WorldWideScience

Sample records for liquid water path

  1. Comparison of global cloud liquid water path derived from microwave measurements with CERES-MODIS

    Science.gov (United States)

    Yi, Y.; Minnis, P.; Huang, J.; Lin, B.; Ayers, K.; Sun-Mack, S.; Fan, A.

    Cloud liquid water path LWP is a crucial parameter for climate studies due to the link that it provides between the atmospheric hydrological and radiative budgets Satellite-based visible infrared techniques such as the Visible Infrared Solar Split-Window Technique VISST can retrieve LWP for water clouds assumes single-layer over a variety of surfaces If the water clouds are overlapped by ice clouds the LWP of the underlying clouds can not be retrieved by such techniques However microwave techniques may be used to retrieve the LWP underneath ice clouds due to the microwave s insensitivity to cloud ice particles LWP is typically retrieved from satellite-observed microwave radiances only over ocean due to variations of land surface temperature and emissivity Recently Deeter and Vivekanandan 2006 developed a new technique for retrieving LWP over land In order to overcome the sensitivity to land surface temperature and emissivity their technique is based on a parameterization of microwave polarization-difference signals In this study a similar regression-based technique for retrieving LWP over land and ocean using Advanced Microwave Scanning Radiometer - EOS AMSR-E measurements is developed Furthermore the microwave surface emissivities are also derived using clear-sky fields of view based on the Clouds and Earth s Radiant Energy System Moderate-resolution Imaging Spectroradiometer CERES-MODIS cloud mask These emissivities are used in an alternate form of the technique The results are evaluated using independent measurements such

  2. Modeling the Liquid Water Transport in the Gas Diffusion Layer for Polymer Electrolyte Membrane Fuel Cells Using a Water Path Network

    Directory of Open Access Journals (Sweden)

    Dietmar Gerteisen

    2013-09-01

    Full Text Available In order to model the liquid water transport in the porous materials used in polymer electrolyte membrane (PEM fuel cells, the pore network models are often applied. The presented model is a novel approach to further develop these models towards a percolation model that is based on the fiber structure rather than the pore structure. The developed algorithm determines the stable liquid water paths in the gas diffusion layer (GDL structure and the transitions from the paths to the subsequent paths. The obtained water path network represents the basis for the calculation of the percolation process with low calculation efforts. A good agreement with experimental capillary pressure-saturation curves and synchrotron liquid water visualization data from other literature sources is found. The oxygen diffusivity for the GDL with liquid water saturation at breakthrough reveals that the porosity is not a crucial factor for the limiting current density. An algorithm for condensation is included into the model, which shows that condensing water is redirecting the water path in the GDL, leading to an improved oxygen diffusion by a decreased breakthrough pressure and changed saturation distribution at breakthrough.

  3. An Uncertainty Data Set for Passive Microwave Satellite Observations of Warm Cloud Liquid Water Path

    Science.gov (United States)

    Greenwald, Thomas J.; Bennartz, Ralf; Lebsock, Matthew; Teixeira, João.

    2018-04-01

    The first extended comprehensive data set of the retrieval uncertainties in passive microwave observations of cloud liquid water path (CLWP) for warm oceanic clouds has been created for practical use in climate applications. Four major sources of systematic errors were considered over the 9-year record of the Advanced Microwave Scanning Radiometer-EOS (AMSR-E): clear-sky bias, cloud-rain partition (CRP) bias, cloud-fraction-dependent bias, and cloud temperature bias. Errors were estimated using a unique merged AMSR-E/Moderate resolution Imaging Spectroradiometer Level 2 data set as well as observations from the Cloud-Aerosol Lidar with Orthogonal Polarization and the CloudSat Cloud Profiling Radar. To quantify the CRP bias more accurately, a new parameterization was developed to improve the inference of CLWP in warm rain. The cloud-fraction-dependent bias was found to be a combination of the CRP bias, an in-cloud bias, and an adjacent precipitation bias. Globally, the mean net bias was 0.012 kg/m2, dominated by the CRP and in-cloud biases, but with considerable regional and seasonal variation. Good qualitative agreement between a bias-corrected AMSR-E CLWP climatology and ship observations in the Northeast Pacific suggests that the bias estimates are reasonable. However, a possible underestimation of the net bias in certain conditions may be due in part to the crude method used in classifying precipitation, underscoring the need for an independent method of detecting rain in warm clouds. This study demonstrates the importance of combining visible-infrared imager data and passive microwave CLWP observations for estimating uncertainties and improving the accuracy of these observations.

  4. Observed and simulated temperature dependence of the liquid water path of low clouds

    Energy Technology Data Exchange (ETDEWEB)

    Del Genio, A.D.; Wolf, A.B. [NASA Goddard Institute for Space Studies, New York, NY (United States)

    1996-04-01

    Data being acquired at the Atmospheric Radiation Measurement (ARM) Southern great Plains (SGP) Cloud and Radiation Testbed (CART) site can be used to examine the factors determining the temperature dependence of cloud optical thickness. We focus on cloud liquid water and physical thickness variations which can be derived from existing ARM measurements.

  5. Path integral molecular dynamics within the grand canonical-like adaptive resolution technique: Simulation of liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, Animesh, E-mail: animesh@zedat.fu-berlin.de; Delle Site, Luigi, E-mail: dellesite@fu-berlin.de [Institute for Mathematics, Freie Universität Berlin, Berlin (Germany)

    2015-09-07

    Quantum effects due to the spatial delocalization of light atoms are treated in molecular simulation via the path integral technique. Among several methods, Path Integral (PI) Molecular Dynamics (MD) is nowadays a powerful tool to investigate properties induced by spatial delocalization of atoms; however, computationally this technique is very demanding. The above mentioned limitation implies the restriction of PIMD applications to relatively small systems and short time scales. One of the possible solutions to overcome size and time limitation is to introduce PIMD algorithms into the Adaptive Resolution Simulation Scheme (AdResS). AdResS requires a relatively small region treated at path integral level and embeds it into a large molecular reservoir consisting of generic spherical coarse grained molecules. It was previously shown that the realization of the idea above, at a simple level, produced reasonable results for toy systems or simple/test systems like liquid parahydrogen. Encouraged by previous results, in this paper, we show the simulation of liquid water at room conditions where AdResS, in its latest and more accurate Grand-Canonical-like version (GC-AdResS), is merged with two of the most relevant PIMD techniques available in the literature. The comparison of our results with those reported in the literature and/or with those obtained from full PIMD simulations shows a highly satisfactory agreement.

  6. The impact of horizontal heterogeneities, cloud fraction, and cloud dynamics on warm cloud effective radii and liquid water path from CERES-like Aqua MODIS retrievals

    OpenAIRE

    D. Painemal; P. Minnis; S. Sun-Mack

    2013-01-01

    The impact of horizontal heterogeneities, liquid water path (LWP from AMSR-E), and cloud fraction (CF) on MODIS cloud effective radius (re), retrieved from the 2.1 μm (re2.1) and 3.8 μm (re3.8) channels, is investigated for warm clouds over the southeast Pacific. Values of re retrieved using the CERES Edition 4 algorithms are averaged at the CERES footprint resolution (~ 20 km), while heterogeneities (Hσ) are calculated as the ratio between the standard deviation and mean...

  7. The impact of horizontal heterogeneities, cloud fraction, and liquid water path on warm cloud effective radii from CERES-like Aqua MODIS retrievals

    OpenAIRE

    Painemal, D.; Minnis, P.; Sun-Mack, S.

    2013-01-01

    The impact of horizontal heterogeneities, liquid water path (LWP from AMSR-E), and cloud fraction (CF) on MODIS cloud effective radius (re), retrieved from the 2.1 μm (re2.1) and 3.8 μm (re3.8) channels, is investigated for warm clouds over the southeast Pacific. Values of re retrieved using the CERES algorithms are averaged at the CERES footprint resolution (∼20 km), while heterogeneities (Hσ) are calculated as the ratio between the standard deviation and mean 0.64 μm reflectance. ...

  8. Cloud Droplet Size and Liquid Water Path Retrievals From Zenith Radiance Measurements: Examples From the Atmospheric Radiation Measurement Program and the Aerosol Robotic Network

    Science.gov (United States)

    Chiu, J. C.; Marshak, A.; Huang, C.-H.; Varnai, T.; Hogan, R. J.; Giles, D. M.; Holben, B. N.; Knyazikhin, Y.; O'Connor, E. J.; Wiscombe, W. J.

    2012-01-01

    The ground-based Atmospheric Radiation Measurement Program (ARM) and NASA Aerosol Robotic Network (AERONET) routinely monitor clouds using zenith radiances at visible and near-infrared wavelengths. Using the transmittance calculated from such measurements, we have developed a new retrieval method for cloud effective droplet size and conducted extensive tests for non-precipitating liquid water clouds. The underlying principle is to combine a water-absorbing wavelength (i.e. 1640 nm) with a nonwater-absorbing wavelength for acquiring information on cloud droplet size and optical depth. For simulated stratocumulus clouds with liquid water path less than 300 g/sq m and horizontal resolution of 201m, the retrieval method underestimates the mean effective radius by 0.8 m, with a root-mean-squared error of 1.7 m and a relative deviation of 13 %. For actual observations with a liquid water path less than 450 gm.2 at the ARM Oklahoma site during 2007-2008, our 1.5 min-averaged retrievals are generally larger by around 1 m than those from combined ground-based cloud radar and microwave radiometer at a 5min temporal resolution. We also compared our retrievals to those from combined shortwave flux and microwave observations for relatively homogeneous clouds, showing that the bias between these two retrieval sets is negligible, but the error of 2.6 m and the relative deviation of 22% are larger than those found in our simulation case. Finally, the transmittance-based cloud effective droplet radii agree to better than 11% with satellite observations and have a negative bias of 1 m. Overall, the retrieval method provides reasonable cloud effective radius estimates, which can enhance the cloud products of both ARM and AERONET.

  9. Water evaporation: a transition path sampling study.

    Science.gov (United States)

    Varilly, Patrick; Chandler, David

    2013-02-07

    We use transition path sampling to study evaporation in the SPC/E model of liquid water. On the basis of thousands of evaporation trajectories, we characterize the members of the transition state ensemble (TSE), which exhibit a liquid-vapor interface with predominantly negative mean curvature at the site of evaporation. We also find that after evaporation is complete, the distributions of translational and angular momenta of the evaporated water are Maxwellian with a temperature equal to that of the liquid. To characterize the evaporation trajectories in their entirety, we find that it suffices to project them onto just two coordinates: the distance of the evaporating molecule to the instantaneous liquid-vapor interface and the velocity of the water along the average interface normal. In this projected space, we find that the TSE is well-captured by a simple model of ballistic escape from a deep potential well, with no additional barrier to evaporation beyond the cohesive strength of the liquid. Equivalently, they are consistent with a near-unity probability for a water molecule impinging upon a liquid droplet to condense. These results agree with previous simulations and with some, but not all, recent experiments.

  10. The impact of horizontal heterogeneities, cloud fraction, and cloud dynamics on warm cloud effective radii and liquid water path from CERES-like Aqua MODIS retrievals

    Science.gov (United States)

    Painemal, D.; Minnis, P.; Sun-Mack, S.

    2013-05-01

    The impact of horizontal heterogeneities, liquid water path (LWP from AMSR-E), and cloud fraction (CF) on MODIS cloud effective radius (re), retrieved from the 2.1 μm (re2.1) and 3.8 μm (re3.8) channels, is investigated for warm clouds over the southeast Pacific. Values of re retrieved using the CERES Edition 4 algorithms are averaged at the CERES footprint resolution (~ 20 km), while heterogeneities (Hσ) are calculated as the ratio between the standard deviation and mean 0.64 μm reflectance. The value of re2.1 strongly depends on CF, with magnitudes up to 5 μm larger than those for overcast scenes, whereas re3.8 remains insensitive to CF. For cloudy scenes, both re2.1 and re3.8 increase with Hσ for any given AMSR-E LWP, but re2.1 changes more than for re3.8. Additionally, re3.8 - re2.1 differences are positive ( 50 g m-2, and negative (up to -4 μm) for larger Hσ. Thus, re3.8 - re2.1 differences are more likely to reflect biases associated with cloud heterogeneities rather than information about the cloud vertical structure. The consequences for MODIS LWP are also discussed.

  11. The impact of horizontal heterogeneities, cloud fraction, and liquid water path on warm cloud effective radii from CERES-like Aqua MODIS retrievals

    Science.gov (United States)

    Painemal, D.; Minnis, P.; Sun-Mack, S.

    2013-10-01

    The impact of horizontal heterogeneities, liquid water path (LWP from AMSR-E), and cloud fraction (CF) on MODIS cloud effective radius (re), retrieved from the 2.1 μm (re2.1) and 3.8 μm (re3.8) channels, is investigated for warm clouds over the southeast Pacific. Values of re retrieved using the CERES algorithms are averaged at the CERES footprint resolution (∼20 km), while heterogeneities (Hσ) are calculated as the ratio between the standard deviation and mean 0.64 μm reflectance. The value of re2.1 strongly depends on CF, with magnitudes up to 5 μm larger than those for overcast scenes, whereas re3.8 remains insensitive to CF. For cloudy scenes, both re2.1 and re3.8 increase with Hσ for any given AMSR-E LWP, but re2.1 changes more than for re3.8. Additionally, re3.8-re2.1 differences are positive ( 45 gm-2, and negative (up to -4 μm) for larger Hσ. While re3.8-re2.1 differences in homogeneous scenes are qualitatively consistent with in situ microphysical observations over the region of study, negative differences - particularly evinced in mean regional maps - are more likely to reflect the dominant bias associated with cloud heterogeneities rather than information about the cloud vertical structure. The consequences for MODIS LWP are also discussed.

  12. The impact of horizontal heterogeneities, cloud fraction, and liquid water path on warm cloud effective radii from CERES-like Aqua MODIS retrievals

    Directory of Open Access Journals (Sweden)

    D. Painemal

    2013-10-01

    Full Text Available The impact of horizontal heterogeneities, liquid water path (LWP from AMSR-E, and cloud fraction (CF on MODIS cloud effective radius (re, retrieved from the 2.1 μm (re2.1 and 3.8 μm (re3.8 channels, is investigated for warm clouds over the southeast Pacific. Values of re retrieved using the CERES algorithms are averaged at the CERES footprint resolution (∼20 km, while heterogeneities (Hσ are calculated as the ratio between the standard deviation and mean 0.64 μm reflectance. The value of re2.1 strongly depends on CF, with magnitudes up to 5 μm larger than those for overcast scenes, whereas re3.8 remains insensitive to CF. For cloudy scenes, both re2.1 and re3.8 increase with Hσ for any given AMSR-E LWP, but re2.1 changes more than for re3.8. Additionally, re3.8–re2.1 differences are positive (Hσ 45 gm−2, and negative (up to −4 μm for larger Hσ. While re3.8–re2.1 differences in homogeneous scenes are qualitatively consistent with in situ microphysical observations over the region of study, negative differences – particularly evinced in mean regional maps – are more likely to reflect the dominant bias associated with cloud heterogeneities rather than information about the cloud vertical structure. The consequences for MODIS LWP are also discussed.

  13. Hard paths, soft paths or no paths? Cross-cultural perceptions of water solutions

    Science.gov (United States)

    Wutich, A.; White, A. C.; White, D. D.; Larson, K. L.; Brewis, A.; Roberts, C.

    2014-01-01

    In this study, we examine how development status and water scarcity shape people's perceptions of "hard path" and "soft path" water solutions. Based on ethnographic research conducted in four semi-rural/peri-urban sites (in Bolivia, Fiji, New Zealand, and the US), we use content analysis to conduct statistical and thematic comparisons of interview data. Our results indicate clear differences associated with development status and, to a lesser extent, water scarcity. People in the two less developed sites were more likely to suggest hard path solutions, less likely to suggest soft path solutions, and more likely to see no path to solutions than people in the more developed sites. Thematically, people in the two less developed sites envisioned solutions that involve small-scale water infrastructure and decentralized, community-based solutions, while people in the more developed sites envisioned solutions that involve large-scale infrastructure and centralized, regulatory water solutions. People in the two water-scarce sites were less likely to suggest soft path solutions and more likely to see no path to solutions (but no more likely to suggest hard path solutions) than people in the water-rich sites. Thematically, people in the two water-rich sites seemed to perceive a wider array of unrealized potential soft path solutions than those in the water-scarce sites. On balance, our findings are encouraging in that they indicate that people are receptive to soft path solutions in a range of sites, even those with limited financial or water resources. Our research points to the need for more studies that investigate the social feasibility of soft path water solutions, particularly in sites with significant financial and natural resource constraints.

  14. Effects of Aerosol on Cloud Liquid Water Path: Statistical Method a Potential Source for Divergence in Past Observation Based Correlative Studies

    Directory of Open Access Journals (Sweden)

    Ousmane Sy Savane

    2015-03-01

    Full Text Available Studies show a divergence in correlation between aerosol and cloud proxies, which has been thought of in the past as the results of varying physical mechanisms. Though modeling studies have supported this idea, from an observational standpoint it is difficult to attribute with confidence the correlations to specific physical mechanisms. We explore a methodology to assess the correlation between cloud water path and aerosol optical depth using Moderate-resolution Imaging Spectroradiometer (MODIS Aqua retrieved aerosol and cloud properties for absorbing and non-absorbing aerosol types over land and over the Atlantic Ocean for various meteorological conditions. The data covers a three-month period, June through August, during which different aerosol types are predominant in specific regions. Our approach eliminates outliers; sorts the data into aerosol bins; and the mean Aerosol Optical Depth (AOD value for each bin and the corresponding mean Cloud Water Path (CWP value are determined. The mean CWP is plotted against the mean AOD. The response curve for all aerosol types shows a peak CWP value corresponding to an aerosol loading value AODpeak. The peak is used to divide the total range of aerosol loading into two sub ranges. For AOD value below AODpeak, mean CWP and mean AOD are positively correlated. The correlation between mean CWP and mean AOD is negative for aerosol loading above AODpeak. Irrespective of aerosol type, atmospheric water vapor content and lower tropospheric static stability, the peak observed for each aerosol type seems to describe a universal feature that calls for further investigation. It has been observed for a variety of geographical locations and different seasons.

  15. Complexation reactions in pyridine and 2,6-dimethylpyridine-water system: The quantum-chemical description and the path to liquid phase separation

    Science.gov (United States)

    Chernia, Zelig; Tsori, Yoav

    2018-03-01

    Phase separation in substituted pyridines in water is usually described as an interplay between temperature-driven breakage of hydrogen bonds and the associating interaction of the van der Waals force. In previous quantum-chemical studies, the strength of hydrogen bonding between one water and one pyridine molecules (the 1:1 complex) was assigned a pivotal role. It was accepted that the disassembly of the 1:1 complex at a critical temperature leads to phase separation and formation of the miscibility gap. Yet, for over two decades, notable empirical data and theoretical arguments were presented against that view, thus revealing the need in a revised quantum-mechanical description. In the present study, pyridine-water and 2,6-dimethylpyridine-water systems at different complexation stages are calculated using high level Kohn-Sham theory. The hydrophobic-hydrophilic properties are accounted for by the polarizable continuum solvation model. Inclusion of solvation in free energy of formation calculations reveals that 1:1 complexes are abundant in the organically rich solvents but higher level oligomers (i.e., 2:1 dimers with two pyridines and one water molecule) are the only feasible stable products in the more polar media. At the critical temperature, the dissolution of the external hydrogen bonds between the 2:1 dimer and the surrounding water molecules induces the demixing process. The 1:1 complex acts as a precursor in the formation of the dimers but is not directly involved in the demixing mechanism. The existence of the miscibility gap in one pyridine-water system and the lack of it in another is explained by the ability of the former to maintain stable dimerization. Free energy of formation of several reaction paths producing the 2:1 dimers is calculated and critically analyzed.

  16. Water: The Strangest Liquid

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Anders

    2009-02-24

    Water, H2O, is familiar to everyone - it shapes our bodies and our planet. But despite its abundance, water has remained a mystery, exhibiting many strange properties that are still not understood. Why does the liquid have an unusually large capacity to store heat? And why is it denser than ice? Now, using the intense X-ray beams from particle accelerators, investigations into water are leading to fundamental discoveries about the structure and arrangement of water molecules. This lecture will elucidate the many mysteries of water and discuss current studies that are revolutionizing the way we see and understand one of the most fundamental substances of life.

  17. Light Path Model of Fiber Optic Liquid Level Sensor Considering Residual Liquid Film on the Wall

    Directory of Open Access Journals (Sweden)

    Zhijun Zhang

    2015-01-01

    Full Text Available The working principle of the refractive-type fiber optic liquid level sensor is analyzed in detail based on the light refraction principle. The optic path models are developed in consideration of common simplification and the residual liquid film on the glass tube wall. The calculating formulae for the model are derived, constraint conditions are obtained, influencing factors are discussed, and the scopes and skills of application are analyzed through instance simulations. The research results are useful in directing the correct usage of the fiber optic liquid level sensor, especially in special cases, such as those involving viscous liquid in the glass tube monitoring.

  18. Identifying the primitive path mesh in entangled polymer liquids

    International Nuclear Information System (INIS)

    Sukumaran, Sathish K.; Kremer, Kurt; Grest, Gary Stephen; Everaers, Ralf

    2004-01-01

    Similar to entangled ropes, polymer chains cannot slide through each other. These topological constraints, the so-called entanglements, dominate the viscoelastic behavior of high-molecular-weight polymeric liquids. Tube models of polymer dynamics and rheology are based on the idea that entanglements confine a chain to small fluctuations around a primitive path which follows the coarse-grained chain contour. To establish the microscopic foundation for these highly successful phenomenological models, we have recently introduced a method for identifying the primitive path mesh that characterizes the microscopic topological state of computer-generated conformations of long-chain polymer melts and solutions. Here we give a more detailed account of the algorithm and discuss several key aspects of the analysis that are pertinent for its successful use in analyzing the topology of the polymer configurations. We also present a slight modification of the algorithm that preserves the previously neglected self-entanglements and allows us to distinguish between local self-knots and entanglements between distant sections of the same chain. Our results indicate that the latter make a negligible contribution to the tube and that the contour length between local self-knots, N 1k is significantly larger than the entanglement length N e

  19. The impact of cloud vertical profile on liquid water path retrieval based on the bispectral method: A theoretical study based on large-eddy simulations of shallow marine boundary layer clouds

    Science.gov (United States)

    Miller, Daniel J.; Zhang, Zhibo; Ackerman, Andrew S.; Platnick, Steven; Baum, Bryan A.

    2018-01-01

    Passive optical retrievals of cloud liquid water path (LWP), like those implemented for Moderate Resolution Imaging Spectroradiometer (MODIS), rely on cloud vertical profile assumptions to relate optical thickness (τ) and effective radius (re) retrievals to LWP. These techniques typically assume that shallow clouds are vertically homogeneous; however, an adiabatic cloud model is plausibly more realistic for shallow marine boundary layer cloud regimes. In this study a satellite retrieval simulator is used to perform MODIS-like satellite retrievals, which in turn are compared directly to the large-eddy simulation (LES) output. This satellite simulator creates a framework for rigorous quantification of the impact that vertical profile features have on LWP retrievals, and it accomplishes this while also avoiding sources of bias present in previous observational studies. The cloud vertical profiles from the LES are often more complex than either of the two standard assumptions, and the favored assumption was found to be sensitive to cloud regime (cumuliform/stratiform). Confirming previous studies, drizzle and cloud top entrainment of dry air are identified as physical features that bias LWP retrievals away from adiabatic and toward homogeneous assumptions. The mean bias induced by drizzle-influenced profiles was shown to be on the order of 5–10 g/m2. In contrast, the influence of cloud top entrainment was found to be smaller by about a factor of 2. A theoretical framework is developed to explain variability in LWP retrievals by introducing modifications to the adiabatic re profile. In addition to analyzing bispectral retrievals, we also compare results with the vertical profile sensitivity of passive polarimetric retrieval techniques. PMID:29637042

  20. The impact of cloud vertical profile on liquid water path retrieval based on the bispectral method: A theoretical study based on large-eddy simulations of shallow marine boundary layer clouds.

    Science.gov (United States)

    Miller, Daniel J; Zhang, Zhibo; Ackerman, Andrew S; Platnick, Steven; Baum, Bryan A

    2016-04-27

    Passive optical retrievals of cloud liquid water path (LWP), like those implemented for Moderate Resolution Imaging Spectroradiometer (MODIS), rely on cloud vertical profile assumptions to relate optical thickness ( τ ) and effective radius ( r e ) retrievals to LWP. These techniques typically assume that shallow clouds are vertically homogeneous; however, an adiabatic cloud model is plausibly more realistic for shallow marine boundary layer cloud regimes. In this study a satellite retrieval simulator is used to perform MODIS-like satellite retrievals, which in turn are compared directly to the large-eddy simulation (LES) output. This satellite simulator creates a framework for rigorous quantification of the impact that vertical profile features have on LWP retrievals, and it accomplishes this while also avoiding sources of bias present in previous observational studies. The cloud vertical profiles from the LES are often more complex than either of the two standard assumptions, and the favored assumption was found to be sensitive to cloud regime (cumuliform/stratiform). Confirming previous studies, drizzle and cloud top entrainment of dry air are identified as physical features that bias LWP retrievals away from adiabatic and toward homogeneous assumptions. The mean bias induced by drizzle-influenced profiles was shown to be on the order of 5-10 g/m 2 . In contrast, the influence of cloud top entrainment was found to be smaller by about a factor of 2. A theoretical framework is developed to explain variability in LWP retrievals by introducing modifications to the adiabatic r e profile. In addition to analyzing bispectral retrievals, we also compare results with the vertical profile sensitivity of passive polarimetric retrieval techniques.

  1. Autodissociation of a water molecule in liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Geissler, Phillip L.; Dellago, Christoph; Chandler, David; Hutter, Jurg; Parrinello, Michele

    2000-04-01

    The dissociation of a water molecule in liquid water is the fundamental event in acid-base chemistry, determining the pH of water.Because the microscopic dynamics of this autodissociation are difficult to probe, both by experiment and by computer simulation, its mechanism has been unknown. Here we report several autodissociation trajectories generated by ab initio molecular dynamics [1]. These trajectories, which were harvested using transition path sampling [2-4], reveal the mechanism for the first time. Rare fluctuations in solvation energies destabilize an oxygen-hydrogen bond. Through the transfer of one or more protons along a hydrogen bond.

  2. Metastable liquid-liquid transition in a molecular model of water

    Science.gov (United States)

    Palmer, Jeremy C.; Martelli, Fausto; Liu, Yang; Car, Roberto; Panagiotopoulos, Athanassios Z.; Debenedetti, Pablo G.

    2014-06-01

    Liquid water's isothermal compressibility and isobaric heat capacity, and the magnitude of its thermal expansion coefficient, increase sharply on cooling below the equilibrium freezing point. Many experimental, theoretical and computational studies have sought to understand the molecular origin and implications of this anomalous behaviour. Of the different theoretical scenarios put forward, one posits the existence of a first-order phase transition that involves two forms of liquid water and terminates at a critical point located at deeply supercooled conditions. Some experimental evidence is consistent with this hypothesis, but no definitive proof of a liquid-liquid transition in water has been obtained to date: rapid ice crystallization has so far prevented decisive measurements on deeply supercooled water, although this challenge has been overcome recently. Computer simulations are therefore crucial for exploring water's structure and behaviour in this regime, and have shown that some water models exhibit liquid-liquid transitions and others do not. However, recent work has argued that the liquid-liquid transition has been mistakenly interpreted, and is in fact a liquid-crystal transition in all atomistic models of water. Here we show, by studying the liquid-liquid transition in the ST2 model of water with the use of six advanced sampling methods to compute the free-energy surface, that two metastable liquid phases and a stable crystal phase exist at the same deeply supercooled thermodynamic condition, and that the transition between the two liquids satisfies the thermodynamic criteria of a first-order transition. We follow the rearrangement of water's coordination shell and topological ring structure along a thermodynamically reversible path from the low-density liquid to cubic ice. We also show that the system fluctuates freely between the two liquid phases rather than crystallizing. These findings provide unambiguous evidence for a liquid-liquid transition in

  3. Water quality for liquid wastes

    International Nuclear Information System (INIS)

    Mizuniwa, Fumio; Maekoya, Chiaki; Iwasaki, Hitoshi; Yano, Hiroaki; Watahiki, Kazuo.

    1985-01-01

    Purpose: To facilitate the automation of the operation for a liquid wastes processing system by enabling continuous analysis for the main ingredients in the liquid wastes accurately and rapidly. Constitution: The water quality monitor comprises a sampling pipeway system for taking out sample water for the analysis of liquid wastes from a pipeway introducing liquid wastes to the liquid wastes concentrator, a filter for removing suspended matters in the sample water and absorption photometer as a water quality analyzer. A portion of the liquid wastes is passed through the suspended matter filter by a feedpump. In this case, sulfate ions and chloride ions in the sample are retained in the upper portion of a separation color and, subsequently, the respective ingredients are separated and leached out by eluting solution. Since the leached out ingredients form ferric ions and yellow complexes respectively, their concentrations can be detected by the spectrum photometer. Accordingly, concentration for the sodium sulfate and sodium chloride in the liquid wastes can be analyzed rapidly, accurately and repeatedly by which the water quality can be determined rapidly and accurately. (Yoshino, Y.)

  4. Shallow Water Tuned Liquid Dampers

    DEFF Research Database (Denmark)

    Krabbenhøft, Jørgen

    that for realistic roughness parameters the bottom friction has very limited effect on the liquid sloshing behavior and can be neglected. Herby the postulate is verified. Based on the mathematical model three dimensionless parameters are derived showing that the response of the damper depends solely on ratio......The use of sloshing liquid as a passive means of suppressing the rolling motion of ships was proposed already in the late 19th century. Some hundred years later the use of liquid sloshing devices, often termed Tuned Liquid Dampers (TLD), began to find use in the civil engineering community....... The TLDs studied in this thesis essentially consist of a rectangular container partially filled with liquid in the form of plain tap water. The frequency of the liquid sloshing motion, which is adjusted by varying the length of the tank and the depth of the wa- ter, is tuned to the structural frequency...

  5. Electrically excited liquid water

    NARCIS (Netherlands)

    Wexler, A.D.

    2016-01-01

    Water is essential to a healthy and secure world. Developing new technologies which can take full advantage of the unique attributes of water is important for meeting the ever increasing global demand while reducing the production footprint. Water exhibits unexpected departures in more than 70

  6. The structure of liquid water

    International Nuclear Information System (INIS)

    Marin, B.

    1969-01-01

    We have tried to expose a bibliography so complete as possible on structure of liquid water. One synthesis of the different models of water structure is presently impossible, so, we have exposed the main properties of water. We have pointed out the new hypotheses on the electronic structure of water molecule and on the theory of hydrogen bond. After that, we have put together the studies of structure by spectroscopy and given the main deductions of some workers on this subject. We have also exposed the characteristics of processes: relaxation and dielectric constant, influence of temperature on structure. At last, we have considered briefly the partition and thermodynamic functions established from the various models proposed. (author) [fr

  7. Liquid scintillator mixable with water

    International Nuclear Information System (INIS)

    Benson, R.H.

    1976-01-01

    A liquid scintillator mixable with water is described consisting of an aromatic solvent (xylene), a scintillation material and an ethoxylated alkyl phenol (as surface-active substance). So far such kinds of system have not given good measurements on counting samples with high water content. Due to the invention's composition one gets good results even with counting samples having a water content of over 30% if the alkyl substituent of the alkyl phenol contains 7, 10, 11, 13, 14, 15 or 16 C atoms and the ratio n/x of the number n of C atoms of the alkyl substituents to the average number x of the ethoxy groups of the ethoxylated alkyl phenols lie between 0.83 and 1.67. The following alkyl phenols are mentioned: heptyl phenol (n/x between 0.83 and 1.08), decyl phenol (n/x between 0.90 and 1.17), hendecyl phenol (n/x between 0.93 and 1.22), tridecyl phenol (n/x between 0.97 and 1.34), tetradecyl phenol (n/x between 1.08 and 1.55), pentadecyl phenol (n/x between 1.15 and 1.67), hexadecyl phenol (n/x between 1.33 and 1.51). (UWI) [de

  8. Water tube liquid metal control

    International Nuclear Information System (INIS)

    Campbell, J.W.E.

    1981-01-01

    An improved heat exchanger for use in liquid metal cooled nuclear power reactors is described in which the heat is transferred between the flow of liquid metal which is to be cooled and a forced flow of liquid which is wholly or partly evaporated. (U.K.)

  9. Quantum density fluctuations in liquid neon from linearized path-integral calculations

    International Nuclear Information System (INIS)

    Poulsen, Jens Aage; Scheers, Johan; Nyman, Gunnar; Rossky, Peter J.

    2007-01-01

    The Feynman-Kleinert linearized path-integral [J. A. Poulsen et al., J. Chem. Phys. 119, 12179 (2003)] representation of quantum correlation functions is applied to compute the spectrum of density fluctuations for liquid neon at T=27.6 K, p=1.4 bar, and Q vector 1.55 Aa -1 . The calculated spectrum as well as the kinetic energy of the liquid are in excellent agreement with the experiment of Cunsolo et al. [Phys. Rev. B 67, 024507 (2003)

  10. Determination of ice water path in ice-over-water cloud systems using combined MODIS and AMSR-E measurements

    Science.gov (United States)

    Huang, Jianping; Minnis, Patrick; Lin, Bing; Yi, Yuhong; Fan, T.-F.; Sun-Mack, Sunny; Ayers, J. K.

    2006-11-01

    To provide more accurate ice cloud microphysical properties, the multi-layered cloud retrieval system (MCRS) is used to retrieve ice water path (IWP) in ice-over-water cloud systems globally over oceans using combined instrument data from Aqua. The liquid water path (LWP) of lower-layer water clouds is estimated from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) measurements. The properties of the upper-level ice clouds are then derived from Moderate Resolution Imaging Spectroradiometer (MODIS) measurements by matching simulated radiances from a two-cloud-layer radiative transfer model. The results show that the MCRS can significantly improve the accuracy and reduce the over-estimation of optical depth and IWP retrievals for ice-over-water cloud systems. The mean daytime ice cloud optical depth and IWP for overlapped ice-over-water clouds over oceans from Aqua are 7.6 and 146.4 gm-2, respectively, down from the initial single-layer retrievals of 17.3 and 322.3 gm-2. The mean IWP for actual single-layer clouds is 128.2 gm-2.

  11. Evaluating the Liquid Liquid Phase Transition Hypothesis of Supercoooled Water

    Science.gov (United States)

    Limmer, David; Chandler, David

    2011-03-01

    To explain the anomalous behavior of supercooled water it has been conjectured that buried within an experimentally inaccessible region of liquid water's phase diagram there exists a second critical point, which is the terminus of a first order transition line between two distinct liquid phases. The so-called liquid-liquid phase transition (LLPT) has since generated much study, though to date there is no consensus on its existence. In this talk, we will discuss our efforts to systematically study the metastable phase diagram of supercooled water through computer simulation. By employing importance-sampling techniques, we have calculated free energies as a function of the density and long-range order to determine unambiguously if two distinct liquid phases exist. We will argue that, contrary to the LLPT hypothesis, the observed phenomenology can be understood as a consequence of the limit of stability of the liquid far away from coexistence. Our results suggest that homogeneous nucleation is the cause of the increased fluctuations present upon supercooling. Further we will show how this understanding can be extended to explain experimental observations of hysteresis in confined supercooled water systems.

  12. Electrokinetic Power Generation from Liquid Water Microjets

    Energy Technology Data Exchange (ETDEWEB)

    Duffin, Andrew M.; Saykally, Richard J.

    2008-02-15

    Although electrokinetic effects are not new, only recently have they been investigated for possible use in energy conversion devices. We have recently reported the electrokinetic generation of molecular hydrogen from rapidly flowing liquid water microjets [Duffin et al. JPCC 2007, 111, 12031]. Here, we describe the use of liquid water microjets for direct conversion of electrokinetic energy to electrical power. Previous studies of electrokinetic power production have reported low efficiencies ({approx}3%), limited by back conduction of ions at the surface and in the bulk liquid. Liquid microjets eliminate energy dissipation due to back conduction and, measuring only at the jet target, yield conversion efficiencies exceeding 10%.

  13. Comment on "Spontaneous liquid-liquid phase separation of water"

    Science.gov (United States)

    Limmer, David T.; Chandler, David

    2015-01-01

    Yagasaki et al. [Phys. Rev. E 89, 020301 (2014), 10.1103/PhysRevE.89.020301] present results from a molecular dynamics trajectory illustrating coarsening of ice, which they interpret as evidence of transient coexistence between two distinct supercooled phases of liquid water. We point out that neither two distinct liquids nor criticality are demonstrated in this simulation study. Instead, the illustrated trajectory is consistent with coarsening behaviors analyzed and predicted in earlier work by others.

  14. Comment on "Spontaneous liquid-liquid phase separation of water".

    Science.gov (United States)

    Limmer, David T; Chandler, David

    2015-01-01

    Yagasaki et al. [Phys. Rev. E 89, 020301 (2014)] present results from a molecular dynamics trajectory illustrating coarsening of ice, which they interpret as evidence of transient coexistence between two distinct supercooled phases of liquid water. We point out that neither two distinct liquids nor criticality are demonstrated in this simulation study. Instead, the illustrated trajectory is consistent with coarsening behaviors analyzed and predicted in earlier work by others.

  15. Radioactive liquid water processing method

    International Nuclear Information System (INIS)

    Yasumura, Keijiro; Noda, Tetsuya; Kobayashi, Fumio.

    1993-01-01

    Alkaline earth metals and heavy metals are added to radioactive liquid wastes containing a surface active agent comprising alkali metal salts of higher fatty acids. These metals form metal soaps with the surface active agent dissolved in the liquid wastes and crystallized. The crystallized metal soaps are introduced to a filtering column filled with a burnable polymeric fibrous filtering material. The filtering material is burnt. This can remove the surface active agent to remove COD without using an active carbon. (T.M.)

  16. Kapitza Resistance between Few-Layer Graphene and Water: Liquid Layering Effects

    DEFF Research Database (Denmark)

    Alexeev, Dmitry; Chen, Jie; Walther, Jens Honore

    2015-01-01

    difference in the phonon mean free path between the FLG and water. Remarkably, RK is strongly dependent on the layering of water adjacent to the FLG, exhibiting an inverse proportionality relationship to the peak density of the first water layer, which is consistent with better acoustic phonon matching...... between FLG and water. These findings suggest novel ways to engineer the thermal transport properties of solid−liquidinterfaces by controlling and regulating the liquid layering at the interface....

  17. Measurement of the Jones matrix of liquid crystal displays using a common path interferometer

    International Nuclear Information System (INIS)

    Sarkadi, Tamás; Koppa, Pál

    2011-01-01

    We propose a robust interferometric method to measure the Jones matrix of polarization components, especially liquid crystal displays. Phase values are measured by a simple common path interferometer containing a birefringent crystal as beam splitter and a polarizer as beam combiner. This solution eliminates the sensitivity of traditional interferometric techniques to vibration, temperature variation or wavefront distortion. The proposed phase measurement method is applicable to the measurement of both spatially homogeneous and binary modulated states, thus the modulation transfer function and inter-pixel interference can also be studied. We demonstrate this technique by the measurement of a liquid crystal on silicon display. The resulting Jones matrix, as a function of displayed gray level, can be efficiently embedded in any numeric model of an optical system containing the analyzed spatial light modulator

  18. Kinetic energy of solid and liquid para-hydrogen: a path integral Monte Carlo simulation

    International Nuclear Information System (INIS)

    Zoppi, M.; Neumann, M.

    1992-01-01

    The translational (center of mass) kinetic energy of solid and liquid para-hydrogen have been recently measured by means of Deep Inelastic Neutron Scattering. We have evaluated the same quantity, in similar thermodynamic conditions, by means of Path Integral Monte Carlo computer simulation, modelling the system as composed of a set of spherical molecules interacting through a pairwise additive Lennard-Jones potential. In spite of the crude approximations on the interaction potential, the agreement is excellent. The pressure was also computed by means of the same simulations. This quantity, compared with the equation of state for solid para-hydrogen given by Driessen and Silvera, gives an agreement of a lesser quality and a negative value for the liquid state. We attribute this discrepancy to the limitations of the Lennard-Jones potential. (orig.)

  19. Ternary (liquid + liquid) equilibria of {bis(trifluoromethylsulfonyl)-amide based ionic liquids + butan-1-ol + water}

    International Nuclear Information System (INIS)

    Marciniak, Andrzej; Wlazło, Michał; Gawkowska, Joanna

    2016-01-01

    Highlights: • Ternary (liquid + liquid) equilibria for 3 ionic liquid + butanol + water systems. • The influence of ionic liquid structure on phase diagrams is discussed. • Influence of IL structure on S and β for butanol/water separation is discussed. - Abstract: Ternary (liquid + liquid) phase equilibria for 3 systems containing bis(trifluoromethylsulfonyl)-amide ionic liquids (1-buthyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)-amide, 1-(2-methoxyethyl)-1-methylpiperidinium bis(trifluoromethylsulfonyl)-amide, {1-(2-methoxyethyl)-1-methylpyrrolidinium bis(trifluorylsulfonyl)-amide) + butan-1-ol + water} have been determined at T = 298.15 K. The selectivity and solute distribution ratio were calculated for investigated systems and compared with literature data for other systems containing ionic liquids. In each system total solubility of butan-1-ol and low solubility of water in the ionic liquid is observed. The experimental results have been correlated using NRTL model. The influence of the structure of ionic liquid on phase equilibria, selectivity and solute distribution ratio is shortly discussed.

  20. On the path to ordering standardized advanced light water reactors

    International Nuclear Information System (INIS)

    Sliter, G.E.

    1997-01-01

    The international Advanced Light Water Reactor (ALWR) program is specifying, designing, and certifying the next generation of nuclear power plants. Begun in the mid-1980's, the program is on track to permit ordering and construction of families of standardized plants at the start of the twenty-first century. ALWRs will be constructed only if they are economically competitive with alternative forms of electricity generation and are recognized as acceptable and favorable by the public, prospective owners, and investors. This paper first gives an overview of the major building blocks ensuring safe, reliable, and economic designs and the status of those designs. Next it lays out the path the industry has charted toward adopting the ALWR option and indicates the status of three key steps -- design certification, utility requirements, and first-of-a-kind engineering. Lastly, the paper focuses on one of the most important building blocks for ensuring economic viability -- life-cycle standardization. Among the topics are the definition and scope of standardization; its advantages and disadvantages; design team standardization plans that describe the desired or optimum degree of standardization and the processes used to achieve it; and the need for an agreement among all plant owners and operators for implementing and sustaining standardization in families of ALWRs. 10 refs., 5 figs

  1. Liquid chromatographic determination of water

    Science.gov (United States)

    Fortier, N.E.; Fritz, J.S.

    1990-11-13

    A sensitive method for the determination of water in the presence of common interferences is presented. The detection system is based on the effect of water on the equilibrium which results from the reaction aryl aldehydes, such as cinnamaldehyde and methanol in the eluent to form cinnamaldehyde dimethylacetal, plus water. This equilibrium is shifted in a catalytic atmosphere of a hydrogen ion form past column reactor. The extent of the shift and the resulting change in absorbance are proportional to the amount of water present. 1 fig.

  2. Crack path in liquid metal embrittlement: experiments with steels and modeling

    Directory of Open Access Journals (Sweden)

    T. Auger

    2016-01-01

    Full Text Available We review the recent experimental clarification of the fracture path in Liquid Metal Embrittlement with austenitic and martensitic steels. Using state of the art characterization tools (Focused Ion Beam and Transmission Electron Microscopy a clear understanding of crack path is emerging for these systems where a classical fractographic analysis fails to provide useful information. The main finding is that most of the cracking process takes place at grain boundaries, lath or mechanical twin boundaries while cleavage or plastic flow localization is rarely the observed fracture mode. Based on these experimental insights, we sketch an on-going modeling strategy for LME crack initiation and propagation at mesoscopic scale. At the microstructural scale, crystal plasticity constitutive equations are used to model the plastic deformation in metals and alloys. The microstructure used is either extracted from experimental measurements by 3D-EBSD (Electron Back Scattering Diffraction or simulated starting from a Voronoï approach. The presence of a crackwithin the polycrystalline aggregate is taken into account in order to study the surrounding plastic dissipation and the crack path. One key piece of information that can be extracted is the typical order of magnitude of the stress-strain state at GB in order to constrain crack initiation models. The challenges of building predictive LME cracking models are outlined.

  3. Liquid metals replace water steam

    Energy Technology Data Exchange (ETDEWEB)

    Kozlov, V

    1976-12-01

    The techniques are described of power generation with regard to their effectiveness which depends on the efficiency of the conversion of thermal energy into electric energy. The magnetohydrodynamic conversion of energy is based on the use of induced electromotive force which results from the movement of the conductor in the magnetic field. The use of liquid metal as the working medium makes it possible to increase the initial temperature of the magnetohydrodynamic cycle to the limit of the highest technically attainable temperatures. The total efficiency of energy conversion in magnetohydrodynamic converters is 2 to 6%.

  4. Liquid metals replace water steam

    International Nuclear Information System (INIS)

    Kozlov, V.

    1976-01-01

    The techniques are described of power generation with regard to their effectiveness which depends on the efficiency of the conversion of thermal energy into electric energy. The magnetohydrodynamic conversion of energy is based on the use of induced electromotive force which results from the movement of the conductor in the magnetic field. The use of liquid metal as the working medium makes it possible to increase the initial temperature of the magnetohydrodynamic cycle to the limit of the highest technically attainable temperatures. The total efficiency of energy conversion in magnetohydrodynamic converters is 2 to 6%. (J.B.)

  5. Liquid Water Restricts Habitability in Extreme Deserts

    Science.gov (United States)

    Cockell, Charles S.; Brown, Sarah; Landenmark, Hanna; Samuels, Toby; Siddall, Rebecca; Wadsworth, Jennifer

    2017-04-01

    Liquid water is a requirement for biochemistry, yet under some circumstances it is deleterious to life. Here, we show that liquid water reduces the upper temperature survival limit for two extremophilic photosynthetic microorganisms (Gloeocapsa and Chroococcidiopsis spp.) by greater than 40°C under hydrated conditions compared to desiccated conditions. Under hydrated conditions, thermal stress causes protein inactivation as shown by the fluorescein diacetate assay. The presence of water was also found to enhance the deleterious effects of freeze-thaw in Chroococcidiopsis sp. In the presence of water, short-wavelength UV radiation more effectively kills Gloeocapsa sp. colonies, which we hypothesize is caused by factors including the greater penetration of UV radiation into hydrated colonies compared to desiccated colonies. The data predict that deserts where maximum thermal stress or irradiation occurs in conjunction with the presence of liquid water may be less habitable to some organisms than more extreme arid deserts where organisms can dehydrate prior to being exposed to these extremes, thus minimizing thermal and radiation damage. Life in extreme deserts is poised between the deleterious effects of the presence and the lack of liquid water.

  6. Liquid Water Restricts Habitability in Extreme Deserts.

    Science.gov (United States)

    Cockell, Charles S; Brown, Sarah; Landenmark, Hanna; Samuels, Toby; Siddall, Rebecca; Wadsworth, Jennifer

    2017-04-01

    Liquid water is a requirement for biochemistry, yet under some circumstances it is deleterious to life. Here, we show that liquid water reduces the upper temperature survival limit for two extremophilic photosynthetic microorganisms (Gloeocapsa and Chroococcidiopsis spp.) by greater than 40°C under hydrated conditions compared to desiccated conditions. Under hydrated conditions, thermal stress causes protein inactivation as shown by the fluorescein diacetate assay. The presence of water was also found to enhance the deleterious effects of freeze-thaw in Chroococcidiopsis sp. In the presence of water, short-wavelength UV radiation more effectively kills Gloeocapsa sp. colonies, which we hypothesize is caused by factors including the greater penetration of UV radiation into hydrated colonies compared to desiccated colonies. The data predict that deserts where maximum thermal stress or irradiation occurs in conjunction with the presence of liquid water may be less habitable to some organisms than more extreme arid deserts where organisms can dehydrate prior to being exposed to these extremes, thus minimizing thermal and radiation damage. Life in extreme deserts is poised between the deleterious effects of the presence and the lack of liquid water. Key Words: Deserts-Extremophiles-Stress-High temperatures-UV radiation-Desiccation. Astrobiology 17, 309-318.

  7. Perspective on the structure of liquid water

    International Nuclear Information System (INIS)

    Nilsson, A.; Pettersson, L.G.M.

    2011-01-01

    Graphical abstract: Liquid water can be described in a fluctuating inhomogeneous picture with two local structural motifs that are spatially separated. At ambient temperatures most molecules favor a closer packing than tetrahedral, with strongly distorted hydrogen bonds giving higher density (yellow), which allows the quantized librational modes to be excited and contribute to the entropy, but with enthalpically favored tetrahedrally bonded water patches appearing as fluctuations (blue), i.e. a competition between entropy and enthalpy. Upon cooling water the amount of molecules participating in tetrahedral structures and the size of the tetrahedral patches increase. Highlights: ► Two components maximizing either enthalpy (tetrahedral, low-density) or entropy (non-specific H-bonding, higher density). ► Interconvert discontinuously and ratio depends on temperature. ► Density fluctuations on 1 nm length scale. ► Increasing size in supercooled region. ► Connection to Widom line and 2nd critical point. - Abstract: We present a picture that combines discussions regarding the thermodynamic anomalies in ambient and supercooled water with recent interpretations of X-ray spectroscopy and scattering data of water in the ambient regime. At ambient temperatures most molecules favor a closer packing than tetrahedral, with strongly distorted hydrogen bonds, which allows the quantized librational modes to be excited and contribute to the entropy, but with enthalpically favored tetrahedrally bonded water patches appearing as fluctuations, i.e. a competition between entropy and enthalpy. Upon cooling water the amount of molecules participating in tetrahedral structures and the size of the tetrahedral patches increase. The two local structures are connected to the liquid–liquid critical point hypothesis in supercooled water corresponding to high density liquid and low density liquid. We will discuss the interpretation of X-ray absorption spectroscopy, X-ray emission

  8. Kinetics of proton migration in liquid water.

    Science.gov (United States)

    Chen, Hanning; Voth, Gregory A; Agmon, Noam

    2010-01-14

    We have utilized multistate empirical valence bond (MS-EVB3) simulations of protonated liquid water to calculate the relative mean-square displacement (MSD) and the history-independent time correlation function, c(t), of the hydrated proton center of excess charge (CEC) with respect to the water molecule on which it has initially resided. The MSD is nonlinear for the first 15 ps, suggesting that the relative diffusion coefficient increases from a small value, D(0), at short separations to its larger bulk value, D(infinity), at large separations. With the ensuing distance-dependent diffusion coefficient, D(r), the time dependence of both the MSD and c(t) agrees quantitatively with the solution of a diffusion equation for reversible geminate recombination. This suggests that the relative motion of the CEC is not independent from the nearby water molecules, in agreement with theoretical and experimental observations that large water clusters participate in the mechanism of proton mobility.

  9. Exposure Path Perceptions and Protective Actions in Biological Water Contamination Emergencies

    Directory of Open Access Journals (Sweden)

    Michael K. Lindell

    2015-01-01

    Full Text Available This study extends the Protective Action Decision Model, developed to address disaster warning responses in the context of natural hazards, to “boil water” advisories. The study examined 110 Boston residents' and 203 Texas students' expectations of getting sick through different exposure paths for contact with contaminated water. In addition, the study assessed respondents' actual implementation (for residents or behavioral expectations (for students of three different protective actions – bottled water, boiled water, and personally chlorinated water – as well as their demographic characteristics and previous experience with water contamination. The results indicate that people distinguish among the exposure paths, but the differences are small (one-third to one-half of the response scale. Nonetheless, the perceived risk from the exposure paths helps to explain why people are expected to consume (or actually consumed bottled water rather than boiled or personally chlorinated water. Overall, these results indicate that local authorities should take care to communicate the relative risks of different exposure paths and should expect that people will respond to a boil water order primarily by consuming bottled water. Thus, they should make special efforts to increase supplies of bottled water in their communities during water contamination emergencies.

  10. Water in Room Temperature Ionic Liquids

    Science.gov (United States)

    Fayer, Michael

    2014-03-01

    Room temperature ionic liquids (or RTILs, salts with a melting point below 25 °C) have become a subject of intense study over the last several decades. Currently, RTIL application research includes synthesis, batteries, solar cells, crystallization, drug delivery, and optics. RTILs are often composed of an inorganic anion paired with an asymmetric organic cation which contains one or more pendant alkyl chains. The asymmetry of the cation frustrates crystallization, causing the salt's melting point to drop significantly. In general, RTILs are very hygroscopic, and therefore, it is of interest to examine the influence of water on RTIL structure and dynamics. In addition, in contrast to normal aqueous salt solutions, which crystallize at low water concentration, in an RTIL it is possible to examine isolated water molecules interacting with ions but not with other water molecules. Here, optical heterodyne-detected optical Kerr effect (OHD-OKE) measurements of orientational relaxation on a series of 1-alkyl-3-methylimidazolium tetrafluoroborate RTILs as a function of chain length and water concentration are presented. The addition of water to the longer alkyl chain RTILs causes the emergence of a long time bi-exponential orientational anisotropy decay. Such decays have not been seen previously in OHD-OKE experiments on any type of liquid and are analyzed here using a wobbling-in-a-cone model. The orientational relaxation is not hydrodynamic, with the slowest relaxation component becoming slower as the viscosity decreases for the longest chain, highest water content samples. The dynamics of isolated D2O molecules in 1-butyl-3-methylimidazolium hexafluorophosphate (BmImPF6) were examined using two dimensional infrared (2D IR) vibrational echo spectroscopy. Spectral diffusion and incoherent and coherent transfer of excitation between the symmetric and antisymmetric modes are examined. The coherent transfer experiments are used to address the nature of inhomogeneous

  11. Molar excess volumes of liquid hydrogen and neon mixtures from path integral simulation

    International Nuclear Information System (INIS)

    Challa, S.R.; Johnson, J.K.

    1999-01-01

    Volumetric properties of liquid mixtures of neon and hydrogen have been calculated using path integral hybrid Monte Carlo simulations. Realistic potentials have been used for the three interactions involved. Molar volumes and excess volumes of these mixtures have been evaluated for various compositions at 29 and 31.14 K, and 30 atm. Significant quantum effects are observed in molar volumes. Quantum simulations agree well with experimental molar volumes. Calculated excess volumes agree qualitatively with experimental values. However, contrary to the existing understanding that large positive deviations from ideal mixtures are caused due to quantum effects in Ne - H 2 mixtures, both classical as well as quantum simulations predict the large positive deviations from ideal mixtures. Further investigations using two other Ne - H 2 potentials of Lennard - Jones (LJ) type show that excess volumes are very sensitive to the cross-interaction potential. We conclude that the cross-interaction potential employed in our simulations is accurate for volumetric properties. This potential is more repulsive compared to the two LJ potentials tested, which have been obtained by two different combining rules. This repulsion and a comparatively lower potential well depth can explain the positive deviations from ideal mixing. copyright 1999 American Institute of Physics

  12. Streamers in water and other dielectric liquids

    International Nuclear Information System (INIS)

    Kolb, J F; Joshi, R P; Xiao, S; Schoenbach, K H

    2008-01-01

    Experimental results on the inception and propagation of streamers in water generated under the application of high electric fields are reviewed. Characteristic parameters, such as breakdown voltage, polarity of the applied voltage, propagation velocities and other phenomenological features, are compared with similar phenomena in other dielectric liquids and in gases. Consequently, parameters that are expected to influence the development of streamers in water are discussed with respect to the analogous well-established models and theories for the related mechanisms in gases. Most of the data support the notion that an initial low-density nucleation site or gas-filled bubble assists the initiation of a streamer. Details of this theory are laid out explaining the observed differences in the breakdown originating from the anode versus the cathode locations. The mechanisms can also be applied to streamer propagation, although some observations cannot be satisfactorily explained.

  13. Bridging the Gap: The 'Soft Path' for Improving Resilience and Adaptability of Water Systems (Invited)

    Science.gov (United States)

    Gleick, P. H.

    2010-12-01

    The failure of traditional water management systems in the 20th century -- what I call the "hard path for water" -- is evident in several ways, including the persistent inability to meet basic human needs for safe water and adequate sanitation for vast populations, ongoing and accelerating aquatic ecosystem collapses , and growing political disputes over water allocation, management, and use, even in regions where substantial investment in water has been made. Progress in resolving these problems, especially in the face of unavoidable climate changes, growing populations, and constrained financial systems, will require bridging hydrologic and social sciences in new ways. Integrating social and cultural knowledge with new economic and technological tools and classical hydrologic and climatological sciences can produce a new “soft path for water” that offers the opportunity to move toward sustainable water systems. This talk will define the soft path for water and offer examples of innovative steps already being taken along that path in the western United States, South Africa, India, and elsewhere.

  14. Polarized View of Supercooled Liquid Water Clouds

    Science.gov (United States)

    Alexandrov, Mikhail D.; Cairns, Brian; Van Diedenhoven, Bastiaan; Ackerman, Andrew S.; Wasilewski, Andrzej P.; McGill, Matthew J.; Yorks, John E.; Hlavka, Dennis L.; Platnick, Steven E.; Arnold, G. Thomas

    2016-01-01

    Supercooled liquid water (SLW) clouds, where liquid droplets exist at temperatures below 0 C present a well known aviation hazard through aircraft icing, in which SLW accretes on the airframe. SLW clouds are common over the Southern Ocean, and climate-induced changes in their occurrence is thought to constitute a strong cloud feedback on global climate. The two recent NASA field campaigns POlarimeter Definition EXperiment (PODEX, based in Palmdale, California, January-February 2013) and Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS, based in Houston, Texas in August- September 2013) provided a unique opportunity to observe SLW clouds from the high-altitude airborne platform of NASA's ER-2 aircraft. We present an analysis of measurements made by the Research Scanning Polarimeter (RSP) during these experiments accompanied by correlative retrievals from other sensors. The RSP measures both polarized and total reflectance in 9 spectral channels with wavelengths ranging from 410 to 2250 nm. It is a scanning sensor taking samples at 0.8deg intervals within 60deg from nadir in both forward and backward directions. This unique angular resolution allows for characterization of liquid water droplet size using the rainbow structure observed in the polarized reflectances in the scattering angle range between 135deg and 165deg. Simple parametric fitting algorithms applied to the polarized reflectance provide retrievals of the droplet effective radius and variance assuming a prescribed size distribution shape (gamma distribution). In addition to this, we use a non-parametric method, Rainbow Fourier Transform (RFT),which allows retrieval of the droplet size distribution without assuming a size distribution shape. We present an overview of the RSP campaign datasets available from the NASA GISS website, as well as two detailed examples of the retrievals. In these case studies we focus on cloud fields with spatial features

  15. A unique circular path of moving single bubble sonoluminescence in water

    International Nuclear Information System (INIS)

    Sadighi-Bonabi, Rasoul; Mirheydari, Mona; Ebrahimi, Homa; Rezaee, Nastaran; Nikzad, Lida

    2011-01-01

    Based on a quasi-adiabatic model, the parameters of the bubble interior for a moving single bubble sonoluminescence (m-SBSL) in water are calculated. By using a complete form of the hydrodynamic force, a unique circular path for the m-SBSL in water is obtained. The effect of the ambient pressure variation on the bubble trajectory is also investigated. It is concluded that as the ambient pressure increases, the bubble moves along a circular path with a larger radius and all bubble parameters, such as gas pressure, interior temperature and light intensity, increase. A comparison is made between the parameters of the moving bubble in water and those in N-methylformamide. With fluid viscosity increasing, the circular path changes into an elliptic form and the light intensity increases. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  16. Liquid water content variation with altitude in clouds over Europe

    Science.gov (United States)

    Andreea, Boscornea; Sabina, Stefan

    2013-04-01

    Cloud water content is one of the most fundamental measurements in cloud physics. Knowledge of the vertical variability of cloud microphysical characteristics is important for a variety of reasons. The profile of liquid water content (LWC) partially governs the radiative transfer for cloudy atmospheres, LWC profiles improves our understanding of processes acting to form and maintain cloud systems and may lead to improvements in the representation of clouds in numerical models. Presently, in situ airborne measurements provide the most accurate information about cloud microphysical characteristics. This information can be used for verification of both numerical models and cloud remote sensing techniques. The aim of this paper was to analyze the liquid water content (LWC) measurements in clouds, in time of the aircraft flights. The aircraft and its platform ATMOSLAB - Airborne Laboratory for Environmental Atmospheric Research is property of the National Institute for Aerospace Research "Elie Carafoli" (INCAS), Bucharest, Romania. The airborne laboratory equipped for special research missions is based on a Hawker Beechcraft - King Air C90 GTx aircraft and is equipped with a sensors system CAPS - Cloud, Aerosol and Precipitation Spectrometer (30 bins, 0.51-50 m). The processed and analyzed measurements are acquired during 4 flights from Romania (Bucharest, 44°25'57″N 26°06'14″E) to Germany (Berlin 52°30'2″N 13°23'56″E) above the same region of Europe. The flight path was starting from Bucharest to the western part of Romania above Hungary, Austria at a cruse altitude between 6000-8500 m, and after 5 hours reaching Berlin. In total we acquired data during approximately 20 flight hours and we presented the vertical and horizontal LWC variations for different cloud types. The LWC values are similar for each type of cloud to values from literature. The vertical LWC profiles in the atmosphere measured during takeoff and landing of the aircraft have shown their

  17. Path Complexity in Virtual Water Maze Navigation: Differential Associations with Age, Sex, and Regional Brain Volume.

    Science.gov (United States)

    Daugherty, Ana M; Yuan, Peng; Dahle, Cheryl L; Bender, Andrew R; Yang, Yiqin; Raz, Naftali

    2015-09-01

    Studies of human navigation in virtual maze environments have consistently linked advanced age with greater distance traveled between the start and the goal and longer duration of the search. Observations of search path geometry suggest that routes taken by older adults may be unnecessarily complex and that excessive path complexity may be an indicator of cognitive difficulties experienced by older navigators. In a sample of healthy adults, we quantify search path complexity in a virtual Morris water maze with a novel method based on fractal dimensionality. In a two-level hierarchical linear model, we estimated improvement in navigation performance across trials by a decline in route length, shortening of search time, and reduction in fractal dimensionality of the path. While replicating commonly reported age and sex differences in time and distance indices, a reduction in fractal dimension of the path accounted for improvement across trials, independent of age or sex. The volumes of brain regions associated with the establishment of cognitive maps (parahippocampal gyrus and hippocampus) were related to path dimensionality, but not to the total distance and time. Thus, fractal dimensionality of a navigational path may present a useful complementary method of quantifying performance in navigation. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  18. Relationship between ice water path and downward longwave radiation for clouds optically thin in the infrared: Observations and model calculations

    Science.gov (United States)

    Uttal, Taneil; Matrosov, Sergey Y.; Snider, Jack B.; Kropfli, Robert A.

    1994-01-01

    A vertically pointing 3.2-cm radar is used to observe altostratus and cirrus clouds as they pass overhead. Radar reflectivities are used in combination with an empirical Z(sub i)-IWC (ice water content) relationship developed by Sassen (1987) to parameterize IWC, which is then integrated to obtain estimates of ice water path (IWP). The observed dataset is segregated into all-ice and mixed-phase periods using measurements of integrated liquid water paths (LWP) detected by a collocated, dual-channel microwave radiometer. The IWP values for the all ice periods are compared to measurements of infrared (IR) downward fluxes measured by a collocated narrowband (9.95-11.43 microns) IR radiometer, which results in scattergrams representing the observed dependence of IR fluxes on IWP. A two-stream model is used to calculate the infrared fluxes expected from ice clouds with boundary conditions specified by the actual clouds, and similar curves relating IWP and infrared fluxes are obtained. The model and observational results suggest that IWP is one of the primary controls on infrared thermal fluxes for ice clouds.

  19. Soil water retention curves of remoulded clay on drying and wetting paths

    International Nuclear Information System (INIS)

    Zhang Xiwei; Zhang Jian

    2010-01-01

    The present research focuses on the laboratory measurement of the Soil Water Retention Curve (SWRC), that expresses the relationship between water content (gravimetric or volumetric) or degree of saturation and soil suction. The SWRC plays an important role in an unsaturated soil mechanics framework and is required for the numerical modelling of any process of flow and transport in unsaturated soil problems, already as a part of constitutive model of unsaturated soil. Six remoulded London Clay samples were performed SWRC testing on the drying and wetting path, meanwhile measurement the volume change. The effect of initial water content and various drying/wetting paths were considered in the tests. The results of SWRC show that hysteretic characteristic in boundary drying/wetting curve, the water holding capacity was increased due to the increase of the initial water content. The shape of the SWRC strongly depended on the volume change. (authors)

  20. Iron oxidation kinetics and phosphate immobilization along the flow-path from groundwater into surface water

    NARCIS (Netherlands)

    Van Der Grift, B.; Rozemeijer, J. C.; Griffioen, J.; Van Der Velde, Y.

    2014-01-01

    The retention of phosphorus in surface waters through co-precipitation of phosphate with Fe-oxyhydroxides during exfiltration of anaerobic Fe(II) rich groundwater is not well understood. We developed an experimental field set-up to study Fe(II) oxidation and P immobilization along the flow-path from

  1. Iron oxidation kinetics and phosphate immobilization along the flow-path from groundwater into surface water.

    NARCIS (Netherlands)

    Grift, van der B.; Rozemeijer, J.C.; Griffioen, J.; Velde, van der Y.

    2014-01-01

    The retention of phosphorus in surface waters though co-precipitation of phosphate with Fe-oxyhydroxides during exfiltration of anaerobic Fe(II) rich groundwater is not well understood. We developed an experimental field set-up to study Fe(II) oxidation and 5 P immobilization along the flow-path

  2. Iron oxidation kinetics and phosphate immobilization along the flow-path from groundwater into surface water

    NARCIS (Netherlands)

    van der Grift, B.; Rozemeijer, J. C.; Griffioen, J.; van der Velde, Y.

    2014-01-01

    The retention of phosphorus in surface waters though co-precipitation of phosphate with Fe-oxyhydroxides during exfiltration of anaerobic Fe(II) rich groundwater is not well understood. We developed an experimental field set-up to study Fe(II) oxidation and P immobilization along the flow-path from

  3. Decompression-induced melting of ice IV and the liquid-liquid transition in water

    Science.gov (United States)

    Mishima, Osamu; Stanley, H. Eugene

    1998-03-01

    Although liquid water has been the focus of intensive research for over 100 years, a coherent physical picture that unifies all of the known anomalies of this liquid, is still lacking. Some of these anomalies occur in the supercooled region, and have been rationalized on the grounds of a possible retracing of the liquid-gas spinodal (metastability limit) line into the supercooled liquid region, or alternatively the presence of a line of first-order liquid-liquid phase transitions in this region which ends in a critical point,. But these ideas remain untested experimentally, in part because supercooled water can be probed only above the homogeneous nucleation temperature TH at which water spontaneously crystallizes. Here we report an experimental approach that is not restricted by the barrier imposed by TH, involving measurement of the decompression-induced melting curves of several high-pressure phases of ice in small emulsified droplets. We find that the melting curve for ice IV seems to undergo a discontinuity at precisely the location proposed for the line of liquid-liquid phase transitions. This is consistent with, but does not prove, the coexistence of two different phases of (supercooled) liquid water. From the experimental data we calculate a possible Gibbs potential surface and a corresponding equation of state for water, from the forms of which we estimate the coordinates of the liquid-liquid critical point to be at pressure Pc ~ 0.1GPa and temperature Tc ~ 220K.

  4. Scanning Raman lidar for tropospheric water vapor profiling and GPS path delay correction

    Science.gov (United States)

    Tarniewicz, Jerome; Bock, Olivier; Pelon, Jacques R.; Thom, Christian

    2002-01-01

    The design of a ground based and transportable combined Raman elastic-backscatter lidar for the remote sensing of lower tropospheric water vapor and nitrogen concentration is described. This lidar is intended to be used for an external calibration of the wet path delay of GPS signals. A description of the method used to derive water vapor and nitrogen profiles in the lower troposphere is given. The instrument has been tested during the ESCOMPTE campaign in June 2001 and first measurements are presented.

  5. Separation of water from organic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Meldrum, I.G.; Villiers Naylor, T. de.

    1990-04-10

    This invention relates to the separation of water from fluids by the pervaporation process using a membrane. The invention is characterized in that the membrane has an active layer which consists essentially only of polymers of an unsaturated organic acid, the acid having not more than 6 carbon atoms for every acid group (not counting any carbon atoms in the acid groups), and the polymer having at least a substantial proportion of the acid groups in the form of a salt. The preferred fluids for use in the process of the invention are organic fluids, such as a hydrocarbon gas (in particular, methane) or a liquid. The process is especially suitable for separating water from mixtures with alkanols, in particular alkanols having 1 to 5 carbon atoms in the molecule, such as ethanol and isopropanol. The unsaturated organic acid may be a sulfur acid, such as a sulfonate or a sulfate or a phosphorus acid, but is preferably a carboxylic acid. Thus, the active layer may be poly(acrylic acid) or poly(maleic acid). The cation of the salt form of the acid groups is preferably an alkali metal, especially cesium. Experiments are described to illustrate the invention. 13 tabs.

  6. (Liquid + liquid), (solid + liquid), and (solid + liquid + liquid) equilibria of systems containing cyclic ether (tetrahydrofuran or 1,3-dioxolane), water, and a biological buffer MOPS

    International Nuclear Information System (INIS)

    Altway, Saidah; Taha, Mohamed; Lee, Ming-Jer

    2015-01-01

    Graphical abstract: - Highlights: • MOPS buffer induced liquid phase splitting for mixtures of water with THF or 1,3-dioxolane. • Phase boundaries of LLE, SLE, and SLLE were determined experimentally. • Tie-lines at LLE and at SLLE were also measured. • Phase diagrams of MOPS + water + THF or 1,3-dioxolane are prepared. • LLE tie-line data are correlated satisfactorily with the NRTL model. - Abstract: Two liquid phases were formed as the addition of a certain amount of biological buffer 3-(N-morpholino)propane sulfonic acid (MOPS) in the aqueous solutions of tetrahydrofuran (THF) or 1,3-dioxolane. To evaluate the feasibility of recovering the cyclic ethers from their aqueous solutions with the aid of MOPS, we determined experimentally the phase diagrams of the ternary systems of {cyclic ether (THF or 1,3-dioxolane) + water + MOPS} at T = 298.15 K under atmospheric pressure. In this study, the solubility data of MOPS in water and in the mixed solvents of water/cyclic ethers were obtained from the results of a series of density measurements, while the (liquid + liquid) and the (solid + liquid + liquid) phase boundaries were determined by visually inspection. Additionally, the tie-line results for (liquid + liquid) equilibrium (LLE) and for (solid + liquid + liquid) equilibrium (SLLE) were measured using an analytical method. The reliability of the experimental LLE tie-line results data was validated by using the Othmer–Tobias correlation. These LLE tie-line values were correlated well with the NRTL model. The phase diagrams obtained from this study reveal that MOPS is a feasible green auxiliary agent to recover the cyclic ethers from their aqueous solutions, especially for 1,3-dioxolane

  7. Path-integral theory of the scattering of 4He atoms at the surface of liquid 4He

    International Nuclear Information System (INIS)

    Swanson, D.R.; Edwards, D.O.

