped MgO on foam ceramic honeycomb catalyst is finely dispersed in the MgO support. Performance of the synthesized Fe3+ doped magnesium oxide on the honeycomb catalyst was examined for hydrogen sulfide (H2S oxidation by double packed column scrubbers. The absorption column was used for H2S scrubbing from biogas by deionized water absorption and catalytic column was used as catalyst bed for degradation of absorbed H2S in scrubbing water. In the catalytic column, counter current flow of the scrubbing water and air through the catalyst pack was performed for H2S oxidation accompany with catalyst regeneration. System capacity for H2S removal from gas stream showed 98% constant along 3 hr testing time at room temperature.

  9. Continuous cadmium removal from aqueous solutions by seaweed in a packed-bed column under consecutive sorption-desorption cycles

    International Nuclear Information System (INIS)

    Jafari, Seyed Ali; Jamali, Abbas

    2016-01-01

    Packed-bed column process efficiency for cadmium adsorption from aqueous solution was investigated under different bed heights (2.6 to 7.5 cm) and feed flow rates (15 to 30 ml min -1 ). The column was filled with brown seaweed, Sargassum angustifolium. Three simplified models, including Bed Depth Service Time, Thomas, and Yoon- Nelson were employed for describing the experimental breakthrough curves as well as achieving design parameters. Bed lifetime was also evaluated in several consecutive sorption-desorption cycles. Cadmium concentration of 0.005mg l−1, as a standard limit for potable water, was considered as the breakthrough concentration. The maximum column performance was achieved 81% at 7.5 cm bed length and flow rate of 15 ml min -1 . Indeed, increasing the bed height increased the sorption performance and service time, while increasing the feed flow rate had a negative effect. Maximum sorption capacity value remained almost constant by the bed height changes; however, increase in the feed flow rate slightly decreased it. The modeling results revealed that the Yoon-Nelson model was more accurate than Thomas for describing the experimental breakthrough data, especially at low flow rates. Column service time predictions were surprisingly achieved using the Bed Depth Service Time model even at extrapolations. 20% reduction in column adsorption efficiency was observed at the end of four consecutive sorption-desorption cycles; however, desorption efficiencies were achieved more than 99% in each cycle.

  10. Continuous cadmium removal from aqueous solutions by seaweed in a packed-bed column under consecutive sorption-desorption cycles

    Energy Technology Data Exchange (ETDEWEB)

    Jafari, Seyed Ali; Jamali, Abbas [Persian Gulf Research Institute, Persian Gulf University, 75169, Bushehr (Iran, Islamic Republic of)

    2016-04-15

    Packed-bed column process efficiency for cadmium adsorption from aqueous solution was investigated under different bed heights (2.6 to 7.5 cm) and feed flow rates (15 to 30 ml min{sup -1}). The column was filled with brown seaweed, Sargassum angustifolium. Three simplified models, including Bed Depth Service Time, Thomas, and Yoon- Nelson were employed for describing the experimental breakthrough curves as well as achieving design parameters. Bed lifetime was also evaluated in several consecutive sorption-desorption cycles. Cadmium concentration of 0.005mg l−1, as a standard limit for potable water, was considered as the breakthrough concentration. The maximum column performance was achieved 81% at 7.5 cm bed length and flow rate of 15 ml min{sup -1}. Indeed, increasing the bed height increased the sorption performance and service time, while increasing the feed flow rate had a negative effect. Maximum sorption capacity value remained almost constant by the bed height changes; however, increase in the feed flow rate slightly decreased it. The modeling results revealed that the Yoon-Nelson model was more accurate than Thomas for describing the experimental breakthrough data, especially at low flow rates. Column service time predictions were surprisingly achieved using the Bed Depth Service Time model even at extrapolations. 20% reduction in column adsorption efficiency was observed at the end of four consecutive sorption-desorption cycles; however, desorption efficiencies were achieved more than 99% in each cycle.

  11. Arsenic Removal from Aqueous Solution Using Pure and Metal-Doped Titania Nanoparticles Coated on Glass Beads: Adsorption and Column Studies

    Directory of Open Access Journals (Sweden)

    M. Ihsan Danish

    2013-01-01

    Full Text Available Nanosized metal oxide, Titania, provides high surface area and specific affinity for the adsorption of heavy metals, including arsenic (As, which is posing a great threat to the world population due to its carcinogenic nature. In this study, As(III adsorption was studied on pure and metal- (Ag- and Fe- doped Titania nanoparticles. The nanoparticles were synthesized by liquid impregnation method with some modifications, with crystallite size in the range of 30 to 40 nm. Band gap analysis, using Kubelka-Munk function showed a shift of absorption band from UV to visible region for the metal-doped Titania. Effect of operational parameters like dose of nanoparticles, initial As(III concentration, and pH was evaluated at 25°C. The data obtained gave a good fit with Langmuir and Freundlich isotherms and the adsorption was found to conform to pseudo-second-order kinetics. In batch studies, over 90% of arsenic removal was observed for both types of metal-doped Titania nanoparticles from a solution containing up to 2 ppm of the heavy metal. Fixed bed columns of nanoparticles, coated on glass beads, were used for As(III removal under different operating conditions. Thomas and Yoon-Nelson models were applied to predict the breakthrough curves and to find the characteristic column parameters useful for process design. The columns were regenerated using 10% NaOH solution.

  12. Enantioselective Analytical- and Preparative-Scale Separation of Hexabromocyclododecane Stereoisomers Using Packed Column Supercritical Fluid Chromatography.

    Science.gov (United States)

    Riddell, Nicole; Mullin, Lauren Gayle; van Bavel, Bert; Ericson Jogsten, Ingrid; McAlees, Alan; Brazeau, Allison; Synnott, Scott; Lough, Alan; McCrindle, Robert; Chittim, Brock

    2016-11-10

    Hexabromocyclododecane (HBCDD) is an additive brominated flame retardant which has been listed in Annex A of the Stockholm Convention for elimination of production and use. It has been reported to persist in the environment and has the potential for enantiomer-specific degradation, accumulation, or both, making enantioselective analyses increasingly important. The six main stereoisomers of technical HBCDD (i.e., the (+) and (-) enantiomers of α-, β-, and γ-HBCDD) were separated and isolated for the first time using enantioselective packed column supercritical fluid chromatography (pSFC) separation methods on a preparative scale. Characterization was completed using published chiral liquid chromatography (LC) methods and elution profiles, as well as X-ray crystallography, and the isolated fractions were definitively identified. Additionally, the resolution of the enantiomers, along with two minor components of the technical product (δ- and ε-HBCDD), was investigated on an analytical scale using both LC and pSFC separation techniques, and changes in elution order were highlighted. Baseline separation of all HBCDD enantiomers was achieved by pSFC on an analytical scale using a cellulose-based column. The described method emphasizes the potential associated with pSFC as a green method of isolating and analyzing environmental contaminants of concern.

  13. Use of a Packed-Column Bioreactor for Isolation of Diverse Protease-Producing Bacteria from Antarctic Soil

    Science.gov (United States)

    Wery, Nathalie; Gerike, Ursula; Sharman, Ajay; Chaudhuri, Julian B.; Hough, David W.; Danson, Michael J.

    2003-01-01

    Seventy-five aerobic heterotrophs have been isolated from a packed-column bioreactor inoculated with soil from Antarctica. The column was maintained at 10°C and continuously fed with a casein-containing medium to enrich protease producers. Twenty-eight isolates were selected for further characterization on the basis of morphology and production of clearing zones on skim milk plates. Phenotypic tests indicated that the strains were mainly psychrotrophs and presented a high morphological and metabolical diversity. The extracellular protease activities tested were optimal at neutral pH and between 30 and 45°C. 16S ribosomal DNA sequence analyses showed that the bioreactor was colonized by a wide variety of taxons, belonging to various bacterial divisions: α-, β-, and γ-Proteobacteria; the Flexibacter-Cytophaga-Bacteroides group; and high G+C gram-positive bacteria and low G+C gram-positive bacteria. Some strains represent candidates for new species of the genera Chryseobacterium and Massilia. This diversity demonstrates that the bioreactor is an efficient enrichment tool compared to traditional isolation strategies. PMID:12620829

  14. Evaluation of monolithic and sub 2 microm particle packed columns for the rapid screening for illicit drugs--application to the determination of drug contamination on Irish euro banknotes.

    Science.gov (United States)

    Bones, Jonathan; Macka, Mirek; Paull, Brett

    2007-03-01

    A study comparing recently available 100 x 3 mm id, 200 x 3 mm id monolithic reversed-phase columns with a 50 x 2.1 mm id, 1.8 microm particle packed reversed-phase columns was carried out to determine the most efficient approach (using traditional van Deemter analysis and a modern kinetic plot approach) for the rapid screening of samples for 16 illicit drugs and associated metabolites. A plot of column backpressure versus plate number (N) showed a significant advantage of using the monolithic phases, with the 20 cm monolithic column exhibiting a maximum 15,000 plates at a column backpressure of approximately 70 bar, compared to approximately 7000 plates at 150 bar for the 5 cm 1.8 microm particle packed column. Optimum linear velocities were found to be 0.40 mm s(-1), 0.52 mm s(-1) and 0.98 mm s(-1) for the three above columns, respectively. The 20 cm monolithic column was subsequently applied to the separation and determination of illicit drug contamination on Irish euro banknotes, using methanol extraction followed by LC-MS/MS. Method performance data showed that the new LC-MS/MS method was significantly more sensitive than previous GC-MS/MS based methods for this application, with detection limits in the pg note(-1) region, based upon a 20 microL standard injection. All of the notes examined tested positive for trace quantities of cocaine, with benzoylecgonine detected on 12 of the 45 notes sampled. Traces of heroin were also detected on three of the 45 notes.

  15. Deuterium exchange reaction in a trickle bed packed with a mixture of hydrophobic catalyst and hydrophilic packings

    Energy Technology Data Exchange (ETDEWEB)

    Seungwoo Paek [KAERI (Korea, Republic of); Heui-Joo Choi; DO-Hee Ahn; Kwang-Rag Kim; Minsoo Lee; Sung-Paal Yim; Hongsuk Chung

    2006-07-01

    Full text of publication follows: The isotopic exchange reaction between hydrogen and water on the platinum supported catalysts provides a useful step for separating hydrogen isotopes such as deuterium and tritium. The CECE (Combined Electrolysis Catalytic Exchange) with a hydrophobic catalyst is a very effective method to remove small quantities of tritium from light or heavy waste water streams because of its high separation factor and mild operating conditions. The CECE column is composed of an electrolysis cell and a liquid phase catalytic exchange column. This paper deals with the experiments for the hydrogen isotopic exchange reaction in a trickle bed reactor packed with a hydrophobic catalyst in order to develop the catalytic column of the CECE. Hydrophobic Pt/SDBC catalyst which has been developed for the LPCE column of WTRF (Wolsong Tritium Removal Facility) was tested in a trickle bed reactor. The catalyst column was packed with a mixture of hydrophobic catalyst and hydrophilic packing (Dixon gauze ring) to improve liquid distribution and vapor/liquid transfer area. An experimental apparatus was built for the test of the catalyst at various temperatures and gas velocities. The catalyst was packed wet into the column and water was injected at the top through a liquid distributor and trickled through a catalyst mixture. Hydrogen gas passed up the column and deuterium was transferred to water stream flowing counter currently. The temperature of the column was controlled to maintain at 60 deg. C using water jackets around the reactor and equilibrator, a feed waster heater, and a circulation water heater. A metal bellows pump was used to circulate the hydrogen gas at the typical flow rate of 60 LPM.The reactor pressure was controlled to maintain at 135 kPa (abs) by a water column. Gas samples were drawn off from the top and bottom of the column. The difference in deuterium concentration between the inlet and outlet gas samples was analyzed using Gas

  16. Gamma ray scanning as troubleshooting tool for unusual and large diameter refinery vacuum columns

    International Nuclear Information System (INIS)

    Sarkar, T.K.; Chawla, R.; Banik, S.; Chopra, S.J.; Singh, G.; Pant, H.J.; Sreeramakrishnan, P.; Dhar, D.C.; Pushpangathan, P.N.; Sharma, V.K.

    1997-01-01

    Gamma scanning of trayed and packed columns is widely used to obtain density profiles and identify on-line problems such as: damaged tray or packing, foaming, flooding, maldistribution, weeping and entrainment, etc. However, scanning of large diameter tray or packed columns requires expertise in handling high intensity gamma sources along with thorough understanding of distillation engineering. Engineers India Limited and the Bhabha Atomic Research Centre undertook scanning of two such large diameter (8.4 m and 7.4 m) trayed and packed refinery vacuum distillation columns and successfully diagnosed the problems and suggested remedial actions. Radiography testing of small diameter columns can be used to confirm gamma scanning results. One such example for ammonia separator column is given

  17. Practical issues relating to soil column chromatography for sorption parameter determination.

    Science.gov (United States)

    Bi, Erping; Schmidt, Torsten C; Haderlein, Stefan B

    2010-08-01

    Determination of sorption distribution coefficients (K(d)) of organic compounds by a dynamic soil column chromatography (SCC) method was developed and validated. Eurosoil 4, quartz, and alumina were chosen as exemplary packing materials. Heterocyclic aromatic compounds were selected in the validation of SCC. The prerequisites of SCC with regard to column dimension, packing procedure, and sample injection volume are discussed. Reproducible soil column packing was achieved by addition of a pre-column and an HPLC pump for subsequent compression of the packed material. Various methods to determine retention times from breakthrough curves are discussed and the use of the half mass method is recommended. To dilute soil with inert material can prevent column-clogging and help to complete experiments in a reasonable period of time. For the chosen probe compounds, quartz rather than alumina proved a suitable dilution material. Non-equilibrium issue can be overcome by conducting the experiments under different flowrates and/or performing numerical simulation. Copyright 2010 Elsevier Ltd. All rights reserved.

  18. Radial heterogeneity of some analytical columns used in high-performance liquid chromatography.

    Science.gov (United States)

    Abia, Jude A; Mriziq, Khaled S; Guiochon, Georges A

    2009-04-10

    An on-column electrochemical microdetector was used to determine accurately the radial distribution of the mobile phase velocity and of the column efficiency at the exit of three common analytical columns, namely a 100 mm x 4.6mm C18 bonded silica-based monolithic column, a 150 mm x 4.6mm column packed with 2.7 microm porous shell particles of C18 bonded silica (HALO), and a 150 mm x 4.6mm column packed with 3 microm fully porous C18 bonded silica particles (LUNA). The results obtained demonstrate that all three columns are not radially homogeneous. In all three cases, the efficiency was found to be lower in the wall region of the column than in its core region (the central core with a radius of 1/3 the column inner radius). The decrease in local efficiency from the core to the wall regions was lower in the case of the monolith (ca. 25%) than in that of the two particle-packed columns (ca. 35-50%). The mobile phase velocity was found to be ca. 1.5% higher in the wall than in the core region of the monolithic column while, in contrast, it was ca. 2.5-4.0% lower in the wall region for the two particle-packed columns.

  19. CFD simulation of alleviation of fluid back mixing by baffles in bubble column

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Y.K.; Peng, F.F.; Wolfe, E. [Sedgman LLC, Pittsburgh, PA (United States)

    2006-07-15

    The global back mixing of liquid in an open flotation column is harmful to mineral separations. The inclusion of baffles and packing in open columns can dampen the effects of global back mixing. A mathematical model based on the principle of fluid dynamics is helpful in designing baffled or packed columns. This paper presents a two-dimensional Euler-Lagrangian model to simulate the multiphase flow for some cases of baffled and packed columns. Fluid motion is calculated by directly solving the Navier-Stokes equations by a SIMPLE approach. Bubbles are moved in a Lagrangian frame through the interaction forces imposed by the gas-fluid coupling. The simulated results successfully reveal that the liquid back-mixing effect in the open bubble columns can be alleviated by baffles or packings.

  20. Quantitative determination of glycine in aqueous solution using glutamate dehydrogenase-immobilized glyoxal agarose beads.

    Science.gov (United States)

    Keskin, Semra Yilmazer; Keskin, Can Serkan

    2014-01-01

    In this study, an enzymatic procedure for the determination of glycine (Gly) was developed by using a column containing immobilized glutamate dehydrogenase (GDH) on glyoxal agarose beads. Ammonia is produced from the enzymatic reactions between Gly and GDH with NAD(+) in phosphate buffer medium. The indophenol blue method was used for ammonia detection based on the spectrophotometric measurements of blue-colored product absorbing at 640 nm. The calibration graph is linear in the range of 0.1-10 mM of Gly concentrations. The effect of pH, temperature, and time interval was studied to find column stability, and also the interference effects of other amino acids was investigated. The interaction between GDH and glyoxal agarose beads was analyzed by Fourier transform infrared (FTIR) spectroscopy. The morphology of the immobilized and non-immobilized agarose beads were characterized by atomic force microscopy (AFM).

  1. Flow injection on-line preconcentration of low levels of Cr(VI) with detection by ETAAS

    DEFF Research Database (Denmark)

    Som-aum, Waraporn; Liawruangrath, Saisunee; Hansen, Elo Harald

    2002-01-01

    A flow injection (FI) on-line sorption preconcentration procedure utilizing a packed column reactor and combined with electrothermal atomic absorption spectrometry (ETAAS) is proposed for the determination of low levels of Cr(VI) in water samples. Polytetrafluoroethylene (PTFE) beads packed in a ...

  2. Breakthrough characteristics of gas absorption in a packed column

    International Nuclear Information System (INIS)

    Shitanda, Shoji; Fukada, Satoshi; Koto, Kenji; Mitsuishi, Nobuo

    1979-01-01

    In nuclear industries, the operations to collect or recover various radioactive and non-radioactive gases with a number of absorption or adsorption reagents are practically utilized or planned. Specifically in the operations of recovering hydrogen isotopes, the direct collecting method with active metals such as uranium, zirconium (Zr) and yttrium is watched with keen interest. In this study, the capability of recovering hydrogen by means of Zr was investigated through the estimation of rate-determining step, by flowing the gas mixture of hydrogen and argon after activating metallic Zr under the condition of high temperature and high vacuum, and by determining overall mass transfer coefficient from the absorption breakthrough curves. The details of a packed column and the flowsheet are also described, and the deterioration of Zr powder is considered. That is, the diffusion speed and absorbing reaction speed of hydrogen in Zr particles are supposed to be slow and dominant in mass transfer speed. Further, since gas mixture does not simply diffuse in Zr particles, but the reaction plane seems to move toward the center from the surface in the case of Zr, different from general adsorbents, the moving speed seems to give large effect on the rate-determining step. It is ensured that the hydrogen absorption with Zr powder is so active that hydrogen in gas flow can easily be recovered, and its separation from other gases can be effectively carried out by the desorption of hydrogen from Zr powder by heating it in vacuum. (Wakatsuki, Y.)

  3. Effects of the gas-liquid ratio on the optimal quantity of the catalyst for the CECE process with a homogeneously packed LPCE column

    International Nuclear Information System (INIS)

    Ushida, A.; Sugiyama, T.; Yamamoto, I.

    2007-01-01

    In order to improve the separative performance of a CECE (Combined Electrolysis Catalytic Exchange) process we have been carried out experimental studies on hydrogen isotope separation by a CECE process using with a LPCE (Liquid Phase Catalytic Exchange) column of trickle-type bed. Two types of trickle beds were tested in our previous study. One was the layered bed where layers of Kogel catalysts and that of Dixon gauze rings were filled in the column alternately. The other was the homogeneous bed where Kogel catalysts and Dixon gauze rings were mixed and filled in the column homogeneously. We found two major points: 1) the homogeneous bed was more efficient than the layered bed and 2) there was an optimal quantity of the catalyst for both types of beds to obtain the largest separation factor. The optimal quantity of the catalyst is affected by various factors such as catalytic activity, flow rates of fluid, temperature and so on. In this study we focused on an effect of the gasliquid ratio. The purpose of the present study is to investigate experimentally the effect of the gas-liquid ratio on the optimal quantity of the catalyst using with a homogeneous bed. The column is a Pyrex glass tube with 25 mm internal diameter and 60 cm length. The column is filled with Kogel catalysts (1.0 wt% Pt deposited) and Dixon gauze rings. A catalyst packed-ratio is defined as a ratio of the grain-volume of catalyst to the grain volume of the whole packings, where grain volumes mean the volume of a sphere with average diameter of the Kogel catalyst and the volume of a cylinder which has the outer shape same as a Dixon gauze ring. Hydrogen-deuterium isotope separation with the CECE equipment was performed at 101 kPa, 343 K for various values of the catalyst packed-ratio and for various values of the gas-liquid ratio. Hydrogen gas was generated by the Solid Polymer Electrolysis (SPE) electrolyzer. Maximum production rate and purity of hydrogen gas are 1 m3/h and 99.99%. The

  4. Effect of algal density in bead, bead size and bead concentrations ...

    African Journals Online (AJOL)

    Laboratory experiments were performed to study nitrogen and phosphorus uptake by the unicellular green microalga Chlorella vulgaris immobilized in calcium alginate beads. Different cell stockings in beads, different bead sizes and different algal bead concentrations in wastewaters were tested. Significant higher nutrients ...

  5. Enantioselective Analytical- and Preparative-Scale Separation of Hexabromocyclododecane Stereoisomers Using Packed Column Supercritical Fluid Chromatography

    Directory of Open Access Journals (Sweden)

    Nicole Riddell

    2016-11-01

    Full Text Available Hexabromocyclododecane (HBCDD is an additive brominated flame retardant which has been listed in Annex A of the Stockholm Convention for elimination of production and use. It has been reported to persist in the environment and has the potential for enantiomer-specific degradation, accumulation, or both, making enantioselective analyses increasingly important. The six main stereoisomers of technical HBCDD (i.e., the (+ and (− enantiomers of α-, β-, and γ-HBCDD were separated and isolated for the first time using enantioselective packed column supercritical fluid chromatography (pSFC separation methods on a preparative scale. Characterization was completed using published chiral liquid chromatography (LC methods and elution profiles, as well as X-ray crystallography, and the isolated fractions were definitively identified. Additionally, the resolution of the enantiomers, along with two minor components of the technical product (δ- and ε-HBCDD, was investigated on an analytical scale using both LC and pSFC separation techniques, and changes in elution order were highlighted. Baseline separation of all HBCDD enantiomers was achieved by pSFC on an analytical scale using a cellulose-based column. The described method emphasizes the potential associated with pSFC as a green method of isolating and analyzing environmental contaminants of concern.

  6. Comparison of Granular Activated Carbon, Natural Clinoptilolite Zeolite, and Anthracite Packed Columns in Removing Mercury from Drinking Water

    Directory of Open Access Journals (Sweden)

    Mohammad Taghi Samadi

    2010-01-01

    Full Text Available Development of effective methods for the removal of such pollutants as heavy metals (e.g., mercury from surface and ground water resources introduced by municipal and industrial wastewaters seems to be inevitable, especially in the face of the importance of water reuse in combating water shortages, limited availability of water resources, and imminent risks of a water crisis in Iran. A number of methods are already available for the removal of mercury from water resources. However, these techniques must be investigated for their practicability and economy, in addition to their not only effectiveness. In this research, granular activated carbon, natural zeolite, and anthracite packed-columns were investigated as cheap and effective adsorbents for the removal of mercury. Moreover, the effects of changes in pH (6-8, influent mercury concentrations (0.25, 0.5, 0.75, and 1 ppm, contact time (0.5, 1, 2, 3 hr were investigated. Mercury concentration in the samples was determined using a ditizon indicator and spectrophotometry at 492 nm. Results showed that decreasing influent mercury concentration from 1 ppm to 0.25 ppm (under constant conditions increased the removal efficiencies of anthracite, granular activated carbon, and zeolite columns from22%, 63%, and 55% to 28%, 72%, and 64%, respectively. Increasing contact time from 0.5 hr to 3 hr caused the removal efficiencies of these columns to increase from 22%, 56%, and 54% to 42%, 86%, and 82%, respectively. Also, increasing pH level led to increased removal efficiencies of the studied columns. It was found that contact time played a more effective role in enhancing mercury removal efficiency in the granular activated carbon column than in the other two columns. The ranges of mercury removal efficiency obtained for the granular activated carbon, natural zeolite, and anthracite columns under various conditions were (51%-92%, (42%-88%, and (16%-52%, respectively. Based on these results, granular

  7. Process and device for fabrication of ice beads and application to abrasive blasting with ice beads for surface treatments

    International Nuclear Information System (INIS)

    Barnier, M.; Manificat, A.; Perroud, P.

    1989-01-01

    A device is described for cleaning and decontamination by abrasive blasting with ice beads. It comprises a water injector, with many holes, at the top of a column feeded with cold gas where solidification of water droplets begins, solidification is completed in a cooling liquids, ice is extracted by a screw and pushed to the projection nozzle with cold gas [fr

  8. Elution behavior of poly(ethylene glycol) through poly(vinyl alcohol) gel column using several solvents as eluents

    International Nuclear Information System (INIS)

    Hirayama, Chuichi; Motozato, Yoshiaki; Matsumoto, Kazuaki.

    1983-01-01

    γ-Irradiated poly(vinyl alcohol) beads, which were sufficiently allowed to swell in water, were washed with methanol, and then were packed into column. Gel chromatography was performed using methanol, benzene, esters and ketones as eluents and poly(ethylene glycol) as a sample. When the elution was carried out using methanol and benzene as eluents, elution behavior of samples was ordinary. When ethyl formate, methyl acetate and ethyl propionate were used as eluents, samples were slightly adsorbed and the elution was delayed. In the case the elution was carried out using ethyl acetate, propyl acetate, butyl acetate and ethyl methyl ketone as eluents, samples were adsorbed strongly on the bed material, and the adsorption curve was analogous to the calibration curve using methanol as an eluent. Dried poly(vinyl alcohol) gel as a packing material, showed ordinary elution behaviors for the samples. The adsorption of poly(ethylene glycol) on the present bed material was attributed to the existence of hydrated water on poly(vinyl alcohol) gel matrix. (author)

  9. Boron isotope fractionation in column chromatography with glucamine type fibers

    International Nuclear Information System (INIS)

    Sonoda, Akinari; Makita, Yoji; Hirotsu, Takahiro

    2008-01-01

    Glucamine type polymers have specific affinity toward boric acid and borate ion. Among them, Chelest Fiber GRY-L showed larger fractionation for boron isotopes than other polymers in our previous study. For this study, we used Chelest Fibers with different fiber lengths (1.0 mm, 0.5 mm, and 0.3 mm) as column packing materials to perform chromatographic separation of boron isotopes. The shorter fiber has larger packing density when packed into the column using a dry method. The 0.3-mm-long fiber has a larger backpressure than fibers of other lengths. Boron adsorption capacities were measured using the breakthrough operation. At this time, the 0.5-mm-long fiber showed the highest capacity. When we measured the isotope ratio profile for fibers of different length using column chromatography, 0.5-mm-long fibers displayed the highest boron isotope fractionation. The 0.5-mm-long fiber is promising as a packing material of column chromatography for boron isotope separation. We also changed operation methods. The lower eluent concentration and the slower flow rate are suitable for boron isotope separation. (author)

  10. Influence of pressure on the properties of chromatographic columns. II. The column hold-up volume.

    Science.gov (United States)

    Gritti, Fabrice; Martin, Michel; Guiochon, Georges

    2005-04-08

    The effect of the local pressure and of the average column pressure on the hold-up column volume was investigated between 1 and 400 bar, from a theoretical and an experimental point of view. Calculations based upon the elasticity of the solids involved (column wall and packing material) and the compressibility of the liquid phase show that the increase of the column hold-up volume with increasing pressure that is observed is correlated with (in order of decreasing importance): (1) the compressibility of the mobile phase (+1 to 5%); (2) in RPLC, the compressibility of the C18-bonded layer on the surface of the silica (+0.5 to 1%); and (3) the expansion of the column tube (columns packed with the pure Resolve silica (0% carbon), the derivatized Resolve-C18 (10% carbon) and the Symmetry-C18 (20% carbon) adsorbents, using water, methanol, or n-pentane as the mobile phase. These solvents have different compressibilities. However, 1% of the relative increase of the column hold-up volume that was observed when the pressure was raised is not accounted for by the compressibilities of either the solvent or the C18-bonded phase. It is due to the influence of the pressure on the retention behavior of thiourea, the compound used as tracer to measure the hold-up volume.

  11. A novel microfluidic concept for bioanalysis using freely moving beads trapped in recirculating flows

    NARCIS (Netherlands)

    Lettieri, Gian-Luca; Dodge, Arash; Boer, Gerben; De Rooij, Nico F.; Verpoorte, Elisabeth

    2003-01-01

    There are only a few examples in which beads are employed for heterogeneous assays on microfluidic devices, because of the difficulties associated with packing and handling these in etched microstructures. This contribution describes a microfluidic device that allows the capture, preconcentration,

  12. Packed bed reactor for degradation of simulated cyanide-containing wastewater.

    Science.gov (United States)

    Kumar, Virender; Kumar, Vijay; Bhalla, Tek Chand

    2015-10-01

    The discharge of cyanide-containing effluents into the environment contaminates water bodies and soil. Effective methods of treatment which can detoxify cyanide are the need of the hour. The aim of the present study is to develop a bioreactor for complete degradation of cyanide using immobilized cells of Serratia marcescens RL2b. Alginate-entrapped cells of S. marcescens RL2b were used for complete degradation of cyanide in a packed bed reactor (PBR). Cells grown in minimal salt medium (pH 6.0) were harvested after 20 h and exhibited 0.4 U mg -1  dcw activity and 99 % cyanide degradation in 10 h. These resting cells were entrapped using 3 % alginate beads and packed in a column reactor (20 × 1.7 cm). Simulated cyanide (12 mmol l -1 )-containing wastewater was loaded and fractions were collected after different time intervals at various flow rates. Complete degradation of 12 m mmol l -1 (780 mg l -1 ) cyanide in 10 h was observed at a flow rate of 1.5 ml h -1 . The degradation of cyanide in PBR showed direct dependence on retention time. The retention time of cyanide in the reactor was 9.27 h. The PBR can degrade 1.2 g of cyanide completely in 1 day.

  13. Removal of the brilliant blue through packed columns using corncobs

    Directory of Open Access Journals (Sweden)

    Angelina Hormaza Anaguano

    2014-05-01

    Full Text Available This research shows the adsorbent potential of corncobs in the removal of the anionic bright blue colorant on packed beds. It was evaluated the effect of pH parameters from this medium, particle size, saline presence and column height. The samples were analyzed by defined intervals of time. The colorant quantity removed was quantified by means of ultraviolet-visible spectroscopy. Models of Adams-Bohart, Thomas and Yoon-Nelson were used to predict the breakthrough curves using nonlinear regression and so set the characteristic parameters of the process. BDST model was used to express the influence of bed height into the breakthrough curve. It was found that acid pH (pH = 2.0 smaller particle size (0.3 mm < x < 0.5 mm and larger bed height (Z = 20 cm favor the transfer of colorant to the adsorbent material, reaching greater retention of bright blue on the corncob. The presence of NaCl in the solution reduces the efficiency of adsorption. In terms of models, the Thomas model presented the best setting for the description of the breakthrough curve to the experimental conditions (R2 = 0.93 -0.94, while Adams-Bohart model offered a good fit (R2 = 0.96-0.99 for the dynamic behavior limited  to the initial part of the process. Yoon-Nelson model presented a considerable drift between the experimental data and the predicted data. Finally, the BDST model showed a good correlation, R2 = 0.92 -0.99, establishing that the height is a determining factor for scaling of process

  14. Plasticity of an Amorphous Assembly of Elastic Gel Beads

    Science.gov (United States)

    Grosshans, D.; Knaebel, A.; Lequeux, F.

    1995-01-01

    We have studied the rheological properties of an assembly of swollen gel beads in a lack of solvent. The system is an amorphous assembly of packed soft spheres in a given volume. We have studied the plastic behavior of the system, and interpreted it in terms of bead rearrangements within the assembly. Nous avons étudié les propriétés rhéologiques d'un assemblage de billes de gel gonflées en défaut de solvant. Le système est donc une assemblée amorphe de sphères molles écrasées à volume total constant. Nous avons étudié divers aspects du comportement plastique et nous l'avons interprété en termes de réorganisations de billes dans l'assemblage.

  15. Ni(II) ion-imprinted solid-phase extraction and preconcentration in aqueous solutions by packed-bed columns

    International Nuclear Information System (INIS)

    Ersoez, Arzu; Say, Ridvan; Denizli, Adil

    2004-01-01

    Solid-phase extraction (SPE) columns packed with materials based on molecularly imprinted polymers (MIPs) were used to develop selective separation and preconcentration for Ni(II) ion from aqueous solutions. SPE is more rapid, simple and economical method than the traditional liquid-liquid extraction. MIPs were used as column sorbent to increase the grade of selectivity in SPE columns. In this study, we have developed a polymer obtained by imprinting with Ni(II) ion as a ion-imprinted SPE sorbent. For this purpose, NI(II)-methacryloylhistidinedihydrate (MAH/Ni(II)) complex monomer was synthesized and polymerized with cross-linking ethyleneglycoldimethacrylate to obtain [poly(EGDMA-MAH/Ni(II))]. Then, Ni(II) ions were removed from the polymer getting Ni(II) ion-imprinted sorbent. The MIP-SPE preconcentration procedure showed a linear calibration curve within concentration range from 0.3 to 25 ng/ml and the detection limit was 0.3 ng/ml (3 s) for flame atomic absorption spectrometry (FAAS). Ni(II) ion-imprinted microbeads can be used several times without considerable loss of adsorption capacity. When the adsorption capacity of nickel imprinted microbeads were compared with non-imprinted microbeads, nickel imprinted microbeads have higher adsorption capacity. The K d (distribution coefficient) values for the Ni(II)-imprinted microbeads show increase in K d for Ni(II) with respect to both K d values of Zn(II), Cu(II) and Co(II) ions and non-imprinted polymer. During that time K d decreases for Zn(II), Cu(II) and Co(II) ions and the k' (relative selectivity coefficient) values which are greater than 1 for imprinted microbeads of Ni(II)/Cu(II), Ni(II)/Zn(II) and Ni(II)/Co(II) are 57.3, 53.9, and 17.3, respectively. Determination of Ni(II) ion in sea water showed that the interfering matrix had been almost removed during preconcentration. The column was good enough for Ni determination in matrixes containing similar ionic radii ions such as Cu(II), Zn(II) and Co(II)

  16. Simultaneous removal of SO2 and NOX with ammonia absorbent in a packed column

    International Nuclear Information System (INIS)

    Jia, Yong; Du, Daqian; Zhang, Xinxi; Ding, Xilou; Zhong, Oin

    2013-01-01

    Catalytic oxidation of NO followed by simultaneous removal of SO 2 and NO X with ammonia is a promising method for control of coal-fired flue gas pollutants. We investigated simultaneous absorption of SO 2 and NO X in a packed column with ammonia, and found that SO 2 and NO X could promote absorption with each other in the process of simultaneous removal SO 2 and NO X . The removal efficiency of SO 2 and NO X was, respectively, about 98% and 70.9% at pH 5.5, temperature 323.15 K, SO 2 concentration 1,800x10 −6 , NO X concentration 400x10 −6 and m NO2 /m NO 1 in our experimental system. The experimental results also show that the formation of sulfite oxidized by reacting with dissolved NO 2 and the molar ratio of sulfite to total sulfur is more than 0.8 in the solution. Accordingly, the energy consumption for sulfite oxidation would be greatly reduced in the process of simultaneous desulfurization and denitrification with ammonia

  17. Mass transfer model liquid phase catalytic exchange column simulation applicable to any column composition profile

    Energy Technology Data Exchange (ETDEWEB)

    Busigin, A. [NITEK USA Inc., Ocala, FL (United States)

    2015-03-15

    Liquid Phase Catalytic Exchange (LPCE) is a key technology used in water detritiation systems. Rigorous simulation of LPCE is complicated when a column may have both hydrogen and deuterium present in significant concentrations in different sections of the column. This paper presents a general mass transfer model for a homogenous packed bed LPCE column as a set of differential equations describing composition change, and equilibrium equations to define the mass transfer driving force within the column. The model is used to show the effect of deuterium buildup in the bottom of an LPCE column from non-negligible D atom fraction in the bottom feed gas to the column. These types of calculations are important in the design of CECE (Combined Electrolysis and Catalytic Exchange) water detritiation systems.

  18. Single column and two-column H-D-T distillation experiments at TSTA

    International Nuclear Information System (INIS)

    Yamanishi, T.; Yoshida, H.; Hirata, S.; Naito, T.; Naruse, Y.; Sherman, R.H.; Bartlit, J.R.; Anderson, J.L.

    1988-01-01

    Cryogenic distillation experiments were peformed at TSTA with H-D-T system by using a single column and a two-column cascade. In the single column experiment, fundamental engineering data such as the liquid holdup and the HETP were measured under a variety of operational condtions. The liquid holdup in the packed section was about 10 /approximately/ 15% of its superficial volume. The HETP values were from 4 to 6 cm, and increased slightly with the vapor velocity. The reflux ratio had no effect on the HETP. For the wo-colunn experiemnt, dynamic behavior of the cascade was observed. 8 refs., 7 figs., 2 tabs

  19. The current revolution in column technology: how it began, where is it going?

    Science.gov (United States)

    Gritti, Fabrice; Guiochon, Georges

    2012-03-09

    This work revisits the exceptionally rapid evolution of the technology of chromatographic columns and the important progress in speed of analysis and resolution power that was achieved over the last ten years. Whereas columns packed with 10 and 5 μm fully porous particles dominated the field for nearly thirty years (1975-2000), it took barely six years to see the commercialization of monolithic silica rods (2000), their raise to fame and decay to oblivion, the development of finer fully porous particles with size down to 1.7 μm (2006), and of sub-3 μm superficially porous particles (2006). Analysis times and plate heights delivered by columns packed with these recent packing materials have then been improved by more than one order of magnitude in this short period of time. This progress has rendered practically obsolete the age-old design of LC instruments. For low molecular weight compounds, analysts can now achieve peak capacities of 40 peaks in about 15s with a hold-up time of the order of 1.5s , in gradient elution, by operating columns packed with sub-3 μm shell particles at elevated temperatures, provided that they use optimized high pressure liquid chromatographs. This is the ultimate limit allowed by modern instruments, which have an extra-column band broadening contribution of 7 μL² at 4.0 mL/min and data acquisition rate of 160 Hz. The best 2.1 mm × 50 mm narrow-bore columns packed with 1.7 μm silica core-shell particles provide peaks that have a variance of 2.1 μL² for k=1. Finally, this work discusses possible ways to accelerate separations and, in the same time perform these separations at the same level of efficiency as they have today. It seems possible to pack columns with smaller particles, probably down to 1 μm and operate them with current vHPLC equipments for separations of biochemicals. Analyses of low molecular weight compounds will require new micro-HPLC systems able to operate 1mm I.D. columns at pressures up to 5 kbar, which

  20. Estimation of Chromatographic Columns Performances using Computer Tomography and CFD Simulations

    DEFF Research Database (Denmark)

    Schmidt, Irma; Lottes, Florian; Minceva, Mirjana

    2011-01-01

    The flow inside a chromatographic column depends decisively on the packed bed inside. Non‐destructive X‐ray computed tomography (CT) was applied as a novel measurement technique to visualize the distribution of velocity and axial dispersion coefficients in preparative scale columns. The results...... show, that spherical particles seem to be more efficient than irregular ones in terms of HETP, which has to be partly a result of the more homogeneous flow profile they induce. The prediction of column performance in dependence of the structure of the packed bed was simulated by CFD (Computational...

  1. Beads.

    Science.gov (United States)

    Weewish Tree, 1979

    1979-01-01

    Beads served both as ornaments and as a medium of exchange, and the Indians manufactured them from such natural sources as bones, stones, beans, nuts, animal teeth, and polished antlers. Even after the introduction of European glass beads, the Indians continued to make their favorite beads from the natural sources. (DS)

  2. Optimization of the isotope separation in columns

    International Nuclear Information System (INIS)

    Kaminskij, V.A.; Vetsko, V.M.; Tevzadze, G.A.; Devdariani, O.A.; Sulaberidze, G.A.

    1982-01-01

    The general method for the multi-parameter optimization of cascade plants of packed columns is proposed. As an optimization effectiveness function a netcost of the isotopic product is selected. The net cost is comprehensively characterizing the sum total of capital costs for manufacturing the products as well as determining the choice of the most effective directions for capital investments and rational limits of improvement of the products quality. The method is based on main representations of the cascade theory, such as the ideal flow profile and form efficiency as well as mathematical model of the packed column specifying the bonds between its geometric and operating parameters. As a result, the isotopic products cost function could be bound with such parameters as the equilibrium stage height, ultimate packing capacity, its element dimensions, column diameter. It is concluded that the suggested approach to the optimization of isotope separation processes is rather a general one. It permits to solve a number of special problems, such as estimation of advisability of using heat-pump circuits and determining the rational automation level. Besides, by means of the method suggested one can optimize the process conditions with regard to temperature and pressure

  3. Evaluation of diminished microbial contamination in handling of a novel daily disposable flat pack contact lens.

    Science.gov (United States)

    Nomachi, Miya; Sakanishi, Kotaro; Ichijima, Hideji; Cavanagh, H Dwight

    2013-05-01

    To evaluate the efficacy of a novel daily disposable (DD) flat package in regard to microbial contamination on the anterior and posterior surfaces of a contact lens (CL) during handling of the lens for insertion. Four kinds of commercially available general blister-packed daily disposable contact lenses (DD CLs) as controls and a novel Magic 1-day Menicon Flat Pack as a test lens were used for this in vitro study. Lenses were removed from their packages using fingers coated with fluorescein 3 to 5 μm beads or an approximately 7×10(2) to 2×10(3) colony-forming unit (CFU)/mL Staphylococcus aureus suspension. The transfer of fluorescein beads to the surface of the lenses was then observed by fluorescence microscopy. Microbial contamination on the lenses was observed by light microscopy after a 2-day incubation period; and, the number of colonies isolated from the contaminated lenses was determined after 4 days of incubation. The number of fluorescein beads on the Magic lens was significantly less (p<0.05) than that of the general blister-packed control lenses. Adherence of microbial colonies was observed on both inner and outer surfaces of general blister-packed lenses, whereas no colony formation was found on the inner surface of the Magic lens, and the lowest bacterial adherence was observed for the Magic lens. The data demonstrated that placement of the Magic DD lens onto the eye is accompanied by diminished microbial contamination compared with general blister-packed DD CLs. Eye care professionals; however, should instruct patients to comply with intended use of DD CLs to prevent CL-associated microbial keratitis. In all cases, hand washing is mandated prelens insertion.

  4. Lead Biosorption by Self-Immobilized Rhizopus nigricans Pellets in a Laboratory Scale Packed Bed Column: Mathematical Model and Experiment

    Directory of Open Access Journals (Sweden)

    Adela Kogej

    2010-01-01

    Full Text Available The biosorption of lead ions from aqueous solution on a self-immobilized Rhizopus nigricans biomass has been studied. Experiments were performed in a laboratory scale packed bed column at different liquid flow rates and biosorbent bed heights. Recorded experimental breakthrough curves were compared to those predicted by a mathematical model, which was developed to simulate a packed bed biosorption process by a soft, self-immobilized fungal biosorbent. In the range of examined experimental conditions, the biomass characteristics such as pellet porosity and biosorption capacity substantially affected the predicted response curve. General correlations for the estimation of the intra-pellet effective diffusivity, the external mass transfer coefficient, as well as axial dispersion were successfully applied in this biological system with specific mechanical properties. Under the experimental conditions, mass transfer is controlled by the external film resistance, while the intra-pellet mass transfer resistance, as well as the effect of axial dispersion, can be neglected. A new parameter α, the fraction of active biomass, with an average value of α=0.7, was introduced to take into account the specific biomass characteristics, and consequently the observed non-ideal liquid flow through the bed of fungal pellets.

  5. Removal of copper, nickel and zinc ions from aqueous solution by chitosan-8-hydroxyquinoline beads

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Francisco C.F.; Dias, Francisco S.; Vasconcellos, Luiz C.G. [Departamento de Quimica Organica e Inorganica, Campus do Pici - Universidade Federal do Ceara, Fortaleza (Brazil); Sousa, Francisco W. [Departamento de Engenharia Hidraulica e Ambiental, Campus do Pici - Universidade Federal do Ceara, Fortaleza (Brazil); Cavalcante, Rivelino M.; Carvalho, Tecia V.; Queiroz, Danilo C. [Departamento de Quimica Analitica e Fisico Quimica, Campus do Pici - Universidade Federal do Ceara, Fortaleza (Brazil); Nascimento, Ronaldo F.

    2008-03-15

    In this work, 8-hydroxyquinoline is used as the active sites in cross-linked chitosan beads with epichlorohydrin (CT-8HQ). The CT-8HQ material was shaped in bead form and used for heavy metal removal from aqueous solution. The study was carried out at pH 5.0 with both batch and column methods and the maximum adsorption capacity of metal ions by the CT-8HQ was attained in 4 h in the batch experiment. The adsorption capacity order was: Cu{sup 2+} > Ni{sup 2+} > Zn{sup 2+} for both mono- and multi-component systems with batch conditions. From breakthrough curves with column conditions, the adsorption capacity followed the order Cu{sup 2+} > Zn{sup 2+} > Ni{sup 2+} for both mono- and multi-component systems. The CT-8HQ beads maintained good metal adsorption capacity for all five cycles with absorbent restoration achieved with the use of 1.0 mol L{sup -1} HCl solution, with 90% regeneration. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  6. Film packed lithium-ion battery with polymer stabilizer

    International Nuclear Information System (INIS)

    Satoh, Masaharu; Nakahara, Kentaro

    2004-01-01

    The 1600 mAh class of film packed lithium-ion battery has been fabricated with the polymer stabilizer. The adhesive polymer covered with fluorinated polymer beads enables to penetrate into the prismatically wounded jerry-roll layers and connects the electrode layers and separator film. The battery demonstrates the improved properties after repeating the charge and discharge processes and should be useful for the various electronics equipment such as notebook type computer

  7. Antimony sorption properties of chitosan - nano TiO2 composite beads

    International Nuclear Information System (INIS)

    Nishad, Padala Abdul; Bhaskarapillai, Anupkumar; Velmurugan, Sankaralingam

    2015-01-01

    Routine decontamination campaigns of nuclear reactors are generally effective in removing various radionuclides such as cobalt, caesium, etc., and bring down the radiation field. However, during some of the decontamination campaigns, the radiation field at some surfaces was seen to have actually gone up. This was found to be due to lack of removal of antimony isotopes by the regular ion exchange resins used, which subsequently deposited over out of core surfaces leading to increased radiation field on those surfaces. Thus there exists a need for efficient antimony removal system. We have synthesised nano titania impregnated - epichlorohydrin crosslinked chitosan beads, which were found to have high sorption capacity for antimony. The beads, which were synthesised in formats suitable for large scale (column mode) applications, were shown to be effective sorbent of antimony in both +3 and +5 oxidation states. The sorbent exhibited complete removal of antimony from its aqueous solutions of concentration ranging from 150 ppb to 120 ppm. In order to understand the sorption mechanism and to fine tune the bead composition, the effect of crosslinker concentration used during the synthesis on the swelling and sorption properties of the beads was investigated in detail. The variation effected significant changes in physical parameters such as bead diameter, swelling ratio, equilibrium water content and true wet density. Sorption capacity, unlike with regular resins, was found to increase with increase in crosslinker amount. The antimony sorption capacity of the crosslinked beads prepared by crosslinking 0.3 g uncrosslinked beads with 6.4 mmol epichlorohydrin (crosslinker) was 493 μmol/g. Non-crosslinked beads showed a capacity of 75 μmol/g, while the crosslinked beads made with the least amount of crosslinker (0.64 mmol per 0.3 g beads) showed a capacity of 133 μmol/g. These results indicate the possible involvement of the crosslinker in the sorption. (author)

  8. Mass transfer models analysis for the structured packings

    International Nuclear Information System (INIS)

    Suastegui R, A.O.

    1997-01-01

    The models that have been developing, to understand the mechanism of the mass transfer through the structured packings, present limitations for their application, existing then uncertainty in order to use them in the chemical industrial processes. In this study the main parameters used in the mass transfer are: the hydrodynamic of the bed of the column, the geometry of the bed, physical-chemical properties of the mixture and the flow regime of the operation between the flows liquid-gas. The sensibility of each one of these parameters generate an arduous work to develop right proposals and good interpretation of the phenomenon. With the purpose of showing the importance of these parameters mentioned in the mass transfer, this work is analyzed the process of absorption for the system water-air, using the models to the structured packings in packed columns. The models selected were developed by Bravo and collaborators in 1985 and 1992, in order to determine the parameters previous mentioned for the system water-air, using a structured packing built in the National Institute of Nuclear Research. In this work is showed the results of the models application and their discussion. (Author)

  9. Goddard rattler-jamming mechanism for quantifying pressure dependence of elastic moduli of grain packs

    Energy Technology Data Exchange (ETDEWEB)

    Pride, Steven R.; Berryman, James G.

    2009-01-05

    An analysis is presented to show how it is possible for unconsolidated granular packings to obey overall non-Hertzian pressure dependence due to the imperfect and random spatial arrangements of the grains in these packs. With imperfect arrangement, some gaps that remain between grains can be closed by strains applied to the grain packing. As these gaps are closed, former rattler grains become jammed and new stress-bearing contacts are created that increase the elastic stiffness of the packing. By allowing for such a mechanism, detailed analytical expressions are obtained for increases in bulk modulus of a random packing of grains with increasing stress and strain. Only isotropic stress and strain are considered in this analysis. The model is shown to give a favorable fit to laboratory data on variations in bulk modulus due to variations in applied pressure for bead packs.

  10. LIQUID-LIQUID EXTRACTION COLUMNS

    Science.gov (United States)

    Thornton, J.D.

    1957-12-31

    This patent relates to liquid-liquid extraction columns having a means for pulsing the liquid in the column to give it an oscillatory up and down movement, and consists of a packed column, an inlet pipe for the dispersed liquid phase and an outlet pipe for the continuous liquid phase located in the direct communication with the liquid in the lower part of said column, an inlet pipe for the continuous liquid phase and an outlet pipe for the dispersed liquid phase located in direct communication with the liquid in the upper part of said column, a tube having one end communicating with liquid in the lower part of said column and having its upper end located above the level of said outlet pipe for the dispersed phase, and a piston and cylinder connected to the upper end of said tube for applying a pulsating pneumatic pressure to the surface of the liquid in said tube so that said surface rises and falls in said tube.

  11. Operational parameters and their influence on particle-side mass transfer resistance in a packed bed bioreactor

    OpenAIRE

    Hussain, Amir; Kangwa, Martin; Yumnam, Nivedita; Fernandez-Lahore, Marcelo

    2015-01-01

    The influence of internal mass transfer on productivity as well as the performance of packed bed bioreactor was determined by varying a number of parameters; chitosan coating, flow rate, glucose concentration and particle size. Saccharomyces cerevisiae cells were immobilized in chitosan and non-chitosan coated alginate beads to demonstrate the effect on particle side mass transfer on substrate consumption time, lag phase and ethanol production. The results indicate that chitosan coating, bead...

  12. Film packed lithium-ion battery with polymer stabilizer

    Energy Technology Data Exchange (ETDEWEB)

    Satoh, Masaharu; Nakahara, Kentaro [NEC Corp., Environment and Material Research Labs., Kawasaki, Kanagawa (Japan)

    2004-11-30

    The 1600 mAh class of film packed lithium-ion battery has been fabricated with the polymer stabilizer. The adhesive polymer covered with fluorinated polymer beads enables to penetrate into the prismatically wound jerry-roll layers and connects the electrode layers and separator film. The battery demonstrates the improved properties after repeating the charge and discharge processes and should be useful for the various electronic equipment such as notebook type computers. (Author)

  13. Immobilized yeast in bioreactor for alcohol fermentation

    International Nuclear Information System (INIS)

    Handy, M.K.; Kim, K.

    1986-01-01

    Mutant of Saccharomyces cerevisiae was developed using a Co-60 source. Cells were immobilized onto sterile, channeled alumina beads and packed into bioreactor column under controlled temperature. Feedstocks containing substrate and nutrients were fed into the bioreactor at specific rates. Beads with greatest porosity and surface area produced the most ethanol. Factors affecting ethanol productivity included: temperature, pH, flow rate, nutrients and substrate in the feedstock

  14. Fiber-based monolithic columns for liquid chromatography.

    Science.gov (United States)

    Ladisch, Michael; Zhang, Leyu

    2016-10-01

    Fiber-based monoliths for use in liquid chromatographic separations are defined by columns packed with aligned fibers, woven matrices, or contiguous fiber structures capable of achieving rapid separations of proteins, macromolecules, and low molecular weight components. A common denominator and motivating driver for this approach, first initiated 25 years ago, was reducing the cost of bioseparations in a manner that also reduced residence time of retained components while achieving a high ratio of mass to momentum transfer. This type of medium, when packed into a liquid chromatography column, minimized the fraction of stagnant liquid and resulted in a constant plate height for non-adsorbing species. The uncoupling of dispersion from eluent flow rate enabled the surface chemistry of the stationary phase to be considered separately from fluid transport phenomena and pointed to new ways to apply chemistry for the engineering of rapid bioseparations. This paper addresses developments and current research on fiber-based monoliths and explains how the various forms of this type of chromatographic stationary phase have potential to provide new tools for analytical and preparative scale separations. The different stationary phases are discussed, and a model that captures the observed constant plate height as a function of mobile phase velocity is reviewed. Methods that enable hydrodynamically stable fiber columns to be packed and operated over a range of mobile phase flow rates, together with the development of new fiber chemistries, are shown to provide columns that extend the versatility of liquid chromatography using monoliths, particularly at the preparative scale. Graphical Abstract Schematic representation of a sample mixture being separated by a rolled-stationary phase column, resulting separated peaks shown in the chromatogram.

  15. New Structured Packing CUB for Purification of Exhaust Gases

    Directory of Open Access Journals (Sweden)

    Irina Novikova

    2016-10-01

    Full Text Available New structured packing for heat and mass transfer processes named CUB is presented in our article. The packing can be applied in packed towers for exhaust gas cleaning instead random packing, for example, rings type that are the most used in such processes. The advantages of the new packing over random packing are lower pressure drop, capability of purification and as a consequence long-term service of the packing. The researches of intensity of liquid-phase mass-transfer in packed bed depending on liquid spray rate and gas velocity were carried out. Obtained data show that packing CUB is more effective than the most popular type of structured packing under all other conditions being equal. As experimental data shown heat transfer coefficient was up by 17% and mass transfer coefficient was up by 51%. We found out optimal geometry of cross section of the new packing, namely, number of elements and parameters of one element. The new construction of structured packing is applicable for both type of column cross-section round and square.

  16. The 4-parameter Compressible Packing Model (CPM) including a critical cavity size ratio

    Science.gov (United States)

    Roquier, Gerard

    2017-06-01

    The 4-parameter Compressible Packing Model (CPM) has been developed to predict the packing density of mixtures constituted by bidisperse spherical particles. The four parameters are: the wall effect and the loosening effect coefficients, the compaction index and a critical cavity size ratio. The two geometrical interactions have been studied theoretically on the basis of a spherical cell centered on a secondary class bead. For the loosening effect, a critical cavity size ratio, below which a fine particle can be inserted into a small cavity created by touching coarser particles, is introduced. This is the only parameter which requires adaptation to extend the model to other types of particles. The 4-parameter CPM demonstrates its efficiency on frictionless glass beads (300 values), spherical particles numerically simulated (20 values), round natural particles (125 values) and crushed particles (335 values) with correlation coefficients equal to respectively 99.0%, 98.7%, 97.8%, 96.4% and mean deviations equal to respectively 0.007, 0.006, 0.007, 0.010.

  17. Gas-solid trickle flow hydrodynamics in a packed column

    NARCIS (Netherlands)

    Westerterp, K.R.; Kuczynski, M.

    1987-01-01

    The pressure gradient and the static and the dynamic hold-up have been measured for a system consisting of a Fluid Cracking Catalyst (FCC) of 30–150 × 10−6 m diameter, trickling over a packed bed and with a gas streaming in countercurrent flow. The experiments were carried out at ambient conditions

  18. Water flow induced transport of Pseudomonas fluorescens cells through soil columns as affected by inoculant treatment

    NARCIS (Netherlands)

    Hekman, W.E.; Heijnen, C.E.; Trevors, J.T.; Elsas, van J.D.

