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Sample records for ammonia-water rectifyng column

  1. INFRARED SPECTRA OF AMMONIA-WATER ICES

    SciTech Connect

    Zheng Weijun; Jewitt, David; Kaiser, Ralf I. E-mail: ralfk@hawaii.edu

    2009-03-15

    We conducted a systematic study of the near-IR and mid-IR spectra of ammonia-water ices at various NH{sub 3}/H{sub 2}O ratios. The differences between the spectra of amorphous and crystalline ammonia-water ices were also investigated. The 2.0 {mu}m ammonia band central wavelength is a function of the ammonia/water ratio. It shifts from 2.006 {+-} 0.003 {mu}m (4985 {+-} 5 cm{sup -1}) to 1.993 {+-} 0.003 {mu}m (5018 {+-} 5 cm{sup -1}) as the percentage of ammonia decreases from 100% to 1%. The 2.2 {mu}m ammonia band center shifts from 2.229 {+-} 0.003 {mu}m (4486 {+-} 5 cm{sup -1}) to 2.208 {+-} 0.003 {mu}m (4528 {+-} 5 cm{sup -1}) over the same range. Temperature-dependent shifts of those bands are below the uncertainty of the measurement, and therefore are not detectable. These results are important for comparison with astronomical observations as well as for estimating the concentration of ammonia in outer solar system ices.

  2. Radiation chemistry in ammonia-water ices

    SciTech Connect

    Loeffler, M. J.; Raut, U.; Baragiola, R. A.

    2010-02-07

    We studied the effects of 100 keV proton irradiation on films of ammonia-water mixtures between 20 and 120 K. Irradiation destroys ammonia, leading to the formation and trapping of H{sub 2}, N{sub 2}, NO, and N{sub 2}O, the formation of cavities containing radiolytic gases, and ejection of molecules by sputtering. Using infrared spectroscopy, we show that at all temperatures the destruction of ammonia is substantial, but at higher temperatures (120 K), it is nearly complete ({approx}97% destroyed) after a fluence of 10{sup 16} ions/cm{sup 2}. Using mass spectroscopy and microbalance gravimetry, we measure the sputtering yield of our sample and the main components of the sputtered flux. We find that the sputtering yield depends on fluence. At low temperatures, the yield is very low initially and increases quadratically with fluence, while at 120 K the yield is constant and higher initially. The increase in the sputtering yield with fluence is explained by the formation and trapping of the ammonia decay products, N{sub 2} and H{sub 2}, which are seen to be ejected from the ice at all temperatures.

  3. Radiation Chemistry in Ammonia-Water Ices

    NASA Technical Reports Server (NTRS)

    Loeffler, M. J.; Raut, U.; Baragiola, R. A.

    2010-01-01

    We studied the effects of 100 keV proton irradiation on films of ammonia-water mixtures between 20 and 120 K. Irradiation destroys ammonia, leading to the formation and trapping of H2, N2 NO, and N2O, the formation of cavities containing radiolytic gases, and ejection of molecules by sputtering. Using infrared spectroscopy, we show that at all temperatures the destruction of ammonia is substantial, but at higher temperatures (120 K), it is nearly complete (approximately 97% destroyed) after a fluence of 10(exp 16) ions per square centimeter. Using mass spectroscopy and microbalance gravimetry, we measure the sputtering yield of our sample and the main components of the sputtered flux. We find that the sputtering yield depends on fluence. At low temperatures, the yield is very low initially and increases quadratically with fluence, while at 120 K the yield is constant and higher initially. The increase in the sputtering yield with fluence is explained by the formation and trapping of the ammonia decay products, N2 and H2 which are seen to be ejected from the ice at all temperatures.

  4. Corrosion protection of steel in ammonia/water heat pumps

    DOEpatents

    Mansfeld, Florian B.; Sun, Zhaoli

    2003-10-14

    Corrosion of steel surfaces in a heat pump is inhibited by adding a rare earth metal salt to the heat pump's ammonia/water working fluid. In preferred embodiments, the rare earth metal salt includes cerium, and the steel surfaces are cerated to enhance the corrosion-inhibiting effects.

  5. Silicate interactions with ammonia-water fluids on early Titan

    NASA Astrophysics Data System (ADS)

    Engel, S.; Lunine, J. I.

    1994-02-01

    Plausible models of the early history of Titan suggest that ammonia and water were present in liquid form at the surface. We show here by thermodynamic modeling that such an ocean could have reacted with silicates to put substantial quantities of sodium and potassium into solution. Following the formation of an ice crust by cooling, mantle ammonia-water fluids enriched in potassium would have been brought to the surface through the cryogenic equivalent of volcanism. Later impacts would have released the Ar-40 produced by decay of the K-40 into the atmosphere. The abundance of atmospheric Ar-40, measurable by the Huygens probe gas chromatograph mass spectrometer, may be dominated by this source and hence gives a proxy indication of the volume of ammonia-water resurfacing on Titan over geologic time.

  6. Silicate interactions with ammonia-water fluids on early Titan

    NASA Technical Reports Server (NTRS)

    Engel, Steffi; Lunine, Jonathan I.

    1994-01-01

    Plausible models of the early history of Titan suggest that ammonia and water were present in liquid form at the surface. We show here by thermodynamic modeling that such an ocean could have reacted with silicates to put substantial quantities of sodium and potassium into solution. Following the formation of an ice crust by cooling, mantle ammonia-water fluids enriched in potassium would have been brought to the surface through the cryogenic equivalent of volcanism. Later impacts would have released the Ar-40 produced by decay of the K-40 into the atmosphere. The abundance of atmospheric Ar-40, measurable by the Huygens probe gas chromatograph mass spectrometer, may be dominated by this source and hence gives a proxy indication of the volume of ammonia-water resurfacing on Titan over geologic time.

  7. Rheology of water and ammonia-water ices

    NASA Technical Reports Server (NTRS)

    Goldsby, D. L.; Kohlstedt, D. L.; Durham, W. B.

    1993-01-01

    Creep experiments on fine-grained water and ammonia-water ices have been performed at one atmosphere and high confining pressure in order to develop constitutive relationships necessary to model tectonic processes and interpret surface features of icy moons of the outer solar system. The present series of experiments explores the effects of temperature, strain rate, grain size, and melt fraction on creep strength. In general, creep strength decreases with increasing temperature, decreasing strain rate, and increasing melt fraction. A transition from dislocation creep to diffusion creep occurs at finer grain sizes, higher temperatures, and lower strain rates.

  8. Energy analysis of an ammonia-water absorption refrigeration system

    SciTech Connect

    Dincer, I.; Dost, S.

    1996-09-01

    Absorption refrigeration systems (ARSs) are run on heat-operated cycles. In these systems a secondary fluid (i.e., absorbent) is used to absorb the primary fluid (i.e., refrigerant) vaporized in the evaporator. ARSs for industrial and domestic applications have been attracting increasing interest throughout the world. A simple energy analysis technique for ammonia-water refrigeration systems is presented and verified with actual experimental data taken from the literature. Comparison was made in terms of the coefficient of performance, and very good agreement was found.

  9. BLISTERING AND EXPLOSIVE DESORPTION OF IRRADIATED AMMONIA-WATER MIXTURES

    SciTech Connect

    Loeffler, M. J.; Baragiola, R. A. E-mail: raul@virginia.edu

    2012-01-10

    We present laboratory studies on the thermal evolution of a solid ammonia-water mixture after it has been irradiated at 20, 70, and 120 K. In samples irradiated at {<=}70 K, we observed fast outbursts that appear to indicate grain ejection and correlate well with the formation of micron-sized scattering centers. The occurrence of this phenomenon at the lower irradiation temperatures indicates that our results may be most relevant for understanding the release of gas and grains by comets and the surfaces of some of the colder icy satellites. We observe outgassing at temperatures below those where ice sublimates, which suggests that comets containing radiolyzed material may have outbursts farther from the Sun that those that are passive. In addition, the estimated size of the grains ejected from our sample is on the order of the size of E-ring particles, suggesting that our results give a plausible mechanism for how micron-sized grains could be formed from an icy surface. Finally, we propose that the presence of the {approx}4.5 {mu}m N{sub 2}O absorption band on an icy surface in outer space will serve to provide indirect evidence for radiation-processed ices that originally contained ammonia or nitrogen, which could be particularly useful since nitrogen is such a weak absorber in the infrared and ammonia is rapidly decomposed by radiolysis.

  10. Ammonia-water bubble absorber with a plate heat exchanger

    SciTech Connect

    Kang, Y.T.; Kashiwagi, Takao; Christensen, R.N.

    1998-10-01

    The objectives of this paper are to develop a design model for a bubble absorber with plate heat exchangers and to evaluate the heat and mass transfer resistances within both liquid and bubble. Parametric analysis was performed to find optimum design conditions for the bubble absorber. An offset strip fin (OSF) is used to enhance heat transfer performance in the coolant region of a standard plate heat exchanger. It was found that the heat transfer resistance was dominant in the vapor region, while the mass transfer resistance was dominant in the liquid region. The mass transfer area was found to have more significant effect on the size of the bubble absorber than the heat transfer area. The direction of mass transfer was confirmed in the simulation of the countercurrent bubble absorber. The present design model predicts the water desorption process up to the length of 12.5 cm from the bottom of the bubble absorber. All geometric variables could be selected optimally for given thermal conditions by the design model developed in this paper. This is a significant contribution in designing the ammonia-water bubble absorber.

  11. Calorimetric studies of the ammonia-water system with application to the outer solar system

    NASA Astrophysics Data System (ADS)

    Yarger, J.; Lunine, J. I.; Burke, M.

    1993-07-01

    A series of heating experiments was performed on the condensed ammonia-water system using a differential scanning calorimeter (DSC). The water-rich samples were cooled quickly to below 130 K, then heated at a variety of rates. Rather than a single peritectic melt at 176 K, expected for the equilibrium system of water ice and ammonia dihydrate, four enthalpic transitions were repeatedly seen in the temperature range 150-176 K. These transitions are generally consistent with the earlier calorimetric results of Van Kasteren (1973), who interpreted the lowest temperature exotherm as crystallization of an amorphous ammonia-water compound formed during cooling. We propose that both sets of experiments are seeing the crystallization of ammonia monohydrate, which is metastable relative to the dihydrate, followed by partial remelting and crystallization of dihydrate upon further heating. The apparent stability of the monohydrate in the dihydrate equilibrium field implies a potentially complex behavior of ammonia-water ices in satellites. Possible self-heating of the mixture by several tens of degrees up to the 170 K eutectic could make mobilization of ammonia-water liquids in icy satellite interiors energetically easier than previously thought.

  12. Calorimetric studies of the ammonia-water system with application to the outer solar system

    NASA Technical Reports Server (NTRS)

    Yarger, Jeffery; Lunine, Jonathan I.; Burke, Michael

    1993-01-01

    A series of heating experiments was performed on the condensed ammonia-water system using a differential scanning calorimeter (DSC). The water-rich samples were cooled quickly to below 130 K, then heated at a variety of rates. Rather than a single peritectic melt at 176 K, expected for the equilibrium system of water ice and ammonia dihydrate, four enthalpic transitions were repeatedly seen in the temperature range 150-176 K. These transitions are generally consistent with the earlier calorimetric results of Van Kasteren (1973), who interpreted the lowest temperature exotherm as crystallization of an amorphous ammonia-water compound formed during cooling. We propose that both sets of experiments are seeing the crystallization of ammonia monohydrate, which is metastable relative to the dihydrate, followed by partial remelting and crystallization of dihydrate upon further heating. The apparent stability of the monohydrate in the dihydrate equilibrium field implies a potentially complex behavior of ammonia-water ices in satellites. Possible self-heating of the mixture by several tens of degrees up to the 170 K eutectic could make mobilization of ammonia-water liquids in icy satellite interiors energetically easier than previously thought.

  13. Temperature Dependence of Cryogenic Ammonia-Water Ice Mixtures and Implications for Icy Satellite Surfaces

    NASA Technical Reports Server (NTRS)

    Dalton, J. B., III; Curchin, J. M.; Clark, R. N.

    2001-01-01

    Infrared spectra of ammonia-water ice mixtures reveal temperature-dependent absorption bands due to ammonia. These features, at 1.04, 2.0, and 2.25 microns, may shed light on the surface compositions of the Galilean and Saturnian satellites. Additional information is contained in the original extended abstract.

  14. Equation of state of ammonia-water liquid - Derivation and planetological applications

    NASA Technical Reports Server (NTRS)

    Croft, S. K.; Lunine, J. I.; Kargel, J.

    1988-01-01

    The present least-squares fit calculation of the equation of state for ammonia-water liquid has yielded results for the zero-100 wt pct NH3, 170-300 K temperature, and zero-10 kb pressure parameter ranges. In conjunction with solid density and thermodynamic measurements, the present calculated and measured liquid densities are used to yield estimates of density and thermal expansion at 1 bar for the solid phases of ammonia's monohydrate, dihydrate, and hemihydrate between absolute zero and their respective melting points. Attention is given to the implications for icy satellite morphologic and tectonic forms of peritectic ammonia-water liquid that is neutrally buoyant relative to the corresponding solid phases.

  15. Marangoni condensation of ammonia-water vapor mixtures on a horizontal tube

    NASA Astrophysics Data System (ADS)

    Dong, Bin; Zhao, Jun; Wang, Shixue

    2013-07-01

    In this paper, the Marangoni condensation of ammonia-water mixture on a horizontal smooth tube was investigated. The research presented here concerns the external condensation of down-flowing ammonia-water vapors on a 100mm long cooled horizontal copper tube of 16mm external diameter. The results showed that, with the change of the surface subcooling, the condensation heat transfer coefficients revealed nonlinear characteristics with peak values. With the increase of the ammonia vapor concentration, the condensation heat transfer coefficient decreased notably. The condensation heat transfer enhancement had been realized by addition of ammonia to water almost in all the experimental surface subcoolings. The maximum ratio of heat transfer coefficient compared to the pure steam is 1.9 at the ammonia vapor concentration of 0.38%.

  16. Experimental and analytical study of condensation of ammonia-water mixtures

    SciTech Connect

    Panchal, C.B.; Kuru, W.C.; Chen, F.C.; Domingo, N.; HuangFu, E.P.

    1997-06-01

    The need for more energy efficient power generation and recent environmental issues of CFCs prompted the development of combined steam and Kalina cycle power systems, and advanced ammonia/water absorption heat pumps. However, the working media and associated thermal design aspects require new concepts for maintaining high thermal effectiveness and phase equilibrium for achieving maximum possible thermodynamic advantages. In the present study, a theoretical analysis was carried for the condensation of ammonia/water mixtures on a vertical tube. A set of equations was formulated and a calculation algorithm was developed to predict the local rate of heat and mass fluxes for binary ammonia-water systems. The predicted rate of condensation was compared with the experimental data obtained at Oak Ridge National Laboratory (ORNL) for a mixture of 90% ammonia and 10% water. The role of diffusion in simultaneous heat and mass transfer associated with condensation was analyzed by comparing the results from three limiting cases, which include equilibrium conditions, and liquid-phase diffusion of finite and infinite values. The results showed that the vapor-phase diffusion is a controlling mechanism.

  17. Determining the composition of ammonia/water mixtures using short-wave near-infrared spectroscopy.

    PubMed

    Barba, M Isabel; Salavera, Daniel; Larrechi, M Soledad; Coronas, Alberto

    2016-01-15

    This paper proposes a methodology based on short-wave near-infrared spectroscopy to determine the ammonia content of ammonia/water mixtures with ammonia mass fraction in the range 0.35-0.65. Establishing this methodology meant modeling the relationship between the pressure bar (15-25)bar, temperature (20-50)°C and composition of the ammonia-water in the mixture (0.35-0.65 in ammonia mass fraction) with absorbance at 1033nm. The experiments were designed to optimize experimental work. A 2(3) factorial design+3 center points was used to establish and analyze the significance of the variables in the absorbance using analysis of variance (ANOVA). A linear model for absorbance was obtained using the least squares method. The trueness of the results versus the values obtained was assessed using a reference method; density measurement was chosen for this study. The accuracy of the results in terms of root-mean-square deviation (RMSD) was 3.7%. The methodology proposed represents a fast alternative for the "in-situ" measurement of the ammonia composition of ammonia-water mixtures in absorption refrigeration systems. PMID:26592584

  18. The ammonia-water system and the chemical differentiation of icy satellites

    USGS Publications Warehouse

    Hogenboom, D.L.; Kargel, J.S.; Consolmagno, G.J.; Holden, T.C.; Lee, L.; Buyyounouski, M.

    1997-01-01

    We report the discovery of the first high-pressure polymorphs of ammonia hydrates: ammonia monohydrate II and ammonia dihydrate II. The subsolidus transitions and melting curves of these substances are shown by their volume-temperature functions; uncalibrated calorimetry corroborates these phase changes. From 20 to 300 MPa ammonia dihydrate and ice melt at a eutectic to form water-rich liquids; at lower and higher pressures, ammonia dihydrate melts incongruently to ammonia-rich liquids. The new data are consistent with independently known thermodynamic parameters of the ammonia-water system. These results fill in an important region of pressure-temperature space not previously studied; a body of previous data reported by other investigators covers a complementary region (higher pressures), but in the light of the new data those earlier results now appear to have been misinterpreted. We show that a suitable reinterpretation of the previous data supports the identification of at least one high-pressure polymorph of each compound. The behavior of the system H2O-NH3in many ways follows that of MgO-SiO2, and the roles of ammonia-water in icy satellite evolution may parallel those of magnesium silicates in Earth's structure, volcanism, and deep mantle tectonism. Pressure-related effects, including a pressure influence on the ammonia content of cryomagmas, might be significant in determining some potentially observable aspects of cryovolcanic morphologies, surface compositions, and interior structures of icy satellites. ?? 1997 Academic Press.

  19. Improving the performance of ammonia-water absorption cycles using salt additives and membranes

    SciTech Connect

    Ibrahim, O.M.; Barnett, S.M.; Balamuru, V.G.

    1997-12-31

    This paper proposes a new design of an ammonia-water absorption refrigeration cycle for low-temperature heat sources such as solar energy and waste heat. The proposed cycle uses a salt additive to shift the chemical equilibrium toward more effective separation of ammonia molecules from aqueous solution (i.e., salting out). Since salt additives can affect all aspects of the absorption cycle, membranes have been chosen to control the flow of ions in the cycle and limit their effects to the generation side. This paper describes an absorption cycle that uses membrane separation processes, such as reverse osmosis, dialysis, and electrodialysis. To optimize the performance of the cycle, however, the membranes and salts must be carefully chosen.

  20. THERMODYNAMIC ANALYSIS OF AMMONIA-WATER-CARBON DIOXIDE MIXTURES FOR DESIGNING NEW POWER GENERATION CYCLES

    SciTech Connect

    Ashish Gupta

    2003-01-15

    This project was undertaken with the goal of developing a computational package for the thermodynamic properties of ammonia-water-carbon dioxide mixtures at elevated temperature and pressure conditions. This objective was accomplished by modifying an existing set of empirical equations of state for ammonia-water mixtures. This involved using the Wagner equation of state for the gas phase properties of carbon dioxide. In the liquid phase, Pitzer's ionic model was used. The implementation of this approach in the form of a computation package that can be used for the optimization of power cycles required additional code development. In particular, this thermodynamic model consisted of a large set of non-linear equations. Consequently, in the interest of computational speed and robustness that is required when applied to optimization problems, analytic gradients were incorporated in the Newton solver routines. The equations were then implemented using a stream property predictor to make initial guesses of the composition, temperature, pressure, enthalpy, entropy, etc. near a known state. The predictor's validity is then tested upon the convergence of an iteration. It proved difficult to obtain experimental data from the literature that could be used to test the accuracy of the new thermodynamic property package, and this remains a critical need for future efforts in the area. It was possible, however, to assess the feasibility of using this complicated property prediction package for power cycle design and optimization. Such feasibility was first demonstrated by modification of our Kalina cycle optimization code to use the package with either a deterministic optimizer, MINOS, or a stochastic optimizer using differential evolution, a genetic-algorithm-based technique. Beyond this feasibility demonstration, a new approach to the design and optimization of power cycles was developed using a graph theoretic approach.

  1. Effectiveness of an ammonia-water mixture turbine system to hot water heat source

    SciTech Connect

    Suzuki, Takashi; Noguchi, Hideki; Amano, Yoshiharu; Hashizume, Takumi; Akiba, Masashi; Tanzawa, Yoshiaki; Usui, Akira

    1999-07-01

    An ammonia-water mixture (AWM) turbine system is proposed in the paper. The authors call this Waseda ammonia-water Mixture Turbine System (W-MTS). The paper presents some results of the investigation for design of a bottoming cycle that is supplied steam as heat source. The results of the cycle simulation show that the W-MTS is superior to the other simple Kalina cycles (KCS1 and KCS34) to pressurized hot water and steam as a latent and a sensible heat source at a temperature of 160 C. The main components of the W-MTS are a heat recovery vapor generator, two condensers, an AWM turbine and two separators. The W-MTS features two simple Kalina cycles, KCS-1 and KCS-34. The W-MTS behaves like KCS-1 at low ammonia mass fraction region, and like KCS-34 at high ammonia mass fraction region. The W-MTS shows the higher output power rather than the two simple Kalina cycles at all over the ammonia mass fraction. The W-MTS is expected to be effective with the heat recovery of two preheaters in a AWM-vapor generation not only to sensible heat sources, such as exhaust gas that comes from gas turbine, hot water from a waste heat recovery system, etc., but also latent heat source e.g. steam. The results of the simulation show that the ammonia mass fraction at the inlet of the heat recovery vapor generator, turbine inlet pressure and temperature in the separator are the key parameters for optimizing the operating conditions of the cycles. In the temperature rage between 120 C and 200 C, the W-MTS generates more power rather than two simple Kaline cycles.

  2. DESIGN OF HYBRID POWER GENERATION CYCLES EMPLOYING AMMONIA-WATER-CARBON DIOXIDE MIXTURES

    SciTech Connect

    Ashish Gupta

    2002-06-01

    A power cycle generates electricity from the heat of combustion of fossil fuels. Its efficiency is governed by the cycle configuration, the operating parameters, and the working fluid. Typical. designs use pure water as the fluid. in the last two decades, hybrid cycles based on ammonia-water, and carbon-dioxide mixtures as the working fluid have been proposed. These cycles may improve the power generation efficiency of Rankine cycles by 15%. Improved efficiency is important for two reasons: it lowers the cost of electricity being produced, and by reducing the consumption of fossil fuels per unit power, it reduces the generation of environmental pollutants. The goal of this project is to develop a computational optimization-based method for the design and analysis of hybrid bottoming power cycles to minimize the usage of fossil fuels. The development of this methodology has been achieved by formulating this task as that of selecting the least cost power cycle design from all possible configurations. They employ a detailed thermodynamic property prediction package they have developed under a DOE-FETC grant to model working fluid mixtures. Preliminary results from this work suggest that a pure NH{sub 3} cycle outperforms steam or the expensive Kalina cycle.

  3. Ammonia and ammonium hydroxide sensors for ammonia/water absorption machines: Literature review and data compilation

    NASA Astrophysics Data System (ADS)

    Anheier, N. C., Jr.; McDonald, C. E.; Cuta, J. M.; Cuta, F. M.; Olsen, K. B.

    1995-05-01

    This report describes an evaluation of various sensing techniques for determining the ammonia concentration in the working fluid of ammonia/water absorption cycle systems. The purpose was to determine if any existing sensor technology or instrumentation could provide an accurate, reliable, and cost-effective continuous measure of ammonia concentration in water. The resulting information will be used for design optimization and cycle control in an ammonia-absorption heat pump. Pacific Northwest Laboratory (PNL) researchers evaluated each sensing technology against a set of general requirements characterizing the potential operating conditions within the absorption cycle. The criteria included the physical constraints for in situ operation, sensor characteristics, and sensor application. PNL performed an extensive literature search, which uncovered several promising sensing technologies that might be applicable to this problem. Sixty-two references were investigated, and 33 commercial vendors were identified as having ammonia sensors. The technologies for ammonia sensing are acoustic wave, refractive index, electrode, thermal, ion-selective field-effect transistor (ISFET), electrical conductivity, pH/colormetric, and optical absorption. Based on information acquired in the literature search, PNL recommends that follow-on activities focus on ISFET devices and a fiber optic evanescent sensor with a colormetric indicator. The ISFET and fiber optic evanescent sensor are inherently microminiature and capable of in situ measurements. Further, both techniques have been demonstrated selective to the ammonium ion (NH4(+)). The primary issue remaining is how to make the sensors sufficiently corrosion-resistant to be useful in practice.

  4. Ammonia and ammonium hydroxide sensors for ammonia/water absorption machines: Literature review and data compilation

    SciTech Connect

    Anheier, N.C. Jr.; McDonald, C.E.; Cuta, J.M.; Cuta, F.M.; Olsen, K.B.

    1995-05-01

    This report describes an evaluation of various sensing techniques for determining the ammonia concentration in the working fluid of ammonia/water absorption cycle systems. The purpose of this work was to determine if any existing sensor technology or instrumentation could provide an accurate, reliable, and cost-effective continuous measure of ammonia concentration in water. The resulting information will be used for design optimization and cycle control in an ammonia-absorption heat pump. PNL researchers evaluated each sensing technology against a set of general requirements characterizing the potential operating conditions within the absorption cycle. The criteria included the physical constraints for in situ operation, sensor characteristics, and sensor application. PNL performed an extensive literature search, which uncovered several promising sensing technologies that might be applicable to this problem. Sixty-two references were investigated, and 33 commercial vendors were identified as having ammonia sensors. The technologies for ammonia sensing are acoustic wave, refractive index, electrode, thermal, ion-selective field-effect transistor (ISFET), electrical conductivity, pH/colormetric, and optical absorption. Based on information acquired in the literature search, PNL recommends that follow-on activities focus on ISFET devices and a fiber optic evanescent sensor with a colormetric indicator. The ISFET and fiber optic evanescent sensor are inherently microminiature and capable of in situ measurements. Further, both techniques have been demonstrated selective to the ammonium ion (NH{sub 4}{sup +}). The primary issue remaining is how to make the sensors sufficiently corrosion-resistant to be useful in practice.

  5. A comparison between ammonia-water and water-lithium bromide solutions in vapor absorption refrigeration systems

    SciTech Connect

    Horuz, I.

    1998-07-01

    A Vapor Absorption Refrigeration (VAR) System is similar to a Vapor Compression Refrigeration (VCR) System. In both systems the required refrigeration is provided by refrigerants vaporizing in the evaporator. However, in the VAR System, a physico-chemical process replaces the mechanical process of the VCR system and heat rather than a mechanical and electrical energy is used. The advantages of this system lie in the possibility of utilizing of waste energy from industrial plants as well as of using solar energy. The study included an investigation to analyze the Vapor Absorption Refrigeration systems using ammonia-water and water-lithium bromide solutions. A fundamental VAR system is described and the operating sequence is explained. Since the most common VAR systems use ammonia-water solution with ammonia as the refrigerant and water-lithium bromide solution with water as the refrigerant, the comparison of the two is presented in respect of the coefficient of performance (COP), the cooling capacity and the maximum and minimum system pressures. It is concluded that the VAR system using water-lithium bromide solution provided better performance than the system using ammonia-water solution. However, there are some points to be considered such as: the danger of crystallization and impossibility of operating in very low temperatures because of the use of water as the refrigerant.

  6. An Assessment of Transport Property Estimation Methods for Ammonia-Water Mixtures and Their Influence on Heat Exchanger Size

    NASA Astrophysics Data System (ADS)

    Kærn, M. R.; Modi, A.; Jensen, J. K.; Haglind, F.

    2015-07-01

    Transport properties of fluids are indispensable for heat exchanger design. The methods for estimating the transport properties of ammonia-water mixtures are not well established in the literature. The few existent methods are developed from none or limited, sometimes inconsistent experimental datasets, conducted for the liquid phase only. These datasets are usually confined to low concentrations and temperatures, which are much less than those occurring in Kalina cycle boilers. This paper presents a comparison of various methods used to estimate the viscosity and the thermal conductivity of ammonia-water mixtures. Firstly, the different methods are introduced and compared at various temperatures and pressures. Secondly, their individual influence on the required heat exchanger size (surface area) is investigated. For this purpose, two case studies related to the use of the Kalina cycle are considered: a flue-gas-based heat recovery boiler for a combined cycle power plant and a hot-oil-based boiler for a solar thermal power plant. The different transport property methods resulted in larger differences at high pressures and temperatures, and a possible discontinuous first derivative, when using the interpolative methods in contrast to the corresponding state methods. Nevertheless, all possible mixture transport property combinations used herein resulted in a heat exchanger size within 4.3 % difference for the flue-gas heat recovery boiler, and within 12.3 % difference for the oil-based boiler.

  7. Experimental Investigations on the Characteristics of the Ammonia-Water Absorption Refrigerator for Low Temperature Solution Cycle

    NASA Astrophysics Data System (ADS)

    Takei, Toshitaka; Kimijima, Shinji; Saito, Kiyoshi; Kawai, Sunao

    This report refers to some static characteristics of the ammonia-water absorption refrigerator for low temperature refrigerating process which needs the temperature below the freezing point. Especially, the influence of evaporating temperature and cooling water temperature is clarified by the experimental investigation. In addition to this, the validity of constructed simulation model of this absorption refrigerator is mentioned. The validity of simulation model is verified by the comparison of experimental results and calculation. To examine the characteristics, we conducted the performance test using the trial product of which the standard cooling capacity is 175kW. The performance is estimated according to cooling capacity and COP. As a result, the effects of the evaporating temperature and cooling water temperature on the cooling performance are clarified by the experimental research. Furthermore, the calculation of the static characteristics predicted by the simulation model is in good agreements with the experimental results.

  8. Vapor-Liquid Equilibrium in the Systems Argon-Oxygen and Ammonia-Water Measurements and Modeling for Industrial and Planetary Applications

    NASA Astrophysics Data System (ADS)

    Parikh, Nimmi Chandra

    1997-11-01

    This work presents an integrated approach for characterizing binary vapor-liquid equilibrium (VLE) through a combination of experimental measurements and thermodynamic modeling for low to medium pressure binary VLE. We focus on two dissimilar mixtures: the non-polar argon-oxygen system of importance for industrial air separation processes and the polar ammonia-water system of interest for understanding the atmospheres of Jupiter, Saturn, Uranus, and Neptune. Experimental measurements of pressure, temperature, and phase composition at equilibrium were made for the argon-oxygen system at temperatures from 92K to 115K with a cryogenic VLE apparatus. A second custom-built apparatus was used to measure VLE in the ammonia-water system from 276K to 285K. Our new data, along with existing literature data, were critically evaluated and tested for thermodynamic consistency. A thermodynamic model of the argon-oxygen system from 90K to 120K was developed using an activity coefficient approach to describe nonidealities in the liquid and the virial equation of state to characterize vapor phase nonidealities. The model employs maximum likelihood parameter fitting which takes into account uncertainties in all measured quantities and maximizes the likelihood that the model describes the true behavior of the mixture. For the ammonia-water study a new extension of the thermodynamic model to polar mixtures is presented. Our model has built-in temperature dependence for reliable extrapolation to temperatures beyond the range of the available data. The model constants can be used in a simple iterative procedure to calculate the liquid and vapor compositions of the mixture at specified temperature and pressure. As a demonstration, our ammonia-water model is used to calculate altitude-composition profiles for condensing clouds of liquid ammonia-water solution on Jupiter.

  9. Effect of calcium cyanamide, ammonium bicarbonate and lime mixture, and ammonia water on survival of Ralstonia solanacearum and microbial community.

    PubMed

    Liu, Lijuan; Sun, Chengliang; Liu, Xingxing; He, Xiaolin; Liu, Miao; Wu, Hao; Tang, Caixian; Jin, Chongwei; Zhang, Yongsong

    2016-01-01

    The inorganic nitrogenous amendments calcium cyanamide (CC), ammonia water (AW), and a mixture of ammonium bicarbonate with lime (A+L) are popularly used as fumigants to control soil-borne disease in China. However, it is unclear which of these fumigants is more effective in controlling R. solanacearum. This present study compared the efficiencies of the three nitrogenous amendments listed above at four nitrogen levels in suppressing the survival of R. solanacearum in soil. The CC showed the best ability to suppress R. solanacearum due to its highest capacity to increase soil and NO2(-) contents and pH. However, AW was more suitable to controlling bacterial wilt caused by R. solanacearum because it had a lower cost and its application rate of 0.25 g N kg(-1) soil could effectively suppress the survival of R. solanacearum. Additionally, soil microbial activity and community populations were restored to their initial state four weeks after the application of each fumigant, indicating that the three fumigants had few detrimental impacts on soil microbial activity and community structure with an exception of the suppression of R. solanacearum. The present study provides guidance for the selection of a suitable alkaline nitrogenous amendment and its application rate in controlling bacterial wilt. PMID:26738601

  10. Optimal design of solid oxide fuel cell, ammonia-water single effect absorption cycle and Rankine steam cycle hybrid system

    NASA Astrophysics Data System (ADS)

    Mehrpooya, Mehdi; Dehghani, Hossein; Ali Moosavian, S. M.

    2016-02-01

    A combined system containing solid oxide fuel cell-gas turbine power plant, Rankine steam cycle and ammonia-water absorption refrigeration system is introduced and analyzed. In this process, power, heat and cooling are produced. Energy and exergy analyses along with the economic factors are used to distinguish optimum operating point of the system. The developed electrochemical model of the fuel cell is validated with experimental results. Thermodynamic package and main parameters of the absorption refrigeration system are validated. The power output of the system is 500 kW. An optimization problem is defined in order to finding the optimal operating point. Decision variables are current density, temperature of the exhaust gases from the boiler, steam turbine pressure (high and medium), generator temperature and consumed cooling water. Results indicate that electrical efficiency of the combined system is 62.4% (LHV). Produced refrigeration (at -10 °C) and heat recovery are 101 kW and 22.1 kW respectively. Investment cost for the combined system (without absorption cycle) is about 2917 kW-1.

  11. Effect of calcium cyanamide, ammonium bicarbonate and lime mixture, and ammonia water on survival of Ralstonia solanacearum and microbial community

    PubMed Central

    Liu, Lijuan; Sun, Chengliang; Liu, Xingxing; He, Xiaolin; Liu, Miao; Wu, Hao; Tang, Caixian; Jin, Chongwei; Zhang, Yongsong

    2016-01-01

    The inorganic nitrogenous amendments calcium cyanamide (CC), ammonia water (AW), and a mixture of ammonium bicarbonate with lime (A+L) are popularly used as fumigants to control soil-borne disease in China. However, it is unclear which of these fumigants is more effective in controlling R. solanacearum. This present study compared the efficiencies of the three nitrogenous amendments listed above at four nitrogen levels in suppressing the survival of R. solanacearum in soil. The CC showed the best ability to suppress R. solanacearum due to its highest capacity to increase soil and NO2− contents and pH. However, AW was more suitable to controlling bacterial wilt caused by R. solanacearum because it had a lower cost and its application rate of 0.25 g N kg−1 soil could effectively suppress the survival of R. solanacearum. Additionally, soil microbial activity and community populations were restored to their initial state four weeks after the application of each fumigant, indicating that the three fumigants had few detrimental impacts on soil microbial activity and community structure with an exception of the suppression of R. solanacearum. The present study provides guidance for the selection of a suitable alkaline nitrogenous amendment and its application rate in controlling bacterial wilt. PMID:26738601

  12. Telescoping columns

    NASA Astrophysics Data System (ADS)

    Mazur, J. T.

    1980-12-01

    An extendable column is described which consists of several axially elongated rigid structural sections nested within one another. Each section includes a number of rotatably attached screws running along its length. The next inner section includes threaded lugs oriented to threadingly engage the screws. The column is extended or retracted upon rotation of the screws. The screws of each section are selectively rotated by a motor and an engagement mechanism.

  13. PULSE COLUMN

    DOEpatents

    Grimmett, E.S.

    1964-01-01

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

  14. Thermodynamic analysis of a new combined cooling, heat and power system driven by solid oxide fuel cell based on ammonia-water mixture

    NASA Astrophysics Data System (ADS)

    Ma, Shaolin; Wang, Jiangfeng; Yan, Zhequan; Dai, Yiping; Lu, Bingheng

    2011-10-01

    Although a solid oxide fuel cell combined with a gas turbine (SOFC-GT) has good performance, the temperature of exhaust from gas turbine is still relatively high. In order to recover the waste heat of exhaust from the SOFC-GT to enhance energy conversion efficiency as well as to reduce the emissions of greenhouse gases and pollutants, in this study a new combined cooling, heat and power (CCHP) system driven by the SOFC is proposed to perform the trigeneration by using ammonia-water mixture to recover the waste heat of exhaust from the SOFC-GT. The CCHP system, whose main fuel is methane, can generate electricity, cooling effect and heat effect simultaneously. The overall system performance has been evaluated by mathematical models and thermodynamic laws. A parametric analysis is also conducted to examine the effects of some key thermodynamic parameters on the system performance. Results indicate that the overall energy conversion efficiency exceeds 80% under the given conditions, and it is also found that the increasing the fuel flow rate can improve overall energy conversion efficiency, even though both the SOFC efficiency and electricity efficiency decrease. Moreover, with an increased compressor pressure ratio, the SOFC efficiency, electricity efficiency and overall energy conversion efficiency all increase. Ammonia concentration and pressure entering ammonia-water turbine can also affect the CCHP system performance.

  15. High Pressure Cosmochemistry of Major Planetary Interiors: Laboratory Studies of the Water-rich Region of the System Ammonia-water

    NASA Technical Reports Server (NTRS)

    Nicol, M.; Johnson, M.; Koumvakalis, A. S.

    1985-01-01

    The behavior of gas-ice mixtures in major planets at very high pressures was studied. Some relevant pressure-temperature-composition (P-T-X) regions of the hydrogen (H2)-helium (He)-water (H2O-ammonia (NH3)-methane (CH4) phase diagram were determined. The studies, and theoretical model, of the relevant phases, are needed to interpret the compositions of ice-gas systems at conditions of planetary interest. The compositions and structures of a multiphase, multicomponent system at very high pressures care characterized, and the goal is to characterize this system over a wide range of low and high temperatures. The NH3-H2O compositions that are relevant to planetary problems yet are easy to prepare were applied. The P-T surface of water was examined and the corresponding surface for NH3 was determined. The T-X diagram of ammonia-water at atmospheric pressure was studied and two water-rich phases were found, NH3-2H2O (ammonia dihydrate), which melts incongruently, and NH3.H2O (ammonia monohydrate), which is nonstoichiometric and melts at a higher temperature than the dihydrate. It is suggested that a P-T surface at approximately the monohydrate composition and the P-X surface at room temperature is determined.

  16. Column Liquid Chromatography.

    ERIC Educational Resources Information Center

    Majors, Ronald E.; And Others

    1984-01-01

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

  17. Inelastic column behavior

    NASA Technical Reports Server (NTRS)

    Duberg, John E; Wilder, Thomas W , III

    1952-01-01

    The significant findings of a theoretical study of column behavior in the plastic stress range are presented. When the behavior of a straight column is regarded as the limiting behavior of an imperfect column as the initial imperfection (lack of straightness) approaches zero, the departure from the straight configuration occurs at the tangent-modulus load. Without such a concept of the behavior of a straight column, one is led to the unrealistic conclusion that lateral deflection of the column can begin at any load between the tangent-modulus value and the Euler load, based on the original elastic modulus. A family of curves showing load against lateral deflection is presented for idealized h-section columns of various lengths and of various materials that have a systematic variation of their stress-strain curves.

  18. Distillation Column Modeling Tools

    SciTech Connect

    2001-09-01

    Advanced Computational and Experimental Techniques will Optimize Distillation Column Operation. Distillation is a low thermal efficiency unit operation that currently consumes 4.8 quadrillion BTUs of energy...

  19. Inflatable Column Structure

    NASA Technical Reports Server (NTRS)

    Hedgepeth, J. M.

    1985-01-01

    Lightweight structural member easy to store. Billowing between circumferential loops of fiber inflated column becomes series of cells. Each fiber subjected to same tension along entire length (though tension is different in different fibers). Member is called "isotensoid" column. Serves as jack for automobiles or structures during repairs. Also used as support for temporary bleachers or swimming pools.

  20. Glass-silicon column

    DOEpatents

    Yu, Conrad M.

    2003-12-30

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

  1. JCE Feature Columns

    NASA Astrophysics Data System (ADS)

    Holmes, Jon L.

    1999-05-01

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

  2. Distillation Column Flooding Predictor

    SciTech Connect

    George E. Dzyacky

    2010-11-23

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

  3. Nuclear reactor control column

    SciTech Connect

    Bachovchin, D.M.

    1982-08-10

    The nuclear reactor control column comprises a column disposed within the nuclear reactor core having a variable cross-section hollow channel and containing balls whose vertical location is determined by the flow of the reactor coolant through the column. The control column is divided into three basic sections wherein each of the sections has a different cross-sectional area. The uppermost section of the control column has the greatest crosssectional area, the intermediate section of the control column has the smallest cross-sectional area, and the lowermost section of the control column has the intermediate cross-sectional area. In this manner, the area of the uppermost section can be established such that when the reactor coolant is flowing under normal conditions therethrough, the absorber balls will be lifted and suspended in a fluidized bed manner in the upper section. However, when the reactor coolant flow falls below a predetermined value, the absorber balls will fall through the intermediate section and into the lowermost section, thereby reducing the reactivity of the reactor core and shutting down the reactor.

  4. Nuclear reactor control column

    DOEpatents

    Bachovchin, Dennis M.

    1982-01-01

    The nuclear reactor control column comprises a column disposed within the nuclear reactor core having a variable cross-section hollow channel and containing balls whose vertical location is determined by the flow of the reactor coolant through the column. The control column is divided into three basic sections wherein each of the sections has a different cross-sectional area. The uppermost section of the control column has the greatest cross-sectional area, the intermediate section of the control column has the smallest cross-sectional area, and the lowermost section of the control column has the intermediate cross-sectional area. In this manner, the area of the uppermost section can be established such that when the reactor coolant is flowing under normal conditions therethrough, the absorber balls will be lifted and suspended in a fluidized bed manner in the upper section. However, when the reactor coolant flow falls below a predetermined value, the absorber balls will fall through the intermediate section and into the lowermost section, thereby reducing the reactivity of the reactor core and shutting down the reactor.

  5. Simultaneous Determination of Five Alkaloid Compounds in a Drug Based on a Hydrophilic Monolithic Column by Capillary Electrochromatography.

    PubMed

    Chen, Zongbao; Ye, Qing; Liu, Linghai; Dong, Hongxia

    2016-01-01

    A novel capillary electrochromatography (CEC) method was developed by using a hydrophilic monolithic column for the simultaneous determination of five alkaloids in a drug. The monolithic stationary phase was first prepared via in situ polymerization of acrylamide (AM), glycidyl methacrylate (GMA), N,N'-methylenebisacrylamide (MBA) and 2-acrylamido-2-methyl-1-propane-sulfonic acid (AMPS) in a ternary porogen solvent system consisting of cyclohexanol, dodecanol and toluene. The obtained monolithic stationary phase was subsequently modified by 0.1 mol/L ammonia water for opening epoxide groups of GMA. The separation performance and efficiency of the resulting monolithic column were investigated by the use of five compounds (thiourea, aniline, naphthylamine, diphenylamine and dimethyl acetamide) by CEC. The optimized monolithic column has obtained high column efficiencies with 74,000-121,000 theoretical plates/m. Finally, the prepared monolithic column was used to separate and determine five alkaloids (piperine, nuciferine, kukoline, berberine and tetrandrine) using CEC. Under the conditions of acetonitrile/10 mM phosphate buffer solution (65/35, v/v, pH 8.5) and 15 kV applied voltage, the baseline separation of five alkaloids was achieved. The proposed method has been successfully applied to the determination of berberine in a tablet sample. The percentage of recovery of spiked tablet samples ranged from 93.4 to 108.0% with relative standard deviations (RSDs) <9.20%. PMID:26187925

  6. Microminiature gas chromatographic column

    NASA Technical Reports Server (NTRS)

    Donaldson, R. W., Jr.

    1972-01-01

    Techniques commonly used for fabrication of integrated circuits are utilized to produce long capillary tubes for microminiature chromatographs. Method involves bonding of flat silicon plate to top of spirally grooved silicon chip to close groove and form capillary column.

  7. Distillation Column Flooding Predictor

    SciTech Connect

    2002-02-01

    This factsheet describes a research project whose goal is to develop the flooding predictor, an advanced process control strategy, into a universally useable tool that will maximize the separation yield of a distillation column.

  8. Towards Atomic Column-by-Column Spectroscopy

    SciTech Connect

    Pennycook, S.J.; Rafferty, B.

    1998-09-06

    The optical arrangement of the scanning transmission electron microscope (STEM) is ideally suited for performing analysis of individual atomic columns in materials. Using the incoherent Z-contrast image as a reference, and arranging incoherent conditions also for the spectroscopy, a precise correspondence is ensured between features in the inelastic image and elastic signals. In this way the exact probe position needed to maximise the inelastic signal from a selected column can be located and monitored during the analysis using the much higher intensity elastic signal. Although object functions for EELS are typically less than 1 {Angstrom} full width at half maximum, this is still an order of magnitude larger than the corresponding object functions for elastic (or diffuse) scattering used to form the Z-contrast image. Therefore the analysis is performed with an effective probe that is significantly broader than that used for the reference Z-contrast image. For a 2.2 {Angstrom} probe the effective probe is of the order of 2.5 {Angstrom}, while for a 1.3 {Angstrom} probe the effective probe is 1.6 {Angstrom}. Such increases in effective probe size can significantly reduce or even eliminate contrast between atomic columns that are visible in the image. However, this is only true if we consider circular collector apertures. Calculations based upon the theory of Maslen and Rossouw (Maslen and Rossouw 1984; Rossouw and Maslen 1984) show that employing an annular aperture can reduce the FWHM of the inelastic object function down to values close 0.1 {Angstrom}. With practical aperture sizes it should be possible to achieve this increased spatial resolution without loosing too much signal.

  9. Eruption column physics

    SciTech Connect

    Valentine, G.A.

    1997-03-01

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

  10. A Column Dispersion Experiment.

    ERIC Educational Resources Information Center

    Corapcioglu, M. Y.; Koroglu, F.

    1982-01-01

    Crushed glass and a Rhodamine B solution are used in a one-dimensional optically scanned column experiment to study the dispersion phenomenon in porous media. Results indicate that the described model gave satisfactory results and that the dispersion process in this experiment is basically convective. (DC)

  11. Columns in Clay

    ERIC Educational Resources Information Center

    Leenhouts, Robin

    2010-01-01

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

  12. 11. TIMBER COLUMN AND CAST IRON COLUMN CAP IN FIFTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. TIMBER COLUMN AND CAST IRON COLUMN CAP IN FIFTH FLOOR WAREHOUSE SPACE. VIEW TO SOUTHWEST. - Commercial & Industrial Buildings, Becker-Hazelton Company Warehouse, 280 Iowa Street, Dubuque, Dubuque County, IA

  13. Slurry bubble column hydrodynamics

    NASA Astrophysics Data System (ADS)

    Rados, Novica

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

  14. Microfabricated packed gas chromatographic column

    DOEpatents

    Kottenstette, Richard; Matzke, Carolyn M.; Frye-Mason, Gregory C.

    2003-12-16

    A new class of miniaturized gas chromatographic columns has been invented. These chromatographic columns are formed using conventional micromachining techniques, and allow packed columns having lengths on the order of a meter to be fabricated with a footprint on the order of a square centimeter.

  15. Why Hexagonal Basalt Columns?

    PubMed

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

    2015-10-01

    Basalt columns with their preferably hexagonal cross sections are a fascinating example of pattern formation by crack propagation. Junctions of three propagating crack faces rearrange such that the initial right angles between them tend to approach 120°, which enables the cracks to form a pattern of regular hexagons. To promote understanding of the path on which the ideal configuration can be reached, two periodically repeatable models are presented here involving linear elastic fracture mechanics and applying the principle of maximum energy release rate. They describe the evolution of the crack pattern as a transition from rectangular start configuration to the hexagonal pattern. This is done analytically and by means of three-dimensional finite element simulation. The latter technique reproduces the curved crack path involved in this transition. PMID:26550724

  16. SPIRAL CONTACTOR FOR SOLVENT EXTRACTION COLUMN

    DOEpatents

    Cooley, C.R.

    1961-06-13

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

  17. Buckling of a holey column.

    PubMed

    Pihler-Puzović, D; Hazel, A L; Mullin, T

    2016-09-14

    We report the results from a combined experimental and numerical investigation of buckling in a novel variant of an elastic column under axial load. We find that including a regular line of centred holes in the column can prevent conventional, global, lateral buckling. Instead, the local microstructure introduced by the holes allows the column to buckle in an entirely different, internal, mode in which the holes are compressed in alternate directions, but the column maintains the lateral reflection symmetry about its centreline. The internal buckling mode can be accommodated within a smaller external space than the global one; and it is the preferred buckling mode over an intermediate range of column lengths for sufficiently large holes. For very short or sufficiently long columns a modification of the classical, global, lateral buckling is dominant. PMID:27501288

  18. Dual dorsal columns: a review.

    PubMed

    Beck, C H

    1976-02-01

    Recent evidence indicates that Wall (1970) may have been premature in concluding that dorsal column lesions produce no discernable sensory defects. Much of the negative evidence Wall presented to support this view is inconclusive. In addition several studies have reported significant sensory deficits in animals with severed dorsal columns. On the other hand, the literature strongly supports Wall's view that dorsal column lesions cause motor disturbances. A review of the anatomical and electrophysiological literature reveals growing evidence for the dissociation of two major subsystems relaying in the dorsal column nuclei. The possible functions of these two systems are discussed. PMID:814988

  19. 45. MAIN MEETING ROOM COLUMNS. Ends of gallery columns identified ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. MAIN MEETING ROOM COLUMNS. Ends of gallery columns identified at the time of removal for transfer to the George School for re-erection. The stamp reads, 'REMOVED FROM 12th ST. MTG HSE PHILA 1972'. - Twelfth Street Meeting House, 20 South Twelfth Street, Philadelphia, Philadelphia County, PA

  20. Dorsal column stimulator applications

    PubMed Central

    Yampolsky, Claudio; Hem, Santiago; Bendersky, Damián

    2012-01-01

    Background: Spinal cord stimulation (SCS) has been used to treat neuropathic pain since 1967. Following that, technological progress, among other advances, helped SCS become an effective tool to reduce pain. Methods: This article is a non-systematic review of the mechanism of action, indications, results, programming parameters, complications, and cost-effectiveness of SCS. Results: In spite of the existence of several studies that try to prove the mechanism of action of SCS, it still remains unknown. The mechanism of action of SCS would be based on the antidromic activation of the dorsal column fibers, which activate the inhibitory interneurons within the dorsal horn. At present, the indications of SCS are being revised constantly, while new applications are being proposed and researched worldwide. Failed back surgery syndrome (FBSS) is the most common indication for SCS, whereas, the complex regional pain syndrome (CRPS) is the second one. Also, this technique is useful in patients with refractory angina and critical limb ischemia, in whom surgical or endovascular treatment cannot be performed. Further indications may be phantom limb pain, chronic intractable pain located in the head, face, neck, or upper extremities, spinal lumbar stenosis in patients who are not surgical candidates, and others. Conclusion: Spinal cord stimulation is a useful tool for neuromodulation, if an accurate patient selection is carried out prior, which should include a trial period. Undoubtedly, this proper selection and a better knowledge of its underlying mechanisms of action, will allow this cutting edge technique to be more acceptable among pain physicians. PMID:23230533

  1. Simulated Ionian Column Densities

    NASA Astrophysics Data System (ADS)

    Walker, Andrew C.; Goldstein, D. B.; Varghese, P. L.; Trafton, L. M.; Moore, C. H.

    2010-10-01

    The sublimation atmosphere of Io is modeled using the direct simulation Monte Carlo (DSMC) method. These three-dimensional simulations improve upon previous work by implementing a more accurate two-component surface temperature model. This surface temperature model solves the one-dimensional heat conduction equation with depth for every 1° by 1° surface element. It also includes the following physics: Jovian eclipse, reflected sunlight from Jupiter, latent heat of sublimation/condensation, hot spots, endogenic heating, and independent thermal inertias and albedos for the frost and non-frost surfaces. These simulations model only the dominant dayside atmospheric species, SO2. The non-equilibrium rotational and vibrational energy states of SO2 are treated as well as photo-emission from those states. Plasma heating of the atmosphere by high energy ions and electrons from the Jovian plasma torus is also modeled via a plasma energy flux. Resulting column densities are compared to recent observations in an attempt to constrain the thermal parameters for the frost and non-frost surfaces.

  2. Buckling testing of composite columns

    NASA Astrophysics Data System (ADS)

    Barbero, Ever; Tomblin, John

    1992-11-01

    Euler buckling test results are presented for large composite columns relevant to the mass production of composite structural members by pultrusion. The experimental procedure employed yields highly reproducible and accurate results. All percentage differences between theory and experiment are below 6.2 percent; the theoretically predicted long-column buckling load is accurate even in the case of the most complex composite materials.

  3. Mush Column Magma Chambers

    NASA Astrophysics Data System (ADS)

    Marsh, B. D.

    2002-12-01

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

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

    PubMed

    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. PMID:26343427

  5. Self-regenerating column chromatography

    SciTech Connect

    Park, Woo K.

    1994-12-31

    The present invention provides a process for treating both cations and anions by using a self-regenerating, multi-ionic exchange resin column system which requires no separate regeneration steps. The process involves alternation ion-exchange chromatography for cations and anions in a multi-ionic exchange column packed with a mixture of cation and anion exchange resins. The multi-ionic mixed-charge resin column works as a multifunction column, capable of independently processing either cationic or anionic exchange, or simultaneously processing both cationic and anionic exchanges. The major advantage offered by the alternating multifunction ion exchange process is the self-regeneration of the resins. Applications are to separation of nitrogen and sulfur isotopes.