    1988-01-01

    The path-integral theory of the scattering of a 4 He atom near the free surface of liquid 4 He, which was originally formulated by Echenique and Pendry, has been recalculated with use of a physically realistic static potential and atom-ripplon interaction outside the liquid. The static potential and atom-ripplon interaction are based on the variational calculation of Edwards and Fatouros. An important assumption in the path-integral theory is the ''impulse approximation'': that the motion of the scattered atom is very fast compared with the motion of the surface due to ripplons. This is found to be true only for ripplons with wave vectors smaller than q/sub m/∼0.2 A/sup -1/. If ripplons above q/sub m/ made an important contribution to the scattering of the atom there would be a substantial dependence of the elastic reflection coefficient on the angle of incidence of the atom. Since this is not observed experimentally, it is argued that ripplons above q/sub m/ give a negligible effect and should be excluded from the calculation. With this modification the theory gives a good fit to the experimental reflection coefficient as a function of the momentum and angle of incidence of the atom. The new version of the theory indicates that there is a substantial probability that an atom may reach the surface of the liquid without exciting any ripplons. The theory is not valid when the atom enters the liquid but analysis of the experiments shows that, once inside the liquid, the atom has a negligible chance of being scattered out again

  8. First- and zero-sound velocity and Fermi liquid parameter F2s in liquid 3He determined by a path length modulation technique

    International Nuclear Information System (INIS)

    Hamot, P.J.; Lee, Y.; Sprague, D.T.

    1995-01-01

    We have measured the velocity of first- and zero-sound in liquid 3 He at 12.6 MHz over the pressure range of 0.6 to 14.5 bar using a path length modulation technique that we have recently developed. From these measurements, the pressure dependent value of the Fermi liquid parameter F 2 s was calculated and found to be larger at low pressure than previously reported. These new values of F 2 s indicate that transverse zero-sound is a propagating mode at all pressures. The new values are important for the interpretation of the frequencies of order parameter collective modes in the superfluid phases. The new acoustic technique permits measurements in regimes of very high attenuation with a sensitivity in phase velocity of about 10 ppm achieved by a feedback arrangement. The sound velocity is thus measured continuously throughout the highly attenuating crossover (ωt ∼ 1) regime, even at the lowest pressures

  9. Neutronic studies of a liquid hydrogen-water composite moderator

    International Nuclear Information System (INIS)

    Tahara, T.; Ooi, M.; Iwasa, H.; Kiyanagi, Y.; Iverson, E.B.; Crabtree, J.A.; Lucas, A.T.

    2001-01-01

    A liquid hydrogen-liquid water composite moderator may provide performance like liquid methane at high-power spallation sources where liquid methane is impractical. We have measured the neutronic properties of such a composite moderator, where a hydrogen layer 1.25 cm thick was closely backed by water layers of 1.75 cm and 3.75 cm thickness. We also studied a moderator in which a 1.75 cm water layer was closely backed by a 1.25 cm hydrogen layer. We further performed simulations for each of these systems for comparison to the experimental results. We observed enhancement of the spectral intensity in the 'thermal' energy range as compared to the spectrum from a conventional liquid hydrogen moderator. This enhancement grew more significant as the water thickness increased, although the pulse shapes became wider as well. (author)

  10. Preparation of 'dead water' for low background liquid scintillation counting

    International Nuclear Information System (INIS)

    Morishima, Hiroshige; Koga, Taeko; Niwa, Takeo; Kawai, Hiroshi

    1987-01-01

    'Dead water', low level tritiated water is indispensable to measure tritium concentration in environmental waters using a low background liquid scintillation counter. Water produced by combustion of natural gas, or deep sea water etc. are usually used for the above purpose. A new method of reducing tritium concentration in natural water has been introduced for preparation of 'dead water'. This method is to combine hydrogen-oxygen mixture produced by water electrolysis with hopcalite catalyzer at 700 deg C. Deep well water was electrolized up to 2/3 volume, and tritium concentration of recombined water was reduced to be about one third of that of the original one. (author)

  11. Preliminary experimental study of liquid lithium water interaction

    International Nuclear Information System (INIS)

    You, X.M.; Tong, L.L.; Cao, X.W.

    2015-01-01

    Highlights: • Explosive reaction occurs when lithium temperature is over 300 °C. • The violence of liquid lithium water interaction increases with the initial temperature of liquid lithium. • The interaction is suppressed when the initial water temperature is above 70 °C. • Steam explosion is not ignorable in the risk assessment of liquid lithium water interaction. • Explosion strength of liquid lithium water interaction is evaluated by explosive yield. - Abstract: Liquid lithium is the best candidate for a material with low Z and low activation, and is one of the important choices for plasma facing materials in magnetic fusion devices. However, liquid lithium reacts violently with water under the conditions of loss of coolant accidents. The release of large heats and hydrogen could result in the dramatic increase of temperature and pressure. The lithium–water explosion has large effect on the safety of fusion devices, which is an important content for the safety assessment of fusion devices. As a preliminary investigation of liquid lithium water interaction, the test facility has been built and experiments have been conducted under different conditions. The initial temperature of lithium droplet ranged from 200 °C to 600 °C and water temperature was varied between 20 °C and 90 °C. Lithium droplets were released into the test section with excess water. The shape of lithium droplet and steam generated around the lithium were observed by the high speed camera. At the same time, the pressure and temperature in the test section were recorded during the violent interactions. The preliminary experimental results indicate that the initial temperature of lithium and water has an effect on the violence of liquid lithium water interaction.

  12. Preliminary experimental study of liquid lithium water interaction

    Energy Technology Data Exchange (ETDEWEB)

    You, X.M.; Tong, L.L.; Cao, X.W., E-mail: caoxuewu@sjtu.edu.cn

    2015-10-15

    Highlights: • Explosive reaction occurs when lithium temperature is over 300 °C. • The violence of liquid lithium water interaction increases with the initial temperature of liquid lithium. • The interaction is suppressed when the initial water temperature is above 70 °C. • Steam explosion is not ignorable in the risk assessment of liquid lithium water interaction. • Explosion strength of liquid lithium water interaction is evaluated by explosive yield. - Abstract: Liquid lithium is the best candidate for a material with low Z and low activation, and is one of the important choices for plasma facing materials in magnetic fusion devices. However, liquid lithium reacts violently with water under the conditions of loss of coolant accidents. The release of large heats and hydrogen could result in the dramatic increase of temperature and pressure. The lithium–water explosion has large effect on the safety of fusion devices, which is an important content for the safety assessment of fusion devices. As a preliminary investigation of liquid lithium water interaction, the test facility has been built and experiments have been conducted under different conditions. The initial temperature of lithium droplet ranged from 200 °C to 600 °C and water temperature was varied between 20 °C and 90 °C. Lithium droplets were released into the test section with excess water. The shape of lithium droplet and steam generated around the lithium were observed by the high speed camera. At the same time, the pressure and temperature in the test section were recorded during the violent interactions. The preliminary experimental results indicate that the initial temperature of lithium and water has an effect on the violence of liquid lithium water interaction.

  13. Experimental evidence of a liquid-liquid transition in interfacial water

    Science.gov (United States)

    Zanotti, J.-M.; Bellissent-Funel, M.-C.; Chen, S.-H.

    2005-07-01

    At ambient pressure, bulk liquid water shows an anomalous increase of thermodynamic quantities and apparent divergences of dynamic properties on approaching a temperature Ts of 228 K. At normal pressure, supercooled water spontaneously freezes below the homogeneous nucleation temperature, TH = 235 K. Upon heating, the two forms of Amorphous Solid Water (ASW), LDA (Low Density Amorphous Ice) and HDA (High Density Amorphous Ice), crystallise above TX = 150 K. As a consequence, up to now no experiment has been able to explore the properties of liquid water in this very interesting temperature range between 150 and 235 K. We present nanosecond-time-scale measurements of local rotational and translational dynamics of interfacial, non-crystalline, water from 77 to 280 K. These experimental dynamic results are combined with calorimetric and diffraction data to show that after exhibiting a glass transition at 165 K, interfacial water experiences a first-order liquid-liquid transition at 240 K from a low-density to a high-density liquid. This is the first direct evidence of the existence of a liquid-liquid transition involving water.

  14. Long open-path instrument for simultaneously monitoring of methane, CO2 and water vapor

    Science.gov (United States)

    Simeonov, Valentin; Parlange, Marc

    2013-04-01

    A new, long open-path instrument for monitoring of path-averaged methane, CO2 and water vapor concentrations will be presented. The instrument is built on the monostatic scheme (transceiver -distant retroreflector). A VCSEL with a central wavelength of 1654 nm is used as a light source. The receiver is built around a 20 cm Newtonian telescope. The design optical path length is 2000 m but can be further extended. To avoid distortions in the shape of the spectral lines caused by atmospheric turbulences they are scanned within 1 µs. The expected concentration resolution for the above mentioned path length is of the order of 2 ppb for methane, 100 ppb for CO2 and 100 ppm for water vapor. The instrument is developed at the Swiss Federal Institute of Technology - Lausanne (EPFL) Switzerland and will be used within the GAW+ CH program for long-term monitoring of background methane and CO2 concentrations in the Swiss Alps. The initial calibration validation tests at EPFL were completed in December 2012 and the instrument will be installed at the beginning of 2013 at the High Altitude Research Station Jungfraujoch (HARSJ). The HARSJ is located at 3580 m ASL and is one of the 24 global GAW stations. One of the goals of the project is to compare path-averaged to the ongoing point measurements of methane in order to identify possible influence of the station. Future deployments of a copy of the instrument include the Canadian arctic and Siberian wetlands. The instrument can be used for ground truthing of satellite observation as well.

  15. Heat transfer on liquid-liquid interface of molten-metal and water

    International Nuclear Information System (INIS)

    Tanaka, T.; Saito, Yasushi; Mishima, Kaichiro

    2001-01-01

    Molten-core pool had been formed in the lower-head of TMI-2 pressure vessel at the severe accident. The lower head, however, didn't receive any damage by reactor core cooling. Heat transfer at outside of the lower head and boiling heat transfer at liquid-liquid interface of molten-metal and water, however, are important for initial cooling process of the molten-core pool. The heat transfer experiments for the liquid-liquid interface of molten-metal and water are carried out over the range of natural convection to film boiling region. Phenomenon on the heat transfer experiments are visualized by using of high speed video camera. Wood's metal and U-alloy 78 are used as molten-metal. The test section of the experiments consists of a copper block with heater, wood's metal, and water. Three thermocouple probes are used for temperature measurement of water side and the molten-metal side. Stability of the liquid-liquid interface is depended on the wetness of container wall for molten metal and the temperature distribution of the interface. Entrainment phenomena of molten-metal occurs by a fluctuation of the interface after boiling on the container wall surface. The boiling curves obtained from the liquid-liquid interface experiments are agree with the nucleate boiling and the film boiling correlations of solid-liquid system. (Suetake, M.)

  16. Retrieval of an ice water path over the ocean from ISMAR and MARSS millimeter and submillimeter brightness temperatures

    Science.gov (United States)

    Brath, Manfred; Fox, Stuart; Eriksson, Patrick; Chawn Harlow, R.; Burgdorf, Martin; Buehler, Stefan A.

    2018-02-01

    A neural-network-based retrieval method to determine the snow ice water path (SIWP), liquid water path (LWP), and integrated water vapor (IWV) from millimeter and submillimeter brightness temperatures, measured by using airborne radiometers (ISMAR and MARSS), is presented. The neural networks were trained by using atmospheric profiles from the ICON numerical weather prediction (NWP) model and by radiative transfer simulations using the Atmospheric Radiative Transfer Simulator (ARTS). The basic performance of the retrieval method was analyzed in terms of offset (bias) and the median fractional error (MFE), and the benefit of using submillimeter channels was studied in comparison to pure microwave retrievals. The retrieval is offset-free for SIWP > 0.01 kg m-2, LWP > 0.1 kg m-2, and IWV > 3 kg m-2. The MFE of SIWP decreases from 100 % at SIWP = 0.01 kg m-2 to 20 % at SIWP = 1 kg m-2 and the MFE of LWP from 100 % at LWP = 0.05 kg m-2 to 30 % at LWP = 1 kg m-2. The MFE of IWV for IWV > 3 kg m-2 is 5 to 8 %. The SIWP retrieval strongly benefits from submillimeter channels, which reduce the MFE by a factor of 2, compared to pure microwave retrievals. The IWV and the LWP retrievals also benefit from submillimeter channels, albeit to a lesser degree. The retrieval was applied to ISMAR and MARSS brightness temperatures from FAAM flight B897 on 18 March 2015 of a precipitating frontal system west of the coast of Iceland. Considering the given uncertainties, the retrieval is in reasonable agreement with the SIWP, LWP, and IWV values simulated by the ICON NWP model for that flight. A comparison of the retrieved IWV with IWV from 12 dropsonde measurements shows an offset of 0.5 kg m-2 and an RMS difference of 0.8 kg m-2, showing that the retrieval of IWV is highly effective even under cloudy conditions.

  17. Further evidence of a liquid-liquid transition in interfacial water

    International Nuclear Information System (INIS)

    Zanotti, J-M; Bellissent-Funel, M C; Chen, S-H; Kolesnikov, A I

    2006-01-01

    In a previous paper we combined calorimetric, diffraction and high-resolution quasi-elastic neutron scattering data to show that after exhibiting a glass transition at 165 K, interfacial water experiences a first order liquid-liquid transition at 240 K from a low-density to a high-density liquid. Here we present further evidence of these transitions obtained by high-energy inelastic neutron scattering

  18. New Mexico cloud super cooled liquid water survey final report 2009.

    Energy Technology Data Exchange (ETDEWEB)

    Beavis, Nick; Roskovensky, John K.; Ivey, Mark D.

    2010-02-01

    Los Alamos and Sandia National Laboratories are partners in an effort to survey the super-cooled liquid water in clouds over the state of New Mexico in a project sponsored by the New Mexico Small Business Assistance Program. This report summarizes the scientific work performed at Sandia National Laboratories during the 2009. In this second year of the project a practical methodology for estimating cloud super-cooled liquid water was created. This was accomplished through the analysis of certain MODIS sensor satellite derived cloud products and vetted parameterizations techniques. A software code was developed to analyze multiple cases automatically. The eighty-one storm events identified in the previous year effort from 2006-2007 were again the focus. Six derived MODIS products were obtained first through careful MODIS image evaluation. Both cloud and clear-sky properties from this dataset were determined over New Mexico. Sensitivity studies were performed that identified the parameters which most influenced the estimation of cloud super-cooled liquid water. Limited validation was undertaken to ensure the soundness of the cloud super-cooled estimates. Finally, a path forward was formulized to insure the successful completion of the initial scientific goals which include analyzing different of annual datasets, validation of the developed algorithm, and the creation of a user-friendly and interactive tool for estimating cloud super-cooled liquid water.

  19. Deuterium exchange between liquid water and gaseous hydrogen

    International Nuclear Information System (INIS)

    Dave, S.M.; Ghosh, S.K.; Sadhukhan, H.K.

    1982-01-01

    The overall separation factors for the deuterium exchange between liquid water and gaseous hydrogen have been calculated over a wide range of temperature, pressure and deuterium concentrations. These data would be useful in the design and other considerations for heavy water production, based on hydrogen-water exchange. (author)

  20. Water at silica/liquid water interfaces investigated by DFT-MD simulations

    Science.gov (United States)

    Gaigeot, Marie-Pierre

    This talk is dedicated to probing the microscopic structural organization of water at silica/liquid water interfaces including electrolytes by first principles DFT-based molecular dynamics simulations (DFT-MD). We will present our very recent DFT-MD simulations of electrolytic (KCl, NaCl, NaI) silica/liquid water interfaces in order to unravel the intertwined structural properties of water and electrolytes at the crystalline quartz/liquid water and amorphous silica/liquid water interfaces. DFT-MD simulations provide direct knowledge of the structural organization of water and the H-Bond network formed between the water molecules within the different water layers above the silica surface. One can furthermore extract vibrational signatures of the water molecules within the interfacial layers from the DFT-MD simulations, especially non-linear SFG (Sum Frequency generation) signatures that are active at solid/liquid interfaces. The strength of the simulated spectra is that a detailed analysis of the signatures in terms of the water/water H-Bond networks formed within the interfacial water layers and in terms of the water/silica or water/electrolytes H-Bond networks can be given. Comparisons of SFG spectra between quartz/water/electrolytes and amorphous silica/water/electrolytes interfaces allow us to definitely conclude on how the structural arrangements of liquid water at these electrolytic interfaces modulate the final spectroscopic signatures. Invited speaker.

  1. Communications: On artificial frequency shifts in infrared spectra obtained from centroid molecular dynamics: Quantum liquid water

    Science.gov (United States)

    Ivanov, Sergei D.; Witt, Alexander; Shiga, Motoyuki; Marx, Dominik

    2010-01-01

    Centroid molecular dynamics (CMD) is a popular method to extract approximate quantum dynamics from path integral simulations. Very recently we have shown that CMD gas phase infrared spectra exhibit significant artificial redshifts of stretching peaks, due to the so-called "curvature problem" imprinted by the effective centroid potential. Here we provide evidence that for condensed phases, and in particular for liquid water, CMD produces pronounced artificial redshifts for high-frequency vibrations such as the OH stretching band. This peculiar behavior intrinsic to the CMD method explains part of the unexpectedly large quantum redshifts of the stretching band of liquid water compared to classical frequencies, which is improved after applying a simple and rough "harmonic curvature correction."

  2. (Liquid + liquid) equilibria for (water + 1-propanol or acetone + β-citronellol) at different temperatures

    International Nuclear Information System (INIS)

    Li, Hengde; Han, Yongtao; Huang, Cheng; Yang, Chufen

    2015-01-01

    Graphical abstract: (Liquid + liquid) equilibrium data for systems composed of β-citronellol and aqueous 1-propanol or acetone are presented. Distribution ratios of 1-propanol and acetone in the mixtures are examined. The effect of the temperature on the ternary (liquid + liquid) equilibria is evaluated and discussed. - Highlights: • Ternary (liquid + liquid) equilibria containing β-citronellol are presented. • Distribution ratios of 1-propanol and acetone in the mixtures are examined. • The effect on the temperature of the systems is evaluated and discussed. - Abstract: On this paper, experimental (liquid + liquid) equilibrium (LLE) results are presented for systems composed of β-citronellol and aqueous 1-propanol or acetone. To evaluate the phase separation properties of β-citronellol in aqueous mixtures, LLE values for the ternary systems (water + 1-propanol + β-citronellol) and (water + acetone + β-citronellol) were determined with a tie-line method at T = (283.15, 298.15, and 313.15 ± 0.02) K and atmospheric pressure. The reliability of the experimental tie-lines was verified by the Hand and Bachman equations. Ternary phase diagrams, distribution ratios of 1-propanol and acetone in the mixtures are shown. The effect of the temperature on the ternary (liquid + liquid) equilibria was examined and discussed. The experimental LLE values were satisfactorily correlated by extended UNIQUAC and modified UNIQUAC models

  3. Droplet-Sizing Liquid Water Content Sensor, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Icing is one of the most significant hazards to aircraft. A sizing supercooled liquid water content (SSLWC) sonde is being developed to meet a directly related need...

  4. Novel catalysts for isotopic exchange between hydrogen and liquid water

    International Nuclear Information System (INIS)

    Butler, J.P.; Rolston, J.H.; Stevens, W.H.

    1978-01-01

    Catalytic isotopic exchange between hydrogen and liquid water offers many inherent potential advantages for the separation of hydrogen isotopes which is of great importance in the Canadian nuclear program. Active catalysts for isotopic exchange between hydrogen and water vapor have long been available, but these catalysts are essentially inactive in the presence of liquid water. New, water-repellent platinum catalysts have been prepared by: (1) treating supported catalysts with silicone, (2) depositing platinum on inherently hydrophobic polymeric supports, and (3) treating platinized carbon with Teflon and bonding to a carrier. The activity of these catalysts for isotopic exchange between countercurrent streams of liquid water and hydrogen saturated with water vapor has been measured in a packed trickle bed integral reactor. The performance of these hydrophobic catalysts is compared with nonwetproofed catalysts. The mechanism of the overall exchange reaction is briefly discussed. 6 figures

  5. Institutional path dependence and environmental water recovery in Australia’s Murray-Darling Basin

    Directory of Open Access Journals (Sweden)

    Graham R. Marshall

    2016-10-01

    Full Text Available The concept of institutional path dependence offers useful ways of understanding the trajectories of water policy reforms and how past institutional arrangements, policy paradigms and development patterns constrain current and future choices and limit institutional adaptability. The value of this concept is demonstrated through an analysis of environmental water recovery in Australia’s Murray-Darling Basin, where while significant water volumes have been reallocated to the environment, the costs have also been significant. While there are significant lessons from the Australian experience, attempts to emulate the approach involve substantive risks and may be prohibitively costly for less wealthy nations. Context-specific institutional analysis is emphasised as fundamental to water reform and critical for reform architecture and sequencing. A key finding is that while crisis can provide powerful catalysts for institutional innovation, institutional path dependence in the absence of active and disruptive policy entrepreneurs fosters a strong tendency to reinforce the status quo and limit innovation, potentially exposing social-ecological systems to greater shocks due to climate change and other sources of escalating uncertainty.

  6. The Company Liquidation - A Path to Avert the Accrual of New Liabilities

    Directory of Open Access Journals (Sweden)

    Alexandra-Gabriela Rolea

    2014-12-01

    Full Text Available The economic deficit registered by almost all the countries in the world, the extension above expectations of the economic and financial downfall, the disruption or even collapse of some markets have compelled companies to leave their expectant position. The accrual of liabilities has become the main predicament for many of them and has even determined the governments and international organizations to amend the current legislation in the case of the companies having a significant impact on national economies. Overnight bankruptcies no longer terrify anyone these days, but the troubled investors need a judicious procedure of company liquidation in order to ensure the clearing of the creditors’ debts and, if applicable, the recovery of the capital that they invested. Taking into consideration these aspects, the present study approaches the most important legal, economic and accounting steps that must be followed by companies incorporated in Romania in order to perform the voluntary liquidation.

  7. Heating-induced glass-glass and glass-liquid transformations in computer simulations of water

    Science.gov (United States)

    Chiu, Janet; Starr, Francis W.; Giovambattista, Nicolas

    2014-03-01

    Water exists in at least two families of glassy states, broadly categorized as the low-density (LDA) and high-density amorphous ice (HDA). Remarkably, LDA and HDA can be reversibly interconverted via appropriate thermodynamic paths, such as isothermal compression and isobaric heating, exhibiting first-order-like phase transitions. We perform out-of-equilibrium molecular dynamics simulations of glassy water using the ST2 model to study the evolution of LDA and HDA upon isobaric heating. Depending on pressure, glass-to-glass, glass-to-crystal, glass-to-vapor, as well as glass-to-liquid transformations are found. Specifically, heating LDA results in the following transformations, with increasing heating pressures: (i) LDA-to-vapor (sublimation), (ii) LDA-to-liquid (glass transition), (iii) LDA-to-HDA-to-liquid, (iv) LDA-to-HDA-to-liquid-to-crystal, and (v) LDA-to-HDA-to-crystal. Similarly, heating HDA results in the following transformations, with decreasing heating pressures: (a) HDA-to-crystal, (b) HDA-to-liquid-to-crystal, (c) HDA-to-liquid (glass transition), (d) HDA-to-LDA-to-liquid, and (e) HDA-to-LDA-to-vapor. A more complex sequence may be possible using lower heating rates. For each of these transformations, we determine the corresponding transformation temperature as function of pressure, and provide a P-T "phase diagram" for glassy water based on isobaric heating. Our results for isobaric heating dovetail with the LDA-HDA transformations reported for ST2 glassy water based on isothermal compression/decompression processes [Chiu et al., J. Chem. Phys. 139, 184504 (2013)]. The resulting phase diagram is consistent with the liquid-liquid phase transition hypothesis. At the same time, the glass phase diagram is sensitive to sample preparation, such as heating or compression rates. Interestingly, at least for the rates explored, our results suggest that the LDA-to-liquid (HDA-to-liquid) and LDA-to-HDA (HDA-to-LDA) transformation lines on heating are related

  8. Heating-induced glass-glass and glass-liquid transformations in computer simulations of water

    International Nuclear Information System (INIS)

    Chiu, Janet; Giovambattista, Nicolas; Starr, Francis W.

    2014-01-01

    Water exists in at least two families of glassy states, broadly categorized as the low-density (LDA) and high-density amorphous ice (HDA). Remarkably, LDA and HDA can be reversibly interconverted via appropriate thermodynamic paths, such as isothermal compression and isobaric heating, exhibiting first-order-like phase transitions. We perform out-of-equilibrium molecular dynamics simulations of glassy water using the ST2 model to study the evolution of LDA and HDA upon isobaric heating. Depending on pressure, glass-to-glass, glass-to-crystal, glass-to-vapor, as well as glass-to-liquid transformations are found. Specifically, heating LDA results in the following transformations, with increasing heating pressures: (i) LDA-to-vapor (sublimation), (ii) LDA-to-liquid (glass transition), (iii) LDA-to-HDA-to-liquid, (iv) LDA-to-HDA-to-liquid-to-crystal, and (v) LDA-to-HDA-to-crystal. Similarly, heating HDA results in the following transformations, with decreasing heating pressures: (a) HDA-to-crystal, (b) HDA-to-liquid-to-crystal, (c) HDA-to-liquid (glass transition), (d) HDA-to-LDA-to-liquid, and (e) HDA-to-LDA-to-vapor. A more complex sequence may be possible using lower heating rates. For each of these transformations, we determine the corresponding transformation temperature as function of pressure, and provide a P-T “phase diagram” for glassy water based on isobaric heating. Our results for isobaric heating dovetail with the LDA-HDA transformations reported for ST2 glassy water based on isothermal compression/decompression processes [Chiu et al., J. Chem. Phys. 139, 184504 (2013)]. The resulting phase diagram is consistent with the liquid-liquid phase transition hypothesis. At the same time, the glass phase diagram is sensitive to sample preparation, such as heating or compression rates. Interestingly, at least for the rates explored, our results suggest that the LDA-to-liquid (HDA-to-liquid) and LDA-to-HDA (HDA-to-LDA) transformation lines on heating are related

  9. Heating-induced glass-glass and glass-liquid transformations in computer simulations of water

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, Janet; Giovambattista, Nicolas [Department of Physics, Brooklyn College of the City University of New York, Brooklyn, New York 11210 (United States); Starr, Francis W. [Department of Physics, Wesleyan University, Middletown, Connecticut 06459 (United States)

    2014-03-21

    Water exists in at least two families of glassy states, broadly categorized as the low-density (LDA) and high-density amorphous ice (HDA). Remarkably, LDA and HDA can be reversibly interconverted via appropriate thermodynamic paths, such as isothermal compression and isobaric heating, exhibiting first-order-like phase transitions. We perform out-of-equilibrium molecular dynamics simulations of glassy water using the ST2 model to study the evolution of LDA and HDA upon isobaric heating. Depending on pressure, glass-to-glass, glass-to-crystal, glass-to-vapor, as well as glass-to-liquid transformations are found. Specifically, heating LDA results in the following transformations, with increasing heating pressures: (i) LDA-to-vapor (sublimation), (ii) LDA-to-liquid (glass transition), (iii) LDA-to-HDA-to-liquid, (iv) LDA-to-HDA-to-liquid-to-crystal, and (v) LDA-to-HDA-to-crystal. Similarly, heating HDA results in the following transformations, with decreasing heating pressures: (a) HDA-to-crystal, (b) HDA-to-liquid-to-crystal, (c) HDA-to-liquid (glass transition), (d) HDA-to-LDA-to-liquid, and (e) HDA-to-LDA-to-vapor. A more complex sequence may be possible using lower heating rates. For each of these transformations, we determine the corresponding transformation temperature as function of pressure, and provide a P-T “phase diagram” for glassy water based on isobaric heating. Our results for isobaric heating dovetail with the LDA-HDA transformations reported for ST2 glassy water based on isothermal compression/decompression processes [Chiu et al., J. Chem. Phys. 139, 184504 (2013)]. The resulting phase diagram is consistent with the liquid-liquid phase transition hypothesis. At the same time, the glass phase diagram is sensitive to sample preparation, such as heating or compression rates. Interestingly, at least for the rates explored, our results suggest that the LDA-to-liquid (HDA-to-liquid) and LDA-to-HDA (HDA-to-LDA) transformation lines on heating are related

  10. Path integral centroid molecular dynamics simulations of semiinfinite slab and bulk liquid of para-hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Kinugawa, Kenichi [Nara Women`s Univ., Nara (Japan). Dept. of Chemistry

    1998-10-01

    It has been unsuccessful to solve a set of time-dependent Schroedinger equations numerically for many-body quantum systems which involve, e.g., a number of hydrogen molecules, protons, and excess electrons at a low temperature, where quantum effect evidently appears. This undesirable situation is fatal for the investigation of real low-temperature chemical systems because they are essentially composed of many quantum degrees of freedom. However, if we use a new technique called `path integral centroid molecular dynamics (CMD) simulation` proposed by Cao and Voth in 1994, the real-time semi-classical dynamics of many degrees of freedom can be computed by utilizing the techniques already developed in the traditional classical molecular dynamics (MD) simulations. Therefore, the CMD simulation is expected to be very powerful tool for the quantum dynamics studies or real substances. (J.P.N.)

  11. Liquid nitrogen - water interaction experiments for fusion reactor accident scenarios

    International Nuclear Information System (INIS)

    Duckworth, R.; Murphy, J.; Pfotenhauer, J.; Corradini, M.

    2001-01-01

    With the implementation of superconducting magnets in fusion reactors, the possibility exists for the interaction between water and cryogenic systems. The interaction between liquid nitrogen and water was investigated experimentally and numerically. The rate of pressurization and peak pressure were found to be driven thermodynamically by the expansion of the water and the boil-off of the liquid nitrogen and did not have a vapor explosion nature. Since the peak pressure was small in comparison to previous work with stratified geometries, the role of the geometry of the interacting fluids has been shown to be significant. Comparisons of the peak pressure and the rate of pressurization with respect to the ratio of the liquid nitrogen mass to water mass reveal no functional dependence as was observed in the liquid helium-water experiments. A simple thermodynamic model provides a fairly good description of the pressure rise data. From the data, the model will allow one to extract the interaction area of the water. As with previous liquid helium-water interaction experiments, more extensive investigation of the mass ratio and interaction geometry is needed to define boundaries between explosive and non-explosive conditions. (authors)

  12. Liquid Water in the Extremely Shallow Martian Subsurface

    Science.gov (United States)

    Pavlov, A.; Shivak, J. N.

    2012-01-01

    Availability of liquid water is one of the major constraints for the potential Martian biosphere. Although liquid water is unstable on the surface of Mars due to low atmospheric pressures, it has been suggested that liquid films of water could be present in the Martian soil. Here we explored a possibility of the liquid water formation in the extremely shallow (1-3 cm) subsurface layer under low atmospheric pressures (0.1-10 mbar) and low ("Martian") surface temperatures (approx.-50 C-0 C). We used a new Goddard Martian simulation chamber to demonstrate that even in the clean frozen soil with temperatures as low as -25C the amount of mobile water can reach several percents. We also showed that during brief periods of simulated daylight warming the shallow subsurface ice sublimates, the water vapor diffuses through porous surface layer of soil temporarily producing supersaturated conditions in the soil, which leads to the formation of additional liquid water. Our results suggest that despite cold temperatures and low atmospheric pressures, Martian soil just several cm below the surface can be habitable.

  13. Hydro-mechanical paths within unsaturated compacted soil framed through water retention surfaces

    Directory of Open Access Journals (Sweden)

    Pelizzari Benjamin

    2016-01-01

    Full Text Available Compaction is a key issue of modern earthworks... From sustainable development, a need arise of using materials for compaction under given conditions that would normally be avoid due to unpredictable pathologies. The application of compaction on fine grained soils, without a change of gravimetric water content, lead to very important modifications of the void ratio and hence suction. Therefore the hydro-mechanical behaviour of fine grained soil need to be rendered around three variables: suction, void ratio, saturation degree or water content. The barring capacity of the soil is assessed through Penetrometers (In-situ manual penetrometer, CBR in order to assess gains through compaction. The three states variables are then assessed for in situ and frame through water retention surfaces, realized from Proctor tests, in which compaction effect and path could be described.

  14. The putative liquid-liquid transition is a liquid-solid transition in atomistic models of water. II

    Science.gov (United States)

    Limmer, David T.; Chandler, David

    2013-06-01

    This paper extends our earlier studies of free energy functions of density and crystalline order parameters for models of supercooled water, which allows us to examine the possibility of two distinct metastable liquid phases [D. T. Limmer and D. Chandler, J. Chem. Phys. 135, 134503 (2011), 10.1063/1.3643333 and preprint arXiv:1107.0337 (2011)]. Low-temperature reversible free energy surfaces of several different atomistic models are computed: mW water, TIP4P/2005 water, Stillinger-Weber silicon, and ST2 water, the last of these comparing three different treatments of long-ranged forces. In each case, we show that there is one stable or metastable liquid phase, and there is an ice-like crystal phase. The time scales for crystallization in these systems far exceed those of structural relaxation in the supercooled metastable liquid. We show how this wide separation in time scales produces an illusion of a low-temperature liquid-liquid transition. The phenomenon suggesting metastability of two distinct liquid phases is actually coarsening of the ordered ice-like phase, which we elucidate using both analytical theory and computer simulation. For the latter, we describe robust methods for computing reversible free energy surfaces, and we consider effects of electrostatic boundary conditions. We show that sensible alterations of models and boundary conditions produce no qualitative changes in low-temperature phase behaviors of these systems, only marginal changes in equations of state. On the other hand, we show that altering sampling time scales can produce large and qualitative non-equilibrium effects. Recent reports of evidence of a liquid-liquid critical point in computer simulations of supercooled water are considered in this light.

  15. The putative liquid-liquid transition is a liquid-solid transition in atomistic models of water. II

    International Nuclear Information System (INIS)

    Limmer, David T.; Chandler, David

    2013-01-01

    This paper extends our earlier studies of free energy functions of density and crystalline order parameters for models of supercooled water, which allows us to examine the possibility of two distinct metastable liquid phases [D. T. Limmer and D. Chandler, J. Chem. Phys.135, 134503 (2011) and preprint http://arxiv.org/abs/arXiv:1107.0337 (2011)]. Low-temperature reversible free energy surfaces of several different atomistic models are computed: mW water, TIP4P/2005 water, Stillinger-Weber silicon, and ST2 water, the last of these comparing three different treatments of long-ranged forces. In each case, we show that there is one stable or metastable liquid phase, and there is an ice-like crystal phase. The time scales for crystallization in these systems far exceed those of structural relaxation in the supercooled metastable liquid. We show how this wide separation in time scales produces an illusion of a low-temperature liquid-liquid transition. The phenomenon suggesting metastability of two distinct liquid phases is actually coarsening of the ordered ice-like phase, which we elucidate using both analytical theory and computer simulation. For the latter, we describe robust methods for computing reversible free energy surfaces, and we consider effects of electrostatic boundary conditions. We show that sensible alterations of models and boundary conditions produce no qualitative changes in low-temperature phase behaviors of these systems, only marginal changes in equations of state. On the other hand, we show that altering sampling time scales can produce large and qualitative non-equilibrium effects. Recent reports of evidence of a liquid-liquid critical point in computer simulations of supercooled water are considered in this light

  16. The putative liquid-liquid transition is a liquid-solid transition in atomistic models of water. II

    Energy Technology Data Exchange (ETDEWEB)

    Limmer, David T.; Chandler, David, E-mail: chandler@berkeley.edu [Department of Chemistry, University of California, Berkeley, California 94720 (United States)

    2013-06-07

    This paper extends our earlier studies of free energy functions of density and crystalline order parameters for models of supercooled water, which allows us to examine the possibility of two distinct metastable liquid phases [D. T. Limmer and D. Chandler, J. Chem. Phys.135, 134503 (2011) and preprint http://arxiv.org/abs/arXiv:1107.0337 (2011)]. Low-temperature reversible free energy surfaces of several different atomistic models are computed: mW water, TIP4P/2005 water, Stillinger-Weber silicon, and ST2 water, the last of these comparing three different treatments of long-ranged forces. In each case, we show that there is one stable or metastable liquid phase, and there is an ice-like crystal phase. The time scales for crystallization in these systems far exceed those of structural relaxation in the supercooled metastable liquid. We show how this wide separation in time scales produces an illusion of a low-temperature liquid-liquid transition. The phenomenon suggesting metastability of two distinct liquid phases is actually coarsening of the ordered ice-like phase, which we elucidate using both analytical theory and computer simulation. For the latter, we describe robust methods for computing reversible free energy surfaces, and we consider effects of electrostatic boundary conditions. We show that sensible alterations of models and boundary conditions produce no qualitative changes in low-temperature phase behaviors of these systems, only marginal changes in equations of state. On the other hand, we show that altering sampling time scales can produce large and qualitative non-equilibrium effects. Recent reports of evidence of a liquid-liquid critical point in computer simulations of supercooled water are considered in this light.

  17. The putative liquid-liquid transition is a liquid-solid transition in atomistic models of water. II.

    Science.gov (United States)

    Limmer, David T; Chandler, David

    2013-06-07

    This paper extends our earlier studies of free energy functions of density and crystalline order parameters for models of supercooled water, which allows us to examine the possibility of two distinct metastable liquid phases [D. T. Limmer and D. Chandler, J. Chem. Phys. 135, 134503 (2011) and preprint arXiv:1107.0337 (2011)]. Low-temperature reversible free energy surfaces of several different atomistic models are computed: mW water, TIP4P/2005 water, Stillinger-Weber silicon, and ST2 water, the last of these comparing three different treatments of long-ranged forces. In each case, we show that there is one stable or metastable liquid phase, and there is an ice-like crystal phase. The time scales for crystallization in these systems far exceed those of structural relaxation in the supercooled metastable liquid. We show how this wide separation in time scales produces an illusion of a low-temperature liquid-liquid transition. The phenomenon suggesting metastability of two distinct liquid phases is actually coarsening of the ordered ice-like phase, which we elucidate using both analytical theory and computer simulation. For the latter, we describe robust methods for computing reversible free energy surfaces, and we consider effects of electrostatic boundary conditions. We show that sensible alterations of models and boundary conditions produce no qualitative changes in low-temperature phase behaviors of these systems, only marginal changes in equations of state. On the other hand, we show that altering sampling time scales can produce large and qualitative non-equilibrium effects. Recent reports of evidence of a liquid-liquid critical point in computer simulations of supercooled water are considered in this light.

  18. Path integral Liouville dynamics: Applications to infrared spectra of OH, water, ammonia, and methane

    International Nuclear Information System (INIS)

    Liu, Jian; Zhang, Zhijun

    2016-01-01

    Path integral Liouville dynamics (PILD) is applied to vibrational dynamics of several simple but representative realistic molecular systems (OH, water, ammonia, and methane). The dipole-derivative autocorrelation function is employed to obtain the infrared spectrum as a function of temperature and isotopic substitution. Comparison to the exact vibrational frequency shows that PILD produces a reasonably accurate peak position with a relatively small full width at half maximum. PILD offers a potentially useful trajectory-based quantum dynamics approach to compute vibrational spectra of molecular systems

  19. Reaction path analysis of sodium-water reaction phenomena in support of chemical reaction model development

    International Nuclear Information System (INIS)

    Kikuchi, Shin; Ohshima, Hiroyuki; Hashimoto, Kenro

    2011-01-01

    Computational study of the sodium-water reaction at the gas (water) - liquid (sodium) interface has been carried out using ab initio (first-principle) method. A possible reaction channel has been identified for the stepwise OH bond dissociations of a single water molecule. The energetics including the binding energy of a water molecule to the sodium surface, the activation energies of the bond cleavages, and the reaction energies, have been evaluated, and the rate constants of the first and second OH bond-breakings have been compared. The results are used as the basis for constructing the chemical reaction model used in a multi-dimensional sodium-water reaction code, SERAPHIM, being developed by JAEA toward the safety assessment of the steam generator (SG) in a sodium-cooled fast reactor (SFR). (author)

  20. Potential Energy Landscape of the Liquid-Liquid Phase Transition in Water and the transformation between Low-Density and High-Density Amorphous Ice

    Science.gov (United States)

    Giovambattista, N.; Sciortino, F.; Starr, F. W.; Poole, P. H.

    The potential energy landscape (PEL) formalism is a valuable approach within statistical mechanics for describing supercooled liquids and glasses. We use the PEL formalism and computer simulations to study the transformation between low-density (LDL) and high-density liquid (HDL) water, and between low-density (LDA) and high-density amorphous ice (HDA). We employ the ST2 water model that exhibits a LDL-HDL first-order phase transition and a sharp LDA-HDA transformation, as observed in experiments. Our results are consistent with the view that LDA and HDA configurations are associated with two distinct regions (megabasins) of the PEL that are separated by a potential energy barrier. At higher temperature, we find that LDL configurations are located in the same megabasin as LDA, and that HDL configurations are located in the same megabasin as HDA. We show that the pressure-induced LDL-HDL and LDA-HDA transformations occur along paths that interconnect these two megabasins, but that the path followed by the liquid and the amorphous ice differ. We also study the liquid-to-ice-VII first-order phase transition. The PEL properties across this transition are qualitatively similar to the changes found during the LDA-HDA transformation, supporting the interpretation that the LDA-HDA transformation is a first-order-like phase transition between out-of-equilibrium states.

  1. Behavior of supercooled aqueous solutions stemming from hidden liquid-liquid transition in water.

    Science.gov (United States)

    Biddle, John W; Holten, Vincent; Anisimov, Mikhail A

    2014-08-21

    A popular hypothesis that explains the anomalies of supercooled water is the existence of a metastable liquid-liquid transition hidden below the line of homogeneous nucleation. If this transition exists and if it is terminated by a critical point, the addition of a solute should generate a line of liquid-liquid critical points emanating from the critical point of pure metastable water. We have analyzed thermodynamic consequences of this scenario. In particular, we consider the behavior of two systems, H2O-NaCl and H2O-glycerol. We find the behavior of the heat capacity in supercooled aqueous solutions of NaCl, as reported by Archer and Carter [J. Phys. Chem. B 104, 8563 (2000)], to be consistent with the presence of the metastable liquid-liquid transition. We elucidate the non-conserved nature of the order parameter (extent of "reaction" between two alternative structures of water) and the consequences of its coupling with conserved properties (density and concentration). We also show how the shape of the critical line in a solution controls the difference in concentration of the coexisting liquid phases.

  2. Liquid water transport mechanism in the gas diffusion layer

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, P.; Wu, C.W. [State Key Laboratory of Structure Analysis for Industrial Equipment, Department of Engineering Mechanics, Faculty of Vehicle Engineering and Mechanics, Dalian University of Technology, Dalian 116024 (China)

    2010-03-01

    We developed an equivalent capillary model of a microscale fiber-fence structure to study the microscale evolution and transport of liquid in a porous media and to reveal the basic principles of water transport in gas diffusion layer (GDL). Analytical solutions using the model show that a positive hydraulic pressure is needed to drive the liquid water to penetrate through the porous GDL even consisting of the hydrophilic fibers. Several possible contributions for the water configuration, such as capillary pressure, gravity, vapor condensation, wettability and microstructures of the GDL, are discussed using the lattice Boltzmann method (LBM). It is found that the distribution manners of the fibers and the spatial mixed-wettability in the GDL also play an important role in the transport of liquid water. (author)

  3. When the 'soft-path' gets hard: demand management and financial instability for water utilities

    Science.gov (United States)

    Zeff, H. B.; Characklis, G. W.

    2014-12-01

    In the past, cost benefit analysis (CBA) has been viewed as an effective means of evaluating water utility strategies, particularly those that were dependent on the construction of new supply infrastructure. As water utilities have begun to embrace 'soft-path' approaches as a way to reduce the need for supply-centric development, CBA fails to recognize some important financial incentives affected by reduced water consumption. Demand management, both as a short-term response to drought and in longer-term actions to accommodate demand growth, can introduce revenue risks that adversely affect a utility's ability to repay debt, re-invest in aging infrastructure, or maintain reserve funds for use in a short-term emergency. A utility that does not generate sufficient revenue to support these functions may be subject to credit rating downgrades, which in turn affect the interest rate it pays on its debt. Interest rates are a critical consideration for utility managers in the capital-intensive water sector, where debt payments for infrastructure often account for a large portion of a utility's overall costs. Even a small increase in interest rates can add millions of dollars to the cost of new infrastructure. Recent studies have demonstrated that demand management techniques can lead to significant revenue variability, and credit rating agencies have begun to take notice of drought response plans when evaluating water utility credit ratings, providing utilities with a disincentive to fully embrace soft-path approaches. This analysis examines the impact of demand management schemes on key credit rating metrics for a water utility in Raleigh, North Carolina. The utility's consumer base is currently experiencing rapid population growth, and demand management has the potential to reduce the dependence on costly new supply infrastructure but could lead to financial instability that will significantly increase the costs of financing future projects. This work analyzes how 'soft-path

  4. (Liquid + liquid) equilibrium of {water + phenol + (1-butanol, or 2-butanol, or tert-butanol)} systems

    International Nuclear Information System (INIS)

    Hadlich de Oliveira, Leonardo; Aznar, Martin

    2010-01-01

    (Liquid + liquid) equilibrium (LLE) and binodal curve data were determined for the systems (water + phenol + tert-butanol) at T = 298.15 K, (water + phenol + 2-butanol) and (water + phenol + 1-butanol) at T = 298.15 K and T = 313.15 K by the combined techniques of densimetry and refractometry. Type I curve (for tert-butanol) and Type II curves (for 1- and 2-butanol) were found. The data were correlated with the NRTL model and the parameters estimated present root mean square deviations below 2% for the system with tert-butanol and lower than 0.8% for the other systems.

  5. Bond-Valence Constraints on Liquid Water Structure

    International Nuclear Information System (INIS)

    Bickmore, Barry R.; Rosso, Kevin M.; Brown, I. David; Kerisit, Sebastien N.

    2009-01-01

    The recent controversy about the structure of liquid water pits a new model involving water molecules in relatively stable rings-and-chains structures against the standard model that posits water molecules in distorted tetrahedral coordination. Molecular dynamics (MD) simulations 'both classical and ab initio' almost uniformly support the standard model, but since none of them can yet reproduce all the anomalous properties of water, they leave room for doubt. We argue that it is possible to evaluate these simulations by testing them against their adherence to the bond-valence model, a well known, and quantitatively accurate, empirical summary of the behavior of atoms in the bonded networks of inorganic solids. Here we use the results of ab initio molecular dynamics simulations of ice, water, and several solvated aqueous species to show that the valence sum rule (the first axiom of the bond-valence model,) is followed in both solid and liquid bond networks. We then test MD simulations of water, employing several popular potential models, against this criterion and the experimental O-O radial distribution function. It appears that most of those tested cannot satisfy both criteria well, except TIP4P and TIP5P. If the valence sum rule really can be applied to simulated liquid structures, then it follows that the bonding behaviors of atoms in liquids are in some ways identical to those in solids. We support this interpretation by showing that the simulations produce O-H-O geometries completely consistent with the range of geometries available in solids, and the distributions of instantaneous valence sums reaching the atoms in both the ice and liquid water simulations are essentially identical. Taken together, this is powerful evidence in favor of the standard distorted tetrahedral model of liquid water structure

  6. Passive cooling system for liquid metal cooled nuclear reactors with backup coolant flow path

    International Nuclear Information System (INIS)

    Hunsbedt, A.; Boardman, C.E.

    1993-01-01

    A dual passive cooling system for liquid metal cooled nuclear fission reactors is described, comprising the combination of: a reactor vessel for containing a pool of liquid metal coolant with a core of heat generating fissionable fuel substantially submerged therein, a side wall of the reactor vessel forming an innermost first partition; a containment vessel substantially surrounding the reactor vessel in spaced apart relation having a side wall forming a second partition; a first baffle cylinder substantially encircling the containment vessel in spaced apart relation having an encircling wall forming a third partition; a guard vessel substantially surrounding the containment vessel and first baffle cylinder in spaced apart relation having a side wall forming a forth partition; a sliding seal at the top of the guard vessel edge to isolate the dual cooling system air streams; a second baffle cylinder substantially encircling the guard vessel in spaced part relationship having an encircling wan forming a fifth partition; a concrete silo substantially surrounding the guard vessel and the second baffle cylinder in spaced apart relation providing a sixth partition; a first fluid coolant circulating flow course open to the ambient atmosphere for circulating air coolant comprising at lent one down comer duct having an opening to the atmosphere in an upper area thereof and making fluid communication with the space between the guard vessel and the first baffle cylinder and at least one riser duct having an opening to the atmosphere in the upper area thereof and making fluid communication with the space between the first baffle cylinder and the containment vessel whereby cooling fluid air can flow from the atmosphere down through the down comer duct and space between the forth and third partitions and up through the space between the third and second partition and the riser duct then out into the atmosphere; and a second fluid coolant circulating flow

  7. The puzzling unsolved mysteries of liquid water: Some recent progress

    Science.gov (United States)

    Stanley, H. E.; Kumar, P.; Xu, L.; Yan, Z.; Mazza, M. G.; Buldyrev, S. V.; Chen, S.-H.; Mallamace, F.

    2007-12-01

    Water is perhaps the most ubiquitous, and the most essential, of any molecule on earth. Indeed, it defies the imagination of even the most creative science fiction writer to picture what life would be like without water. Despite decades of research, however, water's puzzling properties are not understood and 63 anomalies that distinguish water from other liquids remain unsolved. We introduce some of these unsolved mysteries, and demonstrate recent progress in solving them. We present evidence from experiments and computer simulations supporting the hypothesis that water displays a special transition point (which is not unlike the “tipping point” immortalized by Malcolm Gladwell). The general idea is that when the liquid is near this “tipping point,” it suddenly separates into two distinct liquid phases. This concept of a new critical point is finding application to other liquids as well as water, such as silicon and silica. We also discuss related puzzles, such as the mysterious behavior of water near a protein.

  8. Path Dependencies and Institutional Bricolage in Post-Soviet Water Governance

    Directory of Open Access Journals (Sweden)

    Jenniver Sehring

    2009-02-01

    Based on empirical findings, four variables through which the neopatrimonial context in both countries impacts water governance are identified: the decision-making process, the agricultural sector, the local governance institutions, and internal water-institutional linkages. A historical-institutionalist perspective shows how path dependencies limit reform effectiveness: institutionalised Soviet and pre-Soviet patterns of behaviour still shape actors’ responses to new challenges. Consequently, rules and organisations established formally by the state or international donor organisations are undermined by informal institutions. Yet, informal institutions are not only an obstacle to reform, but can also support it. They are not static but dynamic. This is elucidated with the concept of 'institutional bricolage', which explains how local actors recombine elements of different institutional logics and thereby change their meaning.

  9. Structure of liquid water at high pressures and temperatures

    CERN Document Server

    Eggert, J H; Loubeyre, P

    2002-01-01

    We report quantitatively accurate structure-factor and radial-distribution-function measurements of liquid water in a diamond-anvil cell (DAC) using x-ray diffraction. During the analysis of our diffraction data, we found it possible (and necessary) to also determine the density. Thus, we believe we present the first-ever diffraction-based determination of a liquid structure factor and equation of state in a DAC experiment.

  10. A new water-based liquid scintillator and potential applications

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, M., E-mail: yeh@bnl.gov [Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Hans, S.; Beriguete, W.; Rosero, R.; Hu, L.; Hahn, R.L. [Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Diwan, M.V.; Jaffe, D.E.; Kettell, S.H.; Littenberg, L. [Physics Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2011-12-21

    In this paper we describe a new type of scintillating liquid based on water. We describe the concept, preparation, and properties of this liquid, and how it could be used for a very large, but economical detector. The applications of such a detector range from fundamental physics such as nucleon decay and neutrino physics to physics with broader application such as neutron detection. We briefly describe the scientific requirements of these applications, and how they can be satisfied by the new material.

  11. The Putative Liquid-Liquid Transition is a Liquid-Solid Transition in Atomistic Models of Water

    Science.gov (United States)

    Chandler, David; Limmer, David

    2013-03-01

    Our detailed and controlled studies of free energy surfaces for models of water find no evidence for reversible polyamorphism, and a general theoretical analysis of the phase behavior of cold water in nano pores shows that measured behaviors of these systems reflect surface modulation and dynamics of ice, not a liquid-liquid critical point. A few workers reach different conclusions, reporting evidence of a liquid-liquid critical point in computer simulations of supercooled water. In some cases, it appears that these contrary results are based upon simulation algorithms that are inconsistent with principles of statistical mechanics, such as using barostats that do not reproduce the correct distribution of volume fluctuations. In other cases, the results appear to be associated with difficulty equilibrating the supercooled material and mistaking metastability for coarsening of the ordered ice phase. In this case, sufficient information is available for us to reproduce the contrary results and to establish that they are artifacts of finite time sampling. This finding leads us to the conclusion that two distinct, reversible liquid phases do not exist in models of supercooled water.

  12. Core-softened fluids, water-like anomalies, and the liquid-liquid critical points.

    Science.gov (United States)

    Salcedo, Evy; de Oliveira, Alan Barros; Barraz, Ney M; Chakravarty, Charusita; Barbosa, Marcia C

    2011-07-28

    Molecular dynamics simulations are used to examine the relationship between water-like anomalies and the liquid-liquid critical point in a family of model fluids with multi-Gaussian, core-softened pair interactions. The core-softened pair interactions have two length scales, such that the longer length scale associated with a shallow, attractive well is kept constant while the shorter length scale associated with the repulsive shoulder is varied from an inflection point to a minimum of progressively increasing depth. The maximum depth of the shoulder well is chosen so that the resulting potential reproduces the oxygen-oxygen radial distribution function of the ST4 model of water. As the shoulder well depth increases, the pressure required to form the high density liquid decreases and the temperature up to which the high-density liquid is stable increases, resulting in the shift of the liquid-liquid critical point to much lower pressures and higher temperatures. To understand the entropic effects associated with the changes in the interaction potential, the pair correlation entropy is computed to show that the excess entropy anomaly diminishes when the shoulder well depth increases. Excess entropy scaling of diffusivity in this class of fluids is demonstrated, showing that decreasing strength of the excess entropy anomaly with increasing shoulder depth results in the progressive loss of water-like thermodynamic, structural and transport anomalies. Instantaneous normal mode analysis was used to index the overall curvature distribution of the fluid and the fraction of imaginary frequency modes was shown to correlate well with the anomalous behavior of the diffusivity and the pair correlation entropy. The results suggest in the case of core-softened potentials, in addition to the presence of two length scales, energetic, and entropic effects associated with local minima and curvatures of the pair interaction play an important role in determining the presence of water

  13. Raman Thermometry Measurements of Free Evaporation from Liquid Water Droplets

    International Nuclear Information System (INIS)

    Smith, Jared D.; Cappa, Christopher D.; Drisdell, Walter S.; Cohen, Ronald C.; Saykally, Richard J.

    2006-01-01

    Recent theoretical and experimental studies of evaporation have suggested that on average, molecules in the higher-energy tail of the Boltzmann distribution are more readily transferred into the vapor during evaporation. To test these conclusions, the evaporative cooling rates of a droplet train of liquid water injected into vacuum have been studied via Raman thermometry. The resulting cooling rates are fit to an evaporative cooling model based on Knudsen's maximum rate of evaporation, in which we explicitly account for surface cooling. We have determined that the value of the evaporation coefficient (γ e ) of liquid water is 0.62 ± 0.09, confirming that a rate-limiting barrier impedes the evaporation rate. Such insight will facilitate the formulation of a microscopic mechanism for the evaporation of liquid water

  14. Retrieval of an ice water path over the ocean from ISMAR and MARSS millimeter and submillimeter brightness temperatures

    Directory of Open Access Journals (Sweden)

    M. Brath

    2018-02-01

    Full Text Available A neural-network-based retrieval method to determine the snow ice water path (SIWP, liquid water path (LWP, and integrated water vapor (IWV from millimeter and submillimeter brightness temperatures, measured by using airborne radiometers (ISMAR and MARSS, is presented. The neural networks were trained by using atmospheric profiles from the ICON numerical weather prediction (NWP model and by radiative transfer simulations using the Atmospheric Radiative Transfer Simulator (ARTS. The basic performance of the retrieval method was analyzed in terms of offset (bias and the median fractional error (MFE, and the benefit of using submillimeter channels was studied in comparison to pure microwave retrievals. The retrieval is offset-free for SIWP  > 0.01 kg m−2, LWP  > 0.1 kg m−2, and IWV  > 3 kg m−2. The MFE of SIWP decreases from 100 % at SIWP  =  0.01 kg m−2 to 20 % at SIWP  =  1 kg m−2 and the MFE of LWP from 100 % at LWP  = 0.05 kg m−2 to 30 % at LWP  =  1 kg m−2. The MFE of IWV for IWV  > 3 kg m−2 is 5 to 8 %. The SIWP retrieval strongly benefits from submillimeter channels, which reduce the MFE by a factor of 2, compared to pure microwave retrievals. The IWV and the LWP retrievals also benefit from submillimeter channels, albeit to a lesser degree. The retrieval was applied to ISMAR and MARSS brightness temperatures from FAAM flight B897 on 18 March 2015 of a precipitating frontal system west of the coast of Iceland. Considering the given uncertainties, the retrieval is in reasonable agreement with the SIWP, LWP, and IWV values simulated by the ICON NWP model for that flight. A comparison of the retrieved IWV with IWV from 12 dropsonde measurements shows an offset of 0.5 kg m−2 and an RMS difference of 0.8 kg m−2, showing that the retrieval of IWV is highly effective even under cloudy conditions.

  15. Water Phase Diagram Is Significantly Altered by Imidazolium Ionic Liquid

    DEFF Research Database (Denmark)

    Chaban, V. V.; Prezhdo, O. V.

    2014-01-01

    We report unusually large changes in the boiling temperature, saturated vapor pressure, and structure of the liquid-vapor interface for a range of 1-butyl-3-methyl tetrafluoroborate, [C4C1IM][BF4]-water mixtures. Even modest molar fractions of [C4C1IM][BF4] significantly affect the phase behavior...... of water, as represented, for instance, by strong negative deviations from Raoult's law, extending far beyond the standard descriptions. The investigation was carried out using classical molecular dynamics employing a specifically refined force field. The changes in the liquid-vapor interface and saturated...

  16. Model potentials in liquid water ionization by fast electron impact

    International Nuclear Information System (INIS)

    De Sanctis, M L; Stia, C R; Fojón, O A; Politis, M-F; Vuilleumier, R

    2015-01-01

    We study the ionization of water molecules in liquid phase by fast electron impact. We use our previous first-order model within an independent electron approximation that allows the reduction of the multielectronic problem into a monoelectronic one. The initial molecular states of the liquid water are represented in a realistic way through a Wannier orbital formalism. We complete our previous study by taking into account approximately the influence of the passive electrons of the target by means of different model potentials. We compute multiple differential cross sections for the most external orbital 1B 1 and compare them with other results

  17. Liquid Water may Stick on Hydrophobic Surfaces

    Indian Academy of Sciences (India)

    IAS Admin

    Common Perception. A surface can be classified as. > Wetting. > Non-wetting. Depending on the spreading characteristics of a droplet of water that splashes on the surface. The behavior of fluid on a solid surface under static and dynamic ..... color of the number density profile. Ions at the interface tend to form pinning zones ...

  18. On the Fluctuations that Order and Frustrate Liquid Water

    Science.gov (United States)

    Limmer, David Tyler

    At ambient conditions, water sits close to phase coexistence with its crystal. More so than in many other materials, this fact is manifested in the fluctuations that maintain a large degree of local order in the liquid. These fluctuations and how they result in long-ranged order, or its absence, are emergent features of many interacting molecules. Their study therefore requires using the tools of statistical mechanics for their their systematic understanding. In this dissertation we develop such an understanding. In particular, we focus on collective behavior that emerges in liquid and solid water. At room temperatures, the thermophysical properties of water are quantified and rationalized with simple molecular models. A key feature of these models is the correct characterization of the competition between entropic forces of packing and the energetic preference for tetrahedral order. At cold temperatures, the properties of ice surfaces are studied with statistical field theory. The theory we develop for the long wavelength features of ice interfaces allows us to explain the existence of a premelting layer on the surface of ice and the stability of ice in confinement. In between these extremes, the dynamics of supercooled water are considered. A detailed theory for the early stages of coarsening is developed and used to explain the peculiar observation of a transient second liquid state of water. When coarsening dynamics are arrested, the result is the formation of a glassy states of water. We show that out-of-equilibrium the phase diagram for supercooled water exhibits a rich amount of structure, including a triple point between two glass phases of water and the liquid. At the end, we explore possible technological implications for the interplay between ordering and frustration in studies of water at metal interfaces.

  19. Rapid determination of 226Ra in drinking water samples using dispersive liquid-liquid microextraction coupled with liquid scintillation counting

    International Nuclear Information System (INIS)

    Sadi, B.K.; Chunsheng Li; Kramer, G.H.; Johnson, C.L.; Queenie Ko; Lai, E.P.C.

    2011-01-01

    A new radioanalytical method was developed for rapid determination of 226 Ra in drinking water samples. The method is based on extraction and preconcentration of 226 Ra from a water sample to an organic solvent using a dispersive liquid-liquid microextraction (DLLME) technique followed by radiometric measurement using liquid scintillation counting. In DLLME for 226 Ra, a mixture of an organic extractant (toluene doped with dibenzo-21-crown-7 and 2-theonyltrifluoroacetone) and a disperser solvent (acetonitrile) is rapidly injected into the water sample resulting in the formation of an emulsion. Within the emulsion, 226 Ra reacts with dibenzo-21-crown-7 and 2-theonyltrifluoroacetone and partitions into the fine droplets of toluene. The water/toluene phases were separated by addition of acetonitrile as a de-emulsifier solvent. The toluene phase containing 226 Ra was then measured by liquid scintillation counting. Several parameters were studied to optimize the extraction efficiency of 226 Ra, including water immiscible organic solvent, disperser and de-emulsifier solvent type and their volume, chelating ligands for 226 Ra and their concentrations, inorganic salt additive and its concentration, and equilibrium pH. With the optimized DLLME conditions, the accuracy (expressed as relative bias, B r ) and method repeatability (expressed as relative precision, S B ) were determined by spiking 226 Ra at the maximum acceptable concentration level (0.5 Bq L -1 ) according to the Guidelines for Canadian Drinking Water Quality. Accuracy and repeatability were found to be less than -5% (B r ) and less than 6% (S B ), respectively, for both tap water and bottled natural spring water samples. The minimum detectable activity and sample turnaround time for determination of 226 Ra was 33 mBq L -1 and less than 3 h, respectively. The DLLME technique is selective for extraction of 226 Ra from its decay progenies. (author)

  20. Economics of liquid hydrogen from water electrolysis

    Science.gov (United States)

    Lin, F. N.; Moore, W. I.; Walker, S. W.

    1985-01-01

    An economical model for preliminary analysis of LH2 cost from water electrolysis is presented. The model is based on data from vendors and open literature, and is suitable for computer analysis of different scenarios for 'directional' purposes. Cost data associated with a production rate of 10,886 kg/day are presented. With minimum modification, the model can also be used to predict LH2 cost from any electrolyzer once the electrolyzer's cost data are available.

  1. A broadband helical saline water liquid antenna for wearable systems

    Science.gov (United States)

    Li, Gaosheng; Huang, Yi; Gao, Gui; Yang, Cheng; Lu, Zhonghao; Liu, Wei

    2018-04-01

    A broadband helical liquid antenna made of saline water is proposed. A transparent hollow support is employed to fabricate the antenna. The rotation structure is fabricated with a thin flexible tube. The saline water with a concentration of 3.5% can be injected into or be extracted out from the tube to change the quantity of the solution. Thus, the tunability of the radiation pattern could be realised by applying the fluidity of the liquid. The radiation feature of the liquid antenna is compared with that of a metal one, and fairly good agreement has been achieved. Furthermore, three statements of the radiation performance corresponding to the ratio of the diameter to the wavelength of the helical saline water antenna have been proposed. It has been found that the resonance frequency increases when the length of the feeding probe or the radius of the vertical part of the liquid decreases. The fractional bandwidth can reach over 20% with a total height of 185 mm at 1.80 GHz. The measured results indicate reasonable approximation to the simulated. The characteristics of the liquid antenna make it a good candidate for various wireless applications, especially the wearable systems.

  2. Ultrafast Librational Relaxation of H2O in Liquid Water

    DEFF Research Database (Denmark)

    Petersen, Jakob; Møller, Klaus Braagaard; Rey, Rossend

    2013-01-01

    The ultrafast librational (hindered rotational) relaxation of a rotationally excited H2O molecule in pure liquid water is investigated by means of classical nonequilibrium molecular dynamics simulations and a power and work analysis. This analysis allows the mechanism of the energy transfer from...... the excited H2O to its water neighbors, which occurs on a sub-100 fs time scale, to be followed in molecular detail, i.e., to determine which water molecules receive the energy and in which degrees of freedom. It is found that the dominant energy flow is to the four hydrogen-bonded water partners in the first...

  3. Liquid velocity in upward and downward air-water flows

    International Nuclear Information System (INIS)

    Sun Xiaodong; Paranjape, Sidharth; Kim, Seungjin; Ozar, Basar; Ishii, Mamoru

    2004-01-01

    Local characteristics of the liquid phase in upward and downward air-water two-phase flows were experimentally investigated in a 50.8-mm inner-diameter round pipe. An integral laser Doppler anemometry (LDA) system was used to measure the axial liquid velocity and its fluctuations. No effect of the flow direction on the liquid velocity radial profile was observed in single-phase liquid benchmark experiments. Local multi-sensor conductivity probes were used to measure the radial profiles of the bubble velocity and the void fraction. The measurement results in the upward and downward two-phase flows are compared and discussed. The results in the downward flow demonstrated that the presence of the bubbles tended to flatten the liquid velocity radial profile, and the maximum liquid velocity could occur off the pipe centerline, in particular at relatively low flow rates. However, the maximum liquid velocity always occurred at the pipe center in the upward flow. Also, noticeable turbulence enhancement due to the bubbles in the two-phase flows was observed in the current experimental flow conditions. Furthermore, the distribution parameter and the void-weighted area-averaged drift velocity were obtained based on the definitions

  4. Boiling water reactor liquid radioactive waste processing system

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    The standard sets forth minimum design, construction and performance requirements with due consideration for operation of the liquid radioactive waste processing system for boiling water reactor plants for routine operation including design basis fuel leakage and design basis occurrences. For the purpose of this standard, the liquid radioactive waste processing system begins at the interfaces with the reactor coolant pressure boundary, at the interface valve(s) in lines from other systems and at those sumps and floor drains provided for liquid waste with the potential of containing radioactive material. The system terminates at the point of controlled discharge to the environment, at the point of interface with the waste solidification system and at the point of recycle back to storage for reuse. The standard does not include the reactor coolant clean-up system, fuel pool clean-up system, sanitary waste system, any nonaqueous liquid system or controlled area storm drains

  5. Experimental Evidence of Low Density Liquid Water under Decompression

    Science.gov (United States)

    Shen, G.; Lin, C.; Sinogeikin, S. V.; Smith, J.

    2017-12-01

    Water is not only the most important substance for life, but also plays important roles in liquid science for its anomalous properties. It has been widely accepted that water's anomalies are not a result of simple thermal fluctuation, but are connected to the formation of various structural aggregates in the hydrogen bonding network. Among several proposed scenarios, one model of fluctuations between two different liquids has gradually gained traction. These two liquids are referred to as a low-density liquid (LDL) and a high-density liquid (HDL) with a coexistence line in the deeply supercooled regime at elevated pressure. The LDL-HDL transition ends with decreasing pressure at a liquid-liquid critical point (LLCP) with its Widom line extending to low pressures. Above the Widom line lies mostly HDL which is favored by entropy, while LDL, mostly lying below the Widom line, is favored by enthalpy in the tetrahedral hydrogen bonding network. The origin of water's anomalies can then be explained by the increase in structural fluctuations, as water is cooled down to deeply supercooled temperatures approaching the Widom line. Because both the LLCP and the LDL-HDL transition line lie in water's "no man's land" between the homogeneous nucleation temperature (TH, 232 K) and the crystallization temperature (TX, 150 K), the success of experiments exploring this region has been limited thus far. Using a rapid decompression technique integrated with in situ x-ray diffraction, we observe that a high-pressure ice phase transforms to a low-density noncrystalline (LDN) form upon rapid release of pressure at temperatures of 140-165K. The LDN subsequently crystallizes into ice-Ic through a diffusion-controlled process. The change in crystallization rate with temperature indicates that the LDN is a LDL with its tetrahedrally-coordinated network fully developed and clearly linked to low-density amorphous ices. The observation of the tetrahedral LDL supports the two-liquid model for

  6. Pre-concentration of uranium from water samples by dispersive liquid-liquid micro-extraction

    Energy Technology Data Exchange (ETDEWEB)

    Khajeh, Mostafa; Nemch, Tabandeh Karimi [Zabol Univ. (Iran, Islamic Republic of). Dept. of Chemistry

    2014-07-01

    In this study, a simple and rapid dispersive liquid-liquid microextraction (DLLME) was developed for the determination of uranium in water samples prior to high performance liquid chromatography with diode array detection. 1-(2-pyridylazo)-2-naphthol (PAN) was used as complexing agent. The effect of various parameters on the extraction step including type and volume of extraction and dispersive solvents, pH of solution, concentration of PAN, extraction time, sample volume and ionic strength were studied and optimized. Under the optimum conditions, the limit of detection (LOD) and preconcentration factor were 0.3 μg L{sup -1} and 194, respectively. Furthermore, the relative standard deviation of the ten replicate was <2.6%. The developed procedure was then applied to the extraction and determination of uranium in the water samples.