    1994-01-01

    Water flow induced transport of Pseudomonas fluorescens cells through soil columns was measured as affected by the inoculant treatment. Bacterial cells were introduced into the topsoil of columns, either encapsulated in alginate beads of different types or mixed with bentonite clay in concentrations

  19. Acquisition of reproducible transmission near-infrared (NIR) spectra of solid samples with inconsistent shapes by irradiation with isotropically diffused radiation using polytetrafluoroethylene (PTFE) beads.

    Science.gov (United States)

    Lee, Jinah; Duy, Pham Khac; Yoon, Jihye; Chung, Hoeil

    2014-06-21

    A bead-incorporated transmission scheme (BITS) has been demonstrated for collecting reproducible transmission near-infrared (NIR) spectra of samples with inconsistent shapes. Isotropically diffused NIR radiation was applied around a sample and the surrounding radiation was allowed to interact homogeneously with the sample for transmission measurement. Samples were packed in 1.40 mm polytetrafluoroethylene (PTFE) beads, ideal diffusers without NIR absorption, and then transmission spectra were collected by illuminating the sample-containing beads using NIR radiation. When collimated radiation was directly applied, a small portion of the non-fully diffused radiation (NFDR) propagated through the void space of the packing and eventually degraded the reproducibility. Pre-diffused radiation was introduced by placing an additional PTFE disk in front of the packing to diminish NFDR, which produced more reproducible spectral features. The proposed scheme was evaluated by analyzing two different solid samples: density determination for individual polyethylene (PE) pellets and identification of mining locality for tourmalines. Because spectral collection was reproducible, the use of the spectrum acquired from one PE pellet was sufficient to accurately determine the density of nine other pellets with different shapes. The differentiation of tourmalines, which are even more dissimilar in appearance, according to their mining locality was also feasible with the help of the scheme.

  20. New proposition on performance evaluation of hydrophobic Pt catalyst packed in trickle bed

    International Nuclear Information System (INIS)

    Shimizu, Masami; Kitamoto, Asashi; Takashima, Yoichi.

    1983-01-01

    On the evaluation of the performance of the hydrophobic Pt catalyst packed in the trickle-bed test column, the conventionally defined (Ksub(y)a) and the newly defined (Ksub(f))sub (G) are compared with each other as a measure of the overall D-transfer coefficient. The value of (Ksub(y)a) varies in a wide range in accordance with the length of the test column. On the other hand (Ksub(f))sub (G sub (l = L)) has a finite value in the test column longer than about 0.5 m. By considering the values of ksub(g) and ksub(l) which are the constituents of (Ksub(f))sub (G), it is possible to improve the hydrophobic Pt catalyst trickle bed and to design the H 2 /H 2 O-isotopic exchange trickle-bed column packed with this catalyst. (author)

  1. Experimental investigation of liquid chromatography columns by means of computed tomography

    DEFF Research Database (Denmark)

    Astrath, D.U.; Lottes, F.; Vu, Duc Thuong

    2007-01-01

    The efficiency of packed chromatographic columns was investigated experimentally by means of computed tomography (CT) techniques. The measurements were carried out by monitoring tracer fronts in situ inside the chromatographic columns. The experimental results were fitted using the equilibrium di...

  2. Determination of cadmium with 6-bromo-2-benzothiazolylazo-2-naphthol gel

    International Nuclear Information System (INIS)

    Lee, Yong-Keun; Ueno, Keihei.

    1980-01-01

    A simple and rapid semiquantitative procedure has been developed for the determination of sub-ppm level of cadmium in environmental aquatic samples by using an analytical micro-column packed with reagent gel beads. Reagent gel beads were prepared by treating the cross-linked polystyrene beads (2% divinylbenzene, (70 -- 100) mesh in dry condition) with 0.02% chlorobenzene solution of 6-bromo-2-benzothiazolylazo-2-naphthol (BTAN) for 24 h at room temperature. The gel beads were packed into a glass column (2.5 mm bore, 120 mm length). When a sample solution containing cadmium, buffered to pH 10 with Clark-Lubs buffer, was passed through the BTAN gel column at a flow rate of 0.2 ml/min, the original pink color of the reagent gel turned to red-violet from the up-stream of the column. As the length of colored band was proportional to the total amount of cadmium in the sample solution passed through the column, the concentration of cadmium can be determined from the calibration line which had been prepared by using the standard solution. Cadmium ion at (0.05 -- 0.1)ppm and (0.2 -- 0.5)ppm levels could be determined with +-10% and +-5% relative errors, respectively. Of the foreign metals, 40-fold excess of Cr(VI), 20-fold excess of Al and Ni, 10-fold excess of Co(II), Hg(II), Fe(III) and Ag, and 5-fold excess of Cu(II) could be masked with Zincon, Tiron, thiourea and sodium fluoride. As for Zn(II), interferences could be masked up to identical amount with Cd with Zincon. This method was successfully applied to the analysis of cadmium in environmental aquatic samples. (author)

  3. Process development of continuous glycerolysis in an immobilized enzyme-packed reactor for industrial monoacylglycerol production

    DEFF Research Database (Denmark)

    Damstrup, Marianne; Kiil, Søren; Jensen, Anker Degn

    2007-01-01

    Continuous and easily operated glycerolysis was studied in different lipase-packed columns to evaluate the most potential process set-ups for industrial monoacylglycerol (MAG) production. Practical design-related issues such as enzyme-filling degree, required reaction time, mass transfer investig......Continuous and easily operated glycerolysis was studied in different lipase-packed columns to evaluate the most potential process set-ups for industrial monoacylglycerol (MAG) production. Practical design-related issues such as enzyme-filling degree, required reaction time, mass transfer...

  4. Mass spectrometric protein characterization in proteome analysis using GELoader tip micro-columns packed with various chromatographic material

    International Nuclear Information System (INIS)

    Larsen, M.R.

    2001-01-01

    In the early 90'ies mass spectrometry (MS) was introduced as a tool for identifying proteins in protein sequence databases. Since then it has become an integrated tool in protein characterization and is today routinely used to identify proteins separated by gel electrophoresis. A two-tiered mass spectrometric protein identification strategy has recently been proposed. In the first strategy peptide mass maps obtained from the protein of interest are compared with theoretically derived peptide mass maps from proteins in protein sequence databases. If the protein cannot be identified by this strategy, tandem mass spectrometric sequencing is used to generate enough sequence data to identify the protein in protein sequence databases or expressed sequence tag (EST) databases. However, the above strategies primarily identify a protein relatively to the DNA sequence, in which no information about e.g. post-translational modifications (PTMs) is stored. PTMs are known to modify the function, location, solubility and activity of proteins in the cell, and they are therefore very important for understanding living cells. More than 200 different PTMs are known, of which glycosylation, phosphorylation and proteolytic processing are the most common ones. Mass spectrometric analysis of PTMs on gel-separated proteins requires a higher amount of protein than for identification only. In addition, higher sequence coverage from the peptide mass maps or pre-purification of the modified peptides prior to MS analysis, is necessary for detection of putative modified peptides. In this study a multi-tiered strategy, in which GELoader tip micro-columns packed with increasingly more hydrophobic chromatographic material are used in combination with mass spectrometry, is described. The ultimate aim was to gain increased sequence coverage from peptide mixtures derived from gel-separated proteins, in order to locate modified peptides. Graphite powder is described as an alternative to traditional

  5. Finite dipolar hexagonal columns on piled layers of triangular lattice

    International Nuclear Information System (INIS)

    Matsushita, Katsuyoshi; Sugano, Ryoko; Kuroda, Akiyoshi; Tomita, Yusuke; Takayama, Hajime

    2007-01-01

    We have investigated, by the Monte Carlo simulation, spin systems which represent moments of arrayed magnetic nanoparticles interacting with each other only by the dipole-dipole interaction. In the present paper we aim the understanding of finite size effects on the magnetic nanoparticles arrayed in hexagonal columns cut out from the close-packing structures or from those with uniaxial compression. In columns with the genuine close-packing structures, we observe a single vortex state which is also observed previously in finite two-dimensional systems. On the other hand in the system with the inter-layer distance set 1/2 times of the close-packing one, we found ground states which depend on the number of layers. The dependence is induced by a finite size effect and is related to a orientation transition in the corresponding bulk system

  6. Evaluation of chromatographic columns packed with semi- and fully porous particles for benzimidazoles separation.

    Science.gov (United States)

    Gonzalo-Lumbreras, Raquel; Sanz-Landaluze, Jon; Cámara, Carmen

    2015-07-01

    The behavior of 15 benzimidazoles, including their main metabolites, using several C18 columns with standard or narrow-bore diameters and different particle size and type were evaluated. These commercial columns were selected because their differences could affect separation of benzimidazoles, and so they can be used as alternative columns. A simple screening method for the analysis of benzimidazole residues and their main metabolites was developed. First, the separation of benzimidazoles was optimized using a Kinetex C18 column; later, analytical performances of other columns using the above optimized conditions were compared and then individually re-optimized. Critical pairs resolution, analysis run time, column type and characteristics, and selectivity were considered for chromatographic columns comparison. Kinetex XB was selected because it provides the shortest analysis time and the best resolution of critical pairs. Using this column, the separation conditions were re-optimized using a factorial design. Separations obtained with the different columns tested can be applied to the analysis of specific benzimidazoles residues or other applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Pulsing flow in trickle bed columns

    NARCIS (Netherlands)

    Blok, Jan Rudolf

    1981-01-01

    In the operation of a packed column with cocurrent downflow of gas and liquid (trickle bed) several flowpatterns can be observed depending on the degree of interaction between gas and liquid. At low liquid and gas flow rates - low interaction - gascontinuous flow occurs. In this flowregime, the

  8. 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.

  9. Inert carriers for column extraction chromatography

    International Nuclear Information System (INIS)

    Katykhin, G.S.

    1978-01-01

    Inert carriers used in column extraction chromatography are reviewed. Such carriers are devided into two large groups: hydrophilic carriers which possess high surface energy and are well wetted only with strongly polar liquids (kieselguhrs, silica gels, glasses, cellulose, Al 2 O 3 ) and water-repellent carriers which possess low surface energy and are well wetted with various organic solvents (polyethylene, polytetrafluorethylene polytrifluorochlorethylene). Properties of various carriers are presented: structure, chemical and radiation stability, adsorption properties, extracting agent capacity. The effect of structure and sizes of particles on the efficiency of chromatography columns is considered. Ways of immovable phase deposition on the carrier and the latter's regeneration. Peculiarities of column packing for preparative and continuous chromatography are discussed

  10. Solid foam packings for multiphase reactors: Modelling of liquid holdup and mass transfer

    NARCIS (Netherlands)

    Stemmet, C.P.; Schaaf, van der J.; Kuster, B.F.M.; Schouten, J.C.

    2006-01-01

    In this paper, experimental and modeling results are presented of the liquid holdup and gas–liquid mass transfer characteristics of solid foam packings. Experiments were done in a semi-2D transparent bubble column with solid foam packings of aluminum in the range of 5–40 pores per inch (ppi). The

  11. Comparison of non-magnetic and magnetic beads in bead-based assays

    NARCIS (Netherlands)

    Hansenová Maňásková, S.; van Belkum, A.; Endtz, H.P.; Bikker, F.J.; Veerman, E.C.I.; van Wamel, W.J.B.

    2016-01-01

    Multiplex bead-based flow cytometry is an attractive way for simultaneous, rapid and cost-effective analysis of multiple analytes in a single sample. Previously, we developed various bead-based assays using non-magnetic beads coated with Staphylococcus aureus and Streptococcus pneumoniae antigens

  12. Three versus five micrometer chlorinated polysaccharide-based packings in chiral capillary electrochromatography: performance evaluation.

    Science.gov (United States)

    Hendrickx, Ans; De Klerck, Katrijn; Mangelings, Debby; Clincke, Lies; Heyden, Yvan Vander

    2014-01-01

    In this study, a test set of 44 nonacidic compounds was analyzed on four 3 µm chlorinated polysaccharide-based chiral stationary phases with cellulose tris (3-chloro-4-methylphenylcarbamate) (Lux Cellulose-2®; LC2), amylose tris (5-chloro-2-methylphenylcarbamate) (Lux Amylose-2®, LA2), cellulose tris (4-chloro-3-methylphenylcarbamate) (Lux Cellulose-4®; LC4) and cellulose tris (3,5-dichlorophenylcarbamate) (Sepapak-5®, Sp5) as selectors. The analysis times, retention factors, efficiencies and enantioselectivities were compared with the results obtained on their 5 µm analogs. All 3 µm packings, except for LA2, individually separated more compounds than their 5 µm analogs. When the cumulative success rates on the 3 and 5 µm packings were considered, it was observed that they were similar for both particle sizes; the combination of three or four 5 µm columns separated one compound more from the considered test set than that of the same number of 3 µm columns. Furthermore, it was observed that the 3 and 5 µm packings showed some complementarity. Only four compounds were not separated on any of the columns, while the use of only either the 3 or 5 µm columns resulted in 10 and nine not-separated compounds, respectively. The analyses on 5 µm LC2 and Sp5 were faster than on their 3 µm analogs. For LC4 the 3 µm packing showed the shortest analysis times and diverse analysis times for both particle sizes were obtained on LA2. Furthermore, three out of four 3 µm packings, that is, LC2, LC4, and Sp5, were found to be more efficient than their 5 µm analogs. Copyright © 2013 John Wiley & Sons, Ltd.

  13. Heat Transfer Analysis for a Fixed CST Column

    International Nuclear Information System (INIS)

    Lee, S.Y.

    2004-01-01

    In support of a small column ion exchange (SCIX) process for the Savannah River Site waste processing program, a transient two-dimensional heat transfer model that includes the conduction process neglecting the convection cooling mechanism inside the crystalline silicotitanate (CST) column has been constructed and heat transfer calculations made for the present design configurations. For this situation, a no process flow condition through the column was assumed as one of the reference conditions for the simulation of a loss-of-flow accident. A series of the modeling calculations has been performed using a computational heat transfer approach. Results for the baseline model indicate that transit times to reach 130 degrees Celsius maximum temperature of the CST-salt solution column are about 96 hours when the 20-in CST column with 300 Ci/liter heat generation source and 25 degrees Celsius initial column temperature is cooled by natural convection of external air as a primary heat transfer mechanism. The modeling results for the 28-in column equipped with water jacket systems on the external wall surface of the column and water coolant pipe at the center of the CST column demonstrate that the column loaded with 300 Ci/liter heat source can be maintained non-boiling indefinitely. Sensitivity calculations for several alternate column sizes, heat loads of the packed column, engineered cooling systems, and various ambient conditions at the exterior wall of the column have been performed under the reference conditions of the CST-salt solution to assess the impact of those parameters on the peak temperatures of the packed column for a given transient time. The results indicate that a water-coolant pipe at the center of the CST column filled with salt solution is the most effective one among the potential design parameters related to the thermal energy dissipation of decay heat load. It is noted that the cooling mechanism at the wall boundary of the column has significant

  14. Operational parameters and their influence on particle-side mass transfer resistance in a packed bed bioreactor.

    Science.gov (United States)

    Hussain, Amir; Kangwa, Martin; Yumnam, Nivedita; Fernandez-Lahore, Marcelo

    2015-12-01

    The influence of internal mass transfer on productivity as well as the performance of packed bed bioreactor was determined by varying a number of parameters; chitosan coating, flow rate, glucose concentration and particle size. Saccharomyces cerevisiae cells were immobilized in chitosan and non-chitosan coated alginate beads to demonstrate the effect on particle side mass transfer on substrate consumption time, lag phase and ethanol production. The results indicate that chitosan coating, beads size, glucose concentration and flow rate have a significant effect on lag phase duration. The duration of lag phase for different size of beads (0.8, 2 and 4 mm) decreases by increasing flow rate and by decreasing the size of beads. Moreover, longer lag phase were found at higher glucose medium concentration and also with chitosan coated beads. It was observed that by increasing flow rates; lag phase and glucose consumption time decreased. The reason is due to the reduction of external (fluid side) mass transfer as a result of increase in flow rate as glucose is easily transported to the surface of the beads. Varying the size of beads is an additional factor: as it reduces the internal (particle side) mass transfer by reducing the size of beads. The reason behind this is the distance for reactants to reach active site of catalyst (cells) and the thickness of fluid created layer around alginate beads is reduced. The optimum combination of parameters consisting of smaller beads size (0.8 mm), higher flow rate of 90 ml/min and glucose concentration of 10 g/l were found to be the maximum condition for ethanol production.

  15. Determination of Intrinsic Permeability for Packed Waste of Indonesian Solid Waste

    Directory of Open Access Journals (Sweden)

    Benno Rahardyan

    2010-11-01

    Full Text Available Gas permeability and intrinsic permeability are the major parameters to promote aeration for packed waste. The objectives of this research are to identify physical parameters of gas transfer from a various type of packed wastes and examine ventilation design theory for landfill to enhance waste stabilization. Method to determine value of gas permeability and intrinsic permeability for packed waste is by flushing the packed column containing various type and physical characteristics of wastes with an air pump. Permeability was calculated by measuring pressure gradient on sampling points of the column using inclined manometer at distance 10 cm, 23 cm, 46 cm, 69 cm, 92 cm and 115 cm from origin. Gas permeability is specifically relied on physical parameters of wastes as follows, density, moisture content, particle size and gas velocity on the surface of compacted waste layer. Compost has finer pore structure and smaller pore size than leaves as well as mixed organic (65% and inorganic wastes (35%. The experiment found the intrinsic permeability of leaves waste are in the order of 10-11 to 10-8 m2, 10-11 to 10-9 m2 for compost and 10-9 m2 for mixed organic (65% and inorganic wastes (35%.

  16. Characterization of metallic surfaces in phosphorous-bronze ordered packings

    International Nuclear Information System (INIS)

    Sandru, Claudia; Titescu, Gh.

    1997-01-01

    Copper and its alloys, particularly the phosphorous bronze, are characterized by a high water wettability as compared with other materials. This feature led to utilization of phosphorous bronze in fabrication of contact elements, a packing type equipping the distillation columns. For heavy water separation by isotopic distillation under vacuum, ordered packings of phosphorous bronze networks were fabricated. The superior performances of these packings are determined by the material and also by the geometrical form and the state of the metallic surface. Thus, a procedure of evaluating the wettability has been developed, based on tests of the network material. The results of the tests constitute a criterion of rating the functional performances of packings, particularly of their efficiencies. Also, investigation techniques of the chemical composition and of the thickness of superficial layer on the packing were developed. It was found that the packing surface presents a layer of about 5-20 μm formed mainly by oxides of copper, tin, and, depending on the packing treatment, of oxides of other elements coming from the treatment agent. The paper presents characterization of phosphorous bronze treated with potassium permanganate, a specific treatment for improving the functional performances of the packings used in the heavy water concentration and re-concentration installations

  17. Approximate transient and long time limit solutions for the band broadening induced by the thin sidewall-layer in liquid chromatography columns.

    Science.gov (United States)

    Broeckhoven, Ken; Desmet, Gert

    2007-11-16

    Using a combination of both analytical and numerical techniques, approximate analytical expressions have been established for the transient and long time limit band broadening, originating from the presence of a thin disturbed sidewall layer in liquid chromatography columns, including packed, monolithic as well as microfabricated columns. The established expressions can be used to compare the importance of a thin disturbed sidewall layer with that of other radial heterogeneity effects (such as transcolumn packing density variations due to the relief of packing stresses). The expressions are independent of the actual velocity profile inside the layer as long as the disturbed sidewall layer occupies less than 2.5% of the column width.

  18. HPLC-CUPRAC post-column derivatization method for the determination of antioxidants: a performance comparison between porous silica and core-shell column packing.

    Science.gov (United States)

    Haque, Syed A; Cañete, Socrates Jose P

    2018-01-01

    An HPLC method employing a post-column derivatization strategy using the cupric reducing antioxidant capacity reagent (CUPRAC reagent) for the determining antioxidants in plant-based materials leverages the separation capability of regular HPLC approaches while allowing for detection specificity for antioxidants. Three different column types, namely core-shell and porous silica including two chemically different core-shell materials (namely phenyl-hexyl and C18), were evaluated to assess potential improvements that could be attained by changing from a porous silica matrix to a core-shell matrix. Tea extracts were used as sample matrices for the evaluation specifically looking at catechin and epigallocatechin gallate (EGCG). Both the C18 and phenyl-hexyl core-shell columns showed better performance compared to the C18 porous silica one in terms of separation, peak shape, and retention time. Among the two core-shell materials, the phenyl-hexyl column showed better resolving power compared to the C18 column. The CUPRAC post-column derivatization method can be improved using core-shell columns and suitable for quantifying antioxidants, exemplified by catechin and EGCG, in tea samples.

  19. An on-line monitor for cation exchange elution chromatography using lithium silicate glass beads as solid scintillator

    International Nuclear Information System (INIS)

    Zhu Rongbao; Yang Liucheng; Wei Liansheng; Ji Liqiang; Zhang Zengrui

    1988-03-01

    A new type of on-line monitoring system used to monitor radioactive nuclides with α or soft β radiation in the effluent from a high pressure ion exchange column is described. The beads made of cerium-impregnated lithium silicate glass are used as scientillation material. They are filled into a quartz glass tube to form a flow cell. By reducing the diameter of glass beads to more closly approximate the average range of α or soft β radiation in solution, the absolute counting efficiency for 241 Am, 242 Cm α radiation have reached and 85.8% and 92.8% respectively, for 14 C, 90 Sr- 90 Y β radiation, 62.1% and 88.6% respectively. These values can be comparable to those achieved with on-line liquid scientillation technique. When the total amount of 241 Am added into column is decreased to 7.4 Bq it is still possible to obtain a clear chromatography peak (half peak width = 0.22 mL)

  20. Evaluation of a subsurface oxygenation technique using colloidal gas aphron injections into packed column reactors

    International Nuclear Information System (INIS)

    Wills, R.A.; Coles, P.

    1991-11-01

    Bioremediation may be a remedial technology capable of decontaminating subsurface environments. The objective of this research was to evaluate the use of colloidal gas aphron (CGA) injection, which is the injection of micrometer-size air bubbles in an aqueous surfactant solution, as a subsurface oxygenation technique to create optimal growth conditions for aerobic bacteria. Along with this, the capability of CGAs to act as a soil-washing agent and free organic components from a coal tar-contaminated matrix was examined. Injection of CGAs may be useful for remediation of underground coal gasification (UCG) sites. Because of this, bacteria and solid material from a UCG site located in northeastern Wyoming were used in this research. Colloidal gas aphrons were generated and pumped through packed column reactors (PCRS) containing post-burn core materials. For comparison, PCRs containing sand were also studied. Bacteria from this site were tested for their capability to degrade phenol, a major contaminant at the UCG site, and were also used to bioaugment the PCR systems. In this study we examined: (1) the effect of CGA injection on dissolved oxygen concentrations in the PCR effluents, (2) the effect of CGA, H 2 O 2 , and phenol injections on bacterial populations, (3) the stability and transport of CGAs over distance, and (4) CGA injection versus H 2 O 2 injection as an oxygenation technique

  1. New series of paper pack vending machines; Paper pack jido hanbaiki no shin series

    Energy Technology Data Exchange (ETDEWEB)

    Ohashi, M. [Fuji Denki Reiki Co. Ltd., Tokyo (Japan); Umino, S. [Fuji Electric Co. Ltd., Tokyo (Japan)

    1996-07-10

    This paper presents series of paper pack vending machines. These machines may be broadly classified into those of cold drinks and of hot and cold drinks depending on the storage temperature of products. The former is the machine for cooling dairy products at 10{degree}C with a combined stacking by direct-stacked racks and chain-multiracks. The latter is provided with divided storing chambers with each chamber selectively cooled or heated. Products in the hot chamber are canned coffee and the like set at 55{degree}C. The temperature control is performed by a microcomputer. The chain-multiracks are provided with advantages such as capability of handling various kinds of container shapes, storing drinks and foods vertically, replacing products by the change of a shelf attachment with one operation, and storing one liter packs by setting pair columns. The direct-stacked racks are provided with advantages such as versatility of handling various kinds of containers and miniaturization of the mechanism other than the storage part. The installation space was reduced by devising the opening and closing of the door. The control part is capable of setting temperatures differently for cans and paper packs. 7 figs., 1 tab.

  2. Sangadzhi Kononov, Buddhist Prayer Beads

    OpenAIRE

    Churyumov, Anton; Kovaeva, Bair

    2016-01-01

    Prayer beads have special dividers that divide the beads into 7, 21 and 33. Apart from using in prayers, the Kalmyks also keep beads as amulets that are believed to have strong energy. After prayers, old people often bless their children and grandchildren with their beads. Such beads are also kept in families from one generation to the next. Sangadzhi believes that prayer beads store inside them the energy of mantras that have been read with them. There is an interesting story about the pray...

  3. The Performance of the Trickle Bed Reactor Packed with the Pt/SDBC Catalyst Mixture for the CECE Process

    International Nuclear Information System (INIS)

    Seungwoo Paek; Do-Hee Ahn; Heui-Joo Choi; Kwang-Rag Kim; Hongsuk Chung; Sung-Paal Yim; Minsoo Lee; Kyu-Min Song; Soon Hwan Sohn

    2006-01-01

    The CECE (Combined Electrolysis Catalytic Exchange) process with a hydrophobic catalyst is a very effective method to remove small quantities of tritium from light or heavy waste water streams because of its high separation factor and mild operating conditions. The CECE process is composed of an electrolysis cell and a LPCE (Liquid Phase Catalytic Exchange) column. This paper describes the experimental results of the hydrogen isotopic exchange reaction in a trickle bed reactor packed with a hydrophobic catalyst for the development of the LPCE column of the CECE process. The hydrophobic Pt/SDBC (Styrene Divinyl Benzene Copolymer) catalyst has been developed by Korean researchers for the LPCE column of WTRF (Wolsong Tritium Removal Facility). An experimental apparatus was constructed for the various experiments with the different parameters, such as hydrogen flow rate, temperature, and the structure of the mixed catalyst column. The catalyst column was packed with a mixture of hydrophobic catalyst and hydrophilic packing (Dixon gauze ring). The performance of the catalyst bed was expressed as an overall rate constant Kya. To improve the performance of the trickle bed, the modification of the catalyst bed design (changing the shape of the catalyst complex and diluting with inert) has been investigated. (author)

  4. Characterization of the efficiency of microbore liquid chromatography columns by van Deemter and kinetic plot analysis.

    Science.gov (United States)

    Hetzel, Terence; Loeker, Denise; Teutenberg, Thorsten; Schmidt, Torsten C

    2016-10-01

    The efficiency of miniaturized liquid chromatography columns with inner diameters between 200 and 300 μm has been investigated using a dedicated micro-liquid chromatography system. Fully porous, core-shell and monolithic commercially available stationary phases were compared applying van Deemter and kinetic plot analysis. The sub-2 μm fully porous as well as the 2.7 μm core-shell particle packed columns showed superior efficiency and similar values for the minimum reduced plate heights (2.56-2.69) before correction for extra-column contribution compared to normal-bore columns. Moreover, the influence of extra-column contribution was investigated to demonstrate the difference between apparent and intrinsic efficiency by replacing the column by a zero dead volume union to determine the band spreading caused by the system. It was demonstrated that 72% of the intrinsic efficiency could be reached. The results of the kinetic plot analysis indicate the superior performance of the sub-2 μm fully porous particle packed column for ultra-fast liquid chromatography. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Mass and heat transfer on B7 ordered packing in hydrogen isotope separation by distillation

    International Nuclear Information System (INIS)

    Croitoru, Cornelia; Pop, Floarea; Titescu, Gheorghe; Stefanescu, Ioan; Trancota, Dan; Peculea, Marius

    2002-01-01

    This work presents theoretical and experimental data referring to mass and heat transfer on B7 ordered packing in deuterium isotope separation by distillation. The first part is devoted to the study of mass transfer in hydrogen isotopic distillation while the second one treats the mass and heat transfer in water isotopic distillation. A stationary mathematical model for the mass and heat transfer was developed based on multitubular column model with wet wall. This model allowed the calculation starting from theoretical data of the ordered packing efficiency, expressed by the transfer unit height, TUH. Also, from theoretical data the mass and heat transfer coefficients were determined. A test of the mathematical model was performed with the experimental data obtained from two laboratory installations for hydrogen isotope separation by distillation. From the first installation, experimental data concerning the B7 ordered packing efficiency were obtained for the deuterium separation by cryogenic distillation at the - 250 deg C level. With the second one data referring to the mass and heat transfer on the same packing were obtained for the deuterium separation by water distillation under vacuum at the 60 deg C level. The values of TUH, mass and heat transfer coefficients as theoretically evaluate and experimentally checked are in agreement with the respective values obtained in separation processes in chemical industry. This is the fact which endorses utilization of the model of multitubular column with wet wall for describing the transfer processes in distillation columns equipped with B7 ordered packing

  6. Comparative studies of Iodo-bead and chloramine-T methods for the radioiodination of human alpha-fetoprotein

    International Nuclear Information System (INIS)

    Lee, D.S.C.; Griffiths, B.W.

    1984-01-01

    Human alpha-fetoprotein (h-AFP) of iodination grade was radiolabeled with Na 125 I by chloramine-T (conventional method) and by Iodo-bead (solid-phase method) under standard and varied conditions, such as quantity of h-AFP and volume of the reaction mixture. The authors have modified the chloramine-T method and developed a protocol for the Iodo-bead method of iodination. The results show that while the chloramine-T method yields radiolabeled h-AFP of apparently 40% higher specific radioactivity (SR) than those of the Iodo-bead method, the latter appears to be a simpler, more controllable and milder method, giving rise to a more stable population of [ 125 I]h-AFP. This is supported by the results of radioactive counting of [ 125 I]h-AFP collected from a Sephadex G-50 column after radioiodination, storage stability and immunoreactivity with anti-h-AFP. (Auth.)

  7. A two-channel detection method for autofluorescence correction and efficient on-bead screening of one-bead one-compound combinatorial libraries using the COPAS fluorescence activated bead sorting system

    International Nuclear Information System (INIS)

    Hintersteiner, Martin; Auer, Manfred

    2013-01-01

    One-bead one-compound combinatorial library beads exhibit varying levels of autofluorescence after solid phase combinatorial synthesis. Very often this causes significant problems for automated on-bead screening using TentaGel beads and fluorescently labeled target proteins. Herein, we present a method to overcome this limitation when fluorescence activated bead sorting is used as the screening method. We have equipped the COPAS bead sorting instrument with a high-speed profiling unit and developed a spectral autofluorescence correction method. The correction method is based on a simple algebraic operation using the fluorescence data from two detection channels and is applied on-the-fly in order to reliably identify hit beads by COPAS bead sorting. Our method provides a practical tool for the fast and efficient isolation of hit beads from one-bead one-compound library screens using either fluorescently labeled target proteins or biotinylated target proteins. This method makes hit bead identification easier and more reliable. It reduces false positives and eliminates the need for time-consuming pre-sorting of library beads in order to remove autofluorescent beads. (technical note)

  8. Establishing column batch repeatability according to Quality by Design (QbD) principles using modeling software.

    Science.gov (United States)

    Rácz, Norbert; Kormány, Róbert; Fekete, Jenő; Molnár, Imre

    2015-04-10

    Column technology needs further improvement even today. To get information of batch-to-batch repeatability, intelligent modeling software was applied. Twelve columns from the same production process, but from different batches were compared in this work. In this paper, the retention parameters of these columns with real life sample solutes were studied. The following parameters were selected for measurements: gradient time, temperature and pH. Based on calculated results, batch-to-batch repeatability of BEH columns was evaluated. Two parallel measurements on two columns from the same batch were performed to obtain information about the quality of packing. Calculating the average of individual working points at the highest critical resolution (R(s,crit)) it was found that the robustness, calculated with a newly released robustness module, had a success rate >98% among the predicted 3(6) = 729 experiments for all 12 columns. With the help of retention modeling all substances could be separated independently from the batch and/or packing, using the same conditions, having high robustness of the experiments. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. New Nanoparticles Dispersing Beads Mill with Ultra Small Beads and its Application

    International Nuclear Information System (INIS)

    Inkyo, M; Tahara, T; Imajyo, Y

    2011-01-01

    Two of the major problems related to nanoparticle dispersion with a conventional beads mill are re-agglomeration and damage to the crystalline structure of the particles. The Ultra Apex Mill was developed to solve these problems by enabling the use of ultra-small beads with a diameter of less than 0.1mm. The core of this breakthrough development is centrifugation technology which allows the use of beads as small as 0.015mm. When dispersing agglomerated nanoparticles the impulse of the small beads is very low which means there is little influence on the particles. The surface energy of the nanoparticles remains low so the properties are not likely to change. As a result, stable nanoparticle dispersions can be achieved without re-cohesion. The Ultra Apex Mill is superior to conventional beads mills that are limited to much larger bead sizes. The technology of the Ultra Apex Mill has pioneered practical applications for nanoparticles in various fields: composition materials for LCD screens, ink-jet printing, ceramic condensers and cosmetics.

  10. Dynamic Deformation and Collapse of Granular Columns

    Science.gov (United States)

    Uenishi, K.; Tsuji, K.; Doi, S.

    2009-12-01

    Large dynamic deformation of granular materials may be found in nature not only in the failure of slopes and cliffs — due to earthquakes, rock avalanches, debris flows and landslides — but also in earthquake faulting itself. Granular surface flows often consist of solid grains and intergranular fluid, but the effect of the fluid may be usually negligible because the volumetric concentration of grains is in many cases high enough for interparticle forces to dominate momentum transport. Therefore, the investigation of dry granular flow of a mass might assist in further understanding of the above mentioned geophysical events. Here, utilizing a high-speed digital video camera system, we perform a simple yet fully-controlled series of laboratory experiments related to the collapse of granular columns. We record, at an interval of some microseconds, the dynamic transient granular mass flow initiated by abrupt release of a tube that contains dry granular materials. The acrylic tube is partially filled with glass beads and has a cross-section of either a fully- or semi-cylindrical shape. Upon sudden removal of the tube, the granular solid may fragment under the action of its own weight and the particles spread on a rigid horizontal plane. This study is essentially the extension of the previous ones by Lajeunesse et al. (Phys. Fluids 2004) and Uenishi and Tsuji (JPGU 2008), but the striped layers of particles in a semi-cylindrical tube, newly introduced in this contribution, allow us to observe the precise particle movement inside the granular column: The development of slip lines inside the column and the movement of particles against each other can be clearly identified. The major controlling parameters of the spreading dynamics are the initial aspect ratio of the granular (semi-)cylindrical column, the frictional properties of the horizontal plane (substrate) and the size of beads. We show the influence of each parameter on the average flow velocity and final radius

  11. Future perspectives of using hollow fibers as structured packings in light hydrocarbon distillation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Dali [Los Alamos National Laboratory; Orler, Bruce [Los Alamos National Laboratory; Tornga, Stephanie [Los Alamos National Laboratory; Welch, Cindy [Los Alamos National Laboratory

    2011-01-26

    Olefin and paraffin are the largest chemical commodities. Furthermore, they are major building blocks for the petrochemical industry. Each year, petroleum refining, consumes 4,500 TBtu/yr in separation energy, making it one of the most energy-intensive industries in the United States). Just considering liquefied petroleum gas (ethane/propane/butane) and olefins (ethylene and propylene) alone, the distillation energy consumption is about 400 TBtu/yr in the US. Since petroleum distillation is a mature technology, incremental improvements in column/tray design will only provide a few percent improvements in the performance. However, each percent saving in net energy use amounts to savings of 10 TBtu/yr and reduces CO{sub 2} emissions by 0.2 MTon/yr. In practice, distillation columns require 100 to 200 trays to achieve the desired separation. The height of a transfer unit (HTU) of conventional packings is typical in the range of 36-60 inch. Since 2006, we had explored using several non-selective membranes as the structured packings to replace the conventional packing materials used in propane and propylene distillation. We obtained the lowest HTU of < 8 inch for the hollow fiber column, which was >5 times shorter than that of the conventional packing materials. In 2008, we also investigated this type of packing materials in iso-/n-butane distillation. Because of a slightly larger relative volatility of iso-/n-butane than that of propane/propylene, a wider and a more stable operational range was obtained for the iso-/n-butane pair. However, all of the experiments were conducted on a small scale with flowrate of < 25 gram/min. Recently, we demonstrated this technology on a larger scale (<250 gram/min). Within the loading range of F-factor < 2.2 Pa{sup 0.5}, a pressure drop on the vapor side is below 50 mbar/m, which suggests that the pressure drop of hollow fibers packings is not an engineering barrier for the applications in distillations. The thermal stability study

  12. Friction of N-bead macromolecules in solution: Effects of the bead-solvent interaction

    International Nuclear Information System (INIS)

    Uvarov, Alexander; Fritzsche, Stephan

    2006-01-01

    The role of the bead-solvent interaction has been studied for its influence on the dynamics of an N-bead macromolecule which is immersed into a solution. Using a Fokker-Planck equation for the phase-space distribution function of the macromolecule, we show that all the effects of the solution can be treated entirely in terms of the friction tensors which are assigned to each pair of interacting beads in the chain. For the high-density as well as for the critical solvent, the properties of these tensors are discussed in detail and are calculated by using several (realistic) choices of the bead-solvent potential. From the friction tensors, moreover, an expression for the center-of-mass friction coefficient of a (N-bead) chain macromolecule is derived. Numerical data for this coefficient for 'truncated' Lennard-Jones bead-solvent potential are compared with results from molecular dynamic simulations and from the phenomenological theoretical data as found in the literature

  13. Development and optimization of water treatment reactors using TiO2-modified polymer beads with a refractive index identical to that of water

    Science.gov (United States)

    Myoga, Arata; Iwashita, Ryutaro; Unno, Noriyuki; Satake, Shin-ichi; Taniguchi, Jun; Yuki, Kazuhisa; Seki, Yohji

    2018-06-01

    Various water purification reactors were constructed using beads of TiO2-coated MEXFLON, which is a fluoropolymer exhibiting a refractive index identical to that of water. The performance of these reactors was evaluated in a recirculation experiment utilizing an aqueous solution of methylene blue. Reactor pipes (length = 150 mm, internal diameter = 10 mm) were made of a fluorinated ethylene polymer with a refractive index of 1.338 and contained 206-bead clusters. A UV lamp was used to irradiate eight reactor pipes surrounding it. The above-mentioned eight bead-packed pipes were connected both in series and in parallel, and the performances of these two reactor types were compared. A pseudo-first-order rate constant of 0.70 h- 1 was obtained for the series connection, whereas the corresponding value for the parallel connection was 1.5 times smaller, confirming the effectiveness of increasing the reaction surface by employing a larger number of beads.

  14. Development and optimization of water treatment reactors using TiO2-modified polymer beads with a refractive index identical to that of water

    Science.gov (United States)

    Myoga, Arata; Iwashita, Ryutaro; Unno, Noriyuki; Satake, Shin-ichi; Taniguchi, Jun; Yuki, Kazuhisa; Seki, Yohji

    2018-03-01

    Various water purification reactors were constructed using beads of TiO2-coated MEXFLON, which is a fluoropolymer exhibiting a refractive index identical to that of water. The performance of these reactors was evaluated in a recirculation experiment utilizing an aqueous solution of methylene blue. Reactor pipes (length = 150 mm, internal diameter = 10 mm) were made of a fluorinated ethylene polymer with a refractive index of 1.338 and contained 206-bead clusters. A UV lamp was used to irradiate eight reactor pipes surrounding it. The above-mentioned eight bead-packed pipes were connected both in series and in parallel, and the performances of these two reactor types were compared. A pseudo-first-order rate constant of 0.70 h- 1 was obtained for the series connection, whereas the corresponding value for the parallel connection was 1.5 times smaller, confirming the effectiveness of increasing the reaction surface by employing a larger number of beads.

  15. Poly(glycidyl methacrylate) beads embedded cryogels for pseudo-specific affinity depletion of albumin and immunoglobulin G

    Energy Technology Data Exchange (ETDEWEB)

    Bereli, Nilay; Sener, Guelsu; Altintas, Evrim Banu; Yavuz, Handan [Department of Chemistry, Biochemistry Division, Hacettepe University, Ankara (Turkey); Denizli, Adil, E-mail: denizli@hacettepe.edu.tr [Department of Chemistry, Biochemistry Division, Hacettepe University, Ankara (Turkey)

    2010-01-30

    Depletion of high abundant proteins like albumin and immunoglobulin G (IgG) can be beneficial in the analysis of serum proteins. For this purpose, Cibacron Blue F3GA and iminodiacetic acid (IDA)-Cu{sup 2+} containing poly(glycidyl methacrylate) (PGMA) beads (1.6 {mu}m in diameter) were embedded into the poly(hydroxyethyl methacrylate) (PHEMA) cryogel. The PGMA beads were prepared by dispersion polymerization. The PGMA beads were modified with Cibacron Blue F3GA and iminodiacetic acid (IDA)-Cu{sup 2+} for simultaneous albumin and IgG depletion, respectively. The PHEMA cryogel was synthesized by free radical polymerization in the presence of the modified PGMA beads. The PHEMA and PHEMA/PGMA composite cryogels were characterized by swelling measurements and scanning electron microscopy (SEM). Protein depletion studies were carried out in a continuous experimental set-up in a stacked column. Albumin adsorption capacity of the PGMA-Cibacron Blue F3GA beads embedded PHEMA cryogel (PHEMA/PGMA-Cibacron Blue F3GA) was 342 mg/g and IgG adsorption capacity of the PGMA-IDA-Cu{sup 2+} beads embedded PHEMA cryogel (PHEMA/PGMA-IDA-Cu{sup 2+}) was 257 mg/g. The composite cryogels depleted albumin and IgG from human serum with 89.4% and 93.6% efficiency, respectively. High desorption values (over 90% for both modified cryogels) were achieved with 0.05 M phosphate buffer containing1.0 M NaCl.

  16. Properties Influencing Plasma Discharges in Packed Bed Reactors

    Science.gov (United States)

    Kruszelnicki, Juliusz; Engeling, Kenneth W.; Foster, John E.; Kushner, Mark J.

    2016-09-01

    Atmospheric pressure dielectric barrier discharges (DBDs) sustained in packed bed reactors (PBRs) are being investigated for CO2 removal and conversion of waste gases into higher value compounds. We report on results of a computational investigation of PBR-DBD properties using the plasma hydrodynamics simulator nonPDPSIM with a comparison to experiments. Dielectric beads (rods in 2D) were inserted between two coplanar electrodes, 1 cm apart filled by humid air. A step-pulse of -30 kV was applied to the top electrode. Material properties of the beads (dielectric constant, secondary emission coefficient) and gas properties (photoionization and photo-absorption cross-sections, temperature) were varied. We found that photoionization plays a critical role in the propagation of the discharge through the PBR, as it serves to seed charges in regions of high electric field. Increasing rates of photo-ionization enable increases in the discharge propagation velocity, ionization rates and production of radicals. A transition between DBD-like and arc-like discharges occurs as the radiation mean free path decreases. Increasing the dielectric constant of the beads increased electric fields in the gas, which translated to increased discharge propagation velocity and charge density until ɛ/ɛ0 100. Secondary electron emission coefficient and gas temperature have minimal impacts on the discharge propagation though the latter did affect the production of reactive species. Work supported by US DOE Office of Fusion Energy Science and the National Science Foundation.

  17. Freezing process in unsaturated packed beds; Fuhowa ryushi sonai ni okeru suibun toketsu

    Energy Technology Data Exchange (ETDEWEB)

    Akahori, M; Aoki, K; Hattori, M [Nagaoka University of Technology, Niigata (Japan); Tani, T [Oji Paper Co. Ltd., Tokyo (Japan)

    1998-04-25

    The freezing process in unsaturated packed beds has been investigated experimentally and theoretically. Water transport to the frozen front plays an important part on freezing. The rate of the absorption of water into frozen layer depended on the freezing heat flux and the water saturation at the freezing front. As a result, ice content in the frozen layer was related to the rate of the absorption of water and the freezing heat flux. A one-dimensional freezing model in unsaturated packed beds has been presented, accounting for the water transport. The predicted water saturation and temperature distributions in the body and the thickness of frozen layer were compared with the experimental results using a porous bed composed of glass beads. 12 refs., 10 figs., 1 tab.

  18. Fluoride retardation from quartz sand-packed column tests

    Directory of Open Access Journals (Sweden)

    Eduardo Usunoff

    2009-06-01

    Full Text Available Inasmuch as both low and high concentrations of F- in groundwater have different detrimental effects on human health (increased dental caries, and mottled enamel or even severe structural bone deformations, respectively, many efforts have focused on the movement of such anion in aqueous systems. It is so because water drinking is the main intake of F- by humans. This paper presents the results of seven dynamic experiments in which solutions of varying [F-], pH, and flow velocities circulated through columns packed with clean quartz sand. The breakthrough data were analyzed by means of a computer code adapted to the estimation of equilibrium and non-equilibrium solute transport parameters from miscible displacement experiments in a steady-state, uniform flow field using a pulse-type or continuous source. It was found that larger retardation factors (R are associated with low pH, low [F-] in the feed solutions, and larger flow velocities. Such results appear to be related to the form of the F species, the rather weak bond between the adsorbate and the quartz sand, and stronger anion repulsion at low pore velocities. The estimated values for R vary between 1,22 and 1,50, whereas the distribution coefficients were in the range of 0,1 to 0,05 L kg-1. It should be said that the breakthrough curves display hysteresis, leading to a desorption behavior that proceeds faster than the adsorption process.Puesto que tanto valores bajos como altos de F- en las aguas subterráneas tienen efectos adversos en la salud de los humanos (mayor cantidad de caries, y manchas del esmalte dental e incluso deformaciones óseas, respectivamente, han sido muchos los esfuerzos destinados a dilucidar el movimiento de especies fluoradas en ambientes acuosos. Ello es así porque el consumo de agua por parte de seres humanos representa la mayor fuente de ingreso de F-. Este trabajo presenta los resultados de siete experimentos dinámicos en los que soluciones de diferentes [F

  19. Automated Hydrophobic Interaction Chromatography Column Selection for Use in Protein Purification

    Science.gov (United States)

    Murphy, Patrick J. M.; Stone, Orrin J.; Anderson, Michelle E.

    2011-01-01

    In contrast to other chromatographic methods for purifying proteins (e.g. gel filtration, affinity, and ion exchange), hydrophobic interaction chromatography (HIC) commonly requires experimental determination (referred to as screening or "scouting") in order to select the most suitable chromatographic medium for purifying a given protein 1. The method presented here describes an automated approach to scouting for an optimal HIC media to be used in protein purification. HIC separates proteins and other biomolecules from a crude lysate based on differences in hydrophobicity. Similar to affinity chromatography (AC) and ion exchange chromatography (IEX), HIC is capable of concentrating the protein of interest as it progresses through the chromatographic process. Proteins best suited for purification by HIC include those with hydrophobic surface regions and able to withstand exposure to salt concentrations in excess of 2 M ammonium sulfate ((NH4)2SO4). HIC is often chosen as a purification method for proteins lacking an affinity tag, and thus unsuitable for AC, and when IEX fails to provide adequate purification. Hydrophobic moieties on the protein surface temporarily bind to a nonpolar ligand coupled to an inert, immobile matrix. The interaction between protein and ligand are highly dependent on the salt concentration of the buffer flowing through the chromatography column, with high ionic concentrations strengthening the protein-ligand interaction and making the protein immobile (i.e. bound inside the column) 2. As salt concentrations decrease, the protein-ligand interaction dissipates, the protein again becomes mobile and elutes from the column. Several HIC media are commercially available in pre-packed columns, each containing one of several hydrophobic ligands (e.g. S-butyl, butyl, octyl, and phenyl) cross-linked at varying densities to agarose beads of a specific diameter 3. Automated column scouting allows for an efficient approach for determining which HIC media

  20. Beautiful Beads: A Lesson in Making Beads with Friendly Clay. AMACO[R] Lesson.

    Science.gov (United States)

    Gamble, Harriet; Gamble, David

    This lesson resource includes a brief summary of the history of bead making and historic fascination with beads as adornment. A focus on design elements, color theory, craftsmanship, and technical skill in bead making is encouraged. The plan includes lesson goals and objectives; background preparation; a glossary of terms; a list of supplies; and…

  1. Multiplexed detection of DNA sequences using a competitive displacement assay in a microfluidic SERRS-based device.

    Science.gov (United States)

    Yazdi, Soroush H; Giles, Kristen L; White, Ian M

    2013-11-05

    We demonstrate sensitive and multiplexed detection of DNA sequences through a surface enhanced resonance Raman spectroscopy (SERRS)-based competitive displacement assay in an integrated microsystem. The use of the competitive displacement scheme, in which the target DNA sequence displaces a Raman-labeled reporter sequence that has lower affinity for the immobilized probe, enables detection of unlabeled target DNA sequences with a simple single-step procedure. In our implementation, the displacement reaction occurs in a microporous packed column of silica beads prefunctionalized with probe-reporter pairs. The use of a functionalized packed-bead column in a microfluidic channel provides two major advantages: (i) immobilization surface chemistry can be performed as a batch process instead of on a chip-by-chip basis, and (ii) the microporous network eliminates the diffusion limitations of a typical biological assay, which increases the sensitivity. Packed silica beads are also leveraged to improve the SERRS detection of the Raman-labeled reporter. Following displacement, the reporter adsorbs onto aggregated silver nanoparticles in a microfluidic mixer; the nanoparticle-reporter conjugates are then trapped and concentrated in the silica bead matrix, which leads to a significant increase in plasmonic nanoparticles and adsorbed Raman reporters within the detection volume as compared to an open microfluidic channel. The experimental results reported here demonstrate detection down to 100 pM of the target DNA sequence, and the experiments are shown to be specific, repeatable, and quantitative. Furthermore, we illustrate the advantage of using SERRS by demonstrating multiplexed detection. The sensitivity of the assay, combined with the advantages of multiplexed detection and single-step operation with unlabeled target sequences makes this method attractive for practical applications. Importantly, while we illustrate DNA sequence detection, the SERRS-based competitive

  2. Glass bead cultivation of fungi

    DEFF Research Database (Denmark)

    Droce, Aida; Sørensen, Jens Laurids; Giese, H.

    2013-01-01

    Production of bioactive compounds and enzymes from filamentous fungi is highly dependent on cultivation conditions. Here we present an easy way to cultivate filamentous fungi on glass beads that allow complete control of nutrient supply. Secondary metabolite production in Fusarium graminearum...... and Fusarium solani cultivated on agar plates, in shaking liquid culture or on glass beads was compared. Agar plate culture and glass bead cultivation yielded comparable results while liquid culture had lower production of secondary metabolites. RNA extraction from glass beads and liquid cultures was easier...... to specific nutrient factors. •Fungal growth on glass beads eases and improves fungal RNA extraction....

  3. Breakthrough properties of chloride ions in columns of lead phosphate hydroxide

    International Nuclear Information System (INIS)

    Akiba, Kenichi; Hashimoto, Hiroyuki; Mimura, Hitoshi; Shindo, Manabu.

    1994-01-01

    Breakthrough properties of chloride ion (Cl - ) have been studied by using columns packed with a granular anion-exchanger of lead phosphate hydroxide (Pb 10 (PO 4 ) 6 (OH) 2 , IXE-1000G). The column utilization of the ratio of breakthrough capacity to total capacity increased with decreasing particle size and increasing temperature. The collection of Cl - from a simulated waste solution was improved by the addition of cation-exchange to IXE-1000G; the adsorption capacity of the column of IXE-1000G/IXE-300G (Sb type cation-exchanger) was over 0.16 mmol Cl - /g, yielding a relatively high column utilization of 75%. (author)

  4. Confocal nanoscanning, bead picking (CONA): PickoScreen microscopes for automated and quantitative screening of one-bead one-compound libraries.

    Science.gov (United States)

    Hintersteiner, Martin; Buehler, Christof; Uhl, Volker; Schmied, Mario; Müller, Jürgen; Kottig, Karsten; Auer, Manfred

    2009-01-01

    Solid phase combinatorial chemistry provides fast and cost-effective access to large bead based libraries with compound numbers easily exceeding tens of thousands of compounds. Incubating one-bead one-compound library beads with fluorescently labeled target proteins and identifying and isolating the beads which contain a bound target protein, potentially represents one of the most powerful generic primary high throughput screening formats. On-bead screening (OBS) based on this detection principle can be carried out with limited automation. Often hit bead detection, i.e. recognizing beads with a fluorescently labeled protein bound to the compound on the bead, relies on eye-inspection under a wide-field microscope. Using low resolution detection techniques, the identification of hit beads and their ranking is limited by a low fluorescence signal intensity and varying levels of the library beads' autofluorescence. To exploit the full potential of an OBS process, reliable methods for both automated quantitative detection of hit beads and their subsequent isolation are needed. In a joint collaborative effort with Evotec Technologies (now Perkin-Elmer Cellular Technologies Germany GmbH), we have built two confocal bead scanner and picker platforms PS02 and a high-speed variant PS04 dedicated to automated high resolution OBS. The PS0X instruments combine fully automated confocal large area scanning of a bead monolayer at the bottom of standard MTP plates with semiautomated isolation of individual hit beads via hydraulic-driven picker capillaries. The quantification of fluorescence intensities with high spatial resolution in the equatorial plane of each bead allows for a reliable discrimination between entirely bright autofluorescent beads and real hit beads which exhibit an increased fluorescence signal at the outer few micrometers of the bead. The achieved screening speed of up to 200,000 bead assayed in less than 7 h and the picking time of approximately 1 bead

  5. Development of an experimental radioisotope based process tomography system for research applications in a cold trickle bed column

    International Nuclear Information System (INIS)

    Sau, Madhusudan; Kumar, Pravesh; Kumar, Umesh; Acharya, Rajesh; Singh, Gursharan

    2009-01-01

    In chemical and petrochemical engineering applications, random and structured packing are used in process columns to enhance the heat and mass transfer between two phases. The packing used in such columns is meant to obtain a high specific interfacial area. It is of paramount importance for scale-up and design of trickle bed process columns, to understand and predict the complex multiphase fluid dynamics. In simplified terms, the phase holdup, solid packing distribution in terms of density and gas and liquid velocities among other important parameters need to be qualitatively and quantitatively understood. In the petrochemical industry, many processes are carried out using fixed bed reactors with concurrent upward and downward gas and liquid flows. In order to characterize the liquid and gas flow distribution through a mock-up column, data on planar and volume density distribution using computed tomographic measurements are very helpful. The paper describes the development efforts of a multi-detector 137 Cs radioisotope based in-situ tomography scanner suitable for 600mm dia. cold trickle bed reactor. The development work is at present in progress. The schematics and development of the scanner gantry is described in this paper. (author)

  6. Mass and heat transfer on B7 structured packing in the separation of hydrogen isotopes by distillation

    International Nuclear Information System (INIS)

    Croitoru, C.; Pop, F.; Titescu, Gh.; Culcer, M.; Iliescu, M.; Stefanescu, I.; Trancota, D.; Peculea, M.

    2002-01-01

    The paper presents theoretical and experimental data concerning mass and heat transfer on B7 ordered packing, at deuterium separation by distillation. The first section of the paper is dedicated to the mass transfer study of hydrogen distillation, while the second section deals with mass and heat transfer in water distillation. A mathematical model was worked out and compared with experimental data, obtained from two laboratory distillation plants for deuterium separation. From the first plant experimental data concerning B7 ordered packing efficiency of hydrogen cryogenic distillation at 250 deg. C level were obtained. Data concerning mass and heat transfer on the same packing in deuterium separation by water vacuum distillation at 60 deg. C level were obtained in the second plant. HUT values, mass and heat transfer coefficients both theoretically evaluated and experimentally determined were found to be comparable with those obtained from chemical industry separation processes. The fact justifies the use of multi-tubular column model for description of transfer processes in distillation columns equipped with B7 structured packing. (authors)

  7. Evaluating Design Parameters for Breakthrough Curve Analysis and Kinetics of Fixed Bed Columns for Cu(II Cations Using Lignocellulosic Wastes

    Directory of Open Access Journals (Sweden)

    Zaira Zaman Chowdhury

    2014-12-01

    Full Text Available A continuous adsorption study for removal of Cu(II cations from wastewater using a fixed-bed column was conducted. A granular carbonaceous activated adsorbent produced by carbonization of the outer rind, or exocarp, of mangostene fruit shell was used for column packing. The effects of feed flow rate, influent cation concentration, and bed depth on the breakthrough curve were investigated at pH 5.5. Experimental analysis confirmed that the breakthrough curves were dependent on flow rate, initial concentration of Cu(II cations, and bed height related to the amount of activated carbon used for column packing. Thomas, Yoon–Nelson, and Adams–Bohart models were applied to analyze the breakthrough curves at different conditions. Linear regression analysis of experimental data demonstrated that Thomas and Yoon–Nelson models were appropriate to explain the breakthrough curve, while the Adams–Bohart model was only applicable to predict the initial part of the dynamic process. It was concluded that the column packed with fruit rind based activated carbon can be used to treat Cu(II-enriched wastewater.