  6. Self-regenerating column chromatography

    DOEpatents

    Park, W.K.

    1995-05-30

    The present invention provides a process for treating both cations and anions by using a self-regenerating, multi-ionic exchange resin column system which requires no separate regeneration steps. The process involves alternating ion-exchange chromatography for cations and anions in a multi-ionic exchange column packed with a mixture of cation and anion exchange resins. The multi-ionic mixed-charge resin column works as a multi-function column, capable of independently processing either cationic or anionic exchange, or simultaneously processing both cationic and anionic exchanges. The major advantage offered by the alternating multi-function ion exchange process is the self-regeneration of the resins.

  7. LIQUID-LIQUID EXTRACTION COLUMNS

    DOEpatents

    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.

  8. Radiotracer Imaging of Sediment Columns

    NASA Astrophysics Data System (ADS)

    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 (<1 day). This allows multiple measurements to be made on the same column and thus the sediment biology to be monitored non-invasively over time (i.e. after an augmentation has been introduced) and minimizes long-lived radioactive waste. Different parameters can be measured, depending on the tracer type and delivery. A constant infusion of a conservative tracer, such as the positron emitter Br-76 (T1/2= 16.2 hr), measures the exclusion fraction (as

  9. FRACTIONATING COLUMN PRODUCT COLLECTOR CONTROL

    DOEpatents

    Paxson, G.D. Jr.

    1964-03-10

    Means for detecting minute fluid products from a chemical separation column and for advancing a collector tube rack in order to automatically separate and collect successive fractionated products are described. A charge is imposed on the forming drops at the column orifice to create an electric field as the drop falls in the vicinity of a sensing plate. The field is detected by an electrometer tube coupled to the plate causing an output signal to actuate rotation of a collector turntable rack, thereby positioning new collectors under the orifice. The invention provides reliable automatic collection independent of drop size, rate of fall, or chemical composition. (AEC)

  10. Triangular Helical Column for Centrifugal Countercurrent Chromatography.

    PubMed

    Ito, Yoichiro; Yu, Henry

    2009-01-01

    Effective column space and stationary phase retention have been improved by changing the configuration of the helical column originally used for toroidal coil countercurrent chromatography. The use of an equilateral triangular core for the helix column doubles effective column space and retains the stationary phase over 40% of the total column capacity without increasing the column pressure. The present results suggest that the stationary phase retention and the peak resolution will be further improved using new column designs fabricated by a new technology called "laser sintering for rapid prototyping." PMID:20046940

  11. Eruption column modeling of supervolcanoes

    NASA Astrophysics Data System (ADS)

    Dobran, F.

    2010-12-01

    Eruption columns consists of multiphase mixtures of gases and particulate matter in thermodynamic non-equilibrium, and tracking the multitude of interfaces associated with the liquid, solid, and plastic bodies of a wide spectrum of sizes is not practical. The current modeling practice is to use different averaging procedures by employing single-phase continuum models or those from the kinetic theory, together with various conditions that specify the microphysical processes of mixtures. But these models are inadequate to model the eruption columns of supervolcanoes, where the plumes reach the stratosphere and phase change processes contribute to the columns’ dispersion properties on the regional and global scales. A more effective multiphase flow modeling procedure is presented and its computer implementation is discussed.

  12. Stability of elastically supported columns

    NASA Technical Reports Server (NTRS)

    Niles, Alfred S; Viscovich, Steven J

    1942-01-01

    A criterion is developed for the stiffness required of elastic lateral supports at the ends of a compression member to provide stability. A method based on this criterion is then developed for checking the stability of a continuous beam-column. A related method is also developed for checking the stability of a member of a pin-jointed truss against rotation in the plane of the truss.

  13. Beam Studies with Electron Columns

    SciTech Connect

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

    2009-04-01

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

  14. Water Column Methylation in Estuaries

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  15. Lightweight structural columns. [space erectable trusses

    NASA Technical Reports Server (NTRS)

    Bush, H. G. (Inventor)

    1981-01-01

    Lightweight half-lengths of columns for truss structures are described. The columns are adapted for nestable storage and transport to facilitate fabrication of large area truss structures at a remote site and particularly adaptable for space applications.

  16. Method for packed column separations and purifications

    DOEpatents

    Holman, David A.; Bruckner-Lea, Cynthia J.; Brockman, Fred J.; Chandler, Darrell P.

    2006-08-15

    The invention encompasses a method of packing and unpacking a column chamber. A mixture of a fluid and a matrix material are introduced through a column chamber inlet so that the matrix material is packed within a column chamber to form a packed column. The column chamber having the column chamber inlet or first port for receiving the mixture further has an outlet port and an actuator port. The outlet port is partially closed for capturing the matrix material and permitting the fluid to flow therepast by rotating relative one to the other of a rod placed in the actuator port. Further rotation relative one to the other of the rod and the column chamber opens the outlet and permits the matrix material and the fluid to flow therethrough thereby unpacking the matrix material from the column chamber.

  17. Temperature programmable microfabricated gas chromatography column

    DOEpatents

    Manginell, Ronald P.; Frye-Mason, Gregory C.

    2003-12-23

    A temperature programmable microfabricated gas chromatography column enables more efficient chemical separation of chemical analytes in a gas mixture by the integration of a resistive heating element and temperature sensing on the microfabricated column. Additionally, means are provided to thermally isolate the heated column from their surroundings. The small heat capacity and thermal isolation of the microfabricated column improves the thermal time response and power consumption, both important factors for portable microanalytical systems.

  18. 29 CFR 1926.755 - Column anchorage.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Column anchorage. 1926.755 Section 1926.755 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.755 Column anchorage. (a) General requirements for erection stability. (1) All columns shall be anchored by a minimum of 4...

  19. 29 CFR 1926.755 - Column anchorage.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Column anchorage. 1926.755 Section 1926.755 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.755 Column anchorage. (a) General requirements for erection stability. (1) All columns shall be anchored by a minimum of 4...

  20. Axisymmetric collapses of granular columns

    NASA Astrophysics Data System (ADS)

    Lube, Gert; Huppert, Herbert E.; Sparks, R. Stephen J.; Hallworth, Mark A.

    2004-06-01

    Experimental observations of the collapse of initially vertical columns of small grains are presented. The experiments were performed mainly with dry grains of salt or sand, with some additional experiments using couscous, sugar or rice. Some of the experimental flows were analysed using high-speed video. There are three different flow regimes, dependent on the value of the aspect ratio a {=} h_i/r_i, where h_i and r_i are the initial height and radius of the granular column respectively. The differing forms of flow behaviour are described for each regime. In all cases a central, conically sided region of angle approximately 59(°) , corresponding to an aspect ratio of 1.7, remains undisturbed throughout the motion. The main experimental results for the final extent of the deposit and the time for emplacement are systematically collapsed in a quantitative way independent of any friction coefficients. Along with the kinematic data for the rate of spread of the front of the collapsing column, this is interpreted as indicating that frictional effects between individual grains in the bulk of the moving flow only play a role in the last instant of the flow, as it comes to an abrupt halt. For a {<} 1.7, the measured final runout radius, r_infty, is related to the initial radius by r_infty {=} r_i(1 {+} 1.24a); while for 1.7 {<} a the corresponding relationship is r_infty {=} r_i(1 {+} 1.6a(1/2) ). The time, t_infty, taken for the grains to reach r_infty is given by t_infty {=} 3(h_i/g)(1/2} {=} 3(r_i/g)({1/2}a^{1/2)) , where g is the gravitational acceleration. The insights and conclusions gained from these experiments can be applied to a wide range of industrial and natural flows of concentrated particles. For example, the observation of the rapid deposition of the grains can help explain details of the emplacement of pyroclastic flows resulting from the explosive eruption of volcanoes.

  1. Oscillating water column structural model

    SciTech Connect

    Copeland, Guild; Bull, Diana L; Jepsen, Richard Alan; Gordon, Margaret Ellen

    2014-09-01

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

  2. Characterization of polyacrylamide based monolithic columns.

    PubMed

    Plieva, Fatima M; Andersson, Jonatan; Galaev, Igor Yu; Mattiasson, Bo

    2004-07-01

    Supermacroporous monolithic polyacrylamide (pAAm)-based columns have been prepared by radical cryo-copolymerization (copolymerization in the moderately frozen system) of acrylamide with functional co-monomer, allyl glycidyl ether (AGE), and cross-linker N,N'-methylene-bis-acrylamide (MBAAm) directly in glass columns (ID 10 mm). The monolithic columns have uniform supermacroporous sponge-like structure with interconnected supermacropores of pore size 5-100 microm. The monoliths can be dried and stored in the dry state. High mechanical stability of the monoliths allowed sterilization by autoclaving. Column-to-column reproducibility of pAAm-monoliths was demonstrated on 5 monolithic columns from different batches prepared under the same cryostructuration conditions. PMID:15354560

  3. REDISTRIBUTOR FOR LIQUID-LIQUID EXTRACTION COLUMNS

    DOEpatents

    Bradley, J.G.

    1957-10-29

    An improved baffle plate construction to intimately mix immiscible liquid solvents for solvent extraction processes in a liquid-liquid pulse column is described. To prevent the light and heavy liquids from forming separate continuous homogeneous vertical channels through sections of the column, a baffle having radially placed rectangular louvers with deflection plates opening upon alternate sides of the baffle is placed in the column, normal to the axis. This improvement substantially completely reduces strippiig losses due to poor mixing.

  4. Transverse Reinforcement in Reinforced Concrete Columns

    NASA Astrophysics Data System (ADS)

    Gramblička, Štefan; Veróny, Peter

    2013-11-01

    In the article we are dealing with the influence of transverse reinforcement to the resistance of a cross-section of the reinforced concrete columns and also with the effective detailing of the column reinforcement. We are verifying the correctness of design guides for detailing of transverse reinforcement. We are also taking into account the diameter of stirrups and its influence over transverse deformation of column.

  5. Soil column leaching of pesticides.

    PubMed

    Katagi, Toshiyuki

    2013-01-01

    In this review, I address the practical and theoretical aspects of pesticide soil mobility.I also address the methods used to measure mobility, and the factors that influence it, and I summarize the data that have been published on the column leaching of pesticides.Pesticides that enter the unsaturated soil profile are transported downwards by the water flux, and are adsorbed, desorbed, and/or degraded as they pass through the soil. The rate of passage of a pesticide through the soil depends on the properties of the pesticide, the properties of the soil and the prevailing environmental conditions.Because large amounts of many different pesticides are used around the world, they and their degradates may sometimes contaminate groundwater at unacceptable levels.It is for this reason that assessing the transport behavior and soil mobility of pesticides before they are sold into commerce is important and is one indispensable element that regulators use to assess probable pesticide safety. Both elementary soil column leaching and sophisticated outdoor lysimeter studies are performed to measure the leaching potential for pesticides; the latter approach more reliably reflects probable field behavior, but the former is useful to initially profile a pesticide for soil mobility potential.Soil is physically heterogeneous. The structure of soil varies both vertically and laterally, and this variability affects the complex flow of water through the soil profile, making it difficult to predict with accuracy. In addition, macropores exist in soils and further add to the complexity of how water flow occurs. The degree to which soil is tilled, the density of vegetation on the surface, and the type and amounts of organic soil amendments that are added to soil further affect the movement rate of water through soil, the character of soil adsorption sites and the microbial populations that exist in the soil. Parameters that most influence the rate of pesticide mobility in soil are

  6. MRSQ informatics education columns: passing the baton.

    PubMed

    Hasman, Linda; Hoberecht, Toni; Pullen, Kimberly

    2012-01-01

    This is the last Informatics Education column under the current editors. The outgoing co-editor identifies several key themes that describe the column during her tenure. The main theme discovered while reviewing the columns published over the last five years is technology. Technological changes and advances have affected the way in which librarians conduct instruction, such as incorporating e-learning with traditional workshops and in-class sessions. Technology plays a key role in all of the themes that emerged. The incoming editors imagine what the future themes will be for the Informatics Education column. PMID:23092421

  7. Micro cell isolation column for allergic diagnosis

    NASA Astrophysics Data System (ADS)

    Kobayashi, Koichiro; Sakamoto, Kenji; Yanase, Yuhki; Hide, Michihiro; Miyake, Ryo

    2016-03-01

    We suggest a new micro cell isolation column of basophils for an allergic diagnostic system for detecting human basophils activations. Surface plasmon resonance imaging (SPRI) biosensors using human basophils allow allergic diagnosis of less than 1 ml of peripheral blood. However, an isolation of basophils from a small amount of blood is not easy. In this study, we constructed a new micro cell isolation column for basophils with poly(dimethylsiloxane) (PDMS) microflow pass including magnetic particles. Furthermore, we determined whether leukocytes were captured by the micro cell isolation column from a small amount of blood. We can isolate basophils from other leukocytes by using the micro cell isolation column.

  8. Interstitial gas effect on vibrated granular columns

    NASA Astrophysics Data System (ADS)

    Pastenes, Javier C.; Géminard, Jean-Christophe; Melo, Francisco

    2014-06-01

    Vibrated granular materials have been intensively used to investigate particle segregation, convection, and heaping. We report on the behavior of a column of heavy grains bouncing on an oscillating solid surface. Measurements indicate that, for weak effects of the interstitial gas, the temporal variations of the pressure at the base of the column are satisfactorily described by considering that the column, despite the observed dilation, behaves like a porous solid. In addition, direct observation of the column dynamics shows that the grains of the upper and lower surfaces are in free fall in the gravitational field and that the dilation is due to a small delay between their takeoff times.

  9. Circulation in gas-slurry column reactors

    SciTech Connect

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

    1990-08-15

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

  10. Modeling of column apparatuses: A review

    SciTech Connect

    Doichinova, M. E-mail: petyabs@yahoo.com; Popova-Krumova, P. E-mail: petyabs@yahoo.com

    2013-12-18

    This paper presents a review of the modeling method on the base of the physical approximations of the mechanics of continua, which have been developed for processes in column apparatuses. This method includes diffusion type of model for modeling of mass transfer with chemical reaction in column apparatuses with and without circulation zones. The diffusion type of model is used for modeling of scale effect in column apparatuses too. The study concluded that the proposal method is possibility for investigation the influence of radial non uniformity of the velocity distribution on the process efficiency, influence of zones breadths on the mass transfer efficiency in the column. The method of the column apparatuses modeling can be used for modeling of physical and chemical absorption, chemical adsorption, homogeneous and heterogeneous (catalytic) chemical reactions, airlift reactors for chemical and photochemical reactions.

  11. Modeling of column apparatuses: A review

    NASA Astrophysics Data System (ADS)

    Doichinova, M.; Popova-Krumova, P.

    2013-12-01

    This paper presents a review of the modeling method on the base of the physical approximations of the mechanics of continua, which have been developed for processes in column apparatuses. This method includes diffusion type of model for modeling of mass transfer with chemical reaction in column apparatuses with and without circulation zones. The diffusion type of model is used for modeling of scale effect in column apparatuses too. The study concluded that the proposal method is possibility for investigation the influence of radial non uniformity of the velocity distribution on the process efficiency, influence of zones breadths on the mass transfer efficiency in the column. The method of the column apparatuses modeling can be used for modeling of physical and chemical absorption, chemical adsorption, homogeneous and heterogeneous (catalytic) chemical reactions, airlift reactors for chemical and photochemical reactions.

  12. Contributions to reversed-phase column selectivity: III. Column hydrogen-bond basicity.

    PubMed

    Carr, P W; Dolan, J W; Dorsey, J G; Snyder, L R; Kirkland, J J

    2015-05-22

    Column selectivity in reversed-phase chromatography (RPC) can be described in terms of the hydrophobic-subtraction model, which recognizes five solute-column interactions that together determine solute retention and column selectivity: hydrophobic, steric, hydrogen bonding of an acceptor solute (i.e., a hydrogen-bond base) by a stationary-phase donor group (i.e., a silanol), hydrogen bonding of a donor solute (e.g., a carboxylic acid) by a stationary-phase acceptor group, and ionic. Of these five interactions, hydrogen bonding between donor solutes (acids) and stationary-phase acceptor groups is the least well understood; the present study aims at resolving this uncertainty, so far as possible. Previous work suggests that there are three distinct stationary-phase sites for hydrogen-bond interaction with carboxylic acids, which we will refer to as column basicity I, II, and III. All RPC columns exhibit a selective retention of carboxylic acids (column basicity I) in varying degree. This now appears to involve an interaction of the solute with a pair of vicinal silanols in the stationary phase. For some type-A columns, an additional basic site (column basicity II) is similar to that for column basicity I in primarily affecting the retention of carboxylic acids. The latter site appears to be associated with metal contamination of the silica. Finally, for embedded-polar-group (EPG) columns, the polar group can serve as a proton acceptor (column basicity III) for acids, phenols, and other donor solutes. PMID:25890437

  13. Mechanical interactions of UIS support columns. [LMFBR

    SciTech Connect

    Kennedy, J.M.; Belytschko, T.B.

    1983-01-01

    Code development involving above-core structures (ACS) has recently focused on modeling the complexities of mechanical interactions in the ACS support columns which play a very important role in their behavior. These developments are directed toward two considerations: (1) the prediction of the forces exerted by the column in a hypothetical core-disruptive accident (HCDA) in order that the motion of the ACS can be predicted in a coupled fluid-structure analysis, (2) the calculation of the strains and deformations of the support columns so that situations which lead to complete failure can be identified. Finite element capabilities have been developed to handle various types of plant design for the analysis of coupled hydrodynamics and structural response. Beam elements, which previously represented the support columns were able to account for geometric nonlinearities and material nonlinearities, however, changes in the column cross section were not treated. Therefore, one of the aims of this study was to examine the effect of the change in cross section on the behavior of the support columns. A second effect which has been studied is the behavior of support columns consisting of two concentric cylinders.

  14. Microwaves Scattering by Underdense Inhomogeneous Plasma Column

    NASA Astrophysics Data System (ADS)

    Zhang, Lin; Ouyang, Jiting

    2016-03-01

    The scattering characteristics of microwaves (MWs) by an underdense inhomogeneous plasma column have been investigated. The plasma column is generated by hollow cathode discharge (HCD) in a glass tube filled with low pressure argon. The plasma density in the column can be varied by adjusting the discharge current. The scattering power of X-band MWs by the column is measured at different discharge currents and receiving angles. The results show that the column can affect the properties of scattering wave significantly regardless of its plasma frequency much lower than the incident wave frequency. The power peak of the scattering wave shifts away from 0° to about ±15° direction. The finite-different time-domain (FDTD) method is employed to analyze the wave scattering by plasma column with different electron density distributions. The reflected MW power from a metal plate located behind the column is also measured to investigate the scattering effect on reducing MW reflectivity of a metal target. This study is expected to deepen the understanding of plasma-electromagnetic wave interaction and expand the applications concerning plasma antenna and plasma stealth.

  15. How to Calculate Molecular Column Density

    NASA Astrophysics Data System (ADS)

    Mangum, Jeffrey G.; Shirley, Yancy L.

    2015-03-01

    The calculation of the molecular column density from molecular spectral (rotational or ro-vibrational) transition measurements is one of the most basic quantities derived from molecular spectroscopy. Starting from first principles where we describe the basic physics behind the radiative and collisional excitation of molecules and the radiative transfer of their emission, we derive a general expression for the molecular column density. As the calculation of the molecular column density involves a knowledge of the molecular energy level degeneracies, rotational partition functions, dipole moment matrix elements, and line strengths, we include generalized derivations of these molecule-specific quantities. Given that approximations to the column density equation are often useful, we explore the optically thin, optically thick, and low-frequency limits to our derived general molecular column density relation. We also evaluate the limitations of the common assumption that the molecular excitation temperature is constant and address the distinction between beam-averaged and source-averaged column densities. As non-LTE approaches to the calculation of molecular spectral line column density have become quite common, we summarize non-LTE models that calculate molecular cloud volume densities, kinetic temperatures, and molecular column densities. We conclude our discussion of the molecular column density with worked examples for C18O, C17O, N2H+, NH3, and H2CO. Ancillary information on some subtleties involving line profile functions, conversion between integrated flux and brightness temperature, the calculation of the uncertainty associated with an integrated intensity measurement, the calculation of spectral line optical depth using hyperfine or isotopologue measurements, the calculation of the kinetic temperature from a symmetric molecule excitation temperature measurement, and relative hyperfine intensity calculations for NH3 are presented in appendices. The intent of

  16. Neural network modeling of distillation columns

    SciTech Connect

    Baratti, R.; Vacca, G.; Servida, A.

    1995-06-01

    Neural network modeling (NNM) was implemented for monitoring and control applications on two actual distillation columns: the butane splitter tower and the gasoline stabilizer. The two distillation columns are in operation at the SARAS refinery. Results show that with proper implementation techniques NNM can significantly improve column operation. The common belief that neural networks can be used as black-box process models is not completely true. Effective implementation always requires a minimum degree of process knowledge to identify the relevant inputs to the net. After background and generalities on neural network modeling, the paper describes efforts on the development of neural networks for the two distillation units.

  17. Redesigned Air-Column Resonance Apparatus

    NASA Astrophysics Data System (ADS)

    Singh, Gurbax; Graf, Erlend H.

    2003-02-01

    This paper describes a redesigned air-column resonance apparatus that offers several advantages over the traditional one.2 It does away with water or the long rod to vary the length of the air column. Instead a specially designed piston is moved inside a plastic or glass tube by external magnets to vary the length of the air column. Plastic tubes of various sizes are commercially available,3 but we salvaged one from an old commercial resonance apparatus. The tube has 2.85-cm inner and 3.15-cm outer diameter, respectively. The redesigned resonance apparatus can be operated in either the horizontal or the vertical position.

  18. Use of MiniColumns for linear isotherm parameter estimation and prediction of benchtop column performance.

    PubMed

    Keller, William R; Evans, Steven T; Ferreira, Gisela; Robbins, David; Cramer, Steven M

    2015-10-30

    In this paper, a comparison between experimental chromatography data and column simulations is carried out to determine the efficacy of using miniaturized chromatography columns (MiniColumns) for both column modeling parameter estimation and process development. Normalization of the data with respect to column volumes along with appropriate translations to account for system differences is shown to result in comparability of the experimental data for the MiniColumn and benchtop systems. A parameter estimation protocol is then employed to determine the linear steric mass-action (SMA) isotherm and lumped mass transport parameters for two cation exchange resins. The models are then validated and simulations using different parameter sets from the MiniColumn and benchtop systems are shown to result in similar predicted chromatography profiles and calculated retention volumes. The parameters generated from the MiniColumn system are demonstrated to be well suited for predicting experimental data from the benchtop system. These simulation results, the ability to operate MiniColumns in parallel, and the significantly lower material requirements per experiment support an industry trend toward increased usage of miniaturized chromatography columns as a scale-down model for process development. PMID:26422303

  19. AVIRIS Spectrometer Maps Total Water Vapor Column

    NASA Technical Reports Server (NTRS)

    Conel, James E.; Green, Robert O.; Carrere, Veronique; Margolis, Jack S.; Alley, Ronald E.; Vane, Gregg A.; Bruegge, Carol J.; Gary, Bruce L.

    1992-01-01

    Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) processes maps of vertical-column abundances of water vapor in atmosphere with good precision and spatial resolution. Maps provide information for meteorology, climatology, and agriculture.

  20. The accretion column of AE Aqr

    NASA Astrophysics Data System (ADS)

    Rodrigues, Claudia; Costa, D. Joaquim; Luna, Gerardo; Lima, Isabel J.; Silva, Karleyne M. G.; De Araujo, Jose Carlos N.; Coelho, Jaziel

    2016-07-01

    AE Aqr is a magnetic cataclysmic variable, whose white dwarf rotates at the very fast rate of 33 s modulating the flux from high-energies to optical wavelengths. There are many studies of the origin of its emission, which consider emission from a rotating magnetic field or from an accretion column. Recently, MAGIC observations have discarded AE Aqr emission in very high energy gamma-rays discarding non-thermal emission. Furthermore, soft and hard X-ray data from Swift and NuSTAR were fitted using thermal models. Here we present the modelling of AE Aqr X-ray spectra and light curve considering the emission of a magnetic accretion column using the Cyclops code. The model takes into consideration the 3D geometry of the system, allowing to properly represent the white-dwarf auto eclipse, the pre-shock column absorption, and the varying density and temperature of a tall accretion column.

  1. PRTR ion exchange vault column sampling

    SciTech Connect

    Cornwell, B.C.

    1995-03-14

    This report documents ion exchange column sampling and Non Destructive Assay (NDA) results from activities in 1994, for the Plutonium Recycle Test Reactor (PRTR) ion exchange vault. The objective was to obtain sufficient information to prepare disposal documentation for the ion exchange columns found in the PRTR Ion exchange vault. This activity also allowed for the monitoring of the liquid level in the lower vault. The sampling activity contained five separate activities: (1) Sampling an ion exchange column and analyzing the ion exchange media for purpose of waste disposal; (2) Gamma and neutron NDA testing on ion exchange columns located in the upper vault; (3) Lower vault liquid level measurement; (4) Radiological survey of the upper vault; and (5) Secure the vault pending waste disposal.

  2. A Versatile, Automatic Chromatographic Column Packing Device

    ERIC Educational Resources Information Center

    Barry, Eugene F.; And Others

    1977-01-01

    Describes an inexpensive apparatus for packing liquid and gas chromatographic columns of high efficiency. Consists of stainless steel support struts, an Automat Getriebmotor, and an associated three-pulley system capable of 10, 30, and 300 rpm. (MLH)

  3. Modeling Tropical Precipitation in a Single Column.

    NASA Astrophysics Data System (ADS)

    Sobel, Adam H.; Bretherton, Christopher S.

    2000-12-01

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

  4. Magnetic Shaping of Molten Metal Columns

    NASA Astrophysics Data System (ADS)

    Shercliff, J. A.

    1981-04-01

    In continuous casting the vertically falling liquid column may be shaped by externally applied, horizontal, high-frequency magnetic fields. The free-boundary problem with allowance for surface tension is solved in a two-dimensional approximation by combined complex-variable and numerical methods in the cases where the far field is either uniform or of quadrupole form, or where the field is produced by four vertical conductors centred on the column. Stirring of the fluid is ignored.

  5. Flow in a metal hydride chromatographic column

    SciTech Connect

    Nichols, G.S.

    1990-01-01

    The flow of hydrogen isotopes in a metal hydride chromatographic column is calculated by a one-dimensional finite difference method. The Ergun equation is used to define the gas flow; and equilibrium pressure isotherms are used to define the column holdup. Solid phase loadings are shown to move as a wave front on absorption, but remain more uniform on desorption. 3 refs., 4 figs.

  6. Quality improvements of cell membrane chromatographic column.

    PubMed

    Ding, Xuan; Chen, Xiaofei; Cao, Yan; Jia, Dan; Wang, Dongyao; Zhu, Zhenyu; Zhang, Juping; Hong, Zhanying; Chai, Yifeng

    2014-09-12

    Cell Membrane Chromatography (CMC) is a biological affinity chromatographic method using a silica stationary phase covered with specific cell membrane. However, its short life span and poor quality control was highlighted in a lot of research articles. In this study, special attention has been paid to the disruption, cell load and packing procedure in order to improve the quality of the CMC columns. Hereto, two newly established CMC models, HSC-T6/CMC and SMMC-7721/CMC have been developed and used in this research project. The optimization of the abovementioned parameters resulted in a better reproducibility of the retention time of the compound GFT (RSD<10%) and improved significantly the quality of the CMC columns. 3.5×10(7)cells were the optimal cell load for the preparation of the CMC columns, the disruption condition was optimized to 5 cycles (400W and 20s interval per cycle) by an ultrasonic processor reducing the total time of cell disruption to 1.5min and the packing flow rate was optimized by applying a linear gradient program. Additionally, 4% paraformaldehyde (PFA) was employed to improve the column quality and prolong the column life span. The results showed that the retention time was longer with PFA treated columns than the ones obtained with the control groups. PMID:25115453

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

    NASA Technical Reports Server (NTRS)

    Huz, Kateryna

    2014-01-01

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

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

    SciTech Connect

    Busigin, A.

    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.

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

    PubMed Central

    Plenis, Alina; Rekowska, Natalia; Bączek, Tomasz

    2016-01-01

    This article focuses on correlating the column classification obtained from the method created at the Katholieke Universiteit Leuven (KUL), with the chromatographic resolution attained in biomedical separation. In the KUL system, each column is described with four parameters, which enables estimation of the FKUL value characterising similarity of those parameters to the selected reference stationary phase. Thus, a ranking list based on the FKUL value can be calculated for the chosen reference column, then correlated with the results of the column performance test. In this study, the column performance test was based on analysis of moclobemide and its two metabolites in human plasma by liquid chromatography (LC), using 18 columns. The comparative study was performed using traditional correlation of the FKUL values with the retention parameters of the analytes describing the column performance test. In order to deepen the comparative assessment of both data sets, factor analysis (FA) was also used. The obtained results indicated that the stationary phase classes, closely related according to the KUL method, yielded comparable separation for the target substances. Therefore, the column ranking system based on the FKUL-values could be considered supportive in the choice of the appropriate column for biomedical analysis. PMID:26805819

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

    PubMed

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

    2016-01-01

    A protocol for the use of reaction flow high performance liquid chromatography columns for methods employing post column derivatization (PCD) is presented. A major difficulty in adapting PCD to modern HPLC systems and columns is the need for large volume reaction coils that enable reagent mixing and then the derivatization reaction to take place. This large post column dead volume leads to band broadening, which results in a loss of observed separation efficiency and indeed detection in sensitivity. In reaction flow post column derivatization (RF-PCD) the derivatization reagent(s) are pumped against the flow of mobile phase into either one or two of the outer ports of the reaction flow column where it is mixed with column effluent inside a frit housed within the column end fitting. This technique allows for more efficient mixing of the column effluent and derivatization reagent(s) meaning that the volume of the reaction loops can be minimized or even eliminated altogether. It has been found that RF-PCD methods perform better than conventional PCD methods in terms of observed separation efficiency and signal to noise ratio. A further advantage of RF-PCD techniques is the ability to monitor effluent coming from the central port in its underivatized state. RF-PCD has currently been trialed on a relatively small range of post column reactions, however, there is currently no reason to suggest that RF-PCD could not be adapted to any existing one or two component (as long as both reagents are added at the same time) post column derivatization reaction. PMID:27168419

  11. Modeling of rotating disc contactor (RDC) column

    NASA Astrophysics Data System (ADS)

    Ismail, Wan Nurul Aiffah; Zakaria, Siti Aisyah; Noor, Nor Fashihah Mohd; Sulong, Ibrahim; Arshad, Khairil Anuar

    2014-12-01

    Liquid-liquid extraction is one of the most important separation processes. Different kinds of liquid-liquid extractor such as Rotating Disc Contactor (RDC) Column being used in industries. The study of liquid-liquid extraction in an RDC column has become a very important subject to be discussed not just among chemical engineers but mathematician as well. In this research, the modeling of small diameter RDC column using the chemical system involving cumene/isobutryric asid/water are analyzed by the method of Artificial Neural Network (ANN). In the previous research, we begin the process of analyzed the data using methods of design of the experiments (DOE) to identify which factor and their interaction factor are significant and to determine the percentage of contribution of the variance for each factor. From the result obtained, we continue the research by discussed the development and validation of an artificial neural network model in estimating the concentration of continuous and concentration of dispersed outlet for an RDC column. It is expected that an efficient and reliable model will be formed to predict RDC column performance as an alternative to speed up the simulation process.

  12. Counterflow isotachophoresis in a monolithic column.

    PubMed

    Liu, Bingwen; Cong, Yongzheng; Ivory, Cornelius F

    2014-09-01

    This study describes stationary counterflow isotachophoresis (ITP) in a poly(acrylamide-co-N,N'-methylenebisacrylamide) monolithic column as a means for improving ITP processing capacity and reducing dispersion. The flow profile in the monolith was predicted using COMSOL's Brinkman Equation application mode, which revealed that the flow profile was mainly determined by monolith permeability. As monolith permeability decreases, the flow profile changes from a parabolic shape to a plug shape. An experimental monolithic column was prepared in a fused-silica capillary using an ultraviolet-initiated polymerization method. A monolithic column made from 8% (wt.) monomer was chosen for the stationary counterflow ITP experiments. Counterflow ITP in the monolithic column showed undistorted analyte zones with significantly reduced dispersion compared to the severe dispersion observed in an open capillary. Particularly, for r-phycoerythrin focused by counterflow ITP, its zone width in the monolithic column was only one-third that observed in an open capillary. These experiments demonstrate that stationary counterflow ITP in monoliths can be a robust and practical electrofocusing method. PMID:24935025

  13. Analysis of stone-column reinforced foundations

    NASA Astrophysics Data System (ADS)

    Lee, J. S.; Pande, G. N.

    1998-12-01

    A numerical model is proposed to analyse elastic as well as elastoplastic behaviour of stone-column reinforced foundations. The stone-columns are assumed to be dispersed within the in situ soil and a homogenization technique is invoked to establish equivalent material properties for in situ soil and stone-column composite. The difficulties encountered in carrying out elastoplastic analyses of composite materials are overcome by adopting a separate yield function for each of the constituent materials and a sub-iteration procedure within an implicit backward Euler stress integration scheme. In the proposed procedure, equilibrium as well as kinematic conditions implied in the homogenization procedure are satisfied for both elastic as well as elastoplastic stress states.The proposed model is implemented in an axi-symmetric finite element code and numerical prediction is made for the behaviour of model circular footings resting on stone-column reinforced foundations. This prediction indicates good agreement with experimental observation. Finally, a new scheme in which the length of stone-column is variable is proposed and its behaviour is examined through a numerical example.

  14. Non-planar microfabricated gas chromatography column

    DOEpatents

    Lewis, Patrick R.; Wheeler, David R.

    2007-09-25

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

  15. Neutron camera employing row and column summations

    DOEpatents

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

    2016-06-14

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

  16. Final Report, Distillation Column Flooding Predictor

    SciTech Connect

    George E. Dzyacky

    2003-05-31

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

  17. Optical Measurement Technique for Space Column Characterization

    NASA Technical Reports Server (NTRS)

    Barrows, Danny A.; Watson, Judith J.; Burner, Alpheus W.; Phelps, James E.

    2004-01-01

    A simple optical technique for the structural characterization of lightweight space columns is presented. The technique is useful for determining the coefficient of thermal expansion during cool down as well as the induced strain during tension and compression testing. The technique is based upon object-to-image plane scaling and does not require any photogrammetric calibrations or computations. Examples of the measurement of the coefficient of thermal expansion are presented for several lightweight space columns. Examples of strain measured during tension and compression testing are presented along with comparisons to results obtained with Linear Variable Differential Transformer (LVDT) position transducers.

  18. 29 CFR 1926.756 - Beams and columns.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Beams and columns. 1926.756 Section 1926.756 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.756 Beams and columns. (a.... (c) (1) Double connections at columns and/or at beam webs over a column. When two structural...

  19. 29 CFR 1926.756 - Beams and columns.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 8 2013-07-01 2013-07-01 false Beams and columns. 1926.756 Section 1926.756 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.756 Beams and columns. (a.... (c) (1) Double connections at columns and/or at beam webs over a column. When two structural...

  20. 29 CFR 1926.756 - Beams and columns.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 8 2012-07-01 2012-07-01 false Beams and columns. 1926.756 Section 1926.756 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.756 Beams and columns. (a.... (c) (1) Double connections at columns and/or at beam webs over a column. When two structural...

  1. 29 CFR 1926.756 - Beams and columns.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Beams and columns. 1926.756 Section 1926.756 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.756 Beams and columns. (a.... (c) (1) Double connections at columns and/or at beam webs over a column. When two structural...

  2. Flow of ices in the Ammonia-Water System

    NASA Technical Reports Server (NTRS)

    Durham, W. B.; Kirby, S. H.; Stern, L. A.

    1993-01-01

    We have fabricated in the laboratory and subsequently deformed crystalline hydrates and partial melts of the water-rich end of the NH3-H2O system, with the aim of improving our understanding of physical processes occurring in icy moons of the outer solar system. Deformation experiments were carried out at constant strain rate. The range of experimental variables are given. Phase relationships in the NH3-H2O system indicate that water ice and ammonia dihydrate, NH3-2H2O, are the stable phases under our experiment conditions. X-ray diffraction of our samples usually revealed these as the dominant phases, but we have also observed an amorphous phase (in unpressurized samples only) and occasionally significant ammonia monohydrate, NH3-H2O. The onset of partial melting at the peritectic temperature at about 176 K appeared as a sharp transition in strength observed in samples of x(sub NH3) = 0.05 and 0.01, the effect of melt was less pronounced. For any given water ice + dihydrate alloy in the subsolidus region, we observed one rheological law over the entire temperature range from 175 K to about 140 K. Below 140 K, a shear instability similar to that occurring in pure water ice under the same conditions limited our ability to measure ductile flow. The rheological laws for the several alloys vary systematically from that of pure ice to that of dihydrate. Pure dihydrate is about 4 orders of magnitude less viscous than water ice just below the peritectic temperature, but because of a very pronounced temperature dependence in dihydrate (100 kJ/mol versus 43 kJ/mol for water ice) the viscosity of dihydrate equals or exceeds that of water ice at T less than 140 K. The large variation in viscosity of dihydrate with relatively small changes in temperature may be helpful in explaining the rich variety of tectonic and volcanic features seen on the surfaces of icy moons in the outer solar system.

  3. Systems For Column-Based Separations, Methods Of Forming Packed Columns, And Methods Of Purifying Sample Components

    DOEpatents

    Egorov, Oleg B.; O'Hara, Matthew J.; Grate, Jay W.; Chandler, Darrell P.; Brockman, Fred J.; Bruckner-Lea, Cynthia J.

    2006-02-21

    The invention encompasses systems for column-based separations, methods of packing and unpacking columns and methods of separating components of samples. In one aspect, the invention includes a method of packing and unpacking a column chamber, comprising: a) packing a matrix material within a column chamber to form a packed column; and b) after the packing, unpacking the matrix material from the column chamber without moving the column chamber. In another aspect, the invention includes a system for column-based separations, comprising: a) a fluid passageway, the fluid passageway comprising a column chamber and a flow path in fluid communication with the column chamber, the flow path being obstructed by a retaining material permeable to a carrier fluid and impermeable to a column matrix material suspended in the carrier fluid, the flow path extending through the column chamber and through the retaining material, the flow path being configured to form a packed column within the column chamber when a suspension of the fluid and the column matrix material is flowed along the flow path; and b) the fluid passageway extending through a valve intermediate the column chamber and the retaining material.

  4. Systems for column-based separations, methods of forming packed columns, and methods of purifying sample components

    DOEpatents

    Egorov, Oleg B.; O'Hara, Matthew J.; Grate, Jay W.; Chandler, Darrell P.; Brockman, Fred J.; Bruckner-Lea, Cynthia J.

    2000-01-01

    The invention encompasses systems for column-based separations, methods of packing and unpacking columns and methods of separating components of samples. In one aspect, the invention includes a method of packing and unpacking a column chamber, comprising: a) packing a matrix material within a column chamber to form a packed column; and b) after the packing, unpacking the matrix material from the column chamber without moving the column chamber. In another aspect, the invention includes a system for column-based separations, comprising: a) a fluid passageway, the fluid passageway comprising a column chamber and a flow path in fluid communication with the column chamber, the flow path being obstructed by a retaining material permeable to a carrier fluid and impermeable to a column matrix material suspended in the carrier fluid, the flow path extending through the column chamber and through the retaining material, the flow path being configured to form a packed column within the column chamber when a suspension of the fluid and the column matrix material is flowed along the flow path; and b) the fluid passageway extending through a valve intermediate the column chamber and the retaining material.

  5. Systems For Column-Based Separations, Methods Of Forming Packed Columns, And Methods Of Purifying Sample Components.

    DOEpatents

    Egorov, Oleg B.; O'Hara, Matthew J.; Grate, Jay W.; Chandler, Darrell P.; Brockman, Fred J.; Bruckner-Lea, Cynthia J.

    2004-08-24

    The invention encompasses systems for column-based separations, methods of packing and unpacking columns and methods of separating components of samples. In one aspect, the invention includes a method of packing and unpacking a column chamber, comprising: a) packing a matrix material within a column chamber to form a packed column; and b) after the packing, unpacking the matrix material from the column chamber without moving the column chamber. In another aspect, the invention includes a system for column-based separations, comprising: a) a fluid passageway, the fluid passageway comprising a column chamber and a flow path in fluid communication with the column chamber, the flow path being obstructed by a retaining material permeable to a carrier fluid and impermeable to a column matrix material suspended in the carrier fluid, the flow path extending through the column chamber and through the retaining material, the flow path being configured to form a packed column within the column chamber when a suspension of the fluid and the column matrix material is flowed along the flow path; and b) the fluid passageway extending through a valve intermediate the column chamber and the retaining material.

  6. Density Gradient Columns for Chemical Displays.

    ERIC Educational Resources Information Center

    Guenther, William B.

    1986-01-01

    Procedures for preparing density gradient columns for chemical displays are presented. They include displays illustrating acid-base reactions, metal ion equilibria, and liquid density. The lifetime of these metastable displays is surprising, some lasting for months in display cabinets. (JN)

  7. Thermal Analysis of LANL Ion Exchange Column

    SciTech Connect

    Laurinat, J.E.

    1999-06-16

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

  8. Inklings: Collected Columns on Leadership and Creativity.

    ERIC Educational Resources Information Center

    Campbell, David P.

    This book brings together 35 of David P. Campbell's essays originally published as a regular column in a quarterly publication called "Issues and Observations." The articles deal with topics ranging from leadership issues such as risk-taking, executive motivation, decision making, and corporate taboos, to more general concerns such as father-son…

  9. Diatextual Analysis of the Advice Column.

    ERIC Educational Resources Information Center

    Mininni, Giuseppe

    1991-01-01

    Examined rhetorical and argumentative aspects of the "communication contract" stipulated in asking for and providing psychological advice in a mass media setting such as an advice column were examined. Letters from two Italian and two British magazines were used for the study. (14 references) (LB)

  10. Extendible column can be stowed on drum

    NASA Technical Reports Server (NTRS)

    Holtz, G. M.; Howard, E. A.

    1965-01-01

    Column formed from a series of segments held together by an internal spring or cable can be coiled on a drum or extended into a rigid structure. This storable coil is useful in boring for soil samples and supporting electrical and optical sensors.

  11. On Row Rank Equal Column Rank

    ERIC Educational Resources Information Center

    Khalili, Parviz

    2009-01-01

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

  12. "Dry-column" chromatography of plant pigments

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

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

  13. An Improved Row/Column Scanning System.

    ERIC Educational Resources Information Center

    Weiss, Lawrence H.

    The use of row/column scanning, a technique for accessing a large number of selections with a single volitional action, is considered for individuals with disabilities. It is explained that such a scanning approach is particularly useful for those with only one volitional action, or those, such as people with cerebral palsy, who have pointing…

  14. WATER COLUMN DATA AND SPECTRAL IRRADIANCE MODEL

    EPA Science Inventory

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

  15. Contexts for Column Addition and Subtraction

    ERIC Educational Resources Information Center

    Lopez Fernandez, Jorge M.; Velazquez Estrella, Aileen

    2011-01-01

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

  16. A comparison study of in-column and on-column detection for electrochromatography.

    PubMed

    Zhang, Qier; Xu, Lingjia; Zhou, Zhuoheng; Yang, Lijun; Wang, Qiuquan; Zhang, Bo

    2014-10-01

    Duplex capillary columns, the standard for electrochromatography using optical detection, consist of a packed and an open section. Normally, optical detection is performed in an on-column manner, i.e. at a point right after the packed section. It was deemed that band broadening may take place when an analyte band travels from the packed bed, through the frit and down to the open section. In this study, without using any sintering steps for fritting or window creation, robust packed capillary columns were prepared using transparent capillaries based on single particle fritting technology. The detection point could be easily shifted by simply sliding the transparent column against the ultraviolet (UV) beam. In this way, the band broadening effect was directly evaluated as a function of the detection point, which was positioned before or after the end frit. The consistent van Deemter curves recorded indicate that there was no efficiency difference between the positions investigated. The result proved that the significant band broadening effect previously observed via on-column detection should be caused by the sintered frit used, while the single particle frit made through a purely physical process did not lead to efficiency degradation. The conservative separation performance recorded at different positions around the column's end also suggests the applicability of on-line tandem detection strategy, e.g. UV followed by mass spectrometry (MS), on the same capillary column, which should be a promising approach to mining multiplex detection information from a single microseparation process. PMID:25171946

  17. ON THE ORIGIN OF THE HIGH COLUMN DENSITY TURNOVER IN THE H I COLUMN DENSITY DISTRIBUTION

    SciTech Connect

    Erkal, Denis; Gnedin, Nickolay Y.; Kravtsov, Andrey V.

    2012-12-10

    We study the high column density regime of the H I column density distribution function and argue that there are two distinct features: a turnover at N{sub H{sub I}} Almost-Equal-To 10{sup 21} cm{sup -2}, which is present at both z = 0 and z Almost-Equal-To 3, and a lack of systems above N{sub H{sub I}} Almost-Equal-To 10{sup 22} cm{sup -2} at z = 0. Using observations of the column density distribution, we argue that the H I-H{sub 2} transition does not cause the turnover at N{sub H{sub I}} Almost-Equal-To 10{sup 21} cm{sup -2} but can plausibly explain the turnover at N{sub H{sub I}} {approx}> 10{sup 22} cm{sup -2}. We compute the H I column density distribution of individual galaxies in the THINGS sample and show that the turnover column density depends only weakly on metallicity. Furthermore, we show that the column density distribution of galaxies, corrected for inclination, is insensitive to the resolution of the H I map or to averaging in radial shells. Our results indicate that the similarity of H I column density distributions at z = 3 and 0 is due to the similarity of the maximum H I surface densities of high-z and low-z disks, set presumably by universal processes that shape properties of the gaseous disks of galaxies. Using fully cosmological simulations, we explore other candidate physical mechanisms that could produce a turnover in the column density distribution. We show that while turbulence within giant molecular clouds cannot affect the damped Ly{alpha} column density distribution, stellar feedback can affect it significantly if the feedback is sufficiently effective in removing gas from the central 2-3 kpc of high-redshift galaxies. Finally, we argue that it is meaningful to compare column densities averaged over {approx} kpc scales with those estimated from quasar spectra that probe sub-pc scales due to the steep power spectrum of H I column density fluctuations observed in nearby galaxies.

  18. Do column frits contribute to the on-column, flow-induced degradation of macromolecules?

    PubMed

    Striegel, André M

    2014-09-12

    Flow-induced, on-column degradation is a major hindrance to the accurate characterization of ultra-high molar mass macromolecules and colloids. This degradation is a direct result of the large shear rates which are generated within the column, which cause chain scission to occur both in the interstitial medium and, it has been postulated, at the packing particle pore boundary. An additional putative source of degradation has been the column frits, though little experimental evidence exists to either support or refute this claim. To this effect, the present experiments examine the role of the frits in the degradation of high molar mass macromolecules. Two narrow dispersity polystyrene standards, the molar mass of which differs by a factor of two, were analyzed on three different size-exclusion chromatography (SEC) columns, each with frits of different pore size, at various flow rates. In the smallest pore size column, which also contained the smallest frits and which was packed with the smallest diameter particles, the larger standard was forced to degrade by increasing the flow rate of the mobile phase. During the course of the latter portion of the study, the inlet and the outlet frits were removed from the column, in stepwise fashion. It was concluded that neither frit played any appreciable role in the degradation. Results of our studies were applied to explain previously observed degradation in ultra-high pressure liquid chromatography of polymers. The general conclusion arrived at herein is that the column frits are likely to have a secondary role (as compared to interstitial and pore boundary stresses), or no role at all, in polymer degradation for cases where the frit radius is larger than or equal to the hydraulic radius rcof the column. PMID:25085820

  19. Design procedures for fiber composite structural components: Rods, columns and beam columns

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.

    1983-01-01

    Step by step procedures are described which are used to design structural components (rods, columns, and beam columns) subjected to steady state mechanical loads and hydrothermal environments. Illustrative examples are presented for structural components designed for static tensile and compressive loads, and fatigue as well as for moisture and temperature effects. Each example is set up as a sample design illustrating the detailed steps that are used to design similar components.

  20. Design criteria for pultruded fiber-reinforced polymer composite columns

    NASA Astrophysics Data System (ADS)

    Choi, Yeol

    This dissertation investigated the behavior of pultruded fiber-reinforced polymer (FRP) composite columns under extensive time-independent short-term and time-dependent long-term experiments. Based on the experimental results, analytical studies were performed to propose a design approach for pultruded FRP composite columns. In the time-independent short-term tests, a total of 100 tests on wide flange, I-shape and box section columns were selected to develop the empirical column strength equation. All column tests were performed with pinned-pinned end conditions using either a 30 feet reaction frame or a MTS machine depending on the column length. The experimental results from short-term column tests provided valuable realistic information, such as the ultimate column capacity, failure mode, and column strength equation for pultruded FRP composite columns subjected to axial compression. To develop empirical column strength equation, ultimate column capacity at failure may be examined by plotting of the ultimate compressive stress versus effective slenderness ratio, and then nondimensionalize the ultimate compressive stress and slenderness ratio to compare columns having different cross sections. Finally, a set of empirical column strength equations of FRP composite column was developed from the column strength curves using curve-fitting technique. In the time-dependent long-term creep tests, a total of 4 box and 4 wide flange section columns were tested to investigate time-dependent deformation of pultruded FRP composite columns. The cross-section used in the investigation is 4 in. x 4 in. x 1/4 in. (100 mm x 100 mm x 6.4 mm) and length is 4 feet (1.2 m) with box and wide flange sections. Creep tests were carried out at four different loading levels; 20, 30, 40 and 50 percents of the ultimate column strength from the short-term column tests. The axial time-dependent deformation under sustained loading was monitored for time duration up to 2,500 hours. The

  1. Modeling of Crystalline Silicotitanate Ion Exchange Columns

    SciTech Connect

    Walker, D.D.

    1999-03-09

    Non-elutable ion exchange is being considered as a potential replacement for the In-Tank Precipitation process for removing cesium from Savannah River Site (SRS) radioactive waste. Crystalline silicotitanate (CST) particles are the reference ion exchange medium for the process. A major factor in the construction cost of this process is the size of the ion exchange column required to meet product specifications for decontaminated waste. To validate SRS column sizing calculations, SRS subcontracted two reknowned experts in this field to perform similar calculations: Professor R. G. Anthony, Department of Chemical Engineering, Texas A&038;M University, and Professor S. W. Wang, Department of Chemical Engineering, Purdue University. The appendices of this document contain reports from the two subcontractors. Definition of the design problem came through several meetings and conference calls between the participants and SRS personnel over the past few months. This document summarizes the problem definition and results from the two reports.

  2. Maypole (Hoop/Column) concept development program

    NASA Technical Reports Server (NTRS)

    Sullivan, M. R.

    1982-01-01

    The program is divided into six tasks: preliminary design and performance; materials development; advanced concepts; economic assessment; demonstration/verification models; and a 15 meter engineering model. All support the main objective of the program which is the technology development necessary to evaluate, design, manufacture, package, transport and deploy the Hoop/Column reflector by means of a ground-based test program. Progress for each task is reported.

  3. Dynamics of a Tapped Granular Column

    NASA Astrophysics Data System (ADS)

    Rosato, Anthony; Blackmore, Denis; Zuo, Luo; Hao, Wu; Horntrop, David

    2015-11-01

    We consider the behavior of a column of spheres subjected to a time-dependent vertical taps. Of interest are various dynamical properties, such as the motion of its mass center, its response to taps of different intensities and forms, and the effect of system size and material properties. The interplay between diverse time and length scales are the key contributors to the column's evolving dynamics. Soft sphere discrete element simulations were conducted over a very wide parameter space to obtain a portrait of column behavior as embodied by the collective dynamics of the mass center motion. Results compared favorably with a derived reduced-order paradigm of the mass center motion (surprisingly analogous to that for a single bouncing ball on an oscillating plate) with respect to dynamical regimes and their transitions. A continuum model obtained from a system of Newtonian equations, as a locally averaged limit in the transport mode along trajectories is described, and a numerical solution protocol for a one-dimensional system is outlined. Typical trajectories and density evolution profiles are shown. We conclude with a discussion of our investigations to relate predictions of the continuum and reduced dynamical systems models with discrete simulations.

  4. Whose Cortical Column Would that Be?

    PubMed Central

    da Costa, Nuno Maçarico; Martin, Kevan A. C.

    2010-01-01

    The cortical column has been an invaluable concept to explain the functional organization of the neocortex. While this idea was born out of experiments that cleverly combined electrophysiological recordings with anatomy, no one has ‘seen’ the anatomy of a column. All we know is that when we record through the cortex of primates, ungulates, and carnivores in a trajectory perpendicular to its surface there is a remarkable constancy in the receptive field properties of the neurons regarding one set of stimulus features. There is no obvious morphological analog for this functional architecture, in fact much of the anatomical data seems to challenge it. Here we describe historically the origins of the concept of the cortical column and the struggles of the pioneers to define the columnar architecture. We suggest that in the concept of a ‘canonical circuit’ we may find the means to reconcile the structure of neocortex with its functional architecture. The canonical microcircuit respects the known connectivity of the neocortex, and it is flexible enough to change transiently the architecture of its network in order to perform the required computations. PMID:20640245

  5. Employing anatomical knowledge in vertebral column labeling

    NASA Astrophysics Data System (ADS)

    Yao, Jianhua; Summers, Ronald M.

    2009-02-01

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

  6. Cooling of a Tapped Granular Column

    NASA Astrophysics Data System (ADS)

    Rosato, Anthony; Zuo, Luo; Blackmore, Denis

    2013-11-01

    We present the results of a discrete element investigation of the cooling of a tapped column of uniform, inelastic spherical particles (d) as it evolves to a state of zero kinetic energy. A linear loading-unloading soft contact model is employed, while tapping is simulated by applying a half-sine pulse of amplitude a/ d and frequency f to a rigid floor supporting the column. For sufficiently energetic taps, the column dilates and then contracts over a time scale ts, which depends on the number of particles N, restitution coefficient e, as well as tap parameters (a/ d, f) . Simulation data for (1 <= N <= 50) with other parameters being held constant suggested that a time-averaged collision frequency fc scaled with N. Values of ts, determined by identifying the instant when the kinetic energy thereafter remained less than 0.001%of its maximum value, were well-correlated with the form α (e) N-1 + β (e) . Lastly, simulations were in good agreement with physical considerations, suggesting that ts should scale with (1 - e2)-1 and inversely with fc. Supported in part by NSF Grant CMMI-1029809.