  7. Pre-concentration of uranium from water samples by dispersive liquid-liquid micro-extraction

    International Nuclear Information System (INIS)

    Khajeh, Mostafa; Nemch, Tabandeh Karimi

    2014-01-01

    In this study, a simple and rapid dispersive liquid-liquid microextraction (DLLME) was developed for the determination of uranium in water samples prior to high performance liquid chromatography with diode array detection. 1-(2-pyridylazo)-2-naphthol (PAN) was used as complexing agent. The effect of various parameters on the extraction step including type and volume of extraction and dispersive solvents, pH of solution, concentration of PAN, extraction time, sample volume and ionic strength were studied and optimized. Under the optimum conditions, the limit of detection (LOD) and preconcentration factor were 0.3 μg L -1 and 194, respectively. Furthermore, the relative standard deviation of the ten replicate was <2.6%. The developed procedure was then applied to the extraction and determination of uranium in the water samples.

  8. Study of the liquid water luminescence induced by charged particles

    International Nuclear Information System (INIS)

    Rusu, Mircea; Stere, Oana; Haiduc, Maria; Caramete, Laurentiu

    2004-01-01

    Many observations suggested that liquid water (with impurities) could give a luminescence output when irradiated with charged particles. We investigate theoretical and practical possibility of detecting such luminescence. Preliminary results on this possibility are presented, and a layout of the device proposed for measuring luminescence is given. (authors)

  9. Water detritiation: better catalysts for liquid phase catalytic exchange

    International Nuclear Information System (INIS)

    Braet, J.

    2005-01-01

    Fusion reactors are our hope for a clean nuclear energy. But as they shall handle huge amounts of tritium, 1.5 10 19 Bq GWth -1 a -1 or about 50 000 times more tritium than light water fission reactors, they need detritiation. Most tritium losses can be trapped as or can easily be transformed into tritiated water. Water detritiation is preferably based on the multiplication of the large equilibrium isotope effect during the exchange reaction of tritium between hydrogen gas and liquid water in a counter current trickle bed reactor. Such LPCE (Liquid Phase Catalytic Exchange) requires an efficient hydrophobic catalyst. SCK-CEN invented and developed such a catalyst in the past. In combination with an appropriate packing, different batches of this catalyst performed very well during years of extensive testing, allowing to develop the ELEX process for water detritiation at inland reprocessing plants. The main objectives of this study were to reproduce and possibly improve the SCK-CEN catalyst for tritium exchange between hydrogen and liquid water; and to demonstrate the high overall exchange rate and thus high detritiation factors that can be realized with it in a small and simple LPCE column under typical but conservative operating conditions

  10. Strong low-pass filtering effects on water vapour flux measurements with closed-path eddy correlation systems

    DEFF Research Database (Denmark)

    Ibrom, Andreas; Dellwik, Ebba; Flyvbjerg, Henrik K.

    2007-01-01

    datasets for this substantial measurement error. In contrast to earlier studies, a large number of spectra and raw data have been used in the analysis to define the low-pass filtering characteristic of the EC system. This revealed that the cut-off frequency of the closed-path EC system for water vapour......Turbulent water vapour fluxes measured with closed-path eddy correlation (EC) systems are unintentionally low-pass filtered by the system in a manner that varies with environmental conditions. Why and how is described here. So is the practical method that systematically corrects long-term flux...... concentration measurements decreases exponentially with increasing relative humidity. After correction for this unintended filtering, the fluxes are consistent with CO2 and H2O fluxes that were measured with an open-path sensor at the same time. The correction of water vapour flux measurements over a Beech...

  11. Comparison of conventional Papanicolaou smear and SurePath® liquid-based cytology in the Copenhagen population screening programme for cervical cancer

    DEFF Research Database (Denmark)

    Kirschner, Benny; Simonsen, Kåre; Junge, Jette

    2006-01-01

    OBJECTIVE: To compare diagnostic performance of conventional Papanicolaou smear with SurePath liquid-based cytology in a population screening programme. METHODS: A retrospective comparison was performed on data from two 18-month periods of the screening programme for cervical cancer in the munici......OBJECTIVE: To compare diagnostic performance of conventional Papanicolaou smear with SurePath liquid-based cytology in a population screening programme. METHODS: A retrospective comparison was performed on data from two 18-month periods of the screening programme for cervical cancer...... in the municipality of Copenhagen with conventional Papanicolaou technique (n = 82,116) and liquid-based cytology (n = 84,414). RESULTS: After the conversion to liquid-based cytology the percentage of unsatisfactory samples decreased from 2.3% to 0.3% (P ...-based technique. CONCLUSIONS: This study showed the number of unsatisfactory samples to be significantly reduced with the liquid-based technique. The data suggest that there is an increased detection rate of cervical precancerous lesions with liquid-based cytology, but the number of false positive tests is still...

  12. Iron oxidation kinetics and phosphate immobilization along the flow-path from groundwater into surface water

    Science.gov (United States)

    van der Grift, B.; Rozemeijer, J. C.; Griffioen, J.; van der Velde, Y.

    2014-11-01

    The retention of phosphorus in surface waters through co-precipitation of phosphate with Fe-oxyhydroxides during exfiltration of anaerobic Fe(II) rich groundwater is not well understood. We developed an experimental field set-up to study Fe(II) oxidation and P immobilization along the flow-path from groundwater into surface water in an agricultural experimental catchment of a small lowland river. We physically separated tube drain effluent from groundwater discharge before it entered a ditch in an agricultural field. Through continuous discharge measurements and weekly water quality sampling of groundwater, tube drain water, exfiltrated groundwater, and surface water, we investigated Fe(II) oxidation kinetics and P immobilization processes. The oxidation rate inferred from our field measurements closely agreed with the general rate law for abiotic oxidation of Fe(II) by O2. Seasonal changes in climatic conditions affected the Fe(II) oxidation process. Lower pH and lower temperatures in winter (compared to summer) resulted in low Fe oxidation rates. After exfiltration to the surface water, it took a couple of days to more than a week before complete oxidation of Fe(II) is reached. In summer time, Fe oxidation rates were much higher. The Fe concentrations in the exfiltrated groundwater were low, indicating that dissolved Fe(II) is completely oxidized prior to inflow into a ditch. While the Fe oxidation rates reduce drastically from summer to winter, P concentrations remained high in the groundwater and an order of magnitude lower in the surface water throughout the year. This study shows very fast immobilization of dissolved P during the initial stage of the Fe(II) oxidation process which results in P-depleted water before Fe(II) is completely depleted. This cannot be explained by surface complexation of phosphate to freshly formed Fe-oxyhydroxides but indicates the formation of Fe(III)-phosphate precipitates. The formation of Fe(III)-phosphates at redox gradients

  13. Effects of water chemistry on flow accelerated corrosion and liquid droplet impingement

    International Nuclear Information System (INIS)

    Uchida, Shunsuke; Naitoh, Masanori; Okada, Hidetoshi; Uehara, Yasushi; Koshizuka, Seiichi; Lister, Derek H.

    2009-01-01

    Overlapping effects of flow dynamics and corrosion are important issues to determine reliability and lifetime of major structures and components in light water reactor plants. Flow accelerated corrosion (FAC) and liquid droplet impingement (LDI) are typical phenomena due to both interactions. In order to evaluation local wall thinning due to FAC and LDI, 6 step evaluation procedures have been proposed. (1) Flow pattern along the flow path was obtained with 1D computational flow dynamics (CFD) codes, (2) Corrosive conditions, e.g., oxygen concentration along the flow path were calculated with a hydrazine oxygen reaction code for FAC evaluation, while flow pattern of liquid droplets in high velocity steam and possibility of their collision to pipe inner surface were evaluated for LDI evaluation. (3) Mass transfer coefficient at the structure surface was calculated with 3D CFD codes for FAC evaluation, while frequency of oxide film rupture due to droplet collision was calculated for LDI evaluation. (4) High risk zones for FAC/LDI occurrence were evaluated by coupling major parameters, and then, (5) Wall thinning rates were calculated with the coupled model of static electrochemical analysis and dynamic double oxide layer analysis at the identified high FAC/LDI risk zone. (author)

  14. Multiscale network model for simulating liquid water and water vapour transfer properties of porous materials

    NARCIS (Netherlands)

    Carmeliet, J.; Descamps, F.; Houvenaghel, G.

    1999-01-01

    A multiscale network model is presented to model unsaturated moisture transfer in hygroscopic capillary-porous materials showing a broad pore-size distribution. Both capillary effects and water sorption phenomena, water vapour and liquid water transfer are considered. The multiscale approach is

  15. Assessing Receiving Water Quality Impacts due to Flow Path Alteration in Residential Catchments, using the Stormwater and Wastewater Management Model

    Science.gov (United States)

    Wolosoff, S. E.; Duncan, J.; Endreny, T.

    2001-05-01

    The Croton water supply system, responsible for supplying approximately 10% of New York City's water, provides an opportunity for exploration into the impacts of significant terrestrial flow path alteration upon receiving water quality. Natural flow paths are altered during residential development in order to allow for construction at a given location, reductions in water table elevation in low lying areas and to provide drainage of increased overland flow volumes. Runoff conducted through an artificial drainage system, is prevented from being attenuated by the natural environment, thus the pollutant removal capacity inherent in most natural catchments is often limited to areas where flow paths are not altered by development. By contrasting the impacts of flow path alterations in two small catchments in the Croton system, with different densities of residential development, we can begin to identify appropriate limits to the re-routing of runoff in catchments draining into surface water supplies. The Stormwater and Wastewater Management Model (SWMM) will be used as a tool to predict the runoff quantity and quality generated from two small residential catchments and to simulate the potential benefits of changes to the existing drainage system design, which may improve water quality due to longer residence times.

  16. Cytological Evaluation and REBA HPV-ID HPV Testing of Newly Developed Liquid-Based Cytology, EASYPREP: Comparison with SurePath.

    Science.gov (United States)

    Lee, Youn Soo; Gong, Gyungyub; Sohn, Jin Hee; Ryu, Ki Sung; Lee, Jung Hun; Khang, Shin Kwang; Cho, Kyung-Ja; Kim, Yong-Man; Kang, Chang Suk

    2013-06-01

    The objective of this study was to evaluate a newly-developed EASYPREP liquid-based cytology method in cervicovaginal specimens and compare it with SurePath. Cervicovaginal specimens were prospectively collected from 1,000 patients with EASYPREP and SurePath. The specimens were first collected by brushing for SurePath and second for EASYPREP. The specimens of both methods were diagnosed according to the Bethesda System. Additionally, we performed to REBA HPV-ID genotyping and sequencing analysis for human papillomavirus (HPV) on 249 specimens. EASYPREP and SurePath showed even distribution of cells and were equal in cellularity and staining quality. The diagnostic agreement between the two methods was 96.5%. Based on the standard of SurePath, the sensitivity, specificity, positive predictive value, and negative predictive value of EASYPREP were 90.7%, 99.2%, 94.8%, and 98.5%, respectively. The positivity of REBA HPV-ID was 49.4% and 95.1% in normal and abnormal cytological samples, respectively. The result of REBA HPV-ID had high concordance with sequencing analysis. EASYPREP provided comparable results to SurePath in the diagnosis and staining quality of cytology examinations and in HPV testing with REBA HPV-ID. EASYPREP could be another LBC method choice for the cervicovaginal specimens. Additionally, REBA HPV-ID may be a useful method for HPV genotyping.

  17. Liquid microjet - a new tool for environmental water quality monitoring?

    International Nuclear Information System (INIS)

    Holstein, W.; Buntine, M.

    2001-01-01

    Our ability to provide real-time, cost-effective and efficient technologies for water quality monitoring remains a critical global environmental research issue. Each year, ground and surface waterways around the world, the global marine environment and the especially-fragile interzonal estuarine ecosystems are being placed under severe stress due to ever-increasing levels of pollutants entering the earth's aquasphere. An almost revolutionary breakthrough in water quality monitoring would be achieved with the development of a real-time, broad-spectrum chemical analysis technology. In this article, a real-time mass spectrometric based water quality monitoring centre around in vacuo liquid microjet injection methodologies is presented

  18. (Ternary liquid + liquid) equilibria for (water + acetone + α-pinene, or β-pinene, or limonene) mixtures

    International Nuclear Information System (INIS)

    Li Xiaoli; Tamura, Kazuhiro

    2010-01-01

    (Ternary liquid + liquid) equilibria (tie-lines) of (water + acetone + α-pinene) at T = (288.15, 298.15, and 308.15) K and (water + acetone + β-pinene, or limonene) at T = 298.15 K have been measured. The experimental (ternary liquid + liquid) equilibrium data have been correlated successfully by the original UNIQUAC and modified UNIQUAC models. The modified UNIQUAC model reproduced accurately the experimental results for the (water + acetone + α-pinene) system at all the temperatures but fairly agreed with the experimental data for the (water + acetone + β-pinene, or limonene) systems.

  19. Final Scientific/Technical Report. A closed path methane and water vapor gas analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Liukang [LI-COR Inc., Lincoln, NE (United States); McDermitt, Dayle [LI-COR Inc., Lincoln, NE (United States); Anderson, Tyler [LI-COR Inc., Lincoln, NE (United States); Riensche, Brad [LI-COR Inc., Lincoln, NE (United States); Komissarov, Anatoly [LI-COR Inc., Lincoln, NE (United States); Howe, Julie [LI-COR Inc., Lincoln, NE (United States)

    2012-02-01

    Robust, economical, low-power and reliable closed-path methane (CH4), carbon dioxide (CO2), and water vapor (H2O) analyzers suitable for long-term measurements are not readily available commercially. Such analyzers are essential for quantifying the amount of CH4 and CO2 released from various ecosystems (wetlands, rice paddies, forests, etc.) and other surface contexts (e.g. landfills, animal husbandry lots, etc.), and for understanding the dynamics of the atmospheric CH4 and CO2 budget and their impact on climate change and global warming. The purpose of this project is to develop a closed-path methane, carbon dioxide gas and water vapor analyzer capable of long-term measurements in remote areas for global climate change and environmental research. The analyzer will be capable of being deployed over a wide range of ecosystems to understand methane and carbon dioxide exchange between the atmosphere and the surface. Measurements of methane and carbon dioxide exchange need to be made all year-round with limited maintenance requirements. During this Phase II effort, we successfully completed the design of the electronics, optical bench, trace gas detection method and mechanical infrastructure. We are using the technologies of two vertical cavity surface emitting lasers, a multiple-pass Herriott optical cell, wavelength modulation spectroscopy and direct absorption to measure methane, carbon dioxide, and water vapor. We also have designed the instrument application software, Field Programmable Gate Array (FPGA), along with partial completion of the embedded software. The optical bench has been tested in a lab setting with very good results. Major sources of optical noise have been identified and through design, the optical noise floor is approaching -60dB. Both laser modules can be temperature controlled to help maximize the stability of the analyzer. Additionally, a piezo electric transducer has been

  20. (Liquid + liquid) equilibrium of (dibutyl ether + methanol + water) at different temperatures

    International Nuclear Information System (INIS)

    Arce, Alberto; Rodriguez, Hector; Rodriguez, Oscar; Soto, Ana

    2005-01-01

    (Liquid + liquid) equilibrium data for the ternary system (dibutyl ether + methanol + water) were experimentally determined at T = (298.15, 308.15, and 318.15) K. The experimental results were correlated by means of the NRTL and UNIQUAC equations, the best results being achieved with the UNIQUAC equation, both for the individual correlations at each temperature and for the overall correlation considering all the three experimental data sets. The experimental tie-lines were also compared to the values predicted by the UNIFAC method

  1. Liquid radioactive waste processing system for pressurized water reactor plants

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    This Standard sets forth design, construction, and performance requirements, with due consideration for operation, of the Liquid Radioactive Waste Processing System for pressurized water reactor plants for design basis inputs. For the purpose of this Standard, the Liquid Radioactive Waste Processing System begins at the interfaces with the reactor coolant pressure boundary and the interface valve(s) in lines from other systems, or at those sumps and floor drains provided for liquid waste with the potential of containing radioactive material; and it terminates at the point of controlled discharge to the environment, at the point of interface with the waste solidification system, and at the point of recycle back to storage for reuse

  2. Liquid-liquid critical point in a simple analytical model of water

    Science.gov (United States)

    Urbic, Tomaz

    2016-10-01

    A statistical model for a simple three-dimensional Mercedes-Benz model of water was used to study phase diagrams. This model on a simple level describes the thermal and volumetric properties of waterlike molecules. A molecule is presented as a soft sphere with four directions in which hydrogen bonds can be formed. Two neighboring waters can interact through a van der Waals interaction or an orientation-dependent hydrogen-bonding interaction. For pure water, we explored properties such as molar volume, density, heat capacity, thermal expansion coefficient, and isothermal compressibility and found that the volumetric and thermal properties follow the same trends with temperature as in real water and are in good general agreement with Monte Carlo simulations. The model exhibits also two critical points for liquid-gas transition and transition between low-density and high-density fluid. Coexistence curves and a Widom line for the maximum and minimum in thermal expansion coefficient divides the phase space of the model into three parts: in one part we have gas region, in the second a high-density liquid, and the third region contains low-density liquid.

  3. Investigation of real tissue water equivalent path lengths using an efficient dose extinction method

    Science.gov (United States)

    Zhang, Rongxiao; Baer, Esther; Jee, Kyung-Wook; Sharp, Gregory C.; Flanz, Jay; Lu, Hsiao-Ming

    2017-07-01

    For proton therapy, an accurate conversion of CT HU to relative stopping power (RSP) is essential. Validation of the conversion based on real tissue samples is more direct than the current practice solely based on tissue substitutes and can potentially address variations over the population. Based on a novel dose extinction method, we measured water equivalent path lengths (WEPL) on animal tissue samples to evaluate the accuracy of CT HU to RSP conversion and potential variations over a population. A broad proton beam delivered a spread out Bragg peak to the samples sandwiched between a water tank and a 2D ion-chamber detector. WEPLs of the samples were determined from the transmission dose profiles measured as a function of the water level in the tank. Tissue substitute inserts and Lucite blocks with known WEPLs were used to validate the accuracy. A large number of real tissue samples were measured. Variations of WEPL over different batches of tissue samples were also investigated. The measured WEPLs were compared with those computed from CT scans with the Stoichiometric calibration method. WEPLs were determined within  ±0.5% percentage deviation (% std/mean) and  ±0.5% error for most of the tissue surrogate inserts and the calibration blocks. For biological tissue samples, percentage deviations were within  ±0.3%. No considerable difference (extinction measurement took around 5 min to produce ~1000 WEPL values to be compared with calculations. This dose extinction system measures WEPL efficiently and accurately, which allows the validation of CT HU to RSP conversions based on the WEPL measured for a large number of samples and real tissues.

  4. Satellite retrieval of the liquid water fraction in tropical clouds between −20 and −38 °C

    Directory of Open Access Journals (Sweden)

    D. L. Mitchell

    2012-07-01

    Full Text Available This study describes a satellite remote sensing method for directly retrieving the liquid water fraction in mixed phase clouds, and appears unique in this respect. The method uses MODIS split-window channels for retrieving the liquid fraction from cold clouds where the liquid water fraction is less than 50% of the total condensate. This makes use of the observation that clouds only containing ice exhibit effective 12-to-11 μm absorption optical thickness ratios (βeff that are quasi-constant with retrieved cloud temperature T. This observation was made possible by using two CO2 channels to retrieve T and then using the 12 and 11 μm channels to retrieve emissivities and βeff. Thus for T < −40 °C, βeff is constant, but for T > −40 °C, βeff slowly increases due to the presence of liquid water, revealing mean liquid fractions of ~ 10% around −22 °C from tropical clouds identified as cirrus by the cloud mask. However, the uncertainties for these retrievals are large, and extensive in situ measurements are needed to refine and validate these retrievals. Such liquid levels are shown to reduce the cloud effective diameter De such that cloud optical thickness will increase by more than 50% for a given water path, relative to De corresponding to pure ice clouds. Such retrieval information is needed for validation of the cloud microphysics in climate models. Since low levels of liquid water can dominate cloud optical properties, tropical clouds between −25 and −20 °C may be susceptible to the first aerosol indirect effect.

  5. In-syringe dispersive liquid-liquid microextraction with liquid chromatographic determination of synthetic pyrethroids in surface water

    Directory of Open Access Journals (Sweden)

    Saeed S. Albaseer

    2012-03-01

    Full Text Available An indigenously fabricated in laboratory glass syringe was used for in-syringe dispersive liquid-liquid microextraction (is-DLLME and preconcentration of synthetic pyrethroids (SPs from surface waters suitable for their determination by high performance liquid chromatography. In contrast to classical DLLME, is-DLLME allows the use of lighter-than-water organic solvents and the analysis of environmental contaminants’ samples without prior filtration, which is of great importance due to the high affinity of pyrethroids to adsorb to solid particulates present in environmental samples. The effects of various parameters on the extraction efficiency were evaluated and optimized systemically using one-factor-at-a-time method (OFAT and statistically using full factorial design (24. Three SPs (viz.; cypermethrin, resmethrin and permethrin were analyzed. The method showed good accuracy with RSD% in the range of of 4.8–6.9%. The method detection limits of the three pesticides ranged from 0.14 to 0.16 ng mL-1. The proposed method was applied for the determination of synthetic pyrethroids in lake water

  6. Deuterium isotope separation factor between hydrogen and liquid water

    International Nuclear Information System (INIS)

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

    1976-01-01

    The overall deuterium isotope separation factor between hydrogen and liquid water, α, has been measured directly for the first time between 280 and 370 0 K. The data are in good agreement with values of α calculated from literature data on the equilibrium constant for isotopic exchange between hydrogen and water vapor, K 1 , and the liquid-vapor separation factor, α/sub V/. The temperature dependence of α over the range 273-473 0 K based upon these new experimental results and existing literature data is given by the equation ln α = -0.2143 + (368.9/T) + (27,870/T 2 ). Measurements on α/sub V/ given in the literature have been surveyed and the results are summarized over the same temperature range by the equation ln α/sub V/ = 0.0592 - (80.3/T) +

  7. On the Fluctuations that Order and Frustrate Liquid Water

    OpenAIRE

    Limmer, David

    2013-01-01

    At ambient conditions, water sits close to phase coexistence with its crystal. More so than in many other materials, this fact is manifested in the fluctuations that maintain a large degree of local order in the liquid. These fluctuations and how they result in long-ranged order, or its absence, are emergent features of many interacting molecules. Their study therefore requires using the tools of statistical mechanics for their their systematic understanding. In this dissertation we develop s...

  8. Binary, ternary and quaternary liquid-liquid equilibria in 1-butanol, oleic acid, water and n-heptane mixtures

    NARCIS (Netherlands)

    Winkelman, J. G. M.; Kraai, G. N.; Heeres, H. J.

    2009-01-01

    This work reports on liquid-liquid equilibria in the system 1-butanol, oleic acid, water and n-heptane used for biphasic, lipase catalysed esterifications. The literature was studied on the mutual solubility in binary systems of water and each of the organic components. Experimental results were

  9. Interplay of the Glass Transition and the Liquid-Liquid Phase Transition in Water

    Science.gov (United States)

    Giovambattista, Nicolas

    2013-03-01

    Most liquids can form a single glass or amorphous state when cooled sufficiently fast (in order to prevent crystallization). However, there are a few substances that are relevant to scientific and technological applications which can exist in at least two different amorphous states, a property known as polyamorphism. Examples include silicon, silica, and in particular, water. In the case of water, experiments show the existence of a low-density (LDA) and high-density (HDA) amorphous ice that are separated by a dramatic, first-order like phase transition. It has been argued that the LDA-HDA transformation evolves into a first-order liquid-liquid phase transition (LLPT) at temperatures above the glass transition temperature Tg. However, obtaining direct experimental evidence of the LLPT has been challenging since the LLPT occurs at conditions where water rapidly crystallizes. In this talk, I will (i) discuss the general phenomenology of polyamorphism in water and its implications, and (ii) explore the effects of a LLPT on the pressure dependence of Tg(P) for LDA and HDA. Our study is based on computer simulations of two water models - one with a LLPT (ST2 model), and one without (SPC/E model). In the absence of a LLPT, Tg(P) for all glasses nearly coincide. Instead, when there is a LLPT, different glasses exhibit dramatically different Tg(P) loci which are directly linked with the LLPT. Available experimental data for Tg(P) are only consistent with the scenario that includes a LLPT (ST2 model) and hence, our results support the view that a LLPT may exist for the case of water.

  10. Measuring Low Concentrations of Liquid Water in Soil

    Science.gov (United States)

    Buehler, Martin

    2009-01-01

    An apparatus has been developed for measuring the low concentrations of liquid water and ice in relatively dry soil samples. Designed as a prototype of instruments for measuring the liquidwater and ice contents of Lunar and Martian soils, the apparatus could also be applied similarly to terrestrial desert soils and sands. The apparatus is a special-purpose impedance spectrometer: Its design is based on the fact that the electrical behavior of a typical soil sample is well approximated by a network of resistors and capacitors in which resistances decrease and capacitances increase (and, hence, the magnitude of impedance decreases) with increasing water content.

  11. Emergence of the Coherent Structure of Liquid Water

    Directory of Open Access Journals (Sweden)

    Ivan Bono

    2012-07-01

    Full Text Available We examine in some detail the interaction of water molecules with the radiative electromagnetic field and find the existence of phase transitions from the vapor phase to a condensed phase where all molecules oscillate in unison, in tune with a self-trapped electromagnetic field within extended mesoscopic space regions (Coherence Domains. The properties of such a condensed phase are examined and found to be compatible with the phenomenological properties of liquid water. In particular, the observed value of critical density is calculated with good accuracy.

  12. Simultaneous Water Vapor and Dry Air Optical Path Length Measurements and Compensation with the Large Binocular Telescope Interferometer

    Science.gov (United States)

    Defrere, D.; Hinz, P.; Downey, E.; Boehm, M.; Danchi, W. C.; Durney, O.; Ertel, S.; Hill, J. M.; Hoffmann, W. F.; Mennesson, B.; hide

    2016-01-01

    The Large Binocular Telescope Interferometer uses a near-infrared camera to measure the optical path length variations between the two AO-corrected apertures and provide high-angular resolution observations for all its science channels (1.5-13 microns). There is however a wavelength dependent component to the atmospheric turbulence, which can introduce optical path length errors when observing at a wavelength different from that of the fringe sensing camera. Water vapor in particular is highly dispersive and its effect must be taken into account for high-precision infrared interferometric observations as described previously for VLTI/MIDI or the Keck Interferometer Nuller. In this paper, we describe the new sensing approach that has been developed at the LBT to measure and monitor the optical path length fluctuations due to dry air and water vapor separately. After reviewing the current performance of the system for dry air seeing compensation, we present simultaneous H-, K-, and N-band observations that illustrate the feasibility of our feed forward approach to stabilize the path length fluctuations seen by the LBTI nuller uses a near-infrared camera to measure the optical path length variations between the two AO-corrected apertures and provide high-angular resolution observations for all its science channels (1.5-13 microns). There is however a wavelength dependent component to the atmospheric turbulence, which can introduce optical path length errors when observing at a wavelength different from that of the fringe sensing camera. Water vapor in particular is highly dispersive and its effect must be taken into account for high-precision infrared interferometric observations as described previously for VLTI MIDI or the Keck Interferometer Nuller. In this paper, we describe the new sensing approach that has been developed at the LBT to measure and monitor the optical path length fluctuations due to dry air and water vapor separately. After reviewing the current

  13. Experimental measurement and prediction of (liquid + liquid + liquid) equilibrium for the system (n-hexadecane + water + triacetin)

    International Nuclear Information System (INIS)

    Revellame, Emmanuel D.; Holmes, William E.; Hernandez, Rafael; French, W. Todd; Forks, Allison; Ashe, Taylor; Estévez, L. Antonio

    2016-01-01

    Highlights: • Phase diagram for the system n-hexadecane + water + triacetin was established at T = 296.15 K and atmospheric pressure (0.1 MPa). • Both NRTL and UNIQUAC activity coefficient model adequately predicts the LLLE of the ternary system. • The phase equilibrium of the system is predominantly dictated by enthalpic contributions to the activity coefficient. - Abstract: The phase diagram for the ternary system containing (n-hexadecane + water + triacetin) was obtained experimentally at T = 296.15 K and ambient pressure. Results show that this system is of Type 3 according to the Treybal classification of ternary system. NRTL and UNIQUAC interaction parameters were calculated from binary phase equilibrium values and were used to predict the (liquid + liquid + liquid) equilibrium (LLLE) region. Results indicated that both NRTL and UNIQUAC could predict the LLLE region of the system with similar precision as indicated by the comparable standard deviations. This indicates that the enthalpic contribution to the activity coefficient is predominant and entropic contributions can be neglected.

  14. Selective extraction of emerging contaminants from water samples by dispersive liquid-liquid microextraction using functionalized ionic liquids.

    Science.gov (United States)

    Yao, Cong; Li, Tianhao; Twu, Pamela; Pitner, William R; Anderson, Jared L

    2011-03-25

    Functionalized ionic liquids containing the tris(pentafluoroethyl)trifluorophosphate (FAP) anion were used as extraction solvents in dispersive liquid-liquid microextraction (DLLME) for the extraction of 14 emerging contaminants from water samples. The extraction efficiencies and selectivities were compared to those of an in situ IL DLLME method which uses an in situ metathesis reaction to exchange 1-butyl-3-methylimidazolium chloride (BMIM-Cl) to 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide (BMIM-NTf(2)). Compounds containing tertiary amine functionality were extracted with high selectivity and sensitivity by the 1-(6-amino-hexyl)-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate (HNH(2)MPL-FAP) IL compared to other FAP-based ILs and the BMIM-NTf(2) IL. On the other hand, polar or acidic compounds without amine groups exhibited higher enrichment factors using the BMIM-NTf(2) IL. The detection limits for the studied analytes varied from 0.1 to 55.1 μg/L using the traditional IL DLLME method with the HNH(2)MPL-FAP IL as extraction solvent, and from 0.1 to 55.8 μg/L using in situ IL DLLME method with BMIM-Cl+LiNTf(2) as extraction solvent. A 93-fold decrease in the detection limit of caffeine was observed when using the HNH(2)MPL-FAP IL compared to that obtained using in situ IL DLLME method. Real water samples including tap water and creek water were analyzed with both IL DLLME methods and yielded recoveries ranging from 91% to 110%. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Resonant inelastic X-ray scattering of liquid water

    International Nuclear Information System (INIS)

    Nilsson, Anders; Tokushima, Takashi; Horikawa, Yuka; Harada, Yoshihisa; Ljungberg, Mathias P.; Shin, Shik; Pettersson, Lars G.M.

    2013-01-01

    Highlights: ► Two peaks are observed in the lone pair region of the XES spectrum of water assigned to tetrahedral and distorted hydrogen bonding configurations. ► The isotope effect observed as different relative peak heights is due to spectral line shape differences. ► The two different hydrogen bonding environments can be related to local structures mimicking either low density water or high density water. -- Abstract: We review recent studies using resonant inelastic X-ray scattering (RIXS) or also here denoted X-ray emission spectroscopy (XES) on liquid water and the assignment of the two sharp peaks in the lone-pair region. Using the excitation energy dependence we connect the two peaks to specific features in the X-ray absorption (XAS) spectrum which have independently been assigned to molecules in tetrahedral or distorted configurations. The polarization dependence shows that both peaks are of 1b 1 origin supporting an interpretation in terms of two structural species, tetrahedral or disordered, which is furthermore consistent with the temperature-dependence of the two peaks. We discuss effects of life-time vibrational interference and how this affects the two components differently and also leads to differences in the relative peak heights for H 2 O and D 2 O. We show furthermore that the inherent structure in molecular dynamics simulations contain the structural bimodality suggested by XES, but this is smeared out in the real structure when temperature is included. We present a discussion around alternative interpretations suggesting that the origin of the two peaks is related to ultrafast dissociation and show evidence that such a model is inconsistent with several experimental observations and theoretical concepts. We conclude that the peaks reflect a temperature-dependent balance in fluctuations between tetrahedral and disordered structures in the liquid. This is well-aligned with theories of water under supercooled conditions and higher pressures

  16. Resonant inelastic X-ray scattering of liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Anders, E-mail: nilsson@slac.stanford.edu [SUNCAT Ctr Interface Sci and Catalysis, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Department of Physics, AlbaNova University Center, Stockholm University, SE-10691 (Sweden); Tokushima, Takashi [RIKEN/Spring-8, Sayo-cho, Sayo, Hyogo 679-5148 (Japan); Horikawa, Yuka [RIKEN/Spring-8, Sayo-cho, Sayo, Hyogo 679-5148 (Japan); Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Harada, Yoshihisa [RIKEN/Spring-8, Sayo-cho, Sayo, Hyogo 679-5148 (Japan); Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Synchrotron Radiation Research Organization, The University of Tokyo, Sayo-cho, Sayo, Hyogo 679-5165 (Japan); Ljungberg, Mathias P. [Department of Physics, AlbaNova University Center, Stockholm University, SE-10691 (Sweden); Institut de Ciencia de Materials de Barcelona (ICMAB-CSIC), Campus UAB, E-08193 Bellaterra (Spain); Shin, Shik [RIKEN/Spring-8, Sayo-cho, Sayo, Hyogo 679-5148 (Japan); Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Synchrotron Radiation Research Organization, The University of Tokyo, Sayo-cho, Sayo, Hyogo 679-5165 (Japan); Pettersson, Lars G.M. [Department of Physics, AlbaNova University Center, Stockholm University, SE-10691 (Sweden)

    2013-06-15

    Highlights: ► Two peaks are observed in the lone pair region of the XES spectrum of water assigned to tetrahedral and distorted hydrogen bonding configurations. ► The isotope effect observed as different relative peak heights is due to spectral line shape differences. ► The two different hydrogen bonding environments can be related to local structures mimicking either low density water or high density water. -- Abstract: We review recent studies using resonant inelastic X-ray scattering (RIXS) or also here denoted X-ray emission spectroscopy (XES) on liquid water and the assignment of the two sharp peaks in the lone-pair region. Using the excitation energy dependence we connect the two peaks to specific features in the X-ray absorption (XAS) spectrum which have independently been assigned to molecules in tetrahedral or distorted configurations. The polarization dependence shows that both peaks are of 1b{sub 1} origin supporting an interpretation in terms of two structural species, tetrahedral or disordered, which is furthermore consistent with the temperature-dependence of the two peaks. We discuss effects of life-time vibrational interference and how this affects the two components differently and also leads to differences in the relative peak heights for H{sub 2}O and D{sub 2}O. We show furthermore that the inherent structure in molecular dynamics simulations contain the structural bimodality suggested by XES, but this is smeared out in the real structure when temperature is included. We present a discussion around alternative interpretations suggesting that the origin of the two peaks is related to ultrafast dissociation and show evidence that such a model is inconsistent with several experimental observations and theoretical concepts. We conclude that the peaks reflect a temperature-dependent balance in fluctuations between tetrahedral and disordered structures in the liquid. This is well-aligned with theories of water under supercooled conditions and

  17. Ionic liquids as entrainers for water + ethanol, water + 2-propanol, and water + THF systems: A quantum chemical approach

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Vijay Kumar [Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam (India); Banerjee, Tamal, E-mail: tamalb@iitg.ernet.i [Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam (India)

    2010-07-15

    Ionic liquids (ILs) are used as entrainers in azeotropic systems such as water + ethanol, water + 2-propanol, and water + tetrahydrofuran (THF). Ionic liquids consisting of a cation and an anion has limitless combinations, thereby making experimentation expensive and time taking. For the prediction of the liquid phase nonidealities resulting from molecular interactions, 'COnductor-like Screening MOdel for Real Solvents' (COSMO-RS) approach is used in this work for the screening of potential ionic liquids. Initially benchmarking has been done on 12 reported isobaric IL based ternary systems with an absolute average deviation of 4.63% in vapor phase mole fraction and 1.07% in temperature. After successful benchmarking, ternary vapor + liquid equilibria for the azeotropic mixture of (a) ethanol + water, (b) 2-propanol + water, and (c) THF + water with combinations involving 10 cations (imidazolium, pyridinium, quinolium) and 24 anions were predicted. The VLE prediction, which gave the relative volatility, showed that the imidazolium based ionic liquid were the best entrainer for the separation of the three systems at their azeotropic point. ILs with [MMIM] cation in combination with acetate [OAc], chloride [Cl], and bromide [Br] anion gave the highest relative volatility.

  18. Performance of Water-Based Liquid Scintillator: An Independent Analysis

    Directory of Open Access Journals (Sweden)

    D. Beznosko

    2014-01-01

    Full Text Available The water-based liquid scintillator (WbLS is a new material currently under development. It is based on the idea of dissolving the organic scintillator in water using special surfactants. This material strives to achieve the novel detection techniques by combining the Cerenkov rings and scintillation light, as well as the total cost reduction compared to pure liquid scintillator (LS. The independent light yield measurement analysis for the light yield measurements using three different proton beam energies (210 MeV, 475 MeV, and 2000 MeV for water, two different WbLS formulations (0.4% and 0.99%, and pure LS conducted at Brookhaven National Laboratory, USA, is presented. The results show that a goal of ~100 optical photons/MeV, indicated by the simulation to be an optimal light yield for observing both the Cerenkov ring and the scintillation light from the proton decay in a large water detector, has been achieved.

  19. Spectrophotometric determination of mercury in water samples after preconcentration using dispersive liquid-liquid microextraction.

    Science.gov (United States)

    Lemos, Valfredo Azevedo; dos Santos, Liz Oliveira; Silva, Eldevan dos Santos; Vieira, Emanuel Vitor dos Santos

    2012-01-01

    A simple method for the determination of mercury in water samples after preconcentration using dispersive liquid-liquid microextraction is described. The procedure is based on the extraction of mercury in the form of a complex and its subsequent determination by spectrophotometry. The complex is formed between Hg(II) and 2-(2-benzothiazolylazo)-p-cresol. The detection at 650 nm is performed directly in the metal-rich phase, which is spread on a triacetylcellulose membrane. The method eliminates the need to use a cuvet or large quantities of samples and reagents. The parameters that influence the preconcentration were studied, and the analytical characteristics were determined. The enrichment factor and the consumptive index for this method were 64 and 0.16 mL, respectively. The LOD (3.3 microg/L) and LOQ (11.1 microg/L) were also determined. The accuracy of the method was tested by the determination of mercury in certified reference materials BCR 397 (Human Hair) and SRM 2781 (Domestic Sludge). The method was applied to the determination of mercury in samples of drinking water, sea water, and river water.

  20. Reactive liquid/liquid extraction of heavy metals from landfill seepage waters. Its characterisation and application

    International Nuclear Information System (INIS)

    Woller, N.

    1994-06-01

    This study demonstrates the applicability of liquid-liquid extraction by means of the commercial complexers LIX26 R and LIX84 R to heavy metal removal from waste waters. The composition of this oil-soluble complex is MeR 2 , where Me denotes Hg 2+ , Cd 2+ , Zn 2+ , Cu 2+ , and Ni 2+ , and R denotes LIX84 R . This composition makes the complex electrically neutral, and all polar groups are located inside the molecule. The extraction efficiency of the complexer LIX84 R for the various metal ions is evident in the succession Cu 2+ , Ni 2+ >> Zn 2+ > Hg 2+ > Cd 2+ . These heavy metal ions are even readily extractable at chloride concentrations of up to 1 mol/l. As the structure of the complexer is that of an oil-soluble surfactant with complexing properties, it accumulates at the phase boundary between oil and water. Measurement of interfacial tension in various solvent systems showed that the polar solvent chloroform permits only a weak accumulation of the complexer (400 nmol/m 2 ), whereas the unpolar solvent kerosine permits greater accumulation specifically on the water side of the phase boundary (1958 nmol/m 2 ). Organic solvents solvate the complexer so well, that it is even removed from the air side of the phase boundary. The differing accumulation of the complexer at the water/oil phase boundary explains the differing increase of phase separation time for polar and unpolar solvents. (orig.) [de

  1. Ionic liquid foam floatation coupled with ionic liquid dispersive liquid-liquid microextraction for the separation and determination of estrogens in water samples by high-performance liquid chromatography with fluorescence detection.

    Science.gov (United States)

    Zhang, Rui; Wang, Chuanliu; Yue, Qiaohong; Zhou, Tiecheng; Li, Na; Zhang, Hanqi; Hao, Xiaoke

    2014-11-01

    An ionic liquid foam floatation coupled with ionic liquid dispersive liquid-liquid microextraction method was proposed for the extraction and concentration of 17-α-estradiol, 17-β-estradiol-benzoate, and quinestrol in environmental water samples by high-performance liquid chromatography with fluorescence detection. 1-Hexyl-3-methylimidazolium tetrafluoroborate was applied as foaming agent in the foam flotation process and dispersive solvent in microextraction. The introduction of the ion-pairing and salting-out agent NH4 PF6 was beneficial to the improvement of recoveries for the hydrophobic ionic liquid phase and analytes. Parameters of the proposed method including concentration of 1-hexyl-3-methylimidazolium tetrafluoroborate, flow rate of carrier gas, floatation time, types and concentration of ionic liquids, salt concentration in samples, extraction time, and centrifugation time were evaluated. The recoveries were between 98 and 105% with relative standard deviations lower than 7% for lake water and well water samples. The isolation of the target compounds from the water was found to be efficient, and the enrichment factors ranged from 4445 to 4632. This developing method is free of volatile organic solvents compared with regular extraction. Based on the unique properties of ionic liquids, the application of foam floatation, and dispersive liquid-liquid microextraction was widened. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Effect of water and ionic liquids on biomolecules.

    Science.gov (United States)

    Saha, Debasis; Mukherjee, Arnab

    2018-02-08

    The remarkable progress in the field of ionic liquids (ILs) in the last two decades has involved investigations on different aspects of ILs in various conditions. The nontoxic and biocompatible nature of ILs makes them a suitable substance for the storage and application of biomolecules. In this regard, the aqueous IL solutions have attracted a large number of studies to comprehend the role of water in modulating various properties of biomolecules. Here, we review some of the recent studies on aqueous ILs that concern the role of water in altering the behavior of ILs in general and in case of biomolecules solvated in ILs. The different structural and dynamic effects caused by water have been highlighted. We discuss the different modes of IL interaction that are responsible for stabilization and destabilization of proteins and enzymes followed by examples of water effect on this. The role of water in the case of nucleic acid storage in ILs, an area which has mostly been underrated, also has been emphasized. Our discussions highlight the fact that the effects of water on IL behavior are not general and are highly dependent on the nature of the IL under consideration. Overall, we aim to draw attention to the significance of water dynamics in the aqueous IL solutions, a better understanding of which can help in developing superior storage materials for application purposes.

  3. Gas hydrate inhibition by perturbation of liquid water structure

    Science.gov (United States)

    Sa, Jeong-Hoon; Kwak, Gye-Hoon; Han, Kunwoo; Ahn, Docheon; Lee, Kun-Hong

    2015-06-01

    Natural gas hydrates are icy crystalline materials that contain hydrocarbons, which are the primary energy source for this civilization. The abundance of naturally occurring gas hydrates leads to a growing interest in exploitation. Despite their potential as energy resources and in industrial applications, there is insufficient understanding of hydrate kinetics, which hinders the utilization of these invaluable resources. Perturbation of liquid water structure by solutes has been proposed to be a key process in hydrate inhibition, but this hypothesis remains unproven. Here, we report the direct observation of the perturbation of the liquid water structure induced by amino acids using polarized Raman spectroscopy, and its influence on gas hydrate nucleation and growth kinetics. Amino acids with hydrophilic and/or electrically charged side chains disrupted the water structure and thus provided effective hydrate inhibition. The strong correlation between the extent of perturbation by amino acids and their inhibition performance constitutes convincing evidence for the perturbation inhibition mechanism. The present findings bring the practical applications of gas hydrates significantly closer, and provide a new perspective on the freezing and melting phenomena of naturally occurring gas hydrates.

  4. Interfacial thermodynamics of water and six other liquid solvents.

    Science.gov (United States)

    Pascal, Tod A; Goddard, William A

    2014-06-05

    We examine the thermodynamics of the liquid-vapor interface by direct calculation of the surface entropy, enthalpy, and free energy from extensive molecular dynamics simulations using the two-phase thermodynamics (2PT) method. Results for water, acetonitrile, cyclohexane, dimethyl sulfoxide, hexanol, N-methyl acetamide, and toluene are presented. We validate our approach by predicting the interfacial surface tensions (IFT--excess surface free energy per unit area) in excellent agreement with the mechanical calculations using Kirkwood-Buff theory. Additionally, we evaluate the temperature dependence of the IFT of water as described by the TIP4P/2005, SPC/Ew, TIP3P, and mW classical water models. We find that the TIP4P/2005 and SPC/Ew water models do a reasonable job of describing the interfacial thermodynamics; however, the TIP3P and mW are quite poor. We find that the underprediction of the experimental IFT at 298 K by these water models results from understructured surface molecules whose binding energies are too weak. Finally, we performed depth profiles of the interfacial thermodynamics which revealed long tails that extend far into what would be considered bulk from standard Gibbs theory. In fact, we find a nonmonotonic interfacial free energy profile for water, a unique feature that could have important consequences for the absorption of ions and other small molecules.

  5. Interplay of the Glass Transition and the Liquid-Liquid Phase Transition in Water

    Science.gov (United States)

    Giovambattista, Nicolas; Loerting, Thomas; Lukanov, Boris R.; Starr, Francis W.

    2012-01-01

    Water has multiple glassy states, often called amorphous ices. Low-density (LDA) and high-density (HDA) amorphous ice are separated by a dramatic, first-order like phase transition. It has been argued that the LDA-HDA transformation connects to a first-order liquid-liquid phase transition (LLPT) above the glass transition temperature Tg. Direct experimental evidence of the LLPT is challenging to obtain, since the LLPT occurs at conditions where water rapidly crystallizes. In this work, we explore the implications of a LLPT on the pressure dependence of Tg(P) for LDA and HDA by performing computer simulations of two water models – one with a LLPT, and one without. In the absence of a LLPT, Tg(P) for all glasses nearly coincide. When there is a LLPT, different glasses exhibit dramatically different Tg(P) which are directly linked with the LLPT. Available experimental data for Tg(P) are only consistent with the scenario including a LLPT. PMID:22550566

  6. Reaction of water vapor with a clean liquid uranium surface

    International Nuclear Information System (INIS)

    Siekhaus, W.

    1985-01-01

    To study the reaction of water vapor with uranium, we have exposed clean liquid uranium surfaces to H 2 O under UHV conditions. We have measured the surface concentration of oxygen as a function of exposure, and determined the maximum attainable surface oxygen concentration X 0 /sup s/ as a function of temperature. We have used these measurements to estimate, close to the melting point, the solubility of oxygen (X 0 /sup b/, -4 ) and its surface segregation coefficient β/sup s/(> 10 3 ). 8 refs., 5 figs., 1 tab

  7. Simulating liquid water for determining its structural and transport properties

    International Nuclear Information System (INIS)

    Arismendi-Arrieta, Daniel; Medina, Juan S.; Fanourgakis, George S.; Prosmiti, Rita; Delgado-Barrio, Gerardo

    2014-01-01

    Molecular dynamics simulations are carried out for calculating structural and transport properties of pure liquid water, such as radial distribution functions and self-diffusion and viscosity coefficients, respectively. We employed reparameterized versions of the ab initio water potential by Niesar, Clementi and Corongiu (NCC). In order to investigate the role of the electrostatic contribution, the partial charges of the NCC model are adjusted so that to reproduce the dipole moment values of the SPC/E, SPC/Fw and TIP4P/2005 water models. The single and collective transport coefficients are obtained by employing the Green–Kubo relations at various temperatures. Additionally, in order to overcome convergence difficulties arising from the long correlation times of the stress-tensor autocorrelation functions, a previously reported fitting scheme was employed. The present results indicate that there is a significant relationship between the dipole moment value of the model, and the calculated transport coefficients. We found that by adjusting the molecular dipole moment of the NCC to the value of the TIP4P/2005, the obtained values for the self-diffusion and viscosity coefficients are in better agreement with experiment, compared to the values obtained with the original NCC model. Even though the predictions of the present model exhibits an overall correct behavior, we conclude that further improvements are still required. In order to achieve that, a careful reparameterization of the repulsion–dispersion terms of the potential model is proposed. Also, the effect of the inclusion of many-body effects such as polarizability, should also be investigated. - Highlights: ► Transport properties of liquid water are important in bio-simulations. ► Self-diffusion coefficient, shear and bulk viscosities calculations from NVE molecular dynamics simulations. ► Their comparison with experimental data provides information on intermolecular forces, and serve to develop water

  8. Process and apparatus for removing layers of liquids floating on the surface of water

    Energy Technology Data Exchange (ETDEWEB)

    1968-11-12

    This apparatus is towed or pushed by suitable means and collects a suitable thickness of the floating liquid and of water. The 2 liquids are then separated, the purified water is rejected outboard, and the polluting liquid is collected in a reservoir of the apparatus, from which it can easily be pumped and recovered in tanks.

  9. Importance of vegetation, topography and flow paths for water transit times of base flow in alpine headwater catchments

    Directory of Open Access Journals (Sweden)

    M. H. Mueller

    2013-04-01

    Full Text Available The mean transit time (MTT of water in a catchment gives information about storage, flow paths, sources of water and thus also about retention and release of solutes in a catchment. To our knowledge there are only a few catchment studies on the influence of vegetation cover changes on base flow MTTs. The main changes in vegetation cover in the Swiss Alps are massive shrub encroachment and forest expansion into formerly open habitats. Four small and relatively steep headwater catchments in the Swiss Alps (Ursern Valley were investigated to relate different vegetation cover to water transit times. Time series of water stable isotopes were used to calculate MTTs. The high temporal variation of the stable isotope signals in precipitation was strongly dampened in stream base flow samples. MTTs of the four catchments were 70 to 102 weeks. The strong dampening of the stable isotope input signal as well as stream water geochemistry points to deeper flow paths and mixing of waters of different ages at the catchments' outlets. MTTs were neither related to topographic indices nor vegetation cover. The major part of the quickly infiltrating precipitation likely percolates through fractured and partially karstified deeper rock zones, which increases the control of bedrock flow paths on MTT. Snow accumulation and the timing of its melt play an important role for stable isotope dynamics during spring and early summer. We conclude that, in mountainous headwater catchments with relatively shallow soil layers, the hydrogeological and geochemical patterns (i.e. geochemistry, porosity and hydraulic conductivity of rocks and snow dynamics influence storage, mixing and release of water in a stronger way than vegetation cover or topography do.

  10. Gastric emptying of liquids in rats dehydrated by water deprivation

    Directory of Open Access Journals (Sweden)

    Baracat E.C.E.

    1997-01-01

    Full Text Available The gastric emptying of liquids was investigated in male Wistar rats (8 to 10 weeks old, 210-300 g dehydrated by water deprivation. In this model of dehydration, weight loss, hematocrit and plasma density were significantly higher in the dehydrated animals than in the control groups after 48 and 72 h of water deprivation (P<0.05. Three test meals (saline (N = 10, water (N = 10 and a WHO rehydrating solution containing in one liter 90 mEq sodium, 20 mEq potassium, 80 mEq chloride and 30 mEq citrate (N = 10 were used to study gastric emptying following water deprivation for 24, 48 and 72 h. After 72 h, gastric emptying of the water (39.4% retention and rehydrating solution (49.2% retention test meals was significantly retarded compared to the corresponding control groups (P<0.05, Mann-Whitney test. The 72-h period of deprivation was used to study the recovery from dehydration, and water was supplied for 60 or 120 min after 67 h of deprivation. Body weight loss, hematocrit and plasma density tended to return to normal when water was offered for 120 min. In the animals supplied with water for 60 min, there was a recovery in the gastric emptying of water while the gastric emptying of the rehydrating solution was still retarded (53.1% retention; P<0.02, Kruskal-Wallis test. In the group supplied with water for 120 min, the gastric emptying of the rehydrating (51.7% retention and gluco-saline (46.0% retention solutions tended to be retarded (P = 0.04, Kruskal-Wallis test. In this model of dehydration caused by water deprivation, with little alteration in the body electrolyte content, gastric emptying of the rehydrating solution was retarded after rehydration with water. We conclude that the mechanisms whereby receptors in the duodenal mucosa can modify gastric motility are altered during dehydration caused by water deprivation

  11. Cervical histology after routine ThinPrep or SurePath liquid-based cytology and computer-assisted reading in Denmark

    DEFF Research Database (Denmark)

    Rebolj, Matejka; Rask, Johanne; van Ballegooijen, Marjolein

    2015-01-01

    nationwide registers, technological phases were identified by slide preparation, reading technique, and triage of borderline cytology. Trends in the detection of cervical intraepithelial neoplasia (CIN) were an indicator of the technology's relative sensitivity, and trends in false-positive tests......BACKGROUND: We compared the sensitivity and specificity of liquid-based cytology (LBC) and computer-assisted reading for SurePath/FocalPoint and ThinPrep with those of manually read conventional cytology in routine cervical screening in four Danish laboratories. METHODS: Using data from five...

  12. Long-Term Stability of Human Genomic and Human Papillomavirus DNA Stored in BD SurePath and Hologic PreservCyt Liquid-Based Cytology Media

    Science.gov (United States)

    Agreda, Patricia M.; Beitman, Gerard H.; Gutierrez, Erin C.; Harris, James M.; Koch, Kristopher R.; LaViers, William D.; Leitch, Sharon V.; Maus, Courtney E.; McMillian, Ray A.; Nussbaumer, William A.; Palmer, Marcus L. R.; Porter, Michael J.; Richart, Gregory A.; Schwab, Ryan J.

    2013-01-01

    We evaluated the effect of storage at 2 to 8°C on the stability of human genomic and human papillomavirus (HPV) DNA stored in BD SurePath and Hologic PreservCyt liquid-based cytology media. DNA retained the ability to be extracted and PCR amplified for more than 2.5 years in both medium types. Prior inability to detect DNA in archived specimens may have been due to failure of the extraction method to isolate DNA from fixed cells. PMID:23678069

  13. In Situ Raman Study of Liquid Water at High Pressure.

    Science.gov (United States)

    Romanenko, Alexandr V; Rashchenko, Sergey V; Goryainov, Sergey V; Likhacheva, Anna Yu; Korsakov, Andrey V

    2018-06-01

    A pressure shift of Raman band of liquid water (H 2 O) may be an important tool for measuring residual pressures in mineral inclusions, in situ barometry in high-pressure cells, and as an indicator of pressure-induced structural transitions in H 2 O. However, there was no consensus as to how the broad and asymmetric water Raman band should be quantitatively described, which has led to fundamental inconsistencies between reported data. In order to overcome this issue, we measured Raman spectra of H 2 O in situ up to 1.2 GPa using a diamond anvil cell, and use them to test different approaches proposed for the description of the water Raman band. We found that the most physically meaningful description of water Raman band is the decomposition into a linear background and three Gaussian components, associated with differently H-bonded H 2 O molecules. Two of these components demonstrate a pronounced anomaly in pressure shift near 0.4 GPa, supporting ideas of structural transition in H 2 O at this pressure. The most convenient approach for pressure calibration is the use of "a linear background + one Gaussian" decomposition (the pressure can be measured using the formula P (GPa) = -0.0317(3)·Δν G (cm -1 ), where Δν G represents the difference between the position of water Raman band, fitted as a single Gaussian, in measured spectrum and spectrum at ambient pressure).

  14. Rapid determination of octanol-water partition coefficient using vortex-assisted liquid-liquid microextraction.

    Science.gov (United States)

    Román, Iván P; Mastromichali, Anna; Tyrovola, Konstantina; Canals, Antonio; Psillakis, Elefteria

    2014-02-21

    Vortex-assisted liquid-liquid microextraction (VALLME) coupled with high-performance liquid chromatography (HPLC) is proposed here for the rapid determination of octanol-water partitioning coefficients (Kow). VALLME uses vortex agitation, a mild emulsification procedure, to disperse microvolumes of octanol in the aqueous phase thus increasing the interfacial contact area and ensuring faster partitioning rates. With VALLME, 2min were enough to achieve equilibrium conditions between the octanolic and aqueous phases. Upon equilibration, separation was achieved using centrifugation and the octanolic microdrop was collected and analyzed in a HPLC system. Six model compounds with logKow values ranging between ∼0.5 and 3.5 were used during the present investigations. The proposed method produced logKow values that were consistent with previously published values and the recorded uncertainty was well within the acceptable log unit range. Overall, the key features of the proposed Kow determination procedure comprised speed, reliability, simplicity, low cost and minimal solvent consumption. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Disintegration of liquid metals by low pressure water blasting

    International Nuclear Information System (INIS)

    Heshmatpour, B.; Copeland, G.L.

    1981-01-01

    The feasibility of disintegrating metals by a low cost system and subsequently incorporating them into grout mixtures has been demonstrated. A low pressure water blasting technique consisting of multiple nozzles and a converging-line jet stream was developed to disintegrate liquid metals and produce coarse metal powder and shot. Molten iron resulted in spherical shot, while copper, aluminum, and tin produced irregular shaped particles. The particle size was between 0.05 and 3 mm (0.002 and 0.1 in.), and about half the particles were smaller than 1 mm (0.04 in.) in all cases. The water consumption was rather low, while the production rate was relatively high. The method proved to be simple and reliable. The coarse metal powders were suspendable in grout fluids, indicating that they are probably disposable by the shale hydrofracture technique

  16. Assessing modelled spatial distributions of ice water path using satellite data

    Science.gov (United States)

    Eliasson, S.; Buehler, S. A.; Milz, M.; Eriksson, P.; John, V. O.

    2010-05-01

    The climate models used in the IPCC AR4 show large differences in monthly mean cloud ice. The most valuable source of information that can be used to potentially constrain the models is global satellite data. For this, the data sets must be long enough to capture the inter-annual variability of Ice Water Path (IWP). PATMOS-x was used together with ISCCP for the annual cycle evaluation in Fig. 7 while ECHAM-5 was used for the correlation with other models in Table 3. A clear distinction between ice categories in satellite retrievals, as desired from a model point of view, is currently impossible. However, long-term satellite data sets may still be used to indicate the climatology of IWP spatial distribution. We evaluated satellite data sets from CloudSat, PATMOS-x, ISCCP, MODIS and MSPPS in terms of monthly mean IWP, to determine which data sets can be used to evaluate the climate models. IWP data from CloudSat cloud profiling radar provides the most advanced data set on clouds. As CloudSat data are too short to evaluate the model data directly, it was mainly used here to evaluate IWP from the other satellite data sets. ISCCP and MSPPS were shown to have comparatively low IWP values. ISCCP shows particularly low values in the tropics, while MSPPS has particularly low values outside the tropics. MODIS and PATMOS-x were in closest agreement with CloudSat in terms of magnitude and spatial distribution, with MODIS being the best of the two. As PATMOS-x extends over more than 25 years and is in fairly close agreement with CloudSat, it was chosen as the reference data set for the model evaluation. In general there are large discrepancies between the individual climate models, and all of the models show problems in reproducing the observed spatial distribution of cloud-ice. Comparisons consistently showed that ECHAM-5 is the GCM from IPCC AR4 closest to satellite observations.

  17. Distribution of binding energies of a water molecule in the water liquid-vapor interface

    Energy Technology Data Exchange (ETDEWEB)

    Chempath, Shaji [Los Alamos National Laboratory; Pratt, Lawrence R [TULANE UNIV

    2008-01-01

    Distributions of binding energies of a water molecule in the water liquid-vapor interface are obtained on the basis of molecular simulation with the SPC/E model of water. These binding energies together with the observed interfacial density profile are used to test a minimally conditioned Gaussian quasi-chemical statistical thermodynamic theory. Binding energy distributions for water molecules in that interfacial region clearly exhibit a composite structure. A minimally conditioned Gaussian quasi-chemical model that is accurate for the free energy of bulk liquid water breaks down for water molecules in the liquid-vapor interfacial region. This breakdown is associated with the fact that this minimally conditioned Gaussian model would be inaccurate for the statistical thermodynamics of a dilute gas. Aggressive conditioning greatly improves the performance of that Gaussian quasi-chemical model. The analogy between the Gaussian quasi-chemical model and dielectric models of hydration free energies suggests that naive dielectric models without the conditioning features of quasi-chemical theory will be unreliable for these interfacial problems. Multi-Gaussian models that address the composite nature of the binding energy distributions observed in the interfacial region might provide a mechanism for correcting dielectric models for practical applications.

  18. Water-soluble, triflate-based, pyrrolidinium ionic liquids

    International Nuclear Information System (INIS)

    Moreno, M.; Montanino, M.; Carewska, M.; Appetecchi, G.B.; Jeremias, S.; Passerini, S.

    2013-01-01

    Highlights: • Water-soluble, pyrrolidinium triflate ILs as solvents for extraction processes. • Electrolyte components for high safety, electrochemical devices. • Effect of the oxygen atom in the alkyl main side chain of pyrrolidinium cation. -- Abstract: The physicochemical and electrochemical properties of the water-soluble, N-methoxyethyl-N-methylpyrrolidinium trifluoromethanesulfonate (PYR 1(2O1) OSO 2 CF 3 ) ionic liquid (IL) were investigated and compared with those of commercial N-butyl-N-methylpyrrolidinium trifluoromethanesulfonate (PYR 14 OSO 2 CF 3 ). The results have shown that the transport properties are well correlated with the rheological and thermal behavior. The incorporation of an oxygen atom in the pyrrolidinium cation aliphatic side chain resulted in enhanced flexibility of the ether side chain, this supporting for the higher ionic conductivity, self-diffusion coefficient and density of PYR 1(2O1) OSO 2 CF 3 with respect to PYR 14 OSO 2 CF 3 , whereas no relevant effect on the crystallization of the ionic liquid was found. Finally, the presence of the ether side chain material in the pyrrolidinium cation led to a reduction in electrochemical stability, particularly on the cathodic verse

  19. Thermodynamic mechanism of density anomaly of liquid water

    Directory of Open Access Journals (Sweden)

    Makoto eYasutomi

    2015-03-01

    Full Text Available Although density anomaly of liquid water has long been studied by many different authors up to now, it is not still cleared what thermodynamic mechanism induces the anomaly. The thermodynamic properties of substances are determined by interparticle interactions. We analyze what characteristics of pair potential cause the density anomaly on the basis of statistical mechanics and thermodynamics using a thermodynamically self-consistent Ornstein-Zernike approximation (SCOZA. We consider a fluid of spherical particles with a pair potential given by a hard-core repulsion plus a soft-repulsion and an attraction. We show that the density anomaly occurs when the value of the soft-repulsive potential at hard-core contact is in some proper range, and the range depends on the attraction. Further, we show that the behavior of the excess internal energy plays an essential role in the density anomaly and the behavior is mainly determined by the values of the soft-repulsive potential, especially near the hard core contact. Our results show that most of ideas put forward up to now are not the direct causes of the density anomaly of liquid water.

  20. Column carbon dioxide and water vapor measurements by an airborne triple-pulse integrated path differential absorption lidar: novel lidar technologies and techniques with path to space

    Science.gov (United States)

    Singh, U. N.; Petros, M.; Refaat, T. F.; Yu, J.; Ismail, S.

    2017-09-01

    The 2-micron wavelength region is suitable for atmospheric carbon dioxide (CO2) measurements due to the existence of distinct absorption features for the gas at this wavelength region [1]. For more than 20 years, researchers at NASA Langley Research Center (LaRC) have developed several high-energy and high repetition rate 2-micron pulsed lasers [2]. Currently, LaRC team is engaged in designing, developing and demonstrating a triple-pulsed 2-micron direct detection Integrated Path Differential Absorption (IPDA) lidar to measure the weighted-average column dry-air mixing ratios of carbon dioxide (XCO2) and water vapor (XH2O) from an airborne platform [1, 3-5]. This novel technique allows measurement of the two most dominant greenhouse gases, simultaneously and independently, using a single instrument. This paper will provide status and details of the development of this airborne 2-micron triple-pulse IPDA lidar. The presented work will focus on the advancement of critical IPDA lidar components. Updates on the state-of-the-art triple-pulse laser transmitter will be presented including the status of seed laser locking, wavelength control, receiver and detector upgrades, laser packaging and lidar integration. Future plans for IPDA lidar ground integration, testing and flight validation will also be discussed. This work enables new Earth observation measurements, while reducing risk, cost, size, volume, mass and development time of required instruments.

  1. RIMAPS characterization of a surface in the variable aperture fracture model and determination of the main paths for water flow

    International Nuclear Information System (INIS)

    Fuentes, Nestor O.

    2003-01-01

    To understand the real incidence of fracture geometry in the unsteady behavior of flowing water channels, the RIMAPS (Rotated Image with Maximum Average Power Spectrum) technique is used to determine the main directions of these channels. This new characterization technique works on digitized images obtained from the surfaces under study. The present work presents the results of a comparison between the flow directions predicted by RIMAPS and the real channels directions observed in a laboratory experiment. A perfect accordance was verified between the directions obtained in both cases. It can be concluded from these results that geometrical characteristics of a fracture surface determine the main path directions for water flow. (author)

  2. The structure of liquid water; La structure de l'eau liquide

    Energy Technology Data Exchange (ETDEWEB)

    Marin, B [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-07-01

    We have tried to expose a bibliography so complete as possible on structure of liquid water. One synthesis of the different models of water structure is presently impossible, so, we have exposed the main properties of water. We have pointed out the new hypotheses on the electronic structure of water molecule and on the theory of hydrogen bond. After that, we have put together the studies of structure by spectroscopy and given the main deductions of some workers on this subject. We have also exposed the characteristics of processes: relaxation and dielectric constant, influence of temperature on structure. At last, we have considered briefly the partition and thermodynamic functions established from the various models proposed. (author) [French] Nous nous sommes proposes d'ecrire une bibliographie aussi complete que possible sur la structure de l'eau liquide. Apres avoir rappele les differentes tentatives d'etablissement de modele de structure, et s'etre rendu compte qu'une synthese s'averait impossible, il nous est apparu souhaitable d'exposer les principales proprietes de l'eau. C'est ainsi que nous avons donne les hypotheses les plus recentes sur la structure electronique de la molecule d'eau ainsi que celles concernant la theorie de la liaison hydrogene. Puis nous avons rassemble les etudes de structure par spectroscopie et fourni les deductions auxquelles les divers auteurs sont arrives. Nous avons egalement expose les caracteristiques des processus tels que: relaxation et constante dielectrique, l'influence de la temperature sur la structure et enfin nous avons donne brievement les fonctions de partition et les grandeurs thermodynamiques etablies a partir des divers modeles proposes. (auteur)

  3. (Liquid + liquid) phase equilibrium and critical behavior of binary solution {heavy water + 2,6-dimethylpyridine}

    International Nuclear Information System (INIS)

    Xu, Chen; Chai, Shouning; Yin, Tianxiang; Chen, Zhiyun; Shen, Weiguo

    2015-01-01

    Highlights: • Coexistence curves, heat capacities and turbidities were measured. • Deuterium effect on coexistence curves was discussed. • Universal critical amplitude ratios were tested. • Asymmetry of coexistence curves was analyzed by the complete scaling theory. - Abstract: The (liquid + liquid) coexistence curves, the isobaric heat capacities per unit volume and the turbidities for the binary solution of {heavy water + 2,6-dimethylpyridine} have been precisely measured. The values of the critical exponents were obtained, which confirmed the 3D-Ising universality. It was found that the critical temperature dropped by 5.9 K and the critical amplitude of the coexistence curve significantly increased as compared to the binary solution of {water + 2,6-dimethylpyridine}. The complete scaling theory was applied to well describe the asymmetric behavior of the diameter of the coexistence curve as the heat capacity contribution was considered. Moreover, the values of the critical amplitudes of the correlation length and the osmotic compressibility were deduced, which together with the critical amplitudes of the coexistence curve and the heat capacity to test universal amplitude ratios

  4. Layering of confined water between two graphene sheets and its liquid–liquid transition

    International Nuclear Information System (INIS)

    Zhou Xuyan; Duan Yunrui; Wang Long; Liu Sida; Li Tao; Li Yifan; Li Hui

    2017-01-01

    Molecular dynamics (MD) simulations are performed to explore the layering structure and liquid–liquid transition of liquid water confined between two graphene sheets with a varied distance at different pressures. Both the size of nanoslit and pressure could cause the layering and liquid–liquid transition of the confined water. With increase of pressure and the nanoslit’s size, the confined water could have a more obvious layering. In addition, the neighboring water molecules firstly form chain structure, then will transform into square structure, and finally become triangle with increase of pressure. These results throw light on layering and liquid–liquid transition of water confined between two graphene sheets. (paper)

  5. Graphene oxide-based efficient and scalable solar desalination under one sun with a confined 2D water path.

    Science.gov (United States)

    Li, Xiuqiang; Xu, Weichao; Tang, Mingyao; Zhou, Lin; Zhu, Bin; Zhu, Shining; Zhu, Jia

    2016-12-06

    Because it is able to produce desalinated water directly using solar energy with minimum carbon footprint, solar steam generation and desalination is considered one of the most important technologies to address the increasingly pressing global water scarcity. Despite tremendous progress in the past few years, efficient solar steam generation and desalination can only be achieved for rather limited water quantity with the assistance of concentrators and thermal insulation, not feasible for large-scale applications. The fundamental paradox is that the conventional design of direct absorber-bulk water contact ensures efficient energy transfer and water supply but also has intrinsic thermal loss through bulk water. Here, enabled by a confined 2D water path, we report an efficient (80% under one-sun illumination) and effective (four orders salinity decrement) solar desalination device. More strikingly, because of minimized heat loss, high efficiency of solar desalination is independent of the water quantity and can be maintained without thermal insulation of the container. A foldable graphene oxide film, fabricated by a scalable process, serves as efficient solar absorbers (>94%), vapor channels, and thermal insulators. With unique structure designs fabricated by scalable processes and high and stable efficiency achieved under normal solar illumination independent of water quantity without any supporting systems, our device represents a concrete step for solar desalination to emerge as a complementary portable and personalized clean water solution.