  8. Pressure drop effects on selectivity and resolution in packed-column supercritical fluid chromatography

    NARCIS (Netherlands)

    Lou, X.W.; Janssen, J.G.M.; Snijders, H.M.J.; Cramers, C.A.M.G.

    1996-01-01

    The influence of pressure drop on retention, selectivity, plate height and resolution was investigated systematically in packed supercritical fluid chromatography (SFC) using pure carbon dioxide as the mobile phase. Numerical methods developed previously which enabled the prediction of pressure

  9. Successive pretreatment and enzymatic saccharification of sugarcane bagasse in a packed bed flow-through column reactor aiming to support biorefineries.

    Science.gov (United States)

    Terán-Hilares, R; Reséndiz, A L; Martínez, R T; Silva, S S; Santos, J C

    2016-03-01

    A packed bed flow-through column reactor (PBFTCR) was used for pretreatment and subsequent enzymatic hydrolysis of sugarcane bagasse (SCB). Alkaline pretreatment was performed at 70 °C for 4h with fresh 0.3M NaOH solution or with liquor recycled from a previous pretreatment batch. Scheffersomyces stipitis NRRL-Y7124 was used for fermentation of sugars released after enzymatic hydrolysis (20 FPU g(-1) of dry SCB). The highest results for lignin removal were 61% and 52%, respectively, observed when using fresh NaOH or the first reuse of the liquor. About 50% of cellulosic and 57% of hemicellulosic fractions of pretreated SCBs were enzymatically hydrolyzed and the maximum ethanol production was 23.4 g L(-1) (ethanol yield of 0.4 gp gs(-1)), with near complete consumption of both pentoses and hexoses present in the hydrolysate during the fermentation. PBFTCR as a new alternative for SCB-biorefineries is presented, mainly considering its simple configuration and efficiency for operating with a high solid:liquid ratio. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Admittance Scanning for Whole Column Detection.

    Science.gov (United States)

    Stamos, Brian N; Dasgupta, Purnendu K; Ohira, Shin-Ichi

    2017-07-05

    Whole column detection (WCD) is as old as chromatography itself. WCD requires an ability to interrogate column contents from the outside. Other than the obvious case of optical detection through a transparent column, admittance (often termed contactless conductance) measurements can also sense changes in the column contents (especially ionic content) from the outside without galvanic contact with the solution. We propose here electromechanically scanned admittance imaging and apply this to open tubular (OT) chromatography. The detector scans across the column; the length resolution depends on the scanning velocity and the data acquisition frequency, ultimately limited by the physical step resolution (40 μm in the present setup). Precision equal to this step resolution was observed for locating an interface between two immiscible liquids inside a 21 μm capillary. Mechanically, the maximum scanning speed was 100 mm/s, but at 1 kHz sampling rate and a time constant of 25 ms, the highest practical scan speed (no peak distortion) was 28 mm/s. At scanning speeds of 0, 4, and 28 mm/s, the S/N for 180 pL (zone length of 1.9 mm in a 11 μm i.d. column) of 500 μM KCl injected into water was 6450, 3850, and 1500, respectively. To facilitate constant and reproducible contact with the column regardless of minor variations in outer diameter, a double quadrupole electrode system was developed. Columns of significant length (>1 m) can be readily scanned. We demonstrate its applicability with both OT and commercial packed columns and explore uniformity of retention along a column, increasing S/N by stopped-flow repeat scans, etc. as unique applications.

  11. Effects of modifiers in packed and open-tubular supercritical fluid chromatography

    NARCIS (Netherlands)

    Janssen, J.G.M.; Schoenmakers, P.J.; Cramers, C.A.M.G.

    1991-01-01

    The applicability of packed and open columns for supercritical fluid chromatography using pure carbon dioxide for the elution of a number of selected test components was investigated. It is showns that the number of solutes that can be eluted as symmetrical peaks is much larger in open-tubular

  12. Microfluidic magnetic bead conveyor belt

    NARCIS (Netherlands)

    van Pelt, S.; Frijns, A.J.H.; den Toonder, J.M.J.

    2017-01-01

    Magnetic beads play an important role in the miniaturization of clinical diagnostics systems. In lab-on-chip platforms, beads can be made to link to a target species and can then be used for the manipulation and detection of this species. Current bead actuation systems utilize complex on-chip coil

  13. Transient methods to characterize flows and mass transfer in a packed column by tracers; Methodes transitoires de caracterisation des ecoulements et du transfert de masse dans une colonne a garnissage a l'aide de traceurs

    Energy Technology Data Exchange (ETDEWEB)

    Perrin, S.

    1998-06-11

    The aim of this study is to propose a packed column characterization method in the form of phases flows and mass transfer model, in which the parameters are estimated by transient technique. After a bibliographic study a model is performed and validated. It allows efficiency and precision in the parameters choice. Two tracer techniques have been implemented: they show interesting possibilities of flow diagnosis. (A.L.B.)

  14. Absorption column working study for iodine formed in spent fuel reprocessing plant gaseous effluents: hydrodynamic and mass transfer

    International Nuclear Information System (INIS)

    Vignau, B.

    1986-09-01

    The hydrodynamic and matter transfer parameters has been studied on absorption columns destined to trap iodine issued of spent fuel reprocessing plants. These columns have different packing - Raschig rings (glass, ceramic, PVC, steel) - Berl saddles (ceramic) - Weaved metallic thread (steel). The effect of dimension and of packing structure on gas pressure drop and on liquid holdup has been evaluated. The partial transfer coefficients of I 2 -Air-NaOH system has been the object of an experimental study. This system can be simulated by CO 2 -Air-NaOH system [fr

  15. The control of beads diameter of bead-on-string electrospun nanofibers and the corresponding release behaviors of embedded drugs

    Energy Technology Data Exchange (ETDEWEB)

    Li, Tingxiao [Key Laboratory of Textile Science and Technology (Donghua University), Ministry of Education of China, Shanghai 201620 (China); College of Textiles, Donghua University, Shanghai 201620 (China); Ding, Xin, E-mail: xding@dhu.edu.cn [Key Laboratory of Textile Science and Technology (Donghua University), Ministry of Education of China, Shanghai 201620 (China); College of Textiles, Donghua University, Shanghai 201620 (China); Tian, Lingling, E-mail: lingling_tian@nus.edu.sg [Center of Nanofibers & Nanotechnology, Department of Mechanical Engineering, National University of Singapore, 117576 (Singapore); Hu, Jiyong; Yang, Xudong [Key Laboratory of Textile Science and Technology (Donghua University), Ministry of Education of China, Shanghai 201620 (China); College of Textiles, Donghua University, Shanghai 201620 (China); Ramakrishna, Seeram [Center of Nanofibers & Nanotechnology, Department of Mechanical Engineering, National University of Singapore, 117576 (Singapore); Guangdong-Hongkong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou 510632 (China)

    2017-05-01

    Bead-on-string nanofibers, with appropriate control of the beads diameter, are potential fibrous structures for efficient encapsulation of particle drugs in micron scales and could achieve controlled drug release for tissue engineering applications. In this study, the beads diameter of electrospun bead-on-string nanofibers was controlled by adjusting the concentration of spinning polymer, poly (lactic-co-glycolic acid) (PLGA), and the solvent ratio of chloroform to acetone. The images of the scanning electron microscopy (SEM) suggested that bead-on-string nanofibers could be successfully obtained only with a certain range of PLGA solution concentration. Moreover, with the decrease in the solvent ratio of chloroform to acetone, the range was left-shifted towards a smaller concentration. In addition, increase in the PLGA solution concentration within the range the beads diameter became greater and the shape of the beads changed from oval to slender when increasing the PLGA concentration within the range. The bead-on-string nanofibers with different beads diameter were further used to load micro-particle drugs of tetracycline hydrochloride, as a model drug, to examine the release behavior of nanofibers scaffold. The release profiles of drug loaded bead-on-string nanofibers demonstrated the possibility to alleviate the burst drug release by means of beads diameter control. - Highlights: • Bead diameter of bead-on-string electrospun nanofibers was controlled by varying solvent ratio and polymer concentration. • The effect of the addition of particle drugs on BD of bead-on-string electrospun nanofibers was studied. • The corresponding release behaviors of nanofibers with different BD loading micro-particle drugs were investigated. • Bead-on-string nanofibers with bigger BD could alleviate the initial burst release.

  16. The control of beads diameter of bead-on-string electrospun nanofibers and the corresponding release behaviors of embedded drugs

    International Nuclear Information System (INIS)

    Li, Tingxiao; Ding, Xin; Tian, Lingling; Hu, Jiyong; Yang, Xudong; Ramakrishna, Seeram

    2017-01-01

    Bead-on-string nanofibers, with appropriate control of the beads diameter, are potential fibrous structures for efficient encapsulation of particle drugs in micron scales and could achieve controlled drug release for tissue engineering applications. In this study, the beads diameter of electrospun bead-on-string nanofibers was controlled by adjusting the concentration of spinning polymer, poly (lactic-co-glycolic acid) (PLGA), and the solvent ratio of chloroform to acetone. The images of the scanning electron microscopy (SEM) suggested that bead-on-string nanofibers could be successfully obtained only with a certain range of PLGA solution concentration. Moreover, with the decrease in the solvent ratio of chloroform to acetone, the range was left-shifted towards a smaller concentration. In addition, increase in the PLGA solution concentration within the range the beads diameter became greater and the shape of the beads changed from oval to slender when increasing the PLGA concentration within the range. The bead-on-string nanofibers with different beads diameter were further used to load micro-particle drugs of tetracycline hydrochloride, as a model drug, to examine the release behavior of nanofibers scaffold. The release profiles of drug loaded bead-on-string nanofibers demonstrated the possibility to alleviate the burst drug release by means of beads diameter control. - Highlights: • Bead diameter of bead-on-string electrospun nanofibers was controlled by varying solvent ratio and polymer concentration. • The effect of the addition of particle drugs on BD of bead-on-string electrospun nanofibers was studied. • The corresponding release behaviors of nanofibers with different BD loading micro-particle drugs were investigated. • Bead-on-string nanofibers with bigger BD could alleviate the initial burst release.

  17. Fused Bead Analysis of Diogenite Meteorites

    Science.gov (United States)

    Mittlefehldt, D.W.; Beck, B.W.; McSween, H.Y.; Lee, C.T. A.

    2009-01-01

    Bulk rock chemistry is an essential dataset in meteoritics and planetary science [1]. A common method used to obtain the bulk chemistry of meteorites is ICP-MS. While the accuracy, precision and low detection limits of this process are advantageous [2], the sample size used for analysis (approx.70 mg) can be a problem in a field where small and finite samples are the norm. Fused bead analysis is another bulk rock analytical technique that has been used in meteoritics [3]. This technique involves forming a glass bead from 10 mg of sample and measuring its chemistry using a defocused beam on a microprobe. Though the ICP-MS has lower detection limits than the microprobe, the fused bead method destroys a much smaller sample of the meteorite. Fused bead analysis was initially designed for samples with near-eutectic compositions and low viscosities. Melts generated of this type homogenize at relatively low temperatures and produce primary melts near the sample s bulk composition [3]. The application of fused bead analysis to samples with noneutectic melt compositions has not been validated. The purpose of this study is to test if fused bead analysis can accurately determine the bulk rock chemistry of non-eutectic melt composition meteorites. To determine this, we conduct two examinations of the fused bead. First, we compare ICP-MS and fused bead results of the same samples using statistical analysis. Secondly, we inspect the beads for the presence of crystals and chemical heterogeneity. The presence of either of these would indicate incomplete melting and quenching of the bead.

  18. Measurement of capacity coefficient of inclined liquid phase catalytic exchange column for tritiated water processing

    International Nuclear Information System (INIS)

    Yamai, Hideki; Konishi, Satoshi; Yamanishi, Toshihiko; Okuno, Kenji

    1994-01-01

    Liquid phase catalytic exchange (LPCE) is effective method for enrichment and removal of tritium from tritiated water. Capacity coefficients of operating LPCE column that are essential to evaluate column performance were measured. Experiments were performed with short catalyst packed columns and effect of inclination was studied. Method for evaluation of capacity coefficients was established from measurement of isotope concentration of liquid, vapor, gas phases at the two ends of the column. The capacity coefficients were measured under various superficial gas velocities. Feasibility study of helical columns with roughened inner surface was performed with short inclined columns. The column performance was not strongly affected by the inclination. The result indicates technological feasibility of helical LPCE column, that is expected to have operation stability and reduced height

  19. Magnetic bead detection using nano-transformers

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Kwon; Ahn, Doyeol [Institute of Quantum Information Processing and Systems, University of Seoul, 90 Jeonnong, Dongdaemun, Seoul 130-743 (Korea, Republic of); Hwang, Jong Seung; Hwang, Sung Woo, E-mail: dahn@uos.ac.kr [Research Center for Time-domain Nano-functional Devices and School of Electrical Engineering, Korea University, 5-1 Anam, Sungbuk, Seoul 136-701 (Korea, Republic of)

    2010-11-19

    A novel scheme to detect magnetic beads using a nano-scale transformer with a femtoweber resolution is reported. We have performed a Faraday's induction experiment with the nano-transformer at room temperature. The transformer shows the linear output voltage responses to the sinusoidal input current. When magnetic beads are placed on the transformer, the output responses are increased by an amount corresponding to the added magnetic flux from the beads when compared with the case of no beads on the transformer. In this way, we could determine whether magnetic beads are on top of the transformer in a single particle level.

  20. Magnetic bead detection using nano-transformers.

    Science.gov (United States)

    Kim, Hyung Kwon; Hwang, Jong Seung; Hwang, Sung Woo; Ahn, Doyeol

    2010-11-19

    A novel scheme to detect magnetic beads using a nano-scale transformer with a femtoweber resolution is reported. We have performed a Faraday's induction experiment with the nano-transformer at room temperature. The transformer shows the linear output voltage responses to the sinusoidal input current. When magnetic beads are placed on the transformer, the output responses are increased by an amount corresponding to the added magnetic flux from the beads when compared with the case of no beads on the transformer. In this way, we could determine whether magnetic beads are on top of the transformer in a single particle level.

  1. Compressibility effects in packed and open tubular gas and supercritical fluid chromatography

    NARCIS (Netherlands)

    Janssen, J.G.M.; Snijders, H.M.J.; Cramers, C.A.; Schoenmakers, P.J.

    1992-01-01

    The influence of the pressure drop on the efficiency and speed of anal. in packed and open tubular supercrit. fluid chromatog. (SFC) is described: methods previously developed to describe the effects of mobile phase compressibility on the performance of open tubular columns in SFC have been extended

  2. ANALYSIS OF TRICKLE BED AND PACKED BUBBLE COLUMN BIOREACTORS FOR COMBINED CARBON OXIDATION AND NITRIFICATION

    Directory of Open Access Journals (Sweden)

    Iliuta I.

    2002-01-01

    Full Text Available Biological removal of nitrogen and carbon by combined nitrification-oxidation in gas-liquid trickle-bed reactors (TBRs and packed bubble columns (PBCs was analyzed theoretically using a transient two-dimensional model. The model describes TBR and PBC performances at steady state as well as their transient response to a pulse or step increase in inlet methanol and NH4+-nitrogen concentrations. The hydrodynamic parameters were determined from residence time distribution measurements, using an imperfect pulse method for time-domain analysis of nonideal pulse tracer response. A transient diffusion model of the tracer in the porous particle coupled with the piston-dispersion-exchange model was used to interpret the residence time distribution curves obtained. Gas-liquid mass transfer parameters were determined by a stationary method based on the least-squares fit of the calculated concentration profiles in gas phase to the experimental values. Analysis of steady-state performances showed that under like operating conditions, the TBR outperforms the PBC in terms of conversions. A pulse change in the inlet methanol or NH4+-nitrogen concentration causes a negligible transient change in the outlet methanol concentration and a negligible or high transient change in the outlet NH4+-nitrogen concentration. A step change in the inlet methanol concentration causes the negligible transient change in the methanol outlet concentration and a relatively important transient change in the NH4+-nitrogen outlet concentration. A step increase in the NH4+-nitrogen inlet concentration induces a drastic transient change in the NH4+-nitrogen outlet concentration but a negligible transient change in the methanol outlet concentration.

  3. Development of a process for continuous extraction of uranium from seawater

    International Nuclear Information System (INIS)

    Yun, C.K.

    1982-03-01

    Hydrous titanium oxide, titanium phosphate, galena (PbS), polystyrene beads containing TBP were preliminarily tested, using artificial seawater. Galena indicated the capacity of 1.1mg U/g PbS and faster reaction rates, whereas, hydrous titanium oxide showed 0.6mg U/g Ti and slow rates. The adsorption performance of galena was not changed after repeated use and regeneration with dil. HCl solutions. The effective surface of galena beads was 0.4mm in depth. Elution of uranium form adsorbents was examined by both acid and alkali methods; the latter showed preferred condition. Secondary concentration of uranium by Amberlite IRA-400 was also studies. Eventually, two types of packed systems with galena (columns and panels) were installed in the seawater channel of a thermal power plant. The maximum adsorption of 150μg U/g PbS was obtained using the packed column. Based on the experimental data, the authors made a conceptual design for a test plant of the production capacity 12Kg U 3 O 8 /y. The construction would cost about $1 million and the operation cost is estimated at $115.20/lb U 3 O 8

  4. Hydrogen production in the K-Basin ion exchange columns, modules and cartridge filters

    International Nuclear Information System (INIS)

    1994-01-01

    K-Basin uses ion exchange modules and ion exchange (IX) columns for removing radionuclides from the basin water. When the columns and modules are loaded, they are removed from service, drained and stored. After a few IX columns accumulate in storage, they are moved to a burial box. One of the burial box contains 33 columns and the other, six. The radionuclides act on the liquid left within and adhering to the beads to produce hydrogen. This report describes the generation rate, accumulation rate and significance of that accumulation. This summary also highlights those major areas of concern to the external (to Westinghouse Hanford Company [WHC]) reviewers. Appendix H presents the comments made by the external reviewers and, on a separate sheet, the responses to those comments. The concerns regarding the details of the analytical approach, are addressed in Appendix H and in the appropriate section

  5. Hydrogen production in the K-Basin ion exchange columns, modules and cartridge filters

    Energy Technology Data Exchange (ETDEWEB)

    1994-12-21

    K-Basin uses ion exchange modules and ion exchange (IX) columns for removing radionuclides from the basin water. When the columns and modules are loaded, they are removed from service, drained and stored. After a few IX columns accumulate in storage, they are moved to a burial box. One of the burial box contains 33 columns and the other, six. The radionuclides act on the liquid left within and adhering to the beads to produce hydrogen. This report describes the generation rate, accumulation rate and significance of that accumulation. This summary also highlights those major areas of concern to the external (to Westinghouse Hanford Company [WHC]) reviewers. Appendix H presents the comments made by the external reviewers and, on a separate sheet, the responses to those comments. The concerns regarding the details of the analytical approach, are addressed in Appendix H and in the appropriate section.

  6. Carbon dioxide degassing in fresh and saline water I: Degassing performance of a cascade column

    DEFF Research Database (Denmark)

    Moran, Damian

    2010-01-01

    A study was undertaken to measure carbon dioxide degassing in a cascade column operating with both fresh (0‰) and saline water (35‰ NaCl) at 15 °C. The cascade column contained bio-block type packing material, was 1.7 m long in each dimension, and was tested both with and without countercurrent a...

  7. DNA packing in chromatine, a manifestation of the Bonnet transformation.

    Science.gov (United States)

    Blum, Z; Lidin, S

    1988-08-01

    The packing of DNA is described using the formalism of differential geometry. Winding of the DNA double helix around the histone 2-5 octamer forming a nucleosome and the condensation of the so-formed bead-on-a-string chromatine aided by histone 1 is interpreted as two consecutive isometric, i.e. Bonnet, transformations. The DNA double helix can be approximated to a helicoid which can be transformed isometrically to a catenoid, an approximation of the nucleosome. Owing to the organization of the histone octamer the extended chromatine takes a helicoidal shape allowing a second Bonnet transformation to consummate the condensation into a chromatine fibre.

  8. Surface streamer propagations on an alumina bead: experimental observation and numerical modeling

    Science.gov (United States)

    Kang, Woo Seok; Kim, Hyun-Ha; Teramoto, Yoshiyuki; Ogata, Atsushi; Lee, Jin Young; Kim, Dae-Woong; Hur, Min; Song, Young-Hoon

    2018-01-01

    A surface streamer in a simplified packed-bed reactor has been studied both experimentally (through time-resolved ICCD imaging) and theoretically (through two-dimensional numerical modeling). The propagation of streamers on an alumina spherical bead without catalytic coating shows three distinct phases—the generation and propagation of a primary streamer (PS) with a moderate velocity and electric field, fast PS acceleration with an enhanced electric field, and slow secondary streamer (SS) propagation. The velocity of the streamer is less than that of propagation in a gaseous media. The electric field and velocity at the streamer front are maximized when a PS propagates during the interval from the midpoint of the bead to the bottom electrode. The SS exhibits a much lower velocity and electric field compared with the PS. The PS velocity is affected by an external applied voltage, especially when it approaches the ground electrode. However, that of the SS remains constant regardless of the voltage change. The simulation shows that the PS exhibits a high electric field mainly created by the space charge induced by electrons, whereas the SS relies on ion movement with electron decay in a charge-filled thin streamer body.

  9. Safety operation of chromatography column system with discharging hydrogen radiolytically generated

    International Nuclear Information System (INIS)

    Watanabe, S; Sano, Y.; Nomura, K.; Koma, Y.; Okamoto, Y.

    2015-01-01

    The extraction chromatography technology is one of the promising methods for the partitioning of minor actinides (Am and Cm) from spent nuclear fuels. In the extraction chromatography system, the accumulation of hydrogen gas in the chromatography column is suspected to lead to fire or explosion. In order to prevent hazardous accidents, it is necessary to evaluate behaviors of gas radiolytically generated inside the column. In this study, behaviors of gas inside the extraction chromatography column were investigated through experiments and Computation Fluid Dynamics (CFD) simulation. N_2 gas once accumulated as bubbles in the packed bed was hardly discharged by the flow of mobile phase. However, the CFD simulation and X-ray imaging on γ-ray irradiated column revealed that during operation the hydrogen gas generated in the column was dissolved into the mobile phase without accumulation and then discharged. (authors)

  10. Ideal versus real automated twin column recycling chromatography process.

    Science.gov (United States)

    Gritti, Fabrice; Leal, Mike; McDonald, Thomas; Gilar, Martin

    2017-07-28

    The full baseline separation of two compounds (selectivity factors αchromatography is used to confirm that the speed-resolution performance of the TCRSP is intrinsically superior to that of the single-column process. This advantage is illustrated in this work by developing an automated TCRSP for the challenging separation of two polycyclic aromatic hydrocarbon (PAH) isomers (benzo[a]anthracene and chrysene) in the reversed-phase retention mode at pressure smaller than 5000psi. The columns used are the 3.0mm×150mm column packed with 3.5μm XBridge BEH-C 18 material (α=1.010) and the 3.0mm or 4.6mm×150mm columns packed with the same 3.5μm XSelect HSST 3 material (α=1.025). The isocratic mobile phase is an acetonitrile-water mixture (80/20, v/v). Remarkably, significant differences are observed between the predicted retention times and efficiencies of the ideal TCRSP (given by the number of cycles multiplied by the retention time and efficiency of one column) and those of the real TCRSP. The fundamental explanation lies in the pressure-dependent retention of these PAHs or in the change of their partial molar volume as they are transferred from the mobile to the stationary phase. A revisited retention and efficiency model is then built to predict the actual performance of real TCRSPs. The experimental and calculated resolution data are found in very good agreement for a change, Δv m =-10cm 3 /mol, of the partial molar volume of the two PAH isomers upon transfer from the acetonitrile-water eluent mixture to the silica-C 18 stationary phase. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Water infiltration and heat transfer in one dimensional unsaturated packed beds; Fuhowa ryushi sonai no ichijigen suibun nagare to dennetsu tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, K; Akahori, M; Hattori, M [Nagaoka University of Technology, Niigata (Japan); Shiraishi, N [Toshiba Corp., Tokyo (Japan)

    1998-05-25

    Water and heat transport in unsaturated packed beds due to supplying hot water have been investigated experimentally and theoretically. Using various sizes of glass beads, capillary pressure and permeability in packed beds were measured in unsaturated beds. The distributions in water saturation and temperature were predicted for one dimensional packed bed, based on a model assuming local thermal equilibrium among water, gas and particles at any specific space. The predicted temperature distributions were compared with the experimental results obtained using various glass sizes. In layered packed beds, water saturation becomes discontinuous at the interface of two layers because of the difference of the water characteristics between two beds. Water penetrates faster in coarse-over fine-textured profile compared with in fine-over coarse-textured profile. Similarly, the temperature rises faster in former profile under the same supplied heat quantity. 11 refs., 13 figs., 1 tab.

  12. Removal of nitrate, ammonia and phosphate from aqueous solutions in packed bed filter using biochar augmented sand media

    Directory of Open Access Journals (Sweden)

    El Hanandeh Ali

    2017-01-01

    Full Text Available Nutrients from wastewater are a major source of pollution because they can cause significant impact on the ecosystem. Accordingly, it is important that the nutrient concentrations are kept to admissible levels to the receiving environment. Often regulatory limits are set on the maximum allowable concentrations in the effluent. Therefore, wastewater must be treated to meet safe levels of discharge. In this study, laboratory investigation of the efficiency of packed bed filters to remove nitrate, ammonium and phosphate from aqueous solutions were conducted. Sand and sand augmented with hydrochloric acid treated biochar (SBC were used as packing media. Synthetic wastewater solution was prepared with PO43−, NO3−, NH4+ concentrations 20, 10, 50 mg/L, respectively. Each experiment ran for a period of five days; samples from the effluent were collected on alternate days. All experiments were duplicated. Over the experiment period, the average removal efficiency of PO43−, NO3−, NH4+ were 99.2%, 72.9%, 96.7% in the sand packed columns and 99.2%, 82.3%, 97.4% in the SBC packed columns, respectively. Although, the presence of biochar in the packing media had little effect on phosphate and ammonium removal, it significantly improved nitrate removal.

  13. 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.

  14. Direct chromatographic analysis of metabolites of lipophilic tracers in whole blood by ISRP chromatography

    International Nuclear Information System (INIS)

    Rosenspire, K.C.; Hirth, W.; Jurisson, S.; Nowotnik, D.P.; Eckelman, W.C.; Nunn, A.D.

    1991-01-01

    HPLC using columns packed with 5 μ Internal Surface Reverse Phase (ISRP) resin have shown utility in the analysis of lipophilic drugs and their metabolites by direct injection of serum or plasma samples. We have developed a method for rapid on-line separation of small hydrophobic components from cellular whole blood components. This is achieved through the use of 75 μ GFF (glycine-phenylalanine-phenylalanine) glass bead ISRP chromatographic material packed into a small HPLC column, and used in conjunction with an HPLC system containing a switching valve and a second analytical column. When heparinized whole blood is applied to a 75 μ GFF ISRP column, and the column eluted with an isotonic eluent, lipophilic compounds free in plasma are retained by the column, while plasma proteins, blood cells, and compounds bound to these blood components pass through the ISRP column. Following the elution of these components, the lipophilic compounds retained on the ISRP column are eluted by increasing the percentage of organic solvent in the eluent, and are further resolved (if required) by the analytical column. We have applied this analytical method to the study of metabolism of the 99m Tc-BATO (Boronic acid Adducts of Technetium diOxime) cerebral and myocardial perfusion tracers. (author)

  15. Disposal of bead ion exchange resin wastes

    International Nuclear Information System (INIS)

    Gay, R.L.; Granthan, L.F.

    1985-01-01

    Bead ion exchange resin wastes are disposed of by a process which involves spray-drying a bead ion exchange resin waste in order to remove substantially all of the water present in such waste, including the water on the surface of the ion exchange resin beads and the water inside the ion exchange resin beads. The resulting dried ion exchange resin beads can then be solidified in a suitable solid matrix-forming material, such as a polymer, which solidifies to contain the dried ion exchange resin beads in a solid monolith suitable for disposal by burial or other conventional means

  16. 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.

  17. Multi-column adsorption systems with condenser for tritiated water vapor removal

    International Nuclear Information System (INIS)

    Kotoh, Kenji; Kudo, Kazuhiko

    1996-01-01

    Two types of multi-column adsorption system are proposed as the system for removal of tritiated moisture from tritium process gases or/and handling room atmospheres. The types are of recycle use of adsorption columns, and are composed of twin or triplet columns and one condenser which is used for collecting the adsorbed moisture from columns in desorption process. The systems utilize the dry gas from a working column as the purge gas for regenerating a saturated column and appropriate an active column for recovery of the tritiated moisture passing through the condenser. Each column hence needs the additional amount of adsorbent for collecting the moisture from the condenser. In the modeling and design of an adsorption column, it is primary to estimate the necessary amount of a candidate adsorbent for its packed-bed. The performance of the proposed systems is examined here by analyzing the dependence of the necessary amount of adsorbent for their columns on process operational conditions and adsorbent moisture-adsorption characteristics. The result shows that the necessary amount is sensitive to the types of adsorption isotherm, and suggests that these systems should employ adsorbents which exhibit the Langmuir-type isotherms. (author)

  18. Surface Characterization of Some Novel Bonded Phase Packing Materials for HPLC Columns Using MAS-NMR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Jude Abia

    2015-03-01

    Full Text Available Information on the surface properties of three novel chemically bonded phase packing materials for High performance liquid chromatography (HPLC were obtained using spectra obtained by solid state cross-polarization (CP magic-angle spinning (MAS nuclear magnetic resonance (NMR spectroscopic experiments for the 29Si, and 13C nuclei. These packing materials were: Cogent bidentate C18 bonded to type-C silica, hybrid packing materials XTerra MS C18, and XBridge Prep. C18. The spectra obtained using cross-polarization magic angle spinning (CP-MAS on the Cogent bidentate C18 bonded to type-C silica show the surface to be densely populated with hydride groups (Si-H, with a relative surface coverage exceeding 80%. The hybrid packing materials XTerra and XBridge gave spectra that reveal the silicon atoms to be bonded to organic moieties embedded in the molecular structure of these materials with over 90% of the alkyl silicon atoms found within the completely condensed silicon environments. The hydrolytic stability of these materials were investigated in acidic aqueous solutions at pHs of 7.0 and 3.0, and it was found that while the samples of XTerra and XBridge were not affected by hydrolysis at this pH range, the sample of Cogent lost a significant proportion of its Si-H groups after five days of treatment in acidic aqueous solution.

  19. Miniaturized protein separation using a liquid chromatography column on a flexible substrate

    International Nuclear Information System (INIS)

    Yang Yongmo; Chae, Junseok

    2008-01-01

    We report a prototype protein separator that successfully miniaturizes existing technology for potential use in biocompatible health monitoring implants. The prototype is a liquid chromatography (LC) column (LC mini-column) fabricated on an inexpensive, flexible, biocompatible polydimethylsiloxane (PDMS) enclosure. The LC mini-column separates a mixture of proteins using size exclusion chromatography (SEC) with polydivinylbenzene beads (5–20 µm in diameter with 10 nm pore size). The LC mini-column is smaller than any commercially available LC column by a factor of ∼11 000 and successfully separates denatured and native protein mixtures at ∼71 psi of the applied fluidic pressure. Separated proteins are analyzed using NuPAGE-gel electrophoresis, high-performance liquid chromatography (HPLC) and an automated electrophoresis system. Quantitative HPLC results demonstrate successful separation based on intensity change: within 12 min, the intensity between large and small protein peaks changed by a factor of ∼20. In further evaluation using the automated electrophoresis system, the plate height of the LC mini-column is between 36 µm and 100 µm. The prototype LC mini-column shows the potential for real-time health monitoring in applications that require inexpensive, flexible implant technology that can function effectively under non-laboratory conditions

  20. Application of Nanofiber-packed SPE for Determination of Urinary 1-Hydroxypyrene Level Using HPLC.

    Science.gov (United States)

    Ifegwu, Okechukwu Clinton; Anyakora, Chimezie; Chigome, Samuel; Torto, Nelson

    2014-01-01

    It is always desirable to achieve maximum sample clean-up, extraction, and pre-concentration with the minimum possible organic solvent. The miniaturization of sample preparation devices was successfully demonstrated by packing 10 mg of 11 electrospun polymer nanofibers into pipette tip micro column and mini disc cartridges for efficient pre-concentration of 1-hydroxypyrene in urine samples. 1-hydroxypyrene is an extensively studied biomarker of the largest class of chemical carcinogens. Excretory 1-hydroxypyrene was monitored with HPLC/fluorescence detector. Important parameters influencing the percentage recovery such as fiber diameter, fiber packing amount, eluent, fiber packing format, eluent volume, surface area, porosity, and breakthrough parameters were thoroughly studied and optimized. Under optimized condition, there was a near perfect linearity of response in the range of 1-1000 μg/L with a coefficient of determination (r (2)) between 0.9992 and 0.9999 and precision (% RSD) ≤7.64% (n = 6) for all the analysis (10, 25, and 50 μg/L). The Limit of detection (LOD) was between 0.022 and 0.15 μg/L. When compared to the batch studies, both disc packed nanofiber sorbents and pipette tip packed sorbents exhibited evident dominance based on their efficiencies. The experimental results showed comparable absolute recoveries for the mini disc packed fibers (84% for Nylon 6) and micro columns (80% for Nylon 6), although the disc displayed slightly higher recoveries possibly due to the exposure of the analyte to a larger reacting surface. The results also showed highly comparative extraction efficiencies between the nanofibers and conventional C-18 SPE sorbent. Nevertheless, miniaturized SPE devices simplified sample preparation, reducing back pressure, time of the analysis with acceptable reliability, selectivity, detection levels, and environmental friendliness, hence promoting green chemistry.

  1. 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.

  2. Activity behavior of a HPLC column including α-chymotrypsin immobilized monosized-porous particles

    International Nuclear Information System (INIS)

    Bilici, Z.; Camli, S.T.; Unsal, E.; Tuncel, A.

    2004-01-01

    In this study, a polymer-based, α-chymotrypsin (CT) immobilized HPLC column was prepared as a potential material for affinity-HPLC and chiral separation applications. Monosized-macroporous particles were synthesized as the support material by a relatively new polymerization protocol, the so-called, 'modified seeded polymerization'. The particles were obtained in the form of styrene-glycidyl methacrylate- divinylbenzene terpolymer approximately 11 μm in size. The particles were treated with aqueous ammonia to have primary amine groups on the porous surface. The amine functionalized particles were reacted by glutaraldehyde and the enzyme, CT, was covalently attached. CT carrying monosized-porous particles were slurry packed into the HPLC column 50 mmx4.6 mm in size. Since the activity behavior of immobilized CT played an important role in the enantiomeric separations performed by similar columns, the enzymatic activity behavior of the column produced by our protocol was determined. For this purpose, HPLC column was used as a packed bed reactor and the enzymatic reaction was continuously followed by measuring the absorbance of the output flow by the UV-detector of HPLC. S-shaped absorbance-time curves were obtained by monitoring the reactor output both in dynamic and steady-state periods. The columns with relatively lower immobilized enzyme content were more sensitive to the changes in the operating conditions and responded with more appreciable substrate conversion changes. The maximum reaction rate of the immobilized enzyme was estimated as approximately 25% of the free one by the mathematical model describing the activity behavior of the column. No significant loss was observed in the activity of the immobilized enzyme during the course of the experiments

  3. Microfluidic magnetic bead conveyor belt.

    Science.gov (United States)

    van Pelt, Stijn; Frijns, Arjan; den Toonder, Jaap

    2017-11-07

    Magnetic beads play an important role in the miniaturization of clinical diagnostics systems. In lab-on-chip platforms, beads can be made to link to a target species and can then be used for the manipulation and detection of this species. Current bead actuation systems utilize complex on-chip coil systems that offer low field strengths and little versatility. We demonstrate a novel system based on an external rotating magnetic field and on-chip soft-magnetic structures to focus the field locally. These structures were designed and optimized using finite element simulations in order to create a number of local flux density maxima. These maxima, to which the magnetic beads are attracted, move over the chip surface in a continuous way together with the rotation of the external field, resulting in a mechanism similar to that of a conveyor belt. A prototype was fabricated using PDMS molding techniques mixed with iron powder for the magnetic structures. In the subsequent experiments, a quadrupole electromagnet was used to create the rotating external field. We observed that beads formed agglomerates that rolled over the chip surface, just above the magnetic structures. Field rotation frequencies between 0.1-50 Hz were tested resulting in magnetic bead speeds of over 1 mm s -1 for the highest frequency. With this, we have shown that our novel concept works, combining a simple design and simple operation with a powerful and versatile method for bead actuation. This makes it a promising method for further research and utilization in lab-on-chip systems.

  4. Use of a pulsed column with discs and crowns for uranium extraction from phosphoric acid

    International Nuclear Information System (INIS)

    1982-04-01

    The physico-chemistry of the system phosphoric acid-uranium-dioctylpyrophosphoric acid is studied for the determination of analytical methods and extraction parameters (oxidation state of uranium and iron, phosphorus concentration, extractant concentration). Extraction is then realized on a pilot scale with a liquid-liquid extraction column 4m high and of 50 mm in diameter with a column packing made of discs and crowns. Column efficiency is evaluated by studying uranium transfer as a function of operating conditions. The results obtained are extrapolated to an industrial scale and a comparative economic evaluation is made between a pulsed column and a mixer-settler [fr

  5. High-efficiency liquid chromatography on conventional columns and instrumentation by using temperature as a variable I. Experiments with 25 cm x 4.6 mm I.D., 5 microm ODS columns.

    Science.gov (United States)

    Lestremau, François; Cooper, Andrew; Szucs, Roman; David, Frank; Sandra, Pat

    2006-03-24

    High plate numbers were obtained in conventional LC by coupling columns and by using temperature to reduce the viscosity of the mobile phase. At 80 degrees C up to eight columns of 25 cm x 4.6 mm I.D. packed with 5 microm ODS particles could be coupled generating 180,000 effective plates while the pressure drop was only 350bar. For routine work, a set of four columns is preferred. The analysis times on one column operated at 30 degrees C and 1 mL/min flow rate and on four columns at 80 degrees C and 2 mL/min flow rate are the same in isoeluotropic conditions while the resolution is doubled. Multicolumn systems were successfully applied in isocratic and gradient mode for the analysis of pharmaceutical and environmental samples.

  6. Tritium Isotope Separation Using Adsorption-Distillation Column

    International Nuclear Information System (INIS)

    Fukada, Satoshi

    2005-01-01

    In order to miniaturize the height of a distillation tower for the detritiation of waste water from fusion reactors, two experiments were conducted: (1) liquid frontal chromatography of tritium water eluting through an adsorption column and (2) water distillation using a column packed with adsorbent particles. The height of the distillation tower depends on the height equivalent to a theoretical plate, HETP, and the equilibrium isotope separation factor, α H-T equi . The adsorption action improved not only HETP but also α H-T equi . Since the adsorption-distillation method proposed here can shorten the tower height with keeping advantages of the distillation, it may bring an excellent way for miniaturizing the distillation tower to detritiate a large amount of waste water from fusion reactors

  7. A cryogenic distillation column cascade for a fusion reactor

    International Nuclear Information System (INIS)

    Kinoshita, M.

    1984-01-01

    A cryogenic distillation column cascade composed of only two columns is proposed. Compared with the Tritium Systems Test Assembly (TSTA) cascade, the tritium inventory is about 1.5 times more and the packed height of the highest column increases by about 40%. However, the number of the columns is halved with the separation performance unchanged. The number of the instruments needed and the number of the process parameters to be monitored are also reduced. Unlike in the case of the TSTA cascade, the performance of the proposed cascade is not subject to the flow rate of the neutral beam injector recycle stream. The high performance can be maintained even if the protium percentage in the raw fuel input increases significantly (e.g., from 1 to 3%), just by adjusting the flow rates of the top, bottom, and side streams. Because of this great flexibility, it is worthwhile to build and study the proposed cascade as a possible alternative to the TSTA cascade

  8. Direct friction measurement in draw bead testing

    DEFF Research Database (Denmark)

    Olsson, David Dam; Bay, Niels; Andreasen, Jan Lasson

    2005-01-01

    The application of draw beads in sheet metal stamping ensures controlled drawing-in of flange parts. Lubrication conditions in draw beads are severe due to sliding under simultaneous bending. Based on the original draw bead test design by Nine [1] comprehensive studies of friction in draw beads...... have been reported in literature. A major drawback in all these studies is that friction is not directly measured, but requires repeated measurements of the drawing force with and without relative sliding between the draw beads and the sheet material. This implies two tests with a fixed draw bead tool...... and a freely rotating tool respectively, an approach, which inevitably implies large uncertainties due to scatter in the experimental conditions. In order to avoid this problem a new draw bead test is proposed by the authors measuring the friction force acting on the tool radius directly by a build...

  9. RpeakChrom: Novel R package for the automated characterization and optimization of column efficiency in high-performance liquid chromatography analysis.

    Science.gov (United States)

    Peris-Díaz, Manuel David; Alcoriza-Balaguer, Maria Isabel; García-Cañaveras, Juan Carlos; Santonja, Francisco; Sentandreu, Enrique; Lahoz, Agustín

    2017-11-01

    Characterization of chromatographic columns using the traditional van Deemter method is limited by the necessity of calculating extra-column variance, issue particularly relevant when modeling asymmetrical peaks eluted from monolithic columns. A novel R package that implements Parabolic Variance Modified Gaussian approach for accurate peak modeling, van Deemter equation and two alternatives approaches, based on van Deemter, has been developed to calculate the height equivalent to a theoretical plate (HETP). To assess package capabilities conventional packed reverse-phase and monolithic HPLC columns were characterized. Peaks eluted from the monolithic column showed a high value of factor asymmetry due, in part, to the contribution of extra-column factors. Such deviation can be circumvented by the two alternatives approaches implemented in the R-package. Furthermore, increased values of eddy diffusion and mass transfer kinetics terms in HETP were observed for the packed column, while accuracy was below 9% in all cases. These results showed the usefulness of the R-package for both modeling chromatographic peaks and assessing column efficiency. The RpeakChrom package could become a helpful tool for testing new stationary phases during column development and to evaluate column during its lifetime. This R tool is freely available from CRAN (https://CRAN.R-project.org/package=RpeakChrom). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Beads from Inhumation Rite Burials of Gnezdovo Burial Mound

    Directory of Open Access Journals (Sweden)

    Dobrova Olga P.

    2017-12-01

    Full Text Available The beads from 33 inhumation burials at Gnezdovo burial mound are examined in the article. The beads (total 367 were crafted from stretched tube (258, stretched stick (3, winding (45, press molding (2 pcs., welding (2 pcs., and mosaic beads (9 pcs.. The burial mound contains virtually no broken beads, including the settlement's most common yellow glass beads. Besides glass beads, cornelian, crystal, amber and faience beads have been registered among the burial mound material, as well as beads crafted with metal. Apart from beads, grave inventories contained a series of pendants with a bead strung on a wire ring. The considered complexes contain five pendants of this type. Besides Gnezdovo, similar pendants have been discovered in Kiev, Timerev, Pskov and Vladimir barrows. A comparison between bead sets from Gnezdovo and Kiev burial mounds allows to conclude that the general composition and occurrence frequency of beads is identical for these burials. At the same time, beads crafted with rock crystal, cornelian and metal are more frequently discovered in Kiev inhumations.

  11. A String of Beads

    Science.gov (United States)

    Mead, Kelly C.

    2006-01-01

    In this article, the author relates how she designed a math activity she called Beads to use in conjunction with their school's 100th day celebration. Beads has provided her kindergarten class with many opportunities to practice a variety of math skills - counting, patterning, sorting, comparing, making sets, predicting, identifying numerals,…

  12. Column Chromatography To Obtain Organic Cation Sorption Isotherms.

    Science.gov (United States)

    Jolin, William C; Sullivan, James; Vasudevan, Dharni; MacKay, Allison A

    2016-08-02

    Column chromatography was evaluated as a method to obtain organic cation sorption isotherms for environmental solids while using the peak skewness to identify the linear range of the sorption isotherm. Custom packed HPLC columns and standard batch sorption techniques were used to intercompare sorption isotherms and solid-water sorption coefficients (Kd) for four organic cations (benzylamine, 2,4-dichlorobenzylamine, phenyltrimethylammonium, oxytetracycline) with two aluminosilicate clay minerals and one soil. A comparison of Freundlich isotherm parameters revealed isotherm linearity or nonlinearity was not significantly different between column chromatography and traditional batch experiments. Importantly, skewness (a metric of eluting peak symmetry) analysis of eluting peaks can establish isotherm linearity, thereby enabling a less labor intensive means to generate the extensive data sets of linear Kd values required for the development of predictive sorption models. Our findings clearly show that column chromatography can reproduce sorption measures from conventional batch experiments with the benefit of lower labor-intensity, faster analysis times, and allow for consistent sorption measures across laboratories with distinct chromatography instrumentation.

  13. The employment of cellulose pressure columns for the chromatographic separation of radioactive nuclides

    International Nuclear Information System (INIS)

    Meier, H.; Zimmerhackl, E.; Unger, E.; Zeitler, G.; Albrecht, W.; Boesche, D.; Hecker, W.; Menge, P.

    1975-01-01

    A study was made of the separation properties of cellulose pressure columns operating at a slight over-pressure of around 1 atmosphere, with respect to the length of the column packing, the flow rate, and the load. The optimal separation stage heights of the columns are situated at H=0.16 mm. Since as a consequence of the favorable separation stage heights observed at column lengths of 3 to 7 cm, separation stage numbers of 200 to 400 are attained, and hence it is possible to attain separations within several minutes with flow rates of 1 ml/min. The choice of the mobile phase is made easier by the fact that paper chromatographic Rsub(f)-values can be transferred to the cellulose pressure column with the aid of a transfer function. (author)

  14. Preparation of metal-resistant immobilized sulfate reducing bacteria beads for acid mine drainage treatment.

    Science.gov (United States)

    Zhang, Mingliang; Wang, Haixia; Han, Xuemei

    2016-07-01

    Novel immobilized sulfate-reducing bacteria (SRB) beads were prepared for the treatment of synthetic acid mine drainage (AMD) containing high concentrations of Fe, Cu, Cd and Zn using up-flow anaerobic packed-bed bioreactor. The tolerance of immobilized SRB beads to heavy metals was significantly enhanced compared with that of suspended SRB. High removal efficiencies of sulfate (61-88%) and heavy metals (>99.9%) as well as slightly alkaline effluent pH (7.3-7.8) were achieved when the bioreactor was fed with acidic influent (pH 2.7) containing high concentrations of multiple metals (Fe 469 mg/L, Cu 88 mg/L, Cd 92 mg/L and Zn 128 mg/L), which showed that the bioreactor filled with immobilized SRB beads had tolerance to AMD containing high concentrations of heavy metals. Partially decomposed maize straw was a carbon source and stabilizing agent in the initial phase of bioreactor operation but later had to be supplemented by a soluble carbon source such as sodium lactate. The microbial community in the bioreactor was characterized by denaturing gradient gel electrophoresis (DGGE) and sequencing of partial 16S rDNA genes. Synergistic interaction between SRB (Desulfovibrio desulfuricans) and co-existing fermentative bacteria could be the key factor for the utilization of complex organic substrate (maize straw) as carbon and nutrients source for sulfate reduction. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Kinetics of plasma membrane electron transport in a pulmonary endothelial cell-column.

    Science.gov (United States)

    Olson, L E; Merker, M P; Bongard, R D; Brantmeier, B M; Audi, S H; Linehan, J H; Dawson, C A

    1998-01-01

    Thiazine dyes such as toluidine blue O (TBO) are reduced at the luminal endothelial surface. The purpose of this study was to determine the rate of this reaction in endothelial cells in culture. A multiple indicator dilution method was used to measure the reaction kinetics during transient passage of a TBO-containing bolus through a chromatographic column filled with bovine pulmonary arterial endothelial cells grown on microcarrier beads (cell-column). A bolus containing TBO and an inert extracellular reference indicator (FITC-Dextran) was injected upstream of the cell-column, and the indicator concentrations were measured downstream using on-line photodetection. The effects of column flow rate, PO2, and TBO concentration were studied. The fraction of TBO reduced upon passage through the cell-column decreased with increasing flow indicating that the reaction rate rather than TBO delivery controlled TBO reduction. The fraction of TBO reduced did not change with PO2 or dose in the ranges studied. TBO reduction was about 10 times that for steady state TBO sequestration by these cells which, along with the lack of a PO2 effect indicates that the rapid rate of reduction is not the rate-limiting step in steady state sequestration.

  16. Microstructural Study on Oxygen Permeated Arc Beads

    Directory of Open Access Journals (Sweden)

    Kuan-Heng Liu

    2015-01-01

    Full Text Available We simulated short circuit of loaded copper wire at ambient atmosphere and successfully identified various phases of the arc bead. A cuprous oxide flake was formed on the surface of the arc bead in the rapid solidification process, and there were two microstructural constituents, namely, Cu-κ eutectic structure and solutal dendrites. Due to the arc bead formed at atmosphere during the local equilibrium solidification process, the phase of arc bead has segregated to the cuprous oxide flake, Cu-κ eutectic, and Cu phase solutal dendrites, which are the fingerprints of the arc bead permeated by oxygen.

  17. In-bead screening

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to screening of one-bead-one-compound (OBOC) combinatorial libraries which is useful for the discovery of compounds displaying molecular interactions with a biological or a physicochemical system, such as substrates and inhibitors of enzymes and the like. The invention...... provides a method for screening a library of compounds for their interaction with a physico- chemical or biological system and a corresponding kit for performing the method of screening a one-bead-one-compound library of compounds....

  18. Influence of packing motives on charge Carrier mobility in perylene tetracarboxdiimide derivatives

    Energy Technology Data Exchange (ETDEWEB)

    May, Falk; Andrienko, Denis [Max-Planck Institute for Polymer Research, Mainz (Germany); Marcon, Valentina [Center of Smart Interfaces, Darmstadt (Germany)

    2010-07-01

    Discotic mesophases are known for their ability to self-assemble into columnar structures and can serve as semiconducting molecular wires. Charge carrier mobility along these wires strongly depends on molecular packing which is controlled by intermolecular interactions. In this work we compare the influence of side chains on the packing motives of perylene tetracarboxdiimide (PDI) derivatives. Two different (alkyl and glycol) side chains are considered. We first establish how the packing of side chains affects the molecular orientation within the columns using molecular dynamics. Then, using the high temperature non-adiabatic limit of Marcus theory for hopping rates and solving the rate equation for charge transport, we analyze the link between the secondary structure and charge carrier mobility. This analysis eventually provides a pathway to rational design of columnar assemblies of PDI derivatives with high charge mobilities.

  19. Pulse column hydrodynamics for liquid-liquid extraction with truncated-disc packing

    International Nuclear Information System (INIS)

    Bracou, H.; Hanssens, A.

    1993-01-01

    The experimental installation is composed of a stainless steel truncated disc packing with 25% of axial transparency, 25 mm of distance between the plates and 50 mm of diameter (DT 25/25/50 stainless steel). The phase system used during these tests is the hydrogenated tetra-propylene (HTP dispersed phase) /water (continuous phase) in continuous aqueous operating ''FAC'' method. The aim of this work is to gather the whole requisite data to the modelization stage based on the extrapolation of a mathematical tool, type population evaluation with a double object to supply the basis information useful for the model, and to establish an experimental data base for the model validation. 9 refs., 4 figs

  20. Towards Hypoxia-responsive Drug-eluting Embolization Beads.

    Science.gov (United States)

    Ashrafi, Koorosh; Heaysman, Clare L; Phillips, Gary J; Lloyd, Andrew W; Lewis, Andrew L

    2017-05-30

    Drug release from chemoembolization microspheres stimulated by the presence of a chemically reducing environment may provide benefits for targeting drug resistant and metastatic hypoxic tumours. A water-soluble disulfide-based bifunctional cross-linker bis(acryloyl)-(l)-cystine (BALC) was synthesised, characterised and incorporated into a modified poly(vinyl) alcohol (PVA) hydrogel beads at varying concentrations using reverse suspension polymerisation. The beads were characterised to confirm the amount of cross-linker within each formulation and its effects on the bead properties. Elemental and UV/visible spectroscopic analysis confirmed the incorporation of BALC within the beads and sizing studies showed that in the presence of a reducing agent, all bead formulations increased in mean diameter. The BALC beads could be loaded with doxorubicin hydrochloride and amounts in excess of 300mg of drug per mL of hydrated beads could be achieved but required conversion of the carboxylic acid groups of the BALC to their sodium carboxylate salt forms. Elution of doxorubicin from the beads demonstrated a controlled release via ionic exchange. Some formulations exhibited an increase in size and release of drug in the presence of a reducing agent, and therefore demonstrated the ability to respond to an in vitro reducing environment. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Self-organizing magnetic beads for biomedical applications

    International Nuclear Information System (INIS)

    Gusenbauer, Markus; Kovacs, Alexander; Reichel, Franz; Exl, Lukas; Bance, Simon; Özelt, Harald; Schrefl, Thomas

    2012-01-01

    In the field of biomedicine magnetic beads are used for drug delivery and to treat hyperthermia. Here we propose to use self-organized bead structures to isolate circulating tumor cells using lab-on-chip technologies. Typically blood flows past microposts functionalized with antibodies for circulating tumor cells. Creating these microposts with interacting magnetic beads makes it possible to tune the geometry in size, position and shape. We developed a simulation tool that combines micromagnetics and discrete particle dynamics, in order to design micropost arrays made of interacting beads. The simulation takes into account the viscous drag of the blood flow, magnetostatic interactions between the magnetic beads and gradient forces from external aligned magnets. We developed a particle–particle particle–mesh method for effective computation of the magnetic force and torque acting on the particles. - Highlights: ► We propose to use self-organized bead structures to isolate circulating tumor cells. ► Flexible ways are important to get a high probability of catching cancer cells. ► The beads make it possible to tune the geometry in size position and shape.

  2. Nasal packing with ventilated nasal packs; a comparison with traditional vaseline nasal pack

    International Nuclear Information System (INIS)

    Alam, J.; Siddiqui, M.W.; Abbas, A.; Sami, M.; Ayub, Z.

    2017-01-01

    To compare the benefits of ventilated nasal packing with traditional vaseline guaze nasal packing. Study Design: Randomized controlled trial. Place and Duration of Study: This study was conducted at CMH Multan, from Jun 2014 to Dec 2014. Material and Methods: In this study, sample size of 80 patients was calculated using WHO calculator. Patients were divided in two groups using lottery method endotracheal tube and piece of surgical glove filled with ribbon guaze was utilized for fabricated ventilated nasal pack and compared with traditional nasal packs. Nasal obstruction and sleep disturbance were studied at eight hours and twenty-four hours following surgery using visual analog scale. Results: Mean nasal obstruction with ventilated nasal pack was 45.62 +- 6.17 and with Vaseline nasal pack was 77.67 +- 4.85 which was statistically significant (p=0.001) in both the groups. Mean sleep disturbance in both the groups was 46.32 +- 5.23 and 68.75 +- 2.70 respectively which was statistically significant (p=0.001) in both the groups. Conclusion: Patients with ventilated nasal packs were found to have better tolerance to nasal packs due to less nasal obstruction and sleep disturbance

  3. Metal-Containing Polystyrene Beads as Standards for Mass Cytometry.

    Science.gov (United States)

    Abdelrahman, Ahmed I; Ornatsky, Olga; Bandura, Dmitry; Baranov, Vladimir; Kinach, Robert; Dai, Sheng; Thickett, Stuart C; Tanner, Scott; Winnik, Mitchell A

    2010-01-01

    We examine the suitability of metal-containing polystyrene beads for the calibration of a mass cytometer instrument, a single particle analyser based on an inductively coupled plasma ion source and a time of flight mass spectrometer. These metal-containing beads are also verified for their use as internal standards for this instrument. These beads were synthesized by multiple-stage dispersion polymerization with acrylic acid as a comonomer. Acrylic acid acts as a ligand to anchor the metal ions within the interior of the beads. Mass cytometry enabled the bead-by-bead measurement of the metal-content and determination of the metal-content distribution. Beads synthesized by dispersion polymerization that involved three stages were shown to have narrower bead-to-bead variation in their lanthanide content than beads synthesized by 2-stage dispersion polymerization. The beads exhibited insignificant release of their lanthanide content to aqueous solutions of different pHs over a period of six months. When mixed with KG1a or U937 cell lines, metal-containing polymer beads were shown not to affect the mass cytometry response to the metal content of element-tagged antibodies specifically attached to these cells.