  7. SPEEDUP{trademark} ion exchange column model

    SciTech Connect

    Hang, T.

    2000-03-06

    A transient model to describe the process of loading a solute onto the granular fixed bed in an ion exchange (IX) column has been developed using the SpeedUp{trademark} software package. SpeedUp offers the advantage of smooth integration into other existing SpeedUp flowsheet models. The mathematical algorithm of a porous particle diffusion model was adopted to account for convection, axial dispersion, film mass transfer, and pore diffusion. The method of orthogonal collocation on finite elements was employed to solve the governing transport equations. The model allows the use of a non-linear Langmuir isotherm based on an effective binary ionic exchange process. The SpeedUp column model was tested by comparing to the analytical solutions of three transport problems from the ion exchange literature. In addition, a sample calculation of a train of three crystalline silicotitanate (CST) IX columns in series was made using both the SpeedUp model and Purdue University's VERSE-LC code. All test cases showed excellent agreement between the SpeedUp model results and the test data. The model can be readily used for SuperLig{trademark} ion exchange resins, once the experimental data are complete.

  8. 14. Detail view of columns, capitals and beams at south ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Detail view of columns, capitals and beams at south end of north section of mill. Note the transition from deep pocket to shallow pocket column capitals. - Lowe Mill, Eighth Avenue, Southwest, Huntsville, Madison County, AL

  9. CAR MACHINE SHOP, FIRST FLOOR, DETAIL OF WOOD COLUMN AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CAR MACHINE SHOP, FIRST FLOOR, DETAIL OF WOOD COLUMN AND INVERTED KING-POST TRUSS TO PROVIDE INCREASED SPAN BETWEEN COLUMNS, LOOKING SOUTH. - Southern Pacific, Sacramento Shops, Car Machine Shop, 111 I Street, Sacramento, Sacramento County, CA

  10. 6. HISTORIC AMERICAN BUILDINGS SURVEY, INTERIOR SHOWING ORIGINAL GRANITE COLUMNS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. HISTORIC AMERICAN BUILDINGS SURVEY, INTERIOR SHOWING ORIGINAL GRANITE COLUMNS AND COLUMN BRICKFACED AFTER THE GREAT FIRE 1904 - Old U.S. Appraisers Stores, Gay & Lombard Streets, Baltimore, Independent City, MD

  11. 3. Detail of beam splice and column capital on the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Detail of beam splice and column capital on the second floor of the Cloth Room Building/Old Bleach House, Monadnock Mills. Beam and column edges are chamfered. - Monadnock Mills, 15 Water Street, Claremont, Sullivan County, NH

  12. A Convenient Method for Comparison of Efficiency of Fractionating Columns.

    ERIC Educational Resources Information Center

    Higgins, Robert H.

    1990-01-01

    Presented is a method for demonstrating the use of various fractionating columns to resolve mixtures into individual components and to correlate the resolving powers of column packings to their "hold-up" volumes. Fractions were analyzed using refractive indices. (KR)

  13. 6. Detail view of column capital on second floor of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Detail view of column capital on second floor of original 1895 section of mill. Note insulated water drain pipe adjacent to column which provides roof drainage. - Dixie Cotton Mill, 710 Greenville Street, La Grange, Troup County, GA

  14. 20. Detail of 8" square solid wood column at fruit ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Detail of 8" square solid wood column at fruit and vegetable storage room; note ledger plates bolted to top of column - Fort Hood, World War II Temporary Buildings, Cold Storage Building, Seventeenth Street, Killeen, Bell County, TX

  15. 19. Detail of builtup 5" x 13" column at fruit ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. Detail of built-up 5" x 13" column at fruit and vegetable storage room; note ledger plates bolted to top of column - Fort Hood, World War II Temporary Buildings, Cold Storage Building, Seventeenth Street, Killeen, Bell County, TX

  16. Method to fabricate silicon chromatographic column comprising fluid ports

    DOEpatents

    Manginell, Ronald P.; Frye-Mason, Gregory C.; Heller, Edwin J.; Adkins, Douglas R.

    2004-03-02

    A new method for fabricating a silicon chromatographic column comprising through-substrate fluid ports has been developed. This new method enables the fabrication of multi-layer interconnected stacks of silicon chromatographic columns.

  17. Cross flow flotation column for coal and minerals beneficiation

    SciTech Connect

    Lai, Ralph W.; Patton, Robert A.

    1997-12-01

    An apparatus and process are disclosed for the separation of coal from pyritic impurities using a modified froth flotation system. The froth flotation column incorporates a helical track about the inner wall of the column in a region intermediate between the top and base of the column. A standard impeller located about the central axis of the column is used to generate a centrifugal force thereby increasing the separation efficiency of coal from the pyritic particles and hydrophilic tailings.

  18. Column strength of magnesium alloy AM-57S

    NASA Technical Reports Server (NTRS)

    Holt, M

    1942-01-01

    Tests were made to determine the column strength of extruded magnesium alloy AM-57S. Column specimens were tested with round ends and with flat ends. It was found that the compressive properties should be used in computations for column strengths rather than the tensile properties because the compressive yield strength was approximately one-half the tensile yield strength. A formula for the column strength of magnesium alloy AM-57S is given.

  19. Cross flow cyclonic flotation column for coal and minerals beneficiation

    DOEpatents

    Lai, Ralph W.; Patton, Robert A.

    2000-01-01

    An apparatus and process for the separation of coal from pyritic impurities using a modified froth flotation system. The froth flotation column incorporates a helical track about the inner wall of the column in a region intermediate between the top and base of the column. A standard impeller located about the central axis of the column is used to generate a centrifugal force thereby increasing the separation efficiency of coal from the pyritic particles and hydrophillic tailings.

  20. 24. DETAIL VIEW OF COLUMN #072 DEVIATING FROM VERTICAL IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. DETAIL VIEW OF COLUMN #072 DEVIATING FROM VERTICAL IN ROW OF INTACT COLUMNS, LOOKING NORTHEAST TO SOUTHWEST. (NOTE BOLTED BLOCK SCABBED TO COLUMN AS JOIST/TRUSS SUPPORT) - Oakland Army Base, Transit Shed, East of Dunkirk Street & South of Burma Road, Oakland, Alameda County, CA

  1. 46 CFR 174.085 - Flooding on column stabilized units.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Flooding on column stabilized units. 174.085 Section 174... Units § 174.085 Flooding on column stabilized units. (a) Watertight compartments that are outboard of... of the unit, must be assumed to be subject to flooding as follows: (1) When a column is...

  2. 46 CFR 174.085 - Flooding on column stabilized units.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Flooding on column stabilized units. 174.085 Section 174... Units § 174.085 Flooding on column stabilized units. (a) Watertight compartments that are outboard of... of the unit, must be assumed to be subject to flooding as follows: (1) When a column is...

  3. 46 CFR 174.085 - Flooding on column stabilized units.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Flooding on column stabilized units. 174.085 Section 174... Units § 174.085 Flooding on column stabilized units. (a) Watertight compartments that are outboard of... of the unit, must be assumed to be subject to flooding as follows: (1) When a column is...

  4. 46 CFR 174.085 - Flooding on column stabilized units.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Flooding on column stabilized units. 174.085 Section 174... Units § 174.085 Flooding on column stabilized units. (a) Watertight compartments that are outboard of... of the unit, must be assumed to be subject to flooding as follows: (1) When a column is...

  5. 46 CFR 174.085 - Flooding on column stabilized units.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Flooding on column stabilized units. 174.085 Section 174... Units § 174.085 Flooding on column stabilized units. (a) Watertight compartments that are outboard of... of the unit, must be assumed to be subject to flooding as follows: (1) When a column is...

  6. Stress Analysis of Columns and Beam Columns by the Photoelastic Method

    NASA Technical Reports Server (NTRS)

    Ruffner, B F

    1946-01-01

    Principles of similarity and other factors in the design of models for photoelastic testing are discussed. Some approximate theoretical equations, useful in the analysis of results obtained from photoelastic tests are derived. Examples of the use of photoelastic techniques and the analysis of results as applied to uniform and tapered beam columns, circular rings, and statically indeterminate frames, are given. It is concluded that this method is an effective tool for the analysis of structures in which column action is present, particularly in tapered beam columns, and in statically indeterminate structures in which the distribution of loads in the structures is influenced by bending moments due to axial loads in one or more members.

  7. Column density profiles of multiphase gaseous haloes

    NASA Astrophysics Data System (ADS)

    Liang, Cameron J.; Kravtsov, Andrey V.; Agertz, Oscar

    2016-05-01

    We analyse circumgalactic medium (CGM) in a suite of high-resolution cosmological re-simulations of a Milky Way size galaxy and show that CGM properties are quite sensitive to details of star formation-feedback loop modelling. The simulation that produces a realistic late-type galaxy, fails to reproduce existing observations of the CGM. In contrast, simulation that does not produce a realistic galaxy has the predicted CGM in better agreement with observations. This illustrates that properties of galaxies and properties of their CGM provide strong complementary constraints on the processes governing galaxy formation. Our simulations predict that column density profiles of ions are well described by an exponential function of projected distance d: N ∝ e^{-d/h_s}. Simulations thus indicate that the sharp drop in absorber detections at larger distances in observations does not correspond to a `boundary' of an ion, but reflects the underlying steep exponential column density profile. Furthermore, we find that ionization energy of ions is tightly correlated with the scaleheight hs: h_s ∝ E_ion^{0.74}. At z ≈ 0, warm gas traced by low-ionization species (e.g. Mg II and C IV) has hs ≈ 0.03 - 0.07Rvir, while higher ionization species (O VI and Ne VIII) have hs ≈ 0.32 - 0.45Rvir. Finally, the scaleheights of ions in our simulations evolve slower than the virial radius for z ≤ 2, but similarly to the halo scale radius, rs. Thus, we suggest that the column density profiles of galaxies at different redshifts should be scaled by rs rather than the halo virial radius.

  8. Growing Cobalt Silicide Columns In Silicon

    NASA Technical Reports Server (NTRS)

    Fathauer, Obert W.

    1991-01-01

    Codeposition by molecular-beam epitaxy yields variety of structures. Proposed fabrication process produces three-dimensional nanometer-sized structures on silicon wafers. Enables control of dimensions of metal and semiconductor epitaxial layers in three dimensions instead of usual single dimension (perpendicular to the plane of the substrate). Process used to make arrays of highly efficient infrared sensors, high-speed transistors, and quantum wires. For fabrication of electronic devices, both shapes and locations of columns controlled. One possible technique for doing this electron-beam lithography, see "Making Submicron CoSi2 Structures on Silicon Substrates" (NPO-17736).

  9. Wiring dendrites in layers and columns.

    PubMed

    Luo, Jiangnan; McQueen, Philip G; Shi, Bo; Lee, Chi-Hon; Ting, Chun-Yuan

    2016-06-01

    The most striking structure in the nervous system is the complex yet stereotyped morphology of the neuronal dendritic tree. Dendritic morphologies and the connections they make govern information flow and integration in the brain. The fundamental mechanisms that regulate dendritic outgrowth and branching are subjects of extensive study. In this review, we summarize recent advances in the molecular and cellular mechanisms for routing dendrites in layers and columns, prevalent organizational structures in the brain. We highlight how dendritic patterning influences the formation of synaptic circuits. PMID:27315108

  10. A review of oscillating water columns.

    PubMed

    Heath, T V

    2012-01-28

    This paper considers the history of oscillating water column (OWC) systems from whistling buoys to grid-connected power generation systems. The power conversion from the wave resource through to electricity via pneumatic and shaft power is discussed in general terms and with specific reference to Voith Hydro Wavegen's land installed marine energy transformer (LIMPET) plant on the Scottish island of Islay and OWC breakwater systems. A report on the progress of other OWC systems and power take-off units under commercial development is given, and the particular challenges faced by OWC developers reviewed. PMID:22184660

  11. Gas holdup in slurry bubble columns: Effect of column diameter and slurry concentrations

    SciTech Connect

    Krishna, R.; Swart, J.W.A. de; Ellenberger, J.; Martina, G.B.; Maretto, C.

    1997-02-01

    In processes for converting natural gas to liquid fuels, bubble-column reactors are finding increasing application. To study the influence of particle concentration on the hydrodynamics of bubble-column slurry reactors operating in the heterogeneous flow regime, experiments were carried out in 0.10, 0.19, and 0.38-m-dia. columns using paraffinic oil as the liquid phase and slurry concentrations of up to 36 vol. %. To interpret experimental results a generalization of the two-phase model for gas-solid fluid beds was used to describe bubble hydrodynamics. The two phases identified are: a dilute phase consisting of fast-rising large bubbles that traverse the column virtually in plug flow and a dense phase that is identified with the liquid phase along with solid particles and entrained small bubbles. The dense phase suffers backmixing considerably. Dynamic gas disengagement was experimented in the heterogeneous flow regime to determine the gas voidage in dilute and dense phases. Experimental data show that increasing the solid concentration decreases the total gas holdup significantly, but the influence on the dilute-phase gas holdup is small. The dense-phase gas voidage significantly decreases gas holdup due to enhanced coalescence of small bubbles resulting from introduction of particles. The dense-phase gas voidage is practically independent of the column diameter. The dilute-phase gas holdup, on the other hand, decreases with increasing column diameter, and this dependence could be described adequately with a slight modification of the correlation of Krishna and Ellenberger developed for gas-liquid systems.

  12. 9. Detail view of columns on first floor. This row ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Detail view of columns on first floor. This row of columns indicates the former location of the exterior mill wall before World War II era expansion. The unusual column and beam connection was a key part of the mill structural system patented by Providence, Rhode Island engineers Charles Praray and Charles Makepeace in 1894. Each column was originally located in the apex of triangular window bay, but not connected to the exterior wall. Modifications on the right side of each column support the beams of the addition. - Dixie Cotton Mill, 710 Greenville Street, La Grange, Troup County, GA

  13. Curvature ductility of reinforced and prestressed concrete columns

    SciTech Connect

    Suprenant, B.A.

    1984-01-01

    Engineers are concerned with the survival of reinforced and prestressed concrete columns during earthquakes. The prediction of column survival can be deduced from moment-curvature curves of the column section. An analytical approach is incorporated into a computer model. The computer program is based on assumed stress-strain relations for confined and unconfined concrete, nonprestressed and prestressing steel. The results of studies on reinforced and prestressed concrete columns indicate that reinforced concrete columns may be designed to resist earthquakes, while prestressed concrete columns may not. The initial reduction in moment capacity, after concrete cover spalling, of a prestressed concrete column could be as much as 50%. Analyses indicate that the bond between concrete and prestressing strand after concrete cover spalling is not critical.

  14. Degenerative diseases of the vertebral column.

    PubMed

    Resnick, D

    1985-07-01

    Several distinct degenerative processes affect the articulations of the vertebral column; each is associated with characteristic radiographic and pathologic abnormalities, and many are accompanied by significant clinical manifestations. A discussion of these processes is best accomplished according to the type of joint that is involved. With regard to cartilaginous articulations, of which the intervertebral disk is most important, intervertebral (osteo)chondrosis, spondylosis deformans, and, in the cervical spine, uncovertebral arthrosis are the major degenerative disorders. Osteoarthritis (osteoarthrosis) affects any of the synovium-lined joints of the vertebral column, including the apophyseal, costovertebral, transitional lumbosacral, median atlantoaxial, and sacroiliac articulations. Fibrous articulations, ligaments, or entheses (sites of tendon or ligament attachment to bone) are involved in diffuse idiopathic skeletal hyperostosis, ossification of the posterior spinal ligaments, and Baastrup disease. Of the many complications of these degenerative processes, alignment abnormalities (including segmental instability, degenerative spondylolisthesis, senile kyphosis, and degenerative scoliosis), intervertebral disk displacement, calcification or ossification, and spinal stenosis are the most important. PMID:3923556

  15. Comparison of automated pre-column and post-column analysis of amino acid oligomers

    NASA Technical Reports Server (NTRS)

    Chow, J.; Orenberg, J. B.; Nugent, K. D.

    1987-01-01

    It has been shown that various amino acids will polymerize under plausible prebiotic conditions on mineral surfaces, such as clays and soluble salts, to form varying amounts of oligomers (n = 2-6). The investigations of these surface reactions required a quantitative method for the separation and detection of these amino acid oligomers at the picomole level in the presence of nanomole levels of the parent amino acid. In initial high-performance liquid chromatography (HPLC) studies using a classical postcolumn o-phthalaldehyde (OPA) derivatization ion-exchange HPLC procedure with fluorescence detection, problems encountered included lengthy analysis time, inadequate separation and large relative differences in sensitivity for the separated species, expressed as a variable fluorescent yield, which contributed to poor quantitation. We have compared a simple, automated, pre-column OPA derivatization and reversed-phase HPLC method with the classical post-column OPA derivatization and ion-exchange HPLC procedure. A comparison of UV and fluorescent detection of the amino acid oligomers is also presented. The conclusion reached is that the pre-column OPA derivatization, reversed-phase HPLC and UV detection produces enhanced separation, improved sensitivity and faster analysis than post-column OPA derivatization, ion-exchange HPLC and fluorescence detection.

  16. Comparison between a spray column and a sieve tray column operating as liquid-liquid heat exchangers

    SciTech Connect

    Keller, A.; Jacobs, H.R.; Boehm, R.F.

    1980-12-01

    The performance of a spray column and a sieve tray column was compared as a liquid-liquid heat exchanger. In carrying out these studies a 15.2 cm (6.0 in.) diameter column, 183 cm (6.0 ft) tall was utilized. The performance of the spray column as a heat exchanger was shown to correlate with the model of Letan-Kehat which has as a basis that the heat transfer is dominated by the wakeshedding characteristics of the drops over much of the column length. This model defines several hydrodynamic zones along the column of which the wake formation zone at the bottom appears to have the most efficient heat transfer. The column was also operated with four perforated plates spaced two column diameters apart in order to take advantage of the wake formation zone heat transfer. The plates induce coalescence of the dispersed phase and reformation of the drops, and thus cause a repetition of the wake formation zone. It is shown that the overall volumetric heat transfer coefficient in a perforated plate column is increased by a minimum of eleven percent over that in a spray column. A hydrodynamic model that predicts the performance of a perforated plate column is suggested.

  17. Comparison of two column characterisation systems based on pharmaceutical applications.

    PubMed

    Haghedooren, Erik; Németh, Tamás; Dragovic, Sanja; Noszál, Béla; Hoogmartens, Jos; Adams, Erwin

    2008-05-01

    A useful column characterisation system should help chromatographers to select the most appropriate column to use, e.g. when a particular chromatographic column is not available or when facing the dilemma of selecting a suitable column for analysis according to an official monograph. Official monographs of the European Pharmacopoeia and the United States Pharmacopeia are not allowed to mention the brand name of the stationary phase used for the method development. Also given the overwhelming offer of several hundreds of commercially available reversed-phase liquid chromatographic columns, the choice of a suitable column could be difficult sometimes. To support rational column selection, a column characterisation study was started in our laboratory in 2000. In the same period, Euerby et al. also developed a column characterisation system, which is now released as Column Selector by ACD/Labs. The aim of this project was to compare the two existing column characterisation systems, i.e. the KUL system and the Euerby system. Other research groups active in this field will not be discussed here. Euerby et al. developed a column characterisation system based on 6 test parameters, while the KUL system is based on 4 chromatographic parameters. Comparison was done using a set of 63 columns. For 7 different pharmaceutical separations (fluoxetine, gemcitabine, erythromycin, tetracycline, tetracaine, amlodipine and bisacodyl), a ranking was built based on an F-value (KUL method) or Column Difference Factor value (Euerby method) versus a (virtual) reference column. Both methods showed a similar ranking. The KUL and Euerby methods do not perfectly match, but they yield very similar results, allowing with a relatively high certainty, the selection of similar or dissimilar columns as compared to a reference column. An analyst that uses either of the two methods, will end up with a similar ranking. From a practical point of view, it must be noted that the KUL method only includes 4

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

    NASA Astrophysics Data System (ADS)

    Long, Cameron M.; Borden, Robert C.

    2006-09-01

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

  19. Rapid Column Extraction Methods for Urine

    SciTech Connect

    Maxwell, S.L. III

    2000-06-09

    A new fecal analysis method that dissolves plutonium oxide was developed at the Westinghouse Savannah River Site. Diphonix Resin (Eichrom Industries), is used to pre-concentrate the actinides from digested fecal samples. A rapid microwave digestion technique is used to remove the actinides from the Diphonix Resin, which effectively extracts plutonium and americium from acidic solutions containing hydrofluoric acid. After resin digestion, the plutonium and americium are recovered in a small volume of nitric acid that is loaded onto small extraction chromatography columns, TEVA Resin and TRU Resin (Eichrom Industries). The method enables complete dissolution of plutonium oxide and provides high recovery of plutonium and americium with good removal of thorium isotopes such as thorium-228.

  20. Using hydroacoustic stations as water column seismometers

    NASA Astrophysics Data System (ADS)

    Yildiz, Selda; Sabra, Karim; Dorman, Leroy M.; Kuperman, W. A.

    2013-06-01

    Getting seismic data from the deep oceans usually involves ocean-bottom seismometers, but hydrophone arrays may provide a practical alternative means of obtaining vector data. We here explore this possibility using hydrophone stations of the International Monitoring System, which have been used to study icebergs and T-wave propagation among others. These stations consist of three hydrophones at about the depth of the deep sound channel in a horizontal triangle array with 2 km sides. We use data from these stations in the very low-frequency regime (0.01-0.05 Hz band) to demonstrate that these stations can also be used as water column seismometers. By differencing the acoustic pressure, we obtain vector quantities analogous to what a seismometer would record. Comparing processed hydrophone station records of the 2004 Great Sumatra-Andaman Earthquake with broadband seismograms from a nearby island station, we find that the differenced hydrophones are indeed a practical surrogate for seismometers.

  1. Micro-column plasma emission liquid chromatograph

    DOEpatents

    Gay, Don D.

    1984-01-01

    In a direct current plasma emission spectrometer for use in combination with a micro-column liquid chromatograph, an improved plasma source unit. The plasma source unit includes a quartz capillary tube having an inlet means, outlet off gas means and a pair of spaced electrodes defining a plasma region in the tube. The inlet means is connected to and adapted to receive eluant of the liquid chromatograph along with a stream of plasma-forming gas. There is an opening through the wall of the capillary tube penetrating into the plasma region. A soft glass capillary light pipe is disposed at the opening, is connected to the spectrometer, and is adapted to transmit light passing from the plasma region to the spectrometer. There is also a source of electromotive force connected to the electrodes sufficient to initiate and sustain a plasma in the plasma region of the tube.

  2. Ewing's sarcoma of the vertebral column

    SciTech Connect

    Pilepich, M.V.; Vietti, T.J.; Nesbit, M.E.; Tefft, M.; Kissane, J.; Burgert, O.; Pritchard, D.; Gehan, E.A.

    1981-01-01

    Twenty-two patients with vertebral primaries were registered in the Intergroup Ewing's Sarcoma Study between 1973 and 1977. The radiation doses to the primary tumors ranged between 3800 and 6200 rad. All patients received intensive combination chemotherapy. After a followup ranging between 14 and 62 months, 14 patients remained disease-free. All patients with primary tumor of the cervical and dorsal spine remained disease-free. Of eight patients with lesions in the distal spine, (sacrococcygeal region) six developed recurrence, in three a local recurrence was observed despite doses of 6000 rad or higher. Doses of 5000 rad or less (in addition to combination chemotherapy as used in the Intergroup Ewing's Study) appear adequate in controlling the primary tumors of the proximal segments of the spinal column.

  3. Dynamic CT scanning of spinal column trauma

    SciTech Connect

    Brown, B.M.; Brant-Zawadzki, M.; Cann, C.E.

    1982-12-01

    Dynamic sequential computed tomographic scanning with automatic table incrementation uses low milliampere-second technique to eliminate tube cooling delays between scanning slices and, thus, markedly shortens examination times. A total of 25 patients with spinal column trauma involving 28 levels were studied with dynamic scans and retrospectively reviewed. Dynamic studies were considerably faster than conventional spine examinations and yielded reliable diagnosis. Bone disruption and subluxation was accurately evaluated, and the use of intrathecal metrizamide in low doses allowed direct visualization of spinal cord or radicular compromise. Multiplanar image reformation was aided by the dynamic incrementation technique, since motion between slices (and the resulting misregistration artifact on image reformation) was minimized. A phantom was devised to test spatial resolution of computed tomography for objects 1-3 mm in size and disclosed minimal differences for dynamic and conventional computed tomographic techniques in resolving medium-to-high-contrast objects.

  4. Wide-bore monolithic column for electrochromatography.

    PubMed

    Yuan, Ruijuan; Ding, Guosheng; Guo, Yugao; Liu, Danning; Bao, James J

    2007-06-01

    A new wide-bore electrophoresis (WE) system adopting an inner cooling device was set up to perform electrochromatography. In this system, a quartz tube of 1.2 mm inner diameter was used as the separation channel. The Joule heat generated during electrophoresis was removed timely through the outer surface of the quartz tube and a cooling capillary inserted into the quartz tube. A proper coolant passed through the cooling capillary to further improve the cooling efficiency. In the primary research, a polyacrylamide monolithic column was successfully prepared in this quartz tube. Then it was evaluated in the electrochromatographic mode. An electric field strength as high as 625 V/cm can be applied to this system without obvious deviation of the current from the linear curve of the Ohm plot. Sample volume as high as 1 microL was injected into the WE system and reasonable efficiency was obtained for separation of the test compounds. PMID:17480039

  5. The flotation column as a froth separator

    SciTech Connect

    Schultz, C.W.; Mehta, R.K.; Bates, J.B. )

    1991-12-01

    The Mineral Resources Institute, The University of Alabama, has for the past three years been engaged in a program to develop a beneficiation system for eastern (Devonian) oil shales. One objective of that program was to evaluate advanced technologies for effecting a kerogen-mineral matter separation. Column flotation was among the advanced technologies selected for evaluation. One observation made in the course of optimization testing was that introducing the feed into the froth (above the pulp- froth interface) resulted in an improved combination of concentrate grade and kerogen recovery. This observation was reported in a previous paper. Because the practice of maintaining the pulp froth interface below the feed point is contrary to conventional practice, it was decided to subject the observation to a systematic series of tests. This paper describes a recent series of tests and the results that were obtained.

  6. Kelvin waves in total column ozone

    NASA Technical Reports Server (NTRS)

    Ziemke, J. R.; Stanford, J. L.

    1993-01-01

    Tropical Kelvin waves have been observed previously in ozone mixing ratio data from the SBUV (Solar Backscatter Ultraviolet) and LIMS (Limb Infrared Monitor of the Stratosphere) instruments on board the Nimbus-7 satellite. Kelvin wave features in total column ozone, using version 6 data from the Total Ozone Mapping Spectrometer (TOMS) instrument (also on board Nimbus-7) are investigated. Results show eastward-propagating zonal waves 1-2 with periods approximately 5-15 days, amplitudes approximately 3-5 DU, and latitudinal symmetry typical of Kelvin waves. A simplified model calculation suggests that the primary source for the perturbations is slow Kelvin waves in the lower-to-middle stratosphere. Maximum Kelvin wave signatures occur in conjunction with westward lower-to-middle stratospheric equatorial zonal winds (a quasi-biennial oscillation (QBO) wind modulation effect).

  7. The vertebral column of Australopithecus sediba.

    PubMed

    Williams, Scott A; Ostrofsky, Kelly R; Frater, Nakita; Churchill, Steven E; Schmid, Peter; Berger, Lee R

    2013-04-12

    Two partial vertebral columns of Australopithecus sediba grant insight into aspects of early hominin spinal mobility, lumbar curvature, vertebral formula, and transitional vertebra position. Au. sediba likely possessed five non-rib-bearing lumbar vertebrae and five sacral elements, the same configuration that occurs modally in modern humans. This finding contrasts with other interpretations of early hominin regional vertebral numbers. Importantly, the transitional vertebra is distinct from and above the last rib-bearing vertebra in Au. sediba, resulting in a functionally longer lower back. This configuration, along with a strongly wedged last lumbar vertebra and other indicators of lordotic posture, would have contributed to a highly flexible spine that is derived compared with earlier members of the genus Australopithecus and similar to that of the Nariokotome Homo erectus skeleton. PMID:23580532

  8. Novel electrostatic column for ion projection lithography

    SciTech Connect

    Chalupka, A.; Stengl, G.; Buschbeck, H.; Lammer, G.; Vonach, H.; Fischer, R.; Hammel, E.; Loeschner, H.; Nowak, R.; Wolf, P. ); Finkelstein, W.; Hill, R.W. ); Berry, I.L. ); Harriott, L.R. ); Melngailis, J. ); Randall, J.N. ); Wolfe, J.C. ); Stroh, H.; Wollnik, H. ); Mondelli, A.A.; Petillo, J.J. ); Leung, K. (Lawrence Berkeley Laboratory, University of Californi

    1994-11-01

    Ion projection lithography (IPL) is being considered for high volume sub-0.25-[mu]m lithography. A novel ion-optical column has been designed for exposing 20[times]20 mm[sup 2] fields at 3[times] reduction from stencil mask to wafer substrates. A diverging lens is realized by using the stencil mask as the first electrode of the ion-optical column. The second and third electrode form an accelerating field lens. The aberrations of the first two lenses (diverging lens and field lens) are compensated by an asymmetric Einzel lens projecting an ion image of the stencil mask openings onto the wafer substrate with better than 2 mrad telecentricity. Less than 30 nm intrafield distortion was calculated within 20[times]20 mm[sup 2] exposure fields. The calculation uncertainty is estimated to be about 10 nm. The calculation holds for helium ions with [approx]10 keV ion energy at the stencil mask and 150 keV ion energy at the wafer plane. A virtual ion source size of 10 [mu]m has been assumed. The calculated chromatic aberrations are less than 60 nm, assuming 6 eV energy spread of the ions extracted from a duoplasmatron source. Recently a multicusp ion source has been developed for which preliminary results indicate an energy spread of less than 2 eV. Thus, with a multicusp source chromatic aberrations of less than 20 nm are to be expected. The ion energy at the crossover between the field lens and the asymmetric Einzel lens is 200 keV. Therefore, stochastic space charge induced degradations in resolution can be kept sufficiently low. The divergence of the ion image projected to the wafer plane is less than 2 mrad. Thus, the usable'' depth of focus for the novel ion optics is in the order of 10 [mu]m.

  9. Polar monolithic capillary columns: Analysis of light hydrocarbons

    NASA Astrophysics Data System (ADS)

    Korolev, A. A.; Shiryaeva, V. E.; Popova, T. P.; Kurganov, A. A.

    2013-01-01

    The influence of the nature of the stationary phase and carrier gas (helium, hydrogen, nitrogen, carbon dioxide, or nitrous oxide) on the efficiency and separating ability of monolithic ethyleneglycol dimethacrylate (EDMA) polymer capillary columns was studied using a model mixture of light hydrocarbons C1-C4. The results were compared with the properties of silica gel and divinylbenzene (DVB) monolithic columns. For EDMA polymer monolithic columns, the effect of the carrier gas on the separating ability was markedly lower than for silica gel columns. A reduction in HETP observed in the series He > H2 > N2 > N2O > CO2 is also known for hollow capillary columns with polymer stationary phases, but the change in efficiency was ˜20-30% in this case. Under the optimum conditions, HETP was minimum for the columns when CO2 or N2O was used.

  10. Temperature-compensated 8-bit column driver for AMLCD

    NASA Astrophysics Data System (ADS)

    Dingwall, Andrew G. F.; Lin, Mark L.

    1995-06-01

    An all-digital, 5 V input, 50 Mhz bandwidth, 10-bit resolution, 128- column, AMLCD column driver IC has been designed and tested. The 10-bit design can enhance display definition over 6-bit nd 8-bit column drivers. Precision is realized with on-chip, switched-capacitor DACs plus transparently auto-offset-calibrated, opamp outputs. Increased resolution permits multiple 10-bit digital gamma remappings in EPROMs over temperature. Driver IC features include externally programmable number of output column, bi-directional digital data shifting, user- defined row/column/pixel/frame inversion, power management, timing control for daisy-chained column drivers, and digital bit inversion. The architecture uses fewer reference power supplies.

  11. Parallel array of independent thermostats for column separations

    DOEpatents

    Foret, Frantisek; Karger, Barry L.

    2005-08-16

    A thermostat array including an array of two or more capillary columns (10) or two or more channels in a microfabricated device is disclosed. A heat conductive material (12) surrounded each individual column or channel in array, each individual column or channel being thermally insulated from every other individual column or channel. One or more independently controlled heating or cooling elements (14) is positioned adjacent to individual columns or channels within the heat conductive material, each heating or cooling element being connected to a source of heating or cooling, and one or more independently controlled temperature sensing elements (16) is positioned adjacent to the individual columns or channels within the heat conductive material. Each temperature sensing element is connected to a temperature controller.

  12. Hydrodynamics of photoionized columns in the Eagle Nebula, M 16

    NASA Astrophysics Data System (ADS)

    Williams, R. J. R.; Ward-Thompson, D.; Whitworth, A. P.

    2001-11-01

    We present hydrodynamical simulations of the formation, structure and evolution of photoionized columns, with parameters based on those observed in the Eagle Nebula. On the basis of these simulations we argue that there is no unequivocal evidence that the dense neutral clumps at heads of the columns were cores in the pre-existing molecular cloud. In our simulations, a variety of initial conditions leads to the formation and maintenance of near-equilibrium columns. Therefore, it is likely that narrow columns will often occur in regions with large-scale inhomogeneities, but that observations of such columns can tell us little about the processes by which they formed. The manner in which the columns in our simulations develop suggests that their evolution may result in extended sequences of radiation-induced star formation.

  13. Application of Z-contrast imaging to obtain column-by-column spectroscopic analysis of materials

    SciTech Connect

    Browning, N.D.; Pennycook, S.J.

    1993-01-01

    Z-contrast imaging has been shown to be an effective method for obtaining a high-resolution image from a scanning transmission electron microscope (STEM). The incoherent nature of the high-angle scattering makes image interpretation straightforward and intuitive with the resolution limited only by the 2.2 {Angstrom} electron probe. The optimum experimental conditions for Z-contrast imaging also coincide with those used for analytical microscopy, enabling microanalysis to be performed with the same spatial resolution as the image. The detection limits afforded by a parallel detection system for electron energy loss spectroscopy (EELS) allows column-by-column core-loss spectroscopy to be performed using the Z-contrast image to position the electron probe. Preliminary results from the study of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} illustrate the spatial resolution available with this technique and the potential applications for materials science.

  14. Fracture Behaviour of Glass Columns Experimental Study of Axial Loaded Glass Columns

    NASA Astrophysics Data System (ADS)

    Jakab, A.; Nehme, K.; Nehme, S. G.

    2016-04-01

    Nowadays supporting structures can be transparent due to the development of glass strengthening procedures. The building glass as a versatile building material enables the efforts of the architects due to its transparency. This paper focuses on glass columns in the topic of load-bearing glasses and also on the design and load bearing capacity of fins and stability issues. Laboratory experiments were carried out at the BME, Department of Building Materials and Engineering Geology on the fracture behaviour of centrally compressed glass columns. More than 120 specimens where loaded until fracture. The load and deformations were measured. Based on the experimental results the critical force was determined and with force-deflection diagrams were illustrated the fracture and stability processes. Authors are going to compare the results of the laboratory experiments and theoretical calculations.

  15. Mini-columns for Conducting Breakthrough Experiments. Design and Construction

    SciTech Connect

    Dittrich, Timothy M.; Reimus, Paul William; Ware, Stuart Douglas

    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.

  16. Stability of leaning column at Devils Tower National Monument, Wyoming

    USGS Publications Warehouse

    Harp, Edwin L.; Lindsay, Charles R.

    2006-01-01

    In response to reports from climbers that an 8-meter section (referred to as the leaning column) of the most popular climbing route on Devils Tower in northeastern Wyoming is now moving when being climbed, scientists from the U.S. Geological Survey inspected the site to determine the stability of the column and the underlying column that serves as a support pedestal. Evidence of a recent tensile spalling failure was observed on the pedestal surface immediately beneath the contact with the overlying leaning column. The spalling of a flake-shaped piece of the pedestal, probably due to the high stress concentration exerted by the weight of the leaning column along a linear contact with the pedestal, is likely causing the present movement of the leaning column. Although it is unlikely that climbers will dislodge the leaning column by their weight alone, the possibility exists that additional spalling failures may occur from the pedestal surface and further reduce the stability of the leaning column and result in its toppling. To facilitate detection of further spalling failures from the pedestal, its surface has been coated with a layer of paint. Any new failures from the pedestal could result in the leaning column toppling onto the climbing route or onto the section of the Tower trail below.

  17. Applicability of hydroxylamine nitrate reductant in pulse-column contactors

    SciTech Connect

    Reif, D.J.

    1983-05-01

    Uranium and plutonium separations were made from simulated breeder reactor spent fuel dissolver solution with laboratory-sized pulse column contactors. Hydroxylamine nitrate (HAN) was used for reduction of plutonium (1V). An integrated extraction-partition system, simulating a breeder fuel reprocessing flowsheet, carried out a partial partition of uranium and plutonium in the second contactor. Tests have shown that acceptable coprocessing can be ontained using HAN as a plutonium reductant. Pulse column performance was stable even though gaseous HAN oxidation products were present in the column. Gas evolution rates up to 0.27 cfm/ft/sup 2/ of column cross section were tested and found acceptable.

  18. Monolithic capillary columns based on pentaerythritol tetraacrylate for peptide analysis

    NASA Astrophysics Data System (ADS)

    Kucherenko, E. V.; Melnik, D. M.; Korolev, A. A.; Kanateva, A. Yu.; Pirogov, A. V.; Kurganov, A. A.

    2015-09-01

    Monolythic medium-polar capillary columns based on pentaerythritol tetraacrylate were optimized for separation of peptides. The synthesis temperature and time, the fraction of monomer in the initial polymerization mixture, and the nature of alcohol contained in the complex porogen were chosen as optimization parameters. The highest efficiency was attained for columns obtained with 33 and 34% monomer at a polymerization time of 75 min and a temperature of 75°C. The columns with the optimum structure were effective in separation of a model mixture of five peptides. The sensitivity of the method was 200 ng of peptide per column.

  19. 15. FIRST FLOOR WAREHOUSE SPACE, SHOWING COLUMN / BEAM CONNECTION. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. FIRST FLOOR WAREHOUSE SPACE, SHOWING COLUMN / BEAM CONNECTION. VIEW TO SOUTHWEST. - Commercial & Industrial Buildings, Dubuque Seed Company Warehouse, 169-171 Iowa Street, Dubuque, Dubuque County, IA

  20. Boston Column Network: Compact Solar-Tracking Spectrometers and Differential Column Measurements

    NASA Astrophysics Data System (ADS)

    Chen, J.; Samra, J.; Gottlieb, E.; Budney, J.; Daube, C.; Daube, B. C.; Hase, F.; Gerbig, C.; Chance, K.; Wofsy, S. C.

    2014-12-01

    In urban environments, the surface concentration is influenced by both the dynamics of the planetary boundary layer (PBL) height and by emissions. Path-integrated measurements that integrate through the entire mixed layer are valuable complements to surface data, compatible with the scale of the atmospheric models and therefore help reduce the representation errors in data assimilation studies of surface emission rates. Here we present a ground-based column sensor network in metro Boston. The network extends the existing surface sensor network to the vertical dimension in order to help quantify the concentration gradients across a city using a differential strategy: by measuring the "total column" of greenhouse gases (CO2, CH4, H2O etc.) and pollutants (NO2, O3, CH2O etc.) simultaneously inside and upwind of the urban core. Each stationary network site has a Fourier transform infrared spectrometer (Bruker, EM27Sun), a UV-visible grating spectrometer (Pandora) and a LIDAR (Sigma Space, Mini MPL) to provide PBL height. Two EM27Sun Fourier transform spectrometers at fixed locations are complemented by our self-developed solar-tracking Fourier transform spectrometer (Nicolet) to be used as a mobile unit to acquire cross-sectional slices of total column burdens across the urban dome. In additional to O2, CO2, CH4, H2O measurements, this system is also capable of measuring CO and N2O. This compact, inexpensive instrument uses a diffuser as a part of the tracking optics, which results in a rugged and simplified system. A novel camera-based active tracking schema is developed: the sun image on the diffuser is always regulated to the same position to ensure an accurate tracking. In this paper we will show comparisons between the self-developed solar-tracking system and the commercial Bruker EM27Sun. In addition, initial data for the retrieved column concentrations in and outside of the Boston urban dome will be presented.

  1. Fluid Dynamic Experiments on Mush Column Magmatism

    NASA Astrophysics Data System (ADS)

    Flanagan-Brown, R. E.; Marsh, B. D.

    2001-05-01

    A vertically extensive stack of sills interconnected by pipe-like conduits extending from the mantle through the lithosphere and capped by a volcanic center is a magmatic mush column. At any instant at various locations it contains fractionated and primitive melts as pools of nearly crystal-free magma, pools of crystal-rich magma, thick beds of cumulates, open conduits, and conduits congested by cognate and wall debris. All boundaries of the system are sheathed by solidification fronts. With the wide range of local, characteristic length scales there is a commensurate range of solidification time scales. This creates a complicated series of resistances to magma flow and provides a variety of distinct local physical environments for the chemical modification of magma. The system is driven by over-pressure from the addition of new melt from below. The over-pressure propagates upward by moving magma which flushes conduits, disrupts cumulate beds, and pools or purges sills. A critical aspect of this process is the entrainment, transport, and deposition of crystals throughout the system. Picritic lavas charges with entrained (tramp) olivine of a wide compositional range erupted at many systems (e.g. Jan Mayen, Kilauea, Reunion, etc.) are the final expression of this process. That the size and abundance of these crystals is correlated with eruptive flux (Murata & Richter, AJS, 1966) suggests an important indicator of the overall dynamics of the mush column. A mush column of this basic nature is observed is observed in the McMurdo Dry Valleys region of Antarctica and is inferred beneath Hawaii and the ocean ridges. We have attempted to model this process by studying the entrainment, transport, and deposition of particles in a vertical stack of sills (Plexiglas tanks) connected by resistive conduits (check valves), over-pressured from the base, and open at the top. The system is about two meters in height with water and oil as fluids and particles with Reynolds numbers

  2. Evolution of mantle column beneath Bartoy volcanoes.

    NASA Astrophysics Data System (ADS)

    Ashchepkov, Igor; Karmanov, Nikolai; Kanakin, Sergei; Ntaflos, Theodoros

    2013-04-01

    Pleistocene Bartoy volcanoes 1.5-0.8 Ma (Ashchepkov et al., 2003) represent variable set of hydrous cumulates and megacrysts and peridotite mantle xenoliths from spinel facies (Ashchepkov, 1991; Ionov, Kramm, 1992). Hydrous peridotites give series of the temperature groups: 1) deformed Fe - lherzolites (1200-1100o) , 2) Phl porhyroclastiμ (1100-1020o), 3) Amph -Phl (1020-940o), 4) Dry protogranular (1020-940o), 5)Amph equigranular (940-880o) and 6) dry and fine grained (880-820o). and Fe-rich poikilitic (700-600o) (Ashchepkov, 1991). T according (Nimis, Taylor, 2000) The sequence of the megacrysts crystallized on the wall of basaltic feeder in pre - eruption stage is starting from HT dark green websterites (1300-1200o), black Cpx- Gar varieties (1250-1200o) evolved to Phl -CPx (1200-1130o) and Cpx - Kaers (1130-1020o) - Cpx low in TiO2., Ilm and San (<1000o) like in Vitim (Ashchepkov et la., 2011). The differentiation trends looks branched but the question if they. Differentiation ain relatively large magma bodies p produced Ga- Cpx (+Amph-Phl- Ilm +-San) and then Cpx-Gar -Pl cumulates in( ~8-12 kbar) interval. In the ToC-Fe# diagram the Intermediate trend between lherzolites and megacrysts sub parallel to lherzolitic is correspondent to the fractionation of the hydrous alkali basalt melts in vein network created from the highly H2O bearing basaltic derivates formed in intermediate magma chambers. The interaction of the peridotites with the pulsing rising and evolving basaltic system produced the wall rock metasomatism and separate groups of peridotites in different levels of mantle column. PT calculations show two PT path and probably melt intrusion events. Trace elements in glass from crystalline basalts show Zr, Pb dips and Ta, Nb, Sr enrichment for the black megacrystalline Cpx , Gar series. They show link with evolved basalts by HFSE, Ba enrichment but Cpx from kaersutite and further Gar - Cpx cumulates show depressions in Ta, Nb, Zr, and Pb moderate

  3. Seismogenic frictional melting in the magmatic column

    NASA Astrophysics Data System (ADS)

    Kendrick, J. E.; Lavallée, Y.; Hess, K.-U.; De Angelis, S.; Ferk, A.; Gaunt, H. E.; Dingwell, D. B.; Leonhardt, R.

    2013-10-01

    Lava dome eruptions subjected to high extrusion rates commonly evolve from endogenous to exogenous growth and limits to their structural stability hold catastrophic potential as explosive eruption triggers. In the conduit, strain localisation in magma, accompanied by seismogenic failure, marks the onset of brittle magma ascent dynamics. The rock record of exogenous dome structures preserves vestiges of cataclastic processes (Cashman et al., 2008; Kennedy and Russell, 2011) and of thermal anomalies (Kendrick et al., 2012), key to unravelling subsurface processes. Here, a combined structural, thermal and magnetic investigation of a shear band crosscutting a large block erupted in 2010 at Soufrière Hills volcano (SHV) reveals evidence of faulting and frictional melting within the magmatic column. The mineralogy of this pseudotachylyte vein offers confirmation of complete recrystallisation with an isothermal remanent magnetisation signature that typifies local electric currents in faults. The pseudotachylyte presents an impermeable barrier, which is thought to have influenced the degassing pathway. Such melting events may be linked to the step-wise extrusion of magma accompanied by repetitive long-period (LP) drumbeat seismicity at SHV (Neuberg et al., 2006). Frictional melting of SHV andesite in a high velocity rotary shear apparatus highlights the small slip distances (< 15 cm) required to bring 800 °C magma to melting point at upper conduit stress conditions (10 MPa). We conclude that frictional melting is an inevitable consequence of seismogenic, conduit-dwelling magma fracture during dome building eruptions and that it may have an important influence on magma ascent dynamics.

  4. Seismogenic frictional melting in the magmatic column

    NASA Astrophysics Data System (ADS)

    Kendrick, J. E.; Lavallée, Y.; Hess, K.-U.; De Angelis, S.; Ferk, A.; Gaunt, H. E.; Meredith, P. G.; Dingwell, D. B.; Leonhardt, R.

    2014-04-01

    Lava dome eruptions subjected to high extrusion rates commonly evolve from endogenous to exogenous growth and limits to their structural stability hold catastrophic potential as explosive eruption triggers. In the conduit, strain localisation in magma, accompanied by seismogenic failure, marks the onset of brittle magma ascent dynamics. The rock record of exogenous dome structures preserves vestiges of cataclastic processes and thermal anomalies, key to unravelling subsurface processes. Here, a combined structural, thermal and magnetic investigation of a shear band crosscutting a large block erupted in 2010 at Soufrière Hills volcano (SHV) reveals evidence of faulting and frictional melting within the magmatic column. The mineralogy of this pseudotachylyte vein offers confirmation of complete recrystallisation, altering the structure, porosity and permeability of the material, and the magnetic signature typifies local electric currents in faults. Such melting events may be linked to the step-wise extrusion of magma accompanied by repetitive long-period (LP) drumbeat seismicity at SHV. Frictional melting of Soufrière Hills andesite in a high velocity rotary shear apparatus highlights the small slip distances (< 15 cm) thought to be required to bring 800 °C magma to melting point at upper conduit stress conditions (10 MPa). We conclude that frictional melting is a common consequence of seismogenic magma fracture during dome building eruptions and that it may govern the ascent of magma in the upper conduit.

  5. SPR Hydrostatic Column Model Verification and Validation.

    SciTech Connect

    Bettin, Giorgia; Lord, David; Rudeen, David Keith

    2015-10-01

    A Hydrostatic Column Model (HCM) was developed to help differentiate between normal "tight" well behavior and small-leak behavior under nitrogen for testing the pressure integrity of crude oil storage wells at the U.S. Strategic Petroleum Reserve. This effort was motivated by steady, yet distinct, pressure behavior of a series of Big Hill caverns that have been placed under nitrogen for extended period of time. This report describes the HCM model, its functional requirements, the model structure and the verification and validation process. Different modes of operation are also described, which illustrate how the software can be used to model extended nitrogen monitoring and Mechanical Integrity Tests by predicting wellhead pressures along with nitrogen interface movements. Model verification has shown that the program runs correctly and it is implemented as intended. The cavern BH101 long term nitrogen test was used to validate the model which showed very good agreement with measured data. This supports the claim that the model is, in fact, capturing the relevant physical phenomena and can be used to make accurate predictions of both wellhead pressure and interface movements.

  6. Kelvin waves in total column ozone

    NASA Technical Reports Server (NTRS)

    Ziemke, J. R.; Stanford, J. L.

    1994-01-01

    Tropical Kelvin waves have been observed previously in ozone mixing ratio data from the SBUV (Solar Backscatter Ultraviolet) and LIMS (Limb Infrared Monitor of the Stratosphere) instruments on board the Nimbus-7 satellite. The present study investigates Kelvin wave features in total column ozone, using version 6 data from the Total Ozone Mapping Spectrometer (TOMS) instrument (also on Nimbus-7). Results show eastward-propagating zonal waves 1-2 with periods approx. 5-15 days, amplitudes approx. 3-5 Dobson Units (1-2% of the time mean), and latitudinal symmetry typical of Kelvin waves. The analyses and a linear model in this study suggest that the primary source of the perturbations is slow Kelvin waves in the lower-to-middle stratosphere. Maximum Kelvin wave signatures occur in conjunction with westward lower-to-middle stratospheric equatorial zonal winds (a quasi-biennial oscillation (QBO) wind modulation effect). The significance of these results is that the TOMS data are shown to be useful for investigations with global coverage of a major component of tropical stratospheric dynamics, Kelvin waves. The TOMS data set with its excellent coverage and high quality should be useful in validating model studies in the relatively data sparse and dynamically difficult tropical region.

  7. Direct measurement of clarinet air column oscillations

    NASA Astrophysics Data System (ADS)

    Jones, Jesse; Rogers, Chris; French, Chris

    2003-10-01

    The internal oscillation of a clarinet air column has been directly measured through the implementation of hot-wire anemometry. By taking a series of measurements down the centerline of the bore, velocity and pressure modal shapes of individual harmonics are separated, measured, and plotted. Finally, composite averaged power spectra of the internal oscillation are presented and compared to acoustic measurements acquired outside the clarinet. In many cases, the even harmonics of the internal oscillation dominate over the power found in the odd harmonics. This contradicts the classic model of the clarinet as a cylindrical pipe closed at one end and open at the other (where only odd harmonics are produced). Further, the data from the direct velocity measurements also contradict the externally acquired acoustic data, where odd harmonics generally dominate for the lowest 5-9 harmonics. Thus the clarinet, in theory and practice, is generally considered incapable of generating strong even harmonics. In this research, however, it is seen that dominate even harmonics are generated, but the energy for these frequencies is largely trapped inside the clarinet, whereas the energy associated with the odd harmonics is released to the ambient. [This research was conducted with the support of Selmer Musical Instruments.

  8. Movement of Endotoxin Through Soil Columns

    PubMed Central

    Goyal, Sagar M.; Gerba, Charles P.; Lance, J. Clarence

    1980-01-01

    Land treatment of wastewater is an attractive alternative to conventional sewage treatment systems and is gaining widespread acceptance. Although land application systems prevent surface water pollution and augment the available water supplies, the potential dangers to human health should be evaluated. Since sewage may contain high amounts of bacterial endotoxin, the removal of endotoxin from sewage by percolation through soil was investigated. It was found that 90 to 99% of the endotoxin was removed after travel of sewage through 100 to 250 cm of loamy sand soil. When distilled water was allowed to infiltrate into the soil to simulate rainfall, the endotoxin was mobilized and moved in a concentrated band through the soil column. On testing samples from actual land treatment sites, as much as 480 ng of endotoxin per milliliter was found in some groundwater samples. The presence of endotoxin in potable water is known to be a potential problem under some circumstances, but the importance of endotoxin in water supplies has not been fully assessed. Therefore, the design, operation, and management of land application systems should take into account the fate of endotoxin in groundwater beneath the sites. PMID:7387154

  9. Exploring the Sulfur Nutrient Cycle Using the Winogradsky Column

    ERIC Educational Resources Information Center

    Rogan, Brian; Lemke, Michael; Levandowsky, Michael; Gorrell, Thomas

    2005-01-01

    The Winogradsky column demonstrates how the metabolic diversity of prokaryotes transforms sulfur to different forms with varying redox states and hence, supplies nutrients and/or energy to the organism. The Winogardsky column is an excellent way to show that not all bacteria are pathogens and they have an important role in the geochemical cycling…

  10. Twisting of thin walled columns perfectly restrained at one end

    NASA Technical Reports Server (NTRS)

    Lazzarino, Lucio

    1938-01-01

    Proceeding from the basic assumptions of the Batho-Bredt theory on twisting failure of thin-walled columns, the discrepancies most frequently encountered are analyzed. A generalized approximate method is suggested for the determination of the disturbances in the stress condition of the column, induced by the constrained warping in one of the end sections.