  6. GEOSTAR-II: A Prototype Water Vapor Imager/Sounder for the Path Mission

    Science.gov (United States)

    Gaier, Todd; Lambrigtsen, Bjorn; Kangaslahti, Pekka; Lim, Boon; Tanner, Alan; Harding, Dennis; Owen, Heather; Soria, Mary; ODwyer, Ian; Ruf, Christopher; hide

    2011-01-01

    We describe the development and progress of the GeoSTAR-II risk reduction activity for the NASA Earth Science Decadal Survey PATH Mission. The activity directly addresses areas of technical risk including the system design, low noise receiver production, sub-array development, signal distribution and digital signal processing.

  7. Effects of transient water mass redistribution associated with a tsunami wave on Earth’s pole path

    Directory of Open Access Journals (Sweden)

    G. Soldati

    2007-06-01

    Full Text Available We have quantified the effects of a water mass redistribution associated with the propagation of a tsunami wave on the Earth’s pole path and on the Length-Of-Day (LOD and applied our modeling results to the tsunami following the 2004 giant Sumatra earthquake. We compared the result of our simulations on the instantaneous rotational axis variations with the preliminary instrumental evidence on the pole path perturbation (which has not been confirmed registered just after the occurrence of the earthquake. The detected perturbation in the pole path showed a step-like discontinuity that cannot be attributed to the effect of a seismic dislocation. Our results show that the tsunami induced instantaneous rotational pole perturbation is indeed characterized by a step-like discontinuity compatible with the observations but its magnitude is almost one hundred times smaller than the detected one. The LOD variation induced by the water mass redistribution turns out to be not significant because the total effect is smaller than current measurements uncertainties.

  8. Relative humidity effects on water vapour fluxes measured with closed-path eddy-covariance systems with short sampling lines

    DEFF Research Database (Denmark)

    Fratini, Gerardo; Ibrom, Andreas; Arriga, Nicola

    2012-01-01

    It has been formerly recognised that increasing relative humidity in the sampling line of closed-path eddy-covariance systems leads to increasing attenuation of water vapour turbulent fluctuations, resulting in strong latent heat flux losses. This occurrence has been analyzed for very long (50 m...... from eddy-covariance systems featuring short (4 m) and very short (1 m) sampling lines running at the same clover field and show that relative humidity effects persist also for these setups, and should not be neglected. Starting from the work of Ibrom and co-workers, we propose a mixed method...... and correction method proposed here is deemed applicable to closed-path systems featuring a broad range of sampling lines, and indeed applicable also to passive gases as a special case. The methods described in this paper are incorporated, as processing options, in the free and open-source eddy...

  9. The Relationship Between Dynamics and Structure in the Far Infrared Absorption Spectrum of Liquid Water

    Energy Technology Data Exchange (ETDEWEB)

    Woods, K.

    2005-01-14

    Using an intense source of far-infrared radiation, the absorption spectrum of liquid water is measured at a temperature ranging from 269 to 323 K. In the infrared spectrum we observe modes that are related to the local structure of liquid water. Here we present a FIR measured spectrum that is sensitive to the low frequency (< 100cm{sup -1}) microscopic details that exist in liquid water.

  10. The modelled liquid water balance of the Greenland Ice Sheet

    Science.gov (United States)

    Steger, Christian R.; Reijmer, Carleen H.; van den Broeke, Michiel R.

    2017-11-01

    Recent studies indicate that the surface mass balance will dominate the Greenland Ice Sheet's (GrIS) contribution to 21st century sea level rise. Consequently, it is crucial to understand the liquid water balance (LWB) of the ice sheet and its response to increasing surface melt. We therefore analyse a firn simulation conducted with the SNOWPACK model for the GrIS and over the period 1960-2014 with a special focus on the LWB and refreezing. Evaluations of the simulated refreezing climate with GRACE and firn temperature observations indicate a good model-observation agreement. Results of the LWB analysis reveal a spatially uniform increase in surface melt (0.16 m w.e. a-1) during 1990-2014. As a response, refreezing and run-off also indicate positive changes during this period (0.05 and 0.11 m w.e. a-1, respectively), where refreezing increases at only half the rate of run-off, implying that the majority of the additional liquid input runs off the ice sheet. This pattern of refreeze and run-off is spatially variable. For instance, in the south-eastern part of the GrIS, most of the additional liquid input is buffered in the firn layer due to relatively high snowfall rates. Modelled increase in refreezing leads to a decrease in firn air content and to a substantial increase in near-surface firn temperature. On the western side of the ice sheet, modelled firn temperature increases are highest in the lower accumulation zone and are primarily caused by the exceptional melt season of 2012. On the eastern side, simulated firn temperature increases are more gradual and are associated with the migration of firn aquifers to higher elevations.

  11. Radial dose distribution from carbon ion incident on liquid water

    International Nuclear Information System (INIS)

    Scifoni, E.; Surdutovich, E.; Solov'yov, A.V.; Surdutovich, E.

    2010-01-01

    We report calculations of the radial dose deposited along carbon-ion tracks in liquid water using different techniques depending on the energy range of secondary electrons. The models are developed in relation with the experimental data on electron penetration lengths. For electrons with energies higher than 45 eV, we use the Katz model. However, the main focus is on the low-energy electrons, which are largely responsible for DNA damage within 10 nm from the tracks. For these electrons, the dose calculation is based on their random walk behaviour. The results of this combined approach are compared to experimental measurements. Contributions to the deposited energy by electrons of different ranges of energy are discussed. (authors)

  12. Electrokinetic Hydrogen Generation from Liquid WaterMicrojets

    Energy Technology Data Exchange (ETDEWEB)

    Duffin, Andrew M.; Saykally, Richard J.

    2007-05-31

    We describe a method for generating molecular hydrogen directly from the charge separation effected via rapid flow of liquid water through a metal orifice, wherein the input energy is the hydrostatic pressure times the volume flow rate. Both electrokinetic currents and hydrogen production rates are shown to follow simple equations derived from the overlap of the fluid velocity gradient and the anisotropic charge distribution resulting from selective adsorption of hydroxide ions to the nozzle surface. Pressure-driven fluid flow shears away the charge balancing hydronium ions from the diffuse double layer and carries them out of the aperture. Downstream neutralization of the excess protons at a grounded target electrode produces gaseous hydrogen molecules. The hydrogen production efficiency is currently very low (ca. 10-6) for a single cylindrical jet, but can be improved with design changes.

  13. Cloud Liquid Water, Mean Droplet Radius and Number Density Measurements Using a Raman Lidar

    Science.gov (United States)

    Whiteman, David N.; Melfi, S. Harvey

    1999-01-01

    A new technique for measuring cloud liquid water, mean droplet radius and droplet number density is outlined. The technique is based on simultaneously measuring Raman and Mie scattering from cloud liquid droplets using a Raman lidar. Laboratory experiments on liquid micro-spheres have shown that the intensity of Raman scattering is proportional to the amount of liquid present in the spheres. This fact is used as a constraint on calculated Mie intensity assuming a gamma function particle size distribution. The resulting retrieval technique is shown to give stable solutions with no false minima. It is tested using Raman lidar data where the liquid water signal was seen as an enhancement to the water vapor signal. The general relationship of retrieved average radius and number density is consistent with traditional cloud physics models. Sensitivity to the assumed maximum cloud liquid water amount and the water vapor mixing ratio calibration are tested. Improvements to the technique are suggested.

  14. High-frequency dynamics of liquid and supercritical water

    International Nuclear Information System (INIS)

    Bencivenga, F.; Cunsolo, A.; Krisch, M.; Monaco, G.; Sette, F.; Ruocco, G.

    2007-01-01

    The dynamic structure factor S(Q,ω) of water has been determined by high-resolution inelastic x-ray scattering (IXS) in a momentum (Q) and energy (E) transfer range extending from 2 to 4 nm -1 and from ±40 meV. IXS spectra have been recorded along an isobaric path (400 bar) in a temperature (T) interval ranging from ambient up to supercritical (T>647 K) conditions. The experimental data have been described in the frame of the generalized hydrodynamic theory, utilizing a model based on the memory function approach. This model allows identifying the active relaxation processes which affect the time decay of density fluctuations, as well as a direct determination of the Q, T, and density (ρ) dependencies of the involved transport parameters. The experimental spectra are well described by considering three different relaxation processes: the thermal, the structural, and the instantaneous one. On approaching supercritical conditions, we observe that the microscopic mechanism responsible for the structural relaxation is no longer related to the making and breaking of intermolecular bonds, but to binary intermolecular collisions

  15. The effect of water chemistry on a change in the composition of gas phase in the steam-water path of a supercritical-pressure boiler

    Science.gov (United States)

    Belyakov, I. I.; Belokonova, A. F.

    2010-07-01

    We present the results from an experimental research work on studying the behavior of the gas phase in the path of a supercritical-pressure boiler during its operation with different water chemistries, including all-volatile (hydrazine-ammonia), complexone, neutral oxygenated, and combined oxygenated-ammonia chemistries. It is shown that the minimal content of hydrogen in steam is achieved if feedwater is treated with oxygen.

  16. Water Flow Performance of a Superscale Model of the Fastrac Liquid Oxygen Pump

    Science.gov (United States)

    Skelley, Stephen; Zoladz, Thomas

    2001-01-01

    As part of the National Aeronautics and Space Administration's ongoing effort to lower the cost of access to space, the Marshall Space Flight Center has developed a rocket engine with 60,000 pounds of thrust for use on the Reusable Launch Vehicle technology demonstrator slated for launch in 2000. This gas generator cycle engine, known as the Fastrac engine, uses liquid oxygen and RP-1 for propellants and includes single stage liquid oxygen and RP-1 pumps and a single stage supersonic turbine on a common shaft. The turbopump design effort included the first use and application of new suction capability prediction codes and three-dimensional blade generation codes in an attempt to reduce the turbomachinery design and certification costs typically associated with rocket engine development. To verify the pump's predicted cavitation performance, a water flow test of a superscale model of the Fastrac liquid oxygen pump was conducted to experimentally evaluate the liquid oxygen pump's performance at and around the design point. The water flow test article replicated the flow path of the Fastrac liquid oxygen pump in a 1.582x scale model, including scaled seal clearances for correct leakage flow at a model operating speed of 5000 revolutions per minute. Flow entered the 3-blade axial-flow inducer, transitioned to a shrouded, 6- blade radial impeller, and discharged into a vaneless radial diffuser and collection volute. The test article included approximately 50 total and static pressure measurement locations as well as flush-mounted, high frequency pressure transducers for complete mapping of the pressure environment. The primary objectives of the water flow test were to measure the steady-state and dynamic pressure environment of the liquid oxygen pump versus flow coefficient, suction specific speed, and back face leakage flow rate. Initial results showed acceptable correlation between the predicted and experimentally measured pump head rise at low suction specific speeds

  17. Supercooled and glassy water: Metastable liquid(s), amorphous solid(s), and a no-man's land

    Science.gov (United States)

    Handle, Philip H.; Loerting, Thomas; Sciortino, Francesco

    2017-12-01

    We review the recent research on supercooled and glassy water, focusing on the possible origins of its complex behavior. We stress the central role played by the strong directionality of the water-water interaction and by the competition between local energy, local entropy, and local density. In this context we discuss the phenomenon of polyamorphism (i.e., the existence of more than one disordered solid state), emphasizing both the role of the preparation protocols and the transformation between the different disordered ices. Finally, we present the ongoing debate on the possibility of linking polyamorphism with a liquid-liquid transition that could take place in the no-man's land, the temperature-pressure window in which homogeneous nucleation prevents the investigation of water in its metastable liquid form.

  18. In situ separation of root hydraulic redistribution of soil water from liquid and vapor transport

    Science.gov (United States)

    Jeffrey M. Warren; J. Renée Brooks; Maria I. Dragila; Frederick C. Meinzer

    2011-01-01

    Nocturnal increases in water potential and water content in the upper soil profile are often attributed to root water efflux, a process termed hydraulic redistribution (HR). However, unsaturated liquid or vapor flux of water between soil layers independent of roots also contributes to the daily recovery in water content, confounding efforts to determine the actual...

  19. Direct current dielectrophoretic manipulation of the ionic liquid droplets in water.

    Science.gov (United States)

    Zhao, Kai; Li, Dongqing

    2018-07-13

    The ionic liquids (ILs) as the environmentally benign solvents show great potentials in microemulsion carrier systems and have been widely used in the biochemical and pharmaceutical fields. In the work, the ionic liquid-in-water microemulsions were fabricated by using two kinds of hydrophobic ionic liquid, 1-Butyl-3-methylimidazolium hexafluorophosphate [Bmim][PF 6 ] and 1-Hexyl-3-methylimidazolium hexafluorophosphate [Hmim][PF 6 ] with Tween 20. The ionic liquid droplets in water experience the dielectrophoretic (DEP) forces induced by applying electrical field via a nano-orifice and a micron orifice on the opposite channel walls of a microchannel. The dielectrophoretic behaviors of the ionic liquid-in-water emulsion droplets were investigated under direct current (DC) electric field. The positive and negative DEP behaviors of the ionic liquid-in-water droplets varying with the electrical conductivity of the suspending medium were investigated and two kinds of the ionic liquid droplets of similar sizes were separated by their different DEP behaviors. In addition, the separation of the ionic liquid-in-water droplets by size was conducted. This paper, for the first time to our knowledge, presents the DC-DEP manipulation of the ionic liquid-in-water emulsion droplets by size and by type. This method provides a platform to manipulate the ionic liquid droplets individually. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. E3 Success Story - Path Toward Sustainability Leads to Significant Water Savings: Southwire

    Science.gov (United States)

    Southwire—a manufacturer of wire and cable products— searched for opportunities to reduce its water use and launched a sustainability campaign that established goals to reduce water use by 15 percent and overall carbon footprint by 10 percent.

  1. Spatial correlation of energy deposition events in irradiated liquid water

    International Nuclear Information System (INIS)

    Hamm, R.N.; Wright, H.A.; Turner, J.E.; Ritchie, R.H.

    1978-01-01

    Monte Carlo electron transport computer code is used to study in detail the slowing down of electrons and all of their secondaries with initial energies up to 1.5 MeV in liquid water. The probability distributions for the number of ionizations and for the energy deposited in cubical volume elements from electron tracks in the water are analyzed. Both the electron energies and the sizes of the cubical cells are varied. Results are shown for electron energies between 100 eV and 10 keV and for cell sizes between 40 A and 1500 A. Good general agreement is found with results presented by Paretzke at the last symposium. The code can be used to obtain other basic distributions of importance in microdosimetry. As an example, microdosimetric single-event spectra for 500-eV electrons are computed in cubes with edges that range in size from 40 A to 200 A. The importance of correlations is shown explicitly in a comparison of secondary electrons produced by 60 Co and 50-keV photons

  2. Self Assembly of Ionic Liquids at the Air/Water Interface

    Czech Academy of Sciences Publication Activity Database

    Minofar, Babak

    2015-01-01

    Roč. 3, aug (2015), s. 27-40 ISSN 2245-4551 Institutional support: RVO:67179843 Keywords : Ionic liquids * air/water interface * self assembly * ion-water interaction * ion-ion interaction Subject RIV: CE - Biochemistry

  3. Investigation of the Extinguishing Features for Liquid Fuels and Organic Flammable Liquids Atomized by a Water Flow

    Directory of Open Access Journals (Sweden)

    Voytkov Ivan V.

    2016-01-01

    Full Text Available The processes of heat and mass transfer were investigated experimentally while moving and evaporating the atomized water flow in high-temperature combustion products of typical liquid fuels and organic flammable liquids: gasoline, kerosene, acetone, crude oil, industrial alcohol. We determined typical periods of liquid extinguishing by an atomized water flow of various dispersability. Data of the discharge of extinguishing medium corresponding to various parameters of atomization and duration of using the atomization devices was presented. It is shown that Um≈3.5 m/s is a minimal outflow velocity of droplets during moving while passing the distance of 1m in the high-temperature gas medium to stop the combustion of organic liquids.

  4. Ionic Liquid Dispersive Liquid-Liquid Microextraction Method for the Determination of Irinotecan, an Anticancer Drug, in Water and Urine Samples Using UV-Vis Spectrophotometry.

    Science.gov (United States)

    Uysal, Deniz; Karadaş, Cennet; Kara, Derya

    2017-05-01

    A new, simple, efficient, and environmentally friendly ionic liquid dispersive liquid-liquid microextraction method was developed for the determination of irinotecan, an anticancer drug, in water and urine samples using UV-Vis spectrophotometry. The ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate was used as the extraction solvent, and ethanol was used as the disperser solvent. The main parameters affecting the extraction efficiency, including sample pH, volume of the ionic liquid, choice of the dispersive solvent and its volume, concentration of NaCl, and extraction and centrifugation times, were investigated and optimized. The effect of interfering species on the recovery of irinotecan was also examined. Under optimal conditions, the LOD (3σ) was 48.7 μg/L without any preconcentration. Because the urine sample was diluted 10-fold, the LOD for urine would be 487 μg/L. However, this could be improved 16-fold if preconcentration using a 40 mL aliquot of the sample is used. The proposed method was successfully applied to the determination of irinotecan in tap water, river water, and urine samples spiked with 10.20 mg/L for the water samples and 8.32 mg/L for the urine sample. The average recovery values of irinotecan determined were 99.1% for tap water, 109.4% for river water, and 96.1% for urine.

  5. Quaternary isobaric (vapor + liquid + liquid) equilibrium and (vapor + liquid) equilibrium for the system (water + ethanol + cyclohexane + heptane) at 101.3 kPa

    International Nuclear Information System (INIS)

    Pequenin, Ana; Asensi, Juan Carlos; Gomis, Vicente

    2011-01-01

    Highlights: → Water-ethanol-cyclohexane-heptane and water-cyclohexane-heptane isobaric VLLE. → Isobaric experimental data were determined at 101.3 kPa. → A dynamic recirculating still with an ultrasonic homogenizer was used. → The quaternary system does not present quaternary azeotropes. - Abstract: Experimental isobaric (vapor + liquid + liquid) and (vapor + liquid) equilibrium data for the ternary system {water (1) + cyclohexane (2) + heptane (3)} and the quaternary system {water (1) + ethanol (2) + cyclohexane (3) + heptane (4)} were measured at 101.3 kPa. An all-glass, dynamic recirculating still equipped with an ultrasonic homogenizer was used to determine the VLLE. The results obtained show that the system does not present quaternary azeotropes. The point-by-point method by Wisniak for testing the thermodynamic consistency of isobaric measurements was used to test the equilibrium data.

  6. Field Measurements of Water Continuum and Water Dimer Absorption by Active Long Path Differential Optical Absorption Spectroscopy (DOAS)

    OpenAIRE

    Lotter, Andreas

    2006-01-01

    Water vapor plays an important role in Earth's radiative budget since water molecules strongly absorb the incoming solar shortwave and the outgoing thermal infrared radiation. Superimposed on the water monomer absorption, a water continuum absorption has long been recognized, but its true nature still remains controversial. On the one hand, this absorption is explained by a deformation of the line shape of the water monomer absorption lines as a consequence of a molecular collision. One the o...

  7. (Liquid + liquid) equilibria of four alcohol–water systems containing 1,8-cineole at T = 298.15 K

    International Nuclear Information System (INIS)

    Li, Hengde; Feng, Zhangni; Wan, Li; Huang, Cheng; Zhang, Tianfei; Fang, Yanxiong

    2016-01-01

    Graphical abstract: (Liquid + liquid) equilibria of C_1–C_4 alcohol–water systems containing 1,8-cineole are presented. Distribution ratios of alcohol in the mixtures are examined. The immiscible region of the LLE systems is evaluated and discussed. - Highlights: • Ternary (liquid + liquid) equilibria containing 1,8-cineole are presented. • Distribution ratios of C_1–C_4 alcohol in the mixtures are examined. • The LLE values were correlated using the NRTL and UNIQUAC models. - Abstract: As an eco-friendly compound from essential oils, 1,8-cineole (cineole, eucalyptol) has the potential to replace the ozone depleting industrial solvents. This paper presents experimental (liquid + liquid) equilibrium (LLE) data for four alcohol–water systems containing 1,8-cineole. To evaluate the phase equilibrium properties of 1,8-cineole in aqueous alcohol mixtures, LLE values for the ternary systems (water + methanol or ethanol or 1-propanol or 1-butanol + 1,8-cineole) were determined with a tie-line method at T = 298.15 K under atmospheric pressure. The well-known Hand, Bachman and Othmer–Tobias equations were used to test the reliability of the experimental results. The binodal curves and distribution ratios of alcohol in the mixtures are shown and discussed. The experimental LLE values were satisfactorily correlated by the NRTL and UNIQUAC models.

  8. Analysis of aromatic amines in water samples by liquid-liquid-liquid microextraction with hollow fibers and high-performance liquid chromatography.

    Science.gov (United States)

    Zhao, Limian; Zhu, Lingyan; Lee, Hian Kee

    2002-07-19

    Liquid-liquid-liquid microextraction (LLLME) with hollow fibers in high-performance liquid chromatography (HPLC) has been applied as a rapid and sensitive quantitative method for the detection of four aromatic amines (3-nitroaniline, 4-chloroaniline, 4-bromoaniline and 3,4-dichloroaniline) in environmental water samples. The preconcentration procedure was induced by the pH difference inside and outside the hollow fiber. The target compounds were extracted from 4-ml aqueous sample (donor solution, pH approximately 13) through a microfilm of organic solvent (di-n-hexyl ether), immobilized in the pores of a hollow fiber (1.5 cm length x 0.6 mm I.D.), and finally into 4 microl of acid acceptor solution inside the fiber. After a prescribed period of time, the acceptor solution inside the fiber was withdrawn into the microsyringe and directly injected into the HPLC system for analysis. Factors relevant to the extraction procedure were studied. Up to 500-fold enrichment of analytes could be obtained under the optimized conditions (donor solution: 0.1 M sodium hydroxide solution with 20% sodium chloride and 2% acetone; organic phase: di-n-hexyl ether; acceptor solution: 0.5 M hydrochloric acid and 500 mM 18-crown-6 ether; extraction time of 30 min; stirring at 1,000 rev./min). The procedure also served as a sample clean-up step. The influence of humic acid on the extraction efficiency was also investigated, and more than 85% relative recoveries of the analytes at two different concentrations (20 and 100 microg/l) were achieved at various concentration of humic acid. This technique is a low cost, simple and fast approach to the analysis of polar compounds in aqueous samples.

  9. Angle-resolved photoemission spectroscopy of liquid water at 29.5 eV.

    Science.gov (United States)

    Nishitani, Junichi; West, Christopher W; Suzuki, Toshinori

    2017-07-01

    Angle-resolved photoemission spectroscopy of liquid water was performed using extreme ultraviolet radiation at 29.5 eV and a time-of-flight photoelectron spectrometer. SiC/Mg coated mirrors were employed to select the single-order 19th harmonic from laser high harmonics, which provided a constant photon flux for different laser polarizations. The instrument was tested by measuring photoemission anisotropy for rare gases and water molecules and applied to a microjet of an aqueous NaI solution. The solute concentration was adjusted to eliminate an electric field gradient around the microjet. The observed photoelectron spectra were analyzed considering contributions from liquid water, water vapor, and an isotropic background. The anisotropy parameters of the valence bands (1 b 1 , 3 a 1 , and 1 b 2 ) of liquid water are considerably smaller than those of gaseous water, which is primarily attributed to electron scattering in liquid water.

  10. Angle-resolved photoemission spectroscopy of liquid water at 29.5 eV

    Directory of Open Access Journals (Sweden)

    Junichi Nishitani

    2017-07-01

    Full Text Available Angle-resolved photoemission spectroscopy of liquid water was performed using extreme ultraviolet radiation at 29.5 eV and a time-of-flight photoelectron spectrometer. SiC/Mg coated mirrors were employed to select the single-order 19th harmonic from laser high harmonics, which provided a constant photon flux for different laser polarizations. The instrument was tested by measuring photoemission anisotropy for rare gases and water molecules and applied to a microjet of an aqueous NaI solution. The solute concentration was adjusted to eliminate an electric field gradient around the microjet. The observed photoelectron spectra were analyzed considering contributions from liquid water, water vapor, and an isotropic background. The anisotropy parameters of the valence bands (1b1, 3a1, and 1b2 of liquid water are considerably smaller than those of gaseous water, which is primarily attributed to electron scattering in liquid water.

  11. Hydrogen isotope separation in hydrophobic catalysts between hydrogen and liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Linsen, E-mail: yls2005@mail.ustc.edu.cn [China Academy of Engineering Physics, Mianyang 621900 (China); Luo, Deli [Science and Technology on Surface Physics and Chemistry Laboratory, Jiangyou 621907 (China); Tang, Tao; Yang, Wan; Yang, Yong [China Academy of Engineering Physics, Mianyang 621900 (China)

    2015-11-15

    Hydrogen isotope catalytic exchange between hydrogen and liquid water is a very effective process for deuterium-depleted potable water production and heavy water detritiation. To improve the characteristics of hydrophobic catalysts for this type of reaction, foamed and cellular structures of hydrophobic carbon-supported platinum catalysts were successfully prepared. Separation of deuterium or tritium from liquid water was carried out by liquid-phase catalytic exchange. At a gas–liquid ratio of 1.53 and exchange temperature of 70 °C, the theoretical plate height of the hydrophobic catalyst (HETP = 34.2 cm) was slightly lower than previously reported values. Changing the concentration of the exchange column outlet water yielded nonlinear changes in the height of the packing layer. Configurations of deuterium-depleted potable water and detritiation of heavy water provide references for practical applications.

  12. Measurements and modeling of quaternary (liquid + liquid) equilibria for mixtures of (methanol or ethanol + water + toluene + n-dodecane)

    International Nuclear Information System (INIS)

    Mohammad Doulabi, F.S.; Mohsen-Nia, M.; Modarress, H.

    2006-01-01

    The extraction of aromatic compound toluene from alkane, dodecane, by mixed solvents (water + methanol) (water + ethanol) and (methanol + ethanol) have been studied by (liquid + liquid) equilibrium (LLE) measurements at three temperatures (298.15, 303.15, and 313.15) K and ambient pressure. The compositions of liquid phases at equilibrium were determined by gas liquid chromatography. The experimental tie-line data for three quaternary mixtures of {(water + methanol) + toluene + dodecane}, {(water + ethanol) + toluene + dodecane}, and {(methanol + ethanol) + toluene + dodecane} are presented. The experimental quaternary LLE data have been satisfactorily correlated by using the UNIQUAC and NRTL activity coefficient models. The parameters of the models have been evaluated and presented. The tie-line data of the studied quaternary mixtures also were correlated using the Hand method. The partition coefficients and the selectivity factor of solvent are calculated and compared for the three mixed solvents. The comparisons indicate that the selectivity factor for mixed solvent (methanol + ethanol) is higher than the other two mixed solvents at the three studied temperatures. However, considering the temperature variations of partition coefficients of toluene in two liquid phases at equilibrium, an optimum temperature may be obtained for an efficient extraction of toluene from dodecane by the mixed solvents

  13. Thermodynamic modeling of ternary and quaternary (liquid + liquid) systems containing water, FeCl3, HCl and diisopropyl ether

    International Nuclear Information System (INIS)

    Milosevic, Miran; Hendriks, Ilse; Smits, Ralph E.R.; Schuur, Boelo; Haan, André B. de

    2013-01-01

    Highlights: • Literature data from various sources was validated experimentally. • Ternary and quaternary (liquid + liquid) systems were successfully described with the NRTL model. • Some deflection at higher HCl concentrations between model and data. • Additional data verification proved correctness of the literature data. -- Abstract: Liquid–liquid extraction using ethers as solvents is a potentially energy saving alternative for the concentration of aqueous ferric chloride solutions. Adequate thermodynamic models that describe the behavior of the resulting quaternary systems (FeCl 3 , ether, acid and water) are not available in the literature. In this paper, the development of an equilibrium description applying the NRTL-model is presented, including experimental validation and fitting of the NRTL-parameters on the validated data. Equilibrium experiments were performed for the ternary systems (water + HCl + DiPE) and (water + FeCl 3 + DiPE) and the obtained data is in good agreement with the results from Maljkovic et al.[37] and Cambell et al.[39]. Experimental data of the quaternary system is taken from Maljkovic et al.[37]. The obtained binary interaction parameters to describe the (liquid + liquid) quaternary system (water + FeCl 3 + HCl + DiPE) and the constituting ternaries by the NRTL model are presented. Model predictions are in good agreement with the experimental data

  14. The influence of Critical Zone structure on runoff paths, seasonal water storage, and ecosystem composition

    Science.gov (United States)

    Hahm, W. J.; Dietrich, W. E.; Rempe, D.; Dralle, D.; Dawson, T. E.; Lovill, S.; Bryk, A.

    2017-12-01

    Understanding how subsurface water storage mediates water availability to ecosystems is crucial for elucidating linkages between water, energy, and carbon cycles from local to global scales. Earth's Critical Zone (the CZ, which extends from the top of the vegetation canopy downward to fresh bedrock) includes fractured and weathered rock layers that store and release water, thereby contributing to ecosystem water supplies, and yet are not typically represented in land-atmosphere models. To investigate CZ structural controls on water storage dynamics, we intensively studied field sites in a Mediterranean climate where winter rains arrive months before peak solar energy availability, resulting in strong summertime ecosystem reliance on stored subsurface water. Intra-hillslope and catchment-wide observations of CZ water storage capacity across a lithologic boundary in the Franciscan Formation of the Northern California Coast Ranges reveal large differences in the thickness of the CZ and water storage capacity that result in a stark contrast in plant community composition and stream behavior. Where the CZ is thick, rock moisture storage supports forest transpiration and slow groundwater release sustains baseflow and salmon populations. Where the CZ is thin, limited water storage is used by an oak savanna ecosystem, and streams run dry in summer due to negligible hillslope drainage. At both sites, wet season precipitation replenishes the dynamic storage deficit generated during the summer dry season, with excess winter rains exiting the watersheds via storm runoff as perched groundwater fracture flow at the thick-CZ site and saturation overland flow at the thin-CZ site. Annual replenishment of subsurface water storage even in severe drought years may lead to ecosystem resilience to climatic perturbations: during the 2011-2015 drought there was not widespread forest die-off in the study area.

  15. Radiation in fog: quantification of the impact on fog liquid water based on ground-based remote sensing

    Science.gov (United States)

    Wærsted, Eivind G.; Haeffelin, Martial; Dupont, Jean-Charles; Delanoë, Julien; Dubuisson, Philippe

    2017-09-01

    Radiative cooling and heating impact the liquid water balance of fog and therefore play an important role in determining their persistence or dissipation. We demonstrate that a quantitative analysis of the radiation-driven condensation and evaporation is possible in real time using ground-based remote sensing observations (cloud radar, ceilometer, microwave radiometer). Seven continental fog events in midlatitude winter are studied, and the radiative processes are further explored through sensitivity studies. The longwave (LW) radiative cooling of the fog is able to produce 40-70 g m-2 h-1 of liquid water by condensation when the fog liquid water path exceeds 30 g m-2 and there are no clouds above the fog, which corresponds to renewing the fog water in 0.5-2 h. The variability is related to fog temperature and atmospheric humidity, with warmer fog below a drier atmosphere producing more liquid water. The appearance of a cloud layer above the fog strongly reduces the LW cooling relative to a situation with no cloud above; the effect is strongest for a low cloud, when the reduction can reach 100 %. Consequently, the appearance of clouds above will perturb the liquid water balance in the fog and may therefore induce fog dissipation. Shortwave (SW) radiative heating by absorption by fog droplets is smaller than the LW cooling, but it can contribute significantly, inducing 10-15 g m-2 h-1 of evaporation in thick fog at (winter) midday. The absorption of SW radiation by unactivated aerosols inside the fog is likely less than 30 % of the SW absorption by the water droplets, in most cases. However, the aerosols may contribute more significantly if the air mass contains a high concentration of absorbing aerosols. The absorbed radiation at the surface can reach 40-120 W m-2 during the daytime depending on the fog thickness. As in situ measurements indicate that 20-40 % of this energy is transferred to the fog as sensible heat, this surface absorption can contribute

  16. Ternary and quaternary (liquid + liquid) equilibria for (water + ethanol + α-pinene, +β-pinene, or +limonene) and (water + ethanol + α-pinene + limonene) at the temperature 298.15 K

    International Nuclear Information System (INIS)

    Li Hengde; Tamura, Kazuhiro

    2006-01-01

    (Liquid + liquid) equilibria and tie-lines for the ternary (water + ethanol + α-pinene, or β-pinene or limonene) and quaternary (water + ethanol + α-pinene + limonene) mixtures have been measured at T = 298.15 K. The experimental multicomponent (liquid + liquid) equilibrium data have been successfully represented in terms of the modified UNIQUAC model with binary parameters

  17. Path Dependency

    OpenAIRE

    Mark Setterfield

    2015-01-01

    Path dependency is defined, and three different specific concepts of path dependency – cumulative causation, lock in, and hysteresis – are analyzed. The relationships between path dependency and equilibrium, and path dependency and fundamental uncertainty are also discussed. Finally, a typology of dynamical systems is developed to clarify these relationships.

  18. Liquid Water from First Principles: Validation of Different Sampling Approaches

    Energy Technology Data Exchange (ETDEWEB)

    Mundy, C J; Kuo, W; Siepmann, J; McGrath, M J; Vondevondele, J; Sprik, M; Hutter, J; Parrinello, M; Mohamed, F; Krack, M; Chen, B; Klein, M

    2004-05-20

    A series of first principles molecular dynamics and Monte Carlo simulations were carried out for liquid water to assess the validity and reproducibility of different sampling approaches. These simulations include Car-Parrinello molecular dynamics simulations using the program CPMD with different values of the fictitious electron mass in the microcanonical and canonical ensembles, Born-Oppenheimer molecular dynamics using the programs CPMD and CP2K in the microcanonical ensemble, and Metropolis Monte Carlo using CP2K in the canonical ensemble. With the exception of one simulation for 128 water molecules, all other simulations were carried out for systems consisting of 64 molecules. It is found that the structural and thermodynamic properties of these simulations are in excellent agreement with each other as long as adiabatic sampling is maintained in the Car-Parrinello molecular dynamics simulations either by choosing a sufficiently small fictitious mass in the microcanonical ensemble or by Nos{acute e}-Hoover thermostats in the canonical ensemble. Using the Becke-Lee-Yang-Parr exchange and correlation energy functionals and norm-conserving Troullier-Martins or Goedecker-Teter-Hutter pseudopotentials, simulations at a fixed density of 1.0 g/cm{sup 3} and a temperature close to 315 K yield a height of the first peak in the oxygen-oxygen radial distribution function of about 3.0, a classical constant-volume heat capacity of about 70 J K{sup -1} mol{sup -1}, and a self-diffusion constant of about 0.1 Angstroms{sup 2}/ps.

  19. Microwave-assisted liquid-liquid microextraction based on solidification of ionic liquid for the determination of sulfonamides in environmental water samples.

    Science.gov (United States)

    Song, Ying; Wu, Lijie; Lu, Chunmei; Li, Na; Hu, Mingzhu; Wang, Ziming

    2014-12-01

    An easy, quick, and green method, microwave-assisted liquid-liquid microextraction based on solidification of ionic liquid, was first developed and applied to the extraction of sulfonamides in environmental water samples. 1-Ethy-3-methylimidazolium hexafluorophosphate, which is a solid-state ionic liquid at room temperature, was used as extraction solvent in the present method. After microwave irradiation for 90 s, the solid-state ionic liquid was melted into liquid phase and used to finish the extraction of the analytes. The ionic liquid and sample matrix can be separated by freezing and centrifuging. Several experimental parameters, including amount of extraction solvent, microwave power and irradiation time, pH of sample solution, and ionic strength, were investigated and optimized. Under the optimum experimental conditions, good linearity was observed in the range of 2.00-400.00 μg/L with the correlation coefficients ranging from 0.9995 to 0.9999. The limits of detection for sulfathiazole, sulfachlorpyridazine, sulfamethoxazole, and sulfaphenazole were 0.39, 0.33, 0.62, and 0.85 μg/L, respectively. When the present method was applied to the analysis of environmental water samples, the recoveries of the analytes ranged from 75.09 to 115.78% and relative standard deviations were lower than 11.89%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Dissociative ionization of liquid water induced by vibrational overtone excitation

    International Nuclear Information System (INIS)

    Natzle, W.C.

    1983-03-01

    Photochemistry of vibrationally activated ground electronic state liquid water to produce H + and OH - ions has been initiated by pulsed, single-photon excitation of overtone and combination transitions. Transient conductivity measurements were used to determine quantum yields as a function of photon energy, isotopic composition, and temperature. The equilibrium relaxation rate following perturbation by the vibrationally activated reaction was also measured as a function of temperature reaction and isotopic composition. In H 2 O, the quantum yield at 283 +- 1 K varies from 2 x 10 -9 to 4 x 10 -5 for wave numbers between 7605 and 18140 cm -1 . In D 2 O, the dependence of quantum yield on wavelength has the same qualitative shape as for H 2 O, but is shifted to lower quantum yields. The position of a minimum in the quantum yield versus hydrogen mole fraction curve is consistent with a lower quantum yield for excitation of HOD in D 2 O than for excitation of D 2 O. The ionic recombination distance of 5.8 +- 0.5 A is constant within experimental error with temperature in H 2 O and with isotopic composition at 25 +- 1 0 C

  1. Dissociative ionization of liquid water induced by vibrational overtone excitation

    Energy Technology Data Exchange (ETDEWEB)

    Natzle, W.C.

    1983-03-01

    Photochemistry of vibrationally activated ground electronic state liquid water to produce H/sup +/ and OH/sup -/ ions has been initiated by pulsed, single-photon excitation of overtone and combination transitions. Transient conductivity measurements were used to determine quantum yields as a function of photon energy, isotopic composition, and temperature. The equilibrium relaxation rate following perturbation by the vibrationally activated reaction was also measured as a function of temperature reaction and isotopic composition. In H/sub 2/O, the quantum yield at 283 +- 1 K varies from 2 x 10/sup -9/ to 4 x 10/sup -5/ for wave numbers between 7605 and 18140 cm/sup -1/. In D/sub 2/O, the dependence of quantum yield on wavelength has the same qualitative shape as for H/sub 2/O, but is shifted to lower quantum yields. The position of a minimum in the quantum yield versus hydrogen mole fraction curve is consistent with a lower quantum yield for excitation of HOD in D/sub 2/O than for excitation of D/sub 2/O. The ionic recombination distance of 5.8 +- 0.5 A is constant within experimental error with temperature in H/sub 2/O and with isotopic composition at 25 +- 1/sup 0/C.

  2. Looking for the rainbow on exoplanets covered by liquid and icy water clouds

    NARCIS (Netherlands)

    Karalidi, T.; Stam, D.M.; Hovenier, J.W.

    2012-01-01

    Aims. Looking for the primary rainbow in starlight that is reflected by exoplanets appears to be a promising method to search for liquid water clouds in exoplanetary atmospheres. Ice water clouds, that consist of water crystals instead of water droplets, could potentially mask the rainbow feature in

  3. Pressure Dependence of the Liquid-Liquid Phase Transition of Nanopore Water Doped Slightly with Hydroxylamine, and a Phase Behavior Predicted for Pure Water

    Science.gov (United States)

    Nagoe, Atsushi; Iwaki, Shinji; Oguni, Masaharu; Tôzaki, Ken-ichi

    2014-09-01

    Phase transition behaviors of confined pure water and confined water doped with a small amount of hydroxylamine (HA) with a mole fraction of xHA = 0.03 were examined by high-pressure differential thermal analyses at 0.1, 50, 100, and 150 MPa; the average diameters of silica pores used were 2.0 and 2.5 nm. A liquid-liquid phase transition (LLPT) of the confined HA-doped water was clearly observed and its pressurization effect could be evaluated, unlike in the experiments on undoped water. It was found that pressurization causes the transition temperature (Ttrs) to linearly decrease, indicating that the low-temperature phase has a lower density than the high-temperature one. Transition enthalpy (ΔtrsH) decreased steeply with increasing pressure. Considering the linear decrease in Ttrs with increasing pressure, the steep decrease in ΔtrsH indicates that the LLPT effect of the HA-doped water attenuates with pressure. We present a new scenario of the phase behavior concerning the LLPT of pure water based on the analogy from the behavior of slightly HA-doped water, where a liquid-liquid critical point (LLCP) and a coexistence line are located in a negative-pressure regime but not in a positive-pressure one. It is reasonably understood that doping a small amount of HA into water results in negative chemical pressurization and causes the LLPT to occur even at ambient pressure.

  4. The path of the Levantine intermediate water to the Alboran sea

    Science.gov (United States)

    Font, Jordi

    1987-10-01

    The Levantine Intermediate Water (LIW) traditionally has been assumed to reach the Alboran Sea as a counter-current along the North African coast. Here data are presented that confirm the LIW flow through the sill that separates the Balearic Islands from the mainland, after contouring cyclonically the western Mediterranean along the continental slope. This seems to be a seasonal phenomenon related to the process of deep water formation in the northwestern Mediterranean and to fluctuations in the Ligurian Current. In winter the LIW can circulate across the Catalan Sea without remarkable dilution, while in summer the intermediate outflow has almost lost the LIW water mass characteristics.

  5. Vortex-assisted liquid-liquid microextraction for the rapid screening of short-chain chlorinated paraffins in water.

    Science.gov (United States)

    Chang, Chia-Yu; Chung, Wu-Hsun; Ding, Wang-Hsien

    2016-01-01

    The rapid screening of trace levels of short-chain chlorinated paraffins in various aqueous samples was performed by a simple and reliable procedure based on vortex-assisted liquid-liquid microextraction combined with gas chromatography and electron capture negative ionization mass spectrometry. The optimal vortex-assisted liquid-liquid microextraction conditions for 20 mL water sample were as follows: extractant 400 μL of dichloromethane; vortex extraction time of 1 min at 2500 × g; centrifugation of 3 min at 5000 × g; and no ionic strength adjustment. Under the optimum conditions, the limit of quantitation was 0.05 μg/L. Precision, as indicated by relative standard deviations, was less than 9% for both intra- and inter-day analysis. Accuracy, expressed as the mean extraction recovery, was above 91%. The vortex-assisted liquid-liquid microextraction with gas chromatography and electron capture negative ionization mass spectrometry method was successfully applied to quantitatively extract short-chain chlorinated paraffins from samples of river water and the effluent of a wastewater treatment plant, and the concentrations ranged from 0.8 to 1.6 μg/L. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Influence of the temperature on the (liquid + liquid) phase equilibria of (water + 1-propanl + linalool or geraniol)

    International Nuclear Information System (INIS)

    Wan, Li; Li, Hengde; Huang, Cheng; Feng, Yuqing; Chu, Guoqiang; Zheng, Yuying; Tan, Wei; Qin, Yanlin; Sun, Dalei; Fang, Yanxiong

    2017-01-01

    Highlights: • Ternary LLEs containing linalool and geraniol are presented. • Distribution ratios of 1-propanol in the mixtures are examined. • Influence of the temperature on the LLE is studied. • The LLE data were correlated using the NRTL and UNIQUAC models. - Abstract: Linalool and geraniol are the primary components of rose oil, palmarosa oil, and citronella oil and many other essential oils, and two important compounds used in the flavour and fragrance, cosmetic or pharmaceutical industries. Phase equilibria (LLE, VLE, solubility, etc.) and related thermodynamic properties of a mixture are essential in the processes design and control of mass transfer process. In this work, experimental (liquid + liquid) equilibria data of the systems (water + 1-propanl + linalool) and (water + 1-propanl + geraniol) are presented. The (liquid + liquid) equilibria of both systems were determined with a tie-line method at T = (283.15, 298.15 and 313.15) K under atmospheric pressure. The well-known Hand, Bachman and Othmer–Tobias equations were used to test the reliability of the experimental values. The influence of the temperature on the (liquid + liquid) phase equilibria of the mixtures, the binodal curves and distribution ratios of 1-propanl are shown and discussed. Moreover, the NRTL and UNIQUAC models were applied to fit the data for both ternary systems. The interaction parameters obtained from both models successfully correlated the equilibrium compositions. Furthermore, the ternary systems could be represented using the binary parameters of the thermodynamic model with a function of temperature.

  7. Experimental equivalent cluster-size distributions in nano-metric volumes of liquid water

    International Nuclear Information System (INIS)

    Grosswendt, B.; De Nardo, L.; Colautti, P.; Pszona, S.; Conte, V.; Tornielli, G.

    2004-01-01

    Ionisation cluster-size distributions in nano-metric volumes of liquid water were determined for alpha particles at 4.6 and 5.4 MeV by measuring cluster-size frequencies in small gaseous volumes of nitrogen or propane at low gas pressure as well as by applying a suitable scaling procedure. This scaling procedure was based on the mean free ionisation lengths of alpha particles in water and in the gases measured. For validation, the measurements of cluster sizes in gaseous volumes and the cluster-size formation in volumes of liquid water of equivalent size were simulated by Monte Carlo methods. The experimental water-equivalent cluster-size distributions in nitrogen and propane are compared with those in liquid water and show that cluster-size formation by alpha particles in nitrogen or propane can directly be related to those in liquid water. (authors)

  8. Water-saving liquid-gas conditioning system

    Science.gov (United States)

    Martin, Christopher; Zhuang, Ye

    2014-01-14

    A method for treating a process gas with a liquid comprises contacting a process gas with a hygroscopic working fluid in order to remove a constituent from the process gas. A system for treating a process gas with a liquid comprises a hygroscopic working fluid comprising a component adapted to absorb or react with a constituent of a process gas, and a liquid-gas contactor for contacting the working fluid and the process gas, wherein the constituent is removed from the process gas within the liquid-gas contactor.

  9. Predicting glass-to-glass and liquid-to-liquid phase transitions in supercooled water using classical nucleation theory

    Science.gov (United States)

    Tournier, Robert F.

    2018-01-01

    Glass-to-glass and liquid-to-liquid phase transitions are observed in bulk and confined water, with or without applied pressure. They result from the competition of two liquid phases separated by an enthalpy difference depending on temperature. The classical nucleation equation of these phases is completed by this quantity existing at all temperatures, a pressure contribution, and an enthalpy excess. This equation leads to two homogeneous nucleation temperatures in each liquid phase; the first one (Tn- below Tm) being the formation temperature of an "ordered" liquid phase and the second one corresponding to the overheating temperature (Tn+ above Tm). Thermodynamic properties, double glass transition temperatures, sharp enthalpy and volume changes are predicted in agreement with experimental results. The first-order transition line at TLL = 0.833 × Tm between fragile and strong liquids joins two critical points. Glass phase above Tg becomes "ordered" liquid phase disappearing at TLL at low pressure and at Tn+ = 1.302 × Tm at high pressure.

  10. Mashhad Wise Water Forum: a path to sustainable water resources management in a semi-arid region of Iran

    Science.gov (United States)

    Tabatabaee, Seyyed Alireza; Neyshaboori, Shahnaz; Basirat, Ali; Tavakoli Aminiyan, Samaneh; Mirbehrooziyan, Ahmad; Sakhdari, Hossein; Shafiei, Mojtaba; Davary, Kamran

    2016-04-01

    Water is key to sustainable development especially in semi-arid regions in which the main source of water provision is groundwater. Water has value from a social, economic and environmental perspective and is required to be managed within a sound, integrated socio-economic and environmental framework. Mashhad, the second big city in Iran, has been faced with rapid growth rates of population and economic activities. The groundwater in Mashhad basin has been overexploited to meet the increasing trend of water demand during the past 20 years. Consequently, the region has faced with water scarcity and water quality problems which originates from inefficient use and poor management. To tackle the water issue on a durable basis, within the economic, ecological, and political constraints (i.e. the integrated water resources management, IWRM concept), a Non-Governmental Organization (NGO), named as Mashhad Wise Water Forum (MWWF), has been established in 2013 that encompasses contribution of experts from academia, industry, and governmental policy-makers. The MWWF considers the UN-Water IWRM spiral conceptual model (which contains four stages: Recognizing and identifying; Conceptualizing; Coordinating and planning; Implementing, Monitoring and Evaluating) by implicating participatory water management (water users' involvement) methods in Mashhad basin. Furthermore, the MWWF has planned to look at all dimensions of water crisis (i.e. physical, economic, policy and institutional) particularly institutional dimension by gathering all stockholders, beneficiaries and experts in different parts of water policy making in Mashhad basin. The MWWF vision for Mashhad basin is achieving to sustainable equilibrium of water resources and consumptions in the basin by the prospect to 2040 year. So far, the MWWF has tried to understand and deal with regional diversity in legal systems as well as conflicts between private interests and public welfare in water allocation and management. At

  11. A comparative analysis of conventional and SurePath liquid-based cervicovaginal cytology: A study of 140 cases

    Directory of Open Access Journals (Sweden)

    Jyotsna Sharma

    2016-01-01

    Full Text Available Background: The role of Papanicolaou (Pap test in cervical cancer screening need not be overemphasized. While most Western countries have adopted the liquid-based cytology (LBC, which is considered superior, many developing countries are still using the conventional Pap smear (CPS technique. Objective: To compare the staining and cytomorphological features on conventional versus liquid-based cervicovaginal smears. Materials and Methods: One hundred and forty cervicovaginal smears prepared by the standard conventional and LBC techniques were interpreted as per the Bethesda system of reporting cervicovaginal smears. Twelve parameters were studied, compared, and statistically analyzed. A P value <0.05 was considered to be statistically significant. Results: 129/140 (92% of CPSs and 130/140 (93% LBC smears were satisfactory. LBC had a significantly shorter screening time (2.0 ± 0.08 vs 4.0 ± 0.65 and better representative material than that of CPS (50% vs 42%. Neutrophils were significantly more in CPS than LBC (96% vs 92% with a P value <0.05 while hemorrhagic background and red blood cells (RBCs were more prominent in CPS. LBC showed significant artifactual changes in squamous epithelial cells. Epithelial abnormalities ranging from atypical squamous cells of undetermined significance (ASCUS to high grade squamous intraepithelial lesion (HSIL were seen in 3% (4 and 2% (2 of CPSs and LBCs, respectively. Organisms were better picked up in CPS (99% in CPS vs 73% LBC with a value of P = 0.0001. Conclusion: Although a shorter screening time and cleaner background are the major advantages of LBC, CPS is not inferior to LBC. Considering the high cost, rather than the advantages associated with LBC, we feel that CPS is a better option for developing countries.

  12. Communication: energy benchmarking with quantum Monte Carlo for water nano-droplets and bulk liquid water.

    Science.gov (United States)

    Alfè, D; Bartók, A P; Csányi, G; Gillan, M J

    2013-06-14

    We show the feasibility of using quantum Monte Carlo (QMC) to compute benchmark energies for configuration samples of thermal-equilibrium water clusters and the bulk liquid containing up to 64 molecules. Evidence that the accuracy of these benchmarks approaches that of basis-set converged coupled-cluster calculations is noted. We illustrate the usefulness of the benchmarks by using them to analyze the errors of the popular BLYP approximation of density functional theory (DFT). The results indicate the possibility of using QMC as a routine tool for analyzing DFT errors for non-covalent bonding in many types of condensed-phase molecular system.

  13. Use of Dispersive Liquid-Liquid Microextraction and UV-Vis Spectrophotometry for the Determination of Cadmium in Water Samples

    Directory of Open Access Journals (Sweden)

    J. Pérez-Outeiral

    2014-01-01

    Full Text Available A simple and inexpensive method for cadmium determination in water using dispersive liquid-liquid microextraction and ultraviolet-visible spectrophotometry was developed. In order to obtain the best experimental conditions, experimental design was applied. Calibration was made in the range of 10–100 μg/L, obtaining good linearity (R2 = 0.9947. The obtained limit of detection based on calibration curve was 8.5 μg/L. Intra- and interday repeatability were checked at two levels, obtaining relative standard deviation values from 9.0 to 13.3%. The enrichment factor had a value of 73. Metal interferences were also checked and tolerable limits were evaluated. Finally, the method was applied to cadmium determination in real spiked water samples. Therefore, the method showed potential applicability for cadmium determination in highly contaminated liquid samples.

  14. Ecosystem services and integrated water resource management: different paths to the same end?

    Science.gov (United States)

    Cook, Brian R; Spray, Christopher J

    2012-10-30

    The two concepts that presently dominate water resource research and management are the Global Water Partnership's (GWP, 2000) interpretation of Integrated Water Resource Management (IWRM) and Ecosystem Services (ES) as interpreted by the Millennium Ecosystem Assessment (MA, 2005). Both concepts are subject to mounting criticism, with a significant number of critiques focusing on both their conceptual and methodological incompatibility with management and governance, what has come to be known as the 'implementation gap'. Emergent within the ES and IWRM literatures, then, are two parallel debates concerning the gap between conceptualisation and implementation. Our purpose for writing this review is to argue: 1) that IWRM and ES have evolved into nearly identical concepts, 2) that they face the same critical challenge of implementation, and 3) that, if those interested in water research and management are to have a positive impact on the sustainable utilisation of dwindling water resources, they must break the tendency to jump from concept to concept and confront the challenges that arise with implementation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Revisiting a many-body model for water based on a single polarizable site: from gas phase clusters to liquid and air/liquid water systems.

    Science.gov (United States)

    Réal, Florent; Vallet, Valérie; Flament, Jean-Pierre; Masella, Michel

    2013-09-21

    We present a revised version of the water many-body model TCPE [M. Masella and J.-P. Flament, J. Chem. Phys. 107, 9105 (1997)], which is based on a static three charge sites and a single polarizable site to model the molecular electrostatic properties of water, and on an anisotropic short range many-body energy term specially designed to accurately model hydrogen bonding in water. The parameters of the revised model, denoted TCPE/2013, are here developed to reproduce the ab initio energetic and geometrical properties of small water clusters (up to hexamers) and the repulsive water interactions occurring in cation first hydration shells. The model parameters have also been refined to reproduce two liquid water properties at ambient conditions, the density and the vaporization enthalpy. Thanks to its computational efficiency, the new model range of applicability was validated by performing simulations of liquid water over a wide range of temperatures and pressures, as well as by investigating water liquid/vapor interfaces over a large range of temperatures. It is shown to reproduce several important water properties at an accurate enough level of precision, such as the existence liquid water density maxima up to a pressure of 1000 atm, the water boiling temperature, the properties of the water critical point (temperature, pressure, and density), and the existence of a "singularity" temperature at about 225 K in the supercooled regime. This model appears thus to be particularly well-suited for characterizing ion hydration properties under different temperature and pressure conditions, as well as in different phases and interfaces.

  16. Thermodynamic modeling of ternary and quaternary (liquid + liquid) systems containing water, FeCl3, HCl and diisopropyl ether

    NARCIS (Netherlands)

    Milosevic, M.; Hendriks, I.; Smits, R.E.R.; Schuur, B.; Haan, de A.B.

    2013-01-01

    Liquid–liquid extraction using ethers as solvents is a potentially energy saving alternative for the concentration of aqueous ferric chloride solutions. Adequate thermodynamic models that describe the behavior of the resulting quaternary systems (FeCl3, ether, acid and water) are not available in

  17. Mistletoe infection alters the transpiration flow path and suppresses water regulation of host trees during extreme events

    Science.gov (United States)

    Griebel, A.; Maier, C.; Barton, C. V.; Metzen, D.; Renchon, A.; Boer, M. M.; Pendall, E.

    2017-12-01

    Mistletoe is a globally distributed group of parasitic plants that infiltrates the vascular tissue of its host trees to acquire water, carbon and nutrients, making it a leading agent of biotic disturbance. Many mistletoes occur in water-limited ecosystems, thus mistletoe infection in combination with increased climatic stress may exacerbate water stress and potentially accelerate mortality rates of infected trees during extreme events. This is an emerging problem in Australia, as mistletoe distribution is increasing and clear links between mistletoe infection and mortality have been established. However, direct observations about how mistletoes alter host physiological processes during extreme events are rare, which impedes our understanding of mechanisms underlying increased tree mortality rates. We addressed this gap by continuously monitoring stem and branch sap flow and a range of leaf traits of infected and uninfected trees of two co-occurring eucalypt species during a severe heatwave in south-eastern Australia. We demonstrate that mistletoes' leaf water potentials were maintained 30% lower than hosts' to redirect the trees' transpiration flow path towards mistletoe leaves. Eucalypt leaves reduced water loss through stomatal regulation when atmospheric dryness exceeded 2 kPa, but the magnitude of stomatal regulation in non-infected eucalypts differed by species (between 40-80%). Remarkably, when infected, sap flow rates of stems and branches of both eucalypt species remained unregulated even under extreme atmospheric dryness (>8 kPa). Our observations indicate that excessive water use of mistletoes likely increases xylem cavitation rates in hosts during prolonged droughts and supports that hydraulic failure contributes to increased mortality of infected trees. Hence, in order to accurately model the contribution of biotic disturbances to tree mortality under a changing climate, it will be crucial to increase our process-based understanding of the interaction

  18. The interesting cross-paths of HIV/AIDS and water in Southern Africa ...

    African Journals Online (AJOL)

    HIV/AIDS and water-borne diseases account for a substantial degree of morbidity and mortality in different age groups across the globe, but their ripple effects are more devastating in developing countries. Estimates of the HIV/AIDS epidemic in South Africa vary but attest to a mature and generalised epidemic. Antenatal ...

  19. Nutrients: Learner's Guide for a Critical Path in Water Quality Monitoring.

    Science.gov (United States)

    Glazer, Richard B.; And Others

    This learner's guide on nutrients is derived from a water monitoring curriculum developed at Ulster County Community College. There are 30 modules in this guide; each introduced with a statement of purpose and then broken down into an objective, learning conditions, and performance level. The modules cover: (1) safety; (2) chemical compounds; (3)…

  20. Indicator Organisms: Learner's Guide for a Critical Path in Water Quality Monitoring.

    Science.gov (United States)

    Glazer, Richard B.; And Others

    This learner's guide on indicator organisms is derived from a water monitoring curriculum developed at Ulster County Community College. There are 37 modules in this guide; each is introduced with a statement of purpose and then broken down into units of instruction. These units contain an objective, learning conditions, and a performance level.…

  1. Small-scale experimental study of vaporization flux of liquid nitrogen released on water.

    Science.gov (United States)

    Gopalaswami, Nirupama; Olewski, Tomasz; Véchot, Luc N; Mannan, M Sam

    2015-10-30

    A small-scale experimental study was conducted using liquid nitrogen to investigate the convective heat transfer behavior of cryogenic liquids released on water. The experiment was performed by spilling five different amounts of liquid nitrogen at different release rates and initial water temperatures. The vaporization mass fluxes of liquid nitrogen were determined directly from the mass loss measured during the experiment. A variation of initial vaporization fluxes and a subsequent shift in heat transfer mechanism were observed with changes in initial water temperature. The initial vaporization fluxes were directly dependent on the liquid nitrogen spill rate. The heat flux from water to liquid nitrogen determined from experimental data was validated with two theoretical correlations for convective boiling. It was also observed from validation with correlations that liquid nitrogen was found to be predominantly in the film boiling regime. The substantial results provide a suitable procedure for predicting the heat flux from water to cryogenic liquids that is required for source term modeling. Copyright © 2015 Elsevier B.V. All rights reserved.

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

    International Nuclear Information System (INIS)

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

    1977-01-01

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

  3. Study on novel ionic liquids as extracting agent for priority metals from waste waters

    International Nuclear Information System (INIS)

    Fischer, L.; Falta, T.; Stingeder, G.; Koellensperger, G.; Hann, S.; Kogelnig, D.; Stojanovic, A.; Krachler, R.; Keppler, B.K.

    2009-01-01

    Full text: As the new EU Water Framework Directive (2000/60/EC) sets high environmental quality standards for priority substances in surface water, effective procedures for wastewater treatment are required. The characteristics of ionic liquids (IL) can be adjusted by modifying their ionic composition for liquid-liquid extraction of metals and metal containing compounds (Cd, Hg, Ni, Pb, tributyltin, cancerostatic platinum compounds) from the water phase. The potential of novel IL for selective removal of the above mentioned substances regarding extraction time, pH and matrix were determined by ICPSFMS, HPLC-ICPMS and GC-ICPMS measurements. (author)

  4. Efficiency of inductively torch plasma operating at atmospheric pressure on destruction of chlorinated liquid wastes- A path to the treatment of radioactive organic halogen liquid wastes

    Science.gov (United States)

    Kamgang-Youbi, G.; Poizot, K.; Lemont, F.

    2012-12-01

    The performance of a plasma reactor for the degradation of chlorinated hydrocarbon waste is reported. Chloroform was used as a target for a recently patented destruction process based using an inductive plasma torch. Liquid waste was directly injected axially into the argon plasma with a supplied power of ~4 kW in the presence of oxygen as oxidant and carrier gas. Decomposition was performed at CHCl3 feed rates up to 400 g·h-1 with different oxygen/waste molar ratios, chloroform destruction was obtained with at least 99% efficiency and the energy efficiency reached 100 g·kWh-1. The conversion end products were identified and assayed by online FTIR spectroscopy (CO2, HCl and H2O) and redox titration (Cl2). Considering phosgene as representative of toxic compounds, only very small quantities of toxics were released (rates. The experimental results were very close to the equilibrium composition predicted by thermodynamic calculations. At the bottom of the reactor, the chlorinated acids were successfully trapped in a scrubber and transformed into mineral salts, hence, only CO2 and H2O have been found in the final off-gases composition.

  5. Efficiency of inductively torch plasma operating at atmospheric pressure on destruction of chlorinated liquid wastes- A path to the treatment of radioactive organic halogen liquid wastes

    International Nuclear Information System (INIS)

    Kamgang-Youbi, G; Poizot, K; Lemont, F

    2012-01-01

    The performance of a plasma reactor for the degradation of chlorinated hydrocarbon waste is reported. Chloroform was used as a target for a recently patented destruction process based using an inductive plasma torch. Liquid waste was directly injected axially into the argon plasma with a supplied power of ∼4 kW in the presence of oxygen as oxidant and carrier gas. Decomposition was performed at CHCl 3 feed rates up to 400 g·h −1 with different oxygen/waste molar ratios, chloroform destruction was obtained with at least 99% efficiency and the energy efficiency reached 100 g·kWh −1 . The conversion end products were identified and assayed by online FTIR spectroscopy (CO 2 , HCl and H 2 O) and redox titration (Cl 2 ). Considering phosgene as representative of toxic compounds, only very small quantities of toxics were released ( −1 ) even with high waste feed rates. The experimental results were very close to the equilibrium composition predicted by thermodynamic calculations. At the bottom of the reactor, the chlorinated acids were successfully trapped in a scrubber and transformed into mineral salts, hence, only CO 2 and H 2 O have been found in the final off-gases composition.

  6. Liquid-Liquid Equilibrium data for mono ethylene glycol extraction from water with the new ionic liquid tetraoctyl ammonium 2-methyl-1-naphtoate as solvent

    NARCIS (Netherlands)

    Garcia Chavez, L.Y.; Schuur, Boelo; de Haan, A.B.

    2012-01-01

    Thermal recovery of mono ethylene glycol (MEG) from aqueous streams is one of the most energy demanding operations in industry, because of the large amount of water that needs to be evaporated. The use of alternative technologies such as liquid–liquid extraction could save energy. A new tailor made

  7. Liquid-liquid equilibrium data for mono ethylene glycol extraction from water with the new ionic liquid tetraoctyl ammonium 2-methyl-1-naphtoate as solvent

    NARCIS (Netherlands)

    Garcia Chavez, L.Y.; Schuur, B.; Haan, de A.B.

    2012-01-01

    Thermal recovery of mono ethylene glycol (MEG) from aqueous streams is one of the most energy demanding operations in industry, because of the large amount of water that needs to be evaporated. The use of alternative technologies such as liquid–liquid extraction could save energy. A new tailor made

  8. Primitive Liquid Water of the Solar System in an Aqueous Altered Carbonaceous Chondrite

    Science.gov (United States)

    Tsuchiyama, A.; Miyake, A.; Kitayama, A.; Matsuno, J.; Takeuchi, A.; Uesugi, K.; Suzuki, Y.; Nakano, T.; Zolensky, M. E.

    2016-01-01

    Non-destructive 3D observations of the aqueous altered CM chondrite Sutter's Mill using scanning imaging x-ray microscopy (SIXM) showed that some of calcite and enstatite grains contain two-phase inclusion, which is most probably composed of liquid water and bubbles. This water should be primitive water responsible for aqueous alteration in an asteroid in the early solar system.

  9. Structure of ionic liquid-water mixtures at interfaces: x-ray and neutron reflectometry studies

    International Nuclear Information System (INIS)

    Lauw, Yansen; Rodopoulos, Theo; Horne, Mike; Follink, Bart; Hamilton, Bill; Knott, Robert; Nelson, Andy

    2009-01-01

    Full text: Fundamental studies on the effect of water in ionic liquids are necessary since the overall performance of ionic liquids in many industrial applications is often hampered by the presence of water.[1] Based on this understanding, the surface and interfacial structures of 1-butyl-1methylpyrrolidinium trifluoromethylsulfonylimide [C4mpyr][NTf2] ionic liquid-water mixtures were probed using x-ray and neutron reflectometry techniques. At the gas-liquid surface, a thick cation+water layer was detected next to the phase boundary, followed by an increasing presence of anion towards the bulk. The overall thickness of the surface exhibits non-monotonic trends with an increasing water content, which explains similar phenomenological trends in surface tension reported in the literature.[2] At an electrified interface, the interfacial structure of pure ionic liquids probed by neutron reflectometry shows similar trends to those predicted by a mean-field model.[3] However, the presence of water within the electrical double-layer is less obvious, although it is widely known that water reduces electrochemical window of ionic liquids. To shed light on this issue, further studies are currently in progress.

  10. On the implications of aerosol liquid water and phase separation for organic aerosol mass

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset contains data presented in the figures of the paper "On the implications of aerosol liquid water and phase separation for organic aerosol mass"...

  11. Scanning Multichannel Microwave Radiometer (SMMR) Monthly Mean Atmospheric Liquid Water (ALW) By Prabhakara

    Data.gov (United States)

    National Aeronautics and Space Administration — SMMR_ALW_PRABHAKARA data are Special Multichannel Microwave Radiometer (SMMR) Monthly Mean Atmospheric Liquid Water (ALW) data by Prabhakara.The Prabhakara Scanning...

  12. Divergent trend in density versus viscosity of ionic liquid/water mixtures: a molecular view from guanidinium ionic liquids.

    Science.gov (United States)

    Singh, Akhil Pratap; Gardas, Ramesh L; Senapati, Sanjib

    2015-10-14

    Ionic liquids (ILs) have shown great potential in the dissolution and stability of biomolecules when a low-to-moderate quantity of water is added. Hence, determining the thermophysical properties and understanding these novel mixtures at the molecular level are of both fundamental and practical importance. In this context, here we report the synthesis of two nontoxic guanidinium cation based ILs, tetramethylguanidinium benzoate [TMG][BEN] and tetramethylguanidinium salicylate [TMG][SAL], and present a detailed comparison of their thermophysical properties in the presence of water. The results show that the [TMG][SAL]/water mixtures have higher density and higher apparent molar volume, but a lower viscosity and higher compressibility than the [TNG][BEN]/water mixtures. The measured viscosity and compressibility data are explained from ab initio quantum mechanical calculations and liquid-phase molecular dynamics simulations, where salicylate anions of denser [TMG][SAL]/water were found to exist as isolated ions due to intramolecular H-bonding. On the contrary, intermolecular H-bonding among the benzoate anions and their strong tendency to form an extended H-bonding network with water made [TMG][BEN]/water solutions more viscous and less compressible. This study shows the importance of probing these emerging solvents at the molecular-to-atomic level, which could be helpful in their optimal usage for task-specific applications.

  13. Ab initio calculation of the electronic absorption spectrum of liquid water

    International Nuclear Information System (INIS)

    Martiniano, Hugo F. M. C.; Galamba, Nuno; Cabral, Benedito J. Costa

    2014-01-01

    The electronic absorption spectrum of liquid water was investigated by coupling a one-body energy decomposition scheme to configurations generated by classical and Born-Oppenheimer Molecular Dynamics (BOMD). A Frenkel exciton Hamiltonian formalism was adopted and the excitation energies in the liquid phase were calculated with the equation of motion coupled cluster with single and double excitations method. Molecular dynamics configurations were generated by different approaches. Classical MD were carried out with the TIP4P-Ew and AMOEBA force fields. The BLYP and BLYP-D3 exchange-correlation functionals were used in BOMD. Theoretical and experimental results for the electronic absorption spectrum of liquid water are in good agreement. Emphasis is placed on the relationship between the structure of liquid water predicted by the different models and the electronic absorption spectrum. The theoretical gas to liquid phase blue-shift of the peak positions of the electronic absorption spectrum is in good agreement with experiment. The overall shift is determined by a competition between the O–H stretching of the water monomer in liquid water that leads to a red-shift and polarization effects that induce a blue-shift. The results illustrate the importance of coupling many-body energy decomposition schemes to molecular dynamics configurations to carry out ab initio calculations of the electronic properties in liquid phase

  14. Compact Raman Lidar Measurement of Liquid and Vapor Phase Water Under the Influence of Ionizing Radiation

    Directory of Open Access Journals (Sweden)

    Shiina Tatsuo

    2016-01-01

    Full Text Available A compact Raman lidar has been developed for studying phase changes of water in the atmosphere under the influence of ionization radiation. The Raman lidar is operated at the wavelength of 349 nm and backscattered Raman signals of liquid and vapor phase water are detected at 396 and 400 nm, respectively. Alpha particles emitted from 241Am of 9 MBq ionize air molecules in a scattering chamber, and the resulting ions lead to the formation of liquid water droplets. From the analysis of Raman signal intensities, it has been found that the increase in the liquid water Raman channel is approximately 3 times as much as the decrease in the vapor phase water Raman channel, which is consistent with the theoretical prediction based on the Raman cross-sections. In addition, the radius of the water droplet is estimated to be 0.2 μm.