  4. Glucose production for cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, S; Karube, I

    1977-04-16

    Glucose was produced from cellulose by passing a cellulose solution through a column of an immobilized cellulase which was prepared by coating an inorganic carrier such as macadam or stainless steel beads with collagen containing the cellulase. Thus, 4 mL of 5% cellulase T-AP (60,000 units/g) solution was dissolved in 100 g of 0.9% collagen solution and the solution mixed with 60 g of macadam (diam. = 0.5 to 1.5 mm) and stirred for 10 min. The treated beads were dried in air at 10/sup 0/ to yield an immobilized enzyme retaining 64% of its activity. Through a column (0.8 x 20 cm) packed with 3 g of the immobilized enzyme, 100 mL of 0.33% Avicel SF solution was circulated at 26.4 mL/min at 30/sup 0/ for 60 h. The Avicel SF conversion to glucose was 23%.

  5. Discharge flow of a granular media from a silo: effect of the packing fraction and of the hopper angle

    Science.gov (United States)

    Benyamine, Mebirika; Aussillous, Pascale; Dalloz-Dubrujeaud, Blanche

    2017-06-01

    Silos are widely used in the industry. While empirical predictions of the flow rate, based on scaling laws, have existed for more than a century (Hagen 1852, translated in [1] - Beverloo et al. [2]), recent advances have be made on the understanding of the control parameters of the flow. In particular, using continuous modeling together with a mu(I) granular rheology seem to be successful in predicting the flow rate for large numbers of beads at the aperture (Staron et al.[3], [4]). Moreover Janda et al.[5] have shown that the packing fraction at the outlet plays an important role when the number of beads at the apeture decreases. Based on these considerations, we have studied experimentally the discharge flow of a granular media from a rectangular silo. We have varied two main parameters: the angle of the hopper, and the bulk packing fraction of the granular material by using bidisperse mixtures. We propose a simple physical model to describe the effect of these parameters, considering a continuous granular media with a dilatancy law at the outlet. This model predicts well the dependance of the flow rate on the hopper angle as well as the dependance of the flow rate on the fine mass fraction of a bidisperse mixture.

  6. Core-Shell Columns in High-Performance Liquid Chromatography: Food Analysis Applications

    Science.gov (United States)

    Preti, Raffaella

    2016-01-01

    The increased separation efficiency provided by the new technology of column packed with core-shell particles in high-performance liquid chromatography (HPLC) has resulted in their widespread diffusion in several analytical fields: from pharmaceutical, biological, environmental, and toxicological. The present paper presents their most recent applications in food analysis. Their use has proved to be particularly advantageous for the determination of compounds at trace levels or when a large amount of samples must be analyzed fast using reliable and solvent-saving apparatus. The literature hereby described shows how the outstanding performances provided by core-shell particles column on a traditional HPLC instruments are comparable to those obtained with a costly UHPLC instrumentation, making this novel column a promising key tool in food analysis. PMID:27143972

  7. Humic colloid-borne migration of uranium in sand columns

    International Nuclear Information System (INIS)

    Artinger, R.; Rabung, T.; Kim, J.I.; Sachs, S.; Schmeide, K.; Heise, K.H.; Bernhard, G.; Nitsche, H.

    2002-09-01

    Column experiments were carried out to investigate the influence of humic colloids on subsurface uranium migration. The columns were packed with well-characterized aeolian quartz sand and equilibrated with groundwater rich in humic colloids (dissolved organic carbon (DOC): 30 mg dm -3 ). U migration was studied under an Ar/1% CO 2 gas atmosphere as a function of the migration time, which was controlled by the flow velocity or the column length. In addition, the contact time of U with groundwater prior to introduction into a column was varied. U(VI) was found to be the dominant oxidation state in the spiked groundwater. The breakthrough curves indicate that U was transported as a humic colloid-borne species with a velocity up to 5% faster than the mean groundwater flow. The fraction of humic colloid-borne species increases with increasing prior contact time and also with decreasing migration time. The migration behavior was attributed to a kinetically controlled association/dissociation of U onto and from humic colloids and also a subsequent sorption of U onto the sediment surface. The column experiments provide an insight into humic colloid-mediated U migration in subsurface aquifers

  8. Deuterium exchange reaction between hydrogen and water in a trickle-bed column packed with novel catalysts

    International Nuclear Information System (INIS)

    Ahn, D. H.; Baek, S. W.; Lee, H. S.; Kim, K. R.; Kang, H. S.; Lee, S. H.; Jeong, H. S.

    1998-01-01

    The activity of a novel catalyst (Pt/SDBC) for deuterium exchange reaction between water and hydrogen streams in a trickle bed was measured. The performance of the catalyst was compared with a commercial catalyst with same metal content. The catalytic activity for the bed of wet-proofed catalyst diluted with hydrophillic packing material also measured. The Pt/SDBC catalyst shows higher activity in the liquid phase reaction than the commercial catalyst as measured in the vapor phase reaction. The performance for 50% dilution of the Pt/SDBC catalyst bed with hydrophillic packing material is better than that of the 100% bed due to more liquid holdup and better water distribution

  9. Experimental Study on Pressure Drop and Flow Dispersion in Packed Bed of Natural Zeolite

    Directory of Open Access Journals (Sweden)

    Ruya Petric Marc

    2018-01-01

    Full Text Available The use of conventional correlation for pressure drop and dispersion coefficient calculation may result in inaccurate values for zeolite packed bed as the correlations are generally developed for regularly shaped and uniformly sized particles. To support the research on the application of modified natural zeolite as tar cracking catalyst, the research on the hydrodynamic behaviour of zeolite packed bed has been conducted. Experiments were carried out using a glass column with diameter of 37.8 mm. Natural zeolite with particle size of about 2.91 to 6.4 mm was applied as packing material in the column, and the bed height was varied at 9, 19 and 29 cm. Air was used as the fluid that flows through the bed and nitrogen was used as a tracer for residence time distribution determination. Air flow rates were in the range of 20 to 100 mL/s which correspond to the laminar-transitional flow regime. The pressure drops through the bed were in the range of 1.7 to 95.6 Pa, depending on the air flow rate and bed height. From these values, the parameters in the Ergun equation were estimated, taking into account the contribution by wall effect when the ratio of column to particle diameter is low. The viscous and inertial term constants in the Ergun equation calculated ranges from 179 to 199 and 1.41 to 1.47 respectively while the particle sphericity ranges from 0.56 to 0.59. The reactor Peclet number were determined to range from 5.2 to 5.5, which indicated significant deviation from a plug flow condition.

  10. Electrical Capacitance Volume Tomography for the Packed Bed Reactor ISS Flight Experiment

    Science.gov (United States)

    Marashdeh, Qussai; Motil, Brian; Wang, Aining; Liang-Shih, Fan

    2013-01-01

    Fixed packed bed reactors are compact, require minimum power and maintenance to operate, and are highly reliable. These features make this technology a highly desirable unit operation for long duration life support systems in space. NASA is developing an ISS experiment to address this technology with particular focus on water reclamation and air revitalization. Earlier research and development efforts funded by NASA have resulted in two hydrodynamic models which require validation with appropriate instrumentation in an extended microgravity environment. To validate these models, the instantaneous distribution of the gas and liquid phases must be measured.Electrical Capacitance Volume Tomography (ECVT) is a non-invasive imaging technology recently developed for multi-phase flow applications. It is based on distributing flexible capacitance plates on the peripheral of a flow column and collecting real-time measurements of inter-electrode capacitances. Capacitance measurements here are directly related to dielectric constant distribution, a physical property that is also related to material distribution in the imaging domain. Reconstruction algorithms are employed to map volume images of dielectric distribution in the imaging domain, which is in turn related to phase distribution. ECVT is suitable for imaging interacting materials of different dielectric constants, typical in multi-phase flow systems. ECVT is being used extensively for measuring flow variables in various gas-liquid and gas-solid flow systems. Recent application of ECVT include flows in risers and exit regions of circulating fluidized beds, gas-liquid and gas-solid bubble columns, trickle beds, and slurry bubble columns. ECVT is also used to validate flow models and CFD simulations. The technology is uniquely qualified for imaging phase concentrations in packed bed reactors for the ISS flight experiments as it exhibits favorable features of compact size, low profile sensors, high imaging speed, and

  11. Microfabricated Passive Magnetic Bead separators

    DEFF Research Database (Denmark)

    Hansen, Mikkel Fougt; Lund-Olesen, Torsten; Smistrup, Kristian

    2006-01-01

    The use and manipulation of functionalized magnetic beads for bioanalysis in lab-on-a-chip systems is receiving growing interest. We have developed microfluidic systems with integrated magnetic structures for the capture and release of magnetic beads. The systems are fabricated in silicon by deep...

  12. Mass transfer models analysis for the structured packings; Analisis de los modelos en transferencia de masa para los empaques estructurados

    Energy Technology Data Exchange (ETDEWEB)

    Suastegui R, A O

    1997-12-01

    The models that have been developing, to understand the mechanism of the mass transfer through the structured packings, present limitations for their application, existing then uncertainty in order to use them in the chemical industrial processes. In this study the main parameters used in the mass transfer are: the hydrodynamic of the bed of the column, the geometry of the bed, physical-chemical properties of the mixture and the flow regime of the operation between the flows liquid-gas. The sensibility of each one of these parameters generate an arduous work to develop right proposals and good interpretation of the phenomenon. With the purpose of showing the importance of these parameters mentioned in the mass transfer, this work is analyzed the process of absorption for the system water-air, using the models to the structured packings in packed columns. The models selected were developed by Bravo and collaborators in 1985 and 1992, in order to determine the parameters previous mentioned for the system water-air, using a structured packing built in the National Institute of Nuclear Research. In this work is showed the results of the models application and their discussion. (Author).

  13. Study and selection of structured packing material: metallic, polymeric or ceramic to operate a column of absorption polluting gases coming from brick kilns efficiently

    International Nuclear Information System (INIS)

    Salazar P, A.

    2012-01-01

    In this research three structured packing materials were characterized: a metallic, polymeric and ceramic. The study of the physical properties of structured packing materials, and their behavior within the absorption column allowed to suggest a gas-liquid contactor material with higher mechanical and chemical resistance, which is more efficient for the treatment of sour gases from brick kilns. To study the mechanical properties (hardness, tension and elastic modulus) were used procedures of the American Society for Testing Materials, as well as resistance to corrosion. The geometric characteristics, the density, the melting temperature and the weight were tested with procedures of the measuring equipment. The structure was evaluated by X-ray diffraction, morphology was observed by scanning electron microscopy coupled to a sound of dispersive energy of X-ray, to quantify elemental chemical composition. The interaction of gas-liquid contactors materials in presence of CO 2 , was evaluated in three absorption columns built of Pyrex glass, with a diameter of 0.1016 m, of 1.5 m in height, 0.0081m 2 cross-sectional area, packed with every kind of material: metallic, polymeric and ceramic, processing a gas flow of 20m 3 / h at 9% CO 2 , in air and a liquid flow to 30% of Mea 5 L/min. The results of the properties studied were by the metallic material: more density, higher roughness, the greater tensile strength, greater resistance to corrosion in the presence of an aqueous solution of monoethanolamine (Mea) to 30% by weight, improvement more efficient absorption of CO 2 , and higher modulus of elasticity. The polymeric material was characterized to have lower hardness, lower roughness, lower density, lower melting temperature, greater resistance to corrosion in the presence of 1 N H 2 SO 4 aqueous solution, and allowed an absorption efficiency of CO 2 , 2% lower than that presented by the material metallic. The ceramic material found to be the hardest of the three

  14. Analysis of an industrial process simulator column using third-generation computed tomography

    International Nuclear Information System (INIS)

    Kirita, Rodrigo; Carvalho, Diego Vergacas de Sousa; Mesquita, Carlos Henrique de; Vasquez, Pablo Antonio S.; Hamada, Margarida Mizue

    2011-01-01

    The CT methodology must be tested using a simulator column in the laboratory before applying it in the industrial plants. In this work, using the third-generation industrial computed tomography developed at the IPEN, a gas absorption column, used as a simulator column for industrial process was evaluated. It is a glass cylindrical tube of 90 mm diameter and 1400 mm height constituted the following parts: random packed column, liquid circuit (water), gas circuit and analysis was used as a simulator column. Gamma ray tomography experiments were carried out, using this simulator column empty and filled with water. In this work the scanner was setting for 90 views and 19 projections for each detector totalizing 11970 projections. The resulting images describe the presence of liquid or gas phases and are possible to evaluate the linear attenuation coefficients inside the column. In this case, linear attenuation coefficient for water was 0.0813 cm-1. It was established that the newly developed third-generation fan-beam arrangement gamma scanner unit has a good spatial resolution acceptable given the size of the column used in this study. (author)

  15. Mathematical Kinetic Modelling and Representing Design Equation for a Packed Photoreactor with Immobilised TiO2-P25 Nanoparticles on Glass Beads in the Removal of C.I. Acid Orange 7

    Directory of Open Access Journals (Sweden)

    Sheidaei Behnaz

    2015-06-01

    Full Text Available In this work, a design equation was presented for a batch-recirculated photoreactor composed of a packed bed reactor (PBR with immobilised TiO2-P25 nanoparticle thin films on glass beads, and a continuous-flow stirred tank (CFST. The photoreactor was studied in order to remove C.I. Acid Orange 7 (AO7, a monoazo anionic dye from textile industry, by means of UV/TiO2 process. The effect of different operational parameters such as the initial concentration of contaminant, the volume of solution in CFST, the volumetric flow rate of liquid, and the power of light source in the removal efficiency were examined. A rate equation for the removal of AO7 is obtained by mathematical kinetic modelling. The results of reaction kinetic analysis indicate the conformity of removal kinetics with Langmuir-Hinshelwood model (kL-H = 0.74 mg L-1 min-1, Kads = 0.081 mg-1 L. The represented design equation obtained from mathematical kinetic modelling can properly predict the removal rate constant of the contaminant under different operational conditions (R2 = 0.963. Thus the calculated and experimental results are in good agreement with each other.

  16. To Pack or Not to Pack? A Randomized Trial of Vaginal Packing After Vaginal Reconstructive Surgery.

    Science.gov (United States)

    Westermann, Lauren B; Crisp, Catrina C; Oakley, Susan H; Mazloomdoost, Donna; Kleeman, Steven D; Benbouajili, Janine M; Ghodsi, Vivian; Pauls, Rachel N

    2016-01-01

    Placement of vaginal packing after pelvic reconstructive surgery is common; however, little evidence exists to support the practice. Furthermore, patients have reported discomfort from the packs. We describe pain and satisfaction in women treated with and without vaginal packing. This institutional review board-approved randomized-controlled trial enrolled patients undergoing vaginal hysterectomy with prolapse repairs. The primary outcome was visual analog scales (VASs) for pain on postoperative day 1. Allocation to "packing" ("P") or "no-packing" ("NP") arms occurred intraoperatively at the end of surgery. Visual analog scales regarding pain and satisfaction were completed early on postoperative day 1 before packing removal. Visual analog scale scores for pain, satisfaction, and bother attributable to packing were recorded before discharge. All packing and perineal pads were weighed to calculate a "postoperative vaginal blood loss." Perioperative data were collected from the hospital record. Our sample size estimation required 74 subjects. Ninety-three women were enrolled. After exclusions, 77 were randomized (P, 37; NP, 40). No differences were found in surgical information, hemoglobin levels, or narcotic use between groups. However, "postoperative vaginal blood loss" was greater in packed subjects (P discharge (P, 35.0 vs NP, 40.0; P = 0.43] were not significantly different between treatment arms. Likewise, VAS scores for satisfaction before removal of packing (P, 81.0 vs NP, 90.0; P = 0.08] and before discharge (P, 90.0 vs NP, 90.5; P = 0.60] were not significantly different. Packed patients noted lower nursing verbal pain scores (P = 0.04) and used less ketorolac (P = 0.01). Bother from packing was low overall. Although there was no difference based on VAS, women receiving vaginal packing had lower nursing documented pain and used less ketorolac than packed women. Vaginal packing may provide benefit and can remain part of the surgical practice.

  17. The Beads of Translation: Using Beads to Translate mRNA into a Polypeptide Bracelet

    Science.gov (United States)

    Dunlap, Dacey; Patrick, Patricia

    2012-01-01

    During this activity, by making beaded bracelets that represent the steps of translation, students simulate the creation of an amino acid chain. They are given an mRNA sequence that they translate into a corresponding polypeptide chain (beads). This activity focuses on the events and sites of translation. The activity provides students with a…

  18. Methacrylate-bonded covalent-organic framework monolithic columns for high performance liquid chromatography.

    Science.gov (United States)

    Liu, Li-Hua; Yang, Cheng-Xiong; Yan, Xiu-Ping

    2017-01-06

    Covalent-organic frameworks (COFs) are a newfangled class of intriguing microporous materials. Considering their unique properties, COFs should be promising as packing materials for high performance liquid chromatography (HPLC). However, the irregular shape and sub-micrometer size of COFs synthesized via the traditional methods render the main obstacles for the application of COFs in HPLC. Herein, we report the preparation of methacrylate-bonded COF monolithic columns for HPLC to overcome the above obstacles. The prepared COF bonded monolithic columns not only show good homogeneity and permeability, but also give high column efficiency, good resolution and precision for HPLC separation of small molecules including polycyclic aromatic hydrocarbons, phenols, anilines, nonsteroidal anti-inflammatory drugs and benzothiophenes. Compared with the bare polymer monolithic column, the COF bonded monolithic columns show enhanced hydrophobic, π-π and hydrogen bond interactions in reverse phase HPLC. The results reveal the great potential of COF bonded monoliths for HPLC and COFs in separation sciences. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Continuous Packed Bed Reactor with Immobilized β-Galactosidase for Production of Galactooligosaccharides (GOS

    Directory of Open Access Journals (Sweden)

    Barbara Rodriguez-Colinas

    2016-11-01

    Full Text Available The β-galactosidase from Bacillus circulans was covalently attached to aldehyde-activated (glyoxal agarose beads and assayed for the continuous production of galactooligosaccharides (GOS in a packed-bed reactor (PBR. The immobilization was fast (1 h and the activity of the resulting biocatalyst was 97.4 U/g measured with o-nitrophenyl-β-d-galactopyranoside (ONPG. The biocatalyst showed excellent operational stability in 14 successive 20 min reaction cycles at 45 °C in a batch reactor. A continuous process for GOS synthesis was operated for 213 h at 0.2 mL/min and 45 °C using 100 g/L of lactose as a feed solution. The efficiency of the PBR slightly decreased with time; however, the maximum GOS concentration (24.2 g/L was obtained after 48 h of operation, which corresponded to 48.6% lactose conversion and thus to maximum transgalactosylation activity. HPAEC-PAD analysis showed that the two major GOS were the trisaccharide Gal-β(1→4-Gal-β(1→4-Glc and the tetrasaccharide Gal-β(1→4-Gal-β(1→4-Gal-β(1→4-Glc. The PBR was also assessed in the production of GOS from milk as a feed solution. The stability of the bioreactor was satisfactory during the first 8 h of operation; after that, a decrease in the flow rate was observed, probably due to partial clogging of the column. This work represents a step forward in the continuous production of GOS employing fixed-bed reactors with immobilized β-galactosidases.

  20. Bead Capture on Magnetic Sensors in a Microfluidic System

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Dalslet, Bjarke Thomas; Damsgaard, Christian Danvad

    2009-01-01

    The accumulation of magnetic beads by gravitational sedimentation and magnetic capture on a planar Hall-effect sensor integrated in a microfluidic channel is studied systematically as a function of the bead concentration, the fluid flow rate, and the sensor bias current. It is demonstrated...... that the sedimentation flux is proportional to the bead concentration and has a power law relation to the fluid flow rate. The mechanisms for the bead accumulation are investigated and it is found that gravitational sedimentation dominates the bead accumulation, whereas the stability of the sedimented beads against...

  1. Hydrodynamic chromatography of polystyrene microparticles in micropillar array columns.

    Science.gov (United States)

    Op de Beeck, Jeff; De Malsche, Wim; Vangelooven, Joris; Gardeniers, Han; Desmet, Gert

    2010-09-24

    We report on the possibility to perform HDC in micropillar array columns and the potential advantages of such a system. The HDC performance of a pillar array column with pillar diameter = 5 microm and an interpillar distance of 2.5 microm has been characterized using both a low MW tracer (FITC) and differently sized polystyrene bead samples (100, 200 and 500 nm). The reduced plate height curves that were obtained for the different investigated markers all overlapped very well, and attained a minimum value of about h(min)=0.3 (reduction based on the pillar diameter), corresponding to 1.6 microm in absolute value and giving good prospects for high efficiency separations. The obtained reduced retention time values were in fair agreement with that predicted by the Di Marzio and Guttman model for a flow between flat plates, using the minimal interpillar distance as characteristic interplate distance. Copyright 2010 Elsevier B.V. All rights reserved.

  2. DWPF GLASS BEADS AND GLASS FRIT TRANSPORT DEMONSTRATION

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, D; Bradley Pickenheim, B

    2008-11-24

    DWPF is considering replacing irregularly shaped glass frit with spherical glass beads in the Slurry Mix Evaporator (SME) process to decrease the yield stress of the melter feed (a non-Newtonian Bingham Plastic). Pilot-scale testing was conducted on spherical glass beads and glass frit to determine how well the glass beads would transfer when compared to the glass frit. Process Engineering Development designed and constructed the test apparatus to aid in the understanding and impacts that spherical glass beads may have on the existing DWPF Frit Transfer System. Testing was conducted to determine if the lines would plug with the glass beads and the glass frit slurry and what is required to unplug the lines. The flow loop consisted of vertical and horizontal runs of clear PVC piping, similar in geometry to the existing system. Two different batches of glass slurry were tested: a batch of 50 wt% spherical glass beads and a batch of 50 wt% glass frit in process water. No chemicals such as formic acid was used in slurry, only water and glass formers. The glass beads used for this testing were commercially available borosilicate glass of mesh size -100+200. The glass frit was Frit 418 obtained from DWPF and is nominally -45+200 mesh. The spherical glass beads did not have a negative impact on the frit transfer system. The transferring of the spherical glass beads was much easier than the glass frit. It was difficult to create a plug with glass bead slurry in the pilot transfer system. When a small plug occurred from setting overnight with the spherical glass beads, the plug was easy to displace using only the pump. In the case of creating a man made plug in a vertical line, by filling the line with spherical glass beads and allowing the slurry to settle for days, the plug was easy to remove by using flush water. The glass frit proved to be much more difficult to transfer when compared to the spherical glass beads. The glass frit impacted the transfer system to the point

  3. DWPF GLASS BEADS AND GLASS FRIT TRANSPORT DEMONSTRATION

    International Nuclear Information System (INIS)

    Adamson, D.; Pickenheim, Bradley

    2008-01-01

    DWPF is considering replacing irregularly shaped glass frit with spherical glass beads in the Slurry Mix Evaporator (SME) process to decrease the yield stress of the melter feed (a non-Newtonian Bingham Plastic). Pilot-scale testing was conducted on spherical glass beads and glass frit to determine how well the glass beads would transfer when compared to the glass frit. Process Engineering Development designed and constructed the test apparatus to aid in the understanding and impacts that spherical glass beads may have on the existing DWPF Frit Transfer System. Testing was conducted to determine if the lines would plug with the glass beads and the glass frit slurry and what is required to unplug the lines. The flow loop consisted of vertical and horizontal runs of clear PVC piping, similar in geometry to the existing system. Two different batches of glass slurry were tested: a batch of 50 wt% spherical glass beads and a batch of 50 wt% glass frit in process water. No chemicals such as formic acid was used in slurry, only water and glass formers. The glass beads used for this testing were commercially available borosilicate glass of mesh size -100+200. The glass frit was Frit 418 obtained from DWPF and is nominally -45+200 mesh. The spherical glass beads did not have a negative impact on the frit transfer system. The transferring of the spherical glass beads was much easier than the glass frit. It was difficult to create a plug with glass bead slurry in the pilot transfer system. When a small plug occurred from setting overnight with the spherical glass beads, the plug was easy to displace using only the pump. In the case of creating a man made plug in a vertical line, by filling the line with spherical glass beads and allowing the slurry to settle for days, the plug was easy to remove by using flush water. The glass frit proved to be much more difficult to transfer when compared to the spherical glass beads. The glass frit impacted the transfer system to the point

  4. Accurate measurements of infinite dilution activity coefficients using gas chromatography with static-wall-coated open-tubular columns.

    Science.gov (United States)

    Xu, Qianqian; Su, Baogen; Luo, Xinyi; Xing, Huabin; Bao, Zongbi; Yang, Qiwei; Yang, Yiwen; Ren, Qilong

    2012-11-06

    Wall-coated open-tubular (WCOT) columns provide higher column efficiency and lower solute interfacial adsorption effect than packed columns. However, previous efforts used to measure the infinite dilution activity coefficient (γ(∞)) via a chromatographic technique have used packed columns, because the low carrier gas flow rate (U) and the small stationary phase amount (n(2)) in WCOT columns raise large errors. By rationally revising the γ(∞)-calculation equation for static-wall-coated open-tubular column, we observed that U and n(2) are not necessarily needed and the resulting error could be reduced, and WCOT column gas chromatography subsequently became a superior method for the accurate γ(∞) determination. In this study, we validate our revised γ(∞)-calculation equation by measuring γ(∞) in an ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate system, in which 55 organic compounds covering a wide range of functional groups were used as probe solutes and their γ(∞) values in the ionic liquid were determined at 40.0, 50.0, and 60.0 °C. Experimental error analysis shows that our revised equation remarkably reduces the error compared to the common γ(∞)-calculation equation. Our data is consistent with previously reported values obtained via other techniques, which further proves the credibility of our revised equation. The accurately determined γ(∞) values can be directly used to calculate the partial molar excess enthalpy, selectivity, and capacity, which will benefit for the rapid screening of solvents (especially ionic liquids) in separation approaches.

  5. A spin column-free approach to sodium hydroxide-based glycan permethylation.

    Science.gov (United States)

    Hu, Yueming; Borges, Chad R

    2017-07-24

    Glycan permethylation was introduced as a tool to facilitate the study of glycans in 1903. Since that time, permethylation procedures have been continually modified to improve permethylation efficiency and qualitative applicability. Typically, however, either laborious preparation steps or cumbersome and uneconomical spin columns have been needed to obtain decent permethylation yields on small glycan samples. Here we describe a spin column-free (SCF) glycan permethylation procedure that is applicable to both O- and N-linked glycans and can be employed upstream to intact glycan analysis by MALDI-MS, ESI-MS, or glycan linkage analysis by GC-MS. The SCF procedure involves neutralization of NaOH beads by acidified phosphate buffer, which eliminates the risk of glycan oxidative degradation and avoids the use of spin columns. Optimization of the new permethylation procedure provided high permethylation efficiency for both hexose (>98%) and HexNAc (>99%) residues-yields which were comparable to (or better than) those of some widely-used spin column-based procedures. A light vs. heavy labelling approach was employed to compare intact glycan yields from a popular spin-column based approach to the SCF approach. Recovery of intact N-glycans was significantly better with the SCF procedure (p 0.75; p < 0.01). In summary, the SCF permethylation procedure expedites and economizes both intact glycan analysis and linkage analysis of glycans from whole biospecimens.

  6. A spin column-free approach to sodium hydroxide-based glycan permethylation†

    Science.gov (United States)

    Hu, Yueming; Borges, Chad R.

    2018-01-01

    Glycan permethylation was introduced as a tool to facilitate the study of glycans in 1903. Since that time, permethylation procedures have been continually modified to improve permethylation efficiency and qualitative applicability. Typically, however, either laborious preparation steps or cumbersome and uneconomical spin columns have been needed to obtain decent permethylation yields on small glycan samples. Here we describe a spin column-free (SCF) glycan permethylation procedure that is applicable to both O- and N-linked glycans and can be employed upstream to intact glycan analysis by MALDI-MS, ESI-MS, or glycan linkage analysis by GC-MS. The SCF procedure involves neutralization of NaOH beads by acidified phosphate buffer, which eliminates the risk of glycan oxidative degradation and avoids the use of spin columns. Optimization of the new permethylation procedure provided high permethylation efficiency for both hexose (>98%) and HexNAc (>99%) residues—yields which were comparable to (or better than) those of some widely-used spin column-based procedures. A light vs. heavy labelling approach was employed to compare intact glycan yields from a popular spin-column based approach to the SCF approach. Recovery of intact N-glycans was significantly better with the SCF procedure (p 0.75; p < 0.01). In summary, the SCF permethylation procedure expedites and economizes both intact glycan analysis and linkage analysis of glycans from whole biospecimens. PMID:28635997

  7. Mini-column assay for rapid detection of malachite green in fish.

    Science.gov (United States)

    Shalaby, Ali R; Emam, Wafaa H; Anwar, Mervat M

    2017-07-01

    A simple, rapid and economical mini-column method for detecting malachite green (MG) residue in fish was developed. The method used a column with 2mm ID that was tightly packed with silica gel followed by alumina. Detection of MG was performed by viewing the developed mini-column at visible light by naked eye; where MG was seen as compact green band at the confluence of the silica gel layer with alumina layer. The limit of detection of the assay was 2ng which conform the minimum required performance limit (MRPL). Evaluation utility of the method indicated that all blank and spiked samples at levels below MRPL were assessed as accepted. The intensity of the green band increased whenever MG level in the extract increased; indicated that suggested mini-column technique could be used for semi-quantitative determination of MG in fish samples. The method can be used to select the questionable samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Energy efficient bead milling of microalgae: Effect of bead size on disintegration and release of proteins and carbohydrates.

    Science.gov (United States)

    Postma, P R; Suarez-Garcia, E; Safi, C; Yonathan, K; Olivieri, G; Barbosa, M J; Wijffels, R H; Eppink, M H M

    2017-01-01

    The disintegration of three industry relevant algae (Chlorella vulgaris, Neochloris oleoabundans and Tetraselmis suecica) was studied in a lab scale bead mill at different bead sizes (0.3-1mm). Cell disintegration, proteins and carbohydrates released into the water phase followed a first order kinetics. The process is selective towards proteins over carbohydrates during early stages of milling. In general, smaller beads led to higher kinetic rates, with a minimum specific energy consumption of ⩽0.47kWhkg DW -1 for 0.3mm beads. After analysis of the stress parameters (stress number and stress intensity), it appears that optimal disintegration and energy usage for all strains occurs in the 0.3-0.4mm range. During the course of bead milling, the native structure of the marker protein Rubisco was retained, confirming the mildness of the disruption process. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Sorption of nitrate onto amine-crosslinked wheat straw: characteristics, column sorption and desorption properties.

    Science.gov (United States)

    Xing, Xu; Gao, Bao-Yu; Zhong, Qian-Qian; Yue, Qin-Yan; Li, Qian

    2011-02-15

    The nitrate removal process was evaluated using a fixed-bed column packed with amine-crosslinked wheat straw (AC-WS). Column sorption and desorption characteristics of nitrate were studied extensively. Solid-state (13)C NMR and zeta potential analysis validated the existence of crosslinked amine groups in AC-WS. Raman shift of the nitrate peaks suggested the electrostatic attraction between the adsorbed ions and positively charged amine sites. The column sorption capacity (q(ed)) of the AC-WS for nitrate was 87.27 mg g(-1) in comparison with the raw WS of 0.57 mg g(-1). Nitrate sorption in column was affected by bed height, influent nitrate concentration, flow rate and pH, and of all these, influent pH demonstrated an essential effect on the performance of the column. In addition, desorption and dynamic elution tests were repeated for several cycles, with high desorption rate and slight losses in its initial column sorption capacity. Copyright © 2010 Elsevier B.V. All rights reserved.

  10. Modelling and dynamics of an air separation rectification column as part of an IGCC power plant

    Energy Technology Data Exchange (ETDEWEB)

    Seliger, B.; Hanke-Rauschenbach, R.; Hannemann, F.; Sundmacher, K. [Otto Von Guericke University, Magdeburg (Germany)

    2006-04-15

    An Integrated Gasification Combined Cycle plant (IGCC) opens the well-proven and highly efficient combined cycle process to fossil fuels, like coal or heavy refinery residues. Such a plant thereby possesses a novel linkage of typical energy engineering related units, e.g. a gas turbine and typical process engineering parts, which in the present case is an air separation plant. Different responses from the connected components can cause undesired mass flow fluctuations within the system especially during changing load demands. The cryogenic rectification column, as the core of the air separation plant, strongly affects the system's transient behaviour. The upper part of such a heat-integrated double column, a packed column with structured packing, has therefore been more closely investigated in the present paper. For this purpose, a dynamic model of such a column has been developed which is also able to describe the pressure dynamics supposedly responsible for these mass flow fluctuations. The transient behaviour of the uncontrolled column is analysed and discussed with special regard to pressure dynamics. The column pressure responds to disturbances on two different time scales. The short-term response, which is in the range of 100-200 s, is governed by the transient behaviour of the fluid dynamics and is discussed in detail. The long-term response is dominated by the nonlinear dynamics of the concentration profiles. The time constant of this response depends strongly on the direction and intensity of the disturbance and takes from 10,000 up to several 100,000 s.

  11. HEAT TRANSFER ANALYSIS FOR FIXED CST AND RF COLUMNS

    International Nuclear Information System (INIS)

    Lee, S

    2007-01-01

    In support of a small column ion exchange (SCIX) process for the Savannah River Site waste processing program, transient and steady state two-dimensional heat transfer models have been constructed for columns loaded with cesium-saturated crystalline silicotitanate (CST) or spherical Resorcinol-Formaldehyde (RF) beads and 6 molar sodium tank waste supernate. Radiolytic decay of sorbed cesium results in heat generation within the columns. The models consider conductive heat transfer only with no convective cooling and no process flow within the columns (assumed column geometry: 27.375 in ID with a 6.625 in OD center-line cooling pipe). Heat transfer at the column walls was assumed to occur by natural convection cooling with 35 C air. A number of modeling calculations were performed using this computational heat transfer approach. Minimal additional calculations were also conducted to predict temperature increases expected for salt solution processed through columns of various heights at the slowest expected operational flow rate of 5 gpm. Results for the bounding model with no process flow and no active cooling indicate that the time required to reach the boiling point of ∼130 C for a CST-salt solution mixture containing 257 Ci/liter of Cs-137 heat source (maximum expected loading for SCIX applications) at 35 C initial temperature is about 6 days. Modeling results for a column actively cooled with external wall jackets and the internal coolant pipe (inlet coolant water temperature: 25 C) indicate that the CST column can be maintained non-boiling under these conditions indefinitely. The results also show that the maximum temperature of an RF-salt solution column containing 133 Ci/liter of Cs-137 (maximum expected loading) will never reach boiling under any conditions (maximum predicted temperature without cooling: 88 C). The results indicate that a 6-in cooling pipe at the center of the column provides the most effective cooling mechanism for reducing the maximum

  12. TiO2 beads and TiO2-chitosan beads for urease immobilization

    International Nuclear Information System (INIS)

    Ispirli Doğaç, Yasemin; Deveci, İlyas; Teke, Mustafa; Mercimek, Bedrettin

    2014-01-01

    The aim of the present study is to synthesize TiO 2 beads for urease immobilization. Two different strategies were used to immobilize the urease on TiO 2 beads. In the first method (A), urease enzyme was immobilized onto TiO 2 beads by adsorption and then crosslinking. In the second method (B), TiO 2 beads were coated with chitosan-urease mixture. To determine optimum conditions of immobilization, different parameters were investigated. The parameters of optimization were initial enzyme concentration (0.5; 1; 1.5; 2 mg/ml), alginate concentration (1; 2; 3%), glutaraldehyde concentration (1; 2; 3% v/v) and chitosan concentration (2; 3; 4 mg/ml). The optimum enzyme concentrations were determined as 1.5 mg/ml for A and 1.0 mg/ml for B. The other optimum conditions were found 2.0% (w/v) for alginate concentration (both A and B); 3.0 mg/ml for chitosan concentration (B) and 2.0% (v/v) for glutaraldehyde concentration (A). The optimum temperature (20-60 °C), optimum pH (3.0-10.0), kinetic parameters, thermal stability (4–70 °C), pH stability (4.0-9.0), operational stability (0-230 min) and reusability (20 times) were investigated for characterization. The optimum temperatures were 30 °C (A), 40 °C (B) and 35 °C (soluble). The temperature profiles of the immobilized ureases were spread over a large area. The optimum pH values for the soluble urease and immobilized urease prepared by using methods (A) and (B) were found to be 7.5, 7.0, 7.0, respectively. The thermal stabilities of immobilized enzyme sets were studied and they maintained 50% activity at 65 °C. However, at this temperature free urease protected only 15% activity. - Highlights: • TiO 2 and TiO 2 -chitosan beads for urease immobilization have been prepared and characterized. • The beads used in this work are good matrices for the immobilization of urease. • The immobilized urease was shown to have good properties and stabilities (pH and thermal stability, operational stability). • The 50

  13. ADVANCED DIAGNOSTIC TECHNIQUES FOR THREE-PHASE SLURRY BUBBLE COLUMN REACTORS (SBCR)

    Energy Technology Data Exchange (ETDEWEB)

    M.H. Al-Dahhan; M.P. Dudukovic; L.S. Fan

    2001-07-25

    This report summarizes the accomplishment made during the second year of this cooperative research effort between Washington University, Ohio State University and Air Products and Chemicals. The technical difficulties that were encountered in implementing Computer Automated Radioactive Particle Tracking (CARPT) in high pressure SBCR have been successfully resolved. New strategies for data acquisition and calibration procedure have been implemented. These have been performed as a part of other projects supported by Industrial Consortium and DOE via contract DE-2295PC95051 which are executed in parallel with this grant. CARPT and Computed Tomography (CT) experiments have been performed using air-water-glass beads in 6 inch high pressure stainless steel slurry bubble column reactor at selected conditions. Data processing of this work is in progress. The overall gas holdup and the hydrodynamic parameters are measured by Laser Doppler Anemometry (LDA) in 2 inch slurry bubble column using Norpar 15 that mimic at room temperature the Fischer Tropsch wax at FT reaction conditions of high pressure and temperature. To improve the design and scale-up of bubble column, new correlations have been developed to predict the radial gas holdup and the time averaged axial liquid recirculation velocity profiles in bubble columns.

  14. Deposition behavior of polystyrene latex particles on solid surfaces during migration through an artificial fracture in a granite rock sample

    International Nuclear Information System (INIS)

    Chinju, Hirofumi; Tanaka, Satoru; Kuno, Yoshio

    2001-01-01

    The deposition behavior of colloids during transport through heterogeneous media was observed by conducting column experiments to study migration of polystyrene latex particles (diameter=309 nm) through columns packed with artificially fractured granite rock (length=300 and 150 mm). The experiments were conducted under conditions of different ionic strengths and flow rates. The results were similar to those for colloid deposition in columns packed with glass beads reported previously; the colloid breakthrough curves showed three stages, characterized by different rates of change in the concentration of effluent. Colloid deposition on the fracture surfaces was described by considering strong and weak deposition sites. Scanning Electron Microscopy (SEM) observations indicated the existence of strong and weak sites on the fracture surfaces regardless of mineral composition. The observations also showed that the strong deposition sites tended to exist on surface irregularities such as cracks or protrusions. The degree of colloid deposition increased with increasing ionic strength and decreasing flow rate. The dependencies on ionic strength and flow rate agreed qualitatively with the DLVO theory and the previous experimental results, respectively. (author)

  15. Phenol Biodegradation by Free and Immobilized Candida tropicalis RETL-Crl on Coconut Husk and Loofah Packed in Biofilter Column

    International Nuclear Information System (INIS)

    Shazryenna, D; Ruzanna, R; Jessica, M S; Piakong, M T

    2015-01-01

    Phenols and its derivatives are environmental pollutant commonly found in many industrial effluents. It is toxic in nature and causes various health hazards. However, they are poorly removed in conventional biological processes due to their toxicity. Immobilization of microbial cells has received increasing interest in the field of waste treatment and creates opportunities in a wide range of sectors including environmental pollution control. Live cells of phenol-degrading yeast, Candida tropicalis RETL-Crl, were immobilized on coconut husk and loofah by adsorption. The immobolized particle was packed into biofilter column which used for continuous treatment of a phenol with initial phenol concentration of 3mM. Both loofah and coconut husk have similar phenol biodegradation rate of 0.0188 gL −1 h −1 within 15 hours to achieve a phenol removal efficiency of 100%. However loofah have lower biomass concentration of 4.22 gL −1 compared to biomass concentration on coconut husk, 4.39 gL −1 . Coconut husk contain higher biomass concentration which makes it better support material than loofah. Fibrous matrices such as loofah and coconut husk provide adequate supporting surfaces for cell adsorption, due to their high specific surface area. Therefore, coconut husk and loofah being an agricultural waste product have the potential to be used as low-cost adsorbent and support matrix for microbial culture immobilization for the removal of organic pollutant from wastewater. (paper)

  16. Dry-column chromatography of uranium. Application to chemical analysis of monazite and phosphate rock for uranium

    Energy Technology Data Exchange (ETDEWEB)

    Oguma, K; Kuroda, R [Chiba Univ. (Japan). Faculty of Engineering

    1981-08-01

    A dry-column chromatographic technique has been applied to the separation of uranium from complicated matrices. It has been demonstrated that operating parameters of thin-layer chromatography on silanized silica gel in isopropyl ether - tetrahydrofuran - nitric acid (65:20:3) can be transferred to this technique. Chromatograms are thus easily developed on dry packed column with the solvent system of the type used in the TLC. Uranium is eluted off the column and determined with Arsenazo III spectrophotometrically. The technique is successfully applied to the determination of uranium in monazite and phosphate rock samples with good precision and accuracy.

  17. Single-column ion chromatography with determination of hydrazoic acid produced in spent nuclear fuel reprocessing

    International Nuclear Information System (INIS)

    Ma Guilan; Tan Shuping

    2006-01-01

    The reaction of hydrazine and its derivative with ammonium metavanadate may produce hydrazoic acid (HN 3 ). A single-column ion chromatography is used for the determination of HN 3 after neutralizing the rest acid in the sample with sodium hydroxide. Chromatography separation of HN 3 is carried out on a 25 cm x 0.46 cm (inside diameter) stainless steel column packed with Vydac IC302 ion Chromatography packing. The eluent is 1 mmol/L o-phthalic acid, and the ion is detected by conductivity detector. The detection limit in the presence chromatography is 5 μg/mL, the linear range is from 5 to 201 μg/mL, the linear correlation coefficient is 0.9994, respectively. The analysis accuracy is 2% for standard sample, and the detection limit is 51 μg/mL for HN 3 in the real sample. (authors)

  18. Pre-treatment of pyridine wastewater by new cathodic-anodic-electrolysis packing.

    Science.gov (United States)

    Jin, Yang; Yue, Qinyan; Yang, Kunlun; Wu, Suqing; Li, Shengjie; Gao, Baoyu; Gao, Yuan

    2018-01-01

    A novel cathodic-anodic-electrolysis packing (CAEP) used in the treatment of pyridine wastewater was researched, which mainly consisted of 4,4'-diamino-2,2'-disulfonic acid (DSD acid) industrial iron sludge. The physical properties and morphology of the packing were studied. The CAEP was used in a column reactor during the pretreatment of pyridine wastewater. The influence of pH, hydraulic retention time (HRT), the air-liquid ratio (A/L) and the initial concentration of pyridine were investigated by measuring the removal of total organic carbon (TOC) and pyridine. The characterization results showed that the bulk density, grain density, water absorption percentage and specific surface area were 921kg/m 3 , 1086kg/m 3 , 25% and 29.89m 2 /g, respectively; the removal of TOC and pyridine could reach 50% and 58% at the optimal experimental conditions (pH=3, HRT=8hr, A/L=2). Notably, the surface of the packing was renewed constantly during the running of the filter, and the handling capacity was stable after running for three months. Copyright © 2017. Published by Elsevier B.V.

  19. Calcium Pectinate Beads Formation: Shape and Size Analysis

    Directory of Open Access Journals (Sweden)

    Boon-Beng Lee

    2014-04-01

    Full Text Available The aim of this study was to investigate the inter-relationship between process variables and the size and shape of pectin solution droplets upon detachment from a dripping tip as well as Ca-pectinate beads formed after gelation via image analysis. The sphericity factor (SF of the droplets was generally smaller than 0.05. There was no specific trend between the SF of the droplets and the pectin concentration or the dripping tip radius. The SF the beads formed from high-concentration pectin solutions and a small dripping tip was smaller than 0.05. The results show that the Reynolds number and Ohnesorge number of the droplets fall within the operating region for forming spherical beads in the shape diagram, with the exception to the lower boundary. The lower boundary of the operating region has to be revised to Oh = 2.3. This is because the critical viscosity for Ca-pectinate bead formation is higher than that of Ca-alginate beads. On the other hand, the radius of the droplets and beads increased as the dripping tip radius increased. The bead radius can easily be predicted by Tate’s law equation.

  20. HPMA and HEMA copolymer bead interactions with eukaryotic cells

    Directory of Open Access Journals (Sweden)

    Cristina D. Vianna-Soares

    2004-09-01

    Full Text Available Two different hydrophilic acrylate beads were prepared via aqueous suspension polymerization. Beads produced of a hydroxypropyl methacrylate (HPMA and ethyleneglycol methacrylate (EDMA copolymer were obtained using a polyvinyl alcohol suspending medium. Copolymers of 2hydroxyethyl methacrylate (HEMA, methyl methacrylate (MMA and ethyleneglycol methacrylate (EDMA beads were obtained using magnesium hydroxide as the suspending agent. Following characterization by scanning electron microscopy (SEM, nitrogen sorption analysis (NSA and mercury intrusion porosimetry (MIP, the beads were cultured with monkey fibroblasts (COS7 to evaluate their ability to support cell growth, attachment and adhesion. Cell growth behavior onto small HPMA/EDMA copolymer beads and large HEMA/MMA/EDMA copolymer beads is evaluated regarding their hidrophilicity/hidrophobicity and surface roughness.

  1. Immobilized laccase mediated dye decolorization and transformation pathway of azo dye acid red 27

    OpenAIRE

    Chhabra, Meenu; Mishra, Saroj; Sreekrishnan, Trichur Ramaswamy

    2015-01-01

    Background Laccases have good potential as bioremediating agents and can be used continuously in the immobilized form like many other enzymes. Methods In the present study, laccase from Cyathus bulleri was immobilized by entrapment in Poly Vinyl Alcohol (PVA) beads cross-linked with either nitrate or boric acid. Immobilized laccase was used for dye decolorization in both batch and continuous mode employing a packed bed column. The products of degradation of dye Acid Red 27 were identified by ...

  2. Enhanced desalination performance of membrane capacitive deionization cells by packing the flow chamber with granular activated carbon.

    Science.gov (United States)

    Bian, Yanhong; Yang, Xufei; Liang, Peng; Jiang, Yong; Zhang, Changyong; Huang, Xia

    2015-11-15

    A new design of membrane capacitive deionization (MCDI) cell was constructed by packing the cell's flow chamber with granular activated carbon (GAC). The GAC packed-MCDI (GAC-MCDI) delivered higher (1.2-2.5 times) desalination rates than the regular MCDI at all test NaCl concentrations (∼ 100-1000 mg/L). The greatest performance enhancement by packed GAC was observed when treating saline water with an initial NaCl concentration of 100 mg/L. Several different GAC materials were tested and they all exhibited similar enhancement effects. Comparatively, packing the MCDI's flow chamber with glass beads (GB; non-conductive) and graphite granules (GG; conductive but with lower specific surface area than GAC) resulted in inferior desalination performance. Electrochemical impedance spectroscopy (EIS) analysis showed that the GAC-MCDI had considerably smaller internal resistance than the regular MCDI (∼ 19.2 ± 1.2 Ω versus ∼ 1222 ± 15 Ω at 100 mg/L NaCl). The packed GAC also decreased the ionic resistance across the flow chamber (∼ 1.49 ± 0.05 Ω versus ∼ 1130 ± 12 Ω at 100 mg/L NaCl). The electric double layer (EDL) formed on the GAC surface was considered to store salt ions during electrosorption, and facilitate the ion transport in the flow chamber because of the higher ion conductivity in the EDLs than in the bulk solution, thereby enhancing the MCDI's desalination rate. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Controlled torque on superparamagnetic beads for functional biosensors

    NARCIS (Netherlands)

    Janssen, X.J.A.; Schellekens, A.J.; van Ommering, K.; IJzendoorn, van L.J.; Prins, M.W.J.

    2009-01-01

    We demonstrate that a rotating magnetic field can be used to apply a controlled torque on superparamagnetic beads which leads to a tunable bead rotation frequency in fluid. Smooth rotation is obtained for field rotation frequencies many orders of magnitude higher than the bead rotation frequency. A

  4. Determination of glycated albumin using boronic acid-derived agarose beads on paper-based devices.

    Science.gov (United States)

    Ko, Euna; Tran, Van-Khue; Geng, Yanfang; Kim, Min Ki; Jin, Ga Hyun; Son, Seong Eun; Hur, Won; Seong, Gi Hun

    2018-01-01

    Self-monitoring of glycated albumin (GA), a useful glycemic marker, is an established method for preventing diabetes complications. Here, the paper-based lateral flow assay devices were developed for the sensitive detection of GA and the total human serum albumin (tHSA) in self-monitoring diabetes patients. Boronic acid-derived agarose beads were packed into a hole on a lateral flow channel. These well-coordinated agarose beads were used to capture GA through specific cis-diol interactions and to enhance the colorimetric signals by concentrating the target molecules. The devices exhibited large dynamic ranges (from 10  μ g/ml to 10 mg/ml for GA and from 10 mg/ml to 50 mg/ml for tHSA) and low detection limits (7.1  μ g/ml for GA and 4.7 mg/ml for tHSA), which cover the range of GA concentration in healthy plasma, which is 0.21-1.65 mg/ml (0.6%-3%). In determining the unknown GA concentrations in two commercial human plasma samples, the relative percentage difference between the values found by a standard ELISA kit and those found by our developed devices was 2.62% and 8.80%, which are within an acceptable range. The measurements of GA and tHSA were completed within 20 min for the total sample-to-answer diagnosis, fulfilling the demand for rapid analysis. Furthermore, the recovery values ranged from 99.4% to 110% in device accuracy tests. These results indicate that the developed paper-based device with boronic acid-derived agarose beads is a promising platform for GA and tHSA detection as applied to self-monitoring systems.

  5. Micro-bead injection spectroscopy for label-free automated determination of immunoglobulin G in human serum.

    Science.gov (United States)

    Ramos, Inês I; Magalhães, Luís M; Barreiros, Luisa; Reis, Salette; Lima, José L F C; Segundo, Marcela A

    2018-01-01

    Immunoglobulin G (IgG) represents the major fraction of antibodies in healthy adult human serum, and deviations from physiological levels are a generic marker of disease corresponding to different pathologies. Therefore, screening methods for IgG evaluation are a valuable aid to diagnostics. The present work proposes a rapid, automatic, and miniaturized method based on UV-vis micro-bead injection spectroscopy (μ-BIS) for the real-time determination of human serum IgG with label-free detection. Relying on attachment of IgG in rec-protein G immobilized in Sepharose 4B, a bioaffinity column is automatically assembled, where IgG is selectively retained and determined by on-column optical density measurement. A "dilution-and-shoot" approach (50 to 200 times) was implemented without further sample treatment because interferences were flushed out of the column upon sample loading, with minimization of carryover and cross-contamination by automatically discarding the sorbent (0.2 mg) after each determination. No interference from human serum albumin at 60 mg mL -1 in undiluted sample was found. The method allowed IgG determination in the range 100-300 μg mL -1 (corresponding to 5.0-60 mg mL -1 in undiluted samples), with a detection limit of 33 μg mL -1 (1.7 mg mL -1 for samples, dilution factor of 50). RSD values were time-to-result decreased from several hours to times, showing the potential of the proposed approach as a point-of-care method. Graphical abstract Micro-Bead Injection Spectroscopy method for real time, automated and label-free determination of total serum human Immunoglobulin G (IgG). The method was designed for Lab-on-Valve (LOV) platforms using a miniaturised protein G bioaffinity separative approach. IgG are separated from serum matrix components upon quantification with low non-specific binding in less than 5 min.

  6. Bead magnetorelaxometry with an on-chip magnetoresistive sensor

    DEFF Research Database (Denmark)

    Dalslet, Bjarke Thomas; Damsgaard, Christian Danvad; Donolato, Marco

    2011-01-01

    Magnetorelaxometry measurements on suspensions of magnetic beads are demonstrated using a planar Hall effect sensor chip embedded in a microfluidic system. The alternating magnetic field used for magnetizing the beads is provided by the sensor bias current and the complex magnetic susceptibility...... spectra are recorded as the 2nd harmonic of the sensor response. The complex magnetic susceptibility signal appears when a magnetic bead suspension is injected, it scales with the bead concentration, and it follows the Cole-Cole expression for Brownian relaxation. The complex magnetic susceptibility...... signal resembles that from conventional magnetorelaxometry done on the same samples apart from an offset in Brownian relaxation frequency. The time dependence of the signal can be rationalized as originating from sedimented beads....

  7. Entrapment of laurel lipase in chitosan hydrogel beads.

    Science.gov (United States)

    Yagar, Hulya; Balkan, Ugur

    2017-08-01

    Laurel seed lipase was entrapped within chitosan beads with ionotropic gelatin method using tripolyphosphate (TPP) as multivalent covalent counter ion. Immobilization yield was 78%. First, optimum immobilization conditions were determined, and morphology of chitosan beads was characterized by scanning electron microscopy. Optimum pH and temperature were evaluated as 6.0 and 40 °C, respectively. The immobilized beads saved about 55% of its activities at 60° while saved about 32% at 70 °C for 30 min. V max /K m values were determined as 31.75 and 2.87 using olive oil as substrate for immobilized beads and free enzyme, respectively. Immobilized beads showed the activities during 30 days at +4 °C.

  8. Bead-bead interaction parameters in dissipative particle dynamics: Relation to bead-size, solubility parameter, and surface tension

    Science.gov (United States)

    Maiti, Amitesh; McGrother, Simon

    2004-01-01

    Dissipative particle dynamics (DPD) is a mesoscale modeling method for simulating equilibrium and dynamical properties of polymers in solution. The basic idea has been around for several decades in the form of bead-spring models. A few years ago, Groot and Warren [J. Chem. Phys. 107, 4423 (1997)] established an important link between DPD and the Flory-Huggins χ-parameter theory for polymer solutions. We revisit the Groot-Warren theory and investigate the DPD interaction parameters as a function of bead size. In particular, we show a consistent scheme of computing the interfacial tension in a segregated binary mixture. Results for three systems chosen for illustration are in excellent agreement with experimental results. This opens the door for determining DPD interactions using interfacial tension as a fitting parameter.

  9. Three-bead steering microswimmers

    Science.gov (United States)

    Rizvi, Mohd Suhail; Farutin, Alexander; Misbah, Chaouqi

    2018-02-01

    The self-propelled microswimmers have recently attracted considerable attention as model systems for biological cell migration as well as artificial micromachines. A simple and well-studied microswimmer model consists of three identical spherical beads joined by two springs in a linear fashion with active oscillatory forces being applied on the beads to generate self-propulsion. We have extended this linear microswimmer configuration to a triangular geometry where the three beads are connected by three identical springs in an equilateral triangular manner. The active forces acting on each spring can lead to autonomous steering motion; i.e., allowing the swimmer to move along arbitrary paths. We explore the microswimmer dynamics analytically and pinpoint its rich character depending on the nature of the active forces. The microswimmers can translate along a straight trajectory, rotate at a fixed location, as well as perform a simultaneous translation and rotation resulting in complex curved trajectories. The sinusoidal active forces on the three springs of the microswimmer contain naturally four operating parameters which are more than required for the steering motion. We identify the minimal operating parameters which are essential for the motion of the microswimmer along any given arbitrary trajectory. Therefore, along with providing insights into the mechanics of the complex motion of the natural and artificial microswimmers, the triangular three-bead microswimmer can be utilized as a model for targeted drug delivery systems and autonomous underwater vehicles where intricate trajectories are involved.