  11. SURFACTANT ENHANCED REMEDIATION OF SOIL COLUMNS CONTAMINATED BY RESIDUAL TETRACHLOROETHYLENE

    EPA Science Inventory

    The ability of aqueous surfactant solutions to recover tetrachloroethylene (PCE) entrapped in Ottawa sand was evaluated in four column experiments. Residual PCE was emplaced by injecting 14C-labeled PCE into water-saturated soil columns and displacing the free product ...

  12. 29 CFR 1926.756 - Beams and columns.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) General. (1) During the final placing of solid web structural members, the load shall not be released from... bracing. Solid web structural members used as diagonal bracing shall be secured by at least one bolt per... on opposite sides of a column web, or a beam web over a column, are connected sharing...

  13. An Automated Distillation Column for the Unit Operations Laboratory

    ERIC Educational Resources Information Center

    Perkins, Douglas M.; Bruce, David A.; Gooding, Charles H.; Butler, Justin T.

    2005-01-01

    A batch distillation apparatus has been designed and built for use in the undergraduate unit operations laboratory course. The column is fully automated and is accompanied by data acquisition and control software. A mixture of 1­-propanol and 2-­propanol is separated in the column, using either a constant distillate rate or constant composition…

  14. COLUMN EXPERIMENTS AND ANOMALOUS CONDUCTIVITY IN HYDROCARBON-IMPACTED SOILS

    EPA Science Inventory

    A laboratory experiment was designed to increase the understanding of the geoelectric effects of microbial " degradation of hydrocarbons. Eight large columns were were paired to provide a replicate of each of four experiments. These large-volume columns contained "sterilized" soi...

  15. Polyimide polymer glass-free capillary columns for gas chromatography.

    PubMed

    Webster, Jackie G; Marine, Susan S; Danielson, Neil D

    2011-01-01

    Polymeric polyimide capillary tubing, both uncoated and coated with stationary phases of two polarities, is explored for use as capillary columns for gas chromatography (GC). These glass-free polyimide columns are flexible and their small winding diameter of less than a cm around a solid support makes them compatible for potential use in portable GC instruments. Polyimide columns with dimensions of 0.32 mm i.d. × 3 m are cleaned, annealed at 300°C, and coated using the static method with phenylmethylsilicone (PMS). Separations of volatile organics are investigated isothermally on duplicate sets of polyimide columns by GC with a flame ionization detector using split injection. Unlike the uncoated ones, the coated polyimide columns successfully separate Grob test mix classes of alkanes, amines, and fatty acid methyl esters. The relative standard deviations for retention time and peak area are 0.5 and 2.5 , respectively. With the 3 m PMS-coated column connected to a retention gap to permit operation at its optimum flow rate of 30 cm/s, a plate count of 3200 or plate height of 1 mm is possible. Lack of retention and tailing peaks are evident for the polyimide polymer capillary columns as compared to that of a 3 m commercial cross-linked PMS fused silica capillary. However, headspace analyses of an aromatic hydrocarbon mix and a Clearcoat automotive paint sample are viable applications on the PMS polyimide polymer column. PMID:21682994

  16. Taxicab Correspondence Analysis of Contingency Tables with One Heavyweight Column

    ERIC Educational Resources Information Center

    Choulakian, V.

    2008-01-01

    The aim of this paper is to study the analysis of contingency tables with one heavyweight column or one heavyweight entry by taxicab correspondence analysis (TCA). Given that the mathematics of TCA is simpler than the mathematics of correspondence analysis (CA), the influence of one heavyweight column on the outputs of TCA is studied explicitly…

  17. Gas chromatographic column for the Viking 1975 molecular analysis experiment

    NASA Technical Reports Server (NTRS)

    Novotny, M.; Hayes, J. M.; Bruner, F.; Simmonds, P. G.

    1975-01-01

    A gas chromatographic column has been developed for use in the remote analysis of the Martian surface. The column, which utilizes a liquid-modified organic adsorbent (Tenax) as the stationary phase, provides efficient transmission and resolution of nanogram quantities of organic materials in the presence of millionfold excesses of water and carbon dioxide.

  18. Ultrasonic testing device having an adjustable water column

    SciTech Connect

    Roach, Dennis P.; Neidigk, Stephen O.; Rackow, Kirk A.; Duvall, Randy L.

    2015-09-01

    An ultrasonic testing device having a variable fluid column height is disclosed. An operator is able to adjust the fluid column height in real time during an inspection to to produce optimum ultrasonic focus and separate extraneous, unwanted UT signals from those stemming from the area of interest.

  19. A Better Method for Filling Pasteur Pipet Chromatography Columns

    ERIC Educational Resources Information Center

    Ruekberg, Ben

    2006-01-01

    An alternative method for the preparation of Pasteur pipet chromatography columns is presented that allows the column to be filled with solvent without bubbles and allows greater control of fluid flow while the materials to be separated are added. Students are required to wear gloves and goggles and caution should be used while handling glass…

  20. Seismic retrofitting of bridge columns using shape memory alloys

    NASA Astrophysics Data System (ADS)

    Andrawes, Bassem; Shin, Moochul

    2008-03-01

    This analytical work focuses on enhancing the ductility capacity and damage mitigation of reinforced concrete bridge columns during earthquakes by using innovative active confinement technique. The high recovery stress associated with the shape recovery of shape memory alloys (SMAs) is exploited to apply the confining pressure. A 2-D analytical model for a single column is developed and analyzed. The model is used to evaluate the seismic behavior of the column retrofitted with SMA rings and compare it with the behavior of the column retrofitted with the more conventional approach using carbon fiber reinforced polymer (CFRP) sheets. The stress-strain behavior of the concrete confined with internal ties only, internal ties and external SMA rings, and internal ties and external CFRP sheets is described based on two different constitutive models. The column model is subjected to cyclic loading with increasing amplitude and a ground motion excitation. The analysis shows that the SMA rings provide the column with more damage protection represented by a reduction in the maximum strain by up to 273% compared to CFRP sheets. In addition, the column retrofitted with SMA rings shows smaller lateral drifts compared to the column retrofitted with the CFRP sheets when subjected to the same ground motion excitation. The superior performance of the SMA rings is primarily attributed to the increase in the compressive strength at early stages of loading associated with applying the active confinement pressure.

  1. Stabilization of the Circulation Flow of the Cryogenic Distillation Column

    NASA Astrophysics Data System (ADS)

    Juromskiy, V. M.

    Two-circuit system of automatic stabilization of the hydrodynamics of the cryogenic distillation column is considered. Control system eliminates flooding/depletion of column in long-term mode of operation when the accuracy of stabilization of the circulation flow is better than 1%.

  2. THERMAL MODELING OF ION EXCHANGE COLUMNS WITH SPHERICAL RF RESIN

    SciTech Connect

    Lee, S.; King, W.

    2009-12-30

    Models have been developed to simulate the thermal performance of RF columns fully loaded with radioactive cesium. Temperature distributions and maximum temperatures across the column were calculated during Small Column Ion Exchange (SCIX) process upset conditions with a focus on implementation at Hanford. A two-dimensional computational modeling approach was taken to include conservative, bounding estimates for key parameters such that the results will provide the maximum centerline temperatures achievable under the design configurations using a feed composition known to promote high cesium loading on RF. The current full-scale design for the SCIX system includes a central cooling tube, and one objective of these calculations was to examine its elimination to simplify the design. Results confirmed that a column design without a central cooling tube is feasible for RF, allowing for the possibility of significant design simplifications if it can be assumed that the columns are always filled with liquid. With active cooling through the four outer tubes, the maximum column diameter expected to maintain the temperature below the assumed media and safety limits is 26 inches, which is comparable to the current design diameter. Additional analysis was conducted to predict the maximum column temperatures for the previously unevaluated accident scenario involving inadvertent drainage of liquid from a cesium-saturated column, with retention of the ion exchange media and cesium in the column. As expected, much higher maximum temperatures are observed in this case due to the poor heat transfer properties of air versus liquid. For this hypothetical accident scenario involving inadvertent and complete drainage of liquid from a cesium-saturated column, the modeling results indicate that the maximum temperature within a 28 inch diameter RF column with external cooling is expected to exceed 250 C within 2 days, while the maximum temperature of a 12 inch column is maintained below

  3. Experimental study of wave propagation dynamics of binary distillation columns

    SciTech Connect

    Hwang, Y.L.; Graham, G.K.; Keller, G.E. II; Ting, J.; Helfferich, F.G.

    1996-10-01

    High-purity distillation columns are typically difficult to control because of their severely nonlinear behavior reflected by their sharp composition and temperature profiles. The dynamic behavior of such a column, as characterized by the movement of its sharp profile, was elucidated by a nonlinear wave theory established previously. With binary alcohol mixtures, this study provides an experimental observation of such wave-propagation dynamics of a 40-tray stripping column and a 50-tray fractionation column in response to step disturbances of feed composition, feed flow rate, and reboiler heat supply. These experimental results have verified that the sharp profile in a high-purity column moves as a constant-pattern wave and that the nonlinear wave theory predicts its velocity satisfactorily with very simple mathematics. Results also demonstrate the asymmetric dynamics of the transitions between two steady states.

  4. Design, testing, and simulation of microscale gas chromatography columns

    SciTech Connect

    Hudson, M.L.; Kottenstette, R.; Matzke, C.M.; Frye-Mason, G.C.; Shollenberger, K.A.; Adkins, D.R.; Wong, C.C.

    1998-08-01

    A microscale gas chromatography column is one component in a microscale chemistry laboratory for detecting chemical agents. Several columns were fabricated using the Bosch etch process which allows deep, high aspect ratio channels of rectangular cross-section. A design tool, based on analytical models, was developed to evaluate the effects of operating conditions and column specifications on separation resolution and time. The effects of slip flow, channel configuration, and cross-sectional shape were included to evaluate the differences between conventional round, straight columns and the microscale rectangular, spiral columns. Experimental data were obtained and compared with the predicted flowrates and theoretical number of plates. The design tool was then employed to select more optimum channel dimensions and operating conditions for high resolution separations.

  5. HEAT TRANSFER ANALYSIS FOR ION-EXCHANGE COLUMN SYSTEM

    SciTech Connect

    Lee, S.; King, W.

    2011-05-23

    Models have been developed to simulate the thermal characteristics of Crystalline Silicotitanate (CST) ion exchange media fully loaded with radioactive cesium in a column configuration and distributed within a waste storage tank. This work was conducted to support the Small Column Ion Exchange (SCIX) program which is focused on processing dissolved, high-sodium salt waste for the removal of specific radionuclides (including Cs-137, Sr-90, and actinides) within a High Level Waste (HLW) storage tank at the Savannah River Site. The SCIX design includes CST columns inserted and supported in the tank top risers for cesium removal. Temperature distributions and maximum temperatures across the column were calculated with a focus on process upset conditions. A two-dimensional computational modeling approach for the in-column ion-exchange domain was taken to include conservative, bounding estimates for key parameters such that the results would provide the maximum centerline temperatures achievable under the design configurations using a feed composition known to promote high cesium loading on CST. The current full-scale design for the CST column includes one central cooling pipe and four outer cooling tubes. Most calculations assumed that the fluid within the column was stagnant (i.e. no buoyancy-induced flow) for a conservative estimate. A primary objective of these calculations was to estimate temperature distributions across packed CST beds immersed in waste supernate or filled with dry air under various accident scenarios. Accident scenarios evaluated included loss of salt solution flow through the bed, inadvertent column drainage, and loss of active cooling in the column. The modeling results demonstrate that the baseline design using one central and four outer cooling tubes provides a highly efficient cooling mechanism for reducing the maximum column temperature.

  6. Mitigation of Liquefaction in Sandy Soils Using Stone Columns

    NASA Astrophysics Data System (ADS)

    Selcuk, Levent; Kayabalı, Kamil

    2010-05-01

    Soil liquefaction is one of the leading causes of earthquake-induced damage to structures. Soil improvement methods provide effective solutions to reduce the risk of soil liquefaction. Thus, soil ground treatments are applied using various techniques. However, except for a few ground treatment methods, they generally require a high cost and a lot of time. Especially in order to prevent the risk of soil liquefaction, stone columns conctructed by vibro-systems (vibro-compaction, vibro-replacement) are one of the traditional geotechnical methods. The construction of stone columns not only enhances the ability of clean sand to drain excess pore water during an earthquake, but also increases the relative density of the soil. Thus, this application prevents the development of the excess pore water pressure in sand during earthquakes and keeps the pore pressure ratio below a certain value. This paper presents the stone column methods used against soil liquefaction in detail. At this stage, (a) the performances of the stone columns were investigated in different spacing and diameters of columns during past earthquakes, (b) recent studies about design and field applications of stone columns were presented, and (c) a new design method considering the relative density of soil and the capacity of drenage of columns were explained in sandy soil. Furthermore, with this new method, earthquake performances of the stone columns constructed at different areas were investigated before the 1989 Loma Prieta and the 1994 Northbridge earthquakes, as case histories of field applications, and design charts were compiled for suitable spacing and diameters of stone columns with consideration to the different sandy soil parameters and earhquake conditions. Key Words: Soil improvement, stone column, excess pore water pressure

  7. Novel techniques for slurry bubble column hydrodynamics

    SciTech Connect

    Dudukovic, M.P.

    1999-05-14

    The objective of this cooperative research effort between Washington University, Ohio State University and Exxon Research Engineering Company was to improve the knowledge base for scale-up and operation of slurry bubble column reactors for syngas conversion and other coal conversion processes by increased reliance on experimentally verified hydrodynamic models. During the first year (July 1, 1995--June 30, 1996) of this three year program novel experimental tools (computer aided radioactive particle tracking (CARPT), particle image velocimetry (PIV), heat probe, optical fiber probe and gamma ray tomography) were developed and tuned for measurement of pertinent hydrodynamic quantities, such as velocity field, holdup distribution, heat transfer and bubble size. The accomplishments were delineated in the First Technical Annual Report. The second year (July, 1996--June 30, 1997) was spent on further development and tuning of the novel experimental tools (e.g., development of Monte Carlo calibration for CARPT, optical probe development), building up the hydrodynamic data base using these tools and comparison of the two techniques (PIV and CARPT) for determination of liquid velocities. A phenomenological model for gas and liquid backmixing was also developed. All accomplishments were summarized in the Second Annual Technical Report. During the third and final year of the program (July 1, 1997--June 30, 1998) and during the nine months no cost extension, the high pressure facility was completed and a set of data was taken at high pressure conditions. Both PIV, CT and CARPT were used. More fundamental hydrodynamic modeling was also undertaken and model predictions were compared to data. The accomplishments for this period are summarized in this report.

  8. Column Grid Array Rework for High Reliability

    NASA Technical Reports Server (NTRS)

    Mehta, Atul C.; Bodie, Charles C.

    2008-01-01

    Due to requirements for reduced size and weight, use of grid array packages in space applications has become common place. To meet the requirement of high reliability and high number of I/Os, ceramic column grid array packages (CCGA) were selected for major electronic components used in next MARS Rover mission (specifically high density Field Programmable Gate Arrays). ABSTRACT The probability of removal and replacement of these devices on the actual flight printed wiring board assemblies is deemed to be very high because of last minute discoveries in final test which will dictate changes in the firmware. The questions and challenges presented to the manufacturing organizations engaged in the production of high reliability electronic assemblies are, Is the reliability of the PWBA adversely affected by rework (removal and replacement) of the CGA package? and How many times can we rework the same board without destroying a pad or degrading the lifetime of the assembly? To answer these questions, the most complex printed wiring board assembly used by the project was chosen to be used as the test vehicle, the PWB was modified to provide a daisy chain pattern, and a number of bare PWB s were acquired to this modified design. Non-functional 624 pin CGA packages with internal daisy chained matching the pattern on the PWB were procured. The combination of the modified PWB and the daisy chained packages enables continuity measurements of every soldered contact during subsequent testing and thermal cycling. Several test vehicles boards were assembled, reworked and then thermal cycled to assess the reliability of the solder joints and board material including pads and traces near the CGA. The details of rework process and results of thermal cycling are presented in this paper.

  9. Miniature Distillation Column for Producing LOX From Air

    NASA Technical Reports Server (NTRS)

    Rozzi, Jay C.

    2006-01-01

    The figure shows components of a distillation column intended for use as part of a system that produces high-purity liquid oxygen (LOX) from air by distillation. (The column could be easily modified to produce high-purity liquid nitrogen.) Whereas typical industrial distillation columns for producing high-purity liquid oxygen and/or nitrogen are hundreds of feet tall, this distillation column is less than 3 ft (less than about 0.9 m) tall. This column was developed to trickle-charge a LOX-based emergency oxygen system (EOS) for a large commercial aircraft. A description of the industrial production of liquid oxygen and liquid nitrogen by distillation is prerequisite to a meaningful description of the present miniaturized distillation column. Typically, such industrial production takes place in a chemical processing plant in which large quantities of high-pressure air are expanded in a turboexpander to (1) recover a portion of the electrical power required to compress the air and (2) partially liquefy the air. The resulting two-phase flow of air is sent to the middle of a distillation column. The liquid phase is oxygen-rich, and its oxygen purity increases as it flows down the column. The vapor phase is nitrogen-rich and its nitrogen purity increases as it flows up the column. A heater or heat exchanger, commonly denoted a reboiler, is at the bottom of the column. The reboiler is so named because its role is to reboil some of the liquid oxygen collected at the bottom of the column to provide a flow of oxygen-rich vapor. As the oxygen-rich vapor flows up the column, it absorbs the nitrogen in the down-flowing liquid by mass transfer. Once the vapor leaves the lower portion of the column, it interacts with down-flowing nitrogen liquid that has been condensed in a heat exchanger, commonly denoted a condenser, at the top of the column. Liquid oxygen and liquid nitrogen products are obtained by draining some of the purified product at the bottom and top of the column

  10. Internet delivered question and answer column for patients with schizophrenia.

    PubMed

    Maijala, Riikka; Anttila, Minna; Koivunen, Marita; Pitkänen, Anneli; Kuosmanen, Lauri; Välimäki, Maritta

    2015-01-01

    The purpose of this study was to describe the use of an Internet delivered question and answer column among patients with schizophrenia. The column was developed for research purposes. The study sample consisted of patients (N = 100) admitted to acute inpatient psychiatric care in two hospital districts. Descriptive data were collected from the column to which a nurse replied within 3 days and analysed using qualitative content analysis. The column had four to five questions weekly. The most common age of users was 18-24 years, and the gender distribution was almost equal. Column use was heaviest among students (44%) and least among unemployed people (19%). Out of 85 questions or comments sent to the column, 25 (29%) were related to program training and the remaining 60 (71%) were related to medication (31%), illness and tests (25%), other questions or comments (9%), daily life and coping with it (4%), and places to receive treatment (2%). An Internet delivered question and answer column can be included in the care of patients with schizophrenia. However, it requires a new type of basic and additional education in the field of mental health care in order for nurses to be able to provide nursing via the Internet forum. PMID:24960233

  11. Sources of Variability in the Stratospheric Column of Nitrogen Dioxide

    NASA Technical Reports Server (NTRS)

    Douglass, Anne; Gleason, James; Chin, Mian; Einaudi, Franco (Technical Monitor)

    2001-01-01

    Instruments such as the Global Ozone Monitoring Experiment (GOME, on the European Remote Sensing Satellite (ERS-2), launched 1995), the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY, on ENVISAT, to be launched July 2001) and the Ozone Monitoring Instrument (OMI on EOS Aura, to be launched 2003) make measurements of the total column of NO2. There is interest in separating the stratospheric and tropospheric contributions to the column, as the tropospheric column provides a measure of pollution. We are using a 3D chemistry and transport model driven by winds from the Goddard Space Flight Center Data Assimilation System to examine variability in the stratospheric NO2 column. Model results for NOx = NO + NO2 + 2N2O5 will be shown to compare well with sunset observations from the Halogen Occultation Experiment on the Upper Atmosphere Research Satellite, and to exhibit similar temporal and spatial dependence. Partitioning between NO, NO2, and N2O5 is also shown to compare well with observations. This good agreement supports the use of simulated fields in the stratosphere to derive the tropospheric column from the total column. Preliminary comparisons of the tropospheric column with model simulations for the troposphere will also be shown.

  12. Interpreting satellite column observations of formaldehyde over tropical South America.

    PubMed

    Palmer, Paul I; Barkley, Michael P; Kurosu, Thomas P; Lewis, Alastair C; Saxton, Julie E; Chance, Kelly; Gatti, Luciana V

    2007-07-15

    Space-borne column measurements of formaldehyde (HCHO), a high-yield oxidation product of volatile organic compounds (VOCs), represent important constraints for quantifying net regional fluxes of VOCs. Here, we interpret observed distributions of HCHO columns from the Global Ozone Monitoring Experiment (GOME) over tropical South America during 1997-2001. We present the first comparison of year-long in situ isoprene concentrations and fire-free GOME HCHO columns over a tropical ecosystem. GOME HCHO columns and in situ isoprene concentrations are elevated in the wet and dry seasons, with the highest values in the dry season. Previous analysis of the in situ data highlighted the possible role of drought in determining the elevated concentrations during the dry season, inferring the potential of HCHO columns to provide regional-scale constraints for estimating the role of drought on isoprene emissions. The agreement between the observed annual cycles of GOME HCHO columns and Along-Track Scanning Radiometer firecount data over the Amazon basin (correlations typically greater than 0.75 for a particular year) illustrates the potential of HCHO column to provide quantitative information about biomass burning emissions. PMID:17513262

  13. In-plant testing of microbubble column flotation

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.; Adel, G.T.

    1989-01-01

    A project to evaluate the performance of the Virginia Tech Microbubble Column Flotation (MCF) process in an operating coal preparation plant was initiated during this past quarter. The project is concerned with the collection of process operating data using a 30-inch diameter column, and using this data to scale-up to a prototype, full-scale plant column. The work is being carried out at the Marrowbone Preparation Plant owned by the Shell Mining Corporation. Work has primarily concentrated on finalizing the project work plan (Task 2.1 -- Project Planning), instrumenting the 30-inch diameter column (Task 2.2 -- Advanced Instrumentation) and conducting a preliminary parametric study to evaluate the performance of the column (Task 2.3 -- Detailed Testing). To date, the column has been consistently capable of producing a 9.5% ash product at a 61% combustible recovery from a -150 mesh classifying cyclone overflow containing 55--60% ash at 3--5% solids. Tests conducted over an extended period of time indicate that the column consistently maintains grade in spite of fluctuations in the feed characteristics. 12 figs.

  14. Self-Consistent Monte Carlo Simulations of Positive Column Discharges

    NASA Astrophysics Data System (ADS)

    Lawler, J. E.; Kortshagen, U.

    1998-10-01

    In recent years it has become widely recognized that electron distribution functions in atomic gas positive column discharges are best described as non local over most of the range of R× N (column radius × gas density) where positive columns are stable. The use of an efficient Monte Carlo code with a radial potential expansion in powers of r^2 and with judiciously chosen constraints on the potential near the axis and wall now provides fully self-consistent kinetic solutions using only small computers. A set of solutions at smaller R× N and lower currents are presented which exhibit the classic negative dynamic resistance of the positive column at low currents. The negative dynamic resistance is due to a non-negligible Debye length and is sometimes described as a transition from free to ambipolar diffusion. This phenomenon is sensitive to radial variations of key parameters in the positive column and thus kinetic theory simulations are likely to provide a more realistic description than classic isothermal fluid models of the positive column. Comparisons of kinetic theory simulations to various fluid models of the positive column continue to provide new insight on this `corner stone' problem of Gaseous Electronics.

  15. Investigation of Gas Holdup in a Vibrating Bubble Column

    NASA Astrophysics Data System (ADS)

    Mohagheghian, Shahrouz; Elbing, Brian

    2015-11-01

    Synthetic fuels are part of the solution to the world's energy crisis and climate change. Liquefaction of coal during the Fischer-Tropsch process in a bubble column reactor (BCR) is a key step in production of synthetic fuel. It is known from the 1960's that vibration improves mass transfer in bubble column. The current study experimentally investigates the effect that vibration frequency and amplitude has on gas holdup and bubble size distribution within a bubble column. Air (disperse phase) was injected into water (continuous phase) through a needle shape injector near the bottom of the column, which was open to atmospheric pressure. The air volumetric flow rate was measured with a variable area flow meter. Vibrations were generated with a custom-made shaker table, which oscillated the entire column with independently specified amplitude and frequency (0-30 Hz). Geometric dependencies can be investigated with four cast acrylic columns with aspect ratios ranging from 4.36 to 24, and injector needle internal diameters between 0.32 and 1.59 mm. The gas holdup within the column was measured with a flow visualization system, and a PIV system was used to measure phase velocities. Preliminary results for the non-vibrating and vibrating cases will be presented.

  16. Miniature electron microscope beam column optics

    NASA Astrophysics Data System (ADS)

    Loyd, Jody Stuart

    This investigation is in the area of electrostatic lens design with the overarching goal of contributing to the creation of a miniaturized scanning electron microscope (SEM) for use in mineralogical analysis or detection of signs of life on the surface of Mars. Such an instrument could also have application in the exploration of Earth's moon, planetary moons, asteroids, or comets. Other embodiments could include tabletop or field portable SEMs for use on Earth. The scope of this research is in the design of a beam column that attains focusing, demagnification, and aberration control within the smallest achievable package. The goals of planetary exploration and of spaceflight in general impose severe constraints on the instrument's mass and electrical power consumption, while favoring a robust design of small size and high rigidity that is also simple to align. To meet these requirements a design using electrostatic lenses was favored because of the lower power requirement and mass of electrostatic versus magnetic lenses, their relatively simple construction, as well as inherently easier shielding from extraneous fields. In modeling the lens field, a hybrid of a Boundary Element Method (BEM) and a Fourier series solution was employed, whereby an initial solution from the BEM is used to derive the bounding potential of a cylindrical subdomain for the subsequent Fourier series solution. The approach is applicable to many problems in physics and combines the inherent precision of this series solution with the flexibility of BEM to describe practical, non-idealized electrode shapes. The resulting lens field in the Fourier series subdomain is of higher precision, thereby allowing smaller errors in subsequent calculations of electron ray paths. The effects of aberrations are thus easier to observe in tracing non-paraxial rays. A significant speed increase in tracing rays is also observed. The modeling technique has been validated by reproducing example ray-traces through

  17. Mass partitioning in transitional Plinian columns

    NASA Astrophysics Data System (ADS)

    Carazzo, G.; Kaminski, E.; Tait, S.

    2012-12-01

    The transitional regime of explosive volcanic eruptions is characterized by the coexistence of a stable atmospheric ash plume and an unstable ash fountain collapsing at ground level. Building a detailed understanding of the dynamics of this transitional behavior is of crucial importance for hazard assessment. Elaborate 3D numerical models are commonly used to identify the conditions separating the types of explosive volcanic flow regimes. To develop an alternative approach, we present new laboratory-scale experiments, which consist of injecting upwards a mixture of hot gas and hot particles at a fixed rate into a large chamber of atmospheric air at ambient temperature. The range of conditions imposed at the source allows us to reproduce the main forces acting on the dynamics of a volcanic plume, as inferred from our scaling analysis. The laboratory experiments presented here reproduce closely the different types of flow behavior observed during explosive eruptions, including the transitional regime. We show that the threshold condition for the triggering of the transitional regime is well described by a simple Top-Hat formalism. Furthermore, we identify a key stability parameter controlling the mass partitioning between convective material and collapsing flow that allows us to define a universal scaling relationship. In volcanic plumes, this stability number is found to be sensitive to the magmatic temperature and, to a lesser extent, to the source gas content. It does not depend on the mass discharge rate, even though this parameter strongly controls the initiation of the partial collapse regime. An exhaustive review of geological data on past explosive eruptions suggests that the stability parameter captures well the physics of partial collapse, and can be used to predict the mass of material that will flow to the ground once the eruption column has entered the partial collapse regime. Therefore, our experimentally-determined scaling law coupled with a simple Top

  18. Inner-pipe structure to improve column heterogeneity and peak shape.

    PubMed

    Hu, Di; Mei, Xiang; Shi, Pengchao; Zhou, Xin

    2015-04-01

    Column heterogeneity plays an important role in peak tailing and asymmetric profiles. We have designed a novel column structure (concentric column structure) that has a concentric inner-pipe nested in a column. This structure was studied by a number calculation method and wider diameter column experiments. The results showed that column heterogeneity and column efficiency were improved by inner-pipe structure. Moreover, the results showed that high-efficiency columns were stronger influenced by inner-pipe structure than low-efficiency columns. The influence of an inner-pipe was related to its size. The optimal inner-pipe diameter was nearly 0.625 times of column diameter. By using inner-pipe structure in this way, it was possible to decrease column heterogeneity and increase column efficiency of a wide-diameter column. PMID:25048455

  19. Buckling instability of self-assembled colloidal columns.

    PubMed

    Swan, James W; Vasquez, Paula A; Furst, Eric M

    2014-09-26

    Suspended, slender self-assembled domains of magnetically responsive colloids are observed to buckle in microgravity. Upon cessation of the magnetic field that drives their assembly, these columns expand axially and buckle laterally. This phenomenon resembles the buckling of long beams due to thermal expansion; however, linear stability analysis predicts that the colloidal columns are inherently susceptible to buckling because they are freely suspended in a Newtonian fluid. The dominant buckling wavelength increases linearly with column thickness and is quantitatively described using an elastohydrodynamic model and the suspension thermodynamic equation of state. PMID:25302919

  20. Buckling Instability of Self-Assembled Colloidal Columns

    NASA Astrophysics Data System (ADS)

    Swan, James W.; Vasquez, Paula A.; Furst, Eric M.

    2014-09-01

    Suspended, slender self-assembled domains of magnetically responsive colloids are observed to buckle in microgravity. Upon cessation of the magnetic field that drives their assembly, these columns expand axially and buckle laterally. This phenomenon resembles the buckling of long beams due to thermal expansion; however, linear stability analysis predicts that the colloidal columns are inherently susceptible to buckling because they are freely suspended in a Newtonian fluid. The dominant buckling wavelength increases linearly with column thickness and is quantitatively described using an elastohydrodynamic model and the suspension thermodynamic equation of state.

  1. SENSITIVITY ANALYSIS FOR SALTSTONE DISPOSAL UNIT COLUMN DEGRADATION ANALYSES

    SciTech Connect

    Flach, G.

    2014-10-28

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

  2. Modeling Cooling Rates of Martian Flood Basalt Columns

    NASA Astrophysics Data System (ADS)

    Weiss, D. K.; Jackson, B.; Milazzo, M. P.; Barnes, J. W.

    2011-12-01

    Columnar jointing in large basalt flows have been extensively studied and can provide important clues about the emplacement conditions and cooling history of a basalt flow. The recent discovery of basalt columns on Mars in crater walls near Marte Vallis provides an opportunity to infer conditions on early Mars when the Martian basalt flows were laid down. Comparison of the Martian columns to Earth analogs allows us to gain further insight into the early Martian climate, and among the best terrestrial analogs are the basalt columns in the Columbia River Basalt Group (CRBG) in eastern Washington. The CRBG is one of the youngest (< 17 Myrs old) and most extensively studied basalt provinces in the world, extending over 163,700 square km with total thickness exceeding 1 km in some places. The morphologies and textures of CRBG basalt columns suggest that in many places flows ~100 m thick cooled at uniform rates, even deep in the flow interior. Such cooling seems to require the presence of water in the column joints since the flow interiors should have cooled much more slowly than the flow margins if conductive cooling dominated. Secondary features, such pillow basalts, likewise suggest the basalt flows were in direct contact with standing water in many places. At the resolution provided by the orbiting HiRISE camera (0.9 m), the Martian basalt columns resemble the CRBG columns in many respects, and so, subject to important caveats, inferences linking the morphologies of the CRBG columns to their thermal histories can be extended in some respects to the Martian columns. In this presentation, we will describe our analysis of the HiRISE images of the Martian columns and what can be reasonably inferred about their thermal histories and the conditions under which they were emplaced. We will also report on a field expedition to the CRBG in eastern Washington State. During that expedition, we surveyed basalt column outcrops on the ground and from the air using Unmanned Aerial

  3. Mathematical modeling of three-phase slurry bubble column reactors

    SciTech Connect

    Gamwo, I.K.; Soong, Y.; Schehl, R.R.; Zarochak, M.F.

    1994-12-31

    The behavior of gas-solid-liquid flow in a slurry bubble column reactor was simulated using a well-posed hydrodynamic model. The three phases under study are nitrogen, 5-{mu}m iron oxide, and SASOL wax. The phases volume fractions at various axial and radial positions in the column were computed. Preliminary results of axial solid volume fractions are consistent with experimental observations and demonstrate the potential of this method for design of such reactors. The overall objective of this study is to develop experimentally verified hydrodynamic and Fisher-Tropsch reaction models for slurry bubble column reactors.

  4. Stone Columns - Determination of the soil improvement factor

    NASA Astrophysics Data System (ADS)

    Pivarč, J.

    2011-09-01

    A stone column is one of the soil stabilizing methods that is used to increase strength, decrease the compressibility of soft and loose fine graded soils, accelerate a consolidation effect and reduce the liquefaction potential of soils. The columns consist of compacted gravel or crushed stone arranged by a vibrator. This paper deals with Priebe's theory (1976) on the design of an improvement factor, which belongs among the most used analytical methods and also describes the numerical and laboratory models of stone columns. The improvement factors calculated from numerical and laboratory models are compared with the improvement factors resulting from Priebe's theory.

  5. MODELING AND SIMULATION OF SOLID FLUIDIZATION IN A RESIN COLUMN

    SciTech Connect

    Lee, S.

    2014-06-24

    The objective of the present work is to model the resin particles within the column during fluidization and sedimentation processes using computation fluid dynamics (CFD) approach. The calculated results will help interpret experimental results, and they will assist in providing guidance on specific details of testing design and establishing a basic understanding of particle’s hydraulic characteristics within the column. The model is benchmarked against the literature data and the test data (2003) conducted at Savannah River Site (SRS). The paper presents the benchmarking results and the modeling predictions of the SRS resin column using the improved literature correlations applicable for liquid-solid granular flow.

  6. Polarized light based scheme to monitor column performance in a continuous foam fractionation column

    PubMed Central

    2010-01-01

    Background A polarized light scattering technique was used to monitor the performance of a continuously operated foam fractionation process. The S11 and S12 parameters, elements of the light scattering matrix, combined together (S11+S12) have been correlated with the bubble size and liquid content for the case of a freely draining foam. The performance of a foam fractionation column is known to have a strong dependence on the bubble size distribution and liquid hold up in foam. In this study the enrichment is used as a metric, representative of foam properties and column performance, and correlated to the S11+S12 parameter. Results Three different superficial gas velocities (6.9, 7.5, and 10.6 cm/min) and four different pH values (4.8, 5.5, 6.5, and 7.5) are tested for the foam fractionation of a dilute solution of bovine serum albumin (0.1 mg/ml). As a result, at scattering angle of 125° the magnitude of S11+S12 is higher as the pH increases. When the bubble sizes are small with a larger liquid content, the foam is strongly back scattering resulting in lower values of S11+S12 (at 125°) at pH = 4.8. The light scattering data and the enrichment values are measured over a period of 90 minutes and correlated using a linear model. The predictive power of the model was found to be statistically significant. Conclusion The time average S11+S12 shows a direct proportionality with the enrichment value, indicating that polarized light should be a valuable technique for monitoring foam fractionation columns. Additional knowledge of the nature of dependence between foam properties and S11+S12 combined with models relating the enrichment to the bubble size and liquid hold up is needed to develop an accurate diagnostics tool for monitoring enrichment utilizing S11+S12 measurements. PMID:20398336

  7. Ion chromatographic separation of inorganic ions using a combination of hydrophilic interaction chromatographic column and cation-exchange resin column.

    PubMed

    Arai, Kaori; Mori, Masanobu; Hironaga, Takahiro; Itabashi, Hideyuki; Tanaka, Kazuhiko

    2012-04-01

    A combination of hydrophilic interaction chromatographic (HILIC) column and a weakly acidic cation-exchange resin (WCX) column was used for simultaneous separation of inorganic anions and cations by ion chromatography (IC). Firstly, the capability of HILIC column for the separation of analyte ions was evaluated under acidic eluent conditions. The columns used were SeQuant ZIC-HILIC (ZIC-HILIC) with a sulfobetaine-zwitterion stationary phase (ZIC-HILIC) and Acclaim HILIC-10 with a diol stationary phase (HILIC-10). When using tartaric acid as the eluent, the HILIC columns indicated strong retentions for anions, based on ion-pair interaction. Especially, HILIC-10 could strongly retain anions compared with ZIC-HILIC. The selectivity for analyte anions of HILIC-10 with 5 mmol/L tartaric acid eluent was in the order of I(-) > NO3(-) > Br(-) > Cl(-) > H2PO4(-). However, since HILIC-10 could not separate analyte cations, a WCX column (TSKgel Super IC-A/C) was connected after the HILIC column in series. The combination column system of HILIC and WCX columns could successfully separate ten ions (Na+, NH4+, K+, Mg2+, Ca2+, H2PO4(-), Cl(-), Br(-), NO3(-) and I(-)) with elution of 4 mmol/L tartaric acid plus 8 mmol/L 18-crown-6. The relative standard deviations (RSDs) of analyte ions by the system were in the ranges of 0.02% - 0.05% in retention times and 0.18% - 5.3% in peak areas through three-time successive injections. The limits of detection at signal-to-noise ratio of 3 were 0.24 - 0.30 micromol/L for the cations and 0.31 - 1.2 micromol/L for the anions. This system was applied for the simultaneous determination of the cations and the anions in a vegetable juice sample with satisfactory results. PMID:22799200

  8. Eye of origin guides attention away: An ocular singleton column impairs visual search like a collinear column.

    PubMed

    Chow, Hiu Mei; Jingling, Li; Tseng, Chia-huei

    2016-01-01

    Collinearity and eye of origin were recently discovered to guide attention: Target search is impaired if it is overlapping with a collinear structure (Jingling & Tseng, 2013) but enhanced if the target is an ocular singleton (Zhaoping, 2008). Both are proposed to occur in V1, and we study their interaction here. In our 9 × 9 search display (Experiment 1), all columns consisted of horizontal bars except for one randomly selected column that contained orthogonal bars (collinear distractor). All columns were presented to one eye except for a randomly selected column that was presented to the other eye (ocular distractor). The target could be located on a distractor column (collinear congruent [CC]/ocular congruent [OC]) or not (collinear incongruent [CI]/ocular incongruent [OI]). We expected to find the best search performance for OC + CI targets and the worst search performance for OI + CC targets. The other combinations would depend on the relative strength of collinearity and ocular information in guiding attention. As expected, we observed collinear impairment, but surprisingly, we did not observe any search advantage for OC targets. Our subsequent experiments confirmed that OC search impairment also occurred when color-defined columns (Experiment 2), ocular singletons (Experiments 4 and 5), and noncollinear columns (Experiment 5) were used instead of collinear columns. However, the ocular effect disappeared when paired with luminance-defined columns (Experiments 3A and 3B). Although our results agree well with earlier findings that eye-of-origin information guides attention, they highlight that our previous understanding of search advantage by ocular singleton targets might have been oversimplified. PMID:26790844

  9. INTERIOR VIEW OF THE FIRST FLOOR, SHOWING COLUMNS WITH CONICAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF THE FIRST FLOOR, SHOWING COLUMNS WITH CONICAL CAPITALS. VIEW FACING SOUTH. - U.S. Naval Base, Pearl Harbor, Aviation Storehouse, Vincennes Avenue at Simms Street, Pearl City, Honolulu County, HI

  10. 8. INTERIOR OF BUILDING 242, SHOWING STRUCTURAL COLUMNS AND ROOF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. INTERIOR OF BUILDING 242, SHOWING STRUCTURAL COLUMNS AND ROOF TRUSSES. VIEW TO SOUTH. - Rocky Mountain Arsenal, Chlorine Production Cell Building, 405 feet South of December Seventh Avenue; 330 feet West of D Street, Commerce City, Adams County, CO

  11. 7. DETAIL VIEW SHOWING CONNECTION OF BRIDGE COLUMN, TRUSS, TOP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. DETAIL VIEW SHOWING CONNECTION OF BRIDGE COLUMN, TRUSS, TOP BEAM, AND ARCHED CROSS MEMBER. NOTE KNEE BRACE FOR CROSS MEMBER AND DIAGONAL TENSION BAR - Heber Creeper Railroad Line, Olmstead Bridge, Spanning Provo River, Provo, Utah County, UT

  12. View of first level from north showing interstitial structural columns ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of first level from north showing interstitial structural columns for the Shuttle assemble configuration. - Marshall Space Flight Center, Saturn V Dynamic Test Facility, East Test Area, Huntsville, Madison County, AL

  13. VIEW OF TWO HEAVY WATER STORAGE TANKS (BEHIND SUPPORT COLUMNS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF TWO HEAVY WATER STORAGE TANKS (BEHIND SUPPORT COLUMNS AND STEEL BEAMS), SUB-BASEMENT LEVEL -27’, LOOKING SOUTHWEST - Physics Assembly Laboratory, Area A/M, Savannah River Site, Aiken, Aiken County, SC

  14. INTERIOR FOURTH FLOOR, SOUTH HALF, LOOKING SOUTH. NOTE MUSHROOM COLUMNS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR FOURTH FLOOR, SOUTH HALF, LOOKING SOUTH. NOTE MUSHROOM COLUMNS AND CEILING HAS WOODEN NAILERS. - Colt Fire Arms Company, North Armory, 36-150 Huyshope Avenue, 17-170 Van Dyke Avenue, 49 Vredendale Avenue, Hartford, Hartford County, CT

  15. Detail of large, brick columns and bracket inside Electrical Shop ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of large, brick columns and bracket inside Electrical Shop - Central of Georgia Railway, Savannah Repair Shops & Terminal Facilities, Electrical Shop, Bounded by West Broad, Jones, West Boundary & Hull Streets, Savannah, Chatham County, GA

  16. 17. VIEW OF UNDERSTRUCTURE, SWAY BRACING IN FOREGROUND, COLUMNS, AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. VIEW OF UNDERSTRUCTURE, SWAY BRACING IN FOREGROUND, COLUMNS, AND DECK SOFFIT, LOOKING NORTHEAST TO NORTH ABUTMENT - Chili Bar Bridge, Spanning South Fork of American River at State Highway 193, Placerville, El Dorado County, CA

  17. 18. VIEW OF UNDERSTRUCTURE, SHOWING ARCH RIBS, COLUMNS, AND SWAY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. VIEW OF UNDERSTRUCTURE, SHOWING ARCH RIBS, COLUMNS, AND SWAY BRACING, LOOKING SOUTHWEST FROM NORTH ABUTMENT - Chili Bar Bridge, Spanning South Fork of American River at State Highway 193, Placerville, El Dorado County, CA

  18. Novel Design for Centrifugal Countercurrent Chromatography: I. Zigzag Toroidal Column.

    PubMed

    Yang, Yi; Aisa, Haji Akber; Ito, Yoichiro

    2009-01-01

    The toroidal coil using an equilateral triangular core has improved both retention of the stationary phase and peak resolution of the conventional toroidal coil in centrifugal countercurrent chromatography. To further improve the retention of stationary phase and peak resolution, a novel zigzag toroidal coil was designed and the performance of the system was evaluated at various flow rates. The results indicated that both retention of stationary phase and peak resolution were improved as the flow rate was decreased. Modification of the tubing by pressing at given intervals with a pair of pliers improved the peak resolution without increasing the column pressure. All these separations were performed under low column pressure indicating the separation can be further improved by increasing the column length and/or revolution speed without damaging the separation column. PMID:20046954

  19. Optimization of bubble column performance for nanoparticle collection.

    PubMed

    Cadavid-Rodriguez, M C; Charvet, A; Bemer, D; Thomas, D

    2014-04-30

    Fibrous media embody the most effective and widely used method of separating ultrafine particles from a carrier fluid. The main problem associated with them is filter clogging, which induces an increasingly marked pressure drop with time and thus imposes regular media cleaning or replacement. This context has prompted the idea of investigating bubble columns, which operate at constant pressure drop, as alternatives to fibrous filters. This study examines the influence of different operating conditions, such as liquid height, air flow rate, bubble size and presence of granular beds on ultrafine particle collection. Experimental results show that bubble columns are characterised by high collection efficiency, when they feature a large liquid height and small diameter bubbling orifices, while their efficiencies remain lower than those of fibrous filters. Gas velocity does not greatly influence collection efficiency, but the inclusion of a granular bed, composed of beads, increases the bubble residence time in the column, thereby increasing the column collection efficiency. PMID:24584069

  20. 22. TYPICAL FOR THE FIRST FLOOR INTERIORS, ARE PAIRED COLUMN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. TYPICAL FOR THE FIRST FLOOR INTERIORS, ARE PAIRED COLUMN PILASTERS IN KEENE CEMENT PLASTER. BASE OF PILASTER IS SHOWN. - Pacific Telephone & Telegraph Company Building, 1519 Franklin Street, Oakland, Alameda County, CA

  1. Groundwater arsenic remediation using zerovalent iron: Batch and column tests

    EPA Science Inventory

    Recently, increasing efforts have been made to explore the applicability and limitations of zerovalent iron (Fe0) for the treatment of arsenicbearing groundwater and wastewater. The experimental batch and column tests have demonstrated that arsenate and arsenite are removed effec...

  2. 9. Arch CD ring and spandrel column detail. View east ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Arch C-D ring and spandrel column detail. View east - Ashton Viaduct, State Route 116 (Washington Highway) spanning Blackstone River, Blackstone Canal, & Providence & Worcester Railroad, Ashton, Providence County, RI

  3. 12. East abutment and approach span column detail. View east ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. East abutment and approach span column detail. View east - Ashton Viaduct, State Route 116 (Washington Highway) spanning Blackstone River, Blackstone Canal, & Providence & Worcester Railroad, Ashton, Providence County, RI

  4. Behavior of the mass transfer zone in a biosorption column.

    PubMed

    Naja, Ghinwa; Volesky, Bohumil

    2006-06-15

    Modeling of the mass transfer zone behavior under variable conditions in a flow-through fixed-bed sorption column enabled the prediction of breakthrough curves for Cu2+ and Ca-preloaded Sargassum fluitans biomass. The mass transfer resistance, particle diffusion, and the axial dispersion were incorporated in the model. The dynamics of the mass transfer zone was described under variable sorption column operating conditions including different column lengths and fluid flow rates. Accurate estimation of the behavior of the mass transfer zone as it progressed through the column, reflected eventually in the breakthrough curve, assisted in its relevant interpretations. Furthermore, the proposed mathematical model of the biosorption process was capable of demonstrating the expanding and broadening of the mass transfer zone linked to the equilibrium sorption isotherm. The fundamental understanding of the mass transfer zone dynamics is particularly important for process scale-up where maintaining the process efficiency is critical. PMID:16830573

  5. 9. Detail view of typical wooden column and beam connection, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Detail view of typical wooden column and beam connection, located in second floor carding room of 1866 section of mill. - Riverdale Cotton Mill, Corner of Middle & Lower Streets, Valley, Chambers County, AL

  6. Plane shock wave interaction with a cylindrical water column

    NASA Astrophysics Data System (ADS)

    Sembian, S.; Liverts, M.; Tillmark, N.; Apazidis, N.

    2016-05-01

    A complex system of waves propagating inside a water column due to the impact of plane shock wave is investigated both experimentally and numerically. Flow features, such as, focusing of expansion waves generating large negative pressure, nucleation of cavitation bubbles, and a re-circulation zone are observed and discussed qualitatively and quantitatively. Experiments are conducted on a 22 mm diametrical water column hit by shock waves with Mach numbers 1.75 and 2.4 in a newly constructed exploding wire facility. A new technique to create a properly shaped, repeatable, large diameter water column with straight walls is presented. Qualitative features of the flow are captured using the shadowgraph technique. With the aid of numerical simulations the wave motions inside the column are analyzed; the spatial location of the expansion wave focusing point and the corresponding negative peak pressures is estimated.

  7. The stresses in columns under combined axial and side loads

    NASA Technical Reports Server (NTRS)

    Arnstein, Karl

    1922-01-01

    The problem before us is to determine the total stresses in an axially loaded column of any degree of restraint which is also subject to transverse bending both from a uniformly distributed load and from concentrated loads.

  8. Flexural rigidity of biaxially loaded reinforced concrete rectangular column sections

    NASA Astrophysics Data System (ADS)

    Resheidat, M.; Ghanma, M.; Sutton, C.; Chen, Wai-Fah

    1995-05-01

    An exact analysis is carried out utilizing the parabola-rectangle stress-strain curve for concrete and a typical idealized stress-strain curve for steel to develop the moment-curvature relationship for biaxially loaded reinforced concrete rectangular column sections. Based on that, the flexural rigidity EI of the section is determined at the yield curvature. A computer program is written by FORTRAN 77 to handle the required computations. The influence of material properties, the effect of steel ratios, and the impact of axial loads on the EI estimation were investigated. This study leads to the development of a new equation to estimate the flexural rigidity EI of reinforced concrete biaxially loaded rectangular columns in which these factors were considered. It is shown that the new equation stems from the actual behavior of the column. Therefore, it is recommended for general use in the design of slender columns.

  9. Interior view of first floor lobby with detail of columns; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view of first floor lobby with detail of columns; camera facing north. - Mare Island Naval Shipyard, Hospital Headquarters, Johnson Lane, west side at intersection of Johnson Lane & Cossey Street, Vallejo, Solano County, CA

  10. Detail of columns, cornice and eaves; camera facing southwest. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of columns, cornice and eaves; camera facing southwest. - Mare Island Naval Shipyard, Hospital Headquarters, Johnson Lane, west side at intersection of Johnson Lane & Cossey Street, Vallejo, Solano County, CA

  11. Looking East at Motor Control System, Clarity Columns and Blend ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Looking East at Motor Control System, Clarity Columns and Blend Tank Along East Side of Recycle Recovery Building - Hematite Fuel Fabrication Facility, Recycle Recovery Building, 3300 State Road P, Festus, Jefferson County, MO

  12. 27. VIEW WEST, TYPICAL DOUBLE CONCRETE COLUMN AT EXPANSION JOINT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. VIEW WEST, TYPICAL DOUBLE CONCRETE COLUMN AT EXPANSION JOINT - Route 1 Extension, Southbound Viaduct, Spanning Conrail Yards, Wilson Avenue, Delancy Street, & South Street on Routes 1 & 9 Southbound, Newark, Essex County, NJ

  13. DETAIL OF THE FRONT PORCH SHOWING THE SQUARE COLUMN, COVED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF THE FRONT PORCH SHOWING THE SQUARE COLUMN, COVED CEILING, AND STAINED CONCRETE FLOOR. VIEW FACING NORTHWEST. - Hickam Field, Officers' Housing Type H, 208 Sixth Street, Honolulu, Honolulu County, HI

  14. 61. VIEW EAST, THREE COLUMN CONCRETE PIER (PIER 82) WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    61. VIEW EAST, THREE COLUMN CONCRETE PIER (PIER 82) WITH BEARINGS - Route 1 Extension, Southbound Viaduct, Spanning Conrail Yards, Wilson Avenue, Delancy Street, & South Street on Routes 1 & 9 Southbound, Newark, Essex County, NJ

  15. 16. VIEW EAST, BEARINGS ATOP SINGLE COLUMN PIER Route ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. VIEW EAST, BEARINGS ATOP SINGLE COLUMN PIER - Route 1 Extension, Structure No. 0703-161, Spanning Conrail-Newark & New York Industrial tracks, Richards Lane, & Hawkins Street at Routes 1 & 9 Southbound, Newark, Essex County, NJ

  16. 28. November 1969 CASTIRON DRAGON GROTESQUE BELOW BASE OF COLUMN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. November 1969 CAST-IRON DRAGON GROTESQUE BELOW BASE OF COLUMN SEPARATING WINDOWS ON NORTH SIDE OF RIGGS LIBRARY - Georgetown University, Healy Building, Thirty-seventh & O Streets, Northwest, Washington, District of Columbia, DC

  17. Detail of three trusses resting on one column at the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of three trusses resting on one column at the junction of the roundhouse and care repair shop looking south. - U.S. Steel National Tube Works, Auxiliary Buildings, Along Monongahela River, McKeesport, Allegheny County, PA

  18. 3. Detail of north loading dock area showing column, insulated ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Detail of north loading dock area showing column, insulated doors, and detail of underside of canopy - Fort Hood, World War II Temporary Buildings, Cold Storage Building, Seventeenth Street, Killeen, Bell County, TX

  19. 24. PHOTOGRAPH OF FIRST FLOOR. NOTE BRACKETS ON CENTER COLUMN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. PHOTOGRAPH OF FIRST FLOOR. NOTE BRACKETS ON CENTER COLUMN WHERE BRASS STATUS GAGES WERE MOUNTED TO MONITOR STEAM AND WATER PRESSURES IN YARD MAINS. SEE PHOTO CA-2294-25. - Mare Island Naval Shipyard, Firehouse, Vallejo, Solano County, CA

  20. Exploring the pressure resistance limits of monolithic silica capillary columns.

    PubMed

    Hara, Takeshi; Eeltink, Sebastiaan; Desmet, Gert

    2016-05-13

    We report on an experimental approach to measure the pressure stability and mechanical strength of monolithic silica capillary columns with different diameters (50 and 100μm i.d.) and considering two different domain sizes, typical for the second generation monoliths or smaller. The approach consists of exposing the capillaries to ultra-high pressures (gradually stepwise increased from 20 to 80MPa), with intermediate measurements of the column efficiency, permeability and retention factors to check the mechanical stability of the bed. It was observed that all tested columns withstood the imposed pressure stress, i.e., all the tested parameters remained unaffected up till the maximal test pressure of 80MPa. The applied pressure gradient corresponded to 320MPa/m. The two 100μm i.d.-capillary columns were also exposed to pressures between 80 and 90MPa for a prolonged time (8h), and this did not cause any damage either. PMID:27086284

  1. INTERIOR VIEW OF COLUMN TOPS. CARBON DIOXIDE BUBBLED THROUGH AMMONIONATED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF COLUMN TOPS. CARBON DIOXIDE BUBBLED THROUGH AMMONIONATED SALT BRINE TO MAKE BICARBONATE OF SODA. - Solvay Process Company, SA Wetside Building, Between Willis & Milton Avenue, Solvay, Onondaga County, NY

  2. 47. Pouring deck columns, steampowered concrete mixer at center; direction ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    47. Pouring deck columns, steam-powered concrete mixer at center; direction of view not clear, but probably to north. - Parks Bar Bridge, Spanning Yuba River at State Highway 20, Smartville, Yuba County, CA

  3. HILIC separation mechanisms of tetracyclines on amino bonded silica column

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of mobile phase variations on the chromatographic separation on amino bonded silica column in hydrophilic interaction chromatography (HILIC) were investigated for four zwitterionic tetracyclines (TCs): oxytetracycline, doxycycline, chlortetracycline and tetracycline. A mixed-mode retention m...