  15. Combustion characteristics of nanoaluminum, liquid water, and hydrogen peroxide mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Sabourin, J.L.; Yetter, R.A. [The Pennsylvania State University, Department of Mechanical and Nuclear Engineering, University Park, PA 16801 (United States); Risha, G.A. [The Pennsylvania State University, Division of Business and Engineering, Altoona, PA 16601 (United States); Son, S.F. [Purdue University, School of Mechanical Engineering, West Lafayette, IN 47907 (United States); Tappan, B.C. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2008-08-15

    An experimental investigation of the combustion characteristics of nanoaluminum (nAl), liquid water (H{sub 2}O{sub (l)}), and hydrogen peroxide (H{sub 2}O{sub 2}) mixtures has been conducted. Linear and mass-burning rates as functions of pressure, equivalence ratio ({phi}), and concentration of H{sub 2}O{sub 2} in H{sub 2}O{sub (l)} oxidizing solution are reported. Steady-state burning rates were obtained at room temperature using a windowed pressure vessel over an initial pressure range of 0.24 to 12.4 MPa in argon, using average nAl particle diameters of 38 nm, {phi} from 0.5 to 1.3, and H{sub 2}O{sub 2} concentrations between 0 and 32% by mass. At a nominal pressure of 3.65 MPa, under stoichiometric conditions, mass-burning rates per unit area ranged between 6.93 g/cm{sup 2} s (0% H{sub 2}O{sub 2}) and 37.04 g/cm{sup 2} s (32% H{sub 2}O{sub 2}), which corresponded to linear burning rates of 9.58 and 58.2 cm/s, respectively. Burning rate pressure exponents of 0.44 and 0.38 were found for stoichiometric mixtures at room temperature containing 10 and 25% H{sub 2}O{sub 2}, respectively, up to 5 MPa. Burning rates are reduced above {proportional_to}5 MPa due to the pressurization of interstitial spaces of the packed reactant mixture with argon gas, diluting the fuel and oxidizer mixture. Mass burning rates were not measured above {proportional_to}32% H{sub 2}O{sub 2} due to an anomalous burning phenomena, which caused overpressurization within the quartz sample holder, leading to tube rupture. High-speed imaging displayed fingering or jetting ahead of the normal flame front. Localized pressure measurements were taken along the sample length, determining that the combustion process proceeded as a normal deflagration prior to tube rupture, without significant pressure buildup within the tube. In addition to burning rates, chemical efficiencies of the combustion reaction were determined to be within approximately 10% of the theoretical maximum under all conditions

  16. Determination of trace amount of lead in industrial and municipal effluent water samples based on dispersive liquid-liquid extraction

    Energy Technology Data Exchange (ETDEWEB)

    Shirkhanloo, H. [Iranian Petroleum Industry Health Research Institute, Occupational and Environmental Health Research Center, Tehran (Iran, Islamic Republic of); Sedighi, K.; Mousavi, H. Z., E-mail: hzmousavi@semnan.ac.ir [Semnan University, College of Science, Department of Chemistry, Semnan (Iran, Islamic Republic of)

    2014-10-01

    In this study, a simple, sensitive and accurate method was developed for the determination of lead ion by combining ionic liquid dispersive liquid-liquid extraction (Il-DLL E) with flame atomic absorption spectrometry. Tetraethyl thiuram disulfide (Tetd), acetone and 1-octyl-3m ethylimidazolium hexafluorophosphate [(C{sub 8}MIM) (PF{sub 6})] were used as the chelating agent, dispersive and extraction solvent, respectively. Under the optimal conditions, the calibration graph was linear in the range of 5-190 μg L{sup -1} of lead and the detection limit was 0.8 μg L{sup -1} with a sample volume of 200 ml. The proposed method was validated by the analysis of one certified reference material and applied successfully to the determination of lead in real water samples. (Author)

  17. Determination of trace amount of lead in industrial and municipal effluent water samples based on dispersive liquid-liquid extraction

    International Nuclear Information System (INIS)

    Shirkhanloo, H.; Sedighi, K.; Mousavi, H. Z.

    2014-01-01

    In this study, a simple, sensitive and accurate method was developed for the determination of lead ion by combining ionic liquid dispersive liquid-liquid extraction (Il-DLL E) with flame atomic absorption spectrometry. Tetraethyl thiuram disulfide (Tetd), acetone and 1-octyl-3m ethylimidazolium hexafluorophosphate [(C 8 MIM) (PF 6 )] were used as the chelating agent, dispersive and extraction solvent, respectively. Under the optimal conditions, the calibration graph was linear in the range of 5-190 μg L -1 of lead and the detection limit was 0.8 μg L -1 with a sample volume of 200 ml. The proposed method was validated by the analysis of one certified reference material and applied successfully to the determination of lead in real water samples. (Author)

  18. Ionic liquid-based microwave-assisted dispersive liquid-liquid microextraction and derivatization of sulfonamides in river water, honey, milk, and animal plasma.

    Science.gov (United States)

    Xu, Xu; Su, Rui; Zhao, Xin; Liu, Zhuang; Zhang, Yupu; Li, Dan; Li, Xueyuan; Zhang, Hanqi; Wang, Ziming

    2011-11-30

    The ionic liquid-based microwave-assisted dispersive liquid-liquid microextraction (IL-based MADLLME) and derivatization was applied for the pretreatment of six sulfonamides (SAs) prior to the determination by high-performance liquid chromatography (HPLC). By adding methanol (disperser), fluorescamine solution (derivatization reagent) and ionic liquid (extraction solvent) into sample, extraction, derivatization, and preconcentration were continuously performed. Several experimental parameters, such as the type and volume of extraction solvent, the type and volume of disperser, amount of derivatization reagent, microwave power, microwave irradiation time, pH of sample solution, and ionic strength were investigated and optimized. When the microwave power was 240 W, the analytes could be derivatized and extracted simultaneously within 90 s. The proposed method was applied to the analysis of river water, honey, milk, and pig plasma samples, and the recoveries of analytes obtained were in the range of 95.0-110.8, 95.4-106.3, 95.0-108.3, and 95.7-107.7, respectively. The relative standard deviations varied between 1.5% and 7.3% (n=5). The results showed that the proposed method was a rapid, convenient and feasible method for the determination of SAs in liquid samples. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Hydrothermal decomposition of liquid crystal in subcritical water

    International Nuclear Information System (INIS)

    Zhuang, Xuning; He, Wenzhi; Li, Guangming; Huang, Juwen; Lu, Shangming; Hou, Lianjiao

    2014-01-01

    Highlights: • Hydrothermal technology can effectively decompose the liquid crystal of 4-octoxy-4'-cyanobiphenyl. • The decomposition rate reached 97.6% under the optimized condition. • Octoxy-4'-cyanobiphenyl was mainly decomposed into simple and innocuous products. • The mechanism analysis reveals the decomposition reaction process. - Abstract: Treatment of liquid crystal has important significance for the environment protection and human health. This study proposed a hydrothermal process to decompose the liquid crystal of 4-octoxy-4′-cyanobiphenyl. Experiments were conducted with a 5.7 mL stainless tube reactor and heated by a salt-bath. Factors affecting the decomposition rate of 4-octoxy-4′-cyanobiphenyl were evaluated with HPLC. The decomposed liquid products were characterized by GC-MS. Under optimized conditions i.e., 0.2 mL H 2 O 2 supply, pH value 6, temperature 275 °C and reaction time 5 min, 97.6% of 4-octoxy-4′-cyanobiphenyl was decomposed into simple and environment-friendly products. Based on the mechanism analysis and products characterization, a possible hydrothermal decomposition pathway was proposed. The results indicate that hydrothermal technology is a promising choice for liquid crystal treatment

  20. Combination of solvent extractants for dispersive liquid-liquid microextraction of fungicides from water and fruit samples by liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Pastor-Belda, Marta; Garrido, Isabel; Campillo, Natalia; Viñas, Pilar; Hellín, Pilar; Flores, Pilar; Fenoll, José

    2017-10-15

    A multiresidue method was developed to determine twenty-five fungicides belonging to three different chemical families, oxazoles, strobilurins and triazoles, in water and fruit samples, using dispersive liquid-liquid microextraction (DLLME) and liquid chromatography/tandem mass spectrometry (LC-MS 2 ). Solid-liquid extraction with acetonitrile was used for the analysis in fruits, the extract being used as dispersant solvent in DLLME. Since some of the analytes showed high affinity for chloroform and the others were more efficiently extracted with undecanol, a mixture of both solvents was used as extractant in DLLME. After evaporation of CHCl 3 , the enriched phase was analyzed. Enrichment factors in the 23-119 and 12-60 ranges were obtained for waters and fruits, respectively. The approach was most sensitive for metominostrobin with limits of quantification of 1ngL -1 and 5ngkg -1 in waters and fruits, respectively, while a similar sensitivity was attained for tebuconazole in fruits. Recoveries of the fungicides varied between 86 and 116%. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Ion Transfer Voltammetry Associated with Two Polarizable Interfaces Within Water and Moderately Hydrophobic Ionic Liquid Systems

    DEFF Research Database (Denmark)

    Gan, Shiyu; Zhou, Min; Zhang, Jingdong

    2013-01-01

    An electrochemical system composed of two polarizable interfaces (the metallic electrode|water and water|ionic liquid interfaces), namely two‐polarized‐interface (TPI) technique, has been proposed to explore the ion transfer processes between water and moderately hydrophobic ionic liquids (W...... to an extremely narrow polarized potential window (ppw) caused by these moderately hydrophobic ionic components. In this article, we show that TPI technique has virtually eliminated the ppw limitation based on a controlling step of concentration polarization at the electrode|water interface. With the aid...

  2. Simulation of water vapor condensation on LOX droplet surface using liquid nitrogen

    Science.gov (United States)

    Powell, Eugene A.

    1988-01-01

    The formation of ice or water layers on liquid oxygen (LOX) droplets in the Space Shuttle Main Engine (SSME) environment was investigated. Formulation of such ice/water layers is indicated by phase-equilibrium considerations under conditions of high partial pressure of water vapor (steam) and low LOX droplet temperature prevailing in the SSME preburner or main chamber. An experimental investigation was begun using liquid nitrogen as a LOX simulant. A monodisperse liquid nitrogen droplet generator was developed which uses an acoustic driver to force the stream of liquid emerging from a capillary tube to break up into a stream of regularly space uniformly sized spherical droplets. The atmospheric pressure liquid nitrogen in the droplet generator reservoir was cooled below its boiling point to prevent two phase flow from occurring in the capillary tube. An existing steam chamber was modified for injection of liquid nitrogen droplets into atmospheric pressure superheated steam. The droplets were imaged using a stroboscopic video system and a laser shadowgraphy system. Several tests were conducted in which liquid nitrogen droplets were injected into the steam chamber. Under conditions of periodic droplet formation, images of 600 micron diameter liquid nitrogen droplets were obtained with the stroboscopic video systems.

  3. In Situ Characterization of Boehmite Particles in Water Using Liquid SEM.

    Science.gov (United States)

    Yao, Juan; Arey, Bruce W; Yang, Li; Zhang, Fei; Komorek, Rachel; Chun, Jaehun; Yu, Xiao-Ying

    2017-09-27

    In situ imaging and elemental analysis of boehmite (AlOOH) particles in water is realized using the System for Analysis at the Liquid Vacuum Interface (SALVI) and Scanning Electron Microscopy (SEM). This paper describes the method and key steps in integrating the vacuum compatible SAVLI to SEM and obtaining secondary electron (SE) images of particles in liquid in high vacuum. Energy dispersive x-ray spectroscopy (EDX) is used to obtain elemental analysis of particles in liquid and control samples including deionized (DI) water only and an empty channel as well. Synthesized boehmite (AlOOH) particles suspended in liquid are used as a model in the liquid SEM illustration. The results demonstrate that the particles can be imaged in the SE mode with good resolution (i.e., 400 nm). The AlOOH EDX spectrum shows significant signal from the aluminum (Al) when compared with the DI water and the empty channel control. In situ liquid SEM is a powerful technique to study particles in liquid with many exciting applications. This procedure aims to provide technical know-how in order to conduct liquid SEM imaging and EDX analysis using SALVI and to reduce potential pitfalls when using this approach.

  4. Review of the methods to form hydrogen peroxide in electrical discharge plasma with liquid water

    Science.gov (United States)

    Locke, Bruce R.; Shih, Kai-Yuan

    2011-06-01

    This paper presents a review of the literature dealing with the formation of hydrogen peroxide from plasma processes. Energy yields for hydrogen peroxide generation by plasma from water span approximately three orders of magnitude from 4 × 10-2 to 80 g kWh-1. A wide range of plasma processes from rf to pulsed, ac, and dc discharges directly in the liquid phase have similar energy yields and may thus be limited by radical quenching processes at the plasma-liquid interface. Reactor modification using discharges in bubbles and discharges over the liquid phase can provide modest improvements in energy yield over direct discharge in the liquid, but the interpretation is complicated by additional chemical reactions of gas phase components such as ozone and nitrogen oxides. The highest efficiency plasma process utilizes liquid water droplets that may enhance efficiency by sequestering hydrogen peroxide in the liquid and by suppressing decomposition reactions by radicals from the gas and at the interface. Kinetic simulations of water vapor reported in the literature suggest that plasma generation of hydrogen peroxide should approach 45% of the thermodynamics limit, and this fact coupled with experimental studies demonstrating improvements with the presence of the condensed liquid phase suggest that further improvements in energy yield may be possible. Plasma generation of hydrogen peroxide directly from water compares favorably with a number of other methods including electron beam, ultrasound, electrochemical and photochemical methods, and other chemical processes.

  5. Review of the methods to form hydrogen peroxide in electrical discharge plasma with liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Locke, Bruce R; Shih, Kai-Yuan [Department of Chemical and Biomedical Engineering, Florida State University, Tallahassee, FL 32310 (United States)

    2011-06-15

    This paper presents a review of the literature dealing with the formation of hydrogen peroxide from plasma processes. Energy yields for hydrogen peroxide generation by plasma from water span approximately three orders of magnitude from 4 x 10{sup -2} to 80 g kWh{sup -1}. A wide range of plasma processes from rf to pulsed, ac, and dc discharges directly in the liquid phase have similar energy yields and may thus be limited by radical quenching processes at the plasma-liquid interface. Reactor modification using discharges in bubbles and discharges over the liquid phase can provide modest improvements in energy yield over direct discharge in the liquid, but the interpretation is complicated by additional chemical reactions of gas phase components such as ozone and nitrogen oxides. The highest efficiency plasma process utilizes liquid water droplets that may enhance efficiency by sequestering hydrogen peroxide in the liquid and by suppressing decomposition reactions by radicals from the gas and at the interface. Kinetic simulations of water vapor reported in the literature suggest that plasma generation of hydrogen peroxide should approach 45% of the thermodynamics limit, and this fact coupled with experimental studies demonstrating improvements with the presence of the condensed liquid phase suggest that further improvements in energy yield may be possible. Plasma generation of hydrogen peroxide directly from water compares favorably with a number of other methods including electron beam, ultrasound, electrochemical and photochemical methods, and other chemical processes.

  6. Selective extraction of copper, mercury, silver and palladium ionsfrom water using hydrophobic ionic liquids.

    Energy Technology Data Exchange (ETDEWEB)

    Papaiconomou, Nicolas; Lee, Jong-Min; Salminen, Justin; VonStosch, Moritz; Prausnitz, John M.

    2007-06-25

    Extraction of dilute metal ions from water was performed near room temperature with a variety of ionic liquids. Distribution coefficients are reported for fourteen metal ions extracted with ionic liquids containing cations 1-octyl-4-methylpyridinium [4MOPYR]{sup +}, 1-methyl-1-octylpyrrolidinium [MOPYRRO]{sup +} or 1-methyl-1-octylpiperidinium [MOPIP]{sup +}, and anions tetrafluoroborate [BF{sub 4}]{sup +}, trifluoromethyl sulfonate [TfO]{sup +} or nonafluorobutyl sulfonate [NfO]{sup +}. Ionic liquids containing octylpyridinium cations are very good for extracting mercury ions. However, other metal ions were not significantly extracted by any of these ionic liquids. Extractions were also performed with four new task-specific ionic liquids. Such liquids containing a disulfide functional group are efficient and selective for mercury and copper, whereas those containing a nitrile functional group are efficient and selective for silver and palladium.

  7. Distribution of aquifers, liquid-waste impoundments, and municipal water-supply sources, Massachusetts

    Science.gov (United States)

    Delaney, David F.; Maevsky, Anthony

    1980-01-01

    Impoundments of liquid waste are potential sources of ground-water contamination in Massachusetts. The map report, at a scale of 1 inch equals 4 miles, shows the idstribution of aquifers and the locations of municipal water-supply sources and known liquid-waste impoundments. Ground water, an important source of municipal water supply, is produced from shallow sand and gravel aquifers that are generally unconfined, less than 200 feet thick, and yield less than 2,000 gallons per minute to individual wells. These aquifers commonly occupy lowlands and stream valleys and are most extensive in eastern Massachusetts. Surface impoundments of liquid waste are commonly located over these aquifers. These impoundments may leak and allow waste to infiltrate underlying aquifers and alter their water quality. (USGS)

  8. Pulse radiolysis study on solvated electrons in ionic liquid with controlling water content

    International Nuclear Information System (INIS)

    Yang Jinfeng; Kondoh, T.; Yoshida, Y.; Nagaishi, R.

    2006-01-01

    Room-temperature ionic liquids, which are nonvolatile and nonflammable, have been proposed as 'green solvents' for new applications in chemical synthesis, separation chemistry, electrochemistry and other areas. In the separation chemistry, the hydrophobic ionic liquids have been practically expected to be alternative to traditional organic solvents for solvent extraction of 4f and 5f elements from the viewpoints of the immiscibility in water, especially in the spent nuclear fuel reprocessing. However, the chemical reaction or kinetics studies are important to apply the ionic liquids for various processes. To understand the effects of ionic liquids on chemical reactions, pulse radiolysis studies of ionic liquid have been carried out on nanosecond scale by using a 27 MeV electron beam and an analyzing light source of xenon lamp. In the experiment, a hydrophobic ionic liquid of diethylmethyl(2-methoxy)ammonium-bis(trifluoromethanesulfonyl)imide (DEMMA-TFSI) salt was used. The ionic liquid of DEMMA-TFSI was prepared by reacting equimolar amounts of diethylmethyl(2-methoxy)ammonium chloride (C 10 H 20 F 6 N 2 O 5 S 2 Cl, >98%, Nisshinbo) with lithium bis(trifluoromethanesulfonyl)imide (LiN(SO 2 CF 3 ) 2 , SynQuest Labs., Inc.) in aqueous solutions at room temperature. The ionic liquid was separated from the aqueous phase, purified by repeated extractions with water to LiCl and excess reagent, and finally dried at 110 degree C under vacuum. The transient absorptions of the ionic liquid were measured at wavelengths from 350 to 1400 nm, in which two photodiodes of silicon ( 1000 nm) were used. The spectrum of solvated electrons in the ionic liquid of DEMMA-TFSI was obtained with an absorption peak of 1060 nm and a wide bandwidth of about 600 nm (FWHM). The decay constant of the solvated electrons in the ionic liquid was 1.54 x 10 7 s -1 , which is independent on the wavelength. The absorption peak of the spectrum was blue-shifted from 1060 to 780 nm with increasing water

  9. Process and apparatus for determining the proportion of water in a liquid containing petroleum

    International Nuclear Information System (INIS)

    Smith, H.D. Jr.; Arnold, D.M.

    1980-01-01

    This invention concerns nuclear techniques for determining the proportion or percentage of water contained in a petroleum stream and the salinity level of such water in oil refining and production operations. This technique consists in bombarding the liquid with fast neutrons from an appropriate source, these neutrons being slowed down to the point of becoming slow neutrons that can be captured by the substances present in the liquid thus giving rise to capture gamma rays. The energy spectrum of the gamma rays resulting from the capture of these slow or 'thermal' neutrons obtained in this manner, makes it possible to determine the presence of chlorine in the liquid and to measure its concentration so that if the degree of salinity of the liquid is known, the amount of salt water in it may be determined. Furthermore, the sulphur level can also be determined at the same time as the concentration of chlorine in certain conditions [fr

  10. Interfacial transport phenomena and stability in liquid-metal/water systems: scaling considerations

    International Nuclear Information System (INIS)

    Abdulla, S.; Liu, X.; Anderson, M.; Bonazza, R.; Corradini, M.; Cho, D.

    2001-01-01

    One concept being considered for steam generation in innovative nuclear reactor applications, involves water coming into direct contact with a circulating molten metal. The vigorous agitation of the two fluids, the direct liquid-liquid contact and the consequent large interfacial area give rise to very high heat transfer coefficients and rapid steam generation. For an optimum design of such direct contact heat exchange and vaporization systems, detailed knowledge is necessary of the various flow regimes, interfacial transport phenomena, heat transfer and operational stability. In this paper we describe current results from the first year of this research that studies the transport phenomena involved with the injection of water into molten metals (e.g., lead alloys). In particular, this work discusses scaling considerations related to direct contact heat exchange, our experimental plans for investigation and a test plan for the important experimental parameters; i.e., the water and liquid metal mass flow rates, the liquid metal pool temperature and the ambient pressure of the direct contact heat exchanger. Past experimental work and initial scaling results suggest that our experiments can directly represent the proper liquid metal pool temperature and the water subcooling. The experimental variation in water and liquid metal flow rates and system pressure (1-10 bar), although smaller than the current conceptual system designs, is sufficient to verify the expected scale effects to demonstrate the phenomena. (authors)

  11. Liquid densities and excess molar volumes for (ionic liquids + methanol + water) ternary system at atmospheric pressure and at various temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Deenadayalu, Nirmala [Department of Chemistry, Durban University of Technology, Steve Biko Campus, P.O. Box 1334, Durban, KwaZulu-Natal 4001 (South Africa)], E-mail: NirmalaD@dut.ac.za; Kumar, Satish; Bhujrajh, Pravena [Department of Chemistry, Durban University of Technology, Steve Biko Campus, P.O. Box 1334, Durban, KwaZulu-Natal 4001 (South Africa)

    2007-09-15

    Excess molar volumes, V{sub m}{sup E} have been evaluated from density measurements over the entire composition range for ternary liquid system of ionic liquid (1-ethyl-3-methyl-imidazolium diethylenglycol monomethylether sulphate {l_brace}[EMIM][CH{sub 3}(OCH{sub 2}CH{sub 2}){sub 2}OSO{sub 3}]) (1) + methanol (2) + water (3){r_brace} at T = (298.15, 303.15, and 313.15) K. A vibrating tube densimeter was used for these measurements at atmospheric pressure. The V{sub m}{sup E} values were found to be negative at T = (298.15 and 303.15) K. For {l_brace}[EMIM][CH{sub 3}(OCH{sub 2}CH{sub 2}){sub 2}OSO{sub 3}] (1) + methanol (2) + water (3){r_brace} at T = 313.15 K the V{sub m}{sup E} values become positive at higher mole fraction of ionic liquid and at a corresponding decrease in mole fraction of water. All the experimental data were fitted with the Redlich-Kister equation. The results have also been analysed in term of graph theoretical approach.

  12. Ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction combined with electrothermal atomic absorption spectrometry for a sensitive determination of cadmium in water samples

    International Nuclear Information System (INIS)

    Li Shengqing; Cai Shun; Hu Wei; Chen Hao; Liu Hanlan

    2009-01-01

    A new method was developed for the determination of cadmium in water samples using ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction (IL-based USA-DLLME) followed by electrothermal atomic absorption spectrometry (ETAAS). The IL-based USA-DLLME procedure is free of volatile organic solvents, and there is no need for a dispersive solvent, in contrast to conventional DLLME. The ionic liquid, 1-hexyl-3-methylimidazolium hexafluorophosphate (HMIMPF 6 ), was quickly disrupted by an ultrasonic probe for 1 min and dispersed in water samples like a cloud. At this stage, a hydrophobic cadmium-DDTC complex was formed and extracted into the fine droplets of HMIMPF 6 . After centrifugation, the concentration of the enriched cadmium in the sedimented phase was determined by ETAAS. Some effective parameters of the complex formation and microextraction, such as the concentration of the chelating agent, the pH, the volume of the extraction solvent, the extraction time, and the salt effect, have been optimized. Under optimal conditions, a high extraction efficiency and selectivity were reached for the extraction of 1.0 ng of cadmium in 10.0 mL of water solution employing 73 μL of HMIMPF 6 as the extraction solvent. The enrichment factor of the method is 67. The detection limit was 7.4 ng L - 1 , and the characteristic mass (m 0 , 0.0044 absorbance) of the proposed method was 0.02 pg for cadmium (Cd). The relative standard deviation (RSD) for 11 replicates of 50 ng L - 1 Cd was 3.3%. The method was applied to the analysis of tap, well, river, and lake water samples and the Environmental Water Reference Material GSBZ 50009-88 (200921). The recoveries of spiked samples were in the range of 87.2-106%.

  13. 30 CFR 250.217 - What solid and liquid wastes and discharges information and cooling water intake information must...

    Science.gov (United States)

    2010-07-01

    ... What solid and liquid wastes and discharges information and cooling water intake information must accompany the EP? The following solid and liquid wastes and discharges information and cooling water intake... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What solid and liquid wastes and discharges...

  14. Ionic liquid-based microwave-assisted dispersive liquid-liquid microextraction and derivatization of sulfonamides in river water, honey, milk, and animal plasma

    Energy Technology Data Exchange (ETDEWEB)

    Xu Xu; Su Rui; Zhao Xin; Liu Zhuang; Zhang Yupu; Li Dan; Li Xueyuan; Zhang Hanqi [College of Chemistry, Jilin University, Changchun 130012 (China); Wang Ziming, E-mail: analchem@jlu.edu.cn [College of Chemistry, Jilin University, Changchun 130012 (China)

    2011-11-30

    Graphical abstract: The extraction and derivatization efficiency of SAs is dependent on type and volume of extraction solvent, type and volume of disperser, microwave power and irradiation time, volume of derivatization reagent, pH of sample solution as well as ionic strength. Highlights: Black-Right-Pointing-Pointer A new, rapid and sensitive method for determining sulfonamides (SAs) was proposed. Black-Right-Pointing-Pointer Derivatization, extraction and preconcentration of SAs were performed in one step. Black-Right-Pointing-Pointer IL-based MADLLME and derivatization were first applied for the determination of SAs. Black-Right-Pointing-Pointer Trace SAs in river water, honey, milk, and pig plasma were determined. - Abstract: The ionic liquid-based microwave-assisted dispersive liquid-liquid microextraction (IL-based MADLLME) and derivatization was applied for the pretreatment of six sulfonamides (SAs) prior to the determination by high-performance liquid chromatography (HPLC). By adding methanol (disperser), fluorescamine solution (derivatization reagent) and ionic liquid (extraction solvent) into sample, extraction, derivatization, and preconcentration were continuously performed. Several experimental parameters, such as the type and volume of extraction solvent, the type and volume of disperser, amount of derivatization reagent, microwave power, microwave irradiation time, pH of sample solution, and ionic strength were investigated and optimized. When the microwave power was 240 W, the analytes could be derivatized and extracted simultaneously within 90 s. The proposed method was applied to the analysis of river water, honey, milk, and pig plasma samples, and the recoveries of analytes obtained were in the range of 95.0-110.8, 95.4-106.3, 95.0-108.3, and 95.7-107.7, respectively. The relative standard deviations varied between 1.5% and 7.3% (n = 5). The results showed that the proposed method was a rapid, convenient and feasible method for the determination

  15. A new dispersive liquid-liquid microextraction using ionic liquid based microemulsion coupled with cloud point extraction for determination of copper in serum and water samples.

    Science.gov (United States)

    Arain, Salma Aslam; Kazi, Tasneem Gul; Afridi, Hassan Imran; Arain, Mariam Shahzadi; Panhwar, Abdul Haleem; Khan, Naeemullah; Baig, Jameel Ahmed; Shah, Faheem

    2016-04-01

    A simple and rapid dispersive liquid-liquid microextraction procedure based on ionic liquid assisted microemulsion (IL-µE-DLLME) combined with cloud point extraction has been developed for preconcentration copper (Cu(2+)) in drinking water and serum samples of adolescent female hepatitits C (HCV) patients. In this method a ternary system was developed to form microemulsion (µE) by phase inversion method (PIM), using ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim][PF6]) and nonionic surfactant, TX-100 (as a stabilizer in aqueous media). The Ionic liquid microemulsion (IL-µE) was evaluated through visual assessment, optical light microscope and spectrophotometrically. The Cu(2+) in real water and aqueous acid digested serum samples were complexed with 8-hydroxyquinoline (oxine) and extracted into IL-µE medium. The phase separation of stable IL-µE was carried out by the micellar cloud point extraction approach. The influence of of different parameters such as pH, oxine concentration, centrifugation time and rate were investigated. At optimized experimental conditions, the limit of detection and enhancement factor were found to be 0.132 µg/L and 70 respectively, with relative standard deviation <5%. In order to validate the developed method, certified reference materials (SLRS-4 Riverine water) and human serum (Sero-M10181) were analyzed. The resulting data indicated a non-significant difference in obtained and certified values of Cu(2+). The developed procedure was successfully applied for the preconcentration and determination of trace levels of Cu(2+) in environmental and biological samples. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Path Expressions

    Science.gov (United States)

    1975-06-01

    Traditionally, synchronization of concurrent processes is coded in line by operations on semaphores or similar objects. Path expressions move the...discussion about a variety of synchronization primitives . An analysis of their relative power is found in [3]. Path expressions do not introduce yet...another synchronization primitive . A path expression relates to such primitives as a for- or while-statement of an ALGOL-like language relates to a JUMP

  17. Combining low-cost GPS receivers with upGPR to derive continuously liquid water content, snow height and snow water equivalent in Alpine snow covers

    Science.gov (United States)

    Koch, Franziska; Schmid, Lino; Prasch, Monika; Heilig, Achim; Eisen, Olaf; Schweizer, Jürg; Mauser, Wolfram

    2015-04-01

    The temporal evolution of Alpine snowpacks is important for assessing water supply, hydropower generation, flood predictions and avalanche forecasts. Especially in high mountain regions with an extremely varying topography, it is until now often difficult to derive continuous and non-destructive information on snow parameters. Since autumn 2012, we are running a new low-cost GPS (Global Positioning System) snow measurement experiment at the high alpine study site Weissfluhjoch (2450 m a.s.l.) in Switzerland. The globally and freely broadcasted GPS L1-band (1.57542 GHz) was continuously recorded with GPS antennas, which are installed at the ground surface underneath the snowpack. GPS raw data, containing carrier-to-noise power density ratio (C/N0) as well as elevation and azimuth angle information for each time step of 1 s, was stored and analyzed for all 32 GPS satellites. Since the dielectric permittivity of an overlying wet snowpack influences microwave radiation, the bulk volumetric liquid water content as well as daily melt-freeze cycles can be derived non-destructively from GPS signal strength losses and external snow height information. This liquid water content information is qualitatively in good accordance with meteorological and snow-hydrological data and quantitatively highly agrees with continuous data derived from an upward-looking ground-penetrating radar (upGPR) working in a similar frequency range. As a promising novelty, we combined the GPS signal strength data with upGPR travel-time information of active impulse radar rays to the snow surface and back from underneath the snow cover. This combination allows determining liquid water content, snow height and snow water equivalent from beneath the snow cover without using any other external information. The snow parameters derived by combining upGPR and GPS data are in good agreement with conventional sensors as e.g. laser distance gauges or snow pillows. As the GPS sensors are cheap, they can easily

  18. Modified ionic liquid cold-induced aggregation dispersive liquid-liquid microextraction followed by atomic absorption spectrometry for trace determination of zinc in water and food samples

    International Nuclear Information System (INIS)

    Zeeb, M.; Sadeghi, M.

    2011-01-01

    We report on a new method for the microextraction and determination of zinc (II). The ion is accumulated via ionic-liquid cold-induced aggregation dispersive liquid-liquid microextraction (IL-CIA-DLLME) followed by flame atomic absorption spectrometry (FAAS). The ionic liquid (IL) 1-hexyl-3-methylimidazolium hexafluorophosphate is dispersed into a heated sample solution containing sodium hexafluorophosphate as a common ion source. The solution is then placed in an ice-water bath upon which a cloudy solution forms due to the decrease of the solubility of the IL. Zinc is complexed with 8-hydroxyquinoline and extracted into the IL. The enriched phase is dissolved in a diluting agent and introduced to the FAAS. The method is not influenced by variations in the ionic strength of the sample solution. Factors affecting the performance were evaluated and optimized. At optimum conditions, the limit of detection is 0.18 μg L -1 , and the relative standard deviation is 3.0% (at n=5). The method was validated by recovery experiments and by analyzing a certified reference material and successfully applied to the determination of Zn (II) in water and food samples. (author)

  19. Determination of Gemfibrozil (Lipitor and Lopid in Water, Biological Fluids and Drug Matrix by Dispersive Liquid-Liquid micro Extraction (DLLME and Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Ghorbani A.

    2014-07-01

    Full Text Available In this study Dispersive liquid-liquid micro extraction (DLLME coupled with High performance liquid chromatography was applied for the determination of Gemfibrozil in water, drug`s matrix and biological liquids (human plasma and urine. In this method, the appropriate mixture of extraction solvent (200 μl chlorophorm and disperser solvent (1 ml methanol are injected rapidly into the aqueous sample (10.0 ml by syringe, cloudy solution is formed that consisted of fine particles of extraction solvent which is dispersed entirely into aqueous phase. The mixture was centrifuged and the extraction solvent is sedimented on the bottom of the conical test tube. 50 μl of the sedimented phase is puted in a vial and it`s solvent is evaporated. Then 1ml methanol injected to vial and 20 μL of it injected into the HPLC for separation and determination of Gemfibrozil. Some important parameters, such as kind of extraction and disperser solvent, volume of them, extraction time, pH and ionic strength of the aqueous feed solution were optimized. Under the optimum conditions, the enrichment factors and extraction recoveries were 10 and 93.64%. The linear range was (0.1-100.0 mgl-1, limit of detection was 12.3 mgl-1. The relative standard deviations (RSD for 2 mgl-1 of Gemfibrozil in water were 1.3%, (n=10.

  20. Shallow transient liquid water environments on present-day mars, and their implications for life

    Science.gov (United States)

    Jones, Eriita G.

    2018-05-01

    The identification and characterisation of subsurface liquid water environments on Mars are of high scientific interest. Such environments have the potential to support microbial life, and, more broadly, to develop our understanding of the habitability of planets and moons beyond Earth. Given our current state of knowledge of life on Earth, three pre-requisites are necessary for an environment to be considered 'habitable' and therefore capable of supporting terrestrial-like life: energy, biogenic elements, and liquid water with a sufficiently high water activity. The surface of Mars today is predominately cold and dry, and any liquid water exposed to the atmosphere will vaporise or freeze on timescales of hours to days. These conditions have likely persisted for much of the last 10 million years, and perhaps longer. Despite this, briny liquid water flows (Recurrent Slope Linea) have been observed in a number of locations in the present-day. This review examines evidence from the Phoenix Lander (2008) and the Mars Science Laboratory (2012-current), to assess the occurrence of habitable conditions in the shallow Martian regolith. It will be argued that shallow, transient, liquid water brines are potentially habitable by microbial life, are likely a widespread occurrence on Mars, and that future exploration aimed at finding present-day habitable conditions and potential biology should 'follow the salt'.

  1. Mixed reverse micelles facilitated downstream processing of lipase involving water-oil-water liquid emulsion membrane.

    Science.gov (United States)

    Bhowal, Saibal; Priyanka, B S; Rastogi, Navin K

    2014-01-01

    Our earlier work for the first time demonstrated that liquid emulsion membrane (LEM) containing reverse micelles could be successfully used for the downstream processing of lipase from Aspergillus niger. In the present work, we have attempted to increase the extraction and purification fold of lipase by using mixed reverse micelles (MRM) consisting of cationic and nonionic surfactants in LEM. It was basically prepared by addition of the internal aqueous phase solution to the organic phase followed by the redispersion of the emulsion in the feed phase containing enzyme, which resulted in globules of water-oil-water (WOW) emulsion for the extraction of lipase. The optimum conditions for maximum lipase recovery (100%) and purification fold (17.0-fold) were CTAB concentration 0.075 M, Tween 80 concentration 0.012 M, at stirring speed of 500 rpm, contact time 15 min, internal aqueous phase pH 7, feed pH 9, KCl concentration 1 M, NaCl concentration 0.1 M, and ratio of membrane emulsion to feed volume 1:1. Incorporation of the nonionic surfactant (e.g., Tween 80) resulted in remarkable improvement in the purification fold (3.1-17.0) of the lipase. LEM containing a mixture of nonionic and cationic surfactants can be successfully used for the enhancement in the activity recovery and purification fold during downstream processing of enzymes/proteins. © 2014 American Institute of Chemical Engineers.

  2. CALCULATED AND MEASURED VALUES OF LIQUID WATER CONTENT IN CLEAN AND POLLUTED ENVIRONMENTS

    Czech Academy of Sciences Publication Activity Database

    Fišák, Jaroslav; Řezáčová, Daniela; Mattanen, J.

    2006-01-01

    Roč. 50, č. 1 (2006), s. 121-130 ISSN 0039-3169 R&D Projects: GA AV ČR(CZ) IAA3042301 Institutional research plan: CEZ:AV0Z30420517 Keywords : liquid water content * visibility * air pollutant * fog /cloud water Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 0.603, year: 2006

  3. Vapor-Liquid Equilibrium of Methane with Water and Methanol. Measurements and Modeling

    DEFF Research Database (Denmark)

    Frost, Michael Grynnerup; Karakatsani, Eirini; von Solms, Nicolas

    2014-01-01

    that rely on phase equilibrium data for optimization. The objective of this work is to provide experimental data for hydrocarbon systems with polar chemicals such as alcohols, glycols, and water. New vapor-liquid equilibrium data are reported for methane + water, methane + methanol, and methane + methanol...

  4. Isobaric (vapour + liquid + liquid) equilibrium data for (di-n-propyl ether + n-propyl alcohol + water) and (diisopropyl ether + isopropyl alcohol + water) systems at 100 kPa

    International Nuclear Information System (INIS)

    Lladosa, Estela; Monton, Juan B.; Burguet, MaCruz; Torre, Javier de la

    2008-01-01

    Isobaric (vapour + liquid + liquid) equilibria were measured for the (di-n-propyl ether + n-propyl alcohol + water) and (diisopropyl ether + isopropyl alcohol + water) system at 100 kPa. The apparatus used for the determination of (vapour + liquid + liquid) equilibrium data was an all-glass dynamic recirculating still with an ultrasonic homogenizer couple to the boiling flask. The experimental data demonstrated the existence of a heterogeneous ternary azeotrope for both ternary systems. The (vapour + liquid + liquid) equilibria data were found to be thermodynamically consistent for both systems. The experimental data were compared with the estimation using UNIQUAC and NRTL models and the prediction of UNIFAC model

  5. Synergistic effect of dicarbollide anions in liquid-liquid extraction: a molecular dynamics study at the octanol-water interface.

    Science.gov (United States)

    Chevrot, G; Schurhammer, R; Wipff, G

    2007-04-28

    We report a molecular dynamics study of chlorinated cobalt bis(dicarbollide) anions [(B(9)C(2)H(8)Cl(3))(2)Co](-)"CCD(-)" in octanol and at the octanol-water interface, with the main aim to understand why these hydrophobic species act as strong synergists in assisted liquid-liquid cation extraction. Neat octanol is quite heterogeneous and is found to display dual solvation properties, allowing to well solubilize CCD(-), Cs(+) salts in the form of diluted pairs or oligomers, without displaying aggregation. At the aqueous interface, octanol behaves as an amphiphile, forming either monolayers or bilayers, depending on the initial state and confinement conditions. In biphasic octanol-water systems, CCD(-) anions are found to mainly partition to the organic phase, thus attracting Cs(+) or even more hydrophilic counterions like Eu(3+) into that phase. The remaining CCD(-) anions adsorb at the interface, but are less surface active than at the chloroform interface. Finally, we compare the interfacial behavior of the Eu(BTP)(3)(3+) complex in the absence and in the presence of CCD(-) anions and extractant molecules. It is found that when the CCD(-)'s are concentrated enough, the complex is extracted to the octanol phase. Otherwise, it is trapped at the interface, attracted by water. These results are compared to those obtained with chloroform as organic phase and discussed in the context of synergistic effect of CCD(-) in liquid-liquid extraction, pointing to the importance of dual solvation properties of octanol and of the hydrophobic character of CCD(-) for synergistic extraction of cations.

  6. Path Creation as a Process of Resource Alignment and Anchoring: Industry Formation for On-Site Water Recycling in Beijing

    NARCIS (Netherlands)

    Binz, Christian; Truffer, Bernhard|info:eu-repo/dai/nl/6603148005; Coenen, Lars

    2016-01-01

    Where and how new industrial paths emerge are much debated questions in economic geography, especially in light of the recent evolutionary turn. This article contributes to the ongoing debate on path creation with a new analytical framework that specifies the formation of generic resources in

  7. Dynamics of nanoparticle self-assembly into superhydrophobic liquid marbles during water condensation.

    Science.gov (United States)

    Rykaczewski, Konrad; Chinn, Jeff; Walker, Marlon L; Scott, John Henry J; Chinn, Amy; Jones, Wanda

    2011-12-27

    Nanoparticles adsorbed onto the surface of a drop can fully encapsulate the liquid, creating a robust and durable soft solid with superhydrophobic characteristics referred to as a liquid marble. Artificially created liquid marbles have been studied for about a decade but are already utilized in some hair and skin care products and have numerous other potential applications. These soft solids are usually formed in small quantity by depositing and rolling a drop of liquid on a layer of hydrophobic particles but can also be made in larger quantities in an industrial mixer. In this work, we demonstrate that microscale liquid marbles can also form through self-assembly during water condensation on a superhydrophobic surface covered with a loose layer of hydrophobic nanoparticles. Using in situ environmental scanning electron microscopy and optical microscopy, we study the dynamics of liquid marble formation and evaporation as well as their interaction with condensing water droplets. We demonstrate that the self-assembly of nanoparticle films into three-dimensional liquid marbles is driven by multiple coalescence events between partially covered droplets and is aided by surface flows causing rapid nanoparticle film redistribution. We also show that droplet and liquid marble coalescence can occur due to liquid-to-liquid contact or squeezing of the two objects into each other as a result of compressive forces from surrounding droplets and marbles. Irrelevant of the mechanism, coalescence of marbles and drops can cause their rapid movement across and rolling off the edge of the surface. We also demonstrate that the liquid marbles randomly moving across the surface can be captured and immobilized by hydrophilic surface patterns.

  8. Synergistic multi-sensor and multi-frequency retrieval of cloud ice water path constrained by CloudSat collocations

    International Nuclear Information System (INIS)

    Islam, Tanvir; Srivastava, Prashant K.

    2015-01-01

    The cloud ice water path (IWP) is one of the major parameters that have a strong influence on earth's radiation budget. Onboard satellite sensors are recognized as valuable tools to measure the IWP in a global scale. Albeit, active sensors such as the Cloud Profiling Radar (CPR) onboard the CloudSat satellite has better capability to measure the ice water content profile, thus, its vertical integral, IWP, than any passive microwave (MW) or infrared (IR) sensors. In this study, we investigate the retrieval of IWP from MW and IR sensors, including AMSU-A, MHS, and HIRS instruments on-board the N19 satellite, such that the retrieval is consistent with the CloudSat IWP estimates. This is achieved through the collocations between the passive satellite measurements and CloudSat scenes. Potential benefit of synergistic multi-sensor multi-frequency retrieval is investigated. Two modeling approaches are explored for the IWP retrieval – generalized linear model (GLM) and neural network (NN). The investigation has been carried out over both ocean and land surface types. The MW/IR synergy is found to be retrieved more accurate IWP than the individual AMSU-A, MHS, or HIRS measurements. Both GLM and NN approaches have been able to exploit the synergistic retrievals. - Highlights: • MW/IR synergy is investigated for IWP retrieval. • The IWP retrieval is modeled using CloudSat collocations. • Two modeling approaches are explored – GLM and ANN. • MW/IR synergy performs better than the MW or IR only retrieval

  9. [Determination of four phenolic endocrine disruptors in environmental water samples by high performance liquid chromatography-fluorescence detection using dispersive liquid-liquid microextraction coupled with derivatization].

    Science.gov (United States)

    Wang, Xiaoyan; Qi, Weimei; Zhao, Xian'en; Lü, Tao; Wang, Xiya; Zheng, Longfang; Yan, Yehao; You, Jinmao

    2014-06-01

    To achieve accurate, fast and sensitive detection of phenolic endocrine disruptors in small volume of environmental water samples, a method of dispersive liquid-liquid microextraction (DLLME) coupled with fluorescent derivatization was developed for the determination of bisphenol A, nonylphenol, octylphenol and 4-tert-octylphenol in environmental water samples by high performance liquid chromatography-fluorescence detection (HPLC-FLD). The DLLME and derivatization conditions were investigated, and the optimized DLLME conditions for small volume of environmental water samples (pH 4.0) at room temperature were as follows: 70 microL chloroform as extraction solvent, 400 microL acetonitrile as dispersing solvent, vortex mixing for 3 min, and then high-speed centrifugation for 2 min. Using 2-[2-(7H-dibenzo [a, g] carbazol-7-yl)-ethoxy] ethyl chloroformate (DBCEC-Cl) as precolumn derivatization reagent, the stable derivatives of the four phenolic endocrine disruptors were obtained in pH 10.5 Na2CO3-NaHCO3 buffer/acetonitrile at 50 degrees C for 3 min, and then separated within 10 min by HPLC-FLD. The limits of detection (LODs) were in the range of 0.9-1.6 ng/L, and the limits of quantification (LOQs) were in the range of 3.8-7.1 ng/L. This method had perfect linearity, precision and recovery results, and showed obvious advantages and practicality comparing to the previously reported methods. It is a convenient and validated method for the routine analysis of phenolic endocrine disruptors in waste water of paper mill, lake water, domestic wastewater, tap water, etc.

  10. Automated dispersive liquid-liquid microextraction coupled to high performance liquid chromatography - cold vapour atomic fluorescence spectroscopy for the determination of mercury species in natural water samples.

    Science.gov (United States)

    Liu, Yao-Min; Zhang, Feng-Ping; Jiao, Bao-Yu; Rao, Jin-Yu; Leng, Geng

    2017-04-14

    An automated, home-constructed, and low cost dispersive liquid-liquid microextraction (DLLME) device that directly coupled to a high performance liquid chromatography (HPLC) - cold vapour atomic fluorescence spectroscopy (CVAFS) system was designed and developed for the determination of trace concentrations of methylmercury (MeHg + ), ethylmercury (EtHg + ) and inorganic mercury (Hg 2+ ) in natural waters. With a simple, miniaturized and efficient automated DLLME system, nanogram amounts of these mercury species were extracted from natural water samples and injected into a hyphenated HPLC-CVAFS for quantification. The complete analytical procedure, including chelation, extraction, phase separation, collection and injection of the extracts, as well as HPLC-CVAFS quantification, was automated. Key parameters, such as the type and volume of the chelation, extraction and dispersive solvent, aspiration speed, sample pH, salt effect and matrix effect, were thoroughly investigated. Under the optimum conditions, linear range was 10-1200ngL -1 for EtHg + and 5-450ngL -1 for MeHg + and Hg 2+ . Limits of detection were 3.0ngL -1 for EtHg + and 1.5ngL -1 for MeHg + and Hg 2+ . Reproducibility and recoveries were assessed by spiking three natural water samples with different Hg concentrations, giving recoveries from 88.4-96.1%, and relative standard deviations <5.1%. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Molecular dynamics study of room temperature ionic liquids with water at mica surface

    Directory of Open Access Journals (Sweden)

    Huanhuan Zhang

    2018-04-01

    Full Text Available Water in room temperature ionic liquids (RTILs could impose significant effects on their interfacial properties at a charged surface. Although the interfaces between RTILs and mica surfaces exhibit rich microstructure, the influence of water content on such interfaces is little understood, in particular, considering the fact that RTILs are always associated with water due to their hygroscopicity. In this work, we studied how different types of RTILs and different amounts of water molecules affect the RTIL-mica interfaces, especially the water distribution at mica surfaces, using molecular dynamics (MD simulation. MD results showed that (1 there is more water and a thicker water layer adsorbed on the mica surface as the water content increases, and correspondingly the average location of K+ ions is farther from mica surface; (2 more water accumulated at the interface with the hydrophobic [Emim][TFSI] than in case of the hydrophilic [Emim][BF4] due to the respective RTIL hydrophobicity and ion size. A similar trend was also observed in the hydrogen bonds formed between water molecules. Moreover, the 2D number density map of adsorbed water revealed that the high-density areas of water seem to be related to K+ ions and silicon/aluminum atoms on mica surface. These results are of great importance to understand the effects of hydrophobicity/hydrophicility of RTIL and water on the interfacial microstructure at electrified surfaces. Keywords: Room temperature ionic liquids, Hydrophobicity/hydrophicility, Water content, Electrical double layer, Mica surface

  12. Liquid-liquid equilibria for binary and ternary systems containing glycols, aromatic hydrocarbons, and water: Experimental measurements and modeling with the CPA EoS

    DEFF Research Database (Denmark)

    Folas, Georgios; Kontogeorgis, Georgios; Michelsen, Michael Locht

    2006-01-01

    Liquid-liquid equilibrium data of four binary glycol + aromatic hydrocarbon systems and three ternary systems containing water have been measured at atmospheric pressure. The measured systems are monoethylene glycol (MEG) + benzene or toluene, triethylene glycol (TEG) + benzene or toluene, MEG...... + water + benzene, MEG + water + toluene, and TEG + water + toluene. The binary systems are correlated with the Cubic-Plus-Association (CPA) equation of state while the ternary systems are predicted from interaction parameters obtained from the binary systems. Very satisfactory liquid-liquid equilibrium...... correlations are obtained for the binary systems using temperature-independent interaction parameters, while adequate predictions are achieved for multicomponent water + glycol + aromatic hydrocarbons systems when accounting for the solvation between the aromatic hydrocarbons and glycols or water....

  13. Liquid Water Transport in the Reactant Channels of Proton Exchange Membrane Fuel Cells

    Science.gov (United States)

    Banerjee, Rupak

    Water management has been identified as a critical issue in the development of PEM fuel cells for automotive applications. Water is present inside the PEM fuel cell in three phases, i.e. liquid phase, vapor phase and mist phase. Liquid water in the reactant channels causes flooding of the cell and blocks the transport of reactants to the reaction sites at the catalyst layer. Understanding the behavior of liquid water in the reactant channels would allow us to devise improved strategies for removing liquid water from the reactant channels. In situ fuel cell tests have been performed to identify and diagnose operating conditions which result in the flooding of the fuel cell. A relationship has been identified between the liquid water present in the reactant channels and the cell performance. A novel diagnostic technique has been established which utilizes the pressure drop multiplier in the reactant channels to predict the flooding of the cell or the drying-out of the membrane. An ex-situ study has been undertaken to quantify the liquid water present in the reactant channels. A new parameter, the Area Coverage Ratio (ACR), has been defined to identify the interfacial area of the reactant channel which is blocked for reactant transport by the presence of liquid water. A parametric study has been conducted to study the effect of changing temperature and the inlet relative humidity on the ACR. The ACR decreases with increase in current density as the gas flow rates increase, removing water more efficiently. With increase in temperature, the ACR decreases rapidly, such that by 60°C, there is no significant ACR to be reported. Inlet relative humidity of the gases does change the saturation of the gases in the channel, but did not show any significant effect on the ACR. Automotive powertrains, which is the target for this work, are continuously faced with transient changes. Water management under transient operating conditions is significantly more challenging and has not

  14. Investigation of a separation process involving liquid-water-coal systems

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Jr, D V; Burry, W

    1987-01-01

    A liquid-liquid-solid separation procedure wherein a water-oil-coal-mineral matter slurry is allowed to come to equilibrium through mechanical agitation has for many years been applied to the separation of coal from mineral matter. The product is a black cottage cheese-like mass of agglomerated coal particles and oil suspended in the excess water which supports the dispersed mineral matter particles. A liquid bridge model which was proposed by earlier investigators is reviewed critically and used to estimate the free energy per unit area of the separation of coals of different ranks. Observations of the kinetics of the process suggest that the simple liquid bridge model is insufficient, probably due to the heterogeneous surfaces of the coal. An alternative model is proposed. 14 references.

  15. Disposal of liquid radioactive waste - discharge of radioactive waste waters from hospitals

    International Nuclear Information System (INIS)

    Ludwieg, F.

    1976-01-01

    A survey is given about legal prescriptions in the FRG concerning composition and amount of the liquid waste substances and waste water disposal by emitting into the sewerage, waste water decay systems and collecting and storage of patients excretions. The radiation exposure of the population due to drainage of radioactive waste water from hospitals lower by more than two orders than the mean exposure due to nuclear-medical use. (HP) [de

  16. Liquid and gaseous wastes from pressurised water reactors: International comparison

    International Nuclear Information System (INIS)

    Benedittini, M.

    1989-04-01

    This report presents the main results of a comparison on radioactive effluents releases from ninety-four PWRs in the following countries: Belgium, Federal Republic of Germany, France, Japan, Sweden, Switzerland and the United States. For liquid releases, distinctions have been undertaken between tritium and no tritium activities and for gaseous releases between noble gases and halogens-aerosols. Data have been collected from literature published or by contacting utilities responsible or authorities in order to constitute a data bank. However for the comparison, reactors for which commercial operation starts before July 1974, have been excluded. As far as the main comparative results are concerned, the averages of tritium activity per energy production unit for liquid releases are ranging between 1840 GBq/TWh and 3000 GBq/TWh and two groups of countries may be noted: those for which the results are around 2000 GBq/TWh as Frg, Japan and Switzerland and those which have an activity level around 3000 GBq/TWh as Belgium, France and Sweden. The United States are between these two groups. A factor which may provide an explanation for these discrepancies concerns practices for primary circuit: recycling it, leads to a lower tritium activity for releases and to a higher tritium activity concentration in the primary circuit. Excluding tritium, mean liquid activities per reactor are widely varying from one country to another: - lower than 0,05 GBq in Japan and in Switzerland; - from one thousand to two thousand times higher in France, Sweden and the United States. Discrepancies for gaseous activities are narrower: a factor of 40 in noble gases activities and a factor of 25 for halogens and aerosols activities. In conclusion, for activities of the tritium liquid as well as activities of all other types of radionuclides, countries can be shared in two groups according the activity level - For the lowest: FRG, Japan and Switzerland; - For the highest: Belgium, France and Sweden

  17. Liquid and gaseous wastes from pressurised water reactors: international comparison

    International Nuclear Information System (INIS)

    Benedittini, M.

    1989-04-01

    This report presents the main results of a comparison on radioactive effluents releases from ninety-four PWRs in the following countries: Belgium, Federal Republic of Germany, France, Japan, Sweden, Switzerland and the United States. For liquid releases, distinctions have been undertaken between tritium and no tritium activities and for gaseous releases between noble gases and halogens-aerosols. Data have been collected from literature published or by contacting utilities responsible or authorities in order to constitute a data bank. However for the comparison, reactors for which commercial operation starts before July 1974, have been excluded. As far as the main comparative results are concerned, the averages of tritium activity per energy production unit for liquid releases are ranging between 1840 GBq/TWh and 3000 GBq/TWh and two groups of countries may be noted: those for which the results are around 2000 GBq/TWh as FRG, Japan and Switzerland and those which have an activity level around 3000 GBq/TWh as Belgium, France and Sweden. The United States are between these two groups. A factor which may provide an explanation for these discrepancies concerns practices for primary circuit: recycling it, leads to a lower tritium activity for releases and to a higher tritium activity concentration in the primary circuit. Excluding tritium, mean liquid activities per reactor are widely varying from one country to another: - lower than 0,05 GBq in Japan and in Switzerland; - from one thousand to two thousand times higher in France, Sweden and the United States. Discrepancies for gaseous activities are narrower: a factor of 40 in noble gases activities and a factor of 25 for halogens and aerosols activities. In conclusion, for activities of the tritium liquid as well as activities of all other types of radionuclides, countries can be shared in two groups according the activity level - For the lowest: FRG, Japan and Switzerland; - For the highest: Belgium, France and Sweden

  18. Vapor-liquid equilibria for the acetone-ethanol-n-propanol-tert-butanol-water system

    Energy Technology Data Exchange (ETDEWEB)

    Tochigi, K.; Uchida, K.; Kojima, K.

    1981-12-01

    This study deals with the measurement of vapor-liquid equilibria for the five-component system acetone-ethanol-n-propanol-tert-butanol-water at 760 mmHg and prediction of vapor-liquid equilibria by the ASOG group contribution method. The five-component system in this work is composed of a part of the components obtained during ethanol production by vapor-phase hydration of ethylene. 6 refs.

  19. Extraction of butan-1-ol from water with ionic liquids at T = 308.15 K

    International Nuclear Information System (INIS)

    Domańska, Urszula; Królikowski, Marek

    2012-01-01

    Highlights: ► The LLE ternary phase diagrams with ionic liquids were measured. ► Separation of butan-1-ol/water system with tetracyanoborate-based ILs. ► Low solubility of water in [P 14,6,6,6 ][TCB] was observed. ► [P 14,6,6,6 ][TCB] is proposed for possible use in separation of butan-1-ol from aqueous phase. - Abstract: Ionic liquids (ILs) are novel green solvents that can be proposed for removing butan-1-ol from the aqueous fermentation media. Ternary (liquid + liquid) equilibrium data are presented for {ionic liquid (1) + butan-1-ol (2) + water (3)} at T = 308.15 K and ambient pressure to analyze the performance of the ionic liquid (IL) in the extraction of butan-1-ol from aqueous phase. The tetracyanoborate-based ILs have been studied: 1-hexyl-3-methylimidazolium tetracyanoborate, ([HMIM][TCB]), 1-decyl-3-methylimidazolium tetracyanoborate, ([DMIM][TCB]) and trihexyltetradecylphosphonium tetracyanoborate, ([P 14,6,6,6 ][TCB]). The results are discussed in terms of the selectivity and distribution ratio of separation of related systems. The complete miscibility in the binary liquid systems of butan-1-ol with all used ILs was observed. The imidazolium cation in comparison with phosphonium cation shows lower selectivity and distribution ratio. The IL with the longer alkyl chain at the cation shows higher selectivity and distribution ratio in this process. The non-random two liquid NRTL model was used successfully to correlate the experimental tie-lines and to calculate the phase composition error in mole fraction in the ternary systems. The average root mean square deviation (RMSD) of the phase composition was 0.0027. The data presented here indicates the usefulness of [P 14,6,6,6 ][TCB] as a solvent for the separation of butan-1-ol from water using solvent extraction. The density of [P 14,6,6,6 ][TCB] was measured as a function of temperature.

  20. Correlation of vapor - liquid equilibrium data for acetic acid - isopropanol - water - isopropyl acetate mixtures

    Directory of Open Access Journals (Sweden)

    B. A. Mandagarán

    2006-03-01

    Full Text Available A correlation procedure for the prediction of vapor - liquid equilibrium of acetic acid - isopropanol - water - isopropyl acetate mixtures has been developed. It is based on the NRTL model for predicting liquid activity coefficients, and on the Hayden-O'Connell second virial coefficients for predicting the vapor phase of systems containing association components. When compared with experimental data the correlation shows a good agreement for binary and ternary data. The correlation also shows good prediction for reactive quaternary data.

  1. Mass-controlled capillary viscometer for a Newtonian liquid: Viscosity of water at different temperatures

    Science.gov (United States)

    Digilov, Rafael M.; Reiner, M.

    2007-03-01

    The operation principle of the mass-controlled capillary viscometer is presented for a Newtonian liquid. The derived equation for the temporal changes of the mass in a liquid column draining under gravity through a discharge capillary tube accounts self-consistently for the inertial convective term associated with the acceleration effect. The viscosity of water measured at different temperatures using the new approach is in good agreement with literature data.

  2. Liquid liquid phase distribution equilibria of arsenic and its application to water samples

    International Nuclear Information System (INIS)

    Khan, A.; Ahmed, S.; Rusheed, A.

    1999-01-01

    The presence of arsenic, a toxic element, in the environment, especially in water is a serious pollution problem. The treatment of such contaminated water by ion-exchange or absorption on natural materials is time consuming and/or expensive. The removal of arsenic using 2-benzyl pyridine in benzene and its application to polluted water is described. The present technique reported herein concentrates the arsenic, up to 500 fold or even better. The time required for equilibration is only three minutes or less. No special reagent or solution is required for stripping of arsenic and simple water serves this purpose. The partition coefficients are maximal for concentrated acid solutions which are 10 M HCl +0.1 The presence of arsenic, a toxic element, in the environment, especially in water is a serious pollution problem. The treatment of such contaminated water by ion-exchange or absorption on natural materials is time consuming M KI. Arsenic can be selectively separated from associated copper, cobalt, nickel, iron, chromium and antimony. The method may find its application for the removal/ recovery of arsenic from contaminated soil, residues of incinerator and waste water from smelting of gold, silver and copper ores. (author)

  3. Substrate and surfactant effects on the glass-liquid transition of thin water films.

    Science.gov (United States)

    Souda, Ryutaro

    2006-09-07

    Temperature-programmed time-of-flight secondary ion mass spectrometry (TP-TOF-SIMS) and temperature-programmed desorption (TPD) have been used to perform a detailed investigation of the adsorption, desorption, and glass-liquid transition of water on the graphite and Ni(111) surfaces in the temperature range 13-200 K. Water wets the graphite surface at 100-120 K, and the hydrogen-bonded network is formed preferentially in the first monolayer to reduce the number of nonbonding hydrogens. The strongly chemisorbed water molecules at the Ni(111) surface do not form such a network and play a role in stabilizing the film morphology up to 160 K, where dewetting occurs abruptly irrespective of the film thickness. The surface structure of the water film formed on graphite is fluctuated considerably, resulting in deweting at 150-160 K depending on the film thickness. The dewetted patches of graphite are molecularly clean, whereas the chemisorbed water remains on the Ni(111) surface even after evaporation of the film. The abrupt drop in the desorption rate of water molecules at 160 K, which has been attributed to crystallization in the previous TPD studies, is found to disappear completely when a monolayer of methanol is present on the surface. This is because the morphology of supercooled liquid water is changed by the surface tension, and it is quenched by termination of the free OH groups on the surface. The surfactant methanol desorbs above 160 K since the hydrogen bonds of the water molecules are reconstructed. The drastic change in the properties of supercooled liquid water at 160 K should be ascribed to the liquid-liquid phase transition.

  4. Measurements and correlation of liquid-liquid equilibrium data for the ternary (3-heptanone + phenol + water) system

    International Nuclear Information System (INIS)

    Xu, Gaojie; Yang, Deling; Ning, Pengge; Wang, Qingjie; Gong, Fuchun; Cao, Hongbin

    2017-01-01

    Highlights: • The liquid-liquid equilibrium data for 3-heptanone + phenol + water were measured. • The distribution coefficient of phenol and selectivity for solvent extraction efficiency were calculated. • The NRTL model (two regression methods) and UNIQUAC model were used to correlate the experimental data with good results. • The physical meaning of the regressed binary parameters was explained by intermolecular attractive energy. • The activity coefficient of phenol and enthalpy change in extraction process were investigated. - Abstract: Liquid-liquid equilibrium (LLE) for the ternary (3-heptanone + phenol + water) system has been determined under atmospheric pressure at 298.15 K, 303.15 K, 318.15 K and 323.15 K. The NRTL and UNIQUAC models were used to correlate the experimental results. The corresponding binary parameters were obtained and their physical meaning is explained by intermolecular attractive energy. The results from the two models agree well with experimental values. The NRTL model was more accurate than that of the UNIQUAC model. Meanwhile, the NRTL model was used to regress all the experimental values at different temperatures simultaneously, which is defined as total-regression. Compared with the individual regression by the NRTL model, the total regression by the NRTL model has fewer parameters and covers a wider interpolated range from 298.15 K to 323.15 K. The distribution coefficient for phenol changes with temperature. The phenol concentration can be expressed as a function of activity coefficient of phenol in both phases. The effect of temperature on the extraction performance of 3-heptanone was also investigated. The phenol extraction process by 3-heptanone is exothermic. The increase of temperature is not a benefit to phenol extraction.

  5. Nanosecond Discharge in Bubbled Liquid n-Heptane: Effects of Gas Composition and Water Addition

    KAUST Repository

    Hamdan, Ahmad

    2016-08-30

    Recently, an aqueous discharge reactor was developed to facilitate reformation of liquid fuels by in-liquid plasma. To gain a microscopic understanding of the physical elements behind this aqueous reactor, we investigate nanosecond discharges in liquid n-heptane with single and double gaseous bubbles in the gap between electrodes. We introduce discharge probability (DP) to characterize the stochastic nature of the discharges, and we investigate the dependence of DP on the gap distance, applied voltage, gaseous bubble composition, and the water content in n-heptane/distilled-water emulsified mixtures. Propagation of a streamer through the bubbles indicates no discharges in the liquids. DP is controlled by the properties of the gaseous bubble rather than by the composition of the liquid mixture in the gap with a single bubble; meanwhile, DP is determined by the dielectric permittivity of the liquid mixture in the gap with double bubbles, results that are supported by static electric field simulations. We found that a physical mechanism of increasing DP is caused by an interaction between bubbles and an importance of the dielectric permittivity of a liquid mixture on the local enhancement of field intensity. We also discuss detailed physical characteristics, such as plasma lifetime and electron density within the discharge channel, by estimating from measured emissions with a gated-intensified charge-coupled device and by using spectroscopic images, respectively. © 1973-2012 IEEE.

  6. Water activity in liquid food systems: A molecular scale interpretation.

    Science.gov (United States)

    Maneffa, Andrew J; Stenner, Richard; Matharu, Avtar S; Clark, James H; Matubayasi, Nobuyuki; Shimizu, Seishi

    2017-12-15

    Water activity has historically been and continues to be recognised as a key concept in the area of food science. Despite its ubiquitous utilisation, it still appears as though there is confusion concerning its molecular basis, even within simple, single component solutions. Here, by close examination of the well-known Norrish equation and subsequent application of a rigorous statistical theory, we are able to shed light on such an origin. Our findings highlight the importance of solute-solute interactions thus questioning traditional, empirically based "free water" and "water structure" hypotheses. Conversely, they support the theory of "solute hydration and clustering" which advocates the interplay of solute-solute and solute-water interactions but crucially, they do so in a manner which is free of any estimations and approximations. Copyright © 2017. Published by Elsevier Ltd.

  7. Modeling and analysis of liquid deuterium-water reactions

    International Nuclear Information System (INIS)

    Taleyarkhan, R.P.

    1995-01-01

    This Presentation highlights the following: Overview of LD 2 -water reactions their connections to research reactors with cold sources; some key features and ingredients of vapor explosions in general; Examination of results of 1970 experiment at Grenoble Nuclear Research Center; Thermodynamic evaluations of energetics of explosive LD 2 -D 2 O reactions. This presentation concentrates only on the technical aspects of LD 2 /LH 2 - water reactions; it is not intended to draw/imply safety-related conclusions for research reactors

  8. Revisiting the total ion yield x-ray absorption spectra of liquid water microjets

    International Nuclear Information System (INIS)

    Saykally, Richard J; Cappa, Chris D.; Smith, Jared D.; Wilson, Kevin R.; Saykally, Richard J.

    2008-01-01

    Measurements of the total ion yield (TIY) x-ray absorption spectrum (XAS) of liquid water by Wilson et al. (2002 J. Phys.: Condens. Matter 14 L221 and 2001 J. Phys. Chem. B 105 3346) have been revisited in light of new experimental and theoretical efforts by our group. Previously, the TIY spectrum was interpreted as a distinct measure of the electronic structure of the liquid water surface. However, our new results indicate that the previously obtained spectrum may have suffered from as yet unidentified experimental artifacts. Although computational results indicate that the liquid water surface should exhibit a TIY-XAS that is fundamentally distinguishable from the bulk liquid XAS, the new experimental results suggest that the observable TIY-XAS is actually nearly identical in appearance to the total electron yield (TEY-)XAS, which is a bulk probe. This surprising similarity between the observed TIY-XAS and TEY-XAS likely results from large contributions from x-ray induced electron stimulated desorption of ions, and does not necessarily indicate that the electronic structure of the bulk liquid and liquid surface are identical

  9. Simulation of Water Level Fluctuations in a Hydraulic System Using a Coupled Liquid-Gas Model

    Directory of Open Access Journals (Sweden)

    Chao Wang

    2015-08-01

    Full Text Available A model for simulating vertical water level fluctuations with coupled liquid and gas phases is presented. The Preissmann implicit scheme is used to linearize the governing equations for one-dimensional transient flow for both liquid and gas phases, and the linear system is solved using the chasing method. Some classical cases for single liquid and gas phase transients in pipelines and networks are studied to verify that the proposed methods are accurate and reliable. The implicit scheme is extended using a dynamic mesh to simulate the water level fluctuations in a U-tube and an open surge tank without consideration of the gas phase. Methods of coupling liquid and gas phases are presented and used for studying the transient process and interaction between the phases, for gas phase limited in a chamber and gas phase transported in a pipeline. In particular, two other simplified models, one neglecting the effect of the gas phase on the liquid phase and the other one coupling the liquid and gas phases asynchronously, are proposed. The numerical results indicate that the asynchronous model performs better, and are finally applied to a hydropower station with surge tanks and air shafts to simulate the water level fluctuations and air speed.