  10. Safeguards Analytical Laboratory evaluation program. Part 1. Resin bead mass spectrometry. Part 2. Results of a resin bead field experiment-Tastex-J

    International Nuclear Information System (INIS)

    Walker, R.L.; Smith, D.H.; Carter, J.A.; Musick, W.R.; Donohue, D.L.; Deron, S.; Asakura, Y.; Kagami, K.; Irinouchi, S.; Masui, J.

    1981-01-01

    The first part of this report covers background of resin bead spectrometry and the new batch resin bead method. In the original technique, about ten anion resin beads in the nitrate form were exposed to the diluted sample solution. The solution was adjusted to be a 8 M HNO 3 and to have about 1 μg U per bead. Up to 48 hours of static contact between beads and solution was required for adsorption of 1 to 3 ng Pu and U per bead to be achieved. Under these conditions, contamination was a problem at reprocessing facilities. The new batch techniques reduces the risk of contamination by handling one hundred times more U in the final diluted sample which is exposed to a proportionately larger number of beads. Moreover, it only requires ten minutes adsorption time to provide about 1000 purified samples for mass spectrometry. The amounts of Pu and U adsorbed versus time were determined and results are tabulated. The second part of this report briefly summarizes results of resin bead field tests completed at the Power Reactor and Nuclear Fuel Development Corporation (PNC) reprocessing plant in Tokai-mura, Japan. Both methods, the original small-sample resin bead and the batch technique, were investigated on spent fuel solutions. Beads were prepared at PNC and distributed to IAEA and ORNL along with dried residues for conventional mass spectrometric analysis at IAEA. Parallel measurements were made at PNC using their normal measuring routines. The U and Pu measurements of all resin and those of PNC are in excellent agreement for the batch method. Discrepancies were noted in the U measurements by the original method

  11. TiO₂ beads and TiO₂-chitosan beads for urease immobilization.

    Science.gov (United States)

    Ispirli Doğaç, Yasemin; Deveci, Ilyas; Teke, Mustafa; Mercimek, Bedrettin

    2014-09-01

    The aim of the present study is to synthesize TiO2 beads for urease immobilization. Two different strategies were used to immobilize the urease on TiO2 beads. In the first method (A), urease enzyme was immobilized onto TiO2 beads by adsorption and then crosslinking. In the second method (B), TiO2 beads were coated with chitosan-urease mixture. To determine optimum conditions of immobilization, different parameters were investigated. The parameters of optimization were initial enzyme concentration (0.5; 1; 1.5; 2mg/ml), alginate concentration (1; 2; 3%), glutaraldehyde concentration (1; 2; 3% v/v) and chitosan concentration (2; 3; 4 mg/ml). The optimum enzyme concentrations were determined as 1.5mg/ml for A and 1.0mg/ml for B. The other optimum conditions were found 2.0% (w/v) for alginate concentration (both A and B); 3.0mg/ml for chitosan concentration (B) and 2.0% (v/v) for glutaraldehyde concentration (A). The optimum temperature (20-60°C), optimum pH (3.0-10.0), kinetic parameters, thermal stability (4-70°C), pH stability (4.0-9.0), operational stability (0-230 min) and reusability (20 times) were investigated for characterization. The optimum temperatures were 30°C (A), 40°C (B) and 35°C (soluble). The temperature profiles of the immobilized ureases were spread over a large area. The optimum pH values for the soluble urease and immobilized urease prepared by using methods (A) and (B) were found to be 7.5, 7.0, 7.0, respectively. The thermal stabilities of immobilized enzyme sets were studied and they maintained 50% activity at 65°C. However, at this temperature free urease protected only 15% activity. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Improved Peak Capacity for Capillary Electrophoretic Separations of Enzyme Inhibitors with Activity-Based Detection Using Magnetic Bead Microreactors

    Science.gov (United States)

    Yan, Xiaoyan; Gilman, S. Douglass

    2010-01-01

    A technique for separating and detecting enzyme inhibitors was developed using capillary electrophoresis with an enzyme microreactor. The on-column enzyme microreactor was constructed using NdFeB magnet(s) to immobilize alkaline phosphatase-coated superparamagnetic beads (2.8 μm diameter) inside a capillary before the detection window. Enzyme inhibition assays were performed by injecting a plug of inhibitor into a capillary filled with the substrate, AttoPhos. Product generated in the enzyme microreactor was detected by laser-induced fluorescence. Inhibitor zones electrophoresed through the capillary, passed through the enzyme microreactor, and were observed as negative peaks due to decreased product formation. The goal of this study was to improve peak capacities for inhibitor separations relative to previous work, which combined continuous engagement electrophoretically mediated microanalysis (EMMA) and transient engagement EMMA to study enzyme inhibition. The effects of electric field strength, bead injection time and inhibitor concentrations on peak capacity and peak width were investigated. Peak capacities were increased to ≥20 under optimal conditions of electric field strength and bead injection time for inhibition assays with arsenate and theophylline. Five reversible inhibitors of alkaline phosphatase (theophylline, vanadate, arsenate, L-tryptophan and tungstate) were separated and detected to demonstrate the ability of this technique to analyze complex inhibitor mixtures. PMID:20024913

  13. Tunable bead-on-string microstructures fabricated by mechano-electrospinning

    International Nuclear Information System (INIS)

    Bu Ningbin; Huang Yongan; Deng Huixu; Yin Zhouping

    2012-01-01

    In this paper, bead-on-string microstructures are fabricated by the mechano-electrospinning (MES) process in a continuously tunable manner. The thin jet is pulled onto the substrate by the stable electric field force and tunable mechanical drawing force, and then the bead-on-string structures are generated by means of the force exerted on the jet, which changes from capillary force and resisting viscosity force to friction force at the contact point in the horizontal direction. In a stable bead-on-string formation process, one cycle can be divided into three stages from the point of view of the jet behaviour: being anchored, being stretched, and skipping. The bead size and the bead gap are continuously tunable through the MES process. The fabrication mechanisms of the bead-on-string microstructure are uncovered through theoretical analysis and experimental characterization. When a critical velocity is achieved, the jet directly falls on the substrate without accumulation since the mechanical drawing force in the horizontal direction overtakes the capillary force, which leads the bead-on-string microstructures to a continuous fibre line. It is a flexible and highly controllable method to fabricate bead-on-string microstructures.

  14. A Controlled Drug-Delivery Experiment Using Alginate Beads

    Science.gov (United States)

    Farrell, Stephanie; Vernengo, Jennifer

    2012-01-01

    This paper describes a simple, cost-effective experiment which introduces students to drug delivery and modeling using alginate beads. Students produce calcium alginate beads loaded with drug and measure the rate of release from the beads for systems having different stir rates, geometries, extents of cross-linking, and drug molecular weight.…

  15. Mass transfer between a fluid and an immersed object in liquid–solid packed and fluidized beds

    Directory of Open Access Journals (Sweden)

    NEVENKA BOSKOVIC-VRAGOLOVIC

    2005-11-01

    Full Text Available Themass transfer coefficient between fluid and an immersed sphere in liquid packed and fluidized beds of inert spherical particles have been studied experimentally using a column 40 mm in diameter. The mass transfer data were obtained by studying the transfer of benzoic acid from the immersed sphere to flowing water using the dissolution method. In all runs, the mass transfer rates were determined in the presence of inert glass particles 0.50-2.98 mm in diameter. The influence of different parameters, such as: liquid velocity, particles size and bed voidage, on the mass transfer in packed and fluidized beds is presented. The obtained experimental data for mass transfer in the packed and particulate fluidized bed were correlated by a single correlation, thus confirming the similarity between the two systems.

  16. The Dynamic Behavior of Water Flowing Through Packed Bed of Different Particle Shapes and Sizes

    Directory of Open Access Journals (Sweden)

    Haneen Ahmed Jasim

    2017-12-01

    Full Text Available An experimental study was conducted on pressure drop of water flow through vertical cylindrical packed beds in turbulent region and the influence of the operating parameters on its behavior. The bed packing was made of spherical and non-spherical particles (spheres, Rasching rings and intalox saddle with aspect ratio range 3.46 D/dp 8.486 obtaining bed porosities 0.396 0.84 and Reynolds number 1217 21758. The system is consisted of 5 cm inside diameter Perspex column, 50 cm long; distilled water was pumped through the bed with flow rate 875, 1000, 1125, 1250,1375 and 1500 l/h and inlet water temperature 20, 30, 40 and 50 ˚C. The packed bed system was monitored by using LabVIEW program, were the results have been obtained from Data Acquisition Adaptor (DAQ.

  17. Blood Compatibility of Sulfonated Cladophora Nanocellulose Beads

    Directory of Open Access Journals (Sweden)

    Igor Rocha

    2018-03-01

    Full Text Available Sulfonated cellulose beads were prepared by oxidation of Cladophora nanocellulose to 2,3-dialdehyde cellulose followed by sulfonation using bisulfite. The physicochemical properties of the sulfonated beads, i.e., high surface area, high degree of oxidation, spherical shape, and the possibility of tailoring the porosity, make them interesting candidates for the development of immunosorbent platforms, including their application in extracorporeal blood treatments. A desired property for materials used in such applications is blood compatibility; therefore in the present work, we investigate the hemocompatibility of the sulfonated cellulose beads using an in vitro whole blood model. Complement system activation (C3a and sC5b-9 levels, coagulation activation (thrombin-antithrombin (TAT levels and hemolysis were evaluated after whole blood contact with the sulfonated beads and the results were compared with the values obtained with the unmodified Cladophora nanocellulose. Results showed that neither of the cellulosic materials presented hemolytic activity. A marked decrease in TAT levels was observed after blood contact with the sulfonated beads, compared with Cladophora nanocellulose. However, the chemical modification did not promote an improvement in Cladophora nanocellulose hemocompatibility in terms of complement system activation. Even though the sulfonated beads presented a significant reduction in pro-coagulant activity compared with the unmodified material, further modification strategies need to be investigated to control the complement activation by the cellulosic materials.

  18. Blood Compatibility of Sulfonated Cladophora Nanocellulose Beads.

    Science.gov (United States)

    Rocha, Igor; Lindh, Jonas; Hong, Jaan; Strømme, Maria; Mihranyan, Albert; Ferraz, Natalia

    2018-03-07

    Sulfonated cellulose beads were prepared by oxidation of Cladophora nanocellulose to 2,3-dialdehyde cellulose followed by sulfonation using bisulfite. The physicochemical properties of the sulfonated beads, i.e., high surface area, high degree of oxidation, spherical shape, and the possibility of tailoring the porosity, make them interesting candidates for the development of immunosorbent platforms, including their application in extracorporeal blood treatments. A desired property for materials used in such applications is blood compatibility; therefore in the present work, we investigate the hemocompatibility of the sulfonated cellulose beads using an in vitro whole blood model. Complement system activation (C3a and sC5b-9 levels), coagulation activation (thrombin-antithrombin (TAT) levels) and hemolysis were evaluated after whole blood contact with the sulfonated beads and the results were compared with the values obtained with the unmodified Cladophora nanocellulose. Results showed that neither of the cellulosic materials presented hemolytic activity. A marked decrease in TAT levels was observed after blood contact with the sulfonated beads, compared with Cladophora nanocellulose. However, the chemical modification did not promote an improvement in Cladophora nanocellulose hemocompatibility in terms of complement system activation. Even though the sulfonated beads presented a significant reduction in pro-coagulant activity compared with the unmodified material, further modification strategies need to be investigated to control the complement activation by the cellulosic materials.

  19. Coated Aerogel Beads

    Science.gov (United States)

    Littman, Howard (Inventor); Plawsky, Joel L. (Inventor); Paccione, John D. (Inventor)

    2014-01-01

    Methods and apparatus for coating particulate material are provided. The apparatus includes a vessel having a top and a bottom, a vertically extending conduit having an inlet in the vessel and an outlet outside of the vessel, a first fluid inlet in the bottom of the vessel for introducing a transfer fluid, a second fluid inlet in the bottom of the vessel for introducing a coating fluid, and a fluid outlet from the vessel. The method includes steps of agitating a material, contacting the material with a coating material, and drying the coating material to produce a coated material. The invention may be adapted to coat aerogel beads, among other materials. A coated aerogel bead and an aerogel-based insulation material are also disclosed.

  20. Procedure for preparation of a Ausup(195m) containing liquid, procedure for the execution of a radiodiagnostic examination, and a radioisotope generator for generating a Ausup(195m) containing liquid

    International Nuclear Information System (INIS)

    1980-01-01

    A procedure is described for the preparation of an Ausup(195m) containing fluid by adsorbing the parent isotope Hgsup(195m) onto an adsorption material and then eluting the radioactive daughter isotope Ausup(195m). The packing materials for the chromatographic column are silica gel, porous and massive glass beads. The adsorption materials for Hg 195 are hydrated manganese dioxide, silver, and zinc, cadmium, silver or zirconium sulfides. The procedure for depositing these materials in the packing material is outlined and the most suitable eluting fluid for each adsorption material is presented. The procedure has applications in the execution of a radiodiagnostic examination using an Ausup(195m) labelled fluid. (C.F.)

  1. Graphene Oxide Conjugated Magnetic Beads for RNA Extraction.

    Science.gov (United States)

    Pham, Xuan-Hung; Baek, Ahruem; Kim, Tae Han; Lee, Sang Hun; Rho, Won-Yeop; Chung, Woo-Jae; Kim, Dong-Eun; Jun, Bong-Hyun

    2017-08-04

    A magnetic material that consists of silica-coated magnetic beads conjugated with graphene oxide (GO) was successfully prepared for facile ribonucleic acid (RNA) extraction. When the GO-modified magnetic beads were applied to separate the RNA from the lysed cell, the cellular RNAs were readily adsorbed to and readily desorbed from the surface of the GO-modified magnetic beads by urea. The amount of RNA extracted by the GO-modified magnetic beads was ≈170 % as much as those of the control extracted by a conventional phenol-based chaotropic solution. These results demonstrate that the facile method of RNA separation by using GO-modified magnetic beads as an adsorbent is an efficient and simple way to purify intact cellular RNAs and/or microRNA from cell lysates. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Long-term operational studies of lab-scale pumice-woodchip packed stormwater biofilters.

    Science.gov (United States)

    Cheng, Jing; Yuan, Qingke; Kim, Youngchul

    2017-06-13

    The performance of three pumice-woodchip packed stormwater biofilter (PWSWBF) systems with three packing volume ratios of pumice to woodchip (1:2, 1:1 and 2:1) were compared. The results show that the PWSWBF system packed with a lower percentage of woodchip attained a higher removal efficiency of TCOD, TN, NH 4 -N and TP, whereas all three systems completely removed nitrate. The highest removal efficiencies for TCOD, TN, NH 4 -N, NO 3 -N and TP were 95%, 70%, 86%, 100% and 100%, respectively. In the biofilter with a lower percentage of woodchip, the pollutants that get removed through aerobic biological processes were removed more significantly, which is attributed to less oxygen depletion via woodchip decomposition, which is common under wet conditions. Nitrate was significantly removed via denitrification in all three systems, indicating that the woodchip that occupied one-third of the main media was sufficient for denitrification, and also that the oxygen condition inside the column was proper for denitrification to proceed. A smaller amount of woodchip as the packing material also mitigated the adverse effect of the release of organics from the media during the initial period. In addition, the system showed very good buffering capacity, in that the outflow pH was constant within the optimal range for microorganism growth.

  3. Ecohydraulics of Strings and Beads in Bedrock Rivers

    Science.gov (United States)

    Wohl, E.

    2016-12-01

    Twenty years ago, Jack Stanford and others described rivers in bedrock canyons as resembling beads on a string when viewed in planform. The beads are relatively wide, low gradient river segments with floodplains, whereas the strings are the intervening steep, narrow river segments with minimal floodplain development. This pattern of longitudinal variations in channel and valley morphology along bedrock canyon rivers is very common, from small channels to major rivers such as the Colorado. Basic understanding of river ecosystems, as well as limited studies, indicates that the beads are more retentive and biologically productive. Although both strings and beads can provide habitat for diverse organisms, strings are more likely to serve as migration corridors, whereas beads provide spawning and nursery habitat, facilitate lateral (channel-floodplain) and vertical (channel-hyporheic) exchanges and associated habitat diversity, and retain dissolved and particulate organic matter. Recognition of the different characteristics and functions of strings and beads can be used to identify their spatial distribution along a river or within a river network and the hydraulically driven processes that sustain channel form, water quality, and biota within strings and beads. Diverse modeling approaches can then be used to quantify the fluxes of water and sediment needed to maintain these hydraulically driven processes. This conceptual framework is illustrated using examples from mountain streams in the Southern Rockies and canyon rivers in the southwestern United States.

  4. Study on the etched carnelian beads unearthed in China

    Institute of Scientific and Technical Information of China (English)

    Deyun Zhao

    2014-01-01

    Etched carnelian beads originated in the Indus Civilization;this kind of ornaments and its manufacturing techniques were spread to the whole Eurasia Continent.The etched carnelian beads unearthed in China can be classified into four types,the comparisons of which to their foreign counterparts may reveal their different sources and diffusion routes.The etched carnelian beads and their glass imitations unearthed in China had influences to the making of the glass "eye beads" in

  5. Determining the selectivity of divalent metal cations for the carboxyl group of alginate hydrogel beads during competitive sorption.

    Science.gov (United States)

    An, Byungryul; Lee, Healim; Lee, Soonjae; Lee, Sang-Hyup; Choi, Jae-Woo

    2015-11-15

    To investigate the competitive sorption of divalent metal ions such as Ca(2+), Cu(2+), Ni(2+), and Pb(2+) on alginate hydrogel beads, batch and column tests were conducted. The concentration of carboxyl group was found to be limited in the preparation of spherical hydrogel beads. From kinetic test results, 80% of sorption was observed within 4h, and equilibrium was attained in 48 h. According to the comparison of the total uptake and release, divalent metal ions were found to stoichiometrically interact with the carboxyl group in the alginate polymer chain. From the Langmuir equation, the maximum capacities of Pb(2+), Cu(2+), and Ni(2+) were calculated to be 1.1, 0.48, and 0.13 mmol/g, respectively. The separation factor (α) values for αPb/Cu, αPb/Ni, and αCu/Ni were 14.0, 98.9, and 7.1, respectively. The sorption capacity of Pb(2+) was not affected by the solution pH; however, the sorption capacities of Cu(2+) and Ni(2+) decreased with increasing solution pH, caused by competition with hydrogen. According to the result from the fixed column test, Pb(2+) exhibited the highest affinity, followed by Cu(2+) and Ni(2+), which is in exact agreement with those of kinetic and isotherm tests. The sorbent could be regenerated using 4% HCl, and the regenerated sorbent exhibited 90% capacity upto 9 cycles. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Inhibitive Effect of antibiotic-loaded beads to cure chronic osteomyelitis in developing country : Hand-made vs commercial beads

    NARCIS (Netherlands)

    Rasyid, Hcrmawan N.; Van Horn, Jim R.; Van der Mei, Henny C.; Soegijoko, Sooegijardjo; Busscher, Henk J.; Neut, Danielle; Ibrahim, F; Osman, NAA; Usman, J; Kadri, NA

    2007-01-01

    Local antibiotic-loaded beads have been approved for standard treatment of orthopaedic pathogens, especially chronic osteomyelitis. Septopal (R), the only commercial local antibiotic bead available on the market, is expensive and contains only gentamicin. This study aimed to compare the in vitro

  7. Evaluation of polymeric materials packed in fixed bed column for oil water remediation; Avaliacao de materiais polimericos empacotados em colunas de leito fixo para a remediacao de aguas oleosas

    Energy Technology Data Exchange (ETDEWEB)

    Queiros, Yure G.C.; Barros, Cintia Chagas; Oliveira, Roberta S.; Marques, Luiz R.S.; Cunha, Luciana; Lucas, Elizabete F. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Macromoleculas Eloisa Mano], e-mail: yuregomes@ima.ufrj.br, e-mail: elucas@ima.ufrj.br

    2007-07-01

    Polymeric resins are being tried as an alternative material for treating oily waters from the petroleum industry, which have already been treated by conventional methods. The objective of this work has been to evaluate the purification degree of synthetic oily waters when treated in fixed bed columns packed with polymeric resins made up of hydrophilic and lipophilic moieties. The analysis used for characterizing the total grease and oil content (TOG) was fluorimetry. Starting oily waters of average TOG 50 ppm were prepared. Data obtained from eluted waters did not outweigh 10% of the TOG values of starting solutions in some blends of resins with a pretty good mechanical stability under the increase of pressure. Organoclay material showed a good retention performance, but has presented a mechanical instability too, compromising its use for larger amounts of wastewater. (author)

  8. Temperature-based on-column solute focusing in capillary liquid chromatography reduces peak broadening from pre-column dispersion and volume overload when used alone or with solvent-based focusing.

    Science.gov (United States)

    Groskreutz, Stephen R; Horner, Anthony R; Weber, Stephen G

    2015-07-31

    On-column focusing is essential for satisfactory performance using capillary scale columns. On-column focusing results from generating transient conditions at the head of the column that lead to high solute retention. Solvent-based on-column focusing is a well-known approach to achieve this. Temperature-assisted on-column focusing (TASF) can also be effective. TASF improves focusing by cooling a short segment of the column inlet to a temperature that is lower than the column temperature during the injection and then rapidly heating the focusing segment to the match the column temperature. A troublesome feature of an earlier implementation of TASF was the need to leave the capillary column unpacked in that portion of the column inside the fitting connecting it to the injection valve. We have overcome that problem in this work by packing the head of the column with solid silica spheres. In addition, technical improvements to the TASF instrumentation include: selection of a more powerful thermo-electric cooler to create faster temperature changes and electronic control for easy incorporation into conventional capillary instruments. Used in conjunction with solvent-based focusing and with isocratic elution, volumes of paraben samples (esters of p-hydroxybenzoic acid) up to 4.5-times the column liquid volume can be injected without significant bandspreading due to volume overload. Interestingly, the shapes of the peaks from the lowest volume injections that we can make, 30nL, are improved when using TASF. TASF is very effective at reducing the detrimental effects of pre-column dispersion using isocratic elution. Finally, we show that TASF can be used to focus the neuropeptide galanin in a sample solvent with elution strength stronger than the mobile phase. Here, the stronger solvent is necessitated by the need to prevent peptide adsorption prior to and during analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Configurational Statistics of Magnetic Bead Detection with Magnetoresistive Sensors

    DEFF Research Database (Denmark)

    Henriksen, Anders Dahl; Ley, Mikkel Wennemoes Hvitfeld; Flyvbjerg, Henrik

    2015-01-01

    Magnetic biosensors detect magnetic beads that, mediated by a target, have bound to a functionalized area. This area is often larger than the area of the sensor. Both the sign and magnitude of the average magnetic field experienced by the sensor from a magnetic bead depends on the location...... of the bead relative to the sensor. Consequently, the signal from multiple beads also depends on their locations. Thus, a given coverage of the functionalized area with magnetic beads does not result in a given detector response, except on the average, over many realizations of the same coverage. We present...... a systematic theoretical analysis of how this location-dependence affects the sensor response. The analysis is done for beads magnetized by a homogeneous in-plane magnetic field. We determine the expected value and standard deviation of the sensor response for a given coverage, as well as the accuracy...

  10. Hydrodynamic Torques and Rotations of Superparamagnetic Bead Dimers

    Science.gov (United States)

    Pease, Christopher; Etheridge, J.; Wijesinghe, H. S.; Pierce, C. J.; Prikockis, M. V.; Sooryakumar, R.

    Chains of micro-magnetic particles are often rotated with external magnetic fields for many lab-on-a-chip technologies such as transporting beads or mixing fluids. These applications benefit from faster responses of the actuated particles. In a rotating magnetic field, the magnetization of superparamagnetic beads, created from embedded magnetic nano-particles within a polymer matrix, is largely characterized by induced dipoles mip along the direction of the field. In addition there is often a weak dipole mop that orients out-of-phase with the external rotating field. On a two-bead dimer, the simplest chain of beads, mop contributes a torque Γm in addition to the torque from mip. For dimers with beads unbound to each other, mop rotates individual beads which generate an additional hydrodynamic torque on the dimer. Whereas, mop directly torques bound dimers. Our results show that Γm significantly alters the average frequency-dependent dimer rotation rate for both bound and unbound monomers and, when mop exceeds a critical value, increases the maximum dimer rotation frequency. Models that include magnetic and hydrodynamics torques provide good agreement with the experimental findings over a range of field frequencies.

  11. Capillary trap column with strong cation-exchange monolith for automated shotgun proteome analysis.

    Science.gov (United States)

    Wang, Fangjun; Dong, Jing; Jiang, Xiaogang; Ye, Mingliang; Zou, Hanfa

    2007-09-01

    A 150 microm internal diameter capillary monolithic column with a strong cation-exchange stationary phase was prepared by direct in situ polymerization of ethylene glycol methacrylate phosphate and bisacrylamide in a trinary porogenic solvent consisting dimethylsulfoxide, dodecanol, and N,N'-dimethylformamide. This phosphate monolithic column exhibits higher dynamic binding capacity, faster kinetic adsorption of peptides, and more than 10 times higher permeability than the column packed with commercially available strong cation-exchange particles. It was applied as a trap column in a nanoflow liquid chromatography-tandem mass spectrometry system for automated sample injection and online multidimensional separation. It was observed that the sample could be loaded at a flow rate as high as 40 microL/min with a back pressure of approximately 1300 psi and without compromising the separation efficiency. Because of its good orthogonality to the reversed phase separation mechanism, the phosphate monolithic trap column was coupled with a reversed-phase column for online multidimensional separation of 19 microg of the tryptic digest of yeast proteins. A total of 1522 distinct proteins were identified from 5608 unique peptides (total of 54,780 peptides) at the false positive rate only 0.46%.

  12. Core-Shell Columns in High-Performance Liquid Chromatography: Food Analysis Applications

    OpenAIRE

    Preti, Raffaella

    2016-01-01

    The increased separation efficiency provided by the new technology of column packed with core-shell particles in high-performance liquid chromatography (HPLC) has resulted in their widespread diffusion in several analytical fields: from pharmaceutical, biological, environmental, and toxicological. The present paper presents their most recent applications in food analysis. Their use has proved to be particularly advantageous for the determination of compounds at trace levels or when a large am...

  13. Continuous D-tagatose production by immobilized thermostable L-arabinose isomerase in a packed-bed bioreactor.

    Science.gov (United States)

    Ryu, Se-Ah; Kim, Chang Sup; Kim, Hye-Jung; Baek, Dae Heoun; Oh, Deok-Kun

    2003-01-01

    D-Tagatose was continuously produced using thermostable L-arabinose isomerase immobilized in alginate with D-galactose solution in a packed-bed bioreactor. Bead size, L/D (length/diameter) of reactor, dilution rate, total loaded enzyme amount, and substrate concentration were found to be optimal at 0.8 mm, 520/7 mm, 0.375 h(-1), 5.65 units, and 300 g/L, respectively. Under these conditions, the bioreactor produced about 145 g/L tagatose with an average productivity of 54 g tagatose/L x h and an average conversion yield of 48% (w/w). Operational stability of the immobilized enzyme was demonstrated, with a tagatose production half-life of 24 days.

  14. Hemifield columns co-opt ocular dominance column structure in human achiasma.

    Science.gov (United States)

    Olman, Cheryl A; Bao, Pinglei; Engel, Stephen A; Grant, Andrea N; Purington, Chris; Qiu, Cheng; Schallmo, Michael-Paul; Tjan, Bosco S

    2018-01-01

    In the absence of an optic chiasm, visual input to the right eye is represented in primary visual cortex (V1) in the right hemisphere, while visual input to the left eye activates V1 in the left hemisphere. Retinotopic mapping In V1 reveals that in each hemisphere left and right visual hemifield representations are overlaid (Hoffmann et al., 2012). To explain how overlapping hemifield representations in V1 do not impair vision, we tested the hypothesis that visual projections from nasal and temporal retina create interdigitated left and right visual hemifield representations in V1, similar to the ocular dominance columns observed in neurotypical subjects (Victor et al., 2000). We used high-resolution fMRI at 7T to measure the spatial distribution of responses to left- and right-hemifield stimulation in one achiasmic subject. T 2 -weighted 2D Spin Echo images were acquired at 0.8mm isotropic resolution. The left eye was occluded. To the right eye, a presentation of flickering checkerboards alternated between the left and right visual fields in a blocked stimulus design. The participant performed a demanding orientation-discrimination task at fixation. A general linear model was used to estimate the preference of voxels in V1 to left- and right-hemifield stimulation. The spatial distribution of voxels with significant preference for each hemifield showed interdigitated clusters which densely packed V1 in the right hemisphere. The spatial distribution of hemifield-preference voxels in the achiasmic subject was stable between two days of testing and comparable in scale to that of human ocular dominance columns. These results are the first in vivo evidence showing that visual hemifield representations interdigitate in achiasmic V1 following a similar developmental course to that of ocular dominance columns in V1 with intact optic chiasm. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Creating nanoshell on the surface of titanium hydride bead

    Directory of Open Access Journals (Sweden)

    PAVLENKO Vyacheslav Ivanovich

    2016-12-01

    Full Text Available The article presents data on the modification of titanium hydride bead by creating titanium nanoshell on its surface by ion-plasma vacuum magnetron sputtering. To apply titanium nanoshell on the titanium hydride bead vacuum coating plant of multifunctional nanocomposite coatings QVADRA 500 located in the center of high technology was used. Analysis of the micrographs of the original surface of titanium hydride bead showed that the microstructure of the surface is flat, smooth, in addition the analysis of the microstructure of material surface showed the presence of small porosity, roughness, mainly cavities, as well as shallow longitudinal cracks. The presence of oxide film in titanium hydride prevents the free release of hydrogen and fills some micro-cracks on the surface. Differential thermal analysis of both samples was conducted to determine the thermal stability of the initial titanium hydride bead and bead with applied titanium nanoshell. Hydrogen thermal desorption spectra of the samples of the initial titanium hydride bead and bead with applied titanium nanoshell show different thermal stability of compared materials in the temperature range from 550 to 860о C. Titanium nanoshells applied in this way allows increasing the heat resistance of titanium hydride bead – the temperature of starting decomposition is 695о C and temperature when decomposition finishes is more than 1000о C. Modified in this way titanium hydride bead can be used as a filler in the radiation protective materials used in the construction or upgrading biological protection of nuclear power plants.

  16. Calibration beads containing luminescent lanthanide ion complexes

    Science.gov (United States)

    The reliability of lanthanide luminescence measurements, by both flow cytometry and digital microscopy, will be enhanced by the availability of narrow-band emitting lanthanide calibration beads. These beads can also be used to characterize spectrographic instruments, including mi...

  17. Studies about the transfer phenomena of tritium from liquid to gaseous phase in a catalyst and ordered packing successive system

    International Nuclear Information System (INIS)

    Bornea, Anisia; Cristescu, Ion; Zamfirache, Marius; Varlam, Carmen

    2002-01-01

    The processes for hydrogen isotope separation are very important for nuclear technology. One of the most important processes for tritium separation, is the catalyst isotope exchange water-hydrogen. In a column of isotope exchange tritium is transferred from liquid phase (tritiated heavy water) in gaseous phase (hydrogen). In the experimental setup, which was used, the column of catalytic isotope exchange is filled with successive layers of catalyst and ordered packing. The catalyst consists of 95.5 wt.% of PTFE, 4.1 wt. % of carbon and 0.40 wt. % of platinum and was made of Raschig rings 10 x 10 x 2 mm. The ordered packing was of B7 type and consists of a phosphor bronze wire mesh of 0.18 x 0.48 mm dimension. We analysed the transfer phenomena of tritium from liquid to gaseous phase, in this system. The mathematical model presented in the paper allowed computing experimental data for testing the catalyst performances. In this way the speed constants which characterized the isotopic exchange on the catalysis bed ks, and the distillation on the ordered packing kd, were expressed as function of experimental concentrations and hydrodynamic conditions. (authors)

  18. Continuous adsorption and biotransformation of micropollutants by granular activated carbon-bound laccase in a packed-bed enzyme reactor.

    Science.gov (United States)

    Nguyen, Luong N; Hai, Faisal I; Dosseto, Anthony; Richardson, Christopher; Price, William E; Nghiem, Long D

    2016-06-01

    Laccase was immobilized on granular activated carbon (GAC) and the resulting GAC-bound laccase was used to degrade four micropollutants in a packed-bed column. Compared to the free enzyme, the immobilized laccase showed high residual activities over a broad range of pH and temperature. The GAC-bound laccase efficiently removed four micropollutants, namely, sulfamethoxazole, carbamazepine, diclofenac and bisphenol A, commonly detected in raw wastewater and wastewater-impacted water sources. Mass balance analysis showed that these micropollutants were enzymatically degraded following adsorption onto GAC. Higher degradation efficiency of micropollutants by the immobilized compared to free laccase was possibly due to better electron transfer between laccase and substrate molecules once they have adsorbed onto the GAC surface. Results here highlight the complementary effects of adsorption and enzymatic degradation on micropollutant removal by GAC-bound laccase. Indeed laccase-immobilized GAC outperformed regular GAC during continuous operation of packed-bed columns over two months (a throughput of 12,000 bed volumes). Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. [Evaluation of TB-beads assay utilizing the technique of magnetic beads--an innovative assay method for detection of acid fast bacilli].

    Science.gov (United States)

    Ohkuma, Masanori; Ikeda, Katsuyoshi; Obayashi, Konen; Ando, Yukio; Koriyama, Toyoyasu; Kimu, Minhi; Hirose, Nobuyuki; Nagasawa, Zenzo; Miyamoto, Hiroshi

    2012-01-01

    The centrifuge method with the use of Semi-Alkalin Proteinase (SAP) and NALC-NaOH, recommended by the "2007 edition of the assay guideline for detection of Mycobacterium tuberculosis," has significantly contributed to improving the sensitivities and specificities of both smear and culture tests for detection of acid fast bacilli (AFB). However, this method poses some challenges in terms of its cumbersome and time-consuming assay protocol. "TB-beads (Kyokuto Pharmaceutical Industrial Co., Ltd.)" is a newly-developed method for detection of AFB utilizing magnetic beads. We evaluated the quality of this method in comparison with the centrifuge method, focusing on the results of smear and culture tests. This evaluation study was conducted using both 5 positive and 5 negative sputum samples. The sensitivity of TB-beads for fluorescent smear tests, conducted using "Acri-stain," was almost the same as that of the centrifuge method. One advantage of TB-beads, however, was that it was very convenient to practice microscopic observation due to the clear background of the smeared glass slides. The comparison of the contamination rates between the two methods showed that TB-beads suggested significantly lower contamination rates. The centrifuge method resulted in 50% and 60% of contamination rates for HK Semisolid Isolation Medium and BacT/ALERT MP, respectively. On the other hand, the contamination rates of TB-beads for both of the culture methods were only 10%. With regard to the 5 positive sputum samples, the comparison of the detection rates between the centrifuge and TB-Beads method was made utilizing Myco Acid, Ogawa K, and BacT/ALERT MP. The TB-Beads method suggested higher detection rates for Myco Acid and Ogawa K, while there were no significant differences between the two methods for BacT/ALERT MP (16-23 days). TB-beads is an easy method that allows to simplify the process of smear tests, and contributes to significantly reducing the contamination rate of culture

  20. A novel bench-scale column assay to investigate site-specific nitrification biokinetics in biological rapid sand filters

    DEFF Research Database (Denmark)

    Tatari, Karolina; Smets, Barth F.; Albrechtsen, Hans-Jørgen

    2013-01-01

    A bench-scale assay was developed to obtain site-specific nitrification biokinetic information from biological rapid sand filters employed in groundwater treatment. The experimental set-up uses granular material subsampled from a full-scale filter, packed in a column, and operated with controlled...

  1. Characterising gas behaviour during gas-liquid co-current up-flow in packed beds using magnetic resonance imaging

    OpenAIRE

    Collins, James HP; Sederman, Andrew John; Gladden, Lynn Faith; Afeworki, Mobae; Kushnerick, J Douglas; Thomann, Hans

    2016-01-01

    Magnetic resonance (MR) imaging techniques have been used to study gas phase dynamics during co-current up-flow in a column of inner diameter 43 mm, packed with spherical non-porous elements of diameters of 1.8, 3 and 5 mm. MR measurements of gas hold-up, bubble-size distribution, and bubble-rise velocities were made as a function of flow rate and packing size. Gas and liquid flow rates were studied in the range of 20–250 cm3 s−1 and 0–200 cm3 min−1, respectively. The gas hold-up within the b...

  2. Experimental and Numerical Research Activity on a Packed Bed TES System

    Directory of Open Access Journals (Sweden)

    Mario Cascetta

    2016-09-01

    Full Text Available This paper presents the results of experimental and numerical research activities on a packed bed sensible thermal energy storage (TES system. The TES consists of a cylindrical steel tank filled with small alumina beads and crossed by air used as the heat transfer fluid. Experimental tests were carried out while varying some operating parameters such as the mass flow rate, the inlet–outlet temperature thresholds and the aspect ratio (length over diameter. Numerical simulations were carried out using a one-dimensional model, specifically developed in the Matlab-Simulink environment and a 2D axisymmetric model based on the ANSYS-Fluent platform. Both models are based on a two-equation transient approach to calculate fluid and solid phase temperatures. Thermodynamic properties were considered to be temperature-dependent and, in the Computational Fluid Dynamics (CFD model, variable porosity of the bed in the radial direction, thermal losses and the effective conductivity of the alumina beads were also considered. The simulation results of both models were compared to the experimental ones, showing good agreement. The one-dimensional model has the advantage of predicting the axial temperature distribution with a very low computational cost, but it does not allow calculation of the correct energy stored when the temperature distribution is strongly influenced by the wall. To overcome this problem a 2D CFD model was used in this work.

  3. Discrete dipole approximation simulation of bead enhanced diffraction grating biosensor

    International Nuclear Information System (INIS)

    Arif, Khalid Mahmood

    2016-01-01

    We present the discrete dipole approximation simulation of light scattering from bead enhanced diffraction biosensor and report the effect of bead material, number of beads forming the grating and spatial randomness on the diffraction intensities of 1st and 0th orders. The dipole models of gratings are formed by volume slicing and image processing while the spatial locations of the beads on the substrate surface are randomly computed using discrete probability distribution. The effect of beads reduction on far-field scattering of 632.8 nm incident field, from fully occupied gratings to very coarse gratings, is studied for various bead materials. Our findings give insight into many difficult or experimentally impossible aspects of this genre of biosensors and establish that bead enhanced grating may be used for rapid and precise detection of small amounts of biomolecules. The results of simulations also show excellent qualitative similarities with experimental observations. - Highlights: • DDA was used to study the relationship between the number of beads forming gratings and ratio of first and zeroth order diffraction intensities. • A very flexible modeling program was developed to design complicated objects for DDA. • Material and spatial effects of bead distribution on surfaces were studied. • It has been shown that bead enhanced grating biosensor can be useful for fast detection of small amounts of biomolecules. • Experimental results qualitatively support the simulations and thus open a way to optimize the grating biosensors.

  4. Microarray of DNA probes on carboxylate functional beads surface

    Institute of Scientific and Technical Information of China (English)

    黄承志; 李原芳; 黄新华; 范美坤

    2000-01-01

    The microarray of DNA probes with 5’ -NH2 and 5’ -Tex/3’ -NH2 modified terminus on 10 um carboxylate functional beads surface in the presence of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) is characterized in the preseni paper. it was found that the microarray capacity of DNA probes on the beads surface depends on the pH of the aqueous solution, the concentra-tion of DNA probe and the total surface area of the beads. On optimal conditions, the minimum distance of 20 mer single-stranded DNA probe microarrayed on beads surface is about 14 nm, while that of 20 mer double-stranded DNA probes is about 27 nm. If the probe length increases from 20 mer to 35 mer, its microarray density decreases correspondingly. Mechanism study shows that the binding mode of DNA probes on the beads surface is nearly parallel to the beads surface.

  5. Microarray of DNA probes on carboxylate functional beads surface

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The microarray of DNA probes with 5′-NH2 and 5′-Tex/3′-NH2 modified terminus on 10 m m carboxylate functional beads surface in the presence of 1-ethyl-3-(3-dimethylaminopropyl)- carbodiimide (EDC) is characterized in the present paper. It was found that the microarray capacity of DNA probes on the beads surface depends on the pH of the aqueous solution, the concentration of DNA probe and the total surface area of the beads. On optimal conditions, the minimum distance of 20 mer single-stranded DNA probe microarrayed on beads surface is about 14 nm, while that of 20 mer double-stranded DNA probes is about 27 nm. If the probe length increases from 20 mer to 35 mer, its microarray density decreases correspondingly. Mechanism study shows that the binding mode of DNA probes on the beads surface is nearly parallel to the beads surface.

  6. Effects of agitation rate on aggregation during beads-to-beads subcultivation of microcarrier culture of human mesenchymal stem cells.

    Science.gov (United States)

    Takahashi, Iori; Sato, Keigo; Mera, Hisashi; Wakitani, Shigeyuki; Takagi, Mutsumi

    2017-06-01

    With the aim to utilize human mesenchymal stem cells (hMSCs) grown in large scale for regenerative medicine, effects of agitation rate on aggregation during beads-to-beads subcultivation of microcarrier culture of hMSCs were studied. hMSCs could attach and grew on surface-type microcarriers of Cytodex 1, whereas almost no cell elongation and growth were observed on porous type microcarriers of Cytopores. The percentages of aggregated Cytodex 1 microcarriers at an agitation rate of 60 and 90 rpm were lower than that at 30 rpm, which was the lowest agitation rate necessary for the suspension of Cytodex 1 microcarriers, and the cells grew fastest at 60 rpm. hMSC could be subcultivated on Cytodex 1 by the beads-to-beads method at both 30 and 60 rpm without trypsinization. However, agitation at 60 rpm resulted in a markedly lower percentage of aggregated microcarriers not only before but also after subcultivation. The percentages of CD90- and CD166-positive cells among cells grown on Cytodex 1 at 60 rpm (91.5 and 87.6 %) were comparable to those of cells grown in the pre-culture on dishes. In conclusion, hMSCs could be subcultivated on Cytodex 1 by beads-to-beads method maintaining the expressions of the cell surface antigens CD90 and CD166, while adjusting agitation rate could decrease the microcarrier aggregation.

  7. A Reconciliation of Packed Column Permeability Data: Column Permeability as a Function of Particle Porosity

    Directory of Open Access Journals (Sweden)

    Hubert M. Quinn

    2014-01-01

    Full Text Available In his textbook teaching of packed bed permeability, Georges Guiochon uses mobile phase velocity as the fluid velocity term in his elaboration of the Darcy permeability equation. Although this velocity frame makes a lot of sense from a thermodynamic point of view, it is valid only with respect to permeability at a single theoretical boundary condition. In his more recent writings, however, Guiochon has departed from his long-standing mode of discussing permeability in terms of the Darcy equation and has embraced the well-known Kozeny-Blake equation. In this paper, his teaching pertaining to the constant in the Kozeny-Blake equation is examined and, as a result, a new correlation coefficient is identified and defined herein based on the velocity frame used in his teaching. This coefficient correlates pressure drop and fluid velocity as a function of particle porosity. We show that in their experimental protocols, Guiochon et al. have not adhered to a strict material balance of permeability which creates a mismatch of particle porosity and leads to erroneous conclusions regarding the value of the permeability coefficient in the Kozeny-Blake equation. By correcting the experimental data to properly reflect particle porosity we reconcile the experimental results of Guiochon and Giddings, resulting in a permeability reference chart which is presented here for the first time. This reference chart demonstrates that Guiochon’s experimental data, when properly normalized for particle porosity and other related discrepancies, corroborates the value of 267 for the constant in the Kozeny-Blake equation which was derived by Giddings in 1965.

  8. Half bead welding technique

    International Nuclear Information System (INIS)

    Canonico, D.A.; Holz, P.P.

    1978-05-01

    The ORNL has employed the Section XI half-bead procedure for six repair welds. Table 2 identifies the repairs and the components upon which they were accomplished. The weld repairs were performed to permit us to evaluate material properties, residual stresses, weld repair procedures, and structural behavior of repaired pressure vessels. As a consequence of our study we concluded that when the half bead procedure is correctly applied: (1) there is no metallurgical degradation of the base material, (2) residual stresses of yield point magnitude will be present, and (3) the structural integrity of the pressure vessel is not impaired at Charpy V-notch upper shelf temperatures

  9. Measurement of liquid mixing characteristics in large-sized ion exchange column for isotope separation by stepwise response method

    International Nuclear Information System (INIS)

    Fujine, Sachio; Saito, Keiichiro; Iwamoto, Kazumi; Itoi, Toshiaki.

    1981-07-01

    Liquid mixing in a large-sized ion exchange column for isotope separation was measured by the step-wise response method, using NaCl solution as tracer. A 50 cm diameter column was packed with an ion exchange resin of 200 μm in mean diameter. Experiments were carried out for several types of distributor and collector, which were attached to each end of the column. The smallest mixing was observed for the perforated plate type of the collector, coupled with a minimum stagnant volume above the ion exchange resin bed. The 50 cm diameter column exhibited the better characteristics of liquid mixing than the 2 cm diameter column for which the good performance of lithium isotope separation had already been confirmed. These results indicate that a large increment of throughput is attainable by the scale-up of column diameter with the same performance of isotope separation as for the 2 cm diameter column. (author)

  10. The performance of a trickle-bed reactor packed with a Pt/SDBC catalyst mixture for the CECE process

    International Nuclear Information System (INIS)

    Paek, Seungwoo; Ahn, Do-Hee; Choi, Heui-Joo; Kim, Kwang-Rag; Lee, Minsoo; Yim, Sung-Paal; Chung, Hongsuk; Song, Kyu-Min; Sohn, Soon Hwan

    2007-01-01

    The combined electrolysis and catalytic exchange (CECE) process with a hydrophobic catalyst is a very effective method to remove small quantities of tritium from light or heavy wastewater streams because of its high separation factor and mild operating conditions. A hydrophobic platinum/styrene-divinyl benzene copolymer (Pt/SDBC) catalyst which was developed for the liquid-phase catalytic exchange (LPCE) column of the Wolsong tritium removal facility (WTRF) has been tested in a trickle bed reactor for the design of the CECE process. An experimental apparatus has been built for the testing of the catalyst at various temperatures and gas velocities. The catalyst column was packed with a mixture of a hydrophobic catalyst and a hydrophilic packing (Dixon gauze ring) to improve the liquid distribution and vapor/liquid transfer area. Many tests have been carried out at Korea Atomic Energy Research Institute (KAERI) to measure the activity of the catalyst, K y a (1 s -1 ), under various operating conditions. K y a increases with the hydrogen flow rates in the range of 0.4-1.6 m s -1 at STP. The height of the catalyst column was determined from these K y a values according to the reaction temperatures and hydrogen flow rates

  11. The performance of a trickle-bed reactor packed with a Pt/SDBC catalyst mixture for the CECE process

    Energy Technology Data Exchange (ETDEWEB)

    Paek, Seungwoo [Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)], E-mail: swpaek@kaeri.re.kr; Ahn, Do-Hee; Choi, Heui-Joo; Kim, Kwang-Rag; Lee, Minsoo; Yim, Sung-Paal; Chung, Hongsuk [Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Song, Kyu-Min; Sohn, Soon Hwan [Korea Electric Power Research Institute, 103-16 Munji-dong, Yuseong-gu, Daejeon 305-380 (Korea, Republic of)

    2007-10-15

    The combined electrolysis and catalytic exchange (CECE) process with a hydrophobic catalyst is a very effective method to remove small quantities of tritium from light or heavy wastewater streams because of its high separation factor and mild operating conditions. A hydrophobic platinum/styrene-divinyl benzene copolymer (Pt/SDBC) catalyst which was developed for the liquid-phase catalytic exchange (LPCE) column of the Wolsong tritium removal facility (WTRF) has been tested in a trickle bed reactor for the design of the CECE process. An experimental apparatus has been built for the testing of the catalyst at various temperatures and gas velocities. The catalyst column was packed with a mixture of a hydrophobic catalyst and a hydrophilic packing (Dixon gauze ring) to improve the liquid distribution and vapor/liquid transfer area. Many tests have been carried out at Korea Atomic Energy Research Institute (KAERI) to measure the activity of the catalyst, K{sub y}a (1 s{sup -1}), under various operating conditions. K{sub y}a increases with the hydrogen flow rates in the range of 0.4-1.6 m s{sup -1} at STP. The height of the catalyst column was determined from these K{sub y}a values according to the reaction temperatures and hydrogen flow rates.

  12. Preparation of Affinity Column Based on Zr4+ Ion for Phosphoproteins Isolation

    International Nuclear Information System (INIS)

    Lee, Seon Mi; Bae, In Ae; Park, Jung Hyen; Kim, Tae Dong; Choi, Seong Ho

    2009-01-01

    This paper has described about preparation of Zr 4+ affinity column based on the poly(styreneco- glycidyl methacrylate) prepared by emulsion polymerization of styrene and glycidyl methacrylate in order to isolate phosphopeptide. The Zr 4+ ions were introduced after the phophonation of an epoxy group on polymeric microspheres. The successful preparation of Zr 4+ -immobilized polymeric microsphere stationary phase was confirmed through Fourier transform infrared spectra, optical microscopy, scanning electron microscopy, X-ray photoelectron spectra and inductively coupled plasma-atomic emission spectrometer. The separation efficiency for Zr 4+ affinity column prepared by slurry packing was tested to phosphonated casein and dephosphonated casein. The resolution time (min) of the phosphonated casein was higher than that of dephosphated casein for Zr 4+ affinity polymeric microsphere by liquid chromatography. This Zr 4+ affinity column can be used for isolation of phosphonated casein from casein using liquid chromatography

  13. Study of hydrodynamic and mass transfer parameters in pulsed sieve-plate columns

    International Nuclear Information System (INIS)

    Safdari, J.

    2001-01-01

    One of the most important liquid-liquid extractor in industry is pulsed column. The pulsed columns are generally classified into the following categories: 1-Pulsed perforated-plate column. 2- Pulsed packed column. The pulsed plate column is differential contactor with the application of mechanical energy and is used for a diverse range of processes. Probably its best known application has been in the nuclear fuel industry. The pulsed plate column consists of a cylindrical shell with settling zones at the top and the bottom of the column. The liquids are fed continuously to the column (flowing counter-currently) and are removed continuously from opposite ends of the column. In this work using a pilot pulsed plate column and two different chemical systems (toluene/acetone/water and n-butyl acetate/acetone/water) various experiments are carried out. In each experiment direction of mass transfer is from organic phase (dispersed phase) into aqueous phase (continuous phase) and the continuous phase is water. The main objects of this thesis are as follow: a- Investigation of effect of operating parameters on dispersed phase hold up, volumetric overall mass transfer coefficients based on dispersed and continuous phase, extraction efficiency, pressure drop of column and flooding velocities (maximum column capacities). Obtained results in this part show that if the calorimetric flow rate of aqueous phase or pulsation intensity increase, hold up, volumetric overall mass transfer coefficients based on both two phases and extraction efficiency will increase and flooding velocities will decrease. Also results show that if volumetric flow rate of organic phase increase, hold up, volumetric mass transfer coefficients based on both two phases and pressure drop will increase and extraction efficiency and flooding velocities will decrease. b- Investigation of effect of internal circulation inside drops in designing pulsed perforated-plate column

  14. Two Contrasting Failure Modes of Enteric Coated Beads.

    Science.gov (United States)

    Shi, Galen H; Dong, Xia; Lytle, Michelle; Kemp, Craig A J; Behme, Robert J; Hinds, Jeremy; Xiao, Zhicheng

    2018-04-09

    This study aimed to elucidate the mechanisms and kinetics of coating failure for enteric coated beads exposed to high-humidity conditions at different storage temperatures. Enteric coated beads were placed on high-humidity conditions (75 to 98% relative humidity (RH)) in the temperature range of 5 to 40°C. These stability samples of beads were tested for acid dissolution and water activity and also analyzed with SEM, X-ray CT, and DMA. Exposure of enteric coated beads to high humidity led to increased gastric release of drug which eventually failed the dissolution specification. SEM showed visible cracks on the surface of beads exposed to 5°C/high humidity and fusion of enteric beads into agglomerates at 40°C/high humidity. In a non-destructive time elapse study, X-ray CT demonstrated swelling of microcrystalline cellulose cores, crack initiation, and propagation through the API layer within days under 5°C/98% RH storage conditions and ultimately fracture through the enteric coating. DMA data showed a marked reduction in T g of the enteric coating materials after exposure to humidity. At 5°C/high humidity, the hygroscopic microcrystalline cellulose core absorbed moisture leading to core swelling and consequent fracture through the brittle API and enteric layers. At 40°C (high humidity) which is above the T g of the enteric polymer, enteric coated beads coalesced into agglomerates due to melt flow of the enteric coating. We believe it is the first report on two distinct failure models of enteric coated dosage forms.