  4. In-situ polymerization PLOT columns I: divinylbenzene

    NASA Technical Reports Server (NTRS)

    Shen, T. C.

    1992-01-01

    A novel method for preparation of porous-layer open-tubular (PLOT) columns is described. The method involves a simple and reproducible, straight-forward in-situ polymerization of monomer directly on the metal tube.

  5. PAINT SHOP, DETAIL OF FABRICATED COLUMN AT JUNCTION OF WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PAINT SHOP, DETAIL OF FABRICATED COLUMN AT JUNCTION OF WEST BAY (ORIGINAL) AND CENTER BAYS (SECOND ADDITION), LOOKING NORTHEAST. - Southern Pacific, Sacramento Shops, Paint Shop, 111 I Street, Sacramento, Sacramento County, CA

  6. 19. VIEW SOUTH, NORTH ELEVATION AT DOUBLE COLUMN CONCRETE EXPANSION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. VIEW SOUTH, NORTH ELEVATION AT DOUBLE COLUMN CONCRETE EXPANSION JOINT AT PIER NUMBER 112 - Route 1 Extension, South Street Viaduct, Spanning Conrail & Wheeler Point Road at South Street, Newark, Essex County, NJ

  7. GRAPHITE BLOCKS ARE ARRAYED IN "THERMAL COLUMN" ON NORTH SIDE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GRAPHITE BLOCKS ARE ARRAYED IN "THERMAL COLUMN" ON NORTH SIDE OF REACTOR. INL NEGATIVE NO. 4000. Unknown Photographer, 12/28/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  8. 37. HANGAR FROM RAILROAD DECK TELESCOPED IN COLUMN & SHOWING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. HANGAR FROM RAILROAD DECK TELESCOPED IN COLUMN & SHOWING PIN WHICH TRANSFERS LOAD FROM RAILROAD DECK TO TRUSS WHEN IN DOWN POSITION - Armour, Swift, Burlington Bridge, Kansas City, Jackson County, MO

  9. East side, showing ruin of brownstone column capital that originally ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    East side, showing ruin of brownstone column capital that originally supported the east side portico, a feature that was destroyed in the 1886 earthquake - William Ravenel House, 13 East Battery Street, Charleston, Charleston County, SC

  10. 17. SECOND FLOOR WAREHOUSE SPACE, SHOWING COLUMN AND BEAM CONNECTION. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. SECOND FLOOR WAREHOUSE SPACE, SHOWING COLUMN AND BEAM CONNECTION. VIEW TO NORTHEAST. - Commercial & Industrial Buildings, Dubuque Seed Company Warehouse, 169-171 Iowa Street, Dubuque, Dubuque County, IA

  11. 10. DETAIL OF CAST IRON COLUMN BASE ON FIRST FLOOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. DETAIL OF CAST IRON COLUMN BASE ON FIRST FLOOR STOREFRONT, SHOWING MANUFACTURER'S STAMP: IOWA IRON WOKS CO. DUBUQUE. VIEW TO SOUTHWEST. - Commercial & Industrial Buildings, Dubuque Seed Company Warehouse, 169-171 Iowa Street, Dubuque, Dubuque County, IA

  12. Evaluating two process scale chromatography column header designs using CFD.

    PubMed

    Johnson, Chris; Natarajan, Venkatesh; Antoniou, Chris

    2014-01-01

    Chromatography is an indispensable unit operation in the downstream processing of biomolecules. Scaling of chromatographic operations typically involves a significant increase in the column diameter. At this scale, the flow distribution within a packed bed could be severely affected by the distributor design in process scale columns. Different vendors offer process scale columns with varying design features. The effect of these design features on the flow distribution in packed beds and the resultant effect on column efficiency and cleanability needs to be properly understood in order to prevent unpleasant surprises on scale-up. Computational Fluid Dynamics (CFD) provides a cost-effective means to explore the effect of various distributor designs on process scale performance. In this work, we present a CFD tool that was developed and validated against experimental dye traces and tracer injections. Subsequently, the tool was employed to compare and contrast two commercially available header designs. PMID:24616438

  13. Rapid Column Extraction method for SoilRapid Column Extraction method for Soil

    SciTech Connect

    Maxwell, Sherrod, L. III; Culligan, Brian K.

    2005-11-07

    The analysis of actinides in environmental soil and sediment samples is very important for environmental monitoring as well as for emergency preparedness. A new, rapid actinide separation method has been developed and implemented that provides total dissolution of large soil samples, high chemical recoveries and effective removal of matrix interferences. This method uses stacked TEVA Resin{reg_sign}, TRU Resin{reg_sign} and DGA-Resin{reg_sign} cartridges from Eichrom Technologies (Darien, IL, USA) that allows the rapid separation of plutonium (Pu) neptunium (Np), uranium (U), americium (Am), and curium (Cm) using a single multi-stage column combined with alpha spectrometry. The method combines a rapid fusion step for total dissolution to dissolve refractory analytes and matrix removal using cerium fluoride precipitation to remove the difficult soil matrix. By using vacuum box cartridge technology with rapid flow rates, sample preparation time is minimized.

  14. Efficiency of supercritical fluid chromatography columns in different thermal environments.

    PubMed

    Kaczmarski, Krzysztof; Poe, Donald P; Tarafder, Abhijit; Guiochon, Georges

    2013-05-24

    The efficiency of a packed column eluted with supercritical carbon dioxide at 323K and outlet pressures from 90 to 150bar was studied with the column in two different thermal environments. The 150mm×2.0mm ID stainless steel column was packed with spherical 5-μm porous silica particles with a covalently bonded nonpolar stationary phase, and the test solutes were normal alkanes. When operated in a convective air bath the column exhibited severe efficiency losses when its outlet pressure was below 120bar. The efficiency of the same column enclosed in a shell made of foam insulation was restored at low outlet pressures down to 100bar. The van Deemter plots showed an abnormal dependence of the plate height (HETP) on the flow rate at low outlet pressures, exhibiting a maximum in the HETP at flow rates around 1mL/min and a 20-bar pressure drop. The large efficiency losses at low outlet pressures are due to radial temperature gradients associated with enthalpic expansion and cooling of the mobile phase. The separations were simulated by a numerical model that accounts for axial and radial gradients in the temperature and density along the column. The abnormal van Deemter plots arise from competing processes affecting the radial distribution of the solute migration velocity along the column. The negative impact on efficiency is greatest when the density profile of the mobile phase along the column is close to the critical isopycnic line. The efficiency improves at increased flow rates because of increased cooling at larger pressure drops and increased density along the entire length of the column. The model predicts the unusual trends in the van Deemter plots, but the calculated results at low outlet pressures are strongly influenced by small variations in the porosity distribution in the column, limiting the accuracy of the predicted HETP values. In spite of these difficulties, the model has enabled a detailed analysis of the effects of temperature, pressure and flow

  15. Increasing the Strength of Aluminum-alloy Columns by Prestressing

    NASA Technical Reports Server (NTRS)

    Holt, M; Hartman, E C

    1937-01-01

    A series of tests was made in which the column strength of 17ST tubing was increased as much as 50 percent by prestressing the tubing to 40,000 pounds per square inch in compression under conditions of support that prevented column failure at this stress. This prestressing achieves it's beneficial effects entirely by improving the compressive properties of the material, principally the proportional limit.

  16. Intercomparison of NO column measurements during MAP/GLOBUS 1985

    NASA Technical Reports Server (NTRS)

    Mckenzie, R. L.; Matthews, W. A.; Kondo, Y.; Zander, R.; Demoulin, PH.; Fabian, P.; Murcray, D. G.; Murcray, F. J.; Lado-Bordowsky, O.; Mcpeters, D.

    1988-01-01

    Simultaneous NO column measurements made in France in September, 1985, using several techniques, are compared with one another. The observed NO distributions vary significantly from day to day. It is shown that NO measurements using IR or UV absorption are self-consistent and show good agreement with predictions from a one-dimensional photochemical model. In situ chemiluminescent measurements produced NO columns which were systematically higher than those predicted.

  17. TCAP HYDROGEN ISOTOPE SEPARATION USING PALLADIUM AND INVERSE COLUMNS

    SciTech Connect

    Heung, L.; Sessions, H.; Xiao, S.

    2010-08-31

    The Thermal Cycling Absorption Process (TCAP) was further studied with a new configuration. Previous configuration used a palladium packed column and a plug flow reverser (PFR). This new configuration uses an inverse column to replace the PFR. The goal was to further improve performance. Both configurations were experimentally tested. The results showed that the new configuration increased the throughput by a factor of more than 2.

  18. Design and minimum reflux calculations for multicomponent reactive distillation columns

    SciTech Connect

    Barbosa, D.; Doherty, M.F.

    1987-01-01

    A new set of transformed composition variables is introduced to simplify the design equations for single-feed, multicomponent reactive distillation columns. Based on these equations, a general method of calculating minimum reflux ratios for reactive distillation columns is presented. The new composition variables are also used to derive simple relationships between the dependent design variables, which are not evident when the design equations are written in terms of mole fractions.

  19. Generator for ionic gallium-68 based on column chromatography

    DOEpatents

    Neirinckx, Rudi D.; Davis, Michael A.

    1981-01-01

    A physiologically acceptable solution of gallium-68 fluorides, having an activity of 0.1 to 50 millicuries per milliliter of solution is provided. The solution is obtained from a generator comprising germanium-68 hexafluoride bound to a column of an anion exchange resin which forms gallium-68 in situ by eluting the column with an acid solution to form a solution containing .sup.68 Ga-fluorides. The solution then is neutralized prior to administration.

  20. Modelling aging effects on a thermal cycling absorption process column

    SciTech Connect

    Laquerbe, C.; Contreras, S.; Demoment, J.

    2008-07-15

    Palladium coated on alumina is used in hydrogen separation systems operated at CEA/Valduc, and more particularly in Thermal Cycling Absorption Process columns. With such materials, tritium decay is known to induce aging effects which have direct side effects on hydrogen isotopes absorption isotherms. Furthermore in a TCAP column, aging occurs in an heterogeneous way. The possible impacts of these intrinsic material evolutions on the separation performances are investigated here through a numerical approach. (authors)

  1. The stress profile in a sheared granular column

    NASA Astrophysics Data System (ADS)

    Nott, Prabhu; Mehandia, Vishwajeet; Jyotsna Gutam, Kamala

    2011-11-01

    It has been known for several centuries that the normal stress at the base of a column of granular material deviates from the value dictated by the hydrostatic balance. This was explained by Janssen (1895) as being due to the shear stress imposed by the confining walls on the granular column, as a result of grain-wall friction. The question we address in this presentation is, what is the stress field when the column is sheared? Depending on the assumptions on the kinematics, plasticity theories predict that the stress profile is similar either to that in a static column, or to that in a sheared fluid column. Here, we report the results of our experimental study of slow shear of a granular material in a cylindrical Couette cell, in which all components of the stress were measured at the stationary outer cylinder. The stress was measured as a function of distance from the free surface. The results of our experiments are intriguing: the radial normal stress deviates strongly from the predictions of all available theories and previous experimental measurements. The axial shear stress changes sign when a static column is sheared. We describe these results, and speculate as to which type of theory might explain the observations. Support from the DST, India is gratefully acknowledged.

  2. Zero-valent iron colloid emplacement in sand columns

    SciTech Connect

    Cantrell, K.J.; Kaplan, D.I.

    1997-05-01

    Application of chemically reactive barriers to mitigate contaminant migration is an active area of research and development. Studies were conducted to evaluate a novel approach of emplacing chemically reactive barriers composed of zero-valent iron (Fe{sup 0}) by injecting suspensions of colloidal-size Fe{sup 0} particles into porous media. The specific objective of this study was to evaluate the effect of influent colloid concentration, rate, and volume of colloidal suspensions on Fe{sup 0} colloid emplacement in sand columns. Relatively even distributions of Fe{sup 0} throughout a sand column were obtained at low influent colloid concentrations and high injection rates. As the concentration of influent suspensions was increased, a point was reached beyond which a significant increase in the filtration of Fe{sup 0} particles near the front of the column was observed. This point was also found to occur at lower influent colloid concentrations as the injection rate was decreased, i.e., there was an interactive effect of influent colloid concentration and injection rate on the extent of filtration that occurred near the front of the column. As the volume of the colloidal suspension injected into the column was increased, the distribution of Fe{sup 0} colloids within the column became increasingly even.

  3. Preparing titania aerogel monolithic chromatography columns using supercritical carbon dioxide.

    PubMed

    Sui, Ruohong; Liu, Suya; Lajoie, Gilles A; Charpentier, Paul A

    2010-06-01

    The search for a method to fabricate monolithic inorganic columns has attracted significant recent attention due to their unique ability in separation applications of various biomolecules. Silica and polymer based monolithic columns have been prepared, but titania and other metal oxide monoliths have been elusive, primarily due to their fragility. This article describes a new approach for preparing nanostructured titania based columns, which offer better performance over conventional particle packed columns for separating a wide variety of biomolecules including phosphopeptides. TiO(2) monolithic aerogels were synthesized in separation columns using in situ sol-gel reactions in supercritical carbon dioxide (scCO(2)) followed by calcination, and compared to those prepared in heptanes. The characterization results show that scCO(2) is a better solvent for the sol-gel reactions, providing lower shrinkage with the anatase TiO(2) monolith composed of nanofibers with very high surface areas. The monolithic columns show the ability to isolate phosphopeptides with little flow resistance compared to conventional titania particle based microcolumns. PMID:20373296

  4. Experimental investigations of /sup 238/Pu behavior in soil columns

    SciTech Connect

    Nelson, G.B.; Herrera, B.; Stalnaker, N.D.; Coffelt, K.P.; Patterson, J.H.; Heaton, R.C.; Matlack, G.M.

    1984-05-01

    Two series of experiments were conducted to study the transport of plutonium through soils. The first series involved deposition of small quantities (2.0 to 3.5 mg) of particulate /sup 238/Pu oxide on soil columns containing silt loam soil. When deionized water was allowed to percolate through the columns, plutonium was released into the drainage at the rate of 8 to 15 pg/day. During the 6.8-y experiment, the total amount of plutonium released into the soil drainage amounted to less than 0.01% of the original source. Analysis of the soil as a function of depth at the end of the experiment revealed that more than 99% of the deposited source remained in the uppermost fraction (2.8 cm) of the column. The second series of experiments was performed by pumping water containing plutonium through columns of soil and comparing the amount of plutonium in the column effluents to that in the feed. For a loamy sand soil, the plutonium content of the effluent reached a steady state of 5% of the feed after 500 days. Analysis of the soil at the end of the experiment (1200 days) showed the columns to be approximately 50% saturated. Saturation of the soil with plutonium would require 13 ..mu..g/g and 6.6 y at the feed rate used (averaged of 1.2 ..mu..g/g into 300 g of soil).

  5. Installation of the Pulse-Plate Column Pilot Plant

    SciTech Connect

    Nick R. Mann

    2009-07-01

    There are three primary types of solvent extraction equipment utilized in the nuclear industry for reprocessing of used nuclear fuel; pulse columns, mixer-settlers, and centrifugal contactors. Considerable research and development has been performed at the INL and throughout the DOE complex on the application of centrifugal contactors for used fuel reprocessing and these contactors offer many significant advantages. However, pulse columns have been used extensively in the past in throughout the world for aqueous separations processes and remain the preferred equipment by many commercial entities. Therefore, a pulse-plate column pilot plant has been assembled as part of the Advanced Fuel Cycle Initiative to support experimentation and demonstration of pulse column operation. This will allow the training of personnel in the operation of pulse columns. Also, this capability will provide the equipment to allow for research to be conducted in the operation of pulse columns with advanced solvents and processes developed as part of the fuel cycle research and development being performed in the AFCI program.

  6. Novel highly hydrophilic zwitterionic monolithic column for hydrophilic interaction chromatography.

    PubMed

    Jiang, Zhengjin; Smith, Norman W; Ferguson, Paul D; Taylor, Mark R

    2009-08-01

    A novel zwitterionic hydrophilic porous poly(SPV-co-MBA) monolithic column was prepared by thermal co-polymerisation of 1-(3-sulphopropyl)-4-vinylpyridinium-betaine (4-SPV) and N,N'-methylenebisacrylamide (MBA). An HILIC/RP dual separation mechanism was observed on this optimised poly(SPV-co-MBA) monolithic column and the composition of the mobile phase corresponding to the transition from the HILIC to the RP mode was around 30% ACN in water. Higher hydrophilicity was achieved on this novel monolithic column compared to the poly(N,N-dimethyl-N-methacryloxyethyl-N-(3-sulphopropyl)ammonium betaine-co-ethylene dimethacrylate) monolithic column. Permeability studies showed slight swelling and/or shrinking with mobile phases of different polarity. As might be anticipated, a weak electrostatic interaction for charged analytes was also observed by studying the influence of mobile phase pH and salt concentration on their retention on the poly(SPV-co-MBA) monolithic column. The final optimised poly(SPV-co-MBA) monolith showed comparable selectivities to commercial ZIC-pHILIC phases for polar test analytes. Fast separation of five pyrimidines and purines was achieved in less than 1 min due to the high permeability of the monolithic column. Additionally, baseline separation of nine benzoic acid derivatives was also observed using either a pH or ACN gradient. PMID:19606441

  7. Initial testing of a dynamic column for fine coal flotation

    SciTech Connect

    Lai, R.W.; Patton, R.A.; He, D.X.; Joyce, T.; Chiang, S.H.

    1995-12-31

    This paper describes the design and initial performance of a dynamic column for fine coal column flotation. A dynamic column is a modified conventional column with the insertion of a series of draft tubes that provide individual mixing stages. The mixing is beneficial in generating small and uniform bubbles over a wide range of frother dosages. It is also beneficial in the control of flotation where the fluctuation of froth volume should be minimized. In the modified design, a vortex-inducing plate is attached to the top of each draft tube to create an artificial vortex. In theory the vortex action is desirable for collecting the light clean coal froth within the inner mixing zone, and for passing it upward to the next draft tube stage. The mineral laden slurry, particularly the pyrite, is accelerated outside the vortex zone by centrifugal force to reach the wall where it is carried downward to the bottom of the column. The draft tubes are arranged in a series to accomplish multistage cleaning. The experimental results showed that this dynamic column has the potential advantage of higher throughput and better product recovery as well as improved product quality.

  8. Dynamic effects on cyclotron scattering in pulsar accretion columns

    NASA Technical Reports Server (NTRS)

    Brainerd, J. J.; Meszaros, P.

    1991-01-01

    A resonant scattering model for photon reprocessing in a pulsar accretion column is presented. The accretion column is optically thin to Thomson scattering and optically thick to resonant scattering at the cyclotron frequency. Radiation from the neutron star surface propagates freely through the column until the photon energy equals the local cyclotron frequency, at which point the radiation is scattered, much of it back toward the star. The radiation pressure in this regime is insufficient to stop the infall. Some of the scattered radiation heats the stellar surface around the base of the column, which adds a softer component to the spectrum. The partial blocking by the accretion column of X-rays from the surface produces a fan beam emission pattern. X-rays above the surface cyclotron frequency freely escape and are characterized by a pencil beam. Gravitational light bending produces a pencil beam pattern of column-scattered radiation in the antipodal direction, resulting in a strongly angle-dependent cyclotron feature.

  9. Thermal analysis for ion-exchange column system

    SciTech Connect

    Lee, S. Y.; King, W. D.

    2012-07-01

    Models have been developed to simulate the thermal characteristics of Crystalline Silico-titanate (CST) ion exchange media fully loaded with radioactive cesium in a column configuration and distributed within a waste storage tank. This work was conducted to support the Small Column Ion Exchange (SCIX) program which is focused on processing dissolved, high-sodium salt waste for the removal of specific radionuclides (including Cs-137, Sr-90, and actinides) within a High Level Waste (HLW) storage tank at the Savannah River Site. A two-dimensional computational modeling approach for the in-column ion-exchange domain was taken to include conservative, bounding estimates for key parameters such that the results would provide the maximum centerline temperatures achievable under the design configurations using a feed composition known to promote high cesium loading on CST. A primary objective of these calculations was to estimate temperature distributions across packed CST beds immersed in waste supernate or filled with dry air under various accident scenarios. Accident scenarios evaluated included loss of salt solution flow through the bed, inadvertent column drainage, and loss of active cooling in the column. The modeling results demonstrate that the baseline design using one central and four outer cooling tubes provides a highly efficient cooling mechanism for reducing the maximum column temperature. (authors)

  10. Gas chromatographic column for the storage of sample profiles

    NASA Technical Reports Server (NTRS)

    Dimandja, J. M.; Valentin, J. R.; Phillips, J. B.

    1994-01-01

    The concept of a sample retention column that preserves the true time profile of an analyte of interest is studied. This storage system allows for the detection to be done at convenient times, as opposed to the nearly continuous monitoring that is required by other systems to preserve a sample time profile. The sample storage column is essentially a gas chromatography column, although its use is not the separation of sample components. The functions of the storage column are the selective isolation of the component of interest from the rest of the components present in the sample and the storage of this component as a function of time. Using octane as a test substance, the sample storage system was optimized with respect to such parameters as storage and readout temperature, flow rate through the storage column, column efficiency and storage time. A 3-h sample profile was collected and stored at 30 degrees C for 20 h. The profile was then retrieved, essentially intact, in 5 min at 130 degrees C.

  11. Revised Thermal Analysis of LANL Ion Exchange Column

    SciTech Connect

    Laurinat, J

    2006-04-11

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

  12. Combined medial column primary arthrodesis, middle column open reduction internal fixation, and lateral column pinning for treatment of Lisfranc fracture-dislocation injuries.

    PubMed

    Boffeli, Troy J; Pfannenstein, Ryan R; Thompson, Jonathan C

    2014-01-01

    Lisfranc fracture-dislocation can be a devastating injury with significant long-term sequelae, including degenerative joint disease, progressive arch collapse, and chronic pain that can be potentiated if not effectively treated. We present a case to demonstrate our preferred surgical approach, consisting of combined medial column primary arthrodesis, middle column open reduction internal fixation, and lateral column pinning, with the primary goal of minimizing common long-term complications associated with Lisfranc injuries. We present the case of a typical patient treated according to this combined surgical approach to highlight our patient selection criteria, rationale, surgical technique, and operative pearls. A 36-year-old male who had sustained a homolateral Lisfranc fracture-dislocation injury after falling from a height initially underwent fasciotomy for foot compartment syndrome. The subsequent repair 16 days later involved primary first tarsometatarsal joint fusion, open reduction internal fixation of the second and third tarsometatarsal joints, and temporary pinning of the fourth and fifth tarsometatarsal joints. He progressed well postoperatively, exhibiting an American College of Foot and Ankle Surgeons forefoot score of 90 of 100 at 1 year after surgery with no need for subsequent treatment. Lisfranc fracture-dislocations often exhibit primary dislocation to the medial column and are conducive to arthrodesis to stabilize the tarsometatarsal complex. The middle column frequently involves comminuted intra-articular fractures and will often benefit from less dissection required for open reduction internal fixation instead of primary fusion. We propose that this surgical approach is a viable alternative technique for primary treatment of Lisfranc fracture-dislocation injuries. PMID:24846158

  13. Transport of Silver Nanoparticles in Saturated Soil Columns

    NASA Astrophysics Data System (ADS)

    Sagee, O.; Dror, I.; Berkowitz, B.

    2011-12-01

    The effect of soil properties on the transport of silver nanoparticles (AgNPs) was studied in a set of laboratory column experiments. Mediterranean red sandy clay soil was collected from the upper 0-10 cm layer of an agricultural field at Beit Dagan, Israel. Following sieving, columns were packed with different size fractions (having similar composition and properties) of the soil and fully saturated with water. The transport of AgNPs in the column was monitored by collection of solution from the outlet and analysis by ICP-MS and DLS; bromide was also used as a benchmark tracer. The AgNPs were synthesized from dissolved silver citrate solution by chemical reduction. The produced particles had an average size of ~30 nm, and yielded a stable suspension in water with zeta potential of -40 mV. This facilitated their transport through the negatively charged soil. Two main features were observed. First, in all column experiments, early breakthrough of AgNPs in the soil column was observed, which may indicate preferential flow. Second, the distributions of AgNPs along the soil columns at the end of each experiment suggest that mechanical filtration is the main mechanism for AgNP retention in the soil. AgNP transport through the column decreased when the finer size fraction of the soil was used. Micro-CT and image analysis tools were used to investigate structural features of the soil pore space. These analyses suggest that although there is a difference of about three orders of magnitude between the AgNP particle diameter and the average pore diameter, the pore diameter distribution in the soil strongly affects the transport of AgNPs.

  14. Virus movement in soil columns flooded with secondary sewage effluent.

    PubMed Central

    Lance, J C; Gerba, C P; Melnick, J L

    1976-01-01

    Secondary sewage effluent containing about 3 X 10(4) plaque-forming units of polio virus type 1 (LSc) per ml was passed through columns 250 cm in length packed with calcareous sand from an area in the Salt River bed used for ground-water recharge of secondary sewage effluent. Viruses were not detected in 1-ml samples extracted from the columns below the 160-cm level. However, viruses were detected in 5 of 43 100-ml samples of the column drainage water. Most of the viruses were adsorbed in the top 5 cm of soil. Virus removal was not affected by the infiltration rate, which varied between 15 and 55 cm/day. Flooding a column continuosly for 27 days with the sewage water virus mixture did not saturate the top few centimeters of soil with viruses and did not seem to affect virus movement. Flooding with deionized water caused virus desorption from the soil and increased their movement through the columns. Adding CaCl2 to the deionized water prevented most of the virus desorption. Adding a pulse of deionized water followed by sewage water started a virus front moving through the columns, but the viruses were readsorbed and none was detected in outflow samples. Drying the soil for 1 day between applying the virus and flooding with deionized water greatly reduced desorption, and drying for 5 days prevented desorption. Large reductions (99.99% or more) of virus would be expected after passage of secondary sewage effluent through 250 cm of the calcareous sand similar to that used in our laboratory columns unless heavy rains fell within 1 day after the application of sewage stopped. Such virus movement could be minimized by the proper management of flooding and drying cycles. PMID:185960

  15. High pressure humidification columns: Design equations, algorithm, and computer code

    SciTech Connect

    Enick, R.M.; Klara, S.M.; Marano, J.J.

    1994-07-01

    This report describes the detailed development of a computer model to simulate the humidification of an air stream in contact with a water stream in a countercurrent, packed tower, humidification column. The computer model has been developed as a user model for the Advanced System for Process Engineering (ASPEN) simulator. This was done to utilize the powerful ASPEN flash algorithms as well as to provide ease of use when using ASPEN to model systems containing humidification columns. The model can easily be modified for stand-alone use by incorporating any standard algorithm for performing flash calculations. The model was primarily developed to analyze Humid Air Turbine (HAT) power cycles; however, it can be used for any application that involves a humidifier or saturator. The solution is based on a multiple stage model of a packed column which incorporates mass and energy, balances, mass transfer and heat transfer rate expressions, the Lewis relation and a thermodynamic equilibrium model for the air-water system. The inlet air properties, inlet water properties and a measure of the mass transfer and heat transfer which occur in the column are the only required input parameters to the model. Several example problems are provided to illustrate the algorithm`s ability to generate the temperature of the water, flow rate of the water, temperature of the air, flow rate of the air and humidity of the air as a function of height in the column. The algorithm can be used to model any high-pressure air humidification column operating at pressures up to 50 atm. This discussion includes descriptions of various humidification processes, detailed derivations of the relevant expressions, and methods of incorporating these equations into a computer model for a humidification column.

  16. The cortical column: a structure without a function

    PubMed Central

    Horton, Jonathan C; Adams, Daniel L

    2005-01-01

    This year, the field of neuroscience celebrates the 50th anniversary of Mountcastle's discovery of the cortical column. In this review, we summarize half a century of research and come to the disappointing realization that the column may have no function. Originally, it was described as a discrete structure, spanning the layers of the somatosensory cortex, which contains cells responsive to only a single modality, such as deep joint receptors or cutaneous receptors. Subsequently, examples of columns have been uncovered in numerous cortical areas, expanding the original concept to embrace a variety of different structures and principles. A ‘column’ now refers to cells in any vertical cluster that share the same tuning for any given receptive field attribute. In striate cortex, for example, cells with the same eye preference are grouped into ocular dominance columns. Unaccountably, ocular dominance columns are present in some species, but not others. In principle, it should be possible to determine their function by searching for species differences in visual performance that correlate with their presence or absence. Unfortunately, this approach has been to no avail; no visual faculty has emerged that appears to require ocular dominance columns. Moreover, recent evidence has shown that the expression of ocular dominance columns can be highly variable among members of the same species, or even in different portions of the visual cortex in the same individual. These observations deal a fatal blow to the idea that ocular dominance columns serve a purpose. More broadly, the term ‘column’ also denotes the periodic termination of anatomical projections within or between cortical areas. In many instances, periodic projections have a consistent relationship with some architectural feature, such as the cytochrome oxidase patches in V1 or the stripes in V2. These tissue compartments appear to divide cells with different receptive field properties into distinct

  17. Jupiter's great red spot revisited. [validity of Taylor column theory

    NASA Technical Reports Server (NTRS)

    Hide, R.

    1972-01-01

    On the original Taylor column theory of Jupiter's Great Red Spot, the fixed latitude of the Spot is taken to imply that the Taylor column in Jupiter's atmosphere is associated with a disturbance such as a topographic feature of the surface Q underlying the atmosphere. The alternative suggestion that the Taylor column is produced by a solid raft floating at depth in the atmosphere is somewhat easier to reconcile with the approximately 10s difference between the respective rotation periods P sub S and P sub R of the Red Spot and of the radio sources, but it does not account so readily for the fixed latitude of the Spot unless it can be shown that the raft is in stable equilibrium under the north-south components of the dynamical forces, including wind effects, acting upon it. A slight wavering of the upper end of the Taylor column relative to the lower end could account at least in part for the most rapid variations in P sub S, but the slow large-amplitude variations in P sub S must reflect changes in the longitudinal motion of either the surface Q or of the raft. By generalizing the Proudman-Taylor theorem to the case of a non-homogeneous fluid it is shown that the Taylor column theory does not imply very special and therefore unlikely horizontal and vertical temperature variations in Jupiter's atmosphere, thus refuting a widely-held belief to the contrary.

  18. Purification of large plasmids with methacrylate monolithic columns.

    PubMed

    Krajnc, Nika Lendero; Smrekar, Franci; Cerne, Jasmina; Raspor, Peter; Modic, Martina; Krgovic, Danijela; Strancar, Ales; Podgornik, Ales

    2009-08-01

    The rapid evolution of gene therapy and DNA vaccines results in an increasing interest in producing large quantities of pharmaceutical grade plasmid DNA. Most current clinical trials involve plasmids of 10 kb or smaller in size, however, future requirements for multigene vectors including extensive control regions may require the production of larger plasmids, e. g., 20 kb and bigger. The objective of this study was to examine certain process conditions for purification of large plasmids with the size of up to 93 kb. Since there is a lack of knowledge about production and purification of bigger plasmid DNA, cell lysis and storage conditions were investigated. The impact of chromatographic system and methacrylate monolithic column on the degradation of plasmid molecules under nonbinding conditions at different flow rates was studied. Furthermore, capacity measurements varying salt concentration in loading buffer were performed and the capacities up to 13 mg of plasmid per mL of the monolithic column were obtained. The capacity flow independence in the range from 130 to 370 cm/h was observed. Using high resolution monolithic column the separation of linear and supercoiled isoforms of large plasmids was obtained. Last but not least, since the baseline separation of RNA and pDNA was achieved, the one step purification on larger CIM DEAE 8 mL tube monolithic column was performed and the fractions were analyzed by CIM analytical monolithic columns. PMID:19598166

  19. ENGINEERING DEVELOPMENT OF SLURRY BUBBLE COLUMN REACTOR (SBCR) TECHNOLOGY

    SciTech Connect

    Bernard A. Toseland

    2001-03-31

    The major technical objectives of this program are threefold: (1) to develop the design tools and a fundamental understanding of the fluid dynamics of a slurry bubble column reactor to maximize reactor productivity, (2) to develop the mathematical reactor design models and gain an understanding of the hydrodynamic fundamentals under industrially relevant process conditions, and (3) to develop an understanding of the hydrodynamics and their interaction with the chemistries occurring in the bubble column reactor. Successful completion of these objectives will permit more efficient usage of the reactor column and tighter design criteria, increase overall reactor efficiency, and ensure a design that leads to stable reactor behavior when scaling up to large diameter reactors. Washington University's work for the quarter involved the study of the dynamic simulations of bubble columns in three dimensions. Work was also done in dynamic simulations of two-phase transient flow using CFDLIB. Ohio State measured the axial dispersion coefficients of the liquid phase. The steady-state thermal dispersion method was used to obtain the measurements. Iowa State followed the last quarter's work by using CFDLIB to simulate conditions described in the literature, with the objective of validating the simulation result. The group's work also led to a determination of the adequacy of periodic boundary conditions in representing small columns.

  20. Convective stability of multicomponent fluids in the thermogravitational column.

    PubMed

    Ryzhkov, Ilya I; Shevtsova, Valentina M

    2009-02-01

    A comprehensive linear stability analysis of convection in the thermogravitational column is first performed for multicomponent fluids. Two types of perturbations are investigated: Longitudinal waves propagating in vertical direction of the column and transversal waves propagating perpendicular to the vertical axis and temperature gradient. The stability problems are reduced to those without cross-diffusion effect by a special transformation. The calculations are performed for binary and ternary mixtures by the Galerkin method. It is found that in binary fluids, the onset of longitudinal instability can be monotonic or oscillatory depending on the separation ratio, which characterizes the Soret effect. The difference between stability characteristics of binary and ternary fluids is associated with different diffusion times of components in a ternary system. It is shown that the mechanism of transversal instability is related to the unstable density stratification in the column (in total or due to individual components). The unstable stratification can only be realized in fluids with negative Soret effect. The analogue of exchange of stabilities principle for a plane column with a multicomponent fluid is proved. The obtained results indicate that the thermogravitational column can be used for measuring diffusion and thermal diffusion coefficients in ternary and higher mixtures with one or several components having negative Soret effect. PMID:19391841

  1. Direct coupling of microbore HPLC columns to MS systems

    NASA Technical Reports Server (NTRS)

    Mcnair, H. M.

    1985-01-01

    A detailed investigation using electron microscopy was conducted which examined the conditions of materials used in the construction of stable, high performance microbore liquid chromatography (LC) columns. Small details proved to be important. The effects of temperature on the elution of several homologous series used as probe compounds was examined in reverse phase systems. They showed that accessible temperature changes provide roughly half the increase in solvent strength that would be obtained going from a 100% aqueous to a 100% organic mobile phase, which is sufficient to warrant their use in many analyses requiring the use of gradients. Air circulation temperature control systems provide the easiest means of obtaining rapid, wide range changes in column temperature. However, slow heat transfer from the gas leads to thermal nonuniformity in the column and a decrease in resolution as the temperature program progresses.

  2. Wobbling of a liquid column between unequal discs

    NASA Astrophysics Data System (ADS)

    Martínez, I.; Meseguer, J.; Perales, J. M.

    One of the most puzzling results of an experiment on the stability of long liquid columns under microgravity, performed aboard Spacelab-D2 in 1993 and named STACO, aiming at the analysis of deformations of nearly cylindrical liquid columns under several mechanical disturbances, is revisited here. It corresponds to the unexplained breakage of an 85 mm long liquid bridge of low viscosity silicone oil, established between unequal discs of 30 and 28 mm, intended to counterbalance the expected deformation by residual acceleration found in previous flights, and left idle because the vibrations and oscillations to be applied afterwards were not started, for fear of premature breakage. A detailed image analysis is performed to extract the maximum amount of data, to be able to check against available theories for axisymmetric and non-axisymmetric deformations of a liquid column.

  3. Wobbling of a liquid column between unequal discs

    NASA Astrophysics Data System (ADS)

    Martinez, I.; Meseguer, J.; Perales, J. M.

    One of the most puzzling results of an experiment on the stability of long liquid columns under microgravity, performed aboard Spacelab-D2 in 1993, is revisited. It corresponds to the unexplained breakage of an 85 mm long liquid bridge of low viscosity silicone oil, established between unequal discs of 30 mm and 28 mm to counterbalance the expected deformation by residual acceleration, and left idle because the intended vibrations and oscillations were not started for fear of premature breakage. The basic aim of the experiment was to investigate the deformations of nearly-cylindrical liquid columns under several mechanical disturbances A detailed image analysis is performed to extract the maximum amount of data to be able to check against available theories for axisymmetric and non-axisymmetric deformations of a liquid column.

  4. Hybrid first-principles/neural networks model for column flotation

    SciTech Connect

    Gupta, S.; Liu, P.H.; Svoronos, S.A.; Sharma, R.; Abdel-Khalek, N.A.; Cheng, Y.; El-Shall, H.

    1999-03-01

    A new model for phosphate column flotation is presented which for the first time relates the effects of operating variables such as frother concentration on column performance. This is a hybrid model that combines a first-principles model with artificial neural networks. The first-principles model is obtained from material balances on both phosphate particles and gangue (undesired material containing mostly silica). First-order rates of net attachment are assumed for both. Artificial neural networks relate the attachment rate constants to the operating variables. Experiments were conducted in a 6-in.-dia. (152-mm-dia.) laboratory column to provide data for neural network training and model validation. The model successfully predicts the effects of frother concentration, particle size, air flow rate and bubble diameter on grade and recovery.

  5. Oldshue-Rushton column in supercritical fluid extraction

    SciTech Connect

    Laitinen, A.; Kaunisto, J.

    1999-06-01

    The performance of a mechanically agitated Oldshue-Rushton column using carbon dioxide solvent at 10 MPa and 313 K to extract ethanol from aqueous feed was investigated. The overall mass-transfer coefficient K{sub od}a, the height equivalent to a theoretical stage (HETS), dispersed phase holdup, as well as the column capacity data were measured as a function of solvent-to-feed ratio and rotor speed. The values of overall mass transfer coefficient K{sub od}a generally ranged from 0.009 to 0.012 s{sup {minus}1}, and the values of the HETS ranged from 0.44 to 0.74 m. The total throughput of the Oldshue-Ruston column without agitation was approximately 68 m{sup 3}/h{center_dot}m{sup 2}, whereas at 300 rpm the total throughput was approximately 48 m{sup 3}/h{center_dot}m{sup 2}.

  6. Round robin testing of a percolation column leaching procedure.

    PubMed

    Geurts, Roeland; Spooren, Jeroen; Quaghebeur, Mieke; Broos, Kris; Kenis, Cindy; Debaene, Luc

    2016-09-01

    Round robin test results of a percolation column leaching procedure (CEN/TS 14405:2004), organised by the Flemish Institute for Technological Research (VITO), over a time span of 13years with a participation of between 8 and 18 different laboratories are presented and discussed. Focus is on the leachability of heavy metals As, Cd, Cr, Cu, Hg, Ni, Pb and Zn from mineral waste materials. By performing statistical analyses on the obtained results, insight into the reproducibility and repeatability of the column leaching test is gathered. A ratio of 1:3 between intra- and inter-laboratory variability is found. The reproducibility of the eluates' element concentrations differ significantly between elements, materials and fractions (i.e. different liquid-to-solid ratios). The reproducibility is discussed in light of the application of the column leaching test for legal and environmental policy purposes. In addition, the performances of laboratories are compared. PMID:27311350

  7. Integrity of Bolted Angle Connections Subjected to Simulated Column Removal

    PubMed Central

    Weigand, Jonathan M.; Berman, Jeffrey W.

    2016-01-01

    Large-scale tests of steel gravity framing systems (SGFSs) have shown that the connections are critical to the system integrity, when a column suffers damage that compromises its ability to carry gravity loads. When supporting columns were removed, the SGFSs redistributed gravity loads through the development of an alternate load path in a sustained tensile configuration resulting from large vertical deflections. The ability of the system to sustain such an alternate load path depends on the capacity of the gravity connections to remain intact after undergoing large rotation and axial extension demands, for which they were not designed. This study experimentally evaluates the performance of steel bolted angle connections subjected to loading consistent with an interior column removal. The characteristic connection behaviors are described and the performance of multiple connection configurations are compared in terms of their peak resistances and deformation capacities. PMID:27110059

  8. Glycolipid class profiling by packed-column subcritical fluid chromatography.

    PubMed

    Deschamps, Frantz S; Lesellier, Eric; Bleton, Jean; Baillet, Arlette; Tchapla, Alain; Chaminade, Pierre

    2004-06-18

    The potential of packed-column subcritical fluid chromatography (SubFC) for the separation of lipid classes has been assessed in this study. Three polar stationary phases were checked: silica, diol, and poly(vinyl alcohol). Carbon dioxide (CO2) with methanol as modifier was used as mobile phase and detection performed by evaporative light scattering detection. The influence of methanol content, temperature, and pressure on the chromatographic behavior of sphingolipids and glycolipids were investigated. A complete separation of lipid classes from a crude wheat lipid extract was achieved using a modifier gradient from 10 to 40% methanol in carbon dioxide. Solute selectivity was improved using coupled silica and diol columns in series. Because the variation of eluotropic strength depending on the fluid density changes, a normalized separation factor product (NSP) was used to select the nature, the number and the order of the columns to reach the optimum glycolipid separation. PMID:15248431

  9. A geometric design method for side-stream distillation columns

    SciTech Connect

    Rooks, R.E.; Malone, M.F.; Doherty, M.F.

    1996-10-01

    A side-stream distillation column may replace two simple columns for some applications, sometimes at considerable savings in energy and investment. This paper describes a geometric method for the design of side-stream columns; the method provides rapid estimates of equipment size and utility requirements. Unlike previous approaches, the geometric method is applicable to nonideal and azeotropic mixtures. Several example problems for both ideal and nonideal mixtures, including azeotropic mixtures containing distillation boundaries, are given. The authors make use of the fact that azeotropes or pure components whose classification in the residue curve map is a saddle can be removed as side-stream products. Significant process simplifications are found among some alternatives in example problems, leading to flow sheets with fewer units and a substantial savings in vapor rate.

  10. Intermediate reboiler and condenser arrangement for binary distillation columns

    SciTech Connect

    Agrawal, R.; Herron, D.M.

    1998-06-01

    The most thermodynamically efficient configuration for adding or removing heat from an intermediate location of an ideal binary distillation column distilling pure products is derived. The optimal policy requires that preconditioning of the feed be part of the overall decision-making process. The optimal configuration can be determined through the use of two parameters, {alpha}{sub IR} and {alpha}{sub IC}, that are solely functions of feed composition. Simple and readily usable heuristics using these parameters are developed that help instantly identify the most efficient selection among (1) totally vaporizing and returning a side-draw liquid stream from an intermediate location of the distillation column, (2) partially or totally vaporizing a portion of the given saturated liquid feed, (3) partially or totally condensing a portion of the given saturated vapor feed, and (4) totally condensing and returning a side-draw vapor stream from an intermediate location of the distillation column.

  11. Use of granular slag columns for lead removal.

    PubMed

    Dimitrova, S V

    2002-09-01

    The use of granular blast furnace slag (GBFS)-packed columns to treat lead-containing solutions has been investigated. The results obtained indicated that the slag usage rate decreased with increasing flow velocity, particle size, initial lead concentration and decreasing with bed height. Lead removed selectively in the presence of other heavy metal ions. High concentrations of sodium and especially calcium in the solutions impeded the uptake of lead. For 20 mg l(-1) lead concentration an empty bed contact time greater of 4 min provided to efficient use of the slag bed. Column pH was an important parameter to lead removal under dynamic conditions and reflected the influence of the investigated factors. During all runs lead breakthrough coincided with an abrupt drop in effluent pH. The apparent mechanisms of lead removal in GBFS column are sorption (ion exchange and adsorption) on the slag surface and precipitation. PMID:12405409

  12. Engineering Development of Slurry Bubble Column Reactor (SBCR) Technology

    SciTech Connect

    Toseland, B.A.

    1998-10-29

    The major technical objectives of this program are threefold: (1) to develop the design tools and a fundamental understanding of the fluid dynamics of a slurry bubble column reactor to maximize reactor productivity, (2) to develop the mathematical reactor design models and gain an understanding of the hydrodynamic fundamentals under industrially relevant process conditions, and (3) to develop an understanding of the hydrodynamics and their interaction with the chemistries occurring in the bubble column reactor. Successful completion of these objectives will permit more efficient usage of the reactor column and tighter design criteria, increase overall reactor efficiency, and ensure a design that leads to stable reactor behavior when scaling up to large diameter reactors.

  13. Design and performance of improved Column Parallel CCD, CPC2

    NASA Astrophysics Data System (ADS)

    Banda, Y.; Coulter, P.; Cussans, D.; Damerell, C.; Devetak, E.; Fopma, J.; Foster, B.; Frost, R.; Gao, R.; Goldstein, J.; Greenshaw, T.; Harder, K.; Hawes, B.; Hillert, S.; Jeffery, B.; John, J. J.; Kundu, N.; Li, Y.; Murray, P.; Nomerotski, A.; Perry, C.; Stefanov, K.; Thomas, S.; Velthuis, J.; Wolliscroft, T.; Worm, S.; Yow, J.; Zhang, Z.

    2010-09-01

    The Linear Collider Flavour Identification (LCFI) Collaboration is developing the sensors, readout electronics and mechanical support structures for the vertex detector of the International Linear Collider (ILC). High speed readout is needed to ensure that the occupancy due to the pair production background at the ILC is kept below the 1% level. In order to satisfy this requirement, Column Parallel CCDs (CPCCDs), Column Parallel Readout chips (CPRs) and Column Parallel Driver chips (CPDs) have been developed. The CPCCD has to operate at a clock frequency of 50 MHz, which represents a difficult technical challenge due to the large sensor capacitance. The design and performance of the second generation CPCCD sensors, CPC2, and the new driver chip, CPD1, which meet these challenging requirements, are described.

  14. Numerical study of axisymmetric collapses of submarine granular > columns

    NASA Astrophysics Data System (ADS)

    Monsorno, Davide; Varsakelis, Christos

    2014-11-01

    In this talk, we report on the results of a numerical study of the axisymmetric collapse of subaqueous granular columns. Our study is based on a 2-pressure, 2-velocity continuum flow model for fluid-saturated granular materials. This model is integrated via a multi-phase projection method that incorporates a regularization method for the treatment of material interfaces. In our simulations, a dense column of a granular material immersed in water is placed on a horizontal plane and is allowed to collapse and spread due to its weight. Emphasis is placed on the run-out distance and the termination height and their correlation with the aspect ratio, the volume fraction and the diameter of the grains. Comparisons against experimental measurements and previous numerical predictions are also performed. Finally, in order to examine and quantify the role of the interstitial fluid, we compare our numerical predictions against experimental results from column collapses of dry granular materials.

  15. Contaminated marine sediments: Water column and interstitial toxic effects

    SciTech Connect

    Burgess, R.M.; McKinney, R.A. ); Schweitzer, K.A. ); Phelps, D.K. )

    1993-01-01

    The toxicity that contaminated sediments may introduce into the water column has not been measured extensively. In order to quantify this potential toxicity, the seawater overlying two uncontaminated and three contaminated marine sediments was evaluated in the laboratory with the sea urchin Arbacia punctulata fertilization test. Concentration of polychlorinated biphenyls (PCBs) and copper, as representative contaminants, were also measured. To characterize sources of toxicity, samples were chemically manipulated using reversed-phase chromatography, cation exchange, and chelation. Water column toxicity and contaminant concentrations were higher in the suspended exposures than in bedded exposures. Interstitial water toxicity and contaminant concentrations were generally greater than either bedded or suspended exposures. Chemical manipulation indicated that the observed toxicity in water column exposures was probably caused by metallic and/or nonionic organic contaminants. Conversely, manipulation of interstitial water did not result in significantly reduced toxicity, suggesting that other toxicants such as ammonia and hydrogen sulfide may be active.

  16. Contaminated marine sediments: Water column and interstitial toxic effects

    SciTech Connect

    Burgess, R.M.; Schweitzer, K.A.; McKinney, R.A.; Phelps, D.K.

    1993-01-01

    The toxicity that contaminated sediments may introduce into the water column has not been measured extensively. In order to quantify this potential toxicity, the seawater overlying two uncontaminated and three contaminated marine sediments was evaluated in the laboratory with the sea urchin Arbacia punctulata fertilization test. Concentrations of polychlorinated biphenyls (PCBs) and copper, as representative contaminants, were also measured. To characterize sources of toxicity, samples were chemically manipulated using reversed-phase chromatography, cation exchange, and chelation. Water column toxicity and contaminant concentrations were higher in the suspended exposures than in bedded exposures. Interstitial water toxicity and contaminant concentrations were generally greater than either bedded or suspended exposures. Chemical manipulation indicated that the observed toxicity in water column exposures was probably caused by metallic and/or nonionic organic contaminants. Conversely, manipulation of interstitial waters did not result in significantly reduced toxicity, suggesting that other toxicants such as ammonia and hydrogen sulfide may be active.

  17. ENGINEERING DEVELOPMENT OF SLURRY BUBBLE COLUMN REACTOR (SBCR) TECHNOLOGY

    SciTech Connect

    Bernard A. Toseland, Ph.D.

    2000-01-01

    The major technical objectives of this program are threefold: (1) to develop the design tools and a fundamental understanding of the fluid dynamics of a slurry bubble column reactor to maximize reactor productivity, (2) to develop the mathematical reactor design models and gain an understanding of the hydrodynamic fundamentals under industrially relevant process conditions, and (3) to develop an understanding of the hydrodynamics and their interaction with the chemistries occurring in the bubble column reactor. Successful completion of these objectives will permit more efficient usage of the reactor column and tighter design criteria, increase overall reactor efficiency, and ensure a design that leads to stable reactor behavior when scaling up to large diameter reactors.

  18. Surface wave propagation characteristics in atmospheric pressure plasma column

    NASA Astrophysics Data System (ADS)

    Pencheva, M.; Benova, E.; Zhelyazkov, I.

    2007-04-01

    In the typical experiments of surface wave sustained plasma columns at atmospheric pressure the ratio of collision to wave frequency (ν/ω) is much greater than unity. Therefore, one might expect that the usual analysis of the wave dispersion relation, performed under the assumption ν/ω = 0, cannot give adequate description of the wave propagation characteristics. In order to study these characteristics we have analyzed the wave dispersion relationship for arbitrary ν/ω. Our analysis includes phase and wave dispersion curves, attenuation coefficient, and wave phase and group velocities. The numerical results show that a turning back point appears in the phase diagram, after which a region of backward wave propagation exists. The experimentally observed plasma column is only in a region where wave propagation coefficient is higher than the attenuation coefficient. At the plasma column end the electron density is much higher than that corresponding to the turning back point and the resonance.

  19. Theoretical analysis of the performance of a foam fractionation column

    PubMed Central

    Tobin, S. T.; Weaire, D.; Hutzler, S.

    2014-01-01

    A model system for theory and experiment which is relevant to foam fractionation consists of a column of foam moving through an inverted U-tube between two pools of surfactant solution. The foam drainage equation is used for a detailed theoretical analysis of this process. In a previous paper, we focused on the case where the lengths of the two legs are large. In this work, we examine the approach to the limiting case (i.e. the effects of finite leg lengths) and how it affects the performance of the fractionation column. We also briefly discuss some alternative set-ups that are of interest in industry and experiment, with numerical and analytical results to support them. Our analysis is shown to be generally applicable to a range of fractionation columns. PMID:24808752

  20. Periodic explosions by positive feedback in a rising foam column

    PubMed Central

    Zener, Clarence; Noriega, Jaime

    1982-01-01

    An aqueous foam rising adiabatically in a column suffers a drop in temperature. Under appropriate conditions, such a column periodically explodes. We here trace this explosion to the tight thermal coupling between the foam and its enclosing glass column. When the surface surfactant concentration is unbuffered by micelles, a positive feedback exists between the flow of heat from the walls into the foam and the thermal conductivity of the foam itself. In our highly expanded foam, heat is conducted through the foam cells' interior primarily by the heat-pipe effect. Such an effect is retarded by a dense layer of surfactant molecules. Heat absorption causes cell expansion, which, in a foam unbuffered by micelles, causes a reduction in surface concentration of surfactant molecules and, hence, in an increase in thermal conductivity. This interpretation of our observed periodic explosions is in agreement with all of our observations. PMID:16593192

  1. Validity of the Janssen law in narrow granular columns.

    PubMed

    Bratberg, I; Måløy, K J; Hansen, A

    2005-11-01

    We have performed experiments on narrow granular columns to test the validity of the Janssen law under such conditions. The weight at the bottom of the cylinder and the compression and movement of the packing have been measured. The apparent mass dependence on height is not in good agreement with the Janssen law using a one-parameter fit. A two-parameter fit yielded good results for the apparent mass during upward and downward movement at constant velocity of the granular column inside the enclosing cylinder. The dependence of the apparent mass on the diameter of the column does not follow the Janssen law. Rather, it depends strongly on details of the packing. A slow force relaxation was observed when stopping the translational stage after upward motion. PMID:16231076

  2. ENGINEERING DEVELOPMENT OF SLURRY BUBBLE COLUMN REACTOR (SBCR) TECHNOLOGY

    SciTech Connect

    Bernard A. Toseland, Ph.D.