  10. Determination of thiobencarb in water samples by gas chromatography using a homogeneous liquid-liquid microextraction via flotation assistance procedure

    Directory of Open Access Journals (Sweden)

    H.A. Mashayekhi

    2013-09-01

    Full Text Available Homogeneous liquid-liquid microextraction via flotation assistance (HLLME-FA coupled with gas chromatography-flame ionization detection (GC-FID was applied for the extraction and determination of thiobencarb in water samples. In this study, a special extraction cell was designed to facilitate collection of the low-density solvent extraction. No centrifugation was required in this procedure. The water sample solution was added into the extraction cell which contained an appropriate mixture of toluene (as an extraction solvent and acetone (as a homogeneous solvent. By using air flotation, the organic solvent was collected at the conical part of the designed cell. The effect of the different parameters on the efficiency of extraction such as type and volume of extraction and homogeneous solvents, ionic strength and extraction time were studied and optimized. Under the optimal conditions, linearity of the method was in the range of 1.0-200 µg L-1. The relative standard deviations in the real samples varied from 7.8-11.7 % (n = 3. The proposed method was successfully applied to analysis of thiobencarb in the water samples and satisfactory results were obtained.DOI: http://dx.doi.org/10.4314/bcse.v27i3.4

  11. Development of a dispersive liquid-liquid microextraction method for the determination of polychlorinated biphenyls in water

    International Nuclear Information System (INIS)

    Rezaei, Fatemeh; Bidari, Araz; Birjandi, Afsoon Pajand; Milani Hosseini, Mohammad Reza; Assadi, Yaghoub

    2008-01-01

    A very simple and powerful microextraction procedure, the dispersive liquid-liquid microextraction (DLLME), was used for the determination of the content of 10 polychlorinated biphenyls (PCBs) in water samples, using gas chromatography coupled with electron-capture detection (GC-ECD). The appropriate amount of acetone (disperser solvent) and chlorobenzene (extraction solvent) at the microlevel volume was used for this procedure. The conditions for the microextraction performance were investigated and optimized. The optimized method exhibited a good linearity (R 2 > 0.996) over the studied range (0.005-2 μg L -1 ), illustrating a satisfactory precision level with R.S.D. values between 4.1% and 11.0%. The values of the detection limit (S/N = 3) were found to be lower than 0.002 μg L -1 . Furthermore, a large enrichment factor for the analytes (up to a 540-fold) was achieved in a very short time for only a 5.00-mL water sample. The effectiveness of the method towards real samples was tested by analyzing well, river and seawater samples. The relative recoveries of the well, river and seawater samples, which had been spiked with different levels of PCBs were equal to 92.0-114.0%, 97.0-102.0% and 96.0-103.0%, respectively. The attained results demonstrated that DLLME combined with GC-ECD was a fast and inexpensive technique for the PCBs determination in water samples

  12. Speciation of mercury in water samples by dispersive liquid-liquid microextraction combined with high performance liquid chromatography-inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Jia Xiaoyu; Han Yi; Liu Xinli [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Duan Taicheng, E-mail: tcduan@ciac.jl.cn [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022 (China); Chen Hangting, E-mail: htchen@ciac.jl.cn [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022 (China)

    2011-01-15

    The dispersive liquid-liquid microextraction (DLLME) combined with high performance liquid chromatography-inductively coupled plasma mass spectrometry for the speciation of mercury in water samples was described. Firstly methylmercury (MeHg{sup +}) and mercury (Hg{sup 2+}) were complexed with sodium diethyldithiocarbamate, and then the complexes were extracted into carbon tetrachloride by using DLLME. Under the optimized conditions, the enrichment factors of 138 and 350 for MeHg{sup +} and Hg{sup 2+} were obtained from only 5.00 mL sample solution. The detection limits of the analytes (as Hg) were 0.0076 ng mL{sup -1} for MeHg{sup +} and 0.0014 ng mL{sup -1} for Hg{sup 2+}, respectively. The relative standard deviations for ten replicate measurements of 0.5 ng mL{sup -1} MeHg{sup +} and Hg{sup 2+} were 6.9% and 4.4%, respectively. Standard reference material of seawater (GBW(E)080042) was analyzed to verify the accuracy of the method and the results were in good agreement with the certified values. Finally, the developed method was successfully applied for the speciation of mercury in three environmental water samples.

  13. Speciation of mercury in water samples by dispersive liquid-liquid microextraction combined with high performance liquid chromatography-inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Jia Xiaoyu; Han Yi; Liu Xinli; Duan Taicheng; Chen Hangting

    2011-01-01

    The dispersive liquid-liquid microextraction (DLLME) combined with high performance liquid chromatography-inductively coupled plasma mass spectrometry for the speciation of mercury in water samples was described. Firstly methylmercury (MeHg + ) and mercury (Hg 2+ ) were complexed with sodium diethyldithiocarbamate, and then the complexes were extracted into carbon tetrachloride by using DLLME. Under the optimized conditions, the enrichment factors of 138 and 350 for MeHg + and Hg 2+ were obtained from only 5.00 mL sample solution. The detection limits of the analytes (as Hg) were 0.0076 ng mL -1 for MeHg + and 0.0014 ng mL -1 for Hg 2+ , respectively. The relative standard deviations for ten replicate measurements of 0.5 ng mL -1 MeHg + and Hg 2+ were 6.9% and 4.4%, respectively. Standard reference material of seawater (GBW(E)080042) was analyzed to verify the accuracy of the method and the results were in good agreement with the certified values. Finally, the developed method was successfully applied for the speciation of mercury in three environmental water samples.

  14. Freely accessible water does not decrease consumption of ethanol liquid diets.

    Science.gov (United States)

    de Fiebre, NancyEllen C; de Fiebre, Christopher M

    2003-02-01

    In experimental studies, liquid ethanol diets are usually given as the sole source of nutrition and fluid. Two series of experiments were conducted to examine the effect of freely accessible water on the consumption of ethanol liquid diets in male Long-Evans rats. The consumption of diets and subsequent learning ability of rats were first examined in animals given twice-daily saline injections. One group received diet with no access to water for 12 weeks and was subsequently given free access to water with diets for an additional 12 weeks. A second group was given diet and water ad libitum for 24 weeks. Control animals received an isocaloric sucrose-containing diet (with or without ad libitum access to water). Subsequently, rats were tested for active avoidance learning. In the first 12 weeks, animals with ad libitum access to water drank more diet than did water-restricted animals, and previously water-restricted animals increased their diet consumption when access to water was freely available. All water-restricted animals, in both ethanol- and sucrose-treated groups, showed deficits in active avoidance learning, whereas only ethanol-treated animals in groups with ad libitum access to water showed learning deficits. In the second series of experiments, the effect of saline injections on diet consumption, both in the presence and absence of water, was examined. Although saline injections were associated with decreased diet consumption, there was no effect of free access to water. No differences in blood ethanol concentration were seen among groups. Findings obtained from both series of studies demonstrate that consumption of a Sustacal-based liquid ethanol diet does not decrease if access to water is freely available.

  15. Optical properties and bioavailability of dissolved organic matter along a flow-path continuum from soil pore waters to the Kolyma River mainstem, East Siberia

    Science.gov (United States)

    Frey, Karen E.; Sobczak, William V.; Mann, Paul J.; Holmes, Robert M.

    2016-04-01

    The Kolyma River in northeast Siberia is among the six largest Arctic rivers and drains a region underlain by vast deposits of Holocene-aged peat and Pleistocene-aged loess known as yedoma, most of which is currently stored in ice-rich permafrost throughout the region. These peat and yedoma deposits are important sources of dissolved organic matter (DOM) to inland waters that in turn play a significant role in the transport and ultimate remineralization of organic carbon to CO2 and CH4 along the terrestrial flow-path continuum. The turnover and fate of terrigenous DOM during offshore transport largely depends upon the composition and amount of carbon released to inland and coastal waters. Here, we measured the ultraviolet-visible optical properties of chromophoric DOM (CDOM) from a geographically extensive collection of waters spanning soil pore waters, streams, rivers, and the Kolyma River mainstem throughout a ˜ 250 km transect of the northern Kolyma River basin. During the period of study, CDOM absorption coefficients were found to be robust proxies for the concentration of DOM, whereas additional CDOM parameters such as spectral slopes (S) were found to be useful indicators of DOM quality along the flow path. In particular, the spectral slope ratio (SR) of CDOM demonstrated statistically significant differences between all four water types and tracked changes in the concentration of bioavailable DOC, suggesting that this parameter may be suitable for clearly discriminating shifts in organic matter characteristics among water types along the full flow-path continuum across this landscape. However, despite our observations of downstream shifts in DOM composition, we found a relatively constant proportion of DOC that was bioavailable ( ˜ 3-6 % of total DOC) regardless of relative water residence time along the flow path. This may be a consequence of two potential scenarios allowing for continual processing of organic material within the system, namely (a

  16. Seeing real-space dynamics of liquid water through inelastic x-ray scattering.

    Science.gov (United States)

    Iwashita, Takuya; Wu, Bin; Chen, Wei-Ren; Tsutsui, Satoshi; Baron, Alfred Q R; Egami, Takeshi

    2017-12-01

    Water is ubiquitous on earth, but we know little about the real-space motion of molecules in liquid water. We demonstrate that high-resolution inelastic x-ray scattering measurement over a wide range of momentum and energy transfer makes it possible to probe real-space, real-time dynamics of water molecules through the so-called Van Hove function. Water molecules are found to be strongly correlated in space and time with coupling between the first and second nearest-neighbor molecules. The local dynamic correlation of molecules observed here is crucial to a fundamental understanding of the origin of the physical properties of water, including viscosity. The results also suggest that the quantum-mechanical nature of hydrogen bonds could influence its dynamics. The approach used here offers a powerful experimental method for investigating real-space dynamics of liquids.

  17. Effect of alkanolammonium formates ionic liquids on vapour liquid equilibria of binary systems containing water, methanol, and ethanol

    International Nuclear Information System (INIS)

    Li Xuemei; Shen Chong; Li Chunxi

    2012-01-01

    Highlights ► Vapour pressures for six ternary systems containing an IL were measured. ► Components studied were water, ethanol, methanol, and alkanolammonium formates. ► The isobaric VLE were predicted using the fitted binary NRTL parameters. ► The ILs studied can generate a promising salt effect on VLE of azeotrope. ► [HMEA][HCOO] might be used as a potential entrainer in extractive distillation. - Abstract: Vapour pressures were measured using a quasi-static ebulliometer for the pseudo-binary mixtures of (water + ethanol), (water + methanol), and (methanol + ethanol) containing an alkanolammonium-based ionic liquid (IL), namely, mono-ethanolammonium formate ([HMEA][HCOO]) and di-ethanolammonium formate ([HDEA][HCOO]), respectively, with fixed IL mass fraction of 0.30 and over the temperature ranges of (292.12 to 371.13) K. The vapour pressures of the IL-containing ternary systems were favourably correlated using the NRTL model with an overall average absolute relative deviation (AARD) of 0.0082. Further, the salt effects of [HMEA][HCOO] and [HDEA][HCOO] on isobaric vapour liquid equilibria (VLE) of azeotrope and close boiling mixture, especially for the mixtures of (water + ethanol) and (methanol + ethanol), were investigated and compared with other ILs in terms of the x′–y phase diagrams predicted with the binary NRTL parameters. It is demonstrated that the relative volatilities of ethanol to water and ethanol to methanol are enhanced, and [HMEA][HCOO] might be used as a promising entrainer for the efficient separation of ethanol aqueous solution by special rectification.

  18. If Frisch is true - impacts of varying beam width, resolution, frequency combinations and beam overlap when retrieving liquid water content profiles

    Science.gov (United States)

    Küchler, N.; Kneifel, S.; Kollias, P.; Loehnert, U.

    2017-12-01

    Cumulus and stratocumulus clouds strongly affect the Earth's radiation budget and are a major uncertainty source in weather and climate prediction models. To improve and evaluate models, a comprehensive understanding of cloud processes is necessary and references are needed. Therefore active and passive microwave remote sensing of clouds can be used to derive cloud properties such as liquid water path and liquid water content (LWC), which can serve as a reference for model evaluation. However, both the measurements and the assumptions when retrieving physical quantities from the measurements involve uncertainty sources. Frisch et al. (1998) combined radar and radiometer observations to derive LWC profiles. Assuming their assumptions are correct, there will be still uncertainties regarding the measurement setup. We investigate how varying beam width, temporal and vertical resolutions, frequency combinations, and beam overlap of and between the two instruments influence the retrieval of LWC profiles. Especially, we discuss the benefit of combining vertically, high resolved radar and radiometer measurements using the same antenna, i.e. having ideal beam overlap. Frisch, A. S., G. Feingold, C. W. Fairall, T. Uttal, and J. B. Snider, 1998: On cloud radar and microwave radiometer measurements of stratus cloud liquid water profiles. J. Geophys. Res.: Atmos., 103 (18), 23 195-23 197, doi:0148-0227/98/98JD-01827509.00.

  19. Method for determination of radon-222 in water by liquid scintillation counting

    International Nuclear Information System (INIS)

    Suomela, J.

    1993-06-01

    The procedure for the determination of radon-222 by liquid scintillation counting is quite specific for this radionuclide. Radon-222 is extracted readily from the water sample by an organic scintillant. The decay products of radon-222 will remain in the water phase whilst radon-222 will be extracted into the organic phase. Before measurement the sample is stored for three hours until equilibrium is reached between radon-222 and its alpha emitting decay products. The alpha activity from radon-222 and its decay products is measured in a liquid scintillation counter

  20. Pressure evolution of the high-frequency sound velocity in liquid water

    International Nuclear Information System (INIS)

    Krisch, M.; Sette, F.; D'Astuto, M.; Lorenzen, M.; Mermet, A.; Monaco, G.; Verbeni, R.; Loubeyre, P.; Le Toullec, R.; Ruocco, G.; Cunsolo, A.

    2002-01-01

    The high-frequency sound velocity v ∞ of liquid water has been determined to densities of 1.37 g/cm 3 by inelastic x-ray scattering. In comparison to the hydrodynamic sound velocity v 0 , the increase of v ∞ with density is substantially less pronounced, indicating that, at high density, the hydrogen-bond network is decreasingly relevant to the physical properties of liquid water. Furthermore, we observe an anomaly in v ∞ at densities around 1.12 g/cm 3 , contrasting the smooth density evolution of v 0

  1. (Liquid + liquid) equilibrium data for the system (propylene glycol + water + tetraoctyl ammonium 2-methyl-1-naphthoate)

    NARCIS (Netherlands)

    Garcia Chavez, L.Y.; Shazad, Maryam; Schuur, B.; Haan, de A.B.

    2012-01-01

    Propylene glycol (PG) is an important low toxic glycol, widely used in the food, cosmetics, pharmaceutical and the chemical industries. The recovery of PG from aqueous streams using conventional unit operations such as evaporation is highly energy demanding because of the large amounts of water that

  2. Two-state thermodynamics and the possibility of a liquid-liquid phase transition in supercooled TIP4P/2005 water

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Rakesh S.; Debenedetti, Pablo G. [Department of Chemical & Biological Engineering, Princeton University, Princeton, New Jersey 08544 (United States); Biddle, John W.; Anisimov, Mikhail A., E-mail: anisimov@umd.edu [Institute of Physical Science and Technology and Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742 (United States)

    2016-04-14

    Water shows intriguing thermodynamic and dynamic anomalies in the supercooled liquid state. One possible explanation of the origin of these anomalies lies in the existence of a metastable liquid-liquid phase transition (LLPT) between two (high and low density) forms of water. While the anomalies are observed in experiments on bulk and confined water and by computer simulation studies of different water-like models, the existence of a LLPT in water is still debated. Unambiguous experimental proof of the existence of a LLPT in bulk supercooled water is hampered by fast ice nucleation which is a precursor of the hypothesized LLPT. Moreover, the hypothesized LLPT, being metastable, in principle cannot exist in the thermodynamic limit (infinite size, infinite time). Therefore, computer simulations of water models are crucial for exploring the possibility of the metastable LLPT and the nature of the anomalies. In this work, we present new simulation results in the NVT ensemble for one of the most accurate classical molecular models of water, TIP4P/2005. To describe the computed properties and explore the possibility of a LLPT, we have applied two-structure thermodynamics, viewing water as a non-ideal mixture of two interconvertible local structures (“states”). The results suggest the presence of a liquid-liquid critical point and are consistent with the existence of a LLPT in this model for the simulated length and time scales. We have compared the behavior of TIP4P/2005 with other popular water-like models, namely, mW and ST2, and with real water, all of which are well described by two-state thermodynamics. In view of the current debate involving different studies of TIP4P/2005, we discuss consequences of metastability and finite size in observing the liquid-liquid separation. We also address the relationship between the phenomenological order parameter of two-structure thermodynamics and the microscopic nature of the low-density structure.

  3. Two-state thermodynamics and the possibility of a liquid-liquid phase transition in supercooled TIP4P/2005 water

    International Nuclear Information System (INIS)

    Singh, Rakesh S.; Debenedetti, Pablo G.; Biddle, John W.; Anisimov, Mikhail A.

    2016-01-01

    Water shows intriguing thermodynamic and dynamic anomalies in the supercooled liquid state. One possible explanation of the origin of these anomalies lies in the existence of a metastable liquid-liquid phase transition (LLPT) between two (high and low density) forms of water. While the anomalies are observed in experiments on bulk and confined water and by computer simulation studies of different water-like models, the existence of a LLPT in water is still debated. Unambiguous experimental proof of the existence of a LLPT in bulk supercooled water is hampered by fast ice nucleation which is a precursor of the hypothesized LLPT. Moreover, the hypothesized LLPT, being metastable, in principle cannot exist in the thermodynamic limit (infinite size, infinite time). Therefore, computer simulations of water models are crucial for exploring the possibility of the metastable LLPT and the nature of the anomalies. In this work, we present new simulation results in the NVT ensemble for one of the most accurate classical molecular models of water, TIP4P/2005. To describe the computed properties and explore the possibility of a LLPT, we have applied two-structure thermodynamics, viewing water as a non-ideal mixture of two interconvertible local structures (“states”). The results suggest the presence of a liquid-liquid critical point and are consistent with the existence of a LLPT in this model for the simulated length and time scales. We have compared the behavior of TIP4P/2005 with other popular water-like models, namely, mW and ST2, and with real water, all of which are well described by two-state thermodynamics. In view of the current debate involving different studies of TIP4P/2005, we discuss consequences of metastability and finite size in observing the liquid-liquid separation. We also address the relationship between the phenomenological order parameter of two-structure thermodynamics and the microscopic nature of the low-density structure.

  4. Additional collection devices used in conjunction with the SurePath Liquid-Based Pap Test broom device do not enhance diagnostic utility

    Directory of Open Access Journals (Sweden)

    O'Connor Jason C

    2004-09-01

    Full Text Available Abstract Background We have previously shown that use of an EC brush device in combination with the Rovers Cervex-Brush (SurePath broom offered no significant improvement in EC recovery. Here we determine if use of additional collection devices enhance the diagnostic utility of the SurePath Pap for gynecologic cytology. Methods After informed consent, 37 women ages 18–56 receiving their routine cervical examinations were randomized into four experimental groups. Each group was first sampled with the SurePath broom then immediately re-sampled with an additional collection device or devices. Group 1: Rover endocervix brush (n = 8. Group 2: Medscand CytoBrush Plus GT (n = 7. Group 3: Rover spatula + endocervix brush (n = 11. Group 4: Medscand spatula + CytoBrush Plus GT (n = 11. Results Examination of SurePath broom-collected cytology yielded the following abnormal diagnoses: atypia (n = 2, LSIL (n = 5 and HSIL (n = 3. Comparison of these diagnoses to those obtained from paired samples using the additional collection devices showed that use of a second and or third device yielded no additional abnormal diagnoses. Importantly, use of additional devices did not improve upon the abnormal cell recovery of the SurePath broom and in 4/10 cases under-predicted or did not detect the SurePath broom-collected lesion as confirmed by cervical biopsy. Finally, in 36/37 cases, the SurePath broom successfully recovered ECs. Use of additional devices, in Group 3, augmented EC recovery to 37/37. Conclusions Use of additional collection devices in conjunction with the SurePath broom did not enhance diagnostic utility of the SurePath Pap. A potential but not significant improvement in EC recovery might be seen with the use of three devices.

  5. APTIMA assay on SurePath liquid-based cervical samples compared to endocervical swab samples facilitated by a real time database

    Directory of Open Access Journals (Sweden)

    Khader Samer

    2010-01-01

    Full Text Available Background: Liquid-based cytology (LBC cervical samples are increasingly being used to test for pathogens, including: HPV, Chlamydia trachomatis (CT and Neisseria gonorrhoeae (GC using nucleic acid amplification tests. Several reports have shown the accuracy of such testing on ThinPrep (TP LBC samples. Fewer studies have evaluated SurePath (SP LBC samples, which utilize a different specimen preservative. This study was undertaken to assess the performance of the Aptima Combo 2 Assay (AC2 for CT and GC on SP versus endocervical swab samples in our laboratory. Materials and Methods: The live pathology database of Montefiore Medical Center was searched for patients with AC2 endocervical swab specimens and SP Paps taken the same day. SP samples from CT- and/or GC-positive endocervical swab patients and randomly selected negative patients were studied. In each case, 1.5 ml of the residual SP vial sample, which was in SP preservative and stored at room temperature, was transferred within seven days of collection to APTIMA specimen transfer tubes without any sample or patient identifiers. Blind testing with the AC2 assay was performed on the Tigris DTS System (Gen-probe, San Diego, CA. Finalized SP results were compared with the previously reported endocervical swab results for the entire group and separately for patients 25 years and younger and patients over 25 years. Results: SP specimens from 300 patients were tested. This included 181 swab CT-positive, 12 swab GC-positive, 7 CT and GC positive and 100 randomly selected swab CT and GC negative patients. Using the endocervical swab results as the patient′s infection status, AC2 assay of the SP samples showed: CT sensitivity 89.3%, CT specificity 100.0%; GC sensitivity and specificity 100.0%. CT sensitivity for patients 25 years or younger was 93.1%, versus 80.7% for patients over 25 years, a statistically significant difference (P = 0.02. Conclusions: Our results show that AC2 assay of 1.5 ml SP

  6. Dynamic lifetimes of cagelike water clusters immersed in liquid water and their implications for hydrate nucleation studies

    Energy Technology Data Exchange (ETDEWEB)

    Guo, G.J.; Zhang, Y.G.; Li, M.; Wu, C.H. [Chinese Academy of Sciences, Inst. of Geology and Geophysics, Beijing (China). Key Laboratory of the Study of Earth' s Deep Interior

    2008-07-01

    In hydrate research fields, the hydrate nucleation mechanism still remains as an unsolved question. The static lifetimes of cagelike water clusters (CLWC) immersed in bulk liquid water have recently been measured by performing molecular dynamics simulations in the methane-water system, during which the member-water molecules of CLWCs are not allowed to exchange with their surrounding water molecules. This paper presented a study that measured the dynamic lifetimes of CLWCs permitting such water exchanges. The study involved re-analysis of previous simulation data that were used to study the effect of methane adsorption on the static lifetimes of a dodecahedral water cluster (DWC). The dynamic lifetimes of the DWC were calculated. The results of lifetime measurements of DWC in different systems were provided. The implications of this study for hydrate nucleation were also discussed. It was found that the dynamic lifetimes of CLWCs were not less than the static lifetimes previously obtained, and their ratio increased with the lifetime values. The results strengthened that CLWCs are metastable structures in liquid water and the occurrence probability of long-lived CLWCs will increase if one uses the dynamic lifetimes instead of the static lifetimes. 13 refs., 1 tab., 3 figs.

  7. Effect of simple solutes on the long range dipolar correlations in liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Baul, Upayan, E-mail: upayanb@imsc.res.in; Anishetty, Ramesh, E-mail: ramesha@imsc.res.in; Vemparala, Satyavani, E-mail: vani@imsc.res.in [The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600113 (India); Kanth, J. Maruthi Pradeep, E-mail: jmpkanth@gmail.com [Vectra LLC, Mount Road, Chennai 600006 (India)

    2016-03-14

    Intermolecular correlations in liquid water at ambient conditions have generally been characterized through short range density fluctuations described through the atomic pair distribution functions. Recent numerical and experimental results have suggested that such a description of order or structure in liquid water is incomplete and there exist considerably longer ranged orientational correlations in water that can be studied through dipolar correlations. In this study, using large scale classical, atomistic molecular dynamics simulations using TIP4P-Ew and TIP3P models of water, we show that salts such as sodium chloride (NaCl), potassium chloride (KCl), caesium chloride (CsCl), and magnesium chloride (MgCl{sub 2}) have a long range effect on the dipolar correlations, which cannot be explained by the notion of structure making and breaking by dissolved ions. Observed effects are explained through orientational stratification of water molecules around ions and their long range coupling to the global hydrogen bond network by virtue of the sum rule for water. The observations for single hydrophilic solutes are contrasted with the same for a single methane (CH{sub 4}) molecule. We observe that even a single small hydrophobe can result in enhancement of long range orientational correlations in liquid water, contrary to the case of dissolved ions, which have been observed to have a reducing effect. The observations from this study are discussed in the context of hydrophobic effect.

  8. Vapor-liquid equilibria of the water + 1,3-propanediol and water + 1,3-propanediol + lithium bromide systems

    Energy Technology Data Exchange (ETDEWEB)

    Mun, S Y; Lee, H

    1999-12-01

    Vapor-liquid equilibrium data of the water + 1,3-propanediol and water + 1,3-propanediol + lithium bromide systems were measured at 60, 160, 300, and 760 mmHg at temperatures ranging from 315 to 488 K. The apparatus used in this work is a modified still especially designed for the measurement of low-pressure VLE, in which both liquid and vapor are continuously recirculated. For the analysis of salt-containing solutions, a method incorporating refractometry and gravimetry was used. From the experimental measurements, the effect of lithium bromide on the VLE behavior of water + 1,3-propanediol was investigated. The experimental data of the salt-free system were successfully correlated using the Wilson, NRTL, and UNIQUAC models. In addition, the extended UNIQUAC model of Sander et al. was applied to the VLE calculation of salt-containing mixtures.

  9. Phase equilibria of didecyldimethylammonium nitrate ionic liquid with water and organic solvents

    International Nuclear Information System (INIS)

    Domanska, Urszula; Lugowska, Katarzyna; Pernak, Juliusz

    2007-01-01

    The phase diagrams for binary mixtures of an ammonium ionic liquid, didecyldimethylammonium nitrate, [DDA][NO 3 ], with: alcohols (propan-1-ol, butan-1-ol, octan-1-ol, and decan-1-ol): hydrocarbons (toluene, propylbenzene, hexane, and hexadecane) and with water were determined in our laboratory. The phase equilibria were measured by a dynamic method from T 220 K to either the melting point of the ionic liquid, or to the boiling point of the solvent. A simple liquidus curve in a eutectic system was observed for [DDA][NO 3 ] with: alcohols (propan-1-ol, butan-1-ol, and octan-1-ol); aromatic hydrocarbons (toluene and propylbenzene) and with water. (Solid + liquid) equilibria with immiscibility in the liquid phase were detected with the aliphatic hydrocarbons heptane and hexadecane and with decan-1-ol. (Liquid + liquid) equilibria for the system [DDA][NO 3 ] with hexadecane was observed for the whole mole fraction range of the ionic liquid. The observation of the upper critical solution temperature in binary mixtures of ([DDA][NO 3 ] + decan-1-ol, heptane, or hexadecane) was limited by the boiling temperature of the solvent. Characterisation and purity of the compounds were determined by elemental analysis, water content (Fisher method) and differential scanning microcalorimetry (d.s.c.) analysis. The d.s.c. method of analysis was used to determine melting temperatures and enthalpies of fusion. The thermal stability of the ionic liquid was resolved by the thermogravimetric technique-differential thermal analysis (TG-DTA) technique over a wide temperature range from (200 to 780) K. The thermal decomposition temperature of 50% of the sample was greater than 500 K. The (solid + liquid) phase equilibria, curves were correlated by means of different G Ex models utilizing parameters derived from the (solid + liquid) equilibrium. The root-mean-square deviations of the solubility temperatures for all calculated data are dependent upon the particular system and the particular

  10. Visual observation of gas hydrates nucleation and growth at a water - organic liquid interface

    Science.gov (United States)

    Stoporev, Andrey S.; Semenov, Anton P.; Medvedev, Vladimir I.; Sizikov, Artem A.; Gushchin, Pavel A.; Vinokurov, Vladimir A.; Manakov, Andrey Yu.

    2018-03-01

    Visual observation of nucleation sites of methane and methane-ethane-propane hydrates and their further growth in water - organic liquid - gas systems with/without surfactants was carried out. Sapphire Rocking Cell RCS6 with transparent sapphire cells was used. The experiments were conducted at the supercooling ΔTsub = 20.2 °C. Decane, toluene and crude oils were used as organics. Gas hydrate nucleation occurred on water - metal - gas and water - sapphire - organic liquid three-phase contact lines. At the initial stage of growth hydrate crystals rapidly covered the water - gas or water - organics interfaces (depending on the nucleation site). Further hydrate phase accrete on cell walls (sapphire surface) and into the organics volume. At this stage, growth was accompanied by water «drawing out» from under initial hydrate film formed at water - organic interface. Apparently, it takes place due to water capillary inflow in the reaction zone. It was shown that the hydrate crystal morphology depends on the organic phase composition. In the case of water-in-decane emulsion relay hydrate crystallization was observed in the whole sample, originating most likely due to the hydrate crystal intergrowth through decane. Contacts of such crystals with adjacent water droplets result in rapid hydrate crystallization on this droplet.

  11. Analysis of phenolic acids by ionic liquid-in-water microemulsion liquid chromatography coupled with ultraviolet and electrochemical detector.

    Science.gov (United States)

    Peng, Li-Qing; Cao, Jun; Du, Li-Jing; Zhang, Qi-Dong; Shi, Yu-Tin; Xu, Jing-Jing

    2017-05-26

    An environmentally friendly ionic liquid-in-water (IL/W) microemulsion was established and applied as mobile phase in microemulsion liquid chromatography (MELC) with ultraviolet (UV) detection or electrochemical detector (ECD) for analysis of phenolic compounds in real samples. The optimal condition of the method was using the best composition of microemulsion (0.2% w/v [HMIM]PF 6 , 1.0% w/v SDS, 3.0% w/v n-butanol, 95.8% v/v water, pH 2.5) with UV detection. The validation results indicated that the method provided high degree of sensitivity, precision and accuracy with the low limit of detections ranged from 17.9-238ng/mL, satisfactory mean recovery values in the range of 80.1-105% and good linearity (r 2 >0.9994). Additionally, this method exhibited high selectivity and resolution for the analytes and was more eco-friendly compared with traditional MELC method. Consequently, the established IL/W MELC method was successfully applied to simultaneously separate and determine target compounds in Danshen sample and its preparation. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Automated high performance liquid chromatography and liquid scintillation counting determination of pesticide mixture octanol/water partition rates

    International Nuclear Information System (INIS)

    Moody, R.P.; Carroll, J.M.; Kresta, A.M.

    1987-01-01

    Two novel methods are reported for measuring octanol/water partition rates of pesticides. A liquid scintillation counting (LSC) method was developed for automated monitoring of 14 C-labeled pesticides partitioning in biphasic water/octanol cocktail systems with limited success. A high performance liquid chromatography (HPLC) method was developed for automated partition rate monitoring of several constituents in a pesticide mixture, simultaneously. The mean log Kow +/- SD determined from triplicate experimental runs were for: 2,4-D-DMA (2,4-dichlorophenoxyacetic acid dimethylamine), 0.65 +/- .17; Deet (N,N-diethyl-m-toluamide), 2.02 +/- .01; Guthion (O,O-dimethyl-S-(4-oxo-1,2,3-benzotriazin-3(4H)-ylmethyl) phosphorodithioate), 2.43 +/- .03; Methyl-Parathion (O,O-dimethyl-O-(p-nitrophenyl) phosphorothioate), 2.68 +/- .05; and Fenitrothion (O,O-dimethyl O-(4-nitro-m-tolyl) phosphorothioate), 3.16 +/- .03. A strong positive linear correlation (r = .9979) was obtained between log Kow and log k' (log Kow = 2.35 (log k') + 0.63). The advantages that this automated procedure has in comparison with the standard manual shake-flask procedure are discussed

  13. Determination of lead in environmental waters with dispersive liquid-liquid microextraction prior to atomic fluorescence spectrometry

    International Nuclear Information System (INIS)

    Zhou, Qingxiang; Zhao, Na; Xie, Guohong

    2011-01-01

    This paper established a new, rapid and sensitive method for the determination of lead in water samples preconcentrated by dispersive liquid-liquid microextraction (DLLME) prior to atomic fluorescence spectrometry. Dithizone was used as the chelating agent. In the DLLME procedure, lead formed lead-dithizone complex and migrated into the carbon tetrachloride micro-droplets. Important factors that would affect the extraction efficiency had been investigated including the kind and volume of extraction solvent and dispersive solvent, sample pH, the amount of chelating agent, extraction time and centrifugation time. The results showed that the coexisting ions containing in water samples had no obvious negative effect on the determination of lead. The experimental results indicated that the proposed method had a good linear range of 0.01-100 ng mL -1 (r 2 = 0.9990). The precision was 2.12% (RSD, n = 7) and the detection limit was 0.95 ng L -1 . Proposed method was validated with four real environmental samples and the results indicated that the proposed method was excellent for the future use and satisfied spiked recoveries were in the range of 92.9-97.4%.

  14. A new chiral residue analysis method for triazole fungicides in water using dispersive liquid-liquid microextraction (DLLME).

    Science.gov (United States)

    Luo, Mai; Liu, Donghui; Zhou, Zhiqiang; Wang, Peng

    2013-09-01

    A rapid, simple, reliable, and environment-friendly method for the residue analysis of the enantiomers of four chiral fungicides including hexaconazole, triadimefon, tebuconazole, and penconazole in water samples was developed by dispersive liquid-liquid microextraction (DLLME) pretreatment followed by chiral high-performance liquid chromatography (HPLC)-DAD detection. The enantiomers were separated on a Chiralpak IC column by HPLC applying n-hexane or petroleum ether as mobile phase and ethanol or isopropanol as modifier. The influences of mobile phase composition and temperature on the resolution were investigated and most of the enantiomers could be completely separated in 20 min under optimized conditions. The thermodynamic parameters indicated that the separation was enthalpy-driven. The elution orders were detected by both circular dichroism detector (CD) and optical rotatory dispersion detector (ORD). Parameters affecting the DLLME performance for pretreatment of the chiral fungicides residue in water samples, such as the extraction and dispersive solvents and their volume, were studied and optimized. Under the optimum microextraction condition the enrichment factors were over 121 and the linearities were 30-1500 µg L(-1) with the correlation coefficients (R(2)) over 0.9988 and the recoveries were between 88.7% and 103.7% at the spiking levels of 0.5, 0.25, and 0.05 mg L(-1) (for each enantiomer) with relative standard deviations varying from 1.38% to 6.70% (n = 6) The limits of detection (LODs) ranged from 8.5 to 29.0 µg L(-1) (S/N = 3). © 2013 Wiley Periodicals, Inc.

  15. Structure and dynamics in liquid water from x-ray absorption spectroscopy

    International Nuclear Information System (INIS)

    Wernet, Philippe

    2009-01-01

    Oxygen K-edge x-ray absorption spectra of water are discussed. The spectra of gas-phase water, liquid water and ice illustrate the sensitivity of oxygen K-edge x-ray absorption spectroscopy to hydrogen bonding in water. Transmission mode spectra of amorphous and crystalline ice are compared to x-ray Raman spectra of ice. The good agreement consolidates the experimental spectrum of crystalline ice and represents an incentive for theoretical calculations of the oxygen K-edge absorption spectrum of crystalline ice. Time-resolved infrared-pump and x-ray absorption probe results are finally discussed in the light of this structural interpretation.

  16. Experimental Observation of Bulk Liquid Water Structure in ``No Man's Land''

    Science.gov (United States)

    Sellberg, Jonas; McQueen, Trevor; Huang, Congcong; Loh, Duane; Laksmono, Hartawan; Sierra, Raymond; Hampton, Christina; Starodub, Dmitri; Deponte, Daniel; Martin, Andrew; Barty, Anton; Wikfeldt, Thor; Schlesinger, Daniel; Pettersson, Lars; Beye, Martin; Nordlund, Dennis; Weiss, Thomas; Feldkamp, Jan; Caronna, Chiara; Seibert, Marvin; Messerschmidt, Marc; Williams, Garth; Boutet, Sebastien; Bogan, Michael; Nilsson, Anders

    2013-03-01

    Experiments on pure bulk water below about 235 K have so far been difficult: water crystallization occurs very rapidly below the homogeneous nucleation temperature of 232 K and above 160 K, leading to a ``no man's land'' devoid of experimental results regarding the structure. Here, we demonstrate a new, general experimental approach to study the structure of liquid states at supercooled conditions below their limit of homogeneous nucleation. We use femtosecond x-ray pulses generated by the LCLS x-ray laser to probe evaporatively cooled droplets of supercooled bulk water and find experimental evidence for the existence of metastable bulk liquid water down to temperatures of 223 K in the previously largely unexplored ``no man's land''. We acknoweledge NSF (CHE-0809324), Office of Basic Energy Sciences, and the Swedish Research Council for financial support.

  17. Stability limit of liquid water in metastable equilibrium with subsaturated vapors.

    Science.gov (United States)

    Wheeler, Tobias D; Stroock, Abraham D

    2009-07-07

    A pure liquid can reach metastable equilibrium with its subsaturated vapor across an appropriate membrane. This situation is analogous to osmotic equilibrium: the reduced chemical potential of the dilute phase (the subsaturated vapor) is compensated by a difference in pressure between the phases. To equilibrate with subsaturated vapor, the liquid phase assumes a pressure that is lower than its standard vapor pressure, such that the liquid phase is metastable with respect to the vapor phase. For sufficiently subsaturated vapors, the liquid phase can even assume negative pressures. The appropriate membrane for this metastable equilibrium must provide the necessary mechanical support to sustain the difference in pressure between the two phases, limit nonhomogeneous mechanisms of cavitation, and resist the entry of the dilutant (gases) into the pure phase (liquid). In this article, we present a study of the limit of stability of liquid water--the degree of subsaturation at which the liquid cavitates--in this metastable state within microscale voids embedded in hydrogel membranes. We refer to these structures as vapor-coupled voids (VCVs). In these VCVs, we observed that liquid water cavitated when placed in equilibrium with vapors of activity aw,vapairhumiditynucleation theory or molecular simulations (Pcav=-140 to -180 MPa). To determine the cause of the disparity between the observed and predicted stability limit, we examine experimentally the likelihood of several nonhomogeneous mechanisms of nucleation: (i) heterogeneous nucleation caused by hydrophobic patches on void walls, (ii) nucleation caused by the presence of dissolved solute, (iii) nucleation caused by the presence of pre-existing vapor nuclei, and (iv) invasion of air through the hydrogel membrane into the voids. We conclude that, of these possibilities, (i) and (ii) cannot be discounted, whereas (iii) and (iv) are unlikely to play a role in determining the stability limit.

  18. Probing the electronic structure of liquid water with many-body perturbation theory

    Science.gov (United States)

    Pham, Tuan Anh; Zhang, Cui; Schwegler, Eric; Galli, Giulia

    2014-03-01

    We present a first-principles investigation of the electronic structure of liquid water based on many-body perturbation theory (MBPT), within the G0W0 approximation. The liquid quasiparticle band gap and the position of its valence band maximum and conduction band minimum with respect to vacuum were computed and it is shown that the use of MBPT is crucial to obtain results that are in good agreement with experiment. We found that the level of theory chosen to generate molecular dynamics trajectories may substantially affect the electronic structure of the liquid, in particular, the relative position of its band edges and redox potentials. Our results represent an essential step in establishing a predictive framework for computing the relative position of water redox potentials and the band edges of semiconductors and insulators. Work supported by DOE/BES (Grant No. DE-SC0008938). Work at LLNL was performed under Contract DE-AC52-07NA27344.

  19. Sub- and super-Maxwellian evaporation of simple gases from liquid water

    International Nuclear Information System (INIS)

    Kann, Z. R.; Skinner, J. L.

    2016-01-01

    Non-Maxwellian evaporation of light atoms and molecules (particles) such as He and H 2 from liquids has been observed experimentally. In this work, we use simulations to study systematically the evaporation of Lennard-Jones particles from liquid water. We find instances of sub- and super-Maxwellian evaporation, depending on the mass of the particle and the particle-water interaction strength. The observed trends are in qualitative agreement with experiment. We interpret these trends in terms of the potential of mean force and the effectiveness and frequency of collisions during the evaporation process. The angular distribution of evaporating particles is also analyzed, and it is shown that trends in the energy from velocity components tangential and normal to the liquid surface must be understood separately in order to interpret properly the angular distributions.

  20. Sub- and super-Maxwellian evaporation of simple gases from liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Kann, Z. R.; Skinner, J. L., E-mail: skinner@chem.wisc.edu [Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706 (United States)

    2016-04-21

    Non-Maxwellian evaporation of light atoms and molecules (particles) such as He and H{sub 2} from liquids has been observed experimentally. In this work, we use simulations to study systematically the evaporation of Lennard-Jones particles from liquid water. We find instances of sub- and super-Maxwellian evaporation, depending on the mass of the particle and the particle-water interaction strength. The observed trends are in qualitative agreement with experiment. We interpret these trends in terms of the potential of mean force and the effectiveness and frequency of collisions during the evaporation process. The angular distribution of evaporating particles is also analyzed, and it is shown that trends in the energy from velocity components tangential and normal to the liquid surface must be understood separately in order to interpret properly the angular distributions.

  1. Experimental, Numerical, and Analytical Slosh Dynamics of Water and Liquid Nitrogen in a Spherical Tank

    Science.gov (United States)

    Storey, Jedediah Morse

    2016-01-01

    Understanding, predicting, and controlling fluid slosh dynamics is critical to safety and improving performance of space missions when a significant percentage of the spacecraft's mass is a liquid. Computational fluid dynamics simulations can be used to predict the dynamics of slosh, but these programs require extensive validation. Many experimental and numerical studies of water slosh have been conducted. However, slosh data for cryogenic liquids is lacking. Water and cryogenic liquid nitrogen are used in various ground-based tests with a spherical tank to characterize damping, slosh mode frequencies, and slosh forces. A single ring baffle is installed in the tank for some of the tests. Analytical models for slosh modes, slosh forces, and baffle damping are constructed based on prior work. Select experiments are simulated using a commercial CFD software, and the numerical results are compared to the analytical and experimental results for the purposes of validation and methodology-improvement.

  2. Determination of pentachlorophenol in water and aquifer sediments by high-performance liquid chromatography

    Science.gov (United States)

    Goerlitz, D.F.

    1981-01-01

    Methods for the determination of pentachlorophenol (PCP) in water and aquifer sediments are presented. Reverse-phase high-performance liquid chromotography employing ion suppression and gradient elution is used. PCP can be determined directly in water at a lower limit of detection Of 0.2 micrograms per liter. For extracts of sediment, PCP can be determined to a lower limit of 1.0 micrograms per kilogram.

  3. Normal coordinate treatment of liquid water and calculation of vapor pressure isotope effects

    International Nuclear Information System (INIS)

    Gellai, B.; Van Hook, W.A.

    1983-01-01

    A vibrational analysis of liquid water is reported, assuming a completely hydrogen-bonded network with continuously varying strengths of the hydrogen bonds. Frequency distribution calculations are made for intramolecular stretching and bending modes and for the intramolecular frequency region. The calculated distributions are compared with the experimental spectroscopic ones. As another test, vapor pressure isotope effects are calculated from the theoretical distributions for some isotopic water molecules. Results are compared with those of other authors obtained from a mixture model. (author)

  4. Changes in Search Path Complexity and Length During Learning of a Virtual Water Maze: Age Differences and Differential Associations with Hippocampal Subfield Volumes.

    Science.gov (United States)

    Daugherty, Ana M; Bender, Andrew R; Yuan, Peng; Raz, Naftali

    2016-06-01

    Impairment of hippocampus-dependent cognitive processes has been proposed to underlie age-related deficits in navigation. Animal studies suggest a differential role of hippocampal subfields in various aspects of navigation, but that hypothesis has not been tested in humans. In this study, we examined the association between volume of hippocampal subfields and age differences in virtual spatial navigation. In a sample of 65 healthy adults (age 19-75 years), advanced age was associated with a slower rate of improvement operationalized as shortening of the search path over 25 learning trials on a virtual Morris water maze task. The deficits were partially explained by greater complexity of older adults' search paths. Larger subiculum and entorhinal cortex volumes were associated with a faster decrease in search path complexity, which in turn explained faster shortening of search distance. Larger Cornu Ammonis (CA)1-2 volume was associated with faster distance shortening, but not in path complexity reduction. Age differences in regional volumes collectively accounted for 23% of the age-related variance in navigation learning. Independent of subfield volumes, advanced age was associated with poorer performance across all trials, even after reaching the asymptote. Thus, subiculum and CA1-2 volumes were associated with speed of acquisition, but not magnitude of gains in virtual maze navigation. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  5. Laser spectroscopic visualization of hydrogen bond motions in liquid water

    Science.gov (United States)

    Bratos, S.; Leicknam, J.-Cl.; Pommeret, S.; Gallot, G.

    2004-12-01

    Ultrafast pump-probe experiments are described permitting a visualization of molecular motions in diluted HDO/D 2O solutions. The experiments were realized in the mid-infrared spectral region with a time resolution of 150 fs. They were interpreted by a careful theoretical analysis, based on the correlation function approach of statistical mechanics. Combining experiment and theory, stretching motions of the OH⋯O bonds as well as HDO rotations were 'filmed' in real time. It was found that molecular rotations are the principal agent of hydrogen bond breaking and making in water. Recent literatures covering the subject, including molecular dynamics simulations, are reviewed in detail.

  6. On the mechanism of muonium formation in liquid water

    International Nuclear Information System (INIS)

    Byakov, V.M.; Firsov, V.G.

    1986-01-01

    The experimental data on the influence of some solutes in water on formation probabilities of muonium, positronium and radiolytic hydrogen are compared. It is shown that the inhibiting action is very similar in all cases. This means that the formation mechanisms of muonium, positronium and radiolytic hydrogen have common features. Taking into account that the formation of radiolytic hydrogen and that of positronium proceeds via recombination mechanism with unsolvated electron as one of the precursors, it is asserted that the muonium formation mechanism is similar. (author)

  7. Duration of liquid water habitats on early Mars

    International Nuclear Information System (INIS)

    Mckay, C.P.; Davis, W.L.

    1991-01-01

    The duration of ice-covered lakes after the initial freezing of the early Mars is presently estimated via a climate model whose critical parameter is the existence of peak seasonal temperatures above freezing, and in which the variability of insolation is included. Under conditions in which meltwater was supplied by an ice source, it is found that water habitats could have been maintained under relatively thin ice sheets for as many as 700 million years after the onset of below-freezing global temperatures. The duration of such habitats on the early Mars therefore exceeds the upper limit of the time envisioned for the emergence of aquatic life on earth. 45 refs

  8. Prediction of slant path rain attenuation statistics at various locations

    Science.gov (United States)

    Goldhirsh, J.

    1977-01-01

    The paper describes a method for predicting slant path attenuation statistics at arbitrary locations for variable frequencies and path elevation angles. The method involves the use of median reflectivity factor-height profiles measured with radar as well as the use of long-term point rain rate data and assumed or measured drop size distributions. The attenuation coefficient due to cloud liquid water in the presence of rain is also considered. Absolute probability fade distributions are compared for eight cases: Maryland (15 GHz), Texas (30 GHz), Slough, England (19 and 37 GHz), Fayetteville, North Carolina (13 and 18 GHz), and Cambridge, Massachusetts (13 and 18 GHz).

  9. Fundamental understanding of liquid water effects on the performance of a PEMFC with serpentine-parallel channels

    International Nuclear Information System (INIS)

    Le, Anh Dinh; Zhou Biao

    2009-01-01

    A three-dimensional and unsteady proton exchange membrane fuel cell (PEMFC) model with serpentine-parallel channels has been incorporated to simulate not only the fluid flow, heat transfer, species transport, electrochemical reaction, and current density distribution but also the behaviors of liquid water in the gas-liquid flow of the channels and porous media. Using this general model, the behaviors of liquid water were investigated by performing the motion, deformation, coalescence and detachment of water droplets inside the channels and the penetration of liquid through the porous media at different time instants. The results showed that: tracking the interface of liquid water in a reacting gas-liquid flow in PEMFC can be fulfilled by using volume-of-fluid (VOF) algorithm combined with solving the conservation equations of continuity, momentum, energy, species transport and electrochemistry; the presence of liquid water in the channels has a significant impact on the flow fields, e.g., the gas flow became unevenly distributed due to the blockage of liquid water where the high pressure would be suddenly built up and the reactant gas transport in the channels and porous media would be hindered by liquid water occupation

  10. Kinetics of radiolysis of irradiated ligno celluloses into soluble products in water and rumen liquid

    International Nuclear Information System (INIS)

    Tukenmez, I.; Bakioglu, A.T.; Ersen, M.S.

    1997-01-01

    In order to increase the low bio hydrolysis of ligno celluloses in biotechnological and biological processes where these materials are used as raw materials and ruminant feed, the substrates were pretreated with irradiation to induce radiolytic depolymerisation and then kinetics of their radiolysis into soluble products in water and rumen liquid were analyzed. Wheat straw used as a representative lignocellulose substrate was irradiated at 0-2.5 MGy doses at 20''o''C with an optimum equilibrium humidity of 6.6% in Cs-137 gamma irradiator with a dose rate of 1.8 kGy/h, and soluablefractions in water and in situ rumen liquid were determined gravimetrically. Based on these data, a reaction mechanism was proposed for the radiolysis of ligno celluloses into soluble fractions. From the corresponding reaction rate equations with this mechanism a dose dependent kinetics was derived for the radiolysis of ligno celluloses into water/rumen liquid-soluble products. Defined by this kinetics, the threshold doses for the radiolysis of the substrate into water/rumen liquid-soluble products were respectively found 80.6 kGy and 186.0 kGy, and fractional radiolytic decomposition yields 0.193 MGy''-1''.It was emphasized that developed kinetic models may be used for the process design of irradiation pretreatments to improve the bio hydrolysis of ligno celluloses.(2figs. and 17 refs.)

  11. Measurement of radon 222 in drinking water and air by liquid scintillation

    International Nuclear Information System (INIS)

    Schoenhofer, F.

    1991-01-01

    This is a brief description of the liquid scintillation measuring method for determining radon 222 in drinking water and air. Discussed are the advantages of this method and its reliability or accuracy, as well as some conclusions from the results. (orig.) [de

  12. Changes of liquid Water content in fog at Milešovka Observatory (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Fišák, Jaroslav

    2008-01-01

    Roč. 11, - (2008), s. 5-8 ISSN 1335-339X R&D Projects: GA AV ČR IAA3042301; GA AV ČR 1QS200420562 Institutional research plan: CEZ:AV0Z30420517 Keywords : fog * liquid water content * month changes * Observatory Milešovka * visibility Subject RIV: DG - Athmosphere Sciences, Meteorology

  13. Retrieval of liquid water cloud properties from ground-based remote sensing observations

    NARCIS (Netherlands)

    Knist, C.L.

    2014-01-01

    Accurate ground-based remotely sensed microphysical and optical properties of liquid water clouds are essential references to validate satellite-observed cloud properties and to improve cloud parameterizations in weather and climate models. This requires the evaluation of algorithms for retrieval of

  14. Vapor-Liquid Equilibrium Measurements and Modeling of the Propyl Mercaptan plus Methane plus Water System

    DEFF Research Database (Denmark)

    Awan, Javeed; Thomsen, Kaj; Coquelet, Christophe

    2010-01-01

    In this work, vapor−liquid equilibrium (VLE) measurements of propyl mercaptan (PM) in pure water were performed at three different temperatures, (303, 323, and 365) K, with a pressure variation from (1 to 8) MPa. The total system pressure was maintained by CH4. The inlet mole fraction of propyl...

  15. GENERIC, COMPONENT FAILURE DATA BASE FOR LIGHT WATER AND LIQUID SODIUM REACTOR PRAs

    Energy Technology Data Exchange (ETDEWEB)

    S. A. Eide; S. V. Chmielewski; T. D. Swantz

    1990-02-01

    A comprehensive generic component failure data base has been developed for light water and liquid sodium reactor probabilistic risk assessments (PRAs) . The Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) and the Centralized Reliability Data Organization (CREDO) data bases were used to generate component failure rates . Using this approach, most of the failure rates are based on actual plant data rather than existing estimates .

  16. Parallel gastric emptying of nonhydrolyzable fat and water after a solid-liquid meal in humans

    International Nuclear Information System (INIS)

    Cortot, A.; Phillips, S.F.; Malagelada, J.R.

    1982-01-01

    Our aim was to examine the control of gastric emptying of the oil phase of a mixed solid and liquid meal. Previous studies had shown that liquid dietary fats normally leave the stomach at a slower rate than does water. We wished to determine whether the slower emptying of fats was due to the physical characteristics of food (lower density and greater viscosity than water), to retardation by duodenal feedback mechanisms, or whether both factors contributed. Thus, we quantified the emptying rates of water and sucrose polyester (a nonabsorbable analog of dietary fat) ingested by healthy volunteers as a mixed solid and liquid meal. Gastric emptying was quantified by an intubation-perfusion method incorporating an occlusive jejunal balloon to facilitate recovery. Four phase-specific, nonabsorbable markers were used. [14C[Sucrose octaoleate and polyethylene glycol were incorporated in the meal and traced the lipid and water phases, respectively; [3H]glycerol triether and phenolsulfonphthalein were used as duodenal recovery markers. Sucrose polyester (substituting for dietary fat) was emptied very rapidly, and at about the same rate as was water, in contrast to natural fat, which empties very slowly. Emptying of water was rapid and comparable to that observed after mixed meals containing natural fat. These results imply that gastric emptying of the oil phase is controlled by receptors sensitive to the hydrolytic products of fat digestion and that the slow emptying of dietary fat is not simply due to its lower density

  17. Nanofluid of zinc oxide nanoparticles in ionic liquid for single drop liquid microextraction of fungicides in environmental waters prior to high performance liquid chromatographic analysis.

    Science.gov (United States)

    Amde, Meseret; Tan, Zhi-Qiang; Liu, Rui; Liu, Jing-Fu

    2015-05-22

    Using a nanofluid obtained by dispersing ZnO nanoparticles (ZnO NPs) in 1-hexyl-3-methylimidazolium hexafluorophosphate, new single drop microextraction method was developed for simultaneous extraction of three fungicides (chlorothalonil, kresoxim-methyl and famoxadone) in water samples prior to their analysis by high performance liquid chromatography (HPLC-VWD). The parameters affecting the extraction efficiency such as amount of ZnO NPs in the nanofluid, solvent volume, extraction time, stirring rate, pH and ionic strength of the sample solution were optimized. Under the optimized conditions, the limits of detection were in the range of 0.13-0.19ng/mL, the precision of the method assessed with intra-day and inter-day relative standard deviations were water samples including lake water, river water, as well as effluent and influent of wastewater treatment plant, with recoveries in the range of 74.94-96.11% at 5ng/mL spiking level. Besides to being environmental friendly, the high enrichment factor and the data quality obtained with the proposed method demonstrated its potential for application in multi residue analysis of fungicides in actual water samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. The Inferred Distribution of Liquid Water in Europa's Ice Shell: Implications for the Europa Lander Mission

    Science.gov (United States)

    Noviello, J. L.; Torrano, Z. A.; Rhoden, A.; Manga, M.

    2017-12-01

    A key objective of the Europa lander mission is to identify liquid water within 30 km of the lander (Europa Lander SDT report, 2017), to provide essential context with which to evaluate samples and enable assessment of Europa's overall habitability. To inform lander mission development, we utilize a model of surface feature formation that invokes liquid water within Europa's ice shell to map out the implied 3D distribution of liquid water and assess the likelihood of a lander to be within 30 km of liquid water given regional variability. Europa's surface displays a variety of microfeatures, also called lenticulae, including pits, domes, spots, and microchaos. A recent model by Manga and Michaut (2017) attributes these features to various stages in the thermal-mechanical evolution of liquid water intrusions (i.e. sills) within the ice shell, from sill emplacement to surface breaching (in the case of microchaos) to freezing of the sill. Pits are of particular interest because they appear only when liquid water is still present. Another key feature of the model is that the size of a microfeature at the surface is controlled by the depth of the sill. Hence, we can apply this model to regions of Europa that contain microfeatures to infer the size, depth, and spatial distribution of liquid water within the ice shell. We are creating a database of microfeatures that includes digitized, collated data from previous mapping efforts along with our own mapping study. We focus on images with 220 m/pixel resolution, which includes the regional mapping data sets. Analysis of a preliminary study area suggests that sills are typically located at depths of 2km or less from the surface. We will present analysis of the full database of microfeatures and the corresponding 3D distribution of sills implied by the model. Our preliminary analysis also shows that pits are clustered in some regions, consistent with previous results, although individual pits are also observed. We apply a

  19. Global statistics of liquid water content and effective number density of water clouds over ocean derived from combined CALIPSO and MODIS measurements

    OpenAIRE

    Y. Hu; M. Vaughan; C. McClain; M. Behrenfeld; H. Maring; D. Anderson; S. Sun-Mack; D. Flittner; J. Huang; B. Wielicki; P. Minnis; C. Weimer; C. Trepte; R. Kuehn

    2007-01-01

    International audience; This study presents an empirical relation that links layer integrated depolarization ratios, the extinction coefficients, and effective radii of water clouds, based on Monte Carlo simulations of CALIPSO lidar observations. Combined with cloud effective radius retrieved from MODIS, cloud liquid water content and effective number density of water clouds are estimated from CALIPSO lidar depolarization measurements in this study. Global statistics of the cloud liquid water...

  20. Global statistics of liquid water content and effective number density of water clouds over ocean derived from combined CALIPSO and MODIS measurements

    Science.gov (United States)

    Hu, Y.; Vaughan, M.; McClain, C.; Behrenfeld, M.; Maring, H.; Anderson, D.; Sun-Mack, S.; Flittner, D.; Huang, J.; Wielicki, B.; Minnis, P.; Weimer, C.; Trepte, C.; Kuehn, R.

    2007-03-01

    This study presents an empirical relation that links layer integrated depolarization ratios, the extinction coefficients, and effective radii of water clouds, based on Monte Carlo simulations of CALIPSO lidar observations. Combined with cloud effective radius retrieved from MODIS, cloud liquid water content and effective number density of water clouds are estimated from CALIPSO lidar depolarization measurements in this study. Global statistics of the cloud liquid water content and effective number density are presented.

  1. Non-porous membrane-assisted liquid-liquid extraction of UV filter compounds from water samples.

    Science.gov (United States)

    Rodil, Rosario; Schrader, Steffi; Moeder, Monika

    2009-06-12

    A method for the determination of nine UV filter compounds [benzophenone-3 (BP-3), isoamyl methoxycinnamate, 4-methylbenzylidene camphor, octocrylene (OC), butyl methoxydibenzoylmethane, ethylhexyl dimethyl p-aminobenzoate (OD-PABA), ethylhexyl methoxycinnamate (EHMC), ethylhexyl salicylate and homosalate] in water samples was developed and evaluated. The procedure includes non-porous membrane-assisted liquid-liquid extraction (MALLE) and LC-atmospheric pressure photoionization (APPI)-MS/MS. Membrane bags made of different polymeric materials were examined to enable a fast and simple extraction of the target analytes. Among the polymeric materials tested, low- and high-density polyethylene membranes proved to be well suited to adsorb the analytes from water samples. Finally, 2 cm length tailor-made membrane bags were prepared from low-density polyethylene in order to accommodate 100 microL of propanol. The fully optimised protocol provides recoveries from 76% to 101% and limits of detection (LOD) between 0.4 ng L(-1) (OD-PABA) and 16 ng L(-1) (EHMC). The interday repeatability of the whole protocol was below 18%. The effective separation of matrix molecules was proved by only marginal matrix influence during the APPI-MS analysis since no ion suppression effects were observed. During the extraction step, the influence of the matrix was only significant when non-treated wastewater was analysed. The analysis of lake water indicated the presence of seven UV filter compounds included in this study at concentrations between 40 ng L(-1) (BP-3) and 4381 ng L(-1) (OC). In non-treated wastewater several UV filters were also detected at concentration levels as high as 5322 ng L(-1) (OC).

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

    Directory of Open Access Journals (Sweden)

    B. D. Castro

    2005-09-01

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

  3. Structural transition in a lipid-water liquid system

    International Nuclear Information System (INIS)

    Bulavin, L.A.; Solovjov, D.V.; Solovjov, D.V.; Gorshkova, Yu.Je.; Zhigunov, O.M.; Ivan'kov, O.I.; Ivan'kov, O.I.; Gordelij, V.I.; Gordelij, V.I.; Gordelij, V.I.; Gordelij, V.I.; Kuklin, O.I.; Kuklin, O.I.

    2012-01-01

    Small-angle X-ray scattering technique has been used to study multilayer lipid membranes of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and the 3:1-mixture DPPC/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) in excess water. The temperature dependences of the repetition period for lipid bilayers in the temperature range 20-55 o C are obtained. A comparative analysis of the scattering curves obtained for multilayer membranes showed that, below a temperature of 40 o C , there emerges an additional ordering with a repetition period of 66 A in the lipid mixture, which we associate with the lipid phase separation. A disappearance of the so-called ripple (wave-like) phase of DPPC lipid in the mixture is also observed.

  4. 30 CFR 250.248 - What solid and liquid wastes and discharges information and cooling water intake information must...

    Science.gov (United States)

    2010-07-01

    ... following solid and liquid wastes and discharges information and cooling water intake information must... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What solid and liquid wastes and discharges information and cooling water intake information must accompany the DPP or DOCD? 250.248 Section 250.248...

  5. Shocking Path of Least Resistance Shines Light on Subsurface by Revealing the Paths of Water and the Presence of Faults: Stacked EM Case Studies over Barite Hills Superfund Site in South Carolina

    Science.gov (United States)

    Haggar, K. S.; Nelson, H. R., Jr.; Berent, L. J.

    2017-12-01

    The Barite Hills/Nevada Gold Fields mines are in Late Proterozoic and early Paleozoic rocks of the gold and iron sulfides rich Carolina slate belt. The mines were active from 1989 to1995. EPA and USGS site investigations in 2003 resulted in the declaration of the waste pit areas as a superfund site. The USGS and private consulting firms have evaluated subsurface water flow paths, faults & other groundwater-related features at this superfund site utilizing 2-D conductivity & 3-D electromagnetic (EM) surveys. The USGS employed conductivity to generate instantaneous 2-D profiles to evaluate shallow groundwater patterns. Porous regolith sediments, contaminated water & mine debris have high conductivity whereas bedrock is identified by its characteristic low conductivity readings. Consulting contractors integrated EM technology, magnetic & shallow well data to generate 3-D images of groundwater flow paths at given depths across the superfund site. In so doing several previously undetected faults were identified. Lighting strike data was integrated with the previously evaluated electrical and EM data to determine whether this form of natural-sourced EM data could complement and supplement the more traditional geophysical data described above. Several lightning attributes derived from 3-D lightning volumes were found to correlate to various features identified in the previous geophysical studies. Specifically, the attributes Apparent Resistivity, Apparent Permittivity, Peak Current & Tidal Gravity provided the deepest structural geological framework & provided insights into rock properties & earth tides. Most significantly, Peak Current showed remarkable coincidence with the preferred groundwater flow map identified by one of the contractors utilizing EM technology. This study demonstrates the utility of robust integrated EM technology applications for projects focused on hydrology, geohazards to dams, levees, and structures, as well as mineral and hydrocarbon exploration.

  6. Path Dependence

    DEFF Research Database (Denmark)

    Madsen, Mogens Ove

    Begrebet Path Dependence blev oprindelig udviklet inden for New Institutionel Economics af bl.a. David, Arthur og North. Begrebet har spredt sig vidt i samfundsvidenskaberne og undergået en udvikling. Dette paper propagerer for at der er sket så en så omfattende udvikling af begrebet, at man nu kan...... tale om 1. og 2. generation af Path Dependence begrebet. Den nyeste udvikling af begrebet har relevans for metodologi-diskusionerne i relation til Keynes...

  7. Measurement of liquid-liquid equilibria for condensate + glycol and condensate + glycol + water systems

    DEFF Research Database (Denmark)

    Riaz, Muhammad; Kontogeorgis, Georgios; Stenby, Erling Halfdan

    2011-01-01

    ,2-ethanediol (MEG) + condensate and MEG + water + condensate systems at temperatures from (275 to 323) K at atmospheric pressure. The condensate used in this work is a stabilized natural gas condensate from an offshore field in the North Sea. Compositional analysis of the natural gas condensate was carried out...... by gas chromatography, and detailed separation of individual condensate's components has been carried out. Approximately 85 peaks eluting before nonane were identified by their retention time. Peak areas were converted to mass fraction using 1-heptene as an internal standard. The components were divided...... into boiling range groups from hexane to nonane. Paraffinic (P), naphthenic (N), and aromatic (A) distributions were obtained for the boiling point fractions up to nonane. The average molar mass and the overall density of the condensate were measured experimentally. For the mutual solubility of MEG...

  8. Isobaric vapor-liquid equilibria for the extractive distillation of 2-propanol + water mixtures using 1-ethyl-3-methylimidazolium dicyanamide ionic liquid

    International Nuclear Information System (INIS)

    Orchillés, A. Vicent; Miguel, Pablo J.; González-Alfaro, Vicenta; Llopis, Francisco J.; Vercher, Ernesto; Martínez-Andreu, Antoni

    2017-01-01

    Highlights: • VLE of binary and ternary systems of 2-propanol, water and [emim][DCA] at 100 kPa. • The e-NRTL model fits the VLE data of 2-propanol + water + [emim][DCA] system. • [emim][DCA] breaks the 2-propanol + water azeotrope at an IL mole fraction >0.085. - Abstract: Isobaric vapor–liquid equilibria for the binary systems 2-propanol + water, 2-propanol + 1-ethyl-3-methylimidazolium dicyanamide ([emim][DCA]), and water + [emim][DCA] as well as the vapor–liquid equilibria for the 2-propanol + water + [emim][DCA] ternary system have been obtained at 100 kPa using a recirculating still. The electrolyte nonrandom two-liquid (e-NRTL) model was used for fitting successfully the experimental data. The effect of [emim][DCA] on the 2-propanol + water system has been compared with that produced by other ionic liquids reported in the literature. From the results, [emim][DCA] appears as a good entrainer for the extractive distillation of this solvent mixture, causing the azeotrope to disappear at 100 kPa when the ionic liquid mole fraction is greater than 0.085.

  9. Numerical Investigation of a Liquid-Gas Ejector Used for Shipping Ballast Water Treatment

    Directory of Open Access Journals (Sweden)

    Xueguan Song

    2014-01-01

    Full Text Available Shipping ballast water can have significant ecological and economic impacts on aquatic ecosystems. Currently, water ejectors are widely used in marine applications for ballast water treatment owing to their high suction capability and reliability. In this communication, an improved ballast treatment system employing a liquid-gas ejector is introduced to clear the ballast water to reduce environmental risks. Commonly, the liquid-gas ejector uses ballast water as the primary fluid and chemical ozone as the secondary fluid. In this study, high-pressure water and air, instead of ballast water and ozone, are considered through extensive numerical and experimental research. The ejector is particularly studied by a steady three-dimensional multiphase computational fluid dynamics (CFD analysis with commercial software ANSYS-CFX 14.5. Different turbulence models (including standard k-ε, RNG k-ε, SST, and k-ω with different grid size and bubble size are compared extensively and the experiments are carried out to validate the numerical design and optimization. This study concludes that the RNG k-ε turbulence model is the most efficient and effective for the ballast water treatment system under consideration and simple change of nozzle shape can greatly improve the ejector performance under high back pressure conditions.

  10. Abnormal gas-liquid-solid phase transition behaviour of water observed with in situ environmental SEM.

    Science.gov (United States)

    Chen, Xin; Shu, Jiapei; Chen, Qing

    2017-04-24

    Gas-liquid-solid phase transition behaviour of water is studied with environmental scanning electron microscopy for the first time. Abnormal phenomena are observed. At a fixed pressure of 450 Pa, with the temperature set to -7 °C, direct desublimation happens, and ice grows continuously along the substrate surface. At 550 Pa, although ice is the stable phase according to the phase diagram, metastable liquid droplets first nucleate and grow to ~100-200 μm sizes. Ice crystals nucleate within the large sized droplets, grow up and fill up the droplets. Later, the ice crystals grow continuously through desublimation. At 600 Pa, the metastable liquid grows quickly, with some ice nuclei floating in it, and the liquid-solid coexistence state exists for a long time. By lowering the vapour pressure and/or increasing the substrate temperature, ice sublimates into vapour phase, and especially, the remaining ice forms a porous structure due to preferential sublimation in the concave regions, which can be explained with surface tension effect. Interestingly, although it should be forbidden for ice to transform into liquid phase when the temperature is well below 0 °C, liquid like droplets form during the ice sublimation process, which is attributed to the surface tension effect and the quasiliquid layers.

  11. Processes that generate and deplete liquid water and snow in thin midlevel mixed-phase clouds

    Science.gov (United States)

    Smith, Adam J.; Larson, Vincent E.; Niu, Jianguo; Kankiewicz, J. Adam; Carey, Lawrence D.

    2009-06-01

    This paper uses a numerical model to investigate microphysical, radiative, and dynamical processes in mixed-phase altostratocumulus clouds. Three cloud cases are chosen for study, each of which was observed by aircraft during the fifth or ninth Complex Layered Cloud Experiment (CLEX). These three clouds are numerically modeled using large-eddy simulation (LES). The observed and modeled clouds consist of a mixed-phase layer with a quasi-adiabatic profile of liquid, and a virga layer below that consists of snow. A budget of cloud (liquid) water mixing ratio is constructed from the simulations. It shows that large-scale ascent/descent, radiative cooling/heating, turbulent transport, and microphysical processes are all significant. Liquid is depleted indirectly via depositional growth of snow (the Bergeron-Findeisen process). This process is more influential than depletion of liquid via accretional growth of snow. Also constructed is a budget of snow mixing ratio, which turns out to be somewhat simpler. It shows that snow grows by deposition in and below the liquid (mixed-phase) layer, and sublimates in the remainder of the virga region below. The deposition and sublimation are balanced primarily by sedimentation, which transports the snow from the growth region to the sublimation region below. In our three clouds, the vertical extent of the virga layer is influenced more by the profile of saturation ratio below the liquid (mixed-phase) layer than by the mixing ratio of snow at the top of the virga layer.

  12. Ab Initio Liquid Water Dynamics in Aqueous TMAO Solution.

    Science.gov (United States)

    Usui, Kota; Hunger, Johannes; Sulpizi, Marialore; Ohto, Tatsuhiko; Bonn, Mischa; Nagata, Yuki

    2015-08-20

    Ab initio molecular dynamics (AIMD) simulations in trimethylamine N-oxide (TMAO)-D2O solution are employed to elucidate the effects of TMAO on the reorientational dynamics of D2O molecules. By decomposing the O-D groups of the D2O molecules into specific subensembles, we reveal that water reorientational dynamics are retarded considerably in the vicinity of the hydrophilic TMAO oxygen (O(TMAO)) atom, due to the O-D···O(TMAO) hydrogen-bond. We find that this reorientational motion is governed by two distinct mechanisms: The O-D group rotates (1) after breaking the O-D···O(TMAO) hydrogen-bond, or (2) together with the TMAO molecule while keeping this hydrogen-bond intact. While the orientational slow-down is prominent in the AIMD simulation, simulations based on force field models exhibit much faster dynamics. The simulated angle-resolved radial distribution functions illustrate that the O-D···O(TMAO) hydrogen-bond has a strong directionality through the sp(3) orbital configuration in the AIMD simulation, and this directionality is not properly accounted for in the force field simulation. These results imply that care must be taken when modeling negatively charged oxygen atoms as single point charges; force field models may not adequately describe the hydration configuration and dynamics.