  15. PILOT-SCALE HYDRAULIC TESTING OF RESORCINOL FORMALDEHYDE ION EXCHANGE RESIN

    International Nuclear Information System (INIS)

    Adamson, D

    2007-01-01

    Savannah River National Laboratory (SRNL) performed pilot-scale hydraulic/chemical testing of spherical resorcinol formaldehyde (RF) ion exchange (IX) resin for the River Protection Project Hanford Tank Waste Treatment and Immobilization Plant (WTP) Project. The RF resin cycle testing was conducted in two pilot-scale IX columns, 1/4 and 1/2 scale. A total of twenty-three hydraulic/chemical cycles were successfully completed on the spherical RF resin. Seven of the cycles were completed in the 12-inch IX Column and sixteen cycles were completed in the 24-inch IX Column. Hydraulic testing showed that the permeability of the RF resin remained essentially constant, with no observed trend in the reduction of the permeability as the number of cycles increased. The permeability during the pilot-scale testing was 2 1/2 times better than the design requirements of the WTP full-scale system. The permeability of the resin bed was uniform with respect to changes in bed depth. Upflow Regeneration and Simulant Introduction in the IX columns revealed another RF resin benefit; negligible radial pressures to the column walls from the swelling of resin beads. In downflow of the Regeneration and Simulant Introduction steps, the resin bed particles pack tightly together and produce higher hydraulic pressures than that found in upflow. Also, upflow Simulant Introduction produced an ideal level bed for the twenty cycles completed using upflow Simulant Introduction. Conversely, the three cycles conducted using downflow Simulant Introduction produced an uneven bed surface with erosion around the thermowells. The RF resin bed in both columns showed no tendency to form fissures or pack more densely as the number of cycles increased. Particle size measurements of the RF resin showed no indication of particle size change (for a given chemical) with cycles and essentially no fines formation. Micrographs comparing representative bead samples before and after testing indicated no change in bead

  16. PILOT-SCALE HYDRAULIC TESTING OF RESORCINOL FORMALDEHYDE ION EXCHANGE RESIN

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, D

    2007-01-09

    Savannah River National Laboratory (SRNL) performed pilot-scale hydraulic/chemical testing of spherical resorcinol formaldehyde (RF) ion exchange (IX) resin for the River Protection Project Hanford Tank Waste Treatment & Immobilization Plant (WTP) Project. The RF resin cycle testing was conducted in two pilot-scale IX columns, 1/4 and 1/2 scale. A total of twenty-three hydraulic/chemical cycles were successfully completed on the spherical RF resin. Seven of the cycles were completed in the 12-inch IX Column and sixteen cycles were completed in the 24-inch IX Column. Hydraulic testing showed that the permeability of the RF resin remained essentially constant, with no observed trend in the reduction of the permeability as the number of cycles increased. The permeability during the pilot-scale testing was 2 1/2 times better than the design requirements of the WTP full-scale system. The permeability of the resin bed was uniform with respect to changes in bed depth. Upflow Regeneration and Simulant Introduction in the IX columns revealed another RF resin benefit; negligible radial pressures to the column walls from the swelling of resin beads. In downflow of the Regeneration and Simulant Introduction steps, the resin bed particles pack tightly together and produce higher hydraulic pressures than that found in upflow. Also, upflow Simulant Introduction produced an ideal level bed for the twenty cycles completed using upflow Simulant Introduction. Conversely, the three cycles conducted using downflow Simulant Introduction produced an uneven bed surface with erosion around the thermowells. The RF resin bed in both columns showed no tendency to form fissures or pack more densely as the number of cycles increased. Particle size measurements of the RF resin showed no indication of particle size change (for a given chemical) with cycles and essentially no fines formation. Micrographs comparing representative bead samples before and after testing indicated no change in bead

  17. PILOT-SCALE HYDRAULIC TESTING OF RESORCINOL FORMALDEHYDE ION EXCHANGE RESIN

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, D

    2006-11-08

    Savannah River National Laboratory (SRNL) performed pilot-scale hydraulic/chemical testing of spherical resorcinol formaldehyde (RF) ion exchange (IX) resin for the River Protection Project-Hanford Tank Waste Treatment & Immobilization Plant (WTP) Project. The RF resin cycle testing was conducted in two pilot-scale IX columns, 1/4 and 1/2 scale. A total of twenty-three hydraulic/chemical cycles were successfully completed on the spherical RF resin. Seven of the cycles were completed in the 12 inch IX Column and sixteen cycles were completed in the 24 inch IX Column. Hydraulic testing showed that the permeability of the RF resin remained essentially constant, with no observed trend in the reduction of the permeability as the number of cycles increased. The permeability during the pilot-scale testing was 2 1/2 times better than the design requirements of the WTP full-scale system. The permeability of the resin bed was uniform with respect to changes in bed depth. Upflow Regeneration and Simulant Introduction in the IX columns revealed another RF resin benefit; negligible radial pressures to the column walls from the swelling of resin beads. In downflow of the Regeneration and Simulant Introduction steps, the resin bed particles pack tightly together and produce higher hydraulic pressures than that found in upflow. Also, upflow Simulant Introduction produced an ideal level bed for the twenty cycles completed using upflow Simulant Introduction. Conversely, the three cycles conducted using downflow Simulant Introduction produced an uneven bed surface with erosion around the thermowells. The RF resin bed in both columns showed no tendency to form fissures or pack more densely as the number of cycles increased. Particle size measurements of the RF resin showed no indication of particle size change (for a given chemical) with cycles and essentially no fines formation. Micrographs comparing representative bead samples before and after testing indicated no change in bead

  18. Preparation of Bio-beads and Their Atrazine Degradation Characteristics

    Institute of Scientific and Technical Information of China (English)

    BI Hai-tao; ZHANG Lan-ying; LIU Na; ZHU Bo-lin

    2011-01-01

    Screened atrazine-mineralizing bacterium-Pseudomonas W4 was embedded inside an improved PVAH3BO3 embedment matrix to make bio-beads to degrade atrazine. The atrazine degradation characteristics were studied. The preparation procedure of bio-beads was as follows: (1) preparing a mixture of 100, 12.5, 10, 1.5 and 1 g/L PVA, bentonite(Ca), activated carbon powder, sodium alginate and centrifuged Pseudomonas W4 bacterium, respectively; (2) the mixture was dropped into a gently stirred cross linker solution(pH=6.7) and cured at 10 ℃ for 24 h.The optimal atrazine degradation conditions by bio-beads were as follows: pH=7, the auxiliary carbon source was glucose, and the concentration of glucose was greater than 325 mg/L. The bio-beads demonstrated stronger tolerance ability than the free microorganism to the increase of PCBs, hydrogen ion and hydroxide ion. SEM images show the uniform distribution of the microorganism inside bio-beads and the porous cross-linked structure of bio-beads which provides excellent mass transfer capacity.

  19. Tunable random packings

    International Nuclear Information System (INIS)

    Lumay, G; Vandewalle, N

    2007-01-01

    We present an experimental protocol that allows one to tune the packing fraction η of a random pile of ferromagnetic spheres from a value close to the lower limit of random loose packing η RLP ≅0.56 to the upper limit of random close packing η RCP ≅0.64. This broad range of packing fraction values is obtained under normal gravity in air, by adjusting a magnetic cohesion between the grains during the formation of the pile. Attractive and repulsive magnetic interactions are found to affect stongly the internal structure and the stability of sphere packing. After the formation of the pile, the induced cohesion is decreased continuously along a linear decreasing ramp. The controlled collapse of the pile is found to generate various and reproducible values of the random packing fraction η

  20. Assessment of the Problems of Manual Automobile Tyre Bead ...

    African Journals Online (AJOL)

    The tyre-rim bead bond must be broken to carry out repairs on a failed automobile tyre. The use of the locally fabricated manual bead breaking equipment as it is being practiced today by commercial tyre repair artisans in Nigeria is characterized by drudgery. This article reports a study of the local manual bead breaking ...

  1. Growth and morphology of thermophilic dairy starters in alginate beads.

    Science.gov (United States)

    Lamboley, Laurence; St-Gelais, Daniel; Champagne, Claude P; Lamoureux, Maryse

    2003-06-01

    The aim of this research was to produce concentrated biomasses of thermophilic lactic starters using immobilized cell technology (ICT). Fermentations were carried out in milk using pH control with cells microentrapped in alginate beads. In the ICT fermentations, beads represented 17% of the weight. Some assays were carried out with free cells without pH control, in order to compare the ICT populations with those of classical starters. With Streptococcus thermophilus, overall populations in the fermentor were similar, but maximum bead population for (8.2 x 10(9) cfu/g beads) was 13 times higher than that obtained in a traditional starter (4.9 x 10(8) cfu/ml). For both Lactobacillus helveticus strains studied, immobilized-cell populations were about 3 x 10(9) cfu/g beads. Production of immobilized Lb. bulgaricus 210R strain was not possible, since no increases in viable counts occurred in beads. Therefore, production of concentrated cell suspension in alginate beads was more effective for S. thermophilus. Photomicrographs of cells in alginate beads demonstrated that, while the morphology of S. thermophilus remained unchanged during the ICT fermentation, immobilized cells of Lb. helveticus appeared wider. In addition, cells of Lb. bulgaricus were curved and elongated. These morphological changes would also impair the growth of immobilized lactobacilli.

  2. A novel fiber-packed column for on-line preconcentration and speciation analysis of chromium in drinking water with flame atomic absorption spectrometry.

    Science.gov (United States)

    Monasterio, Romina P; Altamirano, Jorgelina C; Martínez, Luis D; Wuilloud, Rodolfo G

    2009-02-15

    A novel on-line preconcentration and determination system based on a fiber-packed column was developed for speciation analysis of Cr in drinking water samples prior to its determination by flame atomic absorption spectrometry (FAAS). All variables involved in the development of the preconcentration method including, pH, eluent type, sample and eluent flow rates, interfering effects, etc., were studied in order to achieve the best analytical performance. A preconcentration factor of 32 was obtained for Cr(VI) and Cr(III). The levels of Cr(III) species were calculated by difference of total Cr and Cr(VI) levels. Total Cr was determined after oxidation of Cr(III) to Cr(VI) with hydrogen peroxide. The calibration graph was linear with a correlation coefficient of 0.999 at levels near the detection limit and up to at least 50 microg L(-1). The relative standard deviation (R.S.D.) was 4.3% (C=5 microg L(-1) Cr(VI), n=10, sample volume=25 mL). The limit of detection (LOD) for both Cr(III) and Cr(VI) species was 0.3 microg L(-1). Verification of the accuracy was carried out by the analysis of a standard reference material (NIST SRM 1643e "Trace elements in natural water"). The method was successfully applied to the determination of Cr(III) and Cr(VI) species in drinking water samples.

  3. 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.

  4. HIGH ASPECT RATIO ION EXCHANGE RESIN BED - HYDRAULIC RESULTS FOR SPERICAL RESIN BEADS

    International Nuclear Information System (INIS)

    Duignan, M; Charles Nash, C; Timothy Punch, T

    2007-01-01

    A principal role of the DOE Savannah River Site is to safely dispose of a large volume of liquid nuclear waste held in many storage tanks. An in-tank ion exchange unit is being considered for cesium removal to accelerate waste processing. This unit is planned to have a relatively high bed height to diameter ratio (10:1). Complicating the design is the need to cool the ion exchange media; therefore, the ion exchange column will have a central cooling core making the flow path annular. To separate cesium from waste the media being considered is made of resorcinol formaldehyde resin deposited on spherical plastic beads and is a substitute for a previously tested resin made of crystalline silicotitanate. This spherical media not only has an advantage of being mechanically robust, but, unlike its predecessor, it is also reusable, that is, loaded cesium can be removed through elution and regeneration. Resin regeneration leads to more efficient operation and less spent resin waste, but its hydraulic performance in the planned ion exchange column was unknown. Moreover, the recycling process of this spherical resorcinol formaldehyde causes its volume to significantly shrink and swell. To determine the spherical media's hydraulic demand a linearly scaled column was designed and tested. The waste simulant used was prototypic of the wastes' viscosity and density. This paper discusses the hydraulic performance of the media that will be used to assist in the design of a full-scale unit

  5. Bead Collage: An Arts-Based Research Method

    Science.gov (United States)

    Kay, Lisa

    2013-01-01

    In this paper, "bead collage," an arts-based research method that invites participants to reflect, communicate and construct their experience through the manipulation of beads and found objects is explained. Emphasizing the significance of one's personal biography and experiences as a researcher, I discuss how my background as an…

  6. Fluctuations of cytoskeleton-bound microbeads-the effect of bead-receptor binding dynamics

    International Nuclear Information System (INIS)

    Metzner, C; Raupach, C; Mierke, C T; Fabry, B

    2010-01-01

    The cytoskeleton (CSK) of living cells is a crosslinked fiber network, subject to ongoing biochemical remodeling processes that can be visualized by tracking the spontaneous motion of CSK-bound microbeads. The bead motion is characterized by anomalous diffusion with a power-law time evolution of the mean square displacement (MSD), and can be described as a stochastic transport process with apparent diffusivity D and power-law exponent β: MSD ∼ D (t/t 0 ) β . Here we studied whether D and β change with the time that has passed after the initial bead-cell contact, and whether they are sensitive to bead coating (fibronectin, integrin antibodies, poly-L-lysine, albumin) and bead size (0.5-4.5 μm). The measurements are interpreted in the framework of a simple model that describes the bead as an overdamped particle coupled to the fluctuating CSK network by an elastic spring. The viscous damping coefficient characterizes the degree of bead internalization into the cell, and the spring constant characterizes the strength of the binding of the bead to the CSK. The model predicts distinctive signatures of the MSD that change with time as the bead couples more tightly to the CSK and becomes internalized. Experimental data show that the transition from the unbound to the tightly bound state occurs in an all-or-nothing manner. The time point of this transition shows considerable variability between individual cells (2-30 min) and depends on the bead size and bead coating. On average, this transition occurs later for smaller beads and beads coated with ligands that trigger the formation of adhesion complexes (fibronectin, integrin antibodies). Once the bead is linked to the CSK, however, the ligand type and bead size have little effect on the MSD. On longer timescales of several hours after bead addition, smaller beads are internalized into the cell more readily, leading to characteristic changes in the MSD that are consistent with increased viscous damping by the

  7. NUMERICAL SOLUTION OF STEADY STATE DISPERSION FLOW MODEL FOR LACTOSE-LACTASE HYDROLYSIS WITH DIFFERENT KINETICS IN FIXED BED

    Directory of Open Access Journals (Sweden)

    OLAOSEBIKAN ABIDOYE OLAFADEHAN

    2010-06-01

    Full Text Available A detailed computational procedure for evaluating lactose hydrolysis with immobilized enzyme in a packed bed tubular reactor under dispersion flow conditions is presented. The dispersion flow model for lactose hydrolysis using different kinetics, taking cognizance of external mass transfer resistances, was solved by the method of orthogonal collocation. The reliability of model simulations was tested using experimental data from a laboratory packed bed column, where the -galactosidase of Kluyveromyces fragilis was immobilized on spherical chitosan beads. Comparison of the simulated results with experimental exit conversion shows that the dispersion flow model and using Michaelis-Menten kinetics with competitive product (galactose inhibition are appropriate to interpret the experimental results and simulate the process of lactose hydrolysis in a fixed bed.

  8. Elution of Clindamycin and Enrofloxacin From Calcium Sulfate Hemihydrate Beads In Vitro.

    Science.gov (United States)

    Phillips, Heidi; Boothe, Dawn M; Bennett, R Avery

    2015-11-01

    To compare the in vitro elution characteristics of clindamycin and enrofloxacin from calcium sulfate hemihydrate beads containing a single antibiotic, both antibiotics, and each antibiotic incubated in the same eluent well. Experimental in vitro study. Calcium sulfate hemihydrate beads were formed by mixing with clindamycin and/or enrofloxacin to create 4 study groups: (1) 160 mg clindamycin/10 beads; (2) 160 mg enrofloxacin/10 beads; (3) 160 mg clindamycin + 160 mg enrofloxacin/10 beads; and (4) 160 mg clindamycin/5 beads and 160 mg enrofloxacin/5 beads. Chains of beads were formed in triplicate and placed in 5 mL phosphate buffered saline (PBS; pH 7.4 and room temperature) with constant agitation. Antibiotic-conditioned PBS was sampled at 14 time points from 1 hour to 30 days. Clindamycin and enrofloxacin concentrations in PBS were determined using high-performance liquid chromatography. Eluent concentrations from clindamycin-impregnated beads failed to remain sufficiently above minimum inhibitory concentration (MIC) for common infecting bacteria over the study period. Enrofloxacin eluent concentrations remained sufficiently above MIC for common wound pathogens of dogs and cats and demonstrated an atypical biphasic release pattern. No significant differences in elution occurred as a result of copolymerization of the antibiotics into a single bead or from individual beads co-eluting in the same eluent well. Clindamycin-impregnated beads cannot be recommended for treatment of infection at the studied doses; however, use of enrofloxacin-impregnated beads may be justified when susceptible bacteria are cultured. © Copyright 2015 by The American College of Veterinary Surgeons.

  9. Plasma membrane isolation using immobilized concanavalin A magnetic beads.

    Science.gov (United States)

    Lee, Yu-Chen; Srajer Gajdosik, Martina; Josic, Djuro; Lin, Sue-Hwa

    2012-01-01

    Isolation of highly purified plasma membranes is the key step in constructing the plasma membrane proteome. Traditional plasma membrane isolation method takes advantage of the differential density of organelles. While differential centrifugation methods are sufficient to enrich for plasma membranes, the procedure is lengthy and results in low recovery of the membrane fraction. Importantly, there is significant contamination of the plasma membranes with other organelles. The traditional agarose affinity matrix is suitable for isolating proteins but has limitation in separating organelles due to the density of agarose. Immobilization of affinity ligands to magnetic beads allows separation of affinity matrix from organelles through magnets and could be developed for the isolation of organelles. We have developed a simple method for isolating plasma membranes using lectin concanavalin A (ConA) magnetic beads. ConA is immobilized onto magnetic beads by binding biotinylated ConA to streptavidin magnetic beads. The ConA magnetic beads are used to bind glycosylated proteins present in the membranes. The bound membranes are solubilized from the magnetic beads with a detergent containing the competing sugar alpha methyl mannoside. In this study, we describe the procedure of isolating rat liver plasma membranes using sucrose density gradient centrifugation as described by Neville. We then further purify the membrane fraction by using ConA magnetic beads. After this purification step, main liver plasma membrane proteins, especially the highly glycosylated ones and proteins containing transmembrane domains could be identified by LC-ESI-MS/MS. While not described here, the magnetic bead method can also be used to isolate plasma membranes from cell lysates. This membrane purification method should expedite the cataloging of plasma membrane proteome.

  10. A NOVEL APPROACH TO SYNTHESIZE CHITOSAN BEADS CROSSLINKED BY EPICHLOROHYDRIN

    Institute of Scientific and Technical Information of China (English)

    WANG Yongjian; BAI Shu; SUN Yan

    2001-01-01

    The present investigation describes a novel method for preparing spherical chitosan particles based on crosslinking with epichlorohydrin. Certain amount of pre-crosslinking agent was added to form chitosan gels by traditional inverse phase suspension polymerization. Then the gels were crosslinked by epichlorohydrin at basic condition to obtain chitosan beads. The effects of reaction conditions, such as crosslinking time, the amount of crosslinking agent and the NaOtt concentration,on the physical properties of the chitosan beads were investigated. The beads were found to have more amino groups in the polymer chains than the beads crosslinked by glutaraldehyde. The capacity for copper ions is as high as 40mg/g. The beads have good mechanical strength and can be reused.

  11. A NOVEL APPROACH TO SYNTHESIZE CHITOSAN BEADS CROSSLINKED BY EPICHLOROHYDRIN

    Institute of Scientific and Technical Information of China (English)

    WANGYongjina; BAIShu; 等

    2001-01-01

    The present investigation describes a novel method for preparing spherical chitosan particles based on crosslinking with epichlorohydrin.Certain amount of pre-crosslinking agent was added to form chitosan gels by traditional inverse phase suspension polymerization.Then the gels were crosslinked by epichlorohydrin at basic condition to obtain chitosan beads.The effects of reaction conditions,such as crosslinking time,the amount of crosslinking agent and the NaOH concentration,on the physical properties of the chitosan beads were investigated.The beads were found to have more amino groups in the polymer chains than the beads crosslinked by glutaraldehyde.The capacity for copper ions in as high as 40mg/g,The beads have good mechanical strength and can be reused.

  12. Random glycopeptide bead libraries for seromic biomarker discovery

    DEFF Research Database (Denmark)

    Kracun, Stjepan Kresimir; Cló, Emiliano; Clausen, Henrik

    2010-01-01

    have developed a random glycopeptide bead library screening platform for detection of autoantibodies and other binding proteins. Libraries were build on biocompatible PEGA beads including a safety-catch C-terminal amide linker (SCAL) that allowed mild cleavage conditions (I(2)/NaBH(4) and TFA...... to other tumor glycoforms by on-bead enzymatic glycosylation reactions with recombinant glycosyltransferases. Hence, we have developed a high-throughput flexible platform for rapid discovery of O-glycopeptide biomarkers and the method has applicability in other types of assays such as lectin...

  13. Ionically crosslinked alginate–carboxymethyl cellulose beads for the delivery of protein therapeutics

    International Nuclear Information System (INIS)

    Kim, Min Sup; Park, Sang Jun; Gu, Bon Kang; Kim, Chun-Ho

    2012-01-01

    Highlights: ► We prepared Fe 3+ crosslinked alginate–carboxymethyl cellulose (AC) beads. ► Different surface and inner morphology of AC beads were observed on volume of CMC. ► AC beads showed minimum swelling degree in acidic condition. ► Protein release from AC beads was to control in gastrointestinal condition. - Abstract: We developed Fe 3+ -crosslinked alginate–carboxymethyl cellulose (AC) beads in various volume ratios by dropping an AC solution into a ferric chloride solution to form protein therapeutic carrier beads. Scanning electron microscopy revealed that the roughness and pore size of the crosslinked beads increased with the volume ratio of the carboxymethyl cellulose. Fourier transform-infrared analysis revealed the formation of a three-dimensional bonding structure between the anionic polymeric chains of AC and the Fe 3+ ions. The degree of swelling and the release profile of albumin from the beads were investigated under simulated gastrointestinal conditions (pH 1.2, 4.5, and 7.4). The Fe 3+ -crosslinked AC beads displayed different degrees of swelling and albumin release for the various AC volume ratios and under various pH conditions. An in vitro release test was used to monitor the controlled release of albumin from the AC beads under simulated gastrointestinal conditions over 24 h. The Fe 3+ -crosslinked AC beads protected and controlled the release of protein, demonstrating that such beads present a promising protein therapeutic carrier for the oral delivery.

  14. exploring traditional glass bead making techniques in jewellery

    African Journals Online (AJOL)

    User

    Glass bead making techniques and their mass production will help the individual ... communicate cultural values in a symbolic lan- guage which ..... Surface of most of the new beads were rough ... tourism potential to be developed further to.

  15. Chinese and Venetian glass beads excavated from Fais Island in Micronesia

    International Nuclear Information System (INIS)

    Intoh, Michiko

    1997-01-01

    Full text: Over 830 glass beads were excavated from a late prehistoric cemetery site on Fais Island in the Caroline Islands, Micronesia In one of the 13 excavated burials a young woman had more that 310 glass beads around her wrist. Bone collagen from this burial was dated by AMS to 387 + 64 BP. The associated glass beads were classified into three groups based on colour and size. A sample from each group was examined for evidence of manufacturing technique. The chemical composition was determined using an X-ray microanalyser. The first group consisted of more than 300 pale green, transparent glass beads which are less than 2 mm in diameter. The chemical composition is high in PbO (75.22%) while low in MgO. Such a high lead content is characteristic of Chinese glass. The manufacturing technique could not be determined because the surfaces were too eroded. The second group contains several yellow, translucent glass beads. The chemical composition is also high in PbO (54.8%) and low in MgO. The beads were made by winding. The combination of winding and high lead strongly indicates that the beads were made in China. The third group had only one white, translucent glass bead. It has particular white stripes which suggest that it is a 'gooseberry' bead which was made in Venice between the sixteenth and eighteenth centuries. In conclusion, both Chinese and Venetian glass beads co-existed on Fais Island around the time of European contact. They are likely to have been brought in from an area which had access to both beads. Island South-East Asia is tentatively considered to be the source area

  16. Cooling Rates of Lunar Volcanic Glass Beads

    Science.gov (United States)

    Hui, Hejiu; Hess, Kai-Uwe; Zhang, Youxue; Peslier, Anne; Lange, Rebecca; Dingwell, Donald; Neal, Clive

    2016-01-01

    It is widely accepted that the Apollo 15 green and Apollo 17 orange glass beads are of volcanic origin. The diffusion profiles of volatiles in these glass beads are believed to be due to degassing during eruption (Saal et al., 2008). The degree of degassing depends on the initial temperature and cooling rate. Therefore, the estimations of volatiles in parental magmas of lunar pyroclastic deposits depend on melt cooling rates. Furthermore, lunar glass beads may have cooled in volcanic environments on the moon. Therefore, the cooling rates may be used to assess the atmospheric condition in an early moon, when volcanic activities were common. The cooling rates of glasses can be inferred from direct heat capacity measurements on the glasses themselves (Wilding et al., 1995, 1996a,b). This method does not require knowledge of glass cooling environments and has been applied to calculate the cooling rates of natural silicate glasses formed in different terrestrial environments. We have carried out heat capacity measurements on hand-picked lunar glass beads using a Netzsch DSC 404C Pegasus differential scanning calorimeter at University of Munich. Our preliminary results suggest that the cooling rate of Apollo 17 orange glass beads may be 12 K/min, based on the correlation between temperature of the heat capacity curve peak in the glass transition range and glass cooling rate. The results imply that the parental magmas of lunar pyroclastic deposits may have contained more water initially than the early estimations (Saal et al., 2008), which used higher cooling rates, 60-180 K/min in the modeling. Furthermore, lunar volcanic glass beads could have been cooled in a hot gaseous medium released from volcanic eruptions, not during free flight. Therefore, our results may shed light on atmospheric condition in an early moon.

  17. Preparation of Affinity Column Based on Zr{sup 4+} Ion for Phosphoproteins Isolation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seon Mi; Bae, In Ae; Park, Jung Hyen; Kim, Tae Dong; Choi, Seong Ho [Hannam University, Daejeon (Korea, Republic of)

    2009-06-15

    This paper has described about preparation of Zr{sup 4+} affinity column based on the poly(styreneco- glycidyl methacrylate) prepared by emulsion polymerization of styrene and glycidyl methacrylate in order to isolate phosphopeptide. The Zr{sup 4+} ions were introduced after the phophonation of an epoxy group on polymeric microspheres. The successful preparation of Zr{sup 4+}-immobilized polymeric microsphere stationary phase was confirmed through Fourier transform infrared spectra, optical microscopy, scanning electron microscopy, X-ray photoelectron spectra and inductively coupled plasma-atomic emission spectrometer. The separation efficiency for Zr{sup 4+} affinity column prepared by slurry packing was tested to phosphonated casein and dephosphonated casein. The resolution time (min) of the phosphonated casein was higher than that of dephosphated casein for Zr{sup 4+} affinity polymeric microsphere by liquid chromatography. This Zr{sup 4+} affinity column can be used for isolation of phosphonated casein from casein using liquid chromatography.

  18. Ethanol production by immobilized yeast and its CO2 gas effects on a packed bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Cho, G M; Choi, C Y; Choi, Y D; Han, M H

    1982-10-01

    Immobilised yeast trapped in an alginate matrix demonstrated maximum activity at 30 degrees C and showed no pH effect between 3 and 7. Substrate inhibition was observed at glucose concentrations above 8% but the immobilised cells retained 70% of their maximum activity at 20% glucose concentration. The operation stability of immobilised cells was lower in simple glucose solution than in the activation medium in which only 20% of the activity was lost after 10 days operation. Inactivated immobilised yeast beads were reactivated by incubation in activation medium without a significant increase in cell numbers in a bead. During the operation of the immobilised yeast in a packed bed reactor, CO/sub 2/ gas accumulation adversely affected the reactor performance. An ideal plus flow reactor, not taking into account the formation of CO/sub 2/ gas bubbles and the presence of mass trasnfer resistance, was simulated using a kinetic model for the production of ethanol and the simulation results were compared with the actual reactor performance to determine the CO/sub 2/ gas effect, quantitatively. Up to 45% of the substrate conversion was lost due to the accumulation of CO/sub 2/ gas bubbles in all cases. (Refs. 21).

  19. Superparamagnetic poly(methyl methacrylate) beads for nattokinase purification from fermentation broth.

    Science.gov (United States)

    Yang, Chengli; Xing, Jianmin; Guan, Yueping; Liu, Huizhou

    2006-09-01

    An effective method for purification of nattokinase from fermentation broth using magnetic poly(methyl methacrylate) (PMMA) beads immobilized with p-aminobenzamidine was proposed in this study. Firstly, magnetic PMMA beads with a narrow size distribution were prepared by spraying suspension polymerization. Then, they were highly functionalized via transesterification reaction with polyethylene glycol. The surface hydroxyl-modified magnetic beads obtained were further modified with chloroethylamine to transfer the surface amino-modified magnetic functional beads. The morphology and surface functionality of the magnetic beads were examined by scanning electron microscopy and Fourier transform infrared. An affinity ligand, p-aminobenzamidine was covalently immobilized to the amino-modified magnetic beads by the glutaraldehyde method for nattokinase purification directly from the fermentation broth. The purification factor and the recovery of the enzyme activity were found to be 8.7 and 85%, respectively. The purification of nattokinase from fermentation broth by magnetic beads only took 40 min, which shows a very fast purification of nattokinase compared to traditional purification methods.

  20. COMPUTATIONAL AND EXPERIMENTAL MODELING OF SLURRY BUBBLE COLUMN REACTORS

    Energy Technology Data Exchange (ETDEWEB)

    Paul C.K. Lam; Isaac K. Gamwo; Dimitri Gidaspow

    2002-05-01

    The objective of this study was to develop a predictive experimentally verified computational fluid dynamics (CFD) model for gas-liquid-solid flow. A three dimensional transient computer code for the coupled Navier-Stokes equations for each phase was developed and is appended in this report. The principal input into the model is the viscosity of the particulate phase which was determined from a measurement of the random kinetic energy of the 800 micron glass beads and a Brookfield viscometer. The details are presented in the attached paper titled ''CFD Simulation of Flow and Turbulence in a Slurry Bubble Column''. This phase of the work is in press in a referred journal (AIChE Journal, 2002) and was presented at the Fourth International Conference on Multiphase Flow (ICMF 2001) in New Orleans, May 27-June 1, 2001 (Paper No. 909). The computed time averaged particle velocities and concentrations agree with Particle Image Velocimetry (PIV) measurements of velocities and concentrations, obtained using a combination of gamma-ray and X-ray densitometers, in a slurry bubble column, operated in the bubbly-coalesced fluidization regime with continuous flow of water. Both the experiment and the simulation show a down-flow of particles in the center of the column and up-flow near the walls and nearly uniform particle concentration. Normal and shear Reynolds stresses were constructed from the computed instantaneous particle velocities. The PIV measurement and the simulation produced instantaneous particle velocities. The PIV measurement and the simulation produced similar nearly flat horizontal profiles of turbulent kinetic energy of particles. To better understand turbulence we studied fluidization in a liquid-solid bed. This work was also presented at the Fourth International Conference on Multiphase Flow (ICMF 2001, Paper No. 910). To understand turbulence in risers, measurements were done in the IIT riser with 530 micron glass beads using a PIV

  1. Enzymatic synthesis of 13N-β-nicotinamide adenine dinucleotide

    International Nuclear Information System (INIS)

    Lambrecht, R.H.D.; Slegers, G.; Claeys, A.; Vandecasteele, C.

    1985-01-01

    Nitrogen-13-labelled β-nicotinamide adenine dinucleotide ( 13 N-NAD) is an interesting new compound for positron emission tomography. A semi-automatic production method is developed that yields a solution of 13 N-NAD of radiopharmaceutical quality, suitable for human intravenous administration. The 13 N-NAD is prepared enzymatically in one step from cyclotron-produced 13 NH 3 and nicotinic acid adenine dinucleotide (deamido-NAD). The enzyme NAD synthetase (E.C. 6.3.1.5), catalysing this reaction, is extracted and purified from Escherichia coli. The purified enzyme is immobilized by glutaraldehyde coupling to γ-aminopropylsilane-coated porous glass beads. The enzyme-loaded glass beads are packed in a column. The kinetic properties of the column are optimized. For synthetizing 13 N-NAD, the mixture of co-factors and substrates, containing 13 NH 3 , is pumped over the enzyme column. The unreacted 13 NH 3 is separated from 13 N-NAD by on-line passage over a cation exchanger. After passing over a millipore filter, a sterile solution of radiochemically pure 13 N-NAD is obtained, containing 70 mCi in 10 mL. The total synthesis time is 10 minutes. The specific activity is about 120 mCi/μmol at EOB. Quality control includes sterility and pyrogen tests, HPLC and HPTLC analysis. (author)

  2. Effects of Shear Fracture on In-depth Profile Modification of Weak Gels

    Institute of Scientific and Technical Information of China (English)

    Li Xianjie; Song Xinwang; Yue Xiang'an; Hou Jirui; Fang Lichun; Zhang Huazhen

    2007-01-01

    Two sand packs were filled with fine glass beads and quartz sand respectively. The characteristics of crosslinked polymer flowing through the sand packs as well as the influence of shear fracture of porous media on the in-depth profile modification of the weak gel generated from the crosslinked polymer were investigated. The results indicated that under the dynamic condition crosslinking reaction happened in both sand packs,and the weak gels in these two cases became small gel particles after water flooding. The differences were:the dynamic gelation time in the quartz sand pack was longer than that in the glass bead pack. Residual resistance factor (FRR) caused by the weak gel in the quartz sand pack was smaller than that in the glass bead pack. The weak gel became gel particles after being scoured by subsequent flood water. A weak gel with uniform apparent viscosity and sealing characteristics was generated in every part of the glass bead pack,which could not only move deeply into the sand pack but also seal the high capacity channels again when it reached the deep part. The weak gel performed in-depth profile modification in the glass bead pack,while in the quartz sand pack,the weak gel was concentrated with 100 cm from the entrance of the sand pack. When propelled by the subsequent flood water,the weak gel could move towards the deep part of the sand pack but then became tiny gel particles and could not effectively seal the high capacity channels there. The in-depth profile modification of the weak gel was very weak in the quartz sand pack. It was the shear fracture of porous media that mainly affected the properties and weakened the in-depth profile modification of the weak gel.

  3. Transarterial chemoembolization with drug-eluting beads in hepatocellular carcinoma

    Science.gov (United States)

    Nam, Hee Chul; Jang, Bohyun; Song, Myeong Jun

    2016-01-01

    Transarterial chemoembolization (TACE) is a widely used standard treatment for patients with hepatocellular carcinoma (HCC) who are not suitable candidates for curative treatments. The rationale for TACE is that intra-arterial chemotherapy using lipiodol and chemotherapeutic agents, followed by selective vascular embolization, results in a strong cytotoxic effect as well as ischemia (conventional TACE). Recently, drug-eluting beads (DC Beads®) have been developed for transcatheter treatment of HCC to deliver higher doses of the chemotherapeutic agent and to prolong contact time with the tumor. DC Beads® can actively sequester doxorubicin hydrochloride from solution and release it in a controlled sustained fashion. Treatment with DC Beads® substantially reduced the amount of chemotherapeutic agent that reached the systemic circulation compared with conventional, lipiodol-based regimens, significantly reducing drug-related adverse events. In this article, we describe the treatment response, survival, and safety of TACE used with drug-eluting beads for the treatment of HCC and discuss future therapeutic possibilities. PMID:27833376

  4. Environmental Conditions Influencing Sorption of Inorganic Anions to Multiwalled Carbon Nanotubes Studied by Column Chromatography.

    Science.gov (United States)

    Metzelder, Florian; Schmidt, Torsten C

    2017-05-02

    Sorption to carbon-based nanomaterials is typically studied in batch experiments. An alternative method offering advantages to study sorption is column chromatography. Sorbent packed columns are used and sorption data are determined by relating sorbate retention to that of a nonretarded tracer. We have now for the first time applied this technique to study the influence of environmental conditions on sorption of inorganic anions (bromide, nitrite, nitrate, and iodide) to multiwalled carbon nanotubes. Deuterium oxide was used as nonretarded tracer. Sorption isotherms were best described by the Freundlich model. Sorption increased in the order bromide 4.5 the surface charge was negative, but sorption was still detectable at pH 6 and 9. Consequently, other forces than electrostatic attraction contributed to sorption. These forces may include H-bonding as indicated by sorption enthalpy determined by variation of column temperature. Overall, column chromatography represents a promising alternative in sorption studies to reveal sorbent properties.

  5. Bead Capture and Release on a Magnetic Sensor in a Microfluidic System

    DEFF Research Database (Denmark)

    Dalslet, Bjarke Thomas; Damsgaard, Christian Danvad; Freitas, S.C.

    Planar Hall effect magnetic sensors for detection of biological agents using surface treated magnetic beads are integrated with a fluid injection system. The response of the sensors is used to evaluate bead capture rates for different bead concentrations c and fluid flow rates Q, and to monitor...... subsequent removal of the beads. It is found that the capture rate scales directly with c and that it depends linearly on Q. At low Q the capture rate is only partially due to gravitational sedimentation of beads. At higher Q an additional term proportional to Q becomes important, which is attributed...... to capture of beads by the magnetic fields near the sensor. It is shown that beads can be washed off the sensor surface....

  6. Exogenous factors contributing to column bed heterogeneity: Part 1: Consequences of 'air' injections in liquid chromatography.

    Science.gov (United States)

    Samuelsson, Jörgen; Fornstedt, Torgny; Shalliker, Andrew

    2015-08-07

    It has been shown that not only the packing homogeneity, but also factors external to the column bed, such as, frits and distributors can have important effects on the column performance. This current communication is the first in a series focusing on the impact of exogenous factors on the column bed heterogeneity. This study is based on several observations by us and others that chromatographic runs often, for technical reasons, include more or less portions of air in the injections. It is therefore extremely important to find out the impact of air on the column performance, the reliability of the results derived from analyses where air was injected, and the effect on the column homogeneity. We used a photographic approach for visualising the air transport phenomena, and found that the air transport through the column is comprised of many different types of transport phenomena, such as laminal flow, viscous fingering like flows, channels and bulbs, and pulsations. More particularly, the air clouds within the column definitely interact in the adsorption, i.e. mobile phase adsorbed to the column surface is displaced. In addition, irrespective of the type of air transport phenomena, the air does not penetrate the column homogeneously. This process is strongly flow dependent. In this work we study air transport both in an analytical scale and a semi-prep column. Copyright © 2015. Published by Elsevier B.V.

  7. Internal states of model isotropic granular packings. I. Assembling process, geometry, and contact networks.

    Science.gov (United States)

    Agnolin, Ivana; Roux, Jean-Noël

    2007-12-01

    This is the first paper of a series of three, in which we report on numerical simulation studies of geometric and mechanical properties of static assemblies of spherical beads under an isotropic pressure. The influence of various assembling processes on packing microstructures is investigated. It is accurately checked that frictionless systems assemble in the unique random close packing (RCP) state in the low pressure limit if the compression process is fast enough, higher solid fractions corresponding to more ordered configurations with traces of crystallization. Specific properties directly related to isostaticity of the force-carrying structure in the rigid limit are discussed. With frictional grains, different preparation procedures result in quite different inner structures that cannot be classified by the sole density. If partly or completely lubricated they will assemble like frictionless ones, approaching the RCP solid fraction Phi_{RCP} approximately 0.639 with a high coordination number: z* approximately =6 on the force-carrying backbone. If compressed with a realistic coefficient of friction mu=0.3 packings stabilize in a loose state with Phi approximately 0.593 and z* approximately =4.5 . And, more surprisingly, an idealized "vibration" procedure, which maintains an agitated, collisional regime up to high densities results in equally small values of z* while Phi is close to the maximum value Phi_{RCP}. Low coordination packings have a large proportion (>10%) of rattlers--grains carrying no force--the effect of which should be accounted for on studying position correlations, and also contain a small proportion of localized "floppy modes" associated with divalent grains. Low-pressure states of frictional packings retain a finite level of force indeterminacy even when assembled with the slowest compression rates simulated, except in the case when the friction coefficient tends to infinity. Different microstructures are characterized in terms of near

  8. Polymerized serum albumin beads for use as slow-release adjuvants

    International Nuclear Information System (INIS)

    Martin, M.E.D.

    1987-02-01

    Experimental vaccines have been made by covalently bonding virus particles into polymerized rabbit serum albumin beads. Using Nodamura virus as a model antigen, these model vaccines induced specific humoral antibody production, comparable with that achieved using Freund's adjuvants. Virus specific antibodies were also induced when Nodamura virus was covalently attached to the bead surface using different crosslinkers. However, when poliovirus type 2 (Sabin strain) was polymerized into beads, the levels of neutralizing antibodies were insignificant compared with control aqueous vaccines. The synthetic immunostimulator, muramyl dipeptide, was included with bead vaccines in an attempt to potentiate the immune response. Immunostimulation is achieved by a slow release of antigen coinciding with the gradual breakdown of bead structure. Methods used include radio-iodination and radioimmunoassay. 65 figs., 6 tabs., 173 refs

  9. Studies on transfer phenomena of tritium from liquid to gaseous phase in a successive catalyst and ordered packing system

    International Nuclear Information System (INIS)

    Bornea, Anisia; Cristescu, Ion; Zamfirache, Marius; Varlam, Carmen

    2001-01-01

    The processes for hydrogen isotope separation are very important for nuclear technology. One of the most important processes in tritium separation, is the water-hydrogen catalytic isotope exchange. In a column of isotope exchange, tritium is transferred from the liquid phase (tritiated heavy water) to the gaseous phase (hydrogen). In the experimental set-up, which was used, the column of catalytic isotope exchange is filled with successive layers of catalyst Pt/C/PtFe and B7 type ordered packing of phosphor bronze. The tritium transfer from liquid phase to water vapours, is achieved on ordered packing by distillation process: (DTO)L+(D 2 O)V → (D 2 O)L+(DTO)V. On the catalytic tritium transfer from water vapours to hydrogen gas is achieved by the catalytic isotopic exchange process: (DTO)V+(D 2 )G → (D 2 O)V+(DT)G. We analyzed the transfer phenomena of tritium in this system by using the experimental data obtained. The mathematical model presented in the paper allowed computing experimental data for testing the catalyst performances. The transfer equations are solved using the Runge - Kutta method. In this way the speed constants which characterized the isotopic exchange on the catalysis bed ks, and the distillation on the ordered packing kd, were expressed as function of experimental concentrations and hydrodynamic conditions. (authors)

  10. Effect of formulation of alginate beads on their mechanical behavior and stiffness

    Institute of Scientific and Technical Information of China (English)

    Eng-Seng Chan; Tek-Kaun Lim; Wan-Ping Voo; Ravindra Pogaku; Beng Ti Tey; Zhibing Zhang

    2011-01-01

    The aim of this work was to determine the effect of formulation of alginate beads on their mechanical behavior and stiffness when compressed at high speed. The alginate beads were formulated using different types and concentrations of alginate and gelling cations and were produced using an extrusiondripping method. Single wet beads were compressed at a speed of 40 mm/min, and their elastic limits were investigated, and the corresponding force versus displacement data were obtained. The Young's moduli of the beads were determined from the force versus displacement data using the Hertz's contact mechanics theory. The alginate beads were found to exhibit plastic behavior when they were compressed beyond 50% with the exception of copper-alginate beads for which yield occured at lower deformation.Alginate beads made of higher guluronic acid contents and gelling cations of higher chemical affinity were found to have greater stiffness. Increasing the concentration of alginate and gelling ions also generated a similar effect. At such a compression speed, the values of Young's modulus of the beads were found to be in the range between 250 and 900 kPa depending on the bead formulation.

  11. ADSORPTION AND RELEASING PROPERTIES OF BEAD CELLULOSE

    Institute of Scientific and Technical Information of China (English)

    A. Morales; E. Bordallo; V. Leon; J. Rieumont

    2004-01-01

    The adsorption of some dyes on samples of bead cellulose obtained in the Unit of Research-Production "Cuba 9"was studied. Methylene blue, alizarin red and congo red fitted the adsorption isotherm of Langmuir. Adsorption kinetics at pH = 6 was linear with the square root of time indicating the diffusion is the controlling step. At pH = 12 a non-Fickian trend was observed and adsorption was higher for the first two dyes. Experiments carried out to release the methylene blue occluded in the cellulose beads gave a kinetic behavior of zero order. The study of cytochrome C adsorption was included to test a proteinic material. Crosslinking of bead cellulose was performed with epichlorohydrin decreasing its adsorption capacity in acidic or alkaline solution.

  12. Optimization of weld bead geometry of MS plate

    Indian Academy of Sciences (India)

    The considered specimen was checked to harmonize the optimum setting between input factors, for example, welding current, open circuit voltage, and thickness of plate, with respect to obtaining prosperous weld strength as well as bead geometry quality characteristics, for example, tensile strength, bead width, ...

  13. Simultaneous removal of CO2 and H2S using MEA solution in a packed column absorber for biogas upgrading

    Directory of Open Access Journals (Sweden)

    Preecha Kasikamphaiboon

    2013-12-01

    Full Text Available Biogas production and utilization is an emerging alternative energy technology that has gained importance since the price of oil and gas has increased steadily over the last two decades. Biogas primarily consists of methane (CH4 and carbon dioxide (CO2 with smaller amounts of hydrogen sulfide (H2S and ammonia (NH3. For many applications the quality of biogas has to be improved. The main parameters that may require removal in upgrading systems are CO2 and H2S. This work presents the study of simultaneous absorption of CO2 and H2S by Monoethanolamine (MEA solution in a packed column. Simulated biogas containing 40% CO2 and 60% N2 and biogas generated from an anaerobic digestion plant were used as feed gas streams. The effects of gas flow rate, L/G ratio and absorbent concentration were investigated. The performance of the system was found to vary with process parameters. Increasing L/G ratio and MEA concentration causes the system efficiency to increase whereas increasing gas flow rate results in lower efficiency. An operating condition of L/G ratio of 83.3 ml/L, gas flow rate of 3 L/min and MEA concentration of 3 mol/L was found to remove more than 99.5% of CO2 and H2S from biogas. The volumetric overall mass-transfer coefficient (KGav for CO2 removal initially increases with increasing gas flow rate up to a certain value beyond which the coefficient becomes essentially constant. The KGav also increases with increasing L/G ratio throughout the range tested in this study.

  14. On-chip signal amplification of magnetic bead-based immunoassay by aviating magnetic bead chains.

    Science.gov (United States)

    Jalal, Uddin M; Jin, Gyeong Jun; Eom, Kyu Shik; Kim, Min Ho; Shim, Joon S

    2017-11-06

    In this work, a Lab-on-a-Chip (LOC) platform is used to electromagnetically actuate magnetic bead chains for an enhanced immunoassay. Custom-made electromagnets generate a magnetic field to form, rotate, lift and lower the magnetic bead chains (MBCs). The cost-effective, disposable LOC platform was made with a polymer substrate and an on-chip electrochemical sensor patterned via the screen-printing process. The movement of the MBCs is controlled to improve the electrochemical signal up to 230% when detecting beta-type human chorionic gonadotropin (β-hCG). Thus, the proposed on-chip MBC-based immunoassay is applicable for rapid, qualitative electrochemical point-of-care (POC) analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Processes Leading to Beaded Channels Formation in Central Yakutia

    Science.gov (United States)

    Tarbeeva, A. M.; Lebedeva, L.; Efremov, V. S.; Krylenko, I. V.; Surkov, V. V.

    2017-12-01

    Beaded channels, consisting of deepened and widened pools and connecting narrow runs, are common fluvial forms in permafrost regions. Recent studies have shown that beaded channels are very important for connecting alluvial rivers with headwater lakes allowing fish passage and foraging habitats, as well as regulating river runoff. Beaded channels are known as typical thermokarst landforms; however, there is no evidence of their origin and formative processes. Geomorphological analyzes of beaded channels have been completed in several permafrost regions including field observations of Shestakovka River in Central Yakutia. The study aims to recognize the modern exogenic processes and formative mechanisms of beaded river channels. We show that beaded channel of Shestakovka River form in the perennially frozen sand with low ice content, leading us to hypothesize that thermokarst is not the main process of formation. Due to the significant volume of water, the pools don't freeze over entirely during winters, even under harsh climatic conditions. As a result, lenses of pressurized water remain under surface ice underlain by perennially thawed sediments. The presence of thawed sediments under the pools and frozen sediments under the runs leads to uneven thermoerosion of the riverbed during floods, providing the beaded form of the channel. In addition, freezing of pools during winter leads to pressure increasing under ice cover and formation of ice mounds, which crack several times during winter leading to disturbance of riverbanks. Many 1st to 3rd order streams have a specific transitional meandering-to-beaded form resembling the shape of unconfined meandering rivers, but consisting of pools and runs. However, such channels exhibit no evidences of present-day erosion of concave banks and sediment accumulation at the convex banks as typically being observed in normally meandering rivers. Such forms of channels indicates that their formation occurred by the greater channel

  16. Synthesis and characterization of monosize magnetic poly(glycidyl methacrylate) beads

    Institute of Scientific and Technical Information of China (English)

    Evrim Banu Alt1nta(s); Lokman Uzun; Adil Denizli

    2007-01-01

    Monosize, 1.6 μm, magnetic beads of poly(glycidyl methacrylate) [M-poly(GMA)], were prepared by dispersion polymerization in the presence of Fe3O4 nano-powder. Monosize M-poly(GMA) beads were characterized by swelling tests, density measurements, electron spin resonance (ESR), vibrating sample magnetometer (VSM) and scanning electron microscopy (SEM). The characteristic functional groups of M-poly(GMA)beads were analyzed by Fourier transform infrared spectrometer (FTIR). The M-poly(GMA) beads are highly uniform in size and have a spherical shape and non-porous structure. Polydispersity index (PDI) of M-poly(GMA) beads was calculated to be around 1.008. The hydrated density of the M-poly(GMA) beads measured at 25 ℃ was 1.14 g/cm3. The content of oxirane groups on the surface of the M-poly(GMA) sample was found to be 3.46 mmol/g by using perchloric acid titration. The specific surface area of the M-poly(GMA) beads was determined to be 3.2 m2/g.The equilibrium swelling ratio was 52%. The volume fraction of magnetite nanopowder in the M-poly(GMA) beads was found to be 4.5%. The g factor, that can be considered as a quantity characteristic of the molecules in which the unpaired electrons are located, was found to be 2.28for M-poly(GMA). The external magnetic field at resonance was calculated to be 2055 Gs which was found sufficient to excite all of the dipole moments present in 1.0 g of M-poly(GMA) sample.

  17. Influence of Immobilized Biomolecules on Magnetic Bead Plug Formation and Retention in Capillary Electrophoresis

    Science.gov (United States)

    Henken, Rachel L.; Chantiwas, Rattikan; Gilman, S. Douglass

    2012-01-01

    Significant changes in the formation and retention of magnetic bead plugs in a capillary during electrophoresis were studied, and it was demonstrated that these effects were due to the type of biological molecule immobilized on the surface of these beads. Three biological molecules, an antibody, an oligonucleotide and alkaline phosphatase, were attached to otherwise identical streptavidin-coated magnetic beads through biotin-avidin binding in order to isolate differences in bead immobilization in a magnetic field resulting from the type of biological molecule immobilized on the bead surface. Alkaline phosphatase also was attached to the magnetic beads using epoxy groups on the bead surfaces (instead of avidin-biotin binding) to study the impact of immobilization chemistry. The formation and retention of magnetic bead plugs were studied quantitatively using light scattering detection of magnetic particles eluting from the bead plugs and qualitatively using microscopy. Both the type of biomolecule immobilized on the magnetic bead surface and the chemistry used to link the biomolecule to the magnetic bead impacted the formation and retention of the bead plugs. PMID:22437880

  18. LIQUID CHROMATOGRAPHIC / MASS SPECTROMETRIC DETERMINATION OF MORPHINE, CODEINE AND COCAINE IN HUMAN SERA USING A NEW INTERNAL SURFACE REVERSED PHASE COLUMN

    OpenAIRE

    Hattori, Hideki; Arinobu, Tetsuya; Iwai, Masae; Suzuki, Osamu; Seno, Hiroshi

    2003-01-01

    A new internal surface reversed phase column (Shim-pack MAYI-ODS) was used for analysis of morphine, codeine and cocaine in human sera by LC/MS/MS. The column enabled direct injection of crude biological samples without pretreatment realizing a rapid analytical procedure. Therecoveries of morphine, codeine and cocaine spiked into human sera were 50-60 %. The regression equations for morphine, codeine and cocaine in sera, using atropine as internal standard, showed good linearity in the ranges...

  19. Removal of Uranium from Aqueous Solution by Alginate Beads

    Directory of Open Access Journals (Sweden)

    Jing Yu

    2017-04-01

    Full Text Available The adsorption of uranium (VI by calcium alginate beads was examined by batch experiments. The effects of environmental conditions on U (VI adsorption were studied, including contact time, pH, initial concentration of U (VI, and temperature. The alginate beads were characterized by using scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. Fourier transform infrared spectra indicated that hydroxyl and alkoxy groups are present at the surface of the beads. The experimental results showed that the adsorption of U (VI by alginate beads was strongly dependent on pH, the adsorption increased at pH 3∼7, then decreased at pH 7∼9. The adsorption reached equilibrium within 2 minutes. The adsorption kinetics of U (VI onto alginate beads can be described by a pseudo first-order kinetic model. The adsorption isotherm can be described by the Redlich-Peterson model, and the maximum adsorption capacity was 237.15 mg/g. The sorption process is spontaneous and has an exothermic reaction.

  20. Removal of uranium from aqueous solution by aliginate beads

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Jing; Wang, Jian Long [Collaborative Innovation Center for Advanced Nuclear Energy Technology, INET, Tsinghua University, Beijing (China); Jiang, Yizhou [Northwest Institute of Nuclear Technology, Xian (China)

    2017-04-15

    The adsorption of uranium (VI) by calcium alginate beads was examined by batch experiments. The effects of environmental conditions on U (VI) adsorption were studied, including contact time, pH, initial concentration of U (VI), and temperature. The alginate beads were characterized by using scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. Fourier transform infrared spectra indicated that hydroxyl and alkoxy groups are present at the surface of the beads. The experimental results showed that the adsorption of U (VI) by alginate beads was strongly dependent on pH, the adsorption increased at pH 3∼7, then decreased at pH 7∼9. The adsorption reached equilibrium within 2 minutes. The adsorption kinetics of U (VI) onto alginate beads can be described by a pseudo first-order kinetic model. The adsorption isotherm can be described by the Redlich-Peterson model, and the maximum adsorption capacity was 237.15 mg/g. The sorption process is spontaneous and has an exothermic reaction.

  1. On-chip measurements of Brownian relaxation vs. concentration of 40nm magnetic beads

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Rizzi, Giovanni; Hansen, Mikkel Fougt

    2012-01-01

    We present on-chip Brownian relaxation measurements on a logarithmic dilution series of 40 nm beads dispersed in water with bead concentrations between 16 mu g/ml and 4000 mu g/ml. The measurements are performed using a planar Hall effect bridge sensor at frequencies up to 1 MHz. No external fields...... are needed as the beads are magnetized by the field generated by the applied sensor bias current. We show that the Brownian relaxation frequency can be extracted from fitting the Cole-Cole model to measurements for bead concentrations of 64 mu g/ml or higher and that the measured dynamic magnetic response...... is proportional to the bead concentration. For bead concentrations higher than or equal to 500 mu g/ml, we extract a hydrodynamic diameter of 47(1) nm for the beads, which is close to the nominal bead size of 40 nm. Furthermore, we study the signal vs. bead concentration at a fixed frequency close to the Brownian...

  2. Oxytetracycline removal from water by novel microbial embedding gel beads

    Science.gov (United States)

    Wu, Nan; Pan, Peng; Zeng, Ming; Wang, Wei; Xu, Chenshan; Zhang, Zongpeng; Liu, Xinyuan; Wang, Yichao

    2018-01-01

    As a common antibiotic in aquatic environment, excessive oxytetracycline (OTC) is urgent to be removed due to its great biological toxicity. Compared with the traditional activated sludge, microbial embedding can enhance the treating efficiency. In this study, novel microbial embedding gel beads were produced with the additional agent of cyclodextrin (CD). Results show that CD could increase the mass transfer of OTC into gel beads, possibly because of its strong affinity for organic matters. In terms of OTC biodegradation, gel beads with CD were comparable to gel beads without CD, while the former’s sucrose removal efficiency was higher than the latter. The biodegradation of OTC only occurred in the presence of sucrose. The respiration test also confirmed these findings. Overall, the produced novel gel beads modified with CD could improve the removal performance of OTC.

  3. Fixed-bed column study for 90Sr removal from solution by sunflower straw

    International Nuclear Information System (INIS)

    Ai Lian; Luo Xuegang; Lin Xiaoyan; Li Wenming

    2014-01-01

    This paper deals with removal of strontium ions from solution by sunflower straw. Metal sorption performance of the packed column was assessed under variable operating conditions, such as, bed depths, flow rates and initial influent strontium concentration. It was found that the breakthrough time and the depletion time were extended with increase of bed heights but obviously shortened with increase of influent concentration and flow rates, respectively. The equilibrium uptake (q e(exp) ) of sunflower straw increased with increase in initial influent strontium concentration and flow rates but decreased with increase in bed depth, respectively. The data in regard to the effect of bed depths were fitted well to the Bohrat-Adams model. The saturated column was successfully regenerated by 0.1 mol/L hydrogen chloride solution and sunflower straw could be reused in strontium removal. The results indicated that the column could efficiently remove strontium ions from real industrial effluents, and hence the sunflower straw is a good candidate for commercial application. (authors)

  4. Magnetic measurements of suspended functionalised ferromagnetic beads under DC applied fields

    International Nuclear Information System (INIS)

    De Los Santos V, Luis; Llandro, Justin; Lee, Dongwook; Mitrelias, Thanos; Palfreyman, Justin J.; Hayward, Thomas J.; Cooper, Jos; Bland, J.A.C.; Barnes, Crispin H.W.; Arroyo C, Juan L.; Lees, Martin

    2009-01-01

    In this work, a simple technique to obtain the hysteresis loops of magnetic beads (Spherotech Inc.) in liquid suspension is presented. The magnetic measurements were taken in a DC Magnetic Property Measurement System (MPMS-SQUID sensor). Samples were based on ferromagnetic beads (surface-functionalized NH 2 , mean diameter 4.32 μm) prepared in three conditions: dry, suspended in sucrose solution and in suspension after functionalization with fluorophore. Special small containers (1.3 cm long) made of non magnetic plastic were designed to hold the beads in liquid. The results indicate that the bead's remnant magnetization is half of the value at maximum applied field in all cases. However, due to the additional degrees of rotational freedom, beads suspended in a liquid do not present coercivity. The use of ferromagnetic beads and magnetic elements of different architectures for applications in bioassays is also discussed.