    2000-06-01

    The major technical objectives of this program are threefold: (1) to develop the design tools and a fundamental understanding of the fluid dynamics of a slurry bubble column 0reactor to maximize reactor productivity, (2) to develop the mathematical reactor design models and gain an understanding of the hydrodynamic fundamentals under industrially relevant process conditions, and (3) to develop an understanding of the hydrodynamics and their interaction with the chemistries occurring in the bubble column reactor. Successful completion of these objectives will permit more efficient usage of the reactor column and tighter design criteria, increase overall reactor efficiency, and ensure a design that leads to stable reactor behavior when scaling up to large diameter reactors.

  3. ENGINEERING DEVELOPMENT OF SLURRY BUBBLE COLUMN REACTOR (SBCR) TECHNOLOGY

    SciTech Connect

    Bernard A. Toseland

    2002-09-30

    The major technical objectives of this program are threefold: (1) to develop the design tools and a fundamental understanding of the fluid dynamics of a slurry bubble column reactor to maximize reactor productivity, (2) to develop the mathematical reactor design models and gain an understanding of the hydrodynamic fundamentals under industrially relevant process conditions, and (3) to develop an understanding of the hydrodynamics and their interaction with the chemistries occurring in the bubble column reactor. Successful completion of these objectives will permit more efficient usage of the reactor column and tighter design criteria, increase overall reactor efficiency, and ensure a design that leads to stable reactor behavior when scaling up to large diameter reactors.

  4. A Flexible Moisture Content Probe for Unsaturated Soil Column Experiments

    SciTech Connect

    E. D. Mattson; K. E. Baker; C. D. Palmer; J. M Svoboda

    2006-05-01

    A commercially available soil moisture capacitance probe was modified by replacing rigid electrode traces with non-intrusive, flexible circuit board trace electrodes that can be attached to the interior of soil column walls. This new design minimizes soil packing difficulties and potential bias in flow pathways commonly associated with rigid probe installations in column experiments. Testing showed that the modified probe design provides reproducible output independent of sample bulk density. The electrical conductivity of the pore-water solution, however, affects the probe response. For cases where the specific conductance of the pore-water solution is constant, the probe can be calibrated. The flexible electrodes offer a simple means of minimizing sensor intrusion into laboratory soil columns while providing reproducible voltage output that is a function of moisture content.

  5. Mobility of spiromesifen in packed soil columns under laboratory conditions.

    PubMed

    Mate, Ch Jamkhokai; Mukherjee, Irani; Das, Shaon Kumar

    2014-11-01

    On percolating water equivalent to 1,156 mm of rainfall, spiromesifen formulation did not leach out of 25-cm long columns, and 62.7 % of this was recovered in 5-10-cm soil depth. In columns treated with the analytical grade, 52.40 % of the recovered spiromesifen was confined to 0-5-cm soil depth, with 0.04 % in leachate fraction, suggesting high adsorption in soil. Results revealed that percolating 400 mL of water, residues of enol metabolite of spiromesifen was detected up to 20-25-cm soil layer, with 23.50 % residues of spiromesifen in this layer and 1.73 % in the leachate fraction indicating that metabolite is more mobile as compared to the parent compound. Results suggested a significant reduction in leaching losses of enol metabolite in amended soil columns with 5 % nano clay, farmyard manure (FYM), and vermicompost. No enol spiromesifen was recovered in the leachate in columns amended with nano clay, vermicompost, and FYM; however, 85.30, 70.5, and 65.40 %, respectively, was recovered from 0-5 cm-soil depth of column after percolating water equivalent to 1,156 mm of rainfall. Spiromesifen formulation is less mobile in sandy loam soil than analytical grade spiromesifen. The metabolite, enol spiromesifen, is relatively more mobile than the parent compound and may leach into groundwater. The study suggested that amendments were very effective in reducing the downward mobility of enol metabolite in soil column. Further, it resulted in greater retention of enol metabolite in the amendment application zone. PMID:25060860

  6. Volcanoes in the Classroom: Simulating an Eruption Column

    NASA Astrophysics Data System (ADS)

    Harpp, K. S.; Geist, D. J.; Koleszar, A. M.

    2005-12-01

    Few students have the opportunity to witness volcanic eruptions first hand. Analog models of eruptive processes provide ways for students to apply basic physical principles when field observations are not feasible. We describe a safe simulation of violent volcanic explosions, one that can be carried out simply and easily as a demonstration for specialized volcanology classes, introductory classes, and science outreach programs. Volcanic eruptions are fundamentally gas-driven phenomena. Depressurization of volatiles dissolved in magma during ascent is the driving force behind most explosive eruptions. We have developed a demonstration whereby the instructor can initiate a gas-driven eruption, which produces a dramatic but safe explosion and eruptive column. First, one pours liquid nitrogen into a weighted, plastic soda bottle, which is then sealed and placed into a trashcan filled with water. As the liquid nitrogen boils, the pressure inside the bottle increases until the seal fails, resulting in an explosion. The expansive force propels a column of water vertically, to 10 or more meters. Students can operate the demonstration themselves and carry out a sequence of self-designed variations, changing the vent size and viscosity of the "magma", for instance. They can also vary the material used as "tephra", studying the effects of projectile density, column height, and wind direction on tephra distribution. The physical measurements that students collect, such as column height and tephra radius, can be used as the basis for problem sets that explore the dynamics of eruption columns. Possible calculations include ejection velocity, the pressure needed to propel the water column, and average vesicularity of the "magma". Students can then compare their results to observations from real volcanic eruptions. We find this to be an exceedingly effective demonstration of gas-driven liquid explosions and one that is safe if done properly. [NOTE: Please do NOT attempt this

  7. Differential column measurements using compact solar-tracking spectrometers

    NASA Astrophysics Data System (ADS)

    Chen, Jia; Viatte, Camille; Hedelius, Jacob K.; Jones, Taylor; Franklin, Jonathan E.; Parker, Harrison; Gottlieb, Elaine W.; Wennberg, Paul O.; Dubey, Manvendra K.; Wofsy, Steven C.

    2016-07-01

    We demonstrate the use of compact solar-tracking Fourier transform spectrometers (Bruker EM27/SUN) for differential measurements of the column-averaged dry-air mole fractions of CH4 and CO2 within urban areas. Using Allan variance analysis, we show that the differential column measurement has a precision of 0.01 % for XCO2 and XCH4 with an optimum integration time of 10 min, corresponding to Allan deviations of 0.04 ppm and 0.2 ppb, respectively. The sensor system is very stable over time and after relocation across the continent. We report tests of the differential column measurement, and its sensitivity to emission sources, by measuring the downwind-minus-upwind column difference ΔXCH4 across dairy farms in the Chino area, California, and using the data to verify emissions reported in the literature. Ratios of spatial column differences ΔXCH4/ΔXCO2 were observed across Pasadena within the Los Angeles basin, indicating values consistent with regional emission ratios from the literature. Our precise, rapid measurements allow us to determine significant short-term variations (5-10 min) of XCO2 and XCH4 and to show that they represent atmospheric phenomena.Overall, this study helps establish a range of new applications for compact solar-viewing Fourier transform spectrometers. By accurately measuring the small differences in integrated column amounts across local and regional sources, we directly observe the mass loading of the atmosphere due to the influence of emissions in the intervening locale. The inference of the source strength is much more direct than inversion modeling using only surface concentrations and less subject to errors associated with small-scale transport phenomena.

  8. Ammonia impacts on atrazine leaching through undisturbed soil columns

    SciTech Connect

    Liu, Z.; Clay, S.A.; Clay, D.E.

    1995-11-01

    Ammonia-based fertilizers such as anhydrous ammonia, aqua ammonia, and urea, initially increase soil pH, reducing atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) sorption and increasing atrazine desorption. Increased amounts of atrazine in soil solution may increase atrazine`s leaching potential. This laboratory study investigated atrazine leaching behavior when ammonia and atrazine applications overlap. Nondisturbed 15-cm diam. by 15-cm depth soil columns were excavated from a Brandt silty clay loam (fine silty, Pachic Udic Haploboroll) and a Ves clay loam (fine silty, mixed mesic Typic Hapludalf). Concentrated NH{sub 4}OH was applied to the soil surface at 0 or 220 kg N ha{sup -1}. Immediately after fertilizer application, 1.9 kg atrazine (spiked with ring-labeled {sup 14}C-atrazine) ha{sup -1} was applied. One day after chemical application, soil columns were leached with 5.4 L of water. The ammonia application increased leachate and surface soil pH by about 2.5 and 3.5 pH units, respectively. The amount of {sup 14}C collected in leachate from ammonia-treated columns was 60 and 30% greater for the Brandt and Ves soils, respectively, compared with untreated columns. Less {sup 14}C remained in the surface of the ammonia-treated columns than in the surface of the untreated columns. These data indicate that the interaction between ammonia-based fertilizers and atrazine must be considered when evaluating atrazine movement through soil. Applications of atrazine and ammonia-based fertilizers that increase pH should be physically separated to limit the leaching potential of atrazine. 13 refs., 3 figs., 3 tabs.

  9. Relative cooling rates derived from basalt column geometries

    NASA Astrophysics Data System (ADS)

    Woodell, Daniel; Porritt, Lucy; Russell, Kelly

    2015-04-01

    Columnar joints form as a brittle relaxation response to tensile stresses that accumulate during cooling of lava flows, pyroclastic deposits, and intrusive magma bodies. Columnar jointing forms in different deposit types, in deposits of different compositions, and different outcrop geometries. Despite this diversity, columns follow a few "rules": column diameter is inversely proportional to cooling rate (small/quick cooling times, small diameter columns), columns only ever coalesce (never bifurcate), and columnar joints always propagate parallel to but in the opposite direction of heat flow (towards the hottest part of the flow). Using these "rules," cooling histories and emplacement environments can be reconstructed. While column geometries and definitions of various columnar structures vary between authors (upper and lower colonnade and entablature vs. master cracks and pseudopillows), this study focuses on relatively simple outcrops of basalt lava within the Cheakamus River valley near Whistler, BC, Canada. The basalt lavas described here, thought to have erupted subglacially, contain columns comprising only well-defined upper and lower colonnades (i.e., no entablature). Comparing the relative thicknesses of upper and lower colonnades reveals the cooling history, relative cooling rates, and amounts of heat transferred from the upper and lower flow boundaries. Forward numerical models using the finite element method are created with Matlab using the Partial Differential Equation Toolbox to model the outcrops in the Whistler field area, and determine the cooling rates and thermal gradients experienced by the lava flows during their formation. This study finds that noticeable differences in the thickness of upper and lower colonnades within an outcrop occur only when there are large differences in cooling rates between the upper and lower flow surfaces. Modeling shows that the cooling rates must differ by approximately an order of magnitude to produce the observed

  10. Eruption column height: a comparison between ground and satellite measurements

    NASA Astrophysics Data System (ADS)

    Scollo, Simona; Prestifilippo, Michele; Pecora, Emilio; Corradini, Stefano; Merucci, Luca; Spata, Gaetano; Coltelli, Mauro

    2014-05-01

    The eruption column height estimation is an essential parameter to evaluate the total mass eruption rate, the gas and aerosol plume dispersal and retrievals. The column height may be estimated using different systems (e.g. satellite, aircraft and ground observations) which may present marked differences. In this work we use the calibrated images collected by the video-surveillance system of the Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, from the visible camera located in Catania, 27 km from the vent. The analysis is carried out on twenty lava fountains from the New South East Crater during the recent Etna explosive activity. Firstly, we calibrated the camera to estimate its intrinsic parameters and the full camera model. Furthermore, we selected the images which recorded the maximum phase of the eruptive activity. Hence, we applied an appropriate correction to take into account the wind effect. The column height was also evaluated using SEVIRI and MODIS satellite images collected at the same time of the video camera measurements. The satellite column height retrievals is realized by comparing the 11 μm brightness temperature of the most opaque plume pixels with the atmospheric temperature profile measured at Trapani WMO Meteo station (the nearest WMO station to the Etnean area). The comparison between satellite and ground data show a good agreement and the column altitudes ranges between 7.5 and 9 km (upper limit of the camera system). For nine events we evaluated also the thickness of the volcanic plumes in the umbrella region (near the vent) which ranges between 2 and 3 km. The proposed approach help to quantitatively evaluate the column height that may be used by volcanic ash dispersal and sedimentation models for improving forecasts and reducing risks to aviation during volcanic crisis.

  11. Column abundance measurements of atmospheric hydroxyl at 45 deg S

    NASA Technical Reports Server (NTRS)

    Wood, S. W.; Keep, D. J.; Burnett, C. R.; Burnett, E. B.

    1994-01-01

    The first Southern Hemisphere measurements of the vertical column abundance of atmospheric hydroxyl (OH) have been obtained at Lauder, New Zealand (45 deg S) with a PEPSIOS instrument measuring the absorption of sunlight at 308 nm. The variation of column OH with solar zenith angle is similar to that measured at other sites. However average annual abundances of OH are about 20% higher than those found by similar measurements at 40 deg N. Minimum OH abundances about 10% less than average levels at 40 deg N, are observed during austral spring. The OH abundance abruptly increases by 30% in early summer and remains at the elevated level until late the following winter.

  12. Low-frequency flute instabilities of a bounded plasma column.

    NASA Technical Reports Server (NTRS)

    Rognlien, T. D.

    1973-01-01

    Derivation of exact solutions for unstable waves (called flute waves) which occur in a radially bounded plasma column at frequencies below the ion cyclotron frequency. Both analytical and numerical solutions are presented for the m = 1 and m = 2 azimuthal modes for a variety of radial electric field profiles. It is shown that the behavior of the flute waves can depend sensitively on the radial extent of the plasma column. Moreover, it is found that the m = 1 mode and the m = 2 mode do not respond in the same way to changes in the radial boundary position or in the electric field profile.

  13. Non-linear wave interaction in a plasma column

    NASA Technical Reports Server (NTRS)

    Larsen, J.-M.; Crawford, F. W.

    1979-01-01

    Non-linear three-wave interaction is analysed for propagation along a cylindrical plasma column surrounded by an infinite dielectric, in the absence of a static magnetic field. An averaged-Lagrangian method is used, and the results are specialized to parametric interaction and mode conversion, assuming an undepleted pump wave. The theory for these two types of interactions is extended to include imperfect synchronism, and the effects of loss. Computations are presented indicating that parametric growth rates of the order of a fraction of a decibel per centimeter should be obtainable for plausible laboratory plasma column parameters.

  14. Stud Reinforcement in Beam-Column Joints under Seismic Loads

    NASA Astrophysics Data System (ADS)

    Ibrahim, Hatem Hassan Ali

    Current codes recommend large amounts of shear reinforcement for reinforced concrete beam-column joints causing significant congestion. This research aims at investigating experimentally and numerically the efficiency of using studs with a head at each end in lieu of conventional closed hoops in reinforced concrete beam-column joints. The proposed reinforcement reduces congestion and ensures easier assembly of the reinforcing cage, saving labour cost and enhancing performance of the joint. Based on this research, a recommended arrangement and detailing of headed studs and their design for exterior beam-column joint are presented. The experimental investigation consisted of testing ten full-scale beam-column joint specimens under quasi-static cyclic loading. The specimens represented an exterior beam-column joint subassembly isolated at the points of contra-flexure from a typical multi-storey, multi-bay reinforced concrete frame. A test setup was developed to simulate the lateral inter-storey drift. The test parameters included: the type, arrangement and amount of shear reinforcement, the load history and rate of loading, and the amount of reinforcement for out-of-plane confinement of the joint. Envelopes of the hysteretic behaviour of the specimens and the joint deformation under shear stress are presented. The stiffness degradation, the strain levels in the joint reinforcement, the contribution of joint, beam, and column to the inter-storey drift, and the energy dissipation were compared. All the test specimens reinforced with headed studs in the joint achieved considerable enhancement in their behaviour under cyclic loads and exhibited a performance close to that of a joint reinforced with closed hoops and cross ties according to the code. All the specimens with adequate out-of-plane confinement had an equivalent behaviour compared with the code-based specimen and achieved a desirable mode of failure. Use of double-headed studs proved to be a viable option for

  15. A new model for solvent extraction in columns

    SciTech Connect

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

    1989-12-08

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

  16. Slender reinforced concrete columns strengthened with fibre reinforced polymers

    NASA Astrophysics Data System (ADS)

    Gajdošová, K.; Bilčík, J.

    2011-06-01

    The requirement for a long life with relatively low maintenance costs relates to the use of building structures. Even though the structure is correctly designed, constructed and maintained, the need for extensions of its lifetime can appear. The preservation of the original structure with a higher level of resistance or reliability is enabled by strengthening. Conventional materials are replaced by progressive composites - mainly carbon fibre reinforced polymers (CFRP). They are used for strengthening reinforced concrete columns in two ways: added reinforcement in the form of CFRP strips in grooves or CFRP sheet confinement and eventually their combination. This paper presents the effect of the mentioned strengthening methods on slender reinforced concrete columns.

  17. Verification of a model for foam flotation column operation

    SciTech Connect

    Kiefer, J.E.; Rodriguez, J.; McIntyre, G.; Thackston, E.L.; Wilson, D.J.

    1982-01-01

    We report experimental data testing the validity of a mathematical model for the time-dependent operation of a continuous-flow foam floating column.Sodium lauryl sulfate was the surfactant being removed. The responses of the column in steady-state operation and under the influence of rectangular pulses in sodium lauryl sulfates concentration and in hydraulic loading rate were investigated and compared with the results of computer simulation.Effluent surfactant concentrations were well simulated under all conditions. It was found that the fraction of liquid in the Plateau borders varies somewhat with the hydraulic loading rate, which causes some discrepancy between calculated and observed collapsed foamate flow rates.

  18. Column experiments on organic micropollutants - applications and limitations

    NASA Astrophysics Data System (ADS)

    Banzhaf, Stefan; Hebig, Klaus

    2016-04-01

    As organic micropollutants become more and more ubiquitous in the aquatic environment, a sound understanding of their fate and transport behaviour is needed. This is to assure both safe and clean drinking water supply for mankind in the future and to protect the aquatic environment from pollution and negative consequences caused by manmade contamination. Apart from countless field studies, column experiments were and are frequently used to study transport of organic micropollutants. As the transport of (organic) solutes in groundwater is controlled by the chemical and physical properties of the compounds, the solvent (the groundwater including all solutes), and the substrate (the aquifer material), the adjustment and control of these boundary conditions allow to study a multitude of different experimental setups and to address specific research questions. The main purpose, however, remains to study the transport of a specific compound and its sorption and degradation behaviour in a specific sediment or substrate. Apart from the effective control of the individual boundary conditions, the main advantage of columns studies compared to other experimental setups (such as field studies, batch/microcosm studies), is that conservative and reactive solute breakthrough curves are obtained, which represent the sum of the transport processes. The analysis of these curves is well-developed and established. Additionally, limitations of this experimental method are presented here: the effects observed in column studies are often a result of dynamic, non-equilibrium processes. Time (or flow velocity) plays a major role in contrast to batch experiments, in which all processes will be observed until equilibrium is reached in the substrate-solution-system. Slightly modifying boundary conditions in different experiments have a strong influence on transport and degradation behaviour of organic micropollutants. This is a significant severe issue when it comes to general findings on the

  19. Fundamental research on oscillating water column wave power absorbers

    SciTech Connect

    Maeda, H.; Kato, W.; Kinoshita, T.; Masuda, K.

    1985-03-01

    An oscillating water column (OWC) wave power absorber is one of the most promising devices, as well as the Salter Duck and the Clam. This paper presents a simple prediction method, in which the equivalent floating body approximation is used, for absorbing wave power characteristics of an oscillating water column device. The effects of the compressibility of air and inertia of an air turbine and electric generator on absorbed wave power are obtained by using the equivalent electric circuit concept. Both the experimental and theoretical studies are carried out in this paper.

  20. Instrument for the measurement and determination of chemical pulse column parameters

    DOEpatents

    Marchant, Norman J.; Morgan, John P.

    1990-01-01

    An instrument for monitoring and measuring pneumatic driving force pulse parameters applied to chemical separation pulse columns obtains real time pulse frequency and root mean square amplitude values, calculates column inch values and compares these values against preset limits to alert column operators to the variations of pulse column operational parameters beyond desired limits.

  1. 40 CFR Table 25 to Subpart G of... - Effective Column Diameter (Fc)

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Effective Column Diameter (Fc) 25 Table..., Table 25 Table 25 to Subpart G of Part 63—Effective Column Diameter (Fc) Column type Fc (feet) 9-inch by 7-inch built-up columns 1.1 8-inch-diameter pipe columns 0.7 No construction details known 1.0...

  2. 40 CFR Table 25 to Subpart G of... - Effective Column Diameter (Fc)

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Effective Column Diameter (Fc) 25 Table..., Table 25 Table 25 to Subpart G of Part 63—Effective Column Diameter (Fc) Column type Fc (feet) 9-inch by 7-inch built-up columns 1.1 8-inch-diameter pipe columns 0.7 No construction details known 1.0...

  3. If You Were a Molecule in a Chromatography Column, What Would You See?

    ERIC Educational Resources Information Center

    Mattice, John

    2008-01-01

    To visualize what takes place in a chromatography column, enlarge the molecules to human size and expand the columns to keep the ratio of size of molecule to size of column the same. If we were molecules, what would the columns be like? A typical gas chromatography (GC) capillary column would be 50 x 10 [superscript 6] 6 km (31 million mi) long,…

  4. NO2 column changes induced by volcanic eruptions

    NASA Technical Reports Server (NTRS)

    Johnston, Paul V.; Keys, J. Gordon; Mckenzie, Richard L.

    1994-01-01

    Nitrogen dioxide slant column amounts measured by ground-based remote sensing from Lauder, New Zealand (45 deg S) and Campbell Island (53 deg S) during the second half of 1991 and early 1992 show anomalously low values that are attributed to the effects of volcanic eruptions. It is believed that the eruptions of Mount Pinatubo in the Philippines in June 1991 and possibly Mount Hudson in Chile in August 1991 are responsible for the stratospheric changes, which first became apparent in July 1991. The effects in the spring of 1991 are manifested as a reduction in the retrieved NO2 column amounts from normal levels by 35 to 45 percent, and an accompanying increase in the overnight decay of NO2. The existence of an accurate long-term record of column NO2 from the Lauder site enables us to quantify departures from the normal seasonal behavior with some confidence. Simultaneous retrievals of column ozone agree well with Dobson measurements, confirming that only part of the NO2 changes can be attributed to a modification of the scattering geometry by volcanic aerosols. Other reasons for the observed behavior are explored, including the effects of stratospheric temperature increases resulting from the aerosol loading and the possible involvement of heterogeneous chemical processes.

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

    PubMed

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

    2014-10-17

    Monolithic molecularly imprinted polymers extraction columns have been prepared in fused-silica capillaries by UV or thermal polymerization in a two-step process. First, a poly-(trimethylolpropane trimethacrylate) (polyTRIM) core monolith was synthesized either by UV or thermal polymerization. Then it was grafted with the mixture of methacrylic acid (MAA) as a functional monomer, ethylene dimethacrylate (EDMA) as a cross-linking agent, 5,7-dimethoxycoumarin (DMC) as an aflatoxin-mimicking template, toluene as a porogen solvent and 2,2-azobis-(2-methylpropionitrile) (AIBN) as an initiator of the polymerization reaction. Different thermal condition of the photografting and different concentrations of the grafting mixture were tested during polymerization. The extraction capillary columns were evaluated in the terms of their hydrodynamic and chromatographic properties. Retention coefficients for aflatoxin B1 and DMC were used for assessment of the selectivity and imprinting factor. The obtained results indicate that the temperature of photografting and concentration of the grafting mixture are key parameters that determine the quality of the prepared MIPs. From the MIP columns characterized by the highest permeability the column of the highest imprinting factor was applied for isolation of aflatoxins B1, B2, G1 and G2 from the model aqueous sample followed by on-line chromatographic separation. The process was performed using a micro-MISPE-microLC-LIF system of a novel design, which allowed for detection of the eluates from the sample preparation part as well as from the chromatographic separation. PMID:25218633

  6. Assessment of solution uncertainties in single-column modeling frameworks

    SciTech Connect

    Hack, J.J.; Pedretti, J.A.

    2000-01-15

    Single-column models (SCMs) have been extensively promoted in recent years as an effective means to develop and test physical parameterizations targeted for more complex three-dimensional climate models. Although there are some clear advantages associated with single-column modeling, there are also some significant disadvantages, including the absence of large-scale feedbacks. Basic limitations of an SCM framework can make it difficult to interpret solutions, and at times contribute to rather striking failures to identify even first-order sensitivities as they would be observed in a global climate simulation. This manuscript will focus on one of the basic experimental approaches currently exploited by the single-column modeling community, with an emphasis on establishing the inherent uncertainties in the numerical solutions. The analysis will employ the standard physics package from the NCAR CCM3 and will illustrate the nature of solution uncertainties that arise from nonlinearities in parameterized physics. The results of this study suggest the need to make use of an ensemble methodology when conducting single-column modeling investigations.

  7. 14. FIRST FLOOR BLDG. 28: DETAIL OCTAGONAL COLUMN. Fafnir ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. FIRST FLOOR BLDG. 28: DETAIL OCTAGONAL COLUMN. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  8. 10. FIRST FLOOR BLDG. 28B: DETAIL FLARED COLUMN. Fafnir ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. FIRST FLOOR BLDG. 28B: DETAIL FLARED COLUMN. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  9. Combining micro dry column chromatography and mass spectrometry

    NASA Technical Reports Server (NTRS)

    Bauman, A. J.

    1970-01-01

    Dry column chromatography principles applied in microscale produce technique to minimize time in preparing and analyzing colorless constituents of soluble mixtures. Glass pipette microcolumns filled with finely sieved adsorbents permit capillary attraction and separation in 3 to 15 minutes. Technique is adaptable to gas chromatography.

  10. CAR MACHINE SHOP, FIRST FLOOR, DETAIL OF STEEL COLUMN AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CAR MACHINE SHOP, FIRST FLOOR, DETAIL OF STEEL COLUMN AND BEAM ALTERATION, LOOKING SOUTH. MODIFICATION WAS DONE TO ACCOMMODATE MACHINERY DURING THE BUILDING'S USE AS A WHEEL SHOP. - Southern Pacific, Sacramento Shops, Car Machine Shop, 111 I Street, Sacramento, Sacramento County, CA

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

    PubMed

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

    2014-01-01

    Human activity and natural climate trends constitute a major threat to coral reefs worldwide. Models predict a significant reduction in reef spatial extension together with a decline in biodiversity in the relatively near future. In this context, monitoring programs to detect changes in reef ecosystems are essential. In recent years, coral reef mapping using remote sensing data has benefited from instruments with better resolution and computational advances in storage and processing capabilities. However, the water column represents an additional complexity when extracting information from submerged substrates by remote sensing that demands a correction of its effect. In this article, the basic concepts of bottom substrate remote sensing and water column interference are presented. A compendium of methodologies developed to reduce water column effects in coral ecosystems studied by remote sensing that include their salient features, advantages and drawbacks is provided. Finally, algorithms to retrieve the bottom reflectance are applied to simulated data and actual remote sensing imagery and their performance is compared. The available methods are not able to completely eliminate the water column effect, but they can minimize its influence. Choosing the best method depends on the marine environment, available input data and desired outcome or scientific application. PMID:25215941

  12. Water Column Correction for Coral Reef Studies by Remote Sensing

    PubMed Central

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

    2014-01-01

    Human activity and natural climate trends constitute a major threat to coral reefs worldwide. Models predict a significant reduction in reef spatial extension together with a decline in biodiversity in the relatively near future. In this context, monitoring programs to detect changes in reef ecosystems are essential. In recent years, coral reef mapping using remote sensing data has benefited from instruments with better resolution and computational advances in storage and processing capabilities. However, the water column represents an additional complexity when extracting information from submerged substrates by remote sensing that demands a correction of its effect. In this article, the basic concepts of bottom substrate remote sensing and water column interference are presented. A compendium of methodologies developed to reduce water column effects in coral ecosystems studied by remote sensing that include their salient features, advantages and drawbacks is provided. Finally, algorithms to retrieve the bottom reflectance are applied to simulated data and actual remote sensing imagery and their performance is compared. The available methods are not able to completely eliminate the water column effect, but they can minimize its influence. Choosing the best method depends on the marine environment, available input data and desired outcome or scientific application. PMID:25215941

  13. 3. DRAINING & DRYING BUILDING, REINFORCED CONCRETE MUSHROOM COLUMNS WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. DRAINING & DRYING BUILDING, REINFORCED CONCRETE MUSHROOM COLUMNS WITH DROP PANELS SUPPORTING DRAINING BINS (IRON VALVES OF DRAINING BINS ARE EMBEDDED IN THE CEILING), VIEW LOOKING WEST - Mill "C" Complex, Sand Draining & Drying Building, South of Dee Bennet Road, near Illinois River, Ottawa, La Salle County, IL

  14. 23. DETAIL VIEW OF COLUMN #072, SHOWING TOP LEANING TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. DETAIL VIEW OF COLUMN #072, SHOWING TOP LEANING TO SOUTHEAST (LEFT IN PHOTOGRAPH) WITH STEEL PIPE AS TEMPORARY SUPPORT (SEE PHOTOGRAPH NO. CA-125-A-24 BELOW) - Oakland Army Base, Transit Shed, East of Dunkirk Street & South of Burma Road, Oakland, Alameda County, CA

  15. Ciliates along oxyclines of permanently stratified marine water columns.

    PubMed

    Edgcomb, Virginia P; Pachiadaki, Maria

    2014-01-01

    Studies of microbial communities in areas of the world where permanent marine water column oxyclines exist suggest they are "hotspots" of microbial activity, and that these water features and the anoxic waters below them are inhabited by diverse protist taxa, including ciliates. These communities have minimal taxonomic overlap with those in overlying oxic water columns. Some ciliate taxa have been detected in multiple locations where these stable water column oxyclines exist; however, differences in such factors as hydrochemistry in the habitats that have been studied suggest local selection for distinct communities. We compare published data on ciliate communities from studies of deep marine water column oxyclines in Caricao Basin, Venezuela, and the Black Sea, with data from coastal, shallower oxycline waters in Framvaren and Mariager fjords, and from several deep-sea hypersaline anoxic basins in the Eastern Mediterranean Sea. Putative symbioses between Bacteria, Archaea, and ciliates observed along these oxyclines suggests a strategy of cooperative metabolism for survival that includes chemosynthetic autotrophy and exchanges of metabolic intermediates or end products between hosts and their prokaryotic partners. PMID:24801774

  16. 16. View to southeast of underside, showing paired lally columns ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. View to southeast of underside, showing paired lally columns with southeast abutment beyond, floor beams, laterals, and stringers. Paired eye bars of lower chord visible at left. - Red Bank Creek Bridge, Spanning Red Bank Creek at Rawson Road, Red Bluff, Tehama County, CA

  17. Continuous and Batch Distillation in an Oldershaw Tray Column

    ERIC Educational Resources Information Center

    Silva, Carlos M.; Vaz, Raquel V.; Santiago, Ana S.; Lito, Patricia F.

    2011-01-01

    The importance of distillation in the separation field prompts the inclusion of distillation experiments in the chemical engineering curricula. This work describes the performance of an Oldershaw column in the rectification of a cyclohexane/n-heptane mixture. Total reflux distillation, continuous rectification under partial reflux, and batch…

  18. Fragility curves of concrete bridges retrofitted by column jacketing

    NASA Astrophysics Data System (ADS)

    Shinozuka, Masanobu; Kim, Sang-Hoon; Kushiyama, Shigeru; Yi, Jin-Hak

    2002-12-01

    The Northridge earthquake inflicted various levels of damage upon a large number of Caltrans’ bridges not retrofitted by column jacketing. In this respect, this study represents results of fragility curve development for two (2) sample bridges typical in southern California, strengthened for seismic retrofit by means of steel jacketing of bridge columns. Monte Carlo simulation is performed to study nonlinear dynamic responses of the bridges before and after column retrofit. Fragility curves in this study are represented by lognormal distribution functions with two parameters and developed as a function of PGA. The sixty (60) ground acceleration time histories for the Los Angeles area developed for the Federal Emergency Management Agcncy (FEMA) SAC (SEAOC-ATC-CUREe) steel project are used for the dynamic analysis of the bridges. The improvement in the fragility with steel jacketing is quantified by comparing fragility curves of the bridge before and after column retrofit. In this first attempt to formulate the problem of fragility enhancement, the quantification is made by comparing the median values of the fragility curves before and after the retrofit. Under the hypothesis that this quantification also applies to empirical fragility curves developed on the basis of Northridge earthquake damage, the enhanced version of the empirical curves is developed for the ensuing analysis to determine the enhancement of transportation network performance due to the retrofit.

  19. Pressure effects on bubble-column flow characteristics

    SciTech Connect

    Adkins, D.R.; Shollenberger, K.A.; O`Hern, T.J.; Torczynski, J.R.

    1996-03-01

    Bubble-column reactors are used in the chemical processing industry for two-phase and three-phase chemical reactions. Hydrodynamic effects must be considered when attempting to scale these reactors to sizes of industrial interest, and diagnostics are needed to acquire data for the validation of multiphase scaling predictions. This paper discusses the use of differential pressure (DP) and gamma- densitometry tomography (GDT) measurements to ascertain the gas distribution in a two-phase bubble column reactor. Tests were performed on an industrial scale reactor (3-m tall, 0.48-m inside diameter) using a 5-Curie cesium-137 source with a sodium-iodide scintillation detector. GDT results provide information on the time- averaged cross-sectional distribution of gas in the liquid, and DP measurements provide information on the time and volume averaged axial distribution of gas. Close agreement was observed between the two methods of measuring the gas distribution in the bubble column. The results clearly show that, for a fixed volumetric flowrate through the reactor, increasing the system pressure leads to an increase in the gas volume fraction or ``gas holdup`` in the liquid. It is also shown from this work that GDT can provide useful diagnostic information on industrial scale bubble-column reactors.

  20. Herbicide Leaching Column for a Weed Science Teaching Laboratory.

    ERIC Educational Resources Information Center

    Ahrens, W. H.

    1986-01-01

    Presents an experiment which enables weed science students to observe first-hand the process of herbicide leaching in soils. Features of this technique which demonstrate the movement of herbicide within a column of soil are outlined. Diagrams are provided of the apparatus employed in the exercise. (ML)

  1. NORTH BASEMENT WALL. IBEAM COLUMNS HAVE BEEN ENCASED IN CONCRETE. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    NORTH BASEMENT WALL. I-BEAM COLUMNS HAVE BEEN ENCASED IN CONCRETE. STEEL BEAMS LAY ACROSS FIRST FLOOR AWAITING CONCRETE POUR. CAMERA LOOKS SOUTHWEST. INL NEGATIVE NO. 735. Unknown Photographer, 10/6/1950 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  2. A Weekly Column Is a P.R. Plum.

    ERIC Educational Resources Information Center

    Wuehle, Edwin E.

    1988-01-01

    Advises superintendents to increase school visibility by writing a weekly newspaper column that communicates important school information, discusses school issues, recognizes educators' outstanding accomplishments, corrects false impressions or misinformation, and presents the human side of schooling. Several tips are provided for planning,…

  3. Pepsin-modified chiral monolithic column for affinity capillary electrochromatography.

    PubMed

    Hong, Tingting; Chi, Cuijie; Ji, Yibing

    2014-11-01

    Pepsin-modified affinity monolithic capillary electrochromatography, a novel microanalysis system, was developed by the covalent bonding of pepsin on silica monolith. The column was successfully applied in the chiral separation of (±)-nefopam. Furthermore, the electrochromatographic performance of the pepsin-functionalized monolith for enantiomeric analysis was evaluated in terms of protein content, pH of running buffer, sample volume, buffer concentration, applied voltage, and capillary temperature. The relative standard deviation (%RSD) values of retention time (intraday <0.53, n = 10; interday <0.53, n = 10; column-to-column <0.70, n = 20; and batch-to-batch <0.80, n = 20) indicated satisfactory stability of these columns. No appreciable change was observed in retention and resolution for chiral recognition of (±)-nefopam in 50 days with 100 injections. The proteolytic activity of this stationary phase was further characterized with bovine serum albumin as substrate for online protein digestion. As for monolithic immobilized enzyme reactor, successive protein injections confirmed both the operational stability and ability to reuse the bioreactor for at least 20 digestions. It implied that the affinity monolith used in this research opens a new path of exploring particularly versatile class of enzymes to develop enzyme-modified affinity capillary monolith for enantioseparation. PMID:25146884

  4. Comparison of neptunium sorption results using batch and column techniques

    SciTech Connect

    Triay, I.R.; Furlano, A.C.; Weaver, S.C.; Chipera, S.J.; Bish, D.L.

    1996-08-01

    We used crushed-rock columns to study the sorption retardation of neptunium by zeolitic, devitrified, and vitric tuffs typical of those at the site of the potential high-level nuclear waste repository at Yucca Mountain, Nevada. We used two sodium bicarbonate waters (groundwater from Well J-13 at the site and water prepared to simulate groundwater from Well UE-25p No. 1) under oxidizing conditions. It was found that values of the sorption distribution coefficient, Kd, obtained from these column experiments under flowing conditions, regardless of the water or the water velocity used, agreed well with those obtained earlier from batch sorption experiments under static conditions. The batch sorption distribution coefficient can be used to predict the arrival time for neptunium eluted through the columns. On the other hand, the elution curves showed dispersivity, which implies that neptunium sorption in these tuffs may be nonlinear, irreversible, or noninstantaneous. As a result, use of a batch sorption distribution coefficient to calculate neptunium transport through Yucca Mountain tuffs would yield conservative values for neptunium release from the site. We also noted that neptunium (present as the anionic neptunyl carbonate complex) never eluted prior to tritiated water, which implies that charge exclusion does not appear to exclude neptunium from the tuff pores. The column experiments corroborated the trends observed in batch sorption experiments: neptunium sorption onto devitrified and vitric tuffs is minimal and sorption onto zeolitic tuffs decreases as the amount of sodium and bicarbonate/carbonate in the water increases.

  5. Thermal Analysis for Ion-Exchange Column System

    SciTech Connect

    Lee, Si Y.; King, William D.

    2012-12-20

    Models have been developed to simulate the thermal characteristics of crystalline silicotitanate ion exchange media fully loaded with radioactive cesium either in a column configuration or distributed within a waste storage tank. This work was conducted to support the design and operation of a waste treatment process focused on treating dissolved, high-sodium salt waste solutions for the removal of specific radionuclides. The ion exchange column will be installed inside a high level waste storage tank at the Savannah River Site. After cesium loading, the ion exchange media may be transferred to the waste tank floor for interim storage. Models were used to predict temperature profiles in these areas of the system where the cesium-loaded media is expected to lead to localized regions of elevated temperature due to radiolytic decay. Normal operating conditions and accident scenarios (including loss of solution flow, inadvertent drainage, and loss of active cooling) were evaluated for the ion exchange column using bounding conditions to establish the design safety basis. The modeling results demonstrate that the baseline design using one central and four outer cooling tubes provides a highly efficient cooling mechanism for reducing the maximum column temperature. In-tank modeling results revealed that an idealized hemispherical mound shape leads to the highest tank floor temperatures. In contrast, even large volumes of CST distributed in a flat layer with a cylindrical shape do not result in significant floor heating.

  6. Cyclodextrin-Functionalized Monolithic Capillary Columns: Preparation and Chiral Applications.

    PubMed

    Adly, Frady G; Antwi, Nana Yaa; Ghanem, Ashraf

    2016-02-01

    In this review, the recently reported approaches for the preparation of cyclodextrin-functionalized capillary monolithic columns are highlighted, with few applications in chiral separations using capillary liquid chromatography (CLC) and capillary electrochromatography (CEC). Chirality 28:97-109, 2016. © 2015 Wiley Periodicals, Inc. PMID:26563470

  7. Separation of kafirins on surface porous RP-HPLC columns

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface porous HPLC columns were investigated for the separation of kafarins, storage proteins of grain sorghum. Kafirins were successfully separated using C3, C8 and C18 surface porous stationary phases in less than 17 min. Separations using a monolithic C18 stationary phase were also developed ...

  8. 60. DETAIL VIEW OF TWO STEEL STRUCTURAL COLUMNS THAT REPLACED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    60. DETAIL VIEW OF TWO STEEL STRUCTURAL COLUMNS THAT REPLACED THE ORIGINAL BRICK SUPPORTS FOR THE SOUTHERNMOST ARCH ON THE BUILDING'S W WALL WHEN THE S SECTION OF THE BUILDING WAS 'OPENED-UP' DURING THE SECOND WORLD WAR; LOOKING NW. (Ceronie) - Watervliet Arsenal, Building No. 110, Hagner Road between Schull & Whittemore Roads, Watervliet, Albany County, NY

  9. DETAIL VIEW OF THE BRACED IBEAM COLUMNS AT THE END ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF THE BRACED I-BEAM COLUMNS AT THE END OF THE CENTER FLAT TRUSS OF THE ROOF. NOTE THE ORIGINAL LIGHT FIXTURE WITH BENT CONDUIT TUBING. VIEW FACING SOUTHEAST. - U.S. Naval Base, Pearl Harbor, Seaplane Hangar, Lexington Boulevard, south of Enterprise Street, Pearl City, Honolulu County, HI

  10. Water column methanotrophy controlled by a rapid oceanographic switch

    NASA Astrophysics Data System (ADS)

    Steinle, Lea; Graves, Carolyn A.; Treude, Tina; Ferré, Bénédicte; Biastoch, Arne; Bussmann, Ingeborg; Berndt, Christian; Krastel, Sebastian; James, Rachael H.; Behrens, Erik; Böning, Claus W.; Greinert, Jens; Sapart, Célia-Julia; Scheinert, Markus; Sommer, Stefan; Lehmann, Moritz F.; Niemann, Helge

    2015-05-01

    Large amounts of the greenhouse gas methane are released from the seabed to the water column, where it may be consumed by aerobic methanotrophic bacteria. The size and activity of methanotrophic communities, which determine the amount of methane consumed in the water column, are thought to be mainly controlled by nutrient and redox dynamics. Here, we report repeated measurements of methanotrophic activity and community size at methane seeps west of Svalbard, and relate them to physical water mass properties and modelled ocean currents. We show that cold bottom water, which contained a large number of aerobic methanotrophs, was displaced by warmer water with a considerably smaller methanotrophic community within days. Ocean current simulations using a global ocean/sea-ice model suggest that this water mass exchange is consistent with short-term variations in the meandering West Spitsbergen Current. We conclude that the shift from an offshore to a nearshore position of the current can rapidly and severely reduce methanotrophic activity in the water column. Strong fluctuating currents are common at many methane seep systems globally, and we suggest that they affect methane oxidation in the water column at other sites, too.

  11. Column Chromatography To Obtain Organic Cation Sorption Isotherms.

    PubMed

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

    2016-08-01

    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. PMID:27379799

  12. Molecular crowding-based imprinted monolithic column for capillary electrochromatography.

    PubMed

    Zong, Hai-Yan; Liu, Xiao; Liu, Zhao-Sheng; Huang, Yan-Ping

    2015-03-01

    Molecular crowding is a new approach to stabilizing binding sites and improving molecular recognition. In this work, the concept was applied to the preparation of imprinted monolithic columns for CEC. The imprinted monolithic column was synthesized using a mixture of d-zopiclone (d-ZOP)(template), methacrylic acid, ethylene glycol dimethacrylate, and poly(methyl methacrylate) (PMMA) (molecular crowding agent). The resulting PMMA-based imprinted capillary was able to separate ZOP enantiomers in CEC mode. The resolution of enantiomer separation achieved on the d-ZOP-imprinted monolithic column was up to 2.09. Some polymerization factors, such as template-monomer molar ratio, functional monomer-cross-linker molar ratio and the composition of the porogen, on the imprinting effect of resulting molecularly imprinted polymer (MIP) monolithic column were systematically investigated. Chromatographic parameters, including pH values, the content of acetonitrile and the salt concentration on chiral separation were also studied. The results indicated the addition of PMMA resulted in MIPs with superior retention properties and excellent selectivity for d-ZOP, as compared to the MIPs prepared without addition of the crowding-inducing agent. The results revealed that molecular crowding is an effective method for the preparation of a highly efficient MIP stationary phase for chiral separation in CEC. PMID:25404035

  13. Pulsed airborne lidar measurements of atmospheric CO2 column absorption

    NASA Astrophysics Data System (ADS)

    Abshire, James B.; Riris, Haris; Allan, Graham R.; Weaver, Clark J.; Mao, Jianping; Sun, Xiaoli; Hasselbrack, William E.; Kawa, S. Randoph; Biraud, Sebastien

    2010-11-01

    ABSTRACT We report initial measurements of atmospheric CO2 column density using a pulsed airborne lidar operating at 1572 nm. It uses a lidar measurement technique being developed at NASA Goddard Space Flight Center as a candidate for the CO2 measurement in the Active Sensing of CO2 Emissions over Nights, Days and Seasons (ASCENDS) space mission. The pulsed multiple-wavelength lidar approach offers several new capabilities with respect to passive spectrometer and other lidar techniques for high-precision CO2 column density measurements. We developed an airborne lidar using a fibre laser transmitter and photon counting detector, and conducted initial measurements of the CO2 column absorption during flights over Oklahoma in December 2008. The results show clear CO2 line shape and absorption signals. These follow the expected changes with aircraft altitude from 1.5 to 7.1 km, and are in good agreement with column number density estimates calculated from nearly coincident airborne in-situ measurements.

  14. On equilibration of pore water in column leaching tests.

    PubMed

    Grathwohl, Peter

    2014-05-01

    Column leaching tests are closer to natural conditions than batch shaking tests and in the last years have become more popular for assessing the release potential of pollutants from a variety of solids such as contaminated soils, waste, recycling and construction materials. Uncertainties still exist regarding equilibration of the percolating water with the solids, that might potentially lead to underestimation of contaminant concentrations in the effluent. The intention of this paper is to show that equilibration of pore water in a finite bath is fundamentally different from release of a certain fraction of the pollutant from a sample and that equilibrium is reached much faster at low liquid-to-solid ratios typical for column experiments (<0.25) than in batch tests with much higher liquid-to-solid ratios (e.g., 2-10). Two mass transfer mechanisms are elucidated: First-order type release (film diffusion) and intraparticle diffusion. For the latter, mass transfer slows down with time and sooner or later non-equilibrium conditions are observed at the column outlet after percolation has been started. Time scales of equilibrium leaching can be estimated based on a comparison of column length with the length of the mass transfer zone, which is equivalent to a Damköhler number approach. Mass transfer and diffusion coefficients used in this study apply to mass transfer mechanisms limited by diffusion in water, which is typical for release of organic compounds but also for dissolution of soluble minerals such as calcite, gypsum or similar. As a conclusion based on these theoretical considerations column tests (a) equilibrate much faster than batch leaching tests and (b) the equilibrium concentrations are maintained in the column effluent even for slow intraparticle diffusion limited desorption for extended periods of time (>days). Since for equilibration the specific surface area is crucial, the harmonic mean of the grain size is relevant (small grain sizes result in high

  15. Purification of polar compounds from Radix isatidis using conventional C18 column coupled with polar-copolymerized C18 column.

    PubMed

    Zeng, Jing; Guo, Zhimou; Xiao, Yuansheng; Wang, Chaoran; Zhang, Xiuli; Liang, Xinmiao

    2010-11-01

    Regarding hydrophilic interaction chromatography and normal phase liquid chromatography, RPLC is another choice used to separate polar compounds with the improvement of polar-modified C18 stationary phase. In this study, a method using conventional C18 column coupled with polar-copolymerized C18 column was successfully developed for the separation and purification of polar compounds from Radix isatidis, which is one of the most commonly used traditional Chinese medicines (TCMs). An XTerra MS C18 column was used to fractionate the extract of R. isatidis and a homemade polar-copolymerized C18 column was utilized for the final purification due to its good separation selectivity and high resolution for polar compounds. The established purification system demonstrated good orthogonality for the polar compounds. As a result, ten compounds were purified and three of them were identified as 3-methyl-5-vinyloxazolidin-2-one (compound A), 5-hydroxymethyl-2-furaldehyde (compound B) and 3-methylfuran-2-carboxylic acid (compound G) based on the MS, IR and extensive NMR data, respectively. It was demonstrated to be a feasible and powerful technique for the purification of polar compounds under RPLC mode and more chemical information of TCMs will be obtained to interpret the efficiency of TCMs. PMID:20886519

  16. Drivers of column-average CO2 variability at Southern Hemispheric Total Carbon Column Observing Network sites

    NASA Astrophysics Data System (ADS)

    Deutscher, N. M.; Sherlock, V.; Mikaloff Fletcher, S. E.; Griffith, D. W. T.; Notholt, J.; Macatangay, R.; Connor, B. J.; Robinson, J.; Shiona, H.; Velazco, V. A.; Wang, Y.; Wennberg, P. O.; Wunch, D.

    2014-09-01

    We investigate factors that drive the variability in total column CO2 at the Total Carbon Column Observing Network sites in the Southern Hemisphere using fluxes tagged by process and by source region from the CarbonTracker analysed product as well as the Simple Biosphere model. We show that the terrestrial biosphere is the largest driver of variability in the Southern Hemisphere column CO2. However, it does not dominate in the same fashion as in the Northern Hemisphere. Local- and hemispheric-scale biomass burning can also play an important role, particularly at the tropical site, Darwin. The magnitude of seasonal variability in the column-average dry-air mole fraction of CO2, XCO2, is also much smaller in the Southern Hemisphere and comparable in magnitude to the annual increase. Comparison of measurements to the model simulations highlights that there is some discrepancy between the two time series, especially in the early part of the Darwin data record. We show that this mismatch is most likely due to erroneously estimated local fluxes in the Australian tropical region, which are associated with enhanced photosynthesis caused by early rainfall during the tropical monsoon season.

  17. Recent Progress in Monolithic Silica Columns for High-Speed and High-Selectivity Separations

    NASA Astrophysics Data System (ADS)

    Ikegami, Tohru; Tanaka, Nobuo

    2016-06-01

    Monolithic silica columns have greater (through-pore size)/(skeleton size) ratios than particulate columns and fixed support structures in a column for chemical modification, resulting in high-efficiency columns and stationary phases. This review looks at how the size range of monolithic silica columns has been expanded, how high-efficiency monolithic silica columns have been realized, and how various methods of silica surface functionalization, leading to selective stationary phases, have been developed on monolithic silica supports, and provides information on the current status of these columns. Also discussed are the practical aspects of monolithic silica columns, including how their versatility can be improved by the preparation of small-sized structural features (sub-micron) and columns (1 mm ID or smaller) and by optimizing reaction conditions for in situ chemical modification with various restrictions, with an emphasis on recent research results for both topics.

  18. Recent Progress in Monolithic Silica Columns for High-Speed and High-Selectivity Separations.

    PubMed

    Ikegami, Tohru; Tanaka, Nobuo

    2016-06-12

    Monolithic silica columns have greater (through-pore size)/(skeleton size) ratios than particulate columns and fixed support structures in a column for chemical modification, resulting in high-efficiency columns and stationary phases. This review looks at how the size range of monolithic silica columns has been expanded, how high-efficiency monolithic silica columns have been realized, and how various methods of silica surface functionalization, leading to selective stationary phases, have been developed on monolithic silica supports, and provides information on the current status of these columns. Also discussed are the practical aspects of monolithic silica columns, including how their versatility can be improved by the preparation of small-sized structural features (sub-micron) and columns (1 mm ID or smaller) and by optimizing reaction conditions for in situ chemical modification with various restrictions, with an emphasis on recent research results for both topics. PMID:27306311

  19. Structural efficiency of long lightly loaded truss and isogrid columns for space applications

    NASA Technical Reports Server (NTRS)

    Mikulas, M. M., Jr.

    1978-01-01

    The general mass characteristics of long lightly loaded columns for space applications are investigated by studying four column concepts. The first is a simple tubular column, the second is a three longeron truss column constructed of tubular members, the third is a three longeron truss column constructed of solid rod members, and the fourth is an open grid work isogrid wall tubular column. Design procedures, which include an initial imperfection in the straightness of the column, are developed for the different concepts and demonstrated numerically. A new set of structural efficiency parameters are developed for lightly loaded columns and are used to show a comparison of the masses of the four column concepts investigated.

  20. Oblique Shock Wave Effects on Impulsively Accelerated Heavy Gas Column

    NASA Astrophysics Data System (ADS)

    Olmstead, Dell T.

    An experimental study was performed to elucidate the fundamental physics of shock-induced mixing for a simple three-dimensional interface. The interface studied consists of a gravity stabilized SF6-based heavy gas jet that produced a circular column with a diffuse interface into the surrounding air. The effects of density gradient (Atwood number, A), shock strength (Mach number, M), and column inclination angle (theta) were examined. Concentration was measured using Planar Laser Induced Fluorescence (PLIF) of an acetone vapor tracer mixed with the heavy gas jet and illuminated by a pulsed Nd-YAG laser. Shocks with Mach numbers of 1.13, 1.5, 1.7, and 2.0 were used for inclinations of 0° (planar normal shock wave), 20° and 30°. Columns with Atwood numbers of 0.25, 0.4, and 0.60 were tested at Mach 1.7 for inclinations of 0° and 20°. The oblique shock-accelerated cylindrical interface produced a typical Richtmyer-Meshkov instability (RMI) consisting of a primary counter-rotating vortices. The streamwise extent of the vortex pair in the centerline plane (cross-section) images of the column is proportional to √A/√ M, regardless of oblique shock angle for theta < 20. A heretofore unseen manifestation of Kelvin-Helmholtz (K-H) waves on the upstream edge of the column appear for oblique shock acceleration. The upstream edge K-H waves were observed in images from a vertical plane through the center of the column. The wavelength of the upstream edge K-H waves is proportional to theta/M ˙ √A. This upstream edge K-H instability (KHI) caused earlier onset of secondary instabilities in the primary RMI vortices seen in the centerline plane images. The combination of more rapid onset of secondary instabilities in the RMI and upstream edge KHI accelerated transition to turbulence and thus reduced the time to achieve well-mixed flow. Time to reach well-mixed flow was inversely related to Atwood number, and had a weak correlation with Mach number for M>1.13. Transition to

  1. Mt. Pinatubo SO2 Column Measurements From Mauna Loa

    NASA Technical Reports Server (NTRS)

    Goldman, A.; Murcray, F. J.; Rinsland, C. P.; Blatherwick, R. D.; David, S. J.; Murcray, F. H.; Murcray, D. G.