  13. Some new fatigue tests in high temperature water and liquid sodium environment

    International Nuclear Information System (INIS)

    Hattori, Takahiro; Yamauchi, Takayoshi; Kanasaki, Hiroshi; Kondo, Yoshiyuki; Endo, Tadayoshi.

    1987-01-01

    To evaluate the fatigue strength of structural materials for PWR or FBR plants, fatigue test data must be obtained in an environment of simulated primary and secondary water for PWR or of high temperature liquid sodium for FBR. Generally, such tests make it necessary to prepare expensive facilities, so when large amount of fatigue data are required, it is necessary to rationalize and simplify the fatigue tests while maintaining high accuracy. At the Takasago Research Development Center, efforts to rationalize facilities and maintain accuracy in fatigue tests have been made by developing new test methods and improving conventional techniques. This paper introduces a new method of low cycle fatigue test in high temperature water, techniques for automatic measurement of crack initiation and propagation in high temperature water environment and a multiple type fatigue testing machine for high temperature liquid sodium. (author)

  14. Simultaneous Design of Ionic Liquids and Azeotropic Separation for Systems Containing Water

    DEFF Research Database (Denmark)

    Roughton, Brock; Camarda, Kyle V.; Gani, Rafiqul

    Separation of azeotropic mixtures is a very common but challenging task, covering a wide range of industrial sectors and issues. For example, most down-stream separation problems following a synthesis step of pharmaceutical and/or biochemical processes, involve the separation of azeotropes. Also......, many separation tasks in the petrochemical and chemical industries involve separation of azeotropic mixtures. A common issue with the design and operation of these separation tasks is whether or not to use solvents? And, if solvents are to be used, what kind of solvent should be used and what would....... Since a large number of azeotropes encountered include water as one of the compounds, the use of ionic liquids in solvent-based separation of water in azeotropic systems has been investigated. Along with the design of the ionic liquid being used to entrain water, the extractive distillation process has...

  15. PREFACE: Dynamic crossover phenomena in water and other glass-forming liquids Dynamic crossover phenomena in water and other glass-forming liquids

    Science.gov (United States)

    Chen, Sow-Hsin; Baglioni, Piero

    2012-02-01

    This special section has been inspired by the workshop on Dynamic Crossover Phenomena in Water and Other Glass-Forming Liquids, held during November 11-13, 2010 at Pensione Bencistà, Fiesole, Italy, a well-preserved 14th century Italian villa tucked high in the hills overlooking Florence. The meeting, an assembly of world renowned scientists, was organized as a special occasion to celebrate the 75th birthday of Professor Sow-Hsin Chen of MIT, a pioneer in several aspects of complex fluids and soft matter physics. The workshop covered a large variety of experimental and theoretical research topics of current interest related to dynamic crossover phenomena in water and, more generally, in other glass-forming liquids. The 30 invited speakers/lecturers and approximately 60 participants were a select group of prominent physicists and chemists from the USA, Europe, Asia and Mexico, who are actively working in the field. Some highlights of this special issue include the following works. Professor Yamaguchi's group and their collaborators present a neutron spin echo study of the coherent intermediate scattering function of heavy water confined in cylindrical pores of MCM-41-C10 silica material in the temperature range 190-298 K. They clearly show that a fragile-to-strong (FTS) dynamic crossover occurs at about 225 K. They attribute the FTS dynamic crossover to the formation of a tetrahedral-like structure, which is preserved in the bulk-like water confined to the central part of the cylindrical pores. Mamontov and Kolesnikov et al study the collective excitations in an aqueous solution of lithium chloride over a temperature range of 205-270 K using neutron and x-ray Rayleigh-Brillouin (coherent) scattering. They detect both the low-frequency and the high-frequency sounds known to exist in pure bulk water above the melting temperature. They also perform neutron (incoherent) and x-ray (coherent) elastic intensity scan measurements. Clear evidence of the crossover in the

  16. Active probing of cloud multiple scattering, optical depth, vertical thickness, and liquid water content using wide-angle imaging lidar

    Science.gov (United States)

    Love, Steven P.; Davis, Anthony B.; Rohde, Charles A.; Tellier, Larry; Ho, Cheng

    2002-09-01

    At most optical wavelengths, laser light in a cloud lidar experiment is not absorbed but merely scattered out of the beam, eventually escaping the cloud via multiple scattering. There is much information available in this light scattered far from the input beam, information ignored by traditional 'on-beam' lidar. Monitoring these off-beam returns in a fully space- and time-resolved manner is the essence of our unique instrument, Wide Angle Imaging Lidar (WAIL). In effect, WAIL produces wide-field (60-degree full-angle) 'movies' of the scattering process and records the cloud's radiative Green functions. A direct data product of WAIL is the distribution of photon path lengths resulting from multiple scattering in the cloud. Following insights from diffusion theory, we can use the measured Green functions to infer the physical thickness and optical depth of the cloud layer, and, from there, estimate the volume-averaged liquid water content. WAIL is notable in that it is applicable to optically thick clouds, a regime in which traditional lidar is reduced to ceilometry. Here we present recent WAIL data on various clouds and discuss the extension of WAIL to full diurnal monitoring by means of an ultra-narrow magneto-optic atomic line filter for daytime measurements.

  17. Active probing of cloud multiple scattering, optical depth, vertical thickness, and liquid water content using wide-angle imaging LIDAR

    International Nuclear Information System (INIS)

    Love, Steven P.; Davis, Anthony B.; Rohde, Charles A.; Tellier, Larry L.; Ho, Cheng

    2002-01-01

    At most optical wavelengths, laser light in a cloud lidar experiment is not absorbed but merely scattered out of the beam, eventually escaping the cloud via multiple scattering. There is much information available in this light scattered far from the input beam, information ignored by traditional 'on-beam' lidar. Monitoring these off-beam returns in a fully space- and time-resolved manner is the essence of our unique instrument, Wide Angle Imaging Lidar (WAIL). In effect, WAIL produces wide-field (60-degree full-angle) 'movies' of the scattering process and records the cloud's radiative Green functions. A direct data product of WAIL is the distribution of photon path lengths resulting from multiple scattering in the cloud. Following insights from diffusion theory, we can use the measured Green functions to infer the physical thickness and optical depth of the cloud layer, and, from there, estimate the volume-averaged liquid water content. WAIL is notable in that it is applicable to optically thick clouds, a regime in which traditional lidar is reduced to ceilometry. Here we present recent WAIL data oti various clouds and discuss the extension of WAIL to full diurnal monitoring by means of an ultra-narrow magneto-optic atomic line filter for daytime measurements.

  18. Ultrafast soft X-ray photoelectron spectroscopy at liquid water microjets.

    Science.gov (United States)

    Faubel, M; Siefermann, K R; Liu, Y; Abel, B

    2012-01-17

    Since the pioneering work of Kai Siegbahn, electron spectroscopy for chemical analysis (ESCA) has been developed into an indispensable analytical technique for surface science. The value of this powerful method of photoelectron spectroscopy (PES, also termed photoemission spectroscopy) and Siegbahn's contributions were recognized in the 1981 Nobel Prize in Physics. The need for high vacuum, however, originally prohibited PES of volatile liquids, and only allowed for investigation of low-vapor-pressure molecules attached to a surface (or close to a surface) or liquid films of low volatility. Only with the invention of liquid beams of volatile liquids compatible with high-vacuum conditions was PES from liquid surfaces under vacuum made feasible. Because of the ubiquity of water interfaces in nature, the liquid water-vacuum interface became a most attractive research topic, particularly over the past 10 years. PES studies of these important aqueous interfaces remained significantly challenging because of the need to develop high-pressure PES methods. For decades, ESCA or PES (termed XPS, for X-ray photoelectron spectroscopy, in the case of soft X-ray photons) was restricted to conventional laboratory X-ray sources or beamlines in synchrotron facilities. This approach enabled frequency domain measurements, but with poor time resolution. Indirect access to time-resolved processes in the condensed phase was only achieved if line-widths could be analyzed or if processes could be related to a fast clock, that is, reference processes that are fast enough and are also well understood in the condensed phase. Just recently, the emergence of high harmonic light sources, providing short-wavelength radiation in ultrashort light pulses, added the dimension of time to the classical ESCA or XPS technique and opened the door to (soft) X-ray photoelectron spectroscopy with ultrahigh time resolution. The combination of high harmonic light sources (providing radiation with laserlike

  19. Behavior of supercooled aqueous solutions stemming from hidden liquid–liquid transition in water

    Energy Technology Data Exchange (ETDEWEB)

    Biddle, John W.; Holten, Vincent; Anisimov, Mikhail A., E-mail: anisimov@umd.edu [Institute for Physical Science and Technology and Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742 (United States)

    2014-08-21

    A popular hypothesis that explains the anomalies of supercooled water is the existence of a metastable liquid–liquid transition hidden below the line of homogeneous nucleation. If this transition exists and if it is terminated by a critical point, the addition of a solute should generate a line of liquid–liquid critical points emanating from the critical point of pure metastable water. We have analyzed thermodynamic consequences of this scenario. In particular, we consider the behavior of two systems, H{sub 2}O-NaCl and H{sub 2}O-glycerol. We find the behavior of the heat capacity in supercooled aqueous solutions of NaCl, as reported by Archer and Carter [J. Phys. Chem. B 104, 8563 (2000)], to be consistent with the presence of the metastable liquid–liquid transition. We elucidate the non-conserved nature of the order parameter (extent of “reaction” between two alternative structures of water) and the consequences of its coupling with conserved properties (density and concentration). We also show how the shape of the critical line in a solution controls the difference in concentration of the coexisting liquid phases.

  20. Behavior of supercooled aqueous solutions stemming from hidden liquid–liquid transition in water

    International Nuclear Information System (INIS)

    Biddle, John W.; Holten, Vincent; Anisimov, Mikhail A.

    2014-01-01

    A popular hypothesis that explains the anomalies of supercooled water is the existence of a metastable liquid–liquid transition hidden below the line of homogeneous nucleation. If this transition exists and if it is terminated by a critical point, the addition of a solute should generate a line of liquid–liquid critical points emanating from the critical point of pure metastable water. We have analyzed thermodynamic consequences of this scenario. In particular, we consider the behavior of two systems, H 2 O-NaCl and H 2 O-glycerol. We find the behavior of the heat capacity in supercooled aqueous solutions of NaCl, as reported by Archer and Carter [J. Phys. Chem. B 104, 8563 (2000)], to be consistent with the presence of the metastable liquid–liquid transition. We elucidate the non-conserved nature of the order parameter (extent of “reaction” between two alternative structures of water) and the consequences of its coupling with conserved properties (density and concentration). We also show how the shape of the critical line in a solution controls the difference in concentration of the coexisting liquid phases

  1. Electrically tunable spatially variable switching in ferroelectric liquid crystal/water system

    Science.gov (United States)

    Choudhary, A.; Coondoo, I.; Prakash, J.; Sreenivas, K.; Biradar, A. M.

    2009-04-01

    An unusual switching phenomenon in the region outside conducting patterned area in ferroelectric liquid crystal (FLC) containing about 1-2 wt % of water has been observed. The presence of water in the studied heterogeneous system was confirmed by Fourier transform infrared spectroscopy. The observed optical studies have been emphasized on the "spatially variable switching" phenomenon of the molecules in the nonconducting region of the cell. The observed phenomenon is due to diffusion of water between the smectic layers of the FLC and the interaction of the curved electric field lines with the FLC molecules in the nonconducting region.

  2. Quantification of the impact of water as an impurity on standard physico-chemical properties of ionic liquids

    International Nuclear Information System (INIS)

    Andanson, J.-M.; Meng, X.; Traïkia, M.; Husson, P.

    2016-01-01

    Highlights: • Residual water has a negligible impact on density of hydrophobic ionic liquids. • The density of a dry sample can be calculated from the density of a wet ionic liquid. • The viscosity of a dry sample can be calculated from the one of a wet ionic liquid. • Water can be quantified by NMR spectroscopy even in dried hydrophobic ionic liquids. - Abstract: The objective of this work was to quantify the effect of the presence of water as impurity in ionic liquids. First, density and viscosity of five ionic liquids as well as their aqueous solutions were measured. For hydrophobic dried ionic liquids, traces of water (50 ppm) have measurable impact neither on the density nor on the viscosity values. In the concentration range studied (up to 5000 ppm), a linear evolution of the molar volume of the mixture with the mole fraction composition is observed. Practically, this allows to estimate the density of an neat ionic liquid provided (i) the water quantity and (ii) the density of the undried sample are known. This is particularly useful for hydrophilic ionic liquids that are difficult to dry. In the studied concentration range, a linear evolution of the relative viscosity was also depicted as a function of the mass fraction composition. It is thus possible to evaluate the viscosity of the pure ionic liquid knowing the water quantity and the viscosity of the undried sample. The comparison of the results obtained using two viscosimeters confirms that a Stabinger viscosimeter is appropriate to precisely measure ionic liquids viscosities. Second, NMR and IR spectroscopies were used to characterize the pure ionic liquids and their solutions with water. The sensitivity of IR spectroscopy does allow neither the quantification nor the detection of water below 1 mol%. With NMR spectroscopy, water can be quantified using either the intensity or the chemical shift of the water proton peak for mole fractions as low as 200 ppm. It is even possible to detect water in

  3. Account of the intratrack radiolytic processes for interpretation of the AMOC spectrum of liquid water

    International Nuclear Information System (INIS)

    Zvezhinskiy, D S; Stepanov, S V; Butterling, M; Wagner, A; Krause-Rehberg, R

    2013-01-01

    Recent development of the Gamma-induced Positron Spectroscopy (GiPS) setup significantly extends applicability of the Age-Momentum Correlation technique (AMOC) for studies of the bulk samples. It also provides many advantages comparing with conventional positron annihilation experiments in liquids, such as extremely low annihilation fraction in vessel walls, absence of a positron source and positron annihilations in it. We have developed a new approach for processing and interpretation of the AMOC-GiPS data based on the diffusion recombination model of the intratrack radiolytic processes. This approach is verified in case of liquid water, which is considered as a reference medium in the positron and positronium chemistry.

  4. Account of the intratrack radiolytic processes for interpretation of the AMOC spectrum of liquid water

    Science.gov (United States)

    Zvezhinskiy, D. S.; Butterling, M.; Wagner, A.; Krause-Rehberg, R.; Stepanov, S. V.

    2013-06-01

    Recent development of the Gamma-induced Positron Spectroscopy (GiPS) setup significantly extends applicability of the Age-Momentum Correlation technique (AMOC) for studies of the bulk samples. It also provides many advantages comparing with conventional positron annihilation experiments in liquids, such as extremely low annihilation fraction in vessel walls, absence of a positron source and positron annihilations in it. We have developed a new approach for processing and interpretation of the AMOC-GiPS data based on the diffusion recombination model of the intratrack radiolytic processes. This approach is verified in case of liquid water, which is considered as a reference medium in the positron and positronium chemistry.

  5. Purification of inkjet ink from water using liquid phase, electric discharge polymerization and cellulosic membrane filtration.

    Science.gov (United States)

    Jordan, Alexander T; Hsieh, Jeffery S; Lee, Daniel T

    2013-01-01

    A method to separate inkjet ink from water was developed using a liquid phase, electric discharge process. The liquid phase, electric discharge process with filtration or sedimentation was shown to remove 97% of inkjet ink from solutions containing between 0.1-0.8 g/L and was consistent over a range of treatment conditions. Additionally, particle size analysis of treated allyl alcohol and treated propanol confirmed the electric discharge treatment has a polymerization mechanism, and small molecule analysis of treated methanol using gas chromatography and mass spectroscopy confirmed the mechanism was free radical initiated polymerization.

  6. Problems of hydrogen - water vapor - inert gas mixture use in heavy liquid metal coolant technology

    International Nuclear Information System (INIS)

    Ul'yanov, V.V.; Martynov, P.N.; Gulevskij, V.A.; Teplyakov, Yu.A.; Fomin, A.S.

    2014-01-01

    The reasons of slag deposit formation in circulation circuits with heavy liquid metal coolants, which can cause reactor core blockage, are considered. To prevent formation of deposits hydrogen purification of coolant and surfaces of circulation circuit is used. It consists in introduction of gaseous mixtures hydrogen - water vapor - rare gas (argon or helium) directly into coolant flow. The principle scheme of hydrogen purification and the processes occurring during it are under consideration. Measures which make it completely impossible to overlap of the flow cross section of reactor core, steam generators, pumps and other equipment by lead oxides in reactor facilities with heavy liquid metal coolants are listed [ru

  7. Thermally excited capillary waves at vapor/liquid interfaces of water-alcohol mixtures

    International Nuclear Information System (INIS)

    Vaknin, David; Bu Wei; Sung, Jaeho; Jeon, Yoonnam; Kim, Doseok

    2009-01-01

    The density profiles of liquid/vapor interfaces of water-alcohol (methanol, ethanol and propanol) mixtures were studied by surface-sensitive synchrotron x-ray scattering techniques. X-ray reflectivity and diffuse scattering measurements, from the pure and mixed liquids, were analyzed in the framework of capillary wave theory to address the characteristic length scales of the intrinsic roughness and the shortest capillary wavelength (alternatively, the upper wavevector cutoff in capillary wave theory). Our results establish that the intrinsic roughness is dominated by average interatomic distances. The extracted effective upper wavevector cutoff indicates capillary wave theory breaks down at distances of the order of bulk correlation lengths.

  8. Influence of dispersion degree of water drops on efficiency of extinguishing of flammable liquids

    OpenAIRE

    Korolchenko Dmitriy; Voevoda Sergey

    2016-01-01

    Depending on the size of water drops, process of fire extinguishing is focused either in a zone of combustion or on a burning liquid surface. This article considers two alternate solutions of a heat balance equation. The first solution allows us to trace decrease of temperature of a flammable liquid (FL) surface to a temperature lower than fuel flash point at which combustion is stopped. And the second solution allows us to analyze decrease of burnout rate to a negligible value at which steam...

  9. Water liquid-vapor interface subjected to various electric fields: A molecular dynamics study

    Science.gov (United States)

    Nikzad, Mohammadreza; Azimian, Ahmad Reza; Rezaei, Majid; Nikzad, Safoora

    2017-11-01

    Investigation of the effects of E-fields on the liquid-vapor interface is essential for the study of floating water bridge and wetting phenomena. The present study employs the molecular dynamics method to investigate the effects of parallel and perpendicular E-fields on the water liquid-vapor interface. For this purpose, density distribution, number of hydrogen bonds, molecular orientation, and surface tension are examined to gain a better understanding of the interface structure. Results indicate enhancements in parallel E-field decrease the interface width and number of hydrogen bonds, while the opposite holds true in the case of perpendicular E-fields. Moreover, perpendicular fields disturb the water structure at the interface. Given that water molecules tend to be parallel to the interface plane, it is observed that perpendicular E-fields fail to realign water molecules in the field direction while the parallel ones easily do so. It is also shown that surface tension rises with increasing strength of parallel E-fields, while it reduces in the case of perpendicular E-fields. Enhancement of surface tension in the parallel field direction demonstrates how the floating water bridge forms between the beakers. Finally, it is found that application of external E-fields to the liquid-vapor interface does not lead to uniform changes in surface tension and that the liquid-vapor interfacial tension term in Young's equation should be calculated near the triple-line of the droplet. This is attributed to the multi-directional nature of the droplet surface, indicating that no constant value can be assigned to a droplet's surface tension in the presence of large electric fields.

  10. A Liquid Desiccant Cycle for Dehumidification and Fresh Water Supply in Controlled Environment Agriculture

    KAUST Repository

    Lefers, Ryan

    2017-12-01

    Controlled environment agriculture allows the production of fresh food indoors from global locations and contexts where it would not otherwise be possible. Growers in extreme climates and urban areas produce food locally indoors, saving thousands of food import miles and capitalizing upon the demand for fresh, tasty, and nutritious food. However, the growing of food, both indoors and outdoors, consumes huge quantities of water - as much as 70-80% of global fresh water supplies. The utilization of liquid desiccants in a closed indoor agriculture cycle provides the possibility of capturing plant-transpired water vapor. The regeneration/desalination of these liquid desiccants offers the potential to recover fresh water for irrigation and also to re-concentrate the desiccants for continued dehumidification. Through the utilization of solar thermal energy, the process can be completed with a very small to zero grid-energy footprint. The primary research in this dissertation focused on two areas: the dehumidification of indoor environments utilizing liquid desiccants inside membrane contactors and the regeneration of these desiccants using membrane distillation. Triple-bore PVDF hollow fiber membranes yielded dehumidification permeance rates around 0.25-0.31 g m-2 h-1 Pa-1 in lab-scale trials. A vacuum membrane distillation unit utilizing PVDF fibers yielded a flux of 2.8-7.0 kg m-2 hr-1. When the membrane contactor dehumidification system was applied in a bench scale controlled environment agriculture setup, the relative humidity levels responded dynamically to both plant transpiration and dehumidification rates, reaching dynamic equilibrium levels during day and night cycles. In addition, recovered fresh water from distillation was successfully applied for irrigation of crops and concentrated desiccants were successfully reused for dehumidification. If applied in practice, the liquid desiccant system for controlled environment agriculture offers the potential to reduce

  11. Molecular dynamics simulation of nonlinear spectroscopies of intermolecular motions in liquid water.

    Science.gov (United States)

    Yagasaki, Takuma; Saito, Shinji

    2009-09-15

    Water is the most extensively studied of liquids because of both its ubiquity and its anomalous thermodynamic and dynamic properties. The properties of water are dominated by hydrogen bonds and hydrogen bond network rearrangements. Fundamental information on the dynamics of liquid water has been provided by linear infrared (IR), Raman, and neutron-scattering experiments; molecular dynamics simulations have also provided insights. Recently developed higher-order nonlinear spectroscopies open new windows into the study of the hydrogen bond dynamics of liquid water. For example, the vibrational lifetimes of stretches and a bend, intramolecular features of water dynamics, can be accurately measured and are found to be on the femtosecond time scale at room temperature. Higher-order nonlinear spectroscopy is expressed by a multitime correlation function, whereas traditional linear spectroscopy is given by a one-time correlation function. Thus, nonlinear spectroscopy yields more detailed information on the dynamics of condensed media than linear spectroscopy. In this Account, we describe the theoretical background and methods for calculating higher order nonlinear spectroscopy; equilibrium and nonequilibrium molecular dynamics simulations, and a combination of both, are used. We also present the intermolecular dynamics of liquid water revealed by fifth-order two-dimensional (2D) Raman spectroscopy and third-order IR spectroscopy. 2D Raman spectroscopy is sensitive to couplings between modes; the calculated 2D Raman signal of liquid water shows large anharmonicity in the translational motion and strong coupling between the translational and librational motions. Third-order IR spectroscopy makes it possible to examine the time-dependent couplings. The 2D IR spectra and three-pulse photon echo peak shift show the fast frequency modulation of the librational motion. A significant effect of the translational motion on the fast frequency modulation of the librational motion is

  12. Application of an immobilized ionic liquid for the passive sampling of perfluorinated substances in water.

    Science.gov (United States)

    Wang, Lei; Gong, Xinying; Wang, Ruonan; Gan, Zhiwei; Lu, Yuan; Sun, Hongwen

    2017-09-15

    Ionic liquids have been used to efficiently extract a wide range of polar and nonpolar organic contaminants from water. In this study, imidazole ionic liquids immobilized on silica gel were synthesized through a chemical bonding method, and the immobilized dodecylimidazolium ionic liquid was selected as the receiving phase material in a POCIS (polar organic chemical integrative sampler) like passive sampler to monitor five perfluoroalkyl substances (PFASs) in water. Twenty-one days of integrative accumulation was conducted in laboratory scale experiments, and the accumulated PFASs in the samplers were eluted and analyzed by high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The partitioning coefficients of most PFASs between sampler sorbents and water in the immobilized ionic liquid (IIL)-sampler were higher than those in the HLB-sampler, especially for compounds with shorter alkyl chains. The effects of flow velocity, temperature, dissolved organic matter (DOM) and pH on the uptake of these analytes were also evaluated. Under the experimental conditions, the uptake of PFASs in the IIL-sampler slightly increased with the flow velocity and temperature, while different influences of DOM and pH on the uptake of PFAS homologues with short or long chains were observed. The designed IIL-samplers were applied in the influent and effluent of a wastewater treatment plant. All five PFASs could be accumulated in the samplers, with concentrations ranging from 6.5×10 -3 -3.6×10 -1 nmol/L in the influent and from 1.3×10 -2 -2.2×10 -1 nmol/L in the effluent. The calculated time-weighted average concentrations of most PFASs fit well with the detected concentrations of the active sampling, indicating the applicability of the IIL-sampler in monitoring these compounds in water. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Thermal conductivity coefficients of water and heavy water in the liquid state up to 3700C

    International Nuclear Information System (INIS)

    Le Neindre, B.; Bury, P.; Tufeu, R.; Vodar, B.

    1976-01-01

    The thermal conductivity coefficients of water and heavy water of 99.75 percent isotopic purity were measured using a coaxial cylinder apparatus, covering room temperature to their critical temperatures, and pressures from 1 to 500 bar for water, and from 1 to 1000 bar for heavy water. Following the behavior of the thermal conductivity coefficient of water, which shows a maximum close to 135 0 C, the thermal conductivity coefficient of heavy water exhibits a maximum near 95 0 C and near saturation pressures. This maximum is displaced to higher temperatures when the pressure is increased. Under the same temperature and pressure conditions the thermal conductivity coefficient of heavy water was lower than for water. The pressure effect was similar for water and heavy water. In the temperature range of our experiments, isotherms of thermal conductivity coefficients were almost linear functions of density

  14. Barriers Keep Drops Of Water Out Of Infrared Gas Sensors

    Science.gov (United States)

    Murray, Sean K.

    1996-01-01

    Infrared-sensor cells used for measuring partial pressures of CO(2) and other breathable gases modified to prevent entry of liquid water into sensory optical paths of cells. Hydrophobic membrane prevents drops of water entrained in flow from entering optical path from lamp to infrared detectors.

  15. (Liquid + liquid) equilibrium of {l_brace}water + phenol + (1-butanol, or 2-butanol, or tert-butanol){r_brace} systems

    Energy Technology Data Exchange (ETDEWEB)

    Hadlich de Oliveira, Leonardo [School of Chemical Engineering, State University of Campinas, UNICAMP, P.O. Box 6066, 13083-970 Campinas-SP (Brazil); Aznar, Martin, E-mail: maznar@feq.unicamp.b [School of Chemical Engineering, State University of Campinas, UNICAMP, P.O. Box 6066, 13083-970 Campinas-SP (Brazil)

    2010-11-15

    (Liquid + liquid) equilibrium (LLE) and binodal curve data were determined for the systems (water + phenol + tert-butanol) at T = 298.15 K, (water + phenol + 2-butanol) and (water + phenol + 1-butanol) at T = 298.15 K and T = 313.15 K by the combined techniques of densimetry and refractometry. Type I curve (for tert-butanol) and Type II curves (for 1- and 2-butanol) were found. The data were correlated with the NRTL model and the parameters estimated present root mean square deviations below 2% for the system with tert-butanol and lower than 0.8% for the other systems.

  16. In situ liquid water visualization in polymer electrolyte membrane fuel cells with high resolution synchrotron x-ray radiography

    Energy Technology Data Exchange (ETDEWEB)

    Chevalier, S.; Banerjee, R.; Lee, J.; Ge, N.; Lee, C.; Bazylak, A., E-mail: abazylak@mie.utoronto.ca [Dept. of Mechanical & Industrial Engineering, Faculty of Applied Science & Engineering, University of Toronto, Toronto, Ontario (Canada); Wysokinski, T. W.; Belev, G.; Webb, A.; Miller, D.; Zhu, N. [Canadian Light Source, Saskatoon, Saskatchewan (Canada); Tabuchi, Y.; Kotaka, T. [EV System Laboratory, Research Division 2, Nissan Motor Co., Ltd., Yokosuka, Kanagawa (Japan)

    2016-07-27

    In this work, we investigated the dominating properties of the porous materials that impact water dynamics in a polymer electrolyte membrane fuel cell (PEMFC). Visualizations of liquid water in an operating PEMFC were performed at the Canadian Light Source. A miniature fuel cell was specifically designed for X-ray imaging investigations, and an in-house image processing algorithm based on the Beer-Lambert law was developed to extract quantities of liquid water thicknesses (cm) from raw X-ray radiographs. The X-ray attenuation coefficient of water at 24 keV was measured with a calibration device to ensure accurate measurements of the liquid water thicknesses. From this experiment, the through plane distribution of the liquid water in the fuel cell was obtained.

  17. In situ liquid water visualization in polymer electrolyte membrane fuel cells with high resolution synchrotron x-ray radiography

    International Nuclear Information System (INIS)

    Chevalier, S.; Banerjee, R.; Lee, J.; Ge, N.; Lee, C.; Bazylak, A.; Wysokinski, T. W.; Belev, G.; Webb, A.; Miller, D.; Zhu, N.; Tabuchi, Y.; Kotaka, T.

    2016-01-01

    In this work, we investigated the dominating properties of the porous materials that impact water dynamics in a polymer electrolyte membrane fuel cell (PEMFC). Visualizations of liquid water in an operating PEMFC were performed at the Canadian Light Source. A miniature fuel cell was specifically designed for X-ray imaging investigations, and an in-house image processing algorithm based on the Beer-Lambert law was developed to extract quantities of liquid water thicknesses (cm) from raw X-ray radiographs. The X-ray attenuation coefficient of water at 24 keV was measured with a calibration device to ensure accurate measurements of the liquid water thicknesses. From this experiment, the through plane distribution of the liquid water in the fuel cell was obtained.

  18. Reduction of water consumption in bioethanol production from triticale by recycling the stillage liquid phase.

    Science.gov (United States)

    Gumienna, Małgorzata; Lasik, Małgorzata; Szambelan, Katarzyna; Czarnecki, Zbigniew

    2011-01-01

    The distillery stillage is a major and arduous byproduct generated during ethanol production in distilleries. The aim of this study was to evaluate the possibility of the stillage recirculation in the mashing process of triticale for non-byproducts production and reducing the fresh water consumption. The number of recirculation cycles which can be applied without disturbances in the ethanol fermentation process was investigated. Winter triticale BOGO and "Ethanol Red" Saccharomyces cerevisiae yeast were used in the experiments. The method of non-pressure cooking was used for gelatinizingthe triticale, commercial α-amylase SPEZYME ETHYL and glucoamylase FERMENZYME L-400 were applied for starch liquefaction and saccharification. The process was conducted at 30°C for 72 h, next after distillation the stillage was centrifuged and the liquid fraction was used instead of 75% of process water. Ethanol yield from triticale fermentations during 40 cycles ranged between 82% and 95% of theoretical yield preserving yeast vitality and quantity on the same level. The obtained distillates were characterized with enhanced volatile compounds (fusel oil, esters, aldehydes, methanol) as well as protein and potassium concentrations. The liquid part of stillage was proved that can be reused instead of water in bioethanol production from triticale, without disturbing the fermentation process. This investigated solution of distillery byproducts utilization (liquid phase of stillage) constitutes the way which could significantly decrease the bioethanol production costs by reducing the water consumption, as well as wastewater production.

  19. Transient Liquid Water as a Mechanism for Induration of Soil Crusts on Mars

    Science.gov (United States)

    Landis, G. A.; Blaney, D.; Cabrol, N.; Clark, B. C.; Farmer, J.; Grotzinger, J.; Greeley, R.; McLennan, S. M.; Richter, L.; Yen, A.

    2004-01-01

    The Viking and the Mars Exploration Rover missions observed that the surface of Mars is encrusted by a thinly cemented layer tagged as "duricrust". A hypothesis to explain the formation of duricrust on Mars should address not only the potential mechanisms by which these materials become cemented, but also the textural and compositional components of cemented Martian soils. Elemental analyzes at five sites on Mars show that these soils have sulfur content of up to 4%, and chlorine content of up to 1%. This is consistent with the presence of sulfates and halides as mineral cements. . For comparison, the rock "Adirondack" at the MER site, after the exterior layer was removed, had nearly five times lower sulfur and chlorine content , and the Martian meteorites have ten times lower sulfur and chlorine content, showing that the soil is highly enriched in the saltforming elements compared with rock.Here we propose two alternative models to account for the origin of these crusts, each requiring the action of transient liquid water films to mediate adhesion and cementation of grains. Two alternative versions of the transient water hypothesis are offered, a top down hypothesis that emphasizes the surface deposition of frost, melting and downward migration of liquid water and a bottom up alternative that proposes the presence of interstitial ice/brine, with the upward capillary migration of liquid water.

  20. The HKS model for electron production in liquid water by light ions

    International Nuclear Information System (INIS)

    Bernal, M.A.; Liendo, J.A.

    2006-01-01

    The HKS model developed to determine ionization cross sections (ICS) for the interaction of non-relativistic ions with matter, is used for 0.5 MeV protons impinging on liquid water and some inconsistencies between the single (SDCS) and double (DDCS) differential cross section values predicted by the formalism are found. To overcome this problem, new SDCS and DDCS formulas are determined analytically by use of the transition probabilities published by Hansen and Kocbach [J.P. Hansen, L. Kocbach, J. Phys. B 22 (1989) L71]. The new cross section expressions applied to the 0.5 MeV proton on liquid water case, give perfectly consistent SDCS and DDCS values. Furthermore, SDCS and DDCS values predicted from the new formulas for ionization of liquid water by protons (0.5-4.2 MeV/u) and alpha particles (0.3-0.5 MeV/u) are compared with corresponding experimental cross section values reported in the literature for water vapor ionization. Despite of the simplicity of the HKS model, accurate secondary electron energy distributions can be obtained, even for electron energies as low as 10 eV. Although the same accuracy cannot be achieved for electron angular distributions, the HKS formalism can still be used when these distributions are not critical

  1. Seasonally-Active Water on Mars: Vapour, Ice, Adsorbate, and the Possibility of Liquid

    Science.gov (United States)

    Richardson, M. I.

    2002-12-01

    southern caps. Similar climate-models of the water cycle also do not need much exchangeable adsorbed water in order to explain the observed vapour distributions. The possibility of liquid water is tantalizing, but difficult to definitively judge. On scales greater than a meter or so, Mars is most definitely well away from the water triple point--although the surface pressure can exceed 6.1 mbars, the partial pressure of water vapor (to which the triple point refers) is at best orders of magnitude lower. Several careful studies have shown, however, that locally transient (meta-stable) liquid is possible, if the net heating of ice deposits is high enough. This process is aided if the total surface pressure exceeds 6.1mbar (this prevents boiling, or the explosive loss of vapour into the atmosphere) or if the liquid is covered by a thin ice shell, and is only possible if surface temperatures exceed 273K (for pure water, or the appropriate eutectic for brines) and if ice is present. The former challenge is much easier to meet than the latter. The melt scenario requires that ice deposited in winter must be protected from sublimation as surface temperatures increase in spring, but then exposed to the peak of solar heating in summer. Available spacecraft observations of seasonal water will be discussed with the aid of GCM model simulations, and examined in the context of water distributions and phases.

  2. Liquid interfacial water and brines in the upper surface of Mars

    Science.gov (United States)

    Moehlmann, Diedrich

    2013-04-01

    Liquid interfacial water and brines in the upper surface of Mars Diedrich T.F. Möhlmann DLR Institut für Planetenforschung, Rutherfordstr. 2, D - 12489 Berlin, Germany dirk.moehlmann@dlr.de Interfacial water films and numerous brines are known to remain liquid at temperatures far below 0° C. The physical processes behind are described in some detail. Deliquescence, i.e. the liquefaction of hygroscopic salts at the threshold of a specific "Deliquescence Relative Humidity", is shown to be that process, which on present Mars supports the formation of stable interfacial water and bulk liquids in form of temporary brines on and in a salty upper surface of present Mars in a diurnally temporary and repetitive process. Temperature and relative humidity are the governing conditions for deliquescence (and the counterpart "efflorescence") to evolve. The current thermo-dynamical conditions on Mars support these processes to evolve on present Mars. The deliquescence-driven presence of liquid brines in the soil of the upper surface of Mars can expected to be followed by physical and chemical processes like "surface cementation", down-slope flows, and physical and chemical weathering processes. A remarkable and possibly also biologically relevant evolution towards internally interfacial water bearing structures of dendritic capillaries is related to their freezing - thawing driven formation. The internal walls of these network-pores or -tubes can be covered by films of interfacial water, providing that way possibly habitable crack-systems in soil and rock. These evolutionary processes of networks, driven by their tip-growth, can expected to be ongoing also at present.

  3. Water hammer phenomena occurring in nuclear power installations while filling horizontal pipe containing saturated steam with liquid

    Energy Technology Data Exchange (ETDEWEB)

    Selivanov, Y.F.; Kirillov, P.L.; Yefanov, A.D. [Institute of Physics and Power Engineering, Obninsk (Russian Federation)

    1995-09-01

    The potentiality of the water hammer occurrence in nuclear reactor loop components has been considered under the conditions of filling a steam-containing pipeline leg involving horizontal and vertical sections with liquid subcooled to the saturation temperature. As a result of free discharging from the tank, the liquid enters the horizontal pipeline. When the liquid slug formation in the pipeline is fulfilled. The pressure drop being occurred in steam flowing along the pipelines causes the liquid slug to move to the pipeline inlet. When the liquid slug decelerates, a water hammer occurs. This mechanism of water hammer occurrence is tested by experiments. The regimes of the occurrence of multiple considerable water hammers were identified.

  4. Water hammer phenomena occurring in nuclear power installations while filling horizontal pipe containing saturated steam with liquid

    International Nuclear Information System (INIS)

    Selivanov, Y.F.; Kirillov, P.L.; Yefanov, A.D.

    1995-01-01

    The potentiality of the water hammer occurrence in nuclear reactor loop components has been considered under the conditions of filling a steam-containing pipeline leg involving horizontal and vertical sections with liquid subcooled to the saturation temperature. As a result of free discharging from the tank, the liquid enters the horizontal pipeline. When the liquid slug formation in the pipeline is fulfilled. The pressure drop being occurred in steam flowing along the pipelines causes the liquid slug to move to the pipeline inlet. When the liquid slug decelerates, a water hammer occurs. This mechanism of water hammer occurrence is tested by experiments. The regimes of the occurrence of multiple considerable water hammers were identified

  5. Determination of selected azaarenes in water by bonded-phase extraction and liquid chromatography

    Science.gov (United States)

    Steinheimer, T.R.; Ondrus, M.G.

    1986-01-01

    A method for the rapid and simple quantitative determination of quinoline, isoquinoline, and five selected three-ring azaarenes in water has been developed. The azaarene fraction is separated from its carbon analogues on n-octadecyl packing material by edition with acidified water/acetonitrile. Concentration as great as 1000-fold is achieved readily. Instrumental analysis involves high-speed liquid chromatography on flexible-walled, wide-bore columns with fluorescence and ultraviolet detection at several wavelengths employing filter photometers in series. Method-validation data is provided as azaarene recovery efficiency from fortified samples. Distilled water, river water, contaminated ground water, and secondary-treatment effluent have been tested. Recoveries at part-per-billion levels are nearly quantitative for the three-ring compounds, but they decrease for quinoline and isoquinoline. ?? 1986 American Chemical Society.

  6. Investigation on the liquid water droplet instability in a simulated flow channel of PEM fuel cell

    International Nuclear Information System (INIS)

    Ha, Tae Hun; Kim, Bok Yung; Kim, Han Sang; Min, Kyoung Doug

    2008-01-01

    To investigate the characteristics of water droplets on the gas diffusion layer from both top-view and side-view of the flow channel, a rig test apparatus was designed and fabricated with prism attached plate. This experimental device was used to simulate the growth of a single liquid water droplet and its transport process with various air flow velocity and channel height. Not only dry condition but also fully humidified condition was also simulated by using a water absorbing sponge. The detachment height of the water droplet with dry and wet conditions was measured and analyzed. It was found that the droplet tends towards becoming unstable by decreased channel height, increased flow velocity or making a gas diffusion layer (GDL) dryer. Also, peculiar behavior of the water droplet in the channel was presented like attachment to hydrophilic wall or sudden breaking of droplet in case of fully hydrated condition. The simplified force balance model matches with experimental data as well

  7. Thermal bonding of light water reactor fuel using nonalkaline liquid-metal alloy

    International Nuclear Information System (INIS)

    Wright, R.F.; Tulenko, J.S.; Schoessow, G.J.; Connell, R.G. Jr.; Dubecky, M.A.; Adams, T.

    1996-01-01

    Light water reactor (LWR) fuel performance is limited by thermal and mechanical constraints associated with the design, fabrication, and operation of fuel in a nuclear reactor. A technique is explored that extends fuel performance by thermally bonding LWR fuel with a nonalkaline liquid-metal alloy. Current LWR fuel rod designs consist of enriched uranium oxide fuel pellets enclosed in a zirconium alloy cylindrical clad. The space between the pellets and the clad is filled by an inert gas. Because of the low thermal conductivity of the gas, the gas space thermally insulates the fuel pellets from the reactor coolant outside the fuel rod, elevating the fuel temperatures. Filling the gap between the fuel and clad with a high-conductivity liquid metal thermally bonds the fuel to the cladding and eliminates the large temperature change across the gap while preserving the expansion and pellet-loading capabilities. The application of liquid-bonding techniques to LWR fuel is explored to increase LWR fuel performance and safety. A modified version of the ESCORE fuel performance code (ESBOND) is developed to analyze the in-reactor performance of the liquid-metal-bonded fuel. An assessment of the technical feasibility of this concept for LWR fuel is presented, including the results of research into materials compatibility testing and the predicted lifetime performance of liquid-bonded LWR fuel. The results show that liquid-bonded boiling water reactor peak fuel temperatures are 400 F lower at beginning of life and 200 F lower at end of life compared with conventional fuel

  8. Path Creation

    DEFF Research Database (Denmark)

    Karnøe, Peter; Garud, Raghu

    2012-01-01

    This paper employs path creation as a lens to follow the emergence of the Danish wind turbine cluster. Supplier competencies, regulations, user preferences and a market for wind power did not pre-exist; all had to emerge in a tranformative manner involving multiple actors and artefacts. Competenc......This paper employs path creation as a lens to follow the emergence of the Danish wind turbine cluster. Supplier competencies, regulations, user preferences and a market for wind power did not pre-exist; all had to emerge in a tranformative manner involving multiple actors and artefacts....... Competencies emerged through processes and mechanisms such as co-creation that implicated multiple learning processes. The process was not an orderly linear one as emergent contingencies influenced the learning processes. An implication is that public policy to catalyse clusters cannot be based...

  9. In situ separation of root hydraulic redistribution of soil water from liquid and vapor transport

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Jeffrey [ORNL; Brooks, J Renee [U.S. Environmental Protection Agency, Corvallis, OR; Dragila, Maria [Oregon State University, Corvallis; Meinzer, Rick [USDA Forest Service

    2011-01-01

    Nocturnal increases in water potential ( ) and water content (WC) in the upper soil profile are often attributed to root water efflux into the soil, a process termed hydraulic lift or hydraulic redistribution (HR). We have previously reported HR values up to ~0.29 mm day-1 in the upper soil for a seasonally dry old-growth ponderosa pine site. However, unsaturated liquid or vapor flux of water between soil layers independent of roots also contributes to the diurnal patterns in WC, confounding efforts to determine the actual magnitude of HR. In this study, we estimated liquid (Jl) and vapor (Jv) soil water fluxes and their impacts on quantifying HR in situ by applying existing data sets of , WC, temperature (T) and soil physical properties to soil water transport equations. Under moist conditions, Jl between layers was estimated to be larger than necessary to account for measured nocturnal increases in WC of upper soil layers. However, as soil drying progressed unsaturated hydraulic conductivity declined rapidly such that Jl was irrelevant (< 2E-06 cm hr-1 at 0-60 cm depths) to total water flux by early August. In surface soil at depths above 15 cm, large T fluctuations can impact Jv leading to uncertainty concerning the role, if any, of HR in nocturnal WC dynamics. Vapor flux was estimated to be the highest at the shallowest depths measured (20 - 30 cm) where it could contribute up to 40% of hourly increases in nocturnal soil moisture depending on thermal conditions. While both HR and net soil water flux between adjacent layers contribute to WC in the 15-65 cm soil layer, HR was the dominant process and accounted for at least 80% of the diurnal increases in WC. While the absolute magnitude of HR is not easily quantified, total diurnal fluctuations in upper soil water content can be quantified and modeled, and remain highly applicable for establishing the magnitude and temporal dynamics of total ecosystem water flux.

  10. Determination of the air/water partition coefficient of groundwater radon using liquid scintillation counter

    International Nuclear Information System (INIS)

    Lee, K.Y.; Yoon, Y.Y.; Ko, K.S.

    2010-01-01

    A method was studied for measuring air/water partition coefficient (K air/water ) of groundwater radon by a simple procedure using liquid scintillation counter (LSC). In contrast conventional techniques such as equilibrium partitioning in a closed system or air striping methods, the described method allow for a simple and uncomplicated determination of the coefficient. The (K air/water ) of radon in pure water has been well known quantitatively over a wide range of temperatures. In this work, groundwater samples having high radon concentration instead of distilled water have been used to determine the (K air/water ) of radon in the temperature range of 0-25. Aqueous phase in a closed system was used in this study instead of gaseous phase in conventional methods. Three kinds of groundwater taken from different geologic environments were used to investigate the effect of groundwater properties. With the aim to evaluate the reproducibility of the data an appropriate number of laboratory experiments have been carried out. The results show that tie (K air/water ) of radon in the groundwater is smaller than that in the pure water. However, the temperature effect on the coefficient is similar in the groundwater and the pure water. The method using aqueous phase in a closed system by LSC can be used to determine the (K air/water ) of radon in various groundwaters with a simple procedure. The results will be presented at the NAC-IV conference

  11. Generation of reactive species in atmospheric pressure dielectric barrier discharge with liquid water

    Science.gov (United States)

    Zelong, ZHANG; Jie, SHEN; Cheng, CHENG; Zimu, XU; Weidong, XIA

    2018-04-01

    Atmospheric pressure helium/water dielectric barrier discharge (DBD) plasma is used to investigate the generation of reactive species in a gas-liquid interface and in a liquid. The emission intensity of the reactive species is measured by optical emission spectroscopy (OES) with different discharge powers at the gas-liquid interface. Spectrophotometry is used to analyze the reactive species induced by the plasma in the liquid. The concentration of OH radicals reaches 2.2 μm after 3 min of discharge treatment. In addition, the concentration of primary long-lived reactive species such as H2O2, {{{{NO}}}3}- and O3 are measured based on plasma treatment time. After 5 min of discharge treatment, the concentration of H2O2, {{{{NO}}}3}-, and O3 increased from 0 mg · L-1 to 96 mg · L-1, 19.5 mg · L-1, and 3.5 mg · L-1, respectively. The water treated by plasma still contained a considerable concentration of reactive species after 6 h of storage. The results will contribute to optimizing the DBD plasma system for biological decontamination.

  12. (Liquid + liquid) equilibria of (water + linalool + limonene) ternary system at T = (298.15, 308.15, and 318.15) K

    International Nuclear Information System (INIS)

    Gramajo de Doz, Monica B.; Cases, Alicia M.; Solimo, Horacio N.

    2008-01-01

    (Liquid + liquid) equilibrium (LLE) data for {water (1) + linalool (2) + limonene (3)} ternary system at T = (298.15, 308.15, and 318.15 ± 0.05) K are reported. The organic chemicals were quantified by gas chromatography using a flame ionisation detector while water was quantified using a thermal conductivity detector. The effect of the temperature on (liquid + liquid) equilibrium is determined and discussed. Experimental data for the ternary mixture are compared with values calculated by the NRTL and UNIQUAC equations, and predicted by means of the UNIFAC group contribution method. It is found that the UNIQUAC and NRTL models provide a good correlation of the solubility curve at these three temperatures, while comparing the calculated values with the experimental ones, the best fit is obtained with the NRTL model. Finally, the UNIFAC model provides poor results, since it predicts a greater heterogeneous region than experimentally observed

  13. Liquid-solid contact measurements using a surface thermocouple temperature probe in atmospheric pool boiling water

    International Nuclear Information System (INIS)

    Lee, L.Y.W.; Chen, J.C.; Nelson, R.A.

    1984-01-01

    Objective was to apply the technique of using a microthermocouple flush-mounted at the boiling surface for the measurement of the local-surface-temperature history in film and transition boiling on high temperature surfaces. From this measurement direct liquid-solid contact in film and transition boiling regimes was observed. In pool boiling of saturated, distilled, deionized water on an aluminum-coated copper surface, the time-averaged, local-liquid-contact fraction increased with decreasing surface superheat. Average contact duration increased monotonically with decreasing surface superheat, while frequency of liquid contact reached a maximum of approx. 50 contacts/s at a surface superheat of approx. 100 K and decreased gradually to 30 contacts/s near the critical heat flux. The liquid-solid contact duration distribution was dominated by short contacts 4 ms at low surface superheats, passing through a relatively flat contact duration distribution at about 80 0 K. Results of this paper indicate that liquid-solid contacts may be the dominant mechanism for energy transfer in the transition boiling process

  14. Visualization of the collective vortex-like motions in liquid argon and water: Molecular dynamics simulation

    Science.gov (United States)

    Anikeenko, A. V.; Malenkov, G. G.; Naberukhin, Yu. I.

    2018-03-01

    We propose a new measure of collectivity of molecular motion in the liquid: the average vector of displacement of the particles, ⟨ΔR⟩, which initially have been localized within a sphere of radius Rsph and then have executed the diffusive motion during a time interval Δt. The more correlated the motion of the particles is, the longer will be the vector ⟨ΔR⟩. We visualize the picture of collective motions in molecular dynamics (MD) models of liquids by constructing the ⟨ΔR⟩ vectors and pinning them to the sites of the uniform grid which divides each of the edges of the model box into equal parts. MD models of liquid argon and water have been studied by this method. Qualitatively, the patterns of ⟨ΔR⟩ vectors are similar for these two liquids but differ in minor details. The most important result of our research is the revealing of the aggregates of ⟨ΔR⟩ vectors which have the form of extended flows which sometimes look like the parts of vortices. These vortex-like clusters of ⟨ΔR⟩ vectors have the mesoscopic size (of the order of 10 nm) and persist for tens of picoseconds. Dependence of the ⟨ΔR⟩ vector field on parameters Rsph, Δt, and on the model size has been investigated. This field in the models of liquids differs essentially from that in a random-walk model.

  15. Tar removal from biosyngas in the biomass gasification process. (Liquid + liquid) equilibrium {water + solvent (paraxylene and methyl hexadecanoate) + model molecules of tar (benzene, toluene, phenol)}

    International Nuclear Information System (INIS)

    Bassil, Georgio; Mokbel, Ilham; Abou Naccoul, Ramy; Stephan, Juliette; Jose, Jacques; Goutaudier, Christelle

    2012-01-01

    Highlights: ► (Liquid + liquid) equilibria at atmospheric pressure. ► Solubility of benzene (or toluene or phenol) in paraxylene at (303 to 343) K. ► Solubility of benzene (or toluene or phenol) in methyl palmitate or methyl hexadecanoate at (303 to 343) K. ► Correlation of LLE using NRTL model. - Abstract: Tar is generated in the process by the condensation of the gas resulting from biomass gasification. The objective of this work is a contribution to the database on thermodynamic quantity which will be useful at the operation of tar removal from aqueous medium. With this aim, (liquid + liquid) equilibrium of {water + solvent (paraxylene and methyl hexadecanoate) + model molecules of tar (benzene, toluene, phenol)} was studied at temperatures (303.2, 323.2, and 343.2) K. The data obtained were correlated with the non-random two-liquid (NRTL) model.

  16. Differences and similarity in the dynamic and acoustic properties of gas microbubbles in liquid mercury and water

    International Nuclear Information System (INIS)

    Ida, Masato; Haga, Katsuhiro; Kogawa, Hiroyuki; Naoe, Takashi; Futakawa, Masatoshi

    2010-01-01

    Differences and similarities in the dynamics of microbubbles in liquid mercury and water are clarified and summarized in order to evaluate the validity and usefulness of experiments with water as an alternative to experiments with mercury. Pressure-wave induced cavitation in liquid mercury is of particular concern in the high-power pulsed neutron sources working in Japan and the U.S. Toward suppressing the pressure waves and cavitation, injection of gas microbubbles into liquid mercury has been attempted. However, many difficulties arise in mercury experiments mainly because liquid mercury is an opaque liquid. Hence we and collaborators have performed water experiments as an alternative, in conjunction with mercury experiments. In this paper, we discussed how we should use the result with water and how we can make the water experiments meaningful. The non-dimensional numbers of bubbly liquids and bubbles' rise velocity, coalescence frequency, and response to heat input were investigated theoretically for both mercury and water. A suggestion was made to 'see through' bubble distribution in flowing mercury from the result of water study, and a notable similarity was found in the effect of bubbles to absorb thermal expansion of the liquids. (author)

  17. Optical properties and bioavailability of dissolved organic matter along a flow-path continuum from soil pore waters to the Kolyma River, Siberia

    Science.gov (United States)

    Frey, K. E.; Sobczak, W. V.; Mann, P. J.; Holmes, R. M.

    2015-08-01

    The Kolyma River in Northeast Siberia is among the six largest arctic rivers and drains a region underlain by vast deposits of Holocene-aged peat and Pleistocene-aged loess known as yedoma, most of which is currently stored in ice-rich permafrost throughout the region. These peat and yedoma deposits are important sources of dissolved organic matter (DOM) to inland waters that in turn play a significant role in the transport and ultimate remineralization of organic carbon to CO2 and CH4 along the terrestrial flow-path continuum. The turnover and fate of terrigenous DOM during offshore transport will largely depend upon the composition and amount of carbon released to inland and coastal waters. Here, we measured the optical properties of chromophoric DOM (CDOM) from a geographically extensive collection of waters spanning soil pore waters, streams, rivers, and the Kolyma River mainstem throughout a ∼ 250 km transect of the northern Kolyma River basin. During the period of study, CDOM absorbance values were found to be robust proxies for the concentration of DOM, whereas additional CDOM parameters such as spectral slopes (S) were found to be useful indicators of DOM quality along the flow-path. In particular, CDOM absorption at 254 nm showed a strong relationship with dissolved organic carbon (DOC) concentrations across all water types (r2 = 0.958, p CDOM demonstrated statistically significant differences between all four water types and tracked changes in the concentration of bioavailable DOC, suggesting that this parameter may be suitable for clearly discriminating shifts in organic matter characteristics among water types along the full flow-path continuum across this landscape. The heterogeneity of environmental characteristics and extensive continuous permafrost of the Kolyma River basin combine to make this a critical region to investigate and monitor. With ongoing and future permafrost degradation, peat and yedoma deposits throughout the Northeast Siberian

  18. Comparison of dispersive liquid-liquid microextraction and hollow fiber liquid-liquid-liquid microextraction for the determination of fentanyl, alfentanil, and sufentanil in water and biological fluids by high-performance liquid chromatography.

    Science.gov (United States)

    Saraji, Mohammad; Khalili Boroujeni, Malihe; Hajialiakbari Bidgoli, Ali Akbar

    2011-06-01

    Dispersive liquid-liquid microextraction (DLLME) and hollow fiber liquid-liquid-liquid microextraction (HF-LLLME) combined with HPLC-DAD have been applied for the determination of three narcotic drugs (alfentanil, fentanyl, and sufentanil) in biological samples (human plasma and urine). Different DLLME parameters influencing the extraction efficiency such as type and volume of the extraction solvent and the disperser solvent, concentration of NaOH, and salt addition were investigated. In the HF-LLLME, the effects of important parameters including organic solvent type, concentration of NaOH as donor solution, concentration of H(2)SO(4) as acceptor phase, salt addition, stirring rate, temperature, and extraction time were investigated and optimized. The results showed that both extraction methods exhibited good linearity, precision, enrichment factor, and detection limit. Under optimal condition, the limits of detection ranged from 0.4 to 1.9 μg/L and from 1.1 to 2.3 μg/L for DLLME and HF-LLLME, respectively. For DLLME, the intra- and inter-day precisions were 1.7-6.4% and 14.2-15.9%, respectively; and for HF-LLLME were 0.7-5.2% and 3.3-10.1%, respectively. The enrichment factors were from 275 to 325 and 190 to 237 for DLLME and HF-LLLME, respectively. The applicability of the proposed methods was investigated by analyzing biological samples. For analysis of human plasma and urine samples, HF-LLLME showed higher precision, more effective sample clean-up, higher extraction efficiency, lower organic solvent consumption than DLLME.

  19. Ab initio molecular dynamics simulation of liquid water by quantum Monte Carlo

    International Nuclear Information System (INIS)

    Zen, Andrea; Luo, Ye; Mazzola, Guglielmo; Sorella, Sandro; Guidoni, Leonardo

    2015-01-01

    Although liquid water is ubiquitous in chemical reactions at roots of life and climate on the earth, the prediction of its properties by high-level ab initio molecular dynamics simulations still represents a formidable task for quantum chemistry. In this article, we present a room temperature simulation of liquid water based on the potential energy surface obtained by a many-body wave function through quantum Monte Carlo (QMC) methods. The simulated properties are in good agreement with recent neutron scattering and X-ray experiments, particularly concerning the position of the oxygen-oxygen peak in the radial distribution function, at variance of previous density functional theory attempts. Given the excellent performances of QMC on large scale supercomputers, this work opens new perspectives for predictive and reliable ab initio simulations of complex chemical systems

  20. Influence of dispersion degree of water drops on efficiency of extinguishing of flammable liquids

    Directory of Open Access Journals (Sweden)

    Korolchenko Dmitriy

    2016-01-01

    Full Text Available Depending on the size of water drops, process of fire extinguishing is focused either in a zone of combustion or on a burning liquid surface. This article considers two alternate solutions of a heat balance equation. The first solution allows us to trace decrease of temperature of a flammable liquid (FL surface to a temperature lower than fuel flash point at which combustion is stopped. And the second solution allows us to analyze decrease of burnout rate to a negligible value at which steam-air mixture becomes nonflammable. As a result of solve of a heat balance equation it was made the following conclusion: water drops which size is equal to 100 μm will completely evaporate in a zone of combustion with extent of 1 m if the flying speed of drops is even 16 mps (acc. to Stokes v = 3 mps; whereas drops of larger size will evaporate only partially.

  1. Nuclear spin optical rotation and Faraday effect in gaseous and liquid water.

    Science.gov (United States)

    Pennanen, Teemu S; Ikäläinen, Suvi; Lantto, Perttu; Vaara, Juha

    2012-05-14

    Nuclear spin optical rotation (NSOR) of linearly polarized light, due to the nuclear spins through the Faraday effect, provides a novel probe of molecular structure and could pave the way to optical detection of nuclear magnetization. We determine computationally the effects of the liquid medium on NSOR and the Verdet constant of Faraday rotation (arising from an external magnetic field) in water, using the recently developed theory applied on a first-principles molecular dynamics trajectory. The gas-to-liquid shifts of the relevant antisymmetric polarizability and, hence, NSOR magnitude are found to be -14% and -29% for (1)H and (17)O nuclei, respectively. On the other hand, medium effects both enhance the local electric field in water and, via bulk magnetization, the local magnetic field. Together these two effects partially cancel the solvation influence on the single-molecular property. We find a good agreement for the hydrogen NSOR with a recent pioneering experiment on H(2)O(l).

  2. Studies on the liquid-liquid phase distribution equilibria of selenium and its measurement in water using extraction plant with a pulsation column

    International Nuclear Information System (INIS)

    Iskanderani, F.; Sobhi, K.M.; Ejaz, M.

    1989-01-01

    Normal heptane, xylene and a 0.01 molar solution of 4-(5-nonyl)pyridine in toluene were investigated as extractants for selenium(IV) from nitric acid media in potassium iodide. Various parameters affecting the distribution of the element are investigated. Extraction at high aqueous to organic phase volume ratio was studied, using a liquid-liquid extraction plant with a pulsation column. The results were employed to measure selenium in spiked water samples. (author) 24 refs.; 8 figs

  3. Expanding the calculation of activation volumes: Self-diffusion in liquid water

    Science.gov (United States)

    Piskulich, Zeke A.; Mesele, Oluwaseun O.; Thompson, Ward H.

    2018-04-01

    A general method for calculating the dependence of dynamical time scales on macroscopic thermodynamic variables from a single set of simulations is presented. The approach is applied to the pressure dependence of the self-diffusion coefficient of liquid water as a particularly useful illustration. It is shown how the activation volume associated with diffusion can be obtained directly from simulations at a single pressure, avoiding approximations that are typically invoked.

  4. Determination of Picloram in Soil and Water by Reversed-Phase Liquid Chromatography

    Science.gov (United States)

    M.J.M. Wells; J.L. Michael; D.G. Neary

    1984-01-01

    A reversed-phase liquid chromatographic method is presneted for the determination of picloram in the parts per billion (ppb) range in soil, soil solution, and stream samples. Quanitification is effected by UV absorpation at 254 nm. Derivatization is not necessary. The method permits 92% ± 7.1 recovery from water samples and 61.8% ± 11.1 recovery from soil samples....

  5. Standard Test Method for Preparing Aircraft Cleaning Compounds, Liquid Type, Water Base, for Storage Stability Testing

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2002-01-01

    1.1 This test method covers the determination of the stability in storage, of liquid, water-base chemical cleaning compounds, used to clean the exterior surfaces of aircraft. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  6. Liquid Level Sensing System

    Science.gov (United States)

    Korman, Valentin (Inventor); Wiley, John T. (Inventor); Duffell, Amanda G. (Inventor)

    2014-01-01

    A liquid level sensing system includes waveguides disposed in a liquid and distributed along a path with a gap between adjacent waveguides. A source introduces electromagnetic energy into the waveguides at a first end of the path. A portion of the electromagnetic energy exits the waveguides at a second end of the path. A detector measures the portion of the electromagnetic energy exiting the second end of the path.

  7. IR and SFG vibrational spectroscopy of the water bend in the bulk liquid and at the liquid-vapor interface, respectively

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Yicun; Skinner, J. L. [Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706 (United States)

    2015-07-07

    Vibrational spectroscopy of the water bending mode has been investigated experimentally to study the structure of water in condensed phases. In the present work, we calculate the theoretical infrared (IR) and sum-frequency generation (SFG) spectra of the HOH bend in liquid water and at the water liquid/vapor interface using a mixed quantum/classical approach. Classical molecular dynamics simulation is performed by using a recently developed water model that explicitly includes three-body interactions and yields a better description of the water surface. Ab-initio-based transition frequency, dipole, polarizability, and intermolecular coupling maps are developed for the spectral calculations. The calculated IR and SFG spectra show good agreement with the experimental measurements. In the theoretical imaginary part of the SFG susceptibility for the water liquid/vapor interface, we find two features: a negative band centered at 1615 cm{sup −1} and a positive band centered at 1670 cm{sup −1}. We analyze this spectrum in terms of the contributions from molecules in different hydrogen-bond classes to the SFG spectral density and also compare to SFG results for the OH stretch. SFG of the water bending mode provides a complementary picture of the heterogeneous hydrogen-bond configurations at the water surface.

  8. IR and SFG vibrational spectroscopy of the water bend in the bulk liquid and at the liquid-vapor interface, respectively

    Science.gov (United States)

    Ni, Yicun; Skinner, J. L.

    2015-07-01

    Vibrational spectroscopy of the water bending mode has been investigated experimentally to study the structure of water in condensed phases. In the present work, we calculate the theoretical infrared (IR) and sum-frequency generation (SFG) spectra of the HOH bend in liquid water and at the water liquid/vapor interface using a mixed quantum/classical approach. Classical molecular dynamics simulation is performed by using a recently developed water model that explicitly includes three-body interactions and yields a better description of the water surface. Ab-initio-based transition frequency, dipole, polarizability, and intermolecular coupling maps are developed for the spectral calculations. The calculated IR and SFG spectra show good agreement with the experimental measurements. In the theoretical imaginary part of the SFG susceptibility for the water liquid/vapor interface, we find two features: a negative band centered at 1615 cm-1 and a positive band centered at 1670 cm-1. We analyze this spectrum in terms of the contributions from molecules in different hydrogen-bond classes to the SFG spectral density and also compare to SFG results for the OH stretch. SFG of the water bending mode provides a complementary picture of the heterogeneous hydrogen-bond configurations at the water surface.

  9. Rapid Migration of Radionuclides Leaked from High-Level Water Tanks: A Study of Salinity Gradients, Wetted Path Geometry and Water Vapor Transport

    Energy Technology Data Exchange (ETDEWEB)

    Anderson L. Ward; Glendon W. Gee; John S. Selker; Caly Cooper

    2002-04-24

    The basis of this study was the hypothesis that the physical and chemical properties of hypersaline tank waste could lead to wetting from instability and fingered flow following a tank leak. Thus, the goal of this project was to develop an understanding of the impacts of the properties of hypersaline fluids on transport through the unsaturated zone beneath Hanford's Tank Farms. There were three specific objectives (i) to develop an improved conceptualization of hypersaline fluid transport in laboratory (ii) to identify the degree to which field conditions mimic the flow processes observed in the laboratory and (iii) to provide a validation data set to establish the degree to which the conceptual models, embodied in a numerical simulator, could explain the observed field behavior. As hypothesized, high ionic strength solutions entering homogeneous pre-wetted porous media formed unstable wetting fronts a typical of low ionic strength infiltration. In the field, this mechanism could force flow in vertical flow paths, 5-15 cm in width, bypassing much of the media and leading to waste penetration to greater depths than would be predicted by current conceptual models. Preferential flow may lead to highly accelerated transport through large homogeneous units, and must be included in any conservative analysis of tank waste losses through coarse-textured units. However, numerical description of fingered flow using current techniques has been unreliable, thereby precluding tank-scale 3-D simulation of these processes. A new approach based on nonzero, hysteretic contact angles and fluid-dependent liquid entry has been developed for the continuum scale modeling of fingered flow. This approach has been coupled with and adaptive-grid finite-difference solver to permit the prediction of finger formation and persistence form sub centimeter scales to the filed scale using both scalar and vector processors. Although laboratory experiments demonstrated that elevated surface

  10. Rapid Migration of Radionuclides Leaked from High-Level Water Tanks; A Study of Salinity Gradients, Wetted Path Geometry and Water Vapor Transport

    Energy Technology Data Exchange (ETDEWEB)

    Anderson l. Ward; Glendon W. Gee; John S. Selker; Clay Cooper

    2002-04-24

    The basis of this study was the hypothesis that the physical and chemical properties of hypersaline tank waste could lead to wetting from instability and fingered flow following a tank leak. Thus, the goal of this project was to develop an understanding of the impacts of the properties of hypersaline fluids on transport through the unsaturated zone beneath Hanford's Tank Farms. There were three specific objectives (i) to develop an improved conceptualization of hypersaline fluid transport in laboratory (ii) to identify the degree to which field conditions mimic the flow processes observed in the laboratory and (iii) to provide a validation data set to establish the degree to which the conceptual models, embodied in a numerical simulator, could explain the observed field behavior. As hypothesized, high ionic strength solutions entering homogeneous pre-wetted porous media formed unstable wetting fronts atypical of low ionic strength infiltration. In the field, this mechanism could for ce flow in vertical flow paths, 5-15 cm in width, bypassing much of the media and leading to waste penetration to greater depths than would be predicted by current conceptual models. Preferential flow may lead to highly accelerated transport through large homogeneous units, and must be included in any conservative analysis of tank waste losses through coarse-textured units. However, numerical description of fingered flow using current techniques has been unreliable, thereby precluding tank-scale 3-D simulation of these processes. A new approach based on nonzero, hysteretic contract angles and fluid-dependent liquid entry has been developed for the continuum scale modeling of fingered flow. This approach has been coupled with and adaptive-grid finite-difference solver to permit the prediction of finger formation and persistence form sub centimeter scales to the filed scale using both scalar and vector processors. Although laboratory experiments demonstrated that elevated surface

  11. Rapid Migration of Radionuclides Leaked from High-Level Water Tanks: A Study of Salinity Gradients, Wetted Path Geometry and Water Vapor Transport

    International Nuclear Information System (INIS)

    Ward, Anderson L.; Gee, Glendon W.; Selker, John S.; Cooper, Caly

    2002-01-01

    The basis of this study was the hypothesis that the physical and chemical properties of hypersaline tank waste could lead to wetting from instability and fingered flow following a tank leak. Thus, the goal of this project was to develop an understanding of the impacts of the properties of hypersaline fluids on transport through the unsaturated zone beneath Hanford's Tank Farms. There were three specific objectives (i) to develop an improved conceptualization of hypersaline fluid transport in laboratory (ii) to identify the degree to which field conditions mimic the flow processes observed in the laboratory and (iii) to provide a validation data set to establish the degree to which the conceptual models, embodied in a numerical simulator, could explain the observed field behavior. As hypothesized, high ionic strength solutions entering homogeneous pre-wetted porous media formed unstable wetting fronts a typical of low ionic strength infiltration. In the field, this mechanism could force flow in vertical flow paths, 5-15 cm in width, bypassing much of the media and leading to waste penetration to greater depths than would be predicted by current conceptual models. Preferential flow may lead to highly accelerated transport through large homogeneous units, and must be included in any conservative analysis of tank waste losses through coarse-textured units. However, numerical description of fingered flow using current techniques has been unreliable, thereby precluding tank-scale 3-D simulation of these processes. A new approach based on nonzero, hysteretic contact angles and fluid-dependent liquid entry has been developed for the continuum scale modeling of fingered flow. This approach has been coupled with and adaptive-grid finite-difference solver to permit the prediction of finger formation and persistence form sub centimeter scales to the filed scale using both scalar and vector processors. Although laboratory experiments demonstrated that elevated surface tension

  12. Rapid Migration of Radionuclides Leaked from High-Level Water Tanks: A Study of Salinity Gradients, Wetted Path Geometry and Water Vapor Transport

    International Nuclear Information System (INIS)

    Ward, Anderson L.; Gee, Glendon W.; Selker, John S.; Cooper, Clay

    2002-01-01

    The basis of this study was the hypothesis that the physical and chemical properties of hypersaline tank waste could lead to wetting from instability and fingered flow following a tank leak. Thus, the goal of this project was to develop an understanding of the impacts of the properties of hypersaline fluids on transport through the unsaturated zone beneath Hanford's Tank Farms. There were three specific objectives (i) to develop an improved conceptualization of hypersaline fluid transport in laboratory (ii) to identify the degree to which field conditions mimic the flow processes observed in the laboratory and (iii) to provide a validation data set to establish the degree to which the conceptual models, embodied in a numerical simulator, could explain the observed field behavior. As hypothesized, high ionic strength solutions entering homogeneous pre-wetted porous media formed unstable wetting fronts atypical of low ionic strength infiltration. In the field, this mechanism could for ce flow in vertical flow paths, 5-15 cm in width, bypassing much of the media and leading to waste penetration to greater depths than would be predicted by current conceptual models. Preferential flow may lead to highly accelerated transport through large homogeneous units, and must be included in any conservative analysis of tank waste losses through coarse-textured units. However, numerical description of fingered flow using current techniques has been unreliable, thereby precluding tank-scale 3-D simulation of these processes. A new approach based on nonzero, hysteretic contract angles and fluid-dependent liquid entry has been developed for the continuum scale modeling of fingered flow. This approach has been coupled with and adaptive-grid finite-difference solver to permit the prediction of finger formation and persistence form sub centimeter scales to the filed scale using both scalar and vector processors. Although laboratory experiments demonstrated that elevated surface tens ion

  13. Isobaric-isothermal Monte Carlo simulations from first principles: Application to liquid water at ambient conditions

    Energy Technology Data Exchange (ETDEWEB)

    McGrath, M; Siepmann, J I; Kuo, I W; Mundy, C J; VandeVondele, J; Hutter, J; Mohamed, F; Krack, M

    2004-12-02

    A series of first principles Monte Carlo simulations in the isobaric-isothermal ensemble were carried out for liquid water at ambient conditions (T = 298 K and p = 1 atm). The Becke-Lee-Yang-Parr (BLYP) exchange and correlation energy functionals and norm-conserving Goedecker-Teter-Hutter (GTH) pseudopotentials were employed with the CP2K simulation package to examine systems consisting of 64 water molecules. The fluctuations in the system volume encountered in simulations in the isobaric-isothermal ensemble requires a reconsideration of the suitability of the typical charge density cutoff and the regular grid generation method previously used for the computation of the electrostatic energy in first principles simulations in the microcanonical or canonical ensembles. In particular, it is noted that a much higher cutoff is needed and that the most computationally efficient method of creating grids can result in poor simulations. Analysis of the simulation trajectories using a very large charge density cutoff at 1200 Ry and four different grid generation methods point to a substantially underestimated liquid density of about 0.85 g/cm{sup 3} resulting in a somewhat understructured liquid (with a value of about 2.7 for the height of the first peak in the oxygen/oxygen radial distribution function) for BLYP-GTH water at ambient conditions.