  5. Use of antibiotic beads to salvage infected breast implants.

    Science.gov (United States)

    Sherif, Rami D; Ingargiola, Michael; Sanati-Mehrizy, Paymon; Torina, Philip J; Harmaty, Marco A

    2017-10-01

    When an implant becomes infected, implant salvage is often performed where the implant is removed, capsulectomy is performed, and a new implant is inserted. The patient is discharged with a PICC line and 6-8 weeks of intravenous (IV) antibiotics. This method has variable success and subjects the patient to long-term systemic antibiotics. In the 1960s, the use of antibiotic-impregnated beads for the treatment of chronic osteomyelitis was described. These beads deliver antibiotic directly to the site of the infection, thereby eliminating the complications of systemic IV antibiotics. This study aimed to present a case series illustrating the use of STIMULAN calcium sulfate beads loaded with vancomycin and tobramycin to increase the rate of salvage of the infected implant and forgo IV antibiotics. A retrospective analysis was performed of patients who were treated at Mount Sinai Hospital for implant infection with salvage and antibiotic beads. Twelve patients were identified, 10 of whom had breast cancer. Comorbidities included hypertension, smoking, and immunocompromised status. Infections were noted anywhere from 5 days to 8 years postoperatively. Salvage was successful in 9 out of the 12 infected implants using antibiotic bead therapy without home IV antibiotics. The use of antibiotic beads is promising for salvaging infected breast implants without IV antibiotics. Seventy-five percent of the implants were successfully salvaged. Of the three patients who had unsalvageable implants, one was infected with antibiotic-resistant Rhodococcus that was refractory to bead therapy and one was noncompliant with postoperative instructions. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  6. SparseBeads data: benchmarking sparsity-regularized computed tomography

    DEFF Research Database (Denmark)

    Jørgensen, Jakob Sauer; Coban, Sophia B.; Lionheart, William R. B.

    2017-01-01

    -regularized reconstruction. A collection of 48 x-ray CT datasets called SparseBeads was designed for benchmarking SR reconstruction algorithms. Beadpacks comprising glass beads of five different sizes as well as mixtures were scanned in a micro-CT scanner to provide structured datasets with variable image sparsity levels...

  7. Volatile Removal Assembly Flight Experiment and KC-135 Packed Bed Experiment: Results and Lessons Learned

    Science.gov (United States)

    Holder, Donald W.; Parker, David

    2000-01-01

    The Volatile Removal Assembly (VRA) is a high temperature catalytic oxidation process that will be used as the final treatment for recycled water aboard the International Space Station (ISS). The multiphase nature of the process had raised concerns as to the performance of the VRA in a microgravity environment. To address these concerns, two experiments were designed. The VRA Flight Experiment (VRAFE) was designed to test a full size VRA under controlled conditions in microgravity aboard the SPACEHAB module and in a 1 -g environment and compare the performance results. The second experiment relied on visualization of two-phase flow through small column packed beds and was designed to fly aboard NASA's microgravity test bed plane (KC-135). The objective of the KC-135 experiment was to understand the two-phase fluid flow distribution in a packed bed in microgravity. On Space Transportation System (STS) flight 96 (May 1999), the VRA FE was successfully operated and in June 1999 the KC-135 packed bed testing was completed. This paper provides an overview of the experiments and a summary of the results and findings.

  8. Biosorption of uranium by Pseudomonas aeruginosa strain CSU immobilized in a novel matrix

    International Nuclear Information System (INIS)

    Hu, M.C.Z.; Reeves, M.

    1997-01-01

    A number of polymeric materials, including calcium alginate, polyacrylamide, polysulfone, and polyurethane, were evaluated as possible immobilization matrices for lyophilized biomass of P. aeruginoso CSU. Polyurethane-based materials such as hydrogel were identified as superior candidates for biomass immobilization. A novel polyurethane gel-bead fabrication technique was developed and successfully demonstrated at pilot-plant scale for producing mass qualities of spherical, uniform-size beads. The immobilized bacterial biomass was evaluated via the measurement of sorption isotherms and dynamics within a batch, stirred-tank reactor; and loading and elution behavior within a continuous, upflow, packed-bed columnar reactor. Sorption equilibrium and dynamics in a batch stirred tank were modeled with a pore-diffusion mass transfer model, by which a pore-diffusion coefficient was determined to be approximately 2.0 x 10 -6 cm 2 /s for uranyl ion transport through the polyurethane gel matrix. The biosorbent beads were regenerable with dilute (0.01-0.1 M) sodium carbonate solutions. Preliminary column breakthrough-elution studies indicated that P. aeruginosa CSU biomass immobilized within polyurethane gel beads was effective for removal of uranium from low-concentration, acidic wastewater. 35 refs., 9 figs., 4 tabs

  9. REVIEW: CHITOSAN BASED HYDROGEL POLYMERIC BEADS – AS DRUG DELIVERY SYSTEM

    Directory of Open Access Journals (Sweden)

    Manjusha Rani

    2010-11-01

    Full Text Available Chitosan obtained by alkaline deacetylation of chitin is a non-toxic, biocompatible, and biodegradable natural polymer. Chitosan-based hydrogel polymeric beads have been extensively studied as micro- or nano-particulate carriers in the pharmaceutical and medical fields, where they have shown promise for drug delivery as a result of their controlled and sustained release properties, as well as biocompatibility with tissue and cells. To introduce desired properties and enlarge the scope of the potential applications of chitosan, graft copolymerization with natural or synthetic polymers on it has been carried out, and also, various chitosan derivatives have been utilized to form beads. The desired kinetics, duration, and rate of drug release up to therapeutical level from polymeric beads are limited by specific conditions such as beads material and their composition, bead preparation method, amount of drug loading, drug solubility, and drug polymer interaction. The present review summarizes most of the available reports about compositional and structural effects of chitosan-based hydrogel polymeric beads on swelling, drug loading, and releasing properties. From the studies reviewed it is concluded that chitosan-based hydrogel polymeric beads are promising drug delivery systems.

  10. Design of systems for handling radioactive ion exchange resin beads

    International Nuclear Information System (INIS)

    Shapiro, S.A.; Story, G.L.

    1979-01-01

    The flow of slurries in pipes is a complex phenomenon. There are little slurry data available on which to base the design of systems for radioactive ion exchange resin beads and, as a result, the designs vary markedly in operating plants. With several plants on-line, the opportunity now exists to evaluate the designs of systems handling high activity spent resin beads. Results of testing at Robbins and Meyers Pump Division to quantify the behavior of resin bead slurries are presented. These tests evaluated the following slurry parameters; resin slurry velocity, pressure drop, bead degradation, and slurry concentration effects. A discussion of the general characteristics of resin bead slurries is presented along with a correlation to enable the designer to establish the proper flowrate for a given slurry composition and flow regime as a function of line size. Guidelines to follow in designing a resin handling system are presented

  11. Flow Cytometry-Based Bead-Binding Assay for Measuring Receptor Ligand Specificity

    NARCIS (Netherlands)

    Sprokholt, Joris K.; Hertoghs, Nina; Geijtenbeek, Teunis B. H.

    2016-01-01

    In this chapter we describe a fluorescent bead-binding assay, which is an efficient and feasible method to measure interaction between ligands and receptors on cells. In principle, any ligand can be coated on fluorescent beads either directly or via antibodies. Binding between ligand-coated beads

  12. 49 CFR 173.221 - Polymeric beads, expandable and Plastic molding compound.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Polymeric beads, expandable and Plastic molding... Than Class 1 and Class 7 § 173.221 Polymeric beads, expandable and Plastic molding compound. (a) Non-bulk shipments of Polymeric beads (or granules), expandable, evolving flammable vapor and Plastic...

  13. Numerical analysis and optimisation of heavy water upgrading column

    International Nuclear Information System (INIS)

    Sankar, Rama; Ghosh, Brindaban; Bhanja, K.

    2013-01-01

    In the 'Pressurised Heavy Water' type of reactors, heavy water is used both as moderator and coolant. During operation of reactor downgraded heavy water is generated that needs to be upgraded for reuse in the reactor. When the isotopic purity of heavy water becomes less than 99.75%, it is termed as downgraded heavy water. Downgraded heavy water also contains impurity such as corrosion products, dirt, oil etc. Upgradation of downgraded heavy water is normally done in two steps: (i) Purification: In this step downgraded heavy water is first purified to remove corrosion products, dirt, oil, etc. and (ii) Upgradation of heavy water to increase its isotopic purity, this step is carried out by vacuum distillation of downgraded heavy water after purification. This project is aimed at mathematical modelling and numerical simulation of heavy water upgrading column. Modelling and simulation studies of the upgradation column are based on equilibrium stage model to evaluate the effect of feed location, pressure, feed composition, reflux ratio in the packed column for given reboiler and condenser duty of distillation column. State to stage modelling of two-phase two-component flow has constitutes the overall modelling of the column. The governing equations consist of stage-wise species and overall mass continuity and stage-wise energy balance. This results in tridigonal matrix equation for stage liquid fractions for heavy and light water. The stage-wise liquid flow rates and temperatures are governed by stage-wise mass and energy balance. The combined form of the corresponding governing equations, with the incorporation of thermodynamic equation of states, form a system of nonlinear equations. This system have been resolved numerically using modified Newton-Raphson method. A code in the MATLAB platform has been developed by on above numerical procedure. The optimisation of the column operating conditions is to be carried out based on parametric studies and analysis of different

  14. Dry reforming of methane via plasma-catalysis: influence of the catalyst nature supported on alumina in a packed-bed DBD configuration

    Science.gov (United States)

    Brune, L.; Ozkan, A.; Genty, E.; Visart de Bocarmé, T.; Reniers, F.

    2018-06-01

    These days, the consideration of CO2 as a feedstock has become the subject of more interest. The reutilization of CO2 is already possible via cold plasma techniques operating at atmospheric pressure. A promising technology is the dielectric barrier discharge (DBD). In most cases DBDs exhibit a low energy efficiency for CO2 conversion. However, several routes can be used to increase this efficiency and hence, the product formation. One of these routes is the packed-bed DBD configuration with porous beads inside the gap of the DBD, which also allows the coupling of plasma with catalysis. Catalysts can be introduced in such a configuration to exploit the synergistic effect between plasma and catalytically active surfaces, leading to a more efficient process. In this article, the dry reforming of methane (DRM) is studied, which aims to convert both CO2 and CH4, another greenhouse gas, at the same time. The conversions and energy costs of the DRM process are investigated and compared in both the packed-bed DBD configurations containing catalysts (Co, Cu or Ni) and the classical DBD. The change in filamentary behavior is studied in detail and correlated with the obtained conversions using gas chromatography, mass spectrometry and using an oscilloscope. A characterization of the catalysts on the beads is also carried out. Both the CO2 and CH4 conversions are clearly increased with the plasma-catalysis. Moreover, CH4 conversions as high as 90% can be obtained in certain conditions with copper catalysts.

  15. Development of bead-type radiophotoluminescence glass dosimeter applicable to various purposes

    International Nuclear Information System (INIS)

    Sato, F.; Toyota, Y.; Maki, D.; Zushi, N.; Kato, Y.; Yamamoto, T.; Iida, T.

    2013-01-01

    Bead-type radiophotoluminescence (RPL) glass dosimeters were well fabricated with a gas-particle jet flame system for glass melting-cooling process. A rod of silver-activated phosphate glass was pulverized into micrometer-size particles. Spherical glass particles were formed from the pulverized glass particles in the high-temperature jet flame owing to the surface tension of the glass material. Some groups of spherical glass particles were irradiated with X-rays and their RPL was demonstrably observed for their exposure to UV light. A flexible RPL glass sheet was also made of bead-type RPL glass dosimeters and was useful for radiation imaging. Bead-type RPL glass dosimeters are expected to be used for dose monitoring in highly radioactively-contaminated area. -- Highlights: ► We developed bead-type radiophotoluminescence glass dosimeters. ► Bead-type glass RPL dosimeters are satisfactorily used as radiation dosimeters. ► A flexible RPL glass sheet is made of bead-type RPL glass dosimeters

  16. A High-Throughput SU-8Microfluidic Magnetic Bead Separator

    DEFF Research Database (Denmark)

    Bu, Minqiang; Christensen, T. B.; Smistrup, Kristian

    2007-01-01

    We present a novel microfluidic magnetic bead separator based on SU-8 fabrication technique for high through-put applications. The experimental results show that magnetic beads can be captured at an efficiency of 91 % and 54 % at flow rates of 1 mL/min and 4 mL/min, respectively. Integration...... of soft magnetic elements in the chip leads to a slightly higher capturing efficiency and a more uniform distribution of captured beads over the separation chamber than the system without soft magnetic elements....

  17. On the occurrence of ‘bead lightning’ phenomena in long laboratory sparks

    Energy Technology Data Exchange (ETDEWEB)

    Vayanganie, S.P.A., E-mail: amilavayanganie@gmail.com [Atmospheric Physics and Lightning Research Group, University of Colombo, Colombo 03 (Sri Lanka); Cooray, V.; Rahman, Mahbubur; Hettiarachchi, Pasan; Diaz, Oscar [Lightning Research Group, The Ångström Laboratory Division of Electricity, Department of Engineering Sciences, Uppsala University, Box 534, SE-751 21 Uppsala (Sweden); Fernando, M. [Atmospheric Physics and Lightning Research Group, University of Colombo, Colombo 03 (Sri Lanka)

    2016-02-22

    The formation of bead lightning, where the lightning channel appears to break up into luminous fragments, is still an object of speculation. Here we report similar observations in laboratory discharges. Analysis of time resolved photographs shows that the discharge channel exhibits a ‘bead pattern’ in the decaying stage of the discharge and the occurrence of loops in the channel sections where the bead pattern is observed. This result presents the first evidence that the rapid cooling of non-uniform channel sections could lead to the formation of beads. It is suggested that periodically occurring non-uniform channel sections could explain the bead pattern of lightning discharges. - Highlights: • For the first time, the occurrence of bead patterns in the channel of laboratory sparks was reported. • Depending on the geometry some regions of the channel decays faster than the other sections. • A possible mechanism for the occurrence of beads in decaying states of lightning flashes is proposed.

  18. Derringer desirability and kinetic plot LC-column comparison approach for MS-compatible lipopeptide analysis.

    Science.gov (United States)

    D'Hondt, Matthias; Verbeke, Frederick; Stalmans, Sofie; Gevaert, Bert; Wynendaele, Evelien; De Spiegeleer, Bart

    2014-06-01

    Lipopeptides are currently re-emerging as an interesting subgroup in the peptide research field, having historical applications as antibacterial and antifungal agents and new potential applications as antiviral, antitumor, immune-modulating and cell-penetrating compounds. However, due to their specific structure, chromatographic analysis often requires special buffer systems or the use of trifluoroacetic acid, limiting mass spectrometry detection. Therefore, we used a traditional aqueous/acetonitrile based gradient system, containing 0.1% (m/v) formic acid, to separate four pharmaceutically relevant lipopeptides (polymyxin B 1 , caspofungin, daptomycin and gramicidin A 1 ), which were selected based upon hierarchical cluster analysis (HCA) and principal component analysis (PCA). In total, the performance of four different C18 columns, including one UPLC column, were evaluated using two parallel approaches. First, a Derringer desirability function was used, whereby six single and multiple chromatographic response values were rescaled into one overall D -value per column. Using this approach, the YMC Pack Pro C18 column was ranked as the best column for general MS-compatible lipopeptide separation. Secondly, the kinetic plot approach was used to compare the different columns at different flow rate ranges. As the optimal kinetic column performance is obtained at its maximal pressure, the length elongation factor λ ( P max / P exp ) was used to transform the obtained experimental data (retention times and peak capacities) and construct kinetic performance limit (KPL) curves, allowing a direct visual and unbiased comparison of the selected columns, whereby the YMC Triart C18 UPLC and ACE C18 columns performed as best. Finally, differences in column performance and the (dis)advantages of both approaches are discussed.

  19. Evaluation of a novel PTFE material for separation and preconcentration of trace levels of metal ions in sequential injection (SI) and sequential injection lab-on-valve (SI-LOV) systems interfaced with detection by ETAAS

    DEFF Research Database (Denmark)

    Long, Xiangbao; Chomchoei, Roongrat; Gała, Piotr

    The operational characteristics of a novel PTFE bead material, granular Algoflon®, used for separation and preconcentration of metal ions via adsorption of on-line generated non-charged metal complexes, were evaluated in a sequential injection (SI) system furnished with an external packed column...... and in a sequential injection lab-on-valve (SI-LOV) system. Employed for the determination of cadmium(II), complexed with diethyldithiophosphate (DDPA), and detection by electrothermal atomic absorption spectrometry (ETAAS), its performance was compared to that of a previously used material, Aldrich PTFE, which had...... demonstrated that PTFE was the most promising for solid-state pretreatments. By comparing the two materials, the Algoflon® beads exhibited much higher sensitivity (1.6107 versus 0.2956 μg l-1 per integrated absorbance (s)), and better retention efficiency (82% versus 74%) and enrichment factor (20.8 versus 17...

  20. Fluorescent detection of C-reactive protein using polyamide beads

    Science.gov (United States)

    Jagadeesh, Shreesha; Chen, Lu; Aitchison, Stewart

    2016-03-01

    Bacterial infection causes Sepsis which is one of the leading cause of mortality in hospitals. This infection can be quantified from blood plasma using C - reactive protein (CRP). A quick diagnosis at the patient's location through Point-of- Care (POC) testing could give doctors the confidence to prescribe antibiotics. In this paper, the development and testing of a bead-based procedure for CRP quantification is described. The size of the beads enable them to be trapped in wells without the need for magnetic methods of immobilization. Large (1.5 mm diameter) Polyamide nylon beads were used as the substrate for capturing CRP from pure analyte samples. The beads captured CRP either directly through adsorption or indirectly by having specific capture antibodies on their surface. Both methods used fluorescent imaging techniques to quantify the protein. The amount of CRP needed to give a sufficient fluorescent signal through direct capture method was found suitable for identifying bacterial causes of infection. Similarly, viral infections could be quantified by the more sensitive indirect capture method. This bead-based assay can be potentially integrated as a disposable cartridge in a POC device due to its passive nature and the small quantities needed.

  1. Mass transfer in liquid phase catalytic exchange column of trickle bed type

    International Nuclear Information System (INIS)

    Yamanishi, Toshihiko; Iwai, Yasunori; Okuno, Kenji

    1995-09-01

    The mechanism of mass transfer in a liquid phase catalytic exchange column was discussed for a trickle bed type. A new model has been proposed on the basis of this mass transfer mechanism; and several problems for the previous reported models were pointed out in the derivation of the model. An overall rate equation was first derived from the vapor-hydrogen exchange in the model. The mass transfer for the vapor-hydrogen exchange was decomposed to the following three steps: the mass transfer in a gas boundary layer on a catalyst particle; the mass transfer within the pores in the catalyst; and the chemical reaction on the surface of the catalyst. The water-vapor scrubbing process was considered as a series of the mass transfers in gas and liquid boundary layers on the wetted surfaces of the catalyst and packings or wall of the column. Significant subjects to be studied were proposed from the viewpoint of the validity of the model and the optimization of the column. (author)

  2. Unsaturated hydraulic conductivity of sandy soil columns packed to different bulk densities and water uptake by plantroots

    NARCIS (Netherlands)

    Rossi-Pisa, P.

    1978-01-01

    This paper describes a laboratory metbod used to determine both the soil moisture retention curve and the unsaturated hydraulic conductivity in soil columns under transient flow conditions during evaporation.

  3. Development of polymer-extractant composite beads for separation of radionuclides

    International Nuclear Information System (INIS)

    Kumar, Manmohan; Singh, Krishankant; Bajaj, P.N.

    2009-01-01

    A novel micro porous polymer-extractant composite bead system, containing liquid extractant encapsulated in the core of a polymeric shell, with required porosity and hydrophilicity, to allow exchange of radionuclides without, any significant leaching out of the encapsulated extractant, has been developed for solid-liquid extraction of radionuclides from acidic waste solutions. The reuse of the beads is possible as there is practically no change in its radionuclide extraction efficiency, after repeated extraction second time. The high porosity and hydrophilicity of the synthesized TBP-encapsulated polymeric beads is evident from the presence of ∼ 78% water in the swollen condition. Evaluation of the synthesized beads for extraction of uranium and plutonium from aqueous acidic waste solutions, indicated possibility of their use under the conditions of PUREX process. The aliquate 336-encapsulated polymeric beads showed selective extraction of plutonium from aqueous nitrate solutions in the presence of uranium, and back extraction of the loaded plutonium, using dilute nitric acid or ascorbic acid. (author)

  4. Simulation of non-linear coaxial line using ferrite beads

    International Nuclear Information System (INIS)

    Furuya, S.; Matsumoto, H.; Tachi, K.; Takano, S.; Irisawa, J.

    2002-01-01

    A ferrite sharpener is a non-linear coaxial line using ferrite beads, which produces high-voltage, high-dV/dt pulses. We have been examining the characteristics of ferrite sharpeners experimentally, varying various parameters. Also we have made the simulation of the ferrite sharpener and compared the predictions with the experimental results in detail to analyze the characteristics of the sharpener. In this report, calculating the magnetization M of the ferrite bead, we divide the bead into n sections radially instead of adopting M at the average radius in the previous report. (author)

  5. Porous chitosan beads of superior mechanical properties for the covalent immobilization of enzymes.

    Science.gov (United States)

    Wahba, Marwa I

    2017-12-01

    Porous chitosan beads of superior mechanical properties were produced via a two stepped treatment process. First, the chitosan ionotropic gelation solution was supplemented with Na 2 CO 3 , which acted as a porogen. Afterwards, the beads were chemically cross-linked with glutaraldehyde. This treatment also caused the produced porous chitosan beads to acquire higher observed activities of immobilized β-d-galactosidase (β-gal). The observed activities of the β-gal immobilized onto the 0.2M and the 0.35M Na 2 CO 3 treated beads were 1.63 and 1.91 fold respectively, higher than the activity offered by the control beads. Nevertheless, both the control beads and the 0.2M Na 2 CO 3 beads caused the optimum pH range of β-gal to shift from 4.6-5.1 to ∼2.7-5. The enzyme's optimum temperature shifted from 55 to 60°C after its immobilization onto the control chitosan beads whereas the β-gal immobilized onto the 0.2M Na 2 CO 3 chitosan beads exhibited a temperature optimum of 55-60°C. The reusability study revealed the superiority of the 0.2M Na 2 CO 3 treated beads which retained 59.1% of their initial activity during the 13th enzymatic cycle. On the other hand, the control chitosan beads were fragmented and lost their activity after only four enzymatic cycles. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Experiments of HI decomposition in Iodine-sulfur process

    International Nuclear Information System (INIS)

    Yoon, Ho Joon

    2006-02-01

    We performed an experimental study on the HI concentration and decomposition in Iodine-Sulfur process for thermochemical hydrogen production, which is the most expensive and energy consuming stage. For breaking azeotropic restrain, a partial condensing type, perforated plate type, and packed bed distillation column are employed. A Liebig-type condenser was used for a partial condensing distillation test. The perforated plate distillation column has 40 mm diameter and 5 stages with 8 holes per a plate. The packed bed distillation column has 40 mm diameter and was filled with 5 mm glass beads. While no distillation methods are able to change azeotropic conditions at atmospheric pressure, HI decomposition took place in a reboiler at 480 .deg. C. The vapor-liquid equilibrium curve was obtained from the experiment with binary mixtures (HI/H 2 O) at atmospheric pressure. Almost pure H 2 O was evaporated at the lower temperature than 125 .deg. C, and above that temperature binary mixtures (HI/H 2 O) were evaporated until the leftover solution became HI acid of 0.157mol, which was an azeotropic concentration of HI. With a consideration of heat loss, enthalpy of vaporization at azeotropic condition was estimated as 1131 kJ/kg

  7. Experiments of HI decomposition in Iodine-sulfur process

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Ho Joon

    2006-02-15

    We performed an experimental study on the HI concentration and decomposition in Iodine-Sulfur process for thermochemical hydrogen production, which is the most expensive and energy consuming stage. For breaking azeotropic restrain, a partial condensing type, perforated plate type, and packed bed distillation column are employed. A Liebig-type condenser was used for a partial condensing distillation test. The perforated plate distillation column has 40 mm diameter and 5 stages with 8 holes per a plate. The packed bed distillation column has 40 mm diameter and was filled with 5 mm glass beads. While no distillation methods are able to change azeotropic conditions at atmospheric pressure, HI decomposition took place in a reboiler at 480 .deg. C. The vapor-liquid equilibrium curve was obtained from the experiment with binary mixtures (HI/H{sub 2}O) at atmospheric pressure. Almost pure H{sub 2}O was evaporated at the lower temperature than 125 .deg. C, and above that temperature binary mixtures (HI/H{sub 2}O) were evaporated until the leftover solution became HI acid of 0.157mol, which was an azeotropic concentration of HI. With a consideration of heat loss, enthalpy of vaporization at azeotropic condition was estimated as 1131 kJ/kg.

  8. Viscosity of dilute suspensions of rigid bead arrays at low shear: accounting for the variation in hydrodynamic stress over the bead surfaces.

    Science.gov (United States)

    Allison, Stuart A; Pei, Hongxia

    2009-06-11

    In this work, we examine the viscosity of a dilute suspension of irregularly shaped particles at low shear. A particle is modeled as a rigid array of nonoverlapping beads of variable size and geometry. Starting from a boundary element formalism, approximate account is taken of the variation in hydrodynamic stress over the surface of the individual beads. For a touching dimer of two identical beads, the predicted viscosity is lower than the exact value by 5.2%. The methodology is then applied to several other model systems including tetramers of variable conformation and linear strings of touching beads. An analysis is also carried out of the viscosity and translational diffusion of several dilute amino acids and diglycine in water. It is concluded that continuum hydrodynamic modeling with stick boundary conditions is unable to account for the experimental viscosity and diffusion data simultaneously. A model intermediate between "stick" and "slip" could possibly reconcile theory and experiment.

  9. Comparing the efficacy of mature mud pack and hot pack treatments for knee osteoarthritis.

    Science.gov (United States)

    Sarsan, Ayşe; Akkaya, Nuray; Ozgen, Merih; Yildiz, Necmettin; Atalay, Nilgun Simsir; Ardic, Fusun

    2012-01-01

    The objective of this study is to compare the efficacy of mature mud pack and hot pack therapies on patients with knee osteoarthritis. This study was designed as a prospective, randomized-controlled, and single-blinded clinical trial. Twenty-seven patients with clinical and radiologic evidence of knee osteoarthritis were randomly assigned into two groups and were treated with mature mud packs (n 15) or hot packs (n=12). Patients were evaluated for pain [based on the visual analog scale (VAS)], function (WOMAC, 6 min walking distance), quality of life [Short Form-36 (SF-36)], and serum levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and insulin-like growth factor-1 (IGF-1) at baseline, post-treatment, and 3 and 6~months after treatment. The mud pack group shows a significant improvement in VAS, pain, stifness, and physical function domains of WOMAC. The difference between groups of pain and physical activity domains is significant at post-treatment in favor of mud pack. For a 6 min walking distance, mud pack shows significant improvement, and the difference is significant between groups in favor of mud pack at post-treatment and 3 and 6 months after treatment. Mud pack shows significant improvement in the pain subscale of SF-36 at the third month continuing until the sixth month after the treatment. Significant improvements are found for the social function, vitality/energy, physical role disability, and general health subscales of SF-36 in favor of the mud pack compared with the hot pack group at post-treatment. A significant increase is detected for IGF-1 in the mud pack group 3 months after treatment compared with the baseline, and the difference is significant between groups 3 months after the treatment. Mud pack is a favorable option compared with hotpack for pain relief and for the improvement of functional conditions in treating patients with knee osteoarthritis.

  10. Plutonium-239 sorption and transport on/in unsaturated sediments. Comparison of batch and column experiments for determining sorption coefficients

    International Nuclear Information System (INIS)

    Jinchuan Xie; Jiachun Lu; Xiaohua Zhou; Xuhui Wang; Mei Li; Lili Du; Yueheng Liu; Guoqing Zhou

    2013-01-01

    Sorption (distribution) coefficients of plutonium were most often derived by static batch experiments. However, it is not clear how unsaturated flow conditions including moisture content and pore water velocity change the sorption coefficients. Transport experiments of plutonium through the unsaturated sediments packed into the columns were then performed in order to determine the sorption coefficients (column-K ds ). Static batch experiments were also conducted to obtain batch-K ds and then compare the differences between batch-K ds and column-K ds . The results show that unsaturated flow conditions had no significant effect on column-K ds , and the average column-K d value was 1.74 ± 0.02 m 3 /kg. By comparison, batch-K d values spanned several orders of magnitude, regardless of the specified liquid-solid conditions. Moreover, the batch-K d (22.7 m 3 /kg) at the standard L/S (4 mL/g) recommended by ASTM D 4319 was over an order of magnitude larger than the average column-K d . (author)

  11. Modeling of welded bead profile for rapid prototyping by robotic MAG welding

    Institute of Scientific and Technical Information of China (English)

    CAO Yong; ZHU Sheng; WANG Tao; WANG Wanglong

    2009-01-01

    As a deposition technology, robotic metal active gas(MAG) welding has shown new promise for rapid prototyping (RP) of metallic parts. During the process of metal forming using robotic MAG welding, sectional profile of single-pass welded bead is critical to formed accuracy and quality of metal pans. In this paper, the experiments of single-pass welded bead for rapid prototyping using robotic MAG welding were carried out. The effect of some edge detectors on the cross-sectional edge of welded bead was discussed and curve fitting was applied using leat square fitting. Consequently, the mathematical model of welded bead profile was developed. The experimental results show that good shape could be obtained under suitable welding parameters. Canny operawr is suitable to edge detection of welded bead profile, and the mathematical model of welded bead profile developed is approximately parabola.

  12. Argo packing friction research update

    International Nuclear Information System (INIS)

    VanTassell, D.M.

    1994-01-01

    This paper focuses on the issue of valve packing friction and its affect on the operability of motor- and air-operated valves (MOVs and AOVs). At this time, most nuclear power plants are required to perform postmaintenance testing following a packing adjustment or replacement. In many cases, the friction generated by the packing does not impact the operability window of a valve. However, to date there has not been a concerted effort to substantiate this claim. To quantify the effects of packing friction, it has become necessary to develop a formula to predict the friction effects accurately. This formula provides a much more accurate method of predicting packing friction than previously used factors based strictly on stem diameter. Over the past 5 years, Argo Packing Company has been developing and testing improved graphite packing systems at research facilities, such as AECL Chalk River and Wyle Laboratories. Much of this testing has centered around reducing and predicting friction that is related to packing. In addition, diagnostic testing for Generic Letter 89-10 MOVs and AOVs has created a significant data base. In July 1992 Argo asked several utilities to provide running load data that could be used to quantify packing friction repeatability and predictability. This technical paper provides the basis to predict packing friction, which will improve calculations for thrust requirements for Generic Leter 89-10 and future AOV programs. In addition, having an accurate packing friction formula will improve packing performance when low running loads are identified that would indicate insufficient sealing force

  13. pH-Dependent Behavior of Novel Gellan Beads Loaded with Naproxen.

    Science.gov (United States)

    Osmalek, Tomasz; Froelich, Anna; Milanowski, Bartlomiej; Bialas, Magdalena; Hyla, Kinga; Szybowicz, Miroslaw

    2018-01-01

    Oral administration of non-selective COX inhibitors involves the risk of serious side-effects. In the case of naproxen (NPX), the most frequent are those related to malfunctioning of the gastric mucosa. On the other hand, NPX and other NSAIDs are extensively studied in terms of colorectal cancer (CRC) prevention and inhibition, since it has been evidenced that COX-2 corresponds with the risk of the tumor occurrence and growth. Both side-effects in the stomach and possible antitumor activity of NPX justify the attempts to search for novel carriers for NPX with the site specific release in the colon. Thus, the aim of the work was to design, formulate and characterize low-acyl gellan gum (GG) macro beads as potential carriers for the delivery of NPX to the distal parts of the gastrointestinal tract. The beads were obtained by the ionotropic gelation technique. CaCl2 solution was used as a cross-linking medium. After production, the beads were dried and used for further experiments. First, pure NPX and the beads were evaluated by Raman spectroscopy and DSC studies. The surface and morphology of the beads were analyzed by SEM. Next, the drug encapsulation efficiency and content in the beads were determined. The swelling and degradation behavior of the beads were evaluated in four simulated gastrointestinal fluids at different pH (1.2; 4.5; 6.8 and 7.4). The NPX in vitro release studies were conducted on USP I apparatus (rotating basket) at pH=7.4 and compared to the commercial enteric tablet. The polymer content of 0.5 % was considered as too low to obtain spherical beads in the dried form. Raman spectra confirmed that NPX did not undergo structural changes during production process. DSC studies showed that thermal decomposition at lower temperatures was observed for formulations with the lowest amount of GG. It turned out that the most important factor which determined the morphology of the beads was the amount of gellan gum in the initial mixture. The beads revealed

  14. The hydrodynamic behaviour of gas—solid trickle flow over a regularly stacked packing

    OpenAIRE

    Verver, A.B.; van Swaaij, Willibrordus Petrus Maria

    1986-01-01

    The hydrodynamic properties of counter-current gas—solid flow over a regularly stacked packing at trickle flow conditions have been studied. The flow properties of the solids phase were examined, using five types of solid particles with a mean particle diameter ranging from 70 to 880 μm and a particle density from 800 to 7800 kg m−3. Data on the solids hold-up and the pressure drop caused by the solids flow were obtained from experiments in a test column of 0.10 m square cross-section. A part...

  15. An integrated open-cavity system for magnetic bead manipulation.

    Science.gov (United States)

    Abu-Nimeh, F T; Salem, F M

    2013-02-01

    Superparamagnetic beads are increasingly used in biomedical assays to manipulate, transport, and maneuver biomaterials. We present a low-cost integrated system designed in bulk CMOS to manipulate and separate biomedical magnetic beads. The system consists of 8 × 8 coil-arrays suitable for single bead manipulation, or collaborative multi-bead manipulation, using pseudo-parallel executions. We demonstrate the flexibility of the design in terms of different coil sizes, DC current levels, and layout techniques. In one array module example, the size of a single coil is 30 μm × 30 μm and the full array occupies an area of 248 μm × 248 μm in 0.5 μm CMOS technology. The programmable DC current source supports 8 discrete levels up to 1.5 mA. The total power consumption of the entire module is 9 mW when running at full power.

  16. Influence of recycled polystyrene beads on cement paste properties

    Directory of Open Access Journals (Sweden)

    Maaroufi Maroua

    2018-01-01

    Full Text Available In order to keep up with the requirements of sustainable development, there is a growing interest towards reducing the energy consumption in the construction and rehabilitation of buildings and the promotion of recycling waste in building materials. The use of recycled polystyrene beads in cement-based materials composition constitutes a solution to improve the insulation in buildings. This allows also limiting landfill by reusing the polystyrene waste. The aim of this study is to compare some properties and performances of a cement paste containing polystyrene beads to a reference paste designed with only the same cement. An experimental campaign was conducted and the obtained results showed that adding recycled polystyrene beads to a cement paste improves its hygro-thermal properties. Further studies are however necessary to better understand the real role of the polystyrene beads in the heat and mass transfers.

  17. Developement of Spherical Polyurethane Beads

    Institute of Scientific and Technical Information of China (English)

    K. Maeda; H. Ohmori; H. Gyotoku

    2005-01-01

    @@ 1Results and Discussion We established a new method to produce the spherical polyurethane beads which have narrower distribution of particle size. This narrower distribution was achieved by the polyurethane prepolymer which contains ketimine as a blocked chain-extending agent. Firstly, the prepolymer is dispersed into the aqueous solution containing surfactant. Secondaly, water comes into the inside of prepolymer as oil phase. Thirdly, ketimine is hydrolyzed to amine, and amine reacts with prepolymer immediately to be polyurethane.Our spherical polyurethane beads are very suitable for automotive interior parts especially for instrument panel cover sheet producing under the slush molding method, because of good process ability, excellent durability to the sunlight and mechanical properties at low temperature. See Fig. 1 ,Fig. 2 and Fig. 3 (Page 820).

  18. Minimum number of transfer units and reboiler duty for multicomponent distillation columns

    International Nuclear Information System (INIS)

    Pleşu, Valentin; Bonet Ruiz, Alexandra Elena; Bonet, Jordi; Llorens, Joan; Iancu, Petrica

    2013-01-01

    Some guidelines to evaluate distillation columns, considering only basic thermodynamic data and principles, are provided in this paper. The method allows a first insight to the problem by simple calculations, without requiring column variables to ensure rational use of energy and low environmental impact. The separation system is approached by two complementary ways: minimum and infinite reflux flow rate. The minimum reflux provides the minimum energy requirements, and the infinite reflux provides the feasibility conditions. The difficulty of separation can be expressed in terms of number of transfer units (NTU). The applicability of the method is not mathematically limited by the number of components in the mixture. It is also applicable to reactive distillation. Several mixtures, including reactive distillation, are rigorously simulated as illustrative examples, to verify the applicability of the approach. The separation of the mixtures, performed by distillation columns, is feasible if a minimum NTU can be calculated between the distillate and bottom products. Once verified the feasibility of the separation, the maximum thermal efficiency depends only on boiling point of bottom and distillate streams. The minimum energy requirements corresponding to the reboiler can be calculated from the maximum thermal efficiency, and the variation of entropy and enthalpy of mixing between distillate and bottom streams. -- Highlights: • Feasibility analysis complemented with difficulty of separation parameters • Minimum and infinite reflux simplified models for distillation columns • Minimum number of transfer units (NTU) for packed columns at early design stages • Calculation of minimum energy distillation requirements at early design stages • Thermodynamic cycle approach and efficiency for distillation columns

  19. Analysis of platinum content in biodegradable carboplatin-impregnated beads and retrospective assessment of tolerability for intralesional use of the beads in dogs following excision of subcutaneous sarcomas: 29 cases (2011-2014).

    Science.gov (United States)

    Hess, Theresa A; Drinkhouse, Macy E; Prey, Joshua D; Miller, Jonathan M; Fettig, Arthur A; Carberry, Carol A; Brenn, Stephen H; Bailey, Dennis B

    2018-02-15

    OBJECTIVE To evaluate platinum content in biodegradable carboplatin-impregnated beads and retrospectively assess tolerability and outcome data for dogs treated by intralesional placement of such beads following surgical excision of subcutaneous sarcomas. DESIGN Evaluation study and retrospective case series. SAMPLE 9 carboplatin-impregnated beads and 29 client-owned dogs. PROCEDURES Platinum content in 9 carboplatin-impregnated beads from 3 lots was measured by spectrophotometry, and calculated carboplatin content was compared with the labeled content. Medical records were searched to identify dogs with subcutaneous sarcomas for which treatment included placement of carboplatin-impregnated beads between 2011 and 2014. Signalment, tumor characteristics, surgical and histologic data, adverse events, and local recurrences were recorded. Associations between variables of interest and adverse events or local disease-free interval were analyzed. RESULTS In vitro analysis identified a mean ± SD platinum content of 5.38 ± 0.97 mg/bead. Calculated carboplatin content (10.24 ± 1.84 mg/bead) was significantly greater than the labeled amount (4.6 mg/bead). Bead weight and total platinum content differed significantly among lots, but platinum content per bead weight did not. Mild-to-moderate local adverse events were reported for 11 of 29 tumors; all resolved without additional surgery. No dogs had signs of systemic toxicosis. Overall local disease-free rates 1, 2, and 3 years after surgery were 70%, 70%, and 58%, respectively, as determined by Kaplan-Meier analysis. CONCLUSIONS AND CLINICAL RELEVANCE Carboplatin-impregnated beads were well tolerated; however, results of in vitro tests indicated that caution is needed because of manufacturing inconsistencies.

  20. Packing force data correlations

    International Nuclear Information System (INIS)

    Heiman, S.M.

    1994-01-01

    One of the issues facing valve maintenance personnel today deals with an appropriate methodology for installing and setting valve packing that will minimize leak rates, yet ensure functionality of the the valve under all anticipated operating conditions. Several variables can affect a valve packing's ability to seal, such as packing bolt torque, stem finish, and lubrication. Stem frictional force can be an excellent overall indicator of some of the underlying conditions that affect the sealing characteristics of the packing and the best parameter to use when adjusting the packing. This paper addresses stem friction forces, analytically derives the equations related to these forces, presents a methodology for measuring these forces on valve stems, and attempts to correlate the data directly to the underlying variables

  1. Surface imprinted beads for the recognition of human serum albumin.

    Science.gov (United States)

    Bonini, Francesca; Piletsky, Sergey; Turner, Anthony P F; Speghini, Adolfo; Bossi, Alessandra

    2007-04-15

    The synthesis of poly-aminophenylboronic acid (ABPA) imprinted beads for the recognition of the protein human serum albumin (HSA) is reported. In order to create homogeneous recognition sites, covalent immobilisation of the template HSA was exploited. The resulting imprinted beads were selective for HSA. The indirect imprinting factor (IF) calculated from supernatant was 1.6 and the direct IF, evaluated from the protein recovered from the beads, was 1.9. The binding capacity was 1.4 mg/g, which is comparable to commercially available affinity materials. The specificity of the HSA recognition was evaluated with competitive experiments, indicating a molar ratio 4.5/1 of competitor was necessary to displace half of the bound HSA. The recognition and binding of the imprinted beads was also tested with a complex sample, human serum and targeted removal of HSA without a loss of the other protein components was demonstrated. The easy preparation protocol of derivatised beads and a good protein recognition properties make the approach an attractive solution to analytical and bio-analytical problems in the field of biotechnology.

  2. Decolourisation of dyes under electro-Fenton process using Fe alginate gel beads

    International Nuclear Information System (INIS)

    Rosales, E.; Iglesias, O.; Pazos, M.; Sanromán, M.A.

    2012-01-01

    Highlights: ► Catalytic activity of Fe alginate gel beads for the remediation of wastewater was tested. ► New electro-Fenton process for the remediation of polluted wastewater. ► Continuous dye treatment without operational problem with high removal. - Abstract: This study focuses on the application of electro-Fenton technique by use of catalytic activity of Fe alginate gel beads for the remediation of wastewater contaminated with synthetic dyes. The Fe alginate gel beads were evaluated for decolourisation of two typical dyes, Lissamine Green B and Azure B under electro-Fenton process. After characterization of Fe alginate gel beads, the pH effect on the process with Fe alginate beads and a comparative study of the electro-Fenton process with free Fe and Fe alginate bead was done. The results showed that the use of Fe alginate beads increases the efficiency of the process; moreover the developed particles show a physical integrity in a wide range of pH (2–8). Around 98–100% of dye decolourisation was obtained for both dyes by electro-Fenton process in successive batches. Therefore, the process was performed with Fe alginate beads in a bubble continuous reactor. High color removal (87–98%) was attained for both dyes operating at a residence time of 30 min, without operational problems and maintaining particle shapes throughout the oxidation process. Consequently, the stable performance of Fe alginate beads opens promising perspectives for fast and economical treatment of wastewater polluted by dyes or similar organic contaminants.

  3. Decolourisation of dyes under electro-Fenton process using Fe alginate gel beads

    Energy Technology Data Exchange (ETDEWEB)

    Rosales, E.; Iglesias, O.; Pazos, M. [Department of Chemical Engineering, University of Vigo, Isaac Newton Building, Campus As Lagoas, Marcosende 36310, Vigo (Spain); Sanroman, M.A., E-mail: sanroman@uvigo.es [Department of Chemical Engineering, University of Vigo, Isaac Newton Building, Campus As Lagoas, Marcosende 36310, Vigo (Spain)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer Catalytic activity of Fe alginate gel beads for the remediation of wastewater was tested. Black-Right-Pointing-Pointer New electro-Fenton process for the remediation of polluted wastewater. Black-Right-Pointing-Pointer Continuous dye treatment without operational problem with high removal. - Abstract: This study focuses on the application of electro-Fenton technique by use of catalytic activity of Fe alginate gel beads for the remediation of wastewater contaminated with synthetic dyes. The Fe alginate gel beads were evaluated for decolourisation of two typical dyes, Lissamine Green B and Azure B under electro-Fenton process. After characterization of Fe alginate gel beads, the pH effect on the process with Fe alginate beads and a comparative study of the electro-Fenton process with free Fe and Fe alginate bead was done. The results showed that the use of Fe alginate beads increases the efficiency of the process; moreover the developed particles show a physical integrity in a wide range of pH (2-8). Around 98-100% of dye decolourisation was obtained for both dyes by electro-Fenton process in successive batches. Therefore, the process was performed with Fe alginate beads in a bubble continuous reactor. High color removal (87-98%) was attained for both dyes operating at a residence time of 30 min, without operational problems and maintaining particle shapes throughout the oxidation process. Consequently, the stable performance of Fe alginate beads opens promising perspectives for fast and economical treatment of wastewater polluted by dyes or similar organic contaminants.

  4. Comparison of four supports for adsorption of reactive dyes by immobilized Aspergillus fumigatus beads

    Institute of Scientific and Technical Information of China (English)

    WANG Bao-e; HU Yong-you

    2007-01-01

    Four materials, sodium carboxymethylcellulose (Na-CMC), sodium alginate (SA), polyvinyl alcohol (PVA), and chitosan (CTS), were prepared as supports for entrapping fungus Aspergillus fumigatus. The adsorption of synthetic dyes, reactive brilliant blue KN-R, and reactive brilliant red K-2BP, by these immobilized gel beads and plain gel beads was evaluated. The adsorption efficiencies of reactive brilliant red K-2BP and reactive brilliant blue KN-R by CTS immobilized beads were 89.1% and 93.5% in 12 h, respectively. The adsorption efficiency by Na-CMC immobilized beads was slightly lower than that of mycelial pellets. But the dye culture mediums were almost completely decolorized in 48 h using the above-mentioned two immobilized beads (exceeding 95%). The adsorption efficiency by SA immobilized beads exceeded 92% in 48 h. PVA-SA immobilized beads showed the lowest adsorption efficiency, which was 79.8% for reactive brilliant red K-2BP and 92.5% for reactive brilliant blue KN-R in 48 h. Comparing the adsorption efficiency by plain gel beads, Na-CMC plain gel beads ranked next to CTS ones. SA and PVA-SA plain gel beads hardly had the ability of adsorbing dyes. Subsequently, the growth of mycelia in Na-CMC and SA immobilized beads were evaluated. The biomass increased continuously in 72 h. The adsorption capacity of reactive brilliant red K-2BP and reactive brilliant blue KN-R by Na-CMC immobilized beads was 78.0 and 86.7 mg/g, respectively. The SEM micrographs show that the surface structure of Na-CMC immobilized bead is loose and finely porous, which facilitates diffusion of the dyes.

  5. Determination of solute organic concentration in contaminated soils using a chemical-equilibrium soil column system

    DEFF Research Database (Denmark)

    Gamst, Jesper; Kjeldsen, Peter; Christensen, Thomas Højlund

    2007-01-01

    using two soils with different content of organic carbon (f(oc) of 1.5 and 6.5%, respectively). A quadruple blind test of the ER-V system using glass beads in stead of soil showed an acceptable recovery (65-85%) of all of the 11 VOCs tested. Only for the most volatile compound (heptane, K-H similar...... to 80) an unacceptable recovery was found (9%). The contact time needed for obtaining chemical equilibrium was tested in the ER-H system by performing five test with different duration (1, 2, 4, 7 and 19 days) using the low organic carbon soil. Seven days of contact time appeared sufficient...... for determination of solute concentration in a contaminated soil were developed; (1) a chemical Equilibrium and Recirculation column test for Volatile organic chemicals (ER-V) and (2) a chemical Equilibrium and Recirculation column test for Hydrophobic organic chemicals (ER-H). The two test systems were evaluated...

  6. Chemical–physical characterisation of Early Iron Age glass beads from Central Europe

    Energy Technology Data Exchange (ETDEWEB)

    Agua, F.; Conde, J.F.; Kobylińska, U.; Kobyliński, Z.; García-Heras, M.; Villegas, M.A.

    2017-07-01

    Archaeological excavation of the Institute of Archaeology and Ethnology (Polish Academy of Sciences, PAN) at several Iron Age sites located in West Poland and South Germany has allowed the recovery of an important set of coloured glass beads mostly decorated (6th–4th centuries BC). The present paper summarises the results obtained through the chemical and microstructural characterisation of such beads. The research was carried out by binocular microscope observations, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectrometry and visible spectrophotometry. The main objective was to attain information on the production technology and conservation state of these beads. The results indicated that all them were produced with soda lime silicate glass, even though two groups can be separated: (i) beads containing high MgO percentages made from plant ashes as an alkaline source, and (ii) beads containing low MgO percentages made from natron as an alkaline source. As regards decorations, opaque white was obtained from tin oxide, turquoise blue from Cu2+-ions, and opaque yellow from lead antimonate. Additionally, results showed microstructural and microcrystalline differences between some glass beads studied here and other glass beads from Mediterranean areas, dated in the same chronological period. This fact pointed out the valuable role given to these beads by Iron Age communities from Central Europe. (Author)

  7. OBT analysis method using polyethylene beads for limited quantities of animal tissue

    International Nuclear Information System (INIS)

    Kim, S.B.; Stuart, M.

    2015-01-01

    This study presents a polyethylene beads method for OBT determination in animal tissues and animal products for cases where the amount of water recovered by combustion is limited by sample size or quantity. In the method, the amount of water recovered after combustion is enhanced by adding tritium-free polyethylene beads to the sample prior to combustion in an oxygen bomb. The method reduces process time by allowing the combustion water to be easily collected with a pipette. Sufficient water recovery was achieved using the polyethylene beads method when 2 g of dry animal tissue or animal product were combusted with 2 g of polyethylene beads. Correction factors, which account for the dilution due to the combustion water of the beads, are provided for beef, chicken, pork, fish and clams, as well as egg, milk and cheese. The method was tested by comparing its OBT results with those of the conventional method using animal samples collected on the Chalk River Laboratories (CRL) site. The results determined that the polyethylene beads method added no more than 25% uncertainty when appropriate correction factors are used. - Highlights: • Polyethylene beads method for OBT determination in animal tissues and animal products were determined. • The method reduces process time. • The polyethylene beads method added no more than 25% uncertainty when appropriate correction factors are used

  8. Bioleaching of Primary Nickel Ore Using Acidithiobacillus ferrooxidans LR Cells Immobilized in Glass Beads

    Directory of Open Access Journals (Sweden)

    Ellen Cristine Giese

    2015-06-01

    Full Text Available Sulphide minerals are one of the most important sources of value metals. For several years, a large number of hydrometallurgical and biotechnological processes have been developed to leach low-grade sulphide ores and the conditions are well established. However, the management of microorganisms in the bioleaching process is not easy to handle. In this paper, the use of immobilized cells of Acidithiobacillus ferrooxidans LR in glass beads in bioleaching of primary nickel ore was evaluated. The column experiments inoculated with immobilized cells of A. ferrooxidans LR showed the same efficiency than the conventional method using free cells and is promising for application on a larger scale as it ensuring integrity and activity of biomining microorganisms and reduce process costs. DOI: http://dx.doi.org/10.17807/orbital.v7i2.698 

  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. Removal of organic dyes by magnetic alginate beads.

    Science.gov (United States)

    Rocher, Vincent; Siaugue, Jean-Michel; Cabuil, Valérie; Bee, Agnès

    2008-02-01

    This study deals with the development of a clean and safe process for water pollution remediation. We have synthesized a magnetic adsorbent in order to develop a solid-phase extraction process assisted by a magnetic field. To follow an 'ecoconception' approach, magnetic beads containing magnetic nanoparticles and activated carbon are prepared with a biopolymer extracted from algae, sodium alginate. The use of renewable bioresources of low cost and those disposable in large amount allows the development of a product with a low impact on the environment. The adsorption properties of activated carbon and magnetic properties of iron oxide nanoparticles are combined to produce an interesting magnetic composite. Synthesis and characterization of the magnetic beads have been reported. Their adsorption capacity was investigated by measuring the removal of two dyes (methylene blue and methyl orange) of different charges from aqueous solutions. The efficiency of the beads has been compared with that of non-encapsulated activated carbon. The effects of initial dye concentration, pH and calcium content of the beads have been studied. Adsorption kinetics experiments have been carried out and the data have been well fitted by a pseudo-second-order equation.

  11. FUZZY REGRESSION MODEL TO PREDICT THE BEAD GEOMETRY IN THE ROBOTIC WELDING PROCESS

    Institute of Scientific and Technical Information of China (English)

    B.S. Sung; I.S. Kim; Y. Xue; H.H. Kim; Y.H. Cha

    2007-01-01

    Recently, there has been a rapid development in computer technology, which has in turn led todevelop the fully robotic welding system using artificial intelligence (AI) technology. However, therobotic welding system has not been achieved due to difficulties of the mathematical model andsensor technologies. The possibilities of the fuzzy regression method to predict the bead geometry,such as bead width, bead height, bead penetration and bead area in the robotic GMA (gas metalarc) welding process is presented. The approach, a well-known method to deal with the problemswith a high degree of fuzziness, is used to build the relationship between four process variablesand the four quality characteristics, respectively. Using these models, the proper prediction of theprocess variables for obtaining the optimal bead geometry can be determined.

  12. PRELIMINARY STUDY ON RETRO-REFLECTIVE COATED PAPER BASED ON MICRO-GLASS BEADS

    Institute of Scientific and Technical Information of China (English)

    YulongWang; ChuanshanZhao; TaoZhang

    2004-01-01

    High-reflectivity micro-glass bead, as a kind ofretro-reflective material, is widely used in reflectivefabric or film and other reflective coatings. But it israrely used in coated paper. The retro-reflectivetheory of micro-bead is described. Also the effect ofsize of micro-bead, dosage of binder and differentcolor layers on reflective properties of coated paperare discussed in this article. The results show that itsretro-reflective efficiency is good, equally toreflective fabric or film when the micro-glass bead isused in coated paper.

  13. Universal approach for selective trace metal determinations via sequential injection-bead injection-lab-on-valve using renewable hydrophobic bead surfaces as reagent carriers

    DEFF Research Database (Denmark)

    Long, Xiangbao; Miró, Manuel; Hansen, Elo Harald

    2005-01-01

    involves the use of poly(styrene-divinylbenzene) beads containing pendant octadecyl moieties (C18-PS/DVB), which are preimpregnated with a selective organic metal chelating agent prior to the automatic manipulation of the beads in the microbore conduits of the LOV unit. By adapting this approach...

  14. Passive detection of Pb in water using rock phosphate agarose beads.

    Science.gov (United States)

    Edenborn, Harry M; Howard, Bret H; Sams, James I; Vesper, Dorothy J; Edenborn, Sherie L

    2017-08-15

    In this study, passive detectors for Pb were prepared by immobilizing powdered rock phosphate in agarose beads. Rock phosphate has been used to treat Pb-contaminated waters and soil by fixing the metal as an insoluble pyromorphite mineral. Under lab conditions, Pb was rapidly adsorbed from aqueous solution by the beads over time, consistent with the acidic dissolution of rock phosphate, the precipitation of pyromorphite within the pore space of the agarose gel matrix, and surface exchange reactions. Net accumulation of Pb occurred when beads were exposed to simulated periodic releases of Pb over time. Under field conditions, beads in mesh bags were effective at detecting dissolved Pb being transported as surface runoff from a site highly contaminated with Pb. Rates of Pb accumulation in beads under field conditions appeared to be correlated with the frequency of storm events and total rainfall. The rock phosphate agarose bead approach could be an inexpensive way to carry out source-tracking of Pb pollution, to verify the successful remediation of sites with Pb-contaminated soil, and to routinely monitor public water systems for potential Pb contamination. Published by Elsevier B.V.

  15. Formation of beads-on-a-string structures during break-up of viscoelastic filaments

    Science.gov (United States)

    Bhat, Pradeep P.; Appathurai, Santosh; Harris, Michael T.; Pasquali, Matteo; McKinley, Gareth H.; Basaran, Osman A.

    2010-08-01

    Break-up of viscoelastic filaments is pervasive in both nature and technology. If a filament is formed by placing a drop of saliva between a thumb and forefinger and is stretched, the filament's morphology close to break-up corresponds to beads of several sizes interconnected by slender threads. Although there is general agreement that formation of such beads-on-a-string (BOAS) structures occurs only for viscoelastic fluids, the underlying physics remains unclear and controversial. The physics leading to the formation of BOAS structures is probed by numerical simulation. Computations reveal that viscoelasticity alone does not give rise to a small, satellite bead between two much larger main beads but that inertia is required for its formation. Viscoelasticity, however, enhances the growth of the bead and delays pinch-off, which leads to a relatively long-lived beaded structure. We also show for the first time theoretically that yet smaller, sub-satellite beads can also form as seen in experiments.