    1992-01-01

    Absorption features of the nu(sub 1) band of SO2 have been identified in high resolution infrared solar absorption spectra recorded from Mauna Loa, Hawaii, on July 9 and 12, 1991, shortly after the arrival of the first eruption plume from the Mt. Pinatubo volcano in the Phillipines. A total SO2 vertical column amount of (5.1 +/- 0.5) x 10(exp 16) molecules/sq cm on July 9 has been retrieved based on nonlinear least- squares spectral fittings of 9 selected SO2 absorption features with an updated set of SO2 spectral parameters. A SO2 total column upper limit of 0.9 x 10(esp 16) molecules/sq cm deduced from measurements on September 20-24, 1991, is consistent with the dispersion of the SO2 cloud and the rapid conversion of the SO2 vapor into volcanic aerosol particles.

  2. Bubble column apparatus for separating wax from catalyst slurry

    SciTech Connect

    Neathery, James K.; Davis, Burtron H.

    2004-07-13

    Novel methods and devices for production of liquid hydrocarbon products from gaseous reactants are disclosed. In one aspect, a method for separating a liquid hydrocarbon, typically a wax, from a catalyst containing slurry is provided, comprising passing the slurry through at least one downcomer extending from an overhead separation chamber and discharging into the bottom of a slurry bubble column reactor. The downcomer includes a cross-flow filtration element for separating a substantially particle-free liquid hydrocarbon for downstream processing. In another aspect, a method for promoting plug-flow movement in a recirculating slurry bubble column reactor is provided, comprising discharging the recirculating slurry into the reactor through at least one downcomer which terminates near the bottom of the reactor. Devices for accomplishing the above methods are also provided.

  3. Deformation Monitoring of Retrofitted Short Concrete Columns with Laser Sensor

    NASA Astrophysics Data System (ADS)

    Avsar, E. Ö.; Celik, M. F.; Binbir, E.; Arslan, A. E.; Çokkeçeci, D.; Seker, D. Z.; Pala, S.

    2016-06-01

    This paper presents one of the applications of monitoring mechanical tests carried out in Construction Materials Laboratory of Istanbul Technical University. In Turkey, as in many countries, large amount of existing buildings exposed to seismic hazard, therefore various analytical and experimental studies are being conducted to contribute to the solution of the problem. One of the new generation retrofitting techniques is to strength the structural members by using Fiber Reinforcing Polymer (FRP). This study summarize the results of monitoring of deformations short concrete column samples under the incremental compression load. In this study, result of two rectangular short columns are given. One of them was tested as a reference sample, the other sample were tested after strengthening by PET reinforced polymer composite materials. Besides conventional displacement and strain measurement systems, laser scanning method was used to get three dimensional deformed shape of sample at each selected steps.

  4. Column Experiments to Interpret Weathering in Columbia Hills

    NASA Technical Reports Server (NTRS)

    Hausrath, E. M.; Morris, R.V.; Ming, D.W.; Golden, D.C.; Galindo, C.; Sutter, B.

    2009-01-01

    Phosphate mobility has been postulated as an indicator of early aqueous activity on Mars. In addition, rock surfaces analyzed by the Mars Exploration Rover Spirit are consistent with the loss of a phosphate- containing mineral To interpret phosphate alteration behavior on Mars, we performed column dissolution experiments leaching the primary phases Durango fluorapatite, San Carlos olivine, and basalt glass (Stapafjell Volcano, courtesy of S. Gislason, University of Iceland) [3,4]) with acidic solutions. These phases were chosen to represent quickly dissolving phases likely present in Columbia Hills. Column dissolution experiments are closer to natural dissolution conditions than batch experiments, although they can be difficult to interpret. Acidic solutions were used because the leached layers on the surfaces of these rocks have been interpreted as resulting from acid solutions [5].

  5. Method of recovering adsorbed liquid compounds from molecular sieve columns

    DOEpatents

    Burkholder, Harvey R.; Fanslow, Glenn E.

    1983-01-01

    Molecularly adsorbed volatile liquid compounds are recovered from molecular sieve adsorbent columns by directionally applying microwave energy to the bed of the adsorbent to produce a mixed liquid-gas effluent. The gas portion of the effluent generates pressure within the bed to promote the discharge of the effluent from the column bottoms. Preferably the discharged liquid-gas effluent is collected in two to three separate fractions, the second or intermediate fraction having a substantially higher concentration of the desorbed compound than the first or third fractions. The desorption does not need to be assisted by passing a carrier gas through the bed or by applying reduced pressure to the outlet from the bed.

  6. Liquid membrane coated ion-exchange column solids

    DOEpatents

    Barkey, Dale P.

    1989-01-01

    This invention relates to a method for improving the performance of liquid embrane separations by coating a liquid membrane onto solid ion-exchange resin beads in a fixed bed. Ion-exchange beads fabricated from an ion-exchange resin are swelled with water and are coated with a liquid membrane material that forms a film over the beads. The beads constitute a fixed bed ion-exchange column. Fluid being treated that contains the desired ion to be trapped by the ion-exchange particle is passed through the column. A carrier molecule, contained in the liquid membrane ion-exchange material, is selected for the desired ion in the fluid. The carrier molecule forms a complex with the desired ion, transporting it through the membrane and thus separating it from the other ions. The solution is fed continuously until breakthrough occurs at which time the ion is recovered, and the bed is regenerated.

  7. Liquid membrane coated ion-exchange column solids

    DOEpatents

    Barkey, Dale P.

    1988-01-01

    This invention relates to a method for improving the performance of liquid membrane separations by coating a liquid membrane onto solid ion-exchange resin beads in a fixed bed. Ion-exchange beads fabricated from an ion-exchange resin are swelled with water and are coated with a liquid membrane material that forms a film over the beads. The beads constitute a fixed bed ion-exchange column. Fluid being treated that contains the desired ion to be trapped by the ion-exchange particle is passed through the column. A carrier molecule, contained in the liquid membrane ion-exchange material, is selective for the desired ion in the fluid. The carrier molecule forms a complex with the desired ion, transporting it through the membrane and thus separating it from the other ions. The solution is fed continuously until breakthrough occurs at which time the ion is recovered, and the bed is regenerated.

  8. Method of recovering adsorbed liquid compounds from molecular sieve columns

    DOEpatents

    Burkholder, H.R.; Fanslow, G.E.

    1983-12-20

    Molecularly adsorbed volatile liquid compounds are recovered from molecular sieve adsorbent columns by directionally applying microwave energy to the bed of the adsorbent to produce a mixed liquid-gas effluent. The gas portion of the effluent generates pressure within the bed to promote the discharge of the effluent from the column bottoms. Preferably the discharged liquid-gas effluent is collected in two to three separate fractions, the second or intermediate fraction having a substantially higher concentration of the desorbed compound than the first or third fractions. The desorption does not need to be assisted by passing a carrier gas through the bed or by applying reduced pressure to the outlet from the bed. 8 figs.

  9. Tritium Isotope Separation Using Adsorption-Distillation Column

    SciTech Connect

    Fukada, Satoshi

    2005-07-15

    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, {alpha}{sub H-T}{sup equi}. The adsorption action improved not only HETP but also {alpha}{sub H-T}{sup 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.

  10. Using solvent extraction to process nitrate anion exchange column effluents

    SciTech Connect

    Yarbro, S.L.

    1987-10-01

    Octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO), a new organophosphorous extractant, and a new centrifugal mixer-settler both recently developed at Argonne were evaluated for their potential use in the recovery of actinides from nitrate anion exchange column effluents. The performance of the extractant was evaluated by measuring the extraction coefficient values as a function of acid and salt concentration. Additional performance parameters include extraction coefficient behavior as a function of the total metal concentration in the organic phase, and comparison of different stripping and organic scrubbing techniques. A simulated effluent stream was used to evaluate the performance of the centrifugal mixer-settlers by comparing experimental and calculated interstage concentration profiles. Both the CMPO extractant and the centrifugal mixer-settlers have potential for processing nitrate column effluents, particularly if the stripping behavior can be improved. Details of the proposed process are presented in the flowsheet and contactor design analyses.

  11. Collapse of a Liquid Column: Numerical Simulation and Experimental Validation

    NASA Astrophysics Data System (ADS)

    Cruchaga, Marcela A.; Celentano, Diego J.; Tezduyar, Tayfun E.

    2007-03-01

    This paper is focused on the numerical and experimental analyses of the collapse of a liquid column. The measurements of the interface position in a set of experiments carried out with shampoo and water for two different initial column aspect ratios are presented together with the corresponding numerical predictions. The experimental procedure was found to provide acceptable recurrence in the observation of the interface evolution. Basic models describing some of the relevant physical aspects, e.g. wall friction and turbulence, are included in the simulations. Numerical experiments are conducted to evaluate the influence of the parameters involved in the modeling by comparing the results with the data from the measurements. The numerical predictions reasonably describe the physical trends.

  12. Planar transformers for column parallel CCD clock drive

    NASA Astrophysics Data System (ADS)

    Hawes, B.; Cussans, D.; Damerell, C.; Devetak, E.; Fopma, J.; Gao, R.; Goldstein, J.; Greenshaw, T.; Hillert, S.; Kundu, N.; Nomerotski, A.; Perry, C.; Stefanov, K.; Thomas, S.; Worm, S.

    2009-10-01

    The LCFI Collaboration is developing the sensors, readout electronics and mechanical support structures for the Vertex Detector (VXD) of the International Linear Collider (ILC). High-speed readout is needed to ensure that the occupancy due to the pair production background at the ILC is kept below 1% level. In order to satisfy this requirement, Column Parallel CCDs (CPCCDs) and Column Parallel Readout chips (CPRs) have been developed. The CPCCD has to operate at a clock frequency of 50 MHz, which represents a difficult technical challenge due to the relatively large sensor capacitance. The design and performance of planar transformers, which can be used to provide the required 20 A clock current, are described.

  13. In-plant testing of microbubble column flotation

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.; Adel, G.T.; Mankosa, M.J.

    1991-07-31

    Microbubble column flotation (MCF) was developed at the Virginia Center for Coal and Minerals Processing (VCCMP) for the selective recovery of fine particles. Bench-scale test work conducted at VCCMP, largely under the sponsorship of the U.S. Department of Energy (DOE), showed that the technology worked well for both coal and mineral applications. For the technology to be commercially successful, however, a full-scale demonstration of the MCF technology was deemed necessary. This report summarizes the results of work performed under the DOE project entitled In-plant Testing of Microbubble Column Flotation.'' The objectives of this research and development effort were to duplicate the bench-scale performance of the MCF process in a full-scale unit, to verify the scale-up procedure developed in an earlier project, and to demonstrate the applicability of the MCF technology to the coal industry.

  14. In-plant testing of microbubble column flotation. Final report

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.; Adel, G.T.; Mankosa, M.J.

    1991-07-31

    Microbubble column flotation (MCF) was developed at the Virginia Center for Coal and Minerals Processing (VCCMP) for the selective recovery of fine particles. Bench-scale test work conducted at VCCMP, largely under the sponsorship of the U.S. Department of Energy (DOE), showed that the technology worked well for both coal and mineral applications. For the technology to be commercially successful, however, a full-scale demonstration of the MCF technology was deemed necessary. This report summarizes the results of work performed under the DOE project entitled ``In-plant Testing of Microbubble Column Flotation.`` The objectives of this research and development effort were to duplicate the bench-scale performance of the MCF process in a full-scale unit, to verify the scale-up procedure developed in an earlier project, and to demonstrate the applicability of the MCF technology to the coal industry.

  15. Brewer spectrometer total ozone column measurements in Sodankylä

    NASA Astrophysics Data System (ADS)

    Karppinen, Tomi; Lakkala, Kaisa; Karhu, Juha M.; Heikkinen, Pauli; Kivi, Rigel; Kyrö, Esko

    2016-06-01

    Brewer total ozone column measurements started in Sodankylä in May 1988, 9 months after the signing of The Montreal Protocol. The Brewer instrument has been well maintained and frequently calibrated since then to produce a high-quality ozone time series now spanning more than 25 years. The data have now been uniformly reprocessed between 1988 and 2014. The quality of the data has been assured by automatic data rejection rules as well as by manual checking. Daily mean values calculated from the highest-quality direct sun measurements are available 77 % of time with up to 75 measurements per day on clear days. Zenith sky measurements fill another 14 % of the time series and winter months are sparsely covered by moon measurements. The time series provides information to survey the evolution of Arctic ozone layer and can be used as a reference point for assessing other total ozone column measurement practices.

  16. Sustenance of inhomogeneous electron temperature in a magnetized plasma column

    SciTech Connect

    Karkari, S. K. Mishra, S. K.; Kaw, P. K.

    2015-09-15

    This paper presents the equilibrium properties of a magnetized plasma column sustained by direct-current (dc) operated hollow cathode discharge in conjunction with a conducting end-plate, acting as the anode. The survey of radial plasma characteristics, performed in argon plasma, shows hotter plasma in the periphery as compared to the central plasma region; whereas the plasma density peaks at the center. The off-centered peak in radial temperature is attributed due to inhomogeneous power deposition in the discharge volume in conjunction with short-circuiting effect by the conducting end plate. A theoretical model based on particle flux and energy balance is given to explain the observed characteristics of the plasma column.

  17. Hydrodynamics of a packed countercurrent column for the gas extraction

    SciTech Connect

    Stockfleth, R.; Brunner, G.

    1999-10-01

    The hydraulic capacity of a countercurrent column with gauze packing was examined at pressures between 8 and 30 MPa and temperatures between 313 and 373 K. The systems used were water + carbon dioxide, aqueous surfactant solution + carbon dioxide, and Toco, a substance whose physical properties are roughly similar to those of {alpha}-Tocopherol + carbon dioxide. A distinctive change in the flooding mechanisms from liquid layer flooding to bubble column flooding was observed. The different liquids, water and Toco, showed the same flooding behavior, indicating that the influence of the density on the flooding behavior prevails over the influence of any other physical property of the liquid. The foamability of the surfactant solution decreased significantly with increasing pressure--its influence on the flooding behavior could not be proved. The liquid holdup ranged between 2% and 6%. The dry pressure drop adhered to the Ergun equation.

  18. Development of the 15-meter hoop-column antenna system

    NASA Technical Reports Server (NTRS)

    Campbell, T. G.; Butler, D. H.; Belvin, K.; Allen, B. B.

    1985-01-01

    The development of the 15-meter hoop/column antenna system is presented. The 15-meter deployable structure is discussed along with the mulitple-beam feed system development and the structures and RF testing planned in 1985. The topics presented are: overview of antenna development activities; development of 15-meter reflector and kinematic deployment tests; preliminary modal survey test results and future structural dynamics tests; and radio frequency subsystems and near field testing.

  19. Nickel migration and retention dynamics in natural soil columns

    NASA Astrophysics Data System (ADS)

    Raveh-Rubin, Shira; Edery, Yaniv; Dror, Ishai; Berkowitz, Brian

    2015-09-01

    Nickel migration measured in laboratory-scale, natural soil column experiments is shown to display anomalous (non-Fickian) transport, nonequilibrium adsorption and desorption patterns, and precipitation/dissolution. Similar experiments using a conservative tracer also exhibit anomalous behavior. The occurrence of ion exchange of nickel, mainly with calcium (but also with other soil components), is measured in both batch and flow-through column experiments; adsorption and desorption isotherms demonstrate hysteresis. Strong retention of nickel during transport in soil columns leads to delayed initial breakthrough (˜40 pore volumes), slow increase in concentration, and extended concentration tailing at long times. We describe the mechanisms of transport and retention in terms of a continuous time random walk (CTRW) model, and use a particle tracking formulation to simulate nickel migration in the column. This approach allows us to capture the non-Fickian transport and the subtle local effects of adsorption/desorption and precipitation/dissolution. Consideration also of preferential pathways accounts for the evolution of the measured breakthrough curve and measured spatial concentration profiles. The model uses non-Fickian transport parameters estimated from the conservative tracer and, as a starting point, adsorption/desorption parameters based on batch experiments and a precipitation parameter based on Ksp values. The batch parameters are found to underestimate the actual amount of adsorption. We suggest that the sorption and precipitation/dissolution dynamics, and resulting breakthrough curves, are influenced strongly by preferential pathways; such pathways significantly alter the availability of sorption sites and ion availability for precipitation. Analysis of these results provides further understanding of the interaction and dynamics among transport, precipitation, and sorption mechanisms in natural soil.

  20. Detail of plaque beneath column on the south parapet at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of plaque beneath column on the south parapet at the west end of the bridge. The plaque reads “1914; Mayor E.J. Drussel; Councilmen E.S. Henry, E.F. Hogan, R.P. Lamdin, C.F. Ross, J.H. Shuppert; Leonard & Day, Engineers; C.H. Gildersleeve, Builder.” - First Street Bridge, Spanning Napa River at First Street between Soscol Avenue & Juarez Street, Napa, Napa County, CA

  1. Column oil agglomeration of fly ash with ultrasonics

    SciTech Connect

    Gray, M.L.; Champagne, K.J.; Soong, Y.; Finseth, D.H.

    1999-07-01

    A promising oil agglomeration process has been developed for the beneficiation of fly ash using a six-foot agglomeration column. Carbon concentrates have been separated from fly ash with yields greater than 60 % and purities of 55 to 74 %. The parameters examined in the study include ultrasonic exposure, pulse rate, frequency, agitation speed, and blade configuration. The effects of the experimental variables on the quality of separation are discussed.

  2. Simple, analytical criteria for the sequencing of distillation columns

    SciTech Connect

    Malone, M.F.; Douglas, J.M.; Glinos, K.; Marquez, F.E.

    1985-04-01

    A quantitative criterion for the selection of simple distillation sequences is derived for ideal mixtures. A simple cost model, along with a short-cut solution of Underwood's equations, gives an analytical form for the total vapor rate, which is the key design variable. The results for column sequencing that are based on the analytical criterion agree well with more exact solutions, but they indicate that in numerous situations the commonly accepted heuristics are incorrect.

  3. A column generation approach for exact graph coloring

    SciTech Connect

    Mehrotra, A.; Trick, M.

    1994-12-31

    We present a method for solving the independent set formulation of the graph coloring problem (where there is one variable for each independent set in the graph). We use a column generation method for implicit optimization of the linear program at each node of the branch-and-bound tree. This approach, while requiring the solution of a difficult subproblem as well as needing sophisticated branching rules, solves small to moderate size problems quickly. Implementation details and computational experience are also presented.

  4. Cryogenic focussing, ohmically heated on-column trap

    NASA Technical Reports Server (NTRS)

    Springston, Stephen R.

    1991-01-01

    A procedure is described for depositing a conductive layer of gold on the exterior of a fused-silica capillary used in gas chromatography. By subjecting a section of the column near the inlet to a thermal cycle of cryogenic cooling and ohmic heating, volatile samples are concentrated and subsequently injected. The performance of this trap as a chromatographic injector is demonstrated. Several additional applications are suggested and the unique properties of this device are discussed.

  5. Cryogenic focussing, ohmically heated on-column trap

    SciTech Connect

    Springston, S.R.

    1991-12-01

    A procedure is described for depositing a conductive layer of gold on the exterior of a fused-silica capillary used in gas chromatography. By subjecting a section of the column near the inlet to a thermal cycle of cryogenic cooling and ohmic heating, volatile samples are concentrated and subsequently injected. The performance of this trap as a chromatographic injector is demonstrated. Several additional applications are suggested and the unique properties of this device are discussed. 11 refs., 5 figs., 1 tab.

  6. Cystic Abnormalities of the Spinal Cord and Vertebral Column.

    PubMed

    da Costa, Ronaldo C; Cook, Laurie B

    2016-03-01

    Cystic lesions of the vertebral column and spinal cord are important differential diagnoses in dogs with signs of spinal cord disease. Synovial cysts are commonly associated with degenerative joint disease and usually affect the cervical and lumbosacral regions. Arachnoid diverticulum (previously known as cyst) is seen in the cervical region of large breed dogs and thoracolumbar region of small breed dogs. This article reviews the causes, diagnosis, and treatment of these and other, less common, cystic lesions. PMID:26706913

  7. Positive column of the glow discharge in argon

    NASA Astrophysics Data System (ADS)

    Lisovskiy, Valeriy; Artushenko, Ekaterina; Yegorenkov, Vladimir

    2015-09-01

    We report the measurements we performed of the reduced electric field strength E / p in the positive column in the range of the gas pressure and tube radius product of 0.01 column of the constant current discharge in noble gases. We consider the case of a balance between the rate of charged particle production due to direct ionization of gas molecules through electron impact and their escape to the discharge tube walls. Simple expressions for the reduced electric field E / p in the positive column in argon are obtained. The second model consists in considering the production and loss of charged particles and metastable atoms and obtaining a simple equation for the reduced electric field E / p depending on the discharge current density, gas pressure and tube radius. These models furnish a good description of experimental data in the whole range of pR values studied. and Scientific Center of Physical Technologies, Svobody Sq.6, Kharkov, 61022, Ukraine.

  8. The Total Carbon Column Observing Network (TCCON): overview and update

    NASA Astrophysics Data System (ADS)

    Griffith, David; Wennberg, Paul; Notholt, Justus

    2014-05-01

    The Total Carbon Column Observing Network (TCCON) is a network of ground-based Fourier Transform Spectrometers that record direct solar absorption spectra of the atmosphere in the near-infrared. From these spectra, accurate and precise column-averaged abundances of atmospheric constituents including CO2, CH4, N2O, HF, CO, H2O, and HDO, are retrieved. TCCON measurements are linked to WMO calibration scales by comparisons with co-incident in situ profiles measured from aircraft. For CO2, TCCON achieves 1-sigma precision of typically 0.2 ppm for single measurements, and a network wide comparability of better than 0.1 In this paper we present an overview and the current status of the network, ongoing efforts to improve network coverage, precision and accuracy, and examples of TCCON data and their application. Further information about TCCON and a full list of sites and TCCON partners is available from the TCCON wiki, https://tccon-wiki.caltech.edu/ and Wunch et al. (2011). Wunch, D., G.C. Toon, J.-F. Blavier, R. Washenfelder, J. Notholt, B. Connor, D.W.T. Griffith and P.O. Wennberg, The Total Carbon Column Observing Network (TCCON). Philosophical Transactions of the Royal Society A 2011. 369: p. 2087-2112.

  9. Engineered Barrier Systems Thermal-Hydraulic-Chemical Column Test Report

    SciTech Connect

    W.E. Lowry

    2001-12-13

    The Engineered Barrier System (EBS) Thermal-Hydraulic-Chemical (THC) Column Tests provide data needed for model validation. The EBS Degradation, Flow, and Transport Process Modeling Report (PMR) will be based on supporting models for in-drift THC coupled processes, and the in-drift physical and chemical environment. These models describe the complex chemical interaction of EBS materials, including granular materials, with the thermal and hydrologic conditions that will be present in the repository emplacement drifts. Of particular interest are the coupled processes that result in mineral and salt dissolution/precipitation in the EBS environment. Test data are needed for thermal, hydrologic, and geochemical model validation and to support selection of introduced materials (CRWMS M&O 1999c). These column tests evaluated granular crushed tuff as potential invert ballast or backfill material, under accelerated thermal and hydrologic environments. The objectives of the THC column testing are to: (1) Characterize THC coupled processes that could affect performance of EBS components, particularly the magnitude of permeability reduction (increases or decreases), the nature of minerals produced, and chemical fractionation (i.e., concentrative separation of salts and minerals due to boiling-point elevation). (2) Generate data for validating THC predictive models that will support the EBS Degradation, Flow, and Transport PMR, Rev. 01.

  10. The Column Density Variance-{\\cal M}_s Relationship

    NASA Astrophysics Data System (ADS)

    Burkhart, Blakesley; Lazarian, A.

    2012-08-01

    Although there is a wealth of column density tracers for both the molecular and diffuse interstellar medium, there are few observational studies investigating the relationship between the density variance (σ2) and the sonic Mach number ({\\cal M}_s). This is in part due to the fact that the σ2-{\\cal M}_s relationship is derived, via MHD simulations, for the three-dimensional (3D) density variance only, which is not a direct observable. We investigate the utility of a 2D column density \\sigma _{\\Sigma /\\Sigma _0}^2-{\\cal M}_s relationship using solenoidally driven isothermal MHD simulations and find that the best fit follows closely the form of the 3D density \\sigma _{\\rho /\\rho _0}^2-{\\cal M}_s trend but includes a scaling parameter A such that \\sigma _{\\ln (\\Sigma /\\Sigma _0)}^2=A\\times \\ln (1+b^2{\\cal M}_s^2), where A = 0.11 and b = 1/3. This relation is consistent with the observational data reported for the Taurus and IC 5146 molecular clouds with b = 0.5 and A = 0.16, and b = 0.5 and A = 0.12, respectively. These results open up the possibility of using the 2D column density values of σ2 for investigations of the relation between the sonic Mach number and the probability distribution function (PDF) variance in addition to existing PDF sonic Mach number relations.

  11. Dynamic response of the Chamousset rock column (Western Alps, France)

    NASA Astrophysics Data System (ADS)

    Lévy, C.; Baillet, L.; Jongmans, D.; Mourot, P.; Hantz, D.

    This paper investigates the variation of the first resonance frequency of the Chamousset limestone column (21,000 m3, Vercors, French Alps) before its collapse in November 2007. The site was instrumented with seismometers and extensometers during a 4-month period with some gaps in the measurements. Experimental results and numerical modeling showed that the resonance frequency of a prone-to-fall column can be derived from the spectra of continuous seismic noise records. At the Chamousset site, the evolution of the resonance frequency appeared to be strongly controlled by the temperature. When temperatures were positive, slight resonance frequency variations correlated well with thermal fluctuations. Irreversible damage can occur during freeze-thaw cycles and to a lesser extent during strong wind. It coincided with a significant drop in resonance frequency, which was interpreted as the result of rock bridge breakage. This hypothesis is supported by fresh rupture observations after the collapse, seismic event records, and numerical modeling. This study suggests that seismic noise recording could be used for assessing the potential failure of unstable columns in rigid rocks.

  12. Column biosorption of lanthanum and europium by Sargassum.

    PubMed

    Diniz, Vivian; Weber, Martin E; Volesky, Bohumil; Naja, Ghinwa

    2008-01-01

    Batch and column biosorption of La(3+) (lanthanum) and Eu(3+) (europium) was studied using protonated Sargassum polycystum biomass. The ion exchange sorption mechanism was confirmed by the proportional release of protons and by the total normality of the solution, which remained constant during the process. Equilibrium isotherms were determined for the binary systems, La/H and Eu/H for a total normality of 3 meq g(-1), which produced separation factors of 2.7 and 4.7, respectively, demonstrating a higher affinity of the biomass towards europium. Column runs with a single metal feed were used to estimate the intra-particle mass transfer coefficients for La and Eu (6.0 x 10(-4) and 3.7 x 10(-4) min(-1), respectively). Modeling batch and column binary systems with proton as the common ion was able to predict reasonably well the behavior of a ternary system containing protons. The software FEMLAB was used for solving the set of coupled partial differential equations. Moreover, a series of consecutive sorption/desorption runs demonstrated that the metal could be recovered and the biomass reused in multiple cycles by using 0.1N HCl with no apparent loss in the biosorbent metal uptake capacity. PMID:17707878

  13. A photoautotrophic source for lycopane in marine water columns

    NASA Technical Reports Server (NTRS)

    Wakeham, Stuart G.; Freeman, Katherine H.; Pease, Tamara K.; Hayes, J. M.

    1993-01-01

    Suspended particulate matter and recent sediments from diverse oceanic sites have been investigated for their contents of lycopane. Lycopane was present in all samples, including both oxic and anoxic water column and sediments. The highest concentrations in the water column were found in surface waters of the central Pacific gyre (1.5 ng/L) and in the anoxic waters of the Cariaco Trench (1.1 ng/L) and the Black Sea (0.3 ng/L). Vertical concentration profiles suggest that lycopane is probably algal in origin. Moreover, biogeochemical conditions in anoxic zones apparently result in a secondary production of lycopane from an as yet unidentified precursor. Compound-specific carbon isotopic analyses have been carried out on lycopane from water column and sediment samples. Isotopic compositions of lycopane range between -23.6 and -32.9 percent and are consistent with a photoautotrophic origin. We postulate that some lycopane is produced in surface waters of the ocean, while additional lycopane is produced in anoxic zones by anaerobic microbial action on an algal precursor.

  14. Chromatographic behaviors of proteins on cation-exchange column.

    PubMed

    Li, Rong; Chen, Guo-Liang; Zhao, Wen-Ming

    2004-12-01

    A weak cation-exchanger (XIDACE-WCX) has been synthesized by the indirect method. The chromatographic characteristics of the synthesized packing was studied in detail. The standard protein mixture and lysozyme from egg white were separated with the prepared chromatographic column. The chromatographic thermodynamics of proteins was studied in a wide temperature range. Thermodynamic parameters standard enthalpy change (deltaH0) and standard entropy change (deltaS0) and compensation temperature (beta) at protein denaturation were determined in the chromatographic system. By using obtained deltaS0, the conformational change of proteins was judged in the chromatographic process. The linear relationship between deltaH0 and deltaS0 can be used to identify the identity of the protein retention mechanism in the weak cation-exchange chromatography. The interaction between weak cation-exchanger and metal ions was investigated. Several metal chelate columns were prepared. The effects of introducing metal ion into the naked column on protein retention and the retention mechanism of proteins in the metal chalet affinity chromatography were discussed. PMID:15689030

  15. Remote sensing of Akashiwo sanguinea in the vertical column

    NASA Astrophysics Data System (ADS)

    Moore, K.; Broughton, J.; Kudela, R. M.

    2013-12-01

    Harmful algal blooms can be extremely damaging to both humans and marine organisms. Harmful algal blooms have been known to cause deleterious effects due to either toxin production or enhanced biomass; mass mortalities of sea birds, dolphins and other creatures often result. Incidences of harmful algal blooms are increasing, so quantifying their locations is a pressing need for human health and the health of marine ecosystems. Past studies have used remote sensing to image dinoflagellate blooms at the ocean surface, but due to migrations of the dinoflagellates in the water column, surface blooms often correspond to non-optimal solar zenith angles for remote sensing imaging. Here we demonstrate a way to locate the blooms of Akashiwo sanguinea at depth in turbid, coastal water (Case II ocean water). Using Hydrolight to simulate the optical properties of A. sanguinea in Monterey Bay, we develop spectral profiles of dinoflagellate blooms in the vertical column. Spectral mixing analysis is used to process aerial data in ENVI-IDL image analysis software. Application of the model to SAMSON remote sensing imagery reveals strong biological and physical coupling in Monterey Bay, and distinguishes dinoflagellates at the surface from those at greater depth. The model is robust and holds up well under various atmospheric forcings and ocean conditions. This work suggests that harmful algal blooms can be detected far below the ocean surface, with the possibility of tracking dinoflagellate diel migrations in the vertical column from outer space.

  16. Phosphopeptide enrichment using offline titanium dioxide columns for phosphoproteomics.

    PubMed

    Yu, Li-Rong; Veenstra, Timothy

    2013-01-01

    Identification of phosphoproteins or phosphopeptides as cancer biomarkers is an emerging field in phosphoproteomics. Owing to the low stoichiometric nature of protein phosphorylation, phosphoproteins or phosphopeptides must be enriched prior to downstream mass spectrometry analysis. Titanium dioxide (TiO2) has been prevalently used to enrich phosphopeptides from complex proteome samples due to its high affinity for phosphopeptides, and the method is straightforward. In this protocol, an offline phosphopeptide enrichment procedure using TiO2 columns is described. Peptides from a proteome lysate are loaded onto a TiO2 column in an acidic environment, followed by column washing with aqueous, organic, and ammonium glutamate (NH4Glu) buffers at acidic conditions. Phosphopeptides are eluted using an ammonia solution at high pH. Use of NH4Glu significantly reduces nonspecific bindings while a high recovery rate (84 %) of phosphopeptides is retained. The method is optimized for large-scale phosphoproteomic analysis and phosphoprotein biomarker discovery starting from sub-milligram or milligrams of proteome samples. PMID:23625397

  17. Strengthening of defected beam–column joints using CFRP

    PubMed Central

    Mahmoud, Mohamed H.; Afefy, Hamdy M.; Kassem, Nesreen M.; Fawzy, Tarek M.

    2013-01-01

    This paper presents an experimental study for the structural performance of reinforced concrete (RC) exterior beam–column joints rehabilitated using carbon-fiber-reinforced polymer (CFRP). The present experimental program consists of testing 10 half-scale specimens divided into three groups covering three possible defects in addition to an adequately detailed control specimen. The considered defects include the absence of the transverse reinforcement within the joint core, insufficient bond length for the beam main reinforcement and inadequate spliced implanted column on the joint. Three different strengthening schemes were used to rehabilitate the defected beam–column joints including externally bonded CFRP strips and sheets in addition to near surface mounted (NSM) CFRP strips. The failure criteria including ultimate capacity, mode of failure, initial stiffness, ductility and the developed ultimate strain in the reinforcing steel and CFRP were considered and compared for each group for the control and the CFRP-strengthened specimens. The test results showed that the proposed CFRP strengthening configurations represented the best choice for strengthening the first two defects from the viewpoint of the studied failure criteria. On the other hand, the results of the third group showed that strengthening the joint using NSM strip technique enabled the specimen to outperform the structural performance of the control specimen while strengthening the joints using externally bonded CFRP strips and sheets failed to restore the strengthened joints capacity. PMID:25685473

  18. Methodology for optimally sized centrifugal partition chromatography columns.

    PubMed

    Chollet, Sébastien; Marchal, Luc; Jérémy Meucci; Renault, Jean-Hugues; Legrand, Jack; Foucault, Alain

    2015-04-01

    Centrifugal Partition Chromatography (CPC) is a separation process based on the partitioning of solutes between two partially miscible liquid phases. There is no solid support for the stationary phase. The centrifugal acceleration is responsible for both stationary phase retention and mobile phase dispersion. CPC is thus a process based on liquid-liquid mass transfer. The separation efficiency is mainly influenced by the hydrodynamics of the phases in each cell of the column. Thanks to a visualization system, called "Visual CPC", it was observed that the mobile phase can flow through the stationary phase as a sheet, or a spray. Hydrodynamics, which directly governs the instrument efficiency, is directly affected during scale changes, and non-linear phenomena prevent the successful achievement of mastered geometrical scale changes. In this work, a methodology for CPC column sizing is proposed, based on the characterization of the efficiency of advanced cell shapes, taking into account the hydrodynamics. Knowledge about relationship between stationary phase volume, cell efficiency and separation resolution in CPC allowed calculating the optimum cell number for laboratory and industrial scale CPC application. The methodology is highlighted with results on five different geometries from 25 to 5000 mL, for two applications: the separation of alkylbenzene by partitioning with heptane/methanol/water biphasic system; and the separation of peptides by partitioning with n-butanol/acetic acid/water (4/1/5) biphasic system. With this approach, it is possible to predict the optimal CPC column length leading to highest productivity. PMID:25744547

  19. Effects of Cabin Upsets on Adsorption Columns for Air Revitalization

    NASA Technical Reports Server (NTRS)

    LeVan, Douglas

    1999-01-01

    The National Aeronautics and Space Administration (NASA) utilizes adsorption technology as part of contaminant removal systems designed for long term missions. A variety of trace contaminants can be effectively removed from gas streams by adsorption onto activated carbon. An activated carbon adsorption column meets NASA's requirements of a lightweight and efficient means of controlling trace contaminant levels aboard spacecraft and space stations. The activated carbon bed is part of the Trace Contaminant Control System (TCCS) which is utilized to purify the cabin atmosphere. TCCS designs oversize the adsorption columns to account for irregular fluctuations in cabin atmospheric conditions. Variations in the cabin atmosphere include changes in contaminant concentrations, temperature, and relative humidity. Excessively large deviations from typical conditions can result from unusual crew activity, equipment malfunctions, or even fires. The research carried out under this award focussed in detail on the effects of cabin upsets on the performance of activated carbon adsorption columns. Both experiments and modeling were performed with an emphasis on the roll of a change in relative humidity on adsorption of trace contaminants. A flow through fixed-bed apparatus was constructed at the NASA Ames Research Center, and experiments were performed there. Modeling work was performed at the University of Virginia.

  20. Measurement of Carbon Dioxide Column via Space Borne Laser Absorption

    NASA Technical Reports Server (NTRS)

    Heaps, WIlliam S.

    2007-01-01

    In order to better understand the budget of carbon dioxide in the Earth's atmosphere it is necessary to develop a global high precision understanding of the carbon dioxide column. In order to uncover the 'missing sink that is responsible for the large discrepancies in the budget as we presently understand it calculation has indicated that measurement accuracy on the order of 1 ppm is necessary. Because typical column average CO2 has now reached 380 ppm this represents a precision on the order of .25% for these column measurements. No species has ever been measured from space at such a precision. In recognition of the importance of understanding the CO2 budget in order to evaluate its impact on global warming the National Research Council in its decadal survey report to NASA recommended planning for a laser based total CO2 mapping mission in the near future. The extreme measurement accuracy requirements on this mission places very strong requirements on the laser system used for the measurement. This work presents an analysis of the characteristics necessary in a laser system used to make this measurement. Consideration is given to the temperature dependence, pressure broadening, and pressure shift of the CO2 lines themselves and how these impact the laser system characteristics Several systems for meeting these requirements that are under investigation at various institutions in the US as well as Europe will be discussed.

  1. OH Column Abundance Apparent Response to Solar Cycle 23

    NASA Astrophysics Data System (ADS)

    Burnett, C. R.; Minschwaner, K. R.

    2009-12-01

    The 33-year series of high spectral resolution measurements of absorption of sunlight by OH at 308 nm has exhibited temporary decreases of column abundances in 1986, 1997, and 2008 near the times of minimum solar activity. These observations and analyses are of significance as they encompass three complete solar cycles for comparison. During solar cycle 23, the annual average abundances increased approximately 20% from the minimum abundance in 1997 to high-sun enhanced values in 2000-2006, then dropped approximately 15% in 2008. The abundances exhibited a pronounced reduction at solar minimum in August-October 2008, similar to that seen in fall 1986 and fall 1997. The average morning abundances on those occasions were 13% smaller than the 1980-88 corresponding average, about 0.9 x 1013 cm-2, with minimum values broadly consistent with model results. In contrast, high-sun OH abundances observed during periods of solar maximum are approximately 33% larger than modeled abundances. This discrepancy cannot be explained by reasonable adjustments of reaction rates or modeled constituent concentrations in the stratosphere or mesosphere. However, the observed responses to a tropopause fold event in 1988 and to the Pinatubo aerosol in 1991 do suggest an important contribution to the total OH column from the lower stratosphere. In addition to the apparent variations with solar activity, this OH column database contains a number of other effects such as diurnal and seasonal patterns, and geographic differences between observations from Colorado, Florida, Alaska, Micronesia, New Zealand, and New Mexico.

  2. Strengthening of defected beam-column joints using CFRP.

    PubMed

    Mahmoud, Mohamed H; Afefy, Hamdy M; Kassem, Nesreen M; Fawzy, Tarek M

    2014-01-01

    This paper presents an experimental study for the structural performance of reinforced concrete (RC) exterior beam-column joints rehabilitated using carbon-fiber-reinforced polymer (CFRP). The present experimental program consists of testing 10 half-scale specimens divided into three groups covering three possible defects in addition to an adequately detailed control specimen. The considered defects include the absence of the transverse reinforcement within the joint core, insufficient bond length for the beam main reinforcement and inadequate spliced implanted column on the joint. Three different strengthening schemes were used to rehabilitate the defected beam-column joints including externally bonded CFRP strips and sheets in addition to near surface mounted (NSM) CFRP strips. The failure criteria including ultimate capacity, mode of failure, initial stiffness, ductility and the developed ultimate strain in the reinforcing steel and CFRP were considered and compared for each group for the control and the CFRP-strengthened specimens. The test results showed that the proposed CFRP strengthening configurations represented the best choice for strengthening the first two defects from the viewpoint of the studied failure criteria. On the other hand, the results of the third group showed that strengthening the joint using NSM strip technique enabled the specimen to outperform the structural performance of the control specimen while strengthening the joints using externally bonded CFRP strips and sheets failed to restore the strengthened joints capacity. PMID:25685473

  3. Transport of engineered nanoparticles in partially saturated sand columns.

    PubMed

    Yecheskel, Yinon; Dror, Ishai; Berkowitz, Brian

    2016-07-01

    The vadose zone is a critical region controlling fate and transport of contaminants in soils and, ultimately, groundwater. It is therefore important to understand the behavior of engineered nanoparticles (ENPs) in this zone, as a potential group of emerging contaminants. Soil is a significant sink for ENPs; however, only a few studies have considered the fate and transport of ENPs in partially saturated systems, representative of the vadose zone. Here, transport behavior of three commonly used ENPs - gold (Au-NPs), silver (Ag-NPs) and zinc oxide (ZnO-NPs) - is investigated in partially saturated sand columns. High mobilities of Au-NPs and Ag-NPs under different water saturation levels and concentrations were observed. The presence of CaCl2 reduces Ag-NP mobility through chemical interactions, similar to behavior reported in saturated systems. Furthermore, transformation of Ag-NPs in the environment may influence their mobility; aging of Ag-NPs following sulfidation was investigated. The silver sulfide (Ag2S-NPs) remained stable in aqueous suspension, and mobile in the partially saturated sand column. In contrast, the positively-charged ZnO-NPs were completely immobilized in the sand column. Significantly, though, addition of humic acid (HA) to the ZnO-NP suspension reverses particle surface charge and thus increases their mobility. Moreover, remobilization of entrapped ZnO-NPs by HA was demonstrated. PMID:26995325

  4. Prospects for Precision Measurement of CO2 Column from Space

    NASA Technical Reports Server (NTRS)

    Heaps, William S.; Kawa, S. Randolph; Burris, John F.; Wilson, Emily L.; Georgieva, Elena; Miodek, Marty

    2005-01-01

    In order to address the problem of sources and sinks of CO2 measurements are needed on a global scale. Clearly a satellite is a promising approach to meeting this requirement. Unfortunately, most methods for making a CO2 measurement from space involve the whole column. Since sources and sinks at the surface represent a small perturbation to the total column one is faced with the need to measure the column with a precision better than 1%. No species has ever been measured from space at this level. We have developed over the last 3 years a small instrument based upon a Fabry-Perot interferometer that is very sensitive to atmospheric CO2 and has a high signal to noise ratio. We have tested this instrument in a ground based configuration and from aircraft platforms simulating operation from a satellite. We will present results from these tests and discuss ways that this promising new instrument could be used to improve our understanding of the global carbon budget.

  5. Fabry-Perot Interferometer for Column CO2: Airborne

    NASA Technical Reports Server (NTRS)

    Kawa, S. R.; Heaps, W. S.; Mao, J.; Andrews, A. E.; Burris, J. F.; Miodek, M.; Georgieva, E.

    2002-01-01

    Global atmospheric CO2 measurements are essential to resolving significant discrepancies in our understanding of the global carbon budget and, hence, humankind's role in global climate change. The science measurement requirements for CO2 are, however, extremely demanding (precision approximately 0.3%). We are developing a novel application of a Fabry-Perot interferometer to detect spectral absorption of reflected sunlight by CO2 and O2 in the atmosphere that should be able to achieve sufficient sensitivity and signal-to-noise to measure column CO2 at the target specification. We are currently constructing a prototype instrument for deployment on aircraft. The aircraft version will measure total column CO2 and CO2 below the aircraft as well as O2, which allows normalization of CO2 column amounts for varying surface height and pressure. This instrument will be a valuable asset in carbon budget field studies as well as a useful tool for evaluating existing and future space-based CO2 measurements. We will present the instrument concept, sensitivity calculations, and the results of testing a bench system in the laboratory and outdoors on the ground. We will also discuss our plan for deployment on the aircraft and potential flight applications to the CO2 budget problem.

  6. Methane gas seepage - Disregard of significant water column filter processes?

    NASA Astrophysics Data System (ADS)

    Schneider von Deimling, Jens; Schmale, Oliver

    2016-04-01

    Marine methane seepage represents a potential contributor for greenhouse gas in the atmosphere and is discussed as a driver for climate change. The ultimate question is how much methane is released from the seafloor on a global scale and what fraction may reach the atmosphere? Dissolved fluxes from methane seepage sites on the seabed were found to be very efficiently reduced by benthic microbial oxidation, whereas transport of free gas bubbles from the seabed is considered to bypass the effective benthic methane filter. Numerical models are available today to predict the fate of such methane gas bubble release to the water column in regard to gas exchange with the ambient water column, respective bubble lifetime and rise height. However, the fate of rising gas bubbles and dissolved methane in the water column is not only governed by dissolution, but is also affected by lateral oceanographic currents and vertical bubble-induced upwelling, microbial oxidation, and physico-chemical processes that remain poorly understood so far. According to this gap of knowledge we present data from two study sites - the anthropogenic North Sea 22/4b Blowout and the natural Coal Oil point seeps - to shed light into two new processes gathered with hydro-acoustic multibeam water column imaging and microbial investigations. The newly discovered processes are hereafter termed Spiral Vortex and Bubble Transport Mechanism. Spiral Vortex describes the evolution of a complex vortical fluid motion of a bubble plume in the wake of an intense gas release site (Blowout, North Sea). It appears very likely that it dramatically changes the dissolution kinetics of the seep gas bubbles. Bubble Transport Mechanism prescribes the transport of sediment-hosted bacteria into the water column via rising gas bubbles. Both processes act as filter mechanisms in regard to vertical transport of seep related methane, but have not been considered before. Spiral Vortex and Bubble Transport Mechanism represent the

  7. Multisegment Kinematics of the Spinal Column: Soft Tissue Artifacts Assessment.

    PubMed

    Mahallati, Sara; Rouhani, Hossein; Preuss, Richard; Masani, Kei; Popovic, Milos R

    2016-07-01

    A major challenge in the assessment of intersegmental spinal column angles during trunk motion is the inherent error in recording the movement of bony anatomical landmarks caused by soft tissue artifacts (STAs). This study aims to perform an uncertainty analysis and estimate the typical errors induced by STA into the intersegmental angles of a multisegment spinal column model during trunk bending in different directions by modeling the relative displacement between skin-mounted markers and actual bony landmarks during trunk bending. First, we modeled the maximum displacement of markers relative to the bony landmarks with a multivariate Gaussian distribution. In order to estimate the distribution parameters, we measured these relative displacements on five subjects at maximum trunk bending posture. Then, in order to model the error depending on trunk bending angle, we assumed that the error grows linearly as a function of the bending angle. Second, we applied our error model to the trunk motion measurement of 11 subjects to estimate the corrected trajectories of the bony landmarks and investigate the errors induced into the intersegmental angles of a multisegment spinal column model. For this purpose, the trunk was modeled as a seven-segment rigid-body system described using 23 reflective markers placed on various bony landmarks of the spinal column. Eleven seated subjects performed trunk bending in five directions and the three-dimensional (3D) intersegmental angles during trunk bending were calculated before and after error correction. While STA minimally affected the intersegmental angles in the sagittal plane (<16%), it considerably corrupted the intersegmental angles in the coronal (error ranged from 59% to 551%) and transverse (up to 161%) planes. Therefore, we recommend using the proposed error suppression technique for STA-induced error compensation as a tool to achieve more accurate spinal column kinematics measurements. Particularly, for intersegmental

  8. Integration of monolithic frit into the particulate capillary (IMFPC) column in shotgun proteome analysis.

    PubMed

    Wang, Fangjun; Dong, Jing; Ye, Mingliang; Wu, Ren'an; Zou, Hanfa

    2009-10-12

    Capillary column plays an important role in nano-flow liquid chromatography coupled with tandem mass spectrometry for dealing with the high dynamic range and complexity of protein samples in shotgun proteome analysis. In this study, the integrated monolithic frit into the particulate capillary (IMFPC) column was prepared. By comparing the prepared IMFPC column with conventionally fritless capillary column, smaller size of packing materials could be easily packed into the capillary to achieve higher average peak capacity and proteome coverage. As the monolithic emitter was integrated onto this type of column, the void volume between packing particles and electrospray emitter was eliminated and the electrospray quality was improved. The prepared IMFPC column was applied to proteome analysis of mouse liver extracts, and it was observed that the number of identified proteins and peptides increased 14.9 and 12.9% as well as the peak capacity increased 11.6% by using IMFPC column over conventionally fritless capillary column. PMID:19786199

  9. Novel Designs for Centrifugal Countercurrent chromatography: V. Comparative Studies on Performance of Various Column Configurations.

    PubMed

    Yang, Yi; Gu, Dongyu; Aisa, Haji Akber; Ito, Yoichiro

    2010-01-01

    The conventional toroidal coil in centrifugal countercurrent chromatography has a low level of stationary phase retention, since a half of each helical turn is entirely occupied by the mobile phase. In order to cope with this problem, several new column designs including zigzag, saw-tooth and figure-8 patterns have been introduced and their performance was compared in terms of retention of the stationary phase (Sf), peak resolution (Rs), theoretical plate number (N) and column pressures. Overall results of experiments indicate that the figure-8 column yields the highest Rs when the lower phase is used as the mobile phase. Since the column pressure of all these new columns are much lower than that in the traditional toroidal coil column, the separation efficiency can be improved using a long separation column without a risk of column damage by high back pressure. PMID:21057664

  10. The development of an evaluation method for capture columns used in two-dimensional liquid chromatography.

    PubMed

    Cao, Liwei; Yu, Danhua; Wang, Xinliang; Ke, Yanxiong; Jin, Yu; Liang, Xinmiao

    2011-11-01

    Capture columns are important interface tools for on line two-dimensional liquid chromatography (2D-LC). In this study, a systematic method was developed to evaluate and optimize the capture ability of capture columns by off-line method. First, the parameter Δt(R) (Δt(R)=t(2)-t(1)-t(0)-W) was introduced to quantitatively represent the capture ability of the capture column by connecting a capture column behind the first dimensional column. Based on the value of Δt(R), an appropriate capture column was selected after the first dimensional column was fixed. Then, the capture ability of the selected column was promoted by adjusting the mobile phase of the first dimensional column. Capture ability was also optimized using complex sample analysis software system (CSASS) software. Second, the elution mode of the trapped compounds on the capture column was investigated by connecting the capture column before the second dimensional column. More specifically, in mode I, capture column was connected to the second dimension without changing the flow rate direction and the trapped compounds must pass through the capture column and be eluted into the second dimensional column. The contrary connection mode was mode II. It was found that mode I is more suitable method for 2D-LC. Finally, an off-line reversed-phase/hydrophilic interaction liquid chromatography two-dimensional liquid chromatography (RP/HILIC 2D-LC) system with a C18 capture column was developed to demonstrate the practical application of this method. PMID:21995927

  11. Robust naphthyl methacrylate monolithic column for high performance liquid chromatography of a wide range of solutes.

    PubMed

    Jonnada, Murthy; El Rassi, Ziad

    2015-08-28

    An organic monolithic column based on the co-polymerization of 2-naphthyl methacrylate (NAPM) as the functional monomer and trimethylolpropane trimethacrylate (TRIM) as the crosslinker was introduced for high performance reversed-phase liquid chromatography (RPC). The co-polymerization was performed in situ in a stainless steel column of 4.6mm i.d. in the presence of a ternary porogen consisting of 1-dodecanol and cyclohexanol. This monolithic column (referred to as naphthyl methacrylate monolithic column or NMM column) showed high mechanical stability at relatively high mobile phase flow velocity indicating that the column has excellent hydrodynamic characteristics. To characterize the NMM column, different probe molecules including alkyl benzenes, and aniline, benzene, toluene and phenol derivatives were chromatographed on the column and the results in terms of k, selectivity and plate counts were compared to those obtained on an octadecyl silica (ODS) column in order to assess the presence of π-π and hydrophobic interactions on the NMM column under otherwise the same elution conditions. The NMM column offered additional π-π interactions with aromatic molecules in addition to hydrophobic interactions under RPC elution conditions. Run-to-run and column-to-column reproducibility of solute k values were evaluated, and percent relative standard deviation of <1% and ∼2-3.5%, respectively, were obtained. Six standard proteins were readily separated on the NMM column using shallow (30min at 1.0mL/min), steep (10min at 1.0mL/min) and ultra steep (1min at 3.0mL/min) linear gradient elution at increasing ACN concentration in the mobile phase using a 10cm×4.6mm i.d. column in case of shallow and steep linear gradients and a 3cm×4.6mm i.d. column for ultra steep linear gradient. PMID:26228852

  12. Colorful Column Chromatography: A Classroom Demonstration of a Three-Component Separation

    NASA Astrophysics Data System (ADS)

    Heumann, Lars V.

    2008-04-01

    A classroom demonstration detailing the procedure for the separation of a ternary mixture consisting of intensely colored compounds using silica gel column chromatography is described. The audience can follow the compounds during their passage through the column as individual, colored bands while learning about different tools and techniques used in conjunction with column chromatography. Detailed instructions for column preparation and the elution and collection process are provided and permit the easy replication of this demonstration.

  13. Determining the Influence of Groundwater Composition on the Performance of Arsenic Adsorption Columns Using Rapid Small-Scale Column Tests

    NASA Astrophysics Data System (ADS)

    Aragon, A. R.; Siegel, M.