  14. Calculated depth-dose distributions for H+ and He+ beams in liquid water

    International Nuclear Information System (INIS)

    Garcia-Molina, Rafael; Abril, Isabel; Denton, Cristian D.; Heredia-Avalos, Santiago; Kyriakou, Ioanna; Emfietzoglou, Dimitris

    2009-01-01

    We have calculated the dose distribution delivered by proton and helium beams in liquid water as a function of the target-depth, for incident energies in the range 0.5-10 MeV/u. The motion of the projectiles through the stopping medium is simulated by a code that combines Monte Carlo and a finite differences algorithm to consider the electronic stopping power, evaluated in the dielectric framework, and the multiple nuclear scattering with the target nuclei. Changes in projectile charge-state are taken into account dynamically as it moves through the target. We use the MELF-GOS model to describe the energy loss function of liquid water, obtaining a value of 79.4 eV for its mean excitation energy. Our calculated stopping powers and depth-dose distributions are compared with those obtained using other methods to describe the energy loss function of liquid water, such as the extended Drude and the Penn models, as well as with the prediction of the SRIM code and the tables of ICRU.

  15. Effect of liquid nitrogen flow rate on solidification of stagnant water in a horizontal tube

    International Nuclear Information System (INIS)

    Ibrahim, S.M.

    1995-01-01

    Five experiments are conducted to study the effect of liquid nitrogen flow rate on the solidification of stagnant water inside a horizontal stainless steel tube of inner diameter 19.6 cm and 12 mm thick. This tube simulates the down-comer of the nuclear reactor ET-R R-1. The apparatus design is mentioned more detail description. The results show that for the first experiment where the liquid nitrogen flow rate is 30 1/hr, the progress of solidification of water has stopped at a diameter of 12 cm. By increasing the flow rate from 30 1/hr to 40,50 and 60 1/hr, the time of freezing the water inside the tube is decreased from 86 to 67 and 60 minutes respectively. By increasing the liquid nitrogen flow rate to 70 1/hr, there is no much effect on the time of frozen. In all experiments, where the solidification is happened, the ice block formed inside the tube is subjected to a pressure of 3 at mg least, and is succeed to withstand this pressure without any leak. 7 figs

  16. Densities, Viscosities and Derived Thermophysical Properties of Water-Saturated Imidazolium-Based Ionic Liquids.

    Science.gov (United States)

    Martins, Mónia A R; Neves, Catarina M S S; Kurnia, Kiki A; Carvalho, Pedro J; Rocha, Marisa A A; Santos, Luís M N B F; Pinho, Simão P; Freire, Mara G

    2016-01-15

    In order to evaluate the impact of the alkyl side chain length and symmetry of the cation on the thermophysical properties of water-saturated ionic liquids (ILs), densities and viscosities as a function of temperature were measured at atmospheric pressure and in the (298.15 to 363.15) K temperature range, for systems containing two series of bis(trifluoromethylsulfonyl)imide-based compounds: the symmetric [C n C n im][NTf 2 ] (with n = 1-8 and 10) and asymmetric [C n C 1 im][NTf 2 ] (with n = 2-5, 7, 9 and 11) ILs. For water-saturated ILs, the density decreases with the increase of the alkyl side chain length while the viscosity increases with the size of the aliphatic tails. The saturation water solubility in each IL was further estimated with a reasonable agreement based on the densities of water-saturated ILs, further confirming that for the ILs investigated the volumetric mixing properties of ILs and water follow a near ideal behaviour. The water-saturated symmetric ILs generally present lower densities and viscosities than their asymmetric counterparts. From the experimental data, the isobaric thermal expansion coefficient and energy barrier were also estimated. A close correlation between the difference in the energy barrier values between the water-saturated and pure ILs and the water content in each IL was found, supporting that the decrease in the viscosity of ILs in presence of water is directly related with the decrease of the energy barrier.

  17. Electronic structure effects in liquid water studied by photoelectron spectroscopy and density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Nordlund, Dennis; Odelius, Michael; Bluhm, Hendrik; Ogasawara, Hirohito; Pettersson, Lars G.M.; Nilsson, Anders

    2008-04-29

    We present valence photoelectron emission spectra of liquid water in comparison with gas-phase water, ice close to the melting point, low temperature amorphous and crystalline ice. All aggregation states have major electronic structure changes relative to the free molecule, with rehybridization and development of bonding and anti-bonding states accompanying the hydrogen bond formation. Sensitivity to the local structural order, most prominent in the shape and splitting of the occupied 3a{sub 1} orbital, is understood from the electronic structure averaging over various geometrical structures, and reflects the local nature of the orbital interaction.

  18. Determination of 226Ra and 224Ra in drinking waters by liquid scintillation counting

    International Nuclear Information System (INIS)

    Manjon, G.; Vioque, I.; Moreno, H.; Garcia-Tenorio, R.; Garcia-Leon, M.

    1997-01-01

    A method for the determination of Ra-isotopes in water samples has been developed. Ra is coprecipitated with Ba as sulphate. The precipitate is then dissolved with EDTA and counted with a liquid scintillation system after mixing with a scintillation cocktail. The study of the temporal evolution of the separated activity gives the isotopic composition of the sample, i.e. the 224 Ra and 226 Ra contribution to the total activity. The method has been applied to some Spanish drinking waters. (author)

  19. Radiobiological application of simulation of low-energy electron transport in liquid water

    International Nuclear Information System (INIS)

    Eudaldo Puell, Teresa.

    1979-01-01

    A Monte-Carlo transport simulation method, so-called event-after-event method provide results about trajectories of low-energy electrons, slowing-down in liquid water. A radiosensitive target model constituted by water cylindrical volumes, like the ones which surround the DNA molecule, is taken into consideration. The results characterizing the primary physical stage of radiation action, such as, space ionization distributions, interionization distance distributions ..., are obtained in some configurations constituted by single or several targets, in order to approach the biological reality [fr

  20. Electrochemical assessment of water|ionic liquid biphasic systems towards cesium extraction from nuclear waste

    OpenAIRE

    Stockmann, T. Jane; Zhang, Jing; Montgomery, Anne-Marie; Ding, Zhifeng

    2014-01-01

    A room temperature ionic liquid (IL) composed of a quaternary alkylphosphonium (trihexyltetradecylphosphonium, P66614(+)) and tetrakis(pentafluorophenyl) borate anion (TB) was employed within a water| P66614TB (w|P66614TB or w|IL) biphasic system to evaluate cesium ion extraction in comparison to that with a traditional water|organic solvent (w|o) combination. Cs-137 is a major contributor to the radioactivity of spent nuclear fuel as it leaves the reactor, and its extraction efficiency is th...

  1. Evaporation Rates for Liquid Water and Ice Under Current Martian Conditions

    Science.gov (United States)

    Sears, D. W. G.; Moore, S. R.; Meier, A.; Chittenden, J.; Kareev, M.; Farmer, C. B.

    2004-01-01

    A number of studies have been concerned with the evaporation rates under martian conditions in order to place limits on the possible survival time of both liquid water and ice exposed on the surface of Mars. Such studies also aid in assessing the efficacy of an overlying layer of dust or loose regolith material in providing a barrier to free evaporation and thus prolong the lifetime of water in locations where its availability to putative living organisms would be significant. A better quantitative understanding of the effects of phase changes of water in the near surface environment would also aid the evaluation of the possible role of water in the formation of currently observed features, such as gullies in cliff walls and relatively short-term changes in the albedo of small surface areas ('dark stains'). Laboratory measurements aimed at refinement of our knowledge of these values are described here. The establishment of accurate values for evaporation rates and their dependence on the physical conditions of temperature, pressure and energy input, is an important benchmark for the further investigation of the efficacy of barriers to free evaporation in providing a prolonged period of survival of the water, particularly as a liquid.

  2. Zero Liquid Discharge (ZLD) System for Flue-Gas Derived Water From Oxy-Combustion Process

    Energy Technology Data Exchange (ETDEWEB)

    Sivaram Harendra; Danylo Oryshchyn; Thomas Ochs; Stephen J. Gerdemann; John Clark

    2011-10-16

    Researchers at the National Energy Technology Laboratory (NETL) located in Albany, Oregon, have patented a process - Integrated Pollutant Removal (IPR) that uses off-the-shelf technology to produce a sequestration ready CO{sub 2} stream from an oxy-combustion power plant. Capturing CO{sub 2} from fossil-fuel combustion generates a significant water product which can be tapped for use in the power plant and its peripherals. Water condensed in the IPR{reg_sign} process may contain fly ash particles, sodium (from pH control), and sulfur species, as well as heavy metals, cations and anions. NETL is developing a treatment approach for zero liquid discharge while maximizing available heat from IPR. Current treatment-process steps being studied are flocculation/coagulation, for removal of cations and fine particles, and reverse osmosis, for anion removal as well as for scavenging the remaining cations. After reverse osmosis process steps, thermal evaporation and crystallization steps will be carried out in order to build the whole zero liquid discharge (ZLD) system for flue-gas condensed wastewater. Gypsum is the major product from crystallization process. Fast, in-line treatment of water for re-use in IPR seems to be one practical step for minimizing water treatment requirements for CO{sub 2} capture. The results obtained from above experiments are being used to build water treatment models.

  3. EPR Evidence of Liquid Water in Ice: An Intrinsic Property of Water or a Self-Confinement Effect?

    Science.gov (United States)

    Thangswamy, Muthulakshmi; Maheshwari, Priya; Dutta, Dhanadeep; Rane, Vinayak; Pujari, Pradeep K

    2018-06-01

    Liquid water (LW) existence in pure ice below 273 K has been a controversial aspect primarily because of the lack of experimental evidence. Recently, electron paramagnetic resonance (EPR) has been used to study deeply supercooled water in a rapidly frozen polycrystalline ice. The same technique can also be used to probe the presence of LW in polycrystalline ice that has formed through a more conventional, slow cooling one. In this context, the present study aims to emphasize that in case of an external probe involving techniques such as EPR, the results are influenced by the binary phase (BP) diagram of the probe-water system, which also predicts the existence of LW domains in ice, up to the eutectic point. Here we report the results of our such EPR spin-probe studies on water, which demonstrate that smaller the concentration of the probe stronger is the EPR evidence of liquid domains in polycrystalline ice. We used computer simulations based on stochastic Liouville theory to analyze the lineshapes of the EPR spectra. We show that the presence of the spin probe modifies the BP diagram of water, at very low concentrations of the spin probe. The spin probe thus acts, not like a passive reporter of the behavior of the solvent and its environment, but as an active impurity to influence the solvent. We show that there exists a lower critical concentration, below which BP diagram needs to be modified, by incorporating the effect of confinement of the spin probe. With this approach, we demonstrate that the observed EPR evidence of LW domains in ice can be accounted for by the modified BP diagram of the probe-water system. The present work highlights the importance of taking cognizance of the possibility of spin probes affecting the host systems, when interpreting the EPR (or any other probe based spectroscopic) results of phase transitions of host, as its ignorance may lead to serious misinterpretations.

  4. An analysis on water hammer in liquid injection shutdown system of CANDU-9

    International Nuclear Information System (INIS)

    Kim, T. H.; Heo, J.; Han, S. K.; Choi, H. Y.; No, T. S.

    2000-01-01

    The water hammer analysis code, PTRAN, is used for computation of transient pressures and pressure differentials in the Liquid Injection Shutdown System(LISS) piping network of CANDU-9 to ensure that the design allowables for LEVEL C Service Limit are met for the water hammer loads resulting from the water hammer. The LISS piping network of CANDU-9 has incorporated design improvement in considering the water hammer, such as declining the horizontal part of helium header, and raising the elevation of the overall system piping configuration, etc. The maximum pressure in the LISS piping network is found to be 7.92 MPa(a) at the closed valve in the vent line, which is below the allowable working pressure and the valve design pressure under Level C service conditions. And it is also shown that the maximum pressure in CANDU-9 is much lower than that in CANDU-6

  5. Demonstration test on decontamination of contaminated pool water using liquid-solid settling technology with flocculants

    International Nuclear Information System (INIS)

    Aritomi, Masanori; Adachi, Toshihiro; Watanabe, Noriyuki; Tagawa, Akihiro; Hosobuchi, Shigeki; Takanashi, Junko

    2013-01-01

    For the purpose of supplying agricultural water, a stationary purification system for contaminated water had been developed on the basis of the liquid-solid settling technology using flocculants. Two kinds of flocculants had been developed on the basis of preliminary tests: one that compounds iron ferrocyanide and the other that does not. With the use of this system and flocculants, a demonstration test was conducted to apply the decontamination technology on contaminated water in two swimming pools in an elementary school located at Motomiya City, Fukushima Prefecture, Japan. It is proved from the results that both the developed purification system and the flocculants can be established as a practicable decontamination technology for contaminated water: the treatment rate was 10 m 3 /hour and the elimination factor of radioactive materials was higher than 99%. (author)

  6. Analysis of bromate in drinking water using liquid chromatography-tandem mass spectrometry without sample pretreatment.

    Science.gov (United States)

    Kosaka, Koji; Asami, Mari; Takei, Kanako; Akiba, Michihiro

    2011-01-01

    An analytical method for determining bromate in drinking water was developed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The (18)O-enriched bromate was used as an internal standard. The limit of quantification (LOQ) of bromate was 0.2 µg/L. The peak of bromate was separated from those of coexisting ions (i.e., chloride, nitrate and sulfate). The relative and absolute recoveries of bromate in two drinking water samples and in a synthesized ion solution (100 mg/L chloride, 10 mg N/L nitrate, and 100 mg/L sulfate) were 99-105 and 94-105%, respectively. Bromate concentrations in 11 drinking water samples determined by LC-MS/MS were water without sample pretreatment.

  7. Global statistics of liquid water content and effective number concentration of water clouds over ocean derived from combined CALIPSO and MODIS measurements

    Science.gov (United States)

    Hu, Y.; Vaughan, M.; McClain, C.; Behrenfeld, M.; Maring, H.; Anderson, D.; Sun-Mack, S.; Flittner, D.; Huang, J.; Wielicki, B.; Minnis, P.; Weimer, C.; Trepte, C.; Kuehn, R.

    2007-06-01

    This study presents an empirical relation that links the volume extinction coefficients of water clouds, the layer integrated depolarization ratios measured by lidar, and the effective radii of water clouds derived from collocated passive sensor observations. Based on Monte Carlo simulations of CALIPSO lidar observations, this method combines the cloud effective radius reported by MODIS with the lidar depolarization ratios measured by CALIPSO to estimate both the liquid water content and the effective number concentration of water clouds. The method is applied to collocated CALIPSO and MODIS measurements obtained during July and October of 2006, and January 2007. Global statistics of the cloud liquid water content and effective number concentration are presented.

  8. Steam water cycle chemistry of liquid metal cooled innovative nuclear power reactors

    International Nuclear Information System (INIS)

    Yurmanov, Victor; Lemekhov, Vadim; Smykov, Vladimir

    2012-09-01

    selection of chemistry controls is vital for NPPs with liquid metal cooled reactors. This paper highlights principles and approaches to chemistry controls in steam/water cycles of future NPPs with innovative liquid metal cooled reactors. The recommendations on how to arrange chemistry controls in steam/water cycles of future NPPs with innovative liquid metal cooled reactors are based taking into account: - the experience with operation of fossil power industry; - secondary side water chemistry of lead-bismuth eutectics cooled nuclear reactors at submarines; - steam/water cycles of NPPs with sodium cooled fast breeders BN-350 and BN-600; - secondary water chemistry at conventional NPPs with WER, RBMK and some other reactors. (authors)

  9. Improved prediction of octanol-water partition coefficients from liquid-solute water solubilities and molar volumes

    Science.gov (United States)

    Chiou, C.T.; Schmedding, D.W.; Manes, M.

    2005-01-01

    A volume-fraction-based solvent-water partition model for dilute solutes, in which the partition coefficient shows a dependence on solute molar volume (V??), is adapted to predict the octanol-water partition coefficient (K ow) from the liquid or supercooled-liquid solute water solubility (Sw), or vice versa. The established correlation is tested for a wide range of industrial compounds and pesticides (e.g., halogenated aliphatic hydrocarbons, alkylbenzenes, halogenated benzenes, ethers, esters, PAHs, PCBs, organochlorines, organophosphates, carbamates, and amidesureas-triazines), which comprise a total of 215 test compounds spanning about 10 orders of magnitude in Sw and 8.5 orders of magnitude in Kow. Except for phenols and alcohols, which require special considerations of the Kow data, the correlation predicts the Kow within 0.1 log units for most compounds, much independent of the compound type or the magnitude in K ow. With reliable Sw and V data for compounds of interest, the correlation provides an effective means for either predicting the unavailable log Kow values or verifying the reliability of the reported log Kow data. ?? 2005 American Chemical Society.

  10. Theoretical investigation of the ultrafast dissociation of core-ionized water and uracil molecules immersed in liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Stia, C.R.; Fojon, O.A. [Instituto de Fisica Rosario - CONICET-Universidad Nacional de Rosario, Rosario (Argentina); Gaigeot, M.P. [Laboratoire Analyse et Modelisation pour la Biologie et l' Environnement, LAMBE, UMR-CNRS 8587, Universite d' Evry-Val-d' Essonne, 91 - Evry (France); Institut Universitaire de France, 75 - Paris (France); Vuilleumier, R. [Departement de chimie, Ecole Normale Superieure, 75 - Paris (France); Herve du Penhoat, M.A.; Politis, M.F. [Institut de Mineralogie et de Physique des Milieux Condenses, IMPMC, UMR-CNRS 7590, Universite Pierre et Marie Curie, 75 - Paris (France)

    2010-10-15

    We present a series of ab initio density functional based calculations of the fragmentation dynamics of core-ionized biomolecules. The computations are performed for pure liquid water, aqueous and isolated Uracil. Core ionization is described by replacing the 1s{sup 2} pseudopotential of one atom of the target molecule (C, N or O) with a pseudopotential for a 1s{sup 1} core-hole state. Our results predict that the dissociation of core-ionized water molecules may be reached during the lifetime of inner-shell vacancy (less than 10 fs), leading to OH bond breakage as a primary outcome. We also observe a second fragmentation channel in which total Coulomb explosion of the ionized water molecule occurs. Fragmentation pathways are found similar for pure water or when the water molecule is in the primary hydration shell of the uracil molecule. In the latter case, the proton may be transferred towards the uracil oxygen atoms. When the core hole is located on the uracil molecule, ultrafast dissociation is only observed in the aqueous environment and for nitrogen-K vacancies, resulting in proton transfers towards the hydrogen-bonded water molecule. (authors)

  11. LIQUID-LIQUID EQUILIBRIA OF THE TERNARY SYSTEMS PROPIONIC ACID - WATER - SOLVENT (n-AMYL ALCOHOL AND n-AMYL ACETATE

    Directory of Open Access Journals (Sweden)

    Dilek ÖZMEN

    2005-02-01

    Full Text Available The experimental liquid-liquid equilibrium (LLE data have been obtained at 25 oC for ternary systems propionic acid-water-n-amyl alcohol and propionic acid-water-n-amyl acetate. The reliability of the experimental tie line data are checked using the methods of Othmer-Tobias and Hand. The distribution coefficients and separation factors were obtained from experimental results and are also reported. The predicted tie line data obtained by UNIFAC method are compared with experimental data. It is concluded that n-amyl alcohol and n-amyl acetate are suitable separating agents for dilute aqueous propionic acid solutions.

  12. The study of water + HCl + ethanol vapor-liquid equilibrium at 78 kPa

    International Nuclear Information System (INIS)

    Ojeda Toro, Juan Carlos; Dobrosz-Gómez, Izabela; Gómez García, Miguel Ángel

    2017-01-01

    Graphical abstract: Comparison between experimental and calculated saturation temperature of water + HCl + ethanol system using two rigorous electrolyte models. - Highlights: • Data for the water + HCl + ethanol VLE is reported at 78 kPa. • The VLE for the system water + HCl + ethanol was determined. • A new set of parameters for extended UNIQUAC model were correlated. • A new set of parameters for LIQUAC model were correlated. - Abstract: In this work, the isobaric vapor-liquid equilibrium (VLE) data obtained for the ternary system water + HCl + ethanol at 78 kPa, using an Ellis still, were studied. Two rigorous electrolyte models (extended UNIQUAC and LIQUAC) were fitted to the experimental data. Ethanol-H + , water-H + , ethanol-Cl − , water-Cl − , and Cl − -H + interaction parameters were determined. Likewise, Henry’s law constants for the volatile electrolyte were defined. A high goodness of fit was obtained for both electrolyte models; however, the extended UNIQUAC one showed better performance (AAD = 0.1326%). Two azeotropes observed in the system were accurately predicted (ethanol + water: x EtOH = 0.86 at 344.6 K; and HCl + water: x HCl = 0.11 at 375.5 K).

  13. Ecological Security Pattern Analysis Based on InVEST and Least-Cost Path Model: A Case Study of Dongguan Water Village

    Directory of Open Access Journals (Sweden)

    Qian Lin

    2016-02-01

    Full Text Available The famous “world’s factory” city, Dongguan, like many other places in China, is a typical beneficiary of China’s Reform and Opening-up Policy. However, rapid urban sprawl and economic growth are at the expense of the destruction of the local environment. Therefore, it is of great importance to establish an ecological security network for sustainable development. InVEST models, effective tools to measure sensitivity and intensity of external threats to quantify habitat value, are used to calculate habitat quality of water and land. By combining structural connectivity and the Least-Cost Path model (LCP model, in which corridors are determined based on the minimum accumulative cost path between each critical point, ecological security patterns were calculated. According to the results, the northwest region of Dongguan, having a large quantity of farmlands and water and therefore many corridors and critical patches, is the most essential area in the overall security of ecological environments, which should be protected first. If developed, it should be dominated by eco-tourism and eco-agriculture. We hope that research on the ecological network, which includes critical patches and corridors formed by greenland and rivers, will lead toward better-informed proposals for local urban planning and regional sustainable development.

  14. Simultaneous determination of three surfactants and water in shampoo and liquid soap by ATR-FTIR.

    Science.gov (United States)

    Carolei, Luciano; Gutz, Ivano G R

    2005-03-31

    It is demonstrated for the first time that the principal constituents of a shampoo as well as of a liquid soap -three surfactants and water- can be determined directly, simultaneously and quickly in undiluted samples by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy in the middle infrared region, despite the broad absorption bands of the solvent. Two of the surfactants, sodium lauryl ether sulfate (SLES) and cocoamidopropyl betaine (CAPB), are common to both formulations; alkylpolyglucoside (APG) is the third surfactant of the liquid soap and cocodiethanolamide (CDEA), the corresponding ingredient of the shampoo. Absorbance data of the undiluted samples and of the calibration standards was collected in the middle infrared region of the spectrum (800-1600 and 1900-3000cm(-1)). Two methods of multivariate quantification were compared: classical least squares (CLS), where absorbance data measured at 200 wavenumbers was processed, and inverse least squares (ILS), where data at 10 selected wavenumbers was analyzed. A spectra normalization procedure, based on a dominating water band, was examined. Twenty-seven standard mixtures were used for each application, consisting of all combinations at three concentration levels of each surfactant, respectively the lower limit, the expected value and the upper limit accepted in quality control. By favoring wavenumbers where absorption bands of the minor components (APG in the liquid soap and CDEA in the shampoo) are more intense, good results were obtained for 18 simulated samples of shampoo and 18 samples of liquid soap, no matter if calculations were made by CLS or ILS. The relative errors for water (major component, 84-88%) and SLES (7-10%) were always below 2%; for CAPB (2-4%), APG (<2%) and CDEA (<2%), they occasionally reached 5% of the component, an uncertainty of less than 0.07% in terms of the sample weight.

  15. Tomographic retrieval of cloud liquid water fields from a single scanning microwave radiometer aboard a moving platform – Part 1: Field trial results from the Wakasa Bay experiment

    Directory of Open Access Journals (Sweden)

    D. Huang

    2010-07-01

    Full Text Available Tomographic methods offer great potential for retrieving three-dimensional spatial distributions of cloud liquid water from radiometric observations by passive microwave sensors. Fixed tomographic systems require multiple radiometers, while mobile systems can use just a single radiometer. Part 1 (this paper examines the results from a limited cloud tomography trial with a single-radiometer airborne system carried out as part of the 2003 AMSR-E validation campaign over Wakasa Bay of the Sea of Japan. During this trial, the Polarimetric Scanning Radiometer (PSR and Microwave Imaging Radiometer (MIR aboard the NASA P-3 research aircraft provided a useful dataset for testing the cloud tomography method over a system of low-level clouds. We do tomographic retrievals with a constrained inversion algorithm using three configurations: PSR, MIR, and combined PSR and MIR data. The liquid water paths from the PSR retrieval are consistent with those from the MIR retrieval. The retrieved cloud field based on the combined data appears to be physically plausible and consistent with the cloud image obtained by a cloud radar. We find that some vertically-uniform clouds appear at high altitudes in the retrieved field where the radar shows clear sky. This is likely due to the sub-optimal data collection strategy. This sets the stage for Part 2 of this study that aims to define optimal data collection strategies using observation system simulation experiments.

  16. A review of the structure and dynamics of nanoconfined water and ionic liquids via molecular dynamics simulation.

    Science.gov (United States)

    Foroutan, Masumeh; Fatemi, S Mahmood; Esmaeilian, Farshad

    2017-02-01

    During the past decade, the research on fluids in nanoconfined geometries has received considerable attention as a consequence of their wide applications in different fields. Several nanoconfined systems such as water and ionic liquids, together with an equally impressive array of nanoconfining media such as carbon nanotube, graphene and graphene oxide have received increasingly growing interest in the past years. Water is the first system that has been reviewed in this article, due to its important role in transport phenomena in environmental sciences. Water is often considered as a highly nanoconfined system, due to its reduction to a few layers of water molecules between the extended surface of large macromolecules. The second system discussed here is ionic liquids, which have been widely studied in the modern green chemistry movement. Considering the great importance of ionic liquids in industry, and also their oil/water counterpart, nanoconfined ionic liquid system has become an important area of research with many fascinating applications. Furthermore, the method of molecular dynamics simulation is one of the major tools in the theoretical study of water and ionic liquids in nanoconfinement, which increasingly has been joined with experimental procedures. In this way, the choice of water and ionic liquids in nanoconfinement is justified by applying molecular dynamics simulation approaches in this review article.

  17. Impact of water dilution and cation tail length on ionic liquid characteristics: Interplay between polar and non-polar interactions

    International Nuclear Information System (INIS)

    Hegde, Govind A.; Bharadwaj, Vivek S.; Kinsinger, Corey L.; Schutt, Timothy C.; Pisierra, Nichole R.; Maupin, C. Mark

    2016-01-01

    The recalcitrance of lignocellulosic biomass poses a major challenge that hinders the economical utilization of biomass for the production of biofuel, plastics, and chemicals. Ionic liquids have become a promising solvent that addresses many issues in both the pretreatment process and the hydrolysis of the glycosidic bond for the deconstruction of cellulosic materials. However, to make the use of ionic liquids economically viable, either the cost of ionic liquids must be reduced, or a less expensive solvent (e.g., water) may be added to reduce the overall amount of ionic liquid used in addition to reducing the viscosity of the binary liquid mixture. In this work, we employ atomistic molecular dynamics simulations to investigate the impact of water dilution on the overall liquid structure and properties of three imidazolium based ionic liquids. It is found that ionic liquid-water mixtures exhibit characteristics that can be grouped into two distinct regions, which are a function of the ionic liquid concentration. The trends observed in each region are found to correlate with the ordering in the local structure of the ionic liquid that arises from the dynamic interactions between the ion pairs. Simulation results suggest that there is a high level of local ordering in the molecular structure at high concentrations of ionic liquids that is driven by the aggregation of the cationic tails and the anion-water interactions. It is found that as the concentration of ionic liquids in the binary mixture is decreased, there is a point at which the competing self and cross interaction energies between the ionic liquid and water shifts away from a cation-anion dominated regime, which results in a significant change in the mixture properties. This break point, which occurs around 75% w/w ionic liquids, corresponds to the point at which water molecules percolate into the ionic liquid network disrupting the ionic liquids’ nanostructure. It is observed that as the cationic alkyl

  18. Thermodynamic analysis of an innovative liquid desiccant air conditioning system to supply potable water

    International Nuclear Information System (INIS)

    Ahmed, M.A.; Gandhidasan, P.; Zubair, Syed M.; Bahaidarah, Haitham M.

    2017-01-01

    Highlights: • The study objective is to reduce the energy consumption of desiccant AC system. • Heat and mass losses are recovered in the proposed system using a condenser. • The conventional and the proposed systems are compared in terms of COP. • The proposed system performance is better than the conventional system. • The proposed system produces freshwater in addition to space cooling. - Abstract: Liquid desiccant air conditioning systems are cost-effective, environmentally friendly and energy efficient techniques, especially in coastal areas. In the conventional liquid desiccant air conditioning system, the scavenging air is expelled into the atmosphere carrying a considerable amount of energy and water vapor. Thus, there is plenty of room to improve the system performance by recovering these losses. The proposed system consists of a conventional liquid desiccant air conditioning system plus a condenser. The aim of this study is to reduce the energy consumption by recovering the heat from the scavenging air using the condenser while also producing freshwater in addition to space cooling. Lithium chloride (LiCl) is used as the liquid desiccant for this study. The mathematical formulation for simultaneous heat and mass transfer between the condenser and the regenerator was developed to establish a comparison between the performance of the conventional and modified systems. Using the generated model, it is found that the modified system performance is 11.25% better than the conventional system and that it produces 86.4 kg of freshwater per hour as a by-product under the given conditions.

  19. Carbon-based nanomaterial synthesis using nanosecond electrical discharges in immiscible layered liquids: n-heptane and water

    KAUST Repository

    Hamdan, Ahmad; Cha, Min

    2018-01-01

    Plasmas in- or in-contact with liquids have been extensively investigated due to their high potential for a wide range of applications including but not limited to, water treatment, material synthesis and functionalization, bio-medical applications

  20. Water injection into vapor- and liquid-dominated reservoirs: Modeling of heat transfer and mass transport

    Energy Technology Data Exchange (ETDEWEB)

    Pruess, K.; Oldenburg, C.; Moridis, G.; Finsterle, S. [Lawrence Berkeley National Lab., CA (United States)

    1997-12-31

    This paper summarizes recent advances in methods for simulating water and tracer injection, and presents illustrative applications to liquid- and vapor-dominated geothermal reservoirs. High-resolution simulations of water injection into heterogeneous, vertical fractures in superheated vapor zones were performed. Injected water was found to move in dendritic patterns, and to experience stronger lateral flow effects than predicted from homogeneous medium models. Higher-order differencing methods were applied to modeling water and tracer injection into liquid-dominated systems. Conventional upstream weighting techniques were shown to be adequate for predicting the migration of thermal fronts, while higher-order methods give far better accuracy for tracer transport. A new fluid property module for the TOUGH2 simulator is described which allows a more accurate description of geofluids, and includes mineral dissolution and precipitation effects with associated porosity and permeability change. Comparisons between numerical simulation predictions and data for laboratory and field injection experiments are summarized. Enhanced simulation capabilities include a new linear solver package for TOUGH2, and inverse modeling techniques for automatic history matching and optimization.

  1. Interfacial liquid water on Mars and its potential role in formation of hill and dune gullies

    Science.gov (United States)

    Kossacki, Konrad J.; Markiewicz, Wojciech J.

    2010-11-01

    Gullies are among the most intriguing structures identified on the surface of Mars. Most common are gullies located on the slopes of craters which are probably formed by liquid water transported by shallow aquifers (Heldmann, J.L., Carlsson, E., Johansson, H., Mellon, M.T., Toon, O.B. [2007]. Icarus 188, 324-344). Two particular types of gullies are found on slopes of isolated hills and dunes. The hill-slope gullies are located mostly at 50°S, which is at the high end of latitudes of bulk of the gullies found so far. The dune gullies are found in several locations up to 65°S (Reiss, D., Jaumann, R., Kereszturi, A., Sik, A., Neukum, G. [2007]. Lunar Planet. Sci. XXXVIII. Abstract 1993), but the best known are those in Russel crater at 54°S. The hill and dune gullies are longer than others making the aquifers explanation for their formation unlikely (Balme, M., Mangold, N., Baratoux, D., Costard, F., Gosselin, M., Masson, P., Pnet, P., Neukum, G. [2006]. J. Geophys. Res. 111. doi:10.1029/2005JE002607). Recently it has been noted that thin liquid films of interfacial water can play a role in rheological processes on the surface of Mars (Moehlmann, D. [2008]. Icarus 195, 131-139. Kereszturi, A., Moehlmann, D., Berczi, Sz., Ganti, T., Kuti, A., Sik, A., Horvath, A. [2009]. Icarus 201, 492-503.). Here we try to answer the question whether interfacial liquid water may occur on Mars in quantities large enough to play a role in formation of gullies. To verify this hypothesis we have calculated thermal models for hills and dunes of various steepness, orientation and physical properties. We find that within a range of average expected values of parameters it is not possible to have more than a few monolayers of liquid water at depths greater than a centimeter. To create subsurface interfacial water film significantly thicker and hence to produce conditions for the slope instability, parameters have to be chosen to have their extreme realistic values or an additional source

  2. The management plan of liquid effluent in Korean advanced light water reactor

    International Nuclear Information System (INIS)

    Kim, S. H.; Lim, H. S.; Jeong, D. W.; Jeong, D. Y.

    2001-01-01

    Non-radioactive liquid effluent in Korean Advanced Light Water Reactor is transferred and treated in centralized waste treatment facility after the radioactivity in effluent is checked within power block. The liquid effluent from centralized waste treatment facility will be discharged by way of discharge canal in order to be in the sufficient condition. As a result of investigating the radiation monitoring design in accordance with 20 provisions by Korean Regulatory Authority, each effluent radiation monitoring with 20 provisions by Korean Regulatory Authority, each effluent radiation monitoring design satisfies the regulatory guideline. In relation to sampling and analyses, most systems satisfy the regulatory guideline except for some effluents from turbine building. And, though sampling and analyses are performed after radioactivity is monitored at each system in turbine building, these exceptions in turbine building effluents are expected to cause no significant problems because radioactivity is monitored by direct or indirect methods prior to release from turbine building. Integrated monitoring on liquid effluent from the centralized waste water treatment facility is not necessary because radiation monitoring, sampling and analyses on each system within power block are performed, and operational effectiveness compared with cost according to adding the radiation monitoring equipment is too low. So, whether the radiation monitoring in this effluent is reflected on design or not is planned to be determined through discussion with regulatory authority

  3. Ionic liquid-based dispersive microextraction of nitro toluenes in water samples

    International Nuclear Information System (INIS)

    Berton, Paula; Regmi, Bishnu P.; Spivak, David A.; Warner, Isiah M.

    2014-01-01

    We describe a method for dispersive liquid-liquid microextraction of nitrotoluene-based compounds. This method is based on use of the room temperature ionic liquid (RTIL) 1-hexyl-4-methylpyridinium bis(trifluoromethylsulfonyl)imide as the accepting phase, and is shown to work well for extraction of 4-nitrotoluene, 2,4-dinitrotoluene, and 2,4,6-trinitrotoluene. Separation and subsequent detection of analytes were accomplished via HPLC with UV detection. Several parameters that influence the efficiency of the extraction were optimized using experimental design. In this regard, a Plackett–Burman design was used for initial screening, followed by a central composite design to further optimize the influencing variables. For a 5-mL water sample, the optimized IL-DLLME procedure requires 26 mg of the RTIL as extraction solvent and 680 μL of methanol as the dispersant. Under optimum conditions, limits of detection (LODs) are lower than 1.05 μg L −1 . Relative standard deviations for 6 replicate determinations at a 4 μg L −1 analyte level are <4.3 % (calculated using peak areas). Correlation coefficients of >0.998 were achieved. This method was successfully applied to extraction and determination of nitrotoluene-based compounds in spiked tap and lake water samples. (author)

  4. A thermomechanical model for the fragmentation of a liquid metal droplet cooled by water

    Science.gov (United States)

    Ivochkin, Yu P.; Monastyrskiy, V. P.

    2017-11-01

    A thermo mechanical aspect of the fragmentation of a liquid metal droplet, solidified as it falls into cold water, is considered in the presented model. The formation of a solid phase in the form of continuous, fluid-tight and relatively rigid casting skin results in a pressure decrease inside the droplet due to the difference between liquid and solid metal density. Because of the high compression modulus of the melt, the pressure in the droplet becomes negative when the thickness of the solid skin achieves several microns. The tensile stress in the melt results in the deformation of the casting skin or the melt’s continuity violation in the form of a shrinkage pore. The rupture of the deformed solid crust results in the penetration of steam jets into the liquid part of the drop. Due to the difference in pressure in the surrounding steam and in the droplet, the casting skin is crushed and the melt is blown out. Both scenarios contribute to the hydrodynamic destruction of the droplet. The suggested thermo mechanical model gives a qualitative explanation for experimental data. In the experimental part of the work, droplets of molten Sn were solidified in water. The solidified pieces of the droplets usually include deformed, thin-walled shells and dispersed particles. On a qualitative level the composition and shape of the solid fragments can be explained within the bounds of the suggested thermo mechanical model.

  5. Flow paths of water and sediment in a tidal marsh: relations with marsh developmental stage and tidal inundation height

    NARCIS (Netherlands)

    Temmerman, S.; Bouma, T.J.; Govers, G.; Lauwaet, D.

    2005-01-01

    This study provides new insights in the relative role of tidal creeks and the marsh edge in supplying water and sediments to and from tidal marshes for a wide range of tidal inundation cycles with different high water levels and for marsh zones of different developmental stage. Net import or export

  6. Rapid pretreatment and determination of bisphenol A in water samples based on vortex-assisted liquid-liquid microextraction followed by high-performance liquid chromatography with fluorescence detection.

    Science.gov (United States)

    Yang, Xiao; Diao, Chun-Peng; Sun, Ai-Ling; Liu, Ren-Min

    2014-10-01

    A method for the rapid pretreatment and determination of bisphenol A in water samples based on vortex-assisted liquid-liquid microextraction followed by high-performance liquid chromatography with fluorescence detection was proposed in this paper. A simple apparatus consisting of a test tube and a cut-glass dropper was designed and applied to collect the floating extraction drop in liquid-liquid microextraction when low-density organic solvent was used as the extraction solvent. Solidification and melting steps that were tedious but necessary once the low-density organic solvent used as extraction solvent could be avoided by using this apparatus. Bisphenol A was selected as model pollutant and vortex-assisted liquid-liquid microextraction was employed to investigate the usefulness of the apparatus. High-performance liquid chromatography with fluorescence detection was selected as the analytical tool for the detection of bisphenol A. The linear dynamic range was from 0.10 to 100 μg/L for bisphenol A, with good squared regression coefficient (r(2) = 0.9990). The relative standard deviation (n = 7) was 4.7% and the limit of detection was 0.02 μg/L. The proposed method had been applied to the determination of bisphenol A in natural water samples and was shown to be economical, fast, and convenient. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Vortex-assisted magnetic β-cyclodextrin/attapulgite-linked ionic liquid dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography for the fast determination of four fungicides in water samples.

    Science.gov (United States)

    Yang, Miyi; Xi, Xuefei; Wu, Xiaoling; Lu, Runhua; Zhou, Wenfeng; Zhang, Sanbing; Gao, Haixiang

    2015-02-13

    A novel microextraction technique combining magnetic solid-phase microextraction (MSPME) with ionic liquid dispersive liquid-liquid microextraction (IL-DLLME) to determine four fungicides is presented in this work for the first time. The main factors affecting the extraction efficiency were optimized by the one-factor-at-a-time approach and the impacts of these factors were studied by an orthogonal design. Without tedious clean-up procedure, analytes were extracted from the sample to the adsorbent and organic solvent and then desorbed in acetonitrile prior to chromatographic analysis. Under the optimum conditions, good linearity and high enrichment factors were obtained for all analytes, with correlation coefficients ranging from 0.9998 to 1.0000 and enrichment factors ranging 135 and 159 folds. The recoveries for proposed approach were between 98% and 115%, the limits of detection were between 0.02 and 0.04 μg L(-1) and the RSDs changed from 2.96 to 4.16. The method was successfully applied in the analysis of four fungicides (azoxystrobin, chlorothalonil, cyprodinil and trifloxystrobin) in environmental water samples. The recoveries for the real water samples ranged between 81% and 109%. The procedure proved to be a time-saving, environmentally friendly, and efficient analytical technique. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Method and apparatus for electrokinetic co-generation of hydrogen and electric power from liquid water microjets

    Energy Technology Data Exchange (ETDEWEB)

    Saykally, Richard J; Duffin, Andrew M; Wilson, Kevin R; Rude, Bruce S

    2013-02-12

    A method and apparatus for producing both a gas and electrical power from a flowing liquid, the method comprising: a) providing a source liquid containing ions that when neutralized form a gas; b) providing a velocity to the source liquid relative to a solid material to form a charged liquid microjet, which subsequently breaks up into a droplet spay, the solid material forming a liquid-solid interface; and c) supplying electrons to the charged liquid by contacting a spray stream of the charged liquid with an electron source. In one embodiment, where the liquid is water, hydrogen gas is formed and a streaming current is generated. The apparatus comprises a source of pressurized liquid, a microjet nozzle, a conduit for delivering said liquid to said microjet nozzle, and a conductive metal target sufficiently spaced from said nozzle such that the jet stream produced by said microjet is discontinuous at said target. In one arrangement, with the metal nozzle and target electrically connected to ground, both hydrogen gas and a streaming current are generated at the target as it is impinged by the streaming, liquid spray microjet.

  9. Gas-liquid chromatography measurements of activity coefficients at infinite dilution of various organic solutes and water in tri-iso-butylmethylphosphonium tosylate ionic liquid

    International Nuclear Information System (INIS)

    Domanska, Urszula; Paduszynski, Kamil

    2010-01-01

    Activity coefficients at infinite dilution (γ 13 ∞ ) of 33 different solutes (including alkanes, cycloalkanes, alkenes, alkynes, benzene, alkylbenzenes, water, alcohols, MTBE, thiophene and THF) in the ionic liquid tri-iso-butylmethylphosphonium tosylate have been determined by using the GLC method and have been reported over the temperature range (298.15 to 368.15) K. The partial molar excess enthalpies of mixing at infinite dilution have been determined based on temperature dependence of γ 13 ∞ . Selectivity and capacity at infinite dilution has been also calculated for exemplary separation processes in systems n-hexane/benzene and n-hexane/thiophene, to evaluate if the studied ionic liquid is capable to be a good entrainer for these processes, e.g. in the liquid-liquid extraction. The obtained results are promising however the ionic liquid studied shows a lower selectivity than some of imidazolium-based ionic liquids. To our best knowledge, the results indicate that tri-iso-butylmethylphosphonium tosylate is the best for the separation problem of aliphatic hydrocarbons from aromatic hydrocarbons among all of the studied quaternary phosphonium-based ionic liquids.

  10. Model for calculating shock loading and release paths for multicomponent geologic media

    International Nuclear Information System (INIS)

    Butkovich, T.R.; Moran, B.; Burton, D.E.

    1981-07-01

    A model has been devised to calculate shock Hugoniots and release paths off the Hugoniots for multicomponent rocks containing silicate, carbonate, and water. Hugoniot equations of state are constructed from relatively simple measurements of rock properties including bulk density, grain density of the silicate component, and weight fractions of water and carbonate. Release paths off the composite Hugoniot are calculated by mixing release paths off the component Hugoniots according to their weight fractions. If the shock imparts sufficient energy to the component to cause vaporization, a gas equation of state is used to calculate the release paths. For less energetic shocks, the rock component will unload like a solid or liquid, taking into account the irreversible removal of air-filled porosity

  11. Input of 87Sr/86Sr ratios and Sr geochemical signatures to update knowledge on thermal and mineral waters flow paths in fractured rocks (N-Portugal)

    International Nuclear Information System (INIS)

    Marques, J.M.; Carreira, P.M.; Goff, F.; Eggenkamp, H.G.M.; Antunes da Silva, M.

    2012-01-01

    Strontium isotopes and other geochemical signatures are used to determine the relationships between CO 2 -rich thermal (Chaves: 76 °C) and mineral (Vilarelho da Raia, Vidago and Pedras Salgadas: 17 °C) waters discharging along one of the major NNE–SSW trending faults in the northern part of mainland Portugal. The regional geology consists of Hercynian granites (syn-tectonic-310 Ma and post-tectonic-290 Ma) intruding Silurian metasediments (quartzites, phyllites and carbonaceous slates). Thermal and mineral waters have 87 Sr/ 86 Sr isotopic ratios between 0.716713 and 0.728035. 87 Sr/ 86 Sr vs. 1/Sr define three end-members (Vilarelho da Raia/Chaves, Vidago and Pedras Salgadas thermal and mineral waters) trending from rainfall composition towards that of the CO 2 -rich thermal and mineral waters, indicating different underground flow paths. Local granitic rocks have 87 Sr/ 86 Sr ratios of 0.735697–0.789683. There is no indication that equilibrium was reached between the CO 2 -rich thermal and mineral waters and the granitic rocks. The mean 87 Sr/ 86 Sr ratio of the thermal and mineral waters (0.722419) is similar to the Sr isotopic ratios of the plagioclases of the granitic rocks (0.71261–0.72087). The spatial distribution of Sr isotope and geochemical signatures of waters and the host rocks suggests that the thermal and mineral waters circulate in similar but not the same hydrogeological system. Results from this study could be used to evaluate the applicability of this isotope approach in other hydrogeologic investigations.

  12. Scattering data for modelling positron tracks in gaseous and liquid water

    International Nuclear Information System (INIS)

    Blanco, F; Roldán, A M; Krupa, K; García, G; McEachran, R P; Machacek, J R; Buckman, S J; Sullivan, J P; White, R D; Marjanović, S; Petrović, Z Lj; Brunger, M J; Chiari, L; Limão-Vieira, P

    2016-01-01

    We present in this study a self-consistent set of scattering cross sections for positron collisions with water molecules, in the energy range 0.1–10 000 eV, with the prime motivation being to provide data for modelling purposes. The structure of the database is based on a new model potential calculation, including interference terms, which provides differential and integral elastic as well as integral inelastic positron scattering cross sections for water molecules over the whole energy range considered here. Experimental and theoretical data available in the literature have been integrated into the database after a careful analysis of their uncertainties and their self-consistency. These data have been used as input parameters for a step-by-step Monte Carlo simulation procedure, providing valuable information on energy deposition, positron range, and the relative percentages of specific interactions (e.g. positronium formation, direct ionisation, electronic, vibrational and rotational excitations) in gaseous and liquid water. (paper)

  13. Water hyacinth cellulose-based membrane for adsorption of liquid waste dyes and chromium

    Science.gov (United States)

    Agtasia Putri, Cintia; Yulianti, Ian; Desianna, Ika; Sholihah, Anisa; Sujarwata

    2018-04-01

    Water hyacinth (Eichornia crassipes) is a weed in aquatic area whose trunk contains a lot of cellulose. Cellulose contained can be used as dyes adsorbent in a form of composite membrane. This study aims to investigate the capacity of water hyacinth cellulose-based membrane to adsorb dye and Chromium (Cr) contained in liquid. The process of membrane fabrication begins with isolation of water hyacinth cellulose. The isolated cellulose powder was used to make the membrane by mixing it with polyvinyl alcohol-polyethylene glycol (PVA-PEG) with various compositions. The morphology of membrane surface was analyzed using CCD microscope. The analysis using Ultraviolet Visible Spectroscopy (UV-Vis) and Atomic Absorption Spectroscopy (AAS) indicate that the membrane with composition ratio of cellulose: PVA: PEG of 6.5: 2.5: 1 adsorb Cr up to 38.75%.

  14. Mass density fluctuations in quantum and classical descriptions of liquid water

    Science.gov (United States)

    Galib, Mirza; Duignan, Timothy T.; Misteli, Yannick; Baer, Marcel D.; Schenter, Gregory K.; Hutter, Jürg; Mundy, Christopher J.

    2017-06-01

    First principles molecular dynamics simulation protocol is established using revised functional of Perdew-Burke-Ernzerhof (revPBE) in conjunction with Grimme's third generation of dispersion (D3) correction to describe the properties of water at ambient conditions. This study also demonstrates the consistency of the structure of water across both isobaric (NpT) and isothermal (NVT) ensembles. Going beyond the standard structural benchmarks for liquid water, we compute properties that are connected to both local structure and mass density fluctuations that are related to concepts of solvation and hydrophobicity. We directly compare our revPBE results to the Becke-Lee-Yang-Parr (BLYP) plus Grimme dispersion corrections (D2) and both the empirical fixed charged model (SPC/E) and many body interaction potential model (MB-pol) to further our understanding of how the computed properties herein depend on the form of the interaction potential.

  15. Contaminant transport modelling in tidal influenced water body for low level liquid waste discharge out

    International Nuclear Information System (INIS)

    Singh, Sanjay; Naidu, Velamala Simhadri

    2018-01-01

    Low level liquid waste is generated from nuclear reactor operation and reprocessing of spent fuel. This waste is discharged into the water body after removing bulk of its radioactivity. Dispersion of contaminant mainly depends on location of outfall and hydrodynamics of water body. For radiological impact assessment, in most of the analytical formulations, source term is taken as continuous release. However, this may not be always true as the water level is influenced by tidal movement and the selected outfall may come under intertidal zone in due course of the tidal cycle. To understand these phenomena, a case study has been carried out to evaluate hydrodynamic characteristics and dilution potential of outfall located in inter-tidal zone using numerical modelling

  16. Determination of radon concentration in ground water in Aichi Prefecture by liquid scintillation counter

    Energy Technology Data Exchange (ETDEWEB)

    Onuma, A.; Shimizu, M.; Chaya, K.; Hamamura, N. (Aichi Prefectural Inst. of Public Health, Nagoya (Japan)); Kagami, T.

    1982-01-01

    The radon (Rn) concentration in ground water in Aichi Prefecture was determined by the liquid scintillation counter (LSC) method. The measurement of radon by LSC was made by integration counting, keeping the constant LS quantity in a vial and the constant geometry of a photomultiplier. The recovery rate of radon with 226-radium standard solution was 98.7%. The coefficient of variation in the measured values of radon concentration in ground water in Aichi Prefecture by the LSC method was 4.9%. For the same ground waters in the prefecture, the radon concentrations measured by the LSC method and by the conventional IM fontactoscope method were examined comparatively. This gave a regression formula of LSC value = 0.583 x IM value + 1.325 (n = 70, coefficient of correlation 0.966), indicating significant correlation between the two. It is thus shown that the LSC method is an effective means as the IM fontactoscope method.

  17. Determination of radon concentration in ground water in Aichi Prefecture by liquid scintillation counter

    International Nuclear Information System (INIS)

    Onuma, Akiko; Shimizu, Michihiko; Chaya, Kunio; Hamamura, Norikatsu; Kagami, Tadaaki.

    1982-01-01

    The radon (Rn) concentration in ground water in Aichi Prefecture was determined by the liquid scintillation counter (LSC) method. The measurement of radon by LSC was made by integration counting, keeping the constant LS quantity in a vial and the constant geometry of a photomultiplier. The recovery rate of radon with 226-radium standard solution was 98.7%. The coefficient of variation in the measured values of radon concentration in ground water in Aichi Prefecture by the LSC method was 4.9%. For the same ground waters in the prefecture, the radon concentrations measured by the LSC method and by the conventional IM fontactoscope method were examined comparatively. This gave a regression formula of LSC value = 0.583 x IM value + 1.325 (n = 70, coefficient of correlation 0.966), indicating significant correlation between the two. It is thus shown that the LSC method is an effective means as the IM fontactoscope method. (J.P.N.)

  18. Research on Liquid Management Technology in Water Tank and Reactor for Propulsion System with Hydrogen Production System Utilizing Aluminum and Water Reaction

    Science.gov (United States)

    Imai, Ryoji; Imamura, Takuya; Sugioka, Masatoshi; Higashino, Kazuyuki

    2017-12-01

    High pressure hydrogen produced by aluminum and water reaction is considered to be applied to space propulsion system. Water tank and hydrogen production reactor in this propulsion system require gas and liquid separation function under microgravity condition. We consider to install vane type liquid acquisition device (LAD) utilizing surface tension in the water tank, and install gas-liquid separation mechanism by centrifugal force which swirling flow creates in the hydrogen reactor. In water tank, hydrophilic coating was covered on both tank wall and vane surface to improve wettability. Function of LAD in water tank and gas-liquid separation in reaction vessel were evaluated by short duration microgravity experiments using drop tower facility. In the water tank, it was confirmed that liquid was driven and acquired on the outlet due to capillary force created by vanes. In addition of this, it was found that gas-liquid separation worked well by swirling flow in hydrogen production reactor. However, collection of hydrogen gas bubble was sometimes suppressed by aluminum alloy particles, which is open problem to be solved.

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

    International Nuclear Information System (INIS)

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

    1994-01-01

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

  20. Advantages of liquid fluoride thorium reactor in comparison with light water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bahri, Che Nor Aniza Che Zainul, E-mail: anizazainul@gmail.com; Majid, Amran Ab.; Al-Areqi, Wadeeah M. [Nuclear Science Program, School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2015-04-29

    Liquid Fluoride Thorium Reactor (LFTR) is an innovative design for the thermal breeder reactor that has important potential benefits over the traditional reactor design. LFTR is fluoride based liquid fuel, that use the thorium dissolved in salt mixture of lithium fluoride and beryllium fluoride. Therefore, LFTR technology is fundamentally different from the solid fuel technology currently in use. Although the traditional nuclear reactor technology has been proven, it has perceptual problems with safety and nuclear waste products. The aim of this paper is to discuss the potential advantages of LFTR in three aspects such as safety, fuel efficiency and nuclear waste as an alternative energy generator in the future. Comparisons between LFTR and Light Water Reactor (LWR), on general principles of fuel cycle, resource availability, radiotoxicity and nuclear weapon proliferation shall be elaborated.

  1. Process for hydrogen isotope exchange and concentration between liquid water and hydrogen gas and catalyst assembly therefor

    International Nuclear Information System (INIS)

    Stevens, W.H.

    1975-01-01

    A bithermal, catalytic, hydrogen isotope exchange process between liquid water and hydrogen gas to effect concentration of the deuterium isotope of hydrogen is described. Liquid water and hydrogen gas are contacted with one another and with at least one catalytically active metal selected from Group VIII of the Periodic Table; the catalyst body has a water repellent, gas and water vapor permeable, organic polymer or resin coating, preferably a fluorinated olefin polymer or silicone resin coating, so that the isotope exchange takes place by two simultaneously occurring, and closely coupled in space, steps and concentration is effected by operating two interconnected sections containing catalyst at different temperatures. (U.S.)

  2. Tritium Activity Measurement of Water Samples Using Liquid Scintillation Counter and Electrolytical Enrichment

    International Nuclear Information System (INIS)

    Baresic, J.; Krajcar Bronic, I.; Horvatincic, N.; Obelic, B.; Sironic, A.; Kozar-Logar J.

    2011-01-01

    Tritium (3H) activity of natural waters (precipitation, groundwater, surface waters) has recently become too low to be directly measured by low-level liquid scintillation (LSC) techniques. It is therefore necessary to perform electrolytical enrichment of tritium in such waters prior to LSC measurements. Electrolytical enrichment procedure has been implemented at the Rudjer Boskovic Institute (RBI) Tritium Laboratory in 2008, and since then 19 electrolyses have been completed. The mean enrichment factor E (a ratio between the final and initial 3H activities) after stabilisation of the system is E R BI = 22.5 @ 0.5, and the mean enrichment parameter (which describes the process of water mass reduction during electrolysis) is P R BI 0.949 @ 0.003. These values are comparable with those obtained at the Jo@ef Stefan Institute (JSI) Laboratory for liquid scintillation counting, at the electrolysis equipment of the same producer (AGH University of Science and Technology, Krakow, Poland) after 66 electrolyses carried out under identical conditions since 2007: E J SI = 18.9 @ 1.5, and P J SI = 0.896 @ 0.021. Both RBI and JSI laboratories have Ultra-low-level LSC Quantulus 1220 (Wallac, PerkinElmer) for measurement of 3H activity. A set of water samples having 3H activities in the range from 0 TU (''dead-water'' samples) to 18 000 TU (1 TU 0.118 Bq/L) were measured at both laboratories. Samples having 3H activity <200 TU were electrolytically enriched, while the others were measured directly in LSC. A very good agreement was obtained (correlation coefficient 0.991). Both laboratories participated in the IAEA TRIC2008 international intercomparison exercise. The analyses of reported 3H activity results in terms of z and u parameters showed that all results in both laboratories were acceptable. (author)

  3. Phase transitions on (liquid + liquid) equilibria for (water + 1-methylnaphthalene + light aromatic hydrocarbon) ternary systems at T = (563, 573, and 583) K

    International Nuclear Information System (INIS)

    Togo, Masaki; Inamori, Yoshiki; Shimoyama, Yusuke

    2012-01-01

    Highlights: ► Mixtures of (water + 1-methylnaphthalene + light aromatic hydrocarbon) are focused. ► Phase transition pressures on (liquid + liquid) equilibria were measured. ► Effects of aromatic hydrocarbons on phase transition pressure are investigated. ► Phase transition pressures are discussed using dielectric constants of hydrocarbons. - Abstract: Phase transitions for (water + 1-methylnaphthalene + light aromatic hydrocarbon) ternary systems are observed at their (liquid + liquid) equilibria at T = (563, 573, and 583) K and (8.6 to 25.0) MPa. The phase transition pressures at T = (563, 573, and 583) K were measured for the five species of light aromatic hydrocarbons, o-, m-, p-xylenes, ethylbenzene, and mesitylene. The measurements of the phase transition pressures were carried out by changing the feed mole fraction of water and 1-methylnaphthalene in water free, respectively. Effects of the feed mole fraction of water on the phase transition pressures are very small. Increasing the feed mole fraction of 1-methylnaphthalene results in decreasing the phase transition pressures at constant temperature. The slopes depending on the feed mole fraction for 1-methylnaphthalene at the phase transition pressures are decreased with increasing temperature for (water + 1-methylnaphthalene + p-xylene), (water + 1-methylnaphthalene + o-xylene), and (water + 1-methylnaphthalene + mesitylene) systems. For xylene isomers, the highest and lowest of the phase transition pressures are obtained in the case of p- and o-xylenes, respectively. The phase transition pressures for ethylbenzene are lower than those in the case of p-xylene. The similar phase transition pressures are given for p-xylene and mesitylene.

  4. Clean water billing monitoring system using flow liquid meter sensor and SMS gateway

    Science.gov (United States)

    Fahmi, F.; Hizriadi, A.; Khairani, F.; Andayani, U.; Siregar, B.

    2018-03-01

    Public clean water company (PDAM) as a public service is designed and organized to meet the needs of the community. Currently, the number of PDAM subscribers is very big and will continue to grow, but the service and facilities to customers are still done conventionally by visiting the customer’s home to record the last position of the meter. One of the problems of PDAM is the lack of disclosure of PDAM customers’ invoice because it is only done monthly. This, of course, makes PDAM customers difficult to remember the date of payment of water account. Therefore it is difficult to maintain the efficiency. The purpose of this research is to facilitate customers of PDAM water users to know the details of water usage and the time of payment of water bills easily. It also facilitates customers in knowing information related to the form of water discharge data used, payment rates, and time grace payments using SMS Gateway. In this study, Flow Liquid Meter Sensor was used for data retrieval of water flowing in the piping system. Sensors used to require the help of Hall Effect sensor that serves to measure the speed of water discharge and placed on the pipe that has the same diameter size with the sensor diameter. The sensor will take the data from the rate of water discharge it passes; this data is the number of turns of the mill on the sensor. The results of the tests show that the built system works well in helping customers know in detail the amount of water usage in a month and the bill to be paid

  5. Mechanism for migration of light nonaqueous phase liquids beneath the water table

    International Nuclear Information System (INIS)

    Krueger, J.P.; Portman, M.E.

    1991-01-01

    This paper reports on an interesting transport mechanism may account for the presence of light nonaqueous phase liquid (LNAPL) found beneath the water table in fine-grained aquifers. During the course of two separate site investigations related to suspected releases from underground petroleum storage tanks, LNAPL was found 7 to 10 feet below the regional water table. In both cases, the petroleum was present within a sand seam which was encompassed within a deposit of finer-grained sediments. The presence of LNAPL below the water table is uncommon; typically, LNAPL is found floating on the water table or on the capillary fringe. The occurrence of LNAPL below the water table could have resulted from fluctuating regional water levels which allowed the petroleum to enter the sand when the water table was a lower stage or, alternately, could have occurred as a result of the petroleum depressing the water table beneath the level of the sand. In fine-grained soils where the lateral migration rate is low, the infiltrating LNAPL may depress the water table to significant depth. The LNAPL may float on the phreatic surface with the bulk of its volume beneath the phreatic surface. Once present in the sand and surrounded by water-saturated fine-grained sediments, capillary forces prevent the free movement of the petroleum back across the boundary from the coarse-grained sediments to the fine-grained sediments. Tapping these deposits with a coarser grained filter packed monitoring well releases the LNAPL, which may accumulate to considerable thickness in the monitoring well

  6. Ice versus liquid water saturation in simulations of the indian summer monsoon

    Science.gov (United States)

    Glazer, Russell H.; Misra, Vasubandhu

    2018-02-01

    At the same temperature, below 0 °C, the saturation vapor pressure (SVP) over ice is slightly less than the SVP over liquid water. Numerical models use the Clausius-Clapeyron relation to calculate the SVP and relative humidity, but there is not a consistent method for the treatment of saturation above the freezing level where ice and mixed-phase clouds may be present. In the context of current challenges presented by cloud microphysics in climate models, we argue that a better understanding of the impact that this treatment has on saturation-related processes like cloud formation and precipitation, is needed. This study explores the importance of the SVP calculation through model simulations of the Indian summer monsoon (ISM) using the regional spectral model (RSM) at 15 km grid spacing. A combination of seasonal and multiyear simulations is conducted with two saturation parameterizations. In one, the SVP over liquid water is prescribed through the entire atmospheric column (woIce), and in another the SVP over ice is used above the freezing level (wIce). When SVP over ice is prescribed, a thermodynamic drying of the middle and upper troposphere above the freezing level occurs due to increased condensation. In the wIce runs, the model responds to the slight decrease in the saturation condition by increasing, relative to the SVP over liquid water only run, grid-scale condensation of water. Increased grid-scale mean seasonal precipitation is noted across the ISM region in the simulation with SVP over ice prescribed. Modification of the middle and upper troposphere moisture results in a decrease in mean seasonal mid-level cloud amount and an increase in high cloud amount when SVP over ice is prescribed. Multiyear simulations strongly corroborate the qualitative results found in the seasonal simulations regarding the impact of ice versus liquid water SVP on the ISM's mean precipitation and moisture field. The mean seasonal rainfall difference over All India between w

  7. Water-based synthesis of hydrophobic ionic liquids for high-energy electrochemical devices

    International Nuclear Information System (INIS)

    Montanino, Maria; Alessandrini, Fabrizio; Passerini, Stefano; Appetecchi, Giovanni Battista

    2013-01-01

    Highlights: ► Water-based synthesis of ionic liquids with high yield. ► Full recycling of reagents. ► High purity pyrrolidinium-based ionic liquids with exceptional electrochemical stability window. ► Lithium plating from pyrrolidinium-based ionic liquids. -- Abstract: In this work is described an innovative synthesis route for hydrophobic ionic liquids (ILs) composed of N-methyl-N-alkylpyrrolidinium (or piperidinium) or imidazolium or tetralkylammonium cations and (perfluoroalkylsulfonyl)imide, ((C n F 2n+1 SO 2 )(C m F 2m+1 SO 2 )N − ), anions. This synthesis does not require the use of any environmental unfriendly solvent such as acetone, acetonitrile or halogen-containing compounds, which is not welcome in industrial applications. Only water is used as the process solvent throughout the entire process. In addition, the commonly used iodine-containing reagents were replaced by the cheaper, more chemically stable and less toxic bromine-containing compounds. A particular care was devoted to the development of the purification route, which is especially important for ILs to be used in high-energy electrochemical devices such as high voltage supercapacitors and lithium batteries. The effect of the reaction temperature, the time and the stoichiometry in the various steps of the synthesis have been investigated in detail. This novel procedure allowed obtaining ultrapure (>99.9 wt.%), clear, colourless, inodorous ILs with an overall yield above 92 wt.% and moisture content below 1 ppm. NMR measurements were run to confirm the chemical structure whereas elemental analysis and electrochemical tests were performed to check the purity of the synthesized ILs

  8. Selection of ionic liquids as entrainers for separation of (water + ethanol)

    Energy Technology Data Exchange (ETDEWEB)

    Ge Yun [College of Chemical Engineering and Material Science, Zhejiang University of Technology, Hangzhou 310014 (China); Zhang Lianzhong [College of Chemical Engineering and Material Science, Zhejiang University of Technology, Hangzhou 310014 (China)], E-mail: zhanglz@zjut.edu.cn; Yuan Xingcai; Geng Wei; Ji Jianbing [College of Chemical Engineering and Material Science, Zhejiang University of Technology, Hangzhou 310014 (China)

    2008-08-15

    For selection of ionic liquids (ILs) which can be potentially used as entrainers for separation of the azeotropic mixture of (water + ethanol) by extractive distillation, (vapor + liquid) equilibrium was measured for the ternary systems of (water + ethanol + an IL) using a previously proposed ebulliometer. The experimental measurement was performed at p = 100 kPa and in a way of continuous synthesis, in which analysis of liquid phase composition was avoided. While the mole fraction of ethanol calculated on IL-free basis, x{sub 2}{sup '}, was kept almost unchanged at 0.95, isobaric T, x, y data were measured at different IL mass fractions. Activity coefficients, as well as relative volatilities, of the volatile components were obtained from the experimental data without the need of a thermodynamic model of the liquid phase. There were eight ILs in our investigation: 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF{sub 4}]), 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF{sub 4}]), 1-butyl-3-methylimidazolium dicyanamide ([bmim][N(CN){sub 2}]), 1-ethyl-3-methylimidazolium dicyanamide ([emim][N(CN){sub 2}]), 1-butyl-3-methylimidazolium chloride ([bmim][Cl]), 1-ethyl-3-methylimidazolium chloride ([emim][Cl]), 1-butyl-3-methylimidazolium acetate ([bmim][OAc]), and 1-ethyl-3-methylimidazolium acetate ([emim][OAc]). The effect of the ILs on the relative volatility of the volatile components was depicted separately by their effect on the activity coefficients. The results indicated that, among the eight ILs studied, [emim][Cl] has the largest effect on enhancement of the relative volatility. Another IL, [emim][OAc], has also significant effect. Considering the relatively low viscosity and melting point of [emim][OAc], this IL might be favorable candidate as entrainer for potential industrial application.

  9. Full characterization of polypyrrole thin films electrosynthesized in room temperature ionic liquids, water or acetonitrile

    International Nuclear Information System (INIS)

    Viau, L.; Hihn, J.Y.; Lakard, S.; Moutarlier, V.; Flaud, V.; Lakard, B.

    2014-01-01

    Highlights: • Polypyrrole films were electrodeposited from three room temperature ionic liquids. • Polymer films were characterized using many surface analysis techniques. • The incorporation of anions and/or cations inside the polymer films was evidenced. • The influence of the ionic liquid on the polymer properties was deeply studied. - Abstract: Pyrrole was electrochemically oxidized in two conventional media (water and acetonitrile) and in three room temperature ionic liquids: 1-butyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, and 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide. Infrared and Raman Spectroscopies confirmed the formation of polypyrrole by electropolymerization but were unable to demonstrate the presence of anions in the polymer films. The use of ionic liquids as growth media resulted in polymer films having a good electrochemical activity. The difference of activity from one polymer film to the other was mainly attribu