  16. Beaded Fiber Mats of PVA Containing Unsaturated Heteropoly Salt

    Institute of Scientific and Technical Information of China (English)

    Guo Cheng YANG; Yan PAN; Jian GONG; Chang Lu SHAO; Shang Bin WEN; Chen SHAO; Lun Yu QU

    2004-01-01

    Poly(vinyl alcohol) (PVA) fiber mats containing unsaturated heteropoly salt was prepared for the first time. IR, X-ray diffraction and SEM photographs characterized the beaded fiber mats.The viscoelasticity and the conductivity of the solution were the key factors that influence the formation of the beaded fiber mats.

  17. A Pneumatic Actuated Microfluidic Beads-Trapping Device

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Guocheng; Cai, Ziliang; Wang, Jun; Wang, Wanjun; Lin, Yuehe

    2011-08-20

    The development of a polydimethylsiloxane (PDMS) microfluidic microbeads trapping device is reported in this paper. Besides fluid channels, the proposed device includes a pneumatic control chamber and a beads-trapping chamber with a filter array structure. The pneumatic flow control chamber and the beads-trapping chamber are vertically stacked and separated by a thin membrane. By adjusting the pressure in the pneumatic control chamber, the membrane can either be pushed against the filter array to set the device in trapping mode or be released to set the device in releasing mode. In this paper, a computational fluid dynamics simulation was conducted to optimize the geometry design of the filter array structure; the device fabrication was also carried out. The prototype device was tested and the preliminary experimental results showed that it can be used as a beads-trapping unit for various biochemistry and analytical chemistry applications, especially for flow injection analysis systems.

  18. Ultra high pressure liquid chromatography. Column permeability and changes of the eluent properties.

    Science.gov (United States)

    Gritti, Fabrice; Guiochon, Georges

    2008-04-11

    The behavior of four similar liquid chromatography columns (2.1mm i.d. x 30, 50, 100, and 150 mm, all packed with fine particles, average d(p) approximately 1.7 microm, of bridged ethylsiloxane/silica hybrid-C(18), named BEH-C(18)) was studied in wide ranges of temperature and pressure. The pressure and the temperature dependencies of the viscosity and the density of the eluent (pure acetonitrile) along the columns were also derived, using the column permeabilities and applying the Kozeny-Carman and the heat balance equations. The heat lost through the external surface area of the chromatographic column was directly derived from the wall temperature of the stainless steel tube measured with a precision of +/-0.2 degrees C in still air and +/-0.1 degrees C in the oven compartment. The variations of the density and viscosity of pure acetonitrile as a function of the temperature and pressure was derived from empirical correlations based on precise experimental data acquired between 298 and 373 K and at pressures up to 1.5 kbar. The measurements were made with the Acquity UPLC chromatograph that can deliver a maximum flow rate of 2 mL/min and apply a maximum column inlet pressure of 1038 bar. The average Kozeny-Carman permeability constant of the columns was 144+/-3.5%. The temperature hence the viscosity and the density profiles of the eluent along the column deviate significantly from linear behavior under high-pressure gradients. For a 1000 bar pressure drop, we measured DeltaT=25-30 K, (Deltaeta/eta) approximately 100%, and (Deltarho/rho) approximately 10%. These results show that the radial temperature profiles are never fully developed within 1% for any of the columns, even under still-air conditions. This represents a practical advantage regarding the apparent column efficiency at high flow rates, since the impact of the differential analyte velocity between the column center and the column wall is not maximum. The interpretation of the peak profiles recorded in

  19. Preparation and characterization of chitosan/cashew gum beads loaded with Lippia sidoides essential oil

    International Nuclear Information System (INIS)

    Paula, Haroldo C.B.; Sombra, Fernanda Matoso; Cavalcante, Rafaela de Freitas; Abreu, Flavia O.M.S.; Paula, Regina C.M. de

    2011-01-01

    Beads based on chitosan (CH) and cashew gum (CG), were prepared and loaded with an essential oil with larvicide activity (Lippia sidoides - Ls). CH and CH-CG beads were characterized by scanning electron microscopy (SEM), infrared and UV-VIS spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), as well as, regarding their larvicide loading, swelling, in vitro and in vivo release kinetics. The oil encapsulation was evidenced by FTIR analysis and LS loading ranges from 2.4% to 4.4%. CH beads duly showed swelling degree (Q) values from 4.0 to 6.7, reaching equilibrium after 30 min, whereas crosslinked CH-CG beads showed lower swelling values, from 0.4 to 3.8, exhibiting a longer equilibrium time. Liquid transport parameters have revealed diffusion coefficient for CH-CG beads, as low as 2 x 10 -15 m 2 /s. TGA and DSC revealed that CH:CG crosslinked beads are more thermally stable than CH beads. In vitro release follows a non-Fickian diffusion profile for both bead types, however, and a prolonged release being achieved only after beads crosslinking. In vivo release showed that both CH and CH-CG presented a prolonged larvicide effect. These aforesaid results, indicate that CH-CG beads loaded with LS are efficient for A. aegypti larval control.

  20. Dairy workers develop whey to sweeten profits

    Energy Technology Data Exchange (ETDEWEB)

    1982-02-11

    Scientists at the Milk Marketing Board are reported to have developed an enzyme process that will convert whey into protein for animal feed and a liquid sweetener for the food industry. In the process whey wastes are forced under pressure through a column, about 0.5m wide, packed with ceramic beads which carry the enzyme Beta- galactosidase. The enzyme converts whey to a mixture of protein and liquid sweeteners, but is not itself consumed. At present, a pilot plant processes 10,000 liters of whey every day, but when working at full capacity the plant can double or treble that output.

  1. Column Adsorption Studies for the Removal of Cr(VI Ions by Ethylamine Modified Chitosan Carbonized Rice Husk Composite Beads with Modelling and Optimization

    Directory of Open Access Journals (Sweden)

    S. Sugashini

    2013-01-01

    Full Text Available The objective of this present study is the optimization of process parameters in adsorption of Cr(VI ions by ethylamine modified chitosan carbonized rice husk composite beads (EAM-CCRCBs using response surface methodology (RSM and continuous adsorption studies of Cr(VI ions by ethylamine modified chitosan carbonized rice husk composite beads (EAM-CCRCBs. The effect of process variables such as initial metal ion concentration, adsorbent dosage and pH were optimized using RSM in order to ensure high adsorption capacity at low adsorbent dosage and high initial metal ion concentration of Cr(VI in batch process. The optimum condition suggested by the model for the process variable such as adsorbent dosage, pH and initial metal ion concentration was 0.14 g, 300 mg/L and pH2 with maximum removal of 99.8% and adsorption capacity of 52.7 mg/g respectively. Continuous adsorption studies were conducted under optimized initial metal ion concentration and pH for the removal of Cr(VI ions using EAM-CCRCBs. The breakthrough curve analysis was determined using the experimental data obtained from the continuous adsorption. Continuous adsorption modelling such as bed depth service model and Thomson model were established by fitting it with experimental data.

  2. Two kinds of ketoprofen enteric gel beads (CA and CS-SA using biopolymer alginate

    Directory of Open Access Journals (Sweden)

    Bingchao Cheng

    2018-03-01

    Full Text Available To obtain expected rapid-release and sustained-release of ketoprofen gel beads, this paper adopted biopolymer alginate to prepare alginate beads and chitosan-alginate gel beads. Formulation factors were investigated and optimized by the single factor test. The release of ketoprofen from calcium alginate gel beads in pH 1.0 hydrochloric acid solution was less than 10% during 2 h, then in pH6.8 was about 95% during 45 min, which met the requirements of rapid-release preparations. However, the drug release of chitosan-alginate gel beads in pH1.0 was less than 5% during 2 h, then in pH6.8 was about 50% during 6 h and reached more than 95% during 12 h, which had a good sustained-release behavior. In addition, the release kinetics of keteprofen from the calcium alginate gel beads fitted well with the Korsmeyer–Peppas model and followed a case-II transport mechanism. However, the release of keteprofen from the chitosan-alginate gel beads exhibited a non-Fickian mechanism and based on the mixed mechanisms of diffusion and polymer relaxation from chitosan-alginate beads. In a word, alginate gel beads of ketoprofen were instant analgesic, while chitosan-alginate gel beads could control the release of ketoprofen during gastro-intestinal tract and prolong the drug's action time. Keywords: Gel beads, Enteric rapid-release, Enteric sustained-release, Ketoprofen

  3. Improvement of removal characteristics for uranium by immobilization of diphosil powder into alginate bead

    International Nuclear Information System (INIS)

    Kim, K. J.; Kang, I. S.; Lee, Y. H.; Son, J. S.; Hong, K. P.

    2003-01-01

    Chemical wastes containing small amounts of uranium can not be disposed of them as industrial wastes. Especially for the removal of uranium, In this study, the method of immobilizing Diphosil powder within alginate beads is adopted to make a bead from powdered resin. Sodium alginate bead itself showed a capability to uptake uranium to above 60%, but the value was decreased to below 30% after equilibrium. The rate of uranium adsorption increased with increasing content of Diphosil in sodium alginate bead. Diphosil resin itself showed very fast uptake of uranium from early stages, and then the rates were leveled off. Diphosil bead showed a improved capability to uptake uranium considering Diphosil content in the bead, and a considerable potential for further applications of a continuous process by using a bead form of Diphosil

  4. Sensitive detection of nucleic acids by PNA hybridization directed co-localization of fluorescent beads

    DEFF Research Database (Denmark)

    Shiraishi, Takehiko; Deborggraeve, Stijn; Büscher, Philippe

    2011-01-01

    )avidin-coated fluorescent beads, differing in size and color [green beads (1 µm) and red beads (5.9 µm)], thereby allowing distinct detection of each PNA probe by conventional fluorescence microscopy. These two PNA beads showed easily detectable co-localization when simultaneously hybridizing to a target nucleic acid...

  5. A Microfluidic Device for Preparing Next Generation DNA Sequencing Libraries and for Automating Other Laboratory Protocols That Require One or More Column Chromatography Steps

    Science.gov (United States)

    Tan, Swee Jin; Phan, Huan; Gerry, Benjamin Michael; Kuhn, Alexandre; Hong, Lewis Zuocheng; Min Ong, Yao; Poon, Polly Suk Yean; Unger, Marc Alexander; Jones, Robert C.; Quake, Stephen R.; Burkholder, William F.

    2013-01-01

    Library preparation for next-generation DNA sequencing (NGS) remains a key bottleneck in the sequencing process which can be relieved through improved automation and miniaturization. We describe a microfluidic device for automating laboratory protocols that require one or more column chromatography steps and demonstrate its utility for preparing Next Generation sequencing libraries for the Illumina and Ion Torrent platforms. Sixteen different libraries can be generated simultaneously with significantly reduced reagent cost and hands-on time compared to manual library preparation. Using an appropriate column matrix and buffers, size selection can be performed on-chip following end-repair, dA tailing, and linker ligation, so that the libraries eluted from the chip are ready for sequencing. The core architecture of the device ensures uniform, reproducible column packing without user supervision and accommodates multiple routine protocol steps in any sequence, such as reagent mixing and incubation; column packing, loading, washing, elution, and regeneration; capture of eluted material for use as a substrate in a later step of the protocol; and removal of one column matrix so that two or more column matrices with different functional properties can be used in the same protocol. The microfluidic device is mounted on a plastic carrier so that reagents and products can be aliquoted and recovered using standard pipettors and liquid handling robots. The carrier-mounted device is operated using a benchtop controller that seals and operates the device with programmable temperature control, eliminating any requirement for the user to manually attach tubing or connectors. In addition to NGS library preparation, the device and controller are suitable for automating other time-consuming and error-prone laboratory protocols requiring column chromatography steps, such as chromatin immunoprecipitation. PMID:23894273

  6. A microfluidic device for preparing next generation DNA sequencing libraries and for automating other laboratory protocols that require one or more column chromatography steps.

    Directory of Open Access Journals (Sweden)

    Swee Jin Tan

    Full Text Available Library preparation for next-generation DNA sequencing (NGS remains a key bottleneck in the sequencing process which can be relieved through improved automation and miniaturization. We describe a microfluidic device for automating laboratory protocols that require one or more column chromatography steps and demonstrate its utility for preparing Next Generation sequencing libraries for the Illumina and Ion Torrent platforms. Sixteen different libraries can be generated simultaneously with significantly reduced reagent cost and hands-on time compared to manual library preparation. Using an appropriate column matrix and buffers, size selection can be performed on-chip following end-repair, dA tailing, and linker ligation, so that the libraries eluted from the chip are ready for sequencing. The core architecture of the device ensures uniform, reproducible column packing without user supervision and accommodates multiple routine protocol steps in any sequence, such as reagent mixing and incubation; column packing, loading, washing, elution, and regeneration; capture of eluted material for use as a substrate in a later step of the protocol; and removal of one column matrix so that two or more column matrices with different functional properties can be used in the same protocol. The microfluidic device is mounted on a plastic carrier so that reagents and products can be aliquoted and recovered using standard pipettors and liquid handling robots. The carrier-mounted device is operated using a benchtop controller that seals and operates the device with programmable temperature control, eliminating any requirement for the user to manually attach tubing or connectors. In addition to NGS library preparation, the device and controller are suitable for automating other time-consuming and error-prone laboratory protocols requiring column chromatography steps, such as chromatin immunoprecipitation.

  7. Sorption-enhanced water gas shift reaction for high-purity hydrogen production: Application of a Na-Mg double salt-based sorbent and the divided section packing concept

    International Nuclear Information System (INIS)

    Lee, Chan Hyun; Lee, Ki Bong

    2017-01-01

    Highlights: •Na-Mg double salt-based sorbent was used for high-temperature CO 2 sorption. •Divided section packing concept was applied to the SE-WGS reaction. •High-purity H 2 was produced from the SE-WGS reaction with divided section packing. •High-purity H 2 productivity could be further enhanced by modifying packing method. -- Abstract: Hydrogen is considered a promising environmentally benign energy carrier because it has high energy density and produces no pollutants when it is converted into other types of energy. The sorption-enhanced water gas shift (SE-WGS) reaction, where the catalytic WGS reaction and byproduct CO 2 removal are carried out simultaneously in a single reactor, has received considerable attention as a novel method for high-purity hydrogen production. Since the high-purity hydrogen productivity of the SE-WGS reaction is largely dependent on the performance of the CO 2 sorbent, the development of sorbents having high CO 2 sorption capacity is crucial. Recently, a Na-Mg double salt-based sorbent has been considered for high-temperature CO 2 capture since it has been reported to have a high sorption capacity and fast sorption kinetics. In this study, the SE-WGS reaction was experimentally demonstrated using a commercial catalyst and a Na-Mg double salt-based sorbent. However, the SE-WGS reaction with a one-body hybrid solid, a physical admixture of catalyst and sorbent, showed poor reactivity and reduced CO 2 sorption uptake. As a result, a divided section packing concept was suggested as a solution. In the divided section packing method, the degree of mixing for the catalyst and sorbent in a column can be controlled by the number of sections. High-purity hydrogen (<10 ppm CO) was produced directly from the SE-WGS reaction with divided section packing, and the hydrogen productivity was further improved when the reactor column was divided into more sections and packed with more sorbent.

  8. Retention behavior of neutral solutes in pressurized flow-driven capillary electrochromatography using an ODS column.

    Science.gov (United States)

    Nakagawa, Hiroyuki; Kitagawa, Shinya; Araki, Shuki; Ohtani, Hajime

    2006-02-01

    Several alkyl benzenes are separated by pressurized flow-driven capillary electrochromatography using a temperature-controlled capillary column packed with octadecyl siloxane-modified silica gel, and the effect of applied voltage on the retention is investigated. The van't Hoff plot shows good linearity at the column temperature between 305 and 330 K under applications from -6 to +6 kV. The applied voltage causes a relatively large variation in the enthalpy and the entropy of transfer of the solute from the mobile phase to the stationary phase (> 20%). However, the direction of variation in the enthalpy is almost opposite to that in the entropy, both of which might compensate each other. Therefore, the retention factor is not significantly varied (< 4%) by the application of voltage.

  9. Disintegration of Nannochloropsis sp. cells in an improved turbine bead mill.

    Science.gov (United States)

    Pan, Zhidong; Huang, Ying; Wang, Yanmin; Wu, Zhiwei

    2017-12-01

    The Nannochloropsis sp. cells in aqueous solution were disintegrated in an improved bead mill with turbine agitator. The disintegration rates of cell samples disrupted under various operating parameters (i.e., circumferential speed, bead size, disintegration time, and cell concentration) were analyzed. An experimental strategy to optimize the parameters affecting the cell disintegration process was proposed. The results show that Nannochloropsis sp. cells can be effectively disintegrated in the turbine stirred bead mill under the optimum condition (i.e., circumferential speed of 2.3m/s, concentration of 15vol.%, disintegration time of 40min and bead size of 0.3-0.4mm). The disintegration mechanism was discussed via the selection and breakage functions from population balance modelling. It is revealed that the impact and compression effects of stirring beads are more effective for the disruption of coarser fraction of cells, and the shear effect dominates the production of finer fractions of disintegrated cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Alginate/magnetite hybrid beads for magnetically stimulated release of dopamine.

    Science.gov (United States)

    Kondaveeti, Stalin; Cornejo, Daniel R; Petri, Denise Freitas Siqueira

    2016-02-01

    Hybrid beads composed of magnetite nanoparticles (MNP) and alginate (Alg) were synthesized and coded as Alg-MNP. They were incubated in dopamine (DOPA) solution (5 g/L), at pH 7.4 and 8 °C, during 12 h, promoting the DOPA loaded magnetic beads, coded as Alg-MNP/DOPA. The release of DOPA was further evaluated in the absence and the presence of external magnetic field (EMF) of 0.4 T. The products Alg-MNP and Alg-MNP/DOPA were characterized by scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), Fourier transform infrared vibrational spectroscopy (FTIR), UV spectrophotometry, thermogravimetric analyses (TGA), inductively coupled plasma atomic emission spectroscopy (ICP-AES) analyses and superconducting quantum interference device (SQUID) magnetometer. The magnetic and chemical properties of Alg-MNP beads were not affected by DOPA loading. The incorporation of DOPA into the beads depended on the pH and on the negative charge density. At pH 7.4 38% of DOPA were loaded into Alg-MNP beads, whereas at pH 2 or using neat Alg beads (lower charge density than Alg-MNP) the loading efficiency decreased to one third or less. In the absence of EMF, 24% of the loaded DOPA was released from Alg-MNP at pH 7.4 over a period of 26 h. The released amount increased to 33% under the stimulus of EMF. A model was proposed to explain the loading efficiency of charged drugs, as DOPA, into hybrid beads and the role played by EMF on delivery systems, where drug and matrix are oppositely charged. The results suggest that the alginate combined with magnetite nanoparticles is a promising system for release of DOPA in the presence of EMF. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Sequestering HMGB1 via DNA-Conjugated Beads Ameliorates Murine Colitis

    Science.gov (United States)

    Antoine, Daniel J.; Dancho, Meghan; Tsaava, Teá; Li, Jianhua; Lu, Ben; Levine, Yaakov A.; Stiegler, Andrew; Tamari, Yehuda; Al-Abed, Yousef; Roth, Jesse; Tracey, Kevin J.; Yang, Huan

    2014-01-01

    Inflammatory bowel disease (IBD) is chronic inflammation of the gastrointestinal tract that affects millions of people worldwide. Although the etiology of IBD is not clear, it is known that products from stressed cells and enteric microbes promote intestinal inflammation. High mobility group box 1 (HMGB1), originally identified as a nuclear DNA binding protein, is a cytokine-like protein mediator implicated in infection, sterile injury, autoimmune disease, and IBD. Elevated levels of HMGB1 have been detected in inflamed human intestinal tissues and in feces of IBD patients and mouse models of colitis. Neutralizing HMGB1 activity by administration of anti-HMGB1 antibodies or HMGB1-specific antagonist improves clinical outcomes in animal models of colitis. Since HMGB1 binds to DNA with high affinity, here we developed a novel strategy to sequester HMGB1 using DNA immobilized on sepharose beads. Screening of DNA-bead constructs revealed that B2 beads, one linear form of DNA conjugated beads, bind HMGB1 with high affinity, capture HMGB1 ex vivo from endotoxin-stimulated RAW 264.7 cell supernatant and from feces of mice with colitis. Oral administration of B2 DNA beads significantly improved body weight, reduced colon injury, and suppressed colonic and circulating cytokine levels in mice with spontaneous colitis (IL-10 knockout) and with dextran sulfate sodium-induced colitis. Thus, DNA beads reduce inflammation by sequestering HMGB1 and may have therapeutic potential for the treatment of IBD. PMID:25127031

  12. American Spirit Pack Descriptors and Perceptions of Harm: A Crowdsourced Comparison of Modified Packs.

    Science.gov (United States)

    Pearson, Jennifer L; Richardson, Amanda; Feirman, Shari P; Villanti, Andrea C; Cantrell, Jennifer; Cohn, Amy; Tacelosky, Michael; Kirchner, Thomas R

    2016-08-01

    In 2015, the Food and Drug Administration issued warnings to three tobacco manufacturers who label their cigarettes as "additive-free" and/or "natural" on the grounds that they make unauthorized reduced risk claims. The goal of this study was to examine US adults' perceptions of three American Spirit (AS) pack descriptors ("Made with Organic Tobacco," "100% Additive-Free," and "100% US Grown Tobacco") to assess if they communicate reduced risk. In September 2012, three cross-sectional surveys were posted on Amazon Mechanical Turk. Adult participants evaluated the relative harm of a Marlboro Red pack versus three different AS packs with the descriptors "Made with Organic Tobacco," "100% Additive-Free," or "100% US Grown Tobacco" (Survey 1; n = 461); a Marlboro Red pack versus these AS packs modified to exclude descriptors (Survey 2; n = 857); and unmodified versus modified AS pack images (Survey 3; n = 1001). The majority of Survey 1 participants rated the unmodified AS packs as less harmful than the Marlboro Red pack; 35.4%-58.8% of Survey 2 participants also rated the modified (no claims) packs as less harmful than Marlboro Red. In these surveys, prior use of AS cigarettes was associated with reduced perceptions of risk (adjusted odds ratio [AOR] 1.59-2.40). "Made with Organic Tobacco" and "100% Additive-Free" were associated with reduced perceptions of risk when comparing the modified versus the unmodified AS packs (Survey 3). Data suggest that these AS pack descriptors communicate reduced harm messages to consumers. Findings have implications for regulatory actions related to product labeling and packaging. These findings provide additional evidence that the "Made with Organic Tobacco," "100% Additive-Free," and "100% US Grown" descriptors, as well as other aspects of the AS pack design, communicate reduced harm to non-, current, and former smokers. Additionally, they provide support for the importance of FDA's 2015 warning to Santa Fe Natural Tobacco Company on

  13. PRELIMINARY STUDY ON RETRO-REFLECTIVE COATED PAPER BASED ON MICRO-GLASS BEADS

    Institute of Scientific and Technical Information of China (English)

    Yulong Wang; Chuanshan Zhao; Tao Zhang

    2004-01-01

    High-reflectivity micro-glass bead, as a kind of retro-reflective material, is widely used in reflective fabric or film and other reflective coatings. But it is rarely used in coated paper. The retro-reflective theory of micro-bead is described. Also the effect of size of micro-bead, dosage of binder and different color layers on reflective properties of coated paper are discussed in this article. The results show that its retro-reflective efficiency is good, equally to reflective fabric or film when the micro-glass bead is used in coated paper.

  14. Successful subretinal delivery and monitoring of MicroBeads in mice.

    Directory of Open Access Journals (Sweden)

    M Dominik Fischer

    Full Text Available To monitor viability of implanted genetically engineered and microencapsulated human stem cells (MicroBeads in the mouse eye, and to study the impact of the beads and/or xenogenic cells on retinal integrity.MicroBeads were implanted into the subretinal space of SV126 wild type mice using an ab externo approach. Viability of microencapsulated cells was monitored by noninvasive retinal imaging (Spectralis™ HRA+OCT. Retinal integrity was also assessed with retinal imaging and upon the end of the study by light and electron microscopy. The implanted GFP-marked cells encapsulated in subretinal MicroBeads remained viable over a period of up to 4 months. Retinal integrity and viability appeared unaltered apart from the focal damage due to the surgical implantation, GFAP upregulation, and opsin mistargeting in the immediate surrounding tissue.The accessibility for routine surgery and its immune privileged state make the eye an ideal target for release system implants for therapeutic substances, including neurotrophic and anti-angiogenic compounds or protein based biosimilars. Microencapsulated human stem cells (MicroBeads promise to overcome limitations inherent with single factor release systems, as they are able to produce physiologic combinations of bioactive compounds.

  15. Preparation and characterization of chitosan/cashew gum beads loaded with Lippia sidoides essential oil

    Energy Technology Data Exchange (ETDEWEB)

    Paula, Haroldo C.B., E-mail: hpaula@ufc.br [Department of Analytical and Physical Chemistry, Federal University of Ceara, UFC, Fortaleza-CE (Brazil); Sombra, Fernanda Matoso; Cavalcante, Rafaela de Freitas; Abreu, Flavia O.M.S. [Department of Analytical and Physical Chemistry, Federal University of Ceara, UFC, Fortaleza-CE (Brazil); Paula, Regina C.M. de [Department of Organic and Inorganic Chemistry, Federal University of Ceara, UFC, Fortaleza-CE (Brazil)

    2011-03-12

    Beads based on chitosan (CH) and cashew gum (CG), were prepared and loaded with an essential oil with larvicide activity (Lippia sidoides - Ls). CH and CH-CG beads were characterized by scanning electron microscopy (SEM), infrared and UV-VIS spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), as well as, regarding their larvicide loading, swelling, in vitro and in vivo release kinetics. The oil encapsulation was evidenced by FTIR analysis and LS loading ranges from 2.4% to 4.4%. CH beads duly showed swelling degree (Q) values from 4.0 to 6.7, reaching equilibrium after 30 min, whereas crosslinked CH-CG beads showed lower swelling values, from 0.4 to 3.8, exhibiting a longer equilibrium time. Liquid transport parameters have revealed diffusion coefficient for CH-CG beads, as low as 2 x 10{sup -15} m{sup 2}/s. TGA and DSC revealed that CH:CG crosslinked beads are more thermally stable than CH beads. In vitro release follows a non-Fickian diffusion profile for both bead types, however, and a prolonged release being achieved only after beads crosslinking. In vivo release showed that both CH and CH-CG presented a prolonged larvicide effect. These aforesaid results, indicate that CH-CG beads loaded with LS are efficient for A. aegypti larval control.

  16. Asynchronous Magnetic Bead Rotation (AMBR Microviscometer for Label-Free DNA Analysis

    Directory of Open Access Journals (Sweden)

    Yunzi Li

    2014-03-01

    Full Text Available We have developed a label-free viscosity-based DNA detection system, using paramagnetic beads as an asynchronous magnetic bead rotation (AMBR microviscometer. We have demonstrated experimentally that the bead rotation period is linearly proportional to the viscosity of a DNA solution surrounding the paramagnetic bead, as expected theoretically. Simple optical measurement of asynchronous microbead motion determines solution viscosity precisely in microscale volumes, thus allowing an estimate of DNA concentration or average fragment length. The response of the AMBR microviscometer yields reproducible measurement of DNA solutions, enzymatic digestion reactions, and PCR systems at template concentrations across a 5000-fold range. The results demonstrate the feasibility of viscosity-based DNA detection using AMBR in microscale aqueous volumes.

  17. In vivo cleansing efficacy of biodegradable exfoliating beads assessed by skin bioengineering techniques.

    Science.gov (United States)

    Kitsongsermthon, J; Duangweang, K; Kreepoke, J; Tansirikongkol, A

    2017-11-01

    The plastic microbeads, used in many cleansers, will be banned in cosmetic and personal care products within 2017 since they are non-degradable and can disturb the living organisms in water reservoirs. Various choices of biodegradable beads are commercially available, but their efficacy has not been proven yet. This study aimed to compare the cleansing efficacy in dirt and sebum removal aspects of three types of exfoliating beads. The gel scrubs with polyethylene (PE) beads, mannan beads or wax beads, were formulated and evaluated for their stability. The in vivo evaluation was done in 38 healthy volunteers and the skin irritation, efficacy for dirt and sebum removal were measured by Mexameter ® , Colorimeter ® , and Sebumeter ® , respectively. The selected gel scrubs did not cause an irritation in any volunteers. The differences in dirt residues between before and after scrubbing were not statistically significant among three gel scrubs and the similar result was also reported in the sebum removal study. All gel scrubs demonstrated the comparable cleansing efficacy in term of dirt and sebum removal. Thus, mannan beads and wax beads may be replaced non-biodegradable PE beads to achieve the similar cleansing effect. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Concanavalin A immobilized magnetic poly(glycidyl methacrylate) beads for prostate specific antigen binding.

    Science.gov (United States)

    Idil, Neslihan; Perçin, Işık; Karakoç, Veyis; Yavuz, Handan; Aksöz, Nilüfer; Denizli, Adil

    2015-10-01

    The aim of this study was to prepare Concanavalin A (Con A) immobilized magnetic poly(glycidyl methacrylate) (mPGMA) beads for prostate specific antigen (PSA) binding and to study binding capacities of the beads using lectin-glycoprotein interactions. Firstly, iron oxide nanoparticles were synthesized by co-precipitation method and then, beads were synthesized by dispersion polymerization in the presence of iron oxide nanoparticles. Con A molecules were both covalently immobilized onto the beads directly and through the spacer arm (1,6-diaminohexane-HDMA). The total PSA and free PSA binding onto the mPGMA-HDMA-Con A beads were higher than that of the mPGMA-Con A beads. Maximum PSA binding capacity was observed as 91.2 ng/g. Approximately 45% of the bound PSA was eluted by using 0.1 M mannose as elution agent. The mPGMA-HDMA-Con A beads could be reused without a remarkable decrease in the binding capacities after 5 binding-desorption cycles. Serum fractions were analyzed using SDS-PAGE. The mPGMA-HDMA-Con A beads could be useful for the detection of PSA and suggested as a model system for other glycoprotein biomarkers. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Separation of yttrium using carbon nanotube doped polymeric beads impregnated with D2EHPA

    International Nuclear Information System (INIS)

    Dasgupta, Kinshuk; Yadav, Kartikey K.; Singh, D.K.; Anitha, M.; Singh, H.

    2013-01-01

    Di-2-ethylhexyl phosphoric acid impregnated polyethersulfone based composite beads in combination with additives such as polyvinyl alcohol (PVA) and multiwalled carbon nanotube (MWCNT) has been prepared by non-solvent phase inversion method. The synthesized beads were characterized by scanning electron microscopy, thermogravimetry and infra-red spectroscopy. Effect of additives on bead morphology, solvent impregnation capacity, extractability and stability has been examined to compare their suitability for yttrium recovery from acidic medium. Microstructural investigation as well as experimental findings confirmed the role of additives in modifying the pore structures in beads, responsible for varied degree of yttrium extraction. Further the role of metal ion concentration in aqueous phase on its recovery by polymeric beads was also evaluated. Among the tested beads PES/D2EHPA/MWCNT/PVA beads were found to be superior for Y(Ill) extraction. (author)

  20. Air plasma processing of poly(methyl methacrylate) micro-beads: Surface characterisations

    International Nuclear Information System (INIS)

    Liu Chaozong; Cui Naiyi; Osbeck, Susan; Liang He

    2012-01-01

    Highlights: ► PMMA micro-beads were processed using a rotary air plasma reactor. ► Surface chemistry and surface texture of PMMA micro-beads were characterised. ► Surface wettability was evaluated using “floating” water contact angle method. ► Surface oxidation and texture changes induced by air plasma attributed to the improvement of surface wettability. - Abstract: This paper reports the surface processing of poly(methyl methacrylate) (PMMA) micro-beads by using a rotary air plasma reactor, and its effects on surface properties. The surface properties, including surface wettability, surface chemistry and textures of the PMMA beads, were characterised. It was observed that the air plasma processing can improve the surface wettability of the PMMA microbeads significantly. A 15 min plasma processing can reduce the surface water contact angle of PMMA beads to about 50° from its original value of 80.3°. This was accompanied by about 8% increase in surface oxygen concentration as confirmed by XPS analysis. The optical profilometry examination revealed the air plasma processing resulted in a rougher surface that has a “delicate” surface texture. It is concluded that the surface chemistry and texture, induced by air plasma processing, co-contributed to the surface wettability improvement of PMMA micro-beads.

  1. Validity of using modified capillary column with larger diameter to study the Cs diffusion in local Taiwan laterite

    International Nuclear Information System (INIS)

    Tsing-Hai Wang; National Tsing Hua University, Hsinchu, Taiwan; Wen-Chun Yeh; Shih-Chin Tsai; Yi-Lin Jan; Shi-Ping Teng

    2008-01-01

    We have examined the working diameter of capillary columns with diameter of 5, 7, 10 and 20 mm. These modified capillary columns were carefully filled with local Taiwan laterite (LTL). The porosity and density of these packed columns was 0.51±0.02 g/g and 1.27±0.05 g/cm 3 , respectively. The diffusion experiments were then carried out in synthetic groundwater with Cs loading of 0.1mM at room temperature. Experimental results have shown that the diffusion profiles of modified capillary columns fit Fick's second law very well. This result revealed that the working diameter of a capillary column can be expanded to at least to 20 mm without affecting the validity of the derived diffusion coefficients. Among these columns, the ones with 5 mm diameter show the most consistent results of the derived K d , apparent and effective diffusion coefficients. Although the derived distribution and effective diffusion coefficients slightly decrease as the diameter of these columns increases due to the increase of the solid/liquid ratio. These values are still informative of the Cs diffusion in local Taiwan laterite. Moreover, our results clearly demonstrate the potential of using 'modified capillary method' to study the diffusion behaviors of concerned radionuclide because columns with large diameter enable the filling with more versatile geological substances. (author)

  2. Moisture removal rate for air dehumidification by triethylene glycol in a structured packed column

    International Nuclear Information System (INIS)

    Elsarrag, Esam

    2007-01-01

    In this investigation, a desiccant dehumidifier is tested for different ranges of liquid to air flow rate ratios to expand the validity range of the results. Theoretical and experimental studies of the simultaneous heat and mass transfer to evaluate the moisture removal rate are conducted. The model predictions are compared with experimental results with very good agreement. Through the experimental study, the important design variables that affect the moisture removal rate are defined and compared with previous studies. The correlation found in the literature is assessed, and the errors are reported. The parameters that are varied during the experiments included the air and liquid flow rates, the air humidity ratio, the desiccant equilibrium humidity and the packing height. It is found that the liquid flow rate has no significant effect on the moisture removal rate when the liquid to air flow ratio has exceeded the value of 2

  3. Development and evaluation of alginate-chitosan gastric floating beads loading with oxymatrine solid dispersion.

    Science.gov (United States)

    Liu, Yanhua; Chen, Lihong; Zhou, Chengming; Yang, Jianhong; Hou, Yanhui; Wang, Wenping

    2016-01-01

    Oxymatrine (OM) can be metabolized to matrine in gastrointestinal ileocecal valve after oral administration, which affects pharmacological activity and reduce bioavailability of OM. A type of multiple-unit alginate-chitosan (Alg-Cs) floating beads was prepared by the ionotropic gelation method for gastroretention delivery of OM. A solid dispersion technique was applied and incorporated into beads to enhance the OM encapsulation efficiency (EE) and sustain the drug release. The surface morphology and internal hollow structure of beads were evaluated using optical microscopy and scanning electron microscopy (SEM). The developed Alg-Cs beads were spherical in shape with hollow internal structure and had particle size of 3.49 ± 0.09 mm and 1.33 ± 0.09 mm for wet and dried beads. Over 84% of the optimized OM solid dispersion-loaded Alg-Cs beads were able to continuously float over the simulated gastric fluid for 12 h in vitro. The OM solid dispersion-loaded Alg-Cs beads showed drug EE of 67.07%, which was much higher than that of beads loading with pure OM. Compared with the immediate release of OM capsules and pure OM-loaded beads, the release of OM from solid dispersion-loaded Alg-Cs beads was in a sustained-release manner for 12 h. Prolonged gastric retention time of over 8.5 h was achieved for OM solid dispersion-loaded Alg-Cs floating beads in healthy rabbit in in vivo floating ability evaluated by X-ray imaging. The developed Alg-Cs beads loading with OM solid dispersion displayed excellent performance features characterized by excellent gastric floating ability, high drug EE and sustained-release pattern. The study illustrated the potential use of Alg-Cs floating beads combined with the solid dispersion technique for prolonging gastric retention and sustaining release of OM, which could provide a promising drug delivery system for gastric-specific delivery of OM for bioavailability enhancement.

  4. The removal of thermo-tolerant coliform bacteria by immobilized waste stabilization pond algae.

    Science.gov (United States)

    Pearson, H W; Marcon, A E; Melo, H N

    2011-01-01

    This study investigated the potential of laboratory- scale columns of immobilized micro-algae to disinfect effluents using thermo-tolerant coliforms (TTC) as a model system. Cells of a Chlorella species isolated from a waste stabilization pond complex in Northeast Brazil were immobilized in calcium alginate, packed into glass columns and incubated in contact with TTC suspensions for up to 24 hours. Five to six log removals of TTC were achieved in 6 hours and 11 log removals in 12 hours contact time. The results were similar under artificial light and shaded sunlight. However little or no TTC removal occurred in the light in columns of alginate beads without immobilized algae present or when the immobilized algae were incubated in the dark suggesting that the presence of both algae and light were necessary for TTC decay. There was a positive correlation between K(b) values for TTC and increasing pH in the effluent from the immobilized algal columns within the range pH 7.2 and 8.9. The potential of immobilized algal technology for wastewater disinfection may warrant further investigation.

  5. Magnetization of large polystyrene peptide beads for capturing and expanding cancer cells

    International Nuclear Information System (INIS)

    Marik, Jan; Lau, D.H.; Song Aimin; Wang Xiaobing; Liu Ruiwu; Lam, K.S.

    2003-01-01

    A method is described for preparation of large magnetic polystyrene beads coupled with peptide ligands for surface receptors of lung cancer cells. We have demonstrated the feasibility of using these magnetic peptide beads for capturing and enriching lung cancer cells spiked into blood. These magnetic peptide beads potentially can be used to efficiently isolate cancer cells from body fluids

  6. Low-cost commercial glass beads as dosimeters in radiotherapy

    International Nuclear Information System (INIS)

    Jafari, S.M.; Bradley, D.A.; Gouldstone, C.A.; Sharpe, P.H.G.; Alalawi, A.; Jordan, T.J.; Clark, C.H.; Nisbet, A.; Spyrou, N.M.

    2014-01-01

    Recent developments in advanced radiotherapy techniques using small field photon beams, require small detectors to determine the delivered dose in steep dose gradient fields. Commercially available glass jewellery beads exhibit thermoluminescent properties and have the potential to be used as dosimeters in radiotherapy due to their small size ( 60 Co gamma rays over doses ranging from 1 to 2500 cGy. A thermoluminescence (TL) system and an electron paramagnetic resonance (EPR) system were employed for read out. Both the TL and EPR studies demonstrated a radiation-induced signal, the sensitivity of which varied with bead colour. White coloured beads proved to be the most sensitive for both systems. The smallest and therefore least sensitive bead sizes allowed measurement of doses of 1 cGy using the TL system while that for the EPR system was approximately 1000 cGy. The fading rate was found to be 10% 30 days after irradiation with both readout systems. The dose response is linear with measured dose over the dose range 1 to 2500 cGy, with an R 2 correlation coefficient of greater than 0.999. The batch-to-batch reproducibility of a set of dosimeters after a single irradiation was found to be 3% (1 SD). The reproducibility of individual dosimeters was found to be 1.7%. No measurable angular dependence was found (results agreed within 1%). Dose rate response was found to agree within 1% for dose rates of 100 to 600 cGy/min. These results demonstrate the potential use of glass beads as TL dosimeters over the dose range commonly applied in radiotherapy. - Highlights: • We examined the dosimetric properties of a low cost commercially produced glass seed beads. • Glass beads are available in small size of 1–3 mm, suitable for dosimetry of small radiation fields. • The results demonstrate a mean reproducibility of 0.23% (2 SD), batch homogeneity of within 5%. • Dose response was linear over wide dose range tested for 1 cGy to kGy. • Improved fading effect of 10

  7. Rapid bead-based immunoassay for measurement of mannose-binding lectin

    DEFF Research Database (Denmark)

    Bay, J T; Garred, P

    2009-01-01

    have been developed more automated platforms for MBL analysis is urgently needed. To pursue this, we set out to develop a flexible bead-based MBL immunoassay. Serum was obtained from 98 healthy individuals and 50 patients investigated for possible immunodeficiencies. We used the Luminex xMAP bead array...... coefficient were found be 7.88% and 5.70%, respectively. A close correlation between the new assay and a reference MBL measurement ELISA was found (rho 0.9381, P bead-based assay was less sensitive to interfering anti-murine antibodies in the blood samples than when the antibodies employed were...... used in the reference polystyrene-based ELISA. The new assay could be performed in 3 h with less than 25 microl serum required of each sample. These results show that MBL can be measured readily using a bead-based platform, which may form an efficient basis for a multiplex approach to measure different...

  8. Hierarchically templated beads with tailored pore structure for phosphopeptide capture and phosphoproteomics

    DEFF Research Database (Denmark)

    Wierzbicka, Celina; Torsetnes, Silje B.; Jensen, Ole N.

    2017-01-01

    Two templating approaches to produce imprinted phosphotyrosine capture beads with a controllable pore structure are reported and compared with respect to their ability to enrich phosphopeptides from a tryptic peptide mixture. The beads were prepared by the polymerization of urea-based host monomers...... and crosslinkers inside the pores of macroporous silica beads with both free and immobilized template. In the final step the silica was removed by fluoride etching resulting in mesoporous polymer replicas with narrow pore size distributions, pore diameters ≈ 10 nm and surface area > 260 m2 g-1. The beads displayed...... pronounced phosphotyrosine affinity and selectivity in binding tests using model peptides in acetonitrile rich solutions with a performance surpassing solution polymerized bulk imprinted materials. Tests of the beads for the enrichment of phosphopeptides from tryptic digests of twelve proteins revealed both...

  9. Formulation of Synthesized Zinc Oxide Nanopowder into Hybrid Beads for Dye Separation

    Directory of Open Access Journals (Sweden)

    H. Shokry Hassan

    2014-01-01

    Full Text Available The sol-gel prepared zinc oxide nanopowder was immobilized onto alginate-polyvinyl alcohol polymer blend to fabricate novel biocomposite beads. Various physicochemical characterization techniques have been utilized to identify the crystalline, morphological, and chemical structures of both the fabricated zinc oxide hybrid beads and their corresponding zinc oxide nanopowder. The thermal stability investigations demonstrate that ZnO nanopowder stability dramatically decreased with its immobilization into the polymeric alginate and PVA matrix. The formulated beads had very strong mechanical strength and they are difficult to be broken up to 1500 rpm. Moreover, these hybrid beads are chemically stable at the acidic media (pH < 7 especially within the pH range of 2–7. Finally, the applicability of the formulated ZnO hybrid beads for C.I. basic blue 41 (BB41 decolorization from aqueous solution was examined.

  10. Hardness of approximation for strip packing

    DEFF Research Database (Denmark)

    Adamaszek, Anna Maria; Kociumaka, Tomasz; Pilipczuk, Marcin

    2017-01-01

    Strip packing is a classical packing problem, where the goal is to pack a set of rectangular objects into a strip of a given width, while minimizing the total height of the packing. The problem has multiple applications, for example, in scheduling and stock-cutting, and has been studied extensively......)-approximation by two independent research groups [FSTTCS 2016,WALCOM 2017]. This raises a questionwhether strip packing with polynomially bounded input data admits a quasi-polynomial time approximation scheme, as is the case for related twodimensional packing problems like maximum independent set of rectangles or two...

  11. Controlled antiseptic release by alginate polymer films and beads.

    Science.gov (United States)

    Liakos, Ioannis; Rizzello, Loris; Bayer, Ilker S; Pompa, Pier Paolo; Cingolani, Roberto; Athanassiou, Athanassia

    2013-01-30

    Biodegradable polymeric materials based on blending aqueous dispersions of natural polymer sodium alginate (NaAlg) and povidone iodine (PVPI) complex, which allow controlled antiseptic release, are presented. The developed materials are either free standing NaAlg films or Ca(2+)-cross-linked alginate beads, which properly combined with PVPI demonstrate antibacterial and antifungal activity, suitable for therapeutic applications, such as wound dressing. Glycerol was used as the plasticizing agent. Film morphology was studied by optical and atomic force microscopy. It was found that PVPI complex forms well dispersed circular micro-domains within the NaAlg matrix. The beads were fabricated by drop-wise immersion of NaAlg/PVPI/glycerol solutions into aqueous calcium chloride solutions to form calcium alginate beads encapsulating PVPI solution (CaAlg/PVPI). Controlled release of PVPI was possible when the composite films and beads were brought into direct contact with water or with moist media. Bactericidal and fungicidal properties of the materials were tested against Escherichia coli bacteria and Candida albicans fungi. The results indicated very efficient antibacterial and antifungal activity within 48 h. Controlled release of PVPI into open wounds is highly desired in clinical applications to avoid toxic doses of iodine absorption by the wound. A wide variety of applications are envisioned such as external and internal wound dressings with controlled antiseptic release, hygienic and protective packaging films for medical devices, and polymer beads as water disinfectants. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Immobilization of catalase on chitosan and amino acid- modified chitosan beads.

    Science.gov (United States)

    Başak, Esra; Aydemir, Tülin

    2013-08-01

    Bovine liver catalase was covalently immobilized onto amino acid-modified chitosan beads. The beads were characterized with SEM, FTIR, TGA and the effects of immobilization on optimum pH and temperature, thermostability, reusability were evaluated. Immobilized catalase showed the maximal enzyme activity at pH 7.0 at 30°C. The kinetic parameters, Km and Vmax, for immobilized catalase on alanine-chitosan beads and lysine-chitosan beads were estimated to be 25.67 mM, 27 mM and 201.39 μmol H2O2/min, 197.50 μmol H2O2/min, respectively. The activity of the immobilized catalase on Ala-CB and Lys-CB retained 40% of its high initial activity after 100 times of reuse.

  13. Planar Hall effect sensor bridge geometries optimized for magnetic bead detection

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Rizzi, Giovanni; Henriksen, Anders Dahl

    2014-01-01

    Novel designs of planar Hall effect bridge sensors optimized for magnetic bead detection are presented and characterized. By constructing the sensor geometries appropriately, the sensors can be tailored to be sensitive to an external magnetic field, the magnetic field due to beads being magnetized...... by the sensor self-field or a combination thereof. The sensors can be made nominally insensitive to small external magnetic fields, while being maximally sensitive to magnetic beads, magnetized by the sensor self-field. Thus, the sensor designs can be tailored towards specific applications with minimal...... of the dynamic magnetic response of suspensions of magnetic beads with a nominal diameter of 80 nm are performed. Furthermore, a method to amplify the signal by appropriate combinations of multiple sensor segments is demonstrated....

  14. Distribution and biophysical processes of beaded streams in Arctic permafrost landscapes

    Science.gov (United States)

    Arp, Christopher D.; Whitman, Matthew S.; Jones, Benjamin M.; Grosse, Guido; Gaglioti, Benjamin V.; Heim, Kurt C.

    2015-01-01

    Beaded streams are widespread in permafrost regions and are considered a common thermokarst landform. However, little is known about their distribution, how and under what conditions they form, and how their intriguing morphology translates to ecosystem functions and habitat. Here we report on a Circum-Arctic survey of beaded streams and a watershed-scale analysis in northern Alaska using remote sensing and field studies. We mapped over 400 channel networks with beaded morphology throughout the continuous permafrost zone of northern Alaska, Canada, and Russia and found the highest abundance associated with medium- to high- ground ice content permafrost in moderately sloping terrain. In the Fish Creek watershed, beaded streams accounted for half of the drainage density, occurring primarily as low-order channels initiating from lakes and drained lake basins. Beaded streams predictably transition to alluvial channels with increasing drainage area and decreasing channel slope, although this transition is modified by local controls on water and sediment delivery. Comparison of one beaded channel using repeat photography between 1948 and 2013 indicate a relatively stable landform and 14C dating of basal sediments suggest channel formation may be as early as the Pleistocene-Holocene transition. Contemporary processes, such as deep snow accumulation in riparian zones effectively insulates channel ice and allows for perennial liquid water below most beaded stream pools. Because of this, mean annual temperatures in pool beds are greater than 2°C, leading to the development of perennial thaw bulbs or taliks underlying these thermokarst features. In the summer, some pools thermally stratify, which reduces permafrost thaw and maintains coldwater habitats. Snowmelt generated peak-flows decrease rapidly by two or more orders of magnitude to summer low flows with slow reach-scale velocity distributions ranging from 0.1 to 0.01 m/s, yet channel runs still move water rapidly

  15. Modified strip packing heuristics for the rectangular variable-sized bin packing problem

    Directory of Open Access Journals (Sweden)

    FG Ortmann

    2010-06-01

    Full Text Available Two packing problems are considered in this paper, namely the well-known strip packing problem (SPP and the variable-sized bin packing problem (VSBPP. A total of 252 strip packing heuristics (and variations thereof from the literature, as well as novel heuristics proposed by the authors, are compared statistically by means of 1170 SPP benchmark instances in order to identify the best heuristics in various classes. A combination of new heuristics with a new sorting method yields the best results. These heuristics are combined with a previous heuristic for the VSBPP by the authors to find good feasible solutions to 1357 VSBPP benchmark instances. This is the largest statistical comparison of algorithms for the SPP and the VSBPP to the best knowledge of the authors.

  16. Comparison between simulation and experimentally observed interactions between two magnetic beads in a fluidic system

    Energy Technology Data Exchange (ETDEWEB)

    Oduwole, Olayinka, E-mail: olayinka.oduwole@eng.ox.ac.uk; Grob, David Tim, E-mail: tim.grob@eng.ox.ac.uk; Sheard, Steve, E-mail: steve.sheard@eng.ox.ac.uk

    2016-06-01

    Continuous flow separation of magnetic particles within a microfluidic device could lead to improved performance of magnetic bead-based assays but the undesirable formation of bead clusters reduces its efficiency; this efficiency refers to the ability to separate bound magnetic beads from a mixture of particles. Such agglomerates are formed due to magnetic binding forces while hydrodynamic interactions strongly influence the particles' movement. This paper presents a model for interactions between a pair of equal sized super-paramagnetic beads suspended in water within a uniform magnetic field. To the best of our knowledge, we present for the first time a comparison between simulated trajectories and the beads' movement captured on video; the beads were suspended in a stationary fluid placed within a uniform magnetic field. In conclusion, the model is a good approximation for beads interacting with their nearest neighbours and is able to predict the trajectory pattern of these particles in a magnetic bead-based assay. Predicting the magnetically induced interaction of nearby beads will help in determining the density of beads in an assay and in avoiding agglomeration over a fixed time duration. - Highlights: • We modelled the interactions between a pair of super-paramagnetic beads suspended in water within a uniform magnetic field. • We tracked the movement of the bead pair and captured it on video. • We compared the numerical results with the video data and achieved a good agreement. • We predicted the agglomeration time as a function of the separation distance.

  17. Concepts for increasing gentamicin release from handmade bone cement beads

    NARCIS (Netherlands)

    Rasyid, Hermawan N; van der Mei, Henny C; Frijlink, Henderik W; Soegijoko, Soegijardjo; Van Horn, Jim R; Busscher, Hendrik; Neut, Daniëlle

    2009-01-01

    BACKGROUND AND PURPOSE: Commercial gentamicin-loaded bone cement beads (Septopal) constitute an effective delivery system for local antibiotic therapy. These beads are not available in all parts of the world, and are too expensive for frequent use in others. Thus, orthopedic surgeons worldwide make

  18. Permeability change with dissolution and precipitation reaction induced by highly alkaline plume in packed bed with amorphous silica particles

    International Nuclear Information System (INIS)

    Komatsu, Kyo; Kadowaki, Junichi; Niibori, Yuichi; Mimura, Hitoshi; Usui, Hideo

    2008-01-01

    A large amount of cement is used to construct of the geological disposal system. Such a material alters the pH of groundwater to highly alkaline region. The highly alkaline plume contains rich Ca ion compared to the surrounding environment, and the Ca ion reacts with soluble silicic acid. Its product would deposit on the surface of flow-paths in the natural barrier and decrease the permeability. In this study, the influence of Ca ions in highly alkaline plume on flow-paths has been examined by using packed bed column. The column was packed with the amorphous silica particles of 75-150 μm in diameter. The Ca(OH) 2 solution (0.78 mM, 2.58 mM, 4.37 mM, and 8.48 mM, pH: 12.2-12.4) was continuously injected into the column at a constant flow rate (5 ml/min, and 2 ml/min), and the change of permeability was monitored. At the same time, the concentrations of [Ca] total and [Si] in the eluted solution were measured by the inductively coupled plasma atomic emission spectrometry (ICP-AES). The Ca(OH) 2 solutions were prepared with CO 2 -free pure water, and filtrated through 0.45 μm filter. The permeability was normalized by the initial permeability value. In the experiment results, the permeability dramatically changed with increasing Ca concentration, because Ca ions and H 4 SiO 4 (due to the dissolution of SiO 2 ) produce C-S-H gel between the packed particles in the column. The SEM images and XRD analyses showed that the surface of SiO 2 particles was covered with the C-S-H gel precipitation. On the other hand, when the Ca concentration was relatively low, the permeability did not show remarkable change. For the cross section of SiO 2 particles, EPMA analysis suggested the consumption of Ca in the inner pore of the SiO 2 particles. However, the time-change in the concentrations of Si and Ca was not always simple. Such time-change strongly depended not only on pH or Ca concentration, but also on the flow rates. This suggested that mass transport controls the chemical

  19. Wax-incorporated emulsion gel beads of calcium pectinate for intragastric floating drug delivery.

    Science.gov (United States)

    Sriamornsak, Pornsak; Asavapichayont, Panida; Nunthanid, Jurairat; Luangtana-Anan, Manee; Limmatvapirat, Sontaya; Piriyaprasarth, Suchada

    2008-01-01

    The purpose of this study was to prepare wax-incorporated pectin-based emulsion gel beads using a modified emulsion-gelation method. The waxes in pectin-olive oil mixtures containing a model drug, metronidazole, were hot-melted, homogenized and then extruded into calcium chloride solution. The beads formed were separated, washed with distilled water and dried for 12 h. The influence of various types and amounts of wax on floating and drug release behavior of emulsion gel beads of calcium pectinate was investigated. The drug-loaded gel beads were found to float on simulated gastric fluid if the sufficient amount of oil was used. Incorporation of wax into the emulsion gel beads affected the drug release. Water-soluble wax (i.e. polyethylene glycol) increased the drug release while other water-insoluble waxes (i.e. glyceryl monostearate, stearyl alcohol, carnauba wax, spermaceti wax and white wax) significantly retarded the drug release. Different waxes had a slight effect on the drug release. However, the increased amount of incorporated wax in the formulations significantly sustained the drug release while the beads remained floating. The results suggest that wax-incorporated emulsion gel beads could be used as a carrier for intragastric floating drug delivery.

  20. Analysis of surface properties of fixed and live cells using derivatized agarose beads.

    Science.gov (United States)

    Navarro, Vanessa M; Walker, Sherri L; Badali, Oliver; Abundis, Maria I; Ngo, Lylla L; Weerasinghe, Gayani; Barajas, Marcela; Zem, Gregory; Oppenheimer, Steven B

    2002-01-01

    A novel assay has been developed for the histochemical characterization of surface properties of cells based on their adhesion to agarose beads derivatized with more than 100 types of molecules, including sugars, lectins and other proteins, and amino acids. The assay simply involves mixing small quantities of washed cells and beads in droplets on glass microscope slides and determining to which beads various cell types adhere. Distilled water was found to be the best medium for this assay because added ions or molecules in other media inhibit adhesion in some cases. Many cells, however, cannot tolerate distilled water. Here we show that cells fixed with either of two fixatives (1% formaldehyde or Prefer fixative) displayed similar bead-binding properties as did live cells. Specificity of cell-bead binding was tested by including specific free molecules in the test suspensions in hapten-type inhibition experiments. If a hapten compound inhibited live-cell adhesion to a specific bead, it also inhibited fixed-cell adhesion to a specific bead. The results of these experiments suggest that fixed cells display authentic surface properties, opening the door for the use of this assay with many cell types that cannot tolerate distilled water.