    2004-12-01

    The USEPA has established a more stringent drinking water standard for arsenic, reducing the maximum contaminant level (MCL) from 50 μ g/L to 10 μ g/L. This will affect many small communities in the US that lack the appropriate treatment infrastructure and funding to reduce arsenic to such levels. For such communities, adsorption systems are the preferred technology based on ease of operation and relatively lower costs. The performance of adsorption media for the removal of arsenic from drinking water is dependent on site-specific water quality. At certain concentrations, co-occurring solutes will compete effectively with arsenic for sorption sites, potentially reducing the sorption capacity of the media. Due to the site-specific nature of water quality and variations in media properties, pilot scale studies are typically carried out to ensure that a proposed treatment technique is cost effective before installation of a full-scale system. Sandia National Laboratories is currently developing an approach to utilize rapid small-scale columns in lieu of pilot columns to test innovative technologies that could significantly reduce the cost of treatment in small communities. Rapid small-scale column tests (RSSCTs) were developed to predict full-scale treatment of organic contaminants by adsorption onto granular activated carbon (GAC). This process greatly reduced the time and costs required to verify performance of GAC adsorption columns. In this study, the RSSCT methodology is used to predict the removal of inorganic arsenic using mixed metal oxyhydroxide adsorption media. The media are engineered and synthesized from materials that control arsenic behavior in natural and disturbed systems. We describe the underlying theory and application of RSSCTs for the performance evaluation of novel media in several groundwater compositions. Results of small-scale laboratory columns are being used to predict the performance of pilot-scale systems and ultimately to design full

  14. Comparison of the release of constituents from granular materials under batch and column testing.

    PubMed

    Lopez Meza, Sarynna; Garrabrants, Andrew C; van der Sloot, Hans; Kosson, David S

    2008-01-01

    Column leaching testing can be considered a better basis for assessing field impact data than any other available batch test method and thus provides a fundamental basis from which to estimate constituent release under a variety of field conditions. However, column testing is time-intensive compared to the more simplified batch testing, and may not always be a viable option when making decisions for material reuse. Batch tests are used most frequently as a simple tool for compliance or quality control reasons. Therefore, it is important to compare the release that occurs under batch and column testing, and establish conservative interpretation protocols for extrapolation from batch data when column data are not available. Five different materials (concrete, construction debris, aluminum recycling residue, coal fly ash and bottom ash) were evaluated via batch and column testing, including different column flow regimes (continuously saturated and intermittent unsaturated flow). Constituent release data from batch and column tests were compared. Results showed no significant difference between the column flow regimes when constituent release data from batch and column tests were compared. In most cases batch and column testing agreed when presented in the form of cumulative release. For arsenic in carbonated materials, however, batch testing underestimates the column constituent release for most LS ratios and also on a cumulative basis. For cases when As is a constituent of concern, column testing may be required. PMID:18242972

  15. The Winogradsky Column and Biofilms: Models for Teaching Nutrient Cycling and Succession in an Ecosystem.

    ERIC Educational Resources Information Center

    Anderson, Delia Castro; Hairston, Rosalina V.

    1999-01-01

    Presents protocols for setting up a Winogradsky column and biofilm slides, interpreting the chemical transformations that occur in the column as a result of color changes in the soil, identifying common microorganisms, and determining the microbial composition of the column over specified intervals of time. (WRM)

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

    SciTech Connect

    Mriziq, Khaled S; Guiochon, Georges A

    2009-01-01

    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 4.6 mm C18 bonded silica-based monolithic column, a 150 mm x 4.6 mm column packed with 2.7 {micro}m porous shell particles of C18 bonded silica (HALO), and a 150 mm x 4.6 mm column packed with 3 {micro}m 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.

  17. 40 CFR 799.6756 - TSCA partition coefficient (n-octanol/water), generator column method.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .../water), generator column method. 799.6756 Section 799.6756 Protection of Environment ENVIRONMENTAL... coefficient (n-octanol/water), generator column method. (a) Scope—(1) Applicability. This section is intended... liquid chromatographic (DCCLC) technique, a technique commonly referred to as the generator column...

  18. 40 CFR 799.6756 - TSCA partition coefficient (n-octanol/water), generator column method.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .../water), generator column method. 799.6756 Section 799.6756 Protection of Environment ENVIRONMENTAL... coefficient (n-octanol/water), generator column method. (a) Scope—(1) Applicability. This section is intended... liquid chromatographic (DCCLC) technique, a technique commonly referred to as the generator column...

  19. 40 CFR 799.6756 - TSCA partition coefficient (n-octanol/water), generator column method.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .../water), generator column method. 799.6756 Section 799.6756 Protection of Environment ENVIRONMENTAL... coefficient (n-octanol/water), generator column method. (a) Scope—(1) Applicability. This section is intended... liquid chromatographic (DCCLC) technique, a technique commonly referred to as the generator column...

  20. Technically Speaking: Columns from the Monthly Magazine, "The Source," 1987-88. Trace Reprint Series.

    ERIC Educational Resources Information Center

    Borden, Peter A.; And Others

    The "Technically Speaking" columns from several isues of "The Source" magazine are reprinted. The columns were written by Gregg Vanderheiden, Peter Borden, Roger Smith, Jane Berliss, and Charles Lee. Titles of the columns included are: "Technological Advances: A Boon or a Barrier to Persons with Disabilities?"; "Rehabilitation Technology--Hunting…

  1. Advanced IMCW Lidar Techniques for ASCENDS CO2 Column Measurements

    NASA Astrophysics Data System (ADS)

    Campbell, Joel; lin, bing; nehrir, amin; harrison, fenton; obland, michael

    2015-04-01

    Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity-Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These results are extended to include Richardson-Lucy deconvolution techniques to extend the resolution of the lidar beyond that implied by limit of the bandwidth of the modulation.

  2. Dorsal column myelopathy following intrathecal chemotherapy for acute lymphoblastic leukemia

    PubMed Central

    Joseph, Prathap Jacob; Reyes, Maria Regina

    2014-01-01

    Objective/context To describe a distinctive clinical and radiographic pattern of myelopathy following intrathecal chemotherapy. Myelopathy is a rare complication of intrathecal chemotherapy used in the treatment of acute lymphoblastic leukemia (ALL). We present a 42-year-old female with T-cell ALL who developed a myelopathy primarily involving the dorsal columns. Method Case report and literature review. Findings Within 24 hours of an injection of intrathecal methotrexate, cytarabine, and hydrocortisone, the patient developed ascending lower limb numbness and balance difficulties progressing to the inability to ambulate. Clinical examination showed profound loss of lower limb proprioception and light touch sensation below T5, mild proximal limb weakness, but preserved pinprick and temperature sensation with intact bowel and bladder function. Initial thoracic and lumbar spine magnetic resonance imaging (MRI) at 1 week revealed no abnormalities. However, repeat imaging at 6 weeks showed abnormal signal in the posterior cord with sparing of the anterior and lateral columns, diffusely involving the lower cervical cord through the conus medullaris. Dermatomal somatosensory-evoked potential (DSEP) conduction abnormalities were consistent with thoracic myelopathy. An empiric trial of high-dose intravenous corticosteroids during inpatient rehabilitation more than 6 weeks later produced no significant clinical improvement. Conclusion/clinical relevance Preferential and persistent dorsal column myelopathy is a distinctive clinical and radiographic presentation of a rare complication of intrathecal chemotherapy. The MRI abnormalities were initially absent, but evolved to consist of multi-level spinal cord T2 and STIR hyperintensity with regional gadolinium enhancement. DSEPs more accurately reflected the clinical level of spinal cord dysfunction. PMID:24090227

  3. Separation of fructooligosaccharides using zeolite fixed bed columns.

    PubMed

    Kuhn, Raquel Cristine; Maugeri Filho, Francisco

    2010-07-15

    Recent studies have shown that the chromatographic separation of mixtures of monosaccharides and disaccharides may be improved by employing Y zeolites, a procedure which holds promise in the separation of oligosaccharides. In the present study, a column packed with zeolite was employed to study the separation of fructooligosaccharides (FOS). FOS were produced by an enzyme isolated from Rhodotorula sp., which produces GF2 (kestose), GF3 (nystose) and GF4 (frutofuranosyl nystose). The identification and quantification of the sugars were carried out by ion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The separation of fructooligosaccharides was carried out using a fixed bed column packed with Ba2+-exchange Y zeolites. The effects of temperature (40-50 degrees C), injected volume per bed volume (2.55-7.64%), superficial velocity (0.1-0.15 cm min(-1)) and eluent composition (40-60% ethanol) were investigated using a fractionary factorial design with separation efficiency as the response. The results showed that the most favorable conditions for the separation of the oligosaccharide-glucose mixture were 60% ethanol as eluent, temperature of 50 degrees C, superficial velocity of 0.1 cm min(-1) and 2.55% injection volume per bed volume of injection mixture, using two columns in series. The values for separation efficiency were 0.60 for oligosaccharide-glucose, 1.00 for oligosaccharide-fructose, 0.22 for oligosaccharide-sucrose, 0.43 for glucose-fructose, 0.82 for glucose-sucrose and 1.23 for fructose-sucrose. PMID:20617538

  4. Effects of Cabin Upsets on Adsorption Columns for Air Revitalization

    NASA Technical Reports Server (NTRS)

    LeVan, M. Douglas

    1999-01-01

    The National Aeronautics and Space Administration (NASA) utilizes adsorption technology as part of contaminant removal systems designed for long term missions. A variety of trace contaminants can be effectively removed from gas streams by adsorption onto activated carbon. An activated carbon adsorption column meets NASA's requirements of a lightweight and efficient means of controlling trace contaminant levels aboard spacecraft and space stations. The activated carbon bed is part of the Trace Contaminant Control System (TCCS) which is utilized to purify the cabin atmosphere. TCCS designs oversize the adsorption columns to account for irregular fluctuations in cabin atmospheric conditions. Variations in the cabin atmosphere include changes in contaminant concentrations, temperature, and relative humidity. Excessively large deviations from typical conditions can result from unusual crew activity, equipment malfunctions, or even fires. The research carried out under this award focussed in detail on the effects of cabin upsets on the performance of activated carbon adsorption columns. Both experiments and modeling were performed with an emphasis on the roll of a change in relative humidity on adsorption of trace contaminants. A flow through fixed-bed apparatus was constructed at the NASA Ames Research Center, and experiments were performed there by W. Scot Appel under the direction of Dr. John E. Finn. Modeling work was performed at the University of Virginia and at Vanderbilt University by W. Scot Appel under the direction of M. Douglas LeVan. All three participants collaborated in all of the various phases of the research. The most comprehensive document describing the research is the Ph.D. dissertation of W. Scot Appel. Results have been published in several papers and presented in talks at technical conferences. All documents have been transmitted to Dr. John E. Finn.

  5. Estimated global nitrogen deposition using NO2 column density

    USGS Publications Warehouse

    Lu, Xuehe; Jiang, Hong; Zhang, Xiuying; Liu, Jinxun; Zhang, Zhen; Jin, Jiaxin; Wang, Ying; Xu, Jianhui; Cheng, Miaomiao

    2013-01-01

    Global nitrogen deposition has increased over the past 100 years. Monitoring and simulation studies of nitrogen deposition have evaluated nitrogen deposition at both the global and regional scale. With the development of remote-sensing instruments, tropospheric NO2 column density retrieved from Global Ozone Monitoring Experiment (GOME) and Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) sensors now provides us with a new opportunity to understand changes in reactive nitrogen in the atmosphere. The concentration of NO2 in the atmosphere has a significant effect on atmospheric nitrogen deposition. According to the general nitrogen deposition calculation method, we use the principal component regression method to evaluate global nitrogen deposition based on global NO2 column density and meteorological data. From the accuracy of the simulation, about 70% of the land area of the Earth passed a significance test of regression. In addition, NO2 column density has a significant influence on regression results over 44% of global land. The simulated results show that global average nitrogen deposition was 0.34 g m−2 yr−1 from 1996 to 2009 and is increasing at about 1% per year. Our simulated results show that China, Europe, and the USA are the three hotspots of nitrogen deposition according to previous research findings. In this study, Southern Asia was found to be another hotspot of nitrogen deposition (about 1.58 g m−2 yr−1 and maintaining a high growth rate). As nitrogen deposition increases, the number of regions threatened by high nitrogen deposits is also increasing. With N emissions continuing to increase in the future, areas whose ecosystem is affected by high level nitrogen deposition will increase.

  6. Electrophoretic Separation of Single Particles Using Nanoscale Thermoplastic Columns.

    PubMed

    Weerakoon-Ratnayake, Kumuditha M; Uba, Franklin I; Oliver-Calixte, Nyoté J; Soper, Steven A

    2016-04-01

    Phenomena associated with microscale electrophoresis separations cannot, in many cases, be applied to the nanoscale. Thus, understanding the electrophoretic characteristics associated with the nanoscale will help formulate relevant strategies that can optimize the performance of separations carried out on columns with at least one dimension below 150 nm. Electric double layer (EDL) overlap, diffusion, and adsorption/desorption properties and/or dielectrophoretic effects giving rise to stick/slip motion are some of the processes that can play a role in determining the efficiency of nanoscale electrophoretic separations. We investigated the performance characteristics of electrophoretic separations carried out in nanoslits fabricated in poly(methyl methacrylate), PMMA, devices. Silver nanoparticles (AgNPs) were used as the model system with tracking of their transport via dark field microscopy and localized surface plasmon resonance. AgNPs capped with citrate groups and the negatively charged PMMA walls (induced by O2 plasma modification of the nanoslit walls) enabled separations that were not apparent when these particles were electrophoresed in microscale columns. The separation of AgNPs based on their size without the need for buffer additives using PMMA nanoslit devices is demonstrated herein. Operational parameters such as the electric field strength, nanoslit dimensions, and buffer composition were evaluated as to their effects on the electrophoretic performance, both in terms of efficiency (plate numbers) and resolution. Electrophoretic separations performed at high electric field strengths (>200 V/cm) resulted in higher plate numbers compared to lower fields due to the absence of stick/slip motion at the higher electric field strengths. Indeed, 60 nm AgNPs could be separated from 100 nm particles in free solution using nanoscale electrophoresis with 100 μm long columns. PMID:26963496

  7. Coal desulfurization by bacterial treatment and column flotation. Final report

    SciTech Connect

    Kawatra, S.K.

    1994-06-01

    A review of the literature showed that bacterial leaching, using the microorganism Thiobacillus ferrooxidans, was a very effective technique for removing pyrite from coal, as it could dissolve even the finest pyrite particles without the need for expensive reagents or extreme processing conditions. Unfortunately, bacterial leaching is also rather slow, and so the initial goal of this research was to decrease the leaching time as much as possible. However, this still left the bacteria needing approximately a week to remove half of the pyritic sulfur, and so a faster technique was sought. Since it had been reported in the literature that T. ferrooxidans could be used to depress the flotation of pyrite during froth flotation of coal, this was investigated further. By studying the recovery mechanisms of coal-pyrite in froth flotation, it was found that pyrite was being recovered by entrainment and by locking to coal particles, not by true flotation of hydrophobic pyrite. Therefore, no pyrite depressant could be of any significant benefit for keeping pyrite out of the coal froth product, and it was much more important to prevent entrainment from occurring. Countercurrent flotation columns were invented to essentially eliminate entrainment effects, by washing the froth and reducing mixing of the froth and tailings products. Existing flotation columns tend to be quite simple, and in order to give reasonable product quality they must be very tall (typically 30--45 feet). As a result, they have difficulty in handling the high froth volumes which occur in coal flotation, and are awkward to install in existing plants. The bulk of this project therefore concentrated on developing an improved coal flotation column, and testing it under actual plant conditions.

  8. Water column methanotrophy controlled by a rapid oceanographic switch

    NASA Astrophysics Data System (ADS)

    Steinle, Lea; Graves, Carolyn; Treude, Tina; Biastoch, Arne; Ferré, Bénédicte; Bussmann, Ingeborg; Berndt, Christian; Krastel, Sebastian; James, Rachael H.; Behrens, Erik; Böning, Claus W.; Greinert, Jens; Sapart, Célia-Julia; Sommer, Stefan; Lehmann, Moritz F.; Niemann, Helge

    2015-04-01

    Large amounts of the greenhouse gas methane are released from the seabed to the water column where it may be consumed by aerobic methanotrophic bacteria. This microbial filter is consequently the last marine sink for methane before its liberation into the atmosphere. The size and activity of methanotrophic communities, which determine the capacity of the water column methane filter, are thought to be mainly controlled by nutrient and redox dynamics, but little is known about the effects of ocean currents. Here we show that cold bottom water at methane seeps west of Svalbard, containing a large number of aerobic methanotrophs, was rapidly displaced by warmer water with a considerably smaller methanotrophic community. This community replacement led to a reduction of methane oxidation rates of 60 % and was independent of methane input. Measurements of temperature and salinity, combined with the output of a high-resolution ocean/sea-ice simulation model (VIKING20) showed that this water mass exchange was caused by short-term variations of the West Spitsbergen Current (WSC), which is characterized by two principal modes: The warm core of the WSC either flows along the continental shelf break and thus above the methane seeps (nearshore mode), or it meanders offshore thereby entraining colder shelf water, which then flows over the seeps (offshore mode). We could link the larger community to the colder shelf water during the offshore mode, and the smaller community and lower methane oxidation rates to the presence of the warmer WSC water above the seeps. As a result, the meandering of the WSC can be considered as an oceanographic switch severely reducing methanotrophic activity in the water column. Output from the ORCA12 model showed that strong and fluctuating bottom currents are common features at methane seep systems. We thus argue that the variability of physical water mass transport is a globally important control on the distribution and abundance of methanotrophs and

  9. Development of a fritless packed column for capillary electrochromatography-mass spectrometry.

    PubMed

    Bragg, William; Shamsi, Shahab A

    2011-12-01

    A novel procedure was developed for the fabrication of a fritless packed column for the coupling of capillary electrochromatography (CEC) to mass spectrometry (MS). The process involved the formation of internal tapers on two separate columns. Once the internal tapers are formed and the columns are packed, the untapered ends of each column were joined together by a commercially available connector. Several advantages of the fritless columns are described. First, the design used here eventually eliminates the need for any frits thus reducing the possibility of bubble formation seen with fritted packed columns. In addition, this is the first report in which the internal tapers are formed at both the inlet and outlet column ends making the fritless CEC-MS column more robust compared to only one report with externally tapered counterparts. Second, a comparison of internally tapered single frit packed CEC-MS (previously developed in our laboratory) column versus fritless CEC-MS column reported here shows that the latter provides better efficiency, suggesting no dead volume with equally good sensitivity and chiral resolution of (±)-aminoglutethimide. The fritless column procedure is universal and was used to prepare a series of columns with a variety of commercially available packing material (mixed mode strong cation exchange, SCX; mixed mode strong anion exchange, SAX; C-18) for the separation and MS detection of short chain non-chromophoric polar amines, long chain nonchromophic anionic surfactant as well as oligomers of non-chromophoric non-ionic surfactants, respectively. The fritless columns showed good intra-day repeatability and inter-day reproducibility of retention times, chiral and achiral resolutions and peak areas. Very satisfactory column-to-column and operator-to-operator reproducibility was demonstrated. PMID:22035695

  10. Tapped granular column dynamics: simulations, experiments and modeling

    NASA Astrophysics Data System (ADS)

    Rosato, A. D.; Zuo, L.; Blackmore, D.; Wu, H.; Horntrop, D. J.; Parker, D. J.; Windows-Yule, C.

    2016-07-01

    This paper communicates the results of a synergistic investigation that initiates our long term research goal of developing a continuum model capable of predicting a variety of granular flows. We consider an ostensibly simple system consisting of a column of inelastic spheres subjected to discrete taps in the form of half sine wave pulses of amplitude a/ d and period τ . A three-pronged approach is used, consisting of discrete element simulations based on linear loading-unloading contacts, experimental validation, and preliminary comparisons with our continuum model in the form of an integro-partial differential equation.

  11. Evolution of column density distributions within Orion A⋆

    NASA Astrophysics Data System (ADS)

    Stutz, A. M.; Kainulainen, J.

    2015-05-01

    We compare the structure of star-forming molecular clouds in different regions of Orion A to determine how the column density probability distribution function (N-PDF) varies with environmental conditions such as the fraction of young protostars. A correlation between the N-PDF slope and Class 0 protostar fraction has been previously observed in a low-mass star-formation region (Perseus); here we test whether a similar correlation is observed in a high-mass star-forming region. We used Herschel PACS and SPIRE cold dust emission observations to derive a column density map of Orion A. We used the Herschel Orion Protostar Survey catalog to accurately identify and classify the Orion A young stellar object content, including the cold and relatively short-lived Class 0 protostars (with a lifetime of ~0.14 Myr). We divided Orion A into eight independent regions of 0.25 square degrees (13.5 pc2); in each region we fit the N-PDF distribution with a power law, and we measured the fraction of Class 0 protostars. We used a maximum-likelihood method to measure the N-PDF power-law index without binning the column density data. We find that the Class 0 fraction is higher in regions with flatter column density distributions. We tested the effects of incompleteness, extinction-driven misclassification of Class 0 sources, resolution, and adopted pixel-scales. We show that these effects cannot account for the observed trend. Our observations demonstrate an association between the slope of the power-law N-PDF and the Class 0 fractions within Orion A. Various interpretations are discussed, including timescales based on the Class 0 protostar fraction assuming a constant star-formation rate. The observed relation suggests that the N-PDF can be related to an evolutionary state of the gas. If universal, such a relation permits evaluating the evolutionary state from the N-PDF power-law index at much greater distances than those accessible with protostar counts. Appendices are available in

  12. Silver-coated monolithic columns for separation in radiopharmaceutical applications.

    PubMed

    Sedlacek, Ondrej; Kucka, Jan; Svec, Frantisek; Hruby, Martin

    2014-04-01

    In this study, we demonstrate the preparation of a macroporous monolithic column containing anchored silver nanoparticles and its use for the elimination of excess radioiodine from the radiolabeled pharmaceutical. The poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolith was first functionalized with cystamine and the free thiol groups liberated by reaction with borohydride. In-house-prepared silver nanoparticles were then attached by interaction with the surface thiols. The deiodization process was demonstrated with the commonly used radiopharmaceutical m-iodobenzylguanidine labeled with radionuclide iodine-125. PMID:24478196

  13. Denitrification in the water column of the central Baltic Sea

    NASA Astrophysics Data System (ADS)

    Dalsgaard, Tage; De Brabandere, Loreto; Hall, Per O. J.

    2013-04-01

    Removal of fixed nitrogen in the water column of the eastern Gotland Basin, central Baltic Sea, was studied during two cruises in September 2008 and August 2010. The water column was stratified with anoxic sulfidic bottom water meeting oxic nitrate containing water at the oxic-anoxic interface. Anammox was never detected whereas denitrification was found in all incubations from anoxic depths and occurred immediately below the oxic-anoxic interface. Sulfide (H2S + HS- + S2-) was in most cases the only electron donor for denitrification but, in contrast to previous findings, denitrification was in some situations driven by organic matter alone. Nitrous oxide (N2O) became an increasingly important product of denitrification with increasing sulfide concentration and was >80% of the total N gas formation at 10 μM sulfide. The potential rates of denitrification measured in incubations at elevated NO3- or sulfide concentrations were converted to in situ rates using the measured water column concentrations of NO3- and sulfide and the actual measured relations between NO3- and sulfide concentrations and denitrification rates. In situ denitrification ranged from 0.24 to 15.9 nM N2 h-1. Assuming that these rates were valid throughout the anoxic NO3- containing zone, depth integrated in situ denitrification rates of 0.06-2.11 mmol N m-2 d-1 were estimated. The thickness of this zone was generally 3-6 m, which is probably what can be maintained through regular turbulent mixing induced by internal waves at the oxic-anoxic interface. However, layers of up to 55 m thickness with low O2 water (<10 μM) were observed which was probably the result of larger scale mixing. In such a layer nitrification may produce NO3- and once the O2 has been depleted denitrification will follow resulting in enormous rates per unit area. Even with an active denitrification layer of 3-6 m thickness the pelagic denitrification per unit area clearly exceeded sediment denitrification rates elsewhere in

  14. Improving the performance of conventional and column froth flotation cells

    SciTech Connect

    Arnold, B.J.

    1995-11-01

    Many existing mining operations hover on the brink of producing competitively priced fuel with marginally acceptable sulfur levels. To remain competitive, these operations need to improve the yield of their coal processing facilities, lower the sulfur content of their clean coal, or lower the ash content of their clean coal. Fine coal cleaning processes offer the best opportunity for coal producers to increase their yield of high quality product. Over 200 coal processing plants in the U.S. already employ some type of conventional or column flotation device to clean fines. an increase in efficiency in these existing circuits could be the margin required to make these coal producers competitive.

  15. Ultrasonic characterizations of slurries in a bubble column reactor

    SciTech Connect

    Soong, Y.; Gamwo, I.K.; Blackwell, A.G.; Harke, F.W.; Ladner, E.P.

    1999-05-01

    An indirect method (ultrasonic) and a direct technique were used to measure solid holdup in a bubble-column reactor. Nitrogen, water, and fine glass beads were used as the gas, liquid, and solid phases, respectively. The solid particle concentration in the slurry was varied from 5 to 30 wt %, and the gas superficial velocity was increased from 0.5 to 12 cm/s. The solid holdup measurements by the ultrasonic technique compared reasonably well with results obtained by the direct sampling technique.

  16. Ether Lipids of Planktonic Archaea in the Marine Water Column

    PubMed Central

    Hoefs, M.; Schouten, S.; De Leeuw, J. W.; King, L. L.; Wakeham, S. G.; Damste, J.

    1997-01-01

    Acyclic and cyclic biphytanes derived from the membrane ether lipids of archaea were found in water column particulate and sedimentary organic matter from several oxic and anoxic marine environments. Compound-specific isotope analyses of the carbon skeletons suggest that planktonic archaea utilize an isotopically heavy carbon source such as algal carbohydrates and proteins or dissolved bicarbonate. Due to their high preservation potential, these lipids provide a fossil record of planktonic archaea and suggest that they have thrived in marine environments for more than 50 million years. PMID:16535669

  17. RETENTION TIME EFFECT ON METAL REMOVAL BY PEAT COLUMNS

    SciTech Connect

    Nelson, E

    2007-02-28

    The potential use of a peat bed to treat the H-12 Outfall discharge to bring it to new compliance limits was previously investigated and reported utilizing a 7 hour retention time. The influence of retention time (contact time) of water with peat moss on the removal of copper from the water was investigated under laboratory conditions using vertical flow peat moss columns. Reduction of the necessary retention time has a large influence on the design sizing of any peat bed that would be constructed to treat the H-12 discharge on a full scale basis. Retention times of 5 hours, 3 hours and 1 hour were tested to determine the copper removal by the peat columns using vertical flow. Water samples were collected after 4, 8, 12, and 16 water volumes had passed through the columns and analyzed for a suite of metals, with quantitative emphasis on copper. Laboratory results indicated that copper removal was very high at each of the 3 retention times tested, ranging from 99.6 % removal at 5 and 3 hours to 98.8% removal at 1 hour. All these values are much lower that the new compliance limit for the outfall. The results also indicated that most divalent metals were removed to their normal reporting detection limit for the analytical methods used, including zinc. Lead levels in the H-12 discharge used in this study were below PQL in all samples analyzed. While each of the retention times studied removed copper very well, there were indications that 1 hour is probably too short for an operational, long-term facility. At that retention time, there was about 6% compaction of the peat in the column due to the water velocity, and this may affect long term hydraulic conductivity of the peat bed. At that retention time, copper concentration in the effluent was higher than the other times tested, although still very low. Because of the potential compacting and somewhat reduced removal efficiency at a 1 hour retention time, it would be prudent to design to at least a 3 hour retention

  18. Curves showing column strength of steel and duralumin tubing

    NASA Technical Reports Server (NTRS)

    Ross, Orrin E

    1929-01-01

    Given here are a set of column strength curves that are intended to simplify the method of determining the size of struts in an airplane structure when the load in the member is known. The curves will also simplify the checking of the strength of a strut if the size and length are known. With these curves, no computations are necessary, as in the case of the old-fashioned method of strut design. The process is so simple that draftsmen or others who are not entirely familiar with mechanics can check the strength of a strut without much danger of error.

  19. Analysis of proteins by CE, CIEF, and microfluidic devices with whole-column-imaging detection.

    PubMed

    Wu, Jiaqi; Wu, Xing-Zheng; Huang, Tiemin; Pawliszyn, Janusz

    2004-01-01

    The recently developed whole-column-imaging detection technique for capillary electrophoresis (CE) and capillary isoelectric focusing (CIEF), a commercial whole-column-imaged CIEF instrument and its standard operation protocol are introduced. Furthermore, new developments and applications of whole-column-imaging detection in protein-protein interaction study, in protein separation using microfluidic devices and CIEF methods without carrier ampholytes, as well as in 2D separation techniques are reviewed. Miniaturization of whole-column-imaging CIEF and axially illuminated fluorescence whole-column-imaging CIEF are also discussed. PMID:15163861

  20. Stationary phase modulation in liquid chromatography through the serial coupling of columns: A review.

    PubMed

    Alvarez-Segura, T; Torres-Lapasió, J R; Ortiz-Bolsico, C; García-Alvarez-Coque, M C

    2016-06-01

    Liquid chromatography with single columns often does not succeed in the analysis of complex samples, in terms of resolution and analysis time. A relatively simple solution to enhance chromatographic resolution is the modulation of the stationary phase through the serial coupling of columns. This can be implemented with any type of column using compatible elution conditions and conventional instruments. This review describes the key features of column coupling and published procedures, where two or more columns were coupled in series to solve separation problems. In all reports, the authors could not resolve their samples with single columns, whereas significant enhancement in chromatographic performance was obtained when the columns were combined. Particularly interesting is the reduction in the analysis time in the isocratic mode, which alleviates the "general elution problem" of liquid chromatography, and may represent a stimulus for the proposal of new procedures, especially in combination with mass spectrometric, electrochemical and refractometric detection. Developments proposed to make the serial coupling of columns useful in routine and research laboratories are outlined, including optimisation strategies that facilitate the selection of the appropriate column combination and elution conditions (solvent content, flow rate or temperature) in both isocratic and gradient modes. The availability of zero dead volume couplers, able to connect standard columns, and the commercialisation of short columns with multiple lengths, have expanded the possibilities of success. PMID:27155298

  1. Problems involving the determination of the column-only band broadening in columns producing narrow and tailed peaks.

    PubMed

    Vanderheyden, Yoachim; Vanderlinden, Kim; Broeckhoven, Ken; Desmet, Gert

    2016-04-01

    We have investigated which of the different existing peak variance read-out methods (including the effect of a deconvolution pre-treatment method) are most suited to eliminate the system contribution from the total observed band broadening observed in LC systems. Emphasis is put on the most demanding case, i.e., the measurement of non-retained component peaks, which typically are very narrow and tailed. The problem with such peaks is that the method that is generally considered to be the only mathematically correct method (i.e., the method of moments) leads to peak variance values that are so strongly dominated by the tail of the peak that they become highly exaggerated and practically meaningless (i.e., they are dominated by the peak width at 10 or 12σt, which corresponds to resolutions and peak purities that are so high they are never pursued in practice). Interestingly, filtering away the extra-column contribution from the entire peak shape using peak deconvolution (wherein not only the second order moment is corrected but also all other moments) produces corrected 4σt- and half height peak widths that are physically meaningful, i.e., the corrected values allow to make sufficiently accurate predictions of how the peak width at 4σt and at half height changes when the column length changes. This result now allows to navigate away from the classical method of moments to define the column plate height, and resort to plate heights based on the practically much more relevant 4σt- and 5σt-widths, provided theses are corrected via peak deconvolution. PMID:26947164

  2. Numerical analysis of soft clay performance reinforced by geosynthetics encased stone columns

    NASA Astrophysics Data System (ADS)

    Nagy, Nabil M.

    2013-10-01

    To improve the behavior of stone columns, the Geosynthetics is used for encasing the stone column as reinforcement material. The Geosynthetics Encased Stone Column (GESC) system has been developed to increase the confinement effect of the ordinary stone columns, and consequently to improve the load carrying capacity of stone columns. In this paper, finite element based numerical study has been carried out using ABAQUS program to study the performance of the GESC systems under different conditions. The influences of some effective parameters were studied to show the improvement in soil bearing and settlement decrease for the stone column-soil system. These include the column dimensions, the encasement stiffness and shear strength of the foundation soil.

  3. The Two-Column Aerosol Project (TCAP) Science Plan

    SciTech Connect

    Berkowitz, CM; Berg, LK; Cziczo, DJ; Flynn, CJ; Kassianov, EI; Fast, JD; Rasch, PJ; Shilling, JE; Zaveri, RA; Zelenyuk, A; Ferrare, RA; Hostetler, CA; Cairns, B; Russell, PB; Ervens, B

    2011-07-27

    The Two-Column Aerosol Project (TCAP) field campaign will provide a detailed set of observations with which to (1) perform radiative and cloud condensation nuclei (CCN) closure studies, (2) evaluate a new retrieval algorithm for aerosol optical depth (AOD) in the presence of clouds using passive remote sensing, (3) extend a previously developed technique to investigate aerosol indirect effects, and (4) evaluate the performance of a detailed regional-scale model and a more parameterized global-scale model in simulating particle activation and AOD associated with the aging of anthropogenic aerosols. To meet these science objectives, the Atmospheric Radiation Measurement (ARM) Climate Research Facility will deploy the ARM Mobile Facility (AMF) and the Mobile Aerosol Observing System (MAOS) on Cape Cod, Massachusetts, for a 12-month period starting in the summer of 2012 in order to quantify aerosol properties, radiation, and cloud characteristics at a location subject to both clear and cloudy conditions, and clean and polluted conditions. These observations will be supplemented by two aircraft intensive observation periods (IOPs), one in the summer and a second in the winter. Each IOP will deploy one, and possibly two, aircraft depending on available resources. The first aircraft will be equipped with a suite of in situ instrumentation to provide measurements of aerosol optical properties, particle composition and direct-beam irradiance. The second aircraft will fly directly over the first and use a multi-wavelength high spectral resolution lidar (HSRL) and scanning polarimeter to provide continuous optical and cloud properties in the column below.

  4. Mini-column screening assay for tetracyclines in chicken.

    PubMed

    Shalaby, Ali R

    2015-01-01

    A simple, rapid, reliable and economical mini-column (MC) method for the detection of tetracyclines (TCs) residues in chicken meat was developed. The method employs a commonly available Pasteur pipette which is tightly packed with silica gel and anhydrous sodium sulfate. Clean-up and detection of illegal levels can be achieved on the same column. Viewing the developed MC under an ultraviolet lamp revealed that TCs can be detected as a compact golden yellow fluorescent band at the junction between the anhydrous sodium sulfate and silica gel layers. Comparing the yellow band of control extracts with those fortified (100 ng ml(-1)) showed no overlap between analyte and impurities. The limit of detection (LOD) of the MC assay was 1 ng, indicating that the chicken sample containing 10 µg TCs kg(-1) sample could be easily detected. Moreover, the intensity of the yellow band increased whenever TCs levels in the extract increased. Evaluation utility of the method with blind samples as controls or samples fortified with total TCs at various levels indicated that the total blank and spiked samples at levels equal or below the permissible limits were assessed as accepted. The method can provide an alternative to microbial screening assays and could be used as an effective pre-screening technique in public health laboratories. PMID:25430068

  5. NEW COLUMN SEPARATION METHOD FOR EMERGENCY URINE SAMPLES

    SciTech Connect

    Maxwell, S; Brian Culligan, B

    2007-08-28

    The Savannah River Site Environmental Bioassay Lab participated in the 2007 NRIP Emergency Response program administered by the National Institute for Standards and Technology (NIST) in May, 2007. A new rapid column separation method was applied directly to the NRIP 2007 emergency urine samples, with only minimal sample preparation to reduce preparation time. Calcium phosphate precipitation, previously used to pre-concentrate actinides and Sr-90 in NRIP 2006 urine and water samples, was not used for the NRIP 2007 urine samples. Instead, the raw urine was acidified and passed directly through the stacked resin columns (TEVA+TRU+SR Resins) to separate the actinides and strontium from the NRIP urine samples more quickly. This improvement reduced sample preparation time for the NRIP 2007 emergency urine analyses significantly. This approach works well for small volume urine samples expected during an emergency response event. Based on initial feedback from NIST, the SRS Environmental Bioassay Lab had the most rapid analysis times for actinides and strontium-90 analyses for NRIP 2007 urine samples.

  6. Distillation column for the XENON1T experiment

    NASA Astrophysics Data System (ADS)

    Fieguth, Alexander; XENON Collaboration

    2016-05-01

    The XENON1T experiment will probe a new parameter space in the direct dark matter search. Besides the enlargement of target mass to the ton scale, a further background reduction with respect to its predecessor XENON100 is necessary. A major contribution to the intrinsic contamination is the β-decaying isotope 85Kr, which leads to the requirement of a concentration less than 0.2 ppt of natural krypton in xenon. Its removal from the xenon gas is achieved by cryogenic distillation. For the new experiment a custom-build distillation column with a separation factor larger than 105 and a throughput of 3kg/h has been designed and built at the University of Muenster. Furthermore its performance has been characterized using different trace gas detection techniques, e.g. a novel 83mKr-tracer method, and its functionality has been tested successfully. The distillation column, which is installed and commissioned at the XENON1T experiment, is ready to process the 3.5 tons of xenon.

  7. Development of the 15 meter diameter hoop column antenna

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The building of a deployable 15-meter engineering model of the 100 meter antenna based on the point-design of an earlier task of this contract, complete with an RF-capable surface is described. The 15 meter diameter was selected so that the model could be tested in existing manufacturing, near-field RF, thermal vacuum, and structural dynamics facilities. The antenna was designed with four offset paraboloidal reflector surfaces with a focal length of 366.85 in and a primary surface accuracy goal of .069 in rms. Surface adjustment capability was provided by manually resetting the length of 96 surface control cords which emanated from the lower column extremity. A detailed description of the 15-meter Hoop/Column Antenna, major subassemblies, and a history of its fabrication, assembly, deployment testing, and verification measurements are given. The deviation for one aperture surface (except the outboard extremity) was measured after adjustments in follow-on tests at the Martin Marietta Near-field Facility to be .061 in; thus the primary surface goal was achieved.

  8. Group type analysis of asphalt by column liquid chromatography

    SciTech Connect

    Zhang, C.; Yang, J.; Xue, Y.; Li, Y.

    2008-07-01

    An improved analysis method for characterization of asphalt was established. The method is based on column chromatography technique. The asphalts were separated into four groups: saturates, aromatics, resins, and asphaltenes, quantitatively. About 0.1 g of sample was required in each analysis. About 20 mL of n-heptanes was used to separate out saturates first. Then about 35 mL of n-heptanes/dichloromethane (.5, v/v) mixture was used to separate out aromatics. About 30 mL of dichloromethane/tetrahydrofuran (1/3, v/v) mixture was used to separate out resin. The quality of the separation was confirmed by infrared spectra (IR) and {sup 1}H NMR analysis. The model compounds, tetracosan for saturates, dibenz(o)anthracen for aromatics, and acetanilide for resins were used for verification. The IR and {sup 1}H NMR analysis of the prepared fractions from the column liquid chromatography were in good agreement that of pure reagents.

  9. Approximations for column effect in airplane wing spars

    NASA Technical Reports Server (NTRS)

    Warner, Edward P; Short, Mac

    1927-01-01

    The significance attaching to "column effect" in airplane wing spars has been increasingly realized with the passage of time, but exact computations of the corrections to bending moment curves resulting from the existence of end loads are frequently omitted because of the additional labor involved in an analysis by rigorously correct methods. The present report represents an attempt to provide for approximate column effect corrections that can be graphically or otherwise expressed so as to be applied with a minimum of labor. Curves are plotted giving approximate values of the correction factors for single and two bay trusses of varying proportions and with various relationships between axial and lateral loads. It is further shown from an analysis of those curves that rough but useful approximations can be obtained from Perry's formula for corrected bending moment, with the assumed distance between points of inflection arbitrarily modified in accordance with rules given in the report. The discussion of general rules of variation of bending stress with axial load is accompanied by a study of the best distribution of the points of support along a spar for various conditions of loading.

  10. Nonlinear effects for the Taylor column for a hemisphere

    NASA Technical Reports Server (NTRS)

    Crisalli, A. J.; Walker, J. D. A.

    1976-01-01

    When a flow is forced past an obstacle in a rapidly rotating fluid, a Taylor column forms. This is defined by a set of vertical detached shear layers circumscribing the obstacle which provide the smooth transition from an external inviscid potential flow to a stagnant core above the obstacle. For a hemispherical object, the main adjustment takes place in an external E to the 1/4 power layer and an internal E to the 2/7 power layer; here, the nonlinear flow in these layers is investigated. The problem in the E to the 1/4 power layer is identical to a problem occurring in magnetohydrodynamic flow; in addition, some features of the magnetohydrodynamic problem have been resolved. Numerical solutions are obtained for the steady nonlinear external E to the 1/4 power layer flow up to the point where unsteady flow separation from the Taylor column is imminent. The response of the internal E to the 2/7 power layer to the flow in the E to the 1/4 power layer is calculated, and the results suggest that the internal shear layer is unlikely to play any significant role in the separation process

  11. Surfactant-Bound Monolithic Columns for Capillary Electrochromatography

    PubMed Central

    Gu, Congying; He, Jun; Jia, Jinping; Fang, Nenghu; Shamsi, Shahab A.

    2010-01-01

    A novel anionic surfactant bound monolithic stationary phase based on 11-acrylaminoundecanoic acid (AAUA) is designed for capillary electrochromatography (CEC). The monolith possessing bonded undecanoyl groups (hydrophobic sites) and carboxyl groups (weak cationic ion-exchange sites) was evaluated as a mixed-mode stationary phase in CEC for the separation of neutral and polar solutes. Using a multivariate D-optimal design the composition of the polymerization mixture was modeled and optimized with five alkylbenzenes (ABs) and seven alkyl phenyl ketones (APKs) as test solutes. The D-optimal design indicates a strong dependence of electrochromatographic parameters on the concentration of AAUA monomer and porogen (water) in the polymerization mixture. A difference of 6%, 8% and 13% RSD between the predicted and the experimental values in terms of efficiency, resolution, and retention time, respectively, indeed confirmed that the proposed approach is practical. The physical (i.e., morphology, porosity and permeability) and chromatographic properties of the monolithic columns were thoroughly investigated. With the optimized monolithic column, high efficiency separation of N-methylcarbamates (NMCs) pesticides and positional isomers was successfully achieved. It appears that this type of mixed-mode monolith (containing both chargeable and hydrophobic sites) may have a great potential as a new generation of CEC stationary phase. PMID:19885887

  12. Modified method to improve the design of Petlyuk distillation columns

    PubMed Central

    2014-01-01

    Background A response surface analysis was performed to study the effect of the composition and feeding thermal conditions of ternary mixtures on the number of theoretical stages and the energy consumption of Petlyuk columns. A modification of the pre-design algorithm was necessary for this purpose. Results The modified algorithm provided feasible results in 100% of the studied cases, compared with only 8.89% for the current algorithm. The proposed algorithm allowed us to attain the desired separations, despite the type of mixture and the operating conditions in the feed stream, something that was not possible with the traditional pre-design method. The results showed that the type of mixture had great influence on the number of stages and on energy consumption. A higher number of stages and a lower consumption of energy were attained with mixtures rich in the light component, while higher energy consumption occurred when the mixture was rich in the heavy component. Conclusions The proposed strategy expands the search of an optimal design of Petlyuk columns within a feasible region, which allow us to find a feasible design that meets output specifications and low thermal loads. PMID:25061476

  13. The Computational Properties of a Simplified Cortical Column Model.

    PubMed

    Cain, Nicholas; Iyer, Ramakrishnan; Koch, Christof; Mihalas, Stefan

    2016-09-01

    The mammalian neocortex has a repetitious, laminar structure and performs functions integral to higher cognitive processes, including sensory perception, memory, and coordinated motor output. What computations does this circuitry subserve that link these unique structural elements to their function? Potjans and Diesmann (2014) parameterized a four-layer, two cell type (i.e. excitatory and inhibitory) model of a cortical column with homogeneous populations and cell type dependent connection probabilities. We implement a version of their model using a displacement integro-partial differential equation (DiPDE) population density model. This approach, exact in the limit of large homogeneous populations, provides a fast numerical method to solve equations describing the full probability density distribution of neuronal membrane potentials. It lends itself to quickly analyzing the mean response properties of population-scale firing rate dynamics. We use this strategy to examine the input-output relationship of the Potjans and Diesmann cortical column model to understand its computational properties. When inputs are constrained to jointly and equally target excitatory and inhibitory neurons, we find a large linear regime where the effect of a multi-layer input signal can be reduced to a linear combination of component signals. One of these, a simple subtractive operation, can act as an error signal passed between hierarchical processing stages. PMID:27617444

  14. Noninvasive Imaging of Tracer Experiments in a Soil Column

    NASA Astrophysics Data System (ADS)

    Jelinkova, V.; Pohlmeier, A.; van Dusschoten, D.; Vereecken, H.; Cislerova, M.

    2008-12-01

    A set of tracer-infiltration experiments on soil columns by means of magnetic resonance imaging (MRI) was performed. Computed tomography (CT) was applied in order to map the spatial distribution of porous media, namely the local densities and porosities, and their variation within the soil sample under test. The CT visualisation was done in order to trace disturbances in the structure as a possible source of preferential flow. By means of MRI the flow paths during the infiltration experiment were visualized using a tracer pulse containing Ni(NO3)2 in a concentration of 0.05 mol/litre. The pulse was added under hydraulic steady state conditions. The tracer motion was monitored through its effect on the signal relaxation of 1H using a 7 Tesla vertical magnet system equipped with a 40 mm RF probe. The boundary condition at the top of the soil columns was maintained using a dripping system connected to a HPLC pump with flow rate set to 0.5 ml/min. Free outflow was used as the bottom boundary condition. The vertical component of the local velocity value was calculated after the experiment. Small disturbances in the tracer front observed during the break-through could be related to the preferential flow phenomena in combination with the air bubble entrapment. This research has been supported by research project SP/2e7/229/07 and DBU - Deutsche Bundesstiftung Umwelt.

  15. PRECISION AND ACCURACY IN THE DETERMINATION OF ORGANICS IN WATER BY FUSED SILICA CAPILLARY COLUMN GAS CHROMOTOGRAPHY/MASS SPECTROMETRY AND PACKED COLUMN GAS CHROMATOGRAPHY/MASS SPECTROMETRY

    EPA Science Inventory

    Two general methods for the identification and measurement of organic compounds in water are compared. One method employs packed column chromatography and the other fused silica capillary column chromatography. The two gas chromatography/mass spectrometry (GC/MS) methods use diff...

  16. Specific Yield--Column drainage and centrifuge moisture content

    USGS Publications Warehouse

    Johnson, A.I.; Prill, R.C.; Morris, D.A.

    1963-01-01

    The specific yield of a rock or soil, with respect to water, is the ratio of (1) the volume of water which, after being saturated, it will yield by gravity to (2) its own volume. Specific retention represents the water retained against gravity drainage. The specific yield and retention when added together are equal to the total interconnected porosity of the rock or soil. Because specific retention is more easily determined than specific yield, most methods for obtaining yield first require the determination of specific retention. Recognizing the great need for developing improved methods of determining the specific yield of water-bearing materials, the U.S. Geological Survey and the California Department of Water Resources initiated a cooperative investigation of this subject. The major objectives of this research are (1) to review pertinent literature on specific yield and related subjects, (2) to increase basic knowledge of specific yield and rate of drainage and to determine the most practical methods of obtaining them, (3) to compare and to attempt to correlate the principal laboratory and field methods now commonly used to obtain specific yield, and (4) to obtain improved estimates of specific yield of water-bearing deposits in California. An open-file report, 'Specific yield of porous media, an annotated bibliography,' by A. I. Johnson, D. A. Morris, and R. C. Prill, was released in 1960 in partial fulfillment of the first objective. This report describes the second phase of the specific-yield study by the U.S. Geological Survey Hydrologic Laboratory at Denver, Colo. Laboratory research on column drainage and centrifuge moisture equivalent, two methods for estimating specific retention of porous media, is summarized. In the column-drainage study, a wide variety of materials was packed into plastic columns of 1- to 8-inch diameter, wetted with Denver tap water, and drained under controlled conditions of temperature and humidity. The effects of cleaning the

  17. Use of emulsified vegetable oil to support bioremediation of TCE DNAPL in soil columns

    NASA Astrophysics Data System (ADS)

    Harkness, Mark; Fisher, Angela

    2013-08-01

    The interaction between emulsified vegetable oil (EVO) and trichloroethylene (TCE) dense non-aqueous phase liquid (DNAPL) was observed using two soil columns and subsequent reductive dechlorination of TCE was monitored over a three year period. Dyed TCE DNAPL (~ 75 g) was emplaced in one column (DNAPL column), while the second was DNAPL-free (plume column). EVO was added to both columns and partitioning of the EVO into the TCE DNAPL was measured and quantified. TCE (1.9 mM) was added to the influent of the plume column to simulate conditions down gradient of a DNAPL source area and the columns were operated independently for more than one year, after which they were connected in series. Initially limited dechlorination of TCE to cDCE was observed in the DNAPL column, while the plume column supported complete reductive dechlorination of TCE to ethene. Upon connection and reamendment of the plume column with EVO, near saturation levels of TCE from the effluent of the DNAPL column were rapidly dechlorinated to c-DCE and VC in the plume column; however, this high rate dechlorination produced hydrochloric acid which overwhelmed the buffering capacity of the system and caused the pH to drop below 6.0. Dechlorination efficiency in the columns subsequently deteriorated, as measured by the chloride production and Dehalococcoides counts, but was restored by adding sodium bicarbonate buffer to the influent groundwater. Robust dechlorination was eventually observed in the DNAPL column, such that the TCE DNAPL was largely removed by the end of the study. Partitioning of the EVO into the DNAPL provided significant operational benefits to the remediation system both in terms of electron donor placement and longevity.

  18. Axial development and radial non-uniformity of flow in packed columns.

    PubMed

    Park, Jaekeun C; Raghavan, Karthik; Gibbs, Stephen J

    2002-02-01

    Flow inhomogeneity and axial development in low-pressure chromatographic columns have been studied by magnetic resonance imaging velocimetry. The columns studied included (a) an 11.7-mm I.D. column packed with either 50 microm diameter porous polyacrylamide, or 99 or 780 microm diameter impermeable polystyrene beads, and (b) a 5-mm I.D. column commercially packed with 10 microm polymeric beads. The packing methods included gravity settling, slurry packing, ultrasonication, and dry packing with vibration. The magnetic resonance method used averaged apparent fluid velocity over both column cross-sections and fluid displacements greater than one particle diameter and hence permits assessment of macroscopic flow non-uniformities. The results confirm that now non-uniformities induced by the conical distributor of the 11.7-mm I.D. column or the presence of voids at the column entrance relax on a length scale of the column radius. All of the 11.7-mm I.D. columns examined exhibit near wall channeling within a few particle diameters of the wall. The origins of this behavior are demonstrated by imaging of the radial dependence of the local porosity for a column packed with 780 microm beads. Columns packed with the 99-microm beads exhibit reduced flow in a region extending from ten to three-to-five particle diameters from the wall. This velocity reduction is consistent with a reduced porosity of 0.35 in this region as compared to approximately 0.43 in the bulk of the column. Ultrasonicated and dry-packed columns exhibit enhanced flow in a region located between approximately eight and 20 particle diameters from the wall. This enhancement maybe caused by packing density inhomogeneity and/or particle size segregation caused by vibration during the packing process. No significant non-uniformities on length scales of 20 microm or greater were observed in the commercially packed column packed with 10 microm particles. PMID:11860146

  19. Temperature-assisted On-column Solute Focusing: A General Method to Reduce Pre-column Dispersion in Capillary High Performance Liquid Chromatography

    PubMed Central

    Groskreutz, Stephen R.; Weber, Stephen G.

    2014-01-01

    Solvent-based on-column focusing is a powerful and well known approach for reducingthe impact of pre-column dispersion in liquid chromatography. Here we describe an orthogonal temperature-based approach to focusing called temperature-assisted on-column solute focusing (TASF). TASF is founded on the same principles as the more commonly used solvent-based method wherein transient conditions are created thatlead to high solute retention at the column inlet. Combining the low thermal mass of capillary columns and the temperature dependence of solute retentionTASF is used effectivelyto compress injection bands at the head of the column through the transient reduction in column temperature to 5 °C for a defined 7 mm segment of a 6 cm long 150 μm I.D. column. Following the 30 second focusing time, the column temperature is increased rapidly to the separation temperature of 60 °C releasing the focused band of analytes. We developed a model tosimulate TASF separations based on solute retention enthalpies, focusing temperature, focusing time, and column parameters. This model guides the systematic study of the influence of sample injection volume on column performance.All samples have solvent compositions matching the mobile phase. Over the 45 to 1050 nL injection volume range evaluated, TASF reducesthe peak width for all soluteswith k’ greater than or equal to 2.5, relative to controls. Peak widths resulting from injection volumes up to 1.3 times the column fluid volume with TASF are less than 5% larger than peak widths from a 45 nL injection without TASF (0.07 times the column liquid volume). The TASF approach reduced concentration detection limits by a factor of 12.5 relative to a small volume injection for low concentration samples. TASF is orthogonal to the solvent focusing method. Thus, it canbe used where on-column focusing is required, but where implementation of solvent-based focusing is difficult. PMID:24973805

  20. Synthesis and characterization of a cellular membrane affinity chromatography column containing histamine 1 and P2Y1 receptors: A multiple G-protein coupled receptor column

    PubMed Central

    Moaddel, Ruin; Musyimi, Harrison K.; Sanghvi, Mitesh; Bashore, Charlene; Frazier, Chester R.; Khadeer, Mohammad; Bhatia, Prateek; Wainer, Irving W.

    2015-01-01

    A cellular membrane affinity chromatography (CMAC) column has been created using cellular membrane fragments from a 1321N1 cell line stably transfected with the P2Y1 receptor. The CMAC(1321N1P2Y1) column contained functional P2Y1 and histamine 1 receptors, which independently bound receptor-specific ligands. The data obtained with the CMAC(1321N1P2Y1) column demonstrate that multiple-G-protein coupled receptor (GPCR) columns can be developed and used to probe interactions with the immobilized receptors and that endogenously expressed GPCRs can be used to create CMAC columns. The results also establish that the histamine 1 receptor can be immobilized with retention of ligand-specific binding. PMID:19